NF-κB Nuclear Translocation Research Articles

Anti-Neuroinflammatory and Neuroprotective Effect of Intermedin B Isolated from the Curcuma longa L. via NF-κB and ROS Inhibition in BV2 Microglia and HT22 Hippocampal Cells.

Compounds derived from Curcuma longa L. (C. longa) have been extensively studied and reported to be effective and safe for the prevention and treatment of various diseases, but most research has been focused on curcuminoids derived from C. longa. As neurodegenerative diseases are associated with oxidation and inflammation, the present study aimed to isolate and identify active compounds other than curcuminoids from C. longa to develop substances to treat these diseases. Seventeen known compounds, including curcuminoids, were chromatographically isolated from the methanol extracts of C. longa, and their chemical structures were identified using 1D and 2D NMR spectroscopy. Among the isolated compounds, intermedin B exhibited the best antioxidant effect in the hippocampus and anti-inflammatory effect in microglia. Furthermore, intermedin B was confirmed to inhibit the nuclear translocation of NF-κB p-65 and IκBα, exerting anti-inflammatory effects and inhibiting the generation of reactive oxygen species, exerting neuroprotective effects. These results highlight the research value of active components other than curcuminoids in C. longa-derived compounds and suggest that intermedin B may be a promising candidate for the prevention of neurodegenerative diseases.

Taurochenodeoxycholic acid reduces astrocytic neuroinflammation and alleviates experimental autoimmune encephalomyelitis in mice

ObjectiveMultiple sclerosis (MS) is an immune regulatory disease that affects the central nervous system (CNS). The main pathological features include demyelination and neurodegeneration, and the pathogenesis is associated with astrocytic neuroinflammation. Taurochenodeoxycholic acid (TCDCA) is one of the conjugated bile acids in animal bile, and it is not clear whether TCDCA could improve MS by inhibiting the activation of astrocytes. This study was aimed to evaluate the effects of TCDCA on experimental autoimmune encephalomyelitis (EAE)—a classical animal model of MS, and to probe its mechanism from the aspect of suppressing astrocytic neuroinflammation. It is expected to prompt the potential application of TCDCA for the treatment of MS. ResultsTCDCA effectively alleviated the progression of EAE and improved the impaired neurobehavior in mice. It mitigated the hyperactivation of astrocytes and down-regulated the mRNA expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 in the brain cortex. In the C6 astrocytic cell line induced by lipopolysaccharide (LPS), TCDCA treatment dose-dependently decreased the production of NO and the protein expression of iNOS and glial fibrillary acidic protein (GFAP). TCDCA consistently inhibited the mRNA expressions of COX2, iNOS and other inflammatory mediators. Furthermore, TCDCA decreased the protein expression of phosphorylated serine/threonine kinase (AKT), inhibitor of NFκB α (IκBα) and nuclear factor κB (NFκB). And TCDCA also inhibited the nuclear translocation of NFκB. Conversely, as an inhibitor of the G-protein coupled bile acid receptor Gpbar1 (TGR5), triamterene eliminated the effects of TCDCA in LPS-stimulated C6 cells. ConclusionTCDCA improves the progress of EAE by inhibiting the astrocytic neuroinflammation, which might be exerted by the regulation of TGR5 mediated AKT/NFκB signaling pathway. These findings may prompt the potential application of TCDCA for MS therapy by suppressing astrocyte inflammation.

Silica nanoparticles promoted pro-inflammatory macrophage and foam cell transformation via ROS/PPARγ/NF-κB signaling

Experimental evidence has pointed out silica nanoparticles (SiNPs) possessing a proatherogenic capability. However, the interplay between SiNPs and macrophages in the pathogenesis of atherosclerosis was poorly understood. Here, we demonstrated SiNPs could promote macrophage adhesion to endothelial cells, accompanied by elevated Vcam1 and Mcp1. Upon SiNPs stimuli, macrophages manifested enhanced phagocytic activity and a pro-inflammatory phenotype, as reflected by the transcriptional determination of M1/M2-related biomarkers. In particular, our data certified the increased macrophage M1 subset facilitated more lipid accumulation and resultant foam cell transformation in comparison to the M2 phenotype. More importantly, the mechanistic investigations revealed ROS-mediated PPARγ/NF-κB signaling was a key contributor to the above phenomena. That was, SiNPs caused ROS accumulation in macrophages, resulting in the deactivation of PPARγ, nuclear translocation of NF-κB, ultimately contributing to macrophage phenotype shift toward M1 and foam cell transformation. Collectively, we first revealed SiNPs facilitated pro-inflammatory macrophage and foam cell transformation via ROS/PPARγ/NF-κB signaling. These data would provide new insight into the atherogenic property of SiNPs in a macrophage model.

Saturated fatty acid-enriched small extracellular vesicles mediate a crosstalk inducing liver inflammation and hepatocyte insulin resistance

Background & AimsLipotoxicity triggers non-alcoholic fatty liver disease (NAFLD) progression owing to the accumulation of toxic lipids in hepatocytes including saturated fatty acids (SFAs), which activate pro-inflammatory pathways. We investigated the impact of hepatocyte- or circulating-derived small extracellular vesicles (sEV) secreted under NAFLD conditions on liver inflammation and hepatocyte insulin signalling. MethodssEV released by primary mouse hepatocytes, characterised and analysed by lipidomics, were added to mouse macrophages/Kupffer cells (KC) to monitor internalisation and inflammatory responses. Insulin signalling was analysed in hepatocytes exposed to conditioned media from sEV-loaded macrophages/KC. Mice were i.v. injected sEV to study liver inflammation and insulin signalling. Circulating sEV from mice and humans with NAFLD were used to evaluate macrophage–hepatocyte crosstalk. ResultsNumbers of sEV released by hepatocytes increased under NAFLD conditions. Lipotoxic sEV were internalised by macrophages through the endosomal pathway and induced pro-inflammatory responses that were ameliorated by pharmacological inhibition or deletion of Toll-like receptor-4 (TLR4). Hepatocyte insulin signalling was impaired upon treatment with conditioned media from macrophages/KC loaded with lipotoxic sEV. Both hepatocyte-released lipotoxic sEV and the recipient macrophages/KC were enriched in palmitic (C16:0) and stearic (C18:0) SFAs, well-known TLR4 activators. Upon injection, lipotoxic sEV rapidly reached KC, triggering a pro-inflammatory response in the liver monitored by Jun N-terminal kinase (JNK) phosphorylation, NF-κB nuclear translocation, pro-inflammatory cytokine expression, and infiltration of immune cells into the liver parenchyma. sEV-mediated liver inflammation was attenuated by pharmacological inhibition or deletion of TLR4 in myeloid cells. Macrophage inflammation and subsequent hepatocyte insulin resistance were also induced by circulating sEV from mice and humans with NAFLD. ConclusionsWe identified hepatocyte-derived sEV as SFA transporters targeting macrophages/KC and activating a TLR4-mediated pro-inflammatory response enough to induce hepatocyte insulin resistance. Impact and ImplicationsSmall extracellular vesicles (sEV) released by the hepatocytes under non-alcoholic fatty liver disease (NAFLD) conditions cause liver inflammation and insulin resistance in hepatocytes via paracrine hepatocyte–macrophage–hepatocyte crosstalk. We identified sEV as transporters of saturated fatty acids (SFAs) and potent lipotoxic inducers of liver inflammation. TLR4 deficiency or its pharmacological inhibition ameliorated liver inflammation induced by hepatocyte-derived lipotoxic sEV. Evidence of this macrophage–hepatocyte interactome was also found in patients with NAFLD, pointing to the relevance of sEV in SFA-mediated lipotoxicity in NAFLD.

Abstract 1482: Critical role of OGT-mediated novel NF-κB o-glcNAcylation in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) has one of the highest mortalities of all malignancies, with a mere 5-year survival of ~10%. However, the current first-line treatments have poor patient outcomes, highlighting the urgent need for innovative therapeutics. The nuclear factor κB (NF-κB) is a crucial transcription factor frequently activated constitutively in PDAC. It mediates the transcription of oncogenic and inflammatory genes that facilitate multiple PDAC phenotypes. Thus, a better understanding of the mechanistic underpinnings of NF-κB activation holds substantial promise in PDAC diagnosis and new therapeutics. The purpose of this study is to identify novel regulation of NF-κB, with the aim of providing new diagnostic and therapeutic strategies for PDAC. Here, we report protein O-GlcNAc transferase (OGT) - mediated NF-κB activation through novel serine O-GlcNAcylation of its p65 subunit. We show that overexpression of serine-to-alanine (S-A) mutant at the O-GlcNAcylation site impaired NF-κB nuclear translocation and transcriptional activity in PDAC cells. Moreover, these S-A p65 mutants downregulate NF-κB-target genes important to major cancer hallmarks and inhibit cellular proliferation, migration, and anchorage-independent growth of PDAC cells compared to WT-p65. Interestingly, this modification happens downstream of the inhibitor of NF-κB (IκBα) degradation. Collectively, we have identified OGT-mediated serine O-GlcNAcylation of NF-κB and determined its mechanistic and cellular function in driving PDAC phenotypes. Thus, our study holds great significance as it uncovers a brand-new strategy for PDAC diagnosis and effective therapeutics development. Citation Format: Aishat Motolani, Matthew Martin, Benlian Wang, Guanglong Jiang, Yunlong Liu, Tao Lu. Critical role of OGT-mediated novel NF-κB o-glcNAcylation in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1482.

Anti-inflammatory steroids from the stems of Solanum nigrum L.

Sixteen previously undescribed steroidal sapogenins along with two known ones were isolated from the stems of Solanum nigrum L. (Solanaceae). Their structures were identified using a combination of 1D and 2D NMR, HR-ESI-MS spectroscopy, the Mosher method, and X-ray diffraction analysis. Compounds 1–8 have an unusual F ring and 9–12 have a derived A ring, both of which are rare skeletons found in natural products. The biological evaluation showed that the isolated steroids exhibited inhibition of nitric oxide in the LPS-induced RAW 264.7 macrophages with IC50 values from 7.4 to 41.3 μM. Further studies revealed that compounds 6 and 10 exhibited anti-inflammatory activity by blocking the nuclear translocation of NF-κB, and down-regulating the expression of iNOS, COX-2, IL-1β, and IL-6 in a concentration-dependent manner. These results suggest that the stems of S. nigrum may serve as a source of anti-inflammatory agents for use in healthy or medicinal products.

Synthesis of Lathyrol PROTACs and Evaluation of Their Anti-Inflammatory Activities.

Lathyrol is a core scaffold structure of many lathyrane diterpenoids with potent anti-inflammatory activity isolated from Euphorbia lathyrism. It was chosen as a framework to design and synthesize a series of proteolysis targeting chimeras. A total of 15 derivatives were obtained. Compound 13 exhibited inhibitory activity on LPS-induced NO production in RAW264.7 cells (IC50 = 5.30 ± 1.23 μM) with low cytotoxicity. Furthermore, compound 13 significantly degraded v-maf musculoaponeurotic fibrosarcoma oncogene homologue F (MAFF) protein, a target of lathyrane diterpenoid, concentration- and time-dependently. The mechanism of action of 13 is related to activating the Keap1/Nrf2 pathway. It also inhibited the expression of NF-κB, blocked the nuclear translocation of NF-κB, and activated autophagy in LPS-induced RAW264.7 cells. Based on the results obtained, compound 13 might be a promising anti-inflammatory agent.

Anti-proliferative and anti-inflammatory eudesmanolides from the flowers of Sphagneticola trilobata (L.) Pruski

Twenty-six eudesmanolides including six undescribed compounds were isolated from the flowers of Sphagneticola trilobata (L.) Pruski. Their structures were elucidated based on the interpretation of spectroscopic techniques, NMR calculation, and DP4+ analysis. The stereochemistry of (1S,4S,5R,6S,7R,8S,9R,10S,11S)-1,4,8- trihydroxy-6-isobutyryloxy-11-methyleudesman-9,12-olide (1) was demonstrated by single crystal X-ray diffraction. All eudesmanolides were evaluated for their anti-proliferative activities against four human tumor cell lines (HepG2, HeLa, SGC-7901, and MCF-7). 1α,4β-Dihydroxy-6α-methacryloxy-8β-isobutyryloxyeudesman-9,12-olide (3) and wedelolide B (8) showed pronounced cytotoxic effects against AGS cell line with IC50 values of 1.31 and 0.89 μM, respectively. Their anti-proliferative activities against AGS cells were exerted through a dose-dependent apoptosis pathway, as verified by cell and nucleus morphological assessment, clone formation assay, and Western blot analysis. Furthermore, 1α,4β,8β-trihydroxy-6β-methacryloxyeudesman-9,12-olide (2) and 1α,4β,9β-trihydroxy-6α-isobutyryloxy- 11α-13-methacryloxyprostatolide (7) performed significant inhibitory effects on lipopolysaccharide-stimulated nitric oxide production in RAW 264.7 macrophages with IC50 values of 11.82 and 11.05 μM, respectively. Moreover, compounds 2 and 7 could block the nuclear translocation of NF-κB and reduce the expression of iNOS, COX-2, IL-1β, and IL-6 to exert anti-inflammatory effects. This study provides evidence for the utilization of the eudesmanolides from S. trilobata as lead compounds for further research due to their cytotoxic potential.

The Protective Effect of 11-Keto-β-Boswellic Acid against Diabetic Cardiomyopathy in Rats Entails Activation of AMPK

This study examined the protective effect of 11-keto-β-boswellic acid (AKBA) against streptozotocin (STZ)-induced diabetic cardiomyopathy (DC) in rats and examined the possible mechanisms of action. Male rats were divided into 5 groups (n = 8/each): (1) control, AKBA (10 mg/kg, orally), STZ (65 mg/kg, i.p.), STZ + AKBA (10 mg/kg, orally), and STZ + AKBA + compound C (CC/an AMPK inhibitor, 0.2 mg/kg, i.p.). AKBA improved the structure and the systolic and diastolic functions of the left ventricles (LVs) of STZ rats. It also attenuated the increase in plasma glucose, plasma insulin, and serum and hepatic levels of triglycerides (TGs), cholesterol (CHOL), and free fatty acids (FFAs) in these diabetic rats. AKBA stimulated the ventricular activities of phosphofructokinase (PFK), pyruvate dehydrogenase (PDH), and acetyl CoA carboxylase (ACC); increased levels of malonyl CoA; and reduced levels of carnitine palmitoyltransferase I (CPT1), indicating improvement in glucose and FA oxidation. It also reduced levels of malondialdehyde (MDA); increased mitochondria efficiency and ATP production; stimulated mRNA, total, and nuclear levels of Nrf2; increased levels of glutathione (GSH), heme oxygenase (HO-1), superoxide dismutase (SOD), and catalase (CAT); but reduced the expression and nuclear translocation of NF-κB and levels of tumor-necrosis factor-α (TNF-α) and interleukin-6 (IL-6). These effects were concomitant with increased activities of AMPK in the LVs of the control and STZ-diabetic rats. Treatment with CC abolished all these protective effects of AKBA. In conclusion, AKBA protects against DC in rats, mainly by activating the AMPK-dependent control of insulin release, cardiac metabolism, and antioxidant and anti-inflammatory effects.

GEF-H1/RhoA signaling pathway mediates pro-inflammatory effects of NF-κB on CD40L-induced pulmonary endothelial cells

One of the key targets of the inflammatory response in acute lung injury (ALI) is the human pulmonary micro-vascular endothelial cells (HPMVECs). Owing to its role in the activation of endothelial cells (ECs), CD40L figures prominently in the pathogenesis of ALI. Increasing evidences have showed that CD40L mediates inflammatory effects on ECs, at least in part, by triggering NF-κB-dependent gene expression. However, the mechanisms of such signal transmission remain unknown. In this study, we found that CD40L stimulated the transactivation of NF-κB and expression of its downstream cytokines in a p38 MAPK-dependent mechanism in HPMVECs. In addition, CD40L-mediated inflammatory effects might be correlated with the activation of the IKK/IκB/NF-κB pathway and nuclear translocation of NF-κB, being accompanied by dynamic cytoskeletal changes. GEF-H1/RhoA signaling is best known for its role in regulating cytoskeletal rearrangements. An interesting finding was that CD40L induced the activation of p38 and IKK/IκB, and the subsequent transactivation of NF-κB via GEF-H1/RhoA signaling. The critical role of GEF-H1/RhoA in CD40L-induced inflammatory responses in the lung was further confirmed in GEF-H1 and RhoA knockout mouse models, both of which were established by adeno-associated virus (AAV)-mediated delivery of sgRNAs into mice with EC-specific Cas9 expression. These results taken together suggested that p38 and IKK/IκB-mediated signaling pathways, both of which lied downstream of GEF-H1/RhoA, may coordinately regulate the transactivation of NF-κB in CD40L-activated HPMVECs. These findings may help to determine key pharmacological targets of intervention for CD40L-activated inflammatory effects associated with ALI.

The Related Mechanisms Predicted through Network-Based Pharmacological Analysis and the Anti-Inflammatory Effects of Fraxinus rhynchophylla Hance Bark on Contact Dermatitis in Mice.

Fraxinus rhynchophylla Hance bark has been used to treat patients with inflammatory or purulent skin diseases in China, Japan, and Korea. This study was undertaken to determine the mechanism responsible for the effects of F. rhynchophylla and whether it has a therapeutic effect in mice with contact dermatitis (CD). In this study, the active compounds in F. rhynchophylla, their targets, and target gene information for inflammatory dermatosis were investigated using network-based pharmacological analysis. Docking analysis was conducted using AutoDock Vina. In addition, the therapeutic effect of an ethanolic extract of F. rhynchophylla (EEFR) on skin lesions and its inhibitory effects on histopathological abnormalities, inflammatory cytokines, and chemokines were evaluated. Finally, its inhibitory effects on the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signalling pathways were observed in RAW 264.7 cells. In our results, seven active compounds were identified in F. rhynchophylla, and six were associated with seven genes associated with inflammatory dermatosis and exhibited a strong binding affinity (<-6 kcal/mol) to prostaglandin G/H synthase 2 (PTGS2). In a murine 1-fluoro-2,4-dinitrobenzene (DNFB) model, topical EEFR ameliorated the surface symptoms of CD and histopathological abnormalities. EEFR also reduced the levels of tumour necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-6, and monocyte chemotactic protein (MCP)-1 in inflamed tissues and inhibited PTGS2, the nuclear translocation of NF-κB (p65), and the activation of c-Jun N-terminal kinases (JNK) in RAW 264.7 cells. In conclusion, the bark of F. rhynchophylla has potential use as a therapeutic or cosmetic agent, and the mechanism responsible for its effects involves the suppression of inflammatory mediators, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor (IκB)-α degradation, the nuclear translocation of NF-κB, and JNK phosphorylation.

Maslinic acid attenuates UVB-induced oxidative damage in HFF-1 cells.

Oxidative damage is one of the major mechanisms of ultraviolet B (UVB)-induced damage to the skin. Maslinic acid (MA) is a natural compound of pentacyclic triterpene acids. It has been proved to have anti-inflammatory and antioxidant properties. This study aimed to explore the effects of MA on oxidative damage in human foreskin fibroblast cells (HFF-1) and the potential molecular mechanisms. A specific dose of UVB radiation was used to induce oxidative damage in HFF-1. Based on this, we performed measurements of cell proliferation, reactive oxygen species (ROS) levels, antioxidant enzyme activity, inflammation-related mediators, and NF-κB nuclear localization with or without the addition of MA. MA significantly promoted cell proliferation viability at 10 and 20 μM. The addition of MA 24 h before UVB irradiation was more effective at enhancing cell proliferation and also produced lower ROS levels compared to co-cultured fibroblasts and MA for 24 h after irradiation. However, there was no statistically significant difference between groups at concentrations of 10 and 20 μM. The pretreatment group with MA had elevated superoxide dismutase and catalase activities, decreased IL-6 generation, and lowered mRNA levels of IL-6, TNF-α and MMP3 in comparison with the UVB-irradiated group without additional MA. Meanwhile, the nuclear translocation of NF-κB and the degradation of IκB were inhibited by MA pretreatment. Taken together, these findings suggest that MA may alleviate UVB-induced oxidative damage in HFF-1 by inhibiting the nuclear translocation of NF-κB.

Anti-inflammatory phenolics and phenylpropanoids from Praxelis clematidea

Praxelis clematidea (Asteraceae) is a noxious invasive exotic plant in southern China, and it has caused great damage to ecological conditions and serious financial losses. In this study, four new phenolics (1, 2, 7, 8), and two new phenylpropanoids (3, 4), along with seventeen known compounds were separated and purified from the whole plant of P. clematidea. Their chemical structures were determined by extensive spectroscopic analysis methods. Additionally, the potential inhibitory activities on nitric oxide (NO) production and NF-κB nuclear translocation in LPS-triggered RAW 264.7 macrophages of the isolated compounds were evaluated. Notably, compounds 2, 7, and 8 showed significant inhibitory activities on NO production, and also inhibited the expression of iNOS and COX-2. Furthermore, compounds 2, 7, and 8 effectively suppressed the NF-κB nuclear translocation. These findings suggest that P. clematidea has the potential to be developed and promoted as a treatment for inflammation-related diseases.

Pre-conditioning of gingival epithelial cells with sub-apoptotic concentrations of curcumin prevents pro-inflammatory cytokine release.

Plaque-induced gingival inflammation (gingivitis) is ubiquitous in humans. The epithelial barrier reacts to the presence of oral bacteria and induces inflammatory cascades. The objective of this study was to investigate the mechanism by which the small molecule micronutrient curcumin could decrease inflammatory response in vitro to oral bacterium heat-killed Fusobacterium nucleatum as curcumin could be a useful compound for combatting gingivitis already consumed by humans. H400 oral epithelial cell line was pre-conditioned with curcumin and the production of cytokines was measured by enzyme-linked immunosorbent assay (ELISA) and translocation of transcription factors was used to monitor inflammatory responses. Haem oxygenase (HO-1) expression and molecules that HO-1 releases were evaluated for their potential to reduce the quantity of cytokine production. Immunofluorescence microscopy and Western blotting were used to evaluate changes in transcription factor and enzyme location. Pre-conditioning of H400 cells with a sub-apoptotic concentration of curcumin (20 μM) attenuated secretion of Granulocyte-Macrophage - Colony-Stimulating Factor (GM-CSF) and reduced NFkB nuclear translocation. This pre-conditioning caused an increase in nuclear Nrf2; an initial drop (at 8h) followed by an adaptive increase (at 24 h) in glutathione; and an increase in haem oxygenase (HO-1) expression. Inhibition of HO-1 by SnPPIX prevented the curcumin-induced attenuation of GM-CSF production. HO-1 catalyses the breakdown of haem to carbon monoxide, free iron and biliverdin: the HO-1/CO anti-inflammatory pathway. Elevations in carbon monoxide, achieved using carbon monoxide releasing molecule-2 (CORM2) treatment alone abrogated F. nucleatum-induced cytokine production. Biliverdin is converted to bilirubin by biliverdin reductase (BVR). This pleiotropic protein was found to increase in cell membrane expression upon curcumin treatment. Curcumin decreased inflammatory cytokine production induced by Fusobacterium nucleatum in H400 oral epithelial cells. The mechanism of action appears to be driven by the increase of haem oxygenase and the production of carbon monoxide.

Cephalic electroacupuncture restores learning and memory in rats with induced ischemic stroke via inhibition of NF-κB nuclear translocation.

Inflammatory responses in the brain contribute to cognitive deficits. Nuclear factor-κB (NF-κB), a critical transcription factor in inflammatory responses, is activated in post-stroke cognitive deficit. Baihui (DU20) and Shenting (DU24) acupoints, the main acupoints of Du Meridian, are widely used to improve cognitive deficits in Chinese patients with stroke. It has been reported that post-stroke cognitive deficits can be treated by electroacupuncture (EA) but the underlying mechanisms of these effects are unclear. Using the rat middle cerebral artery occlusion cerebral ischemia-reperfusion injury model, we found that EA at these 2 acupoints improved neurological function, decreased cerebral infarct lesion volumes, and ameliorated the inflammatory response in the hippocampal CA1 region. The treatment also ameliorated memory and learning deficits by inhibiting the NF-κB signaling pathway in the ischemic hippocampal CA 1 region. This coincided with downregulation of interleukin-1β, interleukin-6, CD45, and tumor necrosis factor-α. We conclude that EA at these 2 acupoints ameliorates memory and learning deficits following experimental cerebral infarction by inhibiting NF-κB-mediated inflammatory injury in the hippocampal CA1 region.

Rapamycin suppresses inflammation and increases the interaction between p65 and IκBα in rapamycin-induced fatty livers.

Rapamycin treatment significantly increases lifespan and ameliorates several aging-related diseases in mice, making it a potential anti-aging drug. However, there are several obvious side effects of rapamycin, which may limit the broad applications of this drug. Lipid metabolism disorders such as fatty liver and hyperlipidemia are some of those unwanted side effects. Fatty liver is characterized as ectopic lipid accumulation in livers, which is usually accompanied by increased inflammation levels. Rapamycin is also a well-known anti-inflammation chemical. How rapamycin affects the inflammation level in rapamycin-induced fatty liver remains poorly understood. Here, we show that eight-day rapamycin treatment induced fatty liver and increased liver free fatty acid levels in mice, while the expression levels of inflammatory markers are even lower than those in the control mice. Mechanistically, the upstream of the pro-inflammatory pathway was activated in rapamycin-induced fatty livers, however, there is no increased NFκB nuclear translocation probably because the interaction between p65 and IκBα was enhanced by rapamycin treatment. The lipolysis pathway in the liver is also suppressed by rapamycin. Liver cirrhosis is an adverse consequence of fatty liver, while prolonged rapamycin treatment did not increase liver cirrhosis markers. Our results indicate that although fatty livers are induced by rapamycin, the fatty livers are not accompanied by increased inflammation levels, implying that rapamycin-induced fatty livers might not be as harmful as other types of fatty livers, such as high-fat diet and alcohol-induced fatty livers.

Sodium selenite inhibits proliferation of lung cancer cells by inhibiting NF-κB nuclear translocation and down-regulating PDK1 expression which is a key enzyme in energy metabolism expression

As a trace element that maintains homeostasis in human body, selenium has significant anti-tumor activity. However, its exact molecular mechanism remains to be elucidated. Sodium selenite (SSe) is the most widely-distributed inorganic selenium in nature. In this study, we selected SSe as the research object to explore its anti-tumor mechanism in lung cancer. In vitro experiment showed that SSe could inhibit the activation of NF-κB signaling pathway, knowing that NF-κB is an important intracellular nuclear transcription factor that regulates the expression of pyruvate dehydrogenase kinase 1 (PDK1), a key energy metabolism switch affecting the survival status of the whole cell.At the same time, Bay11–7082(NF-κB signaling pathway inhibitors) and SSe resulted in phosphorylation of p65 and IκBα, decreased expression of PDK1 and Bcl-2,and increased expression of Bax in lung cancer cells. Our further study demonstrated that the reduction of PDK1 activity inhibited lactate secretion, reduced mitochondrial membrane potential, caused the release of Cytochrome C (Cyto C), activated mitochondrial respiration, and promoted the apoptosis of lung cancer cells. The in vivo experiment revealed that SSe inhibited the activation of NF-κB signaling pathway, decreased the expression of PDK1, and induced lung cancer cell proliferation and apoptosis. All these findings indicated that SSe promoted lung cancer cell apoptosis by inhibiting the activation of NF-κB signaling pathway, down-regulating PDK1 and activating mitochondrial apoptosis pathway.

Inhibition of NF-κB ameliorates aberrant retinal glia activation and inflammatory responses in streptozotocin-induced diabetic rats.

To determine the anti-inflammatory effects of IMD-0354, a specific NF-κB blocker, on glial cells in rats with streptozotocin (STZ)-induced diabetic retinopathy (DR). The following four groups of rats were used: control, control + IMD-0354, STZ, and STZ + IMD-0354. After six weeks of STZ injection, diabetic rats and nondiabetic control rats received IMD-0354 (30 mg/kg) or an equal volume of 4% dimethyl sulfoxide (DMSO) in phosphate-buffered saline intraperitoneally for six consecutive weeks. The following four groups of primary rat retinal microglia and Müller cells were used: control (5 mM), control + IMD-0354, high glucose (20 mM), and high glucose + IMD-0354. The effects of IMD-0354 on nuclear factor-κB (NF-κB) activation, oxidative stress strength, expression of inflammatory cytokines and VEGF (vascular endothelial growth factor), activation of glial cells, and apoptosis of neuron cells were evaluated by immunohistochemistry, oxidative stress assays, western blot, enzyme linked immunosorbent assay (ELISA) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining respectively. Nuclear translocation of NF-κB was markedly increased in diabetic rat retina and high glucose treated glial cells. Systemic administration of IMD-0354 significantly inhibited NF-κB activation in both diabetic rat retina and high glucose treated glial cells, ameliorated oxidative injury, inflammatory responses, VEGF production and glial cell activation, and protected neurons from apoptosis. Our findings indicated that NF-κB activation is acritical step in the abnormal reactivity of glial cells in STZ-induced diabetic rats. Inhibition effect of IMD-0354 on NF-κB activation may represent a promising therapeutic strategy for DR via a variety of mechanisms, including inflammation reduction and glial cells regulation.

A novel IRAK4/PIM1 inhibitor ameliorates rheumatoid arthritis and lymphoid malignancy by blocking the TLR/MYD88-mediated NF-κB pathway.

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a pivotal enzyme in the Toll-like receptor (TLR)/MYD88 dependent signaling pathway, which is highly activated in rheumatoid arthritis tissues and activated B cell-like diffuse large B-cell lymphoma (ABC-DLBCL). Inflammatory responses followed by IRAK4 activation promote B-cell proliferation and aggressiveness of lymphoma. Moreover, proviral integration site for Moloney murine leukemia virus 1 (PIM1) functions as an anti-apoptotic kinase in propagation of ABC-DLBCL with ibrutinib resistance. We developed a dual IRAK4/PIM1 inhibitor KIC-0101 that potently suppresses the NF-κB pathway and proinflammatory cytokine induction invitro and invivo. In rheumatoid arthritis mouse models, treatment with KIC-0101 significantly ameliorated cartilage damage and inflammation. KIC-0101 inhibited the nuclear translocation of NF-κB and activation of JAK/STAT pathway in ABC-DLBCLs. In addition, KIC-0101 exhibited an anti-tumor effect on ibrutinib-resistant cells by synergistic dual suppression of TLR/MYD88-mediated NF-κB pathway and PIM1 kinase. Our results suggest that KIC-0101 is a promising drug candidate for autoimmune diseases and ibrutinib-resistant B-cell lymphomas.

Ginsenoside Re mitigates memory impairments in aged GPx-1 KO mice by inhibiting the interplay between PAFR, NFκB, and microgliosis in the hippocampus.

Ginsenoside Re (GRe) upregulates anti-aging klotho by mainly upregulating glutathione peroxidase-1 (GPx-1). However, the anti-aging mechanism of GPx-1 remains elusive. Here we investigated whether the GRe-mediated upregulation of GPx-1 modulates oxidative and proinflammatory insults. GPx-1 gene depletion altered redox homeostasis and platelet-activating factor receptor (PAFR) and nuclear factor kappa B (NFκB) expression, whereas the genetic overexpression of GPx-1 or GRe mitigated this phenomenon in aged mice. Importantly, the NFκB inhibitor pyrrolidine dithiocarbamate (PDTC) did not affect PAFR expression, while PAFR inhibition (i.e., PAFR knockout or ginkgolide B) significantly attenuated NFκB nuclear translocation, suggesting that PAFR could be an upstream molecule for NFκB activation. Iba-1-labeled microgliosis was more underlined in aged GPx-1 KO than in aged WT mice. Triple-labeling immunocytochemistry showed that PAFR and NFκB immunoreactivities were co-localized in Iba-1-positive populations in aged mice, indicating that microglia released these proteins. GRe inhibited triple-labeled immunoreactivity. The microglial inhibitor minocycline attenuated aging-related reduction in phospho-ERK. The effect of minocycline was comparable with that of GRe. GRe, ginkgolide B, PDTC, or minocycline also attenuated aging-evoked memory impairments. Therefore, GRe ameliorated aging-associated memory impairments in the absence of GPx-1 by inactivating oxidative insult, PAFR, NFkB, and microgliosis.