葡萄糖胺在軟骨細胞上抑制間質分解酵素 -3 之機制
退化性關節炎，是由於關節軟骨內的軟骨細胞合成及降解作用功能失去 平衡所引起。而間質分解酵素（ matrix metalloproteinase ）能降解細胞 外間質，故 MMP 在退化性關節炎病理中扮演重要角色。介白質 -1 （ I nterlukin-1 ）是一種趨化激素，存在於退化性關節炎軟骨及滑液膜中。
IL-1beta 參予基質（ matrix ）降解及減少醣蛋（ proteoglycan ）
合成。 IL-1 藉著調控一氧化氮合成 ? （ nitric oxide synthase ）及 MMP 的活化來參予此代謝過程。葡萄醣胺（ glucosamine ）可能會刺激醣蛋 白合成、抑制醣蛋白降解作用並且在體內刺激軟骨中的醣蛋白再生。在 我們加入 glucosamine 發現， glucosamine 會調控 MMP-3 表現。為了 進一步確認 glucosamine 抑制 MMP-3 的知訊息傳遞路徑，我們使
用 glucosamine 抑制蛋白激 ? 是否有被磷酸化。在我們結果發現， gluc osamine 可誘導 Akt 、 ERK 及 JNK 的活化。而 glucosamine 會使得 p 38 磷酸化及 NF-kB 表現受到抑制。在 Akt 抑制劑部分，當加入 wort mannin ，會抑制 glucosamine 所誘導 Akt 的磷酸化，而不會影響 ERK 的磷酸化。根據以上結果推論， glucosamine 經由活化 Akt 調控軟骨細 胞，進而抑制 IL-1 所誘導 NF-kB 的路徑。
The inhibitory of glucosamine on the MMP-3 expression in chondrocyte
Osteoarthritis （ OA ） is characterized by loss of the functional intergrity of artic ular cartilage due to an imbalance between catabolic and anabolic chondrocyte acti vity. Degradation of the collagenous extracellular matrix by metalloproteases （ M MPs ） play an important role in the pathogenesis of osteoarthritis. Interleukin-1 (I L-1), a cytokine present which in elevated in OA cartilage and synovial fluid.IL-1 i s an important mediator of increase matrix degradation and reduced PG synthesis. I L-1 mediates this process by a number of metabolic processes including up-regulati ng enzymes such as nitric oxide synthase, matrix metalloproteinase. Glucosamine is capable of stimulating PG synthesis, inhibiting the degradation of PGs, and stimulat ing the regeneration of cartilage in vivo. It showed that the expression of metallopr oteases-3 （ MMP-3 ） was downregulated by treatment of glucosamine. To exami ne which signal pathway are involved in the MMP-3 expression by glucosamine, se veral kinase pathway are investigated the phosphorylation status. The result showed that glucosamine activated Akt, ERK and JNK pathway. Beside, glucosamine inhib ited p38 phosphoylation and NF-kB translocated to nucleus. The Akt inhibitors, wo rtmannin, blocked glucosamine stimulated Akt phosphorylation without blocking E RK
