Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Institute of Urology, Anhui Medical University, Hefei, Anhui, China.
J Cell Physiol. 2019 Jul;234(7):11463-11473. doi: 10.1002/jcp.27803. Epub 2018 Dec 26.
This study aims to verify whether the inhibitory effect of Sirtuin 3 (SIRT3) on the formation of renal calcium oxalate crystals was mediated through promoting macrophages (Mϕs) polarization. Identification and quantification of M1 and M2 monocytes were performed using fluorescence-activated cell sorting analysis. SIRT3 protein level and forkhead box O1 (FOXO1) acetylation level were measured using western blot analysis. Cell apoptosis of HK-2 was detected by flow cytometry. Mouse kidney tissues were subjected to Von Kossa staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and immunohistochemical staining for detection of kidney crystals deposition, apoptosis, and expression of crystal-related molecules, respectively. The results showed that human peripheral blood monocytes from patients with kidney stone (KS) exhibited decreased M2 monocytes percentage and SIRT3 expression, whereas increased FOXO1 acetylation compared with the normal controls. In vitro assay revealed that SIRT3 overexpression in bone marrow-derived M0/M1/M2 Mϕs induced M2 polarization and decreased FOXO1 acetylation. Furthermore, FOXO1 knockdown reversed SIRT3-mediated induction of M2 polarization and inhibition of HK-2 (human proximal tubular cell line) apoptosis. Further in vivo experiments demonstrated that SIRT3-overexpressing Mϕs transfusion not only induced M2 polarization, but also alleviated inflammation, apoptosis, and crystals deposition in glyoxylate-induced KS mice. In conclusion, SIRT3 suppresses formation of renal calcium oxalate crystals through promoting M2 polarization via deacetylating FOXO1.
本研究旨在验证 Sirtuin 3（SIRT3）是否通过促进巨噬细胞（Mϕ）极化来抑制肾脏草酸钙晶体的形成。使用荧光激活细胞分选分析鉴定和量化 M1 和 M2 单核细胞。使用 Western blot 分析测量 SIRT3 蛋白水平和叉头框 O1（FOXO1）乙酰化水平。通过流式细胞术检测 HK-2 细胞凋亡。对小鼠肾脏组织进行 Von Kossa 染色、末端脱氧核苷酸转移酶 dUTP 缺口末端标记（TUNEL）染色和免疫组织化学染色，分别检测肾脏晶体沉积、凋亡和晶体相关分子的表达。结果表明，肾结石（KS）患者外周血单核细胞中 M2 单核细胞比例和 SIRT3 表达降低，而 FOXO1 乙酰化水平升高。体外实验表明，骨髓来源的 M0/M1/M2 Mϕs 中 SIRT3 的过表达诱导 M2 极化并降低 FOXO1 乙酰化。此外，FOXO1 敲低逆转了 SIRT3 介导的 M2 极化诱导和 HK-2（人近端肾小管细胞系）凋亡抑制。进一步的体内实验表明，SIRT3 过表达的 Mϕs 转输注不仅诱导 M2 极化，还减轻了乙醛酸盐诱导的 KS 小鼠的炎症、凋亡和晶体沉积。总之，SIRT3 通过去乙酰化 FOXO1 促进 M2 极化来抑制肾脏草酸钙晶体的形成。
