论文部分内容阅读
目的探讨高脂喂食诱导的肥胖大鼠肾周脂肪与肾脏病变的关系及替米沙坦干预的影响和可能作用机制。方法给予20只8周龄雄性Wistar大鼠高脂喂食12周,另取体质量、周龄匹配雄性Wistar大鼠20只,给予普通喂食12周。高脂喂食大鼠中肥胖大鼠造模成功14只,随机分为高脂组(n=7)和高脂治疗组(n=7),分别给予高脂喂食和高脂+替米沙坦8mg/(kg·d)。普通喂食的Wistar大鼠中抽取14只分为普食组(给予标准大鼠饲料)和普食治疗组[标准大鼠饲料+替米沙坦8mg/(kg·d)],每组7只。替米沙坦干预20周后,比较各组大鼠肾功能(尿素氮、肌酐及尿蛋白),同时行肾脏组织切片及苏木素伊红并过碘酸雪夫染色,比较各组大鼠肾脏病理积分;利用Western blot方法检测各组大鼠肾周脂肪组织过氧化物酶体增殖物激活受体γ(PPAR-γ)、脂肪细胞型脂肪酸结合蛋白(aP2)、瘦素及脂联素表达水平;酶联免疫吸附试验检测各组大鼠肾周脂肪组织肿瘤坏死因子(TNF)α表达水平;Real-time聚合酶链反应检测各组大鼠肾周脂肪组织单核细胞趋化蛋白1(MCP-1)及白细胞介素6(IL-6)表达水平。并用各组大鼠肾周脂肪组织制备条件培养基,利用条件培养基培养肾小球内皮细胞及系膜细胞,四甲基偶氮唑盐比色法(MTT)检测细胞增殖情况。结果在32周的实验终点,与普食组相比,高脂组大鼠尿素氮[(20.73±1.29)比(6.36±0.33)mmol/L]、肌酐[(145.32±5.98)比(68.42±4.77)μmol/L]、24h尿蛋白[(312.74±5.51)比(30.14±2.15)mg]增高(均P<0.05)。高脂组大鼠肾周脂肪组织PPAR-γ及aP2表达下降,伴随脂联素表达下降,瘦素、TNF-α、MCP-1及IL-6表达上升(均P<0.05);替米沙坦干预后,刺激PPAR-γ及aP2表达,升高脂联素,降低瘦素、TNF-α、MCP-1及IL-6表达(均P<0.05)。体外实验方面,和普食组大鼠肾周脂肪制备的条件培养基相比,高脂组大鼠肾周脂肪制备的条件培养基培养的肾小球内皮细胞及系膜细胞增殖明显升高(均P<0.05),而在替米沙坦治疗后明显降低(均P<0.05)。普食组与普食治疗组大鼠上述观察指标差异均无统计学意义。结论高脂喂食诱导的肥胖大鼠肾周脂肪组织功能障碍促进肾损害的发生,替米沙坦可以促进高脂喂食诱导的肥胖大鼠肾周脂肪组织脂肪细胞分化,增加保护性脂肪因子(脂联素)分泌,减少脂肪细胞炎症因子(TNF-α)及趋化因子(MCP-1及IL-6)表达,并且降低有害的脂肪因子(瘦素)分泌,最终通过改善肾周脂肪组织功能而产生肾保护作用。
Objective To investigate the relationship between perirenal fat and nephropathy induced by high-fat diet and the effect of telmisartan and its possible mechanism. Methods Twenty male Wistar rats of 8 weeks old were fed with high fat diet for 12 weeks. Twenty healthy male Wistar rats were matched by age and age, and were given normal feeding for 12 weeks. Fourteen obese rats were randomly divided into high fat diet group (n = 7) and high fat diet group (n = 7), and were given high fat diet and high fat diet + telmisartan 8 mg / (kg · d). Fourteen normal Wistar rats were divided into four groups: normal group (given standard rat feed) and general diet group (standard rat fed + telmisartan 8 mg / (kg · d)], 7 in each group . Twenty weeks after the intervention of telmisartan, the renal function (urea nitrogen, creatinine and urinary protein) of rats in each group were compared, and the renal tissue sections and hematoxylin eosin The expression of peroxisome proliferator-activated receptor γ (PPAR-γ), aP2, leptin and adiponectin in perirenal adipose tissue were detected by Western blot. Enzyme-linked immunosorbent assay was used to detect the expression of tumor necrosis factor (TNF) α in perirenal adipose tissue of rats in each group. Real-time polymerase chain reaction was used to detect the expression of monocyte chemoattractant protein-1 (MCP- 1) and interleukin 6 (IL-6) expression levels. Conditioned media was prepared from perirenal adipose tissue of rats in each group. Glomerular endothelial cells and mesangial cells were cultured in conditioned medium. Cell proliferation was detected by MTT assay. Results Compared with the control group, the levels of urea nitrogen ([(20.73 ± 1.29) vs (6.36 ± 0.33) mmol / L] and creatinine [(145.32 ± 5.98) vs 68.42 ± 4.77 μmol / L] and 24 h urine protein [(312.74 ± 5.51) vs (30.14 ± 2.15) mg], respectively (all P <0.05). The expressions of leptin, TNF-α, MCP-1 and IL-6 in perirenal adipose tissues of high-fat diet group were decreased (P <0.05) After intervention with Tan, the expression of PPAR-γ and aP2 were stimulated, adiponectin was increased, and the expressions of leptin, TNF-α, MCP-1 and IL-6 were decreased (all P <0.05). In vitro experiments, the proliferation of glomerular endothelial cells and mesangial cells cultured in perinatal adipose conditioned medium was significantly increased in rats fed with high fat diet as compared with that in normal diet rats All P <0.05), but significantly decreased after treatment with telmisartan (all P <0.05). There was no significant difference in the above indexes between the general diet group and the general diet group. Conclusion The renal dysfunction caused by perirenal adipose tissue in obese rats induced by high-fat diet can promote renal damage. Telmisartan can promote adipocyte differentiation of perirenal adipose tissue in obese rats induced by high-fat diet and increase the content of protective adipokines Reduce the secretion of adipocyte inflammatory cytokines (TNF-α) and chemokines (MCP-1 and IL-6), and reduce the secretion of harmful adipokines (leptin), and finally improve the function of perirenal adipose tissue And produce renal protection.