Figure 5.

A comparison of mRNA profiles for select genes from bursa tissue, tendon and cartilage. (a) Gel-electrophoretic profile of reverse transcription (RT)-PCR from RNA of a subacromial bursa and the underlying torn supraspinatus tendon. Ethidium bromide-stained electrophoresis gels are shown; the image grey scale has been inverted. The samples have been normalized for total RNA extracted from the tissue, and GAPDH and actin are presented as standards. Tissue aliquots were sampled anatomically. The dark arrows indicate mRNA that have been quantified by real-time PCR (Figure 4). An example from cultured human articular chondrocytes has been added for comparison. Note the absence of mRNA from the cartilage proteoglycan aggrecan in the bursa specimens. (b) – Gel-electrophoretic RT-PCR profile of subacromial bursa RNA from 14 patients. Note that the level of IL-1β mRNA is weak or absent in most samples from the bursa; TNF-α is absent in some bursa specimens. BMP, bone morphogenetic protein; COL, collagen type; bFGF, basic fibroblast growth factor; GAPDH, glucosealdehyde phosphate dehydrogenase; IL, interleukin; TGF, tumor growth factor; TNF, tumor necrosis factor; VEGF, vascular endothelial growth factor.