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過度糖化最終產物在 RAW 264.7 細胞誘導 iNOS 表現中蛋白質激脢 C 所扮演的角色

論文名稱:過度糖化最終產物在 RAW 264.7 細胞誘導 iNOS 表現中蛋白質激脢 C 所扮演的角色

研究所名稱 : 台北醫學大學生物醫學技術研究所

研究生姓名 : 張鑑熹

畢業時間 : 八十九學年度第二學期

指導教授 : 李宏謨 博士 台北醫學大學生物醫學技術研究所教授

在 RAW 264.7 巨噬細胞中 BSA-AGEs 可誘導 iNOS 表現。本研究探討 BSA-AGEs 誘導 iNOS 表現過 程中之訊息傳遞路徑,尤其是 PKC 異構脢在 BSA-AGE 誘導 NO 釋放及 iNOS 表現所扮演的角色。

在 RAW 264.7 巨噬細胞中 BSA-AGEs 以具劑量和時間的依存性的誘導 NO 釋放和 iNOS 表現。 tyro sine kinase 抑制劑 genistein 會減弱 BSA-AGE 誘導 RAW 264.7 細胞的 NO 釋放和 iNOS 表現。除此 之外, PI-PLC 抑制劑 U73122 、 PC-PLC 抑制劑 D609 、以及 PKC 抑制劑,包括 staurosporine 、 R o 31-8220 和 Go 6976 都會在 RAW 264.7 巨噬細胞中,依不同濃度而有不同程度抑制 BSA-AGE 誘 導 NO 釋放,及抑制 iNOS 表現,但單獨以 BSA 處理 RAW 264.7 細胞,不會引起 iNOS 表現。加 入 polymyxin B ( LPS 抑制劑)亦不會減弱 BSA-AGEs 誘導 RAW 264.7 細胞之 iNOS 表現。 PI-P LC 抑制劑 U73122 及 tyrosine kinase 抑制劑 genistein 皆會抑制 BSA-AGEs 在 RAW 264.7 細胞引起 PIP2 的水解反應。以 AGEs 刺激 RAW 264.7 細胞時,細胞內 PKC-a, - b1, -d, 和 -h 會從細胞質移到 細胞膜。表示在 RAW 264.7 巨噬細胞中, PKC-a, - b1, -d, 和 -h 有一種或數種參與 AGEs 誘導 NO 產生和 iNOS 的表現。同時 U73122 、 D609 、及 genistein 也減弱 PKC-a, -b1, -d, 和 -h 的移位表 現。

這些數據表示,在 RAW 264.7 巨噬細胞, BSA-AGEs 經過上游 tyrosine kinase ,活化了 PI-PLC 和 PC-PLC ,產生 DAG ,然後活化 PKC 異構脢,並誘導 iNOS 的表現和 NO 的釋放。其中一種或多 種 PKC 異構脢( -a, -b1, -d, -h )參與調控 AGEs 誘導 iNOS 表現。

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Roles of Protein Kinase C on BSA-AGEs-Induced Nitric Oxide Synthase Expression in RAW 264.7 Macrophages

Title of Thesis: Roles of protein kinase C on BSA-AGEs-induced nitric oxide synthase expression in RAW 264.7 macrophages.

Author: Chien-Hsi Chang

Thesis advised by: Horng-Mo Lee Ph.D.

We previously found that Advanced Glycosylation End Products (AGEs) induced nitric oxide synthase (iNOS) expression in RAW 264.7 cells. The Ⅱ signaling pathway involved in protein kinase C activation and the roles of PKC isoforms in AGEs-induced NO production in RAW 264.7 cells were in vestigated. BSA-AGEs caused a dose- and time-dependent increase in NO release and inducible NO synthase (iNOS) expression, but BSA alone did n ot induce iNOS expression. The polymyxin B ( LPS inhibitor ) also did not inhibit BSA-AGEs induced iNOS expression. The tyrosine kinase inhibi tor genistein attenuated BSA-AGEs-induced NO release and iNOS expression in RAW 264.7 cells. Additionally, the phosphoinositide-specific phosph olipase C (PI-PLC) inhibitor, U73122, the phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor, D609, and the PKC inhibitors including staurosporine, Ro 31-8220, and Go 6976 all inhibited the BSA-AGEs-induced iNOS expression. BSA-AGEs stimulated PIP2 turnover was attenuated by PI-PLC inhibitor, U73122 and tyrosine kinase inhibitor, genistein. Western blot analysis revealed that incubation of the RAW 264.7 cells with BS A-AGEs, results in PKC-a, -b1, -d, and -h translocation, indicating the possible involvement of one or all of PKC-a, -b1, -d, and -h in AGEs-mediated effects.

These data suggest that BSA-AGEs activate PI-PLC and PC-PLC via an upstream tyrosine kinase to induce PKC activation, then initiate the expressio n of iNOS and NO release. PKC isoform-a, -b1, -d, and -h were shown to be involved in the regulation of BSA-AGEs-induced iNOS expression.

縮寫詞彙

AGEs, advanced glycosylation end products.

BSA-AGEs, bovine serum albumin derived advanced glycosylation end products

NO, nitric oxide.

iNOS, inducible nitric oxide synthase.

PLC, phospholipase C.

PI-PLC, phosphoinositide-specific phospholipase C.

PC-PLC, phosphatidylcholine-specific phospholipase C.

DAG, diacylglycerol.

IP3, Inositol 1,4,5-trisphosphate.

PIP2, phosphatidylinositol 4,5-bisphosphate .

PKC, protein kinase C.

RAGE, receptor for AGEs.

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