Tian Yu-Ling, Wang Li-Jun, Wu Yue, Zhang Wei-Ping, Liang Xiao, Yuan Zu-Yi
Department of Cardiovascular Medicine, First Affiliated Hospital, Xi'an Jiaotong University College of Medicine, Xi'an 710061, China. E-mail:
Nan Fang Yi Ke Da Xue Xue Bao. 2017 Aug 20;37(8):1003-1009.
To examine whether transforming growth factor-β (TGF-β) pathway and adaptive T cell immunity play roles in the anti-atherosclerotic effects of pioglitazone (PIO) in ApoE mice.
ApoE mice with atherosclerosis induced by high-fat feeding were treated daily with PIO (20 mg/kg) or vehicle for 8 weeks. The protein expressions of TGF-β pathway in the atheromatous lesions of the aorta and the percentages of IFN-γ and Foxp3 cells in the spleen of the mice were examined with immunohistochemical staining. In the in vitro experiment, primary cultured splenocytes were stimulated with oxidized low-density lipoproteins (oxLDL) and treated with PIO either alone or in combination with the PPARγ antagonist GW9662, after which the changes in percentages of CD4IFN-γ cells and CD4CD25Foxp3 cells were analyzed with flow cytometry.
PIO treatment of ApoE mice with high-fat feeding significantly attenuated the progression of atheromatous lesions (P<0.05) and resulted in increased expressions of TGFβ1 (P<0.01), TGFβRII (P<0.05), and p-Smad3 (P<0.05) and a decreased expression of Smad7 (P<0.05) in the lesions. PIO treatment also led to decreased percentage of IFN-γ cells (P<0.05) and increased percentage of Foxp3 cells (P<0.01) in the spleen of the mice. In primary cultured splenocytes, PIO treatment caused significant down-regulation of IFN-γ mRNA (P<0.05) and up-regulation of Foxp3 mRNA (P<0.05) and obviously increased the percentages of CD4IFN-γ cells (P<0.05) and CD4CD25Foxp3 (P<0.05); the effects of PIO on CD4IFN-γ and CD4CD25Foxp3 cells were abolished by treatment of the cells with GW9662.
The anti-atherosclerotic effect of PIO is probably mediated by the TGF-β/Smad signaling pathway and PPAR-γ-dependent modulation of Th1/Treg population.
研究转化生长因子-β（TGF-β）通路及适应性T细胞免疫在吡格列酮（PIO）对载脂蛋白E（ApoE）小鼠抗动脉粥样硬化作用中是否发挥作用。
对通过高脂喂养诱导动脉粥样硬化的ApoE小鼠，每日给予PIO（20mg/kg）或赋形剂，持续8周。采用免疫组织化学染色检测小鼠主动脉粥样硬化病变中TGF-β通路的蛋白表达，以及小鼠脾脏中干扰素-γ（IFN-γ）和叉头框蛋白3（Foxp3）细胞的百分比。在体外实验中，用氧化型低密度脂蛋白（oxLDL）刺激原代培养的脾细胞，并单独或联合过氧化物酶体增殖物激活受体γ（PPARγ）拮抗剂GW9662用PIO处理，之后用流式细胞术分析CD4IFN-γ细胞和CD4CD25Foxp3细胞百分比的变化。
用PIO处理高脂喂养的ApoE小鼠可显著减轻动脉粥样硬化病变的进展（P<0.05），并导致病变中TGFβ1（P<0.01）、TGFβRII（P<0.05）和磷酸化Smad3（p-Smad3，P<0.05）表达增加，Smad7表达降低（P<0.05）。PIO处理还导致小鼠脾脏中IFN-γ细胞百分比降低（P<0.05），Foxp3细胞百分比增加（P<0.01）。在原代培养的脾细胞中，PIO处理导致IFN-γ信使核糖核酸（mRNA）显著下调（P<0.05），Foxp3 mRNA上调（P<0.05），并明显增加CD4IFN-γ细胞（P<0.05）和CD4CD25Foxp3细胞（P<0.05）的百分比；用GW9662处理细胞可消除PIO对CD4IFN-γ和CD4CD25Foxp3细胞的作用。
PIO的抗动脉粥样硬化作用可能由TGF-β/ Smad信号通路及PPAR-γ依赖的辅助性T细胞1型（Th1）/调节性T细胞（Treg）群体调节介导。
