Jin Guiyuan, Yao Xiaoying, Liu Dong, Zhang Juan, Zhang Xiaobei, Yang Yonghong, Bi Yanzhen, Zhang Hui, Dong Guanjun, Tang Huixin, Cheng Shumin, Hong Feng, Si Meng
Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, China.
Institute of Immune Precision Diagnosis and Therapy and Translational Medicine, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, China.
Immun Inflamm Dis. 2023 Dec;11(12):e1114. doi: 10.1002/iid3.1114.
Cells and tissues, such as macrophages, express inducible nitric oxide synthase (INOS) after stimulation by certain factors. INOS helps mediate the macrophage inflammatory reaction, but few studies have explored how INOS affects macrophage function in nonalcoholic fatty liver disease (NAFLD).
This study investigated the role of INOS-mediated macrophage activity in NAFLD.
A high-fat diet was used to establish an NAFLD mouse model. After 12 weeks, blood was collected for immune cell and lipid analyses, and liver tissues were collected for pathological analyses with hematoxylin and eosin and Oil Red O staining. Peritoneal macrophages were extracted in situ, cultured in Dulbecco's modified Eagle's medium, and stimulated with palmitic acid to mimic in vivo conditions for further assays. Real-time polymerase chain reaction, western blot analysis, and immunofluorescence were used to verify the expression of target genes or proteins.
In the NAFLD model, INOS expression in macrophages increased, and INOS knockdown significantly decreased the number of macrophages. Pathological examinations confirmed that INOS knockdown slowed NAFLD progression and macrophage infiltration during inflammation. INOS knockdown also enhanced phagocytosis and lipid transport by macrophages, and increased the expression of autophagy-related molecules in macrophages, which improved the autophagy level, promoted apoptotic cell degradation, and maintained intracellular environment homeostasis.
These results indicate a correlation between INOS expression and macrophage function in NAFLD.
细胞和组织，如巨噬细胞，在受到某些因素刺激后会表达诱导型一氧化氮合酶（INOS）。INOS有助于介导巨噬细胞炎症反应，但很少有研究探讨INOS在非酒精性脂肪性肝病（NAFLD）中如何影响巨噬细胞功能。
本研究调查INOS介导的巨噬细胞活性在NAFLD中的作用。
采用高脂饮食建立NAFLD小鼠模型。12周后，采集血液进行免疫细胞和脂质分析，采集肝脏组织进行苏木精-伊红染色和油红O染色的病理分析。原位提取腹腔巨噬细胞，在杜氏改良 Eagle 培养基中培养，并用棕榈酸刺激以模拟体内条件进行进一步检测。采用实时聚合酶链反应、蛋白质印迹分析和免疫荧光法验证靶基因或蛋白质的表达。
在NAFLD模型中，巨噬细胞中INOS表达增加，INOS基因敲低显著减少巨噬细胞数量。病理检查证实，INOS基因敲低减缓了NAFLD进展以及炎症期间的巨噬细胞浸润。INOS基因敲低还增强了巨噬细胞的吞噬作用和脂质转运，并增加了巨噬细胞中自噬相关分子的表达，从而提高自噬水平，促进凋亡细胞降解，并维持细胞内环境稳态。
这些结果表明NAFLD中INOS表达与巨噬细胞功能之间存在相关性。
