Different effects of implanting vascular bundles and sensory nerve tracts on the expression of neuropeptide receptors in tissue-engineered bone in vivo

• Published in: Biomedical materials (Bristol) 2010-10, Vol.5 (5), p.055002-055002
• Main Authors: Chen, Si-Yuan, Qin, Jun-Jun, Wang, Le, Mu, Tian-Wang, Jin, Dan, Jiang, Shan, Zhao, Pei-Ran, Pei, Guo-Xian
• Format: Article
• Language: English
• Subjects: Animals; Blood Vessels - transplantation; Bone and Bones - surgery; Calcium Phosphates - chemistry; Feasibility Studies; Femur - diagnostic imaging; Femur - injuries; Immunohistochemistry; Nerve Tissue - transplantation; Polymerase Chain Reaction; Rabbits; Radiography; Receptors, Neuropeptide - metabolism; RNA, Messenger - metabolism; Time Factors; Tissue Engineering
• ISSN: 1748-605X; 1748-6041; 1748-605X
• DOI: 10.1088/1748-6041/5/5/055002

We investigated whether implantation of vascular bundles or sensory nerves affected the expression of calcitonin gene-related peptide type I receptor (CGRP1R) and neuropeptide Y1 receptor (NPY1R) in tissue-engineered bone. We implanted osteogenically induced bone marrow mesenchymal stem cells (BMSCs) with β-tricalcium phosphate (β-TCP) as the scaffold material either with sensory nerve tracts (group I, n = 18), vascular bundles (group II, n = 18) or alone (group III, n = 18) to repair a 1.2 cm femur defect in the rabbit. Better osteogenesis was observed by x-ray and histology in groups I and II than in group III at 4, 8 and 12 weeks. Within the new bone, the mRNA levels of the two neuropeptide receptors determined by real-time PCR increased through week 8, and then gradually decreased (P < 0.05). Expression of the neuropeptide receptors determined by immunohistochemistry was lowest at 4 weeks (P < 0.05) and was higher in group II than in group I (P < 0.05). Expression was significantly higher in groups I and II than in group III at all time points. We conclude that implanting vascular bundles into tissue-engineered bone can significantly improve the early expression of CGRP1R and NPY1R. In contrast, implantation of sensory nerves did not show the same dramatic effect as implantation of vascular bundles.