敲除核因子E2相关因子对肾肌成纤维细胞活化与纤维化的影响

目的：研究敲除核因子E2相关因子（Nrf2）对肾组织中肌成纤维细胞的活化及间质纤维化的影响。方法：将实验小鼠分成Nrf2野生型假手术组、Nrf2野生型单侧输尿管梗阻（UUO）组、Nrf2敲除型假手术组、Nrf2敲除型UUO组4个小组，每组6只。生化分析仪检测血肌酐和尿素氮水平；糖原染色（PAS）观察肾组织损伤程度；Masson染色评价肾间质总胶原累积情况；免疫组织化学染色分析肌成纤维细胞标志物α-SMA、基质成分III型胶原及TGF-β1的表达；RT-qPCR检测TGF-β1 mRNA的表达。结果：与Nrf2野生型假手术组比，Nrf2野生型UUO组血肌酐和尿素氮水平明显升高（P＜0.05）。Nrf2敲除型UUO组血肌酐和尿素氮水平与Nrf2野生型UUO组相比，差异无统计学意义（P＞0.05）。PAS染色显示，与Nrf2野生型UUO组相比，Nrf2敲除型UUO组肾组织损伤明显加剧（P＜0.01）。Masson染色显示，与Nrf2野生型UUO组相比，Nrf2敲除型UUO组肾间质总胶原累积明显增加（P＜0.01）。免疫组织化学染色显示，与Nrf2野生型UUO组相比，Nrf2敲除型UUO组肾组织α-SMA和III型胶原的表达明显增加（P＜0.05），而这可能与Nrf2敲除所致的TGF-β1 mRNA和蛋白表达提高有关（P＜0.05）。结论：Nrf2敲除可加剧输尿管梗阻引起的肾损伤及纤维化程度，其机制可能为Nrf2敲除通过提高TGF-β1水平，进而促进肌成纤维细胞过度活化和胶原在肾间质的过度累积。

The knockout of nuclear factor E2 related factor and its effect on myofibroblast activation and renal fibrosis

Objective: To investigate the knockout of nuclear factor E2 related factor (Nrf2) and its effect on the activation of renal myofibroblasts and interstitial fibrosis. Methods: Mice were randomly divided into four groups: Nrf2-wild-type sham group, Nrf2-knock-out sham group, Nrf2-wild-type unilateral ureteral obstruction (UUO) group and Nrf2-knock-out UUO group, with 6 mice in each group. The levels of serum creatinine and urea nitrogen were determined by biochemical analyzer; Periodic acid-Schiff staining (PAS) was used to observe the degree of renal damage; Masson staining was used to evaluate the accumulation of total collagen in renal interstitium; immunohistochemical staining was used to analyze the expression levels of myofibroblastic marker α-SMA, matrix component type III collagen and transforming growth factor β1 (TGF-β1); qRT-PCR was used to detect the mRNA expression of TGF-β1. Results: Compared with the Nrf2-wild-type sham group, the serum creatinine and urea nitrogen levels in the Nrf2-wild-type UUO group were significantly increased (P<0.05). There was no significant difference in serum creatinine and urea nitrogen levels between the Nrf2-wild-type UUO group and the Nrf2-knock-out UUO group (P>0.05). PAS staining showed that renal tissue damage was significantly aggravated in the Nrf2-knock-out UUO group (P<0.01), compared with the Nrf2-wild-type UUO group; Masson staining showed that total accumulation of renal interstitial collagen in the Nrf2-knock-out UUO group was significantly increased (P<0.01), compared with the Nrf2-wild-type UUO group; immunohistochemical staining showed that the expression of α-SMA and type III collagen in renal tissue of Nrf2-knock-out UUO group was significantly increased (P<0.05), compared with the Nrf2-wild-type UUO group, which was related to TGF-β1 mRNA and protein expression caused by Nrf2 knockout (P<0.05). Conclusion: Nrf2 knockout can aggravate the degree of renal injury and fibrosis caused by ureteral obstruction. Its mechanism may be related to Nrf2 knockout that increases TGF-β1 levels, resulting in excessive activation of myofibroblasts and collagen accumulation in renal interstitium.