Gene expressions of Mn-SOD and GPx-1 in streptozotocin-induced diabetes: effect of antioxidants

Increased oxidative stress and impaired antioxidant defense mechanisms are believed to be the important factors contributing to the pathogenesis and progression of diabetes mellitus. In this study, we have reported the effects of the streptozotocin-induced diabetes on the gene expression and the activities of two antioxidant enzymes, manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPx). We also studied the effects of two antioxidants, vitamin C and DL-alpha-lipoic acid (LA), on the system. Our results showed no significant change in both enzymes activities in diabetic animals compared to controls. Similarly, mRNA and protein profiles of MnSOD showed no change. Though the mRNA expression of GPx did not show any change, Western-blot analysis results demonstrated that protein expression is increased. LA, which is a water- and lipid-soluble antioxidant, decreased the protein expression of MnSOD, though mRNA levels and activities remained unchanged. LA treatment increased the GPx activities in diabetic tissues, significantly, and RT-PCR and Western-blot analysis results demonstrated that this increase in activity is not regulated at the gene level, as both mRNA and protein levels did not change. Supplementing the animals with vitamin C, a powerful water-soluble antioxidant, increased the mRNA expression of MnSOD, though the protein expression and the activity did not change statistically. On the other hand GPx activity increased significantly through post-translational modifications, as both mRNA and protein expressions did not change. These results together with our previous findings about the gene expressions of catalase and Cu-Zn SOD indicate the presence of very intricate control mechanisms regulating the activities of antioxidant enzymes in order to prevent the damaging effects of oxidative stress.


Effect of vitamin C and lipoic acid on streptozotocin-induced diabetes gene expression: mRNA and protein expressions of Cu-ZnSOD and catalase
Sadi, Goekhan; Yilmaz, Oekkes; Güray, Nülüfer Tülün (Springer Science and Business Media LLC, 2008-02-01)
The involvement of oxidative stress in the pathogenesis of diabetes mellitus has been confirmed by numerous studies. In this study, the expression of two antioxidant enzymes, superoxide dismutase (SOD), and catalase which are involved in the detoxification of reactive oxygen species was studied in the streptozotocin-induced diabetic rat liver tissues. The enzyme assays showed a significant decrease in both enzymes activities compared to control animals. The RT-PCR and Western-blot analysis results demonstra...
Apolipoprotein A5 polymorphisms in Turkish population: association with serum lipid profile and risk of ischemic stroke
CAN DEMİRDÖĞEN, BİRSEN; Sahin, Esra; Ozcelik, Aysun Turkanoglu; Bek, Semai; Demirkaya, Seref; Adalı, Orhan (Springer Science and Business Media LLC, 2012-12-01)
Atherosclerosis, a major cause of ischemic stroke, may be associated with variability of triglyceride (TG) levels. Apolipoprotein A5 (APOA5) genetic polymorphisms are associated with altered TG levels. The objective of this study was to investigate the coding region polymorphisms S19W (rs3135506) and G185C (rs2075291) and the promoter region polymorphism -1131T > C (rs662799) of the APOA5 gene as risk factors for ischemic stroke in Turkish population. Study group consisted of 272 ischemic stroke patients an...
CASIN and AMD3100 enhance endothelial cell proliferation, tube formation and sprouting.
Kalkan, Batuhan Mert; Akgol, Sezer; Ak, Deniz; Yucel, Dogacan; Esken, Gulen Guney; KOCABAŞ, FATİH (Elsevier BV, 2020-07-01)
Endothelial dysfunction is prominent in atherosclerosis, hypertension, diabetes, peripheral and cardiovascular diseases, and stroke. Novel therapeutic approaches to these conditions often involve development of tissue-engineered veins with ex vivo expanded endothelial cells. However, high cell number requirements limit these approaches to become applicable to clinical applications and highlight the requirement of technologies that accelerate expansion of vascular-forming cells. We have previously shown that...
Oxidative damage and regulation of antioxidant enzymes in streptozotocin induced diabetic rats
Sadi, Gökhan; Güray, Tülin; Department of Biochemistry (2009)
Increased oxidative stress and impaired antioxidant defense mechanisms are believed to be the important factors contributing to the pathogenesis and progression of diabetes mellitus. The products of lipid peroxidation and protein oxidation reactions were all found to be elevated significantly (p<0.05) in diabetic animals and supplementing the animals either individually or in combination, with two powerful antioxidants DL-α-lipoic acid (LA) and vitamin C (VC) brought this increment toward the control values...
Mechanism of inhibition of cytochrome p4501a1 associated 7-ethoxyresorufin o-deethylase (erod) activity and glutathione s-transferase (gst) activities in fish liver by phenolic compounds/flavonoids
Yılmaz, Duygu; Arınç, Emel; Department of Biology (2010)
Flavonoids, present in fruits, vegetables and beverages derived from plants, have been described as health-promoting, disease-preventing dietary supplements, and have activity as cancer preventive agents. The cancer protective effects of flavonoids have been attributed to a wide variety of mechanisms, including modulating enzyme activities resulting in the decreased carcinogenicity of xenobiotics. Cytochrome P4501A1 (CYP1A1) is a Phase I enzyme which is known to be involved in the activation of procarcinoge...
Citation Formats
G. Sadi and N. T. Güray, “Gene expressions of Mn-SOD and GPx-1 in streptozotocin-induced diabetes: effect of antioxidants,” MOLECULAR AND CELLULAR BIOCHEMISTRY, pp. 127–134, 2009, Accessed: 00, 2020. [Online]. Available: