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Find video protocols related to scientific articles indexed in Pubmed.
[Evaluation on the status quo of self monitoring of blood glucose and self-efficacy of diabetes patients in community].
Zhonghua Yu Fang Yi Xue Za Zhi
PUBLISHED: 11-13-2014
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To investigate the status quo and influence factors of self monitoring of blood glucose (SMBG) and self-efficacy of diabetes patients' that participated in community diabetes self management group.
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[Effect of endothelial cell-targeted soluble Notch ligand hD1R protein on expansion and engraftment of cord blood hematopoietic stem/progenitor cells].
Zhonghua Xue Ye Xue Za Zhi
PUBLISHED: 10-24-2014
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To evaluate the effects of endothelial cell- targeted soluble Notch ligand hD1R protein on expansion and engraftment of cord blood hematopoietic stem/progenitor cell (CB HSPCs).
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Isolation and characterization of a thermophilic Bacillus shackletonii K5 from a biotrickling filter for the production of polyhydroxybutyrate.
J Environ Sci (China)
PUBLISHED: 06-11-2014
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Polyhydroxyalkanoates (PHAs) are aliphatic polyesters accumulated intracellularly by both Gram-negative and Gram-positive bacteria. However, compared to the PHAs of Gram-negative bacteria, few endotoxins (lipopolysaccharides, LPS), which would be co-purified with PHAs and cause immunogenic reactions, are found in the PHAs produced by Gram-positive bacteria. A thermophilic Gram-positive bacterium K5, which exhibited good growth and polyhydroxybutyrate (PHB)-accumulating ability, has been isolated and characterized from a biotrickling filter designed for the removal of NOx from flue gas in a coal-fired power plant in China. Based on the biochemical characterization and 16S rRNA gene sequence (Genbank accession no. JX437933), the strain K5 has been identified as Bacillus shackletonii, which has rarely been reported in the literature, and this report is the first time that B. shackletonii has been found to accumulate PHB. The strain K5 was able to utilize glucose as carbon source to synthesize PHB at a broad range of temperatures (from 35 to 50°C), and the ideal temperature was 45°C. The strain K5 could effectively yield PHB of up to 69.9% of its cell dry weight (CDW) (2.28 g/L) in flask experiments employing glucose as carbon source at 45°C, followed by 56.8% and 52.3% of its CDW when using sodium succinate and glycerol as carbon source, respectively. For batch cultivation, the strain K5 was able to produce PHB of up to 72.6% of its cell dry weight (9.76 g/L) employing glucose as carbon source at 45°C and pH7.0.
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RNA-binding protein AUF1 promotes myogenesis by regulating MEF2C expression levels.
Mol. Cell. Biol.
PUBLISHED: 06-02-2014
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The mammalian RNA-binding protein AUF1 (AU-binding factor 1, also known as heterogeneous nuclear ribonucleoprotein D [hnRNP D]) binds to numerous mRNAs and influences their posttranscriptional fate. Given that many AUF1 target mRNAs encode muscle-specific factors, we investigated the function of AUF1 in skeletal muscle differentiation. In mouse C2C12 myocytes, where AUF1 levels rise at the onset of myogenesis and remain elevated throughout myocyte differentiation into myotubes, RNP immunoprecipitation (RIP) analysis indicated that AUF1 binds prominently to Mef2c (myocyte enhancer factor 2c) mRNA, which encodes the key myogenic transcription factor MEF2C. By performing mRNA half-life measurements and polysome distribution analysis, we found that AUF1 associated with the 3' untranslated region (UTR) of Mef2c mRNA and promoted MEF2C translation without affecting Mef2c mRNA stability. In addition, AUF1 promoted Mef2c gene transcription via a lesser-known role of AUF1 in transcriptional regulation. Importantly, lowering AUF1 delayed myogenesis, while ectopically restoring MEF2C expression levels partially rescued the impairment of myogenesis seen after reducing AUF1 levels. We propose that MEF2C is a key effector of the myogenesis program promoted by AUF1.
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An efficient preparative procedure for main flavonoids from the peel of Trichosanthes kirilowii Maxim. using polyamide resin followed by semi-preparative high performance liquid chromatography.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 05-31-2014
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In this study, a simple and efficient preparative procedure was developed for preparation of seven flavonoids from the peel of Trichosanthes kirilowii Maxim. using polyamide resin followed by semi-preparative high performance liquid chromatography (SPHPLC). First, the ethyl acetate fraction from the peel of T. kirilowii Maxim. obtained "prefractionation" using polyamide resin, which yielded two subfractions. And then the two subfractions were isolated by SPHPLC with an isocratic elution of methanol-water. Finally, seven known flavonoids were purified from 35 g of ethyl acetate extract including quercetin-3-O-[?-l-rhamnose (1?2)-?-d-glucopyranosyl]-5-O-?-d-glucopyranoside (19 mg), quercetin-3-O-rutinoside (24 mg), apigenin-7-O-?-d-glucopyranoside (10mg), diosmetin-7-O-?-d-glucopyranoside (45 mg), luteolin (21 mg), apigenin (15 mg), and diosmetin (56 mg). The purities of the compounds were determined by HPLC and the chemical structures were confirmed by UV and NMR analysis. In the present study, a simple, effective, and rapid procedure was established for preparative separation of multiple components from the peel of T. kirilowii Maxim. Furthermore, it was scalable and economical, so it was a promising basis for large-scale preparation of flavonoids from other plant extracts.
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MNKs act as a regulatory switch for eIF4E1 and eIF4E3 driven mRNA translation in DLBCL.
Nat Commun
PUBLISHED: 05-16-2014
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The phosphorylation of eIF4E1 at serine 209 by MNK1 or MNK2 has been shown to initiate oncogenic mRNA translation, a process that favours cancer development and maintenance. Here, we interrogate the MNK-eIF4E axis in diffuse large B-cell lymphoma (DLBCL) and show a distinct distribution of MNK1 and MNK2 in germinal centre B-cell (GCB) and activated B-cell (ABC) DLBCL. Despite displaying a differential distribution in GCB and ABC, both MNKs functionally complement each other to sustain cell survival. MNK inhibition ablates eIF4E1 phosphorylation and concurrently enhances eIF4E3 expression. Loss of MNK protein itself downregulates total eIF4E1 protein level by reducing eIF4E1 mRNA polysomal loading without affecting total mRNA level or stability. Enhanced eIF4E3 expression marginally suppresses eIF4E1-driven translation but exhibits a unique translatome that unveils a novel role for eIF4E3 in translation initiation. We propose that MNKs can modulate oncogenic translation by regulating eIF4E1-eIF4E3 levels and activity in DLBCL.
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Modified bortezomib, adriamycin and dexamethasone (PAD) regimen in advanced multiple myeloma.
Pathol. Oncol. Res.
PUBLISHED: 04-20-2014
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The PAD regime, composed of bortezomib, adriamycin and dexamethasone, improves the outcomes of patients with advanced multiple myeloma (MM), but at the same time produces high frequency of serious toxic side effects. For the first time, we evaluated the efficacy and safety of a bortezomib-dose-reduced PAD regime in the treatment of relapsed/refractory MM in this clinical study. Forty-five patients were treated with two to six 21-day cycles of PAD, comprising bortezomib at 1.3 mg/m(2) (P1AD, n?=?21) or 1.0 mg/m(2) (P2AD, n?=?24) (days 1, 4, 8, 11), adriamycin at 9 mg/m(2) (days 1-4) and dexamethasone at 40 mg/day (days 1-4). Overall, 36 patients (80 %) showed at least partial remission (PR), in which 9 cases (20 %) showed complete remission (CR) and 10 cases (22 %) showed very good partial remission (VGPR). The efficacy of PAD regimen in advanced MM patients was not related to the traditional prognostic factors. There was no significant difference between P1AD and P2AD in the rates of PR, CR or VGPR, 1.5-year progression-free survival (PFS), and overall survival (OS) (81 % vs. 79 %, 48 % vs. 38 %, 64 % vs. 59 %, and 85 % vs. 73 %, respectively). However, the grade 3-4 toxic effects, including thrombocytopenia (13 % vs. 38 %), peripheral neuropathy (8 % vs. 33 %) and 3-4 grade gastrointestinal reaction (13 % vs. 43 %), were markedly inhibited after P2AD compared to P1AD (P?
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Age-related brain expression and regulation of the chemokine CCL4/MIP-1? in APP/PS1 double-transgenic mice.
J. Neuropathol. Exp. Neurol.
PUBLISHED: 03-11-2014
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The detrimental effect of activation of the chemokine CCL4/MIP-1? on neuronal integrity in patients with HIV-associated dementia has directed attention to the potential role of CCL4 expression and regulation in Alzheimer disease. Here, we show that CCL4 mRNA and protein are overexpressed in the brains of APPswe/PS1?E9 (APP/PS1) double-transgenic mice, a model of cerebral amyloid deposition; expression was minimal in brains from nontransgenic littermates or single-mutant controls. Increased levels of CCL4 mRNA and protein directly correlated with the age-related progression of cerebral amyloid-? (A?) levels in APP/PS1 mice. We also found significantly increased expression of activating transcription factor 3 (ATF3), which was positively correlated with age-related A? deposition and CCL4 in the brains of APP/PS1 mice. Results from chromatin immunoprecipitation-quantitative polymerase chain reaction confirmed that ATF3 binds to the promoter region of the CCL4 gene, consistent with a potential role in regulating CCL4 transcription. Finally, elevated ATF3 mRNA expression in APP/PS1 brains was associated with hypomethylation of the ATF3 gene promoter region. These observations prompt the testable hypothesis for future study that CCL4 overexpression, regulated in part by hypomethylation of the ATF3 gene, may contribute to neuropathologic progression associated with amyloid deposition in Alzheimer disease.
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A genetically engineered ovarian cancer mouse model based on fallopian tube transformation mimics human high-grade serous carcinoma development.
J. Pathol.
PUBLISHED: 02-25-2014
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Recent evidence suggests that ovarian high-grade serous carcinoma (HGSC) originates from the epithelium of the fallopian tube. However, most mouse models are based on the previous prevailing view that ovarian cancer develops from the transformation of the ovarian surface epithelium. Here, we report the extensive histological and molecular characterization of the mogp-TAg transgenic mouse, which expresses the SV40 large T-antigen (TAg) under the control of the mouse müllerian-specific Ovgp-1 promoter. Histological analysis of the fallopian tubes of mogp-TAg mice identified a variety of neoplastic lesions analogous to those described as precursors to ovarian HGSC. We identified areas of normal-appearing p53-positive epithelium that are similar to 'p53 signatures' in the human fallopian tube. More advanced proliferative lesions with nuclear atypia and epithelial stratification were also identified that were morphologically and immunohistochemically reminiscent of human serous tubal intraepithelial carcinoma (STIC), a potential precursor of ovarian HGSC. Beside these non-invasive precursor lesions, we also identified invasive adenocarcinoma in the ovaries of 56% of the mice. Microarray analysis revealed several genes differentially expressed between the fallopian tube of mogp-TAg and wild-type (WT) C57BL/6. One of these genes, Top2a, which encodes topoisomerase II?, was shown by immunohistochemistry to be concurrently expressed with elevated p53 and was specifically elevated in mouse STICs but not in the surrounding tissues. TOP2A protein was also found elevated in human STICs, low-grade and high-grade serous carcinoma. The mouse model reported here displays a progression from normal tubal epithelium to invasive HGSC in the ovary, and therefore closely simulates the current emerging model of human ovarian HGSC pathogenesis. This mouse therefore has the potential to be a very useful new model for elucidating the mechanisms of serous ovarian tumourigenesis, as well as for developing novel approaches for the prevention, diagnosis and therapy of this disease.
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SRT2104 extends survival of male mice on a standard diet and preserves bone and muscle mass.
Aging Cell
PUBLISHED: 02-24-2014
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Increased expression of SIRT1 extends the lifespan of lower organisms and delays the onset of age-related diseases in mammals. Here, we show that SRT2104, a synthetic small molecule activator of SIRT1, extends both mean and maximal lifespan of mice fed a standard diet. This is accompanied by improvements in health, including enhanced motor coordination, performance, bone mineral density, and insulin sensitivity associated with higher mitochondrial content and decreased inflammation. Short-term SRT2104 treatment preserves bone and muscle mass in an experimental model of atrophy. These results demonstrate it is possible to design a small molecule that can slow aging and delay multiple age-related diseases in mammals, supporting the therapeutic potential of SIRT1 activators in humans.
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Construction of the Chinese Veteran Clinical Research (CVCR) platform for the assessment of non-communicable diseases.
Chin. Med. J.
PUBLISHED: 01-24-2014
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Based on the excellent medical care and management system for Chinese veterans, as well as the detailed medical documentation available, we aim to construct a Chinese Veteran Clinical Research (CVCR) platform on non-communicable diseases (NCDs) and carry out studies of the primary disabling NCDs.
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The SIRT1 activator SRT1720 extends lifespan and improves health of mice fed a standard diet.
Cell Rep
PUBLISHED: 01-23-2014
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The prevention or delay of the onset of age-related diseases prolongs survival and improves quality of life while reducing the burden on the health care system. Activation of sirtuin 1 (SIRT1), an NAD(+)-dependent deacetylase, improves metabolism and confers protection against physiological and cognitive disturbances in old age. SRT1720 is a specific SIRT1 activator that has health and lifespan benefits in adult mice fed a high-fat diet. We found extension in lifespan, delayed onset of age-related metabolic diseases, and improved general health in mice fed a standard diet after SRT1720 supplementation. Inhibition of proinflammatory gene expression in both liver and muscle of SRT1720-treated animals was noted. SRT1720 lowered the phosphorylation of NF-?B pathway regulators in vitro only when SIRT1 was functionally present. Combined with our previous work, the current study further supports the beneficial effects of SRT1720 on health across the lifespan in mice.
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AMPK agonist AICAR improves cognition and motor coordination in young and aged mice.
Learn. Mem.
PUBLISHED: 01-21-2014
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Normal aging can result in a decline of memory and muscle function. Exercise may prevent or delay these changes. However, aging-associated frailty can preclude physical activity. In young sedentary animals, pharmacological activation of AMP-activated protein kinase (AMPK), a transcriptional regulator important for muscle physiology, enhanced spatial memory function, and endurance. In the present study we investigated effects of AMPK agonist 5-aminoimidazole-4-carboxamide riboside (AICAR) on memory and motor function in young (5- to 7-wk-old) and aged (23-mo-old) female C57Bl/6 mice, and in young (4- to 6-wk-old) transgenic mice with muscle-specific mutated AMPK ?2-subunit (AMPK-DN). Mice were injected with AICAR (500 mg/kg) for 3-14 d. Two weeks thereafter animals were tested in the Morris water maze, rotarod, and open field. Improved water maze performance and motor function were observed, albeit at longer duration of administration, in aged (14-d AICAR) than in young (3-d AICAR) mice. In the AMPK-DN mice, the compound did not enhance behavior, providing support for a muscle-mediated mechanism. In addition, microarray analysis of muscle and hippocampal tissue derived from aged mice treated with AICAR revealed changes in gene expression in both tissues, which correlated with behavioral effects in a dose-dependent manner. Pronounced up-regulation of mitochondrial genes in muscle was observed. In the hippocampus, genes relevant to neuronal development and plasticity were enriched. Altogether, endurance-related factors may mediate both muscle and brain health in aging, and could play a role in new therapeutic interventions.
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Comparative study on the production of poly(3-hydroxybutyrate) by thermophilic Chelatococcus daeguensis TAD1: a good candidate for large-scale production.
Appl. Microbiol. Biotechnol.
PUBLISHED: 01-06-2014
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In spite of numerous advantages on operating fermentation at elevated temperatures, very few thermophilic bacteria with polyhydroxyalkanoates (PHAs)-accumulating ability have yet been found in contrast to the tremendous mesophiles with the same ability. In this study, a thermophilic poly(3-hydroxybutyrate) (PHB)-accumulating bacteria (Chelatococcus daeguensis TAD1), isolated from the biofilm of a biotrickling filter used for NOx removal, was extensively investigated and compared to other PHB-accumulating bacteria. The results demonstrate that C. daeguensis TAD1 is a growth-associated PHB-accumulating bacterium without obvious nutrient limitation, which was capable of accumulating PHB up to 83.6 % of cell dry weight (CDW, w/w) within just 24 h at 45 °C from glucose. Surprisingly, the PHB production of C. daeguensis TAD1 exhibited strong tolerance to high heat stress as well as nitrogen loads compared to that of other PHB-accumulating bacterium, while the optimal PHB amount (3.44?±?0.3 g l(-1)) occurred at 50 °C and C/N?=?30 (molar) with glucose as the sole carbon source. In addition, C. daeguensis TAD1 could effectively utilize various cheap substrates (starch or glycerol) for PHB production without pre-hydrolyzed, particularly the glycerol, exhibiting the highest product yield (Y P/S, 0.26 g PHB per gram substrate used) as well as PHB content (80.4 % of CDW, w/w) compared to other carbon sources. Consequently, C. daeguensis TAD1 is a viable candidate for large-scale production of PHB via utilizing starch or glycerol as the raw materials.
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Down-regulation of eIF4GII by miR-520c-3p represses diffuse large B cell lymphoma development.
PLoS Genet.
PUBLISHED: 01-01-2014
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Deregulation of the translational machinery is emerging as a critical contributor to cancer development. The contribution of microRNAs in translational gene control has been established however; the role of microRNAs in disrupting the cap-dependent translation regulation complex has not been previously described. Here, we established that elevated miR-520c-3p represses global translation, cell proliferation and initiates premature senescence in HeLa and DLBCL cells. Moreover, we demonstrate that miR-520c-3p directly targets translation initiation factor, eIF4GII mRNA and negatively regulates eIF4GII protein synthesis. miR-520c-3p overexpression diminishes cells colony formation and reduces tumor growth in a human xenograft mouse model. Consequently, downregulation of eIF4GII by siRNA decreases translation, cell proliferation and ability to form colonies, as well as induces cellular senescence. In vitro and in vivo findings were further validated in patient samples; DLBCL primary cells demonstrated low miR-520c-3p levels with reciprocally up-regulated eIF4GII protein expression. Our results provide evidence that the tumor suppressor effect of miR-520c-3p is mediated through repression of translation while inducing senescence and that eIF4GII is a key effector of this anti-tumor activity.
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Mice fed rapamycin have an increase in lifespan associated with major changes in the liver transcriptome.
PLoS ONE
PUBLISHED: 01-01-2014
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Rapamycin was found to increase (11% to 16%) the lifespan of male and female C57BL/6J mice most likely by reducing the increase in the hazard for mortality (i.e., the rate of aging) term in the Gompertz mortality analysis. To identify the pathways that could be responsible for rapamycin's longevity effect, we analyzed the transcriptome of liver from 25-month-old male and female mice fed rapamycin starting at 4 months of age. Few changes (<300 transcripts) were observed in transcriptome of rapamycin-fed males; however, a large number of transcripts (>4,500) changed significantly in females. Using multidimensional scaling and heatmap analyses, the male mice fed rapamycin were found to segregate into two groups: one group that is almost identical to control males (Rapa-1) and a second group (Rapa-2) that shows a change in gene expression (>4,000 transcripts) with more than 60% of the genes shared with female mice fed Rapa. Using ingenuity pathway analysis, 13 pathways were significantly altered in both Rapa-2 males and rapamycin-fed females with mitochondrial function as the most significantly changed pathway. Our findings show that rapamycin has a major effect on the transcriptome and point to several pathways that would likely impact the longevity.
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Combined treatment of rapamycin and dietary restriction has a larger effect on the transcriptome and metabolome of liver.
Aging Cell
PUBLISHED: 10-15-2013
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Rapamycin (Rapa) and dietary restriction (DR) have consistently been shown to increase lifespan. To investigate whether Rapa and DR affect similar pathways in mice, we compared the effects of feeding mice ad libitum (AL), Rapa, DR, or a combination of Rapa and DR (Rapa + DR) on the transcriptome and metabolome of the liver. The principal component analysis shows that Rapa and DR are distinct groups. Over 2500 genes are significantly changed with either Rapa or DR when compared with mice fed AL; more than 80% are unique to DR or Rapa. A similar observation was made when genes were grouped into pathways; two-thirds of the pathways were uniquely changed by DR or Rapa. The metabolome shows an even greater difference between Rapa and DR; no metabolites in Rapa-treated mice were changed significantly from AL mice, whereas 173 metabolites were changed in the DR mice. Interestingly, the number of genes significantly changed by Rapa + DR when compared with AL is twice as large as the number of genes significantly altered by either DR or Rapa alone. In summary, the global effects of DR or Rapa on the liver are quite different and a combination of Rapa and DR results in alterations in a large number of genes and metabolites that are not significantly changed by either manipulation alone, suggesting that a combination of DR and Rapa would be more effective in extending longevity than either treatment alone.
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Purification of Coumarin Compounds From Cortex fraxinus by Adsorption Chromatography.
J Chromatogr Sci
PUBLISHED: 10-10-2013
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In this paper, a chromatographic method for isolation and purification of coumarin compounds from Cortex fraxinus was established by using Superose 12 as the separation media for the first time. The conditions for separation were optimized. Four kinds of coumarin compounds including aesuletin, aesculin, fraxetin and fraxin were obtained. The purity of these compounds were 98.5, 99.1, 97.9 and 97.3%, respectively, which were determined by HPLC area normalization method. The chemical structures of the separated compounds were identified according to (1)H and (13)C nuclear magnetic resonance data. The retention behavior of the separated coumarin compounds on Superose 12 was also discussed. The retention is based on a mixture of hydrogen bonding and hydrophobic interactions between the coumarin compounds and the residues of the cross-linking reagents used in the manufacturing process of Superose 12. The results of this paper indicate that Superose 12 is not only suitable for size-exclusion chromatography of proteins and other biological macromolecules but also for low-molecular-weight natural products.
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Age-related changes in microRNA levels in serum.
Aging (Albany NY)
PUBLISHED: 10-04-2013
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MicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally regulate gene expression by targeting specific mRNAs. Altered expression of circulating miRNAs have been associated with age-related diseases including cancer and cardiovascular disease. Although we and others have found an age-dependent decrease in miRNA expression in peripheral blood mononuclear cells (PBMCs), little is known about the role of circulating miRNAs in human aging. Here, we examined miRNA expression in human serum from young (mean age 30 years) and old (mean age 64 years) individuals using next generation sequencing technology and real-time quantitative PCR. Of the miRNAs that we found to be present in serum, three were significantly decreased in 20 older individuals compared to 20 younger individuals: miR-151a-5p, miR-181a-5p and miR-1248. Consistent with our data in humans, these miRNAs are also present at lower levels in the serum of elderly rhesus monkeys. In humans, miR-1248 was found to regulate the expression of mRNAs involved in inflammatory pathways and miR-181a was found to correlate negatively with the pro-inflammatory cytokines IL-6 and TNF? and to correlate positively with the anti-inflammatory cytokines TGF? and IL-10. These results suggest that circulating miRNAs may be a biological marker of aging and could also be important for regulating longevity. Identification of stable miRNA biomarkers in serum could have great potential as a noninvasive diagnostic tool as well as enhance our understanding of physiological changes that occur with age.
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Response of microchip solid-state laser to external frequency-shifted feedback and its applications.
Sci Rep
PUBLISHED: 07-02-2013
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The response of the microchip solid-state Nd:YAG laser, which is subjected to external frequency-shifted feedback, is experimentally and theoretically analysed. The continuous weak response of the laser to the phase and amplitude of the feedback light is achieved by controlling the feedback power level, and this system can be used to achieve contact-free measurement of displacement, vibration, liquid evaporation and thermal expansion with nanometre accuracy in common room conditions without precise environmental control. Furthermore, a strong response, including chaotic harmonic and parametric oscillation, is observed, and the spectrum of this response, as examined by a frequency-stabilised Nd:YAG laser, indicates laser spectral linewidth broadening.
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Metformin improves healthspan and lifespan in mice.
Nat Commun
PUBLISHED: 06-26-2013
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Metformin is a drug commonly prescribed to treat patients with type 2 diabetes. Here we show that long-term treatment with metformin (0.1% w/w in diet) starting at middle age extends healthspan and lifespan in male mice, while a higher dose (1% w/w) was toxic. Treatment with metformin mimics some of the benefits of calorie restriction, such as improved physical performance, increased insulin sensitivity, and reduced low-density lipoprotein and cholesterol levels without a decrease in caloric intake. At a molecular level, metformin increases AMP-activated protein kinase activity and increases antioxidant protection, resulting in reductions in both oxidative damage accumulation and chronic inflammation. Our results indicate that these actions may contribute to the beneficial effects of metformin on healthspan and lifespan. These findings are in agreement with current epidemiological data and raise the possibility of metformin-based interventions to promote healthy aging.
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Estimate of nocturnal blood pressure and detection of non-dippers based on clinical or ambulatory monitoring in the inpatient setting.
BMC Cardiovasc Disord
PUBLISHED: 05-17-2013
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Ambulatory blood pressure monitoring is regarded as the gold standard for monitoring nocturnal blood pressure (NBP) and is usually performed out of office. Currently, a novel method for monitoring NBP is indispensible in the inpatient setting. The widely used manual BP monitoring procedure has the potential to monitor NBP in the hospital setting. The feasibility and accuracy of manual sphygmomanometer to monitor NBP has not been explored widely.
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Calorie restriction in humans inhibits the PI3K/AKT pathway and induces a younger transcription profile.
Aging Cell
PUBLISHED: 04-12-2013
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Caloric restriction (CR) and down-regulation of the insulin/IGF pathway are the most robust interventions known to increase longevity in lower organisms. However, little is known about the molecular adaptations induced by CR in humans. Here, we report that long-term CR in humans inhibits the IGF-1/insulin pathway in skeletal muscle, a key metabolic tissue. We also demonstrate that CR induces dramatic changes of the skeletal muscle transcriptional profile that resemble those of younger individuals. Finally, in both rats and humans, CR evoked similar responses in the transcriptional profiles of skeletal muscle. This common signature consisted of three key pathways typically associated with longevity: IGF-1/insulin signaling, mitochondrial biogenesis, and inflammation. Furthermore, our data identify promising pathways for therapeutic targets to combat age-related diseases and promote health in humans.
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Genome-wide modeling of complex phenotypes in Caenorhabditis elegans and Drosophila melanogaster.
BMC Genomics
PUBLISHED: 02-14-2013
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The genetic and molecular basis for many intermediate and end stage phenotypes in model systems such as C. elegans and D. melanogaster has long been known to involve pleiotropic effects and complex multigenic interactions. Gene sets are groups of genes that contribute to multiple biological or molecular phenomena. They have been used in the analysis of large molecular datasets such as microarray data, Next Generation sequencing, and other genomic datasets to reveal pleiotropic and multigenic contributions to phenotypic outcomes. Many model systems lack species specific organized phenotype based gene sets to enable high throughput analysis of large molecular datasets.
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Age-associated alterations in inducible gene transcription in human CD4+ T lymphocytes.
Aging (Albany NY)
PUBLISHED: 02-07-2013
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Age associated immune dysregulation results in a pro-inflammatory state and increased susceptibility to infections and autoimmune diseases. Studies show that signaling initiated at the T cell antigen receptor (TCR) is impaired in CD4+ T cells from old compared to young mice. Here we examined TCR-inducible gene expression changes in CD4+ T cells during human aging. We reveal a dichotomy in gene expression mediated by the inducible transcription factor NF-?B. Most NF-?B target genes are not induced in a sustained manner in cells derived from older compared to younger individuals. However, a subset of NF-?B target genes including genes associated with chronic pro-inflammatory state in the elderly, such as interleukin 1 and 6, continue to be up-regulated even in the absence of NF-?B induction. In addition, we identify other widespread changes in gene expression between cells derived from older and younger individuals. Surprisingly, many of the most noteworthy age-associated changes in human CD4+ T cells differ from those seen in murine models. Our studies provide the first view of age-associated alteration of TCR-inducible gene expression in human CD4+ T cells.
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Using gene expression programming to infer gene regulatory networks from time-series data.
Comput Biol Chem
PUBLISHED: 02-04-2013
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Gene regulatory networks inference is currently a topic under heavy research in the systems biology field. In this paper, gene regulatory networks are inferred via evolutionary model based on time-series microarray data. A non-linear differential equation model is adopted. Gene expression programming (GEP) is applied to identify the structure of the model and least mean square (LMS) is used to optimize the parameters in ordinary differential equations (ODEs). The proposed work has been first verified by synthetic data with noise-free and noisy time-series data, respectively, and then its effectiveness is confirmed by three real time-series expression datasets. Finally, a gene regulatory network was constructed with 12 Yeast genes. Experimental results demonstrate that our model can improve the prediction accuracy of microarray time-series data effectively.
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Evidence for miR-181 involvement in neuroinflammatory responses of astrocytes.
Glia
PUBLISHED: 01-23-2013
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Inflammation is a common component of acute injuries of the central nervous system (CNS) such as ischemia, and degenerative disorders such as Alzheimers disease. Glial cells play important roles in local CNS inflammation, and an understanding of the roles for microRNAs in glial reactivity in injury and disease settings may therefore lead to the development of novel therapeutic interventions. Here, we show that the miR-181 family is developmentally regulated and present in high amounts in astrocytes compared to neurons. Overexpression of miR-181c in cultured astrocytes results in increased cell death when exposed to lipopolysaccharide (LPS). We show that miR-181 expression is altered by exposure to LPS, a model of inflammation, in both wild-type and transgenic mice lacking both receptors for the inflammatory cytokine TNF-?. Knockdown of miR-181 enhanced LPS-induced production of pro-inflammatory cytokines (TNF-?, IL-6, IL-1?, IL-8) and HMGB1, while overexpression of miR-181 resulted in a significant increase in the expression of the anti-inflammatory cytokine IL-10. To assess the effects of miR-181 on the astrocyte transcriptome, we performed gene array and pathway analysis on astrocytes with reduced levels of miR-181b/c. To examine the pool of potential miR-181 targets, we employed a biotin pull-down of miR-181c and gene array analysis. We validated the mRNAs encoding MeCP2 and X-linked inhibitor of apoptosis as targets of miR-181. These findings suggest that miR-181 plays important roles in the molecular responses of astrocytes in inflammatory settings. Further understanding of the role of miR-181 in inflammatory events and CNS injury could lead to novel approaches for the treatment of CNS disorders with an inflammatory component.
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Changes in mouse cognition and hippocampal gene expression observed in a mild physical- and blast-traumatic brain injury.
Neurobiol. Dis.
PUBLISHED: 01-23-2013
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Warfare has long been associated with traumatic brain injury (TBI) in militarized zones. Common forms of TBI can be caused by a physical insult to the head-brain or by the effects of a high velocity blast shock wave generated by the detonation of an explosive device. While both forms of trauma are distinctly different regarding the mechanism of trauma induction, there are striking similarities in the cognitive and emotional status of survivors. Presently, proven effective therapeutics for the treatment of either form of TBI are unavailable. To be able to develop efficacious therapies, studies involving animal models of physical- and blast-TBI are required to identify possible novel or existing medicines that may be of value in the management of clinical events. We examined indices of cognition and anxiety-like behavior and the hippocampal gene transcriptome of mice subjected to both forms of TBI. We identified common behavioral deficits and gene expression regulations, in addition to unique injury-specific forms of gene regulation. Molecular pathways presented a pattern similar to that seen in gene expression. Interestingly, pathways connected to Alzheimers disease displayed a markedly different form of regulation depending on the type of TBI. While these data highlight similarities in behavioral outcomes after trauma, the divergence in hippocampal transcriptome observed between models suggests that, at the molecular level, the TBIs are quite different. These models may provide tools to help define therapeutic approaches for the treatment of physical- and blast-TBIs. Based upon observations of increasing numbers of personnel displaying TBI related emotional and behavioral changes in militarized zones, the development of efficacious therapies will become a national if not a global priority.
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Long noncoding RNA MALAT1 controls cell cycle progression by regulating the expression of oncogenic transcription factor B-MYB.
PLoS Genet.
PUBLISHED: 01-21-2013
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The long noncoding MALAT1 RNA is upregulated in cancer tissues and its elevated expression is associated with hyper-proliferation, but the underlying mechanism is poorly understood. We demonstrate that MALAT1 levels are regulated during normal cell cycle progression. Genome-wide transcriptome analyses in normal human diploid fibroblasts reveal that MALAT1 modulates the expression of cell cycle genes and is required for G1/S and mitotic progression. Depletion of MALAT1 leads to activation of p53 and its target genes. The cell cycle defects observed in MALAT1-depleted cells are sensitive to p53 levels, indicating that p53 is a major downstream mediator of MALAT1 activity. Furthermore, MALAT1-depleted cells display reduced expression of B-MYB (Mybl2), an oncogenic transcription factor involved in G2/M progression, due to altered binding of splicing factors on B-MYB pre-mRNA and aberrant alternative splicing. In human cells, MALAT1 promotes cellular proliferation by modulating the expression and/or pre-mRNA processing of cell cycle-regulated transcription factors. These findings provide mechanistic insights on the role of MALAT1 in regulating cellular proliferation.
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A case report of acute myeloid leukemia after liver transplantation.
Acta Haematol.
PUBLISHED: 01-05-2013
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Acute myeloid leukemia (AML) is a rare complication observed after liver transplantation and only a handful of cases have been reported until now. We report a case of acute promyelocytic leukemia (APL) after liver transplantation in a 50-year-old man. The case presentation was postodontectomy bleeding with an associative abnormal coagulation test 85 months after liver transplantation. A routine blood test, bone marrow test, chromosome analysis and examination of PML/RAR? chimeric gene confirmed the diagnosis of APL and disseminated intravascular coagulation (DIC). Induction chemotherapy with all-trans retinoic acid, arsenic trioxide and daunorubicin was given to this patient and complete remission was achieved. The patient was subjected to DA (daunorubicin combined with cytarabine) and MA (mitoxantrone combined with cytarabine) regimens after remission induction to consolidate the chemotherapy for two courses of treatment, and subsequently subjected to arsenous acid chemotherapy on a periodic basis. Twenty-two months into the follow-up, sustained bone marrow remission was observed with the adapted treatment regimen.
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Simultaneous determination of fangchinoline and tetrandrine in Stephania tetrandra S. Moore by using 1-alkyl-3-methylimidazolium-based ionic liquids as the RP-HPLC mobile phase additives.
Anal. Chim. Acta
PUBLISHED: 01-02-2013
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A reversed phase high performance liquid chromatography (RP-HPLC) method for simultaneous determination of fangchinoline (FAN) and tetrandrine (TET) in Stephania tetrandra S. Moore was established by using 1-hexyl-3-methylimidazolium tetrafluoroborate as the mobile phase additives in this paper. Four types of 1-alkyl-3-methylimidazolium-based ionic liquids (ILs) were used as additives of the mobile phase to separate FAN and TET by RP-HPLC. The effects of the length of the alkyl group on the imidazolium ring and its counterion, the concentrations of IL and the pH of the mobile phase, which influenced the chromatographic behaviors of FAN and TET, were investigated in detail. The linearity, sensitivity, accuracy and repeatability of the proposed method were also investigated. The probable mechanism of the separation with ILs as the mobile phase additives was explored and discussed.
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Non-steroidal anti-inflammatory drugs decrease E2F1 expression and inhibit cell growth in ovarian cancer cells.
PLoS ONE
PUBLISHED: 01-01-2013
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Epidemiological studies have shown that the regular use of non-steroidal anti-inflammatory (NSAIDs) drugs is associated with a reduced risk of various cancers. In addition, in vitro and experiments in mouse models have demonstrated that NSAIDs decrease tumor initiation and/or progression of several cancers. However, there are limited preclinical studies investigating the effects of NSAIDs in ovarian cancer. Here, we have studied the effects of two NSAIDs, diclofenac and indomethacin, in ovarian cancer cell lines and in a xenograft mouse model. Diclofenac and indomethacin treatment decreased cell growth by inducing cell cycle arrest and apoptosis. In addition, diclofenac and indomethacin reduced tumor volume in a xenograft model of ovarian cancer. To identify possible molecular pathways mediating the effects of NSAID treatment in ovarian cancer, we performed microarray analysis of ovarian cancer cells treated with indomethacin or diclofenac. Interestingly, several of the genes found downregulated following diclofenac or indomethacin treatment are transcriptional target genes of E2F1. E2F1 was downregulated at the mRNA and protein level upon treatment with diclofenac and indomethacin, and overexpression of E2F1 rescued cells from the growth inhibitory effects of diclofenac and indomethacin. In conclusion, NSAIDs diclofenac and indomethacin exert an anti-proliferative effect in ovarian cancer in vitro and in vivo and the effects of NSAIDs may be mediated, in part, by downregulation of E2F1.
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[Comparative study on morphological character of leaves of various farm cultivars of Lonicera japonica].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 10-25-2011
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To provide theoretical evidence for dividing and breeding cultivars of Lonicera japonica, the botanical character of laminas leaves observed and compared.
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Gene expression and pathway analysis of ovarian cancer cells selected for resistance to cisplatin, paclitaxel, or doxorubicin.
J Ovarian Res
PUBLISHED: 10-12-2011
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Resistance to current chemotherapeutic agents is a major cause of therapy failure in ovarian cancer patients, but the exact mechanisms leading to the development of drug resistance remain unclear.
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Impact of pyrrolidine dithiocarbamate and interleukin-6 on mammalian target of rapamycin complex 1 regulation and global protein translation.
J. Pharmacol. Exp. Ther.
PUBLISHED: 09-13-2011
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Interleukin-6 (IL-6) is a proinflammatory cytokine that exerts a wide range of cellular, physiological, and pathophysiological responses. Pyrrolidine dithiocarbamate (PDTC) antagonizes the cellular responsiveness to IL-6 through impairment in signal transducer and activator of transcription-3 activation and downstream signaling. To further elucidate the biological properties of PDTC, global gene expression profiling of human HepG2 hepatocellular carcinoma cells was carried out after treatment with PDTC or IL-6 for up to 8 h. Through an unbiased pathway analysis method, gene array analysis showed dramatic and temporal differences in expression changes in response to PDTC versus IL-6. A significant number of genes associated with metabolic pathways, inflammation, translation, and mitochondrial function were changed, with ribosomal protein genes and DNA damage-inducible transcript 4 protein (DDIT4) primarily up-regulated with PDTC but down-regulated with IL-6. Quantitative polymerase chain reaction and Western blot analyses validated the microarray data and showed the reciprocal expression pattern of the mammalian target of rapamycin (mTOR)-negative regulator DDIT4 in response to PDTC versus IL-6. Cell treatment with PDTC resulted in a rapid and sustained activation of Akt and subsequently blocked the IL-6-mediated increase in mTOR complex 1 function through up-regulation in DDIT4 expression. Conversely, down-regulation of DDIT4 with small interfering RNA dampened the capacity of PDTC to block IL-6-dependent mTOR activation. The overall protein biosynthetic capacity of the cells was severely blunted by IL-6 but increased in a rapamycin-independent pathway by PDTC. These results demonstrate a critical effect of PDTC on mTOR complex 1 function and provide evidence that PDTC can reverse IL-6-related signaling via induction of DDIT4.
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Identification and characterization of unique tumoricidal genes in rat umbilical cord matrix stem cells.
Mol. Pharm.
PUBLISHED: 09-13-2011
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Rat umbilical cord matrix stem cells (UCMSC) have been shown to exhibit a remarkable ability to control rat mammary adenocarcinoma (Mat B III) cell proliferation both in vivo and in vitro. To study the underlying mechanisms and genes involved in Mat B III growth attenuation, total RNA was extracted from the naive rat UCMSC alone and those cocultured with Mat B III in Transwell culture dishes. Gene expression profiles of naive rat UCMSC alone and those cocultured with Mat B III cells were investigated by microarray analysis using an Illumina RatRef-12 Expression BeadChip. The comparison of gene expression profiles between untreated and cocultured rat UCMSC identified five upregulated candidate genes (follistatin (FST), sulfatase1 (SULF-1), glucose phosphate isomerase (GPI), HtrA serine peptidase (HTRA1), and adipocyte differentiation-related protein (ADRP)) and two downregulated candidate genes (transforming growth factor, beta-induced, 68 kDa (TGF?I) and podoplanin (PDPN)) based upon the following screening criteria: (1) expression of the candidate genes should show at least a 1.5-fold change in rat UCMSC cocultured with Mat B III cells; (2) candidate genes encode secretory proteins; and (3) they encode cell growth-related proteins. Following confirmation of gene expression by real-time PCR, ADRP, SULF-1 and GPI were selected for further analysis. Addition of specific neutralizing antibodies against these three gene products or addition of gene-specific siRNAs individually in cocultures of 1:20 rat UCMSC:Mat B III cells significantly increased cell proliferation, implying that these gene products are produced under the cocultured condition and functionally attenuate cell growth. Immunoprecipitation followed by Western blot analysis demonstrated that these proteins are indeed secreted into the culture medium. Individual overexpression of these three genes in rat UCMSC significantly enhanced UCMSC-dependent inhibition of cell proliferation in coculture. These results suggest that ADRP, SULF-1 and GPI act as tumor suppressor genes, and these genes might be involved in rat UCMSC-dependent growth attenuation of rat mammary tumors.
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Microbial removal of NOX at high temperature by a novel aerobic strain Chelatococcus daeguensis TAD1 in a biotrickling filter.
J. Hazard. Mater.
PUBLISHED: 08-22-2011
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The removal of NO(X) at high temperature by Chelatococcus daeguensis TAD1 in a biotrickling filter was studied. Media components of the recycling liquid were screened using Plackett-Burman design and then were optimized using response surface methodology, which enhanced the efficiency of nitrate removal by TAD1. The optimal medium was used to perform long-term experiments of NO(X) removal in a biotrickling filter under high concentrations of O(2) and NO in simulated flue gas. Results showed that the biotrickling filter was able to consistently remove 80.2-92.3% NO(X) when the inlet NO concentration was 600ppm under the conditions of oxygen concentration ranging between 2% and 20% and empty bed residence time (EBRT) being 112.5s. Analyses by polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) indicated that TAD1 was always predominant in the biofilm under a flue gas environment. Overall, the present study demonstrated that utilizing a biotrickling filter inoculated with the aerobic denitrifier TAD1 to remove NO(X) at high temperature was practically feasible.
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[Observation and comparision on morphological characteristics of pollen of Lonicera japonica in different cultivars].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 08-16-2011
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To compare morphological characteristics of pollen of Lonicera japonica in different cultivars cultivated in Shandong and provide a basis for distinguishing different cultivars and selecting fine breeding.
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Aging-kb: a knowledge base for the study of the aging process.
Mech. Ageing Dev.
PUBLISHED: 07-22-2011
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As the science of the aging process moves forward, a recurring challenge is the integration of multiple types of data and information with classical aging theory while disseminating that information to the scientific community. Here we present AGING-kb, a public knowledge base with the goal of conceptualizing and presenting fundamental aspects of the study of the aging process. Aging-kb has two interconnected parts, the Aging-kb tree and the Aging Wiki. The Aging-kb tree is a simple intuitive dynamic tree hierarchy of terms describing the field of aging from the general to the specific. This enables the user to see relationships between areas of aging research in a logical comparative fashion. The second part is a specialized Aging Wiki which allows expert definition, description, supporting information, and documentation of each aging keyword term found in the Aging-kb tree. The Aging Wiki allows community participation in describing and defining concepts and terms in the Wiki format. This aging knowledge base provides a simple intuitive interface to the complexities of aging.
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SRT1720 improves survival and healthspan of obese mice.
Sci Rep
PUBLISHED: 07-18-2011
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Sirt1 is an NAD(+)-dependent deacetylase that extends lifespan in lower organisms and improves metabolism and delays the onset of age-related diseases in mammals. Here we show that SRT1720, a synthetic compound that was identified for its ability to activate Sirt1 in vitro, extends both mean and maximum lifespan of adult mice fed a high-fat diet. This lifespan extension is accompanied by health benefits including reduced liver steatosis, increased insulin sensitivity, enhanced locomotor activity and normalization of gene expression profiles and markers of inflammation and apoptosis, all in the absence of any observable toxicity. Using a conditional SIRT1 knockout mouse and specific gene knockdowns we show SRT1720 affects mitochondrial respiration in a Sirt1- and PGC-1?-dependent manner. These findings indicate that SRT1720 has long-term benefits and demonstrate for the first time the feasibility of designing novel molecules that are safe and effective in promoting longevity and preventing multiple age-related diseases in mammals.
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Krüppel-like factor 4 (KLF4) directly regulates proliferation in thymocyte development and IL-17 expression during Th17 differentiation.
FASEB J.
PUBLISHED: 06-17-2011
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Krüppel-like factor 4 (KLF4), a transcription factor, plays a key role in the pluripotency of stem cells. We sought to determine the function of KLF4 in T-cell development and differentiation by using T-cell-specific Klf4-knockout (KO) mice. We found that KLF4 was highly expressed in thymocytes and mature T cells and was rapidly down-regulated in mature T cells after activation. In Klf4-KO mice, we observed a modest reduction of thymocytes (27%) due to the reduced proliferation of double-negative (DN) thymocytes. We demonstrated that a direct repression of Cdkn1b by KLF4 was a cause of decreased DN proliferation. During in vitro T-cell differentiation, we observed significant reduction of IL-17-expressing CD4(+) T cells (Th17; 24%) but not in other types of Th differentiation. The reduction of Th17 cells resulted in a significant attenuation of the severity (35%) of experimental autoimmune encephalomyelitis in vivo in Klf4-KO mice as compared with the Klf4 wild-type littermates. Finally, we demonstrated that KLF4 directly binds to the promoter of Il17a and positively regulates its expression. In summary, these findings identify KLF4 as a critical regulator in T-cell development and Th17 differentiation.
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Claudin-7 is frequently overexpressed in ovarian cancer and promotes invasion.
PLoS ONE
PUBLISHED: 06-16-2011
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Claudins are tight junction proteins that are involved in tight junction formation and function. Previous studies have shown that claudin-7 is frequently upregulated in epithelial ovarian cancer (EOC) along with claudin-3 and claudin-4. Here, we investigate in detail the expression patterns of claudin-7, as well as its possible functions in EOC.
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Extension of lifespan in C. elegans by naphthoquinones that act through stress hormesis mechanisms.
PLoS ONE
PUBLISHED: 04-01-2011
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Hormesis occurs when a low level stress elicits adaptive beneficial responses that protect against subsequent exposure to severe stress. Recent findings suggest that mild oxidative and thermal stress can extend lifespan by hormetic mechanisms. Here we show that the botanical pesticide plumbagin, while toxic to C. elegans nematodes at high doses, extends lifespan at low doses. Because plumbagin is a naphthoquinone that can generate free radicals in vivo, we investigated whether it extends lifespan by activating an adaptive cellular stress response pathway. The C. elegans capncollar (CNC) transcription factor, SKN-1, mediates protective responses to oxidative stress. Genetic analysis showed that skn-1 activity is required for lifespan extension by low-dose plumbagin in C. elegans. Further screening of a series of plumbagin analogs identified three additional naphthoquinones that could induce SKN-1 targets in C. elegans. Naphthazarin showed skn-1dependent lifespan extension, over an extended dose range compared to plumbagin, while the other naphthoquinones, oxoline and menadione, had differing effects on C. elegans survival and failed to activate ARE reporter expression in cultured mammalian cells. Our findings reveal the potential for low doses of naturally occurring naphthoquinones to extend lifespan by engaging a specific adaptive cellular stress response pathway.
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Extraction and preparative purification of tanshinones from Salvia miltiorrhiza Bunge by high-speed counter-current chromatography.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 03-09-2011
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A method for extraction and preparative separation of tanshinones from Salvia miltiorrhiza Bunge was successfully established in this paper. Tanshinones from Salvia miltiorrhiza Bunge were extracted using ethyl acetate as the extractant under reflux. The extracts were then purified by high speed counter-current chromatography (HSCCC) with light petroleum-ethyl acetate-methanol-water (6:4:6.5:3.5, v/v) as the two phase solvent system. The upper phase was used as the stationary phase and the lower phase as the mobile phase. 8.2mg of dihydrotanshinone I, 5.8 mg of 1,2,15,16-tetrahydrotanshiquinone, 26.3mg of cryptotanshinone, 16.2mg of tanshinone I, 25.6 mg of neo-przewaquinone A, 68.8 mg of tanshinone IIA and 9.3mg of miltirone were obtained from 400mg of extracts from Salvia miltiorrhiza Bunge in one-step HSCCC separation, with the purity of 97. 6%, 95.1%, 99.0%, 99.1%, 93.2%, 99.3% and 98.7%, respectively, as determined by HPLC area normalization method. Their chemical structures were identified by ¹H NMR.
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Multiple oxygen tension environments reveal diverse patterns of transcriptional regulation in primary astrocytes.
PLoS ONE
PUBLISHED: 03-01-2011
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The central nervous system normally functions at O(2) levels which would be regarded as hypoxic by most other tissues. However, most in vitro studies of neurons and astrocytes are conducted under hyperoxic conditions without consideration of O(2)-dependent cellular adaptation. We analyzed the reactivity of astrocytes to 1, 4 and 9% O(2) tensions compared to the cell culture standard of 20% O(2), to investigate their ability to sense and translate this O(2) information to transcriptional activity. Variance of ambient O(2) tension for rat astrocytes resulted in profound changes in ribosomal activity, cytoskeletal and energy-regulatory mechanisms and cytokine-related signaling. Clustering of transcriptional regulation patterns revealed four distinct response pattern groups that directionally pivoted around the 4% O(2) tension, or demonstrated coherent ascending/decreasing gene expression patterns in response to diverse oxygen tensions. Immune response and cell cycle/cancer-related signaling pathway transcriptomic subsets were significantly activated with increasing hypoxia, whilst hemostatic and cardiovascular signaling mechanisms were attenuated with increasing hypoxia. Our data indicate that variant O(2) tensions induce specific and physiologically-focused transcript regulation patterns that may underpin important physiological mechanisms that connect higher neurological activity to astrocytic function and ambient oxygen environments. These strongly defined patterns demonstrate a strong bias for physiological transcript programs to pivot around the 4% O(2) tension, while uni-modal programs that do not, appear more related to pathological actions. The functional interaction of these transcriptional programs may serve to regulate the dynamic vascular responsivity of the central nervous system during periods of stress or heightened activity.
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FACS purification of immunolabeled cell types from adult rat brain.
J. Neurosci. Methods
PUBLISHED: 02-17-2011
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Molecular analysis of brain tissue is greatly complicated by having many different classes of neurons and glia interspersed throughout the brain. Fluorescence-activated cell sorting (FACS) has been used to purify selected cell types from brain tissue. However, its use has been limited to brain tissue from embryos or transgenic mice with promoter-driven reporter genes. To overcome these limitations, we developed a FACS procedure for dissociating intact cell bodies from adult wild-type rat brains and sorting them using commercially available antibodies against intracellular and extracellular proteins. As an example, we isolated neurons using a NeuN antibody and confirmed their identity using microarray and real time PCR of mRNA from the sorted cells. Our FACS procedure allows rapid, high-throughput, quantitative assays of molecular alterations in identified cell types with widespread applications in neuroscience.
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Toll-like receptor 2 (TLR2)-TLR9 crosstalk dictates IL-12 family cytokine production in microglia.
Glia
PUBLISHED: 01-29-2011
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Microglia are the resident mononuclear phagocytes of the CNS parenchyma and represent an initial line of defense against invading microorganisms. Microglia utilize Toll-like receptors (TLRs) for pathogen recognition and TLR2 specifically senses conserved motifs of gram-positive bacteria including lipoproteins, lipoteichoic acids, and peptidoglycan (PGN) leading to cytokine/chemokine production. Interestingly, primary microglia derived from TLR2 knockout (KO) mice over-expressed numerous IL-12 family members, including IL-12p40, IL-12p70, and IL-27 in response to intact S. aureus, but not the less structurally complex TLR2 ligands Pam3CSK4 or PGN. The ability of intact bacteria to augment IL-12 family member expression was specific for gram-positive organisms, since numerous gram-negative strains were unable to elicit exaggerated responses in TLR2 KO microglia. Inhibition of SYK or IRAK4 signaling did not impact heightened IL-12 family member production in S. aureus-treated TLR2 KO microglia, whereas PI3K, MAPK, and JNK inhibitors were all capable of restoring exaggerated cytokine expression to wild type levels. Additionally, elevated IL-12 production in TLR2 KO microglia was ablated by a TLR9 antagonist, suggesting that TLR9 drives IL-12 family member production following exposure to intact bacteria that remains unchecked in the absence of TLR2 signaling. Collectively, these findings indicate crosstalk between TLR2 and TLR9 pathways to regulate IL-12 family member production by microglia. The summation of TLR signals must be tightly controlled to ensure the timely cessation and/or fine tuning of cytokine signaling to avoid nonspecific bystander damage due to sustained IL-12 release.
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Combinative application of pH-zone-refining and conventional high-speed counter-current chromatography for preparative separation of alkaloids from Stephania kwangsiensis.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 01-27-2011
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A method which involves the combination of pH-zone-refining counter-current chromatography (pH-zone-refining CCC) and conventional high-speed counter-current chromatography (HSCCC) was established for the preparative separation of alkaloids from the crude extracts of Stephania kwangsiensis. pH-zone-refining CCC was first performed with the solvent system composed of n-hexane-ethyl acetate-methanol-water (3:7:1:9, v/v), where triethylamine (10 mM) was added to the upper organic stationary phase as a retainer and hydrochloric acid (5 mM) to the aqueous mobile phase as an eluter. From 2.0 g of crude extract, 370 mg of sinoacutine and 600 mg of a mixture of three other alkaloids were obtained. Then, the mixture was further separated by conventional HSCCC with the solvent system composed of n-hexane-ethyl acetate-methanol-water (7:3:6:4, v/v), yielding 42 mg of (-)-crebanine, 50 mg of (-)-stephanine and 30 mg of l-romerine from 150 mg mixture of three other alkaloids, respectively. The purities of the four compounds were all over 98% as determined by HPLC, and the chemical structures of the four compounds were confirmed by positive ESI-MS and (1)H NMR data. Results of the present study successfully indicated that this method was efficient for the preparative separation of alkaloids from natural plants.
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Amitriptyline-mediated cognitive enhancement in aged 3×Tg Alzheimers disease mice is associated with neurogenesis and neurotrophic activity.
PLoS ONE
PUBLISHED: 01-19-2011
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Approximately 35 million people worldwide suffer from Alzheimers disease (AD). Existing therapeutics, while moderately effective, are currently unable to stem the widespread rise in AD prevalence. AD is associated with an increase in amyloid beta (A?) oligomers and hyperphosphorylated tau, along with cognitive impairment and neurodegeneration. Several antidepressants have shown promise in improving cognition and alleviating oxidative stress in AD but have failed as long-term therapeutics. In this study, amitriptyline, an FDA-approved tricyclic antidepressant, was administered orally to aged and cognitively impaired transgenic AD mice (3×TgAD). After amitriptyline treatment, cognitive behavior testing demonstrated that there was a significant improvement in both long- and short-term memory retention. Amitriptyline treatment also caused a significant potentiation of non-toxic A? monomer with a concomitant decrease in cytotoxic dimer A? load, compared to vehicle-treated 3×TgAD controls. In addition, amitriptyline administration caused a significant increase in dentate gyrus neurogenesis as well as increases in expression of neurosynaptic marker proteins. Amitriptyline treatment resulted in increases in hippocampal brain-derived neurotrophic factor protein as well as increased tyrosine phosphorylation of its cognate receptor (TrkB). These results indicate that amitriptyline has significant beneficial actions in aged and damaged AD brains and that it shows promise as a tolerable novel therapeutic for the treatment of AD.
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Global dissociation of HuR-mRNA complexes promotes cell survival after ionizing radiation.
EMBO J.
PUBLISHED: 01-13-2011
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Ionizing radiation (IR) triggers adaptive changes in gene expression. Here, we show that survival after IR strongly depends on the checkpoint kinase Chk2 acting upon its substrate HuR, an RNA-binding protein that stabilizes and/or modulates the translation of target mRNAs. Microarray analysis showed that in human HCT116 colorectal carcinoma cells (WT), IR-activated Chk2 triggered the dissociation of virtually all of HuR-bound mRNAs, since IR did not dissociate HuR target mRNAs in Chk2-null (CHK2-/-) HCT116 cells. Accordingly, several HuR-interacting mRNAs encoding apoptosis- and proliferation-related proteins (TJP1, Mdm2, TP53BP2, Bax, K-Ras) dissociated from HuR in WT cells, but remained bound and showed altered post-transcriptional regulation in CHK2-/- cells. Use of HuR mutants that were not phosphorylatable by Chk2 (HuR(3A)) and HuR mutants mimicking constitutive phosphorylation by Chk2 (HuR(3D)) revealed that dissociation of HuR target transcripts enhanced cell survival. We propose that the release of HuR-bound mRNAs via an IR-Chk2-HuR regulatory axis improves cell outcome following IR.
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ATM regulates a DNA damage response posttranscriptional RNA operon in lymphocytes.
Blood
PUBLISHED: 01-05-2011
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Maintenance of genomic stability depends on the DNA damage response, a biologic barrier in early stages of cancer development. Failure of this response results in genomic instability and high predisposition toward lymphoma, as seen in patients with ataxia-telangiectasia mutated (ATM) dysfunction. ATM activates multiple cell-cycle checkpoints and DNA repair after DNA damage, but its influence on posttranscriptional gene expression has not been examined on a global level. We show that ionizing radiation modulates the dynamic association of the RNA-binding protein HuR with target mRNAs in an ATM-dependent manner, potentially coordinating the genotoxic response as an RNA operon. Pharmacologic ATM inhibition and use of ATM-null cells revealed a critical role for ATM in this process. Numerous mRNAs encoding cancer-related proteins were differentially associated with HuR depending on the functional state of ATM, in turn affecting expression of encoded proteins. The findings presented here reveal a previously unidentified role of ATM in controlling gene expression posttranscriptionally. Dysregulation of this DNA damage response RNA operon is probably relevant to lymphoma development in ataxia-telangiectasia persons. These novel RNA regulatory modules and genetic networks provide critical insight into the function of ATM in oncogenesis.
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DNA repair and the accumulation of oxidatively damaged DNA are affected by fruit intake in mice.
J. Gerontol. A Biol. Sci. Med. Sci.
PUBLISHED: 09-16-2010
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AGING is associated with elevated oxidative stress and DNA damage. To achieve healthy aging, we must begin to understand how diet affects cellular processes. We postulated that fruit-enriched diets might initiate a program of enhanced DNA repair and thereby improve genome integrity. C57Bl/6 J mice were fed for 14 weeks a control diet or a diet with 8% peach or nectarine extract. The activities of DNA repair enzymes, the level of DNA damage, and gene expression changes were measured. Our study showed that repair of various oxidative DNA lesions was more efficient in liver extracts derived from mice fed fruit-enriched diets. In support of these findings, gas chromatography-mass spectrometry analysis revealed that there was a decrease in the levels of formamidopyrimidines in peach-fed mice compared with the controls. Additionally, microarray analysis revealed that NTH1 was upregulated in peach-fed mice. Taken together, these results suggest that an increased intake of fruits might modulate the efficiency of DNA repair, resulting in altered levels of DNA damage.
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Disease and phenotype gene set analysis of disease-based gene expression in mouse and human.
Physiol. Genomics
PUBLISHED: 08-03-2010
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The genetic contributions to common disease and complex disease phenotypes are pleiotropic, multifactorial, and combinatorial. Gene set analysis is a computational approach used in the analysis of microarray data to rapidly query gene combinations and multifactorial processes. Here we use novel gene sets based on population-based human genetic associations in common human disease or experimental genetic mouse models to analyze disease-related microarray studies. We developed a web-based analysis tool that uses these novel disease- and phenotype-related gene sets to analyze microarray-based gene expression data. These gene sets show disease and phenotype specificity in a species-specific and cross-species fashion. In this way, we integrate population-based common human disease genetics, mouse genetically determined phenotypes, and disease or phenotype structured ontologies, with gene expression studies relevant to human disease. This may aid in the translation of large-scale high-throughput datasets into the context of clinically relevant disease phenotypes.
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CD147 and VEGF co-expression predicts prognosis in patients with acute myeloid leukemia.
Jpn. J. Clin. Oncol.
PUBLISHED: 06-17-2010
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To investigate the possible role of CD147 and vascular endothelial growth factor in progression and prognosis of acute myeloid leukemia.
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Molecular changes in brain aging and Alzheimers disease are mirrored in experimentally silenced cortical neuron networks.
Neurobiol. Aging
PUBLISHED: 06-08-2010
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Activity-dependent modulation of neuronal gene expression promotes neuronal survival and plasticity, and neuronal network activity is perturbed in aging and Alzheimers disease (AD). Here we show that cerebral cortical neurons respond to chronic suppression of excitability by downregulating the expression of genes and their encoded proteins involved in inhibitory transmission (GABAergic and somatostatin) and Ca(2+) signaling; alterations in pathways involved in lipid metabolism and energy management are also features of silenced neuronal networks. A molecular fingerprint strikingly similar to that of diminished network activity occurs in the human brain during aging and in AD, and opposite changes occur in response to activation of N-methyl-D-aspartate (NMDA) and brain-derived neurotrophic factor (BDNF) receptors in cultured cortical neurons and in mice in response to an enriched environment or electroconvulsive shock. Our findings suggest that reduced inhibitory neurotransmission during aging and in AD may be the result of compensatory responses that, paradoxically, render the neurons vulnerable to Ca(2+)-mediated degeneration.
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POSH is involved in Eiger-Basket (TNF-JNK) signaling and embryogenesis in Drosophila.
J Genet Genomics
PUBLISHED: 04-29-2010
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TNF? can trigger different signaling pathways, including the JNK pathway, to regulate various biological functions such as cell death, differentiation and proliferation. The scaffold protein POSH (Plenty of SH3 Domains) has been shown to be an important regulator of the JNK pathway, but whether it is involved in TNF-signaling has not been reported. Although POSH has been implicated to play a role in development in zebrafish, it has not been studied in null mutants and the underlying mechanism of its effects is still not clear. In this study, we provide evidence that the JNK pathway scaffold protein, POSH, is involved in TNF (Eiger) signaling in Drosophila. POSH is likely to act downstream of dTAB2 and upstream of dTAK1 in the TNF-JNK signaling pathway. In addition, we found that POSH is essential during Drosophila embryogenesis, including epidermal dorsal closure, similar to other JNK pathway components such as Silpper, Hemipterous, and Basket. We observed defects in F-actin accumulation and adherens junction formation during dorsal closure in different posh null mutants, suggesting that POSH is required for epidermal cell migration and cell-shape change during epidermal dorsal closure.
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Survival effect of PDGF-CC rescues neurons from apoptosis in both brain and retina by regulating GSK3beta phosphorylation.
J. Exp. Med.
PUBLISHED: 03-15-2010
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Platelet-derived growth factor CC (PDGF-CC) is the third member of the PDGF family discovered after more than two decades of studies on the original members of the family, PDGF-AA and PDGF-BB. The biological function of PDGF-CC remains largely to be explored. We report a novel finding that PDGF-CC is a potent neuroprotective factor that acts by modulating glycogen synthase kinase 3beta (GSK3beta) activity. In several different animal models of neuronal injury, such as axotomy-induced neuronal death, neurotoxin-induced neuronal injury, 6-hydroxydopamine-induced Parkinsons dopaminergic neuronal death, and ischemia-induced stroke, PDGF-CC protein or gene delivery protected different types of neurons from apoptosis in both the retina and brain. On the other hand, loss-of-function assays using PDGF-C null mice, neutralizing antibody, or short hairpin RNA showed that PDGF-CC deficiency/inhibition exacerbated neuronal death in different neuronal tissues in vivo. Mechanistically, we revealed that the neuroprotective effect of PDGF-CC was achieved by regulating GSK3beta phosphorylation and expression. Our data demonstrate that PDGF-CC is critically required for neuronal survival and may potentially be used to treat neurodegenerative diseases. Inhibition of the PDGF-CC-PDGF receptor pathway for different clinical purposes should be conducted with caution to preserve normal neuronal functions.
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Single round of antigen receptor signaling programs naive B cells to receive T cell help.
Immunity
PUBLISHED: 02-17-2010
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To simulate transient B cell activation that is the likely initiator of T-dependent responses, we examined the molecular and functional consequences of a single round of immunoglobulin M (IgM) signaling. This form of activation triggered early cytosolic signaling and the transcription factor NF-kappaB activation indistinguishably from conventional continuous IgM crosslinking but did not induce G1 progression. However, single round IgM signaling changed the expression of chemokine and chemokine receptor genes implicated in initiating T-dependent responses, as well as accentuated responsiveness to CD40 signaling. Several features of single-round IgM signaling in vitro were recapitulated in B cells after short-term exposure to antigen in vivo. We propose that transient BCR signals prime B cells to receive T cell help by increasing the probability of B-T encounter and creating a cellular environment that is hyper-responsive to CD40 signaling.
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Methylation of ribosomal protein S10 by protein-arginine methyltransferase 5 regulates ribosome biogenesis.
J. Biol. Chem.
PUBLISHED: 02-16-2010
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Modulation of ribosomal assembly is a fine tuning mechanism for cell number and organ size control. Many ribosomal proteins undergo post-translational modification, but their exact roles remain elusive. Here, we report that ribosomal protein s10 (RPS10) is a novel substrate of an oncoprotein, protein-arginine methyltransferase 5 (PRMT5). We show that PRMT5 interacts with RPS10 and catalyzes its methylation at the Arg(158) and Arg(160) residues. The methylation of RPS10 at Arg(158) and Arg(160) plays a role in the proper assembly of ribosomes, protein synthesis, and optimal cell proliferation. The RPS10-R158K/R160K mutant is not efficiently assembled into ribosomes and is unstable and prone to degradation by the proteasomal pathway. In nucleoli, RPS10 interacts with nucleophosmin/B23 and is predominantly concentrated in the granular component region, which is required for ribosome assembly. The RPS10 methylation mutant interacts weakly with nucleophosmin/B23 and fails to concentrate in the granular component region. Our results suggest that PRMT5 is likely to regulate cell proliferation through the methylation of ribosome proteins, and thus reveal a novel mechanism for PRMT5 in tumorigenesis.
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Sigma-1 receptors regulate hippocampal dendritic spine formation via a free radical-sensitive mechanism involving Rac1xGTP pathway.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 12-11-2009
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Sigma-1 receptors (Sig-1Rs) are endoplasmic reticulum (ER)-resident proteins known to be involved in learning and memory. Dendritic spines in hippocampal neurons play important roles in neuroplasticity and learning and memory. This study tested the hypothesis that Sig-1Rs might regulate denritic spine formation in hippocampal neurons and examined potential mechanisms therein. In rat hippocampal primary neurons, the knockdown of Sig-1Rs by siRNAs causes a deficit in the formation of dendritic spines that is unrelated to ER Ca(2+) signaling or apoptosis, but correlates with the mitochondrial permeability transition and cytochrome c release, followed by caspase-3 activation, Tiam1 cleavage, and a reduction in Rac1.GTP. Sig-1R-knockdown neurons contain higher levels of free radicals when compared to control neurons. The activation of superoxide dismutase or the application of the hydroxyl-free radical scavenger N-acetyl cysteine (NAC) to the Sig-1R-knockdown neurons rescues dendritic spines and mitochondria from the deficits caused by Sig-1R siRNA. Further, the caspase-3-resistant TIAM1 construct C1199DN, a stable guanine exchange factor able to constitutively activate Rac1 in the form of Rac1.GTP, also reverses the siRNA-induced dendritic spine deficits. In addition, constitutively active Rac1.GTP reverses this deficit. These results implicate Sig-1Rs as endogenous regulators of hippopcampal dendritic spine formation and suggest a free radical-sensitive ER-mitochondrion-Rac1.GTP pathway in the regulation of dendritic spine formation in the hippocampus.
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Possible angiogenic roles for claudin-4 in ovarian cancer.
Cancer Biol. Ther.
PUBLISHED: 10-06-2009
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Claudin proteins are frequently overexpressed in various tumors such as breast, prostate and ovarian cancer. While their functions in cancer have not been completely elucidated, roles in survival, adhesion and invasion have been suggested. In order to clarify the roles of claudins in ovarian cancer, we have performed gene expression profiling of ovarian surface epithelial cells overexpressing claudin-4 and compared the expression patterns to the parental, non-expressing cells. Claudin-4 expression leads to the differential expression of several genes, including many that have previously been implicated in angiogenesis. In particular, angiogenic cytokines, such as IL-8, were found elevated while genes of the angiostatic interferon pathway were found downregulated. In vitro assays show that claudin-4-expressing cells produce factors that can stimulate angiogenesis as measured by tube formation and migration in HUVEC cells. In addition, an in vivo mouse dorsal skinfold assay confirms that cells expressing claudin-4 secrete factors that can mediate angiogenesis in the dorsal skin of mice. Our data suggest a novel function for claudin-4 in cancer and provide an additional rationale for its common overexpression in human tumors.
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MyD88 expression by CNS-resident cells is pivotal for eliciting protective immunity in brain abscesses.
ASN Neuro
PUBLISHED: 07-03-2009
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MyD88 KO (knockout) mice are exquisitely sensitive to CNS (central nervous system) infection with Staphylococcus aureus, a common aetiological agent of brain abscess, exhibiting global defects in innate immunity and exacerbated tissue damage. However, since brain abscesses are typified by the involvement of both activated CNS-resident and infiltrating immune cells, in our previous studies it has been impossible to determine the relative contribution of MyD88-dependent signalling in the CNS compared with the peripheral immune cell compartments. In the present study we addressed this by examining the course of S. aureus infection in MyD88 bone marrow chimaera mice. Interestingly, chimaeras where MyD88 was present in the CNS, but not bone marrow-derived cells, mounted pro-inflammatory mediator expression profiles and neutrophil recruitment equivalent to or exceeding that detected in WT (wild-type) mice. These results implicate CNS MyD88 as essential in eliciting the initial wave of inflammation during the acute response to parenchymal infection. Microarray analysis of infected MyD88 KO compared with WT mice revealed a preponderance of differentially regulated genes involved in apoptotic pathways, suggesting that the extensive tissue damage characteristic of brain abscesses from MyD88 KO mice could result from dysregulated apoptosis. Collectively, the findings of the present study highlight a novel mechanism for CNS-resident cells in initiating a protective innate immune response in the infected brain and, in the absence of MyD88 in this compartment, immunity is compromised.
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Direct and indirect roles of RECQL4 in modulating base excision repair capacity.
Hum. Mol. Genet.
PUBLISHED: 06-29-2009
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RECQL4 is a human RecQ helicase which is mutated in approximately two-thirds of individuals with Rothmund-Thomson syndrome (RTS), a disease characterized at the cellular level by chromosomal instability. BLM and WRN are also human RecQ helicases, which are mutated in Bloom and Werners syndrome, respectively, and associated with chromosomal instability as well as premature aging. Here we show that primary RTS and RECQL4 siRNA knockdown human fibroblasts accumulate more H(2)O(2)-induced DNA strand breaks than control cells, suggesting that RECQL4 may stimulate repair of H(2)O(2)-induced DNA damage. RTS primary fibroblasts also accumulate more XRCC1 foci than control cells in response to endogenous or induced oxidative stress and have a high basal level of endogenous formamidopyrimidines. In cells treated with H(2)O(2), RECQL4 co-localizes with APE1, and FEN1, key participants in base excision repair. Biochemical experiments indicate that RECQL4 specifically stimulates the apurinic endonuclease activity of APE1, the DNA strand displacement activity of DNA polymerase beta, and incision of a 1- or 10-nucleotide flap DNA substrate by Flap Endonuclease I. Additionally, RTS cells display an upregulation of BER pathway genes and fail to respond like normal cells to oxidative stress. The data herein support a model in which RECQL4 regulates both directly and indirectly base excision repair capacity.
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A novel combination of factors, termed SPIE, which promotes dopaminergic neuron differentiation from human embryonic stem cells.
PLoS ONE
PUBLISHED: 04-14-2009
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Stromal-Derived Inducing Activity (SDIA) is one of the most efficient methods of generating dopaminergic (DA) neurons from embryonic stem cells (ESC). DA neuron induction can be achieved by co-culturing ESC with the mouse stromal cell lines PA6 or MS5. The molecular nature of this effect, which has been termed "SDIA" is so far unknown. Recently, we found that factors secreted by PA6 cells provided lineage-specific instructions to induce DA differentiation of human ESC (hESC).
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Themis, a T cell-specific protein important for late thymocyte development.
Nat. Immunol.
PUBLISHED: 04-10-2009
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During positive selection, thymocytes transition through a stage during which T cell antigen receptor (TCR) signaling controls CD4-versus-CD8 lineage choice and subsequent maturation. Here we describe a previously unknown T cell-specific protein, Themis, that serves a distinct function during this stage. In Themis(-/-) mice, thymocyte selection was impaired and the number of transitional CD4(+)CD8(int) thymocytes as well as CD4(+) or CD8(+) single-positive thymocytes was lower. Notably, although we detected no overt TCR-proximal signaling deficiencies, Themis(-/-) CD4(+)CD8(int) thymocytes showed developmental defects consistent with attenuated signaling that were reversible by TCR stimulation. Our results identify Themis as a critical component of the T cell developmental program and suggest that Themis functions to sustain and/or integrate signals required for proper lineage commitment and maturation.
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VEGF-B is dispensable for blood vessel growth but critical for their survival, and VEGF-B targeting inhibits pathological angiogenesis.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 04-06-2009
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VEGF-B, a homolog of VEGF discovered a long time ago, has not been considered an important target in antiangiogenic therapy. Instead, it has received little attention from the field. In this study, using different animal models and multiple types of vascular cells, we revealed that although VEGF-B is dispensable for blood vessel growth, it is critical for their survival. Importantly, the survival effect of VEGF-B is not only on vascular endothelial cells, but also on pericytes, smooth muscle cells, and vascular stem/progenitor cells. In vivo, VEGF-B targeting inhibited both choroidal and retinal neovascularization. Mechanistically, we found that the vascular survival effect of VEGF-B is achieved by regulating the expression of many vascular prosurvival genes via both NP-1 and VEGFR-1. Our work thus indicates that the function of VEGF-B in the vascular system is to act as a "survival," rather than an "angiogenic" factor and that VEGF-B inhibition may offer new therapeutic opportunities to treat neovascular diseases.
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Protease activated receptor signaling is required for African trypanosome traversal of human brain microvascular endothelial cells.
PLoS Negl Trop Dis
PUBLISHED: 03-23-2009
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Using human brain microvascular endothelial cells (HBMECs) as an in vitro model for how African trypanosomes cross the human blood-brain barrier (BBB) we recently reported that the parasites cross the BBB by generating calcium activation signals in HBMECs through the activity of parasite cysteine proteases, particularly cathepsin L (brucipain). In the current study, we examined the possible role of a class of protease stimulated HBMEC G protein coupled receptors (GPCRs) known as protease activated receptors (PARs) that might be implicated in calcium signaling by African trypanosomes.
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Exendin-4, a glucagon-like peptide-1 receptor agonist prevents mTBI-induced changes in hippocampus gene expression and memory deficits in mice.
Exp. Neurol.
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Traumatic brain injury (TBI) is a global problem reaching near epidemic numbers that manifests clinically with cognitive problems that decades later may result in dementias like Alzheimers disease (AD). Presently, little can be done to prevent ensuing neurological dysfunctions by pharmacological means. Recently, it has become apparent that several CNS diseases share common terminal features of neuronal cell death. The effects of exendin-4 (Ex-4), a neuroprotective agent delivered via a subcutaneous micro-osmotic pump, were examined in the setting of mild TBI (mTBI). Utilizing a model of mTBI, where cognitive disturbances occur over time, animals were subjected to four treatments: sham; Ex-4; mTBI and Ex-4/mTBI. mTBI mice displayed deficits in novel object recognition, while Ex-4/mTBI mice performed similar to sham. Hippocampal gene expression, assessed by gene array methods, showed significant differences with little overlap in co-regulated genes between groups. Importantly, changes in gene expression induced by mTBI, including genes associated with AD were largely prevented by Ex-4. These data suggest a strong beneficial action of Ex-4 in managing secondary events induced by a traumatic brain injury.
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Prediction of flavin mono-nucleotide binding sites using modified PSSM profile and ensemble support vector machine.
Comput. Biol. Med.
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Flavin mono-nucleotide (FMN) closely evolves in many biological processes. In this study, a computational method was proposed to identify FMN binding sites based on amino acid sequences of proteins only. A modified Position Specific Score Matrix was used to characterize the local environmental sequence information, and a visible improvement of performance was obtained. Also, the ensemble SVM was applied to solve the imbalanced data problem. Additionally, an independent dataset was built to evaluate the practical performance of the method, and a satisfactory accuracy of 87.87% was achieved. It demonstrates that the method is effective in predicting FMN-binding sites.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.