Effects Of Fibronectin And Laminin On Proliferation And Differentiation Of Skeletal Muscle Satellite Cells

Skeletal muscle,as the most tissue component in animals,plays an important biological function.Promoting muscle development and improving animal muscle quality are currently the primary tasks of animal husbandry production.Among them,promoting muscle development is to improve animal production efficiency,improve meat quality and achieve efficient health The main means of breeding goals.The characteristics of muscle fibers can be independently regulated by genetic regulation or internal environmental factors.Extracellular matrix(ECM)is the internal environment on which muscle tissue depends and can control the proliferation and differentiation of muscle stem cells.In this study,the ECM environment was mimic in vitro to optimizing the culture conditions of bovine skeletal muscle satellite cells in vitro,improving their proliferation and differentiation process,and promoting the generation of muscle fibers.This study first explored the effects of FN and LN,two important protein components in ECM,on the proliferation and differentiation of bovine skeletal muscle satellite cells,respectively.The method is to use FN or LN as the surface coating of the cell culture dish in the culture of muscle satellite cells in vitro to mimic the muscle extracellular matrix.The proliferation of myoblasts was detected by Ed U cell proliferation assay.The expression of myoblast proliferation and differentiation marker genes was detected by q RT-PCR and Western blot.Compared with the control group,the number of Ed U-positive cells detected by Ed U proliferation staining in the FN treatment group was significantly down-regulated(P <0.05),and the expression of the proliferation marker gene Pax7 of bovine muscle satellite cells cultured on the FN coating was significantly increased at 12 h It was down-regulated(P <0.05);the expression of differentiation marker gene My HC showed no significant difference between differentiation at 24 h and differentiation at 48 h(P> 0.05).Compared with the control group,there was no significant difference in the number of Ed U positive cells detected by Ed U proliferation staining in the LN treatment group(P> 0.05).The proliferation marker gene Pax7 of bovine skeletal muscle satellite cells cultured on the LN coating was growing There was no significant difference between 12 h and 24 h proliferation(P> 0.05);while the differentiation marker gene My HC was significantly up-regulated on the m RNA expression level at 12 h differentiation(P <0.01),and the protein expression level at 48 h differentiation Increased(P <0.01).Since it is difficult to perform in vivo experiments in cattle,this study used mice as the gastrocnemius-denervator muscle injury model to further explore the role of LN in regulating muscle growth and development in vivo.A gastrocnemius muscle-denervator muscle injury model was constructed.After exogenous injection of LN in gastrocnemius muscle,gastrocnemius muscle wet weight ratio,tissue section HE staining,muscle fiber diameter measurement,q RT-PCR and Western blot were used to detect the myogenic differentiation factor My HC in mice.The results showed that compared with the control group,the wet weight ratio of the gastrocnemius muscle in the LN treatment group was significantly increased(P <0.01),but there was no significant difference in the statistics of muscle fiber diameter measurement data and My HC expression(P> 0.05).This study confirmed that with the in vitro bovine skeletal muscle satellite cell culture model,exogenous plating FN inhibited the proliferation of bovine muscle satellite cells,while exogenous plating LN promoted and advanced the differentiation process of bovine muscle satellite cells,and promoted bovine skeletal muscle The role of satellite cell differentiation and experimental method innovation provide a good foundation for in vitro cell culture;further in vivo experiments in mice have shown that LN can also play a certain regulatory role in vivo.In short,the research results can not only provide a reference for the study of muscle development and differentiation,but also provide a basis for the improvement of meat and beef quality,and have significantly scientific importance for the genetic improvement of livestock and poultry meat traits.