Chicken Skeletal Muscle Satellite Cells Research Articles

Circular RNA profiling identified an abundant circular RNA circTMTC1 that inhibits chicken skeletal muscle satellite cell differentiation by sponging miR-128-3p.

Scope: Myogenesis involves a series of complex cellular and developmental processes regulated by many genes, transcription factors and non-coding RNAs. Recent studies have demonstrated the involvement of circular RNAs (circRNAs) in myogenesis. While previous studies have established a role for some circRNAs, the precise functions and mechanisms of circRNAs in skeletal muscle development are still not completely understood in chicken.Methods: To identify potential circRNAs during chicken embryonic skeletal muscle development, rRNA- libraries sequencing was performed in breast muscles from 12 broilers and 12 layers at four different embryonic points, embryonic day 10 (E10), E13, E16 and E19. Through circRNA differential expression analysis and target miRNA prediction, the circTMTC1 was predicted to participate in the embryonic muscle formation by sponging miRNA, which were verified in vitro experiments.Results: We identified 228 differentially expressed circRNAs between broilers and layers (fold change >2; p-value < 0.05), and 43 circRNAs were differentially expressed at multiple embryonic days. circTMTC1, a novel circRNA transcribed from the TMTC1 gene, was expressed significantly higher in layers than in broilers at E10, E13 and E16. Furthermore, circTMTC1 knockdown accelerated proliferation and differentiation in chicken skeletal muscle satellite cells (SMSCs), besides, circTMTC1-overexpressing cells showed opposite effects. circTMTC1 functioned as a miR-128-3p sponge at the differentiation stage of SMSCs, and circTMTC1 inhibited the expression of miR-128-3p. Furthermore, miR-128-3p promoted differentiation of chicken SMSCs, and circTMTC1 inhibited the promotion effect of miR-128-3p on chicken SMSC differentiation.Conclusion: Our study revealed that circRNAs are differentially expressed during chicken embryonic development between the two chicken models, and circTMTC1 inhibits chicken SMSC differentiation by sponging miR-128-3p.

The effect of temperature on proliferation and differentiation of chicken skeletal muscle satellite cells isolated from different muscle types.

Skeletal muscle satellite cells are a muscle stem cell population that mediate posthatch muscle growth and repair. Satellite cells respond differentially to environmental stimuli based upon their fiber‐type of origin. The objective of this study was to determine how temperatures below and above the in vitro control of 38°C affected the proliferation and differentiation of satellite cells isolated from the chicken anaerobic pectoralis major (p. major) or mixed fiber biceps femoris (b.femoris) muscles. The satellite cells isolated from the p. major muscle were more sensitive to both cold and hot temperatures compared to the b.femoris satellite cells during both proliferation and differentiation. The expressions of myogenic regulatory transcription factors were also different between satellite cells from different fiber types. MyoD expression, which partially regulates proliferation, was generally expressed at higher levels in p. major satellite cells compared to the b.femoris satellite cells from 33 to 43°C during proliferation and differentiation. Similarly, myogenin expression, which is required for differentiation, was also expressed at higher levels in p. major satellite cells in response to both cold and hot temperatures during proliferation and differentiation than b. femoris satellite cells. These data demonstrate that satellite cells from the anaerobic p. major muscle are more sensitive than satellite cells from the aerobic b. femoris muscle to both hot and cold thermal stress during myogenic proliferation and differentiation.

Hepatocyte growth factor plays a dual role in regulating skeletal muscle satellite cell proliferation and differentiation

The role of hepatocyte growth factor (HGF) and its receptor, c-met, in proliferation and differentiation of satellite cells was studied in primary cultures of chicken skeletal muscle satellite cells and a myogenic C2 cell line. HGF mRNA was expressed mainly in the myotubes of both cultures. The addition of conditioned medium derived from those cultures had a scattering effect on the canine kidney epithelial cell line, MDCK. In contrast, c-met mRNA levels decreased during cell differentiation of C2 and primary satellite cells. Application of exogenous HGF to chicken myoblasts resulted in their enhanced DNA synthesis. Among several growth factors, HGF was the first to induce DNA synthesis in quiescent satellite cells, thereby driving them into the cell cycle. Ectopic expression of chicken HGF in primary satellite cells suppressed the activation of muscle-regulatory gene reporter constructs MCK-CAT, MRF4-CAT, MEF2-CAT and 4Rtk-CAT, as well as the gene expression of MyoD and myogenin, and MHC protein expression. Ectopic MyoD reversed HGF's inhibitory effect on MCK transactivation. These data suggest that HGF inhibits cell differentiation by inhibiting the activity of basic helix-loop-helix (bHLH)/E protein heterodimers, thus inhibiting myogenic determination factor activity and subsequent muscle-specific protein expression. During muscle growth and regeneration, HGF plays a dual role in satellite-cell myogenesis, affecting both the proliferation and differentiation of these cells in a paracrine fashion.

Characterization of a plasma membrane glycoprotein common to myoblasts, skeletal muscle satellite cells, and glia

A plasma membrane glycoprotein common to embryonic chick myoblasts and adult chicken skeletal muscle satellite cells is the antigen recognized by monoclonal antibody C3 1 . Although traces of the same antigen are present on some muscle-derived fibroblasts, the density of antigenic sites on myoblasts and satellite cells is so high that these cell types can be identified in tissues by immunocytochemical techniques. The antigen is exposed on the surfaces of myogenic cells growing in tissue culture and can be solubilized with detergent. This and other criteria establish that the antigen is a plasma membrane protein. The antigen, purified by affinity techniques, consists of a single type of polypeptide chain which migrates as a relatively broad band of apparent molecular weight 38,000 Da in SDS-polyacrylamide gel electrophoresis. It has a very small sedimentation constant, suggesting that the solubilized form is either monomeric or dimeric. The concentration of antigenic sites increases during myogenesis in vitro; but during maturation the antigenic sites are lost from muscle fibers. Electron microscopic autoradiographic study of adult muscle labeled with iodinated monoclonal antibody demonstrated unequivocally that the antigenic sites in adult muscle are concentrated in the satellite cells. Although selective for myoblasts, immature myotubes and satellite cells in the myogenic lineage, the monoclonal antibody also binds at rather high levels to peripheral Schwann cells and teloglia, to some nonneuronal cells in cultures derived from embryonic spinal cord, to some glial elements of adult chicken brain, and to several cell types in the early embryo.