论文部分内容阅读
目的通过观察脂氧素A4(LXA4)对链脲佐菌素(STZ)诱导的糖尿病大鼠肾小管上皮细胞Smad7/3、转化生长因子β1(TGF-β1)蛋白水平,及其对TGF-β1诱导的肾小管上皮细胞Smad7/3、Notch-1蛋白水平的影响,探讨LXA4对糖尿病大鼠肾小管上皮细胞纤维化的潜在保护作用。方法雄性SD大鼠随机分为对照组(Con,n=10)、糖尿病组(DM,n=10)、糖尿病+LXA4组(DM+LXA4,n=10),DM+LXA4组以1mg/kg体质量的LXA4隔日1次尾静脉注射,连续8周;肾小管上皮细胞分为Con组、TGF-β1诱导组、LXA4组以及TGF-β1+LXA4组。免疫组织化学法及Western blot法观察STZ诱导的糖尿病大鼠肾小管上皮细胞Smad7/磷酸化Smad3(p-Smad3)及TGF-β1的蛋白水平,并观察LXA4对TGF-β1诱导的肾小管上皮细胞Smad7、p-Smad3及Notch-1的蛋白水平。结果DM+LXA4组Smad7阳性面积率高于DM组及Con组[(24.18±1.38)%vs(18.56±1.13)%,(24.18±1.38)%vs(21.80±1.82)%,P<0.001]。p-Smad3及TGF-β1阳性面积率率低于DM组[(14.17±1.18)%vs(17.89±2.62)%,(20.53±0.83)%vs(24.91±1.82)%,P<0.05或P<0.001],但高于Con组[(14.17±1.18)%vs(12.68±1.33)%,(20.53±0.83)%vs(18.14±1.48)%,P<0.001]。LXA4组尿白蛋白、Ⅳ型胶原(TⅣC)及TGF-β1排泄率低于DM组[(46.90±17.65)vs(70.60±14.99)mg/g,(87.40±16.25)vs(149.30±15.13)μg/ml,(53.60±14.74)vs(125.70±32.22)pg/ml,P<0.001],但高于Con组[(46.90±17.65)vs(16.70±3.34)mg/g,(87.40±16.25)vs(32.00±10.58)μg/ml,(53.60±14.74)vs(27.10±3.38)pg/ml,P<0.001]。LXA4抑制TGF-β1诱导的肾小管上皮细胞p-Smad3、和Notch-1的蛋白水平,上调Smad7的表达(P<0.01)。结论LXA4可以通过上调Smad7、下调p-Smad3、TGF-β1及Notch-1的蛋白水平,预防肾小管上皮细胞纤维化,具有潜在防治TIDM肾病的作用。
Objective To observe the effect of lipoxin A4 (LXA4) on the protein levels of Smad7 / 3 and TGF-β1 in renal tubular epithelial cells induced by streptozotocin (STZ) in diabetic rats and its effect on the expression of TGF-β1 Induced renal tubular epithelial cells Smad7 / 3, Notch-1 protein levels, to explore the potential protective effect of LXA4 on renal tubular epithelial cell fibrosis in diabetic rats. Methods Male Sprague-Dawley rats were randomly divided into control group (Con, n = 10), DM group (n = 10), DM + LXA4 group The body weight of LXA4 was injected intravenously once a day for 8 weeks. The renal tubular epithelial cells were divided into Con group, TGF-β1-induced group, LXA4 group and TGF-β1 + LXA4 group. The protein levels of Smad7 / phospho-Smad3 (p-Smad3) and TGF-β1 in renal tubular epithelial cells of STZ-induced diabetic rats were detected by immunohistochemistry and Western blot. The effects of LXA4 on the expression of TGF-β1-induced renal tubular epithelial cells Smad7, p-Smad3 and Notch-1 protein levels. Results The positive rate of Smad7 in DM + LXA4 group was significantly higher than that in DM group and Con group [(24.18 ± 1.38)% vs (18.56 ± 1.13)%, (24.18 ± 1.38)% vs (21.80 ± 1.82)%, P <0.001]. The positive rates of p-Smad3 and TGF-β1 were lower than those in DM group [(14.17 ± 1.18)% vs (17.89 ± 2.62)% vs (20.53 ± 0.83)% vs (24.91 ± 1.82)%, P <0.05 or P < 0.001], but higher than that in Con group [(14.17 ± 1.18)% vs (12.68 ± 1.33)%, (20.53 ± 0.83)% vs (18.14 ± 1.48)%, P <0.001). The urinary albumin, type Ⅳ collagen and TGF-β1 excretion rate in LXA4 group were lower than those in DM group [(46.90 ± 17.65) vs (70.60 ± 14.99) mg / g, (87.40 ± 16.25) vs (149.30 ± 15.13) μg / (53.60 ± 14.74) vs (12.70 ± 32.22) pg / ml, P <0.001, but higher than that in Con group [(46.90 ± 17.65) vs (16.70 ± 3.34) mg / g vs (87.40 ± 16.25 vs (32.00 ± 10.58) μg / ml, (53.60 ± 14.74) vs (27.10 ± 3.38) pg / ml, P <0.001]. LXA4 inhibited TGF-β1-induced tubular epithelial cells p-Smad3 and Notch-1 protein levels, up-regulated Smad7 expression (P <0.01). Conclusion LXA4 can prevent renal tubular epithelial cell fibrosis by up-regulating Smad7, down-regulating the protein level of p-Smad3, TGF-β1 and Notch-1, and has the potential to prevent and treat TIDM nephropathy.