Altered expression of specific Antioxidant (SOD1 and SOD2) and DNA repair (XRCC1 and OGG1) genes in patients with Newly Diagnosed Type-2 Diabetes Mellitus

BACKGROUND: Uncontrolled increase in Reactive Oxygen Species (ROS) leads to the release of free radicals. Additionally, when antioxidants go below a certain level, major molecules of our system such as DNA, proteins, and many other macromolecules get damaged, leading to cancer, heart diseases, and metabolic syndromes like diabetes. Therefore, we in our study focused on newly diagnosed Type 2 Diabetes Mellitus (T2DM) patients and tried to evaluate the expression of antioxidant enzyme encoding genes; Superoxide Dismutase 1(SOD1) and Superoxide Dismutase 2 (SOD2) and DNA repair genes; X-ray repair cross-complementing 1(oCC1) and 8-oxoguanine DNA glycosylase 1 (OGG1) in them. METHODS: Expression analysis was performed by RT-PCR on 60 subjects (30 T2DM cases and 30 non-diabetic controls). The level of the SOD enzyme was also estimated in a serum sample by the colorimetric method. Biochemical parameters such as fasting plasma glucose (FBG), glycated haemoglobin (HbA1c), high sensitivity C-reactive protein (hsCRP), and lipid profile were estimated in an auto analyzer. Receiver operating characteristic (ROC) curve analysis was done, the area under the curve for mRNA expression and enzyme level was calculated to determine their potential as markers in newly diagnosed T2DM. RESULTS: Down-regulation of both SOD1 (0.43 fold, p=0.02) and SOD2(0.41 fold, p=0.13) and up-regulation of both oCC1(1.15 fold, p>0.05) and OGG1(1.49 fold, p>0.05) was observed in patients with T2DM. We also observed a significant decrease (p=0.02) in SOD enzyme levels in diabetic cases than in controls (599.8 +/- 178.9 and 691.3 +/- 127.3). CONCLUSION: We report that antioxidant repair genes are downregulated and DNA repair genes are upregulated in newly diagnosed T2DM patients. SOD levels and SOD1 gene expression can serve as informative biomarkers for identifying T2DM patients.