Telocytes accompanying cardiomyocyte in primary culture: two‐ and three‐dimensional culture environment

Abstract

Recently, the presence of telocytes was demonstrated in human and mammalian tissues and organs (digestive and extra-digestive organs, genitourinary organs, heart, placenta, lungs, pleura, striated muscle). Noteworthy, telocytes seem to play a significant role in the normal function and regeneration of myocardium. By cultures of telocytes in two- and three-dimensional environment we aimed to study the typical morphological features as well as functionality of telocytes, which will provide important support to understand their in vivo roles. Neonatal rat cardiomyocytes were isolated and cultured as seeding cells in vitro in two-dimensional environment. Furthermore, engineered myocardium tissue was constructed from isolated cells in three-dimensional collagen/Matrigel scaffolds. The identification of telocytes was performed by using histological and immunohistochemical methods. The results showed that typical telocytes are distributed among cardiomyocytes, connecting them by long telopodes. Telocytes have a typical fusiform cell body with two or three long moniliform telopodes, as main characteristics. The vital methylene blue staining showed the existence of telocytes in primary culture. Immunohistochemistry demonstrated that some c-kit or CD34 immuno-positive cells in engineered heart tissue had the morphology of telocytes, with a typical fusiform cell body and long moniliform telopodes. Also, a significant number of vimentin+ telocytes were present within engineered heart tissue. We suggest that the model of three-dimensional engineered heart tissue could be useful for the ongoing research on the functional relationships of telocytes with cardiomyocytes. Because the heart has the necessary potential of changing the muscle and non-muscle cells during the lifetime, telocytes might play an active role in the heart regeneration process. Moreover, telocytes might be a useful tool for cardiac tissue engineering.

Multiple immunophenotypes of cardiac telocytes

“…Vimentin is an intermediate filament protein which is widely distributed in mesenchymal cells. It was also shown that some c-kit or CD34 immunopositive cells in engineered heart tissue have the morphology of telocytes, with a typical fusiform cell body and long moniliform telopodes, suggesting a possible role in the heart regeneration process, and a possible value as a tool for cardiac tissue engineering [25]. More importantly, we also found that cardiac TCs positively expressed stem cell markers nanog and sca-1.…”

Distribution and characteristics of telocytes as nurse cells in the architectural organization of engineered heart tissues

“…We have previously isolated and cultured telocytes from neonatal rat cardiac tissue in two-and three-dimensional environments in vitro [27]. Our previous study confirmed that typical telocytes existed in primary culture in vitro and some c-kit, vimentin, or CD34-positive cells in EHTs exhibited the morphology of telocytes.…”

“…EHTs were constructed by combining freshly isolated cardiac cells from one-day-old Wistar rats with a collagen/Matrigel mixture as described previously [25,27]. In brief, 0.5 mL 2× H-DMEM (Invitrogen, Carlsbad, CA, USA) containing 20% fetal bovine serum (Invitrogen) was mixed with 0.5 mL liquid collagen type I and Matrigel (4 : 1, (v/v); Becton Dickinson Biosciences, San Jose, CA, USA).…”

Myocardial Telocyte-Like Cells: A Review Including New Evidence

“…Telocytes accompanying cardiomyocyte in primary culture: two-and three-dimensional culture environment [Zhou et al, 2010a] Cardiac telocytes were decreased during myocardial infarction and their therapeutic effects for ischaemic heart in rat [Zhao et al, 2013] Intramyocardial transplantation of cardiac telocytes decreases myocardial infarction and improves post-infarcted cardiac function in rats [Zhao et al, 2014] Comparative analysis of telomerase activity in CD117(+) CD34(+) cardiac telocytes with bone mesenchymal stem cells, cardiac fibroblasts and cardiomyocytes [Li et al, 2015] Histological and immunohistochemical study of cardiac telocytes in a rat model of isoproterenol-induced myocardial infarction with a reference to the effect of grape seed extract [Nour et al, 2017] J Cell Mol Med…”