Ali Abdullah
Cardiff University, UK
Title: Ankle cartilage is more resilient to cytokine-induced catabolism than knee cartilage: A potential target for prevention of knee arthritis?
Biography:
Ali Abdullah is a 5th year Medical student and has attained a BSc in Biomedical Sciences (Anatomy) from Cardiff University. He has previously presented research at various national conferences.
Abstract:
Introduction & Aim: The variation in prevalence of osteoarthritis has been hypothesized to result from the differential responsiveness of joints to catabolic stimuli; therefore the aim of this study was to determine whether ankle cartilage is less susceptible to the catabolic effects of pro-inflammatory cytokines when compared to the knee.
Methods: Human cartilage explants were taken from the talar domes (n=12) and the femoral condyles (n=7) following surgical amputation. Explants were cultured in the presence or absence of either a combination of high or low concentration of cytokines, and media analyzed up to 28 days. Sulphated glycosaminoglycan (sGAG) release to the media and expression levels of nitric oxide and prostaglandin E2 (PGE2) were measured.
Results: Significantly more sGAG was lost from knee cartilage explants exposed to 100 ng/ml TNFα (22.2% vs. 13.2%, P=0.01) and 100 ng/ml TNFα in combination with 5 ng/ml IL-1α (27.5% vs. 16.0%, P=0.02) compared to sGAG release from the ankle; low cytokine concentrations did not affect sGAG release. All high concentration cytokine treatments resulted in production of more nitrite and PGE2 compared to low concentrations; however, no significant differences between the knee and ankle were noted for nitrite although there was significantly more PGE2 production in knee cartilage.
Discussion: Cartilage explants from the knee and ankle have a divergent response to stimulation by pro-inflammatory cytokines, with high concentrations of TNFα alone, or in combination with IL-1α amplifying cartilage degeneration. This differential response may account for the high prevalence of knee arthritis compared to ankle OA and provide a future pharmacological target to treat OA of the knee.