OPG/RANKL/RANK信号通路在脓毒症相关急性肾损伤小鼠中的研究

Study of the OPG/RANKL/RANK signaling pathway in mice treated with sepsis-related acute kidney injury

目的:探讨骨保护素(OPG)/核因子⁃κB受体活化因子配体(RANKL)/核因子⁃κB受体激活因子(RANK)信号通路因子在脓毒症相关急性肾损伤(SA⁃AKI)小鼠中的改变及可能的作用,为SA⁃AKI的机制研究探索新的思路。方法:通过盲肠结扎穿孔手术(CLP)建立SA⁃AKI模型组(CLP组),对照组为假手术组(Sham组),只行开腹不做盲肠结扎穿孔操作。术后24 h采血并处死留取小鼠肾脏组织,用试剂盒检测血清Scr、BUN水平,酶联免疫测定法(ELISA)检验血清中IL⁃6、TNF⁃α、IL⁃1β水平,苏木精⁃伊红染色(HE)观测肾组织病理学变化,聚合酶链反应(RT⁃qPCR)和蛋白质印迹实验(Western blotting)检验小鼠肾组织中OPG、RANKL、RANK的mRNA和蛋白水平。结果:与Sham组对比,CLP组Scr、BUN、IL⁃6、TNF⁃α、IL⁃1β水平显著升高,差异均具有统计学意义(P<0.05);与Sham组对比,CLP组肾小球充血水肿,部分缺血皱缩,球囊间隙扩大,部分肾小管中可见坏死的上皮细胞,管腔扩大,肾间质水肿,少量炎性细胞浸润;与Sham组相比较,CLP组肾组织中OPG和RANK的mRNA表达显著上调,而RANKL的mRNA表达明显下降,差异均具有统计学意义(P<0.05);与Sham组相比较,CLP组肾脏组织中OPG及RANK的蛋白表达均升高,而RANKL的蛋白表达明显下降,差异均具有统计学意义(P<0.05)。结论:在脓毒症的小鼠模型中OPG及RANK表达升高,RANKL表达下降,表明OPG/RANKL/RANK信号通路可能参与了SA⁃AKI的病理生理过程。

Objective:The objective of this study was to investigate the alterations and potential implications of the Osteoprotegerin(OPG)/Receptor Activator of Nuclear Factor-kappa B Ligand(RANKL)/Receptor Activator of Nuclear Factor-kappa B(RANK)signaling pathway factors in a murine model of sepsis-associated acute kidney injury(SA-AKI).This research aimed to offer novel insights into the mechanistic exploration of SA-AKI.Methods:The SA-AKI model group(CLP group)was established through cecal ligation and puncture surgery(CLP),while the control group consisted of sham-operated animals(Sham group)subjected only to laparotomy without cecal ligation and puncture.Blood samples were collected 24 hours post-surgery,and murine kidney tissues were harvested upon euthanasia.Serum levels of Serum Creatinine(Scr)and Blood Urea Nitrogen(BUN)were quantified using assay kits.Furthermore,serum levels of interleukin-6(IL-6),tumor necrosis factor-alpha(TNF-α),and in-terleukin-1 beta(IL-1β)were assessed through enzyme-linked immunosorbent assay(ELISA).Renal tissue pathological altera-tions were examined employing hematoxylin-eosin staining(HE),and the mRNA and protein levels of OPG,RANKL,and RANK in murine kidney tissues were determined via reverse transcription-quantitative polymerase chain reaction(RT-qPCR)and Western blotting.Results:Comparative analysis revealed that,in comparison to the Sham group,the CLP group demonstrated a significant elevation in the levels of Scr,BUN,IL-6,TNF-α,and IL-1β,with statistically significant disparities(all P<0.05).Histopathological examination of the CLP group's kidneys unveiled glomerular congestion,edema,partial ischemic wrinkling,en-largement of interstitial spaces,the presence of necrotic epithelial cells in select renal tubules,tubular luminal dilation,varying de-grees of interstitial edema,and infiltration by a limited number of inflammatory cells.In parallel,relative to the Sham group,the CLP group exhibited substantial upregulation in mRNA expression of OPG and RANK in renal tissues,while RANKL mRNA expression experienced marked downregulation,with statistically significant distinctions(all P<0.05).Moreover,in comparison with the Sham group,the CLP group demonstrated an elevation in protein expression of OPG and RANK in kidney tissues,whereas RANKL protein expression displayed significant downregulation,with statistically significant differences(all P<0.05).Conclusion:In a murine sepsis model,augmented expression of OPG and RANK,coupled with diminished RANKL expression,suggests the potential involvement of the OPG/RANKL/RANK signaling pathway in the pathophysiological progression of SA-AKI.