Human osteoglycin recombinant 00166-01-100 had been used by Dr.Tanaka K, et al. Role of osteoglycin in the linkage between muscle and bone. J Biol Chem. 2012 Apr 6;287(15):11616-28

Role of osteoglycin in the linkage between muscle and bone

The interaction between muscle tissues and bone metabolism is incompletely understood. We hypothesized that there might be some humoral factors that are produced in muscle tissues and exhibit bone anabolic activity. We, therefore, performed comparative DNA microarray analysis between mouse myoblastic C2C12 cells transfected with either stable empty vector or ALK2 (R206H), the mutation that constitutively activates the bone morphogenetic protein (BMP) receptor, to search for muscle-derived bone anabolic factors. Twenty-five genes whose expression was decreased to <1/4, were identified; these included osteoglycin (OGN). Stable overexpression of OGN significantly decreased the levels of Runx2 and Osterix mRNA compared with those in cells transfected with vector alone in MC3T3-E1 cells. On the other hand, it significantly enhanced the levels of alkaline phosphatase (ALP), type I collagen (Col1), and osteocalcin (OCN) mRNA as well as β-catenin and mineralization. A reduction in endogenous OGN level showed the opposite effects to those of OGN overexpression in MC3T3-E1 and mouse calvarial osteoblastic cells. Transient OGN overexpression significantly suppressed the levels of Runx2, Osterix, ALP, Col1, and OCN mRNA induced by BMP-2 in C2C12 cells. The conditioned medium from OGN-overexpressed and OGN-suppressed myoblastic cells enhanced and decreased, respectively, the levels of ALP, Col1, and β-catenin in MC3T3-E1 cells. Moreover, OGN increased Smad3/4-responsive transcriptional activity as well as Col1 mRNA levels independently of endogenous TGF-β in these cells. In conclusion, this study suggests that OGN may be a crucial humoral bone anabolic factor that is produced by muscle tissues.

Tanaka K, ET AL. J Biol Chem. 2012 Apr 6;287(15):11616-28.

Identification of differentially regulated secretome components during skeletal myogenesis

Myogenesis is a well-characterized program of cellular differentiation that is exquisitely sensitive to the extracellular milieu. Systematic characterization of the myogenic secretome (i.e. the ensemble of secreted proteins) is, therefore, warranted for the identification of novel secretome components that regulate both the pluripotency of these progenitor mesenchymal cells, and also their commitment and passage through the differentiation program. Previously, we have successfully identified 26 secreted proteins in the mouse skeletal muscle cell line C2C12 (1). In an effort to attain a more comprehensive picture of the regulation of myogenesis by its extracellular milieu, quantitative profiling employing stable isotope labeling by amino acids in cell culture was implemented in conjunction with two parallel high throughput online reverse phase liquid chromatography-tandem mass spectrometry systems. In summary, 34 secreted proteins were quantified, 30 of which were shown to be differentially expressed during muscle development. Intriguingly, our analysis has revealed several novel up- and down-regulated secretome components that may have critical biological relevance for both the maintenance of pluripotency and the passage of cells through the differentiation program. In particular, the altered regulation of secretome components, including follistatin-like protein-1, osteoglycin, spondin-2, and cytokine-induced apoptosis inhibitor-1, along with constitutively expressed factors, such as fibulin-2, illustrate dynamic changes in the secretome that take place when differentiation to a specific lineage occurs.

Chan CY, et al. Mol Cell Proteomics. 2011 May;10(5):M110.004804