NF-κB In BV2 Cells Research Articles

Network pharmacology and experimental verification to explore the anti-migraine mechanism of Yufeng Ningxin Tablet.

Yufeng Ningxin Tablet (YNT) is a traditional Chinese medicine formula, that has been used clinically to treat migraine for many years. It is composed of one herb Pueraria lobata var. lobata (Willd.) Ohwi (Relevant Chinese name: Gegen). Previously, it has been recorded by traditional Chinese doctor that Gegen could be used as medicine to treat migraine. However, the underlying mechanism of action remains to be investigated. It was to explore the effect and mechanism of YNT on migraine based on network pharmacology and experimental verification. First, with the network pharmacology, the effective chemical components and target genes of YNT were filtrated, the YNT-compound-migraine-targets network was constructed. The protein-protein interaction network (PPI) and literature reports were combined to identify potential targets of YNT in the treatment of migraine. Then, the representative compounds of YNT were characterized by LC-MS/MS and the major effect components were identified. Finally, the prediction results of network pharmacology were verified by animal and cell experiments. 7 bioactive components of YNT could act on 97 migraine potential targets. The 5 bioactive components could be characterized comprehensively of YNT. The key therapeutic targets and pathways were collected including 5-HT, CGRP, inflammation and nociceptive factors, and NF-κB signaling pathway. Animal experiments showed that YNT could reduce the expression level of 5-HT, CGRP, NF-κB, c-fos and IL-1β. YNT could inhibit LPS-induced neuroinflammation by NF-κB in BV2 cells in vitro. Western blotting analysis results showed YNT inhibited the NF-κB and phospho-NF-κB levels. It is the first time to verify the consistency between the metabolic components of YNT by LC-MS/MS and the active components predicted by network pharmacology. Meanwhile, the potential mechanism of YNT in the treatment of migraine was studied by combining network pharmacology and in vitro and in vivo experiments.

Downregulating expression of OPTN elevates neuroinflammation via AIM2 inflammasome- and RIPK1-activating mechanisms in APP/PS1 transgenic mice

BackgroundNeuroinflammation is thought to be a cause of Alzheimer’s disease (AD), which is partly caused by inadequate mitophagy. As a receptor of mitophagy, we aimed to reveal the regulatory roles of optineurin (OPTN) on neuroinflammation in the pathogenesis of AD.MethodsBV2 cells and APP/PS1 transgenic (Tg) mice were used as in vitro and in vivo experimental models to determine the regulatory roles of OPTN in neuroinflammation of AD. Sophisticated molecular technologies including quantitative (q) RT-PCR, western blot, enzyme linked immunosorbent assay (ELISA), co-immunoprecipitation (Co-IP) and immunofluorescence (IF) were employed to reveal the inherent mechanisms.ResultsAs a consequence, key roles of OPTN in regulating neuroinflammation were identified by depressing the activity of absent in melanoma 2 (AIM2) inflammasomes and receptor interacting serine/threonine kinase 1 (RIPK1)-mediated NF-κB inflammatory mechanisms. In detail, we found that expression of OPTN was downregulated, which resulted in activation of AIM2 inflammasomes due to a deficiency in mitophagy in APP/PS1 Tg mice. By ectopic expression, OPTN blocks the effects of Aβ oligomer (Aβo) on activating AIM2 inflammasomes by inhibiting mRNA expression of AIM2 and apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC), leading to a reduction in the active form of caspase-1 and interleukin (IL)-1β in microglial cells. Moreover, RIPK1 was also found to be negatively regulated by OPTN via ubiquitin protease hydrolysis, resulting in the synthesis of IL-1β by activating the transcriptional activity of NF-κB in BV2 cells. As an E3 ligase, the UBAN domain of OPTN binds to the death domain (DD) of RIPK1 to facilitate its ubiquitination. Based on these observations, ectopically expressed OPTN in APP/PS1 Tg mice deactivated microglial cells and astrocytes via the AIM2 inflammasome and RIPK-dependent NF-κB pathways, leading to reduce neuroinflammation.ConclusionsThese results suggest that OPTN can alleviate neuroinflammation through AIM2 and RIPK1 pathways, suggesting that OPTN deficiency may be a potential factor leading to the occurrence of AD.

Dexmedetomidine Attenuates Neuroinflammation In LPS-Stimulated BV2 Microglia Cells Through Upregulation Of miR-340.

BackgroundDexmedetomidine (Dex) was reported to exhibit anti-inflammatory effect in the nervous system. However, the mechanism by which Dex exhibits anti-inflammation effects on LPS-stimulated BV2 microglia cells remains unclear. Thus, this study aimed to investigate the role of Dex in LPS-stimulated BV2 cells.MethodsThe BV2 cells were stimulated by lipopolysaccharides (LPS). BV2 cells were infected with short-hairpin RNAs targeting NF-κB (NF-κB-shRNAs) and NF-κB overexpression lentivirus, respectively. In addition, miR-340 mimics or miR-340 inhibitor was transfected into BV2 cells, respectively. Meanwhile, the dual-luciferase reporter system assay was used to explore the interaction of miR-340 and NF-κB in BV2 cells. CCK-8 was used to detect the viability of BV2 cells. In addition, Western blotting was used to detect the level of NF-κB in LPS-stimulated BV2 cells. The levels of TNF-α, IL-6, IL-1β, IL-2, IL-12, IL-10 and MCP-1 in LPS-stimulated BV2 cells were measured with ELISA.ResultsThe level of miR-340 was significantly upregulated in Dex-treated BV2 cells. Meanwhile, the level of NF-κB was significantly increased in BV2 cells following infection with lenti-NF-κB, which was markedly reversed by Dex. LPS markedly increased the expression of NF-κB and proinflammatory cytokines in BV2 cells, which were reversed in the presence of Dex. Moreover, miR-340 mimics enhanced the anti-inflammatory effects of Dex in LPS-stimulated BV2 cells via inhibiting NF-κB and proinflammatory cytokines. Furthermore, Dex obviously inhibited LPS-induced phagocytosis in BV2 cells.ConclusionTaken together, our results suggested that Dex might exert anti-inflammatory effects in LPS-stimulated BV2 cells via upregulation of miR-340. Therefore, Dex might serve as a potential agent for the treatment of neuroinflammation.

Farrerol attenuates MPP+ -induced inflammatory response by TLR4 signaling in a microglia cell line.

Farrerol was found to possess neuroprotective effect; however, the mechanism remains unknown. The aim of the present study was to explore the effect of farrerol on MPP+ -induced inflammation in mouse microglial BV-2 cells and to elaborate the underlying mechanism. MTT assay was performed to measure the cell viability. The pro-inflammatory mediators and cytokines including interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α); inducible nitric oxide synthase; and cyclooxygenase 2 were measured. The expression of p-p65, p-IκBα, toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 were analyzed by western blot. We found that farrerol treatment improved cell viability in MPP+ -induced BV-2 cells. MPP+ -induced upregulation of IL-6, IL-1β, and TNF-α was inhibited by farrerol treatment. Farrerol treatment also attenuated MPP+ -induced expression of inducible nitric oxide synthase and cyclooxygenase 2 as well as the activation of NF-κB in BV-2 cells. MPP+ -induced TLR4 signaling was markedly diminished by farrerol treatment. Knockdown of TLR4 attenuated MPP+ -induced inflammatory response in BV-2 cells. In conclusion, farrerol treatment attenuated MPP+ -induced inflammatory response by inhibiting the TLR4 signaling pathway in BV-2 cells. The results indicated that farrerol could be used as a therapeutic agent for preventing or alleviating the neuroinflammation-related diseases, such as Parkinson's disease.

Interference with Protease-activated Receptor 1 Alleviates Neuronal Cell Death Induced by Lipopolysaccharide-Stimulated Microglial Cells through the PI3K/Akt Pathway.

Excessive microglial cells activation in response to inflammatory stimuli leads to synaptic loss, dysfunction, and neuronal cell death. Activated microglia are involved in the pathogenesis of neurological conditions and frequently contribute to several complications. Accumulating evidence suggests that signaling through PAR-1 is involved in inflammation, however, its function has yet to be fully elucidated. Here, we have demonstrated that the suppression of PAR-1 leads to down-regulation of inflammatory factors including IL-1β, IL-6, TNF-α, NO, as well as the prevention of activation of NF-κB in BV2 cells. In addition, we found that a PAR-1 antagonist, SCH, prevented LPS-induced excessive microglial activation in a dose-dependent manner. As a result of SCH treatment, neuronal cell death via up-regulation of Akt-mediated pathways was reduced. Our results demonstrate that the beneficial effects of SCH are linked to its ability to block an inflammatory response. Further, we found that SCH inhibited the death of PC12 neurons from the cytotoxicity of activated BV2 cells via activation of the PI3K/Akt pathway. These neuro-protective effects appear to be related to inhibition of PAR-1, and represents a novel neuroprotective strategy that could has potential for use in therapeutic interventions of neuroinflammatory disease.

Vitamin K2 suppresses rotenone-induced microglial activation in vitro.

Increasing evidence has shown that environmental factors such as rotenone and paraquat induce neuroinflammation, which contributes to the pathogenesis of Parkinson's disease (PD). In this study, we investigated the molecular mechanisms underlying the repression by menaquinone-4 (MK-4), a subtype of vitamin K2, of rotenone-induced microglial activation in vitro. A microglial cell line (BV2) was exposed to rotenone (1 μmol/L) with or without MK-4 treatment. The levels of TNF-α or IL-1β in 100 μL of cultured media of BV2 cells were measured using ELISA kits. BV2 cells treated with rotenone with or without MK4 were subjected to mitochondrial membrane potential, ROS production, immunofluorescence or immunoblot assays. The neuroblastoma SH-SY5Y cells were treated with conditioned media (CM) of BV2 cells that were exposed to rotenone with or without MK-4 treatment, and the cell viability was assessed using MTT assay. In rotenone-treated BV2 cells, MK-4 (0.5-20 μmol/L) dose-dependently suppressed the upregulation in the expression of iNOS and COX-2 in the cells, as well as the production of TNF-α and IL-1β in the cultured media. MK-4 (5-20 μmol/L) significantly inhibited rotenone-induced nuclear translocation of NF-κB in BV2 cells. MK-4 (5-20 μmol/L) significantly inhibited rotenone-induced p38 activation, ROS production, and caspase-1 activation in BV2 cells. MK-4 (5-20 μmol/L) also restored the mitochondrial membrane potential that had been damaged by rotenone. Exposure to CM from rotenone-treated BV2 cells markedly decreased the viability of SH-SY5Y cells. However, this rotenone-activated microglia-mediated death of SH-SY5Y cells was significantly attenuated when the BV2 cells were co-treated with MK-4 (5-20 μmol/L). Vitamin K2 can directly suppress rotenone-induced activation of microglial BV2 cells in vitro by repressing ROS production and p38 activation.

Gua Lou Gui Zhi decoction suppresses LPS-induced activation of the TLR4/NF-κB pathway in BV-2 murine microglial cells

Toll-like receptor4 (TLR4)/nuclear factor-κB (NF-κB) signaling-mediated neuroinflammation contributes to secondary brain damage in ischemic stroke; therefore, anti-inflammatory therapy via suppression of the TLR4/NF-κB pathway could be a promising strategy for the treatment of stroke and post-stroke disabilities. Gua Lou Gui Zhi decoction (GLGZD) has long been used in China to clinically treat dysfunction after stroke such as muscular spasticity, but the precise mechanisms are largely unknown. In the present study, we evaluated the anti-inflammatory effect of GLGZD and investigated the underlying molecular mechanisms using lipopolysaccharide (LPS)-stimulated BV-2 microglial cells as an invitro inflammatory model of neural cells. We found that GLGZD inhibited the inflammatory response in microglial cells as it significantly reduced LPS-induced expression of pro-inflammatory nitric oxide, tumour necrosis factor-α, interleukin (IL)-6 and IL-1β in BV-2 cells, in a dose-dependent manner. In addition, GLGZD treatment significantly decreased the protein expression of TLR4 and myeloid differentiation factor88, inhibited the phosphorylation of IκB and blocked the nuclear translocation of NF-κB in BV-2 cells, demonstrating its inhibitory effect on the activation of TLR4/NF-κB signaling. Collectively, our findings suggest that inhibition of the inflammatory response via suppression of the TLR4/NF-κB pathway may be one of the mechanisms through which GLGZD ameliorates the damage in ischemic cerebral tissues.