Expression Of Elastin In Rat Cardiomyocytes And H9C2 Cardiomyocyte Cell Line

BackgroundElastin is the main component of elastic fiber and it imparts good elasticity to its organs.The precursor of elastin is pre-elastin.Pre-elastin is synthesized in the cell,when it removes some amino acid residues at its carboxyl terminus becoming into tropoelastin,4molecule-tropoelastin crosslinks and polymerizes into an elastin macromolecule.Elastic fiber plays an important role in the development of many diseases,especially myocardial infarction,hypertension and aortic dissection.Studies have shown that fibroblasts,smooth muscle cells and endothelial cells can secrete pro-elastin,whether cardiomyocytes can synthesize and secrete elastin has not been reported in the literature.ObjectiveTo investigate the expression and secretion of elastin in myocardial tissue,neonatal rat cardiomyocytes,H9C2 cardiomyocyte cell line and Human umbilical vein endothelial cell line.it can provide morphological and theoretical basis for cardiac basic medical and clinical research.Methods(1)5 hearts of 6 weeks SD rats and 5 hearts of newborn 3d rats were taken,fixed,dehydrated,embedded and sliced continuously.Then,we can get the frozen sections of myocardial tissue whose thickness is 6μm.(2)The hearts of newborn 3d SD rats were taken and digested with 0.05% trypsin and0.075% type II collagenase.The primary cardiomyocytes of neonatal rats were obtained by differential adherence method.(3)Immunohistochemistry and immunohistochemistry were used to detect the expression of elastin and co-expression of elastin and cardiac troponin T in neonatal rat primary cardiomyocytes,H9C2 cardiomyocyte cell line and Human umbilical vein endothelial cell line.(4)Elisa method was used to detect the content of elastin in cell lines.Results(1)Elastin-positive expression can be observed in the myocardial tissues of newborn and adult SD rats,but it is localized and has no obvious regularity.It can be seen that elastin is distributed on the perivascular and endocardial sides and mainly distributed in the interstitial cells,at the same time we can observe the expresses of elastin in cardiomyocytes,endothelial cells,fibroblasts and smooth muscle cells.Elastin was mainly expressed in the cytoplasm in both the transverse and longitudinal sections of the cardiomyocytes,and a small amount of expression was observed on the nucleus.cardiac troponin T(cTnT)and elastin were co-expressed in both neonatal rat myocardial tissue and adult rat myocardial tissue.(2)Elastin was expressed in neonatal rat cardiomyocytes,H9C2 myocardial cell line and human umbilical vein endothelial cell line.(3)Elisa method could detect elastin in the supernatant of H9C2 myocardial cell line,but no elastin was detected in the supernatant of human umbilical vein endothelial cell line.ConclusionsElastin is expressed in rat cardiomyocytes,H9C2 cardiomyocytes cell line,endothelial cells and Human umbilical vein endothelial cell line.