- 學位論文
醛固酮於心房心肌細胞中透過CREB增加納鈣交換體之表現:在心房震顫中醛固酮之角色含義
Aldosterone Increases Sodium-calcium Exchanger Expression through CREB in Atrail Myocytes: Implications of The Role of Aldosterone in Atrial Fibrillation
摘要
心房震顫是所有心律不整症狀中最為常見的一種，且有相當高的發病率及死亡率。在近幾十年中，許多研究指出腎素-血管張力素-醛固酮系統(rennin-angiotensin-aldosterone system;RAAS)對心房震顫扮演著非常重要的角色，在過去實驗室的研究中發現到經由胞外電位紀錄在HL-1新房心肌細胞中，Angiotensin II (AngII)可以透過鈉鈣交換蛋白 (sodium-calcium exchanger; NCX)及cAMP-response element binding protein (CREB)造成震顫現象。另一方面，aldsoterone也被證實會去誘發心律不整的產生。在本篇研究中，我們想要了解與AngII同屬於RAAS的aldosterone是否會去調控NCX mRNA表現，且也想去了解CREB是否也參與在其中的訊息傳遞。我們發現同樣在不同濃度或不同時間的醛固酮刺激下，NCX mRNA的表現量有隨之上升的情形。同樣也在NCX的基因預測出promoter中有CREB的binding site，利用染色質免疫共沉澱法，確認了CREB的確可以與所預測的結合位做結合。除此之外，同樣利用轉染dominant-negative CREB(pCMV-CREB133和pCMV-KCREB)到HL-1中發現到因醛固酮所造成的NCX mRNA表現量上升的情況因此減弱。最後的實驗發現醛固酮所造成的CREB磷酸化程度的上升並不會因為給予了PKC inhibitor或PKD inhibitor而有所減弱，但再給予蛋白質生成抑制劑(cycloheximide)、礦物質皮質固酮接受器阻斷劑(mineralocorticoid receptor blocker; MR blocker)或活性氧物質清除劑(ROS scavenger; N-acetyl cysteine)後醛固酮所誘導的CREB磷酸化增加則有下降的情形。綜合上述，醛固酮可以增加NCX mRNA的表現量，同時醛固酮可以透過ROS或MR的genomic effect進而增加CREB磷酸化的程度
並列摘要
Atrial fibrillation (AF) is a common arrhythmia that causes significant morbidity and mortality. In recent decades, the rennin-angiotensin-aldosterone system (RAAS) has been proven to play an important role in AF. Previous results in our lab have demonstrated that angiotensin II can induce fibrillary-like electrical activity in HL-1 atrail myocytes through sodium-calcium exchanger (NCX) and cAMP response element-binding protein (CREB). Aldosterone has also been shown to trigger AF. In this study, we investigated whether aldosterone, a critical component in RAAS, can modulate the expression of NCX mRNA and whether CREB is involved in its signaling pathway. We found that aldosterone increased NCX expression through a concentration and time dependent manner. A CREB binding site was identified in the promoter of NCX gene, and binding of CREB to this cognate binding site was confirmed by chromatin-immunoprecipitation assay (ChIP). We further found that aldosterone increased CREB serine 133 phosphorylation, and aldosterone induced NCX expression was attenuated by dominant-negative CREB (pCMV-CREB133 and pCMV-KCREB). Finally, aldosterone induced CREB serine 133 phosphorylation was not inhibited by protein kinase C or protein kinase D inhibitor, but was attenuated by protein synthesis inhibitor cycloheximide, mineralocorticoid receptor blocker spironolactone, and reactive oxygen species scavenger N-acetyl cysteine. In conclusion, aldosterone increases NCX expression thorugh CREB, and aldosterone increases CREB phosphorylation through reactive oxygen species and the genomic effect of mineralocorticoid receptor.
參考文獻
延伸閱讀
- Pai, P. Y., Chou, H. T., Tsou, S. S., Chen, C. C., & Wang, T. F. (1998). 原發性醛類酯醇過多症日夜血壓變化：運用攜帶式二十四小時血壓監視研究與神經荷爾蒙之關係. Mid-Taiwan Journal of Medicine, 3(1), 27-33. https://doi.org/10.6558/MTJM.1998.3(1).5
- Liu, K. (1962). 運動對於醛醇磷脂在各組織之影響. The Chinese Journal of Physiology, 18(), 61-68. https://www.airitilibrary.com/Article/Detail?DocID=03044920-196206-x-18-61-68-a
- 朱培倫（2004）。第二型血管張力素第二型受器對醛固酮分泌和腎上腺細胞自毀的影響及機制之探討〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU.2004.01759
- Ong, S. E., Chaipipat, M., Manotham, K., & Ong, S. E. (2017). Rapid Action of Aldosterone on Protein Levels of Sodium-Hydrogen Exchangers and Protein Kinase C Beta Isoforms in Rat Kidney. International Journal of Endocrinology, 2017(), 1-12. https://doi.org/10.1155/2017/2975853
- Vandergriff, A. C., Andrade, J. B. M. D., Tang, J., Hensley, M. T., Piedrahita, J. A., Caranasos, T. G., & Cheng, K. (2015). Intravenous Cardiac Stem Cell-Derived Exosomes Ameliorate Cardiac Dysfunction in Doxorubicin Induced Dilated Cardiomyopathy. Stem Cells International, 2015(), 754-761-162. https://doi.org/10.1155/2015/960926