Metabolic regulation of inflammasomes in inflammation

Neuroimmune cell interactions and chronic infections in oral cancers

Inflammation is a process that is associated with the activation of distal immunosuppressive pathways that have evolved to restore homeostasis and prevent excessive tissue destruction. However, long-term immunosuppression resulting from systemic and local inflammation that may stem from dysbiosis, infections, or aging poses a higher risk for cancers. Cancer incidence and progression dramatically increase with chronic infections including HIV infection. Thus, studies on pro-tumorigenic effects of microbial stimulants from resident microbiota and infections in the context of inflammation are needed and underway. Here, we discuss chronic infections and potential neuro-immune interactions that could establish immunomodulatory programs permissive for tumor growth and progression.

Untargeted Metabolomic Analysis Reveals Plasma Differences between Mares with Endometritis and Healthy Ones

The aim of this study was to explore alterations in plasma metabolites among mares afflicted with endometritis. Mares were divided into two groups, namely, the equine endometritis group (n = 8) and the healthy control group (n = 8), which included four pregnant and four non-pregnant mares, using a combination of clinical assessment and laboratory confirmation. Plasma samples from both groups of mares were analyzed through untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics. A total of 28 differentially abundant metabolites were identified by screening and identifying differentially abundant metabolites and analyzing the pathway enrichment of differentially. Ten metabolites were identified as potential biomarkers for the diagnosis of endometritis in mares. Among them, seven exhibited a decrease in the endometritis groups, including hexadecanedioic acid, oleoyl ethanolamide (OEA), [fahydroxy(18:0)]12_13-dihydroxy-9z-octa (12,13-diHOME), deoxycholic acid 3-glucuronide (DCA-3G), 2-oxindole, and (+/-)9-HPODE, and 13(S)-HOTRE. On the other hand, three metabolites, adenosine 5'-monophosphate (AMP), 5-hydroxy-dl-tryptophan (5-HTP), and l-formylkynurenine, demonstrated an increase. These substances primarily participate in the metabolism of tryptophan and linolenic acid, as well as fat and energy. In conclusion, metabolomics revealed differentially abundant metabolite changes in patients with mare endometritis. These specific metabolites can be used as potential biomarkers for the non-invasive diagnosis of mare endometritis.

Metabolism-inflammasome crosstalk shapes innate and adaptive immunity

Inflammasomes are a central component of innate immunity and play a vital role in regulating innate immune response. Activation of inflammasomes is also indispensable for adaptive immunity, modulating the development and response of adaptive immunity. Recently, increasing studies have shown that metabolic alterations and adaptations strongly influence and regulate the differentiation and function of the immune system. In this review, we will take a holistic view of how inflammasomes bridge innate and adaptive (especially T cell) immunity and how inflammasomes crosstalk with metabolic signals during the immune responses. And, special attention will be paid to the metabolic control of inflammasome-mediated interactions between innate and adaptive immunity in disease. Understanding the metabolic regulatory functions of inflammasomes would provide new insights into future research directions in this area and may help to identify potential targets for inflammasome-associated diseases and broaden therapeutic avenues.

Clinical research progress of callisperes® of drug-loaded microsphere arterial chemoembolisation in the treatment of solid tumors

The incidence and mortality of cancer is ever-increasing, which poses a significant challengesto human health and a substantial economic burden to patients. At present, chemotherapy is still a primary treatment for various cancers. However, chemotherapy kills tumors but also induces the related side effects, whichadversely impacting patient quality of life and exacerbating suffering. Therefore, there is an urgent need for new and effective treatments that can control tumor growth while reducing the side effects for patients. Arterial chemoembolization has been attracted much attentionwhich attributed to the advantage of ability to embolize tumor vessels to block blood and nutrition supplies. Thus, to achieve local tumor control, it has become an effective means of local tumor control and has been widely used in clinical practice. Despite its efficacy, conventional arterial chemoembolization techniques, limited by embolization materials, have been associated with incomplete embolization and suboptimal drug delivery outcomes. Gradually, researchers have shifted their attention to a new type of embolic material called CalliSperes® drug-eluting embolic bead (DEB). DEB can not only load high doses of drugs, but also has strong sustained drug release ability and good biocompatibility. The integration of DEBs with traditional arterial chemoembolization (DEB-TACE) promises targeted vascular embolization, mitigated tumor ischemia and hypoxia, and direct intravascular chemotherapy delivery. It can prevent cancer cell differentiation and accelerate their death, meanwhile, directly injecting chemotherapy drugs into the target blood vessels reduced the blood concentration of the whole body, thus reduced the toxic and side effects of chemotherapy. Furthermore, DEB-TACE's sustained drug release capability elevates local drug concentrations at the tumor site, amplifying its antitumor efficacy. Therefore, DEB-TACE has become a hot spot in clinical research worldwide. This review introduces the pathogenesis of solid tumors, the background of research and biological characteristics of DEB, and the action mechanism of DEB-TACE, as well as its clinical research in various solid tumors and future prospects. This review aims to provide new ideas for the treatment of DEB-TACE in various solid tumors.

Epigenetic regulation of inflammation: The metabolomics connection

Epigenetic factors are considered the regulator of complex machinery behind inflammatory disorders and significantly contributed to the expression of inflammation-associated genes. Epigenetic modifications modulate variation in the expression pattern of target genes without affecting the DNA sequence. The current knowledge of epigenetic research focused on their role in the pathogenesis of various inflammatory diseases that causes morbidity and mortality worldwide. Inflammatory diseases are categorized as acute and chronic based on the disease severity and are regulated by the expression pattern of various genes. Hence, understanding the role of epigenetic modifications during inflammation progression will contribute to the disease outcomes and therapeutic approaches. This review also focuses on the metabolomics approach associated with the study of inflammatory disorders. Inflammatory responses and metabolic regulation are highly integrated and various advanced techniques are adopted to study the metabolic signature molecules. Here we discuss several metabolomics approaches used to link inflammatory disorders and epigenetic changes. We proposed that deciphering the mechanism behind the inflammation-metabolism loop may have immense importance in biomarkers research and may act as a principal component in drug discovery as well as therapeutic applications.

Pre-treatment with β-hydroxybutyrate mitigates cisplatin-induced acute kidney injury

β-Hydroxybutyrate (β-HB), the primary circulating ketone body, plays a dual role as both a metabolic fuel and an endogenous signaling molecule, offering diverse systemic benefits. Recent studies have highlighted the renoprotective effects of exogenous β-HB therapy in various animal models of kidney disease. In this investigation, our goal was to assess whether pre-treatment with exogenous β-HB could alleviate kidney damage in a mouse model of cisplatin-induced acute kidney injury (AKI). Prior to cisplatin administration, intraperitoneal administration of β-HB was carried out, and the groups were classified into four: Sham, β-HB, cisplatin, and β-HB + cisplatin. The tubular damage score and serum creatinine levels were significantly lower in the β-HB + cisplatin group compared to the cisplatin group. Furthermore, the expression of phosphorylated NF-κB, inflammatory cytokines, and the quantity of F4/80-positive macrophages in the β-HB + cisplatin group were reduced compared to those in the cisplatin group. Additionally, oxidative stress markers for DNA, protein, and lipid in the β-HB + cisplatin group were markedly diminished compared to those in the cisplatin group. The number of TUNEL-positive and cleaved caspase 3-positive tubular cells in the β-HB + cisplatin group was lower than in the cisplatin group. Pre-treating with exogenous β-HB effectively mitigated kidney damage by suppressing inflammation, oxidative stress, and tubular apoptosis in cisplatin-induced AKI. Therefore, exogenous β-HB as a pre-treatment emerges as a promising and novel strategy for preventing cisplatin-induced AKI.

Modulation of macrophage metabolism as an emerging immunotherapy strategy for cancer

Immunometabolism is a burgeoning field of research that investigates how immune cells harness nutrients to drive their growth and functions. Myeloid cells play a pivotal role in tumor biology, yet their metabolic influence on tumor growth and antitumor immune responses remains inadequately understood. This Review explores the metabolic landscape of tumor-associated macrophages, including the immunoregulatory roles of glucose, fatty acids, glutamine, and arginine, alongside the tools used to perturb their metabolism to promote antitumor immunity. The confounding role of metabolic inhibitors on our interpretation of myeloid metabolic phenotypes will also be discussed. A binary metabolic schema is currently used to describe macrophage immunological phenotypes, characterizing inflammatory M1 phenotypes, as supported by glycolysis, and immunosuppressive M2 phenotypes, as supported by oxidative phosphorylation. However, this classification likely underestimates the variety of states in vivo. Understanding these nuances will be critical when developing interventional metabolic strategies. Future research should focus on refining drug specificity and targeted delivery methods to maximize therapeutic efficacy.

β-hydroxybutyrate ameliorates sepsis-induced acute kidney injury

BACKGROUND

Sepsis is a major cause of acute kidney injury (AKI). Recent studies have demonstrated that β-hydroxybutyrate (β-HB) alleviates renal ischemia-reperfusion injury and cisplatin-induced renal injury in murine models. This study aimed to investigate whether β-HB ameliorates sepsis-induced AKI (SIAKI) in a lipopolysaccharide (LPS)-induced mouse sepsis model.

METHODS AND RESULTS

SIAKI was induced by intraperitoneally injecting LPS to C57BL/6 male mice. β-HB was administrated intraperitoneally before LPS injection. The mice were divided into sham, β-HB, LPS, and β-HB + LPS groups. The histological damage score and serum creatinine level were significantly increased in the LPS group mice, but attenuated in the β-HB + LPS group mice. The expression of phosphorylated nuclear factor-κB tumor necrosis factor-α/interleukin-6 and the number of F4/80-positive macrophages in the β-HB + LPS group mice were lower than those in the LPS group mice. The number of TdT-mediated dUTP nick-end labeling (TUNEL)-positive tubular cells, cleaved caspase-3 expression, and Bax/Bcl-2 ratio in the β-HB + LPS group mice were lower than those in the LPS group mice.

CONCLUSION

β-HB pre-treatment ameliorates SIAKI by reducing tubular apoptosis and inflammatory responses. Thus, β-HB pre-treatment could be a potential prophylactic strategy against SIAKI.

Identification of Zip8-correlated hub genes in pulmonary hypertension by informatic analysis

Background

Pulmonary hypertension (PH) is a syndrome characterized by marked remodeling of the pulmonary vasculature and increased pulmonary vascular resistance, ultimately leading to right heart failure and even death. The localization of Zrt/Irt-like Protein 8 (ZIP8, a metal ion transporter, encoded by SLC39A8) was abundantly in microvasculature endothelium and its pivotal role in the lung has been demonstrated. However, the role of Zip8 in PH remains unclear.

Methods

Bioinformatics analysis was employed to identify SLC39A8 expression patterns and differentially expressed genes (DEGs) between PH patients and normal controls (NC), based on four datasets (GSE24988, GSE113439, GSE117261, and GSE15197) from the Biotechnology Gene Expression Omnibus (NCBI GEO) database. Gene set enrichment analysis (GSEA) was performed to analyze signaling pathways enriched for DEGs. Hub genes were identified by cytoHubba analysis in Cytoscape. Reverse transcriptase-polymerase chain reaction was used to validate SLC39A8 and its correlated metabolic DEGs expression in PH (SU5416/Hypoxia) mice.

Results

SLC39A8 expression was downregulated in PH patients, and this expression pattern was validated in PH (SU5416/Hypoxia) mouse lung tissue. SLC39A8-correlated genes were mainly enriched in the metabolic pathways. Within these SLC39A8-correlated genes, 202 SLC39A8-correlated metabolic genes were screened out, and seven genes were identified as SLC39A8-correlated metabolic hub genes. The expression patterns of hub genes were analyzed between PH patients and controls and further validated in PH mice. Finally, four genes (Fasn, Nsdhl, Acat2, and Acly) were downregulated in PH mice. However, there were no significant differences in the expression of the other three hub genes between PH mice and controls. Of the four genes, Fasn and Acly are key enzymes in fatty acids synthesis, Nsdhl is involved in cholesterol synthesis, and Acat2 is implicated in cholesterol metabolic transformation. Taken together, these results provide novel insight into the role of Zip8 in PH.

Molecular Link between Glo-1 Expression and Markers of Hyperglycemia and Oxidative Stress in Vascular Complications of Type 2 Diabetes Mellitus

Chronic hyperglycemia and oxidative stress in Type 2 Diabetes Mellitus trigger cellular dysfunction via the formation of Advanced Glycation End Products (AGEs), resulting in dicarbonyl stress. Glyoxalase-1 (Glo-1) is the main defense against dicarbonyl stress. The aim of this study was to explore any cross-talk between Glo-1 and markers of hyperglycemia and oxidative stress. The siRNA-mediated downregulation of Glo-1 was performed in human microvascular endothelial cell line (HMEC-1). A Glo-1 transgenic rat model was developed. Glo-1 activity, as determined spectrophotometrically, and methylglyoxal were quantified using UPLC-MS/MS and the expression of representative markers of hyperglycemia and oxidative stress was performed using quantitative real-time PCR. A significant increase in the expression of Vascular Cell Adhesion Molecule-1 (VCAM-1) was observed in the case of the siRNA-mediated downregulation of Glo-1 in the microvasculature model under hyperglycemic conditions (p-value < 0.001), as well the as overexpression of Glo-1 in the macrovasculature (p-value = 0.0125). The expression of thioredoxin interacting protein (TXNIP) was found to be significantly upregulated in wildtype diabetic conditions vs. Glo-1 transgenic control conditions (p-value = 0.008), whereas the downregulation of Glo-1 had no impact on TXNIP expression. These findings substantiate the role of VCAM as an important marker of dicarbonyl stress (represented by Glo-1 downregulation), as well as of hyperglycemia, in diabetic vascular complications. Our findings also suggest a potential feedback loop that may exist between Glo-1 and TXNIP, as the highest expression of TXNIP is observed in cases of wildtype diabetic conditions, and the lowest expression of TXNIP is observed when Glo-1 transgene is being expressed in absence of dicarbonyl stress.

IFN-γ and androgens disrupt mitochondrial function in murine myocytes

The effect of cytokines on non-traditional immunological targets under conditions of chronic inflammation is an ongoing subject of study. Fatigue is a symptom often associated with autoimmune diseases. Chronic inflammatory response and activated cell-mediated immunity are associated with cardiovascular myopathies which can be driven by muscle weakness and fatigue. Thus, we hypothesize that immune dysfunction-driven changes in myocyte mitochondria may play a critical role in fatigue-related pathogenesis. We show that persistent low-level expression of IFN-γ in designated IFN-γ AU-Rich Element deletion mice (ARE mice) under androgen exposure resulted in mitochondrial and metabolic deficiencies in myocytes from male or castrated ARE mice. Most notably, echocardiography unveiled that low ejection fraction in the left ventricle post-stress correlated with mitochondrial deficiencies, explaining how heart function decreases under stress. We report that inefficiencies and structural changes in mitochondria, with changes to expression of mitochondrial genes, are linked to male-biased fatigue and acute cardiomyopathy under stress. Our work highlights how male androgen hormone backgrounds and active autoimmunity reduce mitochondrial function and the ability to cope with stress and how pharmacological blockade of stress signal protects heart function. These studies provide new insight into the diverse actions of IFN-γ in fatigue, energy metabolism, and autoimmunity. © 2023 The Pathological Society of Great Britain and Ireland. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

New Insights into NF-κB Signaling in Innate Immunity: Focus on Immunometabolic Crosstalks

The nuclear factor kappa B (NF-κB) is a family of transcription factors that, beyond their numberless functions in various cell processes, play a pivotal role in regulating immune cell activation. Two main pathways-canonical and non-canonical-are responsible for NF-κB activation and heterodimer translocation into the nucleus. A complex crosstalk between NF-κB signaling and metabolism is emerging in innate immunity. Metabolic enzymes and metabolites regulate NF-κB activity in many cases through post-translational modifications such as acetylation and phosphorylation. On the other hand, NF-κB affects immunometabolic pathways, including the citrate pathway, thereby building an intricate network. In this review, the emerging findings about NF-κB function in innate immunity and the interplay between NF-κB and immunometabolism have been discussed. These outcomes allow for a deeper comprehension of the molecular mechanisms underlying NF-κB function in innate immune cells. Moreover, the new insights are important in order to perceive NF-κB signaling as a potential therapeutic target for inflammatory/immune chronic diseases.

Coenzyme Q0 defeats NLRP3-mediated inflammation, EMT/metastasis, and Warburg effects by inhibiting HIF-1α expression in human triple-negative breast cancer cells

Coenzyme Q₀ (CoQ₀) is a derivative quinone from Antrodia camphorata (AC) that exerts anticancer activities. This study examined the anticancer attributes of CoQ₀ (0-4 µM) on inhibited anti-EMT/metastasis and NLRP3 inflammasome, and altered Warburg effects via HIF-1α inhibition in triple-negative breast cancer (MDA-MB-231 and 468) cells. MTT assay, cell migration/invasion assays, Western blotting, immunofluorescence, metabolic reprogramming, and LC-ESI-MS were carried out to assess the therapy potential of CoQ₀. CoQ₀ inhibited HIF-1α expression and suppressed the NLRP3 inflammasome and ASC/caspase-1 expression, followed by downregulation of IL-1β and IL-18 expression in MDA-MB-231 and 468 cells. CoQ₀ ameliorated cancer stem-like markers by decreasing CD44 and increasing CD24 expression. Notably, CoQ₀ modulated EMT by upregulating the epithelial marker E-cadherin and downregulating the mesenchymal marker N-cadherin. CoQ₀ inhibited glucose uptake and lactate accumulation. CoQ₀ also inhibited HIF-1α downstream genes involved in glycolysis, such as HK-2, LDH-A, PDK-1, and PKM-2 enzymes. CoQ₀ decreased extracellular acidification rate (ECAR), glycolysis, glycolytic capacity, and glycolytic reserve in MDA-MB-231 and 468 cells under normoxic and hypoxic (CoCl₂) conditions. CoQ₀ inhibited the glycolytic intermediates lactate, FBP, and 2/3-PG, and PEP levels. CoQ₀ increased oxygen consumption rate (OCR), basal respiration, ATP production, maximal respiration, and spare capacity under normoxic and hypoxic (CoCl₂) conditions. CoQ₀ increased TCA cycle metabolites, such as citrate, isocitrate, and succinate. CoQ0 inhibited aerobic glycolysis and enhanced mitochondrial oxidative phosphorylation in TNBC cells. Under hypoxic conditions, CoQ₀ also mitigated HIF-1α, GLUT1, glycolytic-related (HK-2, LDH-A, and PFK-1), and metastasis-related (E-cadherin, N-cadherin, and MMP-9) protein or mRNA expression in MDA-MB-231 and/or 468 cells. Under LPS/ATP stimulation, CoQ₀ inhibited NLRP3 inflammasome/procaspase-1/IL-18 activation and NFκB/iNOS expression. CoQ₀ also hindered LPS/ATP-stimulated tumor migration and downregulated LPS/ATP-stimulated N-cadherin and MMP-2/-9 expression. The present study revealed that suppression of HIF-1α expression caused by CoQ₀ may contribute to inhibition of NLRP3-mediated inflammation, EMT/metastasis, and Warburg effects of triple-negative breast cancers.

Inflammasomes as biomarkers and therapeutic targets in traumatic brain injury and related-neurodegenerative diseases: A comprehensive overview

Given the ambiguity surrounding traumatic brain injury (TBI) pathophysiology and the lack of any Food and Drug Administration (FDA)-approved neurotherapeutic drugs, there is an increasing need to better understand the mechanisms of TBI. Recently, the roles of inflammasomes have been highlighted as both potential therapeutic targets and diagnostic markers in different neurodegenerative disorders. Indeed, inflammasome activation plays a pivotal function in the central nervous system (CNS) response to many neurological conditions, as well as to several neurodegenerative disorders, specifically, TBI. This comprehensive review summarizes and critically discusses the mechanisms that govern the activation and assembly of inflammasome complexes and the major methods used to study inflammasome activation in TBI and its implication for other neurodegenerative disorders. Also, we will review how inflammasome activation is critical in CNS homeostasis and pathogenesis, and how it can impact chronic TBI sequalae and increase the risk of developing neurodegenerative diseases. Additionally, we discuss the recent updates on inflammasome-related biomarkers and the potential to utilize inflammasomes as putative therapeutic targets that hold the potential to better diagnose and treat subjects with TBI.

NF-κB: blending metabolism, immunity, and inflammation

The procurement and management of nutrients and ability to fight infections are fundamental requirements for survival. These defense responses are bioenergetically costly, requiring the immune system to balance protection against pathogens with the need to maintain metabolic homeostasis. NF-κB transcription factors are central regulators of immunity and inflammation. Over the last two decades, these factors have emerged as a pivotal node coordinating the immune and metabolic systems in physiology and the etiopathogenesis of major threats to human health, including cancer, autoimmunity, chronic inflammation, and others. In this review, we discuss recent advances in understanding how NF-κB-dependent metabolic programs control inflammation, metabolism, and immunity and how improved knowledge of them may lead to better diagnostics and therapeutics for widespread human diseases.

Insights into inflammasome regulation: cellular, molecular, and pathogenic control of inflammasome activation

Maintenance of immune homeostasis is an intricate process wherein inflammasomes play a pivotal role by contributing to innate and adaptive immune responses. Inflammasomes are ensembles of adaptor proteins that can trigger a signal following innate sensing of pathogens or non-pathogens eventuating in the inductions of IL-1β and IL-18. These inflammatory cytokines substantially influence the antigen-presenting cell's costimulatory functions and T helper cell differentiation, contributing to adaptive immunity. As acute and chronic disease conditions may accompany parallel tissue damage, we analyze the critical role of extracellular factors such as cytokines, amyloids, cholesterol crystals, etc., intracellular metabolites, and signaling molecules regulating inflammasome activation/inhibition. We develop an operative framework for inflammasome function and regulation by host cell factors and pathogens. While inflammasomes influence the innate and adaptive immune components' interplay modulating the anti-pathogen adaptive immune response, pathogens may target inflammasome inhibition as a survival strategy. As trapped between health and diseases, inflammasomes serve as promising therapeutic targets and their modus operandi serves as a scientific rationale for devising better therapeutic strategies.

Development of Resistance to Clarithromycin and Amoxicillin-Clavulanic Acid in Lactiplantibacillus plantarum In Vitro Is Followed by Genomic Rearrangements and Evolution of Virulence

Ensuring the safety of the use of probiotics is a top priority. Obviously, in addition to studying the beneficial properties of lactic acid bacteria, considerable attention should be directed to assessing the virulence of microorganisms as well as investigating the possibility of its evolution under conditions of selective pressure. To assess the virulence of probiotics, it is now recommended to analyze the genomes of bacteria in relation to the profiles of the virulome, resistome, and mobilome as well as the analysis of phenotypic resistance and virulence in vitro. However, the corresponding procedure has not yet been standardized, and virulence analysis of strains in vivo using model organisms has not been performed. Our study is devoted to testing the assumption that the development of antibiotic resistance in probiotic bacteria under conditions of selective pressure of antimicrobial drugs may be accompanied by the evolution of virulence. In this regard, special attention is required for the widespread in nature commensals and probiotic bacteria actively used in pharmacology and the food industry. As a result of step-by-step selection from the Lactiplantibacillus plantarum 8p-a3 strain isolated from the “Lactobacterin” probiotic (Biomed, Russia), the L. plantarum 8p-a3-Clr-Amx strain was obtained, showing increased resistance simultaneously to amoxicillin-clavulanic acid and clarithromycin (antibiotics, the combined use of which is widely used for Helicobacter pylori eradication) compared to the parent strain (MIC_{8p-a3-Clr-Amx} of 20 μg/mL and 10 μg/mL, and MIC_8p-a3 of 0.5 μg/mL and 0.05 μg/mL, respectively). The results of a comparative analysis of antibiotic-resistant and parental strains indicate that the development of resistance to the corresponding antimicrobial drugs in L. plantarum in vitro is accompanied by the following: (i) significant changes in the genomic profile (point mutations as well as deletions, insertions, duplications, and displacement of DNA sequences) associated in part with the resistome and mobilome; (ii) changes in phenotypic sensitivity to a number of antimicrobial drugs; and (iii) an increase in the level of virulence against Drosophila melanogaster, a model organism for which L. plantarum is considered to be a symbiont. The data obtained by us indicate that the mechanisms of adaptation to antimicrobial drugs in L. plantarum are not limited to those described earlier and determine the need for comprehensive studies of antibiotic resistance scenarios as well as the trajectories of virulence evolution in probiotic bacteria in vivo and in vitro to develop a standardized system for detecting virulent strains of the corresponding microorganisms.

IMPORTANCE Ensuring the safety of the use of probiotics is a top priority. We found that increased resistance to popular antimicrobial drugs in Lactiplantibacillus plantarum is accompanied by significant changes in the genomic profile and phenotypic sensitivity to a number of antimicrobial drugs as well as in the level of virulence of this bacterium against Drosophila. The data obtained in our work indicate that the mechanisms of antibiotic resistance in this bacterium are not limited to those described earlier and determine the need for comprehensive studies of the potential for the evolution of virulence in lactic acid bacteria in vivo and in vitro and to develop a reliable control system to detect virulent strains among probiotics.

Identifying the cardioprotective mechanism of Danyu Tongmai Granules against myocardial infarction by targeted metabolomics combined with network pharmacology

BACKGROUND

Danyu Tongmai Granules (DY), the commercial Chinese medicine, was well-accepted cardiovascular protective actions in clinic. However, the mechanisms underlying the beneficial effects of DY on cardiovascular disease still need largely to be clarified.

PURPOSE

Therefore, this study was designed to explore potential mechanisms of DY in myocardial infarction (MI) by integrated strategy of metabolomics and network pharmacology.

METHODS

Cardiomyocytes were subjected to H2O2 induced myocardial injury and rats were induced MI via isoproterenol (ISO) injection. The entire metabolic alterations in serum and heart tissues of experimental rats were profiled by UPLC-MS/MS. Based on the identified differential metabolites, the pathway analysis results were obtained and further validated using the network pharmacology approach.

RESULTS

We found that DY exerted significant cardioprotective effects in vitro and in vivo, and ameliorated inflammatory cell infiltration and cardiomyocyte apoptosis induced by ISO. The metabolomics data suggested that DY mainly affected the amino acid metabolism (i.e., valine, leucine and isoleucine biosynthesis, arginine biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, arginine biosynthesis, glycine, serine, as well as the alanine metabolism, aspartate and glutamate metabolism, etc.). Simultaneously, DY participated in the regulation of the biosynthesis of bile acids and biosynthesis of unsaturated fatty acids. Notably, DY significantly reduced the biosynthesis of valine, leucine and isoleucine to regulating the metabolism of branched chain amino acids (BCAAs) in infarcted myocardium, thus blocking the inflammation via inhibiting the expression of NLRP3 inflammasome in ISO-induced rats. The anti-inflammatory system of DY was further validated with the results of network pharmacology.

CONCLUSION

Our study, for the first time, confirmed that DY inhibited inflammation and further exerted significant anti-myocardial infarction effect. Additionally, our work further demonstrated that the myocardial protective effect of DY was contributed to the inhibition of the NLRP3 inflammasome activation by regulating BCAAs in infarcted myocardium using the comprehensive metabolomics, molecular biology and network analysis. Overall, our study gained new insights into the role of the relationship between the metabolic regulation of BCAAs and the NLRP3 inflammasome against MI.

Myeloid Ikaros-SIRT1 signaling axis regulates hepatic inflammation and pyroptosis in ischemia-stressed mouse and human liver

BACKGROUND & AIMS

Although Ikaros (IKZF1) is a well-established transcriptional regulator in leukocyte lymphopoiesis and differentiation, its role in myeloid innate immune responses remains unclear. Sirtuin 1 (SIRT1) is a histone/protein deacetylase involved in cellular senescence, inflammation, and stress resistance. Whether SIRT1 signaling is essential in myeloid cell activation remains uncertain, while the molecular communication between Ikaros and SIRT1, two major transcriptional regulators, has not been studied.

METHODS

We undertook molecular and functional studies to interrogate the significance of the myeloid Ikaros-SIRT1 axis in innate immune activation and whether it may serve as a homeostatic sentinel in human liver transplant recipients (hepatic biopsies) and murine models of sterile hepatic inflammation (liver warm ischemia-reperfusion injury in wild-type, myeloid-specific Sirt1-knockout, and CD11b-DTR mice) as well as primary bone marrow-derived macrophage (BMM) cultures (Ikaros silencing vs. overexpression).

RESULTS

In our clinical study, we identified increased post-reperfusion hepatic Ikaros levels, accompanied by augmented inflammasome signaling yet depressed SIRT1, as a mechanism of hepatocellular damage in liver transplant recipients. In our experimental studies, we identified infiltrating macrophages as the major source of Ikaros in IR-stressed mouse livers. Then, we demonstrated that Ikaros-regulated pyroptosis - induced by canonical inflammasome signaling in BMM cultures - was SIRT1 dependent. Consistent with the latter, myeloid-specific Ikaros signaling augmented hepatic pyroptosis to aggravate pro-inflammatory responses in vivo by negatively regulating SIRT1 in an AMPK-dependent manner. Finally, myeloid-specific SIRT1 was required to suppress pyroptosis, pro-inflammatory phenotype, and ultimately mitigate hepatocellular injury in ischemia-stressed murine livers.

CONCLUSION

These findings identify the Ikaros-SIRT1 axis as a novel mechanistic biomarker of pyroptosis and a putative checkpoint regulator of homeostasis in response to acute hepatic stress/injury in mouse and human livers.

LAY SUMMARY

This report describes how crosstalk between Ikaros and SIRT1, two major transcriptional regulators, influence acute hepatic inflammation in murine models of liver ischemia-reperfusion injury and liver transplant recipients. We show that the myeloid Ikaros-SIRT1 axis regulates inflammasome-pyroptotic cell death and hepatocellular damage in stressed livers. Thus, the Ikaros-SIRT1 axis may serve as a novel checkpoint regulator that is required for homeostasis in response to acute liver injury in mice and humans.

Molecular regulation of neuroinflammation in glaucoma: Current knowledge and the ongoing search for new treatment targets

Neuroinflammation relying on the inflammatory responses of glial cells has emerged as an impactful component of the multifactorial etiology of neurodegeneration in glaucoma. It has become increasingly evident that despite early adaptive and reparative features of glial responses, prolonged reactivity of the resident glia, along with the peripheral immune cells, create widespread toxicity to retinal ganglion cell (RGC) axons, somas, and synapses. As much as the synchronized responses of astrocytes and microglia to glaucoma-related stress or neuron injury, their bi-directional interactions are critical to build and amplify neuroinflammation and to dictate the neurodegenerative outcome. Although distinct molecular programs regulate somatic and axonal degeneration in glaucoma, inhibition of neurodegenerative inflammation can provide a broadly beneficial treatment strategy to rescue RGC integrity and function. Since inflammatory toxicity and mitochondrial dysfunction are converging etiological paths that can boost each other and feed into a vicious cycle, anti-inflammatory treatments may also offer a multi-target potential. This review presents an overview of the current knowledge on neuroinflammation in glaucoma with particular emphasis on the cell-intrinsic and cell-extrinsic factors involved in the reciprocal regulation of glial responses, the interdependence between inflammatory and mitochondrial routes of neurodegeneration, and the research aspects inspiring for prospective immunomodulatory treatments. With the advent of powerful technologies, ongoing research on molecular and functional characteristics of glial responses is expected to accumulate more comprehensive and complementary information and to rapidly move the field forward to safe and effective modulation of the glial pro-inflammatory activities, while restoring or augmenting the glial immune-regulatory and neurosupport functions.

Acetylsalicylic Acid Suppresses Alcoholism-Induced Cognitive Impairment Associated with Atorvastatin Intake by Targeting Cerebral miRNA155 and NLRP3: In Vivo, and In Silico Study

Alcoholism is one of the most common diseases that can lead to the development of several chronic diseases including steatosis, and cognitive dysfunction. Statins are lipid-lowering drugs that are commonly prescribed for patients with fatty liver diseases; however, the exact effect of statins on cognitive function is still not fully understood. In the present study, we have investigated the molecular and microscopic basis of cognitive impairment induced by alcohol and/or Atorvastatin (ATOR) administration to male Wistar albino rats and explored the possible protective effect of acetylsalicylic acid (ASA). The biochemical analysis indicated that either alcohol or ATOR or together in combination produced a significant increase in the nucleotide-binding domain–like receptor 3 (NLRP3), interleukin-1β (IL-1β) miRNA155 expression levels in the frontal cortex of the brain tissue. The histological and morphometric analysis showed signs of degeneration in the neurons and the glial cells with aggregations of inflammatory cells and a decrease in the mean thickness of the frontal cortex. Immunohistochemical analysis showed a significant increase in the caspase-8 immunoreaction in the neurons and glial cells of the frontal cortex. Interestingly, administration of ASA reversed the deleterious effect of the alcohol and ATOR intake and improved the cognitive function as indicated by biochemical and histological analysis. ASA significantly decreased the expression levels of miRNA155, NLRP3, and IL1B, and produced a significant decrease in caspase-8 immunoreaction in the neurons and glial cells of the frontal cortex with a reduction in the process of neuroinflammation and neuronal damage. To further investigate these findings, we have performed an extensive molecular docking study to investigate the binding affinity of ASA to the binding pockets of the NLRP3 protein. Our results indicated that ASA has high binding scores toward the active sites of the NLRP3 NACHT domain with the ability to bind to the NLRP3 pockets by a set of hydrophilic and hydrophobic interactions. Taken together, the present study highlights the protective pharmacological effect of ASA to attenuate the deleterious effect of alcohol intake and long term ATOR therapy on the cognitive function via targeting miRNA155 and NLRP3 proteins.

Herpesviruses and Inflammasomes: One Sensor Does Not Fit All

Herpesviruses are ubiquitous double-stranded DNA viruses that cause lifelong infections and are associated with a variety of diseases. While they have evolved multiple mechanisms to evade the immune system, they are all recognized by the innate immune system, which can lead to both localized and systemic inflammation. A more recently appreciated mechanism of herpesvirus innate immune activation is through inflammasome signaling. The inflammasome is an intracellular multiprotein complex that, when activated, leads to the release of proinflammatory cytokines, including IL-1β and IL-18, and activation of the inflammatory programed cell death pathway known as pyroptosis. Despite the herpesviruses sharing a similar structure, their mechanisms of inflammasome activation and the consequences of inflammasome activation in cases of virus-associated disease are not uniform. This review will highlight the similarities and differences among herpesviruses with regard to their mechanisms of inflammasome activation and impacts on diseases caused by herpesviruses. Furthermore, it will identify areas where additional studies are warranted to better understand the impact of this important innate immune signaling program on the pathogenesis of these common viruses.

NLRP3 Inflammasome Pharmacological Inhibitors in Glycyrrhiza for NLRP3-Driven Diseases Treatment: Extinguishing the Fire of Inflammation

Inflammation is the tissues’ defense response after the body is stimulated by microbial infection or damage signals, and it is initiated when pattern recognition receptors recognize pathogen-related molecular patterns and danger-related molecular patterns. The hyperactivation of NLRP3 inflammasome, the main driving force of immune outbreaks, is involved in a wide range of inflammatory diseases. Meanwhile, growing evidence has indicated that the development of NLRP3-targeted therapies offers great potential and promise for the treatment of related diseases. The search for and development of efficacious anti-inflammatory prodrugs from natural sources of plants and traditional Chinese medicines (TCMs) have received extensive attention. Glycyrrhiza, an important minister in the kingdom of TCMs, has high activity and a wide range of therapeutic effects. Studies have shown that a variety of active components found in Glycyrrhiza, such as licochalcone A, echinatin, isoliquiritigenin, and glycyrrhizin, produce a wide range of anti-inflammatory effects by discouraging NLRP3 inflammasome activation. Here, we summarize the role and mechanism of the active ingredients in Glycyrrhiza that target the NLRP3 inflammasome and treat related inflammatory diseases. We describe a favorable approach for the development of natural, safe, and efficient drugs that exploit these naturally occurring active ingredients to treat NLRP3-driven diseases.

Pyruvate kinase M2 (PKM2) interacts with activating transcription factor 2 (ATF2) to bridge glycolysis and pyroptosis in microglia

Pyruvate kinase M2 (PKM2), a glycolytic rate-limiting enzyme, reportedly plays an important role in tumorigenesis and the inflammatory response by regulating the metabolic reprogramming. However, its contribution to microglial activation during neuroinflammation is still unknown. In this study, we observed an enhanced glycolysis level in the lipopolysaccharide (LPS)-activated microglia. Utilizing the glycolysis inhibitor 2-DG, we proved that LPS requires glycolysis to induce microglial pyroptosis. Moreover, the protein expression, dimer/monomer formation, phosphorylation and nuclear translocation of PKM2 were all increased by LPS. Silencing PKM2 or preventing its nuclear translocation by TEPP-46 significantly alleviated the LPS-induced inflammatory response and pyroptosis in microglia. Employing biological mass spectrometry combined with immunoprecipitation technology, we identified for the first time that PKM2 interacts with activating transcription factor 2 (ATF2) in microglia. Inhibition of glycolysis or preventing PKM2 nuclear aggregation significantly reduced the phosphorylation and activation of ATF2. Furthermore, knocking down ATF2 reduced the LPS-induced pyroptosis of microglia. In vivo, we showed the LPS-induced pyroptosis in the cerebral cortex tissues of mice, and first found that an increased PKM2 expression was co-localized with ATF2 in the inflamed mice brain. Collectively, our data suggested for the first time that PKM2, a key rate-limiting enzyme of the Warburg effect, directly interacts with the pro-inflammatory transcription factor ATF2 to bridge glycolysis and pyroptosis in microglia, which might be a pivotal crosstalk between metabolic reprogramming and neuroinflammation in the CNS.

Loss of β-Arrestins or six Gα proteins in HEK293 cells caused Warburg effect and prevented progesterone-induced rapid proteasomal degradation of progesterone receptor membrane component 1

Hormonal dysregulation plays a significant role in the metabolic switching during malignant transformation. Progesterone Receptor Membrane Component 1 (PGRMC1) is a single-pass transmembrane receptor activated by the binding of progesterone (P4), a sex hormone. In a previous study, P4 treatment caused rapid (within 30 min) induction of aerobic glycolysis in transformed HEK293 cells, a hallmark malignant phenotype known as the Warburg effect. This metabolic reprogramming was associated with the proteasomal degradation of a 70 kilodalton (kDa) PGRMC1. PGRMC1 interacts with a variety of proteins, including G protein-coupled receptors (GPCRs) and P4-PGRMC1 signaling modulates cyclic adenosine monophosphate (cAMP) production. Therefore, we hypothesized that the P4-induced Warburg effect and proteasomal degradation of PGRMC1 involve G proteins and β-Arrestins (ARRBs). In the present study, we investigated P4-induced aerobic glycolysis, proteasomal degradation of p70 PGRMC1, as well as abundance and subcellular translocation of PGRMC1 along with two key glycolytic enzymes Hexokinase 1 (HK1) and Glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) in six Gα subunit (Gsix) proteins or ARRB1/2-deficient HEK293 cells. Loss of ARRB1/2 or Gsix proteins inhibited P4-induced p70 PGRMC1 degradation but failed to prevent the P4-induced Warburg effect. Also, deficiency of ARRB1/2 or Gsix proteins differentially affected the basal as well as P4-induced abundance and subcellular translocation of PGRMC1, HK1, and GAPDH proteins. Overall, the findings indicate that P4-PGRMC1-mediated metabolic reprogramming in HEK293 cells depends on β-Arrestins and Gα proteins suggesting the involvement of an underlying GPCR signal transduction pathway.

Metabolic regulators of enigmatic inflammasomes in autoimmune diseases and crosstalk with innate immune receptors

Nucleotide‐binding domain and leucine‐rich repeat receptor (NLR)‐mediated inflammasome activation is important in host response to microbes, danger‐associated molecular patterns (DAMPs) and metabolic disease. Some NLRs have been shown to interact with distinct cell metabolic pathways and cause negative regulation, tumorigenesis and autoimmune disorders, interacting with multiple innate immune receptors to modulate disease. NLR activation is therefore crucial in host response and in the regulation of metabolic pathways that can trigger a wide range of immunometabolic diseases or syndromes. However, the exact mode by which some of the less well‐studied NLR inflammasomes are activated, interact with other metabolites and immune receptors, and the role they play in the progression of metabolic diseases is still not fully elucidated. In this study, we review up‐to‐date evidence regarding NLR function in metabolic pathways and the interplay with other immune receptors involved in GPCR signalling, gut microbiota and the complement system, in order to gain a better understanding of its link to disease processes.

Significance of African Diets in Biotherapeutic Modulation of the Gut Microbiome

Diet plays an essential role in human development and growth, contributing to health and well-being. The socio-economic values, cultural perspectives, and dietary formulation in sub-Saharan Africa can influence gut health and disease prevention. The vast microbial ecosystems in the human gut frequently interrelate to maintain a healthy, well-coordinated cellular and humoral immune signalling to prevent metabolic dysfunction, pathogen dominance, and induction of systemic diseases. The diverse indigenous diets could differentially act as biotherapeutics to modulate microbial abundance and population characteristics. Such modulation could prevent stunted growth, malnutrition, induction of bowel diseases, attenuated immune responses, and mortality, particularly among infants. Understanding the associations between specific indigenous African diets and the predictability of the dynamics of gut bacteria genera promises potential biotherapeutics towards improving the prevention, control, and treatment of microbiome-associated diseases such as cancer, inflammatory bowel disease, obesity, type 2 diabetes, and cardiovascular disease. The dietary influence of many African diets (especially grain-base such as millet, maize, brown rice, sorghum, soya, and tapioca) promotes gut lining integrity, immune tolerance towards the microbiota, and its associated immune and inflammatory responses. A fibre-rich diet is a promising biotherapeutic candidate that could effectively modulate inflammatory mediators' expression associated with immune cell migration, lymphoid tissue maturation, and signalling pathways. It could also modulate the stimulation of cytokines and chemokines involved in ensuring balance for long-term microbiome programming. The interplay between host and gut microbial digestion is complex; microbes using and competing for dietary and endogenous proteins are often attributable to variances in the comparative abundances of Enterobacteriaceae taxa. Many auto-inducers could initiate the process of quorum sensing and mammalian epinephrine host cell signalling system. It could also downregulate inflammatory signals with microbiota tumour taxa that could trigger colorectal cancer initiation, metabolic type 2 diabetes, and inflammatory bowel diseases. The exploitation of essential biotherapeutic molecules derived from fibre-rich indigenous diet promises food substances for the downregulation of inflammatory signalling that could be harmful to gut microbiota ecological balance and improved immune response modulation.

Inflammasome as an Effective Platform for Fibrosis Therapy

Fibrosis is the final stage of the development of chronic inflammation. It is characterized by excessive deposition of the extracellular matrix, leading to tissue structure damage and organ dysfunction, which is a serious threat to human health and life. However, the molecular mechanism of fibrosis is still unclear. Inflammasome is a molecular complex of proteins that has been becoming a key innate sensor for host immunity and is involved in pyroptosis, pathogen infection, metabolic syndrome, cellular stress, and tumor metastasis. Inflammasome signaling and downstream cytokine responses mediated by the inflammasome have been found to play an important role in fibrosis. The inflammasome regulates the secretion of IL-1β and IL-18, which are both critical for the process of fibrosis. Recently, researches on the function of inflammasome have attracted extensive attention, and data derived from these researches have increased our understanding of the effects and regulation of inflammasome during fibrosis. In this review, we emphasize the growing evidence for both indirect and direct effects of inflammasomes in triggering fibrosis as well as potential novel targets for antifibrotic therapies.

Fa(c)t checking: How fatty acids shape metabolism and function of macrophages and dendritic cells

In recent years there have been major advances in our understanding of the role of free fatty acids (FAs) and their metabolism in shaping the functional properties of macrophages and DCs. This review presents the most recent insights into how cell intrinsic FA metabolism controls DC and macrophage function, as well as the current evidence of the importance of various exogenous FAs (such as polyunsaturated FAs and their oxidation products—prostaglandins, leukotrienes, and proresolving lipid mediators) in affecting DC and macrophage biology, by modulating their metabolic properties. Finally, we explore whether targeted modulation of FA metabolism of myeloid cells to steer their function could hold promise in therapeutic settings.

NLRP3 Inflammasome at the Interface of Inflammation, Endothelial Dysfunction, and Type 2 Diabetes

Type 2 diabetes mellitus (T2DM), accounting for 90–95% cases of diabetes, is characterized by chronic inflammation. The mechanisms that control inflammation activation in T2DM are largely unexplored. Inflammasomes represent significant sensors mediating innate immune responses. The aim of this work is to present a review of links between the NLRP3 inflammasome, endothelial dysfunction, and T2DM. The NLRP3 inflammasome activates caspase-1, which leads to the maturation of pro-inflammatory cytokines interleukin 1β and interleukin 18. In this review, we characterize the structure and functions of NLRP3 inflammasome as well as the most important mechanisms and molecules engaged in its activation. We present evidence of the importance of the endothelial dysfunction as the first key step to activating the inflammasome, which suggests that suppressing the NLRP3 inflammasome could be a new approach in depletion hyperglycemic toxicity and in averting the onset of vascular complications in T2DM. We also demonstrate reports showing that the expression of a few microRNAs that are also known to be involved in either NLRP3 inflammasome activation or endothelial dysfunction is deregulated in T2DM. Collectively, this evidence suggests that T2DM is an inflammatory disease stimulated by pro-inflammatory cytokines. Finally, studies revealing the role of glucose concentration in the activation of NLRP3 inflammasome are analyzed. The more that is known about inflammasomes, the higher the chances to create new, effective therapies for patients suffering from inflammatory diseases. This may offer potential novel therapeutic perspectives in T2DM prevention and treatment.

Cardioprotective role of GTS-21 by attenuating the TLR4/NF-κB pathway in streptozotocin-induced diabetic cardiomyopathy in rats

The cholinergic anti-inflammatory pathway (CAP) was investigated in a variety of inflammatory conditions and constitutes a valuable line in their treatment. In the current study, we investigated the anti-inflammatory effect of GTS-21 (GTS) as a partial selective α7 nicotinic acetylcholine receptor (α7-nAchR) agonist in diabetic cardiomyopathy model in rats. This mechanism was elaborated to study whether it could alleviate the electrocardiographic, histopathological, and molecular levels of Toll-like receptor 4 (TLR4)/nuclear factor κB (NF-κB) pathway proteins. Diabetes was induced by the injection of streptozotocin (STZ) (50 mg/kg). Diabetic rats were treated with GTS (1 or 2 mg/kg/day), methyllycaconitine (MLA), a selective α7-nAchR antagonist (2 mg/kg/day) plus GTS (2 mg/kg/day), or the vehicle. All treatments were given by the intraperitoneal route. Ventricular rate and different electrocardiograph (ECG) anomalies were detected. Plasma levels of cardiac troponin T (cTnT) and creatine kinase MB (CK-MB) were measured by ELISA. Additionally, we elucidated the levels of several proteins involved in the TLR4/NF-κB pathway. Cardiac levels of TLR4 and phosphorylated protein kinase B (p-Akt) were detected by ELISA. The cardiac expression of myeloid differentiation primary response 88 (Myd88), tumor necrosis factor receptor-associated factor 6 (TRAF6), NF-κB, interleukin 1β (IL-1β), and active caspase-1 were evaluated by immunohistochemical staining. Finally, the cardiac levels of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by ELISA. Diabetic rats showed (i) ECG signs of cardiomyopathy such as significant ST segment elevations, prolonged QRS, QT intervals, and ventricular tachycardia; (ii) increased plasma levels of cTnT and CK-MB; (iii) increased expression of cardiac TLR4; (iv) elevated immunohistochemical expression of cardiac, Myd88, TRAF6, and NF-κB; (v) diminution in the cardiac expression of p-Akt; and (vi) adaptive increases in cardiac expression of TNF-α and IL-6. These effects were ameliorated in diabetic rats treated with both doses of GTS. Pretreatment with MLA did not completely reverse the ameliorative effect of GTS on cTnT, TRAF6, TNF-α, and IL-6, thereby reinforcing the presence of possible α7-nAchR-independent mechanisms. The activation of α7-nAchR with GTS offers a promising prophylactic strategy for diabetic cardiomyopathy by attenuating the TLR4/NF-κB pathway.

Micheliolide alleviates ankylosing spondylitis (AS) by suppressing the activation of the NLRP3 inflammasome and maintaining the balance of Th1/Th2 via regulating the NF-κB signaling pathway

Background

Ankylosing spondylitis (AS) is a common form of inflammatory arthritis. Micheliolide (MCL), a sesquiterpene lactone, is reportedly involved in the alleviation of inflammatory response. This study aimed to investigate the mechanism of MCL in the treatment of AS.

Methods

Mice were randomly divided into five groups: the sham group, the MCL (50 mg/kg) group, the AS model group, the AS + MCL (20 mg/kg) group, and the AS + MCL (50 mg/kg) group. After the addition of the inhibitor celastrol, mice were randomly divided into five groups: the sham group, the AS model group, the AS + MCL (50 mg/kg) group, the AS + Celastrol (1 mg/kg) group, and the AS + Celastrol (1 mg/kg) + MCL (50 mg/kg) group.

Results

Compared with the AS model mice, the protein expression levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-18 were decreased after MCL treatment. The protein expression levels of capase-1 p10, IL-1β p17, NOD-like receptor family and pyrin domain containing 3 (NLRP3), caspase-1, and apoptosis-associated speck-like protein (ASC) were also reduced. The protein expression levels of Interferon (IFN)-γ were down-regulated, but levels of IL-4 were increased. Western blotting and immunohistochemistry revealed that the levels of p-IκB α were up-regulated, while the levels of phosphorylated-p65 were down-regulated. After the addition of celastrol, MCL treatment significantly reduced the levels of p-p65, NLRP3, caspase-1, and ASC. Meanwhile, the levels of IFN-γ were markedly down-regulated, but the levels of IL-4 were enhanced.

Conclusions

Our study found that MCL suppressed the activation of NLRP3 inflammasome and maintained the balance of Th1/Th2 via regulating NF-κB signaling. Therefore, MCL could potentially be used to treat AS.

The crosstalk between gut bacteria and host immunity in intestinal inflammation

The gut of mammals is considered as a harmonious ecosystem mediated by intestinal microbiota and the host. Both bacteria and mammalian immune cells show region-related distribution characteristics, and the interaction between the two could be demonstrated by synergetic roles in maintaining intestinal homeostasis and dysregulation in intestinal inflammation. The harmonious interplay between bacteria and host requires fine-tuned regulations by environmental and genetic factors. Thus, the disturbed immune response to microbial components or metabolites and dysbiosis related to immunodeficiency are absolute risk factors to intestinal inflammation and cancer. In this review, we discuss the crosstalk between bacteria and host immunity in the gut and highlight the critical roles of bidirectional regulation between bacteria and the mammalian immune system involved in intestinal inflammation.

Differential DNA Methylation of Networked Signaling, Transcriptional, Innate and Adaptive Immunity, and Osteoclastogenesis Genes and Pathways in Gout

OBJECTIVE

In gout, autoinflammatory responses to urate crystals promote acute arthritis flares, but the pathogeneses of tophi, chronic synovitis, and erosion are less well understood. Defining the pathways of epigenomic immunity training can reveal novel pathogenetic factors and biomarkers. The present study was undertaken to seminally probe differential DNA methylation patterns utilizing epigenome-wide analyses in patients with gout.

METHODS

Peripheral blood mononuclear cells (PBMCs) were obtained from a San Diego cohort of patients with gout (n = 16) and individually matched healthy controls (n = 14). PBMC methylome data were processed with ChAMP package in R. ENCODE data and Taiji data analysis software were used to analyze transcription factor (TF)-gene networks. As an independent validation cohort, whole blood DNA samples from New Zealand Māori subjects (n = 13 patients with gout, n = 16 control subjects without gout) were analyzed.

RESULTS

Differentially methylated loci clearly separated gout patients from controls, as determined by hierarchical clustering and principal components analyses. IL23R, which mediates granuloma formation and cell invasion, was identified as one of the multiple differentially methylated gout risk genes. Epigenome-wide analyses revealed differential methylome pathway enrichment for B and T cell receptor signaling, Th17 cell differentiation and interleukin-17 signaling, convergent longevity regulation, circadian entrainment, and AMP-activated protein kinase signaling, which are pathways that impact inflammation via insulin-like growth factor 1 receptor, phosphatidylinositol 3-kinase/Akt, NF-κB, mechanistic target of rapamycin signaling, and autophagy. The gout cohorts overlapped for 37 (52.9%) of the 70 TFs with hypomethylated sequence enrichment and for 30 (78.9%) of the 38 enriched KEGG pathways identified via TFs. Evidence of shared differentially methylated gout TF-gene networks, including the NF-κB activation-limiting TFs MEF2C and NFATC2, pointed to osteoclast differentiation as the most strongly weighted differentially methylated pathway that overlapped in both gout cohorts.

CONCLUSION

These findings of differential DNA methylation of networked signaling, transcriptional, innate and adaptive immunity, and osteoclastogenesis genes and pathways suggest that they could serve as novel therapeutic targets in the management of flares, tophi, chronic synovitis, and bone erosion in patients with gout.

Type III Secretion Effector VopQ of Vibrio parahaemolyticus Modulates Central Carbon Metabolism in Epithelial Cells

The metabolic response of host cells upon infection is pathogen specific, and infection-induced host metabolic reprogramming may have beneficial effects on the proliferation of pathogens. V. parahaemolyticus contains a range of virulence factors to manipulate host signaling pathways and metabolic processes. In this study, we identified that the T3SS1 VopQ effector rewrites host metabolism in conjunction with the inflammation and cell death processes. Understanding how VopQ reprograms host cell metabolism during the infection could help us to identify novel therapeutic strategies to enhance the survival of host cells during V. parahaemolyticus infection.

Vibrio parahaemolyticus is a Gram-negative halophilic pathogen that frequently causes acute gastroenteritis and occasional wound infection. V. parahaemolyticus contains several virulence factors, including type III secretion systems (T3SSs) and thermostable direct hemolysin (TDH). In particular, T3SS1 is a potent cytotoxic inducer, and T3SS2 is essential for causing acute gastroenteritis. Although much is known about manipulation of host signaling transductions by the V. parahaemolyticus effector, little is known about the host metabolomic changes modulated by V. parahaemolyticus. To address this knowledge gap, we performed a metabolomic analysis of the epithelial cells during V. parahaemolyticus infection using capillary electrophoresis-time of flight mass spectrometry (CE-TOF/MS). Our results revealed significant metabolomic perturbations upon V. parahaemolyticus infection. Moreover, we identified that T3SS1’s VopQ effector was responsible for inducing the significant metabolic changes in the infected cells. The VopQ effector dramatically altered the host cell’s glycolytic, tricarboxylic acid cycle (TCA), and amino acid metabolisms. VopQ effector disrupted host cell redox homeostasis by depleting cellular glutathione and subsequently increasing the level of reactive oxygen species (ROS) production.

IMPORTANCE The metabolic response of host cells upon infection is pathogen specific, and infection-induced host metabolic reprogramming may have beneficial effects on the proliferation of pathogens. V. parahaemolyticus contains a range of virulence factors to manipulate host signaling pathways and metabolic processes. In this study, we identified that the T3SS1 VopQ effector rewrites host metabolism in conjunction with the inflammation and cell death processes. Understanding how VopQ reprograms host cell metabolism during the infection could help us to identify novel therapeutic strategies to enhance the survival of host cells during V. parahaemolyticus infection.

Expression and Contribution of NLRP3 Inflammasome During the Follicular Development Induced by PMSG

Follicular development and following ovulation induced by luteinizing hormone (LH) surge are critical for ovarian functions, but the molecular mechanism regulating ovarian ovulation attracts more attention and remains mainly unknown. Recent researches on the nucleotide leukin rich polypeptide 3 (NLRP3) inflammasome shred light on it. Given pregnant mare serum gonadotropin (PMSG) can not only trigger the follicular development, but also induce the following ovulation, the present study therefore examined that expression and localization of NLRP3 inflammasome through immunohistochemistry and Western blotting during the follicular development induced by PMSG. The results showed expressions of NLRP3 and the adaptor protein apoptosis-associated speck-like protein (ASC) significantly increased in the outside of intrafollicular fluid, further analysis found that caspase-1 was activated and IL-1β production was also upregulated after 52 h-treatment of PMSG. Furthermore, a significant increase of ovulation-related genes, hypoxia inducible factor (HIF)-1α and endothelin (ET)-1, was found after 52 h-treatment of PMSG. To our knowledge, it is the first time to clearly indicated the activation of NLRP3 inflammasome may contribute to the ovulation of PMSG-treated ovaries, which will help to further clarify the ovulatory mechanism in mammals.

Targeting NLRP3 Inflammasome Activation in Severe Asthma

Severe asthma (SA) is a chronic lung disease characterized by recurring symptoms of reversible airflow obstruction, airway hyper-responsiveness (AHR), and inflammation that is resistant to currently employed treatments. The nucleotide-binding oligomerization domain-like Receptor Family Pyrin Domain Containing 3 (NLRP3) inflammasome is an intracellular sensor that detects microbial motifs and endogenous danger signals and represents a key component of innate immune responses in the airways. Assembly of the NLRP3 inflammasome leads to caspase 1-dependent release of the pro-inflammatory cytokines IL-1β and IL-18 as well as pyroptosis. Accumulating evidence proposes that NLRP3 activation is critically involved in asthma pathogenesis. In fact, although NLRP3 facilitates the clearance of pathogens in the airways, persistent NLRP3 activation by inhaled irritants and/or innocuous environmental allergens can lead to overt pulmonary inflammation and exacerbation of asthma manifestations. Notably, administration of NLRP3 inhibitors in asthma models restrains AHR and pulmonary inflammation. Here, we provide an overview of the pathophysiology of SA, present molecular mechanisms underlying aberrant inflammatory responses in the airways, summarize recent studies pertinent to the biology and functions of NLRP3, and discuss the role of NLRP3 in the pathogenesis of asthma. Finally, we contemplate the potential of targeting NLRP3 as a novel therapeutic approach for the management of SA.

Fatigue, Sleep, and Autoimmune and Related Disorders

Profound and debilitating fatigue is the most common complaint reported among individuals with autoimmune disease, such as systemic lupus erythematosus, multiple sclerosis, type 1 diabetes, celiac disease, chronic fatigue syndrome, and rheumatoid arthritis. Fatigue is multi-faceted and broadly defined, which makes understanding the cause of its manifestations especially difficult in conditions with diverse pathology including autoimmune diseases. In general, fatigue is defined by debilitating periods of exhaustion that interfere with normal activities. The severity and duration of fatigue episodes vary, but fatigue can cause difficulty for even simple tasks like climbing stairs or crossing the room. The exact mechanisms of fatigue are not well-understood, perhaps due to its broad definition. Nevertheless, physiological processes known to play a role in fatigue include oxygen/nutrient supply, metabolism, mood, motivation, and sleepiness-all which are affected by inflammation. Additionally, an important contributing element to fatigue is the central nervous system-a region impacted either directly or indirectly in numerous autoimmune and related disorders. This review describes how inflammation and the central nervous system contribute to fatigue and suggests potential mechanisms involved in fatigue that are likely exhibited in autoimmune and related diseases.

Celastrol attenuates ox-LDL-induced mesangial cell proliferation via suppressing NLRP3 inflammasome activation

Mesangial cell (MC) proliferation is one of the important pathological features of obesity-associated nephropathy with unknown etiology. Excessive MC proliferation can cause glomerulosclerosis and renal function loss. Thus, targeting MC proliferation may be a potential strategy for the treatment of obesity-associated kidney disease. The present study was undertaken to investigate the role of celastrol in MC proliferation induced by ox-LDL, as well as the potential mechanisms. Following ox-LDL treatment, MC proliferation was induced and the NLRP3 inflammasome was activated, as evidenced by increased NLRP3 levels, caspase 1 activity, and IL-18 and IL-1β release. Significantly, NLRP3 siRNAs inhibited MC proliferation and delayed cell cycle progression, as indicated by the cell cycle assay and the expression of cyclin A2 and cyclin D1. Given the anti-inflammatory effect of celastrol, we pretreated MCs with celastrol before ox-LDL treatment. As expected, celastrol pretreatment strikingly inhibited NLRP3 inflammasome activation and MC proliferation triggered by ox-LDL. In summary, celastrol potently blocked ox-LDL-induced MC proliferation, possibly by inhibiting NLRP3 inflammasome activation. These findings also suggest that celastrol may be a potential drug for treating proliferative glomerular diseases related to obesity and lipid disorders.

Suppression of Glucagon-Like Peptide-1 Release by Inhibition of Intestinal NLRP3 Inflammasome Activation in Asc-/- and Nlrp3-/- Mice

The glucagon-like peptide-1 (GLP-1) is an insulinotropic hormone secreted by intestinal enteroendocrine L-cells, which plays a crucial role in glucose control, regulation, and protection from different pathological conditions such as diabetes mellitus. The present study sought to test whether GLP-1 release increases gut injury with a high-fat diet (HFD) and whether this GLP-1 release is associated with NLRP3 inflammasome activation. Our results showed that the NLRP3 inflammasome is activated in the intestinal tissue of wild-type mice on a HFD, accompanied by GLP-1 overexpression. The number of intestinal L-cells and the GLP-1 level in serum are increased in WT mice with HFD. However, in the Asc^-/- and Nlrp3^-/- mice, these HFD-induced intestinal and serum GLP-1 changes were suppressed. Using confocal microscopy, the colocalization of GLP-1 and FLICA that labels activated caspase-1 in intestine was decreased in the Asc^-/- and Nlrp3^-/- mice compared to WT mice. Mechanistically, the inhibitor of caspase-1 or HMGB1 blocker is used to demonstrate the regulatory action of NRLP3 inflammasome in GLP-1 release. It was found that the level of GLP-1 and its colocalization with IL-1β were reduced by inhibition of the caspase-1 activity, but not altered by blockade of HMGB1 action. Our results suggest that NLRP3 inflammasome activation triggers GLP-1 production from the intestine, which is associated with IL-1β, but not with HMGB1. These findings for the first time provide evidence that the activation of NLRP3 inflammasome in the intestine increases GLP-1 release in mice, which may serve as an adaptive response to intestinal inflammation.