目的 探究硫辛酸對腦缺血再灌注損傷大鼠神經(jīng)血管單元重塑的作用及對晚期糖基化終產(chǎn)物受體（RAGE）/低密度脂蛋白受體相關(guān)蛋白1（LRP1）的影響。方法 108只雄性Wistar大鼠，除18只作為假手術(shù)組外，其余大鼠采用線栓法制備大腦中動(dòng)脈短暫缺血再灌注（tMCAO）模型。模型成功大鼠根據(jù)神經(jīng)評(píng)分分為模型組、FPS-ZM1 （RAGE抑制劑，1 mg·kg^-1）組和硫辛酸高、中、低劑量組（40、20、10 mg·kg^-1），再灌注2 h后ip給藥，假手術(shù)組和模型組注射等量生理鹽水，每天1次，連續(xù)給藥14 d。術(shù)后1、7、14 d對大鼠進(jìn)行神經(jīng)功能缺損程度評(píng)分（mNSS）和激光散斑成像儀監(jiān)測腦血流量（CBF）。術(shù)后14 d，2，3，5-氯化三苯基四氮唑（TTC）染色法檢測大鼠腦梗死面積；伊文思藍(lán)（EB）檢測血腦屏障通透性；免疫熒光染色檢測腦微血管密度并采用免疫組化法檢測膠質(zhì)纖維酸性蛋白（GFAP）、神經(jīng)元核抗原（NeuN）表達(dá)；實(shí)時(shí)熒光定量PCR（qRT-PCR）檢測血管內(nèi)皮生長因子（VEGF）、促血管生成素1（Ang-1）、促血管生成素2（Ang-2）的mRNA表達(dá)； Western blotting檢測基質(zhì)金屬蛋白酶9（MMP9）、緊密連接相關(guān)蛋白5（claudin5）、RAGE、LRP1蛋白表達(dá)。結(jié)果 與假手術(shù)組比較，模型組大鼠mNSS評(píng)分、腦梗死百分比、EB含量、GFAP陽性細(xì)胞數(shù)、腦組織Ang-2 mRNA水平、MMP9和RAGE蛋白表達(dá)顯著升高（P<0.05），CBF、NeuN陽性細(xì)胞數(shù)、VEGF和Ang-1 mRNA水平、claudin5和LRP1蛋白表達(dá)顯著降低（P<0.05）；與模型組比較，硫辛酸高、中劑量組大鼠mNSS評(píng)分、腦梗死百分比、EB含量、GFAP陽性細(xì)胞數(shù)、腦組織Ang-2 mRNA、MMP9和RAGE蛋白表達(dá)顯著降低（P<0.05），CBF、腦微血管密度、NeuN陽性細(xì)胞數(shù)、VEGF和Ang-1 mRNA、claudin5和LRP1蛋白表達(dá)顯著升高（P<0.05）。結(jié)論 硫辛酸可降低BBB的通透性，促進(jìn)血管新生，對神經(jīng)血管單元起著修復(fù)和保護(hù)作用；其作用機(jī)制可能與下調(diào)RAGE的表達(dá)，上調(diào)LRP1的表達(dá)有關(guān)。

Objective To investigate the effects of lipoic acid on neurovascular unit remodeling and microvascular regeneration in rats with cerebral infarction and the effect of receptor for advanced glycation end products (RAGE)/low-density lipoprotein receptor related protein 1 (LRP1). Methods A total of 108 male Wistar rats were used to establish tMCAO model by suture method except 18 rats as sham operation group. The successful rats were divided into model group, high, medium and low dose lipoic acid groups (40, 20, 10 mg·kg^-1), RAGE inhibitor group (FPS-ZM1, 1.0 mg·kg^-1), with 18 rats in each group. After two hours of reperfusion, the drug was administered, once a day for 14 consecutive days. On the 1st, 7th and 14th day after operation, neurological deficit score (mNSS) was performed, the cerebral blood flow (CBF), cerebral infarction area (CI) and blood-brain barrier permeability (BBB) were measured by laser speckle imaging, 2, 3, 5-triphenyltetrazolium chloride (TTC) staining and Evans blue (EB) respectively; the number of cerebral microvessels was measured by immunofluorescence staining, and the expression of glial fibrillary acidic protein (GFAP) and neuron nuclear antigen (NeuN) were detected by immunohistochemistry; real-time fluorescent quantitative PCR (RTPCR) was used to detect the mRNA expression of vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2); Western blot was used to detect the expression of MMP9, claudin5, RAGE and LRP1. Results Compared with those in sham operation group, mNSS score, cerebral infarction ratio, EB content, GFAP positive cells number, Ang-2 mRNA, MMP9 and RAGE protein expression in brain tissue of rats in model group were significantly increased (P < 0.05), CBF, NeuN positive cells number, VEGF and Ang-1 mRNA, claudin5 and LRP1 protein expression were significantly decreased (P < 0.05); compared with those in the model group, mNSS score, cerebral infarction ratio, EB content, GFAP positive cells number, Ang-2 mRNA, MMP9 and RAGE protein expression in brain tissue of rats in the high and middle dose lipoic acid groups were significantly decreased (P < 0.05), CBF, microvessel density, NeuN positive cells number, VEGF and Ang-1 mRNA, claudin5 and LRP1 protein expression were significantly increased (P < 0.05). Conclusion Lipoic acid can reduce BBB permeability, promote angiogenesis, repair and protect neurovascular units; its mechanism may be related to down-regulating RAGE expression and up-regulating LRP1 expression.

R965

2020年度河北省醫(yī)學(xué)科學(xué)研究指導(dǎo)性課題（20200304）