HDAC4/MEF2C对肺动脉高压肺血管平滑肌增殖调控的实验研究

Pulmonary arterial hypertension (PAH) is a devastating and life-threatening disease, characterized by vascular remodeling, result from hyperproliferation of pulmonary artery smooth muscle cells (PASMCs). To manage PAH successfully, the reversal or inhibition of pulmonary vascular remodeling must be achieved. Recent studies indicate balance of HDAC4/MEF2C is a key, which regulates hyperproliferation of smooth muscle cells. The results from our preliminary experiment show that in the lung of mice PAH model, MEF2C was upregulated, also in mice PASMCs cultured in vitro, MEF2C was regulated by HDAC4 inhibitor. But, the effect of HDAC4/MEF2C in development of PAH is unkown. To reveal does HDAC4/MEF2C play a role in PAH vascular remodeling, the mice PASMCs were divided into four groups the mice PASMCs transfected with HDAC4 vector group or mock-vehicle group, PASMCs with PBS group, and HDAC4 inhibitor group, the cells were cultured in vitro, immunofluorescence was used to detect cell phenotype; RT-PCR, western-blot were adopt to determinate the expression of MEF2C, also CCk-8, Boyden chamber were used to checkout proliferation and migration of cells. To determinated whether MEF2C is the key factor in HDAC4 regulated proliferation, migration of mice PASMCs, MEF2C gene interference was used, and indicators above were messured again. Then mice PAH model was builted with monocrotaline subcutaneous injection, right ventricular pressure was messured to indicate the pressure of pulmonary, HE staining was used to checkout vascule remodeling. Also PASMCs phenotype, expression of MEF2C protein, mRNA, were also detected to confirm the effection of MEF2C in PAH vascular remodeling. Our result will reveal the molecular mechanism of PAH, indicate a new direction of PAH theraphy.

PAH主要病理机制为PASMCs过度增殖导致的肺血管重构。逆转肺血管重构，阻止血管平滑肌细胞迁移增殖，能有效改善肺动脉高压。新近研究表明，HDAC4/MEF2C平衡是调节平滑肌细胞增殖的关键分子。预实验发现，PAH模型小鼠PASMCs存在HDAC4调控的MEF2C高表达。然而HDAC4/MEF2C在PAH中是否发挥关键重要作用，尚不清楚。本项目首先体外以PASMCs为研究对象，通过对HDAC4调节，检测PASMCs表型改变、增殖、迁移及MEF2C表达，探讨HDAC4能否通过MEF2C调控PASMCs增殖迁移；然后利用基因干扰技术阐明MEF2C在平滑肌调控中的关键作用；最后建立PAH小鼠模型，检测右心室压力，肺血管结构变化及MEF2C表达情况，证实HDAC4/MEF2C平衡对小鼠肺动脉平滑肌细胞的影响。项目研究不但进一步认识PAH的病理分子机制，而且为PAH的临床治疗提供新思路。

PAH主要病理机制为PASMCs过度增殖导致的肺血管重构。逆转肺血管重构，阻止血管平滑肌细胞迁移增殖，能有效改善肺动脉高压。为证明HDAC4/MEF2C平衡对小鼠肺动脉高压肺血管重构的影响，本项目成功建立PAH小鼠模型，检测右心室压力，肺血管结构变化及MEF2C表达情况，证实HDAC4/MEF2C平衡对小鼠肺动脉平滑肌细胞的影响。并证明PAH模型小鼠PASMCs存在HDAC4调控的MEF2C高表达，并且HDAC4/MEF2C平衡是调节平滑肌细胞增殖的关键分子。项目研究不但进一步认识PAH的病理分子机制，而且为PAH的临床治疗提供新思路。