PAHSA对老年糖尿病性脑血管病的预防性干预作用及其机制研究

With the accelerated aging process, diabetes mellitus (DM) and cerebrovascular disease (DCD) is increasing. It has the great significance to prove the mechanisms of aging and its intervention of DCD. In 2010 October，Cell magazine first reported that one new hydroxy fatty acid (PAHSA) has the therapeutic potential for DM. We have successfully synthesized the PAHSA. Previous study found that: The aged DM mice tend to suffer cerebral vascular disease (CVD); The autophagy molecule Beclin1 decreased significantly in aged DM mice; The PAHSA level in serum of aged DCD mice was significantly lower than that without DCD in aged DM mice and normal aged mice; Under the environment of DM in vitro, Beclin1 was up-regulated, protective autophagy became activated and apoptosis was reduced in HBVEC with PAHSA intervention. So we want to study the intervention and prevention of PAHSA on the aging process of DCD: Using animal experimental to observe the effect of PAHSA on cerebral vascular aging in aged dbdb mice accompanied by DCD; Using cell experimental to observe the influence of regulating Beclin1 gene on PAHSA cell protection function and its mechanism; Clinical trial to investigate the correlation of PAHSA level and aging process of the aged DCD. To preliminarily clarify the prevention and intervention effect of PAHSA on senile diabetic cerebral vascular aging and its molecular mechanism, and to provide a new target for the prevention and treatment of senile DCD.

随着老龄化进程加剧，糖尿病性脑血管病（DCD）日益增多，探明其衰老机制及干预手段意义重大。Cell杂志2014.10首次报道棕榈酸羟基硬脂酸（PAHSA）具有治疗糖尿病（DM）潜能，我们已成功合成PAHSA。本课题前期研究发现：老年DM小鼠易并发脑血管病（CVD）,伴自噬核心调控分子Beclin1下调；老年DCD小鼠血清PAHSA水平明显低于无DCD老年DM及老年正常小鼠；体外DM环境下人脑血管内皮细胞经PAHSA干预后Beclin1上调，保护性自噬增强，细胞凋亡减少。下一步拟深入探讨PAHSA能否预防干预DCD老化进程：动物实验观察PAHSA对老年dbdb小鼠DCD发病进程的预防干预作用；细胞实验观察调控Beclin1基因对PAHSA细胞保护作用的影响及机制；临床实验观察PAHSA与老年DCD的相关性。初步揭示PAHSA对老年DCD的预防干预作用及其分子机制，为防治DCD提供新研究靶点。

老龄化加剧导致糖尿病性心脑血管病（DCCD）日益增多，探明其机制和干预策略意义重大。PAHSA是一种新发现、可能具有降糖抗炎等作用的支链羟基脂肪酸，推测对DCCD可能具有干预作用。首先，与中科院上海有机所合作，成功合成高纯度9-PAHSA和5-PAHSA，为后续研究奠定了物质基础。临床研究发现老年T2DM患者血清9-PAHSA含量明显低于老年非糖尿病患者，DB/DB鼠也存在类似现象，这为后续研究提供了临床数据和理论基础。同时还发现老年人血清CAⅢ水平与DCCD之间存在相关性。动物实验发现9-PAHSA和5-PAHSA短期干预均可降低DB/DB鼠血糖，但干预30天降糖作用消失，该结果与国外最新报道基本一致。研究发现T2DM鼠易伴发脑小血管病及认知障碍，可能与海马和杏仁核糖代谢减低有关，海马区Beclin1介导的自噬可能在上述机制中扮演重要角色。PAHSA、Egb761及G-CSF均可改善T2DM鼠脑小血管病变及认知情感障碍，但其作用并非依赖于增加胰岛素分泌和降血糖，而可能是通过提高外周组织自噬水平、改善胰岛素抵抗和脂代谢、抑制凋亡、促进BDNF表达及改善微血管密度等作用来实现的。同时，研究发现DB/DB鼠存在心肌功能障碍及BAG3蛋白下调，9-PAHSA干预可部分逆转该现象，提示9-PASHA有助于提高心肌细胞BAG3介导的自噬水平以及心脏结构和功能。体外实验发现血管内皮和平滑肌细胞Beclin1基因过表达后均可促进自噬并对CAⅢ具有一定负反馈调控作用，提示CAⅢ与Beclin1之间可能存在上下游联系并共同发挥细胞保护作用。体外5-PAHSA干预可上调PC12细胞自噬水平，m-TOR及其磷酸化在其中扮演重要角色。为了探索更加有效而安全的化合物，课题组已对9-PAHSA成功进行手性拆分。本课题通过以上临床研究发现血清PAHSA水平与老年DCCD具有内在联系；动物实验发现PAHSA对DCCD具有预防干预作用，其作用并非通过降血糖，而是与Beclin1介导的自噬、改善胰岛素抵抗和脂代谢、抑制凋亡、促进血管新生等机制相关；细胞实验发现PAHSA干预可上调PC12的细胞自噬水平，调控Beclin1基因表达可调节自噬并对CAⅢ具有负反馈调控作用。总之，本研究初步揭示了PAHSA与老年DCCD的相关性及其预防干预价值，拓展了其干预机制研究思路，为干预DCCD提供了新的研究靶点。