Role of JNK/AP-1 signaling pathway in paraquat-induced activation of NLRP3 inflammasome in microglia / 环境与职业医学

Background Paraquat (PQ) is one of the environmental factors that can cause sporadic Parkinson's disease (PD). Microglia-mediated neuroinflammation plays an important role in the occurrence and development of PD. Our previous studies have found that low doses of PQ can activate BV-2 microglia to the M1 phenotype and exert pro-inflammatory effects, but the associated mechanism is not clear yet. Objective To explore the role of c-Jun N-terminal kinase (JNK)/activator protein 1 (AP-1) signaling pathway in PQ-induced activation of the NOD-like receptor thermal protein domain associated protoin 3 (NLRP3) inflammasome in microglia. Methods An in vitro microglia model was established. The cells were treated with 0, 0.03, 0.06,and 0.12 μmol·L−1 PQ for 24 h, the whole cell protein was extracted. The relative expression levels of JNK, AP-1 constituent proteins (c-Jun, c-Fos), NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspasse-1 precursor (pro caspase-1), interleukin-18 (IL-18), and interleukin-1β (IL-1β) were evaluated by Western blotting, to observe the effects of PQ exposure on JNK/AP-1 signaling pathway and NLRP3 inflammasome. After the treatment of 20 μmol·L−1 JNK inhibitor SP600125, the above proteins were detected again, to explore the driving effect of JNK/AP-1 signaling pathway on NLRP3 inflammasome activation. Results After PQ exposure, the relative expression levels of key proteins of JNK, c-Jun, and c-Fos, NLRP3, ASC, and pro caspase-1 in the 0.06 μmol·L−1 PQ group and the 0.12 μmol·L−1 PQ group were higher than those in the 0 μmol·L−1 PQ group (P＜0.05), and the relative expression levels of IL-18 and IL-1β increased with higher exposure (P＜0.05). After the treatment of JNK inhibitor SP600125, the relative expression levels of key proteins of JNK/AP-1 signaling pathway (JNK, c-Jun, and c-Fos), NLRP3 inflammasome (NLRP3, ASC, and Pro caspase-1), and inflammatory factors (IL-18 and IL-1β) in the control group, the 20 μmol·L−1 SP600125 group, and the 20 μmol·L−1 SP600125+0.06 μmol·L−1 PQ group were lower than those in the 0.06 μmol·L−1 PQ group (P＜0.05). Conclusion PQ exposure can activate the JNK/AP-1 signaling pathway and subsequently drive the activation of NLRP3 inflammasome in BV-2 microglia to mediate neuroinflammatory responses..

Proteomic Research on Characteristic Processing Materials of Porcine Cardiac Blood and Porcine Blood from Menghe Medical School and Their Effect on Anti-microglial Inflammatory Damage of Salviae Miltiorrhizae Radix et Rhizoma / 中国实验方剂学杂志

ObjectiveProteomics was used to investigate the protein differences between porcine cardiac blood（PCB） and porcine blood（PB） from Menghe medical school and to compare the effects of both on the microglial inflammation of Salviae Miltiorrhizae Radix et Rhizoma（DS）. MethodNanoliquid chromatography-quadrupole orbitrap mass spectrometry（nLC-MS/MS） and bioinformatics were utilized to compare the proteomic differences of PCB and PB in simulated gastrointestinal digestion. Furthermore， Western blot was used to verify the contents of some shared proteins and differential proteins identified in PCB and PB. In addition， BV2 neuroinflammation model constructed by corticosterone（CORT） and lipopolysaccharide（LPS） was applied to detect the intervention effects of PCB and PB on the levels of tumor necrosis factor（TNF）-α and interleukin（IL）-6 in BV2 inflammatory cells of DS. ResultA total of 69 common proteins and 68 differential proteins were identified in PCB and PB， among which the common proteins included transferrin（Tf） with brain-targeting effect， and the differential proteins in the two were 41 and 27， respectively. Western blot validation showed that the difference in the content of the same protein Tf between PCB and PB was not statistically significant， while the difference in the contents of the specific proteins of creatine kinase M and heart-type fatty acid binding protein（H-FABP） were statistically significant（P<0.05）. Moreover， in vitro experimental studies revealed that compared with the same concentration of DS group， in addition to the 100 mg·L-1 PB-DS group， PCB-DS and PB-DS groups could significantly inhibit the levels of TNF-α and IL-6 in BV2 inflammatory cells（P<0.05， P<0.01）， and PCB-DS group had more significant anti-inflammatory effect than PB-DS group with the same concentration（P<0.05， P<0.01）. ConclusionBoth of PCB and PB can enhance the inhibitory effect of DS on the release of inflammatory factors， thus playing a neuroprotective role， and PCB promotes DS inhibition more significantly， which may be due to the existence of the two involved in energy metabolism-related differential proteins， which can lay a foundation for revealing the scientific connotation of the processing of PCB-DS and PB-DS.

Ginsenoside Rg1 regulating BV2 microglia polarization in lipopolysaccharide-induced inflammatory response via peroxisome proliferator activated receptor γ / 解剖学报

[Abstract] Objective To establish an inflammation model by stimulating BV2 microglia by lipopolysaccharide, and to explore the regulation effect of ginsenoside Rg1 on inflammation by activating peroxisome proliferator activated receptor γ(PPARγ) receptor protein. Methods BV2 microglia were randomly divided into control group, model group, ginsenoside Rg1 group, rosiglitazone group and GW9662 group. The control group did not do any treatment, the model group was treated with 1 mg/ L lipopolysaccharide, and the other groups were treated with lipopolysaccharide added with 0. 4 mmol/ L ginsenoside Rg1, 10 μmol/ L rosiglitazone or 10 μmol/ L respectively. GW9662. The proliferation of BV2 microglia in each group was detected by CCK-8 method; PPAR-γ, phospho-NF-κB p65 (p-NF-κB p65), induced expression of inducible nitric oxide synthase(iNOS) and human arginase 1(ARG-1) proteins. ELISA was used to detect the inflammatory factors interleukin-1β(IL-1β), interleukin-6(IL-6), interleukin-8(IL-8) and the content of tumor necrosis factor-α (TNF-α). Results Compared with the control group, the cell proliferation rate in the model group was significantly increased, and the contents of IL-1β, IL-6, IL-8 and TNF-α increased significantly. The result of immunofluorescence and Western blotting showed that iNOS and p-NF-κB p65 increased significantly, and the positive expressions of PPARγ and ARG-1 decreased significantly(both P<0. 01). The expression level of TNF-α decreased, the positive expressions of iNOS and p-NF-κB p65 decreased significantly, and the positive expressions of PPARγ and ARG-1 increased significantly(all P<0. 01). Conclusion Ginsenoside Rg1 inhibits the inflammatory response of BV2 microglia after lipopolysaccharide stimulation, and its mechanism may be related to the regulation of PPARγ/ NF-κB pathway to promote the M2-type polarization of microglia.

Mechanisms of ferroptosis in microglial cell line BV-2 cells after lead acetate exposure / 环境与职业医学

Background Lead exposure induces microglial cell death, of which the mechanism is unclear. Ferroptosis is a new death form and its role in microglia death has not been reported. Objective To investigate the role of ferroptosis in microglia following lead exposure in order to provide a theoretical basis for the mechanism of lead neurotoxicity. Methods Microglial cell line BV-2 cells were co-cultured with 0, 10, 20 and 40 μmol·L−1 lead acetate for 24 h. The 40 μmol·L−1 lead acetate group with iron chelator (DFO) was named the 40+DFO group. Changes in BV-2 cell morphology after lead exposure were observed under an inverted microscope; tissue iron kit and glutathione kit were used to detect intracellular iron and glutathione (GSH) respectively; flow cytometry was applied to detect lipid reactive oxygen species (lipid ROS) immunofluorescence intensity. Western blotting and qPCR were adopted to detect the expressions of glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), transferrin receptor 1 (TFR-1), divalent metal transporter 1 (DMT1), ferroportin 1 (FPN1) protein and mRNA. Results Compared with the control group, the number of BV-2 cells decreased with increasing doses of lead and the cells showed a large, round amoeboid shape. The intracellular levels of iron of BV-2 cells were (1.08±0.04), (1.29±0.03), and (1.72±0.10) mg·g−1 (calculated by protein, thereafter) in the 10, 20, and 40 μmol·L−1 lead acetate groups, respectively, significantly higher than that in the control group (P<0.05), and the intracellular level of iron in the 40+DFO group, (1.34±0.10) mg·g−1, was lower than that in the 40 μmol·L−1 lead acetate group, (1.72±0.03) mg·g−1 (P<0.05). Compared with the control group, the TFR-1 and DMT1 protein and mRNA expressions were increased in BV-2 cells in the 10, 20, 40 μmol·L−1 lead acetate groups (P<0.05), especially in the 40 μmol·L−1 lead acetate group; the FPN1 protein expression did not change significantly, but the FPN1 mRNA expressions in BV-2 cells in the 10, 20, 40 μmol·L−1 lead acetate groups were significantly decreased (P<0.05). Compared with the control group, the intracellular GSH level decreased and the lipid ROS content increased in all three lead acetate groups; compared with the 40 μmol·L−1 lead acetate group, the GSH level increased by 12.30% and the lipid ROS content decreased by 13.00% in the 40+DFO group (P<0.05). The expressions of GPX4 protein were reduced to 50.00%, 35.00%, and 17.00% of that of the control group in the 10, 20, and 40 μmol·L−1 lead acetate groups respectively, while the expressions of GPX4 mRNA were also significantly reduced; the expressions of SLC7A11 protein and mRNA in the 20 and 40 μmol·L−1 lead acetate groups were lower than that in the control group, with the most significant decrease in the 40 μmol·L−1 lead acetate group (P<0.05). Conclusion Lead exposure could induce ferroptosis in BV-2 cells, in which iron transport imbalance and oxidative damage might be involved.

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.

Lipid-rich fraction of the sclerotium of Tiger Milk Mushroom Lignosus rhinocerotis (Agaricomycetes) attenuates LPS-induced inflammation in BV2 cells via Nrf2 pathway

Lignosus rhinocerotis (tiger milk mushroom) is widely used by the indigenous people of Malaysia as a traditional remedy. The present study was carried out in order to evaluate the antioxidant, cytotoxic and anti-neuroinflammatory activities of L. rhinocerotis extract on brain microglial cells (BV2). The antioxidant activity was evaluated by 2,2-diphenyl-1-picryhydrazyl (DPPH•), 2,2'-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS•+) scavenging assays, and ferric reducing antioxidant power (FRAP). The FRAP, DPPH and ABTS•+ scavenging capacities of the TE3 fraction were 420.77 mg FE/g, 58.01%, and 7%, respectively. The cytotoxic activity was determined by MTS assay. The in vitro model of anti-neuroinflammatory property was evaluated by measuring the production of nitric oxide (NO) in lipopolysaccharide (LPS)-induced BV2 cells. The TE3 fraction showed a significant NO reduction at 1 to 100 µg/mL. The TE3 fraction down-regulated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) genes while it upregulated heme oxygenase (HO-1) and NADPH quinone acceptor oxidoreductase-1 (NQO-1) genes. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) transcription was also activated. The chemical component of the active fraction (TE3) was identified by gas chromatography-mass spectrometry (GCMS). Overall, the BV2 in vitro model anti-neuroinflammatory activity of L. rhinocerotis may be caused by the lipid constituents identified in the fraction

Polygalasaponin F inhibits secretion of IL-1β and its molecular mechanisms / 中国药理学通报

Aim To investigate the effects of polyga-lasaponin F( PS-F) on LPS-induced inflammatory cytokine IL-1β expression in BV2 cells and explore the potential anti-inflammatory mechanism of PS-F. Methods Five groups were included in the experiment, including the control group, the model group and PS-F treatment groups(0. 10, 1.00, 10.00 μmol • L-1). ELISA, quantitative real-time PCR and Western blot were used to assay the mRNA and protein expression of IL-1β. The levels of NLRP3, caspase-1, ASC, caspase-11 protein were examined by Western blot. Results Compared with model group, PS-F treatment groups effectively reduced IL-1β expression in LPS-in-duced inflammatory model in a dose-dependent manner ( P <0. 01 or P <0. 05). Moreover, PS-F significantly inhibited ASC and caspase-11 expression (P < 0. 05 ). Conclusions PS-F inhibited the expression of inflammatory mediator IL-1β by suppressing the activation of NLRP3 inflammasome and inhibiting caspase-11 in LPS-stimulated BV2 cells.

Effects and Underlying Mechanism of Extract of Scutellaria baicalensis Georgi Against LPS-Induced Inflammation in BV2 Cells / 中国药学杂志

OBJECTIVE: To investigate the anti-inflammatory effects of extract of Scutellaria baicalensis Georgi (SGE) and underlying mechanism by using LPS-induced microglial BV2 cells. METHODS: MTT assay was used to observe the cell viability. The content of NO in cell supernatant was measured by Griess reagent. The levels of IL-1β, IL-6 and TNF-α were detected by ELISA kits. The intracellular TLR4 expression was assayed by Western blotting. RESULTS: The levels of NO, IL-1β, IL-6 and TNF-α were significantly increased induced by LPS in the supernatant of BV2 cells (all P < 0.01). However, co-treatment with SGE 100 μg•mL-1 significantly decreased the production of related inflammatory factors including NO (P < 0.01), IL-1β(P < 0.01), IL-6 (P < 0.01) and TNF-α (P < 0.05). Furthermore, SGE significantly inhibited the TLR4 expression induced by LPS in BV2 cells. CONCLUSION: SGE is able to alleviate LPS-induced inflammatory responses in BV2 cells through down-regulation of TLR4 protein expression suggesting that SGE has therapeutic potential for the treatment of neuroinflammatory diseases.

Formyl peptide receptor-2 enhances inflammatory response induced by lipopolysaccharide in BV-2 cells / 中国药理学通报

Aim To investigate the expression of formyl peptide receptor-2 (FPR2) in lipopolysaccharide (LPS)-induced-BV-2 cells,and detect FPR2's influence on inflammatory response induced by LPS.Methods After 1 mg · L-1 LPS acting on BV-2 cells at 12 h,the extrinsic inflammatory model was established.We used the Western blot assay to test the levels of FPR2 protein.And the expressions of phosphorylated NF-κB,TNF-α and IL-1β were investigated when the LPS-induced-BV-2 was incubated with FPR2's agonist MMK-1 and antagonist Boc-2.Transwell assay was also used to detect the LPS-inducedBV-2 migration induced by MMK-1 and Boc-2.Resuits LPS up-regulated the expression of FPR2,and when its agonist was acted on LPS-induced-BV-2,the levels of phosphorylated NF-κB,TNF-α and IL-1β were significantly higher than those of LPS group.In addition,the chemotaxis of LPS-induced-BV-2 also increased by MMK-1.These effects were abolished by Boc-2.Conclusions LPS can increase the expression of FPR2 on BV-2 cells,and FPR2 enhances the inflammatory response induced by LPS.

Protective effect of selective 18 ku translocator protein ligand YL-IPA08 on BV-2 apoptosis induced by corticosterone / 中国药理学与毒理学杂志

OBJECTIVE To investigate the protective effect of selective 18 ku translocator protein (TSPO) ligand YL-IPA08 on corticosterone(CORT)-induced apoptosis of BV-2 cells and its potential mecha?nisms. METHODS BV-2 Cells were pretreated with selective TSPO ligand YL-IPA08 1-100 nmol · L-1 and(or) TSPO antagonist PK11195 100 nmol · L-1 for 2 h,and then co-incubated with CORT for another 24 h. The apoptosis rate was measured by flow cytometry. CCK-8 kit was used to test BV-2 cell viability. The protein expression of TSPO was determined by Western blotting. The level of allopreg?nanolone was detected by ELISA kit. RESULTS In line with positive drug-AC-5216, the cell apoptosis rate decreased in YL-IPA08 1-100 nmol · L-1 and CORT co-treatment groups(P<0.01), which was antago?nized by PK11195 100 nmol · L-1 treatment(P<0.05). Cell viability increased in YL-IPA08 100 nmol · L-1and CORT co-treatment groups (P<0.01), which was blocked by PK11195 100 nmol·L-1 treatment(P<0.01). The expression of TSPO and the level of allopregnanolone(P<0.01) were enhanced by YL-IPA08 100 nmol · L-1 pretreatment followed by CORT treatment. The enhancement of allopregnanolone level was blocked by PK11195 100 nmol·L-1 treatment(P<0.05). CONCLUSION YL-IPA08 can protect BV-2 cells from CORT induced apoptosis. The protective effect of YL-IPA08 may be conferred by the increasing level of TSPO expression and allopregnanolone.

Fibroblast growth factor 10 inhibits lipopolysaccharide-induced microglial activation / 中国病理生理杂志

AIM: To investigate the effects of fibroblast growth factor 10 ( FGF10 ) on lipopolysaccharide ( LPS)-induced microglial activation .METHODS:Mouse BV2 microglial cells were maintained in DMEM in a humidified incubator with 95%/5%( V/V) mixture of air and CO 2 at 37℃.The medium was changed every 1 or 2 d.The cells were digested and passaged every 4 or 5 d.The BV2 microglial cells were first pretreated with FGF 10 (1 mg/L) for 30 min and then stimulated with LPS (500 μg/L).The medium and the cells were collected at different time points .The morphologi-cal changes of microglia were visualized under microscope .To evaluate the microglial activation , the transcription and pro-duction of proinflammatory factor tumor necrosis factor-α( TNF-α) were examined by real-time quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively.RESULTS:The morphology of control BV2 microglia showed circular or oval shape .After exposure to LPS for 24 h, the microglia revealed spindle shaped or multipolar morphology , and the percentage of activated cells was significantly increased compared with control group.Pretreatment with FGF10 successfully inhibited the morphological change from normal to activated shape .LPS sti-mulation for 6 h significantly increased the transcription of TNF-α, while FGF10 pretreatment remarkably reversed the effect.In addition, the production of TNF-αincreased in the presence of LPS stimulation for 24 h compared with control group.Pretreatment with FGF10 suppressed LPS-induced TNF-αexpression.CONCLUSION: Pretreatment with FGF10 inhibits the morphological change from normal to activated shape , and remarkably suppressed the transcription and produc-tion of TNF-α.FGF10 successfully suppresses LPS-induced BV2 microglial activation , indicating that FGF10 is a therapeu-tic agent for the treatment of glia-mediated neuroinflammatory diseases .

Construction and identification of nuclear factor erythroid-2-related factor 2 gene RNA interference recombinant plasmid / 临床神经病学杂志

Objective To construct and identify the shRNA plasmid vector targeting nuclear factor erythroid-2-related factor 2 (Nrf2),and to collect the strongest RNAi effect of Nrf2 shRNA sequence.Methods Nrf2 gene was targeted gene.Three shRNA sequences were designed by software and synthesized by chemical method: shRNA-1,shRNA-2 and shRNA-3.The double strand shRNA oligo was ligated to the vector.The construct was verified by sequencing analysis.BV2 cells were transfected with expressing shRNA plasmid vectors using Lipofectamine 2000.The expression of Nrf2 in the levels of mRNA was detected by real-time PCR,and Western Blot was adopted to abserve the expression of Nrf2 protein.Results Sequencing analysis suggested that the shRNA vectors targeting Nrf2 possessed correct nucleotide sequence and read frame.The result of Real-time PCR and Western Blot showed that the sequence of shRNAi-3 could more effectively knockdown the expression level of Nrf2 than the others.Conclusions The shRNA vectors targeting Nrf2 are successfully constructed and the shRNA can signidicantly inhibit the expression of Nrf2.These findings could provide an experimental basis for further study on Nrf2 signaling pathway in stroke field.

Eeffect of HMGB1 on expression of NF-κB in BV-2 cells stimulated with Aβ25-35 / 中国病理生理杂志

AIM:To investigate the effect of high mobility group box-1 protein (HMGB1) on the expression of nuclear factor-κB ( NF-κB) in BV-2 cells stimulated with amyloid β-protein ( Aβ) 25-35 .METHODS:Cultured BV-2 cells in logarithmic growth phase were divided into 4 groups:normal cell group ( without any treatment ) , model group ( treated with Aβ25-35 at 40 μmol/L) , RNA interference ( RNAi) group ( conducted with HMGB1-siRNA followed by Aβ25-35 stimula-tion) and solvent control group (treated with 0.1% DMSO).After treatment with Aβ25-35 for 24 h, the protein levels of HMGB1 and NF-κB in BV-2 cells were determined by Western blot .RESULTS:Aβ25-35 at 40μmol/L was used to stimu-late BV-2 cells.The GFP fluorescence-tagged HMGB1-siRNA (30 nmol/L) was used to transfect BV-2 cells and its trans-fection efficiency was about 80%~90%.The results of Western blot showed that the protein level of HMGB 1 was signifi-cantly decreased after the interference of siRNA fragment (P<0.05).The protein levels of HMGB1 and nucleic NF-κB p65 were dramatically increased in BV-2 cells stimulated with Aβ25-35(P<0.05).After RNA interference with HMGB1, the expression of HMGB1 and nucleic NF-κB p65 were significantly decreased in BV-2 cells stimulated with Aβ25-35 ( P<0. 05).CONCLUSION:RNA interference with HMGB1 reduces the expression of nucleic NF-κB in BV-2 cells stimulated with Aβ25-35 .

Effect of 14,15-EET on Inflammatory Responses of BV2 Cells After Oxygen and Glucose Depriviation/Reoxygenation / 医药导报

Objective To explore the effect of 14,15-epoxyeicosatrienoic acids (14,15-EET) on the inflammatory response of BV2 cells under oxygen and glucose depriviation/reoxygenation (OGD/R) conditions.Methods BV2 cells were randomly divided into three groups,blank control group,vehicle control group,and 14,15-EET group.Under treatment of 14,15-EET,the concentration of inflammatory factor in BV2 cell culture media was detected by ELISA at different time points (reoxygenation for 0,3,6,12,24 h) after OGD1h.The viability of BV2 cells was detected by MTT assay at different time points.At the same conditions,using Transwell migration experiment,migration ability of BV2 cells was observed.Results The 14,15-EET group had the lower levels of inflammatory factor secretion,lower viability and weaker ability of migration than the vehicle control group.The above results were most statistically significant at OGD1h/R12h.Conclusion 14,15-EET can inhibit the inflammation of BV2 cells induced by the injury of OGD reperfusion.

Optimization of cell density and LPS concentration for the evaluation of nitric oxide production on BV-2 in a Griess assay

Introduction: Production of nitric oxide (NO) is one of the main responses elicited by a variety of immune cells such as macrophages (e.g. microglia, resident macrophages of brain), during inflammation. Evaluation of NO levels in the inflammatory milieu is considered important to the understanding of the intensity of an immune response; and has been performed using different methods including the Griess assay. To assay NO in culture, an appropriate number of cells are stimulated into an inflammatory phenotype. Common stimuli include lipopolysaccharide (LPS), IFN-γ and TNF-α. However, overt stimulation could cause cell cytotoxicity therefore an ideal concentration of LPS should be used. Objective: To set-up a model of BV-2 cell activation that allows the assay of detectable levels of NO. Optimization of BV-2 microglia cell density and LPS concentrations after stimulation by bacterial lipopolysaccharide (LPS) for the Griess assay is demonstrated in this study. Methods: BV-2 microglia were cultured at different cell densities, and treated with LPS at three concentrations (1, 5, 10 µg/ml). NO production in culture supernatants were then measured at 18, 24, 48 and 72 hours. Moreover, methyl tetrazolium assay (MTT) was also performed to ensure that NO measurement is performed at no-cytotoxic concentrations of LPS. Results and Conclusions: NO production follows a temporal pattern. The density of 25000 cells/ well was the ideal seeding density for NO evaluation in BV-2 cells. BV-2 stimulation by LPS is dose dependent, and NO levels are increased proportional to the LPS concentration up to 1.0µg/ml, whereas the higher LPS concentrations are associated with decreased cell viability may be caused by the high toxic levels of LPS or NO. Although Griess assay has been commonly used by the scientists, however, optimization of its parameters on BV-2 cells will be useful for the experiments which will be performed on this particular cell line. The optimized pattern of Griess assay on BV-2 cells was achieved in this study, hence easier and more practical for the future scientists to perform Griess assay on BV-2 cells.

Tamoxifen Induces Apoptosis of Mouse Microglia Cell Line BV-2 Cells via both Mitochondrial and Death Receptor Pathways / 华中科技大学学报（医学）（英德文版）

Little is known about whether tamoxifen (TAM) can affect resting state microglia apoptosis and about the cellular mechanism that may account for this.To explore this question,we incubated the microglia cell line BV-2 cells with TAM at different concentrations.Cell viability was assessed by the MTT assay,and flow cytometric analysis was performed to detect the cell apoptosis rate.Furthermore,mitochondrial membrane potential (△ψm) was tested by flow cytometry,and Bax,Bcl-2,Fas,and Fas-L expression was detected by Western blot.The results demonstrated that TAM decreased cell viability and induced apoptosis of BV-2 cells in a concentration- and time-dependent manner.In addition,disruption of Δψm was followed by up-regulated expression of pro-apoptotic Bax,Fas and Fas-L,and down-regulated expression of anti-apoptotic Bcl-2.These results indicate that TAM may induce apoptosis of BV-2 cells through both mitochondria- and death receptor-mediated pathways.

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.

Effect of nicotine on the activation and resultant death of microglia induced by lipopolysaccharid / 解剖学报

Objective To observe the effect of nicotine(NIC) on the activation and resultant death of microglia induced by LPS. Methods The animal model that exposed to chronic nicotine treatment was established and LPS was injected intraperitoneally to induce the activation of microglia. Furthermore, the CD11b-positive microglia in cerebral cortex, hippocampal and substantia ngra were observed through immunohistochemical staining. BV2 cells(Microglial cell line of mouse) were subcultured, simultaneously the following kits were used including CCK-8 kit assay for cell activity, Nitric oxide assay kit assay for NO release, RT-PCR assay for the iNOS,TNF-α,IL-1β,IL-6,COX-2,IRF-1,Caspase-11 mRNA expression, Western blotting assay for the protein expression of P-I-κB and Caspase-3. Results Nicotine suppressed the CD11b-positive microglia expression in cerebral cortex,hippocampal and substantia ngra induced by LPS;Nicotine inhibited the activation-induced cell death (AICD), attenuated NO release, reduced iNOS,TNF-α,IL-1β,IL-6,COX-2,IRF-1,Caspase-11 mRNA expression, decreased the protein expression including P-I-κB and Caspase-3 of BV2 cells. Conclusion Nicotine pretreatment can suppress the activation and resultant death of microglial cells induced by LPS, which suggests that nicotine may play a neuroprotective role on inflammatory reaction of brain.;