Inhibitory effect of specific knockdown of XBP-1 in smooth muscle cells on cardiopulmonary injury in hypoxia-induced pulmonary hypertension mice
Objective To investigate the preventive effect of specific knockdown of X box-binding protein 1(XBP-1)in smooth muscle cells on cardiopulmonary injury in hypoxia-induced pulmonary hypertension(HPH)mice.Methods Sixty 8-week-old male C57BL/6 mice were selected and randomly divided into control group(NC),HPH group,HPH+shCtrl group,and HPH+shXBP-1 group,respectively.Mice in the control group was placed in normal pressure and oxy-gen environment,and mice in the HPH group,HPH+shCtrl group,and HPH+shXBP-1 group were placed in low pressure and low oxygen environment for HPH modeling.At 3 weeks prior to model construction,mice in the HPH+shXBP-1 group were injected with smooth muscle specific XBP-1 knockdown adeno-associated virus serotype 9(AAV9)virus through the tail vein,and mice in the HPH+shCtrl group were injected with control virus.After anesthesia,right ventricular systolic pressure(RVSP)was measured by cardiac catheter.Right ventricular internal diameter(RVID)and thickness of right ventricle anterior wall(RVAW)were measured with small animal ultrasound instrument.The heart was isolated and right ventricular hypertrophy index(RVHI)was evaluated.Right ventricular myocardium was collected and masson was per-formed to calculate collagen volume fraction(CVF).The blood of mice was collected from periorbital area,and endothelin-1(ET-1)was detected by enzyme-linked immunosorbent assay(ELISA)and the levels of nitric oxide(NO),nitric oxide synthase(NOS)and induced nitric oxide synthase(iNOS)were detected by colorimetry.Alveolar lavage was performed on the left lung,and the bronchoalveolar lavage fluid(BALF)was collected.Interleukin-1β(IL-1β),interleukin-6(IL-6),tumor necrosis factor-α(TNF-α)were detected by ELISA.HE staining was performed on the middle and posterior lobe of the right lung,and the distal pulmonary artery wall thickness ratio(WT% )and pulmonary artery wall area ratio(WA% )were evaluated.The total protein of the right anterior lobe lung was extracted,and the expression of XBP-1 pro-tein was detected by Western blotting.Results The RVSP of the HPH and HPH+shCtrl groups were higher than that of the control group,and the RVSP of the HPH+shXBP-1 group was lower than that of the HPH and HPH+shCtrl group(all P<0.05).Compared with the control group,RVID of the HPH group and HPH+shCtrl group decreased,while RVAW and RVHI increased.Compared with the HPH group and HPH+shCtrl group,RVID increased,while RVAW and RVHI de-creased in the HPH+shXBP-1 group(all P<0.05).The CVF of the HPH group and HPH+shCtrl group was higher than that of the control group,and the CVF was lower in the HPH+shXBP-1 group than in the HPH group and HPH+shCtrl group(all P<0.05).The plasma ET-1 levels of the HPH group and HPH+shCtrl group were higher,and the levels of NO,NOS and iNOS were lower than those of the control group(all P<0.05).The plasma ET-1 level was lower in the HPH+shXBP-1 group than in the HPH group and HPH+shCtrl group,and the levels of NO,NOS and iNOS were higher than those of the HPH group and HPH+shCtrl group(all P<0.05).The levels of IL-1β,IL-6 and TNF-α in BALF of the HPH and HPH+shCtrl groups were higher than those in the control group,and the levels of IL-1β,IL-6 and TNF-α in the HPH+shXBP-1 group were lower than those in the HPH group and HPH+shCtrl groups(all P<0.05).WT% and WA% of the HPH group and HPH+shCtrl group increased in comparison with those of the control group,and the WT% and WA% of the HPH+shXBP-1 group decreased in comparison with those of the HPH group and HPH+shCtrl group(all P<0.05).Com-pared with the control group,the expression of XBP-1 protein increased in the HPH group and HPH+shCtrl group;com-pared with the HPH group and HPH+shCtrl group,the expression of XBP-1 protein decreased in HPH+shXBP-1 group(all P<0.05).Conclusions Specific knockdown of XBP-1 can reduce pulmonary artery pressure and improve heart func-tion,myocardial fibrosis,pulmonary artery remodeling,homeostasis of vasoactive substances and intrapulmonary inflam-mation in HPH mice.XBP-1 may be involved in the process of cardiopulmonary injury in HPH mice.
万方数据
维普
