Li Yan, Liu Yong, Li Furong, Wang Yiqin, Wang Kailong, Zhao Jinghong
Department of Nephrology, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China.
Ann Transl Med. 2022 May;10(10):559. doi: 10.21037/atm-22-1621.
The infiltration and activation of M1-macrophages can promote renal tubular interstitial damage. The study aimed to investigate the effect of V-set and immunoglobulin domain containing 4 (VSIG4) on M1-macrophages activation and acute kidney injury (AKI) mice.
The M1-macrophage markers cluster of differentiation 86 (CD86) and inducible nitric oxide synthase (iNOS) were detected via flow cytometry. Cell viability and expression of inflammatory factors were analyzed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), as well as quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA) assays. Moreover, HK-2 cells stimulated with lipopolysaccharide (LPS) and RAW264.7 cells overexpressing VSIG4 were co-cultured to analyze the effect of VSIG4 suppressing M1-macrophage activation on HK-2 cells via detecting cell proliferation and apoptosis levels. Furthermore, the pathological changes and iNOS expression of kidney tissue in VSIG4 knockout mice with renal ischemia-reperfusion injury (IRI) were detected by hematoxylin and eosin (H&E) and immunohistochemistry (IHC) staining.
Overexpression of VSIG4 partially reversed the phenomenon of M1-macrophageactivation caused by LPS-upregulated CD86 and iNOS expression, reduced cell viability, and induced the expression levels of interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) in RAW264.7. In addition, RAW264.7 cells overexpressing VSIG4 could also alleviate the low proliferation and high apoptotic level of HK-2 cells stimulated with LPS. After VSIG4 knockout, the kidney tissue of AKI mice showed obvious lesions and iNOS expression, indicating that VSIG4 knockout promoted the infiltration of M1-macrophages in the damaged kidney tissue and accelerated kidney tissue lesions.
Overexpression of VSIG4 might alleviate the lesions of kidney tissue in AKI mice via inhibition of the secretion of inflammatory factors in M1-macrophages.
M1巨噬细胞的浸润和激活可促进肾小管间质损伤。本研究旨在探讨含V结构域和免疫球蛋白结构域4（VSIG4）对M1巨噬细胞激活及急性肾损伤（AKI）小鼠的影响。
通过流式细胞术检测M1巨噬细胞标志物分化簇86（CD86）和诱导型一氧化氮合酶（iNOS）。通过3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）、5-乙炔基-2'-脱氧尿苷（EdU）以及定量聚合酶链反应（qPCR）和酶联免疫吸附测定（ELISA）分析细胞活力和炎症因子表达。此外，将脂多糖（LPS）刺激的HK-2细胞与过表达VSIG4的RAW264.7细胞共培养，通过检测细胞增殖和凋亡水平分析VSIG4抑制M1巨噬细胞激活对HK-2细胞的影响。此外，通过苏木精-伊红（H&E）染色和免疫组织化学（IHC）染色检测肾缺血再灌注损伤（IRI）的VSIG4基因敲除小鼠肾组织的病理变化和iNOS表达。
VSIG4的过表达部分逆转了由LPS上调的CD86和iNOS表达引起的M1巨噬细胞激活现象，降低了细胞活力，并诱导了RAW264.7中白细胞介素1β（IL-1β）、白细胞介素6（IL-6）和肿瘤坏死因子-α（TNF-α）的表达水平。此外，过表达VSIG4的RAW264.7细胞还可减轻LPS刺激的HK-2细胞的低增殖和高凋亡水平。VSIG4基因敲除后，AKI小鼠的肾组织出现明显病变和iNOS表达，表明VSIG4基因敲除促进了受损肾组织中M1巨噬细胞的浸润并加速了肾组织病变。
VSIG4的过表达可能通过抑制M1巨噬细胞炎症因子的分泌减轻AKI小鼠肾组织的病变。
