Fig. 4

Characterisation of porcine chondrocytes and cartilage explant. a Proliferation of primary porcine chondrocytes isolated from juvenile (n = 6) and older adult pigs (n = 6). Proliferation was determined by MTS assay over a timecourse of 14 days. (B) Representative light microscope image (6.3X magnification) of porcine chondrocytes in 2D culture showing fibroblast-like morphology. c mRNA expression of type I and Type II collagen in primary porcine chondrocytes (n = 6 animals) compared to non-damaged porcine cartilage explant (n = 5 animals), from older adult pigs. Expression was determined by qRT-PCR normalised to total cDNA concentration. d Secretion of IL-6 from porcine primary chondrocytes from older adult pigs (n = 6) stimulated for 24 h with recombinant IL-1β (0.1–3 ng/ml) or recombinant visfatin (500 ng/ml). IL-6 in cell supernatants was measured by ELISA. * = p < 0.05; *** = p < 0.001 significantly different from un-stimulated control chondrocytes. Bars represent mean ± SEM (n = 6). e Secretion of IL-6 from porcine non-damaged cartilage explants from older adult pigs stimulated for 24 h with recombinant IL-1β (0.1–10 ng/ml) or recombinant visfatin (500 mg/ml) as measured by ELISA. * = p < 0.05; *** = p < 0.001 significantly different from un-stimulated control explants. Bars represent mean ± SEM (n = 20 explants per stimulant). f Detection of sulphated glycosaminoglycan (sGAG) proteoglycan side-chain upon 24 h stimulation of porcine non-damaged cartilage explant from older adult pigs with recombinant IL-1B. sGAG detected by DMMB assay. * = p < 0.05; *** = p < 0.001 significantly different from un-stimulated control explants. Bars represent mean ± SEM (n = 20 explants per stimulant)