Seo Hye-Young, Park Ji Yeon, Lee So-Hee, Lee Hye Won, Han Eugene, Hwang Jae Seok, Kim Mi Kyung, Jang Byoung Kuk
Department of Internal Medicine, School of Medicine, Institute for Medical Science, Keimyung University, Daegu, Korea.
Department of Pathology, Keimyung University School of Medicine, Daegu, Korea.
Cell Biosci. 2025 Mar 15;15(1):36. doi: 10.1186/s13578-025-01376-z.
Cholestatic liver disease, characterized by impaired bile flow, leads to the accumulation of harmful metabolites and toxins, resulting in liver damage. Inflammatory cytokines are crucial for the progression of this condition. Clusterin is a glycoprotein with roles in cell death, lipid transport, and cellular protection. We previously demonstrated that clusterin protects against hepatic steatosis and hepatic fibrosis. This study explored the roles of clusterin in cholestatic liver injury induced by a DDC (3,5-diethoxycarbonyl-1,4-dihydrocollidine) diet.
The study evaluated the impact of clusterin on liver injury in C57BL/6 mice and clusterin-knockout (KO) mice fed a DDC diet for 10-20 days. Primary Kupffer cells (KCs) and hepatocytes (HCs) of these mice were analyzed. Techniques such as Sirius red staining, immunohistochemistry, real-time RT-PCR, enzyme-linked immunosorbent assays, and western blotting were performed to assess the effects of clusterin.
Clusterin expression was upregulated in the cholestatic liver. Clusterin-KO mice exhibited elevated levels of alanine aminotransferase, aspartate aminotransferase, collagen, and αSMA upon DDC diet-induced liver injury. They also had increased levels of markers of endoplasmic reticulum (ER) stress (CHOP, ATF6, and p-eIF2α) and inflammasome activity (NLRP3, ASC, caspase-1, and interleukin 1 beta (IL1β) protein expression, and IL1β and interleukin 18 secretion). Thapsigargin, an ER stress inducer, heightened NLRP3 inflammasome activation in primary KCs and HCs, which was mitigated by overexpression of clusterin.
The absence of clusterin exacerbates ER stress and NLRP3 inflammasome activation in mice fed a DDC diet. Conversely, overexpression of clusterin suppresses these stress responses. Thus, clusterin deficiency is associated with an enhanced inflammasome response in the liver that is linked to upregulation of ER stress.
胆汁淤积性肝病以胆汁流动受损为特征，导致有害代谢产物和毒素的积累，从而造成肝损伤。炎性细胞因子对这种疾病的进展至关重要。簇集素是一种糖蛋白，在细胞死亡、脂质转运和细胞保护中发挥作用。我们之前证明簇集素可预防肝脂肪变性和肝纤维化。本研究探讨了簇集素在由3,5 - 二乙氧羰基 - 1,4 - 二氢可力丁（DDC）饮食诱导的胆汁淤积性肝损伤中的作用。
本研究评估了簇集素对喂食DDC饮食10 - 20天的C57BL/6小鼠和簇集素基因敲除（KO）小鼠肝损伤的影响。对这些小鼠的原代库普弗细胞（KCs）和肝细胞（HCs）进行了分析。采用天狼星红染色、免疫组织化学、实时逆转录聚合酶链反应、酶联免疫吸附测定和蛋白质印迹等技术来评估簇集素的作用。
胆汁淤积性肝脏中簇集素表达上调。在DDC饮食诱导的肝损伤中，簇集素基因敲除小鼠的丙氨酸氨基转移酶、天冬氨酸氨基转移酶、胶原蛋白和α平滑肌肌动蛋白水平升高。它们内质网（ER）应激标志物（CHOP、ATF6和磷酸化真核起始因子2α）和炎性小体活性（NLRP3、凋亡相关斑点样蛋白、半胱天冬酶 - 1和白细胞介素1β（IL1β）蛋白表达以及IL1β和白细胞介素18分泌）水平也升高。内质网应激诱导剂毒胡萝卜素增强了原代KCs和HCs中NLRP3炎性小体的激活，而簇集素的过表达减轻了这种激活。
在喂食DDC饮食的小鼠中，簇集素的缺失加剧了内质网应激和NLRP3炎性小体的激活。相反，簇集素的过表达抑制了这些应激反应。因此，簇集素缺乏与肝脏中炎性小体反应增强有关，而这与内质网应激的上调有关。
