Browsing by Author "Gyanendra Mohan"

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Decreased expression of heat shock proteins may lead to compromised wound healing in type 2 diabetes mellitus patients
(Elsevier Inc., 2015) Kiran Singh; Kanhaiya Singh; Neeraj K. Agrawal; Sanjeev K. Gupta; Gyanendra Mohan; Sunanda Chaturvedi
Background Heat shock proteins (HSPs) are inducible stress proteins expressed in cells exposed to stress. HSPs promote wound healing by recruitment of dermal fibroblasts to the site of injury and bring about protein homeostasis. Diabetic wounds are hard to heal and inadequate HSPs may be important contributors in the etiology of diabetic foot ulcers (DFU). Objective To analyze the differential expression of HSPs and their downstream molecules in human diabetic wounds compared to control wounds. Methods Expressional levels of HSP27, HSP47 and HSP70 and their downstream molecules like TLR4, p38-MAPK were seen in biopsies from 101 human diabetic wounds compared to 8 control subjects without diabetes using RT-PCR, western blot and immunohistochemistry. Results Our study suggested a significant down regulation of HSP70, HSP47 and HSP27 (p value = < 0.001 for HSP70; p value = 0.007 for HSP47; p value = 0.007 for HSP27) in DFU along with their downstream molecules TLR4 and p38-MAPK (p value = 0.006 for p38-MAPK; p value = 0.02 for TLR4). HSP70 levels were significantly lower in male subjects and their levels increased significantly with the grades of wound on Wagner's scale. Infection status of the wounds was found to be significantly associated with the increased levels of HSP70 and HSP27 in infected diabetic wounds. Conclusions Our study demonstrates that the down regulation of HSPs in diabetic wounds is associated with wound healing impairment in T2DM subjects. © 2015 Elsevier Inc. All rights reserved.
Differential expression of matrix metalloproteinase-9 gene in wounds of type 2 diabetes mellitus cases with susceptible -1562c>t genotypes and wound severity
(SAGE Publications Inc., 2014) Kiran Singh; Neeraj K. Agrawal; Sanjeev K. Gupta; Gyanendra Mohan; Sunanda Chaturvedi; Kanhaiya Singh
Coordinated extracellular matrix deposition is a prerequisite for proper wound healing which is mainly orchestrated by matrix metalloproteinases (MMPs). Diabetic wounds generally show compromised wound healing cascade and abnormal MMP9 concentration is one of the cause. Our group have recently shown that the polymorphism -1562 C>T in the promoter region of MMP9 gene is associated with pathogenesis of wound healing impairment in T2DM patients. In present study we have done expression profiling of MMP9 gene in the wound biopsy of DFU cases. Expression level of MMP9 mRNA was then compared with susceptible -1562 C>T genotypes (TT and CT) as well as with different grades of wounds. We also screened the promoter region of MMP9 gene to see the methylation state of CpGs present there. Our study suggests that levels of MMP9 mRNA increase significantly with the wound grades. Moreover, the MMP9 levels in diabetic wounds were also dependent on -1562 C>T polymorphism in the promoter region of MMP9. Diabetic wounds also showed a significant unmethylated status of MMP9 promoter compared to control wounds. In conclusion, The risk genotypes of -1562 C>T polymorphism along with lack of methylation of CpG sites in MMP9 gene promoter may result in altered expression of MMP9 in wounds of T2DM cases resulting into nonhealing chronic ulcers in them. © 2014 The Author(s).
Genetic and epigenetic alterations in Toll like receptor 2 and wound healing impairment in type 2 diabetes patients
(Elsevier Inc., 2015) Kiran Singh; Kanhaiya Singh; Neeraj K. Agrawal; Sanjeev K. Gupta; Gyanendra Mohan; Sunanda Chaturvedi
Aim Persistent hyperglycemic microenvironment in type 2 diabetes mellitus (T2DM) leads to the development of secondary complications like wound healing impairment. Proper co-ordination of innate immune system plays an integral role in wound healing. Toll like receptors (TLRs) are prominent contributors for the induction of the innate immune and inflammation response. TLR2 is an important extracellular member in mammalian TLR family and has been shown to be a potent player in the wound healing mechanism. Methods Expressional status of TLR2 was seen in wounds of T2DM cases with respect to the severity of wounds in 110 human lower extremity wounds. The methylation status of TLR2 promoter was also examined. Results Although TLR2 transcripts were downregulated in T2DM wounds compared to control, their levels tend to increase with the severity of T2DM wounds. The methylation status of TLR2 gene promoter was not significantly different among different grades of wounds in T2DM subjects. The CpG sites investigated were totally or partially methylated in majority of DFU cases. Conclusion TLR2 down regulation in wounds of T2DM patients compared to non diabetic patients may lead to development of non healing chronic ulcers in them. © 2015 Elsevier Inc. All rights reserved.
Increased expression of endosomal members of toll-like receptor family abrogates wound healing in patients with type 2 diabetes mellitus
(Blackwell Publishing Ltd, 2016) Kanhaiya Singh; Neeraj K. Agrawal; Sanjeev K. Gupta; Gyanendra Mohan; Sunanda Chaturvedi; Kiran Singh
The inflammatory phase of wound healing cascade is an important determinant of the fate of the wound. Acute inflammation is necessary to initiate proper wound healing, while chronic inflammation abrogates wound healing. Different endosomal members of toll-like receptor (TLR) family initiate inflammatory signalling via a range of different inflammatory mediators such as interferons, internal tissue damaged-associated molecular patterns (DAMPs) and hyperactive effector T cells. Sustained signalling of TLR9 and TLR7 contributes to chronic inflammation by activating the plasmacytoid dendritic cells. Diabetic wounds are also characterised by sustained inflammatory phase. The objective of this study was to analyse the differential expression of endosomal TLRs in human diabetic wounds compared with control wounds. We analysed the differential expression of TLR7 and TLR9 both at transcriptional and translational levels in wounds of 84 patients with type 2 diabetes mellitus (T2DM) and 6 control subjects without diabetes using quantitative real-time polymerase chain reaction (RT-PCR), western blot and immunohistochemistry. TLR7 and TLR9 were significantly up-regulated in wounds of the patients with T2DM compared with the controls and were dependent on the infection status of the diabetic wounds, and wounds with microbial infection exhibited lower expression levels of endosomal TLRs. Altered endosomal TLR expression in T2DM subjects might be associated with wound healing impairment. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.
P53 gene: Mutation and immunohistochemical analysis in patients with invasive ductal carcinoma of breast
(2013) Shinjini Singh; Sandeep Kumar Rajput; Mritunjai Singh; Pravas Kumar Misra; Gyanendra Mohan; Mohan Kumar; Rakesh Kumar Singh; Indrajeet Singh Gambhir
The p53 tumor suppressor gene is the most commonly mutated gene in cancer. In breast cancer, the presence of p53 gene alterations has been associated with worse prognosis. This study was attempted to associate p53 gene mutations with its protein expression in North Eastern Indian population. We used single-stranded conformation polymorphism to screen samples for mutations in five conserved regions, exons 4, 5, 6, 7 and 8, of the p53 gene. Mutations were confirmed by direct DNA sequencing. Samples were also analyzed for expression of p53 immunohistochemically. We found two critical mutations in the exon 4. A well known missense mutation at codon 72 (pro to arg) with a frequency of 47% was found which was significantly correlated with the immunohistochemical analysis of p53 protein in such patients. A novel nonsense mutation at codon 107 which leads to stop codon was also found. Although the occurrence of this mutation was very less, we did not find expression of p53 protein immunohistochemicaly. We support that mutation in p53 gene can be exploited as a prognostic marker for the early diagnosis of breast cancer, although more clinical and epidemiological data is required to establish this claim. © 2013 Science Publication.