Objective: Tissue engineered bone implanted with sensory nerve can effectively promote angiogenesis and repair of bone defects. To investigate the effects of calcitonin gene-related peptide (CGRP) on proliferation and migration of human umbilical vein endothelial cells (HUVECs) for further revealing the mechanism of tissue engineered bone implanted with sensory nerve promoting angiogenesis.
Methods: HUVECs were collected from human umbilical core, and identified through von Willebrand factor (vWF) and CD31 immunofluorescence. The HUVECs were treated with CGRP and were divided into 6 groups according to CGRP concentration: group A (0 mol/L), group B (1 x 10(-12) mol/L), group C (1 x 10(-11) mol/L), group D (1 x 10(-10) mol/L), group E (1 x 10(-9) mol/L), and group F (1 x 10(-8) mol/L). The expression of the CGRP1 receptor (CGRP1R) was observed in HUVECs by cell immunofluorescence. The growth rate of HUVECs was detected throug AAlarmarBlue at 1, 2, 3, 4, and 5 days. Transwell chamber was used to detect the ability of cell migration. ELISA assay was used to detect the vascular endothelial growth factor (VEGF) secretion and the protein expression of focal adhesion kinase (FAK) was examined using Western blot.
Results: HUVECs were identified through morphology, vWF and CD31 immunofluorescence. HUVECs expressed CGRP1R. CGRP could stimulate HUVECs proliferation in a time- and concentration-dependent manners; the cell growth rates of groups B-F were significantly higher than that of group A at all time (P < 0.05); group F had highest cell growth rate. The number of cell migration of group B-F was significantly higher than that of group A (P < 0.05), which increased more than 3 times. Groups B-F had higher amount of VEGF than group A (P < 0.05), and groups C and D had highest amount of VEGF. FAK expression of groups B-F was significantly increased at 3, 7, and 10 days after CGRP treatment when compared with group A (P < 0.05).
Conclusion: CGRP may enhance the proliferation and migration of HUVECs by increasing the secretion of VEGF and expression of FAK.