摘要
目的研究生长分化因子11（GDF11）对巨噬细胞胆固醇逆转运的影响,并探究GDF11发挥作用的具体机制。方法提取小鼠腹腔巨噬细胞后给予氧化型低密度脂蛋白（ox-LDL）、GDF11和激活素受体样激酶7（ALK7）抑制剂SB431542孵育24 h。利用油红O染色观察细胞脂质蓄积,提取总m RNA和总蛋白后,利用realtime PCR和Western blot检测GDF11、三磷酸腺苷结合盒转运体A1（ABCA1）和三磷酸腺苷结合盒转运体G1（ABCG1）的m RNA和蛋白表达水平。给予小鼠腹腔注射外源GDF11,提取腹腔巨噬细胞用3H标记的胆固醇孵育后注射回小鼠腹腔内,每8 h收集一次小鼠粪便,48 h后收集小鼠肝脏和血液样本,检测样本3H含量,计算胆固醇逆转运水平。结果 ox-LDL孵育24 h显著诱导巨噬细胞内脂质蓄积,同时抑制GDF11 m RNA及蛋白的表达。GDF11处理能有效抑制ox-LDL诱导的巨噬细胞脂质蓄积,同时显著诱导ABCA1 m RNA及蛋白的表达。经外源补充GDF11后显著提高小鼠体内胆固醇逆转运水平。GDF11孵育巨噬细胞后,在给予巨噬细胞ALK7抑制剂SB431542孵育后,GDF11对ox-LDL诱导细胞内脂质蓄积的抑制作用被拮抗,对ABCA1表达的调控作用也被抑制。结论 GDF11通过ALK7调节ABCA1的表达,从而促进巨噬细胞胆固醇逆转运。
Aim To explore the effect of growth differentiation factor 11（ GDF11） on macrophage reverse cholesterol transport and uncover the potential mechanism. Methods Mouse peritoneal macrophages were treated with oxidized low density lipoprotein（ ox-LDL）,GDF11 and activin receptor-like kinase 7（ ALK7） inhibitor SB431542 for 24 hours. The lipid accumulation was observed with oil red O staining,and the m RNA and protein expression levels of GDF11,ABCA1 and ABCG1 were determined by real-time PCR and Western blot. Mice were given intraperitoneal injection of exogenous GDF11. Peritoneal macrophages were labeled with3 H-cholesterol,then the labeled macrophages were injected into mice intraperitoneally. The mice feces were collected every 8 hours and the liver and blood samples of mice were gathered after 48 hours since cell injection. The radioactivity of3 H was detected to measure the reverse cholesterol transport level. Results After treated with ox-LDL for 24 hours,ox-LDL induced the accumulation of lipid in macrophage and inhibited the GDF11 m RNA and protein expression level. GDF11 treatment effectively inhibited the lipid accumulation in macrophage induced by ox-LDL. Exogenous GDF11 effectively induced macrophage ABCA1 m RNA expression and increased the cholesterol reverse transport level in vivo. However,after treated with GDF11 and ALK7 inhibitor SB431542,the inhibitory effect of GDF11 on intracellular lipid accumulation induced by ox-LDL was antagonized,and the upregulation of ABCA1 expression was also inhibited. Conclusion GDF11 regulates the expression of ABCA1 through ALK7,thus promoting the reverse transport of cholesterol in macrophage.
作者
汪雄
张玲
陶凌
WANG Xiong;ZHANG Ling;TAO Ling(Department of Cardiology, Xijing Hospital, Air Force Medical University, Xi＇an, Shaanxi 710032, China)
出处
《中国动脉硬化杂志》
CAS
2018年第4期329-334,共6页
Chinese Journal of Arteriosclerosis
基金
国家自然科学基金青年科学基金项目(81503064)
