NF-κB Activation Research Articles

Exogenous NT-3 Promotes Phenotype Switch of Resident Macrophages and Improves Sciatic Nerve Injury through AMPK/NF-κB Signaling Pathway.

Neurotrophin-3 (NT-3) is an important family of neurotrophic factors with extensive neurotrophic activity, which can maintain the survival and regeneration of nerve cells. However, the mechanism of NT-3 on macrophage phenotype transformation after sciatic nerve injury is not clear. In this study, we constructed a scientific nerve compression injury animal model and administered different doses of NT-3 treatment through osmotic minipump. 7 days after surgery, we collected sciatic nerve tissue and observed the distribution of macrophage phenotype through iNOS and CD206 immunofluorescence. During the experiment, regular postoperative observations were conducted on rats. After the experiment, sciatic nerve tissue was collected for HE staining, myelin staining, immunofluorescence staining, and Western blot analysis. To verify the role of the AMPK/NF-κB pathway, we applied the AMPK inhibitor Compound C and the NF-κB inhibitor BAY11-7082 to repeat the above experiment. Our experimental results reveal that NT-3 promotes sciatic nerve injury repair and polarization of M2 macrophage phenotype, promotes AMPK activation, and inhibits NF-κB activation. The repair effect of high concentration NT-3 on sciatic nerve injury is significantly enhanced compared to low concentration. Compound C administration can weaken the effect of NT-3, while BAY 11-7082 can enhance the effect of NT-3. In short, NT-3 significantly improves sciatic nerve injury in rats, promotes sciatic nerve function repair, accelerates M2 macrophage phenotype polarization, and improves neuroinflammatory response. The protective effects of NT-3 mentioned above are partially related to the AMPK/NF-κB signal axis.

Nuclear Factor Kappa B: A Nobel Therapeutic Target of FlavonoidsAgainst Parkinson's Disease.

Parkinson's disease (PD), the most common brain-related neurodegenerative disorder, is comprised of several pathophysiological mechanisms, such as mitochondrial dysfunction, neuroinflammation, aggregation of misfolded alpha-synuclein, and synaptic loss in the substantia nigra pars compacta region of the midbrain. Misfolded alpha-synuclein, originating from damaged neurons, triggers a series of signaling pathways in both glial and neuronal cells. Activation of such events results in the production and expression of several proinflammatory cytokines via the activation of the nuclear factor κB (NF-κB) signaling pathway. Consequently, this cascade of events worsens the neurodegenerative processes, particularly in conditions, such as PD and synucleinopathies. Microglia, astrocytes, and neurons are just a few of the many cells and tissues that express the NF-κB family of inducible types of transcription factors. The dual role of NF-κB activation can be crucial for neuronal survival, although the classical NF-κB pathway is important for controlling the generation of inflammatory mediators during neuroinflammation. Modulating NF-κB-associated pathways through the selective action of several agents holds promise for mitigating dopaminergic neuronal degeneration and PD. Several naturally occurring compounds in medicinal plants can be an effective treatment option in attenuating PD-associated dopaminergic neuronal loss via selectively modifying the NF-κB-mediated signaling pathways. Recently, flavonoids have gained notable attention from researchers because of their remarkable anti-neuroinflammatory activity and significant antioxidant properties in numerous neurodegenerative disorders, including PD. Several subclasses of flavonoids, including flavones, flavonols, isoflavones, and anthocyanins, have been evaluated for neuroprotective effects against in vitro and in vivo models of PD. In this aspect, the present review highlights the pathological role of NF-κB in the progression of PD and investigates the therapeutic potential of natural flavonoids targeting the NF-κB signaling pathway for the prevention and management of PD-like manifestations with a comprehensive list for further reference. Available facts strongly support that bioactive flavonoids could be considered in food and/or as lead pharmacophores for the treatment of neuroinflammation-mediated PD. Furthermore, natural flavonoids having potent pharmacological properties could be helpful in enhancing the economy of countries that cultivate medicinal plants yielding bioactive flavonoids on a large scale.

Extracellular RNA Induces Neutrophil Recruitment Via Toll-Like Receptor 3 During Venous Thrombosis After Vascular Injury.

Venous thromboembolism is associated with endothelial cell activation that contributes to the inflammation-dependent activation of the coagulation system. Cellular damage is associated with the release of different species of extracellular RNA (eRNA) involved in inflammation and coagulation. TLR3 (toll-like receptor 3), which recognizes (viral) single-stranded or double-stranded RNAs and self-RNA fragments, might be the receptor of these species of eRNA during venous thromboembolism. Here, we investigate how the TLR3/eRNA axis contributes to venous thromboembolism. Thrombus formation and size in wild-type and TLR3 deficient (-/-) mice were monitored by ultrasonography after venous thrombosis induction using the ferric chloride and stasis models. Mice were treated with RNase I, with polyinosinic-polycytidylic acid, a TLR3 agonist, or with RNA extracted from murine endothelial cells. Gene expression and signaling pathway activation were analyzed in HEK293T cells overexpressing TLR3 in response to eRNA or in human umbilical vein endothelial cells transfected with a small interference RNA against TLR3. Plasma clot formation on treated human umbilical vein endothelial cells was analyzed. Thrombosis exacerbated eRNA release invivo and increased eRNA content within the thrombus. RNase I treatment reduced thrombus size compared with vehicle-treated mice (P<0.05). Polyinosinic-polycytidylic acid and eRNA treatments increased thrombus size in wild-type mice (P<0.01 and P<0.05), but not in TLR3-/- mice, by reinforcing neutrophil recruitment (P<0.05). Mechanistically, TLR3 activation in endothelial cells promotes CXCL5 (C-X-C motif chemokine 5) secretion (P<0.001) and NFκB (nuclear factor kappa-light-chain-enhancer of activated B cells) activation (P<0.05). Finally, eRNA triggered plasma clot formation invitro (P<0.01). We show that eRNA and TLR3 activation enhance venous thromboembolism through neutrophil recruitment possibly through secretion of CXCL5, a potent neutrophil chemoattractant.

Catabolic mediators from TLR2-mediated proteoglycan aggrecan peptide-stimulated chondrocytes are reduced by Lactobacillus-conditioned media

In osteoarthritis (OA), extracellular matrix (ECM) digestion by cartilage-degrading enzymes drives cartilage destruction and generates ECM fragments, such as proteoglycan aggrecan (PG) peptides. PG peptides have been shown to induce immunological functions of chondrocytes. However, the role of PG peptides in stimulating catabolic mediators from chondrocytes has not been investigated. Therefore, we aim to determine the effects and its mechanism by which PG peptides induce chondrocytes to produce catabolic mediators in OA. Human chondrocytes were stimulated with IFNγ and various PG peptides either (i) with or (ii) without TLR2 blockade or (iii) with Lactobacillus species-conditioned medium (LCM), a genus of bacteria with anti-inflammatory properties. Transcriptomic analysis, cartilage-degrading enzyme production and TLR2-intracellular signaling activation were investigated. Chondrocytes treated with PG peptides p16-31 and p263-280 increased expression levels of genes associated with chondrocyte hypertrophy, cartilage degradation and proteolytic enzyme production. TLR2 downstream signaling proteins (STAT3, IkBα and MAPK9) were significantly phosphorylated in p263-280 peptide-stimulated chondrocytes. MMP-1 and ADAMTS-4 were significantly reduced in p263-280 peptides-treated condition with TLR2 blockade or LCM treatment. Phosphorylation levels of IkBa, ERK1/2 and MAPK9 were significantly decreased with TLR2 blockade, but only phosphorylation levels of MAPK9 was significantly decreased with LCM treatment. Our study showed that PG peptide stimulation via TLR2 induced cartilage-degrading enzyme production via activation of MAPK, NFκB and STAT3 pathways.

Trifolirhizin reduces osteoclast formation and prevents inflammatory osteolysis by inhibiting RANKL-induced activation of NF-κB and MAPK signaling pathways and ROS.

Inflammatory osteolysis is often caused by the excessive activation of osteoclasts stimulated by bacterial products such as lipopolysaccharide. The natural flavonoid trifolirhizin (TRI) has anti-inflammatory properties; however, its function in inflammatory bone lysis remains unclear. This study aimed to elucidate the potential regulatory mechanisms of TRI in osteoclasts.Tartrate-resistant acid phosphatase (TRAP) staining, acid secretion assays, podosomal actin belt fluorescence staining, and bone resorption assays were used to investigate the effects of TRI on osteoclast differentiation and bone resorption. A reactive oxygen species (ROS) measurement kit was used to detect the effect of TRI on ROS levels in osteoclasts. The effects of TRI on genes and signaling pathways related to osteoclast differentiation were determined by quantitative polymerase chain reaction (qPCR) and western blotting. A mouse model of lipopolysaccharide-mediated inflammatory osteolysis was established, and the effects of TRI treatment on bone mass were observed using micro-CT and histological examination. Mechanistically, TRI reduced ROS production by inhibiting receptor activator of nuclear factor-κB ligand (RANKL)-induced activation of the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, and by upregulating the expression levels of the anti-ROS enzymes heme oxygenase-1 (HO-1) and catalase (CAT), which contributed to the degradation of ROS, ultimately leading to a decrease in osteoclastogenesis. TRI inhibited osteoclast formation and ameliorated lipopolysaccharide (LPS)-mediated inflammatory osteolysis. Thus, TRI may be a candidate agent for anti-inflammatory osteolysis.

Aromadendrin Inhibits Lipopolysaccharide-Induced Inflammation in BEAS-2B Cells and Lungs of Mice.

Aromadendrin is a phenolic compound with various biological effects such as anti-inflammatory properties. However, its protective effects against acute lung injury (ALI) remain unclear. Therefore, this study aimed to explore the ameliorative effects of aromadendrin in an experimental model of lipopolysaccharide (LPS)-induced ALI. In vitro analysis revealed a notable increase in the levels of cytokine/chemokine formation, nuclear factor kappa B (NF-κB) activation, and myeloid differentiation primary response 88 (MyD88)/toll-like receptor (TLR4) expression in LPS-stimulated BEAS-2B lung epithelial cell lines that was ameliorated by aromadendrin pretreatment. In LPS-induced ALI mice, the remarkable upregulation of immune cells (ICs) and IL-1β/IL-6/TNF-α levels in the bronchoalveolar lavage fluid (BALF) and inducible nitric oxide synthase (iNOS)/cyclooxygenase-2 (COX-2)/CD68 expression in lung was decreased by the oral administration of aromadendrin. Histological analysis revealed the presence of cells in the lungs of acute lung injury (ALI) mice, which was alleviated by aromadendrin. In addition, aromadendrin ameliorated lung edema. This in vivo effect of aromadendrin was accompanied by its inhibitory effect on LPS-induced NF-κB activation, MyD88/TLR4 expression, and signal transducer and activator of transcription 3 (STAT3) activation. Furthermore, aromadendrin increased the expression of heme oxygenase-1 (HO-1)/ NAD(P)H quinone dehydrogenase 1 (NQO1) in the lungs of ALI mice. In summary, the in vitro and in vivo studies demonstrated that aromadendrin ameliorated endotoxin-induced pulmonary inflammation by suppressing cytokine formation and NF-κB activation, suggesting that aromadendrin could be a useful adjuvant in the treatment of ALI.

Circulating extracellular microvesicles associated with electronic cigarette use increase endothelial cell inflammation and reduce nitric oxide production.

The purpose of this study was to determine the effect of circulating microvesicles isolated from chronic electronic (e-)cigarette users on cultured human umbilical vein endothelial cell (HUVEC) expression of nuclear factor-κB (NF-κB), cellular cytokine release, phosphorylation of endothelial nitric oxide synthase (eNOS) and NO production. The HUVECs were treated with microvesicles isolated via flow cytometry from nine non-tobacco users (five male and four female; 22±2years of age) and 10 e-cigarette users (six male and four female; 22±2years of age). Microvesicles from e-cigarette users induced significantly greater release of interleukin-6 (183.4±23.6vs. 150.6±15.4 pg/mL; P=0.002) and interleukin-8 (160.0±31.6vs. 129.4±11.2 pg/mL; P=0.01), in addition to expression of p-NF-κB p65 (Ser536) (18.8±3.4 vs. 15.6±1.5 a.u.; P=0.02) from HUVECs compared with microvesicles from non-tobacco users. Nuclear factor-κB p65 was not significantly different between microvesicles from the non-tobacco users and from the e-cigarette users (87.6±8.7vs. 90.4±24.6 a.u.; P=0.701). Neither total eNOS (71.4±21.8vs. 80.4±24.5 a.u.; P=0.413) nor p-eNOS (Thr495) (229.2±26.5vs. 222.1±22.7 a.u.; P=0.542) was significantly different between microvesicle-treated HUVECs from non-tobacco users and e-cigarette users. However, p-eNOS (Ser1177) (28.9±6.2vs. 45.8±9.0 a.u.; P<0.001) expression was significantly lower from e-cigarette users compared with non-tobacco users. Nitric oxide production was significantly lower (8.2±0.6vs. 9.7±0.9μmol/L; P=0.001) in HUVECs treated with microvesicles from e-cigarette users compared with microvesicles from non-tobacco users. This study demonstrated increased NF-κB activation and inflammatory cytokine production, in addition to diminished eNOS activity and NO production resulting from e-cigarette use. HIGHLIGHTS: What is the central question of this study? Circulating microvesicles contribute to cardiovascular health and disease via their effects on the vascular endothelium. The impact of electronic (e-)cigarette use on circulating microvesicle phenotype is not well understood. What is the main finding and its importance? Circulating microvesicles from e-cigarette users increase endothelial cell inflammation and impair endothelial nitric oxide production. Endothelial inflammation and diminished nitric oxide bioavailability are central factors underlying endothelial dysfunction and, in turn, cardiovascular disease risk. Deleterious changes in the functional phenotype of circulating microvesicles might contribute to the reported adverse effects of e-cigarette use on cardiovascular health.

Sex differences in the transcriptional response to acute inflammatory challenge: A randomized controlled trial of endotoxin

BackgroundSex differences in immune-based disorders are well-established, with female sex associated with a markedly heightened risk of autoimmune disease. Female sex is also overrepresented in other conditions associated with elevated inflammation, including depression, chronic pain, and chronic fatigue. The mechanisms underlying these disparities are unclear. This study used an experimental model of inflammatory challenge to interrogate molecular mechanisms that may contribute to female vulnerability to disorders with an inflammatory basis. MethodIn this analysis of a secondary outcome from a randomized controlled trial, 111 participants (67 female) received either a bolus injection of endotoxin (n=59) or placebo (n=52). Participants provided blood samples before and 0.5 hours post-injection for assessment of differential activation of key pro-inflammatory (i.e., activator protein (AP)-1; nuclear factor (NF)-κB) and immunoregulatory (i.e., glucocorticoid receptor (GR); cAMP response element binding protein (CREB)) signaling pathways via genome-wide expression profiling and promoter-based bioinformatics analyses. ResultsRelative to males, females exhibited greater endotoxin-induced increases in bioinformatic measures of CREB transcription factor activity (p’s < 0.01). However, contrary to hypotheses, female vs. male sex was not associated with greater increases in activation of NF-κB, AP-1, or GR in response to endotoxin vs. placebo administration. ConclusionsThis work suggests CREB signaling as a critical upstream biological pathway that should be further interrogated as a mechanism of female vulnerability to immune-related disorders. Future work should clarify whether increased CREB signaling indicates sex differences in activity of the sympathetic nervous system or other physiological pathways that signal through CREB, such as prostaglandin release.

UBE2S facilitates glioblastoma progression through activation of the NF-κB pathway via attenuating K11-linked ubiquitination of AKIP1

BackgroundRapid proliferation is a hallmark of glioblastoma multiforme (GBM) and a major contributor to its recurrence. Aberrant ubiquitination has been implicated in various diseases, including cancer. In our preliminary studies, we identified Ubiquitin-conjugating enzyme E2S (UBE2S) as a potential glioma biomarker, exhibiting close associations with glioma grade and protein phosphatase 1, regulatory subunit 105 (Ki67) expression levels. However, the underlying molecular mechanisms remained elusive. NF-κB is an important signaling pathway that promotes GBM proliferation. Direct intervention targeting NF-κB has not yielded the expected results, prompting the exploration of new molecules for regulating NF-κB as a new direction. MethodsThis study employed methods including yeast two-hybrid and immunoprecipitation to uncover the interaction between UBE2S and A kinase interacting protein 1 (AKIP1). Laser confocal microscopy was used to observe the localization of UBE2S and AKIP1. Dual luciferase reporter genes were utilized to observe the activation of NF-κB. ResultsOur findings demonstrate that UBE2S deficiency significantly impedes GBM progression, both in vitro and in vivo. Mechanistically, UBE2S plays a crucial role in recruiting Ubiquitin Specific Peptidase 15 (USP15), facilitating the removal of K11-linked ubiquitination on AKIP1. This action enhances AKIP1 stability within the GBM context. The resulting increase in AKIP1 levels further augments nuclear factor kappa-B (NF-κB) transcriptional activity, leading to the upregulation of downstream genes regulated by the NF-κB pathway, thereby promoting GBM progression. ConclusionsIn summary, our findings reveal the role of the UBE2S/AKIP1-NF-κB axis in regulating GBM progression and provide novel evidence supporting UBE2S as a potential drug target for GBM.

Spatial and Temporal Distribution Characteristics and Cytotoxicity of Atmospheric PM2.5 in the Main Urban Area of Lanzhou City.

PM2.5, as one of the most harmful pollutant in the atmospheric environment and population health, has received much attention. We monitored PM2.5 levels at five sampling sites in the Lanzhou City and collected PM2.5 particles from two representative sites for cytotoxicity experiment. The cytotoxicity of PM2.5 samples on A549 cells and migration ability of the cells were respectively detected by Cell Counting kit-8 (CCK-8) assay and scratch assay. We detected the levels of cellular inflammatory factors and oxidative damage-related biochemical indexes. RT-qPCR was used to detect the mRNA levels of NF-κB and epithelial-mesenchymal transition (EMT)-related genes. We found that the Lanlian Hotel station had the highest PM2.5 annual average concentration. The annual average concentration change curve of PM2.5 showed a roughly "U"-shaped distribution during the whole sampling period. The cytotoxicity experiment showed the viability of A549 cells decreased and the scratch healing rate increased in the 200 and 400μg/mL PM2.5-treated groups. We also found 400μg/mL PM2.5 induced changes in the mRNA levels of NF-κB and EMT-related genes, the mRNA levels of IKK-α, NIK, and NF-κB in the 400μg/mL PM2.5 group were higher than those in the control group. The mRNA levels of E-cadherin decreased and α-SMA increased in the 400μg/mL PM2.5 groups, and the mRNA levels of Fibronectin increased in the 400μg/mL PM2.5 groups. Moreover, we found hydroxyl radical scavenging ability and T-AOC levels were lower, and LPO levels were higher in the 200 and 400μg/mL PM2.5 groups, and the SOD activity of cells in the 400µg/mL PM2.5 group decreased. And compared with the control group, the levels of TNF-α were higher in the 200 and 400μg/mL PM2.5 groups and the levels of IL-1 were higher in the 400μg/mL PM2.5 group. The results indicated that the cytotoxicity of atmospheric PM2.5 was related to oxidative damage, inflammatory response, NF-κB activity and EMT.

(+)-Catechin attenuates CCI-induced neuropathic pain in male rats by promoting the Nrf2 antioxidant pathway to inhibit ROS/TLR4/NF-κB-mediated activation of the NLRP3 inflammasome.

The objective of this study was to investigate the potential mechanisms by which (+)-catechin alleviates neuropathic pain. Thirty-two male Sprague-Dawley rats were divided into four groups: the sham group, the chronic constriction injury (CCI)group, the CCI+ ibuprofen group, and the CCI+ (+)-catechin group. CCI surgery induces thermal hyperalgesia in rats and (+)-catechin ameliorated CCI-induced thermal hyperalgesia and repaired damaged sciatic nerve in rats. CCI decreased SOD levels in male rat spinal cord dorsal horn and promoted MDA production, induced oxidative stress by increasing NOX4 levels and decreasing antioxidant enzyme HO-1 levels, and also increased protein levels of TLR4, p-NF-κB, NLRP3 inflammasome components, and IL-1β. In contrast, (+)-catechin reversed the above results. In i vitro experiments, (+)-catechin reduced the generation of reactive oxygen species (ROS) in GMI-R1 cells after LPS stimulation and attenuated the co-expression of IBA-1 and NLRP3. It also showed significant inhibition of the NF-κB and NLRP3 inflammatory pathways and activation of the Nrf2-mediated antioxidant system. Overall, these findings suggest that (+)-catechin inhibits the activation of the NLRP3 inflammasome through the triggering of the Nrf2-induced antioxidant system, the inhibition of the TLR4/NF-κB pathway, and the production of ROS to alleviate CCI-induced neuropathic pain in male rats.

Hexokinase 2 nonmetabolic function-mediated phosphorylation of IκBα enhances pancreatic ductal adenocarcinoma progression.

Aberrant signaling in tumor cells induces nonmetabolic functions of some metabolic enzymes in many cellular activities. As a key glycolytic enzyme, the nonmetabolic function of hexokinase 2 (HK2) plays a role in tumor immune evasion. However, whether HK2, dependent of its nonmetabolic activity, plays a role in human pancreatic ductal adenocarcinoma (PDAC) tumorigenesis remains unclear. Here, we demonstrated that HK2 acts as a protein kinase and phosphorylates IκBα at T291 in PDAC cells, activating NF-κB, which enters the nucleus and promotes the expression of downstream targets under hypoxia. HK2 nonmetabolic activity-promoted activation of NF-κB promotes the proliferation, migration, and invasion of PDAC cells. These findings provide new insights into the multifaceted roles of HK2 in tumor development and underscore the potential of targeting HK2 protein kinase activity for PDAC treatment.

The natural sesquiterpene lactone inulicin suppresses the production of pro-inflammatory mediators via inhibiting NF-κB and AP-1 pathways in LPS-activated macrophages

Objective Inulicin is a sesquiterpene lactone in Inulae Flos which is clinically used for the treatment of inflammatory diseases, such as cough, sputum production, and vomiting. This study aimed to demonstrate the anti-inflammatory activity and the underlying mechanism of inulicin by using lipopolysaccharide (LPS)-induced in vitro and in vivo models. Methods LPS-stimulated RAW264.7 macrophages and mouse peritoneal macrophages (MPMs) were used for evaluating the in vitro anti-inflammatory activity of inulicin, while endotoxemia mice were used for evaluating its in vivo action. Cytokines’ levels were determined by ELISA. RT-qPCR and western blot were used for assaying the mRNA and protein levels of target genes. RAW264.7 macrophages transfected with reporter plasmid pNFκB-TA-luc or pAP1-TA-luc were used for assaying the activation of NF-κB or AP-1 signaling. Results Inulicin significantly inhibited LPS-induced production of NO, IL-6, c-c motif chemokine ligand 2 (CCL2), and IL-1β in both RAW264.7 cells and MPMs. Mechanism study indicated that it could suppress inducible nitric oxide synthase, IL-6, CCL2, and IL-1β mRNA levels in LPS-stimulated RAW264.7 cells. Moreover, inulicin inhibited IκBα phosphorylation and prevented the nuclear translocation of p65, thereby inactivating NF-κB signaling. Concurrently, it also inhibited AP-1 signaling by reducing the phosphorylation of C-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). In endotoxemia mice, a single intraperitoneal administration of inulicin could decrease the production of pro-inflammatory cytokines in serum and peritoneal lavage fluid. Conclusions The present study demonstrates that inulicin possesses anti-inflammatory effects in vitro and in vivo, which suggests that inulicin might be a promising candidate for the treatment of inflammatory diseases.

TAX1BP1/A20 inhibited TLR2-NF-κB activation to induce tolerant expression of IL-6 in endothelial cells

The inflammatory cascadedriven by interleukin-6 (IL-6) plays a crucial role in the initiation and progression of chronic inflammatory conditions such as atherosclerosis. Research has demonstrated that prolonged exposure to inflammatory stimuli leads to the development of “immune tolerance” in specialized immune cells such as monocytes and macrophages, serving as a mechanism to prevent tissue damage and curb the inflammatory cascade. However, our recent investigation revealed that immune tolerance did not effectively regulate the production of IL-6 in human umbilical vein endothelial cells (HUVECs) when stimulated by a Toll-like receptor 2 (TLR2) ligand Pam3CSK4, which is a potent activator of the pro-inflammatory transcription factor NF-κB. Furthermore, the negative regulator of NF-κB signaling, A20, was ineffective in suppressing TLR2-induced IL-6 synthesis in this context. Notably, all A20 auxiliary molecules, with the exception of TAX1BP1, were found to be significantly expressed in HUVECs. DNA methylation in TAX1BP1 was confirmed in GEO database. According to the information provided, it is hypothesized that altered DNA methylation in HUVECs could potentially lead to decreased expression of TAX1BP1, thereby impeding A20′s capacity to modulate continuous activation of the TLR2-NF-κB pathway. This may consequently lead to unregulated production of IL-6, evading immune tolerance mechanisms. Subsequent investigations suggested that demethylating TAX1BP1 could enhance its expression, potentially reducing the endogenous IL-6 levels induced by repeated TLR2 stimulation and restoring A20′s inhibitory role in NF-κB signaling. Additionally, over-expression of TAX1BP1 coulddecrease the production of atherosclerosis-associated cytokines like IL-6, MCP-1, ICAM-1, and VCAM-1, while increasing NO release following repeated Pam3cks4 stimulation, along with enhanced co-localization of TAX1BP1 and A20. These findings indicate that inducing immune tolerance in endothelial cells may effectively suppress endogenous IL-6 production and halt the IL-6-mediated inflammatory cascade, with TAX1BP1/A20 identified as crucial components in this process.These insights provide novel perspectives and potential targets for therapeutic strategies in inflammatoryimmunological disorders involving the overproduction of IL-6.

Secretome from iPSC-derived MSCs exerts proangiogenic and immunosuppressive effects to alleviate radiation-induced vascular endothelial cell damage

BackgroundRadiation therapy is the standard of care for central nervous system tumours. Despite the success of radiation therapy in reducing tumour mass, irradiation (IR)-induced vasculopathies and neuroinflammation contribute to late-delayed complications, neurodegeneration, and premature ageing in long-term cancer survivors. Mesenchymal stromal cells (MSCs) are adult stem cells that facilitate tissue integrity, homeostasis, and repair. Here, we investigated the potential of the iPSC-derived MSC (iMSC) secretome in immunomodulation and vasculature repair in response to radiation injury utilizing human cell lines.MethodsWe generated iPSC-derived iMSC lines and evaluated the potential of their conditioned media (iMSC CM) to treat IR-induced injuries in human monocytes (THP1) and brain vascular endothelial cells (hCMEC/D3). We further assessed factors in the iMSC secretome, their modulation, and the molecular pathways they elicit.ResultsIncreasing doses of IR disturbed endothelial tube and spheroid formation in hCMEC/D3. When IR-injured hCMEC/D3 (IR ≤ 5 Gy) were treated with iMSC CM, endothelial cell viability, adherence, spheroid compactness, and proangiogenic sprout formation were significantly ameliorated, and IR-induced ROS levels were reduced. iMSC CM augmented tube formation in cocultures of hCMEC/D3 and iMSCs. Consistently, iMSC CM facilitated angiogenesis in a zebrafish model in vivo. Furthermore, iMSC CM suppressed IR-induced NFκB activation, TNF-α release, and ROS production in THP1 cells. Additionally, iMSC CM diminished NF-kB activation in THP1 cells cocultured with irradiated hCMEC/D3, iMSCs, or HMC3 microglial lines. The cytokine array revealed that iMSC CM contains the proangiogenic and immunosuppressive factors MCP1/CCL2, IL6, IL8/CXCL8, ANG (Angiogenin), GROα/CXCL1, and RANTES/CCL5. Common promoter regulatory elements were enriched in TF-binding motifs such as androgen receptor (ANDR) and GATA2. hCMEC/D3 phosphokinome profiling revealed increased expression of pro-survival factors, the PI3K/AKT/mTOR modulator PRAS40 and β-catenin in response to CM. The transcriptome analysis revealed increased expression of GATA2 in iMSCs and the enrichment of pathways involved in RNA metabolism, translation, mitochondrial respiration, DNA damage repair, and neurodevelopment.ConclusionsThe iMSC secretome is a comodulated composite of proangiogenic and immunosuppressive factors that has the potential to alleviate radiation-induced vascular endothelial cell damage and immune activation.

Ferritin Light Chain Alleviates Cerebral Ischemic-Reperfusion Injury-Induced Neuroinflammation via the HIF1α Mediated NF-κB Signaling Pathways.

Ferritin light chain (FtL) is a complex formed by apoferritin and iron core and is one of the main storage forms of iron. Currently, the precise role of FtL in cerebral ischemia/reperfusion injury (CIRI) remains undetermined. This investigation aimed to elucidate the roles and underlying mechanisms of FtL in CIRI. To induce CIRI, an oxygen-glucose deprivation (OGD) model in microglia and middle cerebral artery occlusion (MCAO) model were established using C57BL/6J mice. The in vivo and in vitro FtL expression patterns were assessed. Furthermore, the potential regulatory mechanism of FtL at the upstream level was also explored. In addition, the in vivo and in vitro role of FtL in post-ischemic inflammation was also clarified. The results indicated that FtL was up-regulated in OGD-induced microglia and CIRI mice. Moreover, OGD activated HIF1α, which interacted with the FtL promoter region as an activator, thereby increasing FtL expression. Furthermore, FtL attenuated the release of pro-inflammatory cytokines (TNFα, IL6) and decreased levels of COX2 and iNOS in microglia; however, FtL knockdown had the opposite effects. Up-regulated FtL was observed to inhibit OGD-induced NF-κB activation in microglia, decreased IκBα degradation, and reduced NF-κB/p65 nuclear translocation. In summary, this study revealed an underlying mechanism of FtL upregulation via HIF1α and highlighted its protective role against post-ischemic neuroinflammation, indicating the potential of FtL as a target for CIRI treatment.

Ammonia transporter RhBG initiates downstream signaling and functional responses by activating NFκB

Transceptors, solute transporters that facilitate intracellular entry of molecules and also initiate intracellular signaling events, have been primarily studied in lower-order species. Ammonia, a cytotoxic endogenous metabolite, is converted to urea in hepatocytes for urinary excretion in mammals. During hyperammonemia, when hepatic metabolism is impaired, nonureagenic ammonia disposal occurs primarily in skeletal muscle. Increased ammonia uptake in skeletal muscle is mediated by a membrane-bound, 12 transmembrane domain solute transporter, Rhesus blood group-associated B glycoprotein (RhBG). We show that in addition to its transport function, RhBG interacts with myeloid differentiation primary response-88 (MyD88) to initiate an intracellular signaling cascade that culminates in activation of NFκB. We also show that ammonia-induced MyD88 signaling is independent of the canonical toll-like receptor-initiated mechanism of MyD88-dependent NFκB activation. In silico, in vitro, and in situ experiments show that the conserved cytosolic J-domain of the RhBG protein interacts with the Toll-interleukin-1 receptor (TIR) domain of MyD88. In skeletal muscle from human patients, human-induced pluripotent stem cell-derived myotubes, and myobundles show an interaction of RhBG-MyD88 during hyperammonemia. Using complementary experimental and multiomics analyses in murine myotubes and mice with muscle-specific RhBG or MyD88 deletion, we show that the RhBG-MyD88 interaction is essential for the activation of NFkB but not ammonia transport. Our studies show a paradigm of substrate-dependent regulation of transceptor function with the potential for modulation of cellular responses in mammalian systems by decoupling transport and signaling functions of transceptors.

Epinephelus coioides Sec3 promotes Singapore grouper iridovirus infection by negatively regulates immune response

Exocyst, a protein complex, plays a crucial role in various cellular functions, including cell polarization, migration, invasion, cytokinesis, and autophagy. Sec3, known as Exoc1, is a key subunit of the Exocyst complex and can be involved in cell survival and apoptosis. In this study, two subtypes of Sec3 were isolated from Epinephelus coioides, an important marine fish in China. The role of E. coioides Sec3 was explored during Singapore grouper iridovirus (SGIV) infection, an important pathogen of marine fish which could induce 90 % mortality. E. coioides Sec3 sequences showed a high similarity with that from other species, indicating the presence of a conserved Sec3 superfamily domain. E. coioides Sec3 mRNA could be detected in all examined tissues, albeit at varying expression levels. SGIV infection could upregulate E. coioides Sec3 mRNA. Upregulated Sec3 significantly promoted SGIV-induced CPE, and the expressions of viral key genes. E. coioides Sec3 could inhibit the activation of NF-κB and AP-1, as well as SGIV-induced cell apoptosis. The results illustrated that E. coioides Sec3 promotes SGIV infection by regulating the innate immune response.

Netrin 1 as a biomarker in cancer: scoping diagnostic, prognostic, and therapeutic perspectives with a focus on oral squamous cell carcinoma

Goal of the review: The utilization of biomarkers to predict cancer risk, prognosis, and treatment outcomes is paramount. Netrin-1 (NTN1), known for its role in commissural axon guidance during embryonic development, has emerged as a versatile molecule with significant implications in cancer and neurobiology. Structurally resembling laminin, Netrin-1 regulates neuronal connectivity and plasticity in adulthood, influencing axonal and dendritic growth, neurotransmission, and cell migration. In addition to its neurological functions, Netrin-1 is increasingly recognized for its involvement in maintaining epithelial tissue and its regulatory roles in fundamental cellular processes, including adhesion, proliferation, differentiation, apoptosis, and angiogenesis.In cancer biology, Netrin-1′s interactions with its receptors, such as DCC [Deleted in Colorectal Cancer] and UNC5 (a homolog of DCC), have been implicated in tumor progression across various physiological systems. Elevated levels of Netrin-1 in colorectal cancer and head and neck squamous cell carcinoma are correlated with increased tumorigenic potential, mediated through pathways involving NFκB activation and anti-apoptotic mechanisms. Mechanically induced hypermethylation and downstream signaling cascades that inhibit apoptosis and promote cell survival are observed upon Netrin-1 binding to DCC.Furthermore, Netrin-1 shows promise as a biomarker for detecting inflammatory activity in diseases such as multiple sclerosis and as a potential diagnostic, prognostic, and therapeutic indicator in oral squamous cell carcinoma. Elevated levels of Netrin-1 in bodily fluids, alongside immunohistochemical evidence, support its potential as a valuable clinical marker in cancer management.This abstract emphasizes Netrin-1′s diverse biological roles, underscoring its potential as a diagnostic tool and therapeutic target in cancer research. The need for further exploration of Netrin-1′s molecular interactions and clinical applications is urgent and crucial to advance personalized medicine approaches and enhance patient outcomes in oncology and neurology.

Protective effects of nordalbergin against LPS-induced endotoxemia through inhibiting MAPK/NF-κB signaling pathway, NLRP3 inflammasome activation, and ROS production.

Nordalbergin is a coumarin extracted from Dalbergia sissoo DC. To date, the biological effects of nordalbergin have not been well investigated. To investigate the anti-inflammatory responses and the anti-oxidant abilities of nordalbergin using lipopolysaccharide (LPS)-activated macrophages and LPS-induced sepsis mouse model. Production of nitrite oxide (NO), prostaglandin E2 (PGE2), pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β), reactive oxygen species (ROS), tissue damage and serum inflammatory markers, and the activation of the NLRP3 inflammasome were examined. Our results indicated that nordalbergin reduced the production of NO and pro-inflammatory cytokines in vitro and ex vivo. Nordalbergin also suppressed iNOS and cyclooxygenase-2 expressions, decreased NF-κB activity, and attenuated MAPKs signaling pathway activation by decreasing JNK and p38 phosphorylation by LPS-activated J774A.1 macrophages. Notably, nordalbergin diminished NLRP3 inflammasome activation via repressing the maturation of IL-1β and caspase-1 and suppressing ROS production by LPS/ATP- and LPS/nigericin-activated J774A.1 macrophages. Furthermore, nordalbergin exhibited protective effects against the infiltration of inflammatory cells and also inhibited the levels of organ damage markers (AST, ALT, BUN) by LPS-challenged mice. Nordalbergin possesses anti-inflammatory effects in macrophage-mediated innate immune responses, alleviates ROS production, decreases NLRP3 activation, and exhibits protective effects against LPS-induced tissue damage in mice.