ACE2内源性激动剂DIZE对糖尿病肾病大鼠的保护作用

目的:观察血管紧张素转换酶2(ACE2)内源性激动剂乙酰甘氨酸重氮氨苯脒(DIZE)对糖尿病肾病(DN)大鼠的保护作用。方法:30只Wistar大鼠随机分为正常对照组(NC组)、DN组和DIZE处理组(DIZE组)。DN组与DIZE组一次性腹腔注射链脲佐菌素(65 mg/kg)建立糖尿病模型,12周后糖尿病肾病大鼠模型建立后给予DIZE 15 mg·kg~(-1)·d~(-1)或等量生理盐水皮下注射4周处理。16周末称量体重和肾重,计算肾质量体质量比(KW/BW),收集血、尿标本,检测血糖(GLU)、24 h尿蛋白(24UP)及血清肌酐(SCr)等指标。通过PAS染色观察各组肾脏病理变化;ELISA法检测大鼠AngⅡ、Ang-(1-7)、TGF-β1及VCAM-1水平的变化;通过免疫组化观察collagenⅠ和FN蛋白表达的变化;利用实时荧光定量PCR(RT-qPCR)技术检测大鼠肾组织collagenⅠ和FN mRNA含量的变化;Western blot观察各组大鼠ACE2蛋白表达的变化。结果:DIZE显著提高了糖尿病大鼠ACE2的表达(P0.05),降低了糖尿病大鼠血浆AngⅡ含量(P0.05),提高了Ang-(1-7)的水平(P0.05)。与NC组大鼠相比,DN组与DIZE组大鼠的24UP、SCr和KW/BW明显升高(P0.05),collagenⅠ和FN mRNA水平及蛋白表达量增加,肾脏组织TGF-β1及VCAM-1明显上升(P0.05)。DIZE组与DN组大鼠相比,24UP和SCr水平降低(P0.05),GLU和KW/BW无明显差异,collagenⅠ和FN mRNA含量及蛋白表达量减少,肾脏组织TGF-β1及VCAM-1水平降低(P0.05)。结论:ACE2内源性激动剂DIZE显著提高了ACE2的活性,增加了Ang-(1-7)的含量,从而降低了肾脏纤维化及炎症水平,并对糖尿病肾病大鼠起到保护性作用。

Protective effect of DIZE,an ACE2 activator,on rats with streptozotocin-induced diabetic nephropathy

AIM: To observed the protective effect of diminazene aceturate (DIZE), an angiotensin-converting enzyme 2 (ACE2) activator, on diabetic nephropathy (DN) rats. METHODS: Male Wistar rats (n=30) were randomly divided into normal control (NC) group, DN group and DIZE group (each group consisted of 10 rats). The rats in DN group and DIZE group were induced by intraperitoneal injection of streptozotocin at dose of 65 mg/kg. After 12 weeks, the rats in DIZE group and DN group received subcutaneous injection of DIZE (15 mg·kg^-1·d^-1) or vehicle for 4 weeks. The samples of blood and urine were collected at week 16, and ratio of kidney weight to body weight (KW/BW), plasma glucose (GLU), 24 h urinary protein (24UP) and serum creatinine (SCr) were measured. The renal pathological changes in each group were observed by periodic acid-Schiff (PAS) staining and immunohistochemistry. The levels of AngⅡ and Ang-(1-7) in the plasma, and TGF-β1 and VCAM-1 in the renal tissues were measured by ELISA. The mRNA and protein levels of collagen I and FN were determined by quantification real-time PCR and immunohistochemistry. The effects of DIZE on the expression of ACE2 in DN rats were determined by Western blot. RESULTS: DIZE remarkably increased the expression of ACE2 and Ang-(1-7) in DN rats. Compared with NC group, the GLU, KW/BW, 24UP, SCr, and the expression of collagen I, FN, TGF-β1 and VCAM-1 in DN group and DIZE group were increased. However, after treatment of the DN rats with DIZE, these indicators were decreased except the KW/BW. The GLU showed no significant change. CONCLUSION: DIZE raised the activity of ACE2 and increased the expression of Ang-(1-7), thus alleviating fibrosis and inflammation in the kidney and having therapeutic potential for diabetic nephropathy.