Evidence supporting neuroprotective effect of adipose derived stem cells on PC12 cells against oxidative stress induced by H2O2.

Adipose-derived stem cells (ADSCs) are a population of cells derived from adipose tissue. ADSCs exhibit multilineage development potential and are able to secrete various factors, which influence adjacent cells. The present study examined the protective effect of ADSC's conditioned media (ADSC-CM) on PC12 cells exposed to H2O2, an oxidative injury model. After isolation, ADSCs were cultured and their osteogenic and adipogenic differentiation confirmed. Then, PC12 cells were co-treated with ADSC-CM and H2O2. Next, the effects of ADSC-CM on neurite outgrowth and cell differentiation in the presence of H2O2 were determined. Moreover, cell viability and apoptotic cell death percentage were evaluated using MTT assay, Hoechst staining and flow cytometry. Our results indicated the neuroprotective effects of ADSC-CM on morphological and morphometrical properties of neuron-like PC12 cells. Additionally, the profound decrease in percentage of apoptotic cells confirmed the protective effects of conditioned media from ADSCs that may be related to the release of trophic factors.

High-fat diet with stress impaired islets' insulin secretion by reducing plasma estradiol and pancreatic GLUT2 protein levels in rats' proestrus phase.

This study was conducted to determine whether two estrus phases (proestrus and diestrus) in female rats may influence the metabolic response to a high-fat diet and/or stress, focusing on pancreatic insulin secretion and content. Animals were divided into high-fat and normal diet groups, then each group was subdivided into stress and non-stress groups, and finally, each one of these was divided into proestrus and diestrus subgroups. At the end of high-fat diet treatment, foot-shock stress was applied to the animals. Then, blood samples were taken to measure plasma factors. Finally, the pancreas was removed for determination of glucose transporter 2 (GLUT2) protein levels and assessment of insulin content and secretion of the isolated islets. In the normal and high-fat diet groups, stress increased plasma corticosterone concentration in both phases. In both study phases, high-fat diet consumption decreased estradiol and increased leptin plasma levels. In the high-fat diet group in response to high glucose concentration, a reduction in insulin secretion was observed in the proestrus phase compared with the same phase in the normal diet group in the presence and absence of stress. Also, high-fat diet decreased the insulin content of islets in the proestrus phase compared with the normal diet. High-fat diet and/or stress caused a reduction in islet GLUT2 protein levels in both phases. In conclusion, it seems possible that high-fat diet alone or combined with foot-shock, predispose female rats to impaired insulin secretion, at least in part, by interfering with estradiol levels in the proestrus phase and decreasing pancreatic GLUT2 protein levels.