从调节SIRT1、SIRT3活性与线粒体功能研究补肾活血方延缓心脏衰老的作用机制

Cardiac aging has become one of the main factors which threaten the health of elderly population. So studying new measures that can delay the process of cardiac aging and exploring its mechanisms are of great significance.The theory of traditional Chinese medicine suggests that the renal deficiency and blood stasis is the basic pathogenesis of aging, and recent studies demonstrate that prescriptions of invigorating the kidney and promoting blood flow have a good effect on delay aging. However, the role of these prescriptions on cardiac aging and its underlying mechanisms are still unknown. Modern medicine studies indicate that mitochondrial dysfunction is directly linked to cardiac aging. Recent aging-related studies find that SIRT1/SIRT3, which belongs to the silent information regulation factor 2 protein family (sirtuin), may have direct regulatory effects on mitochondrial function. Studies have shown that SIRT1/SIRT3 may protect the heart by regulating the mitochondrial function. Based on these information, this project plans to employ the combination of in vivo and in vitro method, along with a series of technology such as the Real-time PCR, Western-blot, Immunofluorescence, Flow cytometry analysis, RNA interfere to study the effects of Bushenhuoxue decoction(Epimedium、Radix Notoginseng) on the mitochondrial function and the activities of SIRT1/SIRT3 in myocardial cell of the aging rats, so as to definite elucidate the role and molecular mechanisms of the Bushenhuoxue decoction to delay cardiac aging.

心脏衰老已成为威胁老年人群健康的主要因素之一，因而研究延缓心脏衰老的新措施具有重要意义。中医理论认为，肾虚血瘀是导致衰老的基本病机；补肾活血法具有良好的延缓人体衰老作用，但补肾活血方药对心脏衰老的防治作用与机制还少有研究。现代医学研究发现，线粒体功能障碍与心脏衰老有着直接联系；且有研究显示，沉默信息调节因子2蛋白(Sirtuin)家族成员中SIRT1、SIRT3可通过调节心肌线粒体功能来发挥心脏保护作用。基于此，本项目拟运用Real-time PCR、western-blot、免疫荧光、流式细胞分析、SiRNA等技术手段，研究补肾活血方（淫羊藿、三七）对衰老大鼠心肌线粒体功能的调节作用，以及其对心肌细胞内SIRT1、SIRT3活性的影响，以期阐明补肾活血方延缓心脏衰老的作用及分子机制。

心脏衰老已成为威胁老年人群健康的主要因素之一，因而研究延缓心脏衰老的新措施具有重要意义。中医理论认为，肾虚血瘀是导致衰老的基本病机；补肾活血法具有良好的延缓人体衰老作用。现代医学研究发现，线粒体功能障碍与心脏衰老密切相关；沉默信息调节因子2蛋白(Sirtuin)家族成员中SIRT1和SIRT3 可通过调节心肌线粒体功能来发挥心脏保护作用。但补肾活血中药（三七/淫羊藿）能否通过调节SIRT1和SIRT3的活性改善线粒体功能，从而延缓心脏衰老还未见相关研究。本课题通过建立D-半乳糖致H9c2心肌细胞衰老模型，明确了三七总皂苷（TPNS）以及三七总皂苷和淫羊藿总黄酮（TFE）联合用药均可以减轻心肌细胞衰老程度，其机制与调节SIRT1和SIRT3表达，从而改善线粒体结构和功能，减少氧化应激有关，且研究显示联合用药（TPNS+TFE）对改善心肌细胞衰老的效果要优于单独用药的效果。通过建立自然衰老大鼠模型并给予三七总皂苷和淫羊藿总黄酮进行干预后，明确了三七总皂苷可明显改善衰老心脏伴随的病理变化如心肌细胞凋亡和心肌纤维化程度增加，可显著减轻衰老心脏组织的氧化应激和炎症反应，其分子机制与调节SIRT1和SIRT3表达，进而调节其下游转录因子如PGC-1α、FoxO3a、NFκB表达以及与氧化应激相关的Mn-SOD表达，增强细胞自噬，改善线粒体结构和功能，减轻氧化应激和炎症反应有关。研究还明确了淫羊藿总黄酮可通过调节内质网应激相关蛋白GRP78、抑制凋亡相关蛋白CHOP、Bax和P-JNK的表达，从而减轻衰老大鼠的心肌细胞凋亡程度。该研究明确了补肾活血方对衰老心肌线粒体功能的保护作用，初步揭示了补肾活血方保护衰老心肌线粒体功能及防治心脏衰老的分子机制，为临床应用补肾活血方预防心脏衰老提供科学依据，并从实验角度阐释肾虚血瘀为心脏衰老病机理论的现代科学内涵。