Suppressed NF-κB P65 Research Articles

Acute Inflammation and Oxidative Stress Induced by Lipopolysaccharide and the Ameliorative Effect of Stingless Bee Honey.

Systemic acute inflammation is the hallmark of sepsis and is associated with multiple organ dysfunction. This study investigated the potential of Stingless Bee Honey (SBH) to suppress lipopolysaccharide (LPS)-induced systemic acute inflammation in rats and to reveal the probable mechanism of action. Rats received 4.6 and 9.2 g/kg SBH for 7 days followed by a single injection of LPS after which blood samples were taken 6h later. LPS induced liver, kidney, heart, and lung injury, were manifested by increased serum transaminases, alkaline phosphatase, creatine kinase, creatinine, and urea, along with multiple histological alterations, particularly leukocyte infiltration. Pro-inflammatory cytokines were elevated in the serum, and NF-κB p65, p38 MAPK, and HMGB-1 were significantly increased in different tissues of LPS-challenged rats. SBH prevented tissue injury, ameliorated pro-inflammatory cytokines, and suppressed NF-κB p65, p38 MAPK, and HMGB-1 in rats that had received LPS. In addition, SBH diminished reactive oxygen species (ROS) production, lipid peroxidation, and oxidative DNA damage, and enhanced glutathione and Nrf2 in LPS-treated rats. SBH prevents systemic acute inflammation by suppressing NF-κB, p38 MAPK, HMGB-1, oxidative stress, and tissue injury in rats. Thus, SBH may represent an effective anti-inflammatory nutraceutical, pending further mechanistic studies.

1095-P: Exendin 4 Decreases Tumor Volume through Attenuation of psma-Induced Activation of NfκB Pathway in HPV-Induced Diabetes/Cancer Model

Background: The diabetes-cancer link may be mediated by inflammation due to infection such as Human Papilloma Virus (HPV). Exendin 4, a Glucagon-like-peptide 1 agonist, has anti-hyperglycemic and anti- inflammatory effect and can attenuate certain cancer growth. Methods: We used RNA microarray analysis to detect the gene expression after Exendin 4 treatment in the db/db mouse tumor, which was established by inoculation of mouse PV cancer cells (CUP-1). The latter originates from the kidney of baby C57BL/6J mice expressing HPV-16 E7 oncogene. We examined the effect of Exendin 4 on cell proliferation, apoptosis and gene expression along the inflammatory pathway in CUP-1 under different glucose environment. We developed CUP-1 cells with or without target gene overexpression (OE) or downregulation (DR) for inoculation into the db/db mouse. We compared RNA expression of the target gene in cervical cancer specimen from patients with or without diabetes. Results: RNA expression of proteasome 20s (psma) was decreased after Exendin 4 treatment in the db/db mouse tumor. High glucose environment increased cell proliferation in CUP-1 cells, which was enhanced after OE of psma but attenuated after DR of psma. Exendin 4 suppressed NFκB P65 and IκB activation in CUP-1 cells under high glucose medium. After inoculation of CUP-1 cells with DR and OE of psma, the tumor size was decreased and increased in db/db mice respectively. Exendin 4 decreased the tumor volume in the db/db mice of psma OE group. In human cervical cancer specimen, RNA expression of psma was increased in patients with diabetes versus those without diabetes. Conclusion: High glucose increased expression of psma, which activated NFκB inflammation pathway and promoted carcinogenesis. Exendin 4 suppressed the NFκB pathway activation and decreased tumor volume with corroborative evidence from human samples, suggesting that the anti-cancer effect of Exendin 4 might be mediated by the psma-NFκB pathway. Disclosure D. Mao: None. J.C. Chan: None.

Evodiamine Inhibits Lipopolysaccharide (LPS)-Induced Inflammation in BV-2 Cells via Regulating AKT/Nrf2-HO-1/NF-κB Signaling Axis.

Neuroinflammation is caused by excessive activation of microglia and plays an essential role in neurodegenerative diseases. After activation, microglia produce several kinds of inflammatory mediators, trigger an excessive inflammatory response, and ultimately destroy the surrounding neurons. Therefore, agents that inhibit neuroinflammation may be potential drug candidates for neurodegenerative diseases. Evodiamine (EV) has anti-inflammatory functions in peripheral tissues. However, whether EV exerts the same function in neuroinflammation is not known. In the present study, the aim was to explore whether EV attenuates microglial overactivation and therefore suppresses the development of neuroinflammation in lipopolysaccharide (LPS)-stimulated BV-2 cells. It was found that EV effectively inhibited expression of proinflammatory mediators (cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α)) via AKT/Nrf2/HO-1 activation and suppressed NF-κB p65 phosphorylation. In addition, EV could suppress LPS-induced inflammatory response and loss of dopaminergic neuron in mouse mesencephalic neuron--glia cells. Hence, these findings demonstrate that EV suppresses neuroinflammation caused by overactivated microglia via regulating the AKT/Nrf2/HO-1/NF-κB signaling axis.

The natural flavonoid galangin ameliorates dextran sulphate sodium-induced ulcerative colitis in mice: Effect on Toll-like receptor 4, inflammation and oxidative stress.

This study was carried out to investigate the potential therapeutic effect of galangin, a promising active principle of honeybee propolis, in dextran sulphate sodium (DSS)-induced colitis in mice. We explored the possible underlying mechanisms for galangin action and the therapeutic benefit of adding galangin to the standard therapy sulphasalazine. A galangin dose of 40mg/kg was selected based on a preliminary dose-selection study for investigation in a 4-week cyclical model of DSS-induced colitis. Mice received 3% DSS in their drinking water during the first and third weeks and were administered the treatments (40mg/kg galangin, 100mg/kg sulphasalazine and a combination of 20mg/kg galangin and 50mg/kg sulphasalazine) daily starting from the second week. Galangin significantly ameliorated DSS-induced histopathological alterations and tissue injury, down-regulated Toll-like receptor 4 expression, suppressed NF-κB p65 activation, lowered inflammatory cytokine levels and demonstrated antioxidant effects. The combination of galangin and sulphasalazine at half doses yielded comparable results to either drug alone at full dose. This study highlights galangin as a promising therapy for colitis management.

Aqueous extract of Bruguiera gymnorrhiza leaves protects against dextran sulfate sodium induced ulcerative colitis in mice via suppressing NF-κB activation and modulating intestinal microbiota.

Ulcerative colitis (UC) is tightly associated with inflammation response and oxidative stress. As a folk medicine applied in treatment of diarrhea, Bruguiera gymnorrhiza also possesses anti-inflammatory and anti-oxidative activities, which indicated that B. gymnorrhiza may exert anti-colitis effect. To investigate effect and mechanism of B. gymnorrhiza on experimental UC. Aqueous extract of B. gymnorrhiza leaves (ABL) was used for investigation in the present study. Murine UC was established through access to 3% dextran sulfate sodium (DSS) for 7 days. Meanwhile, mice accepted treatment with ABL (25, 50, 100mg/kg) or sulfasalazine (200mg/kg) once daily. On the last day, disease activity index (DAI) including body weight loss, fecal character and degree of bloody diarrhea was evaluated, colon segments were obtained for length measurement and further analysis and feces were collected for intestinal microbiota analysis. ABL ameliorated DAI scores, colon length shortening and histopathological damage in DSS-induced colitis mice obviously. SOD activity, levels of MDA and GSH altered by colitis were restored remarkably after ABL treatment. ABL inhibited increases in levels of colonic COX-2, iNOS, TNF-α, IL-6, IL-1β, IL-4, IL-10 and IL-11 in colitis mice. Moreover, ABL prominently suppressed NF-κB p65 and IκB phosphorylation and down-regulated mRNA levels of COX-2, iNOS, TNF-α, IL-6 and IL-1β elevated by colitis. As shown in microbiota analysis, ABL modulated composition of intestinal microbiota of colitis mice. ABL exhibited protective effect against DSS-induced ulcerative colitis through suppressing NF-κB activation and modulating intestinal microbiota.

MPMBP down-regulates Toll-like receptor (TLR) 2 ligand-induced proinflammatory cytokine production by inhibiting NF-κB but not AP-1 activation

MPMBP is a novel non-nitrogen-containing bisphosphonate (non-NBP) which possesses anti-bone resorptive activity and an antioxidant side chain. This study aimed to assess the effects of MPMBP on the production of proinflammatory cytokines and chemokines by the macrophage-like cell line, J774.1, in the presence of Toll-like receptor (TLR) agonists. J774.1 cells were pretreated with or without MPMBP for 5 min, and then incubated with or without Pam3Cys-Ser-(Lys)4 (Pam3CSK4, a TLR2 agonist) or lipid A (a TLR4 agonist) for 24 h. MPMBP down-regulated TLR2 ligand-induced production of IL-6, MCP-1, MIP-1α, and TNF-α, but not TLR4 ligand-induced proinflammatory cytokine production, and was not cytotoxic in J774.1 cells. Cu-CPT22, a TLR2 antagonist, down-regulated Pam3CSK4-induced production of IL-6, MCP-1, and MIP-1α, but not TNF-α. MPMBP inhibited the translocation of NF-κB p65, but not p50, RelB, or p52, and inhibited the activation of JNK, but not p38 MAPK or ERK, in J774.1 cells stimulated with Pam3CSK4. Moreover, MPMBP did not down-regulate AP-1 activation in J774.1 cells stimulated with Pam3CSK4 or lipid A. Our findings suggest that MPMBP inhibits proinflammatory cytokine production in J774.1 cells by suppressing NF-κB p65 activation in the TLR2, but not TLR4, pathway.

MiR-148a suppresses inflammation in lipopolysaccharide-induced endometritis.

Endometritis is a postnatal reproductive disorder disease, which leads to great economic losses for the modern dairy industry. Emerging evidence indicates that microRNAs (miRNAs) play a pivotal role in a variety of diseases and have been identified as critical regulators of the innate immune response. Recent miRNome profile analysis revealed an altered expression level of miR‐148a in cows with endometritis. Therefore, the present study aims to investigate the regulatory role of miR‐148a in the innate immune response involved in endometritis and estimate its potential therapeutic value. Here, we found that miR‐148a expression in lipopolysaccharide (LPS)‐stimulated endometrial epithelial cells was significantly decreased. Our results also showed that overexpression of miR‐148a using agomiR markedly reduced the production of pro‐inflammatory cytokines, such as IL‐1β and TNF‐α. Moreover, overexpression of miR‐148a also suppressed NF‐κB p65 activation by targeting the TLR4‐mediated pathway. Subsequently, we further verified that miR‐148a repressed TLR4 expression by binding to the 3′‐UTR of TLR4 mRNA. Additionally, an experimental mouse endometritis model was employed to evaluate the therapeutic value of miR‐148a. In vivo studies suggested that up‐regulation of miR‐148a alleviated the inflammatory conditions in the uterus as evidenced by H&E staining, qPCR and Western blot assays, while inhibition of miR‐148a had inverse effects. Collectively, pharmacologic stabilization of miR‐148a represents a novel therapy for endometritis and other inflammation‐related diseases.

Fisetin Alleviates Atrial Inflammation, Remodeling, and Vulnerability to Atrial Fibrillation after Myocardial Infarction.

Atrial inflammation and fibrosis are the critical processes involved in atrial fibrillation (AF) after myocardial infarction (MI). Fisetin is a dietary flavonoid that has shown forceful anti-inflammatory and anti-proliferative properties in diverse models of disease. However, fisetin's role in atrial inflammation, fibrosis, and AF vulnerability post-MI remains completely unknown.Rats were subjected to MI surgery, by left anterior descending coronary artery ligation or sham operation, and treated with DMSO or fisetin via intraperitoneal injection. After 28 days, echocardiographic parameters were performed, and AF inducibility was tested. We further evaluated the inflammation, fibrosis of left atria (LA), and related signal pathways by RT-PCR, Western blot, and staining analysis.Compared to the MI group, fisetin treatment improved cardiac function, inhibited macrophage recruitment into the LA and production of IL-1β and TNF-α, and attenuated adverse atrial fibrosis following acute myocardial infarction (AMI). Electrophysiological recordings, using an isolated perfused heart, showed that MI-induced higher inducibility of AF and prolonged AF duration, interatrial conduction time (IACT), atrial effective refractory period (AERP) were significantly alleviated by fisetin. Mechanistically, fisetin markedly increased phosphorylated AMPK (p-AMPK) levels and suppressed NF-κB p65, p38MAPK, and smad3 phosphorylation in the LA post-MI.We demonstrate that fisetin improves LA expansion, cardiac function, atrial inflammation, fibrosis, and vulnerability to AF following MI by possibly regulating AMPK/NF-κB p65 and p38MAPK/smad3 signaling pathways.

Gas6 Attenuates Sepsis-Induced Tight Junction Injury and Vascular Endothelial Hyperpermeability via the Axl/NF-κB Signaling Pathway

Vascular endothelial functional dysregulation and barrier disruption are involved the initiation and development of sepsis. Growth arrest-specific protein 6 (Gas6), one of the endogenous ligands of TAM receptors (Tyro3, Axl, and Mertk), is confirmed to have beneficial functions in hemostasis, inflammation, and cancer growth. Here, we demonstrated the protective effects of Gas6 on multi-organ dysfunction syndrome (MODS) in sepsis and the underlying mechanisms. We investigated Gas6-ameliorated MODS by inhibiting vascular endothelial hyperpermeability in a mouse model of sepsis. Additionally, in vitro, under lipopolysaccharide (LPS) stimulation in vascular endothelial cells, Gas6 attenuated vascular endothelial hyperpermeability by reinforcing the tight junction proteins occludin, zonula occludens-1 (ZO-1), and claudin5. Furthermore, Gas6 substantially suppressed NF-κB p65 activation. In addition, blocking the Gas6 receptor, Axl, partially reduced the protective effect of Gas6 on the vascular endothelial barrier and diminished the inhibitive effect of Gas6 on NF-κB p65 activation. Taken together, this study suggests that Gas6 has a protective effect on MODS in sepsis by inhibiting the vascular endothelial hyperpermeability and alteration of tight junction and that the Axl/NF-κB signaling pathway underlies these effects.

Synthesis and biological evaluation of (1,2,4)triazole[4,3-a]pyridine derivatives as potential therapeutic agents for concanavalin A-induced hepatitis

A series of (1,2,4)triazole[4,3-a]pyridine (TZP) derivatives have been designed and synthesized. Compound 8d was identified as having the most potent inhibitory activity on NO release in response to lipopolysaccharide (LPS) stimulation and inhibition of the migration induced by MCP-1 protein on RAW264.7 macrophages. Based on the screening data, an immunofluorescence assay and a real-time qPCR assay were conducted, indicating that compound 8d suppressed NF-κB p65 translocation and expression of inflammatory genes by concanavalin A (Con A)-induced RAW264.7 macrophages. More importantly, 8d also exhibited potent efficacy, alleviating Con A-induced hepatitis by downregulating the levels of plasma alanine transaminase (ALT), aspartate transaminase (AST) and inflammatory infiltration in a mouse autoimmune hepatitis (AIH) model. In addition, the flow cytometry (FCM) data showed that compound 8d inhibited the accumulation of MDSCs in the liver of Con A-induced mice. These findings raise the possibility that compound 8d might serve as a potential agent for the treatment of AIH.

Identification of narciclasine from Lycoris radiata (L'Her.) Herb. and its inhibitory effect on LPS-induced inflammatory responses in macrophages

Lycoris radiata (L'Her.) Herb. (L. radiata) was traditionally used as a folk medicine in China for treatment of Alzheimer's disease. However, the specific component responsible for its considerable toxicity remained unclear thus restricting its clinical trials. Narciclasine (NCS) was isolated from L. radiata and treatment of NCS for 72 h exhibited significant antiproliferative effects against L02, Hep G2, HT-29 and RAW264.7 cells. However, what needs to be emphasized is that at safe working concentrations of 0.001–0.016 μM, administration of NCS for 24 h inhibited the mRNA expression of inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-ɑ), interleukin-1beta (IL-1β) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-induced macrophages thereby suppressing production of nitric oxide (NO), IL-6, TNF-ɑ and IL-1β. NCS supplementation also inhibited nuclear factor-kappa B (NF-κB) activation by suppressing NF-κB P65 phosphorylation and nuclear translocation, IκBɑ degradation and phosphorylation, and IκKɑ/β phosphorylation. The phosphorylation of c-Jun N-terminal kinase (JNK) and P38, and expression of COX-2 was also attenuated by NCS. These results suggested that NCS might exert anti-inflammatory effects through inhibiting NF-κB and mitogen-activated protein kinase (MAPK) pathways even at very low doses.

TRPV4 Inhibition Improved Myelination and Reduced Glia Reactivity and Inflammation in a Cuprizone-Induced Mouse Model of Demyelination.

The inhibition of demyelination and the promotion of remyelination are both considerable challenges in the therapeutic process for many central nervous system (CNS) diseases. Increasing evidence has demonstrated that neuroglial activation and neuroinflammation are responsible for myelin sheath damage during demyelinating disorders. It has been revealed that the nonselective cation channel transient receptor potential vanilloid 4 (TRPV4) profoundly affects a variety of physiological processes, including inflammation. However, its roles and mechanisms in demyelination have remained unclear. Here, for the first time, we found that there was a significant increase in TRPV4 in the corpus callosum in a demyelinated mouse model induced by cuprizone (CPZ). RN-1734, a TRPV4-antagonist, clearly alleviated demyelination and inhibited glial activation and the production of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) without altering the number of olig2-positive cells. In vitro, RN-1734 treatment clearly inhibited the influx of calcium and decreased the levels of IL-1β and TNF-α in lipopolysaccharide (LPS)-activated microglial cells by suppressing NF-κB P65 phosphorylation. Apoptosis of oligodendrocyte induced by LPS-activated microglia was also alleviated by RN-1734. The results suggest that activation of TRPV4 in microglia is involved in oligodendrocyte apoptosis through the activation of the NF-κB signaling pathway, thus revealing a new mechanism of CNS demyelination.

Acrylamide-induced oxidative stress and inflammatory response are alleviated by N-acetylcysteine in PC12 cells: Involvement of the crosstalk between Nrf2 and NF-κB pathways regulated by MAPKs

Acrylamide (ACR) is a classic neurotoxin in animals and humans. However, the mechanism underlying ACR neurotoxicity remains controversial, and effective prevention and treatment measures against this condition are scarce. This study focused on clarifying the crosstalk between the involved signaling pathways in ACR-induced oxidative stress and inflammatory response and investigating the protective effect of antioxidant N-acetylcysteine (NAC) against ACR in PC12 cells. Results revealed that ACR exposure led to oxidative stress characterized by significant increase in reactive oxygen species (ROS) and malondialdehyde (MDA) levels and glutathione (GSH) consumption. Inflammatory response was observed based on the dose-dependently increased levels of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6). NAC attenuated ACR-induced enhancement of MDA and ROS levels and TNF-α generation. In addition, ACR activated nuclear transcription factor E2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB) signaling pathways. Knockdown of Nrf2 by siRNA significantly blocked the increased NF-κB p65 protein expression in ACR-treated PC12 cells. Down-regulation of NF-κB by specific inhibitor BAY11-7082 similarly reduced ACR-induced increase in Nrf2 protein expression. NAC treatment increased Nrf2 expression and suppressed NF-κB p65 expression to ameliorate oxidative stress and inflammatory response caused by ACR. Further results showed that mitogen-activated protein kinases (MAPKs) pathway was activated prior to the activation of Nrf2 and NF-κB pathways. Inhibition of MAPKs blocked Nrf2 and NF-κB pathways. Collectively, ACR activated Nrf2 and NF-κB pathways which were regulated by MAPKs. A crosstalk between Nrf2 and NF-κB pathways existed in ACR-induced cell damage. NAC protected against oxidative damage and inflammatory response induced by ACR by activating Nrf2 and inhibiting NF-κB pathways in PC12 cells.

Synergism of ursolic acid and cisplatin promotes apoptosis and enhances growth inhibition of cervical cancer cells via suppressing NF-κB p65.

ObjectiveThis study was designed to investigate the effect of combination of ursolic acid (UA) with cisplatin (DDP) on cervical cancer cell proliferation and apoptosis.MethodsThe mRNA and protein expressions of nuclear factor-kappa B (NF-κB) p65 in cervical cancer cells were examined using RT-PCR and western blot. MTT and colony formation assays were performed to examine the DDP toxicity and the proliferation ability of cervical cancer cells. Cell morphology was observed by means of Hoechst33258 and transmission electron microscopy (TEM). The apoptosis rate and cell cycle were assessed through flow cytometry assay. Western blot was used to detect the expression of apoptosis-related molecules.ResultsThe mRNA and protein expressions of NF-κB p65 in cervical cancer cells were significantly higher than that in cervical epithelial cells. The combined treatment of UA and DDP inhibited cervical cancer cell growth and promoted apoptosis more effectively than DDP treatment or UA treatment alone (P < 0.05). Compared with the DDP group and UA group, the expressions of Bcl-2 and NF-κB p65 in DDP +UA group were decreased, while the expressions of Bax, Caspase-3 and PARP cleavage were observably increased. The expression of nuclear NF-κB p65 significantly reduced in UA group and DDP +UA group. si-p65 group displayed a decrease of cell proliferation ability and led to a significant reduction in the number of SiHa cell colony formation.ConclusionThe combination of UA with DDP could more effectively inhibit SiHa cells proliferation and facilitate cell apoptosis through suppressing NF-κB p65.

Oral administration of curcumin and salsalate attenuates high fat diet‐induced up‐regulation of pro‐inflammatory colonic cytokines and suppresses Akt/NFκB signaling in azoxymethane‐treated mice

BackgroundObesity, a robust risk factor for colorectal cancer (CRC), is known to elevate the concentrations of pro‐inflammatory cytokines in the murine colon. Also, signaling through the Akt pathway, which is known to be activated by pro‐inflammatory cytokines, is thought to play a role in colorectal carcinogenesis, in part by enhancing NFκB signaling. Further, we have previously demonstrated that high fat diets (HFD) and excess adiposity each alter the expression of the regulators of colonic Akt signaling in a pattern suggestive of Akt activation.ObjectiveWe sought to determine whether the combination of a pharmacologic agent and a dietary component that each possesses anti‐inflammatory properties might suppress obesity‐induced elevations in colonic cytokines and Akt/NFκB signaling, with the ultimate intent of mitigating the cancer‐promoting effect of obesity.MethodsCurcumin (CUR), a natural polyphenol in turmeric, and salsalate (SAL) a non‐steroidal anti‐inflammatory drug (NSAID) that lacks the gastrointestinal toxicity of other NSAIDs, were tested alone and in combination in the azoxymethane (AOM) model of colonic carcinogenesis in 110 A/J mice, randomized to five groups including a control group receiving a low‐fat diet. AOM (7 mg/kg body weight, 4 weekly injections) in combination with a HFD that contained 60% kcals as fat was used induce a pro‐tumorigenic milieu in the colons of mice.ResultsThe results showed that HFD‐mice had 30.4% greater fat mass and a lower lean mass than did low‐fat diet (10% kcal fat, LFD, p&lt;0.005)‐mice. In the colonic mucosa of the obese mice addition of CUR and SAL (0.2% and 0.15% w/w, respectively) to the diet significantly diminished concentrations of IL‐1β and IL‐6 (p&lt;0.015). Moreover, CUR/SAL co‐treatments also profoundly suppressed phosphorylation of Akt (p&lt;0.044) and concurrently suppressed NF‐κB p65 signaling (p&lt;0.042).ConclusionsOur results demonstrate, for the first time, that co‐administration of CUR and SAL in very low, well‐tolerated, concentrations attenuates inflammatory cytokine levels, Akt activation, and NFkB signaling in the colons of AOM/HFD mice, providing a scientific rationale for using this combination as a chemopreventive regimen to mitigate the risk of obesity‐associated colon cancer.Support or Funding InformationTufts Collaborates Grant; United States Department of Agriculture, Cooperative Agreements #58‐1950‐0‐014 and #58‐1950‐4‐003

Morin impedes Yap nuclear translocation and fosters apoptosis through suppression of Wnt/β-catenin and NF-κB signaling in Mst1 overexpressed HepG2 cells

Recent clinical and experimental evidences strongly acclaim Yes-associated protein (Yap), a key oncogenic driver in liver carcinogenesis, as a therapeutic target. Of the known multiple schemes to inhibit Yap activity, activation of Mammalian Sterile 20-like Kinase 1 (Mst1), an upstream regulator of Yap, appears to be a promising one. In this study, we hypothesize that morin, a bioflavonoid, mediates its anti-cancer effect through the activation of Mst1/hippo signaling in liver cancer cells. To test this hypothesis, both full length Mst1 (F-Mst1) and kinase active N-terminal Mst1 (N-Mst1)-overexpressed HepG2 cells were used. Exposure of F-Mst1 overexpressed HepG2 cells to morin activated Mst1 by caspase-3 cleavage and thereby inhibited Yap nuclear translocation and fostered apoptosis. Morin suppressed NF-κB p65 and Wnt/β-catenin signaling through Mst1 activation via cleavage and phosphorylation, leading to cell death. Annexin-V/PI staining further confirmed the induction of apoptosis in morin treated F-Mst1 overexpressed cells. The present study shows that morin targets cell survival molecules such as NF-κB p65 and β-catenin through activation of hippo signaling. Therefore, morin could be considered as a potential anti-cancer agent against liver cancer.

Plumbagin protects against hydrogen peroxide-induced neurotoxicity by modulating NF-κB and Nrf-2.

IntroductionRedox signaling initiates pathogenesis of neuronal degeneration. Plumbagin is a potential antioxidant with anti-inflammatory, anti-cancer and radio sensitizing properties. In the present study, we aimed to determine the protective role of plumbagin against H2O2-induced neurotoxicity in PC12 cells by determining nuclear factor κB (NF-κB) and nuclear factor E2-related factor 2 (Nrf-2) pathways.Material and methodsWe analyzed oxidative stress by determining reactive oxygen species (ROS) and nitrite levels, and antioxidant enzyme activities. Nrf-2 and NF-κB p65 nuclear localization was determined through immunofluorescence. Further, nuclear levels of p-Nrf-2 and downstream expression of NAD(P)H quinone dehydrogenase 1 (NQO1), heme oxygenase-1 (HO-1) and glutathione-s-transferase (GST) were determined by western blot. Anti-inflammatory activity was analyzed by evaluating NF-κB p65, cyclooxygenase-2 (COX-2) and interleukin (IL-6, IL-8, and MCP-1) expression.ResultsThe results showed that plumbagin increased (p < 0.01) the cell viability against H2O2-induced cell death in PC12 cells. Plumbagin effectively ameliorated H2O2-induced oxidative stress through reducing oxidative stress (p < 0.01) and activating p-Nrf-2 levels. Further, plumbagin up-regulated antioxidant enzyme activities (p < 0.01) against H2O2-induced oxidative stress. Plumbagin showed anti-inflammatory effect by suppressing NF-κB p65 activation and down-regulating NF-κB p65 and COX-2 expression. In addition, plumbagin modulated (p < 0.01) inflammatory cytokine expression against H2O2-induced neurotoxic effects.ConclusionsTogether, our results show that plumbagin modulated NF-κB and Nrf-2 signaling. Thus, plumbagin might be an effective compound in preventing H2O2-induced neurotoxicity and its associated inflammatory responses.

Vaccinium bracteatum Thunb. Exerts Anti-Inflammatory Activity by Inhibiting NF-κB Activation in BV-2 Microglial Cells.

This study was designed to evaluate the pharmacological effects of Vaccinium bracteatum Thunb. methanol extract (VBME) on microglial activation and to identify the underlying mechanisms of action of these effects. The anti-inflammatory properties of VBME were studied using lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. We measured the production of nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase (COX)-2, prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) as inflammatory parameters. We also examined the effect of VBME on intracellular reactive oxygen species (ROS) production and the activity of nuclear factor-kappa B p65 (NF-κB p65). VBME significantly inhibited LPS-induced production of NO and PGE2 and LPS-mediated upregulation of iNOS and COX-2 expression in a dose-dependent manner; importantly, VBME was not cytotoxic. VBME also significantly reduced the generation of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6. In addition, VBME significantly dampened intracellular ROS production and suppressed NF-κB p65 translocation by blocking IκB-α phosphorylation and degradation in LPS-stimulated BV2 cells. Our findings indicate that VBME inhibits the production of inflammatory mediators in BV-2 microglial cells by suppressing NF-κB signaling. Thus, VBME may be useful in the treatment of neurodegenerative diseases due to its ability to inhibit inflammatory mediator production in activated BV-2 microglial cells.

Thiamet G mediates neuroprotection in experimental stroke by modulating microglia/macrophage polarization and inhibiting NF-κB p65 signaling

Inflammatory responses are accountable for secondary injury induced by acute ischemic stroke (AIS). Previous studies indicated that O-GlcNAc modification (O-GlcNAcylation) is involved in the pathology of AIS, and increase of O-GlcNAcylation by glucosamine attenuated the brain damage after ischemia/reperfusion. Inhibition of β-N-acetylglucosaminidase (OGA) with thiamet G (TMG) is an alternative option for accumulating O-GlcNAcylated proteins. In this study, we investigate the neuroprotective effect of TMG in a mouse model of experimental stroke. Our results indicate that TMG administration either before or after middle cerebral artery occlusion (MCAO) surgery dramatically reduced infarct volume compared with that in untreated controls. TMG treatment ameliorated the neurological deficits and improved clinical outcomes in neurobehavioral tests by modulating the expression of pro-inflammatory and anti-inflammatory cytokines. Additionally, TMG administration reduced the number of Iba1+ cells in MCAO mice, decreased expression of the M1 markers, and increased expression of the M2 markers in vivo. In vitro, M1 polarization of BV2 cells was inhibited by TMG treatment. Moreover, TMG decreased the expression of iNOS and COX2 mainly by suppressing NF-κB p65 signaling. These results suggest that TMG exerts a neuroprotective effect and could be useful as an anti-inflammatory agent for ischemic stroke therapy.

Potential Use of Thioalkylated Mannose-Modified Dendrimer (G3)/α-Cyclodextrin Conjugate as an NF-κB siRNA Carrier for the Treatment of Fulminant Hepatitis.

NF-κB and its associated pathways are complicatedly concerned about hepatic homeostasis. Discriminating inhibition of NF-κB signaling has been expected to treat various liver diseases including fulminant hepatitis. To clarify the potential use of thioalkylated mannose-appended dendrimer (generation 3; G3) conjugates with α-cyclodextrin with average degree of substitution of mannose (DSM4) (Man-S-α-CDE (G3, DSM4)) as a novel antigen presenting cell (APC)-specific siRNA carrier, we evaluated the RNAi effect of NF-κB p65 siRNA (sip65) complex with Man-S-α-CDE (G3, DSM4) both in vitro and in vivo. Man-S-α-CDE (G3, DSM4)/sip65 complex significantly suppressed NF-κB p65 mRNA expression and nitric oxide (NO) production from lipopolysaccharide (LPS)-stimulated NR8383 cells, a rat alveolar macrophage cell line, by adequate physicochemical properties and mannose receptor-mediated cellular uptake. Intravenous injection of Man-S-α-CDE (G3, DSM4)/sip65 complex extended the survival rate of LPS-induced fulminant hepatitis model mice. In addition, intravenous administration of Man-S-α-CDE (G3, DSM4)/sip65 complex had the potential to induce the in vivo RNAi effect by significant suppression of mRNA expression of NF-κB p65 and inflammatory cytokines in the liver of fulminant hepatitis model mice induced by LPS/d-galactosamine (d-Gal) without any significant side effects. Also, the serum levels of enzymes were significantly attenuated by injection of Man-S-α-CDE (G3, DSM4)/sip65 complex in fulminant hepatitis model mice. Collectively, these results suggest that Man-S-α-CDE (G3, DSM4) has the potential as a novel APC-selective sip65 carrier for the treatment of LPS/d-Gal-induced fulminant hepatitis in mice.