Background： Telocytes （TCs） are a novel type of interstitial cells, which have been recently described in a large variety of cavitary and noncavitary organs. TCs have small cell bodies, and remarkably thin, long, a...Background： Telocytes （TCs） are a novel type of interstitial cells, which have been recently described in a large variety of cavitary and noncavitary organs. TCs have small cell bodies, and remarkably thin, long, and moniliform prolongations called telopodes （Tps）. Until now, TCs have been found in various loose connective tissues surrounding the arterioles, venules, and capillaries, but as a histological cellular component, whether TCs exist in large arteries remains unexplored. Methods： TCs were identified by transmission electron microscope in the aortic arch of male C57BL/6 mice. Results： TCs in aortic arch had small cell bodies （length： 6.06-13.02 μm： width： 1.05-4.25 μm） with characteristics of specific long （7.74-39.05 μm）, thin, and moniliform Tps; TCs distributed in the whole connective tissue layer of tunica adventitia： TCs in the innermost layer of tunica adventitia, located at the juncture between media and adventitia, with their long axes oriented parallel to the outer elastic membrane： and TCs in outer layers oftunica adventitia, were embedded among transverse and longitudinal oriented collagen fibers,forming a highly complex three-dimensional meshwork. Moreover, desmosomes were observed, serving as pathways connecting neighboring Tps. In addition, vesicles shed from the surface of TCs into the extracellular matrix, participating in some biological processes. Conclusions： TCs in aorta arch are a newly recognized complement distinct from other interstitial cells in large arteries, such as fibroblasts. And further biologically functional correlations need to be elucidated.展开更多
Background： This study characterized the cardiac telocyte （TC） population both in vivo and in vitro, and investigated its telomerase activity related to mitosis. Methods： Using transmission electron microscopy and...Background： This study characterized the cardiac telocyte （TC） population both in vivo and in vitro, and investigated its telomerase activity related to mitosis. Methods： Using transmission electron microscopy and a phase contrast microscope, the typical morphological features of cardiac TCs were observed; by targeting the cell surface proteins CD1 17 and CD34, CD 117^＋CD34^＋ cardiac TCs wcrc sorted via flow cytomctry and validated by immunofluorescence based on the primary cell culture. Then the optimized basal nutrient medium for selected population was examined with the cell counting kit 8. Under this conditioned medium, the process of cell division was captured, and the telomerase activity of CD117^＋ CD34^＋ cardiac TCs was detected in comparison with bone mesenchymal stem cells （BMSCs）, cardiac fibroblasts （CFBs）, cardiomyocytes （CMs）. Results： Cardiac TCs projected characteristic telopodes with thin segments （podomers） in alternation with dilation （podoms）. In addition, 64% of the primary cultured cardiac TCs were composed of CD117^＋CD34^＋ cardiac TCs： which was verified by immunofluorescence. In a live cell imaging system, CD117^＋CD34^＋ cardiac TCs were observed to enter into cell division in a short time. followed by an significant invagination forming across the middle of the cell body. Using a real-time quantitative telomeric-repeat amplification assay, the telomerase concentration in CD117^＋CD34^＋ cardiac TCs was obviously lower than in BMSCs and CFBs, and significantly higher than in CMs. Conclusions： Cardiac TCs represent a unique cell population and CD11 7^＋CD34^＋ cardiac TCs have relative low telomerase activity that differs from BMSCs, CFBs and CMs and thus they might play an important role in maintaining cardiac homeostasis.展开更多
基金This study was supported by a grant from the Young Scientists Fund of the National Natural Science Foundation of China
文摘Background： Telocytes （TCs） are a novel type of interstitial cells, which have been recently described in a large variety of cavitary and noncavitary organs. TCs have small cell bodies, and remarkably thin, long, and moniliform prolongations called telopodes （Tps）. Until now, TCs have been found in various loose connective tissues surrounding the arterioles, venules, and capillaries, but as a histological cellular component, whether TCs exist in large arteries remains unexplored. Methods： TCs were identified by transmission electron microscope in the aortic arch of male C57BL/6 mice. Results： TCs in aortic arch had small cell bodies （length： 6.06-13.02 μm： width： 1.05-4.25 μm） with characteristics of specific long （7.74-39.05 μm）, thin, and moniliform Tps; TCs distributed in the whole connective tissue layer of tunica adventitia： TCs in the innermost layer of tunica adventitia, located at the juncture between media and adventitia, with their long axes oriented parallel to the outer elastic membrane： and TCs in outer layers oftunica adventitia, were embedded among transverse and longitudinal oriented collagen fibers,forming a highly complex three-dimensional meshwork. Moreover, desmosomes were observed, serving as pathways connecting neighboring Tps. In addition, vesicles shed from the surface of TCs into the extracellular matrix, participating in some biological processes. Conclusions： TCs in aorta arch are a newly recognized complement distinct from other interstitial cells in large arteries, such as fibroblasts. And further biologically functional correlations need to be elucidated.
基金Source of Support： This study was supported by a grant from the Young Scientists Fund of the National Natural Science Foundation of China （No, 81300232）. Conflict of Interest： None dec ared.
文摘Background： This study characterized the cardiac telocyte （TC） population both in vivo and in vitro, and investigated its telomerase activity related to mitosis. Methods： Using transmission electron microscopy and a phase contrast microscope, the typical morphological features of cardiac TCs were observed; by targeting the cell surface proteins CD1 17 and CD34, CD 117^＋CD34^＋ cardiac TCs wcrc sorted via flow cytomctry and validated by immunofluorescence based on the primary cell culture. Then the optimized basal nutrient medium for selected population was examined with the cell counting kit 8. Under this conditioned medium, the process of cell division was captured, and the telomerase activity of CD117^＋ CD34^＋ cardiac TCs was detected in comparison with bone mesenchymal stem cells （BMSCs）, cardiac fibroblasts （CFBs）, cardiomyocytes （CMs）. Results： Cardiac TCs projected characteristic telopodes with thin segments （podomers） in alternation with dilation （podoms）. In addition, 64% of the primary cultured cardiac TCs were composed of CD117^＋CD34^＋ cardiac TCs： which was verified by immunofluorescence. In a live cell imaging system, CD117^＋CD34^＋ cardiac TCs were observed to enter into cell division in a short time. followed by an significant invagination forming across the middle of the cell body. Using a real-time quantitative telomeric-repeat amplification assay, the telomerase concentration in CD117^＋CD34^＋ cardiac TCs was obviously lower than in BMSCs and CFBs, and significantly higher than in CMs. Conclusions： Cardiac TCs represent a unique cell population and CD11 7^＋CD34^＋ cardiac TCs have relative low telomerase activity that differs from BMSCs, CFBs and CMs and thus they might play an important role in maintaining cardiac homeostasis.
