The Role Leptin Plays in Osteoarthritis

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Today, obesity is a concerning worldwide epidemic. Recent studies have shown evidence of a link between obesity and chronic inflammation. Researchers are now looking at adipose tissue, which were previously thought only as energy storages, as a cause for inflammatory diseases. Adipose tissue release proteins known as adipokines, some are pro-inflammatory proteins (Ouchi et al., 2011). One of these pro-inflammatory adipokines is leptin. Leptin is most commonly known for decreasing food intake, energy conservation, and a key regulator of body weight, but one of its most important functions could be the role it plays in inflammatory diseases like osteoarthritis (Popa et al., 2005). Osteoarthritis is a degenerative joint disorder; this disease is increasing in severity and frequency around the world (Yang et al., 2013). The risk of osteoarthritis increases when the body mass index increases (Bokarewa et al., 2003). Studies have also found an increase in leptin levels in patients with this type of arthritis. Studies have linked leptin with interleukin-1, VCAM-1, and interleukin-6 as a cause for osteoarthritis. Leptin is an important factor in the mechanism of osteoarthritis.
Leptin levels are high in obese people; these levels are also high in the synovial fluid of osteoarthritis patients. Leptin in the synovial fluid activates multiple pathways. Leptin with pro-inflammatory cytokines cause inflammation. Leptin with interleukin-1 increases the nitrite accumulation in the chondrocyte. Nitrite accumulation can cause apoptosis and extracellular matrix degradation. When leptin is in synergy with interluekin-1, it can activate a signaling pathway that increases the nitrite accumulation. Human primary chondrocytes were used to study nitrit...

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...go, R., Gomez, R., Lago, F., Dieguez, C., Gómez-Reino, J.J., Lago,
F., Gualillo, O. 2005. Signaling pathway involved in nitric oxide synthase type II activation in chondrocytes: synergistic effect of leptin with interleukin-1. Arthritis Res. Ther. 7:R581-R591.
Ouchi, N., Parker, J. L., Lugus, J.J., Walsh, K. 2011. Adipokines in inflammation and metabolic disease. Nat. Rev, Immunol. 11: 85-87.
Popa, C., Netea, M. G., Radstake, T. R., van Riel, P. L., Barrera, P., van der Meer,
J. W. 2005. Markers of inflammation are negatively correlated with serum leptin in rheumatoid arthritis. Annals of the rheumatic diseases. 64: 1195-1198.

Yang, W., Liu, S., Tsai, C., Fong Y., Wang S., Chang, Y., Tang, C. 2013. Leptin Induces IL-6 Expression through OBRl Receptor Signaling Pathway in Human Synovial Fibroblasts. PLoS ONE 8(9): e75551. doi:10.1371/journal.pone.0075551

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