Human lung telocytes could promote the proliferation and angiogenesis of human pulmonary microvascular endothelial cells in vitro

Background

In the previous studies, telocytes were found near the capillaries in many tissues, especially on the extracellular matrix of blood vessels and positive to CD34 and c-kit. Therefore, the present study aimed to explore if telocytes could produce angiogenesis associated cytokines, promote the proliferation and the angiogenesis of vascular endothelial cells in vitro.

Methods

Human lung telocytes were isolated and cultured, and were identified by immunofluorescence cytochemistry with CD34, c-kit and vimentin. Telocytes conditional media (TCM) was prepared, and the expressions of angiogenesis associated cytokines in TCM were detected by ELISA. Human pulmonary microvascular endothelial cells (HPMECs) were cultured with DMEM media or TCM for 72 hours. The proliferation of HPMECs was continuously detected with CCK-8 kit at an interval of 12 hours. HPMECs were also injured by lipopolysaccharide, and cultured with TCM and DMEM respectively, and the tube formation capacity was detected.

Results

Telocytes were positive for CD34, c-kit and vimentin. The expressions of VEGF and EGF in TCM were significantly higher, the proliferation of HPMECs cultured with TCM significantly increased, and the tube formation of HPMECs injured by endotoxin was improved with the culture of TCM, as compared with the culture of DMEM.

Conclusion

The present study provides the evidence that human lung telocytes could produce the growth factors, such as VEGF and EGF. Telocytes conditional media induced the proliferation of pulmonary endothelial cells and prevented from endotoxin-induced compromise of pulmonary endothelial angiogenesis.

Telocytes in the urinary system

BACKGROUND

Telocytes, a new type of interstitial cells, have been identified in many organs in mammals. The present studies aimed at investigating the ultrastructure, distribution and interactions of telocytes with surrounding cells in the urinary system of rats, to confirm the existence of telocytes in kidneys, ureter and urinary bladder.

METHODS

Samples of kidney, ureter, or urinary bladder were harvested for the ultrastructure by the electron microscope. The primary culture of telocytes was performed to investigate the dynamic alterations.

RESULTS

Telocytes mainly located in the sub-capsular space of kidney, or between smooth muscle bundles and in the lamina propria of ureter and urinary bladder. Telocytes established numerous contacts with macrophages in the sub-capsular space of kidney, or with smooth muscle cells, nerve endings as well as blood capillaries in the ureter and urinary bladder. The complete morphology of telocytes with telopodes was observed clearly through the primary cell culture from the kidney tissues of rats.

CONCLUSIONS

Our data evidenced the existence of telocytes in the urinary system, which may contribute to the tissue reparation and regeneration.