Angiogenesis and myogenesis in mouse tibialis anterior muscles during distraction osteogenesis: VEGF, its receptors, and myogenin genes expression

Abstract

Angiogenesis and myogenesis occur in the surrounding skeletal muscles following distraction osteogenesis, but their molecular mechanisms remain unclear. The present study investigated morphological features of lengthened muscles and the time course change of vascular endothelial growth factor (VEGF), its receptors (VEGFR-1 and VEGFR-2) and myogenin gene expression profiles related to angiogenesis and myogenesis in tibialis anterior (TA) muscles with a mouse model of distraction osteogenesis, which involves 1 week of waiting period (latency phase), 2 weeks of intermittent distraction (distraction phase), and 5 weeks of remodeling period (consolidation phase). Macroscopic findings showed that lengthened TA muscles increased to approximately 42% longer and 10% heavier at the end of the process when compared to pre-surgery. During the distraction phase, VEGF and its receptors were induced in the vascular endothelial cells, myogenin-positive satellite cells and myocytes, and subsequently, capillary progression and myogenesis were increased. Real-time RT-PCR showed that Vegf, Vegfr-1, Vegfr-2, and myogenin genes expression was enhanced during the muscle lengthening. Vegf and Vegfr-1 were upregulated following the recession of angiogenesis at the consolidation phase. We conclude that upregulation of VEGF and its receptors by mechanical tension-stress could be involved in the process of angiogenesis and myogenesis in lengthened muscles. ß

Mesenteric neovascularization with distraction-induced intestinal growth: enterogenesis

“…Our lab had struggled to quantify neovascularization in the past relying on methods that have proven unreliable. As well, demonstration of increases in vascularization with tissue engineering has been quite challenging [15]. …”

“…With mechanotransduction, growth is induced by stress through the conversion of mechanical force to chemical signals that stimulate hypertrophy or hyperplasia [13]. This principle has been described for centuries in long bone osteogenesis [14] and has also since been applied to soft tissue for reconstruction [15]. Distraction-induced enterogenesis is a process whereby the intestine lengthens with application of intraluminal linear forces.…”

Positive effect of IGF‐1 injection on gastrocnemius of rat during distraction osteogenesis

“…The primers of Akt1, MyoD, Myogenin, Myostatin, and GAPDH used in the RT‐PCR are gotten from GeneCopoeia Inc (Table ) and the primers of collagen I mRNA (5'‐primer: GAT GAC GTG CAA TGC AAT GAA GAA; 3'‐primer: GCC ATA GGA CAT CTG GGA AGC AA) was synthesized based on previous study . We selected GAPDH as a reference gene to indicate the relative expression level of these genes because GAPDH as a housekeeping gene was widely used for normalization in the PCR analysis of muscle in a DO and in an IGF‐1 administration model . The difference between the threshold cycles (ΔCt = CT Target Gene‐CT Control Gene) was used in the analysis.…”

Periosteal Distraction Osteogenesis: An Effective Method for Bone Regeneration

“…VEGF, as a vascular growth factor, not only is conducive to the formation of blood vessels, but also can promote osteogenesis during the process of distraction [50, 51]; the injection of exogenous VEGF was proved to be beneficial to bone formation in PDO [21]. Another study [35] proved that the newly formed bone by PDO was more mature after adding platelet-rich fibrin (PRF).…”