Effect Of Osteoblast Injury And Inflammatory Factors On Ossification Of Myoblast

Myositis ossificans is a kind of tumor-like lesion occurred in soft tissue especially in muscle. It is divided into two categories: myositis ossificans circumscripta and myositis ossificans progressiva. Myositis ossificans progressiva is a kind of genetic disease, which belongs to connective tissue disease. Myositis ossificans circumscripta often caused by trauma, operation et al.Myositis ossificans traumatica (MOT) is a kind of myositis ossificans circumscripta caused by trauma. Pathogenesis of MOT is not yet clear, trauma, nerve injury and inflammation can turn mesenchymal cell into osteoblast, circumscribed ossification occured. Injury of osteoblast and myoblast, macrophage influx caused by inflammatory reaction, are considered to be factors of MOT.C₂C₁₂ were considered to be muscle satellite cell isolated from the muscle tissue, showed a different differentiation potential in different culture conditions. BMP is the first cytokine that could induce skeletal muscle into bone. BMP-2 inhibition C₂C₁₂ differentiate into muscle tissue, up-regulation osteoblast gene expression. This shows that C₂C₁₂ cells have the potential of osteoblast cells, is an ideal model of MOT. The relationship between inflammatory factors and heterotopic ossification were reported a lot in recent years, but mainly in the cardiac valve and endothelial cells. No reserch about inflammatory factor and myoblasts ossification were reported.We established the C₂C₁₂ myoblast cell line in vitro culture as us experimental model, to study the effort of cell injury and inflammatory factors on myoblast ossification, and discussed the pathogenesy of MOT.[Objective]To explore the effect of osteoblast injury and inflammatory factors on the expression of genes about ossification and myogenesis.[Methods]1. C₂C₁₂ myoblast cells were treated by lysate and supernatant of MC-3T3-E1 cell, we examed the ossification and myogenesis genes expression in C₂C₁₂ myoblast cell.2. C₂C₁₂ and MC-3T3-E1 cells were treated by supernatant of mice peritoneal macrophage and IL-1β, the ossification and myogenesis genes expression in C₂C₁₂ and MC-3T3-E1 cell were examed.3. C₂C₁₂ induced by lysate of MC-3T3-E1 cell were treated by supernatant of mice peritoneal macrophage and IL-1βthe ossification and myogenesis genes expression in C₂C₁₂ cell were examed.4. Statistical analysis: completely random design (One-way ANOVA) , P<0.05 denote statistical significant.[Results] 1.Lysate of MC-3T3-E1 cell could but supernatant of MC-3T3-E1 could not down-regulate MyoD and Myogenin expression, the differences have statistical significant (P=0.000) and up-regulate ALP and OPN expression of C₂C₁₂ cell, the differences have statistical significant (P=0.000).2.Supernatant of mice peritoneal macrophage could but IL-1βcould not up-regulate MyoD and Myogenin expression of C₂C₁₂ cell, the differences have statistical significant (P=0.000); could up-regulate ALP and OPN of MC-3T3-E1 cell, the differences have statistical significant (P=0.000).3.Supernatant of mice peritoneal macrophage and IL-1βcould up-regulate ALP expression of C₂C₁₂ cell induced by lysate of MC-3T3-E1, the differences have statistical significant (P=0.000).[Conclusion]1.Lysate of MC-3T3-E1 cell could up-regulate ossification expression of C₂C₁₂ cell.2.Inflammation factors could up-regulate myogenesis expression in C₂C₁₂ cells and ossification expression in MC-3T3-E1 cells.3.Inflammation factors could promote MyoD and Myogenin expression in C₂C₁₂ cells induced by lysate of MC-3T3-E1. IL-1βmaybe key role in this effect.