Table 2.

The diversity of extracellular protein release by MSCs and osteoblasts during in vitro culture; a summary of protein classes showing at least five identified members. For more details see Table S1.

Extracellular Matrix (n = 34) Collagens (n = 22): Twenty-one distinct collagen alpha-1 chains and the procollagen galactosyltransferase 1 enzyme; including Collagen alpha-1 (XVIII) chain that forms the antiangiogenic Endostatin protein through proteolytic cleavage. Both fibril-forming and fibril-associated collagens are included.

Other extracellular matrix molecules (n = 12): Including four fibulins, two fibrillins and six laminin subunits

Complement Factors (n = 11) Including factors contributing to the activation of the classical and alternative pathway, formation of the C1 complex and formation of the cell membrane attacking complex.

Other Proteases and Protease Inhibitors (n = 26) Including seven cathepsins, seven ADAM/ADAMTS proteases and 12 inhibitory serpins

Cell Surface Molecules (n = 12) Three cadherins, three HLA class I molecules plus HLA-DR alpha, five integrins.

Insulin-Like Growth Factor (n = 9) Including IGF II and eight IGF binding molecules or receptor components.

GTP associated proteins (n = 21) Five GTPases, five septins and 11 RAS-related proteins.

Protein Synthesis, Stabilization and Modulation (n = 156) Including five RNA binding proteins, 12 proteins involved in splicing, 44 ribosomal proteins, 21 proteins involved in translation initiation and elongation. In addition to these proteins:

Chaperons: Seven T complex proteins, 17 heat shock proteins and six Peptidyl-prolyl cis-trans isomerases.

Posttranscriptional modulation: four proteins involved in glycosylation, eight proteins involved in protein phosphorylation, 12 proteins involved in ubiquitination together with 20 proteasomal proteins.

Cytoskeleton (n = 22) 19 actin and actin-interacting proteins, together with three tropomyosins.

Organellar Functions/V-Atpase (n = 9)

Nuclear Proteins (n = 49) Including 18 histones, 20 non-histone chromatin proteins and 11 other nucleoproteins.

Intracellular Transport (n = 14) Six 14-3-3 proteins and eight solute carrier transporters

Metabolism-Redox Balance (n = 10) Four lipoproteins and six peroxiredoxins.

S100 Proteins (n = 8)