β-defensin 2在高度糖化終產物對於腎纖維母細胞NRK-49F誘發的效應中所扮演的角色

Role of β-defensin 2 in advanced glycation end products- induced effects in NRK-49F cells

張雅雯(Ya-Wen Chang)

指導教授 ： 莊麗月

高雄醫學大學/醫學院/生物化學研究所/碩士(2006年)

https://doi.org/10.6832/KMU.2006.00035

摘要

糖尿病腎病變 (diabetic nephropathy) 是糖尿病患者最重要的併發症與死因，而腎細胞過度增生與過度肥大所導致的腎組織間隙纖維化則是糖尿病腎病變的主要病理特徵。造成糖尿病腎病變的因子非常複雜，其中非酵素性糖化作用產生的高度糖化終產物 (advanced glycation end products, AGE) 與糖尿病腎病變致病機轉有密切關係。先前研究發現，高度糖化終產物可促進大鼠腎纖維母細胞 (NRK-49F) 增生，可能是造成腎組織間隙纖維化的原因之一，而高度糖化終產物誘發的腎纖維母細胞增生其作用機轉及媒介也有待更進一步研究。另一方面，過去對於β-defensin的研究多著重於抑菌、吸引免疫細胞 (chemotactic activity) 等免疫相關的功能，近年來則發現β-defensin可以促進細胞增生。因此，我們以大鼠腎纖維母細胞研究高度糖化終產物所引發的增生效應與β-defensin 2之間的關聯性。在AGE刺激下，NRK-49F細胞的β-defensin 2 mRNA表現量明顯增加。當加入calphostin C (PKC inhibitor)、LY294002 (PI3K inhibitor)、PD98059 (ERK inhibitor)、SB203580 (p38 MAPK inhibitor) 以及SP600125 (JNK inhibitor) 後，AGE刺激產生的β-defensin 2表現被抑制，顯示AGE是經由PKC、PI3K、ERK、p38 MAPK、JNK等訊息分子而活化 β-defensin 2。為了解β-defensin 2與腎纖維母細胞增生的關聯性，我們以β-defensin 2刺激NRK-49F細胞並利用 [3H]-thymidine incorporation測定細胞增生的情形，結果顯示，β-defensin 2 會明顯促進NRK-49F細胞增生。進一步我們研究β-defensin 2 刺激細胞增生所調控的細胞週期蛋白質，發現cyclin E、cyclin D1以及 cdk4 在β-defensin 2 刺激下表現量增加。綜合以上結果，我們推測AGE可能是透過活化β-defensin 2而促使腎纖維母細胞增生。

關鍵字

第二型乙型防禦素 ； 高度糖化終產物 ； 腎纖維母細胞 ； 增生

並列摘要

Advanced glycation end-product (AGE) is important in the pathogenesis of diabetic nephropathy which is characterized by cellular hypertrophy / hyperplasia leading to renal fibrosis. However, the biological effects of AGE on renal cells remain poorly understood. Our previous study suggesting that AGE induces mitogenesis in NRK-49F cells, which may result in interstitial renal fibrosis. To further investigate the mechanism by which AGE induces mitogenesis, NRK-49F cells were treated with AGE for various time periods. We found that AGE induced the β-defensin 2 mRNA expression at 48 hours. β-defensin 2 has been described as antimicrobial peptides which exhibited chemotactic activity to recruit dendric cells and T lymphocytes. In recent years, β-defensin 2 was also reported to have growth factor-like mitogenic effects on different cell types. AGE-induced β-defensin 2 mRNA expression was attenuated by pretreatment of calphostin C (PKC inhibitor)、LY294002 (PI3K inhibitor)、PD98059 (ERK inhibitor)、SB203580 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor). To reveal the involvement of β-defensin 2 in mitogenesis of NRK-49F cells, we examined the effects of β-defensin 2 on cell proliferation and cell cycle progression by [3H]-thymidine incorporation assay and Western blotting, respectively. Interestingly, β-defensin 2 induced cell proliferation and promoted cell cycle progression in NRK-49F cells by increased cyclin E、cyclin D1 and cdk4. Together, these results suggested the possibility that AGE may induce renal fibroblasts mitogenesis through activation of β-defensin 2.

並列關鍵字

beta-defensin 2 ； advanced glycation end products ； renal fibroblast ； proliferation

參考文獻

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