Effects Of Valsartan On Apoptosis Of Diabetic Rat Kidney By JNK Pathway

Objective: Diabetic Kidney Disease (DKD) is common and difficult complications of microvascular to Diabetes Mellitus(DM). It is reported that about 20% to 40% of the diabetic complication occurs, if not early detected and treated, ultimately leading to end-stage renal disease(ESRD), of which 5% to 8% of patients died of uremia. Therefore, the effective prevention and treatment of DKD has become an important issue. AngiotensinⅡ(AngⅡ) diabeticplays an important role in the development of DKD. Valsartan, the AngⅡreceptor antagonist ARB can be completely blocked at the receptor level. The current anti-diabetic rats Valsartan renal cell apoptosis and its role in the c-Jun N-terminal kinase (c-Jun N-terminal kinase, JNK) pathway relationship are rarely reported. Application of this topic diabetic rat in the experiment,and the 4th and the 8th are the first experimental detection of blood biochemistry weekend, 24h urinary protein, detection of apoptosis in diabetic rats signal-regulated kinase (apoptosis signaling regulation kinase1, ASK1), MKK7, JNK and phosphorylated c-Jun N-terminal kinase (c-Jun N-terminal kinase phosphorylation, p-JNK) expression, and to valsartan, to explore the kidney of diabetic nephropathy and its mechanism of protection .Methods:Clean 45 Wistar rats, adaptive feeding for a week, 10 are randomly selected as normal control group (N group), the remaining 35 are used to prepare animal models of type 1 diabetes by using intraperitoneal injection of STZ (streptozotocin, STZ, dissolved in 0.1mol / L citrate buffer, pH = 4.5,60 mg / kg), and the control group only inject it with citrate salt buffer, 72 h after the blood from the tip of the tail, blood glucose≥16.7 mmol / L were identified successful diabetes models, and then randomly divided into two groups: 17 for DM, and 17 for T group (1 rats during the experiment was not successful modeling discarded). T group valsartan 10mg/kg ? d orally dissolved in distilled water immediately after the completion of the diabetic, while group N and group DM are given distilled water orally. During the experiment,all rats have free access to water and food, and the rats do not use insulin and other hypoglycemic drugs. All rats are weighed once a week, and are measured blood glucose in the 4th week and the 8th week, with 24-hour urine collection. Half of the rats which are fed group are killed in the 4th and the 8th week, test blood glucose (Glu), triglyceride (TG), total cholesterol (CHOL), creatinine (Scr), blood urea nitrogen (BUN), uric acid (UA), serum albumin (ALB), low density lipoprotein (LDL), high density lipoprotein (HDL);and 24-hour urine protein is measured.Observe the kidney by following methods:detected by immunohistochemistry in renal tissue of the ASK1, JNK, p-JNK expression;western blotting measuring the ASK1, MKK7, JNK, p-JNK protein.flow cytometry method for measuring apoptosis.Collect and organize experimental data, using statistical analysis software SPSS13.0.Results:1.Weight the rats before the experiment, baseline glucose is no significant difference (p>0.05), together with the conditions.2.Only in 8 weeks the UPRO that in group DM and group T has been significantly increased than N group,while group T has less than group DM(P<0.05).3.Changes in body weight and kidney weight index: the weight in group DM and group T has significantly reduced at the 8th week and kidney weight index is significantly increased ,compared with group N (P<0.01),while group T has less weight compared with group DM; group DM and group N is significantly increased in renal weight index at the end of the 8th week(P<0.01), group T is decreased in kidney weight index compared with group DM , but still higher than group N (P<0.01);4.Renal function test: BUN, Scr, UA comparison in the 4th and the 8th week: group DM, group T and group N has no significant difference between in each index in the the same period (P>0.05); 5.Immunohistochemistry resultsASK1: ASK1 of group N is weak in the 4th week, mainly in the distal part of the main renal cortex;ASK1 is not limited to tubular group DM in the 4 the week, and some glomeruli are also seen weaker ,compared with group N, with a significant increase statistically (p<0.05); at the end of the 8th week, cortical tubular and glomerular of ASK1 have increased in group DM ,and tubular has increased more significantly, which tends to diffuse distribution, compared with group N is significant statistically (p<0.05); over time,ASK1 of group T has approximately the same trend with group DM compared with group N and in the 4th week it has creased less than group DM ,which is statistically significant (p<0.05); but in the 8th week, it has a statistically significant decrease ,compared with group DM (p<0.05);JNK, and p-JNK: JNK can almost not be expressed in normal renal tissue (N) ,but in group DM and group T can be showed in renal tubular; p-JNK is expressed very small in normal renal tissue (N),but in group DM and group T are visible over time, and can also be found a small amount in glomerular . DM in the 4th week is significantly higher than N (P<0.05), but T ,which is lower than DM ,has no statistical significance; in the 8th week DM is significantly higher than N (P<0.05), T is lower than DM but higher than N ,which was statistically significant (P<0.05);6.Western blotting resultsASK1: N is a little less, DM is more than N in the 4th and 8th week; and T is more than N but less than DM in the same period ,which are all statistically significant(P<0.05).MKK7: In the 4th week, group DM, group T and group N has no significant difference between in each index(P>0.05);In the 8th week, DM has rapid increase than N, T is more than N, but less than DM, which is statistically significant (P<0.05).JNK: group DM and group T have no significant difference from group N in the 4th week; when group DM increase more than group N, group T decreased compared with group DM in the 8th week ,which has a statistically significant difference (P<0.05), but no difference, compared with group N (P> 0.05);p-JNK:there is no significant difference betweenthe 3 groups in the 4th week; while in the 8th week DM and T are significantly higher than N ,which has a statistically significant difference (P <0.05); T has reduced than DM , which is statistically significant (P <0.05);7.Apoptosis rate by flow cytometry methodIn the 4th week, apoptosis rate of nephridial tissue in group DM is higher than that in group N (P <0.05), group T has a lower apoptosis rate, compared to group DM, which is statistically significant (P <0.05), and has no signifi- cant difference compared with group N ; In the 8th week, apoptosis rate of nephridial tissue in group DM is higher and clearer than that in group N (P <0.05), and group T is significantly decreased in apoptosis rate, compared with group DM,which is statistically significant (P <0.05), and group T is higher than that in group N as for the apoptosis rate ,which is s statistically significant (P<0.05).8.The correlation analysis of MKK7, JNK, p-JNK, ASK1 with apoptotic : the correlation coefficient of MKK7,JNK,p-JNK,ASK1 with apoptotic separa- tely are r = 0.908, 0.838, 0.870, 0.861(P<0.05).Conclusion: the development of diabetic nephropathy, the kidney ASK1, MKK7, JNK, p-JNK expression were increased, suggesting that they may be involved in the pathogenesis of diabetic kidney disease, and application of val- sartan significantly after its expression could be weakened by the JNK path- way induced apoptosis rates were also reduced, suggesting that valsartan may inhibit the activation of JNK pathway, thereby inhibiting apoptosis, play a pro- tective effect on the kidneys.