Inhibition Of NF-κB Activation Research Articles

Exploring the anti-inflammatory activity of the plant-derived phytochemical sulforaphane from cruciferous vegetables

Dysregulation of immune responses results in the development of chronic inflammatory conditions. The current frontline therapy, glucocorticoids, are effective immunosuppressive drugs but come with a trade-off of cumulative, debilitating side effects with sustained use. Clearly, alternative drug options with improved safety profiles are urgently needed. Macrophage Migration Inhibitory Factor (MIF) is a pleotropic pro-inflammatory cytokine and integral component of immune and inflammatory responses. MIF counter-regulates the immunosuppressive effects of glucocorticoids and promotes NLRP3 inflammasome activation.1, 2 Elevated MIF is a feature of multiple diseases, including multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematous. Given the association of increased MIF in serum with multiple disease models, it is considered MIF may be a plausible, specific druggable target in treatment of chronic inflammatory and autoimmune diseases, particularly as a target for glucocorticoid-sparing therapy to reduce the dose or duration of glucocorticoid treatment. The organosulfur isothiocyanate phytochemical sulforaphane (SFN) is extracted from cruciferous vegetables, including broccoli and Brussel sprouts following hydrolysis of its inactive precursor, glucoraphanin. SFN has antioxidant and cancer chemoprotective properties, and promotes NRF2 antioxidant signalling to upregulate the expression of numerous antioxidant enzymes. SFN has been shown to covalently modify MIF with high reactivity and is a potent inhibitor of MIF tautomerase activity. However, to date, no such study has evaluated the role of SFN as a novel inhibitor of MIF-mediated inflammatory pathway activation. Using cell-based assays, we have sought to investigate the role of SFN as an inhibitor of multiple inflammatory pathways which have previously implicated MIF as a possible regulator. Our initial work has examined SFN as an inhibitor of NF-κB activity, inflammasome activation, and evaluated if MIF is required for this effect. RAW264.7 murine macrophage cells stably expressing NF-κB-luciferase reporter construct were pre-treated with SFN (2.5 µM) before the induction of inflammation, via LPS (100ng/mL). For NLRP3 inflammasome activation, cells were subsequently treated with the NLRP3-specific inflammasome activator, nigericin (10 µM). TNF, IFN-β and IL-1β cytokine expression was measured by ELISA and NF-κB activity by luciferase reporter assay. We found SFN is a potent inhibitor of NF-κB activity and inhibits release of the pro-inflammatory cytokine IL-1β through inhibition of NLRP3 inflammasome activation. Finally, co-incubation of SFN with the glucocorticoid dexamethasone significantly suppressed TNF and IFN-β expression, demonstrating steroid sparing activity of SFN in vitro. Thus, SFN may be a suitable treatment for disruption of inflammatory pathways and suggest some of these effects may be mediated through direct interactions with MIF.

African swine fever virus A137R protein inhibits NF-κB activation via suppression of MyD88 signaling in PK15 and 3D4/21 cells in vitro

African swine fever (ASF) is an infectious disease with high mortality caused by African swine fever virus (ASFV), which poses a great threat to the global swine industry. ASFV has evolved multiple strategies to evade host antiviral innate immunity by perturbing inflammatory responses and interferon production. However, the molecular mechanisms underlying manipulation of inflammatory responses by ASFV proteins are not fully understood. Here, we report that A137R protein of ASFV is a key suppressor of host inflammatory responses. Ectopic expression of ASFV A137R in HEK293T cells significantly inhibited the activation of IL-8 and NF-κB promoters triggered by Sendai virus (SeV), influenza A virus (IAV), or vesicular stomatitis virus (VSV). Accordingly, forced A137R expression caused a significant decrease in the production of several inflammatory cytokines such as IL-8, IL-6 and TNF-α in the cells infected with SeV or IAV. Similar results were obtained from experiments using A137R overexpressing PK15 and 3D4/21 cells infected with SeV or VSV. Furthermore, we observed that A137R impaired the activation of MAPK and NF-κB signaling pathways, as enhanced expression of A137R significantly decreased the phosphorylation of JNK, p38 and p65 respectively upon viral infection (SeV or IAV) and IL-1β treatment. Mechanistically, we found that A137R interacted with MyD88, and dampened MyD88-mediated activation of MAPK and NF-κB signaling. Together, these findings uncover a critical role of A137R in restraining host inflammatory responses, and improve our understanding of complicated mechanisms whereby ASFV evades innate immunity.

Acetyl-CoA synthetase 2 induces pyroptosis and inflammation of renal epithelial tubular cells in sepsis-induced acute kidney injury by upregulating the KLF5/NF-κB pathway

BackgroundPyroptosis of the renal tubular epithelial cells (RTECs) and interstitial inflammation are central pathological characteristics of acute kidney injury (AKI). Pyroptosis acts as a pro-inflammatory form of programmed cell death and is mainly dependent on activation of the NLRP3 inflammasome. Previous studies revealed that acetyl-CoA synthetase 2 (ACSS2) promotes inflammation during metabolic stress suggesting that ACSS2 might regulate pyroptosis and inflammatory responses of RTECs in AKI.Methods and resultsThe expression of ACSS2 was found to be significantly increased in the renal epithelial cells of mice with lipopolysaccharide (LPS)-induced AKI. Pharmacological and genetic strategies demonstrated that ACSS2 regulated NLRP3-mediated caspase-1 activation and pyroptosis through the stimulation of the KLF5/NF-κB pathway in RTECs. The deletion of ACSS2 attenuated renal tubular pathological injury and inflammatory cell infiltration in an LPS-induced mouse model, and ACSS2-deficient mice displayed impaired NLRP3 activation-mediated pyroptosis and decreased IL-1β production in response to the LPS challenge. In HK-2 cells, ACSS2 deficiency suppressed NLRP3-mediated caspase-1 activation and pyroptosis through the downregulation of the KLF5/NF-κB pathway. The KLF5 inhibitor ML264 suppressed NF-κB activity and NLRP3-mediated caspase-1 activation, thus protecting HK-2 cells from LPS-induced pyroptosis.ConclusionOur results suggested that ACSS2 regulates activation of the NLRP3 inflammasome and pyroptosis by inducing the KLF5/NF-κB pathway in RTECs. These results identified ACSS2 as a potential therapeutic target in AKI.Graphical We found that the expression of ACSS2 was significantly increased in RTECs in septic AKI. ACSS2-deficient mice displayed resistance to renal damage in this model. ACSS2 regulated NLRP3-mediated caspase-1 activation and pyroptosis through the KLF5/NF-κB pathway in RTECs. Pharmacological inhibition of KLF5 suppressed NLRP3 activation and caspase-1 cleavage by downregulating of NF-κB. Our results suggest that ACSS2 is a pro-pathogenic mediator of cell pyroptosis of RTECs and renal inflammation in sepsis-induced AKI.

BMSCs-derived Exosome CISH Alleviates Myocardial Infarction by Inactivating the NF-κB Pathway to Stimulate Macrophage M2 Polarization.

Current myocardial infarction (MI) treatments are suboptimal, necessitating deeper pathogenesis understanding of MI. This research explored how exosomes (Exo) derived from bone marrow mesenchymal stem cells (BMSCs) contribute to MI mitigation and their therapeutic potential. Isolated BMSCs was identified by microscope, flow cytometry, alizarin red and oil red O staining. Exo were identified by TEM, NTA and western blot. HE staining, masson staining, and cardiac function parameters were used to assess the cardiac function in MI mice. TUNEL staining, western blot and qRT-PCR were used to detect apoptosis, inflammatory factors and M1/M2 markers. The NF-κB pathway activation was detected through western blot assays. Immunofluorescence, qRT-PCR, western blot, and flow cytometry were employed to evaluate macrophage polarization. MI mice showed cardiac injury, increased apoptosis and inflammation, while BMSCs-Exo treatment alleviated these effects. In MI mice, the macrophage M1 polarization was increased and the NF-κB pathway was activated, whereas BMSCs-Exo treatment reversed these changes. Furthermore, CISH expression was reduced in MI mice, but was elevated with BMSCs-Exo treatment. In vitro, LPS shifted RAW264.7 cells to M1 phenotype and activated the NF-κB pathway, yet BMSCs-Exo shifted them to M2 phenotype and inhibited the NF-κB pathway. Mechanistically, BMSCs-Exo induced macrophage M2 polarization by transmitting CISH to inhibit NF-κB activation. BMSCs-Exo mitigates MI by transmitting CISH to inhibit the NF-κB pathway, promoting macrophages to M2 type. This implies BMSCs-Exo could be a useful treatment for MI, and CISH could be a potential therapy target.

IMPACT OF NF-κB AND NRF2 TRANSCRIPTION FACTOR MODULATORS ON METABOLIC CHARACTERISTICS IN MANDIBLE BONES OF RATS DURING RECOVERY FROM INCOMPLETE FRACTURE UNDER CHRONIC ALCOHOL INTOXICATION

This study aims at investigating the influence of specific modulators of NF-κB and Nrf2 transcription factors on oxidative-nitrosative stress indicators and bone biopolymer depolymerization in mandibular bone following incomplete fracture under chronic alcohol intoxication (CAI). Twenty-eight white male Wistar rats were divided into five groups: Group 1 comprised "falsely injured" rats, while Group 2 underwent incomplete mandibular fracture (IMF) under CAI exposure. Rats in groups 3 and 4 received intraperitoneal injections of ammonium pyrrolidinium dithiocarbamate, an inhibitor of NF-κB activation, in a dose of 76 mg/kg, and dimethyl fumarate, an Nrf2 inducer, in a dose of 15 mg/kg three times a week for 14 days following the modeling of IMF under CAI exposure. The activity of total NO synthase, including its constitutive and inducible isoforms, along with ornithine decarboxylase, and concentrations of peroxynitrites of alkaline and alkaline-earth metals, free hydroxyproline, N-acetylneuraminic, and hexuronic acids were assessed in the homogenate of the standard mandible area using a spectrophotometric method. The findings have demonstrated that the administration of ammonium pyrrolidine dithiocarbamate and dimethyl fumarate notably decreased the activity of NO synthase (primarily its inducible isoform) and the concentration of peroxynitrite in the mandibular bone homogenate, while increasing the activity of ornithine decarboxylase, a key enzyme in polyamine biosynthesis. Furthermore, under experimental conditions, the use of ammonium pyrrolidine dithiocarbamate and dimethyl fumarate limited the depolymerization of bone biopolymers (collagen, glycoproteins, and proteoglycans), thereby facilitating effective reparative osteogenesis.

Expression of several deubiquitinase and tyrosine phosphatase genes involved in inflammatory response in lymphoma

Lymphoma represents a heterogeneous group of cancers affecting the lymphatic system, encompassing non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL). The majority of NHL cases originate from B cells. HL is characterized by the presence of rare Hodgkin and Reed-Sternberg cells. Within the context of the inflammatory response, two SH2 domain-containing protein tyrosine phosphatases (SHPs), namely SHP-1 and SHP-2, serve as negative regulators. Deubiquitinating enzymes (DUBs) play a crucial role in inhibiting NF-κB activation in response to various stimuli. This study focuses on the DUBs OTUB1, OTUB2, and Cezanne. Blood samples were collected from 50 NHL patients, 26 HL patients, and 50 healthy individuals. Quantitative RT-PCR was employed to assess the mRNA expression of OTUB1, OTUB2, Cezanne, SHP-1,and SHP-2, while ELISA was used to determine IL-6 and CA125 concentrations. The results revealed that the mRNA level of OTUB1 was significantly downregulated in NHL patients but not in HL patients. Notably, Cezanne expression was downregulated in lymphoma patients, with significantly lower levels observed in HL compared to NHL patients. Furthermore, SHP-1 mRNA expression was significantly lower in the NHL group compared to the HL group or healthy individuals. Conversely, SHP-2 gene expression was upregulated in NHL patients but remained unchanged in HL patients. In conclusion, these findings highlight significant differences in the expressions of DUB and SHP genes and the inflammatory response in lymphoma patients. This study provides a foundation for further investigation into the roles of DUBs and tyrosine phosphatases in regulating the functional activation of lymphoma cells.

Therapeutic potential of salidroside in preserving rat cochlea organ of corti from gentamicin-induced injury through modulation of NRF2 signaling and GSK3β/NF-κB pathway.

Salidroside (SAL) is a phenol glycoside compound found in plants of the Rhodiola genus which has natural antioxidant and free radical scavenging properties. SAL are able to protect against manganese-induced ototoxicity. However, the molecular mechanism by which SAL reduces levels of reactive oxygen species (ROS) is unclear. Here, we established an in vitro gentamicin (GM) ototoxicity model to observe the protective effect of SAL on GM-induced hair cells (HC) damage. Cochlear explants of postnatal day 4 rats were obtained and randomly divided into six groups: two model groups (treatment with 0.2 mM or 0.4 mM GM for 24 h); two 400 μmol/L SAL-pretreated groups pretreatment with SAL for 3 h followed by GM treatment (0.2 mM or 0.4 mM) for 24 h; 400 μmol/L SAL group (treatment with SAL for 24 h); control group (normal cultured cochlear explants). The protective effects of SAL on GM-induced HC damage, and on mRNA and protein levels of antioxidant enzymes were observed. HC loss occurred after 24 h of GM treatment. Pretreatment with SAL significantly reduced GM-induced OHC loss. In cochlear tissues, mRNA and protein levels of NRF2 and HO-1 were enhanced in the GM alone group compared with the SAL pretreatment GM treatment group. SAL may protect against GM-induced ototoxicity by regulating the antioxidant defense system of cochlear tissues; SAL can activate NRF2/HO-1 signaling, inhibit NF-κB activation, activate AKT, and increase inhibitory phosphorylation of GSK3β to decrease GSK3 activity, all of which exert antioxidant effects.

Regulatory impact of statins on macrophage polarization: mechanistic and therapeutic implications.

Statins, also known as HMG-CoA reductase inhibitors, are widely prescribed drugs for the prevention and treatment of cardiovascular diseases. In addition to their lipid-lowering effects, these compounds have been found to possess immune-modulating properties. Macrophages, which are crucial phagocytic cells in the body, can be divided into two main subsets: M1 (proinflammatory) and M2 (anti-inflammatory). While there is evidence suggesting that statins exert an anti-inflammatory action on macrophages and promote their polarization towards the M2 subset, recent studies have identified the proinflammatory impact of statins on macrophages, leading to polarization towards the M1 subset. For example, statins have been shown to inhibit NF-κB activation to promote anti-inflammatory responses. On the other hand, statins can induce NFκB/AP-1 activation and increase IL-1β secretion in macrophages to promote pro-inflammatory responses. This review aims to provide a comprehensive overview of both in vivo and in vitro studies that have investigated the effects of statins on macrophage polarization and inflammatory responses in various diseases. Furthermore, this review seeks to evaluate the underlying mechanisms involved in these effects. By summarizing the existing evidence, this review contributes to our understanding of the complex interactions between statins and macrophages in different disease contexts.

Role of sirtuin 1 (SIRT1) in regulation of autophagy and nuclear factor-kappa Beta (NF-ĸβ) pathways in sorafenib-resistant hepatocellular carcinoma (HCC).

Hepatocellular carcinoma (HCC) remains a major global health problem with high incidence and mortality. Diagnosis of HCC at late stages and tumour heterogeneity in patients with different genetic profiles are known factors that complicate the disease treatment. HCC therapy becomes even more challenging in patients with drug resistance such as resistance to sorafenib, which is a common drug used in HCC patients. Sorafenib resistance can further aggravate HCC by regulating various oncogenic pathways such as autophagy and nuclear factor-kappa Beta (NF-ĸβ) signalling. Sirtuin 1 (SIRT1), is a nicotinamide adenosine dinucleotide (NAD)-dependent histone deacetylases that regulates various metabolic and oncogenic events such as cell survival, apoptosis, autophagy, tumourigenesis, metastasis and drug resistance in various cancers, but its role in HCC, particularly in sorafenib resistance is underexplored. In this study, we generated sorafenib-resistant HepG2 and Huh-7 liver cancer cell models to investigate the role of SIRT1 and its effect on autophagy and nuclear factor-kappa Beta (NF-ĸβ) signalling pathways. Western blot analysis showed increased SIRT1, altered autophagy pathway and activated NF-ĸβ signalling in sorafenib-resistant cells. SIRT1-silenced HCC cells demonstrated down-regulated autophagy in both parental and chemoresistant cells. This may occur through the deacetylation of key autophagy molecules such as FOXO3, beclin 1, ATGs and LC3 by SIRT1, highlighting the role of SIRT1 in autophagy induction. Silencing of SIRT1 also resulted in activated NF-ĸβ signalling. This is because SIRT1 failed to deacetylate p65 subunit of NF-κB, translocate the NF-κB from nucleus to cytoplasm, and suppress NF-κB activity due to the silencing. Hence, the NF-κB transcriptional activity was restored. These findings summarize the role of SIRT1 in autophagy/NF-ĸβ regulatory axis, with a similar trend observed in both parental and sorafenib-resistant cells. The present work promotes a better understanding of the role of SIRT1 in autophagy and NF-ĸβ signalling in HCC and sorafenib-resistant HCC. As some key proteins in these pathways are potential therapeutic targets, a better understanding of SIRT1/autophagy/NF-ĸβ axis could further improve the therapeutic strategies against HCC.

Dynamic bidirectional regulation of NLRC3 and gammaherpesviruses during viral latency in B lymphocytes.

While most NOD-like receptors (NLRs) are predominately expressed by innate immune cells, NLRC3, an inhibitory NLR of immune signaling, exhibits the highest expression in lymphocytes. The role of NLRC3 or any NLRs in B lymphocytes is completely unknown. Gammaherpesviruses, including human Epstein-Barr virus (EBV) and murine gammaherpesvirus 68 (MHV-68), establish latent infection in B lymphocytes, which requires elevated NF-κB. This study shows that during latent EBV infection of human B cells, viral-encoded latent membrane protein 1 (LMP1) decreases NLRC3 transcript. LMP1-induced-NF-κB activation suppresses the promoter activity of NLRC3 via p65 binding to the promoter. Conversely, NLRC3 inhibits NF-κB activation by promoting the degradation of LMP1 in a proteasome-dependent manner. In vivo, MHV-68 infection reduces Nlrc3 transcripts in splenocytes, and Nlrc3-deficient mice show greater viral latency than controls. These results reveal a bidirectional regulatory circuit in B lymphocytes, where viral latent proteinLMP1 reduces NLRC3 expression, while NLRC3 disrupts gammaherpesvirus latency, which is an important step for tumorigenesis.

Tetrandrine alleviates inflammation and promotes macrophage M2 polarization in gouty arthritis by NF-κB-mediated Lcp1.

Gouty arthritis (GA) is an inflammatory disease caused by the deposition of monosodium urate (MSU) crystals into joints. Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid extracted from the root of Stephania tetrandra and can exert an anti-inflammatory function in different diseases. Nevertheless, the specific function of TET in GA remains unclear. We established the GA mouse model by MSU injection into joints of mice. Paw volume and gait score were detected for measuring the degree of joint swelling and the situation of joint dysfunction. Western blot were utilized to test the alterations of M1-related factors (IL-6, IL-1β, TNF-α, IL-12, and iNOS) and M2-related factors (Mgl1, Mgl2, Pgc1-β, Arg-1, and IL-10). The activity of NF-κB p65 in tissues was determined. The interaction of NF-κB p65 and Lcp1 was measured by ChIP and luciferase reporter assay. Lcp1 KO mice were utilized to detect the effect of Lcp1 depletion on GA process. TET treatment markedly suppressed MSU-induced joint swelling, joint dysfunction, and joint injury in GA mice. TET can also reduce inflammatory reactions in MUS-induced mice. Furthermore, we proved that TET facilitated M2 macrophage polarization and inhibited M1 macrophage polarization in GA mice. In addition, TET was found to inhibit NF-κB activity and NF-κB-mediated Lcp1 expression. Lcp1 knockdown can improve joint injury and promote M2 macrophage polarization in GA mice, while this effect was further enhanced by TET. TET alleviates inflammation and facilitates macrophage M2 polarization in GA by NF-κB-mediated Lcp1.

Multichannel-optical imaging for in vivo evaluating the safety and therapeutic efficacy of stem cells in tumor model in terms of cell tropism, proliferation and NF-κB activity

Stem cell-based cancer treatment has garnered significant attention, yet its safety and efficacy remain incompletely understood. The nuclear factor-kappa B (NF-κB) pathway, a critical signaling mechanism involved in tumor growth, angiogenesis, and invasion, serves as an essential metric for evaluating the behavior of stem cells in tumor models. Herein, we report the development of a triple-channel imaging system capable of simultaneously monitoring the tropism of stem cells towards tumors, assessing tumor proliferation, and quantifying tumor NF-κB activity. In this system, we generated a CRISPR-Cas9 gene-edited human glioblastoma cell line, GE-U87-MG, which provided a reliable readout of the proliferation and NF-κB activity of tumors by EF1α-RFLuc- and NF-κB-GLuc-based bioluminescent imaging, respectively. Additionally, near infrared-II emitting Tat-PEG-AgAuSe quantum dots were developed for tracking of stem cell tropism towards tumor. In a representative case involving human mesenchymal stem cells (hMSCs), multichannel imaging revealed no discernible effect of hMSCs on the proliferation and NF-κB activity of GE-U87-MG tumors. Moreover, hMSCs engineered to overexpress the necrosis factor-related apoptosis-inducing ligand were able to inhibit NF-κB activity and growth of GE-U87-MG in vivo. Taken together, our imaging system represents a powerful and feasible approach to evaluating the safety and therapeutic efficacy of stem cells in tumor models.

Lactate Protects Intestinal Epithelial Barrier Function from Dextran Sulfate Sodium-Induced Damage by GPR81 Signaling.

The dysregulation of the intestinal epithelial barrier significantly contributes to the inflammatory progression of ulcerative colitis. Recent studies have indicated that lactate, produced by gut bacteria or derived from fermented foods, plays a key role in modulating inflammation via G-protein-coupled receptor 81 (GPR81). In this study, we aimed to investigate the potential role of GPR81 in the progression of colitis and to assess the impact of lactate/GPR81 signaling on intestinal epithelial barrier function. Our findings demonstrated a downregulation of GPR81 protein expression in patients with colitis. Functional verification experiments showed that Gpr81-deficient mice exhibited more severe damage to the intestinal epithelial barrier and increased susceptibility to DSS-induced colitis, characterized by exacerbated oxidative stress, elevated inflammatory cytokine secretion, and impaired expression of tight-junction proteins. Mechanistically, we found that lactate could suppress TNF-α-induced MMP-9 expression and prevent the disruption of tight-junction proteins by inhibiting NF-κB activation through GPR81 in vitro. Furthermore, our study showed that dietary lactate could preserve intestinal epithelial barrier function against DSS-induced damage in a GPR81-dependent manner in vivo. Collectively, these results underscore the crucial involvement of the lactate/GPR81 signaling pathway in maintaining intestinal epithelial barrier function, providing a potential therapeutic strategy for ulcerative colitis.

Ginsenoside Compound K Reduces Psoriasis-related Inflammation by Activation of the Glucocorticoid Receptor in Keratinocytes.

To investigate the effects and mechanism of Ginsenoside Compound K (GCK) on psoriasis, focusing on the glucocorticoid receptor (GR) in keratinocytes. An imiquimod (IMQ)-induced psoriasis-like dermatitis mouse model was generated to evaluate the anti-inflammatory effect of GCK. Hematoxylin and eosin (H&E) staining was used to assess skin pathological changes. Protein expression of K17 and p-p65 in mice skin was assayed by immunohistochemical. Protein expression and phosphorylation of p65 IκB were assayed by Western blot. Protein expression of K1, K6, K10, K16, K17, and GR were assayed by Western blot and immunofluorescence. Enzyme-linked immunosorbent assay (ELISA) was used to determine cytokine levels of TNF-α, IL-6, CXCL-8, and ICAM-1. Real-time polymerase chain reaction (RT-PCR) was used to quantify TNF-α, IL-6, IL-8, and ICAM-1 mRNA expression. Cell viability was determined by Cell Counting Kit-8(CCK-8) assay. A high-content cell-imaging system was used to assay cell proliferation. Nuclear translocation of p65 and GR was assayed by imaging flow cytometry and immunofluorescence microscopy. Small interfering RNA was used to confirm the role of GR in the anti-inflammatory and immunoregulatory effect of GCK in normal human epidermal keratinecytes (NHEKs). GCK reduced the psoriasis area, severity index, and epidermal thickening in IMQ-induced mice. GCK significantly attenuated the mRNA levels of IL-6, IL-8, TNF-α, and ICAM-1 and reduced epidermal hyperproliferation in the skin of IMQ-induced mice. GCK inhibited in vitro activation of NF-κB, leading to attenuated release of inflammatory mediators (IL-6, IL-8, TNF-α, and ICAM-1) and suppression of NHEK hyperproliferation and abnormal differentiation. These inhibitory effects of GCK were diminished by GR silencing in NHEKs. GCK suppressed psoriasis-related inflammation by suppressing keratinocyte activation, which may be related to promoting GR nuclear translocation and inhibiting NF-κB activation. In summary, GCK appears to be a GR activator and a promising therapeutic candidate for antipsoriatic agents.

Targeting NF-κB signaling cascades of glioblastoma by a natural benzophenone, garcinol, via in vitro and molecular docking approaches.

Glioblastoma multiforme (GBM) is regarded as the most aggressive form of brain tumor delineated by high cellular heterogeneity; it is resistant to conventional therapeutic regimens. In this study, the anti-cancer potential of garcinol, a naturally derived benzophenone, was assessed against GBM. During the analysis, we observed a reduction in the viability of rat glioblastoma C6 cells at a concentration of 30µM of the extract (p < 0.001). Exposure to garcinol also induced nuclear fragmentation and condensation, as evidenced by DAPI-stained photomicrographs of C6 cells. The dissipation of mitochondrial membrane potential in a dose-dependent fashion was linked to the activation of caspases. Furthermore, it was observed that garcinol mediated the inhibition of NF-κB (p < 0.001) and decreased the expression of genes associated with cell survival (Bcl-XL, Bcl-2, and survivin) and proliferation (cyclin D1). Moreover, garcinol showed interaction with NF-κB through some important amino acid residues, such as Pro275, Trp258, Glu225, and Gly259 during molecular docking analysis. Comparative analysis with positive control (temozolomide) was also performed. We found that garcinol induced apoptotic cell death via inhibiting NF-κB activity in C6 cells, thus implicating it as a plausible therapeutic agent for GBM.

The role of extracellular vesicle fusion with target cells in triggering systemic inflammation

Extracellular vesicles (EVs) play a crucial role in intercellular communication by transferring bioactive molecules from donor to recipient cells. As a result, EV fusion leads to the modulation of cellular functions and has an impact on both physiological and pathological processes in the recipient cell. This study explores the impact of EV fusion on cellular responses to inflammatory signaling. Our findings reveal that fusion renders non-responsive cells susceptible to inflammatory signaling, as evidenced by increased NF-κB activation and the release of inflammatory mediators. Syntaxin-binding protein 1 is essential for the merge and activation of intracellular signaling. Subsequent analysis show that EVs transfer their functionally active receptors to target cells, making them prone to an otherwise unresponsive state. EVs in complex with their agonist, require no further stimulation of the target cells to trigger mobilization of NF-κB. While receptor antagonists were unable to inhibit NF-κB activation, blocking of the fusion between EVs and their target cells with heparin mitigated inflammation in mice challenged with EVs.

MicroRNA-146a gene transfer ameliorates senescence and senescence-associated secretory phenotypes in tendinopathic tenocytes.

Tendinopathy is influenced by multiple factors, including chronic inflammation and aging. Senescent cells exhibit characteristics such as the secretion of matrix-degrading enzymes and pro-inflammatory cytokines, collectively known as senescence-associated secretory phenotypes (SASPs). Many of these SASP cytokines and enzymes are implicated in the pathogenesis of tendinopathy. MicroRNA-146a (miR-146a) blocks senescence by targeting interleukin-1β (IL-1β) receptor-associated kinase 4 (IRAK-4) and TNF receptor-associated factor 6 (TRAF6), thus inhibiting NF-κB activity. The aims of this study were to (1) investigate miR-146a expression in tendinopathic tendons and (2) evaluate the role of miR-146a in countering senescence and SASPs in tendinopathic tenocytes. MiR-146a expression was assessed in human long head biceps (LHB) and rat tendinopathic tendons by in situ hybridization. MiR-146a over-expression in rat primary tendinopathic tenocytes was achieved by lentiviral vector-mediated precursor miR-146a transfer (LVmiR-146a). Expression of various senescence-related markers was analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunoblotting and immunofluorescence. MiR-146a expression showed a negative correlation with the severity of tendinopathy in human and rat tendinopathic tendons (p<0.001). Tendinopathic tenocyte transfectants overexpressing miR-146a exhibited downregulation of various senescence and SASP markers, as well as the target molecules IRAK-4 and TRAF6, and the inflammatory mediator phospho-NF-κB. Additionally, these cells showed enhanced nuclear staining of high mobility group box 1 (HMGB1) compared to LVmiR-scramble-transduced controls in response to IL-1β stimulation. We demonstrate that miR-146a expression is negatively correlated with the progression of tendinopathy. Moreover, its overexpression protects tendinopathic tenocytes from SASPs and senescence through the IRAK-4/TRAF6/NF-kB pathway.

Functional characterization of RIP2 in large yellow croaker (Larimichthys crocea), a protein involved in the host antiviral responses via NF-κΒ, IRF3/7 related signaling.

As an adaptor protein functions essentially in the activation of NF-κΒ and MAPK signaling pathways mediated by NOD1 and NOD2, RIP2 plays important roles in the host innate immune responses. In the present study, the RIP2 ortholog termed Lc-RIP2 was identified and characterized in large yellow croaker (Larimichthys crocea). It was revealed that Lc-RIP2 is consisted of an open reading frame (ORF) of 1695 bp, encoding a protein of 564 aa, with an N-terminal kinase domain and a C-terminal caspase activation and recruitment domain (CARD). Subcellular localization assays demonstrated that Lc-RIP2 was a cytosolic protein, which was broadly distributed in the examined tissues/organs, and could be induced in response to poly I:C, LPS, PGN, and Pseudomonas plecoglossicida stimulations in vivo according to qRT-PCR analysis. Notably, Lc-RIP2 overexpression in vitro was sufficient to abolish SVCV proliferation in EPC cells, and could significantly induce the activation of NF-κB, IRF3, IRF7, and IFN1 promoters. In addition, luciferase assays found that Lc-RIP2 could cooperate with Lc-MAVS, Lc-TRAF3, Lc-TRAF6, Lc-IRF3, and Lc-IRF7 in NF-κB activation, associate with Lc-TRIF, Lc-MAVS, Lc-TRAF3, Lc-IRF3, and Lc-IRF7 in IRF3 activation, enhance Lc-TRIF, Lc-MAVS, Lc-TRAF3, and Lc-TRAF6 mediated IRF7 activation, and Lc-IRF3 mediated IFN1 activation, whereas suppress NF-κB activation when co-expressed with Lc-TRIF. Co-immunoprecipitation (Co-IP) assays also demonstrated that Lc-RIP2 interacts separately with Lc-TRIF, Lc-MAVS, Lc-TRAF3, Lc-TRAF6, Lc-IRF3, and Lc-IRF7. It is thus collectively indicated that Lc-RIP2 function dominantly in the regulation of the host innate immune signaling.

Identifying Marine-Derived Tanzawaic Acid Derivatives as Novel Inhibitors against Osteoclastogenesis and Osteoporosis via Downregulation of NF-κB and NFATc1 Activation.

To discover novel osteoclast-targeting antiosteoporosis leads from natural products, we identified 40 tanzawaic acid derivatives, including 22 new ones (1-8, 14-19, 27-32, 37, and 38), from the South China Sea mangrove-derived fungus Penicillium steckii SCSIO 41025. Penicisteck acid F (2), one of the new derivatives showing the most potent NF-κB inhibitory activity, remarkably inhibited osteoclast generation in vitro. Mechanistically, 2 reduced RANKL-induced IκBα degradation, NF-κB p65 nuclear translocation, the activation and nuclear translocation of NFATc1, and the relevant mRNA expression. NF-κB p65 could be a potential molecular target for 2, which has been further determined by the cellular thermal shift assay, surface plasmon resonance, and the gene knock-down assay. Moreover, 2 could also alleviate osteoporosis in ovariectomized mice by reducing the quantities of osteoclasts. Our finding offered a novel potential inhibitor of osteoclastogenesis and osteoporosis for further development of potent antiosteoporosis agents.

Anti-Inflammatory Effects of Idebenone Attenuate LPS-Induced Systemic Inflammatory Diseases by Suppressing NF-κB Activation.

Inflammation is a natural protective process through which the immune system responds to injury, infection, or irritation. However, hyperinflammation or long-term inflammatory responses can cause various inflammatory diseases. Although idebenone was initially developed for the treatment of cognitive impairment and dementia, it is currently used to treat various diseases. However, its anti-inflammatory effects and regulatory functions in inflammatory diseases are yet to be elucidated. Therefore, this study aimed to investigate the anti-inflammatory effects of idebenone in cecal ligation puncture-induced sepsis and lipopolysaccharide-induced systemic inflammation. Murine models of cecal ligation puncture-induced sepsis and lipopolysaccharide-induced systemic inflammation were generated, followed by treatment with various concentrations of idebenone. Additionally, lipopolysaccharide-stimulated macrophages were treated with idebenone to elucidate its anti-inflammatory effects at the cellular level. Idebenone treatment significantly improved survival rate, protected against tissue damage, and decreased the expression of inflammatory enzymes and cytokines in mice models of sepsis and systemic inflammation. Additionally, idebenone treatment suppressed inflammatory responses in macrophages, inhibited the NF-κB signaling pathway, reduced reactive oxygen species and lipid peroxidation, and normalized the activities of antioxidant enzyme. Idebenone possesses potential therapeutic application as a novel anti-inflammatory agent in systemic inflammatory diseases and sepsis.