探討CASK調控的細胞黏附機制及意義

Abstract

作為膜結合關聯鸚鵡翁狀激酶（MAGUK）家族的成員，CASK被視為支架蛋白，對神經元突觸形成至關重要。我們之前的研究表明，CASK可能參與了Ca 2+ -依賴性細胞黏附。因此，我們研究了細胞黏附結構與CASK之間的聯繫。通過在頭頸部癌細胞SAS和角質形成細胞 HaCaT中使用免疫螢光（IF），我們注意到CASK敲除導致細胞-細胞黏附結構（即基於 paxillin 的黏著斑復合物）和細胞-基質黏附結構（即基於 cadherin的緊黏結）的增加，表明CASK可能參與了細胞黏附動態。我們進一步研究了在 CASK敲除期間通過抑制 Rho關聯蛋白激酶（ROCK）或鈣蛋白酶是否調節了細胞動力學的形成或溶解。結果顯示，CASK 敲除的效果與細胞黏附上的 ROCK 抑制是獨立的，而鈣蛋白酶的抑制消除了CASK 敲除對細胞黏附的影響。因此，我們推測 CASK 參與了鈣蛋白酶介導的細胞黏附動態。我們目前正在研究其潛在機制，希望能開發基於 CASK 的治療細胞黏附相關疾病的方法。

As a member of the membrane-associated guanylate kinases (MAGUK) family, CASK is considered as a scaffold protein, and it is crucial for neuronal synapse formation. Our previous research suggested that CASK is potentially involved in Ca2+-dependent cell adhesion. We thus investigated the association between cell adhesion structures and CASK. By using immunofluorescence (IF) in head and neck cancer SAS cells and keratinocyte HaCaT cells, we noticed that CASK knockdown led to an increase in both cell-cell adhesion structures, i.e. paxillin-based focal adhesion complexes, and cell-matrix adhesion structures, i.e. cadherin-based adherens junctions, suggesting that CASK could be involved in cell adhesion dynamics. We further investigated whether CASK regulated the formation or dissolution of cell dynamics by suppressing Rho-associated protein kinase (ROCK) or calpain during CASK knockdown. Interestingly, effects of CASK knockdown were independent of ROCK suppression on cell adhesion, while calpain inhibition abolished effects of CASK knockdown on cell adhesion. Therefore, we speculate that CASK was involved in calpain-mediated cell adhesion dynamics. We are currently investigating its underlying mechanism, hoping to develop CASK-based treatments cell adhesion-related diseases.