Role of bax protein and caspase-3 at high glucose-induced apoptosis in human embryonic kidney [HEK] 293 cells

Hyperglycemia is the principal factor responsible for microvascular complications of diabetes. Diabetic nephropathy is a serious and common complication leading to end stage renal disease. The exact molecular mechanisms of high glucose-induced toxicity on renal cells are still incompletely understood. Therefore in the present study, glucose-induced toxicity was studied in HEK [human embryonic kidney] cells as an in vitro model for diabetic nephropathy. First, the viability of HEK 293 cells exposed to glucose was measured by MTT [Methyl Thiazolyl Tetra-zolium] assay. Caspase-3 activity was determined spectrophotometrically using enzyme specific substrate. Moreover, the alteration in expression of Bax, Bcl[2] and caspase-3 were measured by Western blotting. The results showed that high glucose significantly reduced cell viability after 48 h [p<0.05]. In Western blot analysis, the ratio of Bax/Bcl-2 protein expression in cells treated with high glucose was significantly increased compared to controls [p<0.001]. The activity of caspase-3 was significantly increased in treated cells compared to control [p<0.01]. Moreover, high glucose exposure induced a significant decrease in protein level of procaspase-3 [p<0.01], indicating conversion of pro-form into the mature caspase. On the current data, it could be concluded that high glucose can cause HEK cell death, in which apoptosis plays an important role possibly by the mitochondrial pathway through higher expression of Bax pro-apoptotic protein and also by activation of caspase-3 related pathways

effect of fetal liver-derived cell suspension allotransplantation on patients with diabetes: first year of follow-up

Stem cell-based therapies have recently opened up new horizons for treatment of various types of diseases including diabetes mellitus. However, long-term efficacy and safety of these novel modalities still remain a serious question. Hereby, we aim to report the one-year follow-up results in the diabetic patients who underwent fetal liver-derived hematopoietic stem cell allotransplantation. Fifty six patients with type one [n=30] and type two [n=26] diabetes, aged 10-58 years old [32.8 +/- 16.3] were divided into the intervention and placebo group. The patients in the intervention group underwent fetal liver-derived hematopoietic stem cell transplantation while the patients in the placebo group received 5 ml of normal saline both via an intravenous route. The patients were visited at regular intervals to evaluate the efficacy of transplantation in glycemic control as well as possible complications. In the 6[th] month of the follow-up, there was a significant decrease in HbA[1]c levels in all groups without any rise in the fasting c-peptide. However, none of the precipitants transiently or continuously became insulin free in the first year after transplantation. It can be concluded that, in this study, fetal liver-derived hematopoietic stem cell transplantation had no significant effects on glycemic control. The heterogeneity of our patients might account for the negative results. Hence, longer follow-up results will be reported in the near future.

Study of correlation between systolic blood pressure and angiotensin converting enzyme [ACE] activity in STZ induced diabetic rats

Diabetes mellitus is a worldwide health problem affecting 1-2% of the population. It is responsible for numerous morbidity and mortality consequences due to vascular events such as hypertension, nephropathy and retinopathy. The precise mechanism of hyperglycemia-induced vascular damage is not clearly known. Alteration in Rennin Angiotensin-Aldosterone System [RAAS] and increased Angiotensin Converting Enzyme [ACE] activity is known to be involved in pathogenesis of vascular disorders. This study sought to investigate correlation between systolic blood pressure and ACE activity in STZ induced diabetic rats. Two groups of 8 male Sprauge Dawely rats including control [C] and diabetic group [D] were used in this study. Diabetes induced by injection of 60 mg/kg STZ intraperitoneally. Blood pressure was measured using tail cuff method. ACE activity was determined by HPLC method. At the end of study [four weeks after induction of diabetes] systolic blood pressure increased significantly in D group compared to control rats. ACE activity was increased in aorta, heart, lung and serum of D group which this increment was more pronounced in aorta and heart. Renal ACE activity reduced significantly in this group compared to control. It is concluded that increased ACE activity particularly cardiovascular ACE, could be involved in the diabetes induced hypertension and vasculopathy