| Evidence |
These two cell types were readily distinguished in that SSF expresses collagen genes and stromal cell-derived factor 1 (CXCL12) for the synthesis of extracellular matrix components (Supplementary Fig. S1e_h); and SIF expresses genes producing essential constituents of synovial fluid including lubricin (PRG4) and hyaluronan (HAS1), and the synovial fibroblast biomarker, HTRA1, a secreted enzyme that regulates the availability of insulin-like growth factors (IGFs) by cleaving IGF-binding proteins. |
