NF-κB Activation Research Articles

ROLE OF NF-κB TRANSCRIPTION FACTOR ACTIVATION IN THE PROCESSES OF CONNECTIVE TISSUE COMPONENTS DEGRADATION IN SKELETAL MUSCLES UNDER METABOLIC SYNDROME

Connective tissue, encompassing both cellular and non-cellular elements, plays an important role in the progression of numerous pathological processes across various organs and tissues. Within skeletal muscle tissue, the extracellular matrix not only plays a structural and supporting function, but it is a complex multicomponent system that performs a number of regulatory functions. At present, the effect of activation of the transcription factor NF-κB on the quantitative and qualitative composition of the components of the extracellular matrix in skeletal muscles under metabolic syndrome development is insufficiently studied. The aim of this work is to study the effect of ammonium pyrrolidinedithiocarbamate on the concentration of glycosaminoglycans, the concentration of individual fractions of glycosaminoglycans, the content of free L-oxyproline and sialic acids in the biceps femoris muscle of rats under metabolic syndrome. The study was conducted on 24 male Wistar rats weighing 200-260 g, which were randomly divided into 4 groups of 6 animals each. The first was control; the second made up the metabolic syndrome modeling group. Metabolic syndrome was reproduced by adding a 20% fructose solution to the standard vivarium diet as the only source of drinking water. Metabolic syndrome was modelled for 60 days. The third group received ammonium pyrrolidinedithiocarbamate administration at a dose of 76 mg/kg intraperitoneally (i/p) three times a week for 60 days. The fourth group underwent combined treatment involving the administration of both ammonium pyrrolidinedithiocarbamate and metabolic syndrome modeling. In a 10% homogenate of the biceps femoris muscle, the total concentration of glycosaminoglycans, the concentration of the heparin-heparan fraction of glycosaminoglycans, the keratan-dermatan fraction of glycosaminoglycans, the chondroitin fraction of glycosaminoglycans, and the content of free L-oxyproline and sialic acids were assessed. The introduction of ammonium pyrrolidinedithiocarbamate under metabolic syndrome modelling led to a decrease in the total concentration of glycosaminoglycans by 9.2% compared to the metabolic syndrome group. Under these conditions, the concentration of the heparin-heparan fraction increased by 121.1%, the keratan-dermatan fraction decreased by 32.8%, and the concentration of the chondroitin fraction decreased by 38.7% compared to the metabolic syndrome group. The concentration of free L-oxyproline and sialic acids in the biceps femoris muscle decreased by 19.8% and 24.4%, respectively, compared to the metabolic syndrome group. Blockade of activation of the transcription factor NF-κB by intraperitoneal administration of ammonium pyrrolidinedithiocarbamate against the background of metabolic syndrome modelling leads to a decrease in the depolymerization of glycoproteins and proteoglycans, reduces the intensity of collagenolysis and leads to a redistribution of concentrations of individual fractions of glycosaminoglycans, characterized by an increase in the content of the heparin-heparan fraction and a decrease in chondroitin and keratan-dermatan fractions in the biceps femoris muscle of rats.

The regulating effect of curcumin on NF-κB pathway in neurodegenerative diseases: a review of the underlying mechanisms.

Neurodegenerative diseases are part of the central nervous system (CNS) disorders that indicate their presence with neuronal loss, neuroinflammation, and increased oxidative stress. Several pathophysiological factors and biomarkers are involved in this inflammatory process causing these neurological disorders. The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is an inflammation element, which induced transcription and appears to be one of the important players in physiological procedures, especially nervous disorders. NF-κB can impact upon series of intracellular actions and induce or inhibit many inflammation-related pathways. Multiple reports have focused on the modification of NF-κB activity, controlling its expression, translocation, and signaling pathway in neurodegenerative disorders and injuries like Alzheimer's disease (AD), spinal cord injuries (SCI), and Parkinson's disease (PD). Curcumin has been noted to be a popular anti-oxidant and anti-inflammatory substance and is the foremost natural compound produced by turmeric. According to various studies, when playing an anti-inflammatory role, it interacts with several modulating proteins of long-standing disease signaling pathways and has an unprovocative consequence on pro-inflammatory cytokines. This review article determined to figure out curcumin's role in limiting the promotion of neurodegenerative disease via influencing the NF-κB signaling route. Preclinical studies were gathered from plenty of scientific platforms including PubMed, Scopus, Cochrane, and Google Scholar to evaluate this hypothesis. Extracted findings from the literature review explained the repressing impact of Curcumin on the NF-κB signaling pathway and, occasionally down-regulating the cytokine expression. Yet, there is an essential need for further analysis and specific clinical experiments to fully understand this subject.

Squalene epoxidase promotes the chemoresistance of colorectal cancer via (S)-2,3-epoxysqualene-activated NF-κB

BackgroundWhile de novo cholesterol biosynthesis plays a crucial role in chemotherapy resistance of colorectal cancer (CRC), the underlying molecular mechanism remains poorly understood.MethodsWe conducted cell proliferation assays on CRC cells with or without depletion of squalene epoxidase (SQLE), with or without 5-fluorouracil (5-FU) treatment. Additionally, a xenograft mouse model was utilized to explore the impact of SQLE on the chemosensitivity of CRC to 5-FU. RNA-sequencing analysis and immunoblotting analysis were performed to clarify the mechanism. We further explore the effect of SQLE depletion on the ubiquitin of NF-κB inhibitor alpha (IκBα) and (S)-2,3-epoxysqualene on the binding of IκBα to beta-transducin repeat containing E3 ubiquitin protein ligase (BTRC) by using immunoprecipitation assay. In addition, a cohort of 272 CRC patients were selected for our clinical analyses.ResultsMechanistically, (S)-2,3-epoxysqualene promotes IκBα degradation and subsequent NF-κB activation by enhancing the interaction between BTRC and IκBα. Activated NF-κB upregulates the expression of baculoviral IAP repeat containing 3 (BIRC3), sustains tumor cell survival after 5-FU treatment and promotes 5-FU resistance of CRC in vivo. Notably, the treatment of terbinafine, an inhibitor of SQLE commonly used as antifungal drug in clinic, enhances the sensitivity of CRC to 5-FU in vivo. Additionally, the expression of SQLE is associated with the prognosis of human CRC patients with 5-FU-based chemotherapy.ConclusionsThus, our finding not only demonstrates a new role of SQLE in chemoresistance of CRC, but also reveals a novel mechanism of (S)-2,3-epoxysqualene-dependent NF-κB activation, implicating the combined potential of terbinafine for 5-FU-based CRC treatment.

MiR-1976/NCAPH/P65 axis inhibits the malignant phenotypes of lung adenocarcinoma.

Lung adenocarcinoma (LUAD) is a malignancy with an abysmal survival rate. High metastasis is the leading cause of the low survival rate of LUAD. NCAPH, an oncogene, is involved in the carcinogenesis of LUAD. However, the regulation of NCAPH in LUAD remains controversial. In this work, we identified an up-regulation of NCAPH in LUAD tissues. Patients who expressed more NCAPH had shorter overall survival (OS). Furthermore, NCAPH overexpression promoted LUAD cell migration while inhibiting apoptosis. MiR-1976 and miR-133b were predicted to target NCAPH expression by searching TargetScan and linkedomics databases. Following that, we confirmed that miR-1976 suppressed NCAPH by directly targeting a 7-bp region of NCAPH 3' untranslated regions (UTR). In addition, increased expression of miR-1976 decreased the proliferation & migration and promoted apoptosis of LUAD cells, and the re-introduction of NCAPH reversed these influences. Furthermore, the xenograft and metastasis mouse models also confirmed that miR-1976 inhibited tumor growth and metastasis in vivo by targeting NCAPH. Finally, we found that MiR-1976 targeting NCAPH blocked the activation of NF-κB. In conclusion, miR-1976 inhibits NCAPH activity in LUAD and acts as a tumor suppressor. The miR-1976/NCAPH/NF-κB axis may, in the future, represent crucial diagnostic and prognostic biomarkers and promising therapeutic options.

Protein phosphatase 6 activates NF-κB to confer sensitivity to MAPK pathway inhibitors in KRAS- and BRAF-mutant cancer cells.

The Ras-mitogen-activated protein kinase (MAPK) pathway is a major target for cancer treatment. To better understand the genetic pathways that modulate cancer cell sensitivity to MAPK pathway inhibitors, we performed a CRISPR knockout screen with MAPK pathway inhibitors on a colorectal cancer (CRC) cell line carrying mutant KRAS. Genetic deletion of the catalytic subunit of protein phosphatase 6 (PP6), encoded by PPP6C, rendered KRAS- and BRAF-mutant CRC and BRAF-mutant melanoma cells more resistant to these inhibitors. In the absence of MAPK pathway inhibition, PPP6C deletion in CRC cells decreased cell proliferation in two-dimensional (2D) adherent cultures but accelerated the growth of tumor spheroids in 3D culture and tumor xenografts in vivo. PPP6C deletion enhanced the activation of nuclear factor κB (NF-κB) signaling in CRC and melanoma cells and circumvented the cell cycle arrest and decreased cyclin D1 abundance induced by MAPK pathway blockade in CRC cells. Inhibiting NF-κB activity by genetic and pharmacological means restored the sensitivity of PPP6C-deficient cells to MAPK pathway inhibition in CRC and melanoma cells in vitro and in CRC cells in vivo. Furthermore, a R264 point mutation in PPP6C conferred loss of function in CRC cells, phenocopying the enhanced NF-κB activation and resistance to MAPK pathway inhibition observed for PPP6C deletion. These findings demonstrate that PP6 constrains the growth of KRAS- and BRAF-mutant cancer cells, implicates the PP6-NF-κB axis as a modulator of MAPK pathway output, and presents a rationale for cotargeting the NF-κB pathway in PPP6C-mutant cancer cells.

Osthole exhibits the remedial potential for polycystic ovary syndrome mice through Nrf2-Foxo1-GSH-NF-κB pathway.

Polycystic ovary syndrome (PCOS) is the primary cause of female infertility with a lack of universal therapeutic regimen. Although osthole exhibits numerous pharmacological activities in treating various diseases, its therapeutic effect on PCOS is undiscovered. The present study found that application of osthole improved the symptoms of PCOS mice through preventing ovarian granulosa cells (GCs) production of more estrogen and alleviating the liberation of pro-inflammatory cytokineinterleukin(IL)-1β, IL-6, andtumor necrosis factor alpha. Meanwhile, osthole enhanced ovarian antioxidant capacity and alleviated intracellular reactive oxygen species (ROS) accumulation with a concurrent attenuation for oxidative stress, while intervention of antioxidant enzymic activity and glutathione (GSH)synthesis neutralized the salvation of osthole on GCs secretory disorder and chronic inflammation. Further analysis revealed that osthole restored the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)and forkhead box O 1 (Foxo1) whose repression antagonized the amelioration of osthole on the insufficiency of antioxidant capacity and accumulation of ROS. Moreover, Nrf2 served as an intermedium to mediate the regulation of osthole on Foxo1. Additionally, osthole restricted the phosphorylation of IκBα and nuclear factor kappa B (NF-κB)subunit p65 by DHEA and weakened the transcriptional activity of NF-κB, but this effectiveness was abrogated by the obstruction of Nrf2 and Foxo1, whereas adjunction of GSH renewed the redemptive effect of osthole on NF-κB whose activation caused an invalidation of osthole in rescuing the aberration of GCs secretory function and inflammation response. Collectively, osthole might relieve the symptoms of PCOS mice via Nrf2-Foxo1-GSH-NF-κB pathway.

Acacetin Attenuates Sepsis-induced Acute Lung Injury via NLRC3-NF-κB Pathway.

Acacetin, a flavonoid derived compound has been recognized for its diverse biological activities, such as anti-oxidative and anti-inflammatory effects. Acute lung injury (ALI) is a severe condition characterized by respiratory insufficiency and tissue damage, commonly triggered by pneumonia and severe sepsis. These conditions induce an inflammatory response via Toll-like receptor 4 (TLR4) signaling activation. This study explored acacetin's therapeutic potential against lipopolysaccharide (LPS) induced ALI in mice, focusing on its ability to modulate the NF-κB pathway via regulation of the Nod-like receptor family CARD domain containing 3 (NLRC3), a signal sensor that plays an important role in the regulation of inflammation and the maintenance of homeostasis. Our findings revealed that high-dose acacetin reduced the mortality rate of ALI mice, significantly ameliorated LPS-induced lung pathological changes, reduced lung edema, and decreased the expression of inflammatory mediators in lung tissues. This protective impact of acacetin appears to stem form its capacity to enhance NLRC3 expression, which, intern, can inhibit the activation of NF-κB and subsequently inhibit the production of inflammatory mediators. NLRC3 deficiency inhibits the protective effect of acacetin on ALI mice. Molecular docking also verified that acacetin tightly bound acacetin to NLRC3. Additionally, acacetin was found to influence macrophage recruitment dynamics via NLRC3, inhibiting the overactivation of NLRC3-NF-κB related pathways. Taken together, our results indicate that acacetin inhibited LPS-induced acute lung injury and macrophage overrecruitment to the lungs in mice by upregulating NLRC3.

Protective Role of MerTK in Diabetic Peripheral Neuropathy via Inhibition of the NF-κB Signaling Pathway.

Diabetic peripheral neuropathy (DPN) impacts patient quality of life. In such patients, increased expression of mer tyrosine kinase (MerTK) has been demonstrated; however, its mechanism of action remains unclear. In this study, type 2 diabetes mellitus (T2DM) and DPN models were established in Sprague Dawley rats via low-dose streptozotocin and a high-fat diet and the mode of action of MerTK was examined. MerTK-specific inhibitors were administered by gavage once daily for 2 weeks. Sciatic nerve conduction velocity and nerve structure were measured. The levels of MerTK, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and relevant biochemical indexes were detected. The study revealed upregulation of MerTK expression in T2DM and more so in DPN groups. Inhibiting MerTK led to reduced nerve conduction velocity and further deterioration of sciatic nerve structure, as evidenced by structural morphology. Concurrently, serum levels of total cholesterol, glycated hemoglobin, and triglyceride significantly increased. Moreover, levels of NF-κB increased in both serum and nerve tissue, alongside a significant rise in TNF-α and IL-1β expressions. MerTK could bind to the inhibitor of kappa B kinase beta (Ikbkb) in Schwann cells, establishing Ikbkb as a precursor to NF-κB activation. Inhibition of MerTK exacerbates neuropathy, indicating its protective role in DPN by suppressing the NF-κB pathway, highlighting a potential new target for its diagnosis and treatment.

Hepatoprotective effects of baicalein against liver ischemia-reperfusion injury and partial hepatectomy in a rat model.

Baicalein is the main active flavonoid in Scutellariae Radix and is included in shosaikoto, a Kampo formula used for treating hepatitis and jaundice. However, little is known about its hepatoprotective effects against hepatic ischemia-reperfusion injury (HIRI), a severe clinical condition directly caused by interventional procedures. We aimed to investigate the hepatoprotective effects of baicalein against HIRI and partial hepatectomy (HIRI + PH) and its potential underlying mechanisms. Male Sprague-Dawley rats received either baicalein (5mg/kg) or saline intraperitoneally and underwent a 70% hepatectomy 15min after hepatic ischemia. After reperfusion, liver and blood samples were collected. Survival was monitored 30min after hepatic ischemia and hepatectomy. In interleukin 1β (IL-1β)-treated primary cultured rat hepatocytes, the influence of baicalein on inflammatory mediator production and the associated signaling pathway was analyzed. Baicalein suppressed apoptosis and neutrophil infiltration, which are the features of HIRI + PH treatment-induced histological injury. Baicalein also reduced the mRNA expression of the proinflammatory cytokine tumor necrosis factor-α (TNF-α). In addition, HIRI + PH treatment induced liver enzyme deviations in the serum and hypertrophy of the remnant liver, which were suppressed by baicalein. In the lethal HIRI + PH treatment group, baicalein significantly reduced mortality. In IL-1β-treated rat hepatocytes, baicalein suppressed TNF-α and chemokine mRNA expression as well as the activation of nuclear factor-kappa B (NF-κB) and Akt. Baicalein treatment attenuates HIRI + PH-induced liver injury and may promote survival. This potential hepatoprotection may be partly related to suppressing inflammatory gene induction through the inhibition of NF-κB activity and Akt signaling in hepatocytes.

Exposure to polystyrene nanoplastics induces hepatotoxicity involving NRF2-NLRP3 signaling pathway in mice

Nanoplastic contamination has been of intense concern by virtue of the potential threat to human and ecosystem health. Animal experiments have indicated that exposure to nanoplastics (NPs) can deposit in the liver and contribute to hepatic injury. To explore the mechanisms of hepatotoxicity induced by polystyrene-NPs (PS-NPs), mice and AML-12 hepatocytes were exposed to different dosages of 20 nm PS-NPs in this study. The results illustrated that in vitro and in vivo exposure to PS-NPs triggered excessive production of reactive oxygen species and repressed nuclear factor erythroid-derived 2-like 2 (NRF2) antioxidant pathway and its downstream antioxidase expression, thus leading to hepatic oxidative stress. Moreover, PS-NPs elevated the levels of NLRP3, IL-1β and caspase-1 expression, along with an activation of NF-κB, suggesting that PS-NPs induced hepatocellular inflammatory injury. Nevertheless, the activaton of NRF2 signaling by tert-butylhydroquinone mitigated PS-NPs-caused oxidative stress and inflammation, and inbihited NLRP3 and caspase-1 expression. Conversely, the rescuing effect of NRF2 signal activation was dramatically supressed by treatment with NRF2 inhibitor brusatol. In summary, our results demonstrated that NRF2-NLRP3 pathway is involved in PS-NPs-aroused hepatotoxicity, and the activation of NRF2 signaling can protect against PS-NPs-evoked liver injury. These results provide novel insights into the hepatotoxicity elicited by NPs exposure.

CLK2 mediates IκBα-independent early termination of NF-κB activation by inducing cytoplasmic redistribution and degradation

Activation of the NF-κB pathway is strictly regulated to prevent excessive inflammatory and immune responses. In a well-known negative feedback model, IκBα-dependent NF-κB termination is a delayed response pattern in the later stage of activation, and the mechanisms mediating the rapid termination of active NF-κB remain unclear. Here, we showed IκBα-independent rapid termination of nuclear NF-κB mediated by CLK2, which negatively regulated active NF-κB by phosphorylating the RelA/p65 subunit of NF-κB at Ser180 in the nucleus to limit its transcriptional activation through degradation and nuclear export. Depletion of CLK2 increased the production of inflammatory cytokines, reduced viral replication and increased the survival of the mice. Mechanistically, CLK2 phosphorylated RelA/p65 at Ser180 in the nucleus, leading to ubiquitin‒proteasome-mediated degradation and cytoplasmic redistribution. Importantly, a CLK2 inhibitor promoted cytokine production, reduced viral replication, and accelerated murine psoriasis. This study revealed an IκBα-independent mechanism of early-stage termination of NF-κB in which phosphorylated Ser180 RelA/p65 turned off posttranslational modifications associated with transcriptional activation, ultimately resulting in the degradation and nuclear export of RelA/p65 to inhibit excessive inflammatory activation. Our findings showed that the phosphorylation of RelA/p65 at Ser180 in the nucleus inhibits early-stage NF-κB activation, thereby mediating the negative regulation of NF-κB.

N,N-Diarylsulfonamide Reduces Proinflammatory Cytokine Interleukin-6 Levels in Cells through Nuclear Factor-κB Regulation.

The arylsulfonamides were synthesized from aryl sulfonyl chloride and aromatic amines in dichloromethane in the presence of pyridine. The aryne chemistry was used to prepare diarylsulfonamide from arylsulfonamides and O-silylaryl triflate with CsF in acetonitrile at room temperature for 30 min. The synthesized compounds were evaluated for cytotoxicity followed by the cytokine/inflammatory marker's inhibition capability and its mechanism of action in RAW-264.7 cells. Elevated interleukin-6 (IL-6) levels have been reported in inflammatory conditions and inflammation-associated disorders. Hence, reducing the IL-6 levels in inflammatory conditions can serve as an attractive therapeutic target in dealing the inflammation. Among 42 compounds, seven compounds showed significant inhibition of IL-6 levels in lipopolysaccharide (LPS) challenged RAW-264.7 cells at 12.5 μM concentration. Further, investigation revealed that the IC50 value of these compounds for reducing IL-6 levels was found to be in the range of 2.6 to 9.7 μM. The promising compounds 5y (IC50 of 2.6 μM) and 5n (IC50 of 4.1 μM) along with other derivatives fulfil drug-likeness parameters laid down by Lipinski's rule of five. Further, RT-qPCR and Western-blot analysis revealed that treatment with 5n significantly reduced the expression of pro-inflammatory, inflammatory and macrophage marker's expression (IL-1β, CCL2, COX2 and CD68) compared to LPS control. The mechanistic evaluation showed that 5n exhibited anti-inflammatory properties by modulating the nuclear factor-κB (NF-κB) activation. The identified compound can be a promising candidate for further discovery efforts to generate a preclinical candidate effective in inflammation.

Anti-inflammatory activity of phenolics from Dianella ensifolia

A new diarylpropane (1) along with seventeen known compounds (2–18), were extracted from the entire plant of Dianella ensifolia. The compounds 1–3 were identified as a distinctive group of diarylpropanes. Their structures were determined through comprehensive spectral analysis. An anti-inflammatory activity assay revealed that compound 7 demonstrated significant inhibitory effects on NO generation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, with an IC50 value of 9.93 μg/mL. Further in-depth mechanistic studies indicated that compound 7 suppresses LPS-induced NO production by inhibiting the activation of NF-κB, which subsequently led to a decrease in the expression of nitric oxide synthase enzymes (iNOS).

NF-κB pathway as a molecular target for curcumin in diabetes mellitus treatment: Focusing on oxidative stress and inflammation.

Diabetes mellitus (DM) is a collection of metabolic disorder that is characterized by chronic hyperglycemia. Recent studies have demonstrated the crucial involvement of oxidative stress (OS) and inflammatory reactions in the development of DM. Curcumin (CUR), a natural compound derived from turmeric, exerts beneficial effects on diabetes mellitus through its interaction with the nuclear factor kappa B (NF-κB) pathway. Research indicates that CUR targets inflammatory mediators in diabetes, including tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6), by modulating the NF-κB signaling pathway. By reducing the expression of these inflammatory factors, CUR demonstrates protective effects in DM by improving pancreatic β-cells function, normalizing inflammatory cytokines, reducing OS and enhancing insulin sensitivity. The findings reveal that CUR administration effectively lowered blood glucose elevation, reinstated diminished serum insulin levels, and enhanced body weight in Streptozotocin -induced diabetic rats. CUR exerts its beneficial effects in management of diabetic complications through regulation of signaling pathways, such as calcium-calmodulin (CaM)-dependent protein kinase II (CaMKII), peroxisome proliferator-activated receptor gamma (PPAR-γ), NF-κB, and transforming growth factor β1 (TGFB1). Moreover, CUR reversed the heightened expression of inflammatory cytokines (TNF-α, Interleukin-1 beta (IL-1β), IL-6) and chemokines like MCP-1 in diabetic specimens, vindicating its anti-inflammatory potency in counteracting hyperglycemia-induced alterations. CUR diminishes OS, avert structural kidney damage linked to diabetic nephropathy, and suppress NF-κB activity. Furthermore, CUR exhibited a protective effect against diabetic cardiomyopathy, lung injury, and diabetic gastroparesis. Conclusively, the study posits that CUR could potentially offer therapeutic benefits in relieving diabetic complications through its influence on the NF-κB pathway.

Negative feedback systems for modelling NF-κB transcription factor oscillatory activity

ABSTRACT Low-dimensional negative feedback systems (NFSs) were developed within a signal flow model to describe the oscillatory activities of NF-κB caused by interactions with its inhibitor IκBα. The NFSs were established as 3rd- and 4th-order linear systems containing unperturbed and perturbed negative feedback (NF) loops with constant or time-varying NF strengths and a feed-forward loop. NF-related analytical solutions to the NFSs representing the time courses of NF-κB and IκBα were determined and their exact mathematical relationship was found. The NFS’s parameters were determined to fit the experimental time courses of NF-κB in TNF-α-stimulated embryonic fibroblasts, rela −/− embryonic fibroblasts reconstituted with RelA, C9L cells, GFP-p65 knock-in embryonic fibroblasts and embryogenic fibroblasts lacking Iκβ and IκBε, LPS-stimulated IC-21 macrophages treated or not with DCPA, and anti-IgM-stimulated DT40 B-lymphocytes. The unperturbed and perturbed NFSs describing the above biosystems generated isochronous and non-isochronous solutions, depending on a constant or time-varying NF strength, respectively. The oscillation period of the NF-coupled solutions, the phase difference between them and the time delays in the appearance of cytoplasmic IκBα after stimulation of NF-κB were determined. A significant divergence between the IκBα solutions to the NFSs and the IκBα experimental courses led to a rejection of the NF coupling between NF-κB and IκBα in the above biosystems. It was shown that neither the linearity nor the low dimensionality of the NFSs altered the NF relationship and the divergence between the IκBα solutions to the NFS and IκBα experimental time courses. Although the NF relationship between IκBα and NF-κB was not confirmed in all the experimental data analyzed, delayed negative feedback was found in some cases.

Lycopene promoted M2 macrophage polarization via inhibition of NOTCH1-PI3K-mTOR-NF-κB-JMJD3-IRF4 pathway in response to Escherichia coli infection in J744A.1 cells.

Escherichia coli (E. coli) can induce severe clinical bovine mastitis, which is to blame for large losses experienced by dairy farms. Macrophage polarization into various states is in response to pathogen infections. Lycopene, a naturally occurring hydrocarbon carotenoid, relieved inflammation by controlling M1/M2 status of macrophages. Thus, we wanted to explore the effect of lycopene on polarization states of macrophages in E. coli-induced mastitis. Macrophages were cultivated with lycopene for 24, before E. coli inoculation for 6h. Lycopene (0.5μmol/L) significantly enhanced cell viabilities and significantly reduced lactic dehydrogenase (LDH) levels in macrophages, whereas 2 and 3μmol/L lycopene significantly enhanced LDH activities. Lycopene treatment significantly reduced the increase in LDH release, iNOS, CD86, TNF-α, IL-1β and phosphatase and tensin homolog (PTEN) expressions in E. coli group. 0.5μmol/L lycopene significantly increased E. coli-induced downregulation of CD206, arginase I (ARG1), indoleamine 2,3-dioxygenase (IDO), chitinase 3-like 3 (YM1), PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR), p-mTOR, jumonji domain-containing protein-3 (JMJD3) and interferon regulatory factor 4 (IRF4) levels. Moreover, Ginkgolic acid C17:1 (a specific PTEN inhibitor), 740YPDGFR (a specific PI3K activator), SC79 (a specific AKT activator) or CHPG sodium salt (a specific NF-κB activator) significantly decreased CD206, AGR1, IDO and YM1 expressions in lycopene and E. coli-treated macrophages. Therefore, lycopene increased M2 macrophages via inhibiting NOTCH1-PI3K-mTOR-NF-κB-JMJD3-IRF4 pathway in response to E. coli infection in macrophages. These results contribute to revealing the pathogenesis of E. coli-caused bovine mastitis, providing the new angle of the prevention and management of mastitis.

The haemagglutinin–neuraminidase protein of velogenic Newcastle disease virus enhances viral infection through NF-κB-mediated programmed cell death

The haemagglutinin–neuraminidase (HN) protein, a vital membrane glycoprotein, plays a pivotal role in the pathogenesis of Newcastle disease virus (NDV). Previously, we demonstrated that a mutation in the HN protein is essential for the enhanced virulence of JS/7/05/Ch, a velogenic variant NDV strain originating from the mesogenic vaccine strain Mukteswar. Here, we explored the effects of the HN protein during viral infection in vitro using three viruses: JS/7/05/Ch, Mukteswar, and an HN-replacement chimeric NDV, JS/MukHN. Through microscopic observation, CCK-8, and LDH release assays, we demonstrated that compared with Mukteswar and JS/MukHN, JS/7/05/Ch intensified the cellular damage and mortality attributed to the mutant HN protein. Furthermore, JS/7/05/Ch induced greater levels of apoptosis, as evidenced by the activation of caspase-3/8/9. Moreover, JS/7/05/Ch promoted autophagy, leading to increased autophagosome formation and autophagic flux. Subsequent pharmacological experiments revealed that inhibition of apoptosis and autophagy significantly impacted virus replication and cell viability in the JS/7/05/Ch-infected group, whereas less significant effects were observed in the other two infected groups. Notably, the mutant HN protein enhanced JS/7/05/Ch-induced apoptosis and autophagy by suppressing NF-κB activation, while it mitigated the effects of NF-κB on NDV infection. Overall, our study offers novel insights into the mechanisms underlying the increased virulence of NDV and serves as a reference for the development of vaccines.

A keratinocyte-adipocyte signaling loop is reprogrammed by loss of BTG3 to augment skin carcinogenesis.

Obesity is endemic to many developed countries. Overweight or obesity is associated with an increased risk of developing cancer. Dysfunctional adipose tissue alters cancer cell proliferation and migration; however, whether and how neoplastic epithelial cells communicate with adipose tissue and the underlying mechanism are less clear. BTG3 is a member of the anti-proliferative BTG/Tob family and functions as a tumor suppressor. Here, we demonstrated that BTG3 levels are downregulated in basal cell carcinoma and squamous cell carcinoma compared to normal skin tissue, and Btg3 knockout in mice augmented the development of papilloma in a mouse model of DMBA/TPA-induced skin carcinogenesis. Mechanistically, BTG3-knockout keratinocytes promoted adipocyte differentiation mainly through the release of IL1α, IL10, and CCL4, as a result of elevated NF-κB activity. These adipocytes produced CCL20 and FGF7 in a feedback loop to promote keratinocyte migration. Thus, our findings showcased the role of BTG3 in guarding the interplay between keratinocytes and adjacent adipocytes, and identified the underlying neoplastic molecular mediators that may serve as possible targets in the treatment of skin cancer.

Asiatic acid alleviates vascular remodeling in BAPN-induced aortic dissection through inhibiting NF-κB p65/CX3CL1 signaling.

Inflammation assumes a pivotal role in the aortic remodeling of aortic dissection (AD). Asiatic acid (AA), a triterpene compound, is recognized for its strong anti-inflammatory properties. Yet, its effects on β-aminopropionitrile (BAPN)-triggered AD have not been clearly established. The objective is to determine whether AA attenuates adverse aortic remodeling in BAPN-induced AD and clarify potential molecular mechanisms. Invitro studies, RAW264.7 cells pretreated with AA were challenged with lipopolysaccharide (LPS), and then the vascular smooth muscle cells (VSMCs)-macrophage coculture system was established to explore intercellular interactions. To induce AD, male C57BL/6J mice at three weeks of age were administered BAPN at a dosage of 1 g/kg/d for four weeks. To decipher the mechanism underlying the effects of AA, RNA sequencing analysis was conducted, with subsequent validation of these pathways through cellular experiments. AA exhibited significant suppression of M1 macrophage polarization. In the cell coculture system, AA facilitated the transformation of VSMCs into a contractile phenotype. In the mouse model of AD, AA strikingly prevented the BAPN-induced increases in inflammation cell infiltration and extracellular matrix degradation. Mechanistically, RNA sequencing analysis revealed a substantial upregulation of CX3CL1 expression in BAPN group but downregulation in AA-treated group. Additionally, it was observed that the upregulation of CX3CL1 negated the beneficial impact of AA on the polarization of macrophages and the phenotypic transformation of VSMCs. Crucially, our findings revealed that AA is capable of downregulating CX3CL1 expression, accomplishing this by obstructing the nuclear translocation of NF-κB p65. The findings indicate that AA holds promise as a prospective treatment for adverse aortic remodeling by suppressing the activity of NF-κB p65/CX3CL1 signaling pathway.

Regulatory cellular and molecular networks in the bone microenvironment during aging

Abstract Age-induced abnormalities in bone metabolism disrupt the equilibrium between bone resorption and formation. This largely stems from disturbances in bone homeostasis, in which signaling pathways exert a significant regulatory influence. Aging compromises the functionality of the bone marrow mesenchymal stem cells (BMSCs), ultimately resulting in tissue dysfunction and pathological aging. Age-related bone degradation primarily manifests as reduced bone formation and the increased accumulation of bone marrow fat. Cellular senescence diminishes bone cell vitality, thereby disrupting the balance of bone remodeling. Intensive osteoclast differentiation leads to the generation of more osteoclasts and increased bone resorption. This review provides insight into the impact of aging on bone, encompassing bone cell states during the aging process and bone signaling pathway transformations. It primarily delves into aging-related signaling pathways, such as the bone morphogenetic protein/Smad, Wnt/β-catenin, osteoprotegerin/receptor activator of NF-κB ligand/receptor activator of NF-κB, connexin43/miR21, and nuclear factor erythroid 2-related factor 2/antioxidant response element pathways, seeking to enhance our comprehension of crucial bone cells and their secretory phenotypes during aging. Furthermore, the precise molecular regulatory mechanisms underlying the interactions between bone signaling pathways and aging are investigated.