Effects Of Irbesartan On The Expression Of MiR-192 In Kidney Of DN Rats And Its Role In Renal Protection

Objective: To observe the effects of Irbesartan on the expressions of miR-192,TGF-beta 1,Zeb1 and Collagen I in the kidneys of streptozotocin-induced diabetic nephropathy(DN)rats,and to explore the possible mechanism of Irbesartan in the treatment of DN.Methods: 1.Experimental grouping and establishment of DN rat model:10-week-old male Wistar rats were randomly divided into normal control group,DN model group and Irbesartan treatment group.DN rat model was established by STZ(28mg/kg).The treatment group was given Irbesartan 50mg/kg daily,while the normal group and the model group were given the same amount of saline.2.Main indicators and detection methods: At the age of 22 weeks,rats in each group were sacrificed and their body weight,random blood sugar,urinary microalbumin,serum creatinine and urea nitrogen were measured.HE and Masson staining were used to observe the morphological changes of kidney tissue under light microscope.Total renal miRNA was extracted.The expression of miR-192 in rat kidney tissue was detected by real-time fluorescence quantitative PCR,and the relative expression was calculated.The expression of TGF-beta 1,Zeb1 and Collagen I in rat kidney were detected by Western blotting and immunohistochemistry.Results:1.The protective effect of Irbesartan on kidney damage in DN rats:Compared with the normal group,the body weight,random blood sugar,serum creatinine,urea nitrogen and urinary albumin excretion rate of the model group rats were significantly higher(all P < 0.05);compared with the model group,the urinary albumin excretion rate of the Irbesartan treatment group rats were significantly lower(P < 0.05),and Irbesartan treatment could improve the general situation of DN rats.2.HE and Masson staining of renal histopathology showed no pathological changes of diabetic nephropathy in the normal control group.In DN model group,glomerulus was lobulated,mesangial area was widened,mesangial matrix was increased,granular and vacuolar degeneration could be seen in tubular epithelial cells.Compared with the model group,the pathological changes of renal tissue in the Irbesartan treatment group were improved.3.Realtime-PCR results showed that:(1)Compared with the normal control group,the expression of miR-192 in the kidney of DN rats in DN model group was down-regulated(P < 0.05).(2)Compared with DN model group,the expression of miR-192 was up-regulated in Irbesartan group(P < 0.05).4.The expression of TGF-beta 1,ZEB1,Collagen I protein:The results of WB and immunohistochemistry showed that the expression of TGF-beta 1,ZEB1 and Collagen I in kidney tissue of DN model group increased significantly compared with that of normal rats(P < 0.05);compared with the model group,Irbesartan treatment could reduce the expression of TGF-beta 1,ZEB1 and Collagen I protein significantly(P < 0.05).Conclusion:In this study,we studied the animal model of DN,suggesting that miR-192 participates in the occurrence and development of DN,and proved once again that Irbesartan has the effect of treating DN and protecting kidney.The therapeutic mechanism of Irbesartan on DN may be related to up-regulating the expression of miR-192,reducing the expression of TGF-beta 1 and Zeb1 in its signaling pathway,thereby reducing the deposition of Collagen I in kidney tissue and improving the fibrosis of DN.Improvement of kidney pathology is related.It provides a new experimental and theoretical basis for Irbesartan in the clinical treatment of DN at the molecular level.