Department of Pediatrics, First Hospital of China Medical University, Shenyang, 110001, China.
J Transl Med. 2022 Jan 29;20(1):54. doi: 10.1186/s12967-022-03265-2.
Chronic kidney disease (CKD) is characterized by high morbidity and mortality and is difficult to cure. Renal interstitial fibrosis (RIF) is a major determinant of, and commonly occurs within, CKD progression. Epithelial mesenchymal transition (EMT) has been identified as a crucial process in triggering renal interstitial fibrosis (RIF). Interleukin-like EMT inducer (ILEI) is an important promotor of EMT; this study aims to elucidate the mechanisms involved.
Male C57BL6/J mouse were randomly divided into 6 groups: sham (n = 10), sham with negative control (NC) shRNA (sham + NC, n = 10), sham with ILEI shRNA (sham + shILEI, n = 10), unilateral ureteral obstruction (UUO, n = 10), UUO with NC (UUO + NC, n = 10) and UUO with ILEI shRNA (UUO + shILEI, n = 10). Hematoxylin and eosin (H&E), Masson, and immunohistochemical (IHC) staining and western blotting (WB) were performed on murine kidney tissue to identify the function and mechanism of ILEI in RIF. In vitro, ILEI was overexpressed to induce EMT in HK2 cells and analyzed via transwell, WB, real-time PCR, and co-immunoprecipitation. Finally, tissue from 12 pediatric CKD patients (seven with RIF and five without RIF) were studied with H&E, Masson, and IHC staining.
Our in vitro model revealed that ILEI facilitates RIF in the UUO model via the Akt and ERK pathways. Further experiments in vivo and in vitro revealed that ILEI promotes renal tubular EMT by binding and activating leukemia inhibitory factor receptor (LIFR), in which phosphorylation of Akt and ERK is involved. We further find markedly increased expression levels of ILEI and LIFR in kidneys from pediatric CKD patients with RIF.
Our results indicate that ILEI may be a useful biomarker for renal fibrosis and a potential therapeutic target for modulating RIF.
慢性肾脏病（CKD）具有高发病率和死亡率，且难以治愈。肾间质纤维化（RIF）是 CKD 进展的主要决定因素，并且通常发生在 CKD 进展过程中。上皮间质转化（EMT）已被确定为触发肾间质纤维化（RIF）的关键过程。白细胞介素样 EMT 诱导剂（ILEI）是 EMT 的重要促进剂；本研究旨在阐明相关机制。
雄性 C57BL6/J 小鼠随机分为 6 组：假手术组（n=10）、假手术+阴性对照（NC）shRNA 组（sham+NC，n=10）、假手术+ILEI shRNA 组（sham+shILEI，n=10）、单侧输尿管梗阻（UUO）组（n=10）、UUO+NC 组（UUO+NC，n=10）和 UUO+ILEI shRNA 组（UUO+shILEI，n=10）。对鼠肾组织进行苏木精和伊红（H&E）、马松和免疫组织化学（IHC）染色和 Western blot（WB），以鉴定 ILEI 在 RIF 中的作用和机制。在体外，过表达 ILEI 诱导 HK2 细胞 EMT，并通过 Transwell、WB、实时 PCR 和共免疫沉淀进行分析。最后，对 12 名儿科 CKD 患者（7 名有 RIF，5 名无 RIF）的组织进行 H&E、马松和 IHC 染色。
我们的体外模型表明，ILEI 通过 Akt 和 ERK 通路促进 UUO 模型中的 RIF。进一步的体内和体外实验表明，ILEI 通过与白血病抑制因子受体（LIFR）结合和激活促进肾小管 EMT，其中涉及 Akt 和 ERK 的磷酸化。我们还发现，在有 RIF 的儿科 CKD 患者的肾脏中，ILEI 和 LIFR 的表达水平明显升高。
我们的结果表明，ILEI 可能是肾纤维化的有用生物标志物，也是调节 RIF 的潜在治疗靶点。
