JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Apigenin inhibits migration and invasion via modulation of epithelial mesenchymal transition in prostate cancer.
Mol Med Rep
PUBLISHED: 10-01-2014
Show Abstract
Hide Abstract
The mortality rate associated with prostate cancer is mainly due to metastases rather than primary organ?confined disease. Decreasing the incidence of metastasis is important in treating prostate cancer. 4',5,7?trihydroxyflavone (apigenin) has been demonstrated to be effective in inhibiting several types of cancer. The aim of this study was to investigate the effect and mechanism of apigenin on the movement of prostate cancer cells. In the present study, DU145 cells were treated with varying concentrations of apigenin for different time periods. Cell viability was evaluated using an MTT assay. Cell motility and invasiveness were assayed using wound healing assays and a Matrigel migration and invasion assay. Flow cytometric and western blot analyses were performed to examine the cell cycle and signaling pathways. The results demonstrated that apigenin suppressed the proliferation and inhibited the migration and invasive potential of the DU145 prostate cancer cells in a dose? and time?dependent manner, which was associated with epithelial mesenchymal transition. These findings suggested that apigenin may be effective in treating human prostate cancer.
Related JoVE Video
MicroRNA-320c inhibits tumorous behaviors of bladder cancer by targeting Cyclin-dependent kinase 6.
J. Exp. Clin. Cancer Res.
PUBLISHED: 09-02-2014
Show Abstract
Hide Abstract
BackgroundIncreasing evidence has suggested that dysregulation of microRNAs (miRNAs) could contribute to human disease including cancer. Previous miRNA microarray analysis illustrated that miR-320c is down-regulated in various cancers. However, the roles of miR-320c in human bladder cancer have not been well elucidated. Therefore, this study was performed to investigate the biological functions and molecular mechanisms of miR-320c in human bladder cancer cell lines, discussing whether it could be a therapeutic biomarker of bladder cancer in the future.MethodsTwo human bladder cancer cell lines and samples from thirteen patients with bladder cancer were analyzed for the expression of miR-320c by quantitative RT-PCR. Over-expression of miR-320c was established by transfecting mimics into T24 and UM-UC-3. Cell proliferation and cell cycle were assessed by cell viability assay, flow cytometry and colony formation assay. Cell motility ability was evaluated by transwell assay. The target gene of miR-320c was determined by luciferase assay, quantitative RT-PCR and western blot. The regulation of cell cycle and mobility by miR-320c was analyzed by western blot.ResultsWe observed that miR-320c was down-regulated in human bladder cancer tissues and bladder cancer cell lines T24 and UM-UC-3. Over-expression of miR-320c could induce G1 phase arrest in UM-UC-3 and T24 cells, and subsequently inhibited cell growth. We also indentified miR-320c could impair UM-UC-3 and T24 cell motility. In addition, we identified CDK6, a cell cycle regulator, as a novel target of miR-320c. Moreover, we demonstrated miR-320c could induce bladder cancer cell cycle arrest and mobility via regulating CDK6. We also observed that inhibition of miR-320c or restoration of CDK6 in miR-320c-over-expressed bladder cancer cells partly reversed the suppressive effects of miR-320c.ConclusionsmiR-320c could inhibit the proliferation, migration and invasion of bladder cancer cells via regulating CDK6. Our study revealed that miR-320c could be a therapeutic biomarker of bladder cancer in the future.
Related JoVE Video
De novo comparative transcriptome analysis of Acremonium chrysogenum: high-yield and wild-type strains of cephalosporin C producer.
PLoS ONE
PUBLISHED: 08-13-2014
Show Abstract
Hide Abstract
?-lactam antibiotics are widely used in clinic. Filamentous fungus Acremonium chrysogenum is an important industrial fungus for the production of CPC, one of the major precursors of ?-lactam antibiotics. Although its fermentation yield has been bred significantly over the past decades, little is known regarding molecular changes between the industrial strain and the wild type strain. This limits the possibility to improve CPC production further by molecular breeding. Comparative transcriptome is a powerful tool to understand the molecular mechanisms of CPC industrial high yield producer compared to wild type. A total of 57 million clean sequencing reads with an average length of 100 bp were generated from Illumina sequencing platform. 22,878 sequences were assembled. Among the assembled unigenes, 9502 were annotated and 1989 annotated sequences were assigned to 121 pathways by searching against the Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) database. Furthermore, we compared the transcriptome differences between a high-yield and a wild-type strain during fermentation. A total of 4329 unigenes with significantly different transcription level were identified, among which 1737 were up-regulated and 2592 were down-regulated. 24 pathways were subsequently determined which involve glycerolipid metabolism, galactose metabolism, and pyrimidine metabolism. We also examined the transcription levels of 18 identified genes, including 11 up-regulated genes and 7 down-regulated genes using reverse transcription quantitative -PCR (RT-qPCR). The results of RT-qPCR were consistent with the Illumina sequencing. In this study, the Illumina sequencing provides the most comprehensive sequences for gene expression profile of Acremonium chrysogenum and allows de novo transcriptome assembly while lacking genome information. Comparative analysis of RNA-seq data reveals the complexity of the transcriptome in the fermentation of different yield strains. This is an important public information platform which could be used to accelerate the research to improve CPC production in Acremonium chrysogenum.
Related JoVE Video
Cloning and characterization of the shell matrix protein Shematrin in scallop Chlamys farreri.
Acta Biochim. Biophys. Sin. (Shanghai)
PUBLISHED: 07-07-2014
Show Abstract
Hide Abstract
The Shematrin family is unique to the organic matrices of pearl oyster shells, containing repetitive, low-complexity domains designated as XGnX (where X is a hydrophobic amino acid). Current studies suggested that Shematrins are framework proteins in the prismatic layer of Pinctada fucata; however, the exact function of Shematrin during shell formation is unclear. In this study, we cloned and characterized Shematrin, a protein highly homologous to Shematrin-2, from the mantle tissue of scallop (Chlamys farreri). Semi-quantitative reverse transcript polymerase chain reaction analysis showed that Shematrin is exclusively expressed in the mantle. Knocking down the expression of Shematrin in adult scallops via double-stranded RNA injection led to an abnormal folia surface. After the shell was notched, the expression level of Shematrin remarkably increased and then gradually decreased, suggesting that Shematrin is critically involved in the shell repair progress. Injection of Shematrin double-stranded RNA reduced the speed of shell regeneration and caused abnormal surface morphology of the regenerated shell. The RNA interference and shell notching experiments indicated that Shematrin plays a key role in the folia formation of C. farreri. Structure prediction showed that Shematrin may be an intrinsically disordered protein, with high flexibility and elasticity of the molecular conformation, which facilitate binding multiple protein partners. Based on the structure features, we hypothesized that Shematrin may participate in framework organization via binding with several specific acidic proteins, functioning as a molecular hub in the protein interaction networks.
Related JoVE Video
Emerging role of hydrogen sulfide in hypertension and related cardiovascular diseases.
Br. J. Pharmacol.
PUBLISHED: 06-21-2014
Show Abstract
Hide Abstract
Hydrogen sulfide (H2 S) has traditionally been viewed as a highly toxic gas; however, recent studies have implicated H2 S as a third member of the gasotransmitter family, exhibiting properties similar to nitric oxide (NO) and carbon monoxide (CO). Accumulating evidence has suggested that H2 S influenced a wide range of physiological and pathological processes, among which blood vessel relaxation, cardioprotection and atherosclerosis have been particularly studied. In the cardiovascular system, H2 S production is predominantly catalyzed by cystathionine ?-lyase (CSE). Decreased endogenous H2 S levels have been found in hypertensive patients and animals, and CSE(-/-) mice develop hypertension with age, suggesting that deficiency of H2 S contributes importantly to blood pressure regulation. H2 S supplementation attenuates hypertension in different hypertensive animal models. The mechanism by which H2 S was originally proposed to attenuate hypertension was by virtue of its action on vascular tone, which may be related to effects on different ion channels. Both H2 S and NO cause vasodilation and there is cross talk between these two molecules to regulate blood pressure. Suppression of oxidative stress may also contribute to anti-hypertensive effects of H2 S. This review also summarizes the state of research on H2 S and hypertension in China. A better understanding of the role of H2 S in hypertension and related cardiovascular diseases will allow novel strategies to be devised for their treatment.
Related JoVE Video
Dew inspired breathing-based detection of genetic point mutation visualized by naked eye.
Sci Rep
PUBLISHED: 06-16-2014
Show Abstract
Hide Abstract
A novel label-free method based on breathing-induced vapor condensation was developed for detection of genetic point mutation. The dew-inspired detection was realized by integration of target-induced DNA ligation with rolling circle amplification (RCA). The vapor condensation induced by breathing transduced the RCA-amplified variances in DNA contents into visible contrast. The image could be recorded by a cell phone for further or even remote analysis. This green assay offers a naked-eye-reading method potentially applied for point-of-care liver cancer diagnosis in resource-limited regions.
Related JoVE Video
Downregulation of microRNA-182-5p contributes to renal cell carcinoma proliferation via activating the AKT/FOXO3a signaling pathway.
Mol. Cancer
PUBLISHED: 05-12-2014
Show Abstract
Hide Abstract
Emerging evidence has suggested that dysregulation of miR-182-5p may contribute to tumor development and progression in several types of human cancers. However, its role in renal cell carcinoma (RCC) is still unknown.
Related JoVE Video
Systematic Review and Meta-Analysis of the Effect of Alcohol Intake on the Risk of Urolithiasis Including Dose-Response Relationship.
Urol. Int.
PUBLISHED: 04-02-2014
Show Abstract
Hide Abstract
Objective: We conducted a meta-analysis to quantitatively evaluate the correlation between alcohol consumption and the risk of urolithiasis by summarizing the results of published case-control and cohort studies and the potential dose-response association. Methods: A systematic literature search of articles up to February 2014 was conducted via PubMed, Web of Science, Cochrane Library, Scopus, EMBASE, the Chinese National Knowledge Infrastructure databases, and the references of the retrieved articles. Fixed- or random-effect models were used to summarize the estimates of odds ratio (OR) with 95% confidence interval (95% CI) for the highest versus the lowest consumption of alcohol. A dose-response meta-analysis was also conducted. Results: The pooled OR estimates indicated that alcohol consumption was associated with a decreased risk of urolithiasis (OR = 0.683, 95% CI 0.577-0.808). In addition, the dose-response meta-analysis indicated that the rate of urolithiasis decreased by 10% for a 10 g/day increase in alcohol intake (OR = 0.898, 95% CI 0.851-0.948). No evidence of publication bias was found by Begg's or Egger's test (p = 0.130, p = 0.130, respectively). Conclusion: Our meta-analysis indicated that alcohol intake is associated with a decreased risk of urolithiasis. © 2014 S. Karger AG, Basel.
Related JoVE Video
Bioconversion of deoxysugar moieties to the biosynthetic intermediates of daunorubicin in an engineered strain of Streptomyces coeruleobidus.
Biotechnol. Lett.
PUBLISHED: 03-17-2014
Show Abstract
Hide Abstract
Daunorubicin (DNR) is a representative anthracycline with anti-tumor bioactivity. Its convergent biosynthetic pathway has promoted the research on pursuing novel anthracyclines by combinatorial biosynthesis. SnoaL is a special polyketide cyclase that catalyzes the closure of nogalonic acid methyl ester with the C9-S stereochemistry. In this study, the gene cluster of DNR was cloned, and snoaL was integrated into the DNR biosynthetic pathway for the substitution of dnrD in Streptomyces coeruleobidus DM, which resulted in the production of epi-aklaviketone. The biosynthetic pathway of NDP-4-deacetyl-L-chromose B was then expressed in the engineered strain, which led to the production of corresponding glycosylated anthracycline compounds. Finally, the bioactivities of these engineering strains were evaluated.
Related JoVE Video
Enzymatic synthesis of 2'-deoxyuridine by whole cell catalyst co-expressing uridine phosphorylase and thymidine phosphorylase through auto-induction system.
J. Biosci. Bioeng.
PUBLISHED: 02-24-2014
Show Abstract
Hide Abstract
Genes encoding uridine phosphorylase (UP) and thymidine phosphorylase (TP) from Escherichia coli K12 were cloned and recombined respectively into plasmids pET-21a(+) and pET-28a(+). The recombinant plasmids BL21/pET21a-UP and BL21/pET28a-TP were co-transformed into E. coli BL21(DE3) to construct highly effective BTU strain (BL21/pET28a-TP, pET21a-UP) overexpressing both of UP and TP. BTU was cultivated in ZYM-Fe-5052 medium for 10 h and used as catalyst to synthesize 2'-deoxyuridine (dUR). It was found to increase the productivity of dUR by 8-9 fold when compared to wild E. coli K12 and E. coli BL21(DE3) strains. A series of experiments were carried out to find out the optimal conditions for synthesis of dUR. At 50°C, with 0.25‰ dry wt./v to catalyze the reaction of 2:1 ?-thymidine: uracil (60 mM ?-thymidine, 30 mM uracil), the conversion rate of dUR would reach 61.6% at 1 h, which was much higher than the rates obtained by BTU strain cultured in LB medium and induced by IPTG. This result proved co-expression and auto-induction were efficient methods in enhancing the expression quantity and activity of nucleoside phosphorylases, and they also had significant implications for large-scale industrial production of dUR and synthesis of other nucleoside derivatives.
Related JoVE Video
Characterization of an allylic/benzyl alcohol dehydrogenase from Yokenella sp. strain WZY002, an organism potentially useful for the synthesis of ?,?-unsaturated alcohols from allylic aldehydes and ketones.
Appl. Environ. Microbiol.
PUBLISHED: 02-07-2014
Show Abstract
Hide Abstract
A novel whole-cell biocatalyst with high allylic alcohol-oxidizing activities was screened and identified as Yokenella sp. WZY002, which chemoselectively reduced the C=O bond of allylic aldehydes/ketones to the corresponding ?,?-unsaturated alcohols at 30°C and pH 8.0. The strain also had the capacity of stereoselectively reducing aromatic ketones to (S)-enantioselective alcohols. The enzyme responsible for the predominant allylic/benzyl alcohol dehydrogenase activity was purified to homogeneity and designated YsADH (alcohol dehydrogenase from Yokenella sp.), which had a calculated subunit molecular mass of 36,411 Da. The gene encoding YsADH was subsequently expressed in Escherichia coli, and the purified recombinant YsADH protein was characterized. The enzyme strictly required NADP(H) as a coenzyme and was putatively zinc dependent. The optimal pH and temperature for crotonaldehyde reduction were pH 6.5 and 65°C, whereas those for crotyl alcohol oxidation were pH 8.0 and 55°C. The enzyme showed moderate thermostability, with a half-life of 6.2 h at 55°C. It was robust in the presence of organic solvents and retained 87.5% of the initial activity after 24 h of incubation with 20% (vol/vol) dimethyl sulfoxide. The enzyme preferentially catalyzed allylic/benzyl aldehydes as the substrate in the reduction of aldehydes/ketones and yielded the highest activity of 427 U mg(-1) for benzaldehyde reduction, while the alcohol oxidation reaction demonstrated the maximum activity of 79.9 U mg(-1) using crotyl alcohol as the substrate. Moreover, kinetic parameters of the enzyme showed lower Km values and higher catalytic efficiency for crotonaldehyde/benzaldehyde and NADPH than for crotyl alcohol/benzyl alcohol and NADP(+), suggesting the nature of being an aldehyde reductase.
Related JoVE Video
Dietary carrot consumption and the risk of prostate cancer.
Eur J Nutr
PUBLISHED: 02-03-2014
Show Abstract
Hide Abstract
Previous studies regarding the association between carrot intake and prostate cancer risk have reported inconsistent results. We conducted a meta-analysis to summarize evidence on this association and to quantify the potential dose-response relationship.
Related JoVE Video
Direct renin inhibition with aliskiren protects against myocardial ischemia/reperfusion injury by activating nitric oxide synthase signaling in spontaneously hypertensive rats.
J Am Heart Assoc
PUBLISHED: 01-30-2014
Show Abstract
Hide Abstract
We tested the hypothesis that direct renin inhibition with aliskiren protects against myocardial ischemia/reperfusion (I/R) injury in spontaneously hypertensive rats (SHR), and examined the mechanism by which this occurs.
Related JoVE Video
Amorphous Calcium Carbonate Precipitation by Cellular Biomineralization in Mantle Cell Cultures of Pinctada fucata.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
The growth of molluscan shell crystals is generally thought to be initiated from the extrapallial fluid by matrix proteins, however, the cellular mechanisms of shell formation pathway remain unknown. Here, we first report amorphous calcium carbonate (ACC) precipitation by cellular biomineralization in primary mantle cell cultures of Pinctada fucata. Through real-time PCR and western blot analyses, we demonstrate that mantle cells retain the ability to synthesize and secrete ACCBP, Pif80 and nacrein in vitro. In addition, the cells also maintained high levels of alkaline phosphatase and carbonic anhydrase activity, enzymes responsible for shell formation. On the basis of polarized light microscopy and scanning electron microscopy, we observed intracellular crystals production by mantle cells in vitro. Fourier transform infrared spectroscopy and X-ray diffraction analyses revealed the crystals to be ACC, and de novo biomineralization was confirmed by following the incorporation of Sr into calcium carbonate. Our results demonstrate the ability of mantle cells to perform fundamental biomineralization processes via amorphous calcium carbonate, and these cells may be directly involved in pearl oyster shell formation.
Related JoVE Video
Superselective transcatheter renal artery embolization for the treatment of hemorrhage from non-iatrogenic blunt renal trauma: report of 16 clinical cases.
Ther Clin Risk Manag
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
To explore the therapeutic efficacy and outcome of superselective transcatheter renal artery embolization for the treatment of hemorrhage from non-iatrogenic blunt renal trauma (BRT).
Related JoVE Video
Porphyromonas gingivalis infection reduces regulatory T cells in infected atherosclerosis patients.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Increasing evidence has shown periodontal pathogen Porphyromonas gingivalis (P.gingivalis) infection contributes to atherosclerosis (AS) progression. P.gingivalis fimbriae act as an important virulence factor in AS. Regulatory T cells (Tregs) may play a crucial role in autoimmune response during this process. However, whether P.gingivalis infection is associated with Tregs dysregulation during AS is still unknown and the prevalence of different P.gingivalis FimA genotypes during this process is unclear. Here we analyzed the distribution of Tregs and in P.gingivalis-infected atherosclerotic patients to reveal the relationship between P.gingivalis infection and Tregs reduction/dysfunction and to elucidate their role in periodontitis-AS interaction. FimA genotype was also examined to determine the prevalence of fimbriae. Our results showed that P.gingivalis infection reduced Tregs in atherosclerotic patients compared with non-atherosclerotic patients and health controls. Concentration of TGF-?1, which plays an important role in the development of Tregs, also decreased in P.gingivalis infected patients. Furthermore, type II FimA seems to show higher prevalence than the other five detected types. The population of Tregs further decreased in patients with type II FimA compared with the other types. P.gingivlias FimA genotype II was the dominant type associated with decreased Treg population. These results indicate that P.gingivalis infection may be associated with Tregs dysregulation in AS; type II FimA may be a predominant genotype in this process.
Related JoVE Video
A Novel Acidic Matrix Protein, PfN44, Stabilizes the Magnesium Calcite to Inhibit the Crystallization of Aragonite.
J. Biol. Chem.
PUBLISHED: 12-03-2013
Show Abstract
Hide Abstract
Magnesium is widely used to control calcium carbonate deposition in the shell of pearl oysters. Matrix proteins in the shell are responsible for nucleation and growth of calcium carbonate crystals. However, there is no direct evidence supporting a connection between matrix proteins and magnesium. Here, we identified a novel acidic matrix protein named PfN44 that affected aragonite formation in the shell of the pearl oyster Pinctada fucata. Using immunogold-labeling assays, we found PfN44 in both the nacreous and prismatic layers. In shell repair, PfN44 was repressed while other matrix proteins were upregulated. Disturbing the function of PfN44 by RNAi led to the deposition of porous nacreous tablets with overgrowth of crystals in the nacreous layer. By in vitro circular dichroism spectra and fluorescence quenching, we found that PfN44 bound to both calcium and magnesium with a stronger affinity for magnesium. During in vitro calcium carbonate crystallization and calcification of amorphous calcium carbonate (ACC), PfN44 regulated the magnesium content of crystalline carbonate polymorphs and stabilized magnesium calcite to inhibit aragonite deposition. Taken together, our results suggested that by stabilizing magnesium calcite to inhibit aragonite deposition, PfN44 participated in P. fucata shell formation. These observations extend our understanding of the connections between matrix proteins and magnesium.
Related JoVE Video
MicroRNA-490-5p inhibits proliferation of bladder cancer by targeting c-Fos.
Biochem. Biophys. Res. Commun.
PUBLISHED: 10-31-2013
Show Abstract
Hide Abstract
MicroRNAs (miRNAs) are non-protein-coding sequences that play a crucial role in tumorigenesis by negatively regulating gene expression. Here, we found that miR-490-5p is down-regulated in human bladder cancer tissue and cell lines compared to normal adjacent tissue and a non-malignant cell line. To better characterize the function of miR-490-5p in bladder cancer, we over-expressed miR-490-5p in bladder cancer cell lines with chemically synthesized mimics. Enforced expression of miR-490-5p in bladder cancer cells significantly inhibited the cell proliferation via G1-phase arrest. Further studies found the decreased c-Fos expression at both mRNA and protein levels and Luciferase reporter assays demonstrated that c-Fos is a direct target of miR-490-5p in bladder cancer. These findings indicate miR-490-5p to be a novel tumor suppressor of bladder cancer cell proliferation through targeting c-Fos.
Related JoVE Video
MicroRNA-124-3p inhibits cell migration and invasion in bladder cancer cells by targeting ROCK1.
J Transl Med
PUBLISHED: 08-12-2013
Show Abstract
Hide Abstract
Increasing evidence has suggested that dysregulation of certain microRNAs (miRNAs) may contribute to human disease including carcinogenesis and tumor metastasis in human. miR-124-3p is down-regulated in various cancers, and modulates proliferation and aggressiveness of cancer cells. However, the roles of miR-124-3p in human bladder cancer are elusive. Thus, this study was conducted to investigate the biological functions and its molecular mechanisms of miR-124-3p in human bladder cancer cell lines, discussing whether it has a potential to be a therapeutic biomarker of bladder cancer.
Related JoVE Video
An aptamer based wall-less LSPR array chip for label-free and high throughput detection of biomolecules.
Biosens Bioelectron
PUBLISHED: 07-22-2013
Show Abstract
Hide Abstract
Despite recent progress in localized surface plasmon resonance (LSPR) based bio-sensing, it remains challenging to achieve sensitive and high throughput LSPR detection with facilities available in common laboratories. Here we developed a wall-less LSPR array chip for facile, label-free and high throughput detection of biomolecules using a normal microplate reader. The wall-less LSPR array chip was fabricated by immobilizing plasmonic nanoparticles (NPs) on a hydrophilic-hydrophobic patterned glass slide, enabling high throughput detection. The wall-less configuration simplifies chip fabrication and sample processing, and enables miniaturization to significantly reduce sample and reagent consumption. A double-gold NPs enhanced system comprising of 13-nm-gold NPs conjugated to aptamer modified 39-nm-gold NPs on glass substrate was adopted to constitute competitive replacement assay for signal amplification in small molecule (i.e. ATP) detection. Upon enhancement, the detection sensitivity of ATP was augmented by 5 orders of magnitude from 0.01µM to 100µM measured by the laboratory microplate reader. The wall-less LSPR sensor chip can be widely applied for miniaturized and high throughput detection of a variety of targets in biomedical applications and environmental monitoring using facilities available in common laboratories.
Related JoVE Video
Cruciferous vegetables consumption and risk of renal cell carcinoma: a meta-analysis.
Nutr Cancer
PUBLISHED: 07-18-2013
Show Abstract
Hide Abstract
Previous cohort and case-control studies on the association between cruciferous vegetables consumption and risk of renal cell carcinoma have illustrated conflicting results so far. To demonstrate the potential association between them, a meta-analysis was performed. Eligible studies were retrieved via both computerized searches and review of references. The summary relative risks (RRs) with 95% confidence interval (CI) for the highest vs. the lowest consumption of cruciferous vegetables were calculated. Heterogeneity and publication bias were also evaluated. Stratified analyses were performed as well. Three cohort and 7 case-control studies were included. A significantly decreased risk with renal cell carcinoma was observed in overall cruciferous vegetables consumption group (RR = 0.73; 95% CI, 0.63-0.83) and subgroup of case-control studies (RR = 0.69; 95% CI, 0.60-0.78), but not in cohort studies (RR = 0.96; 95% CI, 0.71-1.21). No heterogeneity and publication bias were detected across studies. Our findings supported that cruciferous vegetables consumption was related to the decreased risk of renal cell carcinoma. Because of the limited number of studies, further well-designed prospective studies and researches need to be conducted to better clarify the protective effect of cruciferous vegetables on renal cell carcinoma and potential mechanism.
Related JoVE Video
Microcryogels as injectable 3D cellular micro-niches for site-directed and augmented cell delivery.
Acta Biomater
PUBLISHED: 06-25-2013
Show Abstract
Hide Abstract
The success of cell therapy for tissue repair and regeneration demands efficient and reliable cell delivery methods. Here we established a novel micro-engineered cryogel (microcryogel) array chip containing microcryogels with pre-defined size and shape as injectable cell delivery vehicles. The microscale macroporous cryogels enabled automatic and homogenous loading of tailored cellular niches (e.g. cells, matrices, bioactive factors) and could be easily harvested from the ready-to-use array chip. In contrast to microscale hydrogels, microcryogels exhibited excellent elasticity and could remainthe shape and integrity after injection through the micro-syringeroutinely used for cell therapy. Human MSCs loaded within microcryogels could be shielded from the mechanical insult and necrosis caused by during direct cell injection.After subcutaneous injection to the mice, cell-loaded microcryogels exhibited concentrated localization and enhanced retention at injection site compared to dissociated cells.To demonstrate the potential therapeutic application for ischemic diseases, site-directed induction of angiogenesis was achieved subcutaneously in mice 2 weeks after injection of NIH/3T3 fibroblast-loaded microcryogels,indicating long-term engraftment, accumulative paracrine stimulation and augmented host tissue integration. Our results convincingly showed the great promise of microcryogels as 3D cellular micro-niches andinjectable cell delivery vehicles to tackle major challenges faced by cell therapy-based regenerative medicine including shear-induced damages, uncontrolled localization, poor retention, limited cellular survival and functionalities in vivo.
Related JoVE Video
Chromium removal using resin supported nanoscale zero-valent iron.
J. Environ. Manage.
PUBLISHED: 06-19-2013
Show Abstract
Hide Abstract
Resin supported nanoscale zero-valent iron (R-nZVI) was synthesized by the borohydride reduction method. Batch experiments were conducted to evaluate the factors affecting Cr(VI) removal. It was found that nZVI loads, resin dose, pH value and initial concentration of Cr(VI) were all important factors. Scanning electron microscopy showed that the nZVI particles in R-nZVI became sphere after reacting with Cr(VI). This phenomenon was attributed to the co-precipitation of Cr(III) and Fe(III) on the surface of resin. X-ray diffraction pattern confirmed that Fe(0) diminished after the reaction. At optimum conditions, the Cr(VI) removal efficiency was 84.4% when the initial concentration of Cr(VI) was 20.0 mg/L. Regeneration of R-nZVI and resin was possible. R-nZVI can also remove Cr(III) efficiently. However, the removal mechanisms of Cr(VI) (anion) and Cr(III) (cation) are different. The former is chemical reduction, while the latter is ion exchange at pH below 6.3 and precipitation at pH above 6.3. This study demonstrates that R-nZVI has the potential to become an effective agent for treating wastewater containing Cr(VI) and Cr(III).
Related JoVE Video
Severe hematuria after transurethral electrocoagulation in a patient with an arteriovesical fistula.
BMC Urol
PUBLISHED: 05-28-2013
Show Abstract
Hide Abstract
Arteriovesical fistulas are extremely rare. Only eleven cases were previously reported in the literature. They can occur iatrogenically, traumatically or spontaneously.
Related JoVE Video
Giant primary retroperitoneal teratoma in an adult female patient: A case report.
Oncol Lett
PUBLISHED: 05-17-2013
Show Abstract
Hide Abstract
The retroperitoneum is an uncommon location for teratoma in adults. The current study presents the case of a rare giant primary retroperitoneal teratoma in a 55-year-old female. The clinical manifestations, diagnosis and surgical treatment procedure of this case are retrospectively reviewed. The patient presented with a complaint of an abdominal palpable mass and fullness for 1 month. The patient suffered a massive hemorrhage during the first exploratory laparotomyand only a small section of the tumor was resected. Pathology revealed a mature retroperitoneal teratoma. Eleven months after the first surgery, the tumor was resected successfully at the second laparotomy. The surgical specimen was a large tumor mass measuring 22×18×10 cm in size and weighing 6 kg. At follow-up, the patient was in a stable condition. This case study highlights the importance of imaging for the development of a pre-operative strategy and performing a safe surgical excision in giant retroperitoneal teratoma cases.
Related JoVE Video
Computed tomography urography for diagnosis of calyceal diverticulum complicated by urolithiasis: the accuracy and the effect of abdominal compression and prolongation of acquisition delay.
Urology
PUBLISHED: 05-12-2013
Show Abstract
Hide Abstract
To evaluate the accuracy of computed tomography urography (CTU) in the detection of caliceal diverticulum (CD) complicated with urolithiasis and the effect of compression and prolongation of acquisition delay.
Related JoVE Video
miR-26a inhibits proliferation and motility in bladder cancer by targeting HMGA1.
FEBS Lett.
PUBLISHED: 05-09-2013
Show Abstract
Hide Abstract
It is increasingly clear that microRNAs play a crucial role in tumorigenesis. Recently, emerging evidence suggested that miR-26a is aberrantly expressed in tumor tissues. In our study, frequent down-regulation of miR-26a was observed in 10 human bladder cancer tissues. Forced expression of miR-26a in the bladder cancer cell line T24 inhibited cell proliferation and impaired cell motility. High mobility group AT-hook 1 (HMGA1), a gene that modulates cell cycle transition and cell motility, was verified as a novel target of miR-26a in bladder cancer. These findings indicate an important role for miR-26a in the molecular etiology of bladder cancer and implicate the potential application of miR-26a in bladder cancer therapy.
Related JoVE Video
Structural characterization of amorphous calcium carbonate-binding protein: an insight into the mechanism of amorphous calcium carbonate formation.
Biochem. J.
PUBLISHED: 05-08-2013
Show Abstract
Hide Abstract
ACC (amorphous calcium carbonate) plays an important role in biomineralization process for its function as a precursor for calcium carbonate biominerals. However, it is unclear how biomacromolecules regulate the formation of ACC precursor in vivo. In the present study, we used biochemical experiments coupled with bioinformatics approaches to explore the mechanisms of ACC formation controlled by ACCBP (ACC-binding protein). Size-exclusion chromatography, chemical cross-linking experiments and negative staining electron microscopy reveal that ACCBP is a decamer composed of two adjacent pentamers. Sequence analyses and fluorescence quenching results indicate that ACCBP contains two Ca²?-binding sites. The results of in vitro crystallization experiments suggest that one Ca²?-binding site is critical for ACC formation and the other site affects the ACC induction efficiency. Homology modelling demonstrates that the Ca²?-binding sites of pentameric ACCBP are arranged in a 5-fold symmetry, which is the structural basis for ACC formation. To the best of our knowledge, this is the first report on the structural basis for protein-induced ACC formation and it will significantly improve our understanding of the amorphous precursor pathway.
Related JoVE Video
Characterization of the Zhikong scallop (Chlamys farreri) mantle transcriptome and identification of biomineralization-related genes.
Mar. Biotechnol.
PUBLISHED: 04-25-2013
Show Abstract
Hide Abstract
Chlamys farreri is a significant species in aquaculture and fishery in East Asia. A deep understanding of its shell formation by studying the transcriptome of the mantle, a key organ in shell formation, could provide important guidance for its culture. Thus, we sequenced and analyzed the mantle transcriptome of C. farreri. The 77,975 unigenes were generated after Illumina sequencing and de novo assembly. The unigenes were annotated using authoritative databases (non-redundant (NR), COG, Gene Ontology (GO), and KEGG) to obtain functional information. BLASTX alignment was performed between unigenes and reported proteins related to biomineralization. The results identified 53 homologous genes representing 17 matrix proteins, most of which are involved in calcite formation, and 171 homologies with 26 proteins related to general processes of biomineralization. The discovery and unusually high expression of MSP-1 suggested its importance in scallops. Homologous unigenes with aragonite-formation-related matrix proteins were much fewer compared with those related to calcite formation. The results implied that, in C. farreri, the number and proportion of matrix proteins related to aragonite formation is much lower than those related to calcite formation, which was consistent with the proportions of aragonite and calcite in C. farreri shells. Thus, the formation of different polymorphs of calcium carbonate (calcite and aragonite) in molluskan shells is regulated by different groups of proteins. Moreover, 17 candidate unigenes, which are probably involved in biomineralization, were predicted by screening for gene products with secreted domains and tandem-arranged repeat units. Our results contribute to the understanding of biomineralization processes and the evolution of shell formation.
Related JoVE Video
MicroRNA-101 suppresses motility of bladder cancer cells by targeting c-Met.
Biochem. Biophys. Res. Commun.
PUBLISHED: 03-31-2013
Show Abstract
Hide Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that play regulatory roles by repressing translation or cleaving RNA transcripts. Here, we report that the expression of microRNA-101 (miR-101) is down-regulated in human bladder cancer tissue versus normal adjacent tissue. To better characterize the role of miR-101 in bladder cancer, we conducted a gain-of-function analysis by transfecting the bladder cancer cell line T24 with chemically synthesized miR-101 mimics. We found that miR-101 directly targets c-Met via its 3-UTR. Specifically, forced expression of miR-101 decreased c-Met expression at both mRNA and protein levels, consequently inhibiting T24 cell migration and invasion in a c-Met-dependent manner. In conclusion, we have shown miR-101 to be a novel suppressor of T24 cell migration and invasion through its negative regulation of c-Met.
Related JoVE Video
Apigenin promotes apoptosis, inhibits invasion and induces cell cycle arrest of T24 human bladder cancer cells.
Cancer Cell Int.
PUBLISHED: 02-17-2013
Show Abstract
Hide Abstract
Apigenin (4,5,7-trihydroxyflavone) was recently shown effective in inhibiting several cancers. The aim of this study was to investigate the effect and mechanism of apigenin in the human bladder cancer cell line T24 for the first time.
Related JoVE Video
MicroRNA-409-3p inhibits migration and invasion of bladder cancer cells via targeting c-Met.
Mol. Cells
PUBLISHED: 02-07-2013
Show Abstract
Hide Abstract
There is increasing evidence suggesting that dysregulation of certain microRNAs (miRNAs) may contribute to tumor progression and metastasis. Previous studies have shown that miR-409-3p is dysregulated in some malignancies, but its role in bladder cancer is still unknown. Here, we find that miR-409-3p is down-regulated in human bladder cancer tissues and cell lines. Enforced expression of miR-409-3p in bladder cancer cells significantly reduced their migration and invasion without affecting cell viability. Bioinformatics analysis identified the pro-metastatic gene c-Met as a potential miR-409-3p target. Further studies indicated that miR-409-3p suppressed the expression of c-Met by binding to its 3-untranslated region. Silencing of c-Met by small interfering RNAs phenocopied the effects of miR-409-3p overexpression, whereas restoration of c-Met in bladder cancer cells bladder cancer cells overexpressing miR-409-3p, partially reversed the suppressive effects of miR-409-3p. We further showed that MMP2 and MMP9 may be downstream effector proteins of miR-409-3p. These findings indicate that miR-409-3p could be a potential tumor suppressor in bladder cancer.
Related JoVE Video
Diabetes mellitus and risk of bladder cancer: a meta-analysis of cohort studies.
PLoS ONE
PUBLISHED: 01-31-2013
Show Abstract
Hide Abstract
Diabetes is associated with increased risk of cancer at several sites, but its association with risk of bladder cancer is still controversial. We examined this association by conducting a systematic review and meta-analysis of cohort studies.
Related JoVE Video
Cavernous hemangioma of the testis mimicking a testicular teratoma.
Exp Ther Med
PUBLISHED: 01-29-2013
Show Abstract
Hide Abstract
In this study we report a case of cavernous hemangioma of the testis, which mimicked a testicular teratoma. A 42-year-old male presented with a left testicular swelling that had arisen suddenly and been present for three months. Scrotal ultrasound revealed a hypoechoic mass with several calcifications in the left testicle. The mass demonstrated blood flow in the color Doppler mode. A radical orchiectomy was performed. Pathological evaluation revealed a testicular cavernous hemangioma with thrombus organization and calcification.
Related JoVE Video
Quantitative assessment of the associations between XRCC1 polymorphisms and bladder cancer risk.
World J Surg Oncol
PUBLISHED: 01-13-2013
Show Abstract
Hide Abstract
The XRCC1 polymorphisms have been implicated in bladder cancer risk, but individually published studies show inconsistent results. The aim of our study was to clarify the effects of XRCC1 variants on bladder cancer risk.
Related JoVE Video
The hydrogen sulfide donor, GYY4137, exhibits anti-atherosclerotic activity in high fat fed apolipoprotein E(-/-) mice.
Br. J. Pharmacol.
PUBLISHED: 01-11-2013
Show Abstract
Hide Abstract
Atherosclerosis is associated with reduced vascular hydrogen sulfide (H2 S) biosynthesis. GYY4137 is a novel slow-releasing H2 S compound that may effectively mimic the time course of H2 S release in vivo. However, it is not known whether GYY4137 affects atherosclerosis.
Related JoVE Video
microRNA-330 inhibits cell motility by downregulating Sp1 in prostate cancer cells.
Oncol. Rep.
PUBLISHED: 01-10-2013
Show Abstract
Hide Abstract
microRNAs (miRNAs), small non-coding RNAs, have emerged as key regulators of a large number of genes. The present study aimed to explore novel biological functions of miR-330 in the human prostate cancer cell lines DU145 and PC3. We confirmed that miR-330 was downregulated and inversely correlated with specificity protein 1 (Sp1) expression. Overexpression of miR-330 by transfection of a chemically synthesized miR-330 mimic induced a reduction in expression levels of the Sp1 protein, accompanied by significant suppression of cellular migration and invasion capability. In addition, the Sp1-knockdown experiments presented similar phenomena. Finally, the luciferase reporter assay validated Sp1 as the direct target of miR-330. These findings indicate that miR-330 acts as an anti-metastatic miRNA in prostate cancer.
Related JoVE Video
Celastrol prevents atherosclerosis via inhibiting LOX-1 and oxidative stress.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Celastrol is a triterpenoid compound extracted from the Chinese herb Tripterygium wilfordii Hook F. Previous research has revealed its anti-oxidant, anti-inflammatory, anti-cancer and immunosuppressive properties. Here, we investigated whether celastrol inhibits oxidized low-density lipoprotein (oxLDL) induced oxidative stress in RAW 264.7 cells. In addition, the effect of celastrol on atherosclerosis in vivo was assessed in apolipoprotein E knockout (apoE(-/-)) mouse fed a high-fat/high-cholesterol diet (HFC). We found that celastrol significantly attenuated oxLDL-induced excessive expression of lectin-like oxidized low density lipoprotein receptor-1(LOX-1) and generation of reactive oxygen species (ROS) in cultured RAW264.7 macrophages. Celastrol also decreased I?B phosphorylation and degradation and reduced production of inducible nitric oxide synthase (iNOS), nitric oxide (NO) and proinflammatory cytokines such as tumor necrosis factor (TNF)-? and IL-6. Celastrol reduced atherosclerotic plaque size in apoE(-/-) mice. The expression of LOX-1 within the atherosclerotic lesions and generation of superoxide in mouse aorta were also significantly reduced by celastrol while the lipid profile was not improved. In conclusion, our results show that celastrol inhibits atherosclerotic plaque developing in apoE(-/-) mice via inhibiting LOX-1 and oxidative stress.
Related JoVE Video
Patterns of expression in the matrix proteins responsible for nucleation and growth of aragonite crystals in flat pearls of Pinctada fucata.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
The initial growth of the nacreous layer is crucial for comprehending the formation of nacreous aragonite. A flat pearl method in the presence of the inner-shell film was conducted to evaluate the role of matrix proteins in the initial stages of nacre biomineralization in vivo. We examined the crystals deposited on a substrate and the expression patterns of the matrix proteins in the mantle facing the substrate. In this study, the aragonite crystals nucleated on the surface at 5 days in the inner-shell film system. In the film-free system, the calcite crystals nucleated at 5 days, a new organic film covered the calcite, and the aragonite nucleated at 10 days. This meant that the nacre lamellae appeared in the inner-shell film system 5 days earlier than that in the film-free system, timing that was consistent with the maximum level of matrix proteins during the first 20 days. In addition, matrix proteins (Nacrein, MSI60, N19, N16 and Pif80) had similar expression patterns in controlling the sequential morphologies of the nacre growth in the inner-film system, while these proteins in the film-free system also had similar patterns of expression. These results suggest that matrix proteins regulate aragonite nucleation and growth with the inner-shell film in vivo.
Related JoVE Video
Cruciferous vegetables intake and risk of prostate cancer: a meta-analysis.
Int. J. Urol.
PUBLISHED: 11-28-2011
Show Abstract
Hide Abstract
To evaluate the relationship between cruciferous vegetables intake and risk of prostate cancer.
Related JoVE Video
Single nucleotide polymorphism WRN Leu1074Phe is associated with prostate cancer susceptibility in Chinese subjects.
Acta Med. Okayama
PUBLISHED: 11-01-2011
Show Abstract
Hide Abstract
Deficiencies in the human DNA repair gene WRN are the cause of Werner syndrome, a rare autosomal recessive disorder characterized by premature aging and a predisposition to cancer. This study evaluated the association of WRN Leu1074Phe (rs1801195), a common missense single nucleotide polymorphism in WRN, with prostate cancer susceptibility in Chinese subjects. One hundred and forty-seven prostate cancer patients and 111 male cancer-free control subjects from 3 university hospitals in China were included. Blood samples were obtained from each subject, and the single nucleotide polymorphism WRN Leu1074Phe was genotyped by using a Snapshot assay. The results showed that WRN Leu1074Phe was associated with the risk of prostate cancer in Chinese men and that the TG/GG genotype displayed a decreased prevalence of prostate cancer compared with the TT genotype (OR?0.58, 95%CI:0.35-0.97, p?0.039). Through stratified analysis, more significant associations were revealed for the TG/GG genotype in the subgroup with diagnosis age ? 72 yr (OR?0.27, 95%CI:0.12-0.61, p?0.002) and in patients with localized diseases (OR?0.36, 95%CI:0.19-0.70, p?0.003). However, no statistically significant difference was found in the subgroup with age ?72 yr or in patients with advanced diseases. We concluded that the genetic variant Leu1074Phe in the DNA repair gene WRN might play a role in the risk of prostate cancer in Chinese subjects.
Related JoVE Video
The role of matrix proteins in the control of nacreous layer deposition during pearl formation.
Proc. Biol. Sci.
PUBLISHED: 09-07-2011
Show Abstract
Hide Abstract
To study the function of pearl oyster matrix proteins in nacreous layer biomineralization in vivo, we examined the deposition on pearl nuclei and the expression of matrix protein genes in the pearl sac during the early stage of pearl formation. We found that the process of pearl formation involves two consecutive stages: (i) irregular calcium carbonate (CaCO(3)) deposition on the bare nucleus and (ii) CaCO(3) deposition that becomes more and more regular until the mature nacreous layer has formed on the nucleus. The low-expression level of matrix proteins in the pearl sac during periods of irregular CaCO(3) deposition suggests that deposition may not be controlled by the organic matrix during this stage of the process. However, significant expression of matrix proteins in the pearl sac was detected by day 30-35 after implantation. On day 30, a thin layer of CaCO(3), which we believe was amorphous CaCO(3), covered large aragonites. By day 35, the nacreous layer had formed. The whole process is similar to that observed in shells, and the temporal expression of matrix protein genes indicated that their bioactivities were crucial for pearl development. Matrix proteins controlled the crystal phase, shape, size, nucleation and aggregation of CaCO(3) crystals.
Related JoVE Video
Alcohol intake and risk of renal cell carcinoma: a meta-analysis of published case-control studies.
Arch Med Sci
PUBLISHED: 09-02-2011
Show Abstract
Hide Abstract
While some studies have indicated that alcohol intake is associated with a decreased risk of renal cell carcinoma, others have not. We conducted a meta-analysis of case-control studies to provide a quantitative assessment of the association between alcohol intake and the risk of renal cell carcinoma.
Related JoVE Video
Association of vitamin D receptor gene polymorphism and calcium urolithiasis in the Chinese Han population.
Urol. Res.
PUBLISHED: 08-17-2011
Show Abstract
Hide Abstract
To investigate the effect of the vitamin D receptor (VDR) Fok I Bsm I Dde I Apa I Taq I polymorphism on the clinical presentation of calcium urolithiasis, 464 patients with urolithiasis and 450 age- and sex-matched healthy controls were recruited from The First Affiliated Hospital of Zhejiang University between January 2010 and March 2011. Five SNPs of VDR polymorphism were detected using polymerase chain reaction-based restriction analysis. The frequency of VDR Apa I genotypes between the patients and the healthy controls was significantly different (P = 0.006). Apa I a allele was found to be associated with increased risk of stone recurrence (P = 0.028). We also found Fok I Dde I Apa I showed a significant difference between male and female in the patients group (P < 0.05). Haplotype analysis of the five VDR polymorphisms showed a significant association with urolithiasis (global-P value = 0.0001). Genetic polymorphisms of VDR are important in the clinical presentation of patients with calcium urolithiasis in the Han population of southern China.
Related JoVE Video
[Heterogenous expression and characterization of cag4 in Helicobacter pylori].
Wei Sheng Wu Xue Bao
PUBLISHED: 08-02-2011
Show Abstract
Hide Abstract
To construct prokaryotic fusion gene expression vector pET-28a-cag pathogenicity island protein 4 (cag4),express the recombinant fusion protein cag4 and analyze the enzyme activity of recombinant protein.
Related JoVE Video
Improved synthesis of 2-deoxyadenosine and 5-methyluridine by Escherichia coli using an auto-induction system.
World J. Microbiol. Biotechnol.
PUBLISHED: 06-29-2011
Show Abstract
Hide Abstract
Nucleoside analogues are used widely for the treatment of viral diseases and cancer, however the preparation of some important intermediates of these nucleoside analogues, including 2-deoxyadenosine (dAR) and 5-methyluridine (5-MU), remains inconvenient. To optimize the synthesis of dAR and 5-MU, recombinant strains and auto-induction medium were employed in this study. E. coli BL21(DE3) strains overexpressing purine nucleoside phosphorylase (PNP), uridine phosphorylase (UP) and thymidine phosphorylase (TP) were constructed and cultured in auto-induction ZYM-Fe-5052 medium for 8 h. The cultures of these strains were then used directly to synthesize dAR and 5-MU. Under optimized conditions, 30 mM adenine was converted to 29 mM dAR in 1 h, and 32 mM 5-MU was obtained from 60 mM thymine, using 6% (v/v) cell solutions as biocatalysts. These results indicate that our convenient and efficient method is ideal for the preparation of dAR and 5-MU, and has potential for the preparation of other nucleoside analogue intermediates.
Related JoVE Video
Parthenolide induces apoptosis and cell cycle arrest of human 5637 bladder cancer cells in vitro.
Molecules
PUBLISHED: 06-20-2011
Show Abstract
Hide Abstract
Parthenolide, the principal component of sesquiterpene lactones present in medical plants such as feverfew (Tanacetum parthenium), has been reported to have anti-tumor activity. In this study, we evaluated the therapeutic potential of parthenolide against bladder cancer and its mechanism of action. Treatment of bladder cancer cells with parthenolide resulted in a significant decrease in cell viability. Parthenolide induced apoptosis through the modulation of Bcl-2 family proteins and poly (ADP-ribose) polymerase degradation. Treatment with parthenolide led to G1 phase cell cycle arrest in 5637 cells by modulation of cyclin D1 and phosphorylated cyclin-dependent kinase 2. Parthenolide also inhibited the invasive ability of bladder cancer cells. These findings suggest that parthenolide could be a novel therapeutic agent for treatment of bladder cancer.
Related JoVE Video
Activation of endothelial nitric oxide synthase is dependent on its interaction with globular actin in human umbilical vein endothelial cells.
J. Mol. Cell. Cardiol.
PUBLISHED: 05-05-2011
Show Abstract
Hide Abstract
Endothelial nitric oxide synthase (eNOS) has been reported to associate with globular actin, and this association increases eNOS activity. Adenosine, histamine, salbutamol and thrombin cause activation of eNOS through widely different mechanisms. Whether these eNOS agonists can regulate eNOS activity through affecting its association with actin is unknown. As previously reported, we confirmed in cultured human umbilical vein endothelial cells (HUVEC) that histamine and thrombin increased intracellular Ca(2+) whereas adenosine and salbutamol did not, and that these four agonists caused different effects on actin filament structure. Nevertheless, despite their divergent effects on intracellular Ca(2+) and on actin filament structure, we found by immunoprecipitation that adenosine, histamine, salbutamol and thrombin all caused an increase in association between eNOS and globular actin. This increase of association was inhibited by pre-treatment with phalloidin, an actin filament stabilizer. All of these agonists also increased phosphorylation of eNOS on serine residue 1177, eNOS activity, and cyclic guanosine-3, 5-monophosphate, and these increases were all attenuated by phalloidin. Agonist-induced phosphorylation of eNOS on serine 1177 was attenuated by Akt inhibition, whereas association of eNOS with actin was not. We also found, in HEK-293 cells transfected with the eNOS mutants eNOS-S1177A or eNOS-S1177D, that the association between eNOS and globular actin was decreased as compared to cells transfected with wild-type eNOS. We conclude that association of globular actin with eNOS plays an essential and necessary role in agonist-induced eNOS activation, through enabling its phosphorylation by Akt at serine residue 1177.
Related JoVE Video
EGCG protects against UVB-induced apoptosis via oxidative stress and the JNK1/c-Jun pathway in ARPE19 cells.
Mol Med Rep
PUBLISHED: 04-07-2011
Show Abstract
Hide Abstract
Ultraviolet B (UVB) radiation is part of the spectrum of light produced by the sun. This form of radiation has been implicated as one of the potential etiological factors causing age-related macular degeneration (AMD). Oxidative injury to the retinal pigment epithelium (RPE) has also been thought to play a key role in AMD. The aim of the present study was to determine the mechanism by which UVB causes damage to the RPE cells, whether it occurs through oxidative stress and the mitogen-activated protein kinase (MAPK) pathway and whether the green tea extract, (-)-epigallocatechin gallate (EGCG), has a protective role. Cell viability assays were used to determine the viability of the cells under different conditions. Cell death caused by apoptosis was determined using fluorescein isothiocyanate conjugated-annexin V/PI labeling, followed by flow cytometry. Intracellular reactive oxygen species (ROS) levels were measured by flow cytometry. Western blot analysis was used to detect UVB-induced MAPK signaling pathways. The findings showed that UVB induced apoptosis, which increased intracellular ROS in ARPE19 cells. Inhibition of c-Jun NH2-terminal kinase (JNK) with a specific inhibitor augmented this apoptosis, and anisomycin (an activator of JNK) attenuated this apoptosis. In addition, UVB decreased the phosphorylation of JNK1 and c-Jun. Finally, EGCG reduced the ROS generation and apoptosis, and also partially blocked the decreased phosphorylation of JNK1 and c-Jun by UVB irradiation. The findings show that UVB irradiation is able to induce apoptosis in ARPE19 cells through oxidative stress, but EGCG treatment attenuates this damage. In this situation, the JNK pathway plays an anti-apoptotic role. The use of selective activators or antioxidants may be useful in reducing the oxidative damage occurring in AMD.
Related JoVE Video
Subcellular localization of N-deoxyribosyltransferase in Lactobacillus fermentum: cell surface association of an intracellular nucleotide metabolic enzyme.
FEMS Microbiol. Lett.
PUBLISHED: 03-31-2011
Show Abstract
Hide Abstract
N-deoxyribosyltransferases are essential enzymes in the nucleotide salvage pathway of lactobacilli. They catalyze the exchange between the purine or pyrimidine bases of 2-deoxyribonucleosides and free pyrimidine or purine bases. In general, N-deoxyribosyltransferases are referred to as cytoplasmic enzymes, although there is no experimental evidence for this subcellular localization. In this work, the subcellular localization of N-deoxyribosyltransferase II (NTD) from Lactobacillus fermentum was examined by subcellular fractionation, transmission electron microscopy, and fluorescence microscopy. Our results indicate that L. fermentum NTD are distributed not only in the cytoplasm but also on the cell wall surface, and further studies showed that surface-attached NTD can be released into the culture broth and conventional buffers.
Related JoVE Video
Transformation of prednisolone to a 20?-hydroxy prednisolone compound by Streptomyces roseochromogenes TS79.
Appl. Microbiol. Biotechnol.
PUBLISHED: 03-03-2011
Show Abstract
Hide Abstract
Prednisolone represents an important compound in pharmaceutical preparations. To obtain more bioactive prednisolone derivatives, the microbial transformation of prednisolone was carried out. The steroid products were assigned by an interpretation of their spectral data using mass spectrometry and proton nuclear magnetic resonance ((1)H NMR) analyses. The product was assigned the chemical structure of 11?, 17?, 20?, 21-tetrahydroxypregna-1,4-diene-3-one (named as 20?-hydroxy prednisolone). The conversion of prednisolone to 20?-hydroxy prednisolone by Streptomyces roseochromogenes TS79 was different from a previous study on the microbial transformation of steroid by this organism, which usually generates a 16?-hydroxy steroid product. The different reaction parameters for maximum conversion of prednisolone were optimized. The analysis revealed that the optimum values of the tested variables were 7.5 mg/ml prednisolone dissolved in DMSO and added to the 24-h pre-culture fermentation culture containing 0.05% MgSO(4) and incubated for 24 h. A conversion of 95.1% of prednisolone was observed, which has the potential to be used in industrial production.
Related JoVE Video
Identification of genes directly involved in shell formation and their functions in pearl oyster, Pinctada fucata.
PLoS ONE
PUBLISHED: 02-24-2011
Show Abstract
Hide Abstract
Mollusk shell formation is a fascinating aspect of biomineralization research. Shell matrix proteins play crucial roles in the control of calcium carbonate crystallization during shell formation in the pearl oyster, Pinctada fucata. Characterization of biomineralization-related genes during larval development could enhance our understanding of shell formation. Genes involved in shell biomineralization were isolated by constructing three suppression subtractive hybridization (SSH) libraries that represented genes expressed at key points during larval shell formation. A total of 2,923 ESTs from these libraries were sequenced and gave 990 unigenes. Unigenes coding for secreted proteins and proteins with tandem-arranged repeat units were screened in the three SSH libraries. A set of sequences coding for genes involved in shell formation was obtained. RT-PCR and in situ hybridization assays were carried out on five genes to investigate their spatial expression in several tissues, especially the mantle tissue. They all showed a different expression pattern from known biomineralization-related genes. Inhibition of the five genes by RNA interference resulted in different defects of the nacreous layer, indicating that they all were involved in aragonite crystallization. Intriguingly, one gene (UD_Cluster94.seq.Singlet1) was restricted to the aragonitic line. The current data has yielded for the first time, to our knowledge, a suite of biomineralization-related genes active during the developmental stages of P. fucata, five of which were responsible for nacreous layer formation. This provides a useful starting point for isolating new genes involved in shell formation. The effects of genes on the formation of the aragonitic line, and other areas of the nacreous layer, suggests a different control mechanism for aragonite crystallization initiation from that of mature aragonite growth.
Related JoVE Video
A possible mechanism for the formation of annual growth lines in bivalve shells.
Sci China Life Sci
PUBLISHED: 02-14-2011
Show Abstract
Hide Abstract
We report a unique shell margin that differed from the usual shell structure of Pinctada fucata. We observed empty organic envelopes in the prismatic layer and the formation of the nacreous layer in the shell margin. All the characteristics of the growing margin indicated that the shell was growing rapidly. To explain this anomaly, we propose the concept of "jumping development". During jumping development, the center of growth in the bivalve shell jumps forward over a short time interval when the position of the mantle changes. Jumping development explains the unusual structure of the anomalous shell and the development of annual growth lines in typical shells. Annual growth lines are the result of a discontinuity in the shell microstructure induced by jumping development.
Related JoVE Video
Vitamin D receptor genetic polymorphisms and the risk of urolithiasis: a meta-analysis.
Urol. Int.
PUBLISHED: 02-12-2011
Show Abstract
Hide Abstract
Genetic variants of vitamin D receptor (VDR) were implicated in urolithiasis susceptibility in several case-control studies. However, these studies so far have provided conflicting results. In order to investigate the potential relationship, a meta-analysis was conducted.
Related JoVE Video
A new method to extract matrix proteins directly from the secretion of the mollusk mantle and the role of these proteins in shell biomineralization.
Mar. Biotechnol.
PUBLISHED: 01-07-2011
Show Abstract
Hide Abstract
Considering the continuous and substantive secretory ability of the mantle in vitro, we report a new technique to produce shell-matrix proteins by inducing the mantle, after removal from the organisms body, to secrete soluble-matrix proteins into phosphate buffer. By this method, a large amount of matrix proteins could be obtained in 2 h. Experiments involving in vitro calcium carbonate crystallization and organic framework calcium carbonate crystallization indicated that these proteins retain high bioactivity and play key roles in shell biomineralization. Phosphate buffer-soluble proteins secreted by the margin of the mantles (MSPs) were used to reconstruct the stages in the growth of the prismatic layer of the decalcified organic frameworks. The MSPs were observed to aggregate calcites in vitro, and this ability enabled the mollusk to form big calcites in the prismatic layer. During shell biomineralization, an important stage after the self-assembly of the biomacromolecules and the formation of crystals is the assembly of the two parts to form a firm structure. Moreover, a new type of matrix protein, functioning as the binding factor between the crystals and the organic frameworks, was shown to exist in the phosphate buffer-soluble proteins secreted by the central part of mantles (CSPs). Nanoscale-sized bowl-like aragonites, with heights of ?800 nm, were induced by CSPs in vitro. This method is a successful example of obtaining functional proteins through secretion by animal tissues.
Related JoVE Video
Pyridoxine improves platelet nitric oxide synthase dysfunction induced by advanced glycation end products in vitro.
Int J Vitam Nutr Res
PUBLISHED: 10-20-2010
Show Abstract
Hide Abstract
Advanced glycation end products (AGEs) increase platelet aggregation and suppress vascular nitric oxide (NO) synthase (NOS) activity, and these effects may contribute to the atherothrombotic disease seen in diabetes. The aims of this study were to determine in vitro whether pyridoxine can abrogate the impairment in platelet NOS activity caused by AGEs, and to determine the mechanism by which it does this. Platelet aggregation was measured by Born aggregometry. Intraplatelet cyclic guanosine-3,5-monophosphate (cGMP, an index of bioactive NO) was measured by radioimmunoassay. Serine-1177-specific phosphorylation of NOS type 3 (NOS-3) and phosphorylation of protein kinase Akt were determined in platelets by Western blotting. Phosphatidylinositol 3-kinase (PI3K) activity in platelets was ascertained by homogeneous time-resolved fluorescence (HTRF) assay. We found that AGE-modified albumin (AGEs) 200 mg/L increased platelet aggregability and decreased intraplatelet cGMP; these effects were largely attenuated by pyridoxine. Western blotting studies revealed that AGEs decreased NOS-3 phosphorylation on serine-1177, increased NOS-3 O-glycosylation, and decreased serine phosphorylation of protein kinase Akt; all of these changes were abrogated by pyridoxine. Direct measurement of PI3K activity in platelets demonstrated that all of the above effects could be attributed to a suppression by AGEs of PI3K activity, which was prevented by co-incubation with pyridoxine. We conclude that pyridoxine is effective in ameliorating the dysfunction of platelet NO signaling in response to AGEs, through improving PI3K activity, and hence downstream Akt phosphorylation and in turn serine-1177 phosphorylation of NOS-3.
Related JoVE Video
RNA interference targeting mutant p53 inhibits growth and induces apoptosis in DU145 human prostate cancer cells.
Med. Oncol.
PUBLISHED: 08-29-2010
Show Abstract
Hide Abstract
p53 is the most frequently mutated tumor suppressor gene in human cancer. Recent studies have indicated that p53 mutants not only lose tumor suppression activity but also gain novel oncogenic functions that contribute to tumor malignancy. In this study, we explored mutant p53 as a target for novel anti-cancer treatment in prostate cancer. Using the DU145 human androgen-independent prostate cancer cell line, we show that silencing of mutant p53 gene by RNA interference led to significant inhibition of cell viability and growth, which was associated with cell cycle arrest at G1 and G2/M phase, and ultimately induced massive apoptosis. Mechanistically, p53-siRNA inhibited phosphatidylinositol 3-kinase/Akt signaling pathway, which might be responsible for the reduced proliferation and apoptosis induction. These findings suggest that RNA interference targeting mutant p53 may serve as a novel therapeutic strategy for the treatment of androgen-independent prostate cancer.
Related JoVE Video
Suppression of migration and invasion of PC3 prostate cancer cell line via activating E-cadherin expression by small activating RNA.
Cancer Invest.
PUBLISHED: 08-06-2010
Show Abstract
Hide Abstract
ABSTRACT Small activating RNAs are a recently discovered group of small, noncoding, and double-stranded RNA molecules that can induce sequence-specific transcriptional gene activation by targeting gene promoter regions. In the present study, we demonstrate that induction of E-cadherin expression by small activating RNA leads to suppression of migration and invasion of PC3 prostate cancer cells. The inhibitory effect was associated with relocalization of ? -catenin from the nucleus to the plasma membrane and decreased ? -catenin-mediated transactivation. These data suggest that activation of E-cadherin by small activating RNA may have a therapeutic benefit for prostate and other types of cancer.
Related JoVE Video
Pinctada fucata mantle gene 3 (PFMG3) promotes differentiation in mouse osteoblasts (MC3T3-E1).
Comp. Biochem. Physiol. B, Biochem. Mol. Biol.
PUBLISHED: 06-10-2010
Show Abstract
Hide Abstract
Nacre is secreted from the mantle of pearl oysters. In vivo and in vitro experiments have demonstrated that water-soluble extracts of nacre stimulate osteoblast differentiation and matrix mineralization, but the component responsible for this activity is unclear. It was reported that Pinctada fucata mantle gene 3 (PFMG3) with an N-terminal signal peptide could be secreted into the nacre of P. fucata. Here we report that PFMG3 is specifically expressed at the outer fold of the mantle and could promote calcium carbonate crystal formation in vitro. Consistent with this observation, we found that matrix mineralization of MC3T3-E1 cells, a murine osteoblast cell line, is accelerated upon treatment with PFMG3. Intriguingly, we observed that alkaline phosphatase activity and cell viability are increased after treating MC3T3-E1 cell with PFMG3. mRNA levels of osteoblast-specific marker genes osteocalcin and osteopontin are also increased. We conclude that PFMG3 from the mantle of P. fucata promotes MC3T3-E1 osteoblast cell differentiation, matrix mineralization, and calcium carbonate deposition in vitro. Our findings provide new evidence that PFMG3 may be used as a potential therapeutic molecule for the treatment of osteoporosis.
Related JoVE Video
Studies on amino acid replacement and inhibitory activity of a beta-lactamase inhibitory peptide.
Biochemistry Mosc.
PUBLISHED: 04-08-2010
Show Abstract
Hide Abstract
An SHV beta-lactamase gene was amplified from a beta-lactam resistant Klebsiella pneumoniae K-71 genomic DNA. After expression and purification, we demonstrated that peptide P1 could inhibit the hydrolysis activity of both TEM-1 and SHV beta-lactamase in vitro. Three mutations were introduced into P1 in which the first residue S was replaced by F, the 18th residue V was mutated to Y, and the 15th residue Y was substituted with A, C, G, and R to obtain the mutants of P1-A, P1-C, P1-G, and P1-R, respectively. The mutant peptides were purified and their inhibitory constants against TEM-1 and SHV beta-lactamase were determined. All these beta-lactamase inhibitory peptides could inhibit the activity of both beta-lactamases, while the mutant peptides showed stronger inhibitory activities against TEM-1 beta-lactamase than against SHV beta-lactamase. Inhibition data suggested that P1-A improved the beta-lactamase inhibitory activity by over 3-fold compare to P1. When P1-A was incubated with K. pneumoniae K-71 in Luria-Bertani medium containing ampicillin, it showed a much stronger growth of inhibition ratio over P1. This study gives us a good candidate for development of novel beta-lactamase inhibitors.
Related JoVE Video
The effects of overexpression of histamine releasing factor (HRF) in a transgenic mouse model.
PLoS ONE
PUBLISHED: 03-08-2010
Show Abstract
Hide Abstract
Asthma is a disease that affects all ages, races and ethnic groups. Its incidence is increasing both in Westernized countries and underdeveloped countries. It involves inflammation, genetics and environment and therefore, proteins that exacerbate the asthmatic, allergic phenotype are important. Our laboratory purified and cloned a histamine releasing factor (HRF) that was a complete stimulus for histamine and IL-4 secretion from a subpopulation of allergic donors basophils. Throughout the course of studying HRF, it was uncovered that HRF enhances or primes histamine release and IL-13 production from all anti-IgE antibody stimulated basophils. In order to further delineate the biology of HRF, we generated a mouse model.
Related JoVE Video
A meta-analysis of alcohol intake and risk of bladder cancer.
Cancer Causes Control
PUBLISHED: 02-26-2010
Show Abstract
Hide Abstract
Epidemiologic studies have reported conflicting results relating alcohol intake to bladder cancer risk. A meta-analysis of cohort and case-control studies was conducted to pool the risk estimates of the association between alcohol intake and bladder cancer.
Related JoVE Video
Cloning and characterization of the activin like receptor 1 homolog (Pf-ALR1) in the pearl oyster, Pinctada fucata.
Comp. Biochem. Physiol. B, Biochem. Mol. Biol.
PUBLISHED: 02-21-2010
Show Abstract
Hide Abstract
The signal transduction mechanisms in mollusks are still elusive since the genome information is incomplete and cell lines are not available. In previous study, we cloned a highly conserved Smad3 homolog (designated as Pf-Smad3) from the pearl oyster, Pinctada fucata. It seems that transforming growth factor beta (TGFbeta) signaling may play similar roles in the oyster as in vertebrate. Here we report a cDNA encoding an activin like receptor 1 homolog (designated as Pf-ALR1) of the oyster, another kind of TGFbeta superfamily member. Compared to the activin receptor-like kinases (ALK) in human, the amino acid sequence of Pf-ALR1 is more similar to that of ALK1, especially the L45 loop. Reverse transcription-polymerase chain reaction results indicate that Pf-ALR1 mRNA is expressed ubiquitously in the adult oyster. Thus, Pf-ALR1 may be important for many physiological processes in the oyster. To lay a basis for further investigation of the TGFbeta signal pathway functions in the oyster shell formation, in this report, the Pf-ALR1 mRNA expression in the oyster mantle was detected by in situ hybridization. The results show that Pf-ALR1 in the oyster mantle is mainly expressed at the inner epithelial cells of the outer fold and the outer epithelial cells of the middle fold, similarly as Pf-Smad3. The mRNA levels of Pf-ALR1 and Pf-Smad3 are all changed after shell notching. These results indicate that both Pf-ALR1 and Pf-Smad3 may take part in shell formation and repair. The results of drug treatment experiments with in-vitro cultured oyster mantle tissue cells demonstrate that the mRNA expression levels of Pf-Smad3, Pf-ALR1 and two oyster nuclear factor-kappaB (NF-kB) members can be adjusted and correlated. All our observations suggest that there should be similar TGFbeta signal pathways in the oyster and vertebrate. However, the potential functions of Pf-ALR1 and the relations of TGFbeta and NF-kB members in the oyster all need to be thoroughly investigated.
Related JoVE Video
The structure-function relationship of MSI7, a matrix protein from pearl oyster Pinctada fucata.
Acta Biochim. Biophys. Sin. (Shanghai)
PUBLISHED: 11-11-2009
Show Abstract
Hide Abstract
We previously identified a matrix protein, MSI7, from pearl oyster Pinctada fucata. According to the structural analysis, the DGD site in the N-terminal of MSI7 is crucial for its role in the shell formation. In this study, we expressed a series of recombinant MSI7 proteins, including the wild-type and several mutants directed at the DGD site, using an Escherichia coli expression system to reveal the structure-function relationship of MSI7. Furthermore, in vitro crystallization, crystallization speed assay, and circular dichroism spectrometry were carried out. Results indicated that wild-type MSI7 could induce the nucleation of aragonite and inhibit the crystallization of calcite. However, none of the mutants could induce the nucleation of aragonite, but all of them could inhibit the crystallization of calcite to some extent. And all the proteins accelerated the crystallization process. Taken together, the results indicated that MSI7 could contribute to aragonite crystallization by inducing the nucleation of aragonite and inhibiting the crystallization of calcite, which agrees with our prediction about its role in the nacreous layer formation of the shell. The DGD site was critical for the induction of the nucleation of aragonite.
Related JoVE Video
Origin of luminescence enhancement and quenching of europium complex in solution phase containing Ag nanoparticles.
J Chem Phys
PUBLISHED: 08-14-2009
Show Abstract
Hide Abstract
Luminescence enhancement and quenching of Eu(TTA)(3) x 2 H(2)O complex in DMF (N,N-dimethylformamide) solution containing silver nanoparticles were observed, which depended on the concentrations of both europium complex and silver nanoparticles. Their origins were discussed based on absorption spectra, excitation and emission spectra, and luminescent decay dynamics. The results indicated that when the concentration of Eu complex was high enough, strong interaction among complex molecules occurred. The presence of Ag nanoparticles definitely decreased the interaction among complex molecules. In the solution containing Ag nanoparticles the electronic-dipole transition rate of (5)D(0)-(7)F(2) increased due to enhanced local field surrounding Eu(3+) ions, while the nonradiative transition rate from (5)D(0) decreased owing to decreased resonant energy transfer among europium complex molecules. These two factors lead to the luminescence enhancement of europium complex. As to the luminescent quenching, was attributed to absorption competition between Ag nanoparticles and europium complex at excited wavelength.
Related JoVE Video
Health-related quality of life after hand-assisted laparoscopic and open radical nephrectomies of renal cell carcinoma.
Int Urol Nephrol
PUBLISHED: 08-12-2009
Show Abstract
Hide Abstract
To compare the health-related quality of life (HRQOL) in contemporaneous groups of patients undergoing hand-assisted laparoscopic radical nephrectomy (HALRN) or open radical nephrectomy (ORN) for renal cell carcinoma (RCC).
Related JoVE Video
Calcineurin mediates the immune response of hemocytes through NF-kappaB signaling pathway in pearl oyster (Pinctada fucata).
Fish Shellfish Immunol.
PUBLISHED: 07-17-2009
Show Abstract
Hide Abstract
Calcineurin (CN), a multifunctional protein, mediates the immune response through diverse signaling pathways in mammals, while the function of CN in the immune response of molluscan hemocytes still remains unclear. In the present study, we detected the distribution of CN in various tissues and the expression levels of Pf-CNA and Pf-CNB gene in hemocytes of Pinctada fucata. After the preparation of hemocyte monolayers, we checked the response of enzymatic activity of CN, the degradation level of IkappaBalpha, the activity of iNOS and the production of NO, and IL-2 to the challenge of lipopolysaccharide (LPS) and cyclosporin A (CsA). CN activity in hemocytes was very sensitive to both the stimulation of LPS and the inhibition of CsA. Most importantly, IkappaBalpha degradation in hemocytes was induced by LPS and attenuated by CsA. Consequently, the activity of iNOS was elevated and the production of NO was increased. Additionally, we found that the synthesis of IL-2 was increased by LPS but was apparently weakened by CsA. In vivo bacterial clearance experiments showed that CsA significantly decreased the ability of in vivo bacteria clearance in pearl oyster. All the results revealed, for the first time, that CN mediated the immune response of molluscan hemocytes via activating NF-kappaB signaling pathway.
Related JoVE Video
Inhibition of TGF-beta receptor I by siRNA suppresses the motility and invasiveness of T24 bladder cancer cells via modulation of integrins and matrix metalloproteinase.
Int Urol Nephrol
PUBLISHED: 07-07-2009
Show Abstract
Hide Abstract
Urinary bladder transitional-cell carcinoma is still challenging because the mechanisms underlying the tumor progression are still largely unknown. Transforming growth factor beta1 (TGF-beta1) is considered a crucial molecule in the tumorigenesis of urinary bladder carcinoma. Many studies have indicated that it is also associated with epithelial-mesenchymal transition, angiogenesis, migration and metastases in many types of malignant tumors.
Related JoVE Video
The property distance index PD predicts peptides that cross-react with IgE antibodies.
Mol. Immunol.
PUBLISHED: 05-12-2009
Show Abstract
Hide Abstract
Similarities in the sequence and structure of allergens can explain clinically observed cross-reactivities. Distinguishing sequences that bind IgE in patient sera can be used to identify potentially allergenic protein sequences and aid in the design of hypo-allergenic proteins. The property distance index PD, incorporated in our Structural Database of Allergenic Proteins (SDAP, http://fermi.utmb.edu/SDAP/), may identify potentially cross-reactive segments of proteins, based on their similarity to known IgE epitopes. We sought to obtain experimental validation of the PD index as a quantitative predictor of IgE cross-reactivity, by designing peptide variants with predetermined PD scores relative to three linear IgE epitopes of Jun a 1, the dominant allergen from mountain cedar pollen. For each of the three epitopes, 60 peptides were designed with increasing PD values (decreasing physicochemical similarity) to the starting sequence. The peptides synthesized on a derivatized cellulose membrane were probed with sera from patients who were allergic to Jun a 1, and the experimental data were interpreted with a PD classification method. Peptides with low PD values relative to a given epitope were more likely to bind IgE from the sera than were those with PD values larger than 6. Control sequences, with PD values between 18 and 20 to all the three epitopes, did not bind patient IgE, thus validating our procedure for identifying negative control peptides. The PD index is a statistically validated method to detect discrete regions of proteins that have a high probability of cross-reacting with IgE from allergic patients.
Related JoVE Video

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.

How does it work?

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.