Telocytes in the urinary system

Abstract

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.

Figure 1

TEM of rat kidney. A Telocyte with its long telopode is visible under sub-capsular space of kidney, and it is near the capillary. Noting the striking labyrinthine network formed by telopode. Telopode is very long with alternation of podom and podomer. Telocyte connects with macrophages by telopode. (TC: telocyte; Tp: telopode; Mac: macrophage; RBC: red blood cell). Magnification is 5000×, and the scale bar is 2 μm.

Figure 2

TEM of rat ureter. Telocyte and telopode exist in lamina propria of ureter, and they connect with capillaries and smooth muscles. Four telocytes are showed. (TC: telocyte; Tp: telopode). Magnification is × 5000, and the scale bar is 2 μm.

Figure 3

TEM of rat ureter. A shows telopode exist in lamina propria of ureter, and it connects with never ending. Podom and podomer are showed clearly. Magnification is × 5000, and the scale bar is 2 μm. B is the enlargement of black dotted frame in A. Magnification is × 15000, and the scale bar is 1 μm.

Figure 4

TEM of rat ureter. A shows typical telopodes (Tp) and telocytes (TC) in the ureter, and telocytes connect with telopodes from other telocytes. B is the enlargement of white dotted frame in A, and the details about the connection between telcoytes (TC) and telopode (Tp, black arrow) are showed clearly. Magnification of A is 5000 ×, and the scale bar is 2 μm. Magnification of B is 20000 ×, and the scale bar is 0.5 μm.

Figure 5

TEM of rat urinary bladder.At least 6 telocytes with their extensive telopodes are visible in the interstitium of epithelium, near the capillaries, and they form a labyrinthine structure. (TC: telocytes; Cap: capillary). Magnification is 3000×, and the scale bar is 5 μm.

Figure 6

Telocytes from rat sub-capsular space of kidney. Primary culture, 5 days. There are two telocytes with typical Tp in A/B, and they connect together. Single telocyte with typical telopode (alternation with podom and podomer) could be seen in C/D clearly. (TC: telocytes; Tp: telopode). Magnification is 200× , and the scale bar is 3 μm.