趨化激素 Eotaxin-1 誘導人類軟骨細胞表現間質分解酵素之分子機
制探討
Studies of the molecular mechanisms of chemokine eotaxin-1 on the
metalloproteinases expression in human chondrocyte
中文摘要 骨關節炎是由於關節軟骨內的軟骨細胞合成及降解的功能異常所 造成， 而間質分解酵素能降解細胞外間質，在骨關節炎病程中也 相當的重要。根據我們之前的研究顯示， 使用 IL-1β、TNF-α 能 刺激軟骨細胞增加eotaxin-1 的表現。最近研究發現，eotaxin-1 是一種CC chemokine，其唯一接受器為 CCR3， 可能與 MMPs 的調節 有關。因此本實驗主要以eotaxin-1 誘導表現 MMP-3 的分子機制進 行研究。與IL-1β相似， eotaxin-1 可以有效的在人類
chondrosarcoma cellSW-1353 與 primary chondrocyte 中誘導
MMP-3 mRNA 及蛋白表現。與 IL-1β 相似， eotaxin-1 可以有效的
在人類chondrocyte cell SW-1353 與 primary chondrocyte 中誘
導MMP-3 mRNA 及蛋白表現。而另一方面， eotaxin-1 也可以在 primary
chondrocyte 中誘導少量 TIMP-1（ tissue inhibitor of
metalloproternase-1） 的表現。為了進一步確認 eotaxin-1 所
誘導MMP-3 之訊息傳遞路徑， 我們使用 eotaxin-1 誘導看蛋白質
激酶是否有磷酸化。在我們的結果之中，發現eotaxin-1 可能有效
誘導ERK、p38 MAPK、JNK、Akt 的活化，依循時間相關性。此外，
我們利用ERK 抑制劑（PD98059）p38 MAPK 抑制劑（SB203580） 和
PI3K 抑制劑（Wortnannin） 可以抑制 Eotaxin-1 誘導 MMP-3 表現。
但是在加入NF-κB 抑制劑（TLCK），卻沒有抑制 Eotaxin-1 所誘導
MMP-3 表現。綜合以上結果， 給予我們足夠的證據推論在 chondrocyte 細胞 SW-1353 中， eotaxin 所誘導 MMP-3 之表現，
可經由活化ERK、p38 MAPK 和 Akt 路徑而來， 但是卻沒有 NF-κB
的參與。結果顯示Eotaxin-1 能增加 MMP-3 表現及其活化路
徑，因此了解Eotaxin-1 與 OA 之間訊號傳遞機制，對未來治
療關節炎有很大幫助。 英文摘要
Osteoarthritis (OA) is characterized by loss of the functional integrity of articular cartilage due to an imbalance between catabolic and anabolic chondrocyte activity. Degradation of the collagenous extracellular matrix by metalloproteases (MMPs)
plays an important role in the pathogenesis of osteoarthritis (OA). Our previous studies suggested that IL-1β、TNF-α could increase the expression of eotaxin-1 in human primary culture chondrocyte. Recently, we found that CCR3 receptor was a potential receptor for eotaxin-1 binding, and
might be involved in MMP-3 expression. In this study, we investigated the molecular mechanism of eotaxin-1 on the MMP-3 expression and the possible role of eotaxin-1 in OA cartilage degradation. Similar to IL-1β,eotaxin-1 in significantly induced MMP-3 expression in both human chondrosarcoma cells
SW-1353 and primary cultured chondrocyte by Western blot and RT-PCR. On the other hand, eotaxin-1 slightly induced the expression of tissue inhibitor of
metallproterase-1(TIMP-1). To examine which signal pathway are involved in the MMP-3 expression by eotaxin-1, several kinase pathway are investigated the
phosphorylation status. The results showed that eotaxin-1 significantly activated ERK, JUK and p38 MAPKs as well as Akt kinase in a time-dependent manner. In addition, ERK, p38 MAPKs, and PI3K inhibitor blocked the MMP-3 induction
by Eotaxin-1. Treatment of NF-κB activation inhibitor could not affect the MMP-3 induction by eotaxin-1, suggesting
that NF-κB pathway might not be involved in MMP-3 expression. These results provide evidence of the catabolic role of Eotaxin-1 in chondrocyte via up-regulation of MMP-3, and indicate that activation of ERK, p38 MAPK, and Akt are involved in the induction of MMP-3 by Eotaxin-1. Our results provide evidence of the catabolic role of Eotaxin-1 in chondrocyte via MMP-3 up-regulation. As well, understanding Eotaxin-1 induced signal pathway, therefore, it may give the conception of new therapeutic approaches for OA.
