Secretome profiling of primary human skeletal muscle cells

Abstract

The skeletal muscle is a metabolically active tissue that secretes various proteins. These so-called myokines have been proposed to affect muscle physiology and to exert systemic effects on other tissues and organs. Yet, changes in the secretory profile may participate in the pathophysiology of metabolic diseases. The present study aimed at characterizing the secretome of differentiated primary human skeletal muscle cells (hSkMC) derived from healthy, adult donors combining three different mass spectrometry based non-targeted approaches as well as one antibody based method. This led to the identification of 548 non-redundant proteins in conditioned media from hSkmc. For 501 proteins, significant mRNA expression could be demonstrated. Applying stringent consecutive filtering using SignalP, SecretomeP and ER_retention signal databases, 305 proteins were assigned as potential myokines of which 12 proteins containing a secretory signal peptide were not previously described. This comprehensive profiling study of the human skeletal muscle secretome expands our knowledge of the composition of the human myokinome and may contribute to our understanding of the role of myokines in multiple biological processes. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge.

Expression of V3 Versican by Rat Arterial Smooth Muscle Cells Promotes Differentiated and Anti-inflammatory Phenotypes

“…Expression of the V3 transcript in vivo has been detected in mouse, rat, and human fetal and adult tissues and cells (46 -50), and most recently, secretion of V3 protein by primary human skeletal muscle cells was detected by proteomic analysis (51). Previous studies have shown that V3 expression induces increases in cell-cell and cell-ECM association (19,(23)(24)(25).…”

“…Our findings that V3 expression induces increases in the differentiated SMC markers as well as in components of basement membrane and elastic fibers suggest that ASMCs can be reprogrammed to actively synthesize the ECM components present in healthy arteries while maintaining a differentiated and contractile phenotype. Intriguingly, proteomic profiling by mass spectrometry has identified V3 as part of the secretome of primary human skeletal muscle cells (51), suggesting it may play an intrinsic role in promoting muscle cell differentiation. FIGURE 5.…”

Roles of Exosome-Like Vesicles Released from Inflammatory C2C12 Myotubes: Regulation of Myocyte Differentiation and Myokine Expression

“…Moreover, probably in an autocrine or paracrine fashion, myokines may regulate skeletal muscle metabolism and differentiation. Using proteomics approaches, several myokines have been identified in human myotubes [18][19][20]. Importantly, various myokines were found in secretory intercellular communicating vesicles, particularly in exosomes [21,22].…”

Myokines in insulin resistance and type 2 diabetes

“…Nowadays, skeletal muscle is recognised as an endocrine organ, and proteins expressed by and released from skeletal muscle have been termed myokines [1]. In three studies using primary human myotubes and proteomic approaches, hundreds of myokines have been identified, including more than 50 novel myokines [2][3][4].…”