Inhibition Of NF-κB Signaling Pathway Research Articles

Lonicera japonica Thunb extract ameliorates lipopolysaccharide-induced acute lung injury associated with luteolin-mediated suppression of NF-κB signaling pathway

ObjectiveLonicera japonica Thunb (LJT) is a commonly used herbal soup to treat inflammation-related diseases. However, the effect of LJT on ALI is unknown. The present study was aimed at investigating the protective effects of LJT extract (LTE) and its active ingredient luteolin (Lut) on lipopolysaccharide (LPS)-stimulated ALI and investigate its potential mechanism.Materials and methodsThe effects of LTE and Lut were explored in an ALI mouse model induced by intraperitoneal injection of lipopolysaccharide (LPS). Besides, the LPS-induced inflammation model in BEAS-2B cells was used to clarify the underlying mechanisms. The ALI pathological changes in lung tissues were tested through Haematoxylin and eosin (HE) staining. The apoptosis of cells in lung tissue and the cell model in vitro was evaluated by TUNEL assays, respectively. Meanwhile, the viability of cells in vitro was evaluated by Cell Counting Kit-8 (CCK-8) assay. The levels/concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β and IL-10 in BALF were detected by enzyme-linked immunosorbent assay (ELISA). Besides, through quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting, the expression of the above-mentioned inflammatory factors and key factors in the NF-κB signaling pathway was examined. The distribution of inflammatory factors in tissue was observed through immunohistochemistry (IHC) assays .ResultsIn relative to LPS-stimulated group, the in vivo study showed that LTE and different concentrations of Lut dramatically alleviated LPS-evoked lung pathological injury and lung edema based on the changes in total protein levels and lung wet/dry (W/D) ratio in the bronchoalveolar lavage fluid (BALF) from ALI mice. LTE and different concentrations of Lut also suppressed the inflammatory response, as reflected by the variations of neutrophil accumulation and the production of proinflammatory and anti-inflammatory cytokines in the lung tissues and BALF of ALI mice. The in vitro research also demonstrated that LTE and Lut visibly facilitated cell viability and restrained the apoptosis of BEAS-2B cells stimulated by LPS. Lut hindered LPS-inducible activation of NF-κB pathway in BEAS-2B cells.ConclusionThe present study proved that LTE might suppress LPS-induced acute injury and inflammation in mice and BEAS-2B cells through the Lut-caused suppression of NF-κB signal path (Figure 1).

GL13K-modified titanium regulates osteogenic differentiation via the NF-κB pathway

The osteoimmune response plays a crucial regulatory role in the osseointegration of dental implants. Previous studies found the antimicrobial peptide coating (GL13K) could activate the immunomodulatory potential of macrophages (Raw 264.7) and promote osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). To further investigate the mechanism of interaction between immunomodulation and differentiation, a co-culture model of the representative cells (Raw 264.7 and BMSCs) was constructed to mimic the immune microenvironment. In this system, GL13K coating of titanium implant effectively inhibited the polarization of the inflammatory M1 type and promoted the polarization of the anti-inflammatory M2 type. Furthermore, the inhibited NF-κB signaling pathway and Mip-2 gene expression were found and validated by bioinformatics analysis and virus-induced gene silencing, which significantly affected the tissue repair process. It can be concluded that the GL13K coating had the potential to establish a localized immune microenvironment conducive to osteogenic differentiation through cellular interactions. Subsequent investigations would be dedicated to a thorough examination of the osseointegration effects of GL13K coating.

Diosgenin alters LPS-induced macrophage polarization by activating PPARγ/NF-κB signaling pathway

Diosgenin (DG) is a steroidal saponin derived from plants, and it exhibits anti-inflammatory properties. In this study, we employed an in vitro model of P.g.-LPS-stimulated mouse macrophage cell line RAW264.7 to investigate the anti-inflammatory effects and mechanism of DG under the condition of altered polarization of macrophages. The RAW264.7 cells were subjected to pre-treatment with DG with or without P.g.-LPS. In cultured macrophages, DG inhibited P.g.-LPS-induced pro-inflammatory M1 macrophages, and increased anti-inflammatory M2 macrophages. Notably, DG reduced the expression of phosphorylation levels of NF-κB p65 and IκB while increasing the expression of PPARγ. Further studies revealed that PPARγ inhibitor GW9662 or PPARγ siRNA reversed the inhibitory effect of DG on M1 phenotype. Collectively, the anti-inflammatory mechanism of DG is related to altering macrophage polarization by activating PPARγ and inhibiting NF-κB signaling pathways.

Amuc_1100 pretreatment alleviates acute pancreatitis in a mouse model through regulating gut microbiota and inhibiting inflammatory infiltration.

Amuc_1100 is a membrane protein from Akkermansia muciniphila, which has been found to play a role in host immunological homeostasis in the gastrointestinal tract by activating TLR2 and TLR4. In this study we investigated the effects and underlying mechanisms of Amuc_1100 on acute pancreatitis (AP) induced in mice by intraperitoneal injection of caerulein and lipopolysaccharide (LPS). The mice were treated with the protein Amuc_1100 (3 μg, i.g.) for 20 days before caerulein injection. Cecal contents of the mice were collected for 16S rRNA sequencing. We found that pretreatment with Amuc_1100 significantly alleviated AP-associated pancreatic injury, reduced serum amylase and lipase. Amuc_1100 pretreatment significantly inhibited the expression of proinflammatory cytokines (TNF-α, IL-1β, IFN-γ and IL-6) in spleen and pancreas through inhibiting NF-κB signaling pathway. Moreover, Amuc_1100 pretreatment significantly decreased the inflammatory infiltration, accompanied by the reduction of Ly6C+ macrophages and neutrophils in the spleen of AP mice. Gut microbiome analysis showed that the abundance of Bacteroidetes, Proteobacteria, Desulfobacterota and Campilobacterota was decreased, while the proportion of Firmicutes and Actinobacteriota was increased in AP mice pretreated with Amuc_1100. We further demonstrated that Amuc_1100 pretreatment restored the enrichment of tryptophan metabolism, which was mediated by intestinal flora. These results provide new evidence that Amuc_1100 lessens the severity of AP through its anti-inflammatory properties with a reduction of macrophages and neutrophil infiltration, as well as its regulation of the composition of intestinal flora and tryptophan metabolism.

TAPI-1 Exhibits Anti-tumor Efficacy in Human Esophageal Squamous Cell Carcinoma Cells via Suppression of NF-κB Signaling Pathway

BackgroundTNF-α processing inhibitor-1 (TAPI-1) is a known metalloproteinase inhibitor with potential anti-inflammatory effects. However, its anti-cancer effects on esophageal squamous cell carcinoma (ESCC) have not been uncovered.AimIn the present study, the effects of TAPI-1 on ESCC cell viability, migration, invasion, and cisplatin resistance and the underlying molecular mechanisms were investigated in TE-1 and Eca109 cells.MethodsTo this end, TE-1 and Eca109 cells were exposed to TAPI-1 for indicated time intervals. Cell viability was assessed using cell counting kit-8 assay and apoptosis was evaluated using flow cytometry assay. Migration and invasion were assessed using Transwell assays. Gene expressions were analyzed using quantitative reverse transcription polymerase chain reaction. The activation of NF-κB signaling pathway was elucidated via Western blot and chromatin immunoprecipitation assay.ResultsWe observed that higher doses (10, 20 μM) of TAPI-1 inhibited ESCC cell viability, while a lower dose (5 μM) of TAPI-1 inhibited ESCC cell migration and invasion and enhanced the chemosensitivity of ESCC cells to cisplatin. Moreover, TAPI-1 suppressed the activation of NF-κB signaling and the target genes expression in the stage of transcription initiation. Furthermore, blocking NF-κB signaling in advance could abolish all the effects of TAPI-1 on ESCC cells.ConclusionOverall, these results indicated that TAPI-1 impairs ESCC cell viability, migration, and invasion and facilitates cisplatin-induced apoptosis via suppression of NF-κB signaling pathway. TAPI-1 may serve as a potential adjuvant agent with cisplatin for ESCC therapy.

SALMONELLA INFECTION: INTERPLAY BETWEEN THE T3SSS EFFECTORS AND NF-ΚB SIGNALING PATHWAY

Salmonella is an important foodborne pathogen that can evade host immune defense by evolving unique mechanisms. Salmonella manipulate host cell various signaling pathways by delivering specific effectors into target cells to establish infection. The nuclear factor-κB (NF-κB) is an important nuclear transcription factor that regulates the host immune system in Salmonella infection. The Salmonella pathogenicity island 1 (SPI-1) and Salmonella pathogenicity island 2 (SPI-2) encode type III secretion systems (T3SSs), effectors that are associated with the NF-κB signaling pathway through regulate host inflammation response. SPI-1 effectors SipA, SopE, SopE2, and SopB all can activate NF-κB signaling pathway to facilitate Salmonella invasion and intracellular carriage. Studies have shown that T3SS1 and/or T3SS2 effectors such as GtgA, GogA and PipA contain two histidine residues and have metalloprotease activity to control Salmonella replication. These zinc metalloproteases redundantly target the NF-κB subunits p65, RelB, and c-Rel, whereas GogA and GtgA only inhibit NF-κB-dependent gene transcription. The T3SS2 effectors SseK1, SseK2, and SseK3 are death domain-containing proteins with N-linked glycosyltransferase characteristics that can inhibit NF-κB activity by inhibiting IκBα phosphorylation in TNF- α-treated 293ET cells. Among them, SseK1 and SseK3 also suppress Salmonella-induced NF-κB activity in macrophages. SseK3-mediated inhibition of the NF-B signaling pathway is not required for protein 32 containing a tripartite E3-ubiquitin ligase motif. In addition, the SPI-2 T3SS effector SpvD inhibits NF-κB activity by preventing nuclear translocation of p65 through interaction with Exportin-2, but this does not affect IκBα degradation, which ultimately leads to systemic Salmonella growth. However, other effectors SptP, AvrA, IpaJ, SspH1, GtgA, GogA, and SPI-2 encoded SseL, SpvB, SseK1, and GogB all can effectively inhibit NF-κB signaling pathway, and contribute to Salmonella intracellular replication and virulence. In this mini-review, we summarize the special mechanism how NF-κB signaling pathway is regulated by Salmonella T3SSs effectors in the persistent infection of Salmonella, which will further elucidate the pathogenesis of Salmonella.

Mesenchymal stem cell conditioned medium alleviates acute lung injury through KGF-mediated regulation of epithelial sodium channels

Acute lung injury (ALI) is a progressive inflammatory injury, and mesenchymal stem cells (MSCs) can be used to treat ALI. MSC-conditioned medium (MSC-CM) contains many cytokines, in which keratinocyte growth factor (KGF) is a soluble factor that plays a role in lung development. We aim to explore the protective effects of MSCs secreted KGF on ALI, and investigate the involvement of epithelial sodium channel (ENaC), which are important in alveolar fluid reabsorption. Both lipopolysaccharides (LPS)-induced mouse and alveolar organoid ALI models were established to confirm the potential therapeutic effect of MSCs secreted KGF. Meanwhile, the expression and regulation of ENaC were determined in alveolar type II epithelial (ATII) cells. The results demonstrated that MSC-CM and KGF could alleviate the extent of inflammation-related pulmonary edema in ALI mice, which was abrogated by a KGF neutralizing antibody. In an alveolar organoid ALI model, KGF in MSC-CM could improve the proliferation and decrease the differentiation of ATII cells. At the cellular level, the LPS-inhibited protein expression of ENaC could be reversed by KGF in MSC-CM. In addition, bioinformatics analysis and our experimental data provided the evidence that the NF-κB signaling pathway may be involved in the regulation of ENaC. Our research confirmed that the therapeutic effect of MSC-CM on edematous ALI was closely related to KGF, which may be involved in the proliferation and differentiation of ATII cells, as well as the upregulation of ENaC expression by the inhibition of NF-κB signaling pathway.

Nyctanthes arbor-tristis bioactive extract ameliorates LPS-induced inflammation through the inhibition of NF-κB signalling pathway

Ethnopharmacological relevanceNyctanthes arbor-tristis L. is a mythical plant used in traditional Indian medicinal systems for the treatment of inflammation, rheumatoid arthritis, and pain-related responses. However, its bioactive compounds and underlying mechanism of action have not been fully elucidated. Aim of the studyThis investigation aimed to study the anti-inflammatory and anti-nociceptive effects of the bioactive extract of N. arbor-tristis (NATE), both in vitro and in vivo, elucidate the possible mechanism of action, and determine its chemicals. Materials and methodsWe studied the anti-inflammatory and anti-nociceptive activities of NATE on lipopolysaccharide-stimulated RAW264.7 macrophages, paw-ear edema, and acetic acid-induced pain in rats and analysed its chemical components using Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC-ESI-MS). ResultsNATE efficiently reduced the production of various inflammatory mediators and factors, such as free radicals, lipid peroxidation, nitrous oxide (NO), reactive oxygen species (ROS), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNFα), interleukin-6 (IL-6), interleukin-1beta (IL-1β), and IL-10, as well as their corresponding mRNA expression in LPS-induced RAW264.7 cells (p < 0.001). Furthermore, NATE inhibited the activation of a key signaling pathway, nuclear factor-kappa B (NF-kB), as it caused a decrease in the degradation of inhibitor of kB alpha (IkBa). Administration of NATE significantly inhibited carrageenan-induced paw edema (p < 0.001), TPA-induced ear edema, and the production of inflammatory factors (p < 0.01). NATE revealed anti-nociceptive impacts in acetic acid-induced writhing and tail immersion experiments (p < 0.001) as well as no toxicity signs. A total of six compounds, namely iridoid glycoside (6,7-di-O-benzonylnyctanthoside), arborsides A, arborsides C, betulinic acid, kaempferol 3-O-glucoside, and kaempferol 3-O-rutinoside, were characterized through the examination of their mass spectra in correlation with those documented in a database of mass spectra. ConclusionsThe present study furnishes scientific corroboration of the inhibitory potency of N. arbor-tristis as a promising herbal treatment for inflammation and pain responses without toxicity, offering a scientific basis for future drug development strategies aimed at ameliorating inflammatory diseases.

Sericic Acid Ameliorates DSS-induced Ulcerative Colitis in Mice by Modulating the NF-κB and Nrf2 Pathways.

Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease. In previous studies, we found extracts from the roots of Rosa odorata Sweet var. gigantea (Coll.et Hemsl.) Rehd. et Wils have a therapeutic effect on UC. Furthermore, sericic acid (SA) is a pentacyclic triterpenoid isolated from this plant that is being used for the first time. The purpose of this study was to investigate whether SA has anti-inflammatory and therapeutic effects on UC and its underlying mechanisms. In this study, we used a dextran sulfate-induced UC mouse model and lipopolysaccharide (LPS)-induced inflammatory cell model along with an enzyme-linked immunosorbent assay (ELISA) to quantify the abundance of inflammatory factors and oxidative stress factors in tissues and cells. HE staining was used to analyze the therapeutic effect of the drugs on the UC mouse model. The expression levels of oxidative stress-related proteins were detected using immunoblotting and immunohistochemistry. The anti-inflammatory targets of SA were screened using protein chip arrays and verified by immunoblotting. We found that SA had anti-inflammatory and antioxidant effects in animal and cellular inflammation models. SA inhibited the levels of NO, TNF-α, IL-6, IL-1β, and MDA in tissues and cells and upregulated the expression level of SOD. Animal experiments showed that SA alleviated the shortening of colon length and colon pathological damage caused by DSS. The antiinflammatory targets of SA were screened using protein chip arrays, and SA was found to inhibit proteins related to the NF-κB signaling pathway. Finally, immunoblotting and immunohistochemistry showed that SA downregulated the expression of p-IKKα/β and its downstream protein p-NF-κB, while promoting the expression of Nrf2 and its downstream protein HO-1. The above results indicated that SA alleviated DSS-induced colitis by inhibiting NF-κB signaling pathway and activating Nrf2 pathway.

Resveratrol attenuates advanced glycation end product-induced senescence and inflammation in human gingival fibroblasts

Background/purposeThe accumulation of advanced glycation end products (AGEs) lead to a series of immune responses such as: increased oxidative stress and inflammation which contribute to the development of diabetic complications and periodontal disease. Resveratrol is a natural compound that has anti-oxidant and anti-inflammatory effects. Studies have found that diabetes-induced periodontitis is mainly caused by oxidative stress, aging and increased inflammation. In view of resveratrol has been proposed to have the ability in anti-oxidant and anti-inflammation in a variety of tissues. However, the role of resveratrol in diabetic periodontitis remains to be investigated. In this study, we aimed to investigate the role of resveratrol in preventing and treating diabetic periodontitis. Materials and methodsFirst, cell proliferation was measured in AGEs-treated human gingival fibroblast with or without resveratrol. We examined the reactive oxygen species (ROS) generation, senescence-associated beta-galactosidase (SA-β-gal) and senescence marker p16 in human gingival fibroblasts (HGFs) stimulated with AGEs with or without the treatment of resveratrol. To determine whether resveratrol has the potential to regulate inflammaging which is mediated via the NF-κB signaling pathway and, the expression of p65 and p-IκB were also investigated. Furthermore, the concentration of interleukin (IL)-6 and IL-8 were also measured in AGEs-stimulated HGFs treated with or without resveratrol. ResultsROS generation, cell senescence, and the secretion of IL-6 and IL-8 were significantly upregulated following the treatment of AGEs. However, the administration of resveratrol suppresses the generation of IL-6 and IL-8 and cell senescence via inhibiting NF-κB signaling pathway. Our results revealed that resveratrol inhibits inflammaging by downregulating NF-κB signaling pathway. ConclusionAccording to our findings, AGEs increase senescence and the production of proinflammatory cytokines in the gingiva, while the administration of resveratrol impedes inflammaging via suppressing NF-κB signaling pathway.

Integrated analysis of microbiome and host transcriptome reveals the damage/protective mechanism of corn oil and olive oil on the gut health of grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatu)

As digestive and immune organs of animals, the gut was frequently used to evaluate the health status of aquatic animals. In previous oil source alternatives study, corn oil (CO) had been found to induce gut inflammation, while olive oil (OO) had been found to be effective in protecting intestinal health. Three diets with different oil sources (fish oil, CO, OO) were formulated for an 8-week culture experiment, and it was proposed to combine 16S sequencing and transcriptome sequencing analysis to preliminarily elucidate the damage/protection mechanism of CO and OO on the gut health of grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatu). We found that CO indeed damaged to gut health and destroyed the gut structure, while OO had a positive outcome in protecting the gut structure, promoting digestibility and relieving enteritis. Photobacterium, Romboutsia and Epulopiscium were significantly enriched in OO group and Staphylococcus were significantly enriched in CO group. Transcriptome sequencing further revealed CO could activated Complement and coagulation cascades, Staphylococcus aureus infection, Systemic lupus erythematosus, and Tuberculosis pathways; conversely, OO activated B-cell signaling receptors, promoted B-cell proliferation and apoptosis, and thus activated B-cell signaling pathways to enhance immunity, whereas OO can regulate IL17 signaling pathway and TNF signaling pathway to inhibit NF-κB signaling pathway to reduce pro-inflammatory response. By integrating the microbiome and transcriptome, further identified all differential microorganisms were directly and significantly correlated with differential genes, and Clostridium_sensu_stricto_1, Romboutsia, Staphylococcus might as the core regulates the expression of differential gene in the organism. These results reveal that different oil sources alter gut gene expression mainly by modulating the composition and abundance of gut microbiota, further regulating the health status of the gut. Gut microbiota could be used as biomarkers to provide reference and solutions for the mitigation of inflammation in aquatic animals.

Abamectin induced brain and liver toxicity in carp: The healing potential of silybin and potential molecular mechanisms

Abamectin (ABM) abuse contaminated aquatic environment and posed a potential threat to fish health as well as public safety. Silybin (SIL), a flavonoid, has been widely used as a novel feed additive to promote fish health. This research was to explore the potential antagonistic mechanism between ABM and SIL on brain and liver toxicity was investigated in common carp. Sixty carp were divided into four groups at random: the Control group, the SIL group, the ABM group, and ABM + SIL group. This experiment lasted for 30 d. According to behavioral observation, the detection of levels of acetylcholinesterase (AchE), iron, and mRNA expression levels of blood-brain barrier (BBB) related tight junction proteins (ZO-1, Claudin7, Occludin, MMP2, MMP9, and MMP13) in brain tissues, it was found that SIL relieved neurobehavioral disorders caused by ABM-induced BBB destruction in carp. H&E staining showed SIL mitigated nerve injury and liver injury caused by ABM. Oil Red O staining and liver-related parameters showed that SIL alleviated hepatotoxicity and lipid metabolism disorder caused by ABM exposure. Furthermore, this work also explored the specific molecular mechanism of SIL in liver protection and neuroprotection. It was shown that SIL lowered ROS levels in liver and brain tissues via the GSK-3β/TSC2/TOR pathway. Simultaneously, SIL inhibited NF-κB signaling pathway and played an anti-inflammatory role. In conclusion, we believed that SIL supplementation has a protective effect on the brain and liver by regulating oxidative stress and inflammation.

Low-energy LED red light inhibits the NF-κB pathway and promotes hPDLSCs proliferation and osteogenesis in a TNF-α environment in vitro.

There are few studies on the effect of low-energy LED red light on periodontal tissue regeneration in an inflammatory environment. In this study, Cell Counting Kit-8(CCK-8) assays were used to detect the effects of TNF-α at three different concentrations (0, 10ng/ml, and 20ng/ml) on the proliferation of human periodontal ligament stem cells (hPDLSCs), and 10ng/ml was selected as the subsequent experimental stimulation concentration. CCK-8 assays were used to detect the effect of LED red light with energy density of 1J/ cm2, 3J/ cm2, and 5J/cm2 on the proliferation of hPDLSCs. The promotion effect of energy density of 5J/cm2 on the proliferation of hPDLSCS was the most obvious (p < 0.05). Set CON group, ODM group, ODM + 10ng/ml TNF-α group, and ODM + 10ng/ml TNF-α + 5J/ cm2 LED red light group. Alkaline phosphatase staining and activity detection, alizarin red staining and calcium nodules quantitative detection of osteoblast differentiation products, real-time fluorescence quantitative PCR detection of osteoblast gene expression (Runx2, Col-I, OPN, OCN). The results showed that ODM showed the strongest osteoblast ability, followed by ODM + 10ng/ml TNF-α + 5J/ cm2 LED red light group. The osteoblast ability of ODM + 10ng/ml TNF-α was decreased, but was not found in CON group. Western blot was used to detect the expression of NF-κB pathway protein and osteoblast-related proteins (Runx2, Col-I, OPN, OCN) after addition of PDTC inhibitor. The results showed that the expression of p-IκBα was increased and the expression of IκBα was decreased (p < 0.05). The expression of osteoblast protein increased after the addition of inhibitor (p < 0.05). Therefore, in an inflammatory environment constructed by 10ng/ml TNF-α, 5J/cm2 LED red light can upregulate the proliferation and osteogenesis of hPDLSCs by inhibiting NF-κB signaling pathway.

Rabdosichuanin C inhibits productions of pro-inflammatory mediators regulated by NF-κB signaling in LPS-stimulated RAW264.7 cells.

Chronic pharyngitis (CP) is an inflammatory disease of the pharyngeal mucosa and its lymphatic tissues that is difficult to treat clinically. However, research on the exact therapeutic agents and molecular mechanisms of CP is still unclear. In this study, we investigated Rabdosichuanin C (RC) to attenuate lipopolysaccharide (LPS)-induced inflammatory damage in RAW264.7 cells by a combination of targeted virtual screening and in vitro activity assay and further clarified its molecular mechanism of action centering on the IκB/nuclear factor kappa B (NF-κB) pathway. Molecular docking and pharmacophore simulation methods were used to screen compounds with IκB inhibitory effects. Expression of genes and proteins related to the IκB/NF-κB signaling pathway by RC in LPS-induced inflammatory injury model of RAW264.7 cells was detected by PCR, enzyme-linked immunosorbent assay, and Western blot. The docking of RC with IκB protein showed good binding energy, and pharmacophore simulations further confirmed the active effect of RC in inhibiting IκB protein. RC intervention in LPS-induced RAW264.7 cells significantly reduced the expression levels of inflammatory factors tumor necrosis factor-α, interleukins-6, iNOS, and CD-86 at the messenger RNA and protein levels, downregulated IκB, p65 protein phosphorylation levels, and significantly inhibited IκB/NF-κB signaling pathway activation. Virtual screening provided us with an effective method to rapidly identify compounds RC that target inhibit the action of IκB, and the activity results showed that RC inhibits NF-κB signaling pathway activation. It is suggested that RC may play a role in the treatment of CP by inhibiting the IκB/NF-κB signaling pathway.

Porcine enteric alphacoronavirus infection increases lipid droplet accumulation to facilitate the virus replication

Coronaviruses are widely transmissible between humans and animals, causing diseases of varying severity. Porcine enteric alphacoronavirus (PEAV) is a newly-discovered pathogenic porcine enteric coronavirus in recent years, which causes watery diarrhea in newborn piglets. The host inflammatory responses to PEAV and its metabolic regulation mechanisms remain unclear, and no antiviral studies have been reported. Therefore, we investigated the pathogenic mechanism and antiviral drugs of PEAV. The transcriptomic analysis of PEAV-infected host cells revealed that PEAV could upregulate lipid metabolism pathways. In lipid metabolism, steady-state energy processes, which can be mediated by lipid droplets (LDs), are the main functions of organelles. LDs are also important in viral infection and inflammation. In infected cells, PEAV increased LD accumulation, upregulated NF-κB signaling, promoted the production of the inflammatory cytokines IL-1β and IL-8, and induced cell death. Inhibiting LD accumulation with a DGAT-1 inhibitor significantly inhibited PEAV replication, downregulated the NF-κB signaling pathway, reduced the production of IL-1β and IL-8, and inhibited cell death. The NF-κB signaling pathway inhibitor BAY11-7082 significantly inhibited LD accumulation and PEAV replication. Metformin hydrochloride also exerted anti-PEAV effects and significantly inhibited LD accumulation, downregulated the NF-κB signaling pathway, reduced the production of IL-1β and IL-8, and inhibited cell death. LD accumulation in the lipid metabolism pathway therefore plays an important role in the replication and pathogenesis of PEAV, and metformin hydrochloride inhibits LD accumulation and the inflammatory response to exert anti-PEAV activity and reducing pathological injury. These findings contribute new targets for developing treatments for PEAV infections.

Inhibition of KIF11 ameliorates osteoclastogenesis via regulating mTORC1-mediated NF-κB signaling

Osteoporosis, characterized by over-production and activation of osteoclasts, has become a major health problem especially in elderly women. In our study, we first tested the effect of Caudatin (Cau) in osteoclastogenesis, which is separated from Cynanchum auriculatum as a species of C-21 steroidal glyosides. The results indicated that Cau suppressed osteoclastogenesis in a time- and dose-dependent manner in vitro. Mechanistically, Cau was identified to inhibit NF-κB signaling pathway via modulation of KIF11-mediated mTORC1 activity. In vivo, by establishing an ovariectomized (OVX) mouse model to mimic osteoporosis, we confirmed that Cau treatment prevented OVX-induced bone loss in mice. In conclusion, we demonstrated that Cau inhibited NF-κB signaling pathway via modulation of KIF11-mediated mTORC1 activity to suppress osteoclast differentiation in vitro as well as OVX-induced bone loss in vivo. This provides the possibility of a novel prospective drug for osteoporosis remedies.

Nuciferine protects against lipopolysaccharide-induced endometritis via inhibiting ferroptosis and modulating AMPKα/mTOR/HIF-1α signaling axis

Nuciferine (NF) is an alkaloid isolated from Nelumbo nucifera and has been reported to exhibit a wide range of pharmacological effects. However, whether NF treatment exhibits a protective effect in endometritis remains unclear. Here, the protective effects of NF on lipopolysaccharide (LPS)-induced endometritis in mice were investigated in our research. The results showed that NF significantly reversed the uterine histopathological changes, inflammatory factor levels and myeloperoxidase (MPO) activity caused by LPS. Furthermore, we found that NF administration improved the reproductive capacity of mice with endometritis. Mechanistically, the expression of MyD88/nuclear factor-kappa B (NF-κB) and MAPK-related proteins in uterine tissue were decreased by NF treatment. Moreover, we observed the occurrence of ferroptosis in the LPS-induced endometritis mouse model, which was noticeably inhibited by NF treatment. In addition, we showed that NF exhibited anti-endometritis activity by modulating AMPKα/mTOR/HIF1α signaling axis. Finally, the molecular mechanism of the NF anti-inflammatory effect was clarified in mouse endometrial epithelial cells (mEECs). NF inhibited the releases of pro-inflammatory factors in LPS-induced mEECs via inhibiting NF-κB signaling pathway. All these findings suggest that NF may ameliorate LPS-induced endometritis caused by LPS, the mechanism of action is related to the ferroptosis, MyD88/NF-κB, MAPK and AMPKα/mTOR/HIF1α signaling pathway.

NOD2 silencing promotes cell apoptosis and inhibits drug resistance in chronic lymphocytic leukemia by inhibiting the NF-κB signaling pathway.

Recent years have witnessed increasing studies on the effect of epigenetic silencing of genes in the progression of chronic lymphocytic leukemia (CLL). This study investigates whether the nucleotide binding oligomerization domain containing 2 (NOD2) participates in the cell apoptosis and drug resistance of CLL cells. Cells were treated with adriamycin (ADR), etoposide, aclacinomycin and daunorubicin. After treatment, drug resistance and cell proliferation were examined to detect the inhibitory effect of ADR on cell proliferation; flow cytometry to identify ADR accumulation, the cell cycle distribution and apoptosis after transfection, and rhodamine 123 accumulation and efflux tests to assess P-glycoprotein (P-gp) function. NOD2 silencing or inhibition of the nuclear factor kappa-B (NF-κB) signaling pathway suppressed the multidrug resistance level in CLL, the inhibition rate, and cell proliferation caused by ADR at concentrations of approximately 0.25-1.5 μmol/L. Greater accumulation of ADR was observed in the CLL-AAT cell line than in the CLL-AAT/A02 cell line, but NOD2 silencing or inhibition of the NF-κB signaling pathway further increased the accumulation of ADR drugs in the CLL-AAT cell line and inhibited the drug efflux pump function of P-gp. Additionally, NOD2 silencing or NF-κB signaling pathway inhibition increased the apoptotic rate. The results of this study indicate that NOD2 promotes cell apoptosis and reduces the drug resistance of CLL by inhibiting the NF-κB signaling pathway.

Piper retrofractum ameliorates imiquimod-induced skin inflammation via modulation of TLR4 axis and suppression of NF-κB activity

Chronic inflammation is a significant concern due to its association with various pathological conditions. As a result, extensive research has been conducted to identify new natural products that can effectively treat acute inflammation, which has the potential to inhibit the chronic inflammation. In our study, we aimed to identify Indonesian medicinal plants with the ability to inhibit proinflammatory agents, specifically targeting NF-κB, a crucial regulator of gene transcription involved in the production of proinflammatory proteins/cytokines. Through a series of identification processes, we found that Piper retrofractum (Javanese chili) extract demonstrated promising inhibitory effects on NF-κB and proinflammatory molecules.Further investigation was conducted using a variety of assays, including reporter assay, viability test, ELISA, and Western blotting. The results revealed that the extract significantly reduced LPS, NO, COX-2, IL-6, IL-1, and NF-κB through the TLR4 axis. Notably, Piper retrofractum extract was found to enhance the survival of human keratinocytes by protecting them from cell death induced by TRAIL, a member of the TNF superfamily. Moreover, immunohistochemistry analysis in an Imiquimod-induced skin inflammation mice model showed downregulation of COX-2 and IL-1β expression upon treatment with the extract.In conclusion, our findings suggest that Piper retrofractum extract possesses anti-inflammatory properties by reducing proinflammatory cytokine production through inhibition of NF-κB signaling pathway. These promising results highlight the potential of Piper retrofractum extract as a candidate for future drug development in the clinical treatment of inflammation-related conditions, offering hope for the advancement of therapeutic interventions.

Houttuynia cordata Thunb repairs steroid-induced avascular necrosis of the femoral head through regulating NF-κB signaling pathway

To investigate the influences of Houttuynia cordata Thunb (HCT) in steroid-induced avascular necrosis of the femoral head (SANFH), we conducted a comprehensive study evaluating the effects of HCT on various aspects. Cell Counting Kit-8 assay was used to examine bone marrow stem cells (BMSCs) cell viability. Flow cytometry and lactate dehydrogenase detection assay were conducted to determine cell apoptosis. The levels of apoptosis-related proteins, osteogenic-related markers, inflammatory factors, and nuclear factor kappa B (NF-κB) pathway-associated proteins were determined via western blotting. Hematoxylin and eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays were utilized to verify the effects of HCT in SANFH rats. Our findings revealed that HCT could enhanced cell viability and arrested cell apoptosis in dexamethasone (Dex)-treated BMSCs. Dex increased the levels of cleaved caspase-3, Bcl2-associated X, interleukin (IL)-1β, IL-18, IL-6, p65, and inhibitor of NF-κB kinase β (IKKβ), while this promoting trend was weakened by HCT. Moreover, pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB signaling pathway) further increased the inhibitory role of apoptosis and the levels of IL-1β, IL-18, and IL-6 and the promotional effect of the levels of RUNX2 and ALP in Dex-treated BMSCs. The in-vivo assays showed that HCT decreased the percentage of empty lacunae, apoptosis, and the levels of IL-1β, IL-18, IL-6, p65, and IKKβ in SANFH rats. In conclusion, our study demonstrated that HCT relieved SANFH, which might be possibly achieved by NF-κB pathway.