Study on relationship between expression of PKCα in glomeruli and development of nephropathy in diabetic rats

AIM:To observe the dynamic changes of expression of PKCα, TGF-β₁ and α-SMA in glomeruli of diabetic rats induced by the alloxon and to invesitigate their roles in the diabetic nephropathy(DN).METHODS:Rats were randomly divided into four groups: normal control group (group A), diabetic group of one week (group B), diabetic group of one month (group C), diabetic group of two months (group D). Immunohistochemistry and Western blotting were used to detect the expression of PKCα, TGF-β₁ and α-SMA in renal tissue of all groups. Blood glucose, triglycerides, cholesterol, creatinine and urine protein were analysed by chemical methods. The morphological changes of renal tissue were checked through microscopy.RESULTS:The expression of PKCα and TGF-β₁ in renal tissue of diabetic groups were increased comparing with those of nomal control group(P<0.05). The mesangial cells expressed α-SMA in two months group. Chronologically the expression of PKCα, TGF-β₁ and α-SMA were positively correlative with each other and the impairment of kidney was also observed.CONCLUSIONS: During the DN process the expression of PKCα increased. PKCα raised GFR and the permeability of glomerular filtration membrane which enhanced urinary albumin excretion. PKCα also increased expression of TGF-β and therefore to induce the expression of α-SMA. The appearance of α-SMA was a marker of the phenotypic transform of renal cells.     

Gene expression of 5α-reductase (type 2) in reproductive gland of pubertal diabetic rats

AIM: To study the molecular mechanism of reproduction dysfunction in pubertal diabetic rat, the level of 5α-reductase (type 2) mRNA in testis, epididymis and prostate in diabetic rat was detected. METHODS: The gene expression of 5α-reductase (type 2) was detected by Northern blot. RESULTS: In the caput of the epididymis, the expression of 5α-reductase (type 2) mRNA of D and ID groups was less than that of C group. CONCLUSION: The decreased expression of 5α-reductase (type 2) results in the decreased production of dihydrotestosterone, which influences the development and function of reproduction system in pubertal rats.     

The role of resistin in obesity and diabetes

Increased evidences indicate that resistin is a new hormone secreted from adipose tissue, it is reported to be an important signal molecule linking between obesity, insulin resistance and type 2 diabetes. Many factors can affect the gene expression of resistin. However, the detailed function of resistin still remains mysterious and much work needs to be undertaken.     

Cell direct reprogramming：a new technique for treating diabetes

Diabetes is characterized by an absolute or relative deficiency in β-cell mass, which cannot be reversed with existing therapeutic strategies. The restoration of the endogenous islet β-cells can stabilize the level of blood glucose. The islet β-cells can be obtained from the directional differentiation of stem cells, but the process is complex and has the risk of teratomas generation. Cell direct reprogramming, one terminal differentiated cell can transdifferentiate into another kind of terminal differentiated cell, which is other than directional differentiation from stem cells. Direct reprogramming gives rise to the generation of islet β-cells from one terminal differentiated cell, may be preferable for diabetes therapy because of its unique advantage.     

Study on the variation of trace elements and oxidative stress in diaphragm of the diabetic rats

AIM:To investigate the relationship between trace elements and oxidative stress in diabetic diaphragm. METHODS: Contents of copper(Cu), manganese(Mn), zinc(Zn), iron(Fe),cadmium(Cd),chromium(Cr),cobalt(Co),molybdenum(Mo) and lithium(Li) in the alloxan-induced diabetic rat diaphragm muscles were measured by atomic absorption spectrophotometer, andtheir superoxide dismutase(SOD) activities and malondiadehyde(MDA) contents were detected. RESULTS: The contents of Cu, Zn, Cr and Li were lower and the Fe and Cd were higher in diabetic rat diaphragm muscles than that of the control group, but there were no significant differences in Mn, Co and Mo, between control and diabetic group. SOD activities decreased significantly and MDA contents increased significantly in diaphragm of diabetic rats as compared with the control group.In addition,in diabetic rats diaphragm, there was a positive correlation between Zn and SOD, and negative correlation between Zn and MDA, and Cd and SOD. CONCLUSION: Changes of the contents of Cu, Zn, Fe, Cd, Cr, Li and the increase of oxidative stress in diaphragm were found in the early diabetes, and Zn, Cd play an importment role in oxidative stress of diabetic diaphragm.