Protection Of Minocycline On Diabetic Renal Tubular Cell Apoptosis Through Regulated GRP78

Objective:Diabetes renal tissue damage is one of the most serious microvascular complications.Apoptosis of rental cells involved in a variety of kidney disease occurrence, developmentand restore process, especially late Diabetic nephropathy (diabetic nephropathy, DN). Thenumber of apoptotic cells glomerular closely related with renal deterioration. Endoplasmicreticulum stress has been confirmed that mediated one pathway of cells apoptosis,andalready proved correlation with diabetes organs damage process in recent years. Glucoseregulatory protein78(GRP78) as a kind of molecular partner in the protein fold andtransport and endoplasmic reticulum play an important role in response to stress, also knownas the endoplasmic reticulum stress protein marker. It has been reported that endoplasmicreticulum stress mediated the beta cells apoptosis and involved in diabetes process.Minocycline is the second generation tetracycline, it has good biocompatibility, absorbilitywell and a long half-life, and ipotropism high or organization penetration strong andantibacterial action good, and make it has the extremely high research and applicationvalue. In recent study found that minocycline not only has antibacterial anti-inflammatoryeffects, in the nervous system also play neural protection. Minocycline worked as caspase(caspase)-l,3inhibitors, can increase the mitochondrial membrane stability, decrease thepermeability, reduce cytochrome c release, restrain small glial cells activatity, reduceneurons and oligodendrocytes apoptosis. Minocycline play a inhibition role in both ofcaspase dependent or independent pathway. Literature reported that minocycline protectedrental ischemia-reperfusion injury via activated TLRs signaling transduction pathway. In thisproject, we will establish a model of diabetes with rat and minocyline treated them in differtime points after diabetes. To observe the protection of minocycline on diabetic rentaldamage and its regulation pathway.Methods:60of wistar rats dividied into four group:20of rats with diabetes model,20of rats withminocycline treatment for2moth,20of minocycline treatment for4moth, and10of ratswith minocycline treated alone,10of rats for normal control group. The rental tissues wereharvested After4months. The pathological HE dyeing methods, observe the diabetic rats kidney damage morphology change. The diabetic rats blood glucose and renal functionchange were detected with the biochemical methods. Immunohistochemical and Westernblotting methods were used to detected GRP-78expression and location in rental tissue. Theenzyme substrate degradation was used to analyzed caspase-12activity of change indiabetic rats kidney tissues with minocycline intervention. and Terminal-deoxynucleoitidylTransferase Mediated Nick End Labeling was used to detect iabetic rats renal tissue cellapoptosis under minocycline treatment protection on diabetic rental damage.Results:At the end of the diabetic course for16weeks, model rats compared with controls,endogenous creatinine clearance (Ccr) reduced, blood urea nitrogen (BUN),24-hour urinaryprotein (Upro) significantly increased; Minocycline intervention group, Ccr increase, BUNand Upro drop, compared with model group remarkable difference. Immunohistochemicaltest results showed that the control group GRP78kidney tissues of negative a weakexpression, model rats in the kidney tissues GRP78protein expression for strong positive.There are significant differences in GRP78expression of model group compared withcontrols. In minocycline intervention group, GRP78express dropped significantly, and theGRP78expression in the half period intervention group than more obvious decline in totalperiod intervention for4mouth. Apoptosis detection results showed that the apoptotic cellsappeared an occasional in negative control group and minocycline treatment alone. modelgroup kidney tissues which numerous apoptotic cells, especially renal tubular epithelium,glomerular visible part of the cell apoptosis. In minocycline group, renal tubular epithelialcell apoptosis significantly reduced. Caspase activity-12detection results showed thatCaspase-12activity of diabetic rats kidney tissues was higher than control, and minocyclinecan effectively reduce Caspase activity-12avtivity.Conclusion:minocycline improve diabetes renal function may carried out with reduced renalorganization partially through excessive activation of endoplasmic reticulum stress response,reduced renal tubular cell apoptosis rate.