Ginsenoside rg(3) attenuates microglia activation following systemic lipopolysaccharide treatment in mice

Neuroinflammation, characterized by activation of microglia and expression of major inflammatory mediators, contributes to neuronal damage in addition to acute and chronic central nervous system (CNS) disease progression. The present study investigated the immune modulatory effects of ginsenoside Rg(3), a principle active ingredient in Panax ginseng, on pro-inflammatory cytokines and microglia activation in brain tissue induced by systemic lipopolysaccharide (LPS) treatment in C57BL/6 mice. Systemic LPS treatment induces immediate microglia activation in the brain. Based on this information, ginsenoside Rg(3) was treated orally with 10, 20, and 30?mg/kg 1?h prior to the LPS (3?mg/kg, intraperitoneally (i.p.)) injection. Ginsenoside Rg(3) at 20 and 30?mg/kg oral doses significantly attenuated up-regulation of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and IL-6 mRNA in brain tissue at 4?h after LPS injection. Morphological activation of microglia and Iba1 protein expression by systemic LPS injection were reduced with ginsenoside Rg(3) (30?mg/kg) treatment. In addition, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in brain tissue were also attenuated with oral treatment of ginsenoside Rg(3) at 30?mg/kg. These results indicate that ginsenoside Rg(3) plays a modulatory role in neuroinflammation. This study shows that ginsenoside Rg(3) attenuates microglia activation using an in vivo animal model.     

丙泊酚对BV-2小胶质细胞活化的影响

目的探讨丙泊酚对脂多糖(LPS)诱导的BV-2小胶质细胞活化的影响及其可能机制。方法体外培养小鼠BV-2小胶质细胞,随机分为LPS 1μg/ml组(A组)、丙泊酚30μM组(B组)、LPS 1μg/ml+丙泊酚30μM组(C组)和空白对照组(D组)。采用RT-PCR检测各组细胞中IL-1β和TNF-αmRNA表达量,Western blot检测总糖原合成酶激酶-3β(GSK-3β)和磷酸化GSK-3β(p-GSK-3β)的蛋白表达水平。结果 A、C组IL-1β、TNF-α及p-GSK-3表达量均较D组明显增加(P<0.05或P<0.01)。与A组相比,C组IL-1β和TNF-αmRNA表达量降低,而p-GSK-3β蛋白表达量增加(P<0.05)。结论丙泊酚30μM能在体外减轻LPS诱导的BV-2小胶质细胞释放IL-1β和TNF-α的水平,此作用可能与抑制GSK-3β活性有关。     

6-Shogaol, a ginger product, modulates neuroinflammation: a new approach to neuroprotection

Inflammatory processes in the central nervous system play an important role in a number of neurodegenerative diseases mediated by microglial activation, which results in neuronal cell death. Microglia act in immune surveillance and host defense while resting. When activated, they can be deleterious to neurons, even resulting in neurodegeneration. Therefore, the inhibition of microglial activation is considered a useful strategy in searching for neuroprotective agents. In this study, we investigated the effects of 6-shogaol, a pungent agent from Zingiber officinale Roscoe, on microglia activation in BV-2 and primary microglial cell cultures. 6-Shogaol significantly inhibited the release of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS) induced by lipopolysaccharide (LPS). The effect was better than that of 6-gingerol, wogonin, or N-monomethyl-l-arginine, agents previously reported to inhibit nitric oxide. 6-Shogaol exerted its anti-inflammatory effects by inhibiting the production of prostaglandin E(2) (PGE(2)) and proinflammatory cytokines, such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), and by downregulating cyclooxygenase-2 (COX-2), p38 mitogen-activated protein kinase (MAPK), and nuclear factor kappa B (NF-κB) expression. In addition, 6-shogaol suppressed the microglial activation induced by LPS both in primary cortical neuron-glia culture and in an in vivo neuroinflammatory model. Moreover, 6-shogaol showed significant neuroprotective effects in vivo in transient global ischemia via the inhibition of microglia. These results suggest that 6-shogaol is an effective therapeutic agent for treating neurodegenerative diseases.     

YC-1 attenuates LPS-induced proinflammatory responses and activation of nuclear factor-kappaB in microglia

BACKGROUND AND PURPOSE: An inflammatory response in the central nervous system mediated by the activation of microglia is a key event in the early stages of the development of neurodegenerative diseases. LPS has been reported to cause marked microglia activation. It is very important to develop drugs that can inhibit microglia activation and neuroinflammation. Here, we investigated the inhibitory effect of YC-1, a known activator of soluble guanylyl cyclase, against LPS-induced inflammatory responses in microglia. EXPERIMENTAL APPROACH: To understand the inhibitory effects of YC-1 on LPS-induced neuroinflammation, primary cultures of rat microglia and the microglia cell line BV-2 were used. To examine the mechanism of action of YC-1, LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production, iNOS, COX-2 and cytokine expression were analyzed by Griess reaction, ELISA, Western blotting and RT-PCR, respectively. The effect of YC-1 on LPS-induced activation of nuclear factor kappa B (NF-kappaB) was studied by NF-kappaB reporter assay and immunofluorocytochemistry. KEY RESULTS: YC-1 inhibited LPS-induced production of NO and PGE2 in a concentration-dependent manner. The protein and mRNA expression of iNOS and COX-2 in response to LPS application were also decreased by YC-1. In addition, YC-1 effectively reduced LPS-induced expression of the mRNA for the proinflammatory cytokines, TNF-alpha and IL-1beta. Furthermore, YC-1 inhibited LPS-induced NF-kappaB activation in microglia. CONCLUSIONS AND IMPLICATIONS: YC-1 was able to inhibit LPS-induced iNOS and COX-2 expression and NF-kappaB activation, indicating that YC-1 may be developed as an anti-inflammatory neuroprotective agent.     

Inhibitory Effects of Lycopene on the Induction of NO,Cytokines, and Mitogen-Activated Protein Kinase Expression by Lipopolysaccharide in Primary Cultured Microglia

Abstract

Microglia are activated in response to brain injury and release neurotoxic factors including nitric oxide (NO) and proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Lycopene, a potent antioxidant, is known to inhibit brain injury. In this study, we found that lycopene (5–20 μ M) significantly inhibited lipopolysaccharide (LPS)-induced NO release in primary cultured microglia. Lycopene (5–20 μM) also concentration-dependently diminished the LPS-induced production of proinflammatory cytokines such as TNF-α and IL-1β in microglia. Further study of the molecular mechanisms revealed that lycopene markedly inhibited extracellular signal-regulated kinase (ERK1/2) but not c-Jun N-terminal kinase (JNK1/2) or p38 mitogen-activated protein kinase (MAPK) phosphorylation stimulated by LPS in microglia. These results suggest that microglial inactivation by lycopene is at least partially due to activation of ERK1/2 phosphorylation Therefore, inhibition of NO and proinflammatory cytokine production in activated microglia by lycopene may represent a powerful and potential therapeutic strategy for various neurodegenerative diseases including ischemia-reperfusion cerebral infarction.     

Celastrol inhibits microglial pyroptosis and attenuates inflammatory reaction in acute spinal cord injury rats

Pyroptosis pathway is closely related to inflammation. However, Celastrol effect on pyroptosis pathway after spinal cord injury (SCI) are poorly understood. We studied the anti-inflammatory and neuroprotective effects of Celastrol on acute spinal cord injury in rats, and its anti-inflammatory effects on lipopolysaccharide (LPS)/ATP-induced microgliosis. Our results show that Celastrol can improve the recovery of hindlimb motor function after SCI in Sprague-Dawley (SD) rats, and reduce the cavity area of spinal cord injury along with the neuronal loss. Celastrol simultaneously reduced the activation of microglia (especially M1 microglia) in the spinal cord, inhibited the pyroptosis-related proteins (NLRP3 ASC Caspase-1 GSDMD), reduced the release of TNF-α IL-1β and IL-18 inflammatory factors, and increased the release of IL10 cytokines. In vitro studies showed that Celastrol reduced the toxicity resulting from the administration of LPS with ATP to BV-2 cells, inhibited the pyroptosis-related proteins (NLRP3 Caspase-1 GSDMD), and inhibited the release of corresponding inflammatory factors. Finally, Celastrol can inhibit the expression of NFκB/p-p65 in vitro and in vivo. Our results show that Celastrol can attenuate the inflammatory response of the spinal cord after SCI, which is associated with inhibition of microglial activation and pyroptosis pathway. Further study to explore the use of Celastrol to treat SCI is warranted.     

L-3-n-Butylphthalide attenuates neuroinflammatory responses by downregulating JNK activation and upregulating Heme oxygenase-1 in lipopolysaccharide-treated mice

Microglia activation-induced neuroinflammation contributes to neuronal damage in neurodegenerative diseases. Inhibition of microglia activation and reduction of major neurotoxic cytokines have been becoming a therapeutic strategy for neurodegenerative diseases. L-3-n-Butylphthalide (L-NBP) has shown the potent neuroprotective effects in stroke and Alzheimer’s disease animal models. The present study investigated the immune modulatory effects of L-NBP on pro-inflammatory cytokines and microglia activation in brain tissue induced by systemic lipopolysaccharide (LPS) treatment in C57BL/6 mice. Our results showed that systemic LPS treatment induced microglia activation in the brain. L-NBP treatment significantly suppressed the expression of proinflammatory cytokines, such as tumor necrosis factor (TNFα), interlukin-1β (IL-1β), interlukin-6 (IL-6), and interlukin-10 (IL-10) in LPS-treated mice. At the meantime, L-NBP treatment decreased the morphological activation of microglia. In addition, the phosphorylation level of JNK MAP kinase-signaling pathway was also inhibited by L-NBP in LPS-treated mice. Furthermore, L-NBP upregulated the expression of heme oxygenase (HO)-1, a key element in the anti-inflammation and anti-oxidative stress. These results suggested that L-NBP might be a promising candidate in delaying and reversing the progress of neurodegenerative diseases by inhibiting microglia activation.     

Zaprinast activates MAPKs, NFκB, and Akt and induces the expressions of inflammatory genes in microglia

Previously, the authors reported that zaprinast, an inhibitor of cGMP-selective phosphodiesterases, induced the secretions of TNF-α and IL-1β by microglia and enhanced the induction of iNOS by lipopolysaccharide (LPS). In this study, the signaling mechanism responsible for microglial activation by zaprinast was investigated and the effects of zaprinast and LPS on microglial activation were compared. Zaprinast was found to activate ERK1/2, p38 MAPK, JNK, NFκB, and PI3K/Akt, and subsequently, induce the mRNA expressions of IL-1α, IL-1β, TNF-α, CCL2, CCL4, CXCL1, CXCL2, and CD14. Associations between signaling pathways and gene expressions were examined by treating microglia with signal inhibitors. PDTC inhibited the induction of all the above genes by zaprinast, and SB203580 inhibited all genes except CXCL1. SP600125, PD98059, and LY294002 inhibited the induction of at least CCL2. Microglial activation by zaprinast was then compared with full-blown activation by LPS. The zaprinast-induced phosphorylations of MAPKs and IκB were less prompt than LPS-induced phosphorylations. IκB degradation by LPS was significant at 10min and did not return to normal, whereas zaprinast induced a later, transient degradation. LPS induced the mRNA expressions of IL-1β, TNF-α, IL-6, CCL2, iNOS, and COX-2, and although zaprinast significantly induced the expressions of all except IL-6 and iNOS, these inductions were far less than those induced by LPS. Collectively, zaprinast was found to upregulate microglial activity mainly via NFκB and p38 MAPK signaling and the subsequent expressions of inflammatory genes. Although, zaprinast was found to have obvious effects on microglia, these were weaker than the effects of LPS.     

DATS通过p38MAPK通路抑制LPS诱导的小鼠MH-S细胞TNF-α及IL-1β表达

目的探讨p38MAPK在二烯丙基三硫(DATS)抑制脂多糖(LPS)诱导小鼠肺泡巨噬细胞促炎细胞因子表达中的作用。方法体外培养MH-S细胞,用DATS和(或)LPS进行干预,Western blot检测细胞p38及磷酸化p38(p-p38)的表达;用LPS和(或)SB203580孵育细胞,反转录PCR检测细胞中TNF-α、IL-1βmRNA表达,Western blot检测细胞磷酸化(p-IκB)及非磷酸化IκB的表达。结果 LPS刺激MH-S细胞可导致p-p38表达增加,呈时间依赖性;用DATS(0.1、0.5、2.5、5.0 mg.L-1)预处理细胞30 min后再给予LPS刺激,p-p38表达呈剂量依赖性下降;单独DATS对p-p38表达无明显影响。p38特异性抑制剂SB203580可剂量依赖性地抑制LPS诱导的p-IκB蛋白、TNF-α及IL-1βmR-NA表达。结论 DATS可通过抑制p38MAPK通路抑制IκB磷酸化及NF-κB活化,进而下调LPS诱导小鼠肺泡巨噬细胞TNF-α、IL-1βmRNA表达。     

Esculentoside A exerts anti-inflammatory activity in microglial cells

Esculentoside A (EsA) is a saponin isolated from the roots of Phytolacca esculenta. This study was designed to evaluate the pharmacological effects of EsA on lipopolysaccharide (LPS)-stimulated BV2 microglia and primary microglia cells. Our results indicated that EsA pretreatment significantly decreased LPS-induced production of Nitric Oxide (NO) and Prostaglandin E2 (PGE2) and impeded LPS-mediated upregulation of pro-inflammatory mediators' expression such as nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-12 (IL-12) and tumor necrosis factor-a (TNF-α) in both BV2 microglia and primary microglia cells. Moreover, EsA markedly suppressed nuclear factor-κB p65 (NF-κB p65) translocation by blocking IκB-α phosphorylation and degradation in LPS-treated BV2 cells. EsA also decreased phosphorylation level of mitogen-activated protein kinases (MAPKs) and inhibited NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome mediated caspase-1 activation in LPS-stimulated BV2 cells. Additionally, EsA decreased β-amyloid_1–42 (Aβ_1–42)-induced production of TNF-α, IL-1β and IL-6 in primary microglia. Thus, EsA might be a promising therapeutic agent for alleviating neuroinflammatory diseases.     

α-Asarone Ameliorates Memory Deficit in Lipopolysaccharide-Treated Mice via Suppression of Pro-Inflammatory Cytokines and Microglial Activation

α-Asarone exhibits a number of pharmacological actions including neuroprotective, anti-oxidative, anticonvulsive, and cognitive enhancing action. The present study investigated the effects of α-asarone on pro-inflammatory cytokines mRNA, microglial activation, and neuronal damage in the hippocampus and on learning and memory deficits in systemic lipopolysaccharide (LPS)-treated C57BL/6 mice. Varying doses of α-asarone was orally administered (7.5, 15, or 30 mg/kg) once a day for 3 days before the LPS (3 mg/kg) injection. α-Asarone significantly reduced TNF-α and IL-1β mRNA at 4 and 24 hours after the LPS injection at dose of 30 mg/kg. At 24 hours after the LPS injection, the loss of CA1 neurons, the increase of TUNEL-labeled cells, and the up-regulation of BACE1 expression in the hippocampus were attenuated by 30 mg/kg of α-asarone treatment. α-Asarone significantly reduced Iba1 protein expression in the hippocampal tissue at a dose of 30 mg/kg. α-Asarone did not reduce the number of Iba1-expressing microglia on immunohistochemistry but the average cell size and percentage areas of Iba1-expressing microglia in the hippocampus were significantly decreased by 30 mg/kg of α-asarone treatment. In the Morris water maze test, α-asarone significantly prolonged the swimming time spent in the target and peri-target zones. α-Asarone also significantly increased the number of target heading and memory score in the Morris water maze. The results suggest that inhibition of pro-inflammatory cytokines and microglial activation in the hippocampus by α-asarone may be one of the mechanisms for the α-asarone-mediated ameliorating effect on memory deficits.     

Sauchinone suppresses lipopolysaccharide-induced inflammatory responses through Akt signaling in BV2 cells

Activated microglial cells play an important role in inflammatory responses in the central nervous system (CNS) that are involved in neurodegenerative diseases. Sauchinone has been shown to modulate the expression of inflammatory factors through nuclear factor-kappa B (NF-κB) signaling pathway. Here, we examined the effect of sauchinone on the inflammatory responses of microglia cells induced by lipopolysaccharide (LPS) and explored the mechanism underlying action of sauchinone. BV2 cells treated with LPS showed an up-regulation of nitric oxide (NO) and prostaglandin (PGE(2)) release, whereas sauchinone suppressed this up-regulation. Sauchinone inhibited both mRNA and protein expression of COX-2, iNOS, TNF-α and IL-1β. In addition, sauchinone blocked the activation of NF-κB through its inhibition of I-κB phosphorylation. Interestingly, sauchinone had no effect on the LPS-induced phosphorylation of mitogen activated protein kinases (MAP kinases; ERK1/2, p38, JNK), but it did inhibit Akt phosphorylation. These results suggest that the inhibitory effect of sauchinone on the LPS-induced production of inflammatory mediator in BV2 cells is associated with the suppression of the NF-κB and Akt signaling pathways. Therefore, sauchinone may be a useful treatment for neurodegenerative disease by inhibiting inflammatory responses in activated microglia.     

LPS诱导小胶质细胞活化模型的建立及评价

目的探讨不同浓度脂多糖(Lipopolysaccharides,LPS)对小胶质细胞活化作用,建立小胶质细胞活化的模型。方法不同浓度LPS(0.01,0.1,1,10,100mg·L-1)刺激原代纯化的小胶质细胞及BV2细胞株,采用MTT法检测细胞活力;采用细胞免疫化学法观察细胞形态变化。结果 LPS(1mg·L-1)可以明显激活原代小胶质细胞,但不影响细胞活力,OX-42染色显示小胶质细胞胞体变大,轴突变短变多,形似"阿米巴状";LPS(10mg·L-1)可以激活BV2细胞,且不降低细胞活力,镜下观察发现BV2细胞胞体明显增大。结论采用LPS(1mg·L-1)刺激原代小胶质细胞,LPS(10mg·L-1)刺激BV2细胞株,可以建立稳定的小胶质细胞活化模型。     

安宫牛黄丸及朱砂和雄黄对脂多糖诱导的神经损伤的作用(英文)

目的探讨朱砂和雄黄在安宫牛黄丸(AGNH)配方中对脂多糖(LPS)介导的神经损伤的保护作用及机制。方法制备大鼠中脑原代神经元-神经胶质细胞联合培养模型。实验分为正常对照组、LPS 10μg.L-1模型组、LPS +朱砂(4和40 mg.L-1)组、LPS +雄黄(4和40 mg.L-1)组和LPS +AGNH(40和400mg.L-1)组。药物与细胞作用30 min后加入LPS;7 d后进行实验指标检测。采用免疫组织化学染色法检测酪氨酸羟化酶阳性的细胞数量和形态学变化以及小神经胶质细胞的激活情况,实时RT-PCR检测细胞中肿瘤坏死因子α(TNF-α)mRNA和诱导型一氧化氮合酶(iNOS)mRNA表达水平,酶联免疫吸附试验(ELISA)与Griess试剂分别检测细胞培养上清液中TNF-α和一氧化氮(NO)的含量。结果与正常对照组比较,LPS10μg.L-1作用于细胞,多巴胺能神经元的数量明显下降了40%(P<0.05);LPS显著诱导小神经胶质细胞的激活,TNF-αmRNA和iNOS mRNA的表达分别增加了9倍和2倍(P<0.05),同时神经元-胶质细胞联合培养上清液中TNF-α和NO的含量分别增加了20倍和30倍(P<0.05)。与LPS模型组比较,AGNH400mg.L-1和雄黄40 mg.L-1能明显拮抗LPS对多巴胺能神经元的毒性作用,多巴胺神经元数量分别上升了40%和30%(P<0.05);AGNH400 mg.L-1和雄黄40 mg.L-1能抑制小神经胶质细胞的激活,小胶质神经细胞中TNF-αmRNA分别下降了61%和52%(P<0.05)和iNOS mRNA的表达分别降低了58%和51%(P<0.05),而且神经元-神经胶质细胞联合培养上清液中TNF-α的含量分别降低了55%和43%(P<0.05)以及NO的含量分别下降了53%和34%(P<0.05)。而朱砂对LPS的作用无影响。结论 AGNH能改善LPS介导的神经元损伤,雄黄是其抗炎作用的有效成分之一,朱砂未见明显的神经保护作用。     

Polydatin alleviates traumatic spinal cord injury by reducing microglial inflammation via regulation of iNOS and NLRP3 inflammasome pathway

Polydatin is a glucoside of resveratrol with lots of functional properties in the central nervous system, such as anti-edema, anti-oxidation and anti-inflammation. The purpose of this study was to evaluate the effects of polydatin on traumatic spinal cord injury (SCI) and explore the relative mechanisms. SCI models were established using the weight-drop method in rats, additionally, single polydatin administration (20, 40 mg/kg body weight) remarkably improved motor function of SCI rat, along with decreased nitric oxide (NO) generation and inflammatory factor (IL-1β, IL-6 and TNF-α) production in spinal cord tissues. Similar to the results of in vivo experiments, the inflammatory response was aggravated with the intervention of lipopolysaccharide (LPS) in BV2 microglia. However, polydatin treatment (1, 2 and 4 μM) inhibited iNOS expression, decreased NLRP3 inflammasome activation, which subsequently relieved microglial inflammation. Above all, our data indicated that polydatin possessed neuroprotective effects in SCI rats, possibly by suppressing iNOS expression and NLRP3 inflammasome activation in microglia.     

Histamine Induces Microglia Activation and the Release of Proinflammatory Mediators in Rat Brain Via H1R or H4R

Histamine is a major peripheral inflammatory mediator and a neurotransmitter in the central nervous system. We have reported that histamine induces microglia activation and releases proinflammatory factors in primary cultured microglia. Whether histamine has similar effects in vivo is unknown. In the present study, we aimed to investigate the role of histamine and its receptors in the release of inflammatory mediators and activation of microglia in rat brain. We site-directed injected histamine, histamine receptor agonists or histamine receptor antagonists in the rat lateral ventricle using stereotaxic techniques. Flow cytometry was employed to determine histamine receptor expression in rat microglia. Microglia activation was assessed by Iba1 immunohistochemistry. The levels of tumour necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and interleukin-10 (IL-10) were measured with commercial enzyme-linked immunosorbent assay (ELISA) kits, TNF-α, IL-1β and IL-10 mRNA expressions were determined with Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). We found that all four types of histamine receptors were expressed in rat brain microglia. Histamine was able to induce microglia activation and subsequent production of the inflammatory factors TNF-α, IL-1β and IL-10, and these effects were partially abolished by H₁R and H₄R antagonists. However, H₂R and H₃R antagonists significantly increased production of TNF-α and IL-1β, and decreased IL-10 levels. The H₁R or H₄R agonists stimulated the production of TNF-α and IL-1β, while the H₂R or H₃R agonists increased IL-10 release. Our results demonstrate that histamine induces microglia activation and the release of both proinflammatory and anti-inflammatory factors in rat brain, thus contributing to the development of inflammation in the brain.

Histamine induces microglia activation and the release of both proinflammatory (TNF-α and IL-1β) and anti-inflammatory factors (IL-10) in rat brain, thus contributing to the development of inflammation in the brain.

     

Phthalide derivative CD21 ameliorates ischemic brain injury in a mouse model of global cerebral ischemia: involvement of inhibition of NLRP3

The activation of NLRP3 inflammasome is closely related to ischemic brain injury and inhibition of NLRP3 inflammasome activation may be a new therapeutic strategy for ischemic stroke. Our previous studies showed that ligustilide (LIG) had a dose-dependent neuroprotective effect on various models of cerebral ischemia and dementia in vivo and in vitro. CD21, a kind of phthalide derivative, was modified from LIG. In this study, we established a global cerebral ischemia–reperfusion model in mice by bilateral common carotid artery ligation (2VO), and explored the neuroprotective effect of CD21 and its anti-inflammatory mechanism on cerebral ischemia mice. CD21 significantly improved weight loss, neurobehavioral deficits and neurons loss in hippocampal CA1 and caudate putamen (CPu) subregions, which were induced by 2VO in mice. CD21 significantly inhibited the overactivation of astrocyte and microglia, and decreased the mRNA level of IL-6, TNF-α and IL-1β. Moreover, CD21 significantly inhibited the activation of TLR4/NF-κB signaling pathway mediated by HMGB1 and NLRP3/ASC/Caspase-1 signaling pathway mediated by Cathepsin B, thus inhibiting the activation of NLRP3 inflammasome. Our results demonstrated that CD21 may exert a neuroprotection by inhibiting NLRP3 inflammasome activation after cerebral ischemia. These findings provide a new strategy for the treatment of ischemic stroke.     

DATS通过NF-κB抑制LPS诱导小鼠肺泡巨噬细胞促炎细胞因子表达

目的探讨二烯丙基三硫(DATS)抑制脂多糖(LPS)诱导小鼠肺泡巨噬细胞肿瘤坏死因子-α(TNF-α)及白介素-1β表达的信号转导机制。方法体外培养MH-S细胞,用DATS和(或)LPS进行干预。反转录PCR检测细胞中TNF-α、IL-1β mRNA表达,电泳迁移率改变分析(EMSA)检测细胞核因子-κB(NF-κB)活性,Western blot检测细胞磷酸化(p-IκB)及非磷酸化IκB的表达。结果LPS刺激MH-S细胞可导致TNF-α、IL-1β mRNA、p-IκB表达增加及NF-κB活性升高。用DATS(0.1、0.5、2.5、5.0mg.L-1)预处理细胞30min后再给予LPS刺激,可使TNF-α、IL-1β mRNA表达降低,并呈剂量依赖性;升高的NF-κB活性及p-IκB表达均显不同程度的抑制。单独DATS对TNF-α、IL-1β mRNA表达及NF-κB活性无影响。结论DATS可通过抑制IκB磷酸化及NF-κB活化,进而下调LPS诱导小鼠肺泡巨噬细胞TNF-α、IL-1β mRNA表达。     

2-Hydroxycircumdatin C inhibits LPS-induced BV2 cells inflammatory response via down-regulation of TLR4-mediated NF-κB/MAPK and JAK2/STAT3 pathways

2-Hydroxycircumdatin C (2-HCC) is a circumdatin-type alkaloid isolated from a coral-associated fungus Aspergillus ochraceus LZDX-32-15. In the present study, we aimed to assess the neuroprotective effects of 2-HCC on the microglia-mediated inflammatory response as well as underlining molecular mechanisms. 2-HCC could significantly down-regulate the overproduction of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) induced by lipopolysaccharide (LPS) both in BV2 cells and primary microglial cells without affecting cell viability. In addition, 2-HCC exerted obvious neuroprotective effects against inflammatory injury in neurons when cocultured with LPS-induced microglia. Mechanism investigation indicated that the anti-inflammatory effect of 2-HCC involved the inhibition of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) and alleviation of the LPS-induced TLR4-NF-κB/MAPK pathway. Furthermore, 2-HCC treatment attenuated LPS-induced activation of the JAK2/STAT3 pathway. In conclusion, these results indicated that the anti-inflammatory and neuroprotective properties of 2-HCC, at least partially, depended upon TLR4-NF-κB/MAPK and JAK2/STAT3 signaling pathways.