动物造模,肺动脉高压 z-bio 2022-12-05 313

　　Objective To investigate the role of endoplasmic reticulum stress mitochondrial autophagy pathway in pulmonary hypertension induced by monocrotaline in rats.

　　Methods Forty five SD rats were randomly divided into three groups: normal control group, monocrotaline induced pulmonary hypertension (PAH) group and 4-phenylbutyric acid (4-PBA) drug intervention group with 15 rats in each group. The mean pulmonary artery pressure and the mean right ventricular pressure were measured by the bioinformatics system; The changes of pulmonary vascular remodeling were observed with hematoxylin eosin staining, and the relevant indexes of pulmonary vascular remodeling were measured with Image J pathological analysis software; The changes of mitochondria in pulmonary vascular smooth muscle cells were observed under electron microscope; The mRNA expression level of key factors of endoplasmic reticulum stress mitochondrial autophagy pathway was determined by qPCR molecular biology.

　　Results (1) The mean pulmonary artery pressure and the mean right ventricular pressure increased in monocrotaline induced PAH group. After 4-PBA intervention, compared with PAH group, the mean pulmonary artery pressure and mean right ventricular pressure decreased (P<0.001). (2) After HE staining, it was found that pulmonary small vessels in PAH group were significantly remodelled, and the measurement of vascular remodeling indicators suggested that the thickness of pulmonary small artery media was increased, and the lumen was narrowed (P<0.05). (3) The ultrastructure of pulmonary vascular smooth muscle cells was observed by electron microscope. It was found that the mitochondria of pulmonary vascular smooth muscle cells in PAH group were swollen, the mitochondrial cristae structure was destroyed, and the dissolution disappeared. The phenomenon of mitochondrial autophagy increased. After endoplasmic reticulum stress was inhibited, the destruction of normal mitochondrial structure and mitochondrial autophagy decreased. (4) The results of mRNA level determination of key factors of endoplasmic reticulum stress mitochondrial autophagy pathway showed that in PAH group, the mRNA expression level of endoplasmic reticulum stress related factors PERK, ATF4, Bcl-2, CHOP was up-regulated (P<0.001), the expression level of mitochondrial fusion key factor Mfn2 (mitofusin-2) was down regulated, the expression of mitochondrial mitosis key factor Drp1 (Drp1) was up regulated (P<0.001), autophagy related 12 (Atg12) The mRNA expression of microtubule associated proteins 1A and 1B (LC3) and p62 (sequence-1, p62/SQSTM1) was up-regulated (P<0.01). After ER stress was inhibited, the mRNA expression of ER stress related factors decreased (P<0.001), the expression of mitochondrial fusion factor Mfn2 was up-regulated (P<0.001), the mRNA expression of mitochondrial mitotic factor Drp1 was down regulated (P<0.001), and the mRNA expression of Atg12, LC3, and p62 was down regulated (P<0.01).

　　Conclusion endoplasmic reticulum stress may play an important role in the development of pulmonary hypertension through mitochondrial autophagy.