白血病抑制因子通过乙酰化STAT3抑制肾间质纤维化的研究

Inhibitory of renal interstitial fibrosis by acetylation of STAT3 with white cell inhibitor

目的研究白血病抑制因子(leukemia inhibitory factor,LIF)对肾间质纤维化的作用及其机制。方法TGF-β和(或)LIF和(或)TSA刺激肾脏成纤维细胞(NRK-49F);TGF-β和(或)LIF刺激Stat3基因敲除细胞(MEF-Stat3-KO);用KM小鼠建立单侧输尿管梗阻(unilateral ureteral obstruction,UUO)模型,腹腔内注射LIF后收集肾脏;用Western Blot方法检测纤维化相关性蛋白(Col3和FN1)和乙酰化Stat3的表达,用RT-PCR方法检测Col3和FN1的mRNA表达,用免疫组化方法检测肾脏组织的Col3、FN1和LIFR、Stat3的沉积。结果在NRK-49F细胞中,LIF降低TGF-β诱导的Col3和FN1的表达;在Stat3-KO细胞中,LIF对Col3和FN1的表达无作用。UUO肾脏中,LIFR和Stat3的表达较假手术组明显减少,LIF注射后Col3和FN1的沉积减少。LIF刺激NRK-49F细胞15 min后,乙酰化Stat3明显增多;TSA刺激细胞后,Col3和FN1的表达降低更加明显。结论 LIF抑制体内外肾间质纤维化,依赖于Stat3,其机制可能包括乙酰化修饰。

Objective To investigate the effect of leukemia inhibitory factor（LIF） on renal interstitial fibrosis and its mechanism. Methods Renal fibroblasts （NRK-49F） were stimulated with TGF-beta and/or LIF, and/or TSA. Stat3 gene knockout cells （MEF-Stat3-KO） were stimulated with TGF-beta and/or LIF. Unilateral ureteral obstruction （UUO） was induced in KM mice and kidneys were collected after intraperitoneal injection of LIF. Western Blot method was used to detect protein expression of collagen 3, fibronectin and acetylated Stat3. RT-PCR method was used to detect mRNA expression of collagen 3 and Fibronectin, and immunohistochemical method was used to detect protein deposition of collagen 3, fibronectin, LIFR and Stat3 in kidney tissue. Results In NRK-49F cells, LIF inhibited TGF-beta-induced Col3 and FN1 expression. In Stat3-KO cells, LIF had no effect on the expression of Co13 and FN1. In UUO kidney, the expression of LIFR and Stat3 decreased significantly compared with that in the control group; after injection of LIF, the deposition of Co13 and FN1 reduced. After stimulation with LIF for 15 min, acetylated Stat3 in NRK-49F cells increased significantly. TSA stimulation reduced the expression of Co13 and FN1 more markedly. Conclusion LIF can inhibit renal interstitial fibrosis both in vitro and in vivo, which may be associated with the acetylation of Stat3.