Effect of lentiviral vector overexpression alpha-calcitonin gene-related peptide on titanium implant osseointegration in alpha-CGRP-deficient mice

摘要

alpha-Calcitonin gene-related peptide (alpha-CGRP) plays a significant pathophysiological role in bone development, metabolism and remodeling around dental implants. However, the half-life of alpha-CGRP in plasma is only 10 min, which affects its long-time application and an alternative approach should be developed to deliver alpha-CGRP over long periods of time. The aim of this study is to investigate whether a lentiviral alpha-CGRP overexpression vector system can express this target-gene longer at peri-implant sites, thus enhancing osseointegration. Animals were divided to the following groups: alpha-CGRP(-/-), alpha-CGRP(-/-) with lentivirus transfection and alpha-CGRP(+/+) mice. MS Spectrum imaging observations identified the successful transfection of alpha-CGRP around experimental implants inserted in the femurs at 5 days after injection. Histomorphometrical analysis indicated an increase of bone-implant contact (BIC) at 1-month healing in the transfection group. Moreover, real-time RT-PCR and western blot results of bone-related markers Runx2, Osterix, and BSP levels elevated in lentivirus-transfected mice at 21 days, compared to the untreated alpha-CGRP(-/-) mice. There was no significant difference between the transfection group and alpha-CGRP(+/+) group. Further alpha-CGRP protein detection confirmed the persistent expression of this transgene at 21 days post-operatively. These results suggest that this lentiviral vector system expresses alpha-CGRP in an effective, appropriate and sustained manner, which might have a potential application in enhancing titanium implant osseointegration. (C) 2016 Elsevier Inc. All rights reserved.