Department of Laboratory Medicine, Taizhou People Hospital, Taizhou 225300, China.
Department of Medicine, Taizhou Polytechnic College, Taizhou 225300, China.
Int Immunopharmacol. 2023 Mar;116:109676. doi: 10.1016/j.intimp.2022.109676. Epub 2023 Feb 8.
There is emerging evidence that long non-coding RNA component of mitochondrial RNA processing endoribonuclease (lncRNA RMRP) is involved in acute kidney injury (AKI) progression, but the specific mechanism of action still requires further investigation.
The lipopolysaccharide (LPS)-treated HK-2 cells were transfected with pcDNA-RMRP or si-RMRP, or transfected with pcDNA-ELAV like RNA binding protein 1 (ELAVL1) or si-ELAVL1, and cell viability, apoptosis, inflammatory factor secretion and oxidative stress were detected. The LPS-treated HK-2 cells were transfected with si-RMRP alone or together with pcDNA-ELAVL1, and cell behaviors were examined. The LPS-treated HK-2 cells were transfected with si-ELAVL1 alone or together with pcDNA- cyclooxygenase-2 (COX2), and the cellular changes were observed. The LPS-treated HK-2 cells were transfected with si-RMRP alone or together with pcDNA-ELAVL1, or together with pcDNA-ELAVL1 and si-COX2, and cell behaviors were examined. A mouse model of AKI was constructed using male C57BL/6 mice by the method of cecal ligation and puncture and intraperitoneal injection of LPS to explore the effect of RMRP silencing on renal injury in vivo.
RMRP and ELAVL1 was upregulated in LPS-treated HK-2 cells, and RMRP or ELAVL1 overexpression inhibited cell viability and promoted cell apoptosis, inflammatory factor secretion and oxidative stress, and RMRP knockdown showed the opposite effects. ELAVL1 upregulated COX2 protein expression and overexpression of COX2 reversed the promoting effects of RMRP knockdown on cell viability, as well as the inhibitory effects on cell apoptosis, inflammatory factor secretion and oxidative stress. Mechanistic findings suggested that RMRP aggravates LPS induced cell injury by activating prostaglandin E (PGE)/janus kinase-2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. We observed that knockdown of RMRP expression significantly alleviated renal tissue apoptosis, inflammatory factor secretion, and oxidative stress with AKI mice.
Our findings may provide a new reference for the treatment of AKI.
越来越多的证据表明，线粒体 RNA 加工内切酶的长非编码 RNA 成分（lncRNA RMRP）参与了急性肾损伤（AKI）的进展，但具体的作用机制仍需要进一步研究。
用脂多糖（LPS）处理 HK-2 细胞，转染 pcDNA-RMRP 或 si-RMRP，或转染 pcDNA-ELAV 样 RNA 结合蛋白 1（ELAVL1）或 si-ELAVL1，检测细胞活力、细胞凋亡、炎症因子分泌和氧化应激。用 LPS 单独处理 HK-2 细胞或与 pcDNA-ELAVL1 共转染 si-RMRP，观察细胞行为。用 LPS 单独处理 HK-2 细胞或与 pcDNA-环氧化酶-2（COX2）共转染 si-ELAVL1，观察细胞变化。用 LPS 单独处理 HK-2 细胞或与 pcDNA-ELAVL1 共转染 si-RMRP，或与 pcDNA-ELAVL1 和 si-COX2 共转染，观察细胞行为。采用盲肠结扎穿孔法和腹腔注射 LPS 构建 AKI 小鼠模型，探讨体内沉默 RMRP 对肾损伤的影响。
LPS 处理的 HK-2 细胞中 RMRP 和 ELAVL1 上调，RMRP 或 ELAVL1 过表达抑制细胞活力，促进细胞凋亡、炎症因子分泌和氧化应激，而 RMRP 敲低则表现出相反的作用。ELAVL1 上调 COX2 蛋白表达，过表达 COX2 逆转了 RMRP 敲低对细胞活力的促进作用，以及对细胞凋亡、炎症因子分泌和氧化应激的抑制作用。机制研究表明，RMRP 通过激活前列腺素 E（PGE）/Janus 激酶-2（JAK2）/信号转导和转录激活因子 3（STAT3）信号通路加重 LPS 诱导的细胞损伤。我们观察到，AKI 小鼠 RMRP 表达下调显著减轻了肾组织细胞凋亡、炎症因子分泌和氧化应激。
我们的研究结果可能为 AKI 的治疗提供新的参考。
