Inter-ictal assay of peripheral circulating inflammatory mediators in migraine patients under adjunctive cervical non-invasive vagus nerve stimulation (nVNS): A proof-of-concept study

Objective

To assay peripheral inter-ictal cytokine serum levels and possible relations with non-invasive vagus nerve stimulation (nVNS) responsiveness in migraineurs.

Dietary n-3 long chain PUFA supplementation promotes a pro-resolving oxylipin profile in the brain

The brain is highly enriched in long chain polyunsaturated fatty acids (LC-PUFAs) that display immunomodulatory properties in the brain. At the periphery, the modulation of inflammation by LC-PUFAs occurs through lipid mediators called oxylipins which have anti-inflammatory and pro-resolving activities when derived from n-3 LC-PUFAs and pro-inflammatory activities when derived from n-6 LC-PUFAs. However, whether a diet rich in LC-PUFAs modulates oxylipins and neuroinflammation in the brain has been poorly investigated. In this study, the effect of a dietary n-3 LC-PUFA supplementation on oxylipin profile and neuroinflammation in the brain was analyzed. Mice were given diets deficient or supplemented in n-3 LC-PUFAs for a 2-month period starting at post-natal day 21, followed by a peripheral administration of lipopolysaccharide (LPS) at adulthood. We first showed that dietary n-3 LC-PUFA supplementation induced n-3 LC-PUFA enrichment in the hippocampus and subsequently an increase in n-3 PUFA-derived oxylipins and a decrease in n-6 PUFA-derived oxylipins. In response to LPS, n-3 LC-PUFA deficient mice presented a pro-inflammatory oxylipin profile whereas n-3 LC-PUFA supplemented mice displayed an anti-inflammatory oxylipin profile in the hippocampus. Accordingly, the expression of cyclooxygenase-2 and 5-lipoxygenase, the enzymes implicated in pro- and anti-inflammatory oxylipin synthesis, was induced by LPS in both diets. In addition, LPS-induced pro-inflammatory cytokine increase was reduced by dietary n-3 LC-PUFA supplementation. These results indicate that brain n-3 LC-PUFAs increase by dietary means and promote the synthesis of anti-inflammatory derived bioactive oxylipins. As neuroinflammation plays a key role in all brain injuries and many neurodegenerative disorders, the present data suggest that dietary habits may be an important regulator of brain cytokine production in these contexts.     

Curcumin attenuates spatial memory impairment by anti-oxidative,anti-apoptosis,and anti-inflammatory mechanism against methamphetamine neurotoxicity in male Wistar rats: Histological and biochemical changes

ObjectiveMethamphetamine is used extensively around the world as a psychostimulant. The complications related to methamphetamine include methamphetamine-induced neurotoxicity, mainly involving intraneuronal processes, such as oxidative stress and excitotoxicity. Curcumin is effective against neuronal injury due to its antioxidant, anti-inflammatory effects. In this study, we examined the protective effects of curcumin against methamphetamine neurotoxicity.MethodsSixty male Wistar rats were divided into the following groups: control (n = 12), DMSO (n = 12), methamphetamine (n = 12), and methamphetamine + curcumin (100 and 200 mg/kg, respectively, intraperitoneal [IP]; n = 12). Neurotoxicity was induced by 40 mg/kg of methamphetamine administrated through 4 injections (4 × 10 mg/kg, q2h, IP). Curcumin (100 and 200 mg/kg) was administered at 7 days after the last methamphetamine injection. By using a Morris water maze task, the hippocampus-dependent memory and spatial learning were evaluated 1 day after the last curcumin injection. Then, the animal brains were isolated for biochemical measurements, as well as glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1(Iba-1) and caspase-3 immunohistochemical staining.ResultsThe current study demonstrated that administration of curcumin significantly attenuates spatial memory impairment (P < 0.01) following methamphetamine neurotoxicity. Curcumin caused a significant increase in the levels of superoxide dismutase and glutathione peroxidase (P < 0.05). However, it decreased tumor necrosis factor (TNF-α) (P < 0.05) and malondialdehyde (P < 0.01) levels as compared to the methamphetamine group. Also, curcumin significantly reduced Iba-1 (P < 0. 01), GFAP and caspase-3 positive cells in the hippocampus (P < 0.001).ConclusionCurcumin exerted neuroprotective effects on methamphetamine neurotoxicity because of its antioxidant and anti-inflammatory effect.     

Inhibition of nitric oxide synthase attenuates blood-brain barrier disruption during experimental meningitis

Increased permeability of the blood-brain (B-B) barrier is observed during meningitis. Preventing B-B barrier alterations is important because adverse neurological outcomes are correlated with breeches in barrier integrity. It was hypothesized that pathological production of nitric oxide (NO) contributes to B-B barrier disruption during meningitis in the rat. Experimental meningitis was induced by intracisternal (i.c.) administration of lipopolysaccharides (LPS) or vehicle. Groups of rats were concomitantly infused intravenously (i.v.) with saline or the NO synthase inhibitor, aminoguanidine (AG). Eight h after i.c. dosing, B-B barrier alterations were quantitated pharmacokinetically using [¹⁴C]sucrose. Serum and regional brain tissues were obtained 0–30 min after tracer dosing and sucrose influx transfer coefficients ( K_{in (app)}) were calculated from the brain tissue data. Compared to the control groups (i.c. vehicle/i.v. saline), the K_{in (app)} of the i.c. LPS/i.v. saline group increased 1.6–2.1-fold in various brain regions, thus confirming previous observations of increased [¹⁴C]sucrose barrier penetration during meningeal inflammation. Remarkably, i.v. administration of AG to i.c. LPS-treated rats significantly inhibited meningeal NO synthesis and decreased K_{in (app)} permeability alterations in the B-B barrier, compared to i.c. LPS/i.v. saline-treated rats. Regional brain K_{in (app)} estimates in the i.c. LPS/i.v. AG group were similar to control groups (i.c. vehicle/i.v. AG and i.c. vehicle/i.v. saline). In conclusion, these data suggest the general concept that excessive NO production during neuroinflammatory diseases contributes to disruption of the blood-brain barrier.     

核苷酸结合寡聚化结构域样受体蛋白3炎症小体在脑卒中后认知障碍中的研究进展

脑卒中后认知障碍(PSCI)是脑卒中患者常见的并发症,严重影响患者的生活质量。目前,PSCI在临床治疗中尚未发现有效的针对性治疗措施。大量研究证实核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎症小体的活化在PSCI中起关键作用,且对其进行的许多抑制性治疗显示出了改善认知障碍的功效。为此,本文总结了NLRP3炎症小体的活化和影响因素及其与PSCI的关系,发现在PSCI的细胞和动物模型中,针对NLRP3或其炎症小体成分的抑制措施可以减轻炎性反应和相应的病理特征,从而促进其认知功能的恢复,因此,靶向NLRP3炎症小体可能是PSCI治疗的新趋势。然而到目前为止,尽管许多药物和治疗措施已成功鉴定出能够抑制NLRP3炎症小体的活化,但其在临床中的治疗效果和安全性仍有待进一步验证。     

从发病机制概述针刺治疗血管性痴呆的研究进展

血管性痴呆是脑血管病变后所引起的认知功能障碍,是临床中较为常见的痴呆类型。其发病机制源于血管系统损害引起低脑血流灌注、氧化应激等一系列病理过程。针灸作为一种非药物疗法,在脑血管病及相关疾病中有较为广泛的临床应用,许多研究都显示了针灸对认知功能的改善作用,并涉及细胞凋亡、氧化应激、神经炎症、神经递质通路等方面的调节作用。因此,现从血管性痴呆的发病机制角度探讨针刺的治疗作用,以期为进一步揭示针灸在血管性痴呆治疗中的潜在机制提供参考。     

木樨草素对脂多糖诱导的小胶质细胞炎性反应的抑制作用

目的:以脂多糖(LPS)刺激小胶质细胞BV-2,体外模拟神经退行性疾病的炎症模型,探讨木樨草素的抗炎作用和机制。方法:采用LPS(0.1μg/mL)刺激小胶质细胞建立炎症模型,MTT法检测木樨草素对BV-2细胞的毒性作用;硝酸还原酶法检测木樨草素对LPS刺激BV-2细胞一氧化氮(NO)表达量的影响;一氧化氮合酶分型法检测木樨草素对LPS刺激BV-2细胞一氧化氮合酶(iNOS)活性的影响;Western Blot法检测木樨草素对LPS刺激BV-2细胞TLR4蛋白表达影响。结果:木樨草素低、中、高剂量及阳性药物能抑制LPS诱导的BV-2炎性反应。结论:木樨草素能够抑制小胶质细胞活化产生的炎症反应,其抗炎作用的机制可能是通过抑制TLR4信号通路而发挥效用。     

“通督启神”针法治疗AD的动物实验研究进展

阿尔茨海默病(AD)是一种以记忆与认知功能障碍为主要临床表现的中枢神经系统退行性疾病,其病因复杂且发病机制尚未明确,具有高发病率、高致残率和高医疗成本的特点,成为当今公共卫生的一大难题。本研究立足于“通督启神”针法治疗AD的基础研究,对近5年“通督启神”针法治疗AD的动物实验相关文献进行整理,从提高脑能量代谢和脑血流量、抑制神经胶质细胞活化和神经炎症反应、良性调节Aβ生成与清除、抗衰老与抗氧化4个方面总结“通督启神”针法的实验效应及作用机制。最后指出未来可结合胆碱能神经、胰岛素信号转导、线粒体结构和功能以及手针、脉冲电针和音乐电针的异同深入研究,为今后“通督启神”针法治疗AD的基础研究提供新的思路与方法。     

Retinal microglia: Just bystander or target for therapy?

Resident microglial cells can be regarded as the immunological watchdogs of the brain and the retina. They are active sensors of their neuronal microenvironment and rapidly respond to various insults with a morphological and functional transformation into reactive phagocytes. There is strong evidence from animal models and in situ analyses of human tissue that microglial reactivity is a common hallmark of various retinal degenerative and inflammatory diseases. These include rare hereditary retinopathies such as retinitis pigmentosa and X-linked juvenile retinoschisis but also comprise more common multifactorial retinal diseases such as age-related macular degeneration, diabetic retinopathy, glaucoma, and uveitis as well as neurological disorders with ocular manifestation. In this review, we describe how microglial function is kept in balance under normal conditions by cross-talk with other retinal cells and summarize how microglia respond to different forms of retinal injury. In addition, we present the concept that microglia play a key role in local regulation of complement in the retina and specify aspects of microglial aging relevant for chronic inflammatory processes in the retina. We conclude that this resident immune cell of the retina cannot be simply regarded as bystander of disease but may instead be a potential therapeutic target to be modulated in the treatment of degenerative and inflammatory diseases of the retina.     

藁本内酯对脂多糖诱导神经炎症的抑制作用

目的 研究藁本内酯(Lig)对细菌脂多糖(LPS)诱导的神经炎症的抑制作用.方法 用1、2.5、5、10、20 μmol·L-Lig作用于小鼠RAW264.7巨噬细胞,加1μg·mL-1LPS刺激构建细胞炎症反应模型,采用MTT法检测细胞毒性,一步法检测NO的释放量,ELISA法检测TNF-α、IL-6的释放量,免疫细胞化学法检测iNOS的水平;将LPS注入小鼠侧脑室构建体内神经炎症模型,术前30 min及术后6h于腹腔注射30 mg· kg-1Lig,造模后24h取大脑,用免疫组织化学法检测GFAP、TNF-α的蛋白表达.结果 经Lig处理后,细胞存活率无明显变化,细胞分泌NO显著减少(P＜0.05或P＜0.01),且呈剂量依赖性,TNF-α、IL-6、iNOS的表达均明显下调(P＜0.05);Lig能显著降低小鼠海马区GFAP、TNF-α的表达(P＜0.01).结论 Lig能够抑制LPS诱导的小鼠体内外的炎症反应,提示Lig对神经炎症相关的多种疾病可能具有潜在的治疗作用.