Expression Of Piezo1 In Intra And Extra Pulmonary Artery And The Effects

[Background]Pulmonary hypertension is a serious and irreversible fatal disease,and vascular remodeling is an important pathological mechanism in the occurrence and development of pulmonary hypertension,characterized by thickening of pulmonary metamuscularis and extension of smooth muscle into non-muscular capillaries,which is mainly caused by proliferation and migration of PASMCs.A large number of studies have shown that Piezo1,the mechanically sensitive calcium channel,is a pulmonary selective cationic channel protein that is conductive to Ca2+,which plays a key role in regulating the physiology and pathology of blood vessels.It has been confirmed that Piezo1 is involved in the physiological and pathological process of vascular endothelial cells and smooth muscle cells.Nowadays,most studies on Piezo1 and blood vessels focus on the vascular endothelium,and it has been confirmed that it is involved in the remodeling of arterioles in terms of arterial smooth muscle.In addition,Piezo1 is involved in the ABR process,which is directly involved in the regulation of blood pressure.Further more,in PAH patients,increased Piezo1 openness has a proliferative effect on arterial smooth muscle cells,which in turn affects their diameter and wall thickness.Remodeling of pulmonary hypertension in only the small and medium-sized artery significantly,because SOCC and ROCC in close to heart and were differentially expressed on peripheral pulmonary artery smooth muscle,and there are differences in calcium regulation ability,especially the TRPC1&6 in the expression of pulmonary artery and pulmonary artery smooth muscle cells,endings are greater than near heart[32],they mediated SOCE and ROCE respectively,in terms of calcium regulation,both mediated increase in calcium ion flow in peripheral level greater than near heart[32].In addition,the intracellular calcium level of peripheral cells was higher and larger than that of proximal cells under hypoxia.So is it similar on Piezo1?In remodeling of pulmonary artery and small artery remodeling artery significantly,whether this calcium channel in different diameter of pulmonary artery and mechanical sensitivity on the expression or function are different,in addition,oxygen lung small artery spasm,and artery basic won't happen this case,the relevant research has shown that as the ion channel transient receptor potential TRPC channel proteins were differentially expressed both inside and outside the pulmonary artery,and,in turn,have different effect on the regulation of Ca2+,so Piezo1 in small and medium-sized whether the expression of arteries and the aorta also have differences,or related to the above situation is not yet studies,which need to be further explored.[Objectives]The purpose of the study was to explore the expression of the mechanically sensitive channel protein Piezo1 in intra and extra pulmonary artery smooth muscle cells,and its regulation of Ca2+.[Methods]1.The internal and external pulmonary arteries were isolated and primary cells were cultured respectively.Using RT-qPCR and Western-Blot to explore the expression level of Piezo1 gene and protein.2.Calcium imaging technology was used to compare and investigate whether the intracellular calcium ion regulation mediated by Piezo1(both intracellular calcium flow and calcium release)under the stimulus of Yodal in pulmonary arterial smooth muscle cells.3.After the smooth muscle primary cells of the internal and external pulmonary arteries were cultured and treated with hypoxia,respectively,it was investigated whether Piezo1 expression and the intracellular calcium regulation mediated by IT were different in the hypoxia case.4.Cell proliferation assay CCK-8 was used to detect the cell proliferation of the two groups under chronic stimulation with certain concentration of Yodal.[Results]1.At mRNA level,there is no significant difference in Piezo1 expression in arterial smooth muscle cells inside and outside the lung.At the protein level,Piezo1 is more expressed in intra-pulmonary arterial smooth muscle cells than in extrapulmonary ones2,pulmonary artery smooth muscle cells inside and outside the Piezol can be mediated calcium ions on the flow,and the two basic calcium level was no significant difference,but the pulmonary artery smooth muscle,and within the pulmonary artery smooth muscle of Piezol under Yodal acute stimulation,can lead to higher levels of calcium in flow,and in removing Yodal stimulation,switch to calcium based liquid perfusion after PSS,a certain period of time,within the pulmonary artery smooth muscle of the more significant the intracellular calcium levels3.There was no significant difference in the calcium release ability of the smooth muscle cells inside and outside the lung4.For a certain concentration of Yodal chronic stimulus,Piezo1 channel is open,and within a certain time,the proliferation of smooth muscle cells in the internal pulmonary artery is obvious,while that in the external pulmonary artery is not obvious5.Hypoxia has no significant effect on the expression and function of Piezo1 in both internal and external pulmonary arterial smooth muscle cells.Compared with the normal oxygen conditions,there was no significant difference in the degree of Piezol-mediated calcium flow in both internal and external smooth muscle cells after simple hypoxia treatment,nor in the relative basic calcium level of the cells and the sustain of Yodal for Piezo1 activation.[Conclusion]The expression of Piezol is different in pulmonary arterial smooth muscle cells inside and outside the lung.Under the acute stimulus of Yodal,the agonist of Piezol,two types of PASMCs are different in the regulation of calcium influx,and the intra pulmonary artery smooth muscle cells is more sensitive to YodalThere is no obvious difference in the function of Piezo1 channel calcium release in the organelle storage of Ca2+and in the organelle membrane of the smooth muscle cells in the intracellular and extracellular arteries.When Piezol is activated in the same stimulus,the increase in intracellular calcium concentration is mainly caused by Piezol mediated intracellular calcium flow in the membraneWhen Piezo1 channel is activated,the proliferation of intra-pulmonary arterial smooth muscle is not obvious,while that of extra-pulmonary arterial smooth muscle is not obvious.