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法尼醇X受体(FXR)通过诱导肝脏抗凝血酶III的表达抑制小鼠凝血过程

栾志琳^1,2, 魏元怡^1,2, 王元辰¹, 明文华¹, 张海博¹, 王冰^1,3, 崔晓慧^1,3, 李彧媛^1,2, 管又飞^1,2, 张晓燕^4,*

¹大连医科大学医学科学研究院，大连 116044；²大连医科大学基础医学院生理学与病理生理学系，大连 116044；³大连医科大学附属大连市中心医院内分泌科，大连 116033；⁴华东师范大学医学与健康研究院，上海 200241

摘要

法尼醇X受体(farnesoid X receptor, FXR)已被发现可在凝血系统中发挥重要作用，包括抑制血小板功能、促进纤维蛋白原表达等。然而至今，FXR在凝血系统中的调节机制尚未完全阐明。本研究旨在探讨FXR对抗凝血酶III (antithrombin III, AT III)的调节作用。用FXR特异性激动剂GW4064 (每天30 mg/kg)处理野生型(WT)和FXR基因敲除(FXR KO) C57BL/6小鼠1和 3 天，结果显示，在WT小鼠上，FXR激动可显著延长凝血酶原时间和活化部分凝血活酶时间，降低活化凝血因子X (activated factor X, FXa)活性，降低活化凝血因子II (activated factor II, FIIa)和凝血酶-抗凝血酶复合物(thrombin-antithrombin complex, TAT)浓度，升高血浆AT III浓度，使血液处于低凝状态；当FXR敲除时，以上指标全部逆转，血液处于高凝状态。激动FXR后，WT小鼠肝脏AT III表达增加；而FXR KO小鼠肝脏中AT III表达较WT小鼠明显降低。体外研究结果显示，GW4064和FXR过表达腺病毒均可显著上调小鼠原代肝细胞中AT III的表达，相反，siRNA敲减FXR可明显抑制AT III表达。AT III启动子区含有FXR结合位点，GW4064可显著上调Luc-AT III荧光素酶活性并增加FXR与AT III启动子区的结合。以上结果提示，FXR可通过直接转录调控AT III的表达而抑制凝血过程。本研究揭示了FXR在凝血平衡中的新作用，提示FXR可能成为血液高凝状态相关疾病的潜在治疗靶点。

关键词： 法尼醇X受体(FXR); 抗凝血酶III (AT III); 抗凝; GW4064

分类号：R55

Farnesoid X receptor (FXR) inhibits coagulation process via inducing hepatic antithrombin III expression in mice

LUAN Zhi-Lin^1,2, WEI Yuan-Yi^1,2, WANG Yuan-Chen¹, MING Wen-Hua¹, ZHANG Hai-Bo¹, WANG Bing^1,3, CUI Xiao-Hui^1,3, LI Yu-Yuan^1,2, GUAN You-Fei^1,2, ZHANG Xiao-Yan^4,*

¹Advanced Institute for Medical Sciences, Dalian Medical University, Dalian 116044, China；²Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China；³Department of Endocrinology, Dalian Municipal Central Hospital, Dalian Medical University, Dalian 116033, China ；⁴Health Science Center, East China Normal University, Shanghai 200241, China

Abstract

Farnesoid X receptor (FXR) has been identified as an inhibitor of platelet function and an inducer of fibrinogen protein complex. However, the regulatory mechanism of FXR in hemostatic system remains incompletely understood. In this study, we aimed to investigate the functions of FXR in regulating antithrombin III (AT III). C57BL/6 mice and FXR knockout (FXR KO) mice were treated with or without GW4064 (30 mg/kg per day). FXR activation significantly prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT), lowered activity of activated factor X (FXa) and concentrations of thrombin-antithrombin complex (TAT) and activated factor II (FIIa), and increased level of AT III, whereas all of these effects were markedly reversed in FXR KO mice. In vivo, hepatic AT III mRNA and protein expression levels were up-regulated in wild-type mice after FXR activation, but down-regulated in FXR KO mice. In vitro study showed that FXR activation induced, while FXR knockdown inhibited, AT III expression in mouse primary hepatocytes. The luciferase assay and ChIP assay revealed that FXR can bind to the promoter region of AT III gene where FXR activation increased AT III transcription. These results suggest FXR activation inhibits coagulation process via inducing hepatic AT III expression in mice. The present study reveals a new role of FXR in hemostatic homeostasis and indicates that FXR might act as a potential therapeutic target for diseases related to hypercoagulation.

Key words: farnesoid X receptor (FXR); antithrombin III (AT III); anticoagulation; GW4064

收稿日期：2021-06-29　　录用日期：2021-07-14

通讯作者：张晓燕　　E-mail: wserien@163.com

DOI: 10.13294/j.aps.2021.0075

引用本文：

栾志琳, 魏元怡, 王元辰, 明文华, 张海博, 王冰, 崔晓慧, 李彧媛, 管又飞, 张晓燕. 法尼醇X受体(FXR)通过诱导肝脏抗凝血酶III的表达抑制小鼠凝血过程[J]. 生理学报 2021; 73 (5): 795-804.

LUAN Zhi-Lin, WEI Yuan-Yi, WANG Yuan-Chen, MING Wen-Hua, ZHANG Hai-Bo, WANG Bing, CUI Xiao-Hui, LI Yu-Yuan, GUAN You-Fei, ZHANG Xiao-Yan. Farnesoid X receptor (FXR) inhibits coagulation process via inducing hepatic antithrombin III expression in mice. Acta Physiol Sin 2021; 73 (5): 795-804