Multiple immunophenotypes of cardiac telocytes

• TCs’ movement and extension of their prolongations lasted for approximately 1.5 h.
• The unique structural characteristics of TCs were observed by SEM for the first time.
• Cardiac TCs cultured in vitro expressed vimentin, CD34, nanog, sca-1 and c-kit.

AimsTelocytes (TCs) form a 3-dimensional network in the myocardial interstitium, which most probably play important role(s) in heart development. However, the dynamics of their prolongations, continuous cell shape changes and adherence properties have not been well documented till recently. The aim of this study was to investigate dynamics of extension of prolongations (Telopods) and multiple phenotypes of cardiac TCs cultured in vitro.MethodsCardiac TCs were isolated from neonatal rats by a combined enzyme digestion process and identified by light microscopy, immunofluorescence analysis and scanning using electron microscopy (SEM). Their continuous changes in shape were analyzed by a Live Cell Imaging System and multiple phenotypes were identified by immunofluorescence analysis using various markers, like vimentin, c-kit, CD34, nanog and sca-1.ResultsCardiac TCs displayed piriform/spindle/triangular shapes with long and slender telopodes showing extremely long prolongations. The morphology of cell body was continuously changing while their prolongations were extending gradually. After adhering to the surface, TCs’ movement and extension of their prolongations lasted for approximately 1.5 h. Cardiac TCs expressed mesenchymal cell marker vimentin, hematopoietic stem cell marker CD34, embryonic stem cell-associated gene of Nanog, and myocardial stem cell markers sca-1 and c-kit.ConclusionThese findings indicate that cultured TCs in vitro have multiple phenotypes, which are most likely important for evaluating their functional roles in heart development.