Sudip K. Datta

Association of glutathione S-transferase M1 and T1 gene polymorphism with oxidative stress in diabetic and nondiabetic chronic kidney disease

Background and Objective: Glutathione S-transferases (GSTs) belong to a family of ubiquitous and multifunctional enzymes that work as one of the endogenous antioxidants in our body. This study was designed to look into the association of GST polymorphism with oxidative stress in both diabetic and nondiabetic chronic kidney disease (CKD). Design and Methods: Three groups of patients (50 in each): diabetics without CKD (DM), diabetic CKD (DM-CKD), and nondiabetic CKD (NDM-CKD) and 50 age- and sex-matched healthy controls were recruited. Genotyping was done for GSTM1 and GSTT1 genes using a multiplex polymerase chain reaction. Serum GST and malondialdehyde (MDA) as a marker of oxidative stress were measured spectrophotometrically. Results: Based on genotyping, subjects were categorized as GSTM1+/GSTT1+, GSTM1−/GSTT1+, GSTM1+/GSTT1−, and GSTM1−/GSTT1−. Serum GST levels were lower among subjects with deletion in one/both GST genes, whereas MDA levels were found to be correspondingly raised. A negative correlation for MDA versus GST levels was observed among genotypes with one/both gene deletions. Presence of GSTM1+/GSTT1− and GSTM1−/GSTT1− was significantly higher among patients with CKD in both diabetics and nondiabetics. Interpretations and Conclusions: GSTM1 and GSTT1 deletions singly or together were associated with lower GST levels and higher oxidative stress in both diabetic and nondiabetic CKD. Interestingly, GSTT1 deletion appears to be associated with both diabetic and nondiabetic CKD irrespective of the GSTM1 status.

Study on organochlorine pesticide levels in chronic kidney disease patients: association with estimated glomerular filtration rate and oxidative stress.

Nephrotoxicity of organochlorine pesticides (OCPs) has been established in experimental animal models. This study was designed to evaluate the relationship of the blood OCPs level with the estimated glomerular filtration rate (eGFR) and oxidative stress (OS) in chronic kidney disease (CKD) patients. Patients in different stages of CKD (n = 150) and age, sex matched healthy controls (n = 96) were recruited. The blood OCPs level were analyzed by gas chromatography, and plasma levels of several OS parameters such as malondialdehyde (MDA), protein carbonyl, advanced oxidation protein products (AOPP), and total thiols were quantified by standard spectrophotometric methods. We observed significantly higher levels of hexachlorocyclohexane (α, γ), endosulfan, aldrin, p,p′‐dichlorodiphenyldichloroethylene (DDE), and total pesticides in CKD patients. Negative correlation was also observed for aldrin, p,p′‐DDE and total pesticides (p < 0.05) with eGFR. Plasma levels of MDA and AOPP showed significant positive association with the total pesticides level, indicating augmentation of OS with increased accumulation of OCPs in CKD patients.

Association of GSTM1 and GSTT1 polymorphism with lipid peroxidation in benign prostate hyperplasia and prostate cancer: A pilot study

Association of glutathione S-transferase (GST) M1 and T1 deletions with benign prostate hyperplasia (BPH) and prostate cancer is well reported. These enzymes metabolize numerous toxins thus protecting from oxidative injury. Oxidative stress has been associated with development of BPH and prostate cancer. The present study was designed to analyze role of GST deletions in development of oxidative stress in these subjects. GSTs are responsible for metabolism of toxins present in tobacco therefore effect of tobacco usage in study groups was also studied. Three groups of subjects: BPH (57 patients), prostate cancer (53 patients) and controls (46 subjects) were recruited. Genotyping was done using a multiplex polymerase chain reaction (PCR) method. Malondialdehyde (MDA) levels as marker of oxidative stress were estimated by measuring thiobarbituric acid reactive substance (TBARS) in plasma. Based on genotyping, subjects were categorized into: GSTM1+/GSTT1+, GSTM1-/GSTT1+, GSTM1+/GSTT1- and GSTM1-/GSTT1-. Significantly higher plasma MDA levels were noticed in GSTM1-/GSTT1- as compared to GSTM1+/GSTT1+ in all study groups. Double deletion (GSTM1-/GSTT1-) is associated with higher oxidative stress which might play a role in the pathogenesis of BPH and prostate cancer. However, other markers of oxidative stress should be analyzed before any firm conclusion.

A preliminary study on the influence of glutathione S transferase T1 (GSTT1) as a risk factor for late onset Alzheimer's disease in North Indian population

INTRODUCTION Oxidative stress plays key role in pathogenesis of Alzheimers disease. Glutathione S-transferases (GSTs), a family of phase-II isoenzymes, play a critical role in providing protection against electrophiles and products of oxidative stress. Among different classes of GSTs, GSTM1 (Mu) and GSTT1 (theta) are found to be genetically deleted which results in decreased expression of the concerned enzyme. This study aims at preliminary analysis of the frequency of deletion of GSTM1 and GSTT1 and their association with late-onset Alzheimers disease. MATERIAL AND METHODS In this study, association of the deletion type polymorphism of GST M1 and T1 as possible risk factors for dementia of Alzheimers type was studied in 50 patients and 100 controls. Dementia was diagnosed by Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria, Mini Mental State Examination (MMSE) and Clinical Dementia Rating (CDR) scale. Genotyping was done by multiplex Polymerase Chain Reaction (PCR). Associations between null genotype of either GSTM1 and GSTT1 or both with Alzheimers disease were analyzed by Chi-Square test. RESULTS Deletion of GSTT1 was found significantly associated with Alzheimers disease (χ(2)=5.08, p=0.02*). CONCLUSIONS The odds of Alzheimers disease in null GSTT1 is found to be increased by 2.47 times in comparison to positive GSTT1.

Association of CYP1A1 gene polymorphism with chronic kidney disease: a case control study.

CYP1A1 is an important xenobiotic metabolizing enzyme, present in liver and kidney. Expression of CYP1A1 enzyme increases manifold when kidney cells are exposed to nephrotoxins/chemicals leading to oxidative stress-induced cell damage. To study the association of CYP1A1 gene polymorphism in patients of chronic kidney disease with unknown etiology (CKDU), we recruited 334 CKDU patients and 334 age and sex matched healthy controls. CYP1A1*2A and *2C polymorphisms were studied by PCR-RFLP and allele specific-PCR respectively. Subjects carrying at least one mutant allele of CYP1A1*2A (TC, CC) and *2C (AG, GG) were shown to be associated with 1.4-2-fold increased risk of CKDU. Also, genotypic combinations of hetero-/homozygous mutants of CYP1A1*2A (TC, CC) with hetero-/homozygous mutant genotypes of CYP1A1*2C (AG, GG) i.e. TC/AG (p<0.01), TC/GG (p<0.05), CC/AG (p<0.05) and CC/GG (p<0.01) were associated with CKDU with an odd ratio ranging 1.8-3.3 times approximately. This study demonstrates association of CYP1A1 polymorphisms with CKDU.

Polymorphisms in the P450 c17 (17-hydroxylase/17, 20-Lyase) gene: association with estradiol and testosterone concentration in hypospadias.

OBJECTIVE To investigate the association of CYP17 polymorphism with 17β-estradiol (E2) and testosterone (T) concentration in hypospadias. METHODS Two-hundred twenty-three boys (91 with hypospadias and 132 age-matched controls) were included in the study. CYP17 polymorphism was evaluated using the polymerase chain reaction-restriction fragment length polymorphism method, whereas T and E2 levels were estimated in serum by enzyme-linked immunosorbent assay. Association between CYP17 genotypes and 17β-E2, T, and their ratio (E2/T) was analyzed by analysis of variance followed by Tukeys test. 17β-E2, T, and E2/T ratio was also compared among the different degrees of hypospadias, as well as in controls, by unpaired Students t-test. RESULTS Significantly low levels of T were observed in severe-degree hypospadias (n = 14; mean ± SD = 1.01 ± 0.57) compared with mild cases (n = 77; mean ± SD = 1.93 ± 1.40) and controls (mean ± SD = 3.32 ± 2.06) (P <.05). E2/T ratio was also significantly higher in hypospadias cases (5.36 ± 3.55) compared with controls (2.21 ± 2.52). Heterozygous variants (A1/A2) of CYP17 were present in higher frequency (OR = 0.96; 95% CI = .518-1.770) and homozygous (A2) variants were less frequently found in hypospadias (OR = 0.87; 95% CI = .363-2.077), but results were insignificant. No association between 17β-E2 and T with different CYP17 genotypes was observed. CONCLUSION Our study suggests that, although polymorphism in CYP17 gene may not be associated with 17β-E2 and T concentrations in hypospadias cases, low levels of T and higher E2/T ratio might possibly act as risk factors for hypospadias.