https://scholars.lib.ntu.edu.tw/handle/123456789/187960
標題: | DIPYRIDAMOLE 抑制人類腹膜表面細胞增生之作用機轉 | 作者: | 蔡敦仁 | 關鍵字: | 腹膜透析;纖維化;細胞週期;dipyriamole;continuous ambulatory peritoneal dialysis;fibrosis;cell-cycle;dipyridamole | 公開日期: | 2000 | 出版社: | 臺北市:國立臺灣大學醫學院內科 | 摘要: | 腹膜硬化症(PF)是腹膜透析(CAPD)病人長期嚴重的合併症之一。PF 的成因目前認 為和人類腹膜表面細胞(HPMC)過度增生伴隨纖維蛋白合成增加有關。然而,HPMC 增 生的調控機轉從未有人報告過。吾人曾經報告dipyridamole 具有抑制細胞增生及預防纖 維化的作用。因此,本計畫擬進一步探究dipyridamole 調控MPMC 增生之效果及其可能機轉。自手術取得的正常腹膜大網分離出HPMC 進行培養。採用MTT(methyltetra zolium assay)方法測量HPMC 增生情形,並利用ELISA 方式測量細胞內cAMP 濃度。細胞週期 的分佈及成份蛋白的表現是採用流式細胞儀及西方點墨法完成。 結果顯示:dipyridamole 可以抑制PDGF 刺激HPMC 增生,使HPMC 停留在G1 期, 此種抑制增生作用可能主要經由增加細胞內cAMP 濃度有關。PDGF 使cyclin D1 濃度增 加,對CDK4 則沒有影響。dipyridamole 不會干擾PDGF 對上述兩者的作用。PDGF 會 使細胞內p27 kip 減少,並促進pRB 蛋白質活化;但是dipyridamole 會抑制這兩種作用進行。結論:dipyridamole 會抑制PDGF 刺激HPMC 增生,此種作用的機轉主要透過增加 細胞內cAMP ,預防HPMC 細胞內p27 kip1 減少,和抑制pRB 蛋白質活化所致。本計畫 成果可以提供作為dipyridamole 預防PF 發生的治療基礎。 Proliferation of human peritoneal mesothelial cells (HPMC) accompanied by collagen synthesis is regarded as the main process predisposing to peritoneal fibrosis (PF) in patients of long-term continuous ambulatory peritoneal dialysis (CAPD). However, the precise molecular mechanism regulating HPMC proliferation has never been reported. We previously had reported that dipyridamole (DP) is potential as an antiproliferative and antifibrotic agent. We thus investigated the mechanism and effect of dipyridamole in regulation of HPMC proliferation. HPMC was cultured from human omentum by an enzyme digestion method. Cell proliferation was measured by methyltetrazolium assay. Intracellular cAMP was measured using an enzyme immunoassay kit. Cell-cycle distribution of HPMC was analyzed by flow cytometry. Expressions of cell-cycle proteins (Cyclin D1, CDK4, pRB and p27 kip1 ) were determined by Western blotting. Addition of DP suppressed PDGF-stimulated HPMC proliferation by cell-cycle arrest at G1 phase. The antimitogenic effect of DP was mediated predominantly through the cAMP pathway. PDGF induced elevated protein levels of cyclin D1 but the CDK4 protein level did not change. Dipyridamole and DBcAMP had no effect on levels of cyclin D1 and CDK4 in PDGF-stimulated HPMC. PDGF decreased p27 kip1 and induced pRB phosphorylation of HPMC. In contrast, dipyridamole attenuated PDGF-stimulated pRB phosphorylation by preventing p27 kip1 degradation. Dipyridamole appears to inhibit PDGF-stimulated HPMC proliferation through increased cAMP, preservation of p27 kip1 and decreased pRb phosphorylation. Our study of dipyridamole may provide a therapeutic basis for clinical applications in the prevention of PF. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/23441 | 其他識別: | 892314B002059 | Rights: | 國立臺灣大學醫學院內科 |
顯示於: | 醫學系 |
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892314B002059.pdf | 770.23 kB | Adobe PDF | 檢視/開啟 |
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