LPS-induced iNOS Protein Expression Research Articles

2-Aryl Propionic Acid Amide Modification of Naproxen and Ibuprofen Dimers for Anti-neuroinflammatory Activity in BV2 mouse Microglial Cells

Inflammation is a common link in the pathophysiology of many neurological illnesses, including Alzheimer’s disease. Activated glial cells contribute to neuroinflammation by producing pro-inflammatory mediators. Naproxen and ibuprofen are nonsteroidal anti-inflammatory drugs with 2-aryl(s) propionic acid as a common pharmacophore. Here we designed a small series of naproxen and ibuprofen amide dimers and tested their effects on the expression of inducible nitric oxide synthase (iNOS), a neuroinflammatory enzyme in lipopolysaccharide (LPS)-stimulated BV2 mouse microglial cells. Of note, treatment with CNU 019, 020, 021, 023, 024, and 027 at 10 M markedly inhibited the LPS-induced iNOS expression in BV2 cells. CNU 024 was tested further at different concentrations to regulate the LPS-induced iNOS expression in BV2 cells. Treatment with CNU 024 at 5, 10, or 20 M dose-dependently suppressed the LPS-induced iNOS protein and mRNA expression levels in BV2 cells, in which maximal inhibition was seen at 20 M. CNU 024 treatment at doses tested further led to a concentration-dependent inhibition of the LPS-induced phosphorylation (activation) of p38 mitogen-activated protein kinase (MAPK) without influencing its total protein expression in BV2 cells, but it did not affect the LPS-induced activation of c-jun N-terminal kinase-1/2 and extracellular signal-regulated kinases-1/2 in these cells. In summary, our results demonstrate that CNU 024 inhibits the LPS-induced iNOS expression in BV2 cells, partly mediated by the inhibition of p38 MAPK. This work shows that CNU 024 could be a valuable ligand for further development as a potential drug candidate for treating neuroinflammatory pathologies.

Anti-Inflammatory Activity of Glabralactone, a Coumarin Compound from Angelica sinensis, via Suppression of TRIF-Dependent IRF-3 Signaling and NF-κB Pathways.

The dried root of Angelica sinensis (A. sinensis) has been widely used in Chinese traditional medicine for various diseases such as inflammation, osteoarthritis, infections, mild anemia, fatigue, and high blood pressure. Searching for the secondary metabolites of A. sinensis has been mainly conducted. However, the bioactivity of coumarins in the plant remains unexplored. Therefore, this study was designed to evaluate the anti-inflammatory activity of glabralactone, a coumarin compound from A. sinensis, using in vitro and in vivo models, and to elucidate the underlying molecular mechanisms of action. Glabralactone effectively inhibited nitric oxide production in lipopolysaccharide- (LPS-) stimulated RAW264.7 macrophage cells. The downregulation of LPS-induced mRNA and protein expression of iNOS, TNF-α, IL-1β, and miR-155 was found by glabralactone. The activation of NF-κB and TRIF-dependent IRF-3 pathway was also effectively suppressed by glabralactone in LPS-stimulated macrophages. Glabralactone (5 and 10 mg/kg) exhibited an in vivo anti-inflammatory activity with the reduction of paw edema volume in carrageenan-induced rat model, and the expressions of iNOS and IL-1β proteins were suppressed by glabralactone in the paw soft tissues of the animal model. Taken together, glabralactone exhibited an anti-inflammatory activity in in vitro and in vivo models. These findings reveal that glabralactone might be one of the potential components for the anti-inflammatory activity of A. sinensis and may be prioritized in the development of a chemotherapeutic agent for the treatment of inflammatory diseases.

FJU-C28 inhibits the endotoxin-induced pro-inflammatory cytokines expression via suppressing JNK, p38 MAPK and NF-κB signaling pathways.

Despite marked improvements in supportive care, the mortality rate of acute respiratory distress syndrome due to the excessive inflammatory response caused by direct or indirect lung injury induced by viral or bacterial infection is still high. In this study, we explored the anti‐inflammatory effect of FJU‐C28, a new 2‐pyridone‐based synthetic compound, on lipopolysaccharide (LPS)‐induced inflammation in vitro and in vivo models. FJU‐C28 suppressed the LPS‐induced mRNA and protein expression of iNOS, COX2 and proinflammatory cytokines. The cytokine protein array results showed that LPS stimulation enhanced the secretion of IL‐10, IL‐6, GCSF, Eotaxin, TNFα, IL‐17, IL‐1β, Leptin, sTNF RII, and RANTES. Conversely, the LPS‐induced secretion of RANTES, TIMP1, IL‐6, and IL‐10 was dramatically suppressed by FJU‐C28. FJU‐C28 suppressed the LPS‐induced expression of RANTES, but its parental compound FJU‐C4 was unable to diminish RANTES in cell culture media or cell lysates. FJU‐C28 blocked the secretion of IL‐6 and RANTES in LPS‐activated macrophages by regulating the activation of JNK, p38 mitogen‐activated protein kinase (MAPK) and nuclear factor‐κB (NF‐κB). FJU‐C28 prevented the LPS‐induced decreases in lung function including vital capacity (VC), lung compliance (C chord), forced expiratory volume at 100 ms (FEV100), and forced vital capacity (FVC) in mice with LPS‐induced systemic inflammatory responses. FJU‐C28 also reduced neutrophil infiltration in the interstitium, lung damage and circulating levels of IL‐6 and RANTES in mice with systemic inflammation. In conclusion, these findings suggest that FJU‐C28 possesses anti‐inflammatory activities to prevent endotoxin‐induced lung function decrease and lung damages by down‐regulating proinflammatory cytokines including IL‐6 and RANTES via suppressing the JNK, p38 MAPK and NF‐κB signaling pathways.

Indomethacin augments lipopolysaccharide-induced expression of inflammatory molecules in the mouse brain.

Indomethacin and other non-steroidal anti-inflammatory drugs (NSAIDs) are used to relieve pain and fever including during infections. However, some studies suggest that NSAIDs protect against neuroinflammation, while some find no effects or worsening of neuroinflammation. We evaluated the effect of indomethacin alone on in combination with minocycline, a drug that inhibits neuroinflammation, on the expression of transcripts of neuroinflammatory molecules-induced by lipopolysaccharide (LPS) in the brain of mice. Inoculation of male BALB/c mice with LPS induced the expression of the microglia marker ionized calcium binding adaptor molecule protein, mRNA expression of the genes for cytokines interleukin-1beta (Il1b) and tumor necrosis factor-alpha (Tnf) and inducible nitric oxide synthase gene (Nos2), but not Il10, in the brain. Treatment with indomethacin had no significant effect on the cytokines or Nos2 mRNA expression in naïve animals. However, pretreatment with indomethacin increased LPS-induced Nos2 mRNA and inducible nitric oxide (iNOS) protein expression, but had no significant effect on LPS-induced mRNA expression of the cytokines. Minocycline reduced LPS-induced Il1b and Tnf, but not Nos2, mRNA expression. Treatment with indomethacin plus minocycline had no effect on LPS-induced Il1b, Tnf and Nos2 mRNA expression. In conclusion these results show that indomethacin significantly augments LPS-induced Nos2 mRNA and iNOS protein expression in the brain. In the presence of indomethacin, minocycline could not inhibit LPS-induced pro-inflammatory cytokine expression. Thus, indomethacin could exacerbate neuroinflammation by increasing the expression of iNOS and also block the anti-inflammatory effects of minocycline.

New anti-neuroinflammatory steroids against LPS induced NO production in BV2 microglia cells by microbial transformation of isorhodeasapogenin.

Microbial transformation of isorhodeasapogenin (1), the major steroidal sapogenin of Tupistra chinensis, was performed with the fungus Syncephalastrum racemosum (AS 3.264). As a result, nine new biotransformation metabolites (2-10) were isolated and their structures were elucidated by spectroscopic analysis. Hydroxylation, oxidation and glycosylation reactions were observed on the B, C, D and F rings of steroidal skeleton. Substrate (1) and its biotransformed metabolites 2-6, 8-10 were evaluated for their anti-neuroinflammatory effect on the NO accumulation induced by LPS in BV-2 cells. All the tested metabolites were found to have more potential anti-neuroinflammatory activity than the substrate. Especially, metabolites 2, 5 and 6 exhibited significant inhibition on NO production after hydroxylation at C-12 or C-15. Moreover, metabolite 2 dose-dependently reduced the LPS-induced protein expression of iNOS and COX-2.

Bioactive Constituents from the Roots of Eurycoma longifolia.

Four new phenolic components, eurylophenolosides A (1) and B (2), eurylolignanosides A (3) and B (4), along with twelve known compounds were isolated from the roots of Eurycoma longifolia Jack. The structure of these components was elucidated by using various spectral techniques and chemical reactions. Among the known isolates, syringaldehyde (12), 3-chloro-4-hydroxybenzoic acid (13), 3-chloro-4-hydroxyl benzoic acid-4-O-β-d-glucopyranoside (14), and isotachioside (15) were isolated from the Eurycoma genus for the first time. Further, the NMR data of 14 was reported here firstly. Meanwhile, the nitric oxide (NO) inhibitory activities of all compounds were examined in lipopolysaccharide (LPS)-stimulated RAW264.7 cells at 40 μM. As results, piscidinol A (6), 24-epi-piscidinol A (7), bourjotinolone A (10), and scopoletin (16) were found to play important role in suppressing NO levels without cytotoxicity. Furthermore, the Western blot method was used to investigate the mechanism of compounds 6, 7, 10, and 16 by analysing the level of inflammation related proteins, such as inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in LPS-stimulated RAW264.7 cells. Consequently, compounds 6, 7, 10, and 16 were found to significantly inhibit LPS-induced protein expression of IL-6, NF-κB and iNOS in NF-κB signaling pathway. Moreover, it was found that the protein expression inhibitory effects of 6, 7, and 16 exhibited in a dose-dependent manner. The mechanism may be related to the inhibition of the iNOS expressions through suppressing the IL-6-induced NF-κB pathway.

Phytochemical profile of hot water extract of Glechoma hederacea and its antioxidant, and anti-inflammatory activities

Glechoma hederacea belongs to the Labiatae family and has many biological activities. The objective of this study was to evaluate the chemical composition, antioxidant and anti-inflammatory activities of a hot water extract of G. hederacea (HWG). Our results indicated that rosmarinic acid, chlorogenic acid, caffeic acid, rutin, genistin, and ferulic acid were the most abundant phytochemicals in HWG. The free radical scavenging capacity of HWG in cell-free systems was evaluated by using the α,α-diphenyl-β-picrylhydrazyl (DPPH) and β-carotene bleaching assays. The antioxidant and anti-inflammatory activities of HWG were determined in vitro in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. The results demonstrated that DAPI staining, the comet assay, and DNA fragmentation showed that HWG prevented LPS-induced DNA damage in RAW264.7 macrophages, reduced the content of LPS-induced nitric oxide (NO) and malondialdehyde (MDA), increased GSH levels, and regulated antioxidant enzyme activities. We also demonstrated that HWG significantly decreased the LPS-induced mRNA expression of iNOS, COX-2, TNF-α, IL-6, and IL-1β in RAW264.7 macrophages, and reduced the LPS-induced protein expression of iNOS and COX-2 in RAW264.7 macrophages. These results show that HWG and its main components possess potent antioxidant and anti-inflammatory properties.

Triptolide up-regulates metabotropic glutamate receptor 5 to inhibit microglia activation in the lipopolysaccharide-induced model of Parkinson’s disease

Metabotropic glutamate receptor (mGlu)5 regulates microglia activation, which contributes to inflammation. However, the role of mGlu5 in neuroinflammation associated with Parkinson’s disease (PD) remains unclear. Triptolide (T10) exerts potent immunosuppressive and anti-inflammatory effects and protects neurons by inhibiting microglia activation. In this study, we investigated the role of mGlu5 in the anti-inflammatory effect of T10 in a lipopolysaccharide (LPS)-induced PD model. In cultured BV2 cells and primary microglia, blocking mGlu5 activity or knocking down its expression abolished T10-inhibited release of proinflammatory cytokines induced by LPS. Moreover, T10 up-regulated mGlu5 expression decreased by LPS through enhancing mRNA expression and protein stability. T10 also reversed the reduction in mGlu5 membrane localization and modulated receptor-mediated mitogen-activated protein kinase activity induced by LPS. Pharmacological inhibition of signaling molecules increased nitric oxide level and inducible nitric oxide synthase (iNOS), tumor necrosis factor-α, and interleukin (IL)-1β and -6 transcript levels that were downregulated by treatment with T10. Consistent with these in vitro findings, blocking mGlu5 attenuated the anti-inflammatory effects of T10 in an LPS-induced PD model and blocked the decreases in the number and morphology of ionized calcium binding adaptor molecule 1-positive microglia and LPS-induced iNOS protein expression caused by T10 treatment. Besides, mGlu5 mediated the effect of T10 on microglia-induced astrocyte activation in vitro and in vivo. The findings provide evidence for a novel mechanism by which mGlu5 regulates T10-inhibited microglia activation via modulating protein expression of the receptor and its intracellular signaling. The study might contribute to the biological effects of Chinese herbs as an approach for protecting against neurotoxicity in PD.

Oleamide suppresses inflammatory responses in LPS-induced RAW264.7 murine macrophages and alleviates paw edema in a carrageenan-induced inflammatory rat model

Oleamide compounds purified from green algae have been used for the prevention and treatment of atherosclerosis, thrombosis, arthritis, and cancer. They function through their metabolic conversion into prostaglandins, thromboxanes, and leukotrienes. However, the actual mechanism of action has not been well characterized. To investigate the underlying anti-inflammatory activity and associated mechanisms, oleamide purified from Codium fragile was studied using RAW264.7 murine macrophages and a carrageenan-induced inflammatory rat model. Our results indicate that pre-treatment of RAW264.7 cells with oleamide significantly suppressed LPS-induced nitrite production and PGE2 secretion. Oleamide inhibited LPS-induced iNOS and COX-2 mRNA and protein expression. It also inhibited the LPS-induced production of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6. In addition, oleamide prevented the nuclear translocation of NF-κB by suppressing the phosphorylation of the inhibitor of kappa B (IκB)-α. Oleamide also suppressed the phosphorylation of mitogen-activated protein kinases such as ERK1/2 and JNK. Furthermore, inhibition of paw swelling (%) was suppressed 2 h after the intraperitoneal injection of oleamide (20 mg/kg, body weight) in a carrageen-induced rat model. Therefore, our results suggest that oleamide can be used as a single ingredient treatment for inflammatory diseases.

Nepetoidin B, a Natural Product, Inhibits LPS-stimulated Nitric Oxide Production via Modulation of iNOS Mediated by NF-κB/MKP-5 Pathways.

Previous reports showed that nepetoidin B (NTB), a natural product isolated from many herbs, has anti-fungal and anti-bacterial effects. In this study, the antiinflammatory effect of NTB was investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The cytotoxic effect of NTB and LPS was determined by MTT assay. The nitric oxide (NO) production was detected by Griess assay. The TNF-α and IL-6 levels were determined by enzyme-linked immunosorbent assay kits. Protein expressions were tested by western blotting. The transcription activity of inducible nitric oxide synthase (iNOS) was detected by luciferase assay. Immunofluorescence assay was used to observe the visualization of NF-κB/p65 nuclear translocation. NTB and LPS showed no obvious cytotoxic effect on RAW 264.7 cells. NTB remarkably inhibited LPS-induced NO and TNF-α secretion in a concentration-dependent manner while showed no significant effect on IL-6 secretion. NTB inhibited LPS-induced iNOS protein expression and transcription activity without affecting cyclooxygenase-2. Furthermore, NTB suppressed LPS-stimulated NF-κB/p65 phosphorylation and nuclear translocation. In addition, NTB significantly inhibited LPS-induced phosphorylation of JNK1/2 and p38MAPK without affecting ERK1/2. LPS-induced inhibition of mitogen-activated protein kinase phosphatase-5 (MKP-5) was completely reversed by NTB. In conclusion, these results suggested that NTB inhibited LPS-stimulated NO production possibly via modulation of iNOS mediated by MKP-5/NF-κB pathways in RAW 264.7 cells. Copyright © 2017 John Wiley & Sons, Ltd.

Pentosan polysulfate inhibits IL-1β-induced iNOS, c-Jun and HIF-1α upregulation in canine articular chondrocytes.

Osteoarthritic (OA) chondrocytes are shown to express inducible nitric oxide synthase (iNOS) which produces high concentrations of nitric oxide (NO), particularly when stimulated with proinflammatory cytokines. NO is involved in OA cartilage degradation. On the other hand, c-Jun N-terminal Kinase (JNK) pathway mediates the activation and transcription of c-Jun, which is required for interleukin-1 (IL-1)-induction of matrix metalloproteinases-13 (MMP-13) in OA pathogenesis. Therefore, the selective inhibition of iNOS and c-Jun is a promising target for treatment and prevention of OA. The purpose of the study was to investigate the inhibitory effects of pentosan polysulfate (PPS) on IL-1β-induced iNOS, c-Jun and HIF-α isoforms upregulation in canine articular chondrocytes (CACs). Primary (P0) chondrocytes were isolated and cultured from femoral head cartilages of three (3) dogs. First passage (P1) chondrocytes were preincubated with 0, 1, 5, 15 and 40 μg/mL of PPS for 4 hr before treatment with 10 ng/mL rhIL-1β for a further 8 hr. In addition, we evaluated the effects of single and multiple cytokine with or without LPS on iNOS protein induction. PPS significantly inhibited (P < 0.05) IL-1β-induced iNOS, c-Jun and HIF-1α mRNA upregulation in a dose-dependent pattern. iNOS mRNA was significantly inhibited at 15 and 40 μg/mL whereas c-Jun and HIF-1α were significantly downregulated at 5, 15 and 40 μg/mL of PPS compared to chondrocytes treated with only rhIL-1β. Intriguingly, CACs were recalcitrant to single IL-1β, TNF-α or LPS-induction of iNOS protein including to a combination of IL-1β+TNF-α, IL-1β+LPS except to TNF-α+LPS and IL-1β+TNF-α+LPS suggestive of a protective mechanism from iNOS detrimental effects on perpetuating OA. IL-1β+TNF-α+LPS-induced iNOS protein expression was significantly abrogated by PPS. We demonstrate for the first time that PPS is a novel inhibitor of IL-1β-induced iNOS, c-Jun, and HIF-1α mRNA upregulation and iNOS protein induction which may be beneficial for prevention and treatment OA.

Six new sesquiterpenoids from Nardostachys chinensis Batal

Six new sesquiterpenoids, namely nardosinanones J-N and nardoaristolone C, were isolated from the rhizomes and roots of Nardostachys chinensis Batal. Their structures were determined by interpretation of spectroscopic data (HR-ESI-MS, 1D and 2D NMR). A combination of X-ray crystal diffraction, ECD calculation, and Mosher ester methods was employed to determine the absolute configuration of the isolated compounds. Compounds 1–2, 4–6 were evaluated anti-inflammatory activities in LPS-stimulated RAW264.7 macrophages. The results showed that compound 5 obviously inhibited LPS-induced iNOS and COX-2 protein expression compared to single LPS stimulation, which indicated the potential effect to medicate anti-inflammatory.

Inhibitory effects of three bisbenzylisoquinoline alkaloids on lipopolysaccharide-induced microglial activation

Three bisbenzylisoquinoline alkaloids (liensinine, neferine, and isoliensinine) inhibit lipopolysaccharide-induced microglial activation.

Berberine Decreased Inducible Nitric Oxide Synthase mRNA Stability through Negative Regulation of Human Antigen R in Lipopolysaccharide-Induced Macrophages.

Berberine, a major isoquinoline alkaloid found in medicinal herbs, has been reported to possess anti-inflammatory effects; however, the underlying mechanisms responsible for its actions are poorly understood. In the present study, we investigated the inhibitory effects of berberine and the molecular mechanisms involved in lipopolysaccharide (LPS)-treated RAW 264.7 and THP-1 macrophages and its effects in LPS-induced septic shock in mice. In both macrophage cell types, berberine inhibited the LPS-induced nitric oxide (NO) production and inducible NO synthase (iNOS) protein expression, but it had no effect on iNOS mRNA transcription. Suppression of LPS-induced iNOS protein expression by berberine occurred via a human antigen R (HuR)-mediated reduction of iNOS mRNA stability. Molecular data revealed that the suppression on the LPS-induced HuR binding to iNOS mRNA by berberine was accompanied by a reduction in nucleocytoplasmic HuR shuttling. Pretreatment with berberine reduced LPS-induced iNOS protein expression and the cytoplasmic translocation of HuR in liver tissues and increased the survival rate of mice with LPS-induced endotoxemia. These results show that the suppression of iNOS protein expression by berberine under LPS-induced inflammatory conditions is associated with a reduction in iNOS mRNA stability resulting from inhibition of the cytoplasmic translocation of HuR.

제주 재래종 감귤 ‘홍귤’, ‘편귤’ 과피 분획물의 항산화, 항염증 효과

한약재로 사용되고 있는 제주 재래 감귤 중 홍귤, 편귤 품종 과피 추출물의 기능성 소재로서의 활용 가능성을 알아보기 위해 용매별 분획물이 보유한 항산화 및 항염증 활성을 조사하였다. 홍귤, 편귤 모두 부탄올 분획물에서 총 페놀성 화합물의 함량이 각각 534.4 mg/g, 342.9 mg/g으로 가장 높았으며, 그 다음으로 에틸아세테이트, 헥산, 그리고 물 분획물 순이었다. 총 플라보노이드 함량에 있어서도 부탄올 분획물에서 홍귤 431.8 mg/g, 편귤 415.7 mg/g으로 가장 높게 나타났다. DPPH 라디칼 소거활성은 부탄올 분획물 1 mg/ml 에서 홍귤(89.2%), 편귤(64.2%) 모두 가장 높았으며, ABTS 라디칼 소거활성에 있어서도 두 품종 모두 부탄올 분획물에서 낮은 농도에서도 매우 우수한 활성을 보였으며 그 뒤로 에틸아세테이트, 헥산, 물 분획물 순이었다. 항염증 효과 측정에서 홍귤, 편귤 에틸아세테이트 분획물 모두 NO, IL-6, iNOS 및 COX-2 단백질 생성 억제 효과를 확인할 수 있었다. 특히 홍귤 에틸아세테이트 분획물 100 &#x3BC;g/ml 농도에서 항염증 효과가 우수하였다. This study investigated the anti-oxidative and anti-inflammatory activity of unripe fruit peel solvent fractions of the native jeju citrus &#x2018;Hongkyool&#x2019; (Citrus tachibana Tanaka) and &#x2018;Pyunkyool&#x2019; (C. tangerina Hort. ex Tanaka). The total polyphenol content and total flavonoid content were highest in the butanol fraction of both &#x2018;Hongkyool&#x2019; (534.4 mg/g, 431.8 mg/g) and &#x2018;Pyunkyool&#x2019; (342.9 mg/g, 415.7 mg/g). In both cultivars, the butanol fraction showed the strong antioxidant activity by DPPH radical scavenging and ABTS radical scavenging. The DPPH radical scavenging of the butanol fraction from &#x2018;Hongkyool&#x2019; and &#x2018;Pyunkyool&#x2019; was 89% and 64% at a concentration of 1 mg/ml, respectively. The ABTS radical scavenging of the butanol fraction from &#x2018;Hongkyool&#x2019; and &#x2018;Pyunkyool&#x2018; was 94% and 85% at a concentration of 1 mg/ml, respectively. We investigated the effect of the anti-inflammatory activity of the ethyl acetate fraction from &#x2018;Hongkyool&#x2019; and &#x2018;Pyunkyool&#x2019; on LPS-induced NO production, IL-6, iNOS, and COX-2 protein expression in Raw 264.7 cells. At concentrations of 50 and 100 &#x3BC;g/ml of the &#x2018;Hongkyool&#x2019; ethyl acetate fraction, the anti-inflammatory effect was excellent. These results suggest that ethyl acetate and butanol fractions from &#x2018;Hongkyool&#x2019; and &#x2018;Pyunkyool&#x2019; could be useful functional materials, with anti-oxidative and anti-inflammatory properties.

Activin suppresses LPS-induced Toll-like receptor, cytokine and inducible nitric oxide synthase expression in normal human melanocytes by inhibiting NF-κB and MAPK pathway activation.

Activins are dimeric growth and differentiation factors that belong to the transforming growth factor(TGF)-β superfamily of structurally related signaling proteins. In the present study, we examined the mechanisms through which activin regulates the lipopolysaccharide(LPS)-induced transcription of Toll-like receptors(TLRs), cytokines and inducible nitric oxide synthase(iNOS) in human melanocytes, as well as the involvement of nuclear factor(NF)-κB and mitogen-activated protein kinase(MAPK) signaling. Cell proliferation was analyzed by cell viability assay, mRNA expression was detected by RT-qPCR, and protein expression was measured by western blot analysis. LPS increased the mRNA expression of TLRs(TLR1-10) and cytokines [interleukin(IL)-1β, IL-6, IL-8 and TNF-α], as well as the mRNA and protein expression of iNOS. Activin decreased the LPS-induced TLR and cytokine mRNA expression, as well as the LPS-induced iNOS mRNA and protein expression. In addition, activin suppressed NF-κBp65 activation and blocked inhibitor of NF-κB(IκBα) degradation in LPS-stimulated melanocytes, and reduced LPS-induced p38MAPK and MEK/ERK activation. On the whole, our results demonstrated that activin inhibited TLR and cytokine expression in LPS-activated normal human melanocytes and suppressed LPS-induced iNOS gene expression. Moreover, the anti-inflammatory effects of activin were shown to be mediated through the suppression of NF-κB and MAPK signaling, resulting in reduced TLR and iNOS expression, and in the inhibition of inflammatory cytokine expression.

Inhibition of endogenous heat shock protein 70 attenuates inducible nitric oxide synthase induction via disruption of heat shock protein 70/Na(+) /H(+) exchanger 1-Ca(2+) -calcium-calmodulin-dependent protein kinase II/transforming growth factor β-activated kinase 1-nuclear factor-κB signals in BV-2 microglia.

Inducible nitric oxide synthase (iNOS) critically contributes to inflammation and host defense. The inhibition of heat shock protein 70 (Hsp70) prevents iNOS induction in lipopolysaccharide (LPS)-stimulated macrophages. However, the role and mechanism of endogenous Hsp70 in iNOS induction in microglia remains unclear. This study addresses this issue in BV-2 microglia, showing that Hsp70 inhibition or knockdown prevents LPS-induced iNOS protein expression and nitric oxide production. Real-time PCR experiments showed that LPS-induced iNOS mRNA transcription was blocked by Hsp70 inhibition. Further studies revealed that the inhibition of Hsp70 attenuated LPS-stimulated nuclear translocation and phosphorylation of nuclear factor (NF)-κB as well as the degradation of inhibitor of κB (IκB)-α and phosphorylation of IκB kinase β (IKKβ). This prevention effect of Hsp70 inhibition on IKKβ-NF-κB activation was found to be dependent on the Ca(2+) /calcium-calmodulin-dependent protein kinase II (CaMKII)/transforming growth factor β-activated kinase 1 (TAK1) signals based on the following observations: 1) chelation of intracellular Ca(2+) or inhibition of CaMKII reduced LPS-induced increases in TAK1 phosphorylation and 2) Hsp70 inhibition reduced LPS-induced increases in CaMKII/TAK1 phosphorylation, intracellular pH value, [Ca(2+) ]i , and CaMKII/TAK1 association. Mechanistic studies showed that Hsp70 inhibition disrupted the association between Hsp70 and Na(+) /H(+) exchanger 1 (NHE1), which is an important exchanger responsible for Ca(2+) influx in LPS-stimulated cells. These studies demonstrate that the inhibition of endogenous Hsp70 attenuates the induction of iNOS, which likely occurs through the disruption of NHE1/Hsp70-Ca(2+) -CaMKII/TAK1-NF-κB signals in BV-2 microglia, providing further insight into the functions of Hsp70 in the CNS.

Propofol attenuates LPS-induced tumor necrosis factor-α, interleukin-6 and nitric oxide expression in canine peripheral blood mononuclear cells possibly through down-regulation of nuclear factor (NF)-κB activation

Sepsis is a major cause of mortality in intensive care medicine. Propofol, an intravenous general anesthetic, has been suggested to have anti-inflammatory properties and able to prevent sepsis induced by Gram-positive and Gram-negative bacteria by down-regulating the gene expression of pro-inflammatory cytokines. However, propofol’s anti-inflammatory effects upon canine peripheral blood mononuclear cells (PBMCs) have not yet been clarified. Here, we isolate canine PBMCs and investigate the effects of propofol on the gene expressions of both lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α and upon the production of nitric oxide (NO). Through real-time quantitative PCR and the Griess reagent system, we found that non-cytotoxic levels of propofol significantly inhibited the release of NO and IL-6 and TNF-α gene expression in LPS-induced canine PBMCs. Western blotting revealed that LPS does significantly increase the expression of inducible NO synthase (iNOS) protein in canine PBMCs, while pretreatment with propofol significantly decreases the LPS-induced iNOS protein expression. Propofol, at concentration of 25 µM and 50 µM, also significantly inhibited the LPS-induced nuclear translocation of nuclear factor (NF)-κB p65 protein in canine PBMCs. This diminished TNF-α, IL-6 and iNOS expression, and NO production was in parallel to the respective decreased NF-κB p65 protein nuclear translocation in the LPS-activated canine PBMCs pretreated with 25 µM and 50 µM propofol. This suggests that non-cytotoxic levels of propofol pretreatment can down-regulate LPS-induced inflammatory responses in canine PBMCs, possibly by inhibiting the nuclear translocation of the NF-κB p65 protein.

P71 - Can semi-synthetic flavonoids return old microglia to their youthful state?

A number of studies have indicated that brain inflammation may deteriorate during normal aging and that neuroinflammation is amplified in age-related neurodegenerative diseases. A pivotal role in age-related neuroinflammatory pathologies is attributed to amplified and prolonged activation of microglia. In addition, microglia from the aged brain were reported as senescent displaying many functional impairments. Flavonoids were shown to be promising molecules in modulation of neuroinflammation. Quercetin, a naturally occurring flavonoid, was proven to downregulate inflammatory genes in microglia. Synthetically modified quercetin, 3´-O-(3-chloropivaloyl)quercetin (CPQ), is assumed to posses better biological availability and enhanced antioxidant properties. In the present study, the antineuroinflammatory capacity of CPQ was assessed in BV-2 microglial cells and rat primary microglia. CPQ suppressed more efficiently than its precursor quercetin LPS-induced NO production and iNOS protein expression. However, neither of the compounds tested influenced significantly phagocytosis of BV-2 cells. In addition, CPQ showed a somewhat better suppression of PMA-induced generation of superoxide than did quercetin. Unlike quercetin, CPQ caused a decline in BV-2 microglia proliferation (without any impact on cell viability) along with interference with cell cycle progression. Both compounds tested at 10uM concentration notably enhanced viability of microglia-enriched cultures prepared from 22-month-old rat brains. This was followed by suppression of lipofuscin-like autofluorescence, improvement of lysosomal function and protection of mitochondria in the old microglia. These results can highlight the therapeutic potential of CPQ as a novel antiinflammatory drug in neurodegenerative diseases. In addition, our data suggest that both natural and semisynthetic flavonoids might protect functions of old microglia [VEGA2/0031/12,1/0076/13;APVV-0052-10;ITMS26240220040].

Total Glucosides of &lt;i&gt;Paeonia lactiflora&lt;/i&gt; Pall Suppress Nitric Oxide Production and iNOS Expression in Lipopolysaccharide-Stimulated RAW264.7 Macrophages

Purpose: To investigate the effect of total glucosides of Paeonia lactiflora (TGPL) on nitric oxide (NO) production and its potential mechanism in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells.Methods: RAW264.7 cells were treated with 10 - 300 µg/ml TGPL and 1 µg/ml LPS. Cell survival was determined by MTT assay. NO level was determined by Griess reaction assay. Inducible NO synthase (iNOS) expression and inhibitor-kBα (IkBα) degradation were determined by Western blot assay. DNA binding activity of NF-kB was determined by ELISA assay using Trans AM™ kit for p65.Results: The concentrations of TGPL (10 - 300 ìg/ml) used in this study did not affect cell survival of RAW264.7 cells, which suggest that 10-300 µg/ml TGPL did not show cytotoxic effect on RAW264.7 cells. NO level and iNOS protein expression significantly increased in LPS-stimulated RAW264.7 cellscompared to the unstimulated cells. However, 10 - 300 µg/ml TGPL significantly decreased LPSinduced NO level and iNOS protein expression compared to LPS-stimulated RAW264.7 cells alone. Furthermore, 10 - 300 µg/mL TGPL significantly reduced the content of IkBα protein in LPS-stimulated RAW264.7 cells, which suggests that TGPL inhibited LPS-induced degradation of IkBα protein. TGPL remarkably repressed LPS-induced DNA binding activity of P65 in RAW264.7 cells.Conclusion: These findings suggest that TGP inhibits NO production and iNOS expression through suppression of NF-kB activation in LPS-stimulated RAW264.7 cells.Keywords: Total glucosides, Paeonia lactiflora, Nitric oxide, iNOs, Nuclear factor-kB