HOXA1 silencing inhibits cisplatin resistance of oral squamous cell carcinoma cells via IκB/NF-κB signaling pathway.

The resistance of oral squamous cell carcinoma (OSCC) cells to cisplatin remains a tough nut to crack in OSCC therapy. Homeobox A1 (HOXA1) overexpression has been detected in head and neck squamous carcinoma (HNSC). Accordingly, this study aims to explore the potential role and mechanism of HOXA1 on cisplatin resistance in OSCC. The expression of HOXA1 in HNSC and its role in overall survival (OS) rate of OSCC patients were analyzed by bioinformatic analysis. Following transfection as needed, OSCC cells were induced by different concentrations of cisplatin, and the cell viability and apoptosis were evaluated by cell counting kit-8 and flow cytometry assays. The mRNA and protein expression levels of HOXA1 and the phosphorylation of IκBα and p65 were determined by real-time quantitative PCR and western blot. HOXA1 expression level was upregulated in HNSC tissues and OSCC cells. Overexpressed HOXA1 was correlated with a low OS rate of OSCC patients. Cisplatin exerted an anti-cancer effect on OSCC cells. HOXA1 silencing or cisplatin suppressed OSCC cell viability, boosted the apoptosis, and repressed the phosphorylation of IκBα and p65. Intriguingly, the combination of HOXA1 silencing and cisplatin generated a stronger anti-cancer effect on OSCC cells than their single use. HOXA1 silencing attenuates cisplatin resistance of OSCC cells via IκB/NF-κB signaling pathway, hinting that HOXA1 is a biomarker associated with OSCC and HOXA1 silencing can enhance the sensitivity of OSCC cells to cisplatin.

Botulinum toxin type A inhibits M1 macrophage polarization by deactivation of JAK2/STAT1 and IκB/NFκB pathway and contributes to scar alleviation in aseptic skin wound healing.

The non-neuronal and non-muscular effects of botulinum toxin type A (BTXA) on scar reduction has been discovered. This study was designed to investigate the effects of BTXA on macrophages polarization during the early stage of skin repair. A skin defect model was established on the dorsal skin of SD rats. BTXA was intracutaneous injected into the edge of wound immediately as the model was established. Histological examinations were performed on scar samples. Raw 264.7 was selected as the cell model of recruited circulating macrophages, and was induced for M1 polarization by LPS. Identify the signaling pathways that primarily regulated M1 polarization and respond to BTXA treatment. Application of BTXA at early stage of injury significantly reduced the scar diameter without delaying wound closure. BTXA treatment improved fiber proliferation and arrangement, and inhibited angiogenesis in scar granular tissue. The number of M1 macrophages and the levels of pro-inflammation were decreased after treated with BTXA in scar tissues. LPS activated JAK2/STAT1 and IκB/NFκB pathways were downregulated by BTXA, as well as LPS induced M1 polarization. At early stage of skin wound healing, injection of BTXA effectively reduced the number of M1 macrophages and the levels of pro-inflammatory mediators which contributes to scar alleviation. BTXA resisted the M1 polarization of macrophages induced by LPS via deactivating the JAK2/STAT1 and IκB/NFκB pathways.

NF-κB as an Inducible Regulator of Inflammation in the Central Nervous System.

The NF-κB (nuclear factor K-light-chain-enhancer of activated B cells) transcription factor family is critical for modulating the immune proinflammatory response throughout the body. During the resting state, inactive NF-κB is sequestered by IκB in the cytoplasm. The proteasomal degradation of IκB activates NF-κB, mediating its translocation into the nucleus to act as a nuclear transcription factor in the upregulation of proinflammatory genes. Stimuli that initiate NF-κB activation are diverse but are canonically attributed to proinflammatory cytokines and chemokines. Downstream effects of NF-κB are cell type-specific and, in the majority of cases, result in the activation of pro-inflammatory cascades. Acting as the primary immune responders of the central nervous system, microglia exhibit upregulation of NF-κB upon activation in response to pathological conditions. Under such circumstances, microglial crosstalk with other cell types in the central nervous system can induce cell death, further exacerbating the disease pathology. In this review, we will emphasize the role of NF-κB in triggering neuroinflammation mediated by microglia.

Polyphenols Targeting NF-κB Pathway in Neurological Disorders: What We Know So Far?

Polyphenolic compounds have shown promising neuroprotective properties, making them a valuable resource for identifying prospective drug candidates to treat several neurological disorders (NDs). Numerous studies have reported that polyphenols can disrupt the nuclear factor kappa B(NF-κB) pathway by inhibiting the phosphorylation or ubiquitination of signaling molecules, which further prevents the degradation of IκB. Additionally, they prevent NF-κB translocation to the nucleus and pro-inflammatory cytokine production. Polyphenols such as curcumin, resveratrol, and pterostilbene had significant inhibitory effects on NF-κB, making them promising candidates for treating NDs. Recent experimental findings suggest that polyphenols possess a wide range of pharmacological properties. Notably, much attention has been directed towards their potential therapeutic effects in NDs such as Alzheimer's disease (AD), Parkinson's disease (PD), cerebral ischemia, anxiety, depression, autism, and spinal cord injury (SCI). Much preclinical data supporting the neurotherapeutic benefits of polyphenols has been developed. Nevertheless, this study has described the significance of polyphenols as potential neurotherapeutic agents, specifically emphasizing their impact on the NF-κB pathway. This article offers a comprehensive analysis of the involvement of polyphenols in NDs, including both preclinical and clinical perspectives.

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

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

NF-κB: a mediator that promotes or inhibits angiogenesis in human diseases?

The nuclear factor of κ-light chain of enhancer-activated B cells (NF-κB) signaling pathway, which is conserved in invertebrates, plays a significant role in human diseases such as inflammation-related diseases and carcinogenesis. Angiogenesis refers to the growth of new capillary vessels derived from already existing capillaries and postcapillary venules. Maintaining normal angiogenesis and effective vascular function is a prerequisite for the stability of organ tissue function, and abnormal angiogenesis often leads to a variety of diseases. It has been suggested that NK-κB signalling molecules under pathological conditions play an important role in vascular differentiation, proliferation, apoptosis and tumourigenesis by regulating the transcription of multiple target genes. Many NF-κB inhibitors are being tested in clinical trials for cancer treatment and their effect on angiogenesis is summarised. In this review, we will summarise the role of NF-κB signalling in various neovascular diseases, especially in tumours, and explore whether NF-κB can be used as an attack target or activation medium to inhibit tumour angiogenesis.

The central inflammatory regulator IκBζ: induction, regulation and physiological functions.

IκBζ (encoded by NFKBIZ) is the most recently identified IkappaB family protein. As an atypical member of the IkappaB protein family, NFKBIZ has been the focus of recent studies because of its role in inflammation. Specifically, it is a key gene in the regulation of a variety of inflammatory factors in the NF-KB pathway, thereby affecting the progression of related diseases. In recent years, investigations into NFKBIZ have led to greater understanding of this gene. In this review, we summarize the induction of NFKBIZ and then elucidate its transcription, translation, molecular mechanism and physiological function. Finally, the roles played by NFKBIZ in psoriasis, cancer, kidney injury, autoimmune diseases and other diseases are described. NFKBIZ functions are universal and bidirectional, and therefore, this gene may exert a great influence on the regulation of inflammation and inflammation-related diseases.

Inhibition of MLCK­mediated migration and invasion in human endometriosis stromal cells by NF­κB inhibitor DHMEQ.

Endometriosis is initiated by the movement of endometrial cells in the uterus to the fallopian tubes, the ovaries and the peritoneal cavity after the shedding of the uterus lining. To cause endometriosis, it is often necessary for these endometrial cells to migrate, invade and grow at the secondary site. In the present study, immortalized human endometriosis stromal cells (HESC) were employed to look for the inhibitors of migration and invasion. Using a chemical library of bioactive metabolites, it was found that an NF­κB inhibitor, DHMEQ, inhibited the migration and invasion of HESC. Both whole­genome array and metastasis PCR array analyses suggested the involvement of myosin light chain kinase (MLCK) in the mechanism of inhibition. DHMEQ was confirmed to inhibit the expression of MLCK and small inhibitory RNA knockdown of MLCK reduced cellular migration and invasion. The addition of DHMEQ to the knockdown cells did not further inhibit migration and invasion. DHMEQ is particularly effective in suppressing disease models by intraperitoneal (IP) administration and this therapy is being developed for the treatment of inflammation and cancer. DHMEQ IP therapy may also be useful for the treatment of endometriosis.

Differential dysregulation of ß-TrCP1 and -2 by HIV-1 Vpu leads to inhibition of canonical and non-canonical NF-κB pathways in infected cells.

The HIV-1 Vpu protein is expressed late in the virus lifecycle to promote infectious virus production and avoid innate and adaptive immunity. This includes the inhibition of the NF-κB pathway which, when activated, leads to the induction of inflammatory responses and the promotion of antiviral immunity. Here we demonstrate that Vpu can inhibit both canonical and non-canonical NF-κB pathways, through the direct inhibition of the F-box protein ß-TrCP, the substrate recognition portion of the Skp1-Cul1-F-box (SCF)ß-TrCP ubiquitin ligase complex. There are two paralogues of ß-TrCP (ß-TrCP1/BTRC and ß-TrCP2/FBXW11), encoded on different chromosomes, which appear to be functionally redundant. Vpu, however, is one of the few ß-TrCP substrates to differentiate between the two paralogues. We have found that patient-derived alleles of Vpu, unlike those from lab-adapted viruses, trigger the degradation of ß-TrCP1 while co-opting its paralogue ß-TrCP2 for the degradation of cellular targets of Vpu, such as CD4. The potency of this dual inhibition correlates with stabilization of the classical IκBα and the phosphorylated precursors of the mature DNA-binding subunits of canonical and non-canonical NF-κB pathways, p105/NFκB1 and p100/NFκB2, in HIV-1 infected CD4+ T cells. Both precursors act as alternative IκBs in their own right, thus reinforcing NF-κB inhibition at steady state and upon activation with either selective canonical or non-canonical NF-κB stimuli. These data reveal the complex regulation of NF-κB late in the viral replication cycle, with consequences for both the pathogenesis of HIV/AIDS and the use of NF-κB-modulating drugs in HIV cure strategies. IMPORTANCE The NF-κB pathway regulates host responses to infection and is a common target of viral antagonism. The HIV-1 Vpu protein inhibits NF-κB signaling late in the virus lifecycle, by binding and inhibiting ß-TrCP, the substrate recognition portion of the ubiquitin ligase responsible for inducing IκB degradation. Here we demonstrate that Vpu simultaneously inhibits and exploits the two different paralogues of ß-TrCP by triggering the degradation of ß-TrCP1 and co-opting ß-TrCP2 for the destruction of its cellular targets. In so doing, it has a potent inhibitory effect on both the canonical and non-canonical NF-κB pathways. This effect has been underestimated in previous mechanistic studies due to the use of Vpu proteins from lab-adapted viruses. Our findings reveal previously unappreciated differences in the ß-TrCP paralogues, revealing functional insights into the regulation of these proteins. This study also raises important implications for the role of NF-κB inhibition in the immunopathogenesis of HIV/AIDS and the way that this may impact on HIV latency reversal strategies based on the activation of the non-canonical NF-κB pathway.

KLF7 promotes adipocyte inflammation and glucose metabolism disorder by activating the PKCζ/NF-κB pathway.

In the obesity context, inflammatory cytokines secreted by adipocytes lead to insulin resistance and are key to metabolic syndrome development. In our previous study, we found that the transcription factor KLF7 promoted the expression of p-p65 and IL-6 in adipocytes. However, the specific molecular mechanism remained unclear. In the present study, we found that the expression of KLF7, PKCζ, p-IκB, p-p65, and IL-6 in epididymal white adipose tissue (Epi WAT) in mice fed a high-fat diet (HFD) was significantly increased. In contrast, the expression of PKCζ, p-IκB, p-p65, and IL-6 was significantly decreased in Epi WAT of KLF7 fat conditional knockout mice. In 3T3-L1 adipocytes, KLF7 promoted the expression of IL-6 via the PKCζ/NF-κB pathway. In addition, we performed luciferase reporter and chromatin immunoprecipitation assays, which confirmed that KLF7 upregulated the expression of PKCζ transcripts in HEK-293T cells. Collectively, our results show that KLF7 promotes the expression of IL-6 by upregulating PKCζ expression and activating the NF-κB signaling pathway in adipocytes.

ATP Consumption Is Coupled with Endocytosis in Exudated Neutrophils.

Neutrophil energy metabolism during phagocytosis has been previously reported, and adenosine triphosphate (ATP) plays a crucial role in endocytosis. Neutrophils are prepared by intraperitoneal injection of thioglycolate for 4 h. We previously reported a system established for measuring particulate matter endocytosis by neutrophils using flow cytometry. In this study, we utilized this system to investigate the relationship between endocytosis and energy consumption in neutrophils. A dynamin inhibitor suppressed ATP consumption triggered by neutrophil endocytosis. In the presence of exogenous ATP, neutrophils behave differently during endocytosis depending on ATP concentration. The inhibition of ATP synthase and nicotinamide adenine dinucleotide phosphate oxidase but not phosphatidylinositol-3 kinase suppresses neutrophil endocytosis. The nuclear factor kappa B was activated during endocytosis and inhibited by I kappa B kinase (IKK) inhibitors. Notably, IKK inhibitors restored endocytosis-triggered ATP consumption. Furthermore, data from the NLR family pyrin domain containing three knockout mice suggest that inflammasome activation is not involved in neutrophil endocytosis or concomitant ATP consumption. To summarize, these molecular events occur via endocytosis, which is closely related to ATP-centered energy metabolism.

YTHDF1 phase separation triggers the fate transition of spermatogonial stem cells by activating the IκB-NF-κB-CCND1 axis.

N6-methyladenosine (m6A) modification controls cell fate determination. Here, we show that liquid-liquid phase separation (LLPS) of YTH N6-methyladenosine RNA binding protein 1 (YTHDF1), a pivotal m6A "reader" protein, promotes the transdifferentiation of spermatogonial stem cells (SSCs) into neural stem cell-like cells by activating the IκB-nuclear factor κB (NF-κB)-CCND1 axis. The inhibition of IκBα/ß mRNA translation mediated by YTHDF1 LLPS is the key to the activation of the IκB-NF-κB-CCND1 axis. Disrupting either YTHDF1 LLPS or NF-κB activation inhibits transdifferentiation efficiency. Moreover, overexpression of the YTH domain of YTHDF1 inhibits the activation of the IκB-NF-κB-CCND1 axis by promoting IκBα/ß mRNA translation. Overexpression of the tau-YTH fusion protein reactivates IκB-NF-κB-CCND1 axis by inhibiting the translation of IκBα/ß mRNAs, and tau LLPS is observed, which can restore transdifferentiation efficiency. Our findings demonstrate that the protein-RNA LLPS plays essential roles in cell fate transition and provide insights into translational medicine and the therapy of neurological diseases.

Sirt4 deficiency promotes the development of atherosclerosis by activating the NF-κB/IκB/CXCL2/3 pathway.

BACKGROUND AND AIMS: As a member of mitochondrial sirtuins, Sirt4 plays a vital role in cellular metabolism and intracellular signal transduction; however, its effect on atherosclerosis is unclear. This study aimed to explore the effect of Sirt4 on atherosclerosis and its underlying mechanism. METHODS: In vivo, Apoe-/- and Apoe-/-/Sirt4-/- mice were fed a high-fat diet to induce atherosclerosis. In vitro, peritoneal macrophages from two mouse types were extracted and treated with oxidized low-density lipoprotein to establish a cell model, THP-1 cells were used to observe the effect of Sirt4 on the adhesion ability of monocytes. The growth and composition of aortic plaques in two mouse types were analyzed by H&E staining, Oil Red O staining, Dil oxidized low-density lipoprotein, immunohistochemistry, real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Transcriptome analysis and Western blotting were performed to explore the specific mechanism. RESULTS: Sirt4 deficiency aggravated atherosclerosis in mice. In vivo, aortic plaque size, lipid content, and expression of related inflammatory factors in Apoe-/-/Sirt4-/- mice were higher than those in the control group, whereas the content of collagen Ⅰ and smooth muscle actin-α was significantly lower. Sirt4-deficient macrophages exhibited stronger lipid phagocytosis in vitro, and the adhesion ability of monocytes increased when Sirt4 expression decreased. Transcriptome analysis showed that the expression of CXCL2 and CXCL3 in Sirt4-deficient peritoneal macrophages increased significantly, which may play a role by activating the NF-κB pathway. In further analysis, the results in vitro and in vivo showed that the expression of VCAM-1 and pro-inflammatory factors, such as IL-6, TNF-α and IL-1ß, increased, whereas the expression of anti-inflammatory factor IL-37 decreased in Sirt4-deficient peritoneal macrophages and tissues. After blocking the effect with NK-κB inhibitor BAY11-7082, the inflammatory reaction in sirt4 deficient macrophages was also significantly decreased. CONCLUSIONS: This study demonstrates that Sirt4 deficiency promotes the development of atherosclerosis by activating the NF-κB/IκB/CXCL2/3 pathway, suggesting that Sirt4 may exhibit a protective effect in atherosclerosis, which provides a new strategy for clinical prevention and treatment of atherosclerosis.

Anti-inflammatory Activity of Gegen Decoction and Its Modulatory Mechanism on the NF-κB and MAPK Signaling Pathways.

Gegen Decoction as anti-inflammatory medicine is used in clinic widespread, however the specific anti-inflammatory molecular mechanism of Gegen Decoction is still unclear. The purpose was to study the anti-inflammatory activity of Gegen Decoction in vivo and to research its anti-inflammatory molecular mechanism. The content of main essential components in Gegen Decoction were determined by HPLC method. The anti-inflammatory activity of Gegen Decoction was confirmed through in vivo animal experiments. Furthermore, RAW 264.7 cells were stimulated by lipopolysaccharides to induce inflammatory reaction, the modulatory effect of Gegen Decoction on the activation process of mitogen-activated protein kinases and nuclear factor-κB signaling pathways was investigated. The content of puerarin was the highest among all the index components. Gegen Decoction inhibited carrageenan-induced paw edema in rats and xylene-induced ear swelling in mice. Gegen Decoction had no obvious toxicity against RAW 264.7 cells at the concentrations of 10-40 mg/mL; significantly inhibited the release of nitric oxide, prostaglandin E2, tumor necrosis factor-α and interleukin-6; down-regulated the high expression of inflammatory proteins inducible nitric oxide synthase and cyclooxygenase-2. It inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs)/extracellular regulated protein kinases (ERK)/c-Jun N-terminal kinase (JNK), the degradation of nuclear factor-κB (NF-κB)/inhibitor of NF-κB-α (IκB-α) and the nuclear translocation of NF-κB/p65 into nucleus. Gegen Decoction exerts significant anti-inflammatory activity, mainly by blocking the activation of both MAPKs and NF-κB pathway.

In-Cell Chemical Crosslinking Identifies Hotspots for SQSTM-1/p62-IκBα Interaction That Underscore a Critical Role of p62 in Limiting NF-κB Activation Through IκBα Stabilization.

We have previously documented that in liver cells, the multifunctional protein scaffold p62/SQSTM1 is closely associated with IκBα, an inhibitor of the transcriptional activator NF-κB. Such an intimate p62-IκBα association we now document leads to a marked 18-fold proteolytic IκBα-stabilization, enabling its nuclear entry and termination of the NF-κB-activation cycle. In p62-/--cells, such termination is abrogated resulting in the nuclear persistence and prolonged activation of NF-κB following inflammatory stimuli. Utilizing various approaches both classic (structural deletion, site-directed mutagenesis) as well as novel (in-cell chemical crosslinking), coupled with proteomic analyses, we have defined the precise structural hotspots of p62-IκBα association. Accordingly, we have identified such IκBα hotspots to reside around N-terminal (K38, K47, and K67) and C-terminal (K238/C239) residues in its fifth ankyrin repeat domain. These sites interact with two hotspots in p62: One in its PB-1 subdomain around K13, and the other comprised of a positively charged patch (R183/R186/K187/K189) between its ZZ- and TB-subdomains. APEX proximity analyses upon IκBα-cotransfection of cells with and without p62 have enabled the characterization of the p62 influence on IκBα-protein-protein interactions. Interestingly, consistent with p62's capacity to proteolytically stabilize IκBα, its presence greatly impaired IκBα's interactions with various 20S/26S proteasomal subunits. Furthermore, consistent with p62 interaction with IκBα on an interface opposite to that of its NF-κB-interacting interface, p62 failed to significantly affect IκBα-NF-κB interactions. These collective findings together with the known dynamic p62 nucleocytoplasmic shuttling leads us to speculate that it may be involved in "piggy-back" nuclear transport of IκBα following its NF-κB-elicited transcriptional activation and de novo synthesis, required for termination of the NF-κB-activation cycle. Consequently, mice carrying a liver-specific deletion of p62-residues 68 to 252 reveal age-dependent-enhanced liver inflammation. Our findings reveal yet another mode of p62-mediated pathophysiologically relevant regulation of NF-κB.

Corylin inhibits the progression of Non-small cell lung cancer cells by regulating NF-κB signaling pathway via targeting p65.

BACKGROUND: Lung cancer is characterized by high-risk and high mortality, among which non-small cell lung cancer (NSCLC) conquers a dominant position. Previous studies have reported that corylin has anti-inflammatory, anti-oxidant, and anti-tumor effects; however, its role in NSCLC cells remains unclear. HYPOTHESIS: Corylin inhibits the progression of NSCLC cells. METHODS: A lentivector NF-κB luciferase reporter was constructed by molecular cloning. Corylin was screened and identified as an NF-κB pathway inhibitor by luciferase reporter assay. Corylin inhibited the expression of NF-κB downstream genes, which was detected by qRT-PCR. The effect of corylin on NSCLC cells was detected by colony formation assay, cell apoptosis, cell proliferation, in vitro invasion, and cell scratch assay. Corylin inhibited p65 nuclear translocation and was detected by molecular docking, immunofluorescence assay, and Western blot analysis. RESULTS: We constructed a lentiviral expression vector, containing an NF-κB luciferase reporter and established a stable A549 cell line for its expression. Using this cell line, corylin was screened and identified as an NF-κB pathway inhibitor. It was found that corylin inhibited the expression of NF-κB downstream genes and inhibited the proliferation and migration of NSCLC cells. Meanwhile, it was also found that corylin significantly reversed the increased proliferation of NSCLC cell lines induced by p65 overexpression. Molecular docking analysis showed that corylin could bind to p65 by hydrogen bonding. Further study showed that corylin inhibited the NF-κB signaling pathway by blocking p65 nuclear translocation. CONCLUSIONS: Our study screened and identified corylin as an NF-κB inhibitor and elucidated the molecular mechanism by which corylin inhibits the growth of NSCLC cells. The present study provides a novel strategy for improving the prognosis and treatment of NSCLC patients.

Oxymatrine attenuated isoproterenol-induced heart failure via the TLR4/NF-κB and MAPK pathways in vivo and in vitro.

Oxymatrine (OMT) is a quinoline alkaloid isolated from the root of the Sophora flavescens that has a variety of biological activities. However, the effect and potential mechanism of OMT on isoproterenol (ISO)-induced heart failure (HF) are not clear. In this study, we found that OMT improved the survival of HL-1 cells induced by ISO. We also demonstrated that OMT significantly inhibited the levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). OMT decreased the levels of the TLR4 and reduced the phosphorylation levels of nuclear factor-κB (NF-κB) inhibitor (IκB), p65, c-Jun N-terminal kinases (JNK) and p38. The inhibitory effect of the TLR4 inhibitor TAK242 on HL-1 cells was evaluated. The results showed that the effect of OMT on the phosphorylation levels of IκBα and p65 was enhanced in HL-1 cells treated with TAK242. Using animal models, OMT significantly reduced ISO-induced cardiac injury, myocardial necrosis, interstitial edema, and fibrosis. In addition, OMT attenuated TNF-α and IL-6 and inhibited the expression of TLR4/NF-κB and MAPK pathway-related proteins. This finding suggests that OMT may alleviate HF by interfering with the TLR4/NF-κB and MAPK pathways.

New insights into the mechanism of ammonia toxicity: Focus on Cactus.

The NF-κB signaling pathway is the most critical pathway in innate immunity. IκB (Cactus) is the primary cytoplasmic inhibitor of NF-κB (Dorsal). In this study, we found that ammonia exposure could significantly induce the expression of Cactus, in a dose-dependent manner in different tissues, with the highest expression in the gill of Corbicula fluminea. The expression pattern-related elements (Tube and Dorsal) in the NF-κB signaling pathway were also analyzed, showing significant up-regulation in 48 h. There was an inhibitory effect between up-regulated Cactus and Dorsal in 72 h, which may regulate Dorsal as a negative feedback pathway function to control the expression of pro-inflammatory cytokines (IL-1ß, IL-6, and TNF-α). Besides, through molecular docking simulation, we found that the Cactus could be directly activated by NH3, complementing the regulatory mechanism of the Cactus. To further test our hypothesis, the levels of pro-inflammatory cytokines decreased after adding PDTC (the antioxidant of Cactus/IκB), suggesting that PDTC can prevent the degradation of Cactus, inhibit Dorsal translocating into the nucleus, and activate the pro-inflammatory cytokines. This revealed the inhibitory effect of Cactus on activating Dorsal/NF-κB factors in the NF-κB signaling pathway. Thus, we suggested that the Cactus is an essential regulator of ammonia-activated inflammation in C. fluminea, which was reported to be activated only by bacteria and immune stimulators. Our study provides a new perspective on the mechanism of ammonia toxicity in invertebrates.

23-O-acetylshengmanol-3-O-α-L-arabinoside alleviates lipopolysaccharide-induced acute lung injury through inhibiting IκB/NF-κB and MAPK/AP-1 signaling pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Cimicifuga foetida L. is a well-established traditional Chinese medicine with heat-clearing and detoxifying effects and has good therapeutic effect on oral mucosal ulcer and pharyngitis. The rhizome of this herb is rich in triterpenoid glycosides, including 23-O-acetylshengmanol-3-o-α-L-arabinoside (DA). AIM OF THE STUDY: Whether and how DA attenuates acute lung injury (ALI) are unclear. Accordingly, we focused on its anti-inflammatory effects and underlying molecular mechanisms in lipopolysaccharide (LPS)-stimulated ALI mice and RAW264.7 cells. MATERIALS AND METHODS: The model of ALI mice was established by exposed intratracheal instillation of LPS. Lung pathological changes were evaluated by hematoxylin and eosin staining. Pulmonary function was assessed by whole-body plethysmography. Total protein content in bronchoalveolar lavage fluid (BALF) was detected by bicinchoninic acid method. Wet/dry lung ratio was used to evaluate the degree of pulmonary edema in mice. The levels of pro-inflammatory mediators were measured using enzyme-linked immunosorbent assay. The relative expression of pro-inflammatory gene mRNA was examined by RT-qPCR. The expression of inflammatory-related proteins was detected by Western blot. RAW264.7 cells were used to test the anti-inflammatory effects of DA in vitro. Cytotoxicity was assessed using a MTT assay. Nitric oxide production was measured by Griess assay. The production and expression of inflammatory mediators and the protein levels of inflammatory signaling molecules in the NF-κB and MAPK pathways were measured. Furthermore, immunofluorescence staining was used to analyze the expression of p-IκBα, p-ERK, and p-p38 in lung macrophages and the nuclear translocation of NF-κB p65 and AP-1 in cells. RESULTS: DA evidently alleviated histopathological changes and ameliorated pulmonary edema. Moreover, DA could reduce excessive inflammatory reaction in lung tissue as manifested by the reduction of proinflammatory mediators (IL-1ß, IL-6, TNF-α, MCP-1, iNOS, and COX-2) in BALF, serum, and lung tissues. Further, DA inhibited the activation of the NLRP3/caspase-1 pathway in the lung. DA reduced the production and expression of the proinflammatory mediators above in RAW264.7 cells. Mechanistically, DA remarkably blocked the nuclear translocation of NF-κB p65, suppressed IκBα phosphorylation, and markedly reduced the nuclear translocation of AP-1 and the phosphorylation of ERK and p38. CONCLUSIONS: The findings demonstrated that DA exerts anti-inflammatory effects in LPS-stimulated ALI mice and macrophages by downregulating the NLRP3/caspase-1 signaling pathway in lung tissue and the IκB/NF-κB and MAPKs/AP-1 pathways in macrophages, suggesting that DA may be promising in ALI treatment.

Engineered nanoparticles as emerging gene/drug delivery systems targeting the nuclear factor-κB protein and related signaling pathways in cancer.

The transcription factor nuclear factor-κB (NF-κB) is a critical regulator of the immune response, inflammation, cell growth, and survival. Canonical and non-canonical pathways, two NF-κB pathways, are activated through diverse stimulators and receptors. NF-κB activity is dysregulated in various inflammation-related diseases and cancers. It was found that the persistent NF-κB activity has a major role in proliferation, apoptosis inhibition, metastasis, and cell cycle disruption in cancer cells and also the survival of cancer stem cells (CSCs) within the tumors. Therefore, suppression of the NF-κB pathway could be a promising therapeutic target for cancer therapy. Different biological inhibitors (e.g., peptides, small molecules, antisense oligonucleotides (ASOs), and antibodies (Abs)) have been demonstrated to inhibit the NF-κB pathway. Low stability in the circulation system, weak availability, and poor cellular uptake of some inhibitors limit their therapeutic applications. To address these drawbacks nanocarrier systems are often formulated and applied in drug delivery as an effective therapeutic approach. Targeted nanosystems (i.e., small molecules, peptides, Abs and Aptamers (Aps) conjugated nanocarriers), as well as smart responsive nanocarriers, can improve the efficiency of therapeutics while reducing the off-target toxicity. This review describes the NF-κB signaling pathways and mechanisms of their over-activation in tumor initiation and progression. The NF-κB inhibitors and their clinical applications are also discussed. It also overviews different nanocarriers used as robust vehicles for the delivery of NF-κB inhibitors and anti-tumor agents to improve the bioavailability of drugs and selective targeting of cancer cells to repress NF-κB activity in tumor cells.