Department of Organ Transplantation, Renmin Hospital of Wuhan University, Wuhan 430060, China.
Department of Nephrology, The First Clinical Medical College of Three Gorges University, Center People's Hospital of Yichang, Yichang, Hubei 443000, China.
Int Immunopharmacol. 2022 Aug;109:108904. doi: 10.1016/j.intimp.2022.108904. Epub 2022 Jun 11.
Acute kidney injury (AKI) is a critical and severe clinical disease caused by a variety of factors. Toll-like receptors (TLRs) play a crucial role in pathogenesis of AKI. Radioprotective 105 kDa protein (RP105) is a member of the TLR family, but the role of RP105 in AKI is unknown. In this study, we overexpressed RP105 in renal tissue and cultured proximal tubular cells in which we then induced ischemic and septic AKI. Renal structure injuries were examined by hematoxylin eosin staining, while renal function was assessed by measuring serum blood urea nitrogen (BUN) and creatinine (SCr) levels. The TUNEL assay was used to detect apoptosis induced changes in the expression of RP105, and nuclear factor κB (NF-κB) in renal tissue detected by Western blot. Inflammatory cytokines including iNOS, IL-1β, IL-6, and TNF-α were detected by quantitative real-time PCR. The inflammatory indicators, F4/80 and MPO, were identified by IHC staining. The results showed that expression of the TLR4/NF-kB signaling pathway was enhanced in renal ischemia-reperfusion injury and septic renal injury, and that overexpression of RP105 in renal tissue alleviated ischemic and septic AKI. Moreover, RP105 gene delivery was associated with reduced renal inflammatory cells infiltration and inflammatory cytokines after AKI. RP105 overexpression also inhibited nuclear translocation of NF-κB after AKI in both in vitro and in vivo, and blunted the interaction between Myeloid Differentiation factor 2 (MD2) and TLR4. These results indicated that RP105 protected against renal ischemic and septic AKI injury by suppressing inflammatory responses mediated by TLR4 signaling pathways. This study suggests that the anti-inflammatory roles of RP105 have potential for preventing and treating renal ischemic and septic AKI.
急性肾损伤（AKI）是由多种因素引起的一种严重的临床疾病。Toll 样受体（TLRs）在 AKI 的发病机制中起着至关重要的作用。辐射保护 105kDa 蛋白（RP105）是 TLR 家族的一员，但 RP105 在 AKI 中的作用尚不清楚。在本研究中，我们在肾组织中过表达 RP105，并在培养的近端肾小管细胞中诱导缺血性和脓毒性 AKI。通过苏木精-伊红染色检查肾结构损伤，通过测量血清血尿素氮（BUN）和肌酐（SCr）水平评估肾功能。通过 TUNEL 检测评估 RP105 表达诱导的细胞凋亡变化，通过 Western blot 检测肾组织中核因子 κB（NF-κB）的表达。通过定量实时 PCR 检测炎性细胞因子，如诱导型一氧化氮合酶（iNOS）、白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）。通过免疫组织化学染色鉴定炎性指标 F4/80 和髓过氧化物酶（MPO）。结果表明，TLR4/NF-κB 信号通路的表达在肾缺血再灌注损伤和脓毒症性肾损伤中增强，肾组织中 RP105 的过表达减轻了缺血性和脓毒性 AKI。此外，AKI 后，RP105 基因传递与肾炎性细胞浸润和炎性细胞因子减少有关。RP105 过表达还抑制了 AKI 后体外和体内 NF-κB 的核转位，并减弱了髓样分化因子 2（MD2）和 TLR4 之间的相互作用。这些结果表明，RP105 通过抑制 TLR4 信号通路介导的炎症反应来保护肾缺血性和脓毒性 AKI 损伤。本研究表明，RP105 的抗炎作用具有预防和治疗肾缺血性和脓毒性 AKI 的潜力。
