The Pathogenic Mechanism Of Plasma Membrane Vesicle-associated Protein In Pulmonary Hypertension

Pulmonary hypertension(PH)is a class of chronic lethal diseases,in the course of the disease due to the pulmonary artery hypersystriction,pulmonary vascular remodeling,in situ thrombosis three synergistic effects led to an increase in pulmonary vascular resistance(PVR),eventually led to the occurrence of PH.It is currently believed that under the stimulation of related factors,the endothelial cells of the pulmonary arteries are damaged,causing endothelial dysfunction,resulting in an imbalance between vasoconstriction and diastolic factors,resulting in abnormal vascular contraction and increased pressure.The plasma membrane of eukaryotic cells is not a completely homogenized phospholipid bilayer,but will differentiate into many substructures with different functions.Caveolae is one of them,a beaker-shaped depression on the plasma membrane,which is the most abundant substructure on the surface of mammalian cell membranes known.As a organelle on the surface of the membrane,in addition to participating in the physiological process of endocytosis,the small concave also plays an important role in maintaining the structure of the cell membrane and mediating cell signaling.In the past,it was thought that small concaves were bare inverted without inclusion,but recent studies have found the presence of a protein complex in the neck of the "flask",called plasmalmma vesicle associated protein(PLVAP),which stabilizes the structure of the small concave and is believed to selectively filter through the material inside and outside the cell by virtue of its special structure,playing the role of a "sieve".Of the three main types of cells that make up the pulmonary blood vessels,they are present only in endothelial cells.This paper mainly studies the pathogenic mechanism of PLVAP in pulmonary arterial hypertension from proteomics,animal models,and cell models of pulmonary arterial hypertension.The main research contents and results are as follows:1.An animal model of MCT-PH in rats 1,2,3,and 4 weeks after MCT intraperitoneal injection was constructed,and the protein abundance of PLVAP in rat lung tissue was found to gradually decrease with the increase of time after MCT intraperitoneal injection by LCMS/MS detection of lung tissues in MCT-induced PH rats.We then constructed a PLVAPrelated PPI network and found that 5 proteins that interact with PLVAP have been thought to be related to PH in previous studies.All of the above results suggest that PLVAP may be involved in the development of pulmonary hypertension,is a biomarker of PH and has the potential to be a therapeutic target for pulmonary hypertension.2.By detecting the changes in protein level and m RNA level of PLVAP,it was found that in the PH model,PLVAP not only had a significant decrease in protein levels,but also similar changes in m RNA levels,which also verified the results we found in the proteome study,and then we used transmission electron microscopy to observe the lung tissue of the control group and the MCT group of rats,we found that there were a large number of small concaves on the endothelial cells of the pulmonary blood vessels of rats,and there was a "lid" on the neck of the small concave.structure,but compared with the control group,the lid of the small concave neck in the pulmonary vascular endothelial cells of rats in the MCT group was significantly reduced,which indicates that the pulmonary vascular structure of MCT rats has changed,which may be related to the mechanism of development of PH.In the PH model of hypoxic mice,by detecting the changes in protein levels and m RNA levels of PLVAP,it was found that PLVAP not only had a significant decrease in protein levels,but also had similar changes in m RNA levels,which was highly similar to the results in MCT rats.We then used transmission electron microscopy to observe the lung tissue of the control group and the hypoxic group of mice,similarly,there are also a large number of small concaves on the endothelial cells of the pulmonary blood vessels of mice,and there is a "lid" structure in the neck of the small concave,compared with the control group,the lid of the small concave neck in the pulmonary vascular endothelial cells of the hypoxic group of mice has a significant reduction,which indicates that the pulmonary vascular structure of the hypoxic mice has changed,further indicating that PLVAP may be related to the occurrence and development of PH.4.Protein expression of PLVAP was significantly downregulated in the lung tissues of patients with idiopathic pulmonary hypertension(IPAH).Treatment of human pulmonary artery endothelial cells(h PAEC)with 1% O2 concentration significantly downregulates protein and m RNA expression of PLVAP and leads to breakage of the "diaphragm" of the small concave neck on the surface of the hpa EC cell membrane.Treatment of h PAEC with dimethoxyenylglycine(DMOG)and the cobalt chloride(Co Cl2)also significantly downregulated protein and m RNA expression of PLVAP.Treatment of h PAEC using PLVAP si RNA will not only lead to a significant increase in the permeability of h PAEC,but will also upregulate the expression of reactive oxygen species(ROS)under normal oxygen,but will not affect the expression of ROS in low oxygen.In summary,this study shows that the expression of PLVAP in MCT rat PH model,chronic hypoxic mouse PH model,lung tissue in IPAH patients,and hypoxia-inducible factor(HIF)activation are significantly downregulated.And PLVAP being knocked down will affect the permeability and ROS content of h PAEC.