Renal telocytes contribute to the repair of ischemically injured renal tubules

Telocytes (TCs), a distinct type of interstitial cells, have been identified in many organs via electron microscopy. However, their precise function in organ regeneration remains unknown. This study investigated the paracrine effect of renal TCs on renal tubular epithelial cells (TECs) in vitro, the regenerative function of renal TCs in renal tubules after ischaemia–reperfusion injury (IRI) in vivo and the possible mechanisms involved. In a renal IRI model, transplantation of renal TCs was found to decrease serum creatinine and blood urea nitrogen (BUN) levels, while renal fibroblasts exerted no such effect. The results of histological injury assessments and the expression levels of cleaved caspase-3 were consistent with a change in kidney function. Our data suggest that the protective effect of TCs against IRI occurs via inflammation-independent mechanisms in vivo. Furthermore, we found that renal TCs could not directly promote the proliferation and anti-apoptosis properties of TECs in vitro. TCs did not display any advantage in paracrine growth factor secretion in vitro compared with renal fibroblasts. These data indicate that renal TCs protect against renal IRI via an inflammation-independent pathway and that growth factors play a significant role in this mechanism. Renal TCs may protect TECs in certain microenvironments while interacting with other cells.