Neuroprotective effects of tongluojiunao in neurons exposed to oxygen and glucose deprivation

Ethnopharmacological relevance

TongLuoJiuNao (TLJN) is an herb extract that mainly contains ginsenoside Rg1 and geniposide, which are clinically used for treating ischemic damages in the brain.

Aim of the study

In the stroke, cerebral ischemia followed by oxygen reperfusion induced apoptosis in hippocampal neurons, while extension of axons and dendrites in neurons may compensate for and repair damages of neuronal network in the hypoxia brain. In this study, we investigated whether TLJN can protect neurons against damages by ischemia in brain vasculature.

Materials and methods

We measured cell viability and lactate dehydrogenase (LDH) release from primary culture of rat hippocampal neurons before and after the neurons were deprived of oxygen and glucose (OGD). In addition, the effects were evaluated with cell viability and neurite outgrowth before or after OGD.

Results

We found that TLJN could play a neuroprotective role to cultured primary rat hippocampal neurons under both normal and oxygen/glucose-deprivation (OGD) conditions. TLJN could protect both cultured primary rat hippocampal neurons and brain microvascular endothelial cells (BMECs) from cell death under both normal and oxygen/glucose-deprivation (OGD) conditions. Moreover, under the same conditions, BMECs-conditioned media pretreated by TNJN could also promote neuron viability and neurite outgrowth, indicating that TLJN stimulated BMECs to secret some neuroprotective/neurotrophic factors.

Conclusion

These findings suggest that TLJN has a marked neuroprotective and neurotrophic roles by either direct or indirect operation, and provide insight into the mechanism of clinical efficacy of this drug against stroke.     

从PI3K/Akt和MAPK/Erk信号通路探讨复方当归注射液对拟缺血神经元的作用

[目的] 探讨复方当归注射液（CAI）干预拟缺血损伤脑微血管内皮细胞（BMECs）后的条件培养液对拟缺血损伤神经元的影响及作用机制。[方法] 原代培养SD大鼠BMECs及皮层神经元，免疫荧光鉴定两种细胞，收集正常BMECs条件培养液（N-CM）、拟缺血损伤BMECs条件培养液（I-CM）及CAI低、中、高剂量干预后的拟缺血损伤BMECs条件培养液（IC-CM，1.25、2.5、5 μL/mL），分别作用于正常神经元和拟缺血损伤神经元，用CCK8法检测各组神经元活性、蛋白免疫印迹（Western Blot）法检测磷脂酰肌醇-3激酶（PI3K）/丝氨酸/苏氨酸激酶（Akt）信号通路Akt的磷酸化水平[磷酸化Akt（p-Akt）/Akt]、丝裂原活化蛋白激酶（MAPK）/细胞外信号调节激酶（Erk）信号通路Erk的磷酸化水平[磷酸化Erk（p-Erk）/Erk]。[结果] 与N-CM处理组相比，I-CM处理组神经元活性显著降低（P<0.01）、Akt磷酸化水平下降（P<0.05）、Erk磷酸化水平显著上升（P<0.01）；CAI干预后IC-CM低剂量处理组神经元活性、Akt磷酸化水平高于I-CM处理组（P<0.05），IC-CM中、高剂量处理组神经元活性、Akt磷酸化水平显著高于I-CM处理组（P<0.01），各IC-CM处理组较I-CM处理组的Erk磷酸化水平变化不明显（P>0.05）。[结论] CAI可通过干预拟缺血损伤内皮细胞进而对拟缺血损伤神经元达到保护作用，该保护作用可能与活化PI3K/Akt信号通路存在相关性，与MAPK/Erk信号通路关联不大。     

HIV/SIV入侵血脑屏障的分子机制探讨

HIV/SIV侵入中枢神经系统(CNS),造成严重的神经病理学改变,引发艾滋病相关的神经认知性障碍(HAND)。尽管有效地使用了高效抗逆转录病毒疗法,HAND在慢性感染者中的发病率仍然很高。通常认为,HIV/SIV在感染早期即可通过感染脑毛细血管内皮细胞或破坏内皮细胞间的紧密连接穿透血脑屏障进入CNS,但其机制尚不明确。目前有几种比较公认的假说,包括病毒直接入侵假说、单核/巨噬细胞入侵假说、T细胞诱导假说和液相入胞假说。本文将就HIV/SIV入侵血脑屏障的分子机制作一综述。     

从PI3K/Akt和MAPK/Erk信号通路探讨复方当归注射液对拟缺血神经元的作用

[目的] 探讨复方当归注射液（CAI）干预拟缺血损伤脑微血管内皮细胞（BMECs）后的条件培养液对拟缺血损伤神经元的影响及作用机制。[方法] 原代培养SD大鼠BMECs及皮层神经元,免疫荧光鉴定两种细胞,收集正常BMECs条件培养液（N-CM）、拟缺血损伤BMECs条件培养液（I-CM）及CAI低、中、高剂量干预后的拟缺血损伤BMECs条件培养液（IC-CM,1.25、2.5、5 μL/mL）,分别作用于正常神经元和拟缺血损伤神经元,用CCK8法检测各组神经元活性、蛋白免疫印迹（Western Blot）法检测磷脂酰肌醇-3激酶（PI3K）/丝氨酸/苏氨酸激酶（Akt）信号通路Akt的磷酸化水平[磷酸化Akt（p-Akt）/Akt]、丝裂原活化蛋白激酶（MAPK）/细胞外信号调节激酶（Erk）信号通路Erk的磷酸化水平[磷酸化Erk（p-Erk）/Erk]。[结果] 与N-CM处理组相比,I-CM处理组神经元活性显著降低（P<0.01）、Akt磷酸化水平下降（P<0.05）、Erk磷酸化水平显著上升（P<0.01）;CAI干预后IC-CM低剂量处理组神经元活性、Akt磷酸化水平高于I-CM处理组（P<0.05）,IC-CM中、高剂量处理组神经元活性、Akt磷酸化水平显著高于I-CM处理组（P<0.01）,各IC-CM处理组较I-CM处理组的Erk磷酸化水平变化不明显（P>0.05）。[结论] CAI可通过干预拟缺血损伤内皮细胞进而对拟缺血损伤神经元达到保护作用,该保护作用可能与活化PI3K/Akt信号通路存在相关性,与MAPK/Erk信号通路关联不大。     

复元醒脑汤对糖尿病脑梗死大鼠BMECs的影响及miRNA-320的调控机制研究

[目的]在细胞水平观察复元醒脑汤对糖尿病脑梗死大鼠缺血脑组织脑微血管内皮细胞(BMECs)的影响,从微小RNA-320(miRNA-320)调控途径探讨复元醒脑汤治疗糖尿病脑梗死的作用机制。[方法]进行复元醒脑汤大鼠灌胃,制备含药血清和对照血清。对糖尿病脑梗死大鼠的缺血脑组织进行BMECs的分离培养,分别加入对照血清、含药血清、转染miRNA-320 inhibitor、中药血清混合转染miRNA-320 inhibitor;实时荧光定量PCR(qPCR)法检测各组BMECs的miRNA-320、胰岛素样生长因子-1(IGF-1)和胰岛素样生长因子受体-1(IGF-1R)基因表达水平,通过甲臜化合物(MTS)检测复元醒脑汤对BMECs增殖能力的影响;通过Transwell实验观察复元醒脑汤对BMECs迁移能力的影响;观察复元醒脑汤对BMECs小管形成能力的影响。[结果]与对照血清组相比,含药血清组、miRNA-320 inhibitor组、含药血清混合miRNA-320 inhibitor组均能使BMECs的增殖、迁移以及小管形成能力显著提高(P0.01),同时显著降低了miRNA-320的表达水平,显著提高了IGF-1的表达水平。[结论]复元醒脑汤能够抑制糖尿病脑梗死大鼠缺血脑组织中miRNA-320表达,增加IGF-1的表达,进而促进BMECs的增殖、迁移及成管能力。     

复元醒脑汤对糖尿病脑梗死大鼠BMECs的影响及miRNA-320的调控机制研究

[目的]在细胞水平观察复元醒脑汤对糖尿病脑梗死大鼠缺血脑组织脑微血管内皮细胞（BMECs）的影响,从微小RNA-320（miRNA-320）调控途径探讨复元醒脑汤治疗糖尿病脑梗死的作用机制。[方法]进行复元醒脑汤大鼠灌胃,制备含药血清和对照血清。对糖尿病脑梗死大鼠的缺血脑组织进行BMECs的分离培养,分别加入对照血清、含药血清、转染miRNA-320 inhibitor、中药血清混合转染miRNA-320 inhibitor;实时荧光定量PCR（qPCR）法检测各组BMECs的miRNA-320、胰岛素样生长因子-1（IGF-1）和胰岛素样生长因子受体-1（IGF-1R）基因表达水平,通过甲臜化合物（MTS）检测复元醒脑汤对BMECs增殖能力的影响;通过Transwell实验观察复元醒脑汤对BMECs迁移能力的影响;观察复元醒脑汤对BMECs小管形成能力的影响。[结果]与对照血清组相比,含药血清组、miRNA-320 inhibitor组、含药血清混合miRNA-320 inhibitor组均能使BMECs的增殖、迁移以及小管形成能力显著提高（P<0.01）,同时显著降低了miRNA-320的表达水平,显著提高了IGF-1的表达水平。[结论]复元醒脑汤能够抑制糖尿病脑梗死大鼠缺血脑组织中miRNA-320表达,增加IGF-1的表达,进而促进BMECs的增殖、迁移及成管能力。     

冰片通过下调TLR4-NF-κB通路缓解LPS诱导的BMECs损伤

目的研究冰片对脂多糖（LPS）引发脑微血管内皮细胞（BMECs）损伤的保护作用及潜在机制。方法原代培养和鉴定大鼠BMECs,并用LPS诱发炎性损伤。利用CCK-8法检测细胞的存活率,并以此优化冰片的给药剂量。继而通过ELISA检测TNF-α、IL-6和IL-8的生成,DCFH-DA探针检测ROS含量,Hoechst 33342染色检测细胞凋亡率,Western blot检测TLR4、p-p65、p65、p-IκBα和IκBα的表达。结果冰片剂量优化结果表明其在10 mg·L^-1和20 mg·L^-1具有良好的剂量-效应依赖性。以它们为低、高剂量,发现冰片可显著减少TNF-α、IL-6和IL-8的分泌和ROS的生成,降低凋亡细胞百分率,减少TLR4、p-p65和IκBα的表达,并增加p65和p-IκBα的表达。结论冰片可通过下调TLR4-NF-κB通路缓解BMECs的炎症反应,进而减少大脑损伤。     

The proinflammatory peptide substance P promotes blood–brain barrier breaching by breast cancer cells through changes in microvascular endothelial cell tight junctions

Neuropeptide substance P (SP) has been implicated in inflammation, pain, depression and breast cancer cell (BCC) growth. Here, we examined the role of SP in trafficking of BCCs (human MDA‐MB‐231 and MDA‐MB‐231BrM2 cells) across the blood–brain barrier (BBB) and brain microvascular endothelial cells (BMECs) using in vitro and in vivo models. SP was secreted from BCCs and mediated adhesion and transmigration of BCCs across human BMECs (HBMECs) in vitro. SP induced activation of HBMECs, leading to secretion of Tumor Necrosis Factor alpha (TNF‐α) and angiopoietin‐2 (Ang‐2) from HBMECs, resulting in changes in localization and distribution of tight junction (TJ) ZO‐1 (tight junction protein zonula occludins‐1) and claudin‐5 structures as well as increased permeability of HBMECs. Using spontaneous breast cancer metastasis mouse model (syngeneic) of GFP‐4T1‐BrM5 mammary tumor cells administered into mammary fat pads of Balb/c mice, SP inhibitor spantide III inhibited in vivo changes in permeability of the BBB and BMEC‐TJs ZO‐1 and claudin‐5 structures as well as decreased tumor cell colonization in brain. Thus, SP secreted from BCCs induces transmigration of BCCs across the BBB, leading to activation of BMECs and secretion of TNF‐α and Ang‐2, resulting in BBB impairment and colonization of tumor cells in brain. Therefore, therapies based on SP inhibition in combination with other therapies may prevent breaching of the BBB by BCCs and their colonization in brain.     

梓醇对高糖致大鼠脑微血管内皮细胞间紧密连接破坏的保护作用研究

梓醇为地黄的主要有效成分,具有缓解脑微血管内皮细胞水肿,促进内皮细胞存活与增殖作用。而其是否对高血糖引发的脑微血管内皮细胞(brain microvascular endothelial cells,BMECs)间紧密连接损伤具保护作用还未知。该文评价了梓醇对高糖致大鼠BMECs紧密连接破坏的保护作用,并对其机制进行了初步研究。原代分离715 d SD大鼠BMECs,经30 mmol·L-1高糖损伤后,观察梓醇对其存活率、内皮素-1分泌、跨膜电阻、紧密连接超微结构、骨架蛋白F-actin重构、紧密连接蛋白和黏附连接蛋白表达的影响。结果表明梓醇(0. 3,3. 0,30. 0μmol·L-1)呈剂量依赖性提高BMECs存活率、降低内皮素-1的分泌、提高BMECs间跨膜电阻;透射电镜结果显示其还能增强BMECs间紧密连接;免疫荧光染色证实梓醇上调紧密连接蛋白claudin-5,ZO-1的表达,逆转高糖所致F-actin细胞骨架重排;q-PCR结果也进一步证实梓醇呈剂量依赖性上调紧密连接蛋白claudin-5,occludin,ZO-1,ZO-2,ZO-3和黏附连接蛋白α-actintin,vinculin,cateinins的mRNA表达(P <0. 05)。该研究表明梓醇对高糖致BMECs的损伤具有保护作用,其机制可能与上调细胞间紧密连接与黏附连接表达,逆转细胞骨架蛋白F-actin重构有关。     

Alisol A 24-acetate protects oxygen–glucose deprivation-induced brain microvascular endothelial cells against apoptosis through miR-92a-3p inhibition by targeting the B-cell lymphoma-2 gene

ContextAlisol A 24-acetate has been used to treat vascular diseases. However, the underlying mechanisms still remain unclear.ObjectiveThe present study evaluated the antiapoptotic effect of alisol A 24-acetate on brain microvascular endothelial cells (BMECs) and explored the underlying mechanisms.Materials and methodsBMECs were injured through oxygen -glucose deprivation (OGD) after alisol A 24-acetate treatment. Cell viability and half-maximal inhibitory concentration (IC₅₀) were measured using CCK-8, whereas inflammatory factors and oxidative stress indicators were measured using enzyme linked immunosorbent assay. Cell invasion and wound healing assays were detected. Cell apoptosis was assessed using flow cytometry. B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X (Bax) expression were analyzed using Western blotting. Dual-luciferase assay was applied to detect target genes of miR-92a-3p.ResultAlisol A 24-acetate had an IC₅₀ of 98.53 mg/L and inhibited cell viability at concentrations over 50mg/L. OGD induced apoptosis and promoted miR-92a-3p overexpression in BMECs. However, alisol A 24-acetate treatment suppressed inflammation, improved migration and invasion abilities, increased Bcl-2 expression, inhibited Bax expression, and repressed apoptosis and miR92a-3p overexpression in OGD-induced BMECs. MiR-92a-3p overexpression promoted cell apoptosis and suppressed Bcl-2 expression, whereas its inhibitor reversed the tendency. Alisol A 24-acetate treatment relieved the effects of miR-92a-3p overexpression. Dual-luciferase assay confirmed that miR-92a-3p negatively regulated the Bcl-2 expression.ConclusionsThese findings suggest that alisol A 24-acetate exerts antiapoptotic effects on OGD-induced BMECs through miR-92a-3p inhibition by targeting the Bcl-2 gene, indicating its potential for BMECs protection and as a novel therapeutic agent for the treatment of cerebrovascular disease.