Increased telocytes involved in the proliferation of vascular smooth muscle cells in rat carotid artery balloon injury.

Telocytes (TCs) are a novel type of interstitial cells that are thought to be involved in tissue regeneration and repair. However, the possible roles of TCs in vascular diseases remain unclear. In this study, we used a rat model of carotid artery balloon injury (CABI) to study the changes and potential roles of vascular TCs after vascular injury. Transmission electron microscopy (TEM) and CD34/vimentin immunolabeling were used to identify and quantify TCs in normal and injured carotid arteries. Quantitative immunofluorescence analysis revealed that, compared with the sham group, the number of TCs in the CABI group increased from 7.2±1.0 to an average of 20.4±1.8 per 1-mm(2) vascular area. The expression level of miR-24 in TCs was three times higher than in vascular smooth muscle cells (VSMCs). The percentage of VSMCs in S phase and G2/M phase increased by approximately 5% when VSMCs were incubated with the supernatant of TCs. The antagomir of miR-24 in TCs reduced the ratio of VSMCs in S phase and G2/M phase. This study illuminates the function of TCs in the proliferation of VSMCs.