Anti-Inflammatory Activity of 1,6,7-Trihydroxy-2-(1,1-dimethyl-2-propenyl)-3-methoxyxanthone Isolated from Cudrania tricuspidata via NF-κB, MAPK, and HO-1 Signaling Pathways in Lipopolysaccharide-Stimulated RAW 264.7 and BV2 Cells.

Neuroinflammation activated by microglia affects inflammatory pain development. This study aimed to explore the anti-inflammatory properties and mechanisms of 1,6,7-trihydroxy-2-(1,1-dimethyl-2-propenyl)-3-methoxyxanthone (THMX) from Cudrania tricuspidata in microglia activation-mediated inflammatory pain. In RAW 264.7 and BV2 cells, THMX has been shown to reduce lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and pro-inflammatory mediators and cytokines, including nitric oxide (NO), prostaglandin (PG) E2, interleukin (IL)-6, and tumor necrosis factor alpha (TNF-α). THMX also decreased LPS-induced phosphorylation of mitogen-activated protein kinase (MAPK) and the activation of p65 nuclear factor kappa B (NF-κB). Interestingly, THMX also activated heme oxygenase (HO)-1 expression. These findings suggest that THMX is a promising biologically active compound against inflammation through preventing MAPKs and NF-ĸB and activating HO-1 signaling pathways.

Linderone Isolated from Lindera erythrocarpa Exerts Antioxidant and Anti-Neuroinflammatory Effects via NF-κB and Nrf2 Pathways in BV2 and HT22 Cells.

Linderone is a major compound in Lindera erythrocarpa and exhibits anti-inflammatory effects in BV2 cells. This study investigated the neuroprotective effects and mechanisms of linderone action in BV2 and HT22 cells. Linderone suppressed lipopolysaccharide (LPS)-induced inducible nitric oxide synthase, cyclooxygenase-2, and pro-inflammatory cytokines (e.g., tumor necrosis factor alpha, interleukin-6, and prostaglandin E-2) in BV2 cells. Linderone treatment also inhibited the LPS-induced activation of p65 nuclear factor-kappa B, protecting against oxidative stress in glutamate-stimulated HT22 cells. Furthermore, linderone activated the translocation of nuclear factor E2-related factor 2 and induces the expression of heme oxygenase-1. These findings provided a mechanistic explanation of the antioxidant and anti-neuroinflammatory effects of linderone. In conclusion, our study demonstrated the therapeutic potential of linderone in neuronal diseases.

Protective Mechanism of Banxia Houputang on Lipopolysaccharide-induced Neuroinflammatory Injury / 中国实验方剂学杂志

ObjectiveTo study the inhibitory effect of Banxia Houputang （BHT） on lipopolysaccharide （LPS）-induced inflammation of microglia （BV2） cells and the neuroprotective effect on human neuroblastoma （SH-SY5Y） cells. MethodAfter the neuroinflammatory model was constructed by LPS inducing BV2 cells， model group （LPS 100 µg·L-1）， administration groups （LPS+1 g·L-1 BHT， LPS+2 g·L-1 BHT， LPS+5 g·L-1 BHT， LPS+10 g·L-1 BHT）， and blank group were given DEME medium at the same volume. In addition， neuronal apoptosis model was established by co-culture of LPS-induced BV2 cell inflammation medium and SH-SY5Y cells （LPS-DMEM） and was administrated according to the above grouping. Cell viability was detected by Cell Counting Kit-8 （CCK-8） assay. The content of nitric oxide （NO） and that of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-6 （IL-6） were determined by Griess aasay and enzyme-linked immunosorbent assay （ELISA）， respectively. The mRNA levels of TNF-α， IL-1β， interleukin-4 （IL-4）， nitric oxide synthase （iNOS）， and interleukin-10 （IL-10） were measured by real-time polymerase chain reaction （Real-rime PCR）. Western blot was used to detect the expression levels of signal transducer and activator of transcription 3 （STAT3）， Janus kinase 2 （JAK2） and nuclear factor kappa-B （NF-κB p65）， protein kinase B （Akt）， inhibitor of nuclear factor κB α （IκBα）， B-cell lymphoma-2 （Bcl-2）， and Bcl-2 associated X protein （Bax）. ResultCompared with blank group， LPS increased the NO release， levels of TNF-α， IL-1β， IL-6， and iNOS and protein expression of Akt， NF-κB p65， IκBα， JAK2 and STAT3， decreased the content of IL-4 and IL-10 in BV2 cells， and induced apoptosis of co-cultured SH-SY5Y cells （P<0.01）. Compared with model group， BHT reduced the content of NO， TNF-α， IL-1β， and iNOS （P<0.01） and protein expression of Akt， NF-κB p65， IκBα， JAK2 and STAT3 （P<0.01）， elevated the content of IL-4 and IL-10 （P<0.01）， and inhibited the apoptosis of SH-SY5Y cells induced by LPS-DMEM （P<0.01）. ConclusionThis experiment reveals that BHT inhibited LPS-induced inflammation in BV2 cells by regulating Akt/NF-κB/JAK2/STAT3 signaling pathway and showed neuroprotective effects on SH-SY5Y cells.

Anti-Neuroinflammatory and Anti-Inflammatory Activities of Phenylheptatriyne Isolated from the Flowers of Coreopsis lanceolata L. via NF-κB Inhibition and HO-1 Expression in BV2 and RAW264.7 Cells.

Aging is associated with immune disregulation and oxidative stress which lead to inflammation and neurodegenerative diseases. We have tried to identify the anti-neuroinflammatory and anti-inflammatory components of Coreopsis lanceolata L. The dried flowers of C. lanceolata were extracted with 70% EtOH, and the obtained extract was divided into CH2Cl2, EtOAc, n-BuOH, and H2O fractions. The CH2Cl2 fraction was separated using silica gel and C-18 column chromatography to yield phenylheptatriyne (1), 2'-hydroxy-3,4,4'-trimethoxychalcone (2), and 4',7-dimethoxyflavanone (3). Additionally, the EtOAc fraction was subjected to silica gel, C-18, and Sephadex LH-20 column chromatography to yield 8-methoxybutin (4) and leptosidin (5). All the compounds isolated from C. lanceolata inhibited the production of nitric oxide (NO) in LPS-induced BV2 and RAW264.7 cells. In addition, phenylheptatriyne and 4',7-dimethoxyflavanone reduced the secretion of inflammatory cytokines, tumor necrosis factor alpha (TNF-α), and interleukin (IL)-6. Among them, phenylheptatriyne was significantly downregulated in the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequently, phenylheptatriyne also effectively inhibited nuclear factor-kappa B (NF-κB) activation in LPS-stimulated BV2 and RAW264.7 cells. Based on these results, the anti-neuroinflammatory effect of phenylheptatriyne isolated from C. lanceolata was confirmed, which may exert a therapeutic effect in treatment of neuroinflammation-related diseases.

miR-142-3p Regulates BDNF Expression in Activated Rodent Microglia Through Its Target CAMK2A.

Microglia, the innate immune effector cells of the mammalian central nervous system (CNS), are involved in the development, homeostasis, and pathology of CNS. Microglia become activated in response to various insults and injuries and protect the CNS by phagocytosing the invading pathogens, dead neurons, and other cellular debris. Recent studies have demonstrated that the epigenetic mechanisms ensure the coordinated regulation of genes involved in microglial activation. In this study, we performed a microRNA (miRNA) microarray in activated primary microglia derived from rat pup's brain and identified differentially expressed miRNAs targeting key genes involved in cell survival, apoptosis, and inflammatory responses. Interestingly, miR-142-3p, one of the highly up-regulated miRNAs in microglia upon lipopolysaccharide (LPS)-mediated activation, compared to untreated primary microglia cells was predicted to target Ca2+/calmodulin dependent kinase 2a (CAMK2A). Further, luciferase reporter assay confirmed that miR-142-3p targets the 3'UTR of Camk2a. CAMK2A has been implicated in regulating the expression of brain-derived neurotrophic factor (BDNF) and long-term potentiation (LTP), a cellular mechanism underlying memory and learning. Given this, this study further focused on understanding the miR-142-3p mediated regulation of the CAMK2A-BDNF pathway via Cyclic AMP-responsive element-binding protein (CREB) in activated microglia. The results revealed that CAMK2A was downregulated in activated microglia, suggesting an inverse relationship between miR-142-3p and Camk2a in activated microglia. Overexpression of miR-142-3p in microglia was found to decrease the expression of CAMK2A and subsequently BDNF through regulation of CREB phosphorylation. Functional analysis through shRNA-mediated stable knockdown of CAMK2A in microglia confirmed that the regulation of BDNF by miR-142-3p is via CAMK2A. Overall, this study provides a database of differentially expressed miRNAs in activated primary microglia and reveals that microglial miR-142-3p regulates the CAMK2A-CREB-BDNF pathway which is involved in synaptic plasticity.

Two new polyacetylene glycosides from rhizomes of Atractylodes lancea / 中草药

Objective: To investigate the chemical components from the 80% EtOH extract of Atractylodes lancea, as well as the inhibitory activities of the isolated compounds on LPS-induced NO production of microglia BV2 cells. Methods: The n-BuOH-soluble fraction of the crude extract was successively chromatographed with Diaion HP-20, Sephadex LH-20, and preparative HPLC C18-column. At last, the planar and stereochemical structures of these obtained compounds were established on the basis of extensive spectroscopic data (HRESIMS, NMR, and ECD, etc). Results: Ten glycosides were isolated from the n-BuOH-soluble fraction of the 80% EtOH extract of A. lancea, including (2E,8R)-decene-4,6-diyne-1,8-diol-1-O-β-D- apiofuranosyl-(1→6)-β-D-glucopyranoside (1), (8S)-decane-4,6-diyne-1,8-diol-8-O-β-D-glucopyranoside (2), (2E,8R)-decene-4,6- diyne-1,8-diol-8-O-β-D-glucopyranoside (3), (2E,8S)-decene-4,6-diyne-1,8-diol-8-O-β-D-glucopyranoside (4), (2E,8E)-2,8- decadiene-4,6-diyne-1,10-diol-1-O-β-D-glucopyranoside (5), (7R,8S)-3',9,9'-trihydroxyl-3-methoxyl-1'-propanol-7,8-dihydrobenzo- funanneoligan-4-O-β-D-glucopyranoside (6), (7'R*,8S*,8'S*)-lyoniresinol 9'-O-β-D-glucopyranoside (7), (7S,8R)-4,9,9'-trihydroxy- 3'-methoxy-8-O-4'-neolignan 7-O-β-D-glucopyranoside (8), methyl salicylate 2-O-α-L-xylopyranosyl-(1→6)-β-D-glucopyranoside (9), and phenylmethanol 7-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (10). Conclusion: Compounds 1 and 2 are named atractyeneyneglycoside A and atractyeneyneglycoside B, while compounds 6, 8-10 are first isolated from the rhizomes of A. lancea. At the concentration of 10 μmol/L, compound 10 exhibited the strongest inhibitory effects on LPS-induced NO production of microglia BV2 cells with the value of 31.18%, while compounds 1 and 2 just showed weaker inhibitory effects with values of 22.01% and 14.09%, respectively.

Carrageenan polysaccharides and oligosaccharides with distinct immunomodulatory activities in murine microglia BV-2 cells.

This study was to investigate the anti-inflammatory activities in vitro of various carrageenans (Car) fractions (κ-, ι-, and λ-types) with well characterized molecular properties, using murine microglia BV-2 cell line treated with lipopolysaccharide (LPS) as model. It is indicated that pretreatments with the oligosaccharide fractions from κ- or ι-carrageenan acid hydrolysates (κ- and ι-CarAOS, respectively) at 125-500 µg/mL significantly and dose-dependently decreased the levels of tumor necrosis factor α (TNF-α) secreted from LPS-treated BV-2 cells, showing promisingly anti-inflammatory effects. Differently, pretreatments of most of polymeric carrageenans at 250-500 µg/mL significantly increased the TNF-α level, implying the co-inflammatory effects with LPS. The co-inflammatory effectiveness of pure carrageenans at 125 µg/mL was notable for λ-Car, followed by ι-Car, and insignificantly for κ-Car. Generally, cytokine TNF-α was a more sensitive biomarker to the presence of carrageenans than was the IL-6. The TNF-α level varied greatly at a low carrageenan concentration (125 µg/mL) and high polymer percentage (e.g. purified κ- and ι-Car). Conclusively, the anti-inflammatory effects on LPS-treated BV-2 cells could be attenuated by pretreatments with κ- and ι-CarAOS at 125-500 µg/mL.

Induction of Cell Death by Betulinic Acid through Induction of Apoptosis and Inhibition of Autophagic Flux in Microglia BV-2 Cells.

Betulinic acid (BA), a natural pentacyclic triterpene found in many medicinal plants is known to have various biological activity including tumor suppression and anti-inflammatory effects. In this study, the cell-death induction effect of BA was investigated in BV-2 microglia cells. BA was cytotoxic to BV-2 cells with IC50 of approximately 2.0 µM. Treatment of BA resulted in a dose-dependent chromosomal DNA degradation, suggesting that these cells underwent apoptosis. Flow cytometric analysis further confirmed that BA-treated BV-2 cells showed hypodiploid DNA content. BA treatment triggered apoptosis by decreasing Bcl-2 levels, activation of capase-3 protease and cleavage of PARP. In addition, BA treatment induced the accumulation of p62 and the increase in conversion of LC3-I to LC3-II, which are important autophagic flux monitoring markers. The increase in LC3-II indicates that BA treatment induced autophagosome formation, however, accumulation of p62 represents that the downstream autophagy pathway is blocked. It is demonstrated that BA induced cell death of BV-2 cells by inducing apoptosis and inhibiting autophagic flux. These data may provide important new information towards understanding the mechanisms by which BA induce cell death in microglia BV-2 cells.

4-hydroxybenzaldehyde-chitooligomers suppresses H2O2-induced oxidative damage in microglia BV-2 cells.

Positive charges of chitooligomer (COS) enable COS to interact with negatively charged anionic groups on the cell surface resulting in an improvement in the biological activity of COS and its derivatives. In this study, 4-hydroxybenzaldehyde-COS (HB-COS) was synthesized and investigated for its abilities against H2O2-induced oxidative stress in microglia BV-2 cells. Under oxidative stress, HB-COS significantly attenuated reactive oxygen species (ROS) generation and DNA oxidation, and upregulated the protein levels of antioxidative enzymes. HB-COS is therefore proposed as a potential protective agent against neuronal damage.

Induction of Cell Death by Betulinic Acid through Induction of Apoptosis and Inhibition of Autophagic Flux in Microglia BV-2 Cells

Betulinic acid (BA), a natural pentacyclic triterpene found in many medicinal plants is known to have various biological activity including tumor suppression and anti-inflammatory effects. In this study, the cell-death induction effect of BA was investigated in BV-2 microglia cells. BA was cytotoxic to BV-2 cells with IC50 of approximately 2.0 μM. Treatment of BA resulted in a dose-dependent chromosomal DNA degradation, suggesting that these cells underwent apoptosis. Flow cytometric analysis further confirmed that BA-treated BV-2 cells showed hypodiploid DNA content. BA treatment triggered apoptosis by decreasing Bcl-2 levels, activation of capase-3 protease and cleavage of PARP. In addition, BA treatment induced the accumulation of p62 and the increase in conversion of LC3-I to LC3-II, which are important autophagic flux monitoring markers. The increase in LC3-II indicates that BA treatment induced autophagosome formation, however, accumulation of p62 represents that the downstream autophagy pathway is blocked. It is demonstrated that BA induced cell death of BV-2 cells by inducing apoptosis and inhibiting autophagic flux. These data may provide important new information towards understanding the mechanisms by which BA induce cell death in microglia BV-2 cells.

ASK1 modulates the expression of microRNA Let7A in microglia under high glucose in vitro condition.

Hyperglycemia results in oxidative stress and leads to neuronal apoptosis in the brain. Diabetes studies show that microglia participate in the progression of neuropathogenesis through their involvement in inflammation in vivo and in vitro. In high-glucose-induced inflammation, apoptosis signal regulating kinase 1 (ASK1) triggers the release of apoptosis cytokines and apoptotic gene expression. MicroRNA-Let7A (miR-Let7A) is reported to be a regulator of inflammation. In the present study, we investigated whether miR-Let7A regulates the function of microglia by controlling ASK1 in response to high-glucose-induced oxidative stress. We performed reverse transcription (RT) polymerase chain reaction, Taqman assay, real-time polymerase chain reaction, and immunocytochemistry to confirm the alteration of microglia function. Our results show that miR-Let7A is associated with the activation of ASK1 and the expression of anti-inflammatory cytokine (interleukin (IL)-10) and Mycs (c-Myc and N-Myc). Thus, the relationship between Let-7A and ASK1 could be a novel target for enhancing the beneficial function of microglia in central nervous system (CNS) disorders.

Inhibitory effect of Corilagin on the inflammatory response of irradiated microglia BV-2 cells / 中华放射医学与防护杂志

Objective To explore the inhibitory effects of Corilagin on the production of proinflammatory cytokines in microglia induced by radiation. Methods The cytotoxicity of Corilagin was measured by MTT assay. Microglia BV-2 cells were irradiated 0 or 32 Gy after pretreated with Corilagin for 12 hours. Realtime-PCR was used to detect the mRNA levels of inflammatory cytokines, such as IL-1β,TNF-α on several time-points. The content of nitric oxide (NO) was determined with nitrate reductase method. The translocation of NF-κB was measured by Western blot and immunocytochemical stain.Confocal microscopy was used to observe the expression of Iba-1 and Nemo. Results No cytotoxicity was detected on BV-2 cells with 1-10 μg/ml Corilagin. Iba-1 expression in microglia cells was activated by irradiation, the expression levels of inflammatory cytokines, such as IL-1β, TNF-α and NO were also elevated. Whereas, the production of IL-1 β, TNF-α in activated microglia cells was significantly inhibited with 5 μg/mL corilagin ( tIL-1β = 6. 341, tTNF-α = 3.41 1, tNO = 3. 134, P ＜ 0. 05 ). Corilagin significantly inhibited the expression of Nemo and the translocation of NF-κB p65. Conclusion Corilagin could inhibit the activation of irradiated microglia cells and down-regulate the expression of inflammatory cytokines, via inhibition of the NF-κB signaling pathway.

PrP 106-126 Altered PrP mRNA Gene Expression in Mouse Microglia BV-2 Cells' / 中国病毒学·英文版

Prion diseases are infectious and fatal neurodegenerative diseases. The pathogenic agent is an abnormal prion protein aggregate. Microglial activation in the centre nervous system is a characteristic feature of prion disease. In this study, we examined the effect of PrP 106-126 on PrP mRNA gene expression in Mouse microglia cells BV-2 by real-time quantitative PCR. PrP mRNA expression level was found to be significantly increased after 18 h exposure of BV-2 cells to PrP 106-126, with 3-fold increase after 18 h and 4.5-fold increase after 24 h and BV-2 cells proliferating occurred correspondingly. Our results provide the first in vitro evidence of the increase of PrP mRNA levels in microglial cells exposed to PrP 106-126, and indicate that microglial cells might play a critical role in prion pathogenesis.