Médecine moléculaire et génétique

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused by alteration in CYP21 gene which ultimately leads to 21-hydroxylase deficiency. The present study aimed at evaluation of 2 common mutations viz, Intron 2 Splice (INT2S) mutation and 8 bp deletions in exon 3 of CYP21 gene and to establish their frequencies in Kashmir population (North India). The mutations were tested by Amplification Refractory Mutation System-PCR (ARMS-PCR) in 50 cases of CAH, proven by clinical features and raised 17-hydroxy progesterone (17OHP) levels.

The results revealed that 15(30%) cases had INT2S mutation while as 8 bp deletion was not detected in any patient. In INT2S mutation, 7 cases were homozygous with I2-G genotype and 8 cases were heterozygous. The frequency of AG heterozygotes was found in 5 cases and CG heterozygote genotype was found in 3 cases. CAH patients with ambiguous genitalia were seen to harbor most of the INT2S mutations with I2-G in 3 cases and CG heterozygotes in 2 cases. In non-consanguineous group of patients, 4 homozygous I2-G mutations and 4 were I2- GC heterozygotes were detected in comparison to 3 and 1 in consanguineous patients respectively. Our study confirms that INT2S mutations but not 8 bp deletions exist in CYP21 gene in CAH patients in Kashmir population.

With increase in awareness about adverse effects of chemical use in food, there is a continuous effort for search of natural alternatives. Several plant extracts and their purified compounds are being explored for their biological efficacy. In the present study, Docynia indica, which grows as a wild tree in North Eastern region of India has been explored for its possible use as a source of natural preservatives. Although some reports about biological activities of D. indica fruit exist in literature, not much is known about its phytochemical profile. Various fruit extracts prepared at different maturity stages of D. indica fruits were analysed for their in vitro antioxidant and antimicrobial potential, and phytochemical profile of their methanolic extracts were determined by high performance liquid chromatography. The immature fruit extract showed high concentration of total phenolics (upto 196.15 mg gallic acid equivalent/ g extract) and flavonoids (up to 100.49 mg rutin equivalent/ g extract) depending on the extraction solvent; and also showed higher antioxidant activity in in vitro assays. Although no definite trend was observed for antibacterial activity based on maturity stages, extraction with the mixture of methanol, acetone and water (1:1:1) was found to show least minimum inhibitory concentration for all the maturity stages. Catechin and ferulic acid were the major phenolics present in D. indica fruits. The antioxidant and antibacterial compounds present in various extracts of D. indica indicate its potential for utilization as food preservative.

There is growing evidence that estrogens may promote tumor progression, including ovarian tumors. Estrogens exert their actions in tissues through two different receptor subtypes (ESR1 and ESR2). Studies have shown that hens develop ovarian cancer spontaneously, therefore providing a suitable animal model for the disease. Our aim was to determine the expression of mRNA and protein of the estrogen receptor subtypes in ovaries of normal hens and ovaries from hens with ovarian cancer. Ovarian tissue from normal hens and hens with ovarian cancer was collected for quantitative real-time PCR and immunofluorescence analysis. Quantitative real-time PCR results showed that the relative mRNA expression of ESR1 and the ratio of ESR1/ESR2 are significantly greater from hens with ovarian cancer when compared to normal ovarian tissue. Immunofluorescence analysis showed differential ESR1 and ESR2 protein expression in ovarian tissue sections from normal hens and hens with ovarian cancer, with results parallel to the mRNA data. There was no significant difference in plasma estradiol levels between normal hens and hens with ovarian cancer. These data suggest an increase in downstream estrogen-mediated actions in chicken ovarian tumors and, indeed, microarray analysis reveals a functionally significant estradiol-signaling pathway in chicken ovarian tumors. Interestingly, expression of a putative ovarian tumor suppressor, EPB41L3, is down regulated in this pathway. Taken together, these results suggest that, in the hen, ESR1 may be mediating a proliferative response in ovarian cancer cells. Although additional studies are required to define the role of ESR1 in tumor formation in the hen, these results support the utility of the hen for testing possible endocrine therapies.

Autoimmune diseases cause numerous health and social problems throughout the world. The common spectrum of autoimmune diseases affect the majority of tissues within the body, including pancreatic beta cells in type 1 diabetes (T1DM), myelin surrounding nerve axons in Multiple sclerosis (MS) and synovial joint antigens in Rheumatoid Arthritis (RA). The diseases are likely caused by a complex interaction between multiple HLA- and non- HLA related genes and environmental factors. The well documented co-clustering of autoimmune diseases within families and individuals, together with apparent sharing of number risk genes between the diseases suggests at least some common mechanisms of autoimmune development.

Diabetic Retinopathy (DR) is the most common microvascular complication of diabetes and is one of the leading causes of visual impairment worldwide. DR is a chronic eye disease that eventually can result in legal blindness due to the evolution towards the major vision-threatening disorders diabetic macular edema (DME) and/or proliferative diabetic retinopathy (PDR). Current treatments with steroids, anti-VEGF compounds or retinal laser photocoagulation have shown a significant improvement in visual acuity in the advanced stage of the disease. However, main concerns are possible side effects and/or the relatively large number of clinical non-responders. A better understanding of the biological and molecular pathways not only in DR patients but also in the preclinical in vivo models would aid the development of novel and more efficient (personalized) therapeutic approaches for DR. This review aims to describe the pathways in a selection of diabetic, non-diabetic and surrogate rodent models of pathogenic neovascularization, vascular permeability, inflammation and neurodegeneration. None of these models can mimic the entire human pathophysiological progression but they all exhibit joint pathophysiological features with human DR pathogenesis. These combined features make these models very relevant in gaining a better understanding of the disease etiology and eventually improved strategies for drug screening. Through highlighting the most important biochemical and molecular pathways that these animal models have in common with DR patients, selection of the most suitable model for mechanistic studies and drug screening can be facilitated.

Aim: Ovarian cancer prognosis is influenced by factors such as intratumoral T-lymphocyte presence and the amount of stroma formation relative to the epithelial tumor compartment. The regulation of these factors is unknown. Matrix metalloproteinases are involved in stromal remodeling and may be involved in T-cell trafficking as well. This study investigates the quantitative relationships between the matrix metalloproteinases MMP-2 and MMP-14 and both relative stroma amounts (‘stroma percentage’) and the presence of T lymphocytes in the stromal and epithelial compartments of ovarian cancer.

Patients and methods: In 86 patients with ovarian cancer, MMP-2 and MMP-14 expression and T-lymphocyte presence was determined using semi quantitative immunohistochemistry. Stroma percentage was determined by area calculation in haematoxylin eosin slides. Per slide, 3 random images at the tumor-stroma interface were investigated.

Results: Epithelial MMP-14 scoring correlated negatively with T-lymphocytes in tumor epithelium: correlation coefficient rho −0.36 (p < 0.01) for CD3, −0.30 (p < 0.01) for CD8 and −0.24 (p < 0.05) for CD45Ro. Stromal MMP-2 was positively related to stroma percentage (rho 0.29; p < 0.01). No significant correlations were found for MMP-14 with stromal amounts, or MMP-2 with T-cell presence in stroma or tumor epithelium.

Conclusion: Opposite to our hypothesis that MMPs reduce stromal amounts and permit T cell trafficking into both stromal and epithelial tumor parts, MMP expression was associated with higher relative stromal amounts and lower presence of T lymphocytes. In particular, we found that epithelial MMP-14 expression was negatively associated with T-lymphocyte presence in the tumor suggesting a role for MMP-14 in negatively regulating T-cell trafficking by other means. Stromal MMP-2 expression was associated with an increase in stromal amounts suggesting an ineffective feedback on tumor stroma volume growth of the expression of this gelatinase. More research is necessary to determine the specific actions of MMPs in ovarian cancer.

The purpose of our study was to develop new delivery systems for drugs effective against breast cancer by using biodegradable and biocompatible capsules. Redox-active microcapsules based on thiolated polymethacrylic acid (PMA) were employed. The interaction of these PMASH capsules with breast cancer cells and the mechanism of their internalization was investigated. PMASH biocompatibility was evaluated by MTT assay. To analyze their potential as drug carrier, we incorporated doxorubicin into the capsules. Confocal microscopy observations showed the presence of capsules inside the cells. Although some drug molecules still appeared co-localized with PMASH capsules, strong doxorubicin fluorescence was observed both in the cytoplasm and nucleus, indicating the disassembling of the capsule into PMASH-drug conjugate after internalization. These results were confirmed by both flow cytometry (time course of capsule uptake) and scanning electron microscopy. PMASH capsules were also internalized in 3D cell structures (spheroids) suggesting their potential use as drug delivery system for treatment of human diseases.

Objectives: Several candidate genes are implicated in the pathogenesis of type 2 diabetes mellitus (T2DM), one of which is interleukin (IL-10). In this investigation, we aimed to study the association between IL-10 (-592A/C) gene polymorphism with its level in T2DM with and without nephropathy.

Methods: IL-10 (-592A/C) gene polymorphism was genotyped using restriction fragment length polymorphism (RFLP-PCR) technique and IL-10 levels were measured in two groups of T2DM, one group complicated with nephropathy and the second non-complicated.

Results: Our results revealed no significant differences in IL-10 (−592A/C) genotypes distribution between the two groups of T2DM patients. IL-10 levels were found significantly elevated in diabetic nephropathy patients compared to T2DM without nephropathy (P<0.05) and were positively correlated to the degree of albuminuria (r=0.61, P<0.01). IL-10 levels increased in IL-10- (−592C/C) genotype compared to IL-10-(−592A/A) and IL-10- (−592A/C) genotypes in diabetic nephropathy patients while such difference was not found in T2DM patients without nephropathy.

Conclusion: IL-10 (-592A/C) gene polymorphism and IL-10 level play a role in the pathogenesis of nephropathy in T2DM.

Epigenetic mechanisms are known to be involved in tissue-specific differentiation. DNA methylation patterns have been shown to be largely conserved across tissues but with variation for specific genes. However, it is unclear whether the variability observed in the methylation profile of a metabolically active tissue is reflected in other sources such as hematopoietic tissue. This study aimed to test blood genome-wide CpG site methylation levels as a surrogate model for visceral adipose tissue (VAT) methylation and to verify whether it appropriately reflects differences in methylation levels found in VAT between men discordant for the metabolic syndrome (MetS). Tissue specimens (VAT and blood samples) were obtained from 16 severely obese individuals discordant for the MetS. CpG sites methylation levels were measured with the Infinium HumanMethylation450 BeadChip and correlations of methylation levels between VAT and blood were computed. Differences in methylation levels between individuals with and without MetS were tested in both tissues. Pathway analysis was conducted for differentially methylated CpG sites common to both tissues. High cross-tissue correlations were observed for VAT and blood (0.952±0.014) while some CpG sites had significantly different methylation levels in VAT versus blood. Differential methylation analysis between individuals with and without MetS demonstrated a higher number of differentially methylated CpG sites in VAT than in blood (11,778 vs. 881, respectively) with nearly 4% of differentially methylated sites found in VAT being also represented in blood. Common differentially methylated sites were involved in inflammatory-, lipid- and diabetes-related pathways. These results suggest that blood methylation levels of specific CpG sites may adequately reflect VAT methylation levels for some of the MetS-related genes, specifically for inflammatory, lipid and glucose metabolism genes.