中草藥對於亨丁頓舞蹈症R6/2小鼠的心臟保護機制

Abstract

亨丁頓舞蹈症是一種遺傳性的神經退化疾病，其特徵在於認知和運動功能的障礙。亨丁頓舞蹈症被認為主要是一種神經退行性疾病；然而，心臟衰竭也是亨丁頓舞蹈症患者的主要死亡原因。許多發生在亨丁頓舞蹈症患者神經元當中的病症，如：粒線體功能障礙和代謝損傷，也會發生在亨丁頓舞蹈症患者的心肌細胞當中。然而，用於保護亨丁頓舞蹈症患者心臟功能的臨床藥物卻很少。在國內，有許多中草藥物可以透過刺激血液循環以及補充細胞能量來緩解心血管疾病；為此，這些中草藥應該可以應用於減輕亨丁頓舞蹈症患者的心臟衰竭。在台灣，中藥配方B307是保護心血管功能的知名保健漢方藥品。本論文探討口服中藥配方B307對於R6/2亨丁頓舞蹈症基因轉殖小鼠的心臟保護作用。R6/2小鼠每日口服中藥配方B307或媒介物，飲食治療兩週。然後，透過非侵入性的心臟超聲波影像和moor FLPI雷射都普勒成像儀器，檢視10週齡R6/2小鼠的心臟功能以及皮膚組織的微循環，接著我們利用免疫組織化學和西方轉漬分析，檢查R6/2小鼠心臟組織中特定蛋白質表現，本論文結果顯示，R6/2小鼠的心臟功能以及皮膚組織在服用中藥配方B307後均獲得顯著改善。並且，R6/2小鼠心臟組織的心肌發炎以及亨丁頓蛋白累積，在服用中藥配方B307後也獲得顯著改善。此外，R6/2小鼠服用中藥配方B307後，心臟組織的VEGF、eNOS、SOD2和Bcl-2的蛋白質表現會顯著增加，而TNF-α、3-NT、4-HNE、Bax、Calpain、Caspase 12、Caspase 9、Caspase 3的蛋白質表現則會顯著降低。由本論文研究發現口服中藥配方B307會有效減輕R6/2小鼠心臟組織的氧化壓力、發炎反應以及細胞凋亡的進程。因此，口服中藥配方B307應該可以通過這些保護機制而達到改善亨丁頓舞蹈症患者的心臟功能失調；因此中藥配方B307可能開發成為改善亨丁頓舞蹈症心臟衰竭的保健漢方藥品。Huntington’s disease (HD) is considered as a irreversibly destructive genetic disease, characterized by cognitive impairment and motor dysfunction. Though HD has been considered as a neurodegenerative disease primarily, cardiac failure is also cause of death in HD patients. Some symptoms such as energetic dysfunction and metabolic injury that occur in HD neurons, and that also can be seen in failing cardiac myocytes of HD. Until now, the clinical drugs with profound cardioprotective effect in HD patients is quite rare. Some Chinese herbs have been claimed to relieve cardiovascular diseases by promoting blood circulation and supplementing vital energy. Thus, some specific Chinese herbs may be used as a potential therapeutic strategy for alleviating cardiac failure in HD patients. The herbal formula B307 is a well-known health supplement for enhancing cardiovascular function in Taiwan. Here we investigated the cardioprotective effects of oral B307 treatment in R6/2 HD mice. R6/2 HD mice were oral treated with B307 or with vehicle diet daily for two weeks. The level of cardiac performance and subcutaneous microcirculation of these R6/2 HD mice were measured at ten-weeks-old by non-invasive echocardiography and moorFLPI Laser Doppler imager respectively. Afterward, R6/2 HD mice and their wild type littermate controls (WT) were sacrificed. The heart tissues were examined by immunohistochemistry and western blotting. Our data showed that cardiac performance and subcutaneous microcirculation were ameliorated in R6/2 HD mice under oral treated with B307. We observed that myocarditis and aggregation of huntingtin protein in heart tissue of R6/2 HD mice were significantly enhanced than that of their WT, but were reduced under oral treated with B307. Proteins expression of VEGF, eNOS, SOD2 and Bcl-2 in heart tissue of R6/2 HD mice were reduced than that of their WT, but were enhanced under oral treated with B307. On the other hand, Proteins expression of 3-NT, 4-HNE, Bax, calpain, caspase-12, caspase-9, caspase-3, and TNF-α in heart tissue of R6/2 HD mice were enhanced than that of their WT, but were reduced under oral treated with B307. Base on our study, inflammation, oxidative stress and apoptosis in heart tissue were alleviated under oral treated with B307. We suggested that oral herbal formula B307 may be beneficial for cardiac protection in HD patients. It is possible that theherbal formula B307 can be developed as a health supplement for ameliorating cardiac failure of HD patients.