Expression And Differences Analysis Of MicroRNA During Canine Mandible Distraction Osteogenesis Relate To Neovascularization And Ossification

Objective:To study the difference expression of microRNA and the mechanism of neovascularization between canine mandible distraction osteogenesis and rapid development period of canine.To investigate the influence of microRNA on osteoblast mineralization and predict microRNA target genes.Methods:Adult dogs and new born dogs were divided into 0-week consolidation group,2-week consolidation group,normal group,and new born 0,2, 4, 8 weeks group.2-week consolidation group were operated on the right side of the mandible and internal distractor was installed in place as designed on dog.After 7-day latency period,the distraction was performed at a rate of lmm/day for 7 days.Specimens were harvested in and around the distraction gap when distraction ended.And macrography and CBCT examination,histological and RNA sequencing and subsequent analysis of specimens were carried out.Results: 1)General observation:Experimental dog of 0-week consolidation group and 2-week consolidation group were successfully achieved according to the experimental design without death,infection,distraction device and titanium nails falling off.The distraction region were surrounded by periosteum;2)CBCT examination:The boundary of distraction gap was clear,but no bone formation was found in distraction gap;3)HE staining micrograph examination:Compared with the normal group,abundant small diameter capillaries and cell can be observed in distraction gap;4)Compared with the normal group and new born 0,2,4,8 weeks group,the expression of miR-142 in 0-week consolidation group were significantly different;5)PSEN1 was predicted as the target gene of miR-142 involved in osteoblast mineralization and neovascularization.Conclusions:miR-142 supports osteoblast mineralization and neovascularization through upregulating PSEN1 expression in a post-transcriptional level.