Parthenolide inhibits IkappaB kinase, NF-kappaB activation, and inflammatory response in cystic fibrosis cells and mice

Huajuxiaoji Formula Alleviates Phenyl Sulfate-Induced Diabetic Kidney Disease by Inhibiting NLRP3 Inflammasome Activation and Pyroptosis

Background: One of the most common microvascular complications of diabetes is diabetic kidney disease (DKD). The Huajuxiaoji formula (HJXJ) has shown clinical efficacy for DKD; however, its regulatory mechanisms against DKD remain elusive. We investigated NLRP3 inflammasome and the mechanisms of HJXJ by which HJXJ alleviates DKD. Methods: Phenyl sulfate (PS) was used to establish DKD models. HJXJ was administered to mice through intragastric or made into a pharmaceutical serum for the cell cultures. Biological indicator levels in mouse blood and urine were analyzed, and kidney tissues were used for HE, Masson, and PAS staining. ELISA and western blotting were used to detect inflammatory cytokines and protein levels, respectively. Reactive oxygen species (ROS) production and pyroptosis were evaluated using flow cytometry. Lentiviral vector-mediated overexpression of NLRP3 was performed to determine whether NLRP3 participates in the antipyroptotic effect of HJXJ. Results: HJXJ significantly reduced the severity of the injury and, in a dose-dependent manner, decreased the levels of biological markers including creatinine, blood urea nitrogen, urine protein, and endotoxin, as well as inflammatory cytokines such as interleukin (IL)-1β, IL-18, tumor necrosis factor-α, and IL-6 in DKD mice. Treatment with HJXJ reversed the downregulation of podocin, nephrin, ZO-1, and occludin and upregulated ROS, NLRP3, Caspase-1 P20, and GSDMD-N induced by PS. Moreover, the upregulation of NLRP3 expression increased the number of cells positive for pyroptosis. HJXJ suppressed pyroptosis and inflammasome activation by inhibiting NLRP3 expression. Conclusions: Generally, HJXJ has the potential to reduce DKD injury and exerts anti-DKD effects by inhibiting the NLRP3-mediated NLRP3 inflammasome activation and pyroptosis in vitro and in vivo.

Parthenolide alleviates indomethacin-induced gastric ulcer in rats via antioxidant, anti-inflammatory, and antiapoptotic activities

Parthenolide (PTL) is a sesquiterpene lactone that occurs naturally. It demonstrates a variety of beneficial effects, such as antioxidant, anti-inflammatory, and antiapoptotic properties. The study investigated the potential protective impact of PTL on indomethacin (INDO) induced stomach ulcers in rats. The rats were classified into 5 distinct categories. Group 1 served as the "control" group. Rats in the second group received a single oral dosage of INDO (50 mg kg-1). Rats in Groups three and four received 20 and 40 mg kg-1 oral PTL 1 h before INDO. Omeprazole (30 mg kg-1) was given orally to Group 5 rats 1 h before INDO. Pretreatment with PTL increased stomach pH and decreased gastric volume as well as reduced the morphological and histological changes induced by INDO. Analysis of probable pathways showed that pre-treatment with PTL successfully reduced oxidative, inflammatory, and apoptotic consequences caused by INDO. The ingestion of PTL leads to a notable increase in the levels of glutathione reduced (GSH) and the activities of superoxide dismutase (SOD) and catalase (CAT). Furthermore, PTL decreased the concentration of malondialdehyde (MDA). In contrast, it was shown that PTL increased both cyclooxygenase-1 (COX-1) and prostaglandin E2 (PGE2). PTL shows a significant decrease in the expression of interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), inducible nitric oxide synthase (iNOS), and nuclear factor kappa B (NF-κB). PTL therapy resulted in a decrease in Bcl-2-associated X protein (Bax) levels and an increase in B-cell lymphoma 2 (Bcl2) levels. In conclusion, PTL offers gastroprotection by its antioxidant, anti-inflammatory, and anti-apoptotic qualities.

Shared Immune Associations Between COVID-19 and Inflammatory Bowel Disease: A Cross-Sectional Observational Study in Shanghai, China

Purpose

The rapid global spread of the SARS-CoV-2 Omicron variant introduces a novel complication: the emergence of IBD (inflammatory bowel disease)-like ulcers in certain patients. This research delves into this new challenge by juxtaposing the clinical manifestations and genetic expression patterns of individuals affected by the Omicron variant of COVID-19 with those diagnosed with IBD. It aims to decode the link between these conditions, potentially shedding light on previously unexplored facets of COVID-19 pathophysiology. This investigation emphasizes gene expression analysis as a key tool to identify wider disease correlations and innovative therapeutic avenues.

Patients and Methods

From March to December 2022, patients with SARS-CoV-2 Omicron infection and inflammatory bowel disease and healthy controls were recruited in Shanghai East Hospital, Shanghai, China. The epidemiological and clinical characteristics of the patients were compared. Four RNA sequencing datasets (GSE205244, GSE201530, GSE174159, and GSE186507) were extracted from the Gene Expression Omnibus database to detect mutually differentially expressed genes and common pathways in patients with SARS-CoV-2 infection and inflammatory bowel disease.

Results

Compared to patients with active inflammatory bowel disease, patients with SARS-CoV-2 infection were more likely to have elevated interferon-α levels and an increased lymphocyte count and less likely to have high interleukin-6, tumor necrosis factor-α, and C-reactive protein levels and an elevated neutrophil count. A total of 51 common differentially expressed genes were identified in the four RNA-sequencing datasets. Enrichment analysis suggested that these genes were related to inflammation and the immune response, especially the innate immune response and nucleotide oligomerization domain-like receptor signaling pathway.

Conclusion

The inflammation and immune-response pathways in COVID-19 and inflammatory bowel disease have several similarities and some differences. The study identifies the NLR signaling pathway's key role in both COVID-19 and IBD, suggesting its potential as a target for therapeutic intervention and vaccine development.

New Insights on NLRP3 Inflammasome: Mechanisms of Activation, Inhibition, and Epigenetic Regulation

Inflammasomes are important modulators of inflammation. Dysregulation of inflammasomes can enhance vulnerability to conditions such as neurodegenerative diseases, autoinflammatory diseases, and metabolic disorders. Among various inflammasomes, Nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) is the best-characterized inflammasome related to inflammatory and neurodegenerative diseases. NLRP3 is an intracellular sensor that recognizes pathogen-associated molecular patterns and damage-associated patterns resulting in the assembly and activation of NLRP3 inflammasome. The NLRP3 inflammasome includes sensor NLRP3, adaptor apoptosis-associated speck-like protein (ASC), and effector cysteine protease procaspase-1 that plays an imperative role in caspase-1 stimulation which further initiates a secondary inflammatory response. Regulation of NLRP3 inflammasome ameliorates NLRP3-mediated diseases. Much effort has been invested in studying the activation, and exploration of specific inhibitors and epigenetic mechanisms controlling NLRP3 inflammasome. This review gives an overview of the established NLRP3 inflammasome assembly, its brief molecular mechanistic activations as well as a current update on specific and non-specific NLRP3 inhibitors that could be used in NLRP3-mediated diseases. We also focused on the recently discovered epigenetic mechanisms mediated by DNA methylation, histone alterations, and microRNAs in regulating the activation and expression of NLRP3 inflammasome, which has resulted in a novel method of gaining insight into the mechanisms that modulate NLRP3 inflammasome activity and introducing potential therapeutic strategies for CNS disorders.

The Role of the Nuclear Factor-Kappa B (NF-κB) Pathway in SARS-CoV-2 Infection

COVID-19 is a global health threat caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is associated with a significant increase in morbidity and mortality. The present review discusses nuclear factor-kappa B (NF-κB) activation and its potential therapeutical role in treating COVID-19. COVID-19 pathogenesis, the major NF-κB pathways, and the involvement of NF-κB in SARS-CoV-2 have been detailed. Specifically, NF-κB activation and its impact on managing COVID-19 has been discussed. As a central player in the immune and inflammatory responses, modulating NF-κB activation could offer a strategic avenue for managing SARS-CoV-2 infection. Understanding the NF-κB pathway's role could aid in developing treatments against SARS-CoV-2. Further investigations into the intricacies of NF-κB activation are required to reveal effective therapeutic strategies for managing and combating the SARS-CoV-2 infection and COVID-19.

Inhibition of microtubule detyrosination by parthenolide facilitates functional CNS axon regeneration

Injured axons in the central nervous system (CNS) usually fail to regenerate, causing permanent disabilities. However, the knockdown of Pten knockout or treatment of neurons with hyper-IL-6 (hIL-6) transforms neurons into a regenerative state, allowing them to regenerate axons in the injured optic nerve and spinal cord. Transneuronal delivery of hIL-6 to the injured brain stem neurons enables functional recovery after severe spinal cord injury. Here we demonstrate that the beneficial hIL-6 and Pten knockout effects on axon growth are limited by the induction of tubulin detyrosination in axonal growth cones. Hence, cotreatment with parthenolide, a compound blocking microtubule detyrosination, synergistically accelerates neurite growth of cultured murine CNS neurons and primary RGCs isolated from adult human eyes. Systemic application of the prodrug dimethylamino-parthenolide (DMAPT) facilitates axon regeneration in the injured optic nerve and spinal cord. Moreover, combinatorial treatment further improves hIL-6-induced axon regeneration and locomotor recovery after severe SCI. Thus, DMAPT facilitates functional CNS regeneration and reduces the limiting effects of pro-regenerative treatments, making it a promising drug candidate for treating CNS injuries.

Reframing the link between metabolism and NLRP3 inflammasome: therapeutic opportunities

Inflammasomes are multiprotein signaling platforms in the cytosol that senses exogenous and endogenous danger signals and respond with the maturation and secretion of IL-1β and IL-18 and pyroptosis to induce inflammation and protect the host. The inflammasome best studied is the Nucleotide-binding oligomerization domain, leucine-rich repeat-containing family pyrin domain containing 3 (NLRP3) inflammasome. It is activated in a two-step process: the priming and the activation, leading to sensor NLRP3 oligomerization and recruitment of both adaptor ASC and executioner pro-caspase 1, which is activated by cleavage. Moreover, NLRP3 inflammasome activation is regulated by posttranslational modifications, including ubiquitination/deubiquitination, phosphorylation/dephosphorylation, acetylation/deacetylation, SUMOylation and nitrosylation, and interaction with NLPR3 protein binding partners. Moreover, the connection between it and metabolism is receiving increasing attention in this field. In this review, we present the structure, functions, activation, and regulation of NLRP3, with special emphasis on regulation by mitochondrial dysfunction-mtROS production and metabolic signals, i.e., metabolites as well as enzymes. By understanding the regulation of NLRP3 inflammasome activation, specific inhibitors can be rationally designed for the treatment and prevention of various immune- or metabolic-based diseases. Lastly, we review current NLRP3 inflammasome inhibitors and their mechanism of action.

Trends in parthenolide research over the past two decades: A bibliometric analysis

Parthenolide (PTL) is a new compound extracted from traditional Chinese medicine. In recent years, it has been proven to play an undeniable role in tumors, autoimmune diseases, and inflammatory diseases. Similarly, an increasing number of experiments have also confirmed the biological mechanism of PTL in these diseases. In order to better understand the development trend and potential hot spots of PTL in cancer and other diseases, we conducted a detailed bibliometric analysis. The purpose of presenting this bibliometric analysis was to highlight and inform researchers of the important research directions, co-occurrence relationships and research status in this field. Publications related to PTL research from 2002 to 2022 were extracted on the web of science core collection (WoSCC) platform. CiteSpace, VOSviewers and R package "bibliometrix" were applied to build relevant network diagrams. The bibliometric analysis was presented in terms of performance analysis (including publication statistics, top publishing countries, top publishing institutions, publishing journals and co-cited journals, authors and co-cited authors, co-cited references statistics, citation bursts statistics, keyword statistics and trend topic statistics) and science mapping (including citations by country, citations by institution, citations by journal, citations by author, co-citation analysis, and keyword co-occurrence). The detailed discussion of the results explained the focus and latest trends from the bibliometric analysis. Finally, the current status and shortcomings of the research field on PTLwere clearly pointed out for reference by scholars.

Gold Nanoparticles Inhibit PMA-Induced MMP-9 Expression via microRNA-204-5p Upregulation and Deactivation of NF-κBp65 in Breast Cancer Cells

OBJECTIVE

Breast cancer (BC) is the most common malignancy in females globally. Matrix metalloproteinase-9 (MMP-9) is crucial to the invasion, progression and spread of BC. Gold nanoparticles (AuNPs) have an anti-tumorigenic role, but their therapeutic role in microRNAs (miRNAs) regulation has not been explored. This study determined the potential of AuNPs against MMP-9 overexpression/production and miRNA-204-5p regulation in BC cells.

METHODS

AuNPs were newly engineered, and their stability was analyzed using the zeta potential, polydispersity index, surface-plasmon-resonance peak and transmission electron microscopy. A bioinformatics algorithm was used to predict the pairing of miRNA in the 3'untranslated-region (3'UTR) of MMP-9 mRNA. TaqMan assays were carried out to quantify miRNA and mRNA, whereas MMP-9-specific immunoassays and gelatin zymography were used to determine protein secretion and activity. The binding of miRNA in MMP-9 mRNA 3'UTR was verified by luciferase reporter clone assays and transfection with anti-miRNAs. In addition, NF-κBp65 activity was determined and confirmed with parthenolide treatment.

RESULTS

Engineered AuNPs were highly stable and spherical in shape, with a mean size of 28.3 nm. Tested in MCF-7 BC cells, microRNA-204-5p directly regulates MMP-9. AuNPs inhibit PMA-induced MMP-9 mRNA and protein via hsa-miR-204-5p upregulation. Anti-miR-204 transfected MCF-7 cells demonstrated enhanced MMP-9 expression (p < 0.001), while AuNPs treatment attenuated MMP-9 expression in a dose-dependent manner (p < 0.05). Moreover, AuNPs also inhibit PMA-induced NF-κBp65 activation in anti-hsa-miR-204 transfected MCF-7 cells.

CONCLUSION

Engineered AuNPs were stable and non-toxic to BC cells. AuNPs inhibit PMA-induced MMP-9 expression, production and activation via NF-κBp65 deactivation and hsa-miR-204-5p upregulation. These novel therapeutic potentials of AuNPs on stimulated BC cells provide novel suggestions that AuNPs inhibit carcinogenic activity via inverse regulation of microRNAs.

Mechanism by Which Inflammation and Oxidative Stress Induce Mineralocorticoid Receptor Gene Expression in Aging Vascular Smooth Muscle Cells

BACKGROUND

Vascular MR (mineralocorticoid receptor) expression increases with age driving aging-associated vascular stiffness and hypertension. MR has two isoforms (1α and 1β) with distinct 5'-untranslated and promoter sequences (P1 and P2), but the gene regulatory mechanisms remain unknown. We investigated mechanisms driving MR gene transcriptional regulation in aging human smooth muscle cells (SMC).

METHODS

MR was quantified in aortic tissue and primary human aortic SMC (HASMC) comparing adult and aged donors and adult HASMC treated with H2O2, to induce aging. Predicted transcription factor (TF) binding sites in the MR gene were validated using chromatin immunoprecipitations and reporter assays. The impact of TF inhibitors on MR isoforms and fibrosis target gene expression was examined.

RESULTS

Expression of both MR mRNA isoforms increased with donor age or H2O2 treatment in HASMCs. HIF1α (hypoxia-inducible factor) and the inflammatory TF NFκB (nuclear factor kappa B) both increased with age in HASMCs and are predicted to bind MR promoters. H2O2 induced HIF1α and NFκB expression and DNA binding of HIF1α to the MR P1 promoter and of NFκB to both MR promoters in HASMCs. HIF1α inhibition decreased MR-1α isoform expression while NFκB inhibition decreased both MR isoforms. HIF1α, NFκB, and MR inhibition decreased the expression of a SMC-MR target gene implicated in vascular fibrosis. In human aortic tissues, expression of HIF1α and NFκB each positively correlated with donor age and MR expression (P<0.0001).

CONCLUSIONS

These data implicate the inflammatory TF, NFκB, and oxidative stress-induced TF, HIF1α, in regulating SMC MR transcription in aging HASMCs, which drives aging-related vascular stiffness and cardiovascular disease.

The FDA-approved drug Auranofin has a dual inhibitory effect on SARS-CoV-2 entry and NF-κB signaling

Patients with severe COVID-19 show an altered immune response that fails to control the viral spread and suffer from exacerbated inflammatory response, which eventually can lead to death. A major challenge is to develop an effective treatment for COVID-19. NF-κB is a major player in innate immunity and inflammatory process. By a high-throughput screening approach, we identified FDA-approved compounds that inhibit the NF-κB pathway and thus dampen inflammation. Among these, we show that Auranofin prevents post-translational modifications of NF-κB effectors and their recruitment into activating complexes in response to SARS-CoV-2 infection or cytokine stimulation. In addition, we demonstrate that Auranofin counteracts several steps of SARS-CoV-2 infection. First, it inhibits a raft-dependent endocytic pathway involved in SARS-CoV-2 entry into host cells; Second, Auranofin alters the ACE2 mobility at the plasma membrane. Overall, Auranofin should prevent SARS-CoV-2 infection and inflammatory damages, offering new opportunities as a repurposable drug candidate to treat COVID-19.

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Original high throughput screening of NF-κB inhibitory drugs

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Auranofin inhibits SARS-CoV-2 replication

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Auranofin increases the ACE2 mobility at the plasma membrane

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Auranofin inhibits ACE-2-dependent SARS-CoV-2 endocytosis

First Discovery of Cholesterol-Lowering Activity of Parthenolide as NPC1L1 Inhibitor

Elevated cholesterol significantly increases the risk of developing atherosclerosis and coronary heart disease. The key to treating hypercholesterolemia is lowering plasma cholesterol levels. There have been no studies on the cholesterol-lowering potential of parthenolide (PTL), a naturally occurring small molecule from Tanacetum parthenium. Here, we first put forth PTL’s cholesterol-lowering ability to inhibit cellular uptake of cholesterol in a dose-dependent manner. Its performance was on par with the positive control drug, ezetimibe. Niemann–Pick C1 Like-1 (NPC1L1) has been identified as a potential therapeutic target for hypercholesterolemia. The interaction of PTL with NPC1L1 could be explained by the results of molecular docking and filipin staining further reinforces this hypothesis. Furthermore, PTL reduced the expression of NPC1L1 in HepG2 cells in a concentration-dependent manner, which suggests that PTL functions as a potential NPC1L1 inhibitor with therapeutic potential for hypercholesterolemia.

3,4-Methylenedioxy-β-Nitrostyrene Alleviates Dextran Sulfate Sodium–Induced Mouse Colitis by Inhibiting the NLRP3 Inflammasome

Inflammatory bowel disease (IBD) has been reported to be associated with NLRP3 inflammasome activation. Therefore inhibiting inflammasome activation could be a new approach to treat IBD. Inflammasome inhibitors NLRP3-IN-2, JC124, and 3,4-methylenedioxy-β-nitrostyrene (MNS) were previously reported to exert anti-inflammatory effects in various disease models but not in the dextran sulfate sodium (DSS)–induced colitis model. Here, we showed that MNS was more efficient in inhibiting the secretion of interleukin-1β (IL-1β) by blocking oligomerization of apoptosis-associated speck-like protein (ASC) than NLRP3-IN-2 and JC124. To investigate the protective effects of MNS on enteritis, we administered intragastric MNS to DSS-induced colitis mice. The results demonstrated that MNS attenuated DSS-induced body weight loss, colon length shortening, and pathological damage. In addition, MNS inhibited the infiltration of macrophages and inflammatory cells and reduced IL-1β and IL-12p40 pro-inflammatory cytokines but had no significant effect on tumor necrosis factor α (TNF-α) and IL-6. Furthermore, we also found that the differentiation of IL-17A⁺interferon-γ (IFN-γ)⁺CD4⁺ T cell was decreased in the colon after MNS treatment, which might be mediated by IL-1β, etc. cytokine release. Taken together, MNS alleviated DSS-induced intestinal inflammation by inhibiting NLRP3 inflammasome activation, which may function as an effective therapeutic for IBD.

The NLRP3 Inflammasome Pathway: A Review of Mechanisms and Inhibitors for the Treatment of Inflammatory Diseases

The NLRP3 inflammasome is a multiprotein complex that plays a pivotal role in regulating the innate immune system and inflammatory signaling. Upon activation by PAMPs and DAMPs, NLRP3 oligomerizes and activates caspase-1 which initiates the processing and release of pro-inflammatory cytokines IL-1β and IL-18. NLRP3 is the most extensively studied inflammasome to date due to its array of activators and aberrant activation in several inflammatory diseases. Studies using small molecules and biologics targeting the NLRP3 inflammasome pathway have shown positive outcomes in treating various disease pathologies by blocking chronic inflammation. In this review, we discuss the recent advances in understanding the NLRP3 mechanism, its role in disease pathology, and provide a broad review of therapeutics discovered to target the NLRP3 pathway and their challenges.

Parthenolide Suppresses T Helper 17 and Alleviates Experimental Autoimmune Encephalomyelitis

T helper (Th) cells play crucial roles in inflammation and adaptive immune system. Importantly, Th17 cells, a major pathogenic Th cell subset, are involved in the pathogenesis of multiple sclerosis (MS) and its classical animal modal experimental autoimmune encephalomyelitis (EAE). Previous studies have shown that parthenolide (PTL), a sesquiterpene lactone, possesses potent anti-cancer and anti-inflammatory activities. However, the immunosuppressive effect of PTL on the pathogenic Th17 cell and MS is unclear. In this study, we showed that PTL treatment could alleviate clinical symptoms by inhibiting inflammatory cell infiltration, reducing inflammation and demyelination of CNS. In addition, the mRNA expression of cytokines and inflammatory factors in CD4⁺ T cells, especially Th1 and Th17 cells, reduced in both CNS and peripheral immune tissue of EAE mice. Furthermore, PTL could inhibit the reactivation of MOG-specific T cells and the differentiation of naïve CD4⁺ T cells into Th17 cells in vitro. We also found that PTL inhibited nuclear factor kappa B (NF-κB) signaling and retinoid-related orphan receptor-γt (RORγt) in mouse Th17 cell and human Jurkat cell line. Taken together, our data demonstrated a critical immune-suppressive effect of PTL on autoimmune inflammation through regulating Th17 cells and the NF-κB/RORγt pathway.

The sesquiterpene lactone estafiatin exerts anti-inflammatory effects on macrophages and protects mice from sepsis induced by LPS and cecal ligation puncture

BACKGROUND

Previously, we found that the water extract of Artermisia scoparia Waldst. & Kit suppressed the cytokine production of lipopolysaccharide (LPS)-stimulated macrophages and alleviated carrageenan-induced acute inflammation in mice. Artemisia contains various sesquiterpene lactones and most of them exert immunomodulatory activity.

PURPOSE

In the present study, we investigated the immunomodulatory effect of estafiatin (EST), a sesquiterpene lactone derived from A. scoparia, on LPS-induced inflammation in macrophages and mouse sepsis model.

STUDY DESIGN AND METHODS

Murine bone marrow-derived macrophages (BMDMs) and THP-1 cells, a human monocytic leukemia cell line, were pretreated with different doses of EST for 2 h, followed by LPS treatment. The gene and protein expression of pro-inflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and inducible nitric oxide synthase (iNOS) were measured by quantitative real-time polymerase chain reaction (qPCR) and Western blot analysis. The activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) was also evaluated at the level of phosphorylation. The effect of EST on inflammatory cytokine production, lung histopathology, and survival rate was assessed in an LPS-induced mice model of septic shock. The effect of EST on the production of cytokines in LPS-stimulated peritoneal macrophages was evaluated by in vitro and ex vivo experiments and protective effect of EST on cecal ligation and puncture (CLP) mice was also assessed.

RESULTS

The LPS-induced expression of IL-6, TNF-α, and iNOS was suppressed at the mRNA and protein levels in BMDMs and THP-1 cells, respectively, by pretreatment with EST. The half-maximal inhibitory concentration (IC50) of EST on IL-6 and TNF-α production were determined as 3.2 μM and 3.1 μM in BMDMs, 3 μM and 3.4 μM in THP1 cells, respectively. In addition, pretreatment with EST significantly reduced the LPS-induced phosphorylation p65, p38, JNK, and ERK in both cell types. In the LPS-induced mice model of septic shock, serum levels of IL-6, TNF-α, IL-1β, CXCL1, and CXCL2 were lower in EST-treated mice than in the control animals. Histopathology analysis revealed that EST treatment ameliorated LPS-induced lung damage. Moreover, while 1 of 7 control mice given lethal dose of LPS survived, 3 of 7 EST-treated (1.25 mg/kg) mice and 5 of 7 EST-treated (2.5 mg/kg) mice were survived. Pretreatment of EST dose-dependently suppressed the LPS-induced production of IL-6, TNF-α and CXCL1 in peritoneal macrophages. In CLP-induced mice sepsis model, while all 6 control mice was dead at 48 h, 1 of 6 EST-treated (1.25 mg/kg) mice and 3 of 6 EST-treated (2.5 mg/kg) mice survived for 96 h.

CONCLUSION

These results demonstrated that EST exerts anti-inflammatory effects on LPS-stimulated macrophages and protects mice from sepsis. Our study suggests that EST could be developed as a new therapeutic agent for sepsis and various inflammatory diseases.

ACT001 attenuates microglia-mediated neuroinflammation after traumatic brain injury via inhibiting AKT/NFκB/NLRP3 pathway

Background

Microglia-mediated neuroinflammatory response following traumatic brain injury (TBI) is considered as a vital secondary injury factor, which drives trauma-induced neurodegeneration and is lack of efficient treatment. ACT001, a sesquiterpene lactone derivative, is reportedly involved in alleviation of inflammatory response. However, little is known regarding its function in regulating innate immune response of central nervous system (CNS) after TBI. This study aimed to investigate the role and underlying mechanism of ACT001 in TBI.

Methods

Controlled cortical impact (CCI) models were used to establish model of TBI. Cresyl violet staining, evans blue extravasation, neurobehavioral function assessments, immunofluorescence and transmission electron microscopy were used to evaluate therapeutic effects of ACT001 in vivo. Microglial depletion was induced by administering mice with colony stimulating factor 1 receptor (CSF1R) inhibitor, PLX5622. Cell-cell interaction models were established as co-culture system to simulate TBI conditions in vitro. Cytotoxic effect of ACT001 on cell viability was assessed by cell counting kit-8 and activation of microglia cells were induced by Lipopolysaccharides (LPS). Pro-inflammatory cytokines expression was determined by Real-time PCR and nitric oxide production. Apoptotic cells were detected by TUNEL and flow cytometry assays. Tube formation was performed to evaluate cellular angiogenic ability. ELISA and western blot experiments were used to determine proteins expression. Pull-down assay was used to analyze proteins that bound ACT001.

Results

ACT001 relieved the extent of blood-brain barrier integrity damage and alleviated motor function deficits after TBI via reducing trauma-induced activation of microglia cells. Delayed depletion of microglia with PLX5622 hindered therapeutic effect of ACT001. Furthermore, ACT001 alleviated LPS-induced activation in mouse and rat primary microglia cells. Besides, ACT001 was effective in suppressing LPS-induced pro-inflammatory cytokines production in BV2 cells, resulting in reduction of neuronal apoptosis in HT22 cells and improvement of tube formation in bEnd.3 cells. Mechanism by which ACT001 functioned was related to AKT/NFκB/NLRP3 pathway. ACT001 restrained NFκB nuclear translocation in microglia cells through inhibiting AKT phosphorylation, resulting in decrease of NLRP3 inflammasome activation, and finally down-regulated microglial neuroinflammatory response.

Conclusions

Our study indicated that ACT001 played critical role in microglia-mediated neuroinflammatory response and might be a novel potential chemotherapeutic drug for TBI.

Parthenolide leads to proteomic differences in thyroid cancer cells and promotes apoptosis

Background

Parthenolide has anti-inflammatory, immunomodulatory and anti-cancer activities. But its effect on thyroid cancer cells is still largely unknown.

Methods

Label-free quantitative proteomics and bioinformatics analysis were used to investigate the differentially expressed proteins and their functions in thyroid cancer treated with parthenolide and control pair. Hoechst 33258 fluorescent staining and Annexin V-FITC/PI double staining flow cytometry were used to detected BCPAP cells apoptosis. Parallel reaction monitoring (PRM) and quantitative real-time PCR were used to verify the expression of apoptosis-related differential proteins and their mRNA.

Results

Sixty up-regulated and 96 down-regulated differentially expressed proteins were identified in parthenolide treated thyroid cancer cells BCPAP compared with control thyroid cancer cells. The proteins were mainly relevant to various biological processes that included metabolic processes, response to extracellular stimulus and interaction with host. The molecular functions of most differentially expressed proteins were associated with binding functions and nucleotidyltransferase activity. According to the Kyoto Encyclopedia of Genes and Genomes, the differentially expressed proteins identified are primarily related to various types of metabolic pathways and DNA replication. In cell experiments in vitro, with the increase of the dose of parthenolide, the number of cells gradually decreased, the apoptosis rate gradually increased. PRM verified that the apoptosis-related proteins HMOX1 and GCLM were up-regulated and IL1B was down-regulated in BCPAP cells treated with parthenolide. The mRNA expressions of HMOX1, GCLM, ITGA6 and CASP8 were up-regulated and HSPA1A was down-regulated by PCR.

Conclusions

Parthenolide may influence the biological behavior of human thyroid cancer cells by affecting the expression of proteins related to cell metabolism and DNA replication. Parthenolide induced significant cellular morphological changes and apoptosis in human thyroid cancer cells, leading to an anti-proliferative effect.

Immunothrombosis and the molecular control of tissue factor by pyroptosis: prospects for new anticoagulants

The interplay between innate immunity and coagulation after infection or injury, termed immunothrombosis, is the primary cause of disseminated intravascular coagulation (DIC), a condition that occurs in sepsis. Thrombosis associated with DIC is the leading cause of death worldwide. Interest in immunothrombosis has grown because of COVID-19, the respiratory disease caused by SARS-CoV-2, which has been termed a syndrome of dysregulated immunothrombosis. As the relatively new field of immunothrombosis expands at a rapid pace, the focus of academic and pharmacological research has shifted from generating treatments targeted at the traditional 'waterfall' model of coagulation to therapies better directed towards immune components that drive coagulopathies. Immunothrombosis can be initiated in macrophages by cleavage of the non-canonical inflammasome which contains caspase-11. This leads to release of tissue factor (TF), a membrane glycoprotein receptor that forms a high-affinity complex with coagulation factor VII/VIIa to proteolytically activate factors IX to IXa and X to Xa, generating thrombin and leading to fibrin formation and platelet activation. The mechanism involves the post-translational activation of TF, termed decryption, and release of decrypted TF via caspase-11-mediated pyroptosis. During aberrant immunothrombosis, decryption of TF leads to thromboinflammation, sepsis, and DIC. Therefore, developing therapies to target pyroptosis have emerged as an attractive concept to counteract dysregulated immunothrombosis. In this review, we detail the three mechanisms of TF control: concurrent induction of TF, caspase-11, and NLRP3 (signal 1); TF decryption, which increases its procoagulant activity (signal 2); and accelerated release of TF into the intravascular space via pyroptosis (signal 3). In this way, decryption of TF is analogous to the two signals of NLRP3 inflammasome activation, whereby induction of pro-IL-1β and NLRP3 (signal 1) is followed by activation of NLRP3 (signal 2). We describe in detail TF decryption, which involves pathogen-induced alterations in the composition of the plasma membrane and modification of key cysteines on TF, particularly at the location of the critical, allosterically regulated disulfide bond of TF in its 219-residue extracellular domain. In addition, we speculate towards the importance of identifying new therapeutics to block immunothrombotic triggering of TF, which can involve inhibition of pyroptosis to limit TF release, or the direct targeting of TF decryption using cysteine-modifying therapeutics.

Anti-Inflammatory and Immunoregulatory Action of Sesquiterpene Lactones

Sesquiterpene lactones (SL), characterized by their high prevalence in the Asteraceae family, are one of the major groups of secondary metabolites found in plants. Researchers from distinct research fields, including pharmacology, medicine, and agriculture, are interested in their biological potential. With new SL discovered in the last years, new biological activities have been tested, different action mechanisms (synergistic and/or antagonistic effects), as well as molecular structure–activity relationships described. The review identifies the main sesquiterpene lactones with interconnections between immune responses and anti-inflammatory actions, within different cellular models as well in in vivo studies. Bioaccessibility and bioavailability, as well as molecular structure–activity relationships are addressed. Additionally, plant metabolic engineering, and the impact of sesquiterpene lactone extraction methodologies are presented, with the perspective of biological activity enhancement. Sesquiterpene lactones derivatives are also addressed. This review summarizes the current knowledge regarding the therapeutic potential of sesquiterpene lactones within immune and inflammatory activities, highlighting trends and opportunities for their pharmaceutical/clinical use.

Identification of NLRP3PYD Homo-Oligomerization Inhibitors with Anti-Inflammatory Activity

Inflammasomes are multiprotein complexes that represent critical elements of the inflammatory response. The dysregulation of the best-characterized complex, the NLRP3 inflammasome, has been linked to the pathogenesis of diseases such as multiple sclerosis, type 2 diabetes mellitus, Alzheimer's disease, and cancer. While there exist molecular inhibitors specific for the various components of inflammasome complexes, no currently reported inhibitors specifically target NLRP3^PYD homo-oligomerization. In the present study, we describe the identification of QM380 and QM381 as NLRP3^PYD homo-oligomerization inhibitors after screening small molecules from the MyriaScreen library using a split-luciferase complementation assay. Our results demonstrate that these NLRP3^PYD inhibitors interfere with ASC speck formation, inhibit pro-inflammatory cytokine IL1-β release, and decrease pyroptotic cell death. We employed spectroscopic techniques and computational docking analyses with QM380 and QM381 and the PYD domain to confirm the experimental results and predict possible mechanisms underlying the inhibition of NLRP3^PYD homo-interactions.

Inflammation, Fibrosis and Cancer: Mechanisms, Therapeutic Options and Challenges

Uncontrolled inflammation is a salient factor in multiple chronic inflammatory diseases and cancers. In this review, we provided an in-depth analysis of the relationships and distinctions between uncontrolled inflammation, fibrosis and cancers, while emphasizing the challenges and opportunities of developing novel therapies for the treatment and/or management of these diseases. We described how drug delivery systems, combination therapy and the integration of tissue-targeted and/or pathways selective strategies could overcome the challenges of current agents for managing and/or treating chronic inflammatory diseases and cancers. We also recognized the value of the re-evaluation of the disease-specific roles of multiple pathways implicated in the pathophysiology of chronic inflammatory diseases and cancers-as well as the application of data from single-cell RNA sequencing in the success of future drug discovery endeavors.

K2P18.1 translates T cell receptor signals into thymic regulatory T cell development

It remains largely unclear how thymocytes translate relative differences in T cell receptor (TCR) signal strength into distinct developmental programs that drive the cell fate decisions towards conventional (Tconv) or regulatory T cells (Treg). Following TCR activation, intracellular calcium (Ca²⁺) is the most important second messenger, for which the potassium channel K_2P18.1 is a relevant regulator. Here, we identify K_2P18.1 as a central translator of the TCR signal into the thymus-derived Treg (tTreg) selection process. TCR signal was coupled to NF-κB-mediated K_2P18.1 upregulation in tTreg progenitors. K_2P18.1 provided the driving force for sustained Ca²⁺ influx that facilitated NF-κB- and NFAT-dependent expression of FoxP3, the master transcription factor for Treg development and function. Loss of K_2P18.1 ion-current function induced a mild lymphoproliferative phenotype in mice, with reduced Treg numbers that led to aggravated experimental autoimmune encephalomyelitis, while a gain-of-function mutation in K_2P18.1 resulted in increased Treg numbers in mice. Our findings in human thymus, recent thymic emigrants and multiple sclerosis patients with a dominant-negative missense K_2P18.1 variant that is associated with poor clinical outcomes indicate that K_2P18.1 also plays a role in human Treg development. Pharmacological modulation of K_2P18.1 specifically modulated Treg numbers in vitro and in vivo. Finally, we identified nitroxoline as a K_2P18.1 activator that led to rapid and reversible Treg increase in patients with urinary tract infections. Conclusively, our findings reveal how K_2P18.1 translates TCR signals into thymic T cell fate decisions and Treg development, and provide a basis for the therapeutic utilization of Treg in several human disorders.

Pathway network of pyroptosis and its potential inhibitors in acute kidney injury

Acute kidney injury (AKI) is a worldwide problem, and there is no effective drug to eliminate AKI. The death of renal cells is an important pathological basis of intrinsic AKI. At present, targeted therapy for TEC death is a research hotspot in AKI therapy. There are many ways of cell death involved in the occurrence and development of AKI, such as apoptosis, necrosis, ferroptosis, and pyroptosis. This article mainly focuses on the role of pyroptosis in AKI. The assembly and activation of NLRP3 inflammasome is a key event in the occurrence of pyroptosis, which is affected by many factors, such as the activation of the NF-κB signaling pathway, mitochondrial instability and excessive endoplasmic reticulum (ER) stress. The activation of NLRP3 inflammasome can trigger its downstream inflammatory cytokines, which will lead to pyroptosis and eventually induce AKI. In this paper, we reviewed the possible mechanism of pyroptosis in AKI and the potential effective inhibitors of various key targets in this process. It may provide potential therapeutic targets for novel intrinsic AKI therapies based on pyroptosis, so as to develop better therapeutic strategies.

Reviewing the importance of TLR-NLRP3-pyroptosis pathway and mechanism of experimental NLRP3 inflammasome inhibitors

Cells encounter continuous challenges due to tissue insult caused by endogenous and/or exogenous stimuli. Among the mechanisms set in place to counterbalance the tissue insult, innate immunity is always at the forefront. Cells of innate immunity efficiently recognize the 'danger signals' via a specialized set of membrane-bound receptors known as Toll-like receptors. Once this interaction is established, toll-like receptor passes on the responsibility to cytosolic NOD-like receptors through a cascade of signalling pathways. Subsequently, NOD-like receptors assemble to a specialized multiprotein intracellular complex, that is inflammasome. Inflammasome activates Caspase-1 and Gasdermin-D which initiate pyroptotic cell death in the affected tissue by two simultaneous mechanisms. Being a protease, caspase-1 cleaves and activates pro-inflammatory cytokines IL-1β and IL-18. On the other hand, Gasdermin-D causes proteolytic cleavage which forms a pore in the cell membrane. This review highlights the molecular events ranging from recognition of stimuli to pyroptosis. The review is also an attempt to discuss the mechanisms of the most specific experimental NLRP3 inhibitors.

A review on importance of bioactive compounds of medicinal plants in treating idiopathic pulmonary fibrosis (special emphasis on isoquinoline alkaloids)

Background

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease of unknown cause which disrupts the normal lung architecture and functions by deregulating immune responses and ultimately leads to the death of the individual. A number of factors can lead to its development and currently there is no cure for this disease.

Main text

There are synthetic drugs available to relieve the symptoms and decelerate its development by targeting pathways involved in the development of IPF, but there had also been various side effects detected by their usage. It is known since decades that medicinal plants and their compounds have been used all over the world in natural medicines to cure various diseases. This review article is focused on the effects of various natural bioactive compounds of 26 plant extracts that show prophylactic and therapeutic properties against the disease and so can be used in treating IPF replacing synthetic drugs and reducing the side effects.

Short conclusion

This review includes different mechanisms that cause pulmonary fibrosis along with compounds that can induce fibrosis, drugs used for the treatment of pulmonary fibrosis, diagnosis, the biochemical tests used for the experimental study to determine the pathogenesis of disease with a special note on Isoquinoline alkaloids and their role in reducing various factors leading to IPF thus providing promising therapeutic approach.

Phytochemicals targeting NF-κB signaling: Potential anti-cancer interventions

Nuclear factor κB (NF-κB) is a ubiquitous regulator of the signalome and is indispensable for various biological cell functions. NF-κB consists of five transcription factors that execute both cytoplasmic and nuclear signaling processes in cells. NF-κB is the only signaling molecule that governs both pro- and anti-apoptotic, and pro- and anti-inflammatory responses. This is due to the canonical and non-canonical components of the NF-κB signaling pathway. Together, these pathways orchestrate cancer-related inflammation, hyperplasia, neoplasia, and metastasis. Non-canonical NF-κB pathways are particularly involved in the chemoresistance of cancer cells. In view of its pivotal role in cancer progression, NF-κB represents a potentially significant therapeutic target for modifying tumor cell behavior. Several phytochemicals are known to modulate NF-κB pathways through the stabilization of its inhibitor, IκB, by inhibiting phosphorylation and ubiquitination thereof. Several natural pharmacophores are known to inhibit the nuclear translocation of NF-κB and associated pro-inflammatory responses and cell survival pathways. In view of this and the high degree of specificity exhibited by various phytochemicals for the NF-κB component, we herein present an in-depth overview of these phytochemicals and discuss their mode of interaction with the NF-κB signaling pathways for controlling the fate of tumor cells for cancer-directed interventions.

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NF-κB plays a pivotal role in the maintenance of homeostasis and various inflammation-mediated pathologies.

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NF-κB is involved in cancer development and progression by modulating growth signaling and apoptosis pathways.

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Phytochemicals modulating NF-κB activity should be exploited to design anticancer drugs with minimal side effects.

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Use of these phytochemicals in adjunctive chemotherapy may enhance the chemosensitivity of existing chemotherapeutic drugs.

Inflammasomes and Type 1 Diabetes

Microbiota have been identified as an important modulator of susceptibility in the development of Type 1 diabetes in both animal models and humans. Collectively these studies highlight the association of the microbiota composition with genetic risk, islet autoantibody development and modulation of the immune responses. However, the signaling pathways involved in mediating these changes are less well investigated, particularly in humans. Importantly, understanding the activation of signaling pathways in response to microbial stimulation is vital to enable further development of immunotherapeutics, which may enable enhanced tolerance to the microbiota or prevent the initiation of the autoimmune process. One such signaling pathway that has been poorly studied in the context of Type 1 diabetes is the role of the inflammasomes, which are multiprotein complexes that can initiate immune responses following detection of their microbial ligands. In this review, we discuss the roles of the inflammasomes in modulating Type 1 diabetes susceptibility, from genetic associations to the priming and activation of the inflammasomes. In addition, we also summarize the available inhibitors for therapeutically targeting the inflammasomes, which may be of future use in Type 1 diabetes.

TLR4 as a therapeutic target for respiratory and neurological complications of SARS-CoV-2

Introduction: The COVID-19 pandemic remains aglobal challenge. While there are mRNA agents on the horizon as apotential prevention, adefinitive drug therapy is an unmet medical need. The hyperinflammatory response, known as the 'cytokine storm', is chiefly responsible for complications and deaths. The binding of spike-glycoprotein of SARS-CoV-2 to TLR4 receptors has been documented in several studies and has been found to play arole in hyperinflammation; hence, there is an interest in TLR4 as apotential drug target.Areas covered: This review discusses the neurological and respiratory complications of SARS-CoV-2 infection and progresses to examine the role of the 'cytokine storm' and the involvement of TLR4 receptors in these complications. The possibility of using TLR4 modulators to curb the complications are considered and finally, ashort perspective on future potential drug treatments is offered. Various databases were searched including Pub-Med, Google Scholar, and Medline. The search mainly included research articles, meta-analysis, retrospective studies, reports, and systematic reviews.Expert opinion: TLR4 modulators are being investigated in clinical trials for COVID-19. Challenges in terms of structural diversity of the agents, their natural origin, and efficacy demand extensive research.

Supercritical CO2 Extraction as a Tool to Isolate Anti-Inflammatory Sesquiterpene Lactones from Cichorium intybus L. Roots

Cichorium intybus L. or chicory plants are a natural source of health-promoting compounds in the form of supplements such as inulin, as well as other bioactive compounds such as sesquiterpene lactones (SLs). After inulin extraction, chicory roots are considered waste, with most SLs not being harnessed. We developed and optimized a new strategy for SL extraction that can contribute to the conversion of chicory root waste into valuable products to be used in human health-promoting applications. In our work, rich fractions of SLs were recovered from chicory roots using supercritical CO2. A response surface methodology was used to optimize the process parameters (pressure, temperature, flow rate, and co-solvent percentage) for the extraction performance. The best operating conditions were achieved at 350 bar, 40 °C, and 10% EtOH as a co-solvent in a 15 g/min flow rate for 120 min. The extraction with supercritical CO2 revealed to be more selective for the SLs than the conventional solid-liquid extraction with ethyl acetate. In our work, 1.68% mass and a 0.09% sesquiterpenes yield extraction were obtained, including the recovery of two sesquiterpene lactones (8-deoxylactucin and 11β,13-dihydro-8-deoxylactucin), which, to the best of our knowledge, are not commercially available. A mixture of the abovementioned compounds were tested at different concentrations for their toxic profile and anti-inflammatory potential towards a human calcineurin/NFAT orthologue pathway in a yeast model, the calcineurin/Crz1 pathway. The SFE extract obtained, rich in SLs, yielded results of inhibition of 61.74 ± 6.87% with 50 µg/mL, and the purified fraction containing 8-deoxylactucin and 11β,13-dihydro-8-deoxylactucin inhibited the activation of the reporter gene up to 53.38 ± 3.9% at 10 µg/mL. The potential activity of the purified fraction was also validated by the ability to inhibit Crz1 nuclear translocation and accumulation. These results reveal a possible exploitable green technology to recover potential anti-inflammatory compounds from chicory roots waste after inulin extraction.

A Drug Screening Pipeline Using 2D and 3D Patient-Derived In Vitro Models for Pre-Clinical Analysis of Therapy Response in Glioblastoma

Glioblastoma is one of the most common and lethal types of primary brain tumor. Despite aggressive treatment with chemotherapy and radiotherapy, tumor recurrence within 6-9 months is common. To overcome this, more effective therapies targeting cancer cell stemness, invasion, metabolism, cell death resistance and the interactions of tumor cells with their surrounding microenvironment are required. In this study, we performed a systematic review of the molecular mechanisms that drive glioblastoma progression, which led to the identification of 65 drugs/inhibitors that we screened for their efficacy to kill patient-derived glioma stem cells in two dimensional (2D) cultures and patient-derived three dimensional (3D) glioblastoma explant organoids (GBOs). From the screening, we found a group of drugs that presented different selectivity on different patient-derived in vitro models. Moreover, we found that Costunolide, a TERT inhibitor, was effective in reducing the cell viability in vitro of both primary tumor models as well as tumor models pre-treated with chemotherapy and radiotherapy. These results present a novel workflow for screening a relatively large groups of drugs, whose results could lead to the identification of more personalized and effective treatment for recurrent glioblastoma.

Inhibition of NF-κB by ACT001 reduces fibroblast activity in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease of unknown etiology and poor prognosis. In IPF, aberrant extracellular matrix production by activated, hyperproliferative fibroblasts drives disease progression but the exact mechanisms by which this occurs remains undefined. The transcription factor nuclear factor kappa-B (NF-ĸB) has been suggested as a potential therapeutic target in IPF and therefore the aim of this study was to investigate the efficacy of ACT001, an NF-ĸB inhibitor, on primary fibroblasts derived from patients with and without IPF. Primary lung fibroblasts derived from eight patients with IPF and eight age-matched non-diseased controls (NDC) were treated with 0-10 µM ACT001 and the effects on fibroblast activity (viability and proliferation, fibroblast-to-myofibroblast transition, fibronectin expression), interleukin (IL)-6 and IL-8 cytokine release were quantified. ACT001 inhibited fibroblast activity in a concentration-dependent manner in both groups of fibroblasts. ACT001 inhibited IL-6 but not IL-8 production in unstimulated fibroblasts. ACT001 is a water-soluble compound with a stable half-life in plasma, thus making it an attractive candidate for further investigation as a therapeutic in IPF. This study adds to the growing body of literature that demonstrates anti-fibrotic activity of NF-ĸB inhibition in the context of IPF.

The Promising Ability of Humulus lupulus L. Iso-α-acids vs. Diabetes, Inflammation, and Metabolic Syndrome: A Systematic Review

For centuries, natural medicines have represented the only option for treating human diseases and, nowadays, plant phytochemicals are considered as promising compounds to treat or prevent chronic conditions. Among them, hop flowers (Humulus lupulus L.), typically used in brewing industries to give the typical aroma and flavor to beer, have attracted particular attention for their health promoting properties. Several in vivo/vitro studies and human interventional trials have demonstrated the beneficial effects of these molecules on weight gain, lipid metabolism, glucose homeostasis, insulin sensitivities, and inflammation by acting on different targets. All these activities suggest a possible role of bitter hop acid in preventing metabolic syndrome and its related diseases. A systematic quest on PubMed and Scopus databases was performed to identify pre-clinical and clinical studies focusing on this topic. This systematic review summarizes the results obtained by different cell lines, animal models, and human interventional trials to propose iso-α-acids as medical nutrition therapy to treat or prevent metabolic syndrome and its related disorders as diabetes, dislipidemia inflammation, etc.

Toll-like receptor 4 (TLR4) antagonists as potential therapeutics for intestinal inflammation

Gastrointestinal inflammation is a hallmark of highly prevalent disorders, including cancer treatment-induced mucositis and ulcerative colitis. These disorders cause debilitating symptoms, have a significant impact on quality of life, and are poorly managed. The activation of toll-like receptor 4 (TLR4) has been proposed to have a major influence on the inflammatory signalling pathways of the intestinal tract. Inhibition of TLR4 has been postulated as an effective way to treat intestinal inflammation. However, there are a limited number of studies looking into the potential of TLR4 antagonism as a therapeutic approach for intestinal inflammation. This review surveyed available literature and reported on the in vitro, ex vivo and in vivo effects of TLR4 antagonism on different models of intestinal inflammation. Of the studies reviewed, evidence suggests that there is indeed potential for TLR4 antagonists to treat inflammation, although only a limited number of studies have investigated treating intestinal inflammation with TLR4 antagonists directly. These results warrant further research into the effect of TLR4 antagonists in the intestinal tract.

Therapeutic role of inflammasome inhibitors in neurodegenerative disorders

Neuroinflammation, characterized by the activation of glial cells, is a hallmark in several neurological and neurodegenerative disorders. Inadequate inflammation cannot eliminate the infection of pathogens, while excessive or hyper-reactive inflammation can cause chronic or systemic inflammatory diseases affecting the central nervous system (CNS). In response to a brain injury or pathogen invasion, the pathogen recognition receptors (PRRs) expressed on glial cells are activated via binding to cellular damage-associated molecular patterns (DAMPs) or pathogen-associated molecular patterns (PAMPs). This subsequently leads to the activation of NOD (nucleotide-binding oligomerization domain)-like receptor proteins (NLRs). In neurodegenerative diseases such as HIV-1-associated neurocognitive disorders (HAND), Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS), chronic inflammation is a critical contributing factor for disease manifestation including pathogenesis. Emerging evidence points to the involvement of "inflammasomes", especially the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing (NLRP) complex in the development of these diseases. The activated NLRP3 results in the proteolytic activation of caspase-1 that facilitates the cleavage of pro-IL-1β and the secretion of IL-1β and IL-18 proinflammatory cytokines. Accordingly, these and other seminal findings have led to the development of NLRP-targeting small-molecule therapeutics as possible treatment options for neurodegenerative disorders. In this review, we will discuss the new advances and evidence-based literature concerning the role of inflammasomes in neurodegenerative diseases, its role in the neurological repercussions of CNS chronic infection, and the examples of preclinical or clinically tested NLRP inhibitors as potential strategies for the treatment of chronic neurological diseases.

Euphopias D–F from Euphorbia L.: quantum chemical calculation-based structure elucidation and their bioactivity of inhibiting NLRP3 inflammasome activation

Euphopias D–F (1–3), three novel carbon skeleton diterpenoids with an inhibitory effect on NLRP3 inflammasome, were isolated and identified from the whole plants of Euphorbia helioscopia.

Dysregulated NF-κB-Dependent ICOSL Expression in Human Dendritic Cell Vaccines Impairs T-cell Responses in Patients with Melanoma

Therapeutic cancer vaccines targeting melanoma-associated antigens are commonly immunogenic but are rarely effective in promoting objective clinical responses. To identify critical molecules for activation of effective antitumor immunity, we have profiled autologous dendritic cell (DC) vaccines used to treat 35 patients with melanoma. We showed that checkpoint molecules induced by ex vivo maturation correlated with in vivo DC vaccine activity. Melanoma patient DCs had reduced expression of cell surface inducible T-cell costimulator ligand (ICOSL) and had defective intrinsic NF-κB signaling. Chromatin immunoprecipitation assays revealed NF-κB-dependent transcriptional regulation of ICOSL expression by DCs. Blockade of ICOSL on DCs reduced priming of antigen-specific CD8⁺ and CD4⁺ T cells from naïve donors in vitro Concentration of extracellular/soluble ICOSL released from vaccine DCs positively correlated with patient clinical outcomes, which we showed to be partially regulated by ADAM10/17 sheddase activity. These data point to the critical role of canonical NF-κB signaling, the regulation of matrix metalloproteinases, and DC-derived ICOSL in the specific priming of cognate T-cell responses in the cancer setting. This study supports the implementation of targeted strategies to augment these pathways for improved immunotherapeutic outcomes in patients with cancer.

Update on the Role of NFκB in Promoting Aggressive Phenotypes of Estrogen Receptor-Positive Breast Cancer

The majority of breast cancers are diagnosed as estrogen receptor-positive (ER+) and respond well to ER-targeted endocrine therapy. Despite the initial treatability of ER+ breast cancer, this subtype still accounts for the majority of deaths. This is partly due to the changing molecular characteristics of tumors as they progress to aggressive, metastatic, and frequently therapy resistant disease. In these advanced tumors, targeting ER alone is often less effective, as other signaling pathways become active, and ER takes on a redundant or divergent role. One signaling pathway whose crosstalk with ER has been widely studied is the nuclear factor kappa B (NFκB) signaling pathway. NFκB is frequently implicated in ER+ tumor progression to an aggressive disease state. Although ER and NFκB frequently co-repress each other, it has emerged that the 2 pathways can positively converge to play a role in promoting endocrine resistance, metastasis, and disease relapse. This will be reviewed here, paying particular attention to new developments in the field. Ultimately, finding targeted therapies that remain effective as tumors progress remains one of the biggest challenges for the successful treatment of ER+ breast cancer. Although early attempts to therapeutically block NFκB activity frequently resulted in systemic toxicity, there are some effective options. The drugs parthenolide and dimethyl fumarate have both been shown to effectively inhibit NFκB, reducing tumor aggressiveness and reversing endocrine therapy resistance. This highlights the need to revisit targeting NFκB in the clinic to potentially improve outcome for patients with ER+ breast cancer.

NLRP3 Inflammasome Activation in Adipose Tissues and Its Implications on Metabolic Diseases

Adipose tissue is an active endocrine and immune organ that controls systemic immunometabolism via multiple pathways. Diverse immune cell populations reside in adipose tissue, and their composition and immune responses vary with nutritional and environmental conditions. Adipose tissue dysfunction, characterized by sterile low-grade chronic inflammation and excessive immune cell infiltration, is a hallmark of obesity, as well as an important link to cardiometabolic diseases. Amongst the pro-inflammatory factors secreted by the dysfunctional adipose tissue, interleukin (IL)-1β, induced by the NLR family pyrin domain-containing 3 (NLRP3) inflammasome, not only impairs peripheral insulin sensitivity, but it also interferes with the endocrine and immune functions of adipose tissue in a paracrine manner. Human studies indicated that NLRP3 activity in adipose tissues positively correlates with obesity and its metabolic complications, and treatment with the IL-1β antibody improves glycaemia control in type 2 diabetic patients. In mouse models, genetic or pharmacological inhibition of NLRP3 activation pathways or IL-1β prevents adipose tissue dysfunction, including inflammation, fibrosis, defective lipid handling and adipogenesis, which in turn alleviates obesity and its related metabolic disorders. In this review, we summarize both the negative and positive regulators of NLRP3 inflammasome activation, and its pathophysiological consequences on immunometabolism. We also discuss the potential therapeutic approaches to targeting adipose tissue inflammasome for the treatment of obesity and its related metabolic disorders.

Inflammasomes in neuroinflammatory and neurodegenerative diseases

Neuroinflammation and neurodegeneration often result from the aberrant deposition of aggregated host proteins, including amyloid‐β, α‐synuclein, and prions, that can activate inflammasomes. Inflammasomes function as intracellular sensors of both microbial pathogens and foreign as well as host‐derived danger signals. Upon activation, they induce an innate immune response by secreting the inflammatory cytokines interleukin (IL)‐1β and IL‐18, and additionally by inducing pyroptosis, a lytic cell death mode that releases additional inflammatory mediators. Microglia are the prominent innate immune cells in the brain for inflammasome activation. However, additional CNS‐resident cell types including astrocytes and neurons, as well as infiltrating myeloid cells from the periphery, express and activate inflammasomes. In this review, we will discuss current understanding of the role of inflammasomes in common degenerative diseases of the brain and highlight inflammasome‐targeted strategies that may potentially treat these diseases.

NLRP3 Inflammasome and Inflammatory Diseases

Almost all human diseases are strongly associated with inflammation, and a deep understanding of the exact mechanism is helpful for treatment. The NLRP3 inflammasome composed of the NLRP3 protein, procaspase-1, and ASC plays a vital role in regulating inflammation. In this review, NLRP3 regulation and activation, its proinflammatory role in inflammatory diseases, interactions with autophagy, and targeted therapeutic approaches in inflammatory diseases will be summarized.

Pharmacological Inhibitors of the NLRP3 Inflammasome

Inflammasomes play a crucial role in innate immunity by serving as signaling platforms which deal with a plethora of pathogenic products and cellular products associated with stress and damage. By far, the best studied and most characterized inflammasome is NLRP3 inflammasome, which consists of NLRP3 (nucleotide-binding domain leucine-rich repeat (NLR) and pyrin domain containing receptor 3), ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain), and procaspase-1. Activation of NLRP3 inflammasome is mediated by highly diverse stimuli. Upon activation, NLRP3 protein recruits the adapter ASC protein, which recruits the procaspase-1 resulting in its cleavage and activation, inducing the maturation, and secretion of inflammatory cytokines and pyroptosis. However, aberrant activation of the NLRP3 inflammasome is implicated in various diseases including diabetes, atherosclerosis, metabolic syndrome, cardiovascular, and neurodegenerative diseases; raising a tremendous clinical interest in exploring the potential inhibitors of NLRP3 inflammasome. Recent investigations have disclosed various inhibitors of the NLRP3 inflammasome pathway which were validated through in vitro studies and in vivo experiments in animal models of NLRP3-associated disorders. Some of these inhibitors directly target the NLRP3 protein whereas some are aimed at other components and products of the inflammasome. Direct targeting of NLRP3 protein can be a better choice because it can prevent off target immunosuppressive effects, thus restrain tissue destruction. This paper will review the various pharmacological inhibitors of the NLRP3 inflammasome and will also discuss their mechanism of action.

Pharmacological Inhibitors of the NLRP3 Inflammasome

Inflammasomes play a crucial role in innate immunity by serving as signaling platforms which deal with a plethora of pathogenic products and cellular products associated with stress and damage. By far, the best studied and most characterized inflammasome is NLRP3 inflammasome, which consists of NLRP3 (nucleotide-binding domain leucine-rich repeat (NLR) and pyrin domain containing receptor 3), ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain), and procaspase-1. Activation of NLRP3 inflammasome is mediated by highly diverse stimuli. Upon activation, NLRP3 protein recruits the adapter ASC protein, which recruits the procaspase-1 resulting in its cleavage and activation, inducing the maturation, and secretion of inflammatory cytokines and pyroptosis. However, aberrant activation of the NLRP3 inflammasome is implicated in various diseases including diabetes, atherosclerosis, metabolic syndrome, cardiovascular, and neurodegenerative diseases; raising a tremendous clinical interest in exploring the potential inhibitors of NLRP3 inflammasome. Recent investigations have disclosed various inhibitors of the NLRP3 inflammasome pathway which were validated through in vitro studies and in vivo experiments in animal models of NLRP3-associated disorders. Some of these inhibitors directly target the NLRP3 protein whereas some are aimed at other components and products of the inflammasome. Direct targeting of NLRP3 protein can be a better choice because it can prevent off target immunosuppressive effects, thus restrain tissue destruction. This paper will review the various pharmacological inhibitors of the NLRP3 inflammasome and will also discuss their mechanism of action.

Collateral Sensitivity of Parthenolide via NF-κB and HIF-α Inhibition and Epigenetic Changes in Drug-Resistant Cancer Cell Lines

Parthenolide (PT) is a sesquiterpene lactone isolated from Tanacetum parthenium. In this study, PT showed varying cytotoxic effects against different solid tumor cell lines. HCT116 (p53^+/+) colon carcinoma cells and their parental HCT116 knockout p53 (p53^-/-) cell lines showed a resistance degree of 2.36. On the other hand, wild-type U87.MG cells or cells transfected with a deletion-activated EGFR cDNA (U87.MGΔEGFR) exhibited slight sensitivity toward PT. Multidrug-resistant MDA-MB-231-BCRP cells were even more sensitive toward PT than sensitive MDA-MB-231-pcDNA cells with a resistance degree of 0.07 (collateral sensitivity). To the best of our knowledge, hypersensitivity (collateral sensitivity) in MDA-MB-231-BCRP cell line is reported in this study for the first time. We attempted to identify the mechanism of collateral sensitivity. Firstly, we found that PT bound to IKK preventing IκBα degradation and eventually inhibition of the nuclear factor kappa B (NF-κB) pathway. Down-regulation of hypoxia inducing factor 1-alpha (HIF-1α) in MDA-MB-231-BCRP resistant cells may be a second mechanism, since it is a target gene of NF-κB. Moreover, PT also showed epigenetic effect by inhibition of HDAC activity as shown using both molecular docking and HDAC activity assay. Based on COMPARE and hierarchical cluster analyses, we found gene expression profiles that predicted sensitivity or resistance of 47 tumor cell lines toward PT. Interestingly, pathway analyses of gene expression profiles revealed NF-κB and HIF signaling as top networks of these genes, cellular functions and canonical pathways influencing the activity of PT against tumor cells. In conclusion, PT exerted profound cytotoxic activity against various cancer cell lines mainly against BCRP-overexpressing tumor cells, suggesting PT as novel candidate for cancer treatment.

Dendritic Cell-Mediated Th2 Immunity and Immune Disorders

Dendritic cells (DCs) are the professional antigen-presenting cells that recognize and present antigens to naïve T cells to induce antigen-specific adaptive immunity. Among the T-cell subsets, T helper type 2 (Th2) cells produce the humoral immune responses required for protection against helminthic disease by activating B cells. DCs induce a Th2 immune response at a certain immune environment. Basophil, eosinophil, mast cells, and type 2 innate lymphoid cells also induce Th2 immunity. However, in the case of DCs, controversy remains regarding which subsets of DCs induce Th2 immunity, which genes in DCs are directly or indirectly involved in inducing Th2 immunity, and the detailed mechanisms underlying induction, regulation, or maintenance of the DC-mediated Th2 immunity against allergic environments and parasite infection. A recent study has shown that a genetic defect in DCs causes an enhanced Th2 immunity leading to severe atopic dermatitis. We summarize the Th2 immune-inducing DC subsets, the genetic and environmental factors involved in DC-mediated Th2 immunity, and current therapeutic approaches for Th2-mediated immune disorders. This review is to provide an improved understanding of DC-mediated Th2 immunity and Th1/Th2 immune balancing, leading to control over their adverse consequences.

Epoxymicheliolide, a novelguaiane-type sesquiterpene lactone, inhibits NF‑κB/COX‑2 signaling pathways by targeting leucine 281 and leucine 25 in IKKβ in renal cell carcinoma

Parthenolide (PTL) is a sesquiterpene lactone compound obtained from Tanacetum parthenium (feverfew) and inhibits the activation of nuclear factor (NF)-κB. Epoxymicheliolide (EMCL) is a compound which is structurally related to PTL; however, EMCL is more stable under acidic and alkaline conditions. As a biologically active molecule, the detailed mechanism by which EMCL inhibits tumor activity remains to be elucidated. The present study evaluated the effect of EMCL on renal cell carcinoma (RCC) cells and identified the underlying mechanisms. It was found that treatment with EMCL significantly inhibited the proliferation of RCC cells in vitro and increased the induction of apoptosis by activating the mitochondria- and caspase-dependent pathway. Simultaneously, EMCL suppressed cell invasion and metastasis by inhibiting epithelial-mesenchymal transition, as observed in a microfluidic chip assay. Furthermore, using immunofluorescence analysis, an electrophoretic mobility shift assay and a dual-luciferase reporter assay, it was shown that treatment with EMCL significantly suppressed the expression of cyclooxygenase-2 by inhibiting the translocation of NF-κB p50/p65 and the activity of NF-κB. Collectively, the results indicated that EMCL suppressed tumor growth by inhibiting the activation of NF-κB and suggested that EMCL may be a novel anticancer agent in the treatment of RCC.

The nuclear factor-kappa B pathway and response to treatment in breast cancer

The nuclear factor-kappa B (NF-κB) pathway is known to contribute to critical signaling in cancer biology, including breast cancer, through promotion of proliferation, angiogenesis, metastasis, tumor progression, inflammation and cell survival. In this review, in vivo and in vitro studies of the NF-κB pathway in breast cancer are discussed, focusing on DNA damage and the epithelial-mesenchymal transition associated with breast cancer stem cell properties. The relationships between NF-κB signaling and conventional cancer treatments in terms of response to chemo- and radiotherapy will also be discussed. Then contribution and involvement of immune system in the NF-κB pathway will be covered. Furthermore, the future perspective of NF-κB targeting as an innovative strategy to overcome refractory breast cancer, including recent updates on out-receptor activator of NF-κB (RANKing), will be covered.

TLR4 Signaling Pathway Modulators as Potential Therapeutics in Inflammation and Sepsis

Toll-Like Receptor 4 (TLR4) signal pathway plays an important role in initiating the innate immune response and its activation by bacterial endotoxin is responsible for chronic and acute inflammatory disorders that are becoming more and more frequent in developed countries. Modulation of the TLR4 pathway is a potential strategy to specifically target these pathologies. Among the diseases caused by TLR4 abnormal activation by bacterial endotoxin, sepsis is the most dangerous one because it is a life-threatening acute system inflammatory condition that still lacks specific pharmacological treatment. Here, we review molecules at a preclinical or clinical phase of development, that are active in inhibiting the TLR4-MyD88 and TLR4-TRIF pathways in animal models. These are low-molecular weight compounds of natural and synthetic origin that can be considered leads for drug development. The results of in vivo studies in the sepsis model and the mechanisms of action of drug leads are presented and critically discussed, evidencing the differences in treatment results from rodents to humans.

Efficacy of parthenolide on lung histopathology in a murine model of asthma

BACKGROUND

Parthenolide is the active constituent of the plant 'Tanacetum parthenium' (Feverfew) which has been used for centuries as a folk remedy for inflammatory conditions.

AIM OF THE STUDY

In this study we aimed to investigate the effects of parthenolide in a murine model of chronic asthma.

MATERIALS AND METHODS

Thirty-five BALB/c mice were divided into five groups; I (control), II (placebo), III (dexamethasone), IV (parthenolide) and V (dexamethasone and parthenolide combination). Lung histology was evaluated after treatment with the study drugs. Levels of interleukin (IL)-4 and IL-5 were determined by ELISA.

RESULTS

Histologic parameters except the number of mast and goblet cells improved in the parthenolide group when compared with placebo. All parameters except basal membrane thickness and number of mast cells were improved significantly better in the group receiving dexamethasone when compared with the parthenolide group. Improvement of most of the histologic parameters was similar in Groups III and V. Interleukin-4 levels were significantly reduced in the parthenolide group when compared to the placebo group.

CONCLUSION

We demonstrated that parthenolide administration alleviated some of the pathological changes in asthma. But parthenolide alone is not efficient as dexamethasone therapy and the parthenolide and dexamethasone combination also did not add any beneficial effect to the dexamethasone treatment.