Astragalus Membranaceus And Puerarin On Diabetic Nephropathy Grp78 In The Endoplasmic Reticulum Stress, The Influence Of Xbp1 Expression

Background:Diabetes (diabetes mellitus, DM)a metabolic syndrome characterized by hyperglycemia, is usually caused by genetic, environmental and immune factors. Diabetic nephropathy (DN) is not only one of the most common microvascular complications of diabetes, but also a major cause of death of diabetic patients. Its main pathological changes are thickening of glomerular and tubular basement membrane, accumulation of mesangial cells in glomerular and tubular extracellular matrix, all of these changes will eventually lead to the decline in renal function. The endoplasmic reticulum stress is the early response of cells to variety of injuries. In recent years, many data indicates that the DN associates with the cellular stress and inflammatory signaling pathway stress, and puts forward all kinds of theories, such as inflammation pathogenesis, oxidative stress doctrine, endoplasmic reticulum stress doctrine. The endoplasmic reticulum stress theory plays an important role. The endoplasmic reticulum stress (ERS) signaling pathway is a common mechanism of early injury response in diabetic organ parenchymal cells. A variety of factors (such as high blood sugar, high blood lipids, balance disorders of Ca2+, hypoxia, oxidative damage, chemical poisons)which can accumulate the unfolded or misfolded proteins in ER lumen would result in functional changes of the endoplasmic reticulum, and lead to the endoplasmic reticulum stress response. ERS is a cellular self-protection mechanism, can make misfolded proteins restore to the correct conformation and to further processing. However, the continous accumulation of unfolded proteins or misfolded proteins in the endoplasmic reticulum, can have toxic effects to cells. Therefore, when the endoplasmic reticulum stress is too strong or continous, the signaling pathway can not ease the stress of the endoplasmic reticulum, cells will start the apoptotic form of death to protect other normal tissues.The literature and preliminary experiments show that Astragalus mongholicus and Puerarin Injection can effectively prevent the DN, but its exact mechanism is unclear, the specific role of the targets is not very clear, so further study of Astragalus mongholicus and Puerarin Injection will play an important role in clinical control of DN. Therefore, by studying the effects of Astragalus mongholicus and Puerarin Injection on the expression of important regulatory proteins of DN endoplasmic reticulum stress in KKAy diabetic mice-GRP78, XBP1(X-box the binding protein1), explores the further treatment mechanism of Astragalus mongholicus and Puerarin Injection in DN.Objective:To observe the effects of Astragalus mongholicus and Puerarin Injection on expression of GRP78and XBP1in endoplasmic reticulum stress of KKAy diabetic mice, and to further explore prevention and treatment effects of Astragalus mongholicus and Puerarin Injection in DN by regulating endoplasmic reticulum stress response, to reveal specific mechanism of Astragalus mongholicus and Puerarin Injection in prevention and treatment in DN, to provide a scientific basis for compatibility of Astragalus mongholicus and Pueraria Injection in clinic.Methods:(1) KKAy mice were randomly divided into model and Astragalus mongholicus and Puerarin Injection group. C57BL/6J mice were used to be controls. Puerarin injection combine Astragalus mongholicus injection group were given by peritoneal from twelve weeks old.They were sacrificed at20weeks of age respectively, were taken blood about1ml, GLU. UREA、 CREA、 TG、 TCwere measured.(2) They were sacrificed at20weeks of age respectively,kidneys were sliced and fixed in4%neutral formalin for over24hours, and then embedded in Paraffin、 cut into4-um thick sections for staining with HE、 PAS and Masson methods. Then slides were observed by microscope.(3) Three groups of kidney tissue RNA were extracted with QIAuN,GRP78and XBP1mRNA were detected in renal tissue of mice by real time-PCR.Result:(l)At20weeks of age KKAymice In the model group, the level of blood-glucose, serum creatinine and serum urea was increased, mesangial matrix was increased, glomerular sclerosis was appeared. The cytoplasmic vacuoles in renal tubular epithelial cells were significant; and connective tissue in renal interstitium increased, compared with the normal group. After therapy, the level of blood-glucose, serum creatinine and serum urea was decreased in Astragalus mongholicus and Puerarin Injection group. After therapy, the level of blood-glucose, serum creatinine and serum urea was decreased in Astragalus mongholicus and Puerarin Injection group.(2) The expression of GRP78and XBP1mRNA were upregulated in kidney of KKAy model mice,after treatment of Astragalus mongholicus combines Puerarin injection, GRP78and XBP1mRNA were detected in renal tissue of mice by real time-PCR.Conclusion:(1) Astragalus mongholicus combines Puerarin injection can derate greatly KKAy mice blood glucose levels, restore glucose steady state, Astragalus mongholicus combines Puerarin injection by reducing GRP78and XBP1expression, alleviate diabetic mice body strong endoplasmic reticulum stress.(2) The possible mechanism of Astragalus mongholicus and Puerarin Injection in easing KKAy body strong endoplasmic reticulum stress:By inhibiting the activation of ATF6 induced by the endoplasmic reticulum stress, blocking shearing process of XBP1to IRE1induced by ATF6, Make the generation of bioactive XBP1-S decreases, slow down overpowered endoplasmic reticulum stress of diabetes, thus increasing the of sensitiity of insulin, reducing blood glucose levels. GRP78symbol factor of endoplasmic reticulum stress, decreases with slowing down of the endoplasmic reticulum stress.