Response In BV-2 Cells Research Articles

MECP2 Increases the Pro-Inflammatory Response of Microglial Cells and Phosphorylation at Serine 423 Regulates Neuronal Gene Expression upon Neuroinflammation.

Methyl-CpG-binding protein 2 (MECP2) is a critical transcriptional regulator for synaptic function. Dysfunction of synapses, as well as microglia-mediated neuroinflammation, represent the earliest pathological events in Alzheimer’s disease (AD). Here, expression, protein levels, and activity-related phosphorylation changes of MECP2 were analyzed in post-mortem human temporal cortex. The effects of wild type and phosphorylation-deficient MECP2 variants at serine 423 (S423) or S80 on microglial and neuronal function were assessed utilizing BV2 microglial monocultures and co-cultures with mouse cortical neurons under inflammatory stress conditions. MECP2 phosphorylation at the functionally relevant S423 site nominally decreased in the early stages of AD-related neurofibrillary pathology in the human temporal cortex. Overexpression of wild type MECP2 enhanced the pro-inflammatory response in BV2 cells upon treatment with lipopolysaccharide (LPS) and interferon-γ (IFNγ) and decreased BV2 cell phagocytic activity. The expression of the phosphorylation-deficient MECP2-S423A variant, but not S80A, further increased the pro-inflammatory response of BV2 cells. In neurons co-cultured with BV2 cells, the MECP2-S423A variant increased the expression of several genes, which are important for the maintenance and protection of neurons and synapses upon inflammatory stress. Collectively, functional analyses in different cellular models suggest that MECP2 may influence the inflammatory response in microglia independently of S423 and S80 phosphorylation, while the S423 phosphorylation might play a role in the activation of neuronal gene expression, which conveys neuroprotection under neuroinflammation-related stress.

Biological evaluation of 7-O-amide hesperetin derivatives as multitarget-directed ligands for the treatment of Alzheimer's disease

A series of 7-O-amide hesperetin derivatives were subjected to multi-target biological evaluation of anti-Alzheimer's disease. Most of the compounds showed good in vitro inhibitory activity against cholinesterase, of which compound 7c (7-O-(4-(morpholinoethyl)-acetamide) hesperetin) was the most effective anti-eqBuChE derivative (IC50 = 0.28 ± 0.05 μM) and exerted neuroprotective effects. Further biological evaluation found that compounds 4d, 4e and 7c showed strong antioxidant, anti-Aβ self-aggregation and anti-neuroinflammatory activities. Compound 7c could inhibit the expression of iNOS and COX-2 proteins and prevent LPS-induced inflammatory response in BV2 cells. In addition, compound 7c could chelate biometal ions such as Cu2+ and Zn2+. In the vivo study, the MWM test confirmed that compound 7c could improve the cognitive impairment caused by scopolamine. In summary, the above studies have shown that the optimized compound 7c has great development potential as MTDL for the treatment of AD.

Impaired autophagy in microglia aggravates dopaminergic neurodegeneration by regulating NLRP3 inflammasome activation in experimental models of Parkinson’s disease

Microglia-mediated inflammation plays an important role in the pathogenesis of several neurodegenerative diseases including Parkinson’s disease (PD). Recently, autophagy has been linked to the regulation of the inflammatory response. However, the potential role of microglial autophagy in the context of PD pathology has not been characterized. In the present study, we investigated whether impaired microglial autophagy would affect dopaminergic neurodegeneration and neuroinflammation both in vivo and in vitro. In vitro, BV2 microglial cells were exposed to LPS in the presence or absence of autophagy-related gene 5 (Atg5) small interference RNA (Atg5-siRNA). For in vivo study, microglial Atg5 conditional knockout (Atg5flox/flox; CX3CR1-Cre) mice and their wild-type littermates (Atg5flox/flox) were intraperitoneally injected with MPTP to induce experimental PD model. Our results revealed that disruption of autophagy by Atg5-siRNA aggravated LPS-induced inflammatory responses in BV2 cells and caused greater apoptosis in SH-SY5Y cells treated with BV2 conditioned medium. In mice, impaired autophagy in microglia exacerbated dopaminergic neuron loss in response to MPTP. The mechanism by which the deficiency of microglial autophagy promoted neuroinflammation and dopaminergic neurodegeneration was related to the regulation of NLRP3 inflammasome activation. These findings demonstrate that impairing microglial autophagy aggravates pro-inflammatory responses to LPS and exacerbates MPTP-induced neurodegeneration by modulating NLRP3 inflammasome responses. We anticipate that enhancing microglial autophagy may be a promising new therapeutic strategy for PD.

C1q/tumor necrosis factor-related protein-1 attenuates microglia autophagy and inflammatory response by regulating the Akt/mTOR pathway

AimsC1q/tumor necrosis factor-related protein-1 (CTRP1) is a newly identified adiponectin paralog that modulates metabolism and inflammation. However, the cerebral function of CTRP1 remains unknown. This study aimed to determine its role and mechanism in cerebral ischemia and reperfusion injury. Main methodsSerum level of CTRP1 as well as high-sensitivity C reactive protein (hs-CRP) in stroke patients was measured by ELISA assay. The levels of TNF-α, IL-1β, and IL-6 were analyzed using ELISA kits. Quantitative RT-PCR, western blot analysis were conducted to detect indicated genes. Key findingsCTRP1 was significantly upregulated in sera from patients with stroke and positive correlation with hs-CRP. CTRP1 was significantly upregulated in BV2 microglia exposed to oxygen and glucose deprivation and reperfusion (OGD/R). Knockdown of CTRP1 by si-CTRP1 transfection markedly enhanced OGD/R-induced autophagy and accelerated the inflammatory response in BV2 cells, as indicated by increased expression of LC3-II/LC3-I and beclin1, as well as increased concentration of the proinflammatory cytokines TNF-α, IL-1β, and IL-6. However, recombinant CTRP1 or overexpression of CTRP1 attenuated OGD/R-induced autophagy and inflammatory response in BV2 cells. Further study demonstrated that knockdown of CTRP1 decreased, while recombinant CTRP1 increased the phosphorylation of Akt and mTOR in BV2 cells. IGF-1, which activates PI3-kinase and MEK1/2, abolished the promotive effect of si-CTRP1, while inhibition of Akt with A6730 reversed the inhibitory effect of recombinant CTRP1 on BV2 cells autophagy and inflammation response. SignificanceCTRP1 inhibited microglia autophagy and inflammation response by regulating the Akt/mTOR pathway.

MicroRNA-21-5p promotes the inflammatory response after spinal cord injury by targeting PLAG1.

The aim of this study was to investigate the expression level of microRNA-21-5p and its target gene PLAG1 in the serum of patients with spinal cord injury (SCI), as well as the role and mechanism of microRNA-21-5p in lipopolysaccharide-induced primary microglial inflammation. The levels of microRNA-21-5p and PLAG1 in the peripheral blood of 24 patients with spinal cord injury and 24 healthy people were examined by quantitative Polymerase Chain Reaction (qPCR) analysis. The expressions of inflammatory factors, including IL-1, IL-6 and TNF-α were measured by enzyme-linked immunosorbent assay (ELISA). After microglial BV2 cells were treated with different concentrations of LPS, microRNA-21-5p, and PLAG1 expressions were examined by qPCR, while IL-1, IL-6, and TNF-α levels in cell supernatant were measured by ELISA. Finally, the binding relationship between microRNA-21-5p and its target gene was analyzed by Luciferase reporter assay. The data showed that microRNA-21-5p was upregulated in the serum of SCI patients, and also increased in LPS-treated cells, with a certain concentration dependence. On the contrary, PLAG1 was remarkably downregulated, suggesting that the above two genes were negatively correlated in SCI patients. ELISA results indicated that the knockdown of microRNA-21-5p or overexpression of PLAG1 reduced the levels of IL-1, IL-6 and TNF-α in BV2 cells. Meanwhile, microRNA-21-5p might be involved in regulating the inflammatory response of BV2 cells by modulating PLAG1. MicroRNA-21-5p promotes the inflammatory response after SCI by targeting PLAG1.

Platycodin D inhibits MPP+-induced inflammatory response in BV-2 cells through the TLR4/MyD88/NF-κB signaling pathway

Parkinson’s disease is a common progressive neurodegenerative disorder associated with inflammation. Platycodin D (PLD) is a triterpenesaponin that has anti-inflammatory and neuro-protective effects. However, the role of PLD in Parkinson’s disease has not been fully investigated. In the current study, we investigated the effect of PLD on 1-methyl-4-phenylpyridinium (MPP+)-induced inflammatory response in BV-2 cells. Our results showed that PLD treatment improved the cell viability of MPP+-induced BV-2 cells. PLD significantly inhibited the levels of inflammatory mediators including nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in MPP+-treated BV-2 cells. The increased productions of inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and IL-6 in MPP+-treated BV-2 cells were also suppressed by PLD. Furthermore, PLD inhibited the activation of TLR4/MyD88/NF-κB pathway in MPP+-treated BV-2 cells. Overexpression of TLR4 reversed the protective effects of PLD on MPP+-treated BV-2 cells. Collectively, PLD protected BV-2 cells from MPP+-induced inflammatory response via regulating the TLR4–MyD88–NF-κB signaling pathway.

Silencing of PTX3 alleviates LPS-induced inflammatory pain by regulating TLR4/NF-κB signaling pathway in mice.

Pentraxin 3 (PTX3), an inflammatory marker and a pattern recognition receptor, plays an important role in promoting the progress of tumor and inflammatory diseases. However, the role of PTX3 in the pathogenesis of inflammatory pain diseases is rarely reported. The purpose of the present study is to investigate the effect of PTX3 on the progression of inflammatory pain and the special molecular mechanism. A mouse BV2 microglia cell activation-mediated inflammatory model was developed with Lipopolysaccharide (LPS) induction, and a mouse inflammatory pain model was established with LPS injection. The effect of PTX3 on microglia inflammatory activation was verified by measuring pro-inflammatory cytokines expression. The mechanical hyperalgesia testing, the thermal preference testing and the cold allodynia testing were used to measure the response of mice to mechanical pain, heat stimulation and cold stimulation, respectively. The results revealed that the expression of PTX3 was decreased in the LPS-induced inflammatory pain mice model. Silencing of PTX3 down-regulated LPS-induced inflammatory factors, including IL-6, NO and TNF-α, and alleviated LPS-induced inflammatory pain in BV2 cells. In addition, overexpression of TLR4 reversed the inhibitory effect of si-PTX3 on LPS-induced inflammatory response in BV2 cells. What is more, silencing of PTX3 inhibited TLR4/NF-κB signaling pathway. Collectively, it suggests that silencing of PTX3 alleviates LPS-induced inflammatory response of BV2 cells potentially by regulating the TLR4/NF-κB signaling pathway.

Melatonin protects against ischemic stroke by modulating microglia/macrophage polarization toward anti-inflammatory phenotype through STAT3 pathway.

AimsMicroglia and infiltrated macrophages play important roles in inflammatory processes after ischemic stroke. Modulating microglia/macrophage polarization from pro‐inflammatory phenotype to anti‐inflammatory state has been suggested as a potential therapeutic approach in the treatment of ischemic stroke. Melatonin has been shown to be neuroprotective in experimental stroke models. However, the effect of melatonin on microglia polarization after stroke and underlying mechanisms remain unknown.MethodsIn vivo, cerebral ischemia was induced by distal middle cerebral artery occlusion (dMCAO) in C57BL/6J mice. Melatonin was injected intraperitoneally (20 mg/kg) at 0 and 24 hours after ischemia. In vitro, the microglial cell line BV2 was stimulated to the pro‐inflammatory state with conditioned media (CM) collected from oxygen‐glucose deprivation (OGD) challenged neuronal cell line Neuro‐2a (N2a). Real‐time PCR was utilized to detect the mRNA expression of microglia phenotype markers. Activation of signal transducer and activator of transcription 3 (STAT3) pathway was determined by Western blot of phosphorylated STAT3 (pSTAT3). A neuron‐microglia co‐culture system was used to determine whether melatonin can inhibit the neurotoxic effect of pro‐inflammatory microglia to post‐OGD neurons.ResultsMelatonin treatment reduced brain infarct and improved neurological functions 3 days after dMCAO, which was accompanied by decreased expression of pro‐inflammatory markers and increased expression of anti‐inflammatory markers in the ischemic brain. In vitro studies confirmed that melatonin directly inhibited the pro‐inflammatory responses in BV2 cells upon exposure to OGD neuron CM. The microglia possessing pro‐inflammatory phenotype exacerbated post‐OGD N2a cells death, whereas melatonin reduced such neurotoxic effect. Further, melatonin enhanced the otherwise inhibited pSTAT3 expression in BV2 cells treated with OGD neuron CM. STAT3 blockade significantly reduced the effect of melatonin on microglial phenotype shift. Conclusion: Melatonin treatment ameliorates brain damage at least partially through shifting microglia phenotype from pro‐inflammatory to anti‐inflammatory polarity in a STAT3‐dependent manner.

MicroRNA-23b alleviates neuroinflammation and brain injury in intracerebral hemorrhage by targeting inositol polyphosphate multikinase

Neuroinflammation plays a critical role in the pathogenesis of intracerebral hemorrhage (ICH), contributing to detrimental brain injury and neurological function deficits. MicroRNA-23b (miR-23b) exerts anti-inflammatory effects in many diseases and is downregulated in patients with ICH. This study aimed to evaluate the involvement of miR-23b in ICH models in vivo and in vitro, using basal ganglia injection of collagenase type VII in rats and hemin stimulation for cells, respectively. Exogenous overexpression of miR-23b by transfection with lentivirus-miR-23b (LV-miR-23b) or miR-23b mimics was evaluated by RT-qPCR. In this study, we found miR-23b was downregulated in the ICH models and its overexpression effectively alleviated neurological deficits, brain edema, hematoma area, and neuronal apoptosis in ICH rats. Western blotting for neuroinflammation markers and immunofluorescence staining for microglial activation demonstrated that miR-23b could alleviate neuroinflammation in ICH in vivo. We also performed an in vitro mechanism study using BV2 microglial cells and HT22 neuronal cell lines to explore how miR-23b modulates neuroinflammation and neuronal protection after ICH. We found that miR-23b significantly decreased hemin-stimulated inflammation response in BV2 cells and attenuated co-cultured HT22 neuronal cell death. Additionally, we verified that miR-23b suppressed inflammation in BV2 cells by targeting inositol polyphosphate multikinase (IPMK) and that autophagy regulation through the Akt/mTOR pathway was involved in miR-23b-regulated inflammation after ICH. Our study illustrated that miR-23b played a protective role in ICH through inhibiting neuroinflammation by targeting IPMK; this mechanism may be related to the regulation of the Akt/mTOR autophagy pathway, making it a potential target for ICH treatment.

TREM2 deficiency aggravates α-synuclein-induced neurodegeneration and neuroinflammation in Parkinson's disease models.

Variants in the gene encoding the triggering receptor expressed on myeloid cells 2 (TREM2) are known to increase the risk of developing Alzheimer disease and Parkinson's disease (PD). However, the potential role of TREM2 effect on synucleinopathy has not been characterized. In this study, we investigated whether loss of TREM2 function affects α-synucleinopathy both in vitro and in vivo. In vitro, BV2 microglial cells were exposed to α-synuclein (α-syn) in the presence or absence of TREM2 small interference RNA. For in vivo studies, wild-type controls and TREM2 gene knockout mice were intracranially injected in the substantia nigra with adeno-associated viral vectors expressing human α-syn (AAV-SYN) to induce PD. Our results revealed that knockdown of TREM2 aggravated α-syn-induced inflammatory responses in BV2 cells and caused greater apoptosis in SH-SY5Y cells treated with BV2-conditioned medium. In mice, TREM2 knockout exacerbated dopaminergic neuron loss in response to AAV-SYN. Moreover, both in vitro and in vivo TREM2 deficiency induced a shift from an anti-inflammatory toward a proinflammatory activation status of microglia. These data suggest that impairing microglial TREM2 signaling aggravates proinflammatory responses to α-syn and exacerbates α-syn-induced neurodegeneration by modulating microglial activation state.-Guo, Y., Wei, X., Yan, H., Qin, Y., Yan, S., Liu, J., Zhao, Y., Jiang, F., Lou, H. TREM2 deficiency aggravates α-synuclein-induced neurodegeneration and neuroinflammation in Parkinson's disease models.

MicroRNA-190 alleviates neuronal damage and inhibits neuroinflammation via Nlrp3 in MPTP-induced Parkinson's disease mouse model.

Parkinson's disease (PD) is neurodegenerative dyskinesia characterized by loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Although neuroinflammation is one of the pathological features of PD, its mechanism of promoting PD is still not fully understood. Recently, the microRNA (miR) is considered to play a critical regulatory role in inflammatory responses. In this study, we examined the anti-inflammatory activity, antineuronal injury, and the underlying target of miR-190 with MPTP-induced PD mouse model and BV2 cells. The results showed that miR-190 is downregulated in lipopolysaccharide (LPS)-induced BV2 cells; however, when the miR-190 overexpressed, the expression of proinflammatory mediators, such as iNOS, IL-6, TNF-α, and TGF-β1, were inhibited and the anti-inflammatory mediator such IL-10 was increased. In addition, we predicted the potential target of miR-190 to be Nlrp3 and verified by luciferase reporter assay. The results also showed that Nlrp3 was upregulated in LPS-induced BV2 cells, whereas knockdown of Nlrp3 inhibited the LPS-induced inflammatory response in BV2 cells. Furthermore, upregulation of miR-190 or knockdown of Nlrp3 inhibited LPS-induced apoptosis in BV2 cells. However, the apoptosis inhibition effect of miR-190 was abrogated by overexpression of Nlrp3. Finally, upregulation of miR-190 inhibited the activation of microglial cells and inflammation and attenuated the tyrosine hydroxylase loss in SNpc in MPTP-induced PD mice. In conclusion, we demonstrated that miR-190 alleviates neuronal damage and inhibits inflammation via negatively regulating the expression and activation of Nlrp3 in MPTP-induced PD mouse model.

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.

Effect of Wasabi Extract on Inflammatory Response of BV2 Cells Induced by Lipopolysaccharide

Objective: This study was to investigate the effect of wasabi extract 6-(methylsulfinyl)hexyl isothiocyanate (6-MITC) on preventing neuroinflammation. Methods: The activation of BV2 microglia cell was introduced by LPS to establish an in vitro neuroinflammatory cell model, and the influence of 6-MITC on the survival rate of BV2 cells was deceted by MTT assay and the mRNA expression level of inflammatory factors in each group were deceted by RT-qPCR. Results: 6-MITC can significantly down-regulate mRNA expression levels of the inflammatory factor interleukin-1β, IL-6, tumor necrosis factor-α (TNF-α) and nitric oxide synthase (iNOS) after activation of BV2 cells induced by LPS. Conclusion: 6-MITC can inhibit LPS-induced microglia activation and decrease inflammatory response of BV2 cells.

IP3-Mediated Calcium Signaling Is Involved in the Mechanism of Fractalkine-Induced Hyperalgesia Response.

BackgroundFractalkine is widely expressed throughout the brain and spinal cord, where it can exert effects on pain enhancement and hyperalgesia by activating microglia through CX3C chemokine receptor 1 (CX3CR1), which triggers the release of several pro-inflammatory cytokines in the spinal cord. Fractalkine has also been shown to increase cytosolic calcium ([Ca2+]i) in microglia.Material/MethodsBased on the characteristics of CX3CR1, a G protein-coupled receptor, we explored the role of inositol 1,4,5-trisphosphate (IP3) signaling in fractalkine-induced inflammatory response in BV-2 cells in vitro. The effect and the underlying mechanism induced by fractalkine in the brain were observed using a mouse model with intracerebroventricular (i.c.v.) injection of exogenous fractalkine.Results[Ca2+]i was significantly increased and IL-1β and TNF-α levels were higher in the fractalkine-treated cell groups than in the farctalkine+ 2-APB groups. We found that i.c.v. injection of fractalkine significantly increased p-p38MAPK, IL-1β, and TNF-α expression in the brain, while i.c.v. injection of a fractalkine-neutralizing antibody (anti-CX3CR1), trisphosphate receptor (IP3R) antagonist (2-APB), or p38MAPK inhibitor (SB203580) prior to fractalkine addition yielded an effective and reliable anti-allodynia effect, following the reduction of p-p38MAPK, IL-1β, and TNF-α expression.ConclusionsOur results suggest that fractalkine leads to hyperalgesia, and the underlying mechanism may be associated with IP3/p38MAPK-mediated calcium signaling and its phlogogenic properties.

Suppressing Irf2bp2 expressions accelerates metabolic syndrome-associated brain injury and hepatic dyslipidemia

Increasing studies indicate that high fat diet (HFD) induces neuroinflammation in animal models with obesity, yet the pathology of it is unclear. Interferon Regulatory Factor 2 Binding Protein 2 (Irf2bp2) is a key regulator of macrophage polarization, playing an essential role in regulating inflammatory response. This study investigated the effects of Irf2bp2 on HFD-induced brain injury, and explored the possible molecular mechanisms using wild type (WT) and Irf2bp2 knockout (KO) mice. The results indicated that HFD-increased body weight of mice was further elevated by Irf2bp2-knockout. In addition, Irf2bp2-deletion accelerated HFD-induced metabolic syndrome, as evidenced by the promoted fasting glucose and insulin levels. In the results of behavioral measurements, Irf2bp2-knockout intensified cognitive deficit in HFD-fed mice by using Y-maze, passive avoidance, and morris water maze (MWM) tests. Further, Irf2bp2-deficiency accelerated the activation of astrocytes and microglia cells, as evidenced by the promoted expressions of glial fibrillary acidic protein (GFAP) and Iba-1 in hippocampus and hypothalamus of HFD-fed mice. HFD for 16 weeks induced oxidative stress in serum and brain of mice, as proved by the up-regulated malondialdehyde (MDA) levels and down-regulated superoxide dismutase (SOD) activity, which were significantly enhanced due to Irf2bp2 knockout. Moreover, HFD-triggered systematic and central nervous inflammation by increasing the release of interleukin 1β (IL-1β) and tumor necrosis factor (TNF)-α, accompanied with elevated p-nuclear factor-κB (NF-κB) expressions. Notably, HFD-induced inflammation was significantly exacerbated by Irf2bp2 deletion. Intriguingly, HFD-induced dyslipidemia in liver of mice was further aggravated by Irf2bp2 suppression. Our in vitro results verified the effects of Irf2bp2-inhibition on the promotion of inflammatory response in BV2 cells and lipid dysfunction in primary hepatocytes. Therefore, the findings above suggested that inhibiting Irf2bp2 expression provided a potential therapeutic approach for the prevention of metabolic syndrome-associated central nervous injury.

Tubeimoside I Protects Dopaminergic Neurons Against Inflammation-Mediated Damage in Lipopolysaccharide (LPS)-Evoked Model of Parkinson's Disease in Rats.

Parkinson’s disease (PD), a frequent degenerative disease in the elderly, is characterized by dopaminergic neurodegeneration in the substantia nigra pars compacta (SNpc). Neuroinflammation caused by over-activated microglia plays a crucial role in the pathogenesis of PD. Tubeimoside I (TBMS1) has a broad anti-inflammatory effect in peripheral tissues, but the effect on neuroinflammation has not been reported. Therefore, we explored whether TBMS1 could protect dopaminergic neurons by inhibiting the activation of microglia in lipopolysaccharide (LPS)-induced PD rat model. In addition, then, the effect and mechanism of TBMS1 on neuroinflammation were assessed in LPS-exposed murine microglial BV-2 cells. The results in vivo showed that TBMS1 suppressed microglial activation and dopaminergic neurons’ reduction in LPS-injected PD rat model. In vitro study found that TBMS1 could inhibit LPS-induced inflammatory responses in BV-2 cells, and this effect was mediated by suppressing the phosphorylation of protein kinase B (AKT), nuclear factor-kappa B (NF-κB p65), p38 and extracellular regulated protein kinases (ERK1/2). Taken together, these results demonstrated for the first time that TBMS1 played a role in protecting dopaminergic neurons by inhibiting neuroinflammation mediated by microglia.

Nuciferine inhibits LPS-induced inflammatory response in BV2 cells by activating PPAR-γ

Nuciferine, a bioactive component extracted from the lotus leaf, has been reported to have various anti-inflammatory effects. In the present study, we aimed to investigate the anti-inflammatory effects and mechanism of nuciferine on lipopolysaccharide (LPS)-stimulated BV2 microglia cells. The anti-inflammatory activity of nuciferine was measured by ELISA to detect the inflammatory mrdiators secretion in LPS-simulated BV2 microglia cells. The results demonstrated that nuciferine significantly inhibited LPS-induced TNF-α, IL-1β, PGE2 and NO secretion. LPS-induced NF-κB activation was also suppressed by nuciferine. Further studies showed that nuciferine increased the expression of PPAR-γ. Functional aspects were analyzed using PPAR-γ specific inhibitor GW9662, which attenuated the LPS-induced secretion of proinflammatory mediators, such as TNF-α, IL-1β, PGE2, and NO. In conclusion, these results suggested that nuciferine activated PPAR-γ, which subsequently inhibited LPS-induced inflammation in BV2 cells.

Curative Anti-Inflammatory Properties of Chinese Optimized Yinxieling Formula in Models of Parkinson's Disease.

Parkinson's disease (PD) is marked by the progressive degeneration of dopaminergic neurons (DAN) accompanied by glial activation. Thus, inhibiting glial activation that occurs during this disease could be an effective method for treating PD. Optimized Yinxieling Formula (OYF), a Chinese medicinal formula, which is used to efficiently treat autoimmune disease psoriasis, has been proved to display potential immunomodulatory effects in inflammation-associated diseases. This study assessed the therapeutic benefits of OYF on glial-mediated neuroinflammation and neuroprotection in PD models in vitro and in vivo. First, the results showed that OYF significantly suppresses LPS-induced proinflammatory cytokine secretion and attenuates the overall inflammatory responses in BV-2 cells. Second, in vivo studies confirm that while the validity of our MPTP-induced PD mouse models possesses activated glia and significant neurobehavioral dysfunction, pretreatment with OYF prevents glial activation and ameliorates movement dysfunction in the MPTP-induced PD mouse models as evaluated by the pole and rotarod tests. Third, transcriptomic analyses were carried out to reveal the underlying molecular mechanism of the OYF treatment. Sixteen pathways were significantly upregulated in the OYF-treated PD model mice, including the cytokine-cytokine receptor interaction, cell adhesion molecules, coagulation, and complement cascades. Fifteen pathways were significantly downregulated in the OYF-treated PD model mice, such as the natural killer cell mediated cytotoxicity, hematopoietic cell lineage, phagosome, and others. These pathways share direct or indirect features of immunomodulation, suggesting that the physiological effects of OYF involve key roles of immune and inflammation regulations. Therefore, we prove that OYF is a useful immunomodulatory formula in developing prevention and treatment methods for neurodegenerative disease PD.

Mechanism of Non-receptor Tyrosine Kinase Src Regulating Neuroinflammation Through Phosphatase and Tensin Homology Protein in Microglia.

Objective To investigate the mechanism of non-receptor tyrosine kinase Src regulating neuroinflammation through phosphatase and tensin homology protein(PTEN)in microglia. Methods BV2 cells were incubated with PTEN inhibitor bpv(HOpic)for 2 hours,and then added with lipopolysaccharide(LPS)to induce neuroinflammation,Western blot was performed to determine the expression of phosphorylated protein kinase B(Akt)to investigate the activity of PTEN. Enzyme-linked immunosorben assay(ELISA)was used to determine the release of tumor necrosis factor α(TNF-α)to assess neuroinflammation.After PTEN inhibitor or Src specific small interfering RNA was added,the change of neuroinflammation was evaluated to study the mechanism of Src regulating neuroinflammation. Results LPS induced significant neuroinflammation in BV2 cells,as indicated by significantly increased expression of p-Akt and release of TNF-α(P<0.001).The PTEN inhibitor signficantly increased Akt phosphorylation(P<0.05)and TNF-α release(P<0.001)in LPS-induced BV2 cells compared to simply LPS-induced cells.The Src small interfering RNA significantly decreased the release of TNF-α(P<0.001)and inhibited PTEN(P<0.001)and Akt(P<0.001)phosphorylation. Conclusion Src kinase may regulate neuroinflammtion response in BV2 cells by regulating the phosphorylation of PTEN.

Neuroprotective Role of Atractylenolide-I in an In Vitro and In Vivo Model of Parkinson's Disease.

Parkinson’s disease (PD) is an age-related neurological disorder characterized by a loss of dopaminergic neurons within the midbrain. Neuroinflammation has been nominated as one of the key pathogenic features of PD. Recently, the inadequate pharmacotherapy and adverse effects of conventional drugs have spurred the development of unconventional medications in the treatment of PD. The purpose of this study is to investigate the anti-neuroinflammatory mechanisms of Atractylenolide-I (ATR-I) in in vivo and in vitro models of PD. Nitrite assay was measured via Griess reaction in lipopolysaccharide (LPS) stimulated BV-2 cells. mRNA and protein levels were determined by a reverse transcription-polymerase chain reaction (RT-PCR) and immunoblot analysis, respectively. Further, flow cytometry, immunocytochemistry, and immunohistochemistry were employed in BV-2 cells and MPTP-intoxicated C57BL6/J mice. Pre-treatment with ATR-I attenuated the inflammatory response in BV-2 cells by abating the nuclear translocation of nuclear factor-κB (NF-κB) and by inducing heme oxygenase-1 (HO-1). The intraperitoneal administration of ATR-I reversed MPTP-induced behavioral deficits, decreased microglial activation, and conferred protection to dopaminergic neurons in the mouse model of PD. Our experimental reports establish the involvement of multiple benevolent molecular events by ATR-I in MPTP-induced toxicity, which may aid in the development of ATR-I as a new therapeutic agent for the treatment of PD.