4-苯基丁酸抑制内质网应激改善高同型半胱氨酸引起的血管重构

摘要 目的：探讨高同型半胱氨酸血症（hyperhomocysteinemia, HHcy）导致血管损伤的机制并证明内质网应激抑制剂4-苯基丁酸（4-PBA）在其中的保护作用。方法：采用蛋氨酸饲料喂养SD大鼠制备HHcy模型，24只大鼠随机分为3组（每组8只）：对照组（Control）、HHcy模型组（HHcy）和4-PBA处理组（4-PBA）；测量大鼠血压和心率，检测血清中同型半胱氨酸浓度，HE染色观察血管形态，Western blot和免疫组化染色观察内质网应激分子GRP78和GRP94的表达，Western blot检测内质网应激促凋亡因子CHOP和Caspase 12的表达，TUNEL染色观察主动脉血管的细胞凋亡。结果：3组大鼠血压和心率没有显著差异（P>0.05）；和Control组比较，HHcy组血清中同型半胱氨酸浓度明显增加（P<0.05），而4-PBA处理组血清同型半胱氨酸浓度与HHcy组比有降低但没有统计学差异（P>0.05）；和Control组比较，HHcy组主动脉血管平滑肌细胞肥大，走行紊乱，部分断裂，细胞核固缩，管壁增厚，内质网应激分子GRP78和GRP94以及促凋亡因子CHOP和Caspase 12的表达明显增加（P<0.05），TUNEL染色阳性细胞也显著增多；而4-PBA处理组能明显改善HHcy组主动脉血管的这些变化（P<0.05）。结论：高同型半胱氨酸血症能引起主动脉血管重构，而4-PBA可通过抑制内质网应激和细胞凋亡改善高同型半胱氨酸血症引起的血管重构。

4-phenylbutyric Acid Alleviating Hyperhomocysteinemia-induced Vascular Remodeling via Inhibiting Endoplasmic Reticulum Stress

ABSTRACT Objective: To investigate the mechanism of hyperhomocysteinemia (HHcy) induced vascular injury and to prove the protective effect of 4-phenylbutyric acid (4-PBA). Methods: Twenty-four SD rats were randomly divided into 3 groups (8 rats in each group): control group (control group), HHcy model group and 4-PBA treated HHcy group. Blood pressure, heart rate and serum homocysteine concentration were detected. Vascular morphology was observed by HE staining. The expressions of endoplasmic reticulum stress molecules GRP78 and GRP94 were observed by Western blot and immunohistochemistry. The expressions of apoptotic-related factors CHOP and caspase 12 were detected by Western blot. The apoptosis of aortic vessels was observed by TUNEL staining. Results: There was no significant difference in blood pressure and heart rate among the three groups(P>0.05). Compared with the control group, serum homocysteine concentration was significantly increased in the HHcy group(P<0.05), while serum homocysteine concentration in 4-PBA treatment group was lower than that in HHcy group, but there was no statistical difference(P>0.05). Compared with the control group, aortic smooth muscle cells in the HHcy group were hypertrophic, disordered and partially broken. The expressions of endoplasmic reticulum stress molecules GRP78 and GRP94 and apoptotic-related factors CHOP and caspase 12 were significantly increased (P<0.05), and TUNEL staining positive cells were also significantly increased. 4-PBA treatment group could significantly improve these changes in HHcy group (P<0.05). Conclusion: Hyperhomocysteinemia could induce aortic vascular remodeling, and 4-PBA could alleviate hyperhomocysteinemia-induced vascular remodeling by inhibiting endoplasmic reticulum stress and apoptosis.