Nuanxinkang Inhibits Endothelial-to-Mesenchymal Transition to Reduce Plaque Formation in Mice with Obstructive Sleep Apnea-Hypopnea Syndrome Comorbid with Atherosclerosis
Objective To investigate the effect and mechanism of Nuanxinkang on plaque formation in obstructive sleep apnea-hypopnea syndrome(OSAHS)comorbid with atherosclerosis(AS)mice by inhibiting endothelial-to-mesenchymal transition(EndMT).Methods Male ApoE-/-mice were randomly divided into six groups:control group,model group,atorvastatin group(2.6 mg·kg-1)and Nuanxinkang low-,medium-and high-dose groups(crude drug 3.5,7.0,14.0 g·kg-1),with eight mice in each group.The mice were exposed to chronic intermittent hypoxia(CIH)environment during sleep for a long time,and fed with high-fat diet to replicate OSAHS comorbid with AS mouse model.Oil red O staining was used to observe the formation of plaque on aortic intima in mice.Masson trichrome staining was used to evaluate the collagen content of atherosclerotic plaques in the aortic root of mice.The expressions of endothelial cell marker CD31 and EndMT marker Vimentin in aortic plaque were detected by immunofluorescence.Blood lipid levels were determined by ELISA;the mRNA expression levels of EndMT markers α-SMA and Cdh2 in aortic tissue were detected by qPCR.Results Compared with the control group,the area of aortic atherosclerotic plaque in the model group was significantly increased(P<0.01),and the area of collagen deposition in the aortic root plaque was significantly increased(P<0.01).The number of CD31 positive cells in the plaque were significantly decreased(P<0.01),and the number of Vimentin positive cells were significantly increased(P<0.01).Serum TG,T-CHO and LDL-C levels were significantly increased(P<0.01),and HDL-C level was significantly decreased(P<0.01).The mRNA expression levels of α-SMA and Cdh2 in aortic tissue were significantly increased(P<0.01).Compared with the model group,the area of aortic atherosclerotic plaque in Nuanxinkang groups were significantly reduced(P<0.05,P<0.01),and the collagen deposition area of aortic root atherosclerotic plaque were significantly reduced(P<0.05,P<0.01).The number of CD31 positive expression cells in the plaque of Nuanxinkang high-dose group were significantly increased(P<0.05),and the number of Vimentin positive expression cells in the plaque of Nuanxinkang medium-and high-dose groups were significantly decreased(P<0.05,P<0.01).The serum TG level of mice in the high-dose group of Nuanxinkang was significantly decreased(P<0.01).The serum T-CHO and LDL-C levels of mice in each Nuanxinkang administration group were significantly decreased(P<0.05,P<0.01).The serum HDL-C levels of mice in the medium-and high-dose groups of Nuanxinkang were significantly increased(P<0.01).The mRNA expression levels of α-SMA and Cdh2 in aortic tissue of mice in each treatment group were significantly decreased(P<0.01).Conclusion Nuanxinkang can effectively reduce the plaque formation in OSAHS comorbid with atherosclerosis mice,which may be related to its inhibition of EndMT and reduction of collagen fiber formation.