Objective To detect the caspase-14 expression in malignant melanoma cells and tumor tissues and its effect on tumor resistance to drug. Methods The mRNA and protein level of caspase-14 in 4 melanoma cell lines (A375, A875, M14, and SK-Mel-1) and the melanocytes, was detected by reverse transcription PCR (RT-PCR) and Western blotting. Caspase-14 expression in 34 malignant melanoma tumor tissues and 10 dermal nevus tissues was determined by in situ hybridization and immunohistochemistry. Results Caspase-14 expression was seen in melanoma cells and melanocytes. It was higher in melanoma-associated antigen 1 recognized by T cells (MART-1) positive cells than in MART-1 negative cells. The cells expressing the lower caspase-14 were more sensitive to the treatment with either chemotherapy drugs camptothecin and cisplatin or radiotherapy than the ones expressing the higher caspase-14 (P<0.01). Caspase-14 expression was observed in 70% dermal nevus, as well as 97% in malignant melanoma tissues, and the difference between them was statistically significant (P<0.05). Conclusion Caspase-14 is expressed in tissues and cells of malignant melanoma. Our data indicated that the expression level of caspase-14 affected the drug sensitivity of melanoma.
Lung cancer is the leading cause of cancer-related mortality worldwide. Despiting the great progress on target agents, majority of people who do not harbor a mutation could not get benefit from them. Immunotherapy, through stimulating the body's immune system to improve the antitumor immunity effect, has been a new therapeutic method for non-small cell lung cancer (NSCLC). Study had been reported that immune checkpoint molecules, including programmed death-1 (PD-1)/PD-ligand (L) 1 axis, are closedly related with cancer generation and development, and play a key role on clinical significance of NSCLC. Activation of PD-1/PD-L1 pathway contributes to tumor immune escape, and block PD-1/PD-L1 pathway can enhance endogenous antimuor immunity. Currently increasing clinical trials suggested that immune checkpoint inhibitors, including anti-PD-1 and anti-PD-L1 monoclonal antibodies turned out to be beneficial and safe in NSCLC. Here, we provide a review on the progress of PD-1/PD-L1 pathway and immune checkpoint inhibitors in NSCLC.
Modal computation with high precision is an important issue for wave propagation in optical waveguides when the eigenmode expansion method is applied. This numerical study of an open waveguide is accomplished by terminating the unbounded regions with perfectly matched layers. Then, by the differential transfer matrix method (DTMM), two nonlinear relations of modes for the TM case are proposed for complex waveguides with varied refractive indexes along the transverse direction. For the gradually varied waveguides, a higher approximation is provided and some asymptotic formulas of leaky modes are created, which may be used as better initial values for some iteration methods. Numerical examples illustrate that our treatment is highly feasible and effective.
Abstract This study presented the complete mitochondrial genome of the Torpedo scad Megalaspis cordyla, the only member of its genus, as well as its phylogenetic position in Carangidae. The genome is 16,566?bp containing the usual 2 rRNA genes, 13 protein-coding genes, 22 tRNA genes, and 1 control region. Gene organization is similar to that observed in most other vertebrates. Gene overlapping and separating were also observed in M. cordyla mitogenome. The overall base compositions of mitogenome was 28.83% A, 25.81% T, 15.93% G, and 29.43% C. Phylogenetic analyses using the concatenated sequence of the protein-coding genes of the reported Carangidae mitogenome showed similar results in the neighbour-joining and Bayesian inference trees. Three clades were formed as Subfamilies Caranginae, Seriolinae and Trachinotinae in Carangidae. M. cordyla was most closely related to the species in genus Caranx.
Abstract The African pompano Alectis ciliaris (Perciformes: Carangidae) is an economic fish species distributed throughout the tropical oceans and seas of the world. In this study, we assembled the complete mitochondrial genome of A. ciliaris from contiguous, overlapping segments amplified by polymerase chain reactions. The complete mitogenome sequence was 16,570?bp in length, consisting of 37 typical animal mitochondrial genes and 1 control region, same with the typical vertebrate mitochondrial gene arrangement. There were 10 regions of gene overlaps totaling 30?bp and 12 intergenic spacer regions totaling 67?bp. The overall base composition of the heavy strand was 28.32% for A, 26.77% for T, 16.16% for G, 28.75% for C with a slight AT bias of 55.09%.
Current treatments for inflammation associated with bronchopulmonary dysplasia fail to show clinical efficacy. Foxm1, a transcription factor of the Forkhead box family, is a critical mediator of lung development and carcinogenesis, but its role in bronchopulmonary dysplasia-associated pulmonary inflammation is unknown. Immunohistochemistry and RNA analysis were used to assess Foxm1 in lung tissue from hyperoxia-treated mice and patients with bronchopulmonary dysplasia. LysM-Cre/Foxm1-/- mice, in which Foxm1 was deleted from myeloid-derived inflammatory cells, including macrophages, monocytes and neutrophils, were exposed to neonatal hyperoxia causing lung injury and remodeling. Measurements of lung function and flow cytometry were used to evaluate effects of Foxm1 deletion on pulmonary inflammation and repair. Increased Foxm1 expression was observed in pulmonary macrophages of hyperoxia-exposed mice and lung tissue from patients with bronchopulmonary dysplasia. After hyperoxia, deletion of Foxm1 from the myeloid cell lineage decreased numbers of interstitial macrophages (CD45+CD11b+Ly6C-Ly6G-F4/80+CD68-) and impaired alveologenesis and lung function. The exaggerated bronchopulmonary dysplasia-like phenotype observed in hyperoxia-exposed LysM-Cre/Foxm1-/- mice was associated with increased expression of neutrophil-derived myeloperoxidase, proteinase 3 and cathepsin-g, all of which are critical for lung remodeling and inflammation. Our data demonstrate that Foxm1 influences pulmonary inflammatory responses to hyperoxia, inhibiting neutrophil-derived enzymes and enhancing monocytic responses that limit alveolar injury and remodeling in neonatal lungs.
RhoB is a member of the Rho small GTPase family that regulates cytoskeletal dynamics and vesicle trafficking. The RhoB homologs, RhoA and RhoC, have been shown to promote cancer progression and metastasis. In contrast, the functions of RhoB in human cancers are context dependent. Although expression of RhoB inversely correlates with disease progression in several epithelial cancers, recent data suggest that RhoB may support malignant phenotypes in certain cancer types.
Ginseng total saponins (GTS) are principal bioactive ingredients of Panax ginseng. In this study, we investigated the antidepressant effect of GTS on the corticosterone-induced mouse depression model and explored the underlying mechanism. Corticosterone (20 mg kg(-1) d(-1)) was subcutaneously administered for 22 d to induce the model, before doses of GTS (12.5, 25, and 50 mg kg(-1) d(-1)) or fluoxetine (10 mg kg(-1) d(-1)) were subsequently given by gavage. On day 20 and 21, depression-like behavior was observed via a forced swimming test and a tail suspension test respectively. At 6 h after the last dose of corticosterone (day 22), all mice were sacrificed followed by serum corticosterone assays and Western blot analysis. The results showed that GTS (25 and 50 mg kg(-1) d(-1))treatments relieved depression-like behavior without altering the elevated serum corticosterone levels. Furthermore, GTS treatments raised the down-regulated levels of hippocampal glycogen synthase kinase-3? (GSK-3?) inhibitory phosphorylation. In contrast, fluoxetine (10 mg kg(-1) d(-1)) treatment reversed the increased corticosterone level and had no effect on the decreased GSK-3? inhibitory phosphorylation. These findings confirmed the antidepressant effect of GTS in the corticosterone-induced mouse depression model. Enhancing GSK-3? inhibitory phosphorylation may be one of the underlying mechanisms.
Lung cancer is the most common cause of cancer mortality worldwide, with an estimated 1.4 million deaths each year. Here we report whole-exome sequencing of nine tumor/normal tissue pairs from Chinese patients with non-small cell lung carcinoma (NSCLC). This allows us to identify a number of significantly mutated genes in NSCLC, which were highly enriched in DNA damage repair, NF-?B pathway, JAK/STAT signaling and chromatin modification. Notably, we identify a histone-lysine methyltransferase gene, namely, MLL2, as one of the most significantly mutated genes in our screen. In a following validation study, we identify deleterious mutations of MLL2 in 12 out of 105 (11.4%) NSCLC patients. Additionally, reduced or lost expression of MLL2 was commonly observed in tumor tissues as compared with paired adjacent non-tumor tissues regardless of mutation status. Together, our study defines the landscape of somatic mutations in Chinese NSCLC and supports the role of MLL2 mutation in the pathogenesis of the disease.
In order to solve the problem that CCDs cannot measure the full spectral range in a single measurement, we propose a new wavelength-fitting algorithm that combines the polynomial algorithm applied to the fixed grating with grating equation without CCD or spectrum assembling. Both the grating rotating angle and pixel coordinate of the CCD are written in our wavelength-fitting function. With the calibration of the 576.96 and 579.07 nm mercury spectral line, we can determine that wavelength error of 576.96 nm is between 0.002 and 0.1 nm and wavelength error of 579.07 nm is between 0.006 and 0.06 nm. The calculation results show that the new algorithm can gain more precise wavelength accuracy without a complex assembling operation.
BackgroundEvidence has demonstrated that central fat distribution produces the most profound metabolic abnormalities and is associated with an increased risk of atherosclerotic cardiovascular diseases. We aimed to investigate whether the indexes of central fat distribution, including waist-to-height ratio (WHtR) and visceral fat area (VFA), were stronger risk factors of subclinical atherosclerosis than body mass index (BMI) in Chinese adults.MethodsA total of 3381 participants aged 40 years or older without history of cardiovascular diseases (CVD) were enrolled in the present cross-sectional study from the Songnan community, Shanghai, China. Height, weight and waist circumference (WC) were measured by experienced physicians. High-resolution B-mode ultrasonography was performed to measure carotid intima-media thickness (CIMT). Regional adiposity was measured by a dual-source computed tomography (CT) scanner.ResultsNormal weight but central obesity group (BMI¿<¿23 kg/m2 and WHtR¿>¿0.5) had higher levels of systolic blood pressure (SBP), fasting plasma glucose (FPG), 2 h post-load glucose (2 h PG), Hemoglobin A1c (HbA1c), and CIMT, as well as an elevated prevalence of hypertension and diabetes compared with overweight/obesity but not central obesity group (BMI¿¿¿23 kg/m2 and WHtR¿¿¿0.5). In logistic regression analysis, WHtR¿>¿0.5 was significantly and independently associated with elevated CIMT (odds ratio [OR] 1.30, 95% confidence interval [CI] 1.01-1.68, p value¿=¿0.044). Similar association was noted for each standard deviation (SD) increase of WHtR (OR 1.25, 95% CI 1.07-1.47, p value¿=¿0.006). Stepwise multiple linear regression analysis revealed that both WHtR and VFA were important determinants of CIMT, independent of other well-recognized risk factors (both p values¿<¿0.01).ConclusionsWHtR and VFA were associated with CIMT, independent of BMI and conventional CVD risk factors. Given the relatively high cost and complexness of VFA measurement, WHtR could be a more convenient and appropriate measure of abdominal obesity in clinical practice.
Mesenchymal stem cells (MSCs) are multipotent stromal cells that exist in many tissues and are capable of differentiating into several different cell types. Exogenously administered MSCs migrate to damaged tissue sites, where they participate in tissue repair. Their communication with the inflammatory microenvironment is an essential part of this process. In recent years, much has been learned about the cellular and molecular mechanisms of the interaction between MSCs and various participants in inflammation. Depending on their type and intensity, inflammatory stimuli confer on MSCs the ability to suppress the immune response in some cases or to enhance it in others. Here we review the current findings on the immunoregulatory plasticity of MSCs in disease pathogenesis and therapy.
Lung cancer is one of the leading causes of cancer-related death in developed countries. Despite decades of intensive efforts to comate this malignant disease, the prognosis of lung cancer remains unfavorable and is especially poor in advanced non-small cell lung cancer (NSCLC). Accumulating evidence indicate that one of the main causes of the poor outcome in NSCLC treatment is the innate resistance of NSCLC patients to anticancer drugs. However, the mechanism underling NSCLC development and drug resistance is not fully understood. Here we show that the mitochondrial class III NAD(+)-dependent deacetylase SIRT5 is overexpressed in human NSCLC and high expression of SIRT5 predicts poor survival. SIRT5 knockdown represses lung cancer cell growth and transformation in vitro and in vivo. Furthermore, we find that SIRT5 knockdown makes lung cancer cells more sensitive to drug (cis-diamminedichloroplatinum [CDDP], 5-fluorouracil [5-FU] or bleomycin) treatment in vitro and in vivo. Mechanically, we identify Nrf2, which is a core transcription factor for lung cancer growth and drug resistance, as a target of SIRT5. SIRT5 mRNA level is positively correlated with the expression of Nrf2 in lung cancer tissues and SIRT5 knockdown reduces the expression of Nrf2 and its downstream drug-resistance genes. Taken together, our findings implicate that SIRT5 as a protein responsible for growth and drug resistance in human NSCLC, and SIRT5 may serve as a potential prognostic factor and drug target for intervention.
Abstract Lesser-spotted leatherjacket Thamnaconus hypargyreus (Tetraodontiformes: Monacanthidae) is an economically important fish species in the South China Sea. In this study, we designed 15 pairs of primers for amplification of the mitochondrial fragments of T. hypargyreus by PCR. The complete mitogenome sequence has 16,438?bp, containing the usual 2 rRNA genes, 13 protein-coding genes, 22 tRNA genes, and 1 control region, the gene composition and order of which are similar to most of other vertebrates. Most mitochondrial genes except ND6 and eight tRNA genes are encoded on the heavy strand. The overall base composition of the heavy strand is 27.5% A, 26.0% T, 17.4% G, 29.1% C with a slight AT bias of 53.5%. There are 12 regions of gene overlaps totaling 32?bp and 11 intergenic spacer regions totaling 68?bp. This mitogenome sequence data of T. hypargyreus would provide the fundamental genetic data for further conservation genetic studies for this important fish species.
Nasopharyngeal carcinoma (NPC) is a leading cause of cancer-related mortality. Radiotherapy is one of the primary modalities for NPC treatment. However, in patients in the late stages of the disease, the local control rate and overall survival rate remain low. Therefore, it is urgent to identify new targets that can improve the outcome of radiotherapy in this neoplasm. In the present study, we investigated the effects of metformin on the radiosensitivity of NPC cells and explored the potential mechanisms. The radiosensitizing effects of metformin on NPC cells were measured by colony formation assay. Cell apoptosis was assessed by Hoechst 33342 staining analysis. DNA damage was detected by monitoring ?-H2AX foci with immunofluorescence. The changes in apotosis-related and DNA damage repair-related proteins were detected by western blotting. Our study demonstrated that metformin significantly reduced the cell viability, enhanced radiosensitivity and potentiated radiation-induced caspase-9/-3 cleavage in the NPC cells. In addition, metformin plus radiation significantly upregulated the expression of p-ATM, p-ATR, ?-H2AX and downregulated the expression of ATM, ATR, p95/NBS1, Rad50, DNA-PK, Ku70 and Ku80. Therefore, our results suggest that metformin possesses a strong radiosensitizing potential in NPC cells. This radiosensitizing effect was associated with inhibition of DNA double-strand break repair processes through HR repair and the NHEJ repair signaling pathway, thereby enhancing radiation-induced cell apoptosis. These findings imply that metformin is a potent radiation-sensitizing agent and may be a promising candidate for clinical evaluation as part of a combined regimen for the treatment of nasopharyngeal carcinoma.
Targeted gene therapy needs to be implemented for future therapies to ensure efficient activity at the site of patient primary tumors or metastases without causing intolerable side-effects. One of the elements of gene therapy is vector, which includes viral and non-viral vector. In the present study, we constructed a novel non-viral targeted gene therapeutic system by using the new minicircle (MC) producing plasmid for Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC). Molecular cloning technique was used to construct plasmids and electrophoretic analysis. Dual-luciferase reporter assay was used to evaluate the expression of luciferase. Fluorescence microscope was used to detect the expression of enhanced green fluorescence protein (EGFP). We constructed a new MC producing system pMC.BESPX-origin of plasmid replication (oriP), and demonstrated that this system could produce highly purified MC-oriP. Furthermore, our results showed that MC-oriP vector produced by the new system could mediate targeted luciferase gene expression in EBV-positive NPC cells. In addition, we verified that MC could mediate enhanced transgene expression compared with parent plasmid through EGFP transfection. The present study constructed a targeted expression vector pMC.BESPX-oriP which could carry diversified therapeutic genes for EBV-positive NPC and provides a new approach for MC-based therapies.
Constitutive activation of the transcription factors nuclear factor ?B (NF-?B) and STAT3 is involved in the development and progression of human colorectal cancer (CRC). Little is known about how these factors become activated in cancer cells. We investigated whether microRNA miR-221 and miR-222 regulate NF-?B and signal transducer and activator of transcription 3 (STAT3) activation in human CRC cell lines.
Ischemic stroke (IS) is a heterogeneous multifactorial disorder caused by both genetic and environmental factors. A genome-wide association study on stroke in Caucasians identified a variant on chromosome 4q25 that is significantly associated with IS, with the strongest risk for cardioembolic stroke (CES). The current study aims to investigate the association of the rs1906591 variant on 4q25 with IS through a case-control study in a Chinese Han population. A total of 712 IS patients and 774 control subjects were involved in the current research. Stroke subtyping was performed according to the Trial of Org 10172 in Acute Stroke Treatment criteria. The genotypes were determined using the SNaPshot technique. The association of the genotypes with the risk of IS was estimated using logistic regression analysis. The rs1906591 single nucleotide polymorphism variant was associated with the CES subtype in both recessive and additive models (recessive model: odds ratio [OR]=2.58, 95% confidence interval [CI] 1.47-4.53, p=0.001, adjusted OR=2.71, 95% CI 1.48-4.96, p=0.001; additive model: OR=2.50, 95% CI 1.19-5.25, p=0.015, adjusted OR=2.83, 95% CI 1.24-6.50, p=0.013). This result indicates that patients with the AA genotype have a higher rate of CES than other genotypes. However, the rs1906591 variant was not significantly associated with the overall incidence of stroke or other stroke subtypes. The rs1906591 variant is significantly associated with CES in the Chinese Han population, but not with other stroke subtypes.
The naked small interfering RNA (siRNA) of caspase-3, a key player in ischemia reperfusion injury, was effective in cold preserved and hemoreperfused kidneys, but not autotransplanted kidneys in our porcine models. Here, chemically modified serum stabilized caspase-3 siRNAs were further evaluated. The left kidney was retrieved and infused by University of Wisconsin solution with/without 0.3?mg caspase-3 or negative siRNA into the renal artery for 24-hour cold storage (CS). After an intravenous injection of 0.9?mg siRNA and right-uninephrectomy, the left kidney was autotransplanted for 2 weeks. The effectiveness of caspase-3 siRNA was confirmed by caspase-3 knockdown in the post-CS and/or post-transplant kidneys with reduced apoptosis and inflammation, while the functional caspase-3 siRNA in vivo was proved by detected caspase-3 mRNA degradation intermediates. HMGB1 protein was also decreased in the post-transplanted kidneys; correlated positively with renal IL-1? mRNA, but negatively with serum IL-10 or IL-4. The minimal off-target effects of caspase-3 siRNA were seen with favorable systemic responses. More importantly, renal function, associated with active caspase-3, HMGB1, apoptosis, inflammation, and tubulointerstitial damage, was improved by caspase-3 siRNA. Taken together, the 2-week autotransplanted kidneys were protected when caspase-3 siRNA administrated locally and systemically, which provides important evidence for future clinical trials.
Aging is associated with a decrease in appetite, energy intake and glucose tolerance. Experimental studies have suggested that ghrelin and obestatin play a role in glucose homeostasis and in the regulation of energy metabolism. However, few studies have been performed on the role of ghrelin and obestatin in middle-aged and old adults.
Abstract Knowledge of population structure is particularly important for long-term fisheries management and conservation. Lesser-spotted leatherjacket Thamnaconus hypargyreus is an economically important fish species in the South China Sea. Fish specimens (totally 158 individuals) used in this study were collected from five geographical locations in the north of the South China Sea and the southwestern Nansha Islands. The results were as follows: a total of 636 nucleotides of the mitochondrial DNA (mtDNA) control region (CR) of T. hypargyreus were amplified by polymerase chain reaction (PCR) technology. Both 103 mutations of nucleotide acids without inserting or deleting one and 91 haplotypes were found among the examined CR fragment. High haplotype diversity (0.9419?±?0.0151) and nucleotide diversity (0.0095?±?0.00506) relatively together with a recent and sudden population expansion which characterizes the genetic population structure of this species. Analysis of molecular variance (AMOVA) and the fixation indices (Fst) of five groups showed that the genetic variance mainly came from individuals within groups, and there was no genetic differentiation between groups. The phylogenetic trees including maximum likelihood (ML) and Bayesian inference (BI) proved no phylogeographic differentiation structure in five groups. The mtDNA marker suggested the five groups should be genetic homogeneity, which implied T. hypargyreus in the north and southwest continental shelf of the South China Sea belongs to one population.
C-kit positive (c-kit(+)) cells are usual tissue-specific stem cells. However, in postnatal testis, undifferentiated spermatogonial stem cells (SSCs) are c-kit negative (c-kit(-)) and activation of c-kit represents the start of SSC differentiation, leaving an intriguing question whether other c-kit(+) cells exist and participate in the postnatal development of testis. To this end, a feasible system for testicular reconstitution, in which a specific type of cells can be manipulated, is needed. Here, we first establish de novo morphogenesis of testis by subcutaneous injection of testicular cells from neonatal testes into the backs of nude mice. We observe testicular tissue formation and spermatogenesis from all injected sites. Importantly, functional spermatids can be isolated from these testicular tissues. Using this system, we systemically analyze the roles of c-kit(+) cells in testicular reconstitution and identify a small population of cells (c-kit(+):CD140a(+):F4/80(+)), which express typical markers of macrophages, are critical for de novo morphogenesis of testis. Interestingly, we demonstrate that these cells are gradually replaced by peripheral blood cells of recipient mice during the morphogenesis of testis. Thus, we develop a system, which may mimic the complete developmental process of postnatal testis, for investigating the testicular development and spermatogenesis.
Influenza is an acute respiratory infectious disease caused by influenza viruses. Its subtype can be distinguished based on the antigenicity of two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). One of the main challenges in anti-influenza drug development is the quick evolution of drug resistance due to virus mutations. One solution to this problem is to develop dual-targeting anti-influenza agents. In this paper, a new rationally designed virtual screening protocol that combines structure-based approaches (molecular docking and molecular dynamic simulations) and ligand-based approaches (support vector machines and 3D shape & electrostatic similarity algorithms) is reported for the virtual screening of dual-targeting agents against HA and NA. The final hits came from the consensus of the ligand- and receptor-based knowledge of HA and NA and were tested using ADMET predictions. Evidence from the binding energy calculations and binding mode analyses suggested that several of the hits are promising as dual-targeting anti-influenza agents. The virtual screening protocol may also lead to the identification of innovative drugs in other fields.
Abstract We investigated blood nesfatin-1 levels in hypertension patients. We found that fasting plasma nesfatin-1 levels were significantly higher in hypertension patients than in control groups, especially in overweight/obese hypertension patients (4.5?±?2.1 versus 3.3?±?1.1?ng/ml, p?0.01). Body mass index, systolic blood pressure and diastolic blood pressure were indeed positively correlated with fasting plasma nesfatin-1 levels (r?=?0.234, p?0.05; r?=?0.304, p?0.01; r?=?0.251, p?0.05; r?=?0.461, p?0.01; respectively). Logistic regression analysis revealed that the plasma level of nesfatin-1 could be independent of risk prediction over standard measures (OR?=?1.547, 95% CI: 1.153-6.273, p?=?0.026). Nesfatin-1 has the incremental contribution to hypertension risk prediction (IDI: 0.014, p?=?0.018; NRI: 0.050, p?=?0.043). The plasma nesfatin-1 level in hypertension patients with microalbuminuria are significantly higher than those without microalbuminuria patients (6.4?±?2.1?ng/ml versus 3.9?±?1.8?ng/ml, p?0.01). Nesfatin-1 might play an important role in obesity hypertension, and its increase could be a risk factor for obesity-associated hypertension.
The arabinogalactan (AG) of the mycobacterial cell wall consists of an arabinan region, a galactan region and a disaccharide linker. Decaprenylphosphoryl-D-arabinose (DPA) is the donor for arabinofuran residues, which are formed from phosphoribose diphosphate (PRPP) and decaprenyl phosphate (DP). DP is sequentially catalyzed by a three-step process that involves a transferase, a phosphatase and an epimerase. Rv3807c is a putative phospholipid phosphatase that might generate the intermediate product of decaprenyl-phosphoryl-ribose (DPR) in DPA biosynthesis. Mycobacterium smegmatis MSMEG_6402 is a homolog gene of Mycobacterium tuberculosis Rv3807c and was substituted for the functional identification of Rv3807c. Previously, we generated a conditional MSMEG_6402 gene knockout strain (M. sm-?M_6402) that exhibited significantly affected cell wall structure. To understand the function of MSMEG_6402 in DPA biosynthesis, this gene was amplified and expressed, and the resulting protein was identified and purified using a His-tagged approach. A MSMEG_6402 enzymatic reaction system with PRPP and DP as substrates was utilized, and the reaction products were separated using thin layer chromatography (TLC). The results revealed a specific lipid-linked sugar band that appeared in the reaction with the addition of MSMEG_6402. Furthermore, ESI-MS detection was utilized in this study, and the results revealed that the enzymatic reaction products involving MSMEG_6402 included DPPR and a sodium ion adduct of DPR. Additionally, the phosphatase activity of MSMEG_6402 was also determined through phosphate group detection using the colorimetric method. Based on our results together with the results of previous studies, including the functional identification and bioinformatics analysis of M. tuberculosis Rv3807c, we propose that MSMEG_6402, as a phosphatase, has an intimate relationship with DPA biosynthesis.
Obesity induced by antipsychotics severely increases the risk of many diseases and significantly reduces quality of life. Genome Wide Association Studies has identified fat-mass and obesity-associated (FTO) gene associated with obesity. The relationship between the FTO gene and drug-induced obesity is unclear.
Extracellular ATP (eATP) plays essential roles in plant growth, development, and stress tolerance. Extracellular ATP-regulated stomatal movement of Arabidopsis thaliana has been reported. Here, ATP was found to promote stomatal opening of Vicia faba in a dose-dependent manner. Three weakly hydrolysable ATP analogs (adenosine 5'-O-(3-thio) triphosphate (ATP?S), 3'-O-(4-benzoyl) benzoyl adenosine 5'-triphosphate (Bz-ATP) and 2-methylthio-adenosine 5'-triphosphate (2meATP)) showed similar effects, indicating that ATP acts as a signal molecule rather than an energy charger. ADP promoted stomatal opening, while AMP and adenosine did not affect stomatal movement. An ATP-promoted stomatal opening was blocked by the NADPH oxidase inhibitor diphenylene iodonium (DPI), the reductant dithiothreitol (DTT) or the Ca(2+) channel blockers GdCl3 and LaCl3. A hyperpolarization-activated Ca(2+) channel was detected in plasma membrane of guard cell protoplast. Extracellular ATP and weakly hydrolyzable ATP analogs activated this Ca(2+) channel significantly. Extracellular ATP-promoted Ca(2+) channel activation was markedly inhibited by DPI or DTT. These results indicated that eATP may promote stomatal opening via reactive oxygen species that regulate guard cell plasma membrane Ca(2+) channels.
Myeloid-derived suppressor cells (MDSCs) play an important role in maintaining immune tolerance in response to tumors and inflammatory diseases. Several liver MDSCs have been described in hepatitis in humans and mouse models. Although all the murine MDSCs are CD11b(+)Gr-1(+), their true phenotype and mechanism of suppression remain elusive. This study revealed that SSC(high)CD11b(high)Ly-6C(high)Ly-6G(low) monocytic cells but not the other liver-infiltrating, CD11b(+)Gr-1(+) subsets could suppress CD4 T cell responses. Their suppressive activity was remarkably effective even at a ratio of 1:50 when co-cultured with CD4 T cells. Mechanistically, the suppression was dependent on nitric oxide production by inducible nitric oxide synthase (iNOS). Furthermore, the suppressive function by these liver MDSCs was found to require direct contact with activated CD4 T cells. Adoptive transfer experiments demonstrate that these liver MDSCs can dramatically ameliorate concanavalin A (Con A)-induced fulminant hepatitis in mice. Finally, MDSC-mediated suppression in vivo was dependent on iNOS expression. Altogether, SSC(high)CD11b(high)Ly-6C(high)Ly-6G(low) cells represent authentic MDSCs in the inflammatory liver and may function to minimize collateral damage caused by an overzealous CD4 T cell response following hepatitis infection.
Increasing studies have suggested that albuminuria might be an important risk factor for peripheral artery disease (PAD). However, studies focusing on the association between low-grade albuminuria and PAD are limited. It would be of great interest to elucidate the association between low-grade albuminuria and PAD in diabetic subjects.
Protein kinases are major signal transduction factors that have a central role in mediating acclimation to environmental changes in eukaryotic organisms. In this study, we cloned and identified three salt overly sensitive 2 (SOS2) genes in the woody plant Populus trichocarpa, designated as PtSOS2.1, PtSOS2.2, and PtSOS2.3, which were transformed into hybrid poplar clone T89 (Populus tremula× Populus tremuloides Michx clone T89) mediated by Agrobacterium tumefaciens. Southern and northern blot analyses verified that the three genes integrated into the plant genome, and were expressed at a stable transcription level. Meanwhile, overexpression of all three PtSOS2 genes did not retard the growth of plants under normal conditions. Instead, it promoted growth in both agar-medium and soil conditions in response to salinity stress. Under salt stress, overexpression of PtSOS2.1, PtSOS2.2, and PtSOS2.3 increased the concentrations of proline and photosynthetic pigments, and the relative water content (RWC), and the activity of antioxidant enzymes, and decreased the malondialdehyde (MDA) concentrations in transgenic lines compared to the control. These results suggest that overexpression of PtSOS2 plays a significant role in improving the salt tolerance of poplars, reducing the damage to membrane structures, and enhancing osmotic adjustment and antioxidative enzyme regulation under salt stress.
Mesenchymal stem cells (MSCs) have demonstrated promising therapeutic potential for a variety of diseases including autoimmune disorders. A fundamental requirement for MSC-mediated in vivo immunosuppression is their effective trafficking. However the mechanism underlying MSC trafficking remains elusive. Here we report that skin-derived MSCs (S-MSCs) secrete high levels of interleukin-6 (IL-6) in inflammatory conditions. Disruption of the il6 or its signaling transducer gp130 blocks voltage-gated calcium (Ca(2+) ) channels (VGCC) critically required for cell contraction involved in the sequential adhesion and de-adhesion events during S-MSC migration. Deletion of il6 gene leads to a severe defect in S-MSC's trafficking and immunosuppressive function in vivo. Thus, this unexpected requirement of autocrine IL-6 for activating Ca(2+) channels uncovers a previously unrecognized link between the IL-6 signaling and the VGCC and provides novel mechanistic insights for the trafficking and immunomodulatory activities of S-MSCs.
Although it is generally accepted that thyroid hormones affect bone metabolism, there is little data on the association of thyroid antibodies with bone status. We aimed to investigate the association between thyroid hormones or antibodies and quantitative ultrasound (QUS) parameters. This was a cross-sectional, population-based study conducted in Nanjing, China. A total of 1,001 Chinese men over 40 years were enrolled. We measured free triiodothyronine, free thyroxin (fT4), thyroid-stimulating hormone, anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin, 25-hydroxyvitamin D, and QUS parameters. After adjusting for potential confounders, QUS values decreased from the lowest to highest tertiles of fT4 in euthyroid men [quantitative ultrasound index (QUI) p = 0.002, broadband ultrasound attenuation (BUA) p = 0.000, speed of sound (SOS) p = 0.009, respectively]. Men with high anti-TPO levels (?200 IU/ml) were found to have lower QUI (p = 0.030), BUA (p = 0.034), and SOS (p = 0.041) values than controls (<200 IU/ml). The prevalence of vitamin D deficiency was significantly higher in individuals with high anti-TPO than those in lower levels (87.5 vs. 59.5 %, p = 0.001). Our results suggest that high fT4 or anti-TPO values are associated with lower QUS parameters. Prospective studies are needed to confirm the precise relationship between thyroid status and osteoporosis.
Mesenchymal stem cells (MSC) are present in most, if not all, tissues and are believed to contribute to tissue regeneration and the tissue immune microenvironment. Murine MSCs exert immunosuppressive effects through production of inducible nitric oxide synthase (iNOS), whereas human MSCs use indoleamine 2,3-dioxygenase (IDO). Thus, studies of MSC-mediated immunomodulation in mice may not be informative in the setting of human disease, although this critical difference has been mainly ignored. To address this issue, we established a novel humanized system to model human MSCs, using murine iNOS(-/-) MSCs that constitutively or inducibly express an ectopic human IDO gene. In this system, inducible IDO expression is driven by a mouse iNOS promoter that can be activated by inflammatory cytokine stimulation in a similar fashion as the human IDO promoter. These IDO-expressing humanized MSCs (MSC-IDO) were capable of suppressing T-lymphocyte proliferation in vitro. In melanoma and lymphoma tumor models, MSC-IDO promoted tumor growth in vivo, an effect that was reversed by the IDO inhibitor 1-methyl-tryptophan. We found that MSC-IDO dramatically reduced both tumor-infiltrating CD8(+) T cells and B cells. Our findings offer an important new line of evidence that interventional targeting of IDO activity could be used to restore tumor immunity in humans, by relieving IDO-mediated immune suppression of MSCs in the tumor microenvironment as well as in tumor cells themselves.
Obesity and insulin resistance are risk factors for cardiovascular diseases. Whether insulin-sensitive obese individuals are at higher risk for cardiovascular diseases is still debated. We aim to investigate whether insulin-sensitive obesity associates with prevalent cardiovascular diseases and 10-year coronary heart disease (CHD) risk.
Chronic stress has dramatic impacts on the immune system and consequently contributes to the onset and progression of a variety of diseases, including cancer, immune disorders, and infections. Recent studies in animals and humans have demonstrated that mesenchymal stem cells (MSCs) significantly modulate the immune system. Here we show that administration of MSCs in vivo prevents lymphocyte depletion induced by physical restraint stress (12:12-h stress-rest, 2 repetitions) in mice. This effect was found to be exerted not through modulation of glucocorticoid levels in the circulation, but rather through direct effects on lymphocyte apoptosis. By testing various possible protective mechanisms, we found that IL-4 provides a strong anti-apoptosis signal to lymphocytes in the presence of dexamethasone. When neutralizing antibody against IL-4 was co-administered with MSCs to restraint-stressed mice, the protective effect of MSCs was diminished. Furthermore, in mice deficient in STAT6, a key molecule in IL-4 receptor-mediated signaling, MSCs had no effect on restraint stress-induced lymphocyte depletion. Additionally, MSCs administered to stressed mice promoted IL-4 production by splenocytes. This study reveals that MSCs can effectively prevent stress-induced lymphocyte apoptosis in an IL-4-dependent manner and provides novel information for the development of countermeasures against the deleterious effects of stress on the immune system.
Decaprenylphosphoryl-d-arabinofuranosyl (DPA), the immediate donor for the polymerized d-Araf residues of mycobacterial arabinan, is synthesized from 5-phosphoribose-1-diphosphate (PRPP) in three-step reactions. (i) PRPP is transferred to decaprenyl-phosphate (DP) to form decaprenylphosphoryl-d-5-phosphoribose (DPPR). (ii) DPPR is dephosphorylated to form decaprenylphosphoryl-d-ribose (DPR). (iii) DPR is formed to DPA by the epimerase. Mycobacterium tuberculosis Rv3806c and heteromeric Rv3790/Rv3791 have been identified as the PRPP: decaprenyl-phosphate 5-phosphoribosyltransferase and the epimerase respectively. Rv3807c, however, as the candidate of phospholipid phosphatase, catalyzing the biosynthesis of decapreny-l-phosphoryl-ribose (DPR) from decaprenylphosphoryl-?-d-5-phosphoribose by dephosphorylating, has no direct experimental evidence of its essentiality in any species of mycobacterium. In this study, Rv3807c gene was amplified from the genome of M. tuberculosis H37Rv by PCR, and was successfully expressed in Escherichia coli BL21 (DE3) via the recombinant plasmid pColdII-Rv3807c. The resulting protein with the 6× His-tag was identified by SDS-PAGE and Western blotting. The protein was predicted through bioinformatics to contain three transmembrane domains, the N-terminal peptide, and a core structure with phosphatidic acid phosphatase type2/haloperoxidase. This study provides biochemical and bioinformatics evidence for the importance of Rv3807c in mycobacteria, and further functional studies will be conducted for validating Rv3807c as a promising phospholipid phosphatase in the synthetic pathway of DPA.
This study aimed to explore the antidepressant mechanisms of ginseng total saponins (GTS) in the corticosterone-induced mouse depression model. In Experiment 1, GTS (50, 25, and 12.5?mg?kg(-1)?d(-1), intragastrically) were given for 3 weeks. In Experiment 2, the same doses of GTS were administrated after each corticosterone (20?mg?kg(-1)?d(-1), subcutaneously) injection for 22 days. In both experiments, mice underwent a forced swimming test and a tail suspension test on day 20 and day 21, respectively, and were sacrificed on day 22. Results of Experiment 1 revealed that GTS (50 and 25?mg?kg(-1)?d(-1)) exhibited antidepressant activity and not statistically altered hippocampal protein levels of brain-derived neurotrophic factor (BDNF) and neurofilament light chain (NF-L). Results of Experiment 2 showed that GTS (50 and 25?mg?kg(-1)?d(-1)) ameliorated depression-like behavior without normalizing hypercortisolism. The GTS treatments reversed the corticosterone-induced changes in mRNA levels of BDNF and NF-L, and protein levels of BDNF NF-L, phosphor-cAMP response element-binding protein (Ser133), and phosphor-glycogen synthase kinase-3 ? (Ser9) in the hippocampus. These findings imply that the effect of GTS on corticosterone-induced depression-like behavior may be mediated partly through interfering with hippocampal GSK-3 ? -CREB signaling pathway and reversing decrease of some plasticity-related proteins.
Although the microbiota has been shown to drive production of interleukin-17A (IL-17A) from T helper 17 cells to promote cell proliferation and tumor growth in colorectal cancer, the molecular mechanisms for microbiota-mediated regulation of tumorigenesis are largely unknown. Here, we found that the innate-like cytokine IL-17C was upregulated in human colorectal cancers and in mouse intestinal tumor models. Alterations in the microbiota drove IL-17C upregulation specifically in intestinal epithelial cells (IECs) through Toll-like receptor (TLR)-MyD88-dependent signaling during intestinal tumorigenesis. Microbiota-driven IL-17C induced Bcl-2 and Bcl-xL expression in IECs in an autocrine manner to promote cell survival and tumorigenesis in both chemically induced and spontaneous intestinal tumor models. Thus, IL-17C promotes cancer development by increasing IEC survival, and the microbiota can mediate cancer pathogenesis through regulation of IL-17C.
Copper is required for structural and catalytic properties of a variety of enzymes participating in many vital biological processes for growth and development. Feeds provide most of the copper as an essential micronutrient consumed by animals, but inorganic copper could not be utilized effectively. In the present study, we aimed to develop transgenic mouse models to test if copper utilization will be increased by providing the animals with an exogenous gene for generation of copper chelatin in saliva. Considering that the S. cerevisiae CUP1 gene encodes a Cys-rich protein that can bind copper as specifically as copper chelatin in yeast, we therefore constructed a transgene plasmid containing the CUP1 gene regulated for specific expression in the salivary glands by a promoter of gene coding pig parotid secretory protein. Transgenic CUP1 was highly expressed in the parotid and submandibular salivary glands and secreted in saliva as a 9-kDa copper-chelating protein. Expression of salivary copper-chelating proteins reduced fecal copper contents by 21.61% and increased body-weight by 12.97%, suggesting that chelating proteins improve the utilization and absorbed efficacy of copper. No negative effects on the health of the transgenic mice were found by blood biochemistry and histology analysis. These results demonstrate that the introduction of the salivary CUP1 transgene into animals offers a possible approach to increase the utilization efficiency of copper and decrease the fecal copper contents.
Mesenchymal stem cells (MSCs) possess potent immunosuppression capacity and could exert strong therapeutic effects in many diseases, especially inflammatory disorders, in animal models and clinical settings. Although inflammatory cytokines are critical in inducing the immune modulatory properties of MSCs, detailed molecular mechanisms are yet to be fully understood. TGF-? is a well-known anti-inflammatory cytokine and exists in various inflammatory processes; therefore, we investigated whether it could synergize with MSCs in suppressing immune responses. To our surprise, we found that TGF-? actually reversed the immunosuppressive effect of MSCs on anti-CD3 activated splenocytes. Using TGF-? unresponsive MSCs, we demonstrated that the TGF-? directly acted on MSCs. Furthermore, we showed that the effect of TGF-? is exerted through inhibiting inflammatory cytokines induced inducible NO synthase (iNOS) expression in a SMAD3-dependent manner. Interestingly, we found that TGF-? produced by MSCs could act in an autocrine manner to reduce inflammatory cytokine-induced inducible NO synthase expression by MSCs themselves. Therefore, our study revealed a previously unrecognized property of TGF-? in promoting immune responses in the presence of MSCs.
Alzheimers disease (AD) is a progressive neurodegenerative disorder characterized by a severe decline of memory performance. A widely studied AD mouse model is the APPswe/PSEN1?E9 (APP/PS1) strain, as mice exhibit amyloid plaques as well as impaired memory capacities. To test whether restoring synaptic plasticity and decreasing ?-amyloid load by Parkin could represent a potential therapeutic target for AD, we crossed APP/PS1 transgenic mice with transgenic mice overexpressing the ubiquitin ligase Parkin and analyzed offspring properties. Overexpression of Parkin in APP/PS1 transgenic mice restored activity-dependent synaptic plasticity and rescued behavioral abnormalities. Moreover, overexpression of Parkin was associated with down-regulation of APP protein expression, decreased ?-amyloid load and reduced inflammation. Our data suggest that Parkin could be a promising target for AD therapy.
High-performance computing (HPC) has become a state strategic technology in a number of countries. One hypothesis is that HPC can accelerate biopharmaceutical innovation. Our experimental data demonstrate that HPC can significantly accelerate biopharmaceutical innovation by employing molecular dynamics-based virtual screening (MDVS). Without using HPC, MDVS for a 10K compound library with tens of nanoseconds of MD simulations requires years of computer time. In contrast, a state of the art HPC can be 600 times faster than an eight-core PC server is in screening a typical drug target (which contains about 40K atoms). Also, careful design of the GPU/CPU architecture can reduce the HPC costs. However, the communication cost of parallel computing is a bottleneck that acts as the main limit of further virtual screening improvements for drug innovations.
Recently, genome-wide association studies (GWAS) have led to the discovery of hundreds of susceptibility loci that are associated with complex metabolic diseases, such as type 2 diabetes and hyperthyroidism. The majority of the susceptibility loci are common across different races or populations; while some of them show ethnicity-specific distribution. Though the abundant novel susceptibility loci identified by GWAS have provided insight into biology through the discovery of new genes or pathways that were previously not known, most of them are in introns and the associated variants cumulatively explain only a small fraction of total heritability. Here we reviewed the genetic studies on the metabolic disorders, mainly type 2 diabetes and hyperthyroidism, including candidate genes-based findings and more recently the GWAS discovery; we also included the clinical relevance of these novel loci and the gene-environmental interactions. Finally, we discussed the future direction about the genetic study on the exploring of the pathogenesis of the metabolic diseases.
We report an approach for generating immobilized monoclonal templates for next- generation sequencing applications. Our isothermal amplification method is based on a template walking mechanism using a pair of low-melting temperature (Tm) solid-surface homopolymer primers and a low-Tm solution phase primer. The method can generate more than one billion submicrometer-sized colonies in a single lane of a next-generation sequencing flowchip. An alternative paired-end sequencing method using interstrand DNA photo cross-linking to covalently link the complementary strands of the original templates to the solid surface is also demonstrated.
Patients with type 2 diabetes are at a high risk of developing microvascular complications such as diabetic retinopathy. Previous literatures showed that low serum bilirubin concentration in type 2 diabetic patients might confer increased risk of diabetic complications. Thus, we aimed to investigate the association between the prevalence of diabetic retinopathy and levels of serum total bilirubin in a Chinese population.
Ischemia reperfusion (IR) and cyclosporine A (CsA) injuries are unavoidable in kidney transplantation and are associated with allograft dysfunction. Herein, the effect and mechanism of a novel tissue protective peptide, helix B surface peptide (HBSP) derived from erythropoietin, were investigated in a rat model. The right kidney was subjected to 45?min ischemia, followed by left nephrectomy and 2-week reperfusion, with or without daily treatment of CsA 25?mg/kg and/or HBSP 8?nmol/kg. Blood urea nitrogen was increased by CsA but decreased by HBSP at 1 week and 2 weeks, while the same changes were revealed in urinary protein/creatinine only at 2 weeks. HBSP also significantly ameliorated tubulointerstitial damage and interstitial fibrosis, which were gradually increased by IR and CsA. In addition, apoptotic cells, infiltrated inflammatory cells, and active caspase-3+ cells were greatly reduced by HBSP in the both IR and IR + CsA groups. The 17?kD active caspase-3 protein was decreased by HBSP in the IR and IR + CsA kidneys, with decreased mRNA only in the IR + CsA kidneys. Taken together, it has been demonstrated, for the first time, that HBSP effectively improved renal function and tissue damage caused by IR and/or CsA, which might be through reducing caspase-3 activation and synthesis, apoptosis, and inflammation.
The treatment of advanced prostate cancer (PCa) remains a challenge. Identification of new molecular mechanisms that regulate PCa initiation and progression would provide targets for the development of new cancer treatments. The Foxm1 transcription factor is highly up-regulated in tumor cells, inflammatory cells, and cells of tumor microenvironment. However, its functions in different cell populations of PCa lesions are unknown. To determine the role of Foxm1 in tumor cells during PCa development, we generated two novel transgenic mouse models, one exhibiting Foxm1 gain-of-function and one exhibiting Foxm1 loss-of-function under control of the prostate epithelial-specific Probasin promoter. In the transgenic adenocarcinoma mouse prostate (TRAMP) model of PCa that uses SV40 large T antigen to induce PCa, loss of Foxm1 decreased tumor growth and metastasis. Decreased prostate tumorigenesis was associated with a decrease in tumor cell proliferation and the down-regulation of genes critical for cell proliferation and tumor metastasis, including Cdc25b, Cyclin B1, Plk-1, Lox, and Versican. In addition, tumor-associated angiogenesis was decreased, coinciding with reduced Vegf-A expression. The mRNA and protein levels of 11?-Hsd2, an enzyme playing an important role in tumor cell proliferation, were down-regulated in Foxm1-deficient PCa tumors in vivo and in Foxm1-depleted TRAMP C2 cells in vitro. Foxm1 bound to, and increased transcriptional activity of, the mouse 11?-Hsd2 promoter through the -892/-879 region, indicating that 11?-Hsd2 was a direct transcriptional target of Foxm1. Without TRAMP, overexpression of Foxm1 either alone or in combination with inhibition of a p19(ARF) tumor suppressor caused a robust epithelial hyperplasia, but was insufficient to induce progression from hyperplasia to PCa. Foxm1 expression in prostate epithelial cells is critical for prostate carcinogenesis, suggesting that inhibition of Foxm1 is a promising therapeutic approach for prostate cancer chemotherapy.
Whether serum magnesium deficiency is independently associated with the prevalence of microalbuminuria is still unclear. The objective of the present study was to elucidate the association between serum magnesium and microalbuminuria in diabetic patients. A cross-sectional study was conducted in 1829 diabetic subjects (aged ? 40 years) from Shanghai, China. Subjects were divided into three groups according to serum magnesium tertiles. A first-voided early-morning spot urine sample was obtained for urinary albumin-creatinine ratio (UACR) measurement. Microalbuminuria was defined as 30?mg/g ? UACR < 300?mg/g. Overall, 208 (11.37%) of the study population had microalbuminuria, with similar proportions in both genders (P = 0.44). The prevalence of microalbuminuria in tertile 1 of serum magnesium was higher than the prevalence in tertile 2 and tertile 3 (15.98%, 9.72%, and 8.46%, resp.; P for trend <0.0001). After adjustment for age, sex, BMI, blood pressure, lipidaemic profile, HbA1c, eGFR, history of cardiovascular disease, HOMA-IR, antihypertensive and antidiabetic medication, and diabetes duration, we found that, compared with the subjects in tertile 3 of serum magnesium, those in tertile 1 had 1.85 times more likeliness to have microalbuminuria. We concluded that low serum magnesium level was significantly associated with the prevalence of microalbuminuria in middle-aged and elderly Chinese.
Evidence has suggested that low serum potassium concentration or low dietary potassium intake can result in many metabolic disorders. Our objective was to evaluate the association between serum potassium level and risk of prevalent metabolic syndrome.
Recent studies have demonstrated direct reprogramming of fibroblasts into a range of somatic cell types, but to date stem or progenitor cells have only been reprogrammed for the blood and neuronal lineages. We previously reported generation of induced hepatocyte-like (iHep) cells by transduction of Gata4, Hnf1?, and Foxa3 in p19 Arf null mouse embryonic fibroblasts (MEFs). Here, we show that Hnf1? and Foxa3, liver organogenesis transcription factors, are sufficient to reprogram MEFs into induced hepatic stem cells (iHepSCs). iHepSCs can be stably expanded in vitro and possess the potential of bidirectional differentiation into both hepatocytic and cholangiocytic lineages. In the injured liver of fumarylacetoacetate hydrolase (Fah)-deficient mice, repopulating iHepSCs become hepatocyte-like cells. They also engraft as cholangiocytes into bile ducts of mice with DDC-induced bile ductular injury. Lineage conversion into bipotential expandable iHepSCs provides a strategy to enable efficient derivation of both hepatocytes and cholangiocytes for use in disease modeling and tissue engineering.
Synchrotron FTIR (S-FTIR) microspectroscopy was used to monitor both protein secondary structures (conformations) and their orientations in single cocoon silk fibers of the Chinese Tussah silk moth ( Antheraea pernyi ). In addition, to understand further the relationship between structure and properties of single silk fibers, we studied the changes of orientation and content of different secondary structures in single A. pernyi silk fibers when subjected to different strains. The results showed that the content and orientation of ?-sheet was almost unchanged for strains from 0 to 0.3. However, the orientation of ?-helix and random coil improved progressively with increasing strain, with a parallel decrease in ?-helix content and an increase in random coil. This clearly indicates that most of the deformation upon stretching of the single fiber is due to the change of orientation in the amorphous regions coupled with a conversion of some of the ?-helix to random coil. These observations provide an explanation for the supercontraction behavior of certain animal silks and are likely to facilitate understanding and optimization of postdrawing used in the conjunction with the wet-spinning of silk fibers from regenerated silk solutions. Thus, our work demonstrates the power of S-FTIR microspectroscopy for studying biopolymers.
Adult stem cells (ASCs) capable of self-renewal and differentiation confer the potential of tissues to regenerate damaged parts. Epigenetic regulation is essential for driving cell fate decisions by rapidly and reversibly modulating gene expression programs. However, it remains unclear how epigenetic factors elicit ASC-driven regeneration. In this paper, we report that an RNA interference screen against 205 chromatin regulators identified 12 proteins essential for ASC function and regeneration in planarians. Surprisingly, the HP1-like protein SMED-HP1-1 (HP1-1) specifically marked self-renewing, pluripotent ASCs, and HP1-1 depletion abrogated self-renewal and promoted differentiation. Upon injury, HP1-1 expression increased and elicited increased ASC expression of Mcm5 through functional association with the FACT (facilitates chromatin transcription) complex, which consequently triggered proliferation of ASCs and initiated blastema formation. Our observations uncover an epigenetic network underlying ASC regulation in planarians and reveal that an HP1 protein is a key chromatin factor controlling stem cell function. These results provide important insights into how epigenetic mechanisms orchestrate stem cell responses during tissue regeneration.
We aimed to study the relationship of elevated C reactive protein (CRP) levels (1.0-2.9 or ?3.0 mg/L) with carotid intima-media thickness (IMT) in Chinese adults with normal low-density lipoprotein (LDL) cholesterol (<100 mg/dL).
To investigate the prevalence of thyroid nodules (TN) among a community population aged >40 years and to explore the association between TN and its metabolic risk factors. Data from 9,533 adults aged over 40 years who participated in the epidemiological investigation of thyroid nodules in a Chinese community-based population from June to December 2011 were included in the analyses. We compared the levels of metabolic indices between the TN group and healthy controls. The prevalence of TN was 46.6 % (39.7 %, men; 50.3 %, women) and it increased significantly with increasing age (P < 0.001). It was significantly higher in the group with hypertension than in that with normotension (P < 0.001) and was 43.0 % in the normal blood glucose group, 49.4 % in the prediabetes group, and 50.9 % in the diabetes group (P < 0.001). Logistic regression analysis indicated that hypertension [odds ratio (OR) = 1.121 (1.025-1.225)] as well as prediabetes and diabetes [OR = 1.130 (1.036-1.233)] were all independent risk factors for TN after adjustment for sex, age, body mass index, blood lipid levels, smoking status, and alcohol consumption. The elderly population had a high prevalence of TN. Hypertension as well as prediabetes and diabetes might be independent risk factors for TN.
Helper T cells are crucial for maintaining proper immune responses. Yet, they have an undefined relationship with one of the most potent immune stimulatory cytokines, granulocyte macrophage-colony-stimulating factor (GM-CSF). By depleting major cytokines during the differentiation of CD4(+) T cells in vitro, we derived cells that were found to produce large amounts of GM-CSF, but little of the cytokines produced by other helper T subsets. By their secretion of GM-CSF, this novel subset of helper T cells (which we have termed ThGM cells) promoted the production of cytokines by other T-cell subtypes, including type 1 helper T cell (Th1), type 2 helper T cell (Th2), type 1 cytotoxic T cell (Tc1), type 2 cytotoxic T cell (Tc2), and naive T cells, as evidenced by the fact that antibody neutralization of GM-CSF abolished this effect. ThGM cells were found to be highly prone to activation-induced cell death (AICD). Inhibitors of TRAIL or granzymes could not block AICD in ThGM cells, whereas inhibition of FasL/Fas interaction partially rescued ThGM cells from AICD. Thus, ThGM cells are a novel subpopulation of T helper cells that produce abundant GM-CSF, exhibit exquisite susceptibility to apoptosis, and therefore play a pivotal role in the regulation of the early stages of immune responses.
Altered functions of microRNAs (miRNAs) have been associated with colorectal cancer (CRC). miR-212 is transcribed from a stable intron of a non-protein coding gene, and is reportedly down-regulated in different tumor types. We investigated the role of miR-212 in colorectal carcinogenesis and progression.
MSCs possess potent immunosuppressive capacity. We have reported that mouse MSCs inhibit T cell proliferation and function via nitric oxide. This immune regulatory capacity of MSCs is induced by the inflammatory cytokines IFN? together with either TNF? or IL-1?. This effect of inflammatory cytokines on MSCs is extraordinary; logarithmic increases in the expression of iNOS and chemokines are often observed. To investigate the molecular mechanisms underlying this robust effect of cytokines, we examined the expression of microRNAs in MSCs before and after cytokine treatment. We found that miR-155 is most significantly up-regulated. Furthermore, our results showed that miR-155 inhibits the immunosuppressive capacity of MSCs by reducing iNOS expression. We further demonstrated that miR-155 targets TAK1-binding protein 2 (TAB2) to regulate iNOS expression. Additionally, knockdown of TAB2 reduced iNOS expression. In summary, our study demonstrated that miR-155 inhibits the immunosuppressive capacity of MSCs by reducing iNOS expression by targeting TAB2. Our data revealed a novel role of miR-155 in regulating the immune modulatory activities of MSCs.
Impairment of lung function was reported to be associated with cardiovascular disease (CVD). The aim of the present study is to evaluate the relationship between lung function and carotid intima-media thickness (cIMT) in participants without chronic pulmonary disease.
The effect of active smoking on development of nonalcoholic fatty liver disease (NAFLD) is controversial, and there are limited clinical data on the relationship between passive smoking and NAFLD. We investigated whether active and passive smoking are associated with NAFLD.
Epidemiologic studies have suggested that abortion may cause long term health consequences such as cardiovascular disease. Until recently, studies focusing on the association between history of abortion and metabolic diseases were limited. In the present study, we aimed to investigate the association between history of abortion and metabolic syndrome (MetS) in middle-aged and elderly Chinese women. A cross-sectional survey was performed in 6302 women (age ? 40 years) in Shanghai. Standardized questionnaire was used to obtain the information about reproductive histories. Overall, we observed a positive association between history of induced abortion and the prevalence of MetS, independent of potential confounding factors. A multivariable-adjusted logistic regression analysis revealed that compared to those without a history of induced abortion, women with a history of induced abortion remained at 1.25 times more likely to have MetS (OR = 1.25, 95% CI = 1.06-1.47, P < 0.05), and the association was number-dependent. However, no significant association between history of spontaneous abortion and the prevalence of MetS was observed. Compared to those without a history of spontaneous abortion, the multivariate-adjusted odds ratio associated with a history of spontaneous abortion for MetS was 0.88 (95% CI = 0.65-1.19, P > 0.05).
Previous studies indicated that apolipoprotein measurements predicted cardiovascular disease (CVD) risk; however, associations between apolipoproteins and carotid intima-media thickness (CIMT) were less explored.
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