SCARF1 通过钙依赖性 PI3K-AKT-STAT3 信号促进枯否细胞的 M2 极化，从而改善肝移植。

SCARF1 promotes M2 polarization of Kupffer cells via calcium-dependent PI3K-AKT-STAT3 signalling to improve liver transplantation.

机构信息

Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.

出版信息

Cell Prolif. 2021 Apr;54(4):e13022. doi: 10.1111/cpr.13022. Epub 2021 Mar 9.

OBJECTIVES

This study aimed to investigate the protective effect of SCARF1 on acute rejection (AR), phagocytic clearance of Kupffer cells (KCs), M2 polarization and the exact mechanism underlying these processes.

METHODS

AAV was transfected into the portal vein of rats, and AR and immune tolerance (IT) models of liver transplantation were established. Liver tissue and blood samples were collected. The level of SCARF1 was detected via WB and immunohistochemical staining. Pathological changes in liver tissue were detected using HE staining. Apoptotic cells were detected using TUNEL staining. KC polarization was assessed via immunohistochemical staining. Primary KCs were isolated and co-cultured with apoptotic T lymphocytes. Phagocytosis of apoptotic cells and polarization of KCs were both detected using immunofluorescence. Calcium concentration was determined using immunofluorescence and a fluorescence microplate reader. The levels of PI3K, p-AKT and P-STAT3 were assessed via WB and immunofluorescence.

RESULTS

Compared to the IT group, the level of SCARF1 was significantly decreased in the AR group. Overexpression of SCARF1 in KCs improved AR and liver function markers. Enhanced phagocytosis mediated by SCARF1 is beneficial for improving the apoptotic clearance of AR and promoting M2 polarization of KCs. SCARF1-mediated enhancement of phagocytosis promotes increased calcium concentration in KCs, thus further activating the PI3K-AKT-STAT3 signalling pathway.

CONCLUSIONS

SCARF1 promotes the M2 polarization of KCs by promoting phagocytosis through the calcium-dependent PI3K-AKT-STAT3 signalling pathway.

目的

本研究旨在探讨 SCARF1 对急性排斥反应（AR）、枯否细胞（KCs）吞噬清除、M2 极化的保护作用及其确切机制。

方法

通过门静脉转染 AAV，建立大鼠肝移植 AR 和免疫耐受（IT）模型。收集肝组织和血液样本。采用 WB 和免疫组化染色检测 SCARF1 水平。采用 HE 染色检测肝组织病理变化。采用 TUNEL 染色检测细胞凋亡。采用免疫组化染色评估 KC 极化。分离原代 KCs 与凋亡 T 淋巴细胞共培养，采用免疫荧光检测细胞吞噬和 KC 极化。采用免疫荧光和荧光微孔板读数检测钙浓度。采用 WB 和免疫荧光检测 PI3K、p-AKT 和 P-STAT3 水平。

结果

与 IT 组相比，AR 组 SCARF1 水平显著降低。在 KCs 中转染 SCARF1 可改善 AR 和肝功能标志物。SCARF1 介导的吞噬增强有利于改善 AR 细胞的凋亡清除，促进 KCs 的 M2 极化。SCARF1 介导的吞噬增强促进 KCs 中钙浓度增加，从而进一步激活 PI3K-AKT-STAT3 信号通路。