Morphological Characteristics And Multiple Differentiation Potentiality Of Telocytes In Neonatal Rat Heart

Background Telocytes(TCs)are a novel interstitial(stromal)cell type described in many tissues and organs.At present,the researches on TCs are mostly confined to the morphology and the formation of fat and osteogenesis,but little researches is about to see if there are characteristics of neural cell differentiation potential and cardiac pacemaker cells.This thesis aims to study whether TCs has the potential of multi differentiation and the relationship between their morphology and function.It is of great significance for the further study to verify the characteristics of TCs and its biological function.Objective The objectives of this thesis are listed as following,study the morphological characteristics of telocyetes(TCs)in neonatal rat hearts,verify whether it has the characteristics of nerve cells and glial cells and the characteristics of the pluripotent differentiation potential of stem cells,provide cytological evidence for the development and utilization of TCs.Methods 1 Enzyme digestion method was adopted to isolate and culture primary cardiac telocytes cells in neonatal rat,and differential adhesion was used to purify the cardiac telocytes.We monitor TCs with well morphological change by live cell imaging system.2 HE staining,immunocytochemistry,and immunofluorescence were used to observe the expression of TCs on vimintin and CD34,as well as the identify telocytes cultured in vitro.3 The morphology of telocytes cultured in vitro was observed under scanning electron microscope.Observation of the ultrastructural of telocytes in neonatal rat heart tissue and its relationship with the neighboring cells was under transmission electron microscope.4 Multi-differentiation of telocytes was induced by osteogenic induction solution,lipid inducing solution and 5a Za.Alizarin red staining,oil red O staining and immunofluorescence technique were used to identify the induced cardiac telocytes.5 Neural induction media was used to induce cardiac TCs.The expression of neuronal and glial cells in the TCs and the induced TCs were detected by immunofluorescence.6 Detect whether TCs expressed cardiac pacemaker cell specific marker protein HCN4.Results 1 The cultured telocytes in neonatal rat were in good state and of high purity.2 The immunocytology staining showed that cultured cells positively expressed CD34,and coexpressed vimentin and CD34.3 Scanning electron microscopes showed that telocytes were composed of cell bodies and processes.The cell body is oval and small.And a variable n?mber(one to five)of extremely long and thin telopodes,with alternating regions of podomers and podoms can be observed.Telocytes has a variable morphology: fusiform/pyriform/triangular depending on the n?mber of Tps.4 Transmission electron microscopes showed that there were a lot of telocytes in the myocardi?m of neonatal rats.The cell body was measured between 9 and 15 ?m.The nucleus is oval,and the ratio of nucleus / cytoplasm is relatively large.The cytoplasmic organelles were abundant,and there were cytoskeletal structures such as microtubules,intermediate filaments,actin filaments and fine filaments.There are caveolae on the cell membrane.Several extremely long(10–1,000mm)with very thin cellular elongations extend from the cell body.Podoms accommodate functional units consisting of caveolae,mitochondria,and endoplasmic reticul?m.TCs are in close contact with cardiac muscle cells,fibroblasts,endothelial cells and peripheral cells.5 After induced in the osteogenesis inducing solution(OS)for 21 days,results of alizarin red dyeing was positive.Results of oil red O staining after 14 days of fat induction was positive.Immunofluorescence staining of c Tn T after 4 weeks of myocardial induction was positive.6 Teocytes does not express NSE?GFAP?OX42?CNpase,and TCs induced to be neurogenesis are not expressed GFAP.7 Teocytes does not express HCN4.Conclusion TCs has the potential of multi differentiation,has the ability to differentiate into bone,fat and cardiac muscle,Nevertheless,it does not have characteristics of nerve cell and pacemaker cells.