[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE AND DESIGN: This study evaluated the effect of an antioxidant, Vitamin E, on cultured chondrocytes against H2O2-induced damage in vitro. MATERIAL: Rat chondrocytes isolated from articular cartilage. TREATMENT: Chondrocytes were pretreated with either 50 or 100 μM Vitamin E or serum-free medium for 24 h followed by their exposure to 200 μM H2O2 for 3 h. Chondrocytes without exposure to H2O2 served as control group. METHODS: The effect of Vitamin E pretreatment was evaluated by examining proteoglycan contents, nitrite levels, viability, apoptosis, and senescence of cultured chondrocytes. RESULTS: Proteoglycan contents increased in groups treated with Vitamin E. Semi-quantitative real-time PCR data also correlated with these results and demonstrated that Vitamin E up-regulated expression of Agc1, Col2a1, and PCNA genes along with down-regulation in the expression of Col1a1 and Casp3 genes. The differentiation index improved after Vitamin E pretreatment. Nitrite levels were reduced with a corresponding increase in cell viability. Reduction in apoptosis and senescence was also observed after Vitamin E pretreatment. Moreover, a dose-dependent effect of Vitamin E was seen. In contrast to 50 μM Vitamin E, 100 μM was more potent in inducing protection of chondrocytes from H2O2-induced oxidative damage. CONCLUSION: Vitamin E reversed the oxidant-induced alterations in chondrocytes and may be a good option to pretreat chondrocytes before transplantation.
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION: The clinical correlation between hepatitis C virus (HCV) NS5A gene mutations and response to antiviral treatment in HCV-3a-infected patients is not as well known as that in HCV-1a-infected and HCV-1b-infected patients. OBJECTIVES: This study attempted to determine mutations in the NS5A gene in isolates of HCV-3a obtained from infected Pakistani patients treated with interferon-α standard therapy and to determine its association with several host factors. METHODS: A total of 71 consecutive chronically infected HCV patients [43 men and 28 women, mean age 38 years (range, 16-70 years)] without previous antiviral therapy, who fulfilled other criteria of the current study were enrolled for antiviral therapy. RESULTS: Of the 71 patients enrolled, 53 completed the course of antiviral therapy. Among them, 23 (43.3%) patients showed an end-of-treatment response, 20 (41.4%) showed a sustained virological response, and three (5.6%) patients were HCV-RNA negative at the end of treatment but developed a relapse thereafter. Only seven (13.2%) patients were virologic nonresponders (NR). Probable transmission risk factors were previous major/minor surgery (20%), transfusion of blood or blood products (2%), dental surgery (10%), or sporadic (unknown; 60%). The estimated duration of infection varied from 6 months to 20 years. The correlation between the number of mutations and several factors was also studied. The first factor that was associated with the number of mutations in the NS5A gene was age older than 40 years, where the difference was statistically significant between viral sequences of patients showing an end-of-treatment response and NR (P<0.001). Further, the difference in the average number of mutations was statistically significant between patients showing sustained virological response and NR (P<0.005). The second and third factors that were found to be associated with number of mutations in the NS5A gene were sex and viral load, respectively. CONCLUSION: Along with host factors such as age older than 40 years, female sex, and low baseline viral load, the less number of mutations in the NS5A gene of HCV-3a is associated with a positive outcome of treatment response in HCV patients receiving interferon plus ribavirin therapy.
European journal of gastroenterology & hepatology 04/2013;
[Show abstract][Hide abstract] ABSTRACT: To identify pathogenic mutations responsible for retinal dystrophy in three consanguineous Pakistani families.
A thorough ophthalmic examination including fundus examination and electroretinography was performed, and blood samples were collected from all participating members. Genomic DNA was extracted, and genome-wide linkage and/or exclusion analyses were completed with fluorescently labeled short tandem repeat microsatellite markers. Two-point Lod scores were calculated, and coding exons along with exon-intron boundaries of RPE65 gene were sequenced, bidirectionally.
Ophthalmic examinations of the patients affected in all three families suggested retinal dystrophy with an early, most probably congenital, onset. Genome-wide linkage and/or exclusion analyses localized the critical interval in all three families to chromosome 1p31 harboring RPE65. Bidirectional sequencing of RPE65 identified a splice acceptor site variation in intron 2: c.95-1G>A, a single base substitution in exon 3: c.179T>C, and a single base deletion in exon 5: c.361delT in the three families, respectively. All three variations segregated with the disease phenotype in their respective families and were absent from ethnically matched control chromosomes.
These results strongly suggest that causal mutations in RPE65 are responsible for retinal dystrophy in the affected individuals of these consanguineous Pakistani families.
[Show abstract][Hide abstract] ABSTRACT: Our aim was to improve the survival and reduce the apoptosis of chondrocytes derived from mesenchymal stem cells from Wharton's jelly of human umbilical cord (WJMSCs) by Lovastatin supplementation under hydrogen-peroxide-induced injury conditions to simulate the osteoarthritic micro-environment. Chondrocytes were differentiated in vitro from WJMSCs. The cultured WJMSCs expressed CD90 (84.07%), CD105 (80.84%), OCT4 (26.90%), CD45 (0.42%) and CD34 (0.48%) as determined by flow cytometry. Increased aggregation of proteoglycans observed by Safranin-O staining accompanied by increased expression of COL2A1, ACAN, SOX9 and BGN shown by immunocytochemistry and reverse transcription with the polymerase chain reaction (PCR) confirmed the chondrogenic differentiation of the WJMSCs. The in vitro differentiated chondrocytes were subjected to oxidative stress by exposure to 200 μM hydrogen peroxide, either in the presence or absence of Lovastatin (2 μM) for 5 h. Lovastatin treatment resulted in decreased apoptosis, senescence and LDH release and in increased viability and proliferation of WJMSC-derived chondrocytes. Real time PCR analysis showed markedly up-regulated expression of prosurvival, proliferation and chondrogenic genes (BCL2L1, BCL2, AKT, PCNA, COL2A1, ACAN, SOX9 and BGN) and significantly down-regulated expression of pro-apoptotic genes (BAX, FADD) in the Lovastatin-treated group in comparison with injured cells. The reduced expression of VEGF and p53 as determined by enzyme-linked immunosorbent assay and PCR suggests the suitability of the use of Lovastatin in adjunct to WJMSC-derived chondrocytes for the treatment of osteoarthritis. We conclude that Lovastatin protects WJMSC-derived chondrocytes from hydrogen-peroxide-induced in vitro injury.
[Show abstract][Hide abstract] ABSTRACT: Human hereditary deafness at the DFNB29 locus on chromosome 21q22.1 is caused by recessive mutations of CLDN14, encoding claudin 14. This tight junction protein is tetramembrane spanning that localizes to the apical tight junctions of organ of Corti hair cells and in many other tissues. Typically, the DFNB29 phenotype is characterized by prelingual, bilateral, sensorineural hearing loss. The goal of this study was to define the identity and frequency of CLDN14 mutations and associated inner ear phenotypes in a cohort of 800 Pakistani families segregating deafness. Hearing loss in 15 multi-generational families was found to co-segregate with CLDN14-linked STR markers. The sequence of the six exons and regions flanking the introns of CLDN14 in these 15 families revealed five likely pathogenic alleles. Two are novel missense substitutions (p.Ser87Ile and p.Ala94Val), whereas p.Arg81His, p.Val85Asp and p.Met133ArgfsX23 have been reported previously. Haplotype analyses indicate that p.Val85Asp and p.Met133ArgfsX23 are founder mutations. The p.Val85Asp accounts for ∼67% of the mutant alleles of CLDN14 in our cohort. Combined with the previously reported data, CLDN14 mutations were identified in 18 of 800 Pakistani families (2.25; 95% CI, 1.4-3.5). Hearing loss in the affected individuals homozygous for CLDN14 mutations varied from moderate to profound. This phenotypic variability may be due to environmental factors (for example drug and noise exposure) and/or genetic modifiers.Journal of Human Genetics advance online publication, 13 December 2012; doi:10.1038/jhg.2012.143.
[Show abstract][Hide abstract] ABSTRACT: Hepatitis C virus (HCV) has been considered to be a significant risk factor in developing liver associated diseases including hepatocellular carcinoma all over the world. HCV is an enveloped positive strand virus comprising a complex between genomic RNA and viral envelope glycoproteins (E1 and E2), which are anchored within host derived double-layered lipid membrane surrounding the nucleocapsid composed of several copies of core protein. HCV cell entry is the first step in infection and viral replication into host cells mainly hepatocytes. HCV cell entry is a complex process involving both the viral (envelope glycoproteins E1/E2) and host factors (cellular receptors and associated factors i.e. CD81, SR-BI, LDL-R, CLDN1, Occludin, DC-SIGN, L-SIGN and Glycosaminoglycans). Besides these the expression of certain other conditions such as polarization and EWI-2 expression inhibits the viral cell entry. Exploring the mechanism of HCV entry will help to better understand the viral life cycle and possible therapeutic targets against HCV infection including viral and host factors involved in this process. New strategies such as RNAi represents a new option for targeting the host or viral factors for prevention and therapeutic against HCV infection. In the current review we try to summarize the current knowledge about mechanism and interaction of cellular and viral factors involved in HCV cell entry and its implication as therapeutic target to inhibit HCV infection.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 08/2012; 12(8):1699-1709.
[Show abstract][Hide abstract] ABSTRACT: Liver fibrosis is a major health problem worldwide and poses a serious obstacle for cell based therapies. Mesenchymal stem cells (MSCs) are multipotent and important candidate cells for future clinical applications however success of MSC therapy depends upon their homing and survival in recipient organs. This study was designed to improve the repair potential of MSCs by transplanting them in sodium nitroprusside (SNP) pretreated mice with CCl(4) induced liver fibrosis.
SNP 100 mM, a nitric oxide (NO) donor, was administered twice a week for 4 weeks to CCl(4)-injured mice. MSCs were isolated from C57BL/6 wild type mice and transplanted in the left lateral lobe of the liver in experimental animals. After 4 weeks, animals were sacrificed and liver improvement was analyzed. Analysis of fibrosis by qRT-PCR and sirius red staining, homing, bilirubin and alkaline phosphatase (ALP) serum levels between different treatment groups were compared to control.
Liver histology demonstrated enhanced MSCs homing in SNP-MSCs group compared to MSCs group. The gene expression of fibrotic markers; αSMA, collagen 1α1, TIMP, NFκB and iNOS was down regulated while cytokeratin 18, albumin and eNOS was up-regulated in SNP-MSCs group. Combine treatment sequentially reduced fibrosis in SNP-MSCs treated liver compared to the other treatment groups. These results were also comparable with reduced serum levels of bilirubin and ALP observed in SNP-MSCs treated group.
This study demonstrated that NO effectively augments MSC ability to repair liver fibrosis induced by CCl(4) in mice and therefore is a better treatment regimen to reduce liver fibrosis.
[Show abstract][Hide abstract] ABSTRACT: Mesenchymal stem cells (MSCs) are an attractive candidate for autologous cell therapy, but their ability to repair damaged myocardium is severely compromised with advanced age. Development of viable autologous cell therapy for treatment of heart failure in the elderly requires the need to address MSC ageing. In this study, MSCs from young (2 months) and aged (24 months) C57BL/6 mice were characterized for gene expression of IGF-1, FGF-2, VEGF, SIRT-1, AKT, p16(INK4a) , p21 and p53 along with measurements of population doubling (PD), superoxide dismutase (SOD) activity and apoptosis. Aged MSCs displayed senescent features compared with cells isolated from young animals and therefore were pre-conditioned with glucose depletion to enhance age affected function. Pre-conditioning of aged MSCs led to an increase in expression of IGF-1, AKT and SIRT-1 concomitant with enhanced viability, proliferation and delayed senescence. To determine the myocardial repair capability of pre-conditioned aged MSCs, myocardial infarction (MI) was induced in 24 months old C57BL/6 wild type mice and GFP expressing untreated and pre-conditioned aged MSCs were transplanted. Hearts transplanted with pre-conditioned aged MSCs showed increased expression of paracrine factors, such as IGF-1, FGF-2, VEGF and SDF-1α. This was associated with significantly improved cardiac performance as measured by dp/dt(max) , dp/dt(min) , LVEDP and LVDP, declined left ventricle (LV) fibrosis and apoptosis as measured by Masson's Trichrome and TUNEL assays, respectively, after 30 days of transplantation. In conclusion, pre-conditioning of aged MSCs with glucose depletion can enhance proliferation, delay senescence and restore the ability of aged cells to repair senescent infarcted myocardium.
Journal of Cellular and Molecular Medicine 03/2012; 16(10):2518-29.
[Show abstract][Hide abstract] ABSTRACT: Today, agriculture is facing a tremendous threat from the climate change menace. As human survival is dependent on a constant supply of food from plants as the primary producers, we must aware of the underlying molecular mechanisms that plants have acquired as a result of molecular evolution to cope this rapidly changing environment. This understanding will help us in designing programs aimed at developing crop plant cultivars best suited to our needs of a sustainable agriculture. The field of systems biology is rapidly progressing, and new insight is coming out about the molecular mechanisms involved in abiotic stress tolerance. There is a cascade of changes in transcriptome, proteome, and metabolome of plants during these stress responses. We have tried to cover most pronounced recent developments in the field of "omics" related to abiotic stress tolerance of plants. These changes are very coordinated, and often there is crosstalk between different components of stress tolerance. The functions of various molecular entities are becoming more clear and being associated with more precise biological phenomenon.
Omics: a journal of integrative biology 03/2012; 16(4):188-99.
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