Activation and regulation of the inflammasomes

Dying for a cause: The pathogenic manipulation of cell death and efferocytic pathways

Cell death is a natural consequence of infection. However, although the induction of cell death was solely thought to benefit the pathogen, compelling data now show that the activation of cell death pathways serves as a nuanced antimicrobial strategy that couples pathogen elimination with the generation of inflammatory cytokines and the priming of innate and adaptive cellular immunity. Following cell death, the phagocytic uptake of the infected dead cell by antigen-presenting cells and the subsequent lysosomal fusion of the apoptotic body containing the pathogen serve as an important antimicrobial mechanism that furthers the development of downstream adaptive immune responses. Despite the complexity of regulated cell death pathways, pathogens are highly adept at evading them. Here, we provide an overview of the remarkable diversity of cell death and efferocytic pathways and discuss illustrative examples of virulence strategies employed by pathogens, including oral pathogens, to counter their activation and persist within the host.

An effective LC-MS method for the simultaneous determination of a potential anti-rheumatoid arthritis drug, carboxyamidotriazole, and its major metabolite in rat plasma

Carboxyamidotriazole (CAI) was previously recognized as a well-tolerated anticancer drug. It has also demonstrated significant anti-inflammatory effects in various cell and animal model experiments, prompting its investigation as a potential treatment for rheumatoid arthritis. In this study, the potential biotransformation metabolites of CAI were identified both in vitro and in vivo. A sensitive, specific, and accurate LC-MS method was developed for the quantitative analysis of CAI and its major metabolite, CAI-OH, in rat plasma. CAI, CAI-OH, and telmisartan (used as an internal standard) were separated using a Zorbax SB C18 column. The mobile phase consisted of water (phase A, containing 0.1% formic acid) and acetonitrile (phase B, containing 0.1% formic acid) at a flow rate of 0.2 mL/min. The analytes were examined using a high-resolution mass spectrometer, with detected mass-to-charge ratios of m/z 424.01293 for CAI, m/z 440.00785 for CAI-OH, and m/z 515.24415 for telmisartan. Good linearity was observed within the range of 10-5000 ng/mL. Both inter- and intra-batch precision (relative standard deviation, %) were below 6%, and the accuracy ranged from 94.9% to 106.1%. The analytes remained stable throughout the entire experimental period. This method was successfully applied in a pharmacokinetic study of CAI following oral administration in rats.

Activation of the NLRP3-CASP-1 inflammasome is restrained by controlling autophagy during Glaesserella parasuis infection

Infection with Glaesserella parasuis, the primary pathogen behind Glässer's disease, is often associated with diverse clinical symptoms, including serofibrinous polyserositis, arthritis, and meningitis. Autophagy plays a dual role in bacterial infections, exerting either antagonistic or synergistic effects depending on the nature of the pathogen. Our previous studies have demonstrated that autophagy serves as a defense mechanism, combating inflammation and invasion caused by infection of highly virulent G. parasuis. However, the precise mechanisms remain to be elucidated. Pathogens exhibit distinct interactions with inflammasomes and autophagy processes. Herein, we explored the effect of autophagy on inflammasomes during G. parasuis infection. We found that G. parasuis infection triggers NLRP3-dependent pro-CASP-1-IL-18/IL-1β processing and maturation pathway, resulting in increased release of IL-1β and IL-18. Inhibition of autophagy enhances NLRP3 inflammasome activity, whereas stimulation of autophagy restricts it during G. parasuis infection. Furthermore, assembled NLRP3 inflammasomes undergo ubiquitination and recruit the autophagic adaptor, p62, facilitating their sequestration into autophagosomes during G. parasuis infection. These results suggest that the induction of autophagy mitigates inflammation by eliminating overactive NLRP3 inflammasomes during G. parasuis infection. Our research uncovers a mechanism whereby G. parasuis infection initiates inflammatory responses by promoting the assembly of the NLRP3 inflammasomes and activating NLRP3-CASP-1, both of which processes are downregulated by autophagy. This suggests that pharmacological manipulation of autophagy could be a promising approach to modulate G. parasuis-induced inflammatory responses.

Illuminating the pathogenic role of SARS-CoV-2: Insights into competing endogenous RNAs (ceRNAs) regulatory networks

The appearance of SARS-CoV-2 in 2019 triggered a significant economic and health crisis worldwide, with heterogeneous molecular mechanisms that contribute to its development are not yet fully understood. Although substantial progress has been made in elucidating the mechanisms behind SARS-CoV-2 infection and therapy, it continues to rank among the top three global causes of mortality due to infectious illnesses. Non-coding RNAs (ncRNAs), being integral components across nearly all biological processes, demonstrate effective importance in viral pathogenesis. Regarding viral infections, ncRNAs have demonstrated their ability to modulate host reactions, viral replication, and host-pathogen interactions. However, the complex interactions of different types of ncRNAs in the progression of COVID-19 remains understudied. In recent years, a novel mechanism of post-transcriptional gene regulation known as "competing endogenous RNA (ceRNA)" has been proposed. Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and viral ncRNAs function as ceRNAs, influencing the expression of associated genes by sequestering shared microRNAs. Recent research on SARS-CoV-2 has revealed that disruptions in specific ceRNA regulatory networks (ceRNETs) contribute to the abnormal expression of key infection-related genes and the establishment of distinctive infection characteristics. These findings present new opportunities to delve deeper into the underlying mechanisms of SARS-CoV-2 pathogenesis, offering potential biomarkers and therapeutic targets. This progress paves the way for a more comprehensive understanding of ceRNETs, shedding light on the intricate mechanisms involved. Further exploration of these mechanisms holds promise for enhancing our ability to prevent viral infections and develop effective antiviral treatments.

Ursolic acid alleviates lupus nephritis by suppressing SUMO1-mediated stabilization of NLRP3

BACKGROUND

Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease that affects multiple organs and cause a wide range of severe clinical manifestations, including lupus nephritis (LN), which is a major risk factor for morbidity and mortality in individual with SLE. Ursolic acid (UA) is a natural compound with favorable anti-inflammatory properties and has been employed to treat multiple disease, including inflammatory diseases, diabetes, and Parkinson's disease. However, its therapeutic potential on LN and the underlying mechanisms remains unclear.

PURPOSE

This aim of this study was to investigate the impact of UA on LN and its underlying mechanism.

METHODS

MRL/lpr lupus-prone mouse model was used and UA was administered orally for 8 weeks. Dexamethasone was used as a positive control. After 8 weeks of administration, the spleen-to-body-weight ratio, renal function, urine albumin excretion, cytokines levels, and the deposition of immune complex were measured. The primary mouse glomerular mesangial cells (GMCs) and SV40-MES-13 were stimulated by lipopolysaccharide (LPS), either alone or in combination with nigericin, to establish an in vitro model. The activation of NLRP3 inflammasome were investigated both in vivo and in vitro using qRT-PCR, immunoblotting, and immunofluorescence.

RESULTS

Our results revealed that UA prominently alleviated LN in MRL/lpr lupus-prone mice, leading to a significant reduction in proteinuria production, infiltration of immune cells infiltration, and histopathological damage in the renal tissue. In addition, UA exerted inhibitory effects on the secretion of IL-1β, IL-18, and caspase-1, pyroptosis, and ASC speck formation in primary mouse GMCs and SV40-MES-13 cells. Furthermore, UA facilitated the degradation of NLRP3 by suppressing SUMO1-mediated SUMOylation of NLRP3.

CONCLUSION

UA possess a therapeutical effect on LN in MRL/lpr mice by enhancing the degradation of NLRP3 through inhibition of SUMO1-mediated SUMOylation of NLRP3. Our findings provide a basis for proposing UA as a potential candidate for the treatment of LN.

Palmitoylation at a conserved cysteine residue facilitates gasdermin D-mediated pyroptosis and cytokine release

Gasdermin D (GSDMD)-mediated pyroptotic cell death drives inflammatory cytokine release and downstream immune responses upon inflammasome activation, which play important roles in host defense and inflammatory disorders. Upon activation by proteases, the GSDMD N-terminal domain (NTD) undergoes oligomerization and membrane translocation in the presence of lipids to assemble pores. Despite intensive studies, the molecular events underlying the transition of GSDMD from an autoinhibited soluble form to an oligomeric pore form inserted into the membrane remain incompletely understood. Previous work characterized S-palmitoylation for gasdermins from bacteria, fungi, invertebrates, as well as mammalian gasdermin E (GSDME). Here, we report that a conserved residue Cys191 in human GSDMD was S-palmitoylated, which promoted GSDMD-mediated pyroptosis and cytokine release. Mutation of Cys191 or treatment with palmitoyltransferase inhibitors cyano-myracrylamide (CMA) or 2-bromopalmitate (2BP) suppressed GSDMD palmitoylation, its localization to the membrane and dampened pyroptosis or IL-1β secretion. Furthermore, Gsdmd-dependent inflammatory responses were alleviated by inhibition of palmitoylation in vivo. By contrast, coexpression of GSDMD with palmitoyltransferases enhanced pyroptotic cell death, while introduction of exogenous palmitoylation sequences fully restored pyroptotic activities to the C191A mutant, suggesting that palmitoylation-mediated membrane localization may be distinct from other molecular events such as GSDMD conformational change during pore assembly. Collectively, our study suggests that S-palmitoylation may be a shared regulatory mechanism for GSDMD and other gasdermins, which points to potential avenues for therapeutically targeting S-palmitoylation of gasdermins in inflammatory disorders.

Macrophage α7nAChR alleviates the inflammation of neonatal necrotizing enterocolitis through mTOR/NLRP3/IL-1β pathway

BACKGROUND

Neonatal necrotizing enterocolitis (NEC) is one of the most prevalent and severe intestinal emergencies in newborns. The inflammatory activation of macrophages is associated with the intestinal injury of NEC. The neuroimmune regulation mediated by α7 nicotinic acetylcholine receptor (α7nAChR) plays an important role in regulating macrophage activation and inflammation progression, but in NEC remains unclear. This study aims to explore the effect of macrophage α7nAChR on NEC.

METHODS

Mice NEC model were conducted with high-osmolarity formula feeding, hypoxia, and cold stimulation. The α7nAChR agonist PNU-282987 and mTOR inhibitor rapamycin were treated by intraperitoneal injections in mice. The expression and distribution of macrophages, α7nAChR, and phospho-mammalian target of rapamycin (p-mTOR) in the intestines of NEC patients and mice was assessed using immunohistochemistry, immunofluorescence, and flow cytometry. The expression of NLRP3, activated caspase-1 and IL-1β in mice intestines was detected by flow cytometry, western blot or ELISA. In vitro, the mouse RAW264.7 macrophage cell line was also cultured followed by various treatments. Expression of p-mTOR, NLRP3, activated caspase-1, and IL-1β in macrophages was determined.

RESULTS

Macrophages accumulated in the intestines and the expression of α7nAChR in the mucosal and submucosal layers of the intestines was increased in both the NEC patients and mice. The p-mTOR and CD68 were increased and co-localized in intestines of NEC patients. In vitro, α7nAChR agonist PNU-282987 significantly reduced the increase of NLRP3, activated caspase-1, and IL-1β in macrophages. PNU-282987 also significantly reduced the increase of p-mTOR. The effect was blocked by AMPK inhibitor compound C. The expression of NLRP3, activated caspase-1, and IL-1β was inhibited after mTOR inhibitor rapamycin treatment. In NEC model mice, PNU-282987 reduced the expression of p-mTOR, NLRP3, activated caspase-1, and IL-1β in the intestine. Meanwhile, rapamycin significantly attenuated NLRP3 activation and the release of IL-1β. Moreover, the proportion of intestinal macrophages and intestinal injury decreased after PNU-282987 treatment.

CONCLUSION

Macrophage α7nAChR activation mitigates NLRP3 inflammasome activation by modulating mTOR phosphorylation, and subsequently alleviates intestinal inflammation and injury in NEC.

Medical treatments for abdominal aortic aneurysm: an overview of clinical trials

INTRODUCTION

Abdominal aortic aneurysm is a progressive, segmental, abdominal aortic dilation associated with a high mortality rate. Abdominal aortic aneurysms with diameters larger than 55 mm are associated with a high risk of rupture, and the most effective treatment options are surgical repair. Close observation and lifestyle adjustments are recommended for smaller abdominal aortic aneurysms with lower rupture risk. The development of medical therapies that limit or prevent the progression, expansion, and eventual rupture of abdominal aortic aneurysms remains an unmet clinical need.

AREAS COVERED

This review provides an overview of completed and ongoing clinical trials examining the efficacies of various drug classes, including antibiotics, antihypertensive drugs, hypolipidemic drugs, hypoglycemic drugs, and other potential therapies for abdominal aortic aneurysms. A search of PubMed, Web of Science, Clinical Trials, and another six clinical trial registries was conducted in January 2024.

EXPERT OPINION

None of the drugs have enough evidence to indicate that they can effectively inhibit the dilation of abdominal aortic aneurysm. More clinical trial data is required to support the efficacy of propranolol. Future research should also explore different drug delivery mechanisms, such as nanoparticles, to elevate drug concentration at the aneurysm wall.

Bacillus cereus CwpFM induces colonic tissue damage and inflammatory responses through oxidative stress and the NLRP3/NF-κB pathway

Bacillus cereus (B. cereus) from cow milk poses a threat to public health, causing food poisoning and gastrointestinal disorders in humans. We identified CwpFM, an enterotoxin from B. cereus, caused oxidative stress and inflammatory responses in mouse colon and colonic epithelial cells. Colon proteomics revealed that CwpFM elevated proteins associated with inflammation and oxidative stress. Notably, CwpFM induced activation of the NLRP3/NF-κB signaling, but suppressed antioxidant NFE2L2/HO-1 expression in the intestine and epithelial cells. Consistently, CwpFM exposure led to cytotoxicity and ROS accumulation in Caco-2 cells in a dose-dependent manner. Further, NAC (ROS inhibitor) treatment abolished NLRP3/NF-κB activation due to CwpFM. Moreover, overexpression of Nfe2l2 or activation of NFE2L2 by NK-252 reduced ROS production and inhibited activation of the NLRP3/NF-κB pathway. Inhibition of NF-κB by ADPC and/or suppression of NLRP3 by MCC950 attenuated CwpFM-induced inflammatory responses in Caco-2 cells. Collectively, CwpFM induced oxidative stress and NLRP3/NF-κB activation by inhibiting the NFE2L2/HO-1 signaling and ROS accumulation, leading to the development of intestinal inflammation. Our data elucidate the role of oxidative stress and innate immunity in CwpFM enterotoxicity and contribute to developing diagnostic and therapeutic products for B. cereus-related food safety issues.

TSPO deficiency exacerbates acute lung injury via NLRP3 inflammasome-mediated pyroptosis

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a common cause of respiratory failure in many critically ill patients. Although inflammasome activation plays an important role in the induction of acute lung injury (ALI) and ARDS, the regulatory mechanism of this process is still unclear. When cells are stimulated by inflammation, the integrity and physiological function of mitochondria play a crucial part in pyroptosis. However, the underlying mechanisms and function of mitochondrial proteins in the process of pyroptosis are largely not yet known. Here, we identified the 18-kDa translocator protein (TSPO), a mitochondrial outer membrane protein, as an important mediator regulating nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation in macrophages during ALI.

METHODS

TSPO gene knockout (KO) and lipopolysaccharide (LPS)-induced ALI/ARDS mouse models were employed to investigate the biological role of TSPO in the pathogenesis of ARDS. Murine macrophages were used to further characterize the effect of TSPO on the NLRP3 inflammasome pathway. Activation of NLRP3 inflammasome was preformed through LPS + adenosine triphosphate (ATP) co-stimulation, followed by detection of mitochondrial membrane potential, reactive oxygen species (ROS) production, and cell death to evaluate the potential biological function of TSPO. Comparisons between two groups were performed with a two-sided unpaired t -test.

RESULTS

TSPO- KO mice exhibited more severe pulmonary inflammation in response to LPS-induced ALI. TSPO deficiency resulted in enhanced activation of the NLRP3 inflammasome pathway, promoting more proinflammatory cytokine production of macrophages in LPS-injured lung tissue, including interleukin (IL)-1β, IL-18, and macrophage inflammatory protein (MIP)-2. Mitochondria in TSPO -KO macrophages tended to depolarize in response to cellular stress. The increased production of mitochondrial damage-associated molecular pattern led to enhanced mitochondrial membrane depolarization and pyroptosis in TSPO -KO cells.

CONCLUSION

TSPO may be the key regulator of cellular pyroptosis, and it plays a vital protective role in ARDS occurrence and development.

The Interplay of HIV and Long COVID in Sub-Saharan Africa: Mechanisms of Endothelial Dysfunction

PURPOSE OF REVIEW

Long COVID affects approximately 5 million people in Africa. This disease is characterized by persistent symptoms or new onset of symptoms after an acute SARS-CoV-2 infection. Specifically, the most common symptoms include a range of cardiovascular problems such as chest pain, orthostatic intolerance, tachycardia, syncope, and uncontrolled hypertension. Importantly, these conditions appear to have endothelial dysfunction as the common denominator, which is often due to impaired nitric oxide (NO) mechanisms. This review discusses the role of mechanisms contributing to endothelial dysfunction in Long COVID, particularly in people living with HIV.

RECENT FINDINGS

Recent studies have reported that increased inflammation and oxidative stress, frequently observed in Long COVID, may contribute to NO dysfunction, ultimately leading to decreased vascular reactivity. These mechanisms have also been reported in people living with HIV. In regions like Africa, where HIV infection is still a major public health challenge with a prevalence of approximately 26 million people in 2022. Specifically, endothelial dysfunction has been reported as a major mechanism that appears to contribute to cardiovascular diseases and the intersection with Long COVID mechanisms is of particular concern. Further, it is well established that this population is more likely to develop Long COVID following infection with SARS-CoV-2. Therefore, concomitant infection with SARS-CoV-2 may lead to accelerated cardiovascular disease. We outline the details of the worsening health problems caused by Long COVID, which exacerbate pre-existing conditions such as endothelial dysfunction. The overlapping mechanisms of HIV and SARS-CoV-2, particularly the prolonged inflammatory response and chronic hypoxia, may increase susceptibility to Long COVID. Addressing these overlapping health issues is critical as it provides clinical entry points for interventions that could improve and enhance outcomes and quality of life for those affected by both HIV and Long COVID in the region.

The role of the NLRP3 inflammasome in atherosclerotic disease: Systematic review and meta-analysis

Atherosclerosis is a chronic, progressive cardiovascular disease characterized by cholesterol deposition within blood vessel walls. Recent literature has suggested that the NLRP3 [NOD (nucleotide oligomerization domain)-, LRR (leucine-rich repeat)-, and PYD (pyrin domain)-containing protein 3] inflammasome is a key mediator in the development, progression, and destabilization of atherosclerotic plaques. This review aims to evaluate the current literature on the role of NLRP3 in human atherosclerosis. This systematic review was registered on the PROSPERO database (ID = CRD42022340039) and involved the search of a total of 8 databases. Records were screened in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A total of 20 studies were included and quality assessed using the NIH: NHLBI tool. Six were eligible for meta-analysis using RevMan 5.4.1. We identified 20 relevant articles representing 3388 participants. NLRP3 mRNA levels and downstream cytokines, interleukin (IL)-1β and IL-18 were found to be associated with atherosclerotic disease. Fold changes in NLRP3 mRNA levels were most strongly associated with high risk atherosclerotic disease, compared to controls [0.84 (95 % CI: 0.41-1.28)]. IL-1β mRNA fold change was more robustly associated with high-risk atherosclerotic disease [0.61 (95 % CI: 0.10-1.13)] than IL-18 [0.47 (95 % CI: 0.02-0.91)]. NLRP3, IL-1β, and IL-18 are associated with high-risk atherosclerotic disease. However, given the scope of this review, the role of this inflammasome and its cytokine counterparts in acting as prognosticators of coronary artery disease severity is unclear. Several upstream activators such as cholesterol crystals are involved in the canonical or non-canonical activation of the NLRP3 inflammasome and its downstream cytokines. These findings highlight the necessity for further research to delineate the exact mechanisms of NLRP3 inflammasome activation and potential drug targets.

Itaconate as a key player in cardiovascular immunometabolism

Cardiovascular diseases (CVDs) are the leading cause of death globally, resulting in a major health burden. Thus, an urgent need exists for exploring effective therapeutic targets to block progression of CVDs and improve patient prognoses. Immune and inflammatory responses are involved in the development of atherosclerosis, ischemic myocardial damage responses and repair, calcification, and stenosis of the aortic valve. These responses can involve both large and small blood vessels throughout the body, leading to increased blood pressure and end-organ damage. While exploring potential avenues for therapeutic intervention in CVDs, researchers have begun to focus on immune metabolism, where metabolic changes that occur in immune cells in response to exogenous or endogenous stimuli can influence immune cell effector responses and local immune signaling. Itaconate, an intermediate metabolite of the tricarboxylic acid (TCA) cycle, is related to pathophysiological processes, including cellular metabolism, oxidative stress, and inflammatory immune responses. The expression of immune response gene 1 (IRG1) is upregulated in activated macrophages, and this gene encodes an enzyme that catalyzes the production of itaconate from the TCA cycle intermediate, cis-aconitate. Itaconate and its derivatives have exerted cardioprotective effects through immune modulation in various disease models, such as ischemic heart disease, valvular heart disease, vascular disease, heart transplantation, and chemotherapy drug-induced cardiotoxicity, implying their therapeutic potential in CVDs. In this review, we delve into the associated signaling pathways through which itaconate exerts immunomodulatory effects, summarize its specific roles in CVDs, and explore emerging immunological therapeutic strategies for managing CVDs.

Targeting inflammasomes and pyroptosis in retinal diseases-molecular mechanisms and future perspectives

Retinal diseases encompass various conditions associated with sight-threatening immune responses and are leading causes of blindness worldwide. These diseases include age-related macular degeneration, diabetic retinopathy, glaucoma and uveitis. Emerging evidence underscores the vital role of the innate immune response in retinal diseases, beyond the previously emphasized T-cell-driven processes of the adaptive immune system. In particular, pyroptosis, a newly discovered programmed cell death process involving inflammasome formation, has been implicated in the loss of membrane integrity and the release of inflammatory cytokines. Several disease-relevant animal models have provided evidence that the formation of inflammasomes and the induction of pyroptosis in innate immune cells contribute to inflammation in various retinal diseases. In this review article, we summarize current knowledge about the innate immune system and pyroptosis in retinal diseases. We also provide insights into translational targeting approaches, including novel drugs countering pyroptosis, to improve the diagnosis and treatment of retinal diseases.

GLUT1 Promotes NLRP3 Inflammasome Activation of Airway Epithelium in Lipopolysaccharide-Induced Acute Lung Injury

Acute lung injury (ALI) is a devastating clinical syndrome caused by different factors, with high morbidity and mortality. Lung injury and inflammation caused by lipopolysaccharide (LPS) can be modulated by NLRP3 inflammasome activation, yet its exact function within the airway epithelium is still unknown. Meanwhile, glucose transporter protein 1 (GLUT1) contributes to a number of inflammatory illnesses, including ALI. The present study aimed to assess GLUT1's function in NLRP3 inflammasome activation of airway epithelium in LPS-induced acute lung injury. BALB/c mice and BEAS-2B cells were exposed to LPS (5 mg/kg and 200 μg/mL, respectively), with or without GLUT1 antagonists (WZB117 or BAY876). LPS up-regulated pulmonary expression of NLRP3 and GLUT1 in mice, which could be blocked by WZB117 or BAY876. Pharmacological inhibition of GLUT1 in vivo significantly attenuated lung tissue damage, neutrophil accumulation, and proinflammatory factors release (TNF-α, IL-6, and IL-1β) in LPS-exposed mice. Meanwhile, the activation markers of NLRP3 inflammasome (ASC, caspase-1, IL-1β, and IL-18) induced by LPS were also suppressed. In cultured BEAS-2B cells, LPS induced an increase in GLUT1 expression and triggered activation of the NLRP3 inflammasome, both of which were inhibited by GLUT1 antagonists. These results illustrate that GLUT1 participates in LPS-induced ALI and promotes the activation of the NLRP3 inflammasome in airway epithelial cells.

Identification and Validation of PKR as a Direct Target for the Novel Sulfonamide-Substituted Tetrahydroquinoline Nonselective Inhibitor of the NLRP3 Inflammasome

The NLRP3 inflammasome is a critical component of the innate immune system. The persistent abnormal activation of the NLRP3 inflammasome is implicated in numerous human diseases. Herein, sulfonamide-substituted tetrahydroquinoline derivative S-9 was identified as the most promising NLRP3 inhibitor, without obvious cytotoxicity. In vitro, S-9 inhibited the priming and activation stages of the NLRP3 inflammasome. Incidentally, we also observed that S-9 had inhibitory effects on the NLRC4 and AIM2 inflammasomes. To elucidate the multiple anti-inflammatory activities of S-9, photoaffinity probe P-2, which contained a photoaffinity label and a functional handle, was developed for target identification by chemical proteomics. We identified PKR as a novel target of S-9 in addition to NLRP3 by target fishing. Furthermore, S-9 exhibited a significant anti-neuroinflammatory effect in vivo. In summary, our findings show that S-9 is a promising lead compound targeting both PKR and NLRP3 that could emerge as a molecular tool for treating inflammasome-related diseases.

Challenges and Future Perspectives in Modeling Neurodegenerative Diseases Using Organ-on-a-Chip Technology

Neurodegenerative diseases (NDDs) affect more than 50 million people worldwide, posing a significant global health challenge as well as a high socioeconomic burden. With aging constituting one of the main risk factors for some NDDs such as Alzheimer's disease (AD) and Parkinson's disease (PD), this societal toll is expected to rise considering the predicted increase in the aging population as well as the limited progress in the development of effective therapeutics. To address the high failure rates in clinical trials, legislative changes permitting the use of alternatives to traditional pre-clinical in vivo models are implemented. In this regard, microphysiological systems (MPS) such as organ-on-a-chip (OoC) platforms constitute a promising tool, due to their ability to mimic complex and human-specific tissue niches in vitro. This review summarizes the current progress in modeling NDDs using OoC technology and discusses five critical aspects still insufficiently addressed in OoC models to date. Taking these aspects into consideration in the future MPS will advance the modeling of NDDs in vitro and increase their translational value in the clinical setting.

Correlation of LLT-1 and NLRC4 inflammasome and its effect on glioblastoma prognosis

PURPOSE

LLT-1 is a well-known ligand for the natural killer (NK) cell inhibitory receptor NKRP1A. Here, we examined NLRC4 inflammasome components and LLT-1 expression in glioblastoma (GBM) tissues to elucidate potential associations and interactions between these factors.

METHODS

GBM tissues were collected for RNA sequencing (RNA-seq) and Immunofluorescent experiments. Colocalization of LLT-1 and other proteins was assessed by immunofluorescence. Computational analyses utilized RNA-seq data from 296 to 52 patients from the Chinese Glioma Genome Atlas and CHA medical records, respectively. These data were subjected to survival, non-negative matrix factorization clustering, Gene Ontology enrichment, and protein-protein interaction analyses. Receptor-ligand interactions between tumor and immune cells were confirmed by single-cell RNA-seq analysis.

RESULTS

In GBM tissues, LLT-1 was predominantly colocalized with glial fibrillary acidic protein (GFAP)-expressing astrocytes, but not with microglial markers like Iba-1. Additionally, LLT-1 and activated NLRC4 inflammasomes were mainly co-expressed in intratumoral astrocytes, suggesting an association between LLT-1, NLRC4, and glioma malignancy. High LLT-1 expression correlates with poor prognosis, particularly in the mesenchymal subtype, and is associated with TNF and NOD-like receptor signaling pathway enrichment, indicating a potential role in tumor inflammation and progression. At the single-cell level, mesenchymal-like malignant cells showed high NF, NLR, and IL-1 signaling pathway enrichment compared to other malignant cell types.

CONCLUSION

We revealed an association between NLRC4 inflammasome activity and LLT-1 expression, suggesting a novel regulatory pathway involving TNF, inflammasomes, and IL-1, potentially offering new NK-cell-mediated anti-glioma approaches.

Potentials of Natural Antioxidants in Reducing Inflammation and Oxidative Stress in Chronic Kidney Disease

Chronic kidney disease (CKD) presents a substantial global public health challenge, with high morbidity and mortality. CKD patients often experience dyslipidaemia and poor glycaemic control, further exacerbating inflammation and oxidative stress in the kidney. If left untreated, these metabolic symptoms can progress to end-stage renal disease, necessitating long-term dialysis or kidney transplantation. Alleviating inflammation responses has become the standard approach in CKD management. Medications such as statins, metformin, and GLP-1 agonists, initially developed for treating metabolic dysregulation, demonstrate promising renal therapeutic benefits. The rising popularity of herbal remedies and supplements, perceived as natural antioxidants, has spurred investigations into their potential efficacy. Notably, lactoferrin, Boerhaavia diffusa, Amauroderma rugosum, and Ganoderma lucidum are known for their anti-inflammatory and antioxidant properties and may support kidney function preservation. However, the mechanisms underlying the effectiveness of Western medications and herbal remedies in alleviating inflammation and oxidative stress occurring in renal dysfunction are not completely known. This review aims to provide a comprehensive overview of CKD treatment strategies and renal function preservation and critically discusses the existing literature's limitations whilst offering insight into the potential antioxidant effects of these interventions. This could provide a useful guide for future clinical trials and facilitate the development of effective treatment strategies for kidney functions.

Inflammasomes in chronic liver disease: hepatic injury, fibrosis progression and systemic inflammation

Chronic liver disease (CLD) leads to hepatocellular injury that triggers a pro-inflammatory state in several parenchymal and non-parenchymal hepatic cell types ultimately resulting in liver fibrosis, cirrhosis, portal hypertension (PH) and liver failure. Thus, an improved understanding of the inflammasomes - as key molecular drivers of liver injury - supports the development of novel diagnostic or prognostic biomarkers and effective therapeutics. In liver disease, innate immune cells respond to hepatic noxes by activating cell-intrinsic inflammasomes via toll-like receptors (TLRs) and nuclear factor kappa-B (NF-κB) and release of pro-inflammatory cytokines (such as IL-1β, IL-18, TNF-α and IL-6). Subsequently, cells of the adaptive immune system are recruited to fuel hepatic inflammation, and liver parenchymal cells may undergo programmed cell-death mediated by gasdermin D, termed pyroptosis. With liver disease progression, there is a shift towards a type 2 inflammatory response, which promotes tissue repair but also fibrogenesis. Inflammasome activation may also occur at extrahepatic sites, such as the white adipose tissue in metabolic dysfunction-associated steatohepatitis (MASH). In end-stage liver disease, flares of inflammation (e.g., in severe alcohol-related hepatitis) that spark on a dysfunctional immune system, contribute to inflammasome-mediated liver injury and potentially result in organ dysfunctions/failures, as seen in acute-on-chronic liver failure (ACLF). This review provides an overview on current concepts regarding inflammasome activation in liver disease progression and related biomarkers and therapeutic approaches that are being developed for patients with liver disease.

Neonatal Chlamydia muridarum respiratory infection causes neuroinflammation within the brainstem during the early postnatal period

Respiratory infections are one of the most common causes of illness and morbidity in neonates worldwide. In the acute phase infections are known to cause wide-spread peripheral inflammation. However, the inflammatory consequences to the critical neural control centres for respiration have not been explored. Utilising a well characterised model of neonatal respiratory infection, we investigated acute responses within the medulla oblongata which contains key respiratory regions. Neonatal mice were intranasally inoculated within 24 h of birth, with either Chlamydia muridarum or sham-infected, and tissue collected on postnatal day 15, the peak of peripheral inflammation. A key finding of this study is that, while the periphery appeared to show no sex-specific effects of a neonatal respiratory infection, sex had a significant impact on the inflammatory response of the medulla oblongata. There was a distinct sex-specific response in the medulla coincident with peak of peripheral inflammation, with females demonstrating an upregulation of anti-inflammatory cytokines and males showing very few changes. Microglia also demonstrated sex-specificity with the morphology of females and males differing based upon the nuclei. Astrocytes showed limited changes during the acute response to neonatal infection. These data highlight the strong sex-specific impact of a respiratory infection can have on the medulla in the acute inflammatory phase.

Argon neuroprotection in ischemic stroke and its underlying mechanism

Ischemic stroke (IS), primarily caused by cerebrovascular obstruction, results in severe neurological deficits and has emerged as a leading cause of death and disability worldwide. Recently, there has been increasing exploration of the neuroprotective properties of the inert gas argon. Argon has exhibited impressive neuroprotection in many in vivo and ex vivo experiments without signs of adverse effects, coupled with the advantages of being inexpensive and easily available. However, the efficient administration strategy and underlying mechanisms of neuroprotection by argon in IS are still unclear. This review summarizes current research on the neuroprotective effects of argon in IS with the goal to provide effective guidance for argon application and to elucidate the potential mechanisms of argon neuroprotection. Early and appropriate argon administration at as high a concentration as possible offers favorable neuroprotection in IS. Argon inhalation has been shown to provide some long-term protection benefits. Argon provides the anti-oxidative stress, anti-inflammatory and anti-apoptotic cytoprotective effects mainly around Toll-like receptor 2/4 (TLR2/4), mediated by extracellular signal-regulated kinase 1/2 (ERK1/2), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), nuclear factor kappa-B (NF-ĸB) and B-cell leukemia/lymphoma 2 (Bcl-2). Therefore, argon holds significant promise as a novel clinical neuroprotective gas agent for ischemic stroke after further researches to identify the optimal application strategy and elucidate the underlying mechanism.

Transmissible gastroenteritis virus induces inflammatory responses via RIG-I/NF-κB/HIF-1α/glycolysis axis in intestinal organoids and in vivo

Transmissible gastroenteritis virus (TGEV)-induced enteritis is characterized by watery diarrhea, vomiting, and dehydration, and has high mortality in newborn piglets, resulting in significant economic losses in the pig industry worldwide. Conventional cell lines have been used for many years to investigate inflammation induced by TGEV, but these cell lines may not mimic the actual intestinal environment, making it difficult to obtain accurate results. In this study, apical-out porcine intestinal organoids were employed to study TEGV-induced inflammation. We found that apical-out organoids were susceptible to TGEV infection, and the expression of representative inflammatory cytokines was significantly upregulated upon TGEV infection. In addition, retinoic acid-inducible gene I (RIG-I) and the nuclear factor-kappa B (NF-κB) pathway were responsible for the expression of inflammatory cytokines induced by TGEV infection. We also discovered that the transcription factor hypoxia-inducible factor-1α (HIF-1α) positively regulated TGEV-induced inflammation by activating glycolysis in apical-out organoids, and pig experiments identified the same molecular mechanism as the ex vivo results. Collectively, we unveiled that the inflammatory responses induced by TGEV were modulated via the RIG-I/NF-κB/HIF-1α/glycolysis axis ex vivo and in vivo. This study provides novel insights into TGEV-induced enteritis and verifies intestinal organoids as a reliable model for investigating virus-induced inflammation.

IMPORTANCE

Intestinal organoids are a newly developed culture system for investigating immune responses to virus infection. This culture model better represents the physiological environment compared with well-established cell lines. In this study, we discovered that inflammatory responses induced by TGEV infection were regulated by the RIG-I/NF-κB/HIF-1α/glycolysis axis in apical-out porcine organoids and in pigs. Our findings contribute to understanding the mechanism of intestinal inflammation upon viral infection and highlight apical-out organoids as a physiological model to mimic virus-induced inflammation.

Kaempferol Alleviates Hepatic Injury in Nonalcoholic Steatohepatitis (NASH) by Suppressing Neutrophil-Mediated NLRP3-ASC/TMS1-Caspase 3 Signaling

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a significant hepatic condition that has gained worldwide attention. Kaempferol (Kae), renowned for its diverse biological activities, including anti-inflammatory, antioxidant, anti-aging, and cardio-protective properties, has emerged as a potential therapeutic candidate for non-alcoholic steatohepatitis (NASH). Despite its promising therapeutic potential, the precise underlying mechanism of Kae's beneficial effects in NASH remains unclear. Therefore, this study aims to clarify the mechanism by conducting comprehensive in vivo and in vitro experiments.

RESULTS

In this study, a murine model of non-alcoholic steatohepatitis (NASH) was established by feeding C57BL/6 female mice a high-fat diet for 12 weeks. Kaempferol (Kae) was investigated for its ability to modulate systemic inflammatory responses and lipid metabolism in this model (20 mg/kg per day). Notably, Kae significantly reduced the expression of NLRP3-ASC/TMS1-Caspase 3, a crucial mediator of liver tissue inflammation. Additionally, in a HepG2 cell model induced with palmitic acid/oleic acid (PA/OA) to mimic NASH conditions, Kae demonstrated the capacity to decrease lipid droplet accumulation and downregulate the expression of NLRP3-ASC/TMS1-Caspase 3 (20 µM and the final concentration to 20 nM). These findings suggest that Kae may hold therapeutic potential in the treatment of NASH by targeting inflammatory and metabolic pathways.

CONCLUSIONS

These findings suggest that kaempferol holds potential as a promising therapeutic intervention for ameliorating non-alcoholic fatty liver disease (NAFLD).

Inflammasomes Are Influenced by Epigenetic and Autophagy Mechanisms in Colorectal Cancer Signaling

Inflammasomes contribute to colorectal cancer signaling by primarily inducing inflammation in the surrounding tumor microenvironment. Its role in inflammation is receiving increasing attention, as inflammation has a protumor effect in addition to inducing tissue damage. The inflammasome's function is complex and controlled by several layers of regulation. Epigenetic processes impact the functioning or manifestation of genes that are involved in the control of inflammasomes or the subsequent signaling cascades. Researchers have intensively studied the significance of epigenetic mechanisms in regulation, as they encompass several potential therapeutic targets. The regulatory interactions between the inflammasome and autophagy are intricate, exhibiting both advantageous and harmful consequences. The regulatory aspects between the two entities also encompass several therapeutic targets. The relationship between the activation of the inflammasome, autophagy, and epigenetic alterations in CRC is complex and involves several interrelated pathways. This article provides a brief summary of the newest studies on how epigenetics and autophagy control the inflammasome, with a special focus on their role in colorectal cancer. Based on the latest findings, we also provide an overview of the latest therapeutic ideas for this complex network.

Pyroptosis is involved in the immune microenvironment regulation of unexplained recurrent miscarriage

Unexplained recurrent miscarriage (URM) is a common pregnancy complication with few effective therapies. Moreover, little is known regarding the role of pyroptosis in the regulation of the URM immune microenvironment. To address this issue, gene expression profiles of publicly available placental datasets GSE22490 and GSE76862 were downloaded from the Gene Expression Omnibus database. Pyroptosis-related differentially expressed genes were identified and a total of 16 differentially expressed genes associated with pyroptosis were detected, among which 1 was upregulated and 15 were downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that the functionally enriched modules and pathways of these genes are closely related to immune and inflammatory responses. Four hub genes were identified: BTK, TLR8, NLRC4, and TNFSF13B. BTK, TLR8, and TNFSF13B were highly connected with immune cells, according to the correlation analysis of four hub genes and 20 different types of immune cells (p < 0.05). The four hub genes were used as research objects to construct the interaction networks. Chorionic villus tissue was used for quantitative real-time polymerase chain reaction and western blot to confirm the expression levels of hub genes, and the results showed that the expression of the four hub genes was significantly decreased in the chorionic villus tissue in the URM group. Collectively, the present study indicates that perhaps pyroptosis is essential to the diversity and complexity of the URM immune microenvironment, and provides a theoretical basis and research ideas for subsequent target gene verification and mechanism research.

Correlation between abnormal cellular immune and changes of magnetic resonance spectroscopy in patients with Alzheimer's disease

BACKGROUND

Evidence from previous studies indicates that neuroinflammation contributes to the onset of Alzheimer's Disease (AD). Moreover, cellular dysfunction is induced by impaired signaling of neurotransmitters. This study aimed to explore the correlation between cellular immune dysfunction and neurotransmitter changes through cranial Magnetic Resonance Spectroscopy (MRS) in AD patients.

METHODS

Here, 32 AD, 40 Vascular Dementia (VD), and 35 Non-Dementia Elderly Control (NDE) cases were enrolled. Flow cytometry was performed to characterize lymphocyte subsets in plasma samples. The IL-1β and Caspase-1 levels were detected by ELISA. The NLRP3 expression level was measured by Western Blot (WB). The equivalence of N-acetylaspartate (NAA), Creatine (Cr), Choline (Cho), and Inositol (MI) in bilateral hippocampi of patients was examined by MRS. The association of NAA/Cr or MI/Cr ratios with the proportion of T lymphocyte subsets or NK cell subsets was determined through single-factor correlation analysis.

RESULTS

The proportion of T lymphocyte subsets was significantly lower in the AD group than in the NDE group (P < 0.01). On the other hand, the Caspase-1, NLRP3, and IL-1β protein expression levels were significantly higher in the AD group than in the other groups. Further analysis showed that the NAA/Cr ratio was lower in the AD group than in the NDE group. Additionally, a significant positive correlation was found between the NAA/Cr ratio and the MMSE score (r = 0.81, P < 0.01). Moreover, a significant positive correlation was observed between the NAA/Cr and T lymphocyte ratios. The NAA/Cr ratio was significantly negatively correlated with the proportion of NK cells in the blood (r = －0.83, P < 0.01). A significant negative correlation was also recorded between the MI/Cr and T cell ratios in blood samples.

CONCLUSIONS

Impaired cellular immune dysfunction in AD patients was significantly correlated with abnormal MRS. Neuroimmune dysfunction may contribute to the pathogenesis of AD and alter the metabolism of neurotransmitters such as aspartic acid and MI in the brains of AD patients.

TRIAL REGISTRATION

Not applicable.

Role of microglia in stroke

Microglia play key roles in the post-ischemic inflammatory response and damaged tissue removal reacting rapidly to the disturbances caused by ischemia and working to restore the lost homeostasis. However, the modified environment, encompassing ionic imbalances, disruption of crucial neuron-microglia interactions, spreading depolarization, and generation of danger signals from necrotic neurons, induce morphological and phenotypic shifts in microglia. This leads them to adopt a proinflammatory profile and heighten their phagocytic activity. From day three post-ischemia, macrophages infiltrate the necrotic core while microglia amass at the periphery. Further, inflammation prompts a metabolic shift favoring glycolysis, the pentose-phosphate shunt, and lipid synthesis. These shifts, combined with phagocytic lipid intake, drive lipid droplet biogenesis, fuel anabolism, and enable microglia proliferation. Proliferating microglia release trophic factors contributing to protection and repair. However, some microglia accumulate lipids persistently and transform into dysfunctional and potentially harmful foam cells. Studies also showed microglia that either display impaired apoptotic cell clearance, or eliminate synapses, viable neurons, or endothelial cells. Yet, it will be essential to elucidate the viability of engulfed cells, the features of the local environment, the extent of tissue damage, and the temporal sequence. Ischemia provides a rich variety of region- and injury-dependent stimuli for microglia, evolving with time and generating distinct microglia phenotypes including those exhibiting proinflammatory or dysfunctional traits and others showing pro-repair features. Accurate profiling of microglia phenotypes, alongside with a more precise understanding of the associated post-ischemic tissue conditions, is a necessary step to serve as the potential foundation for focused interventions in human stroke.

Liquid-liquid phase separation in innate immunity

Intrinsic and innate immune responses are essential lines of defense in the body's constant surveillance of pathogens. The discovery of liquid-liquid phase separation (LLPS) as a key regulator of this primal response to infection brings an updated perspective to our understanding of cellular defense mechanisms. Here, we review the emerging multifaceted role of LLPS in diverse aspects of mammalian innate immunity, including DNA and RNA sensing and inflammasome activity. We discuss the intricate regulation of LLPS by post-translational modifications (PTMs), and the subversive tactics used by viruses to antagonize LLPS. This Review, therefore, underscores the significance of LLPS as a regulatory node that offers rapid and plastic control over host immune signaling, representing a promising target for future therapeutic strategies.

Subacute ruminal acidosis induces pyroptosis via the mitophagy-mediated NLRP3 inflammasome activation in the livers of dairy cows fed a high-grain diet

High-grain (HG) feeding can trigger subacute ruminal acidosis (SARA) and subsequent liver tissue injury. This study investigated pyroptosis and NLRP3 inflammasome activation in SARA-induced liver injury, and the role of mitophagy during this process. Twelve mid-lactating Holstein cows equipped with rumen fistulas were randomly divided into 2 groups: a low-grain (LG) diet group (grain:forage = 4:6) and a HG diet group (grain:forage = 6:4). Each group had 6 cows. The experiment lasted for 3 wk. The ruminal fluid was collected through the rumen fistula on experimental d 20 and 21, and the pH immediately measured. At the end of the experiment, all animals were slaughtered, and peripheral blood and liver tissue were collected. The ruminal pH was lower in the HG group than that in the LG group at all time points. In addition, the ruminal pH in the HG group was lower than 5.6 at 3 consecutive time points after feeding (4, 6, and 8 h on d 20; 2, 4, and 6 h on d 21), indicating that HG feeding induced SARA. The content of lipopolysaccharide, IL-1β, and apoptosis-related cysteine protease 1 (caspase-1) and the activity of alanine aminotransferase and aspartate aminotransferase in the blood plasma of the HG group were all significantly increased. Hepatic caspase-1 activity was increased in the livers of the HG group. The increased expression levels of pyroptosis- and NLRP3 inflammasome-related genes IL1B, IL18, gasdermin D (GSDMD), apoptosis-associated speck-like protein containing a card (ASC), NLR family pyrin domain-containing 3 (NLRP3), and caspase-1 (CASP1) in liver tissue of the HG group were detected. Furthermore, western blot analysis showed that HG feeding led to increased expression of pyroptosis- and NLRP3 inflammasome-related proteins GSDMD N-terminal (GSDMD-NT), IL-1β, IL-18, cleaved-caspase-1, ASC, NLRP3, and cleaved-caspase-11 and upregulated expression of mitophagy-related proteins microtubule-associated protein 1 light chain 3 II (MAP1LC3-II), beclin 1 (BECN1), Parkin, and PTEN-induced kinase 1 (PINK1) in liver tissue. Collectively, our results revealed that SARA caused increased mitophagy and activated the NLRP3 inflammasome, causing pyroptosis and subsequent liver injury in dairy cows fed a HG diet.

Pyroptosis in sepsis induced organ dysfunction

As an uncontrolled inflammatory response to infection, sepsis and sepsis induced organ dysfunction are great threats to the lives of septic patients. Unfortunately, the pathogenesis of sepsis is complex and multifactorial, which still needs to be elucidated. Pyroptosis is a newly discovered atypical form of inflammatory programmed cell death, which depends on the Caspase-1 dependent classical pathway or the non-classical Caspase-11 (mouse) or Caspase-4/5 (human) dependent pathway. Many studies have shown that pyroptosis is related to sepsis. The Gasdermin proteins are the key molecules in the membrane pores formation in pyroptosis. After cut by inflammatory caspase, the Gasdermin N-terminal fragments with perforation activity are released to cause pyroptosis. Pyroptosis is closely related to the occurrence and development of sepsis induced organ dysfunction. In this review, we summarized the molecular mechanism of pyroptosis, the key role of pyroptosis in sepsis and sepsis induced organ dysfunction, with the aim to bring new diagnostic biomarkers and potential therapeutic targets to improve sepsis clinical treatments.

Honokiol Exhibits Anti-NLRP3 Inflammasome and Antimicrobial Properties in Neisseria gonorrhoeae-Infected Macrophages

Purpose

The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, crucial in infectious and inflammatory diseases by regulating IL-1β, presents a target for disease management. Neisseria gonorrhoeae causes gonorrhea in over 87 million people annually, with previous research revealing NLRP3 inflammasome activation in infected macrophages. No natural products have been reported to counteract this activation. Exploring honokiol, a phenolic compound from Chinese herbal medicine, we investigated its impact on NLRP3 inflammasome activation in N. gonorrhoeae-infected macrophages.

Methods

Honokiol's impact on the protein expression of pro-inflammatory mediators was analyzed using ELISA and Western blotting. The generation of intracellular H2O2 and mitochondrial reactive oxygen species (ROS) was detected through specific fluorescent probes (CM-H2DCFDA and MitoSOX, respectively) and analyzed by flow cytometry. Mitochondrial membrane integrity was assessed using specific fluorescent probes (MitoTracker and DiOC2(3)) and analyzed by flow cytometry. Additionally, the effect of honokiol on the viability of N. gonorrhoeae was examined through an in vitro colony-forming units assay.

Results

Honokiol effectively inhibits caspase-1, caspase-11 and GSDMD activation and reduces the extracellular release of IL-1β, NLRP3, and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) in N. gonorrhoeae-infected macrophages. Detailed investigations have demonstrated that honokiol lowers the production of H2O2 and the phosphorylation of ERK1/2 in N. gonorrhoeae-infected macrophages. Importantly, the phosphorylation of JNK1/2 and p38 and the activation of NF-κB remain unaffected. Moreover, honokiol reduces the N. gonorrhoeae-mediated generation of reactive oxygen species within the mitochondria, preserving their integrity. Additionally, honokiol suppresses the expression of the pro-inflammatory mediator IL-6 and inducible nitric oxide synthase induced by N. gonorrhoeae independently of NLRP3. Impressively, honokiol exhibits in vitro anti-gonococcal activity against N. gonorrhoeae.

Conclusion

Honokiol inhibits the NLRP3 inflammasome in N. gonorrhoeae-infected macrophages and holds great promise for further development as an active ingredient in the prevention and treatment of symptoms associated with gonorrhea.

Molecular regulation of NLRP3 inflammasome activation during parasitic infection

Parasitic diseases are a serious global health concern, causing many common and severe infections, including Chagas disease, leishmaniasis, and schistosomiasis. The NLRP3 inflammasome belongs to the NLR (nucleotide-binding domain leucine-rich-repeat-containing proteins) family, which are cytosolic proteins playing key roles in the detection of pathogens. NLRP3 inflammasomes are activated in immune responses to Plasmodium, Leishmania, Toxoplasma gondii, Entamoeba histolytica, Trypanosoma cruzi, and other parasites. The role of NLRP3 is not fully understood, but it is a crucial component of the innate immune response to parasitic infections and its functions as a sensor triggering the inflammatory response to the invasive parasites. However, while this response can limit the parasites' growth, it can also result in potentially catastrophic host pathology. This makes it essential to understand how NLRP3 interacts with parasites to initiate the inflammatory response. Plasmodium hemozoin, Leishmania glycoconjugate lipophosphoglycan (LPG) and E. histolytica Gal/GalNAc lectin can stimulate NLRP3 activation, while the dense granule protein 9 (GRA9) of T. gondii has been shown to suppress it. Several other parasitic products also have diverse effects on NLRP3 activation. Understanding the mechanism of NLRP3 interaction with these products will help to develop advanced therapeutic approaches to treat parasitic diseases. This review summarizes current knowledge of the NLRP3 inflammasome's action on the immune response to parasitic infections and aims to determine the mechanisms through which parasitic molecules either activate or inhibit its action.

Research on the Mechanism and Application of Acupuncture Therapy for Asthma: A Review

Asthma is a high-risk disease based on airway hyperresponsiveness (AHR). In this review, we found that there are many studies on clinical therapy for asthma that focus on the efficacy of acupuncture therapy and its mechanisms, including the functional connectivity of different brain regions, with the aid of functional magnetic resonance imaging (fMRI), immune responses/cell recognition (innate lymphoid cells and balance of Th1/Th2 and Treg/Th17), intracellular mechanism (autophagy, endoplasmic reticulum stress, and epigenetic alteration), and ligand-receptor/chemical signaling pathway (neurotransmitter, hormone, and small molecules). In this review, we summarized the clinical and experimental evidence for the mechanisms of acupuncture therapy in asthma to offer insights into drug discovery and clinical therapy. Given the paucity of clinical studies on the mechanisms of acupuncture in the treatment of asthma, this review notably included studies based on animal models to investigate the mechanisms of acupuncture in the treatment of asthma.

Andrographolide Attenuates NLRP3 Inflammasome Activation and Airway Inflammation in Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

The aim of this study is to uncover the anti-inflammatory propertity of andrographolide (AGP) in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and the underlying mechanisms related to the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome pathway.

Methods

An in vivo experiment was conducted on murine model of AECOPD through endotracheal atomization of elastase and lipopolysaccharide (LPS). Intraperitoneal AGP was administered four times. NLRP3 inflammasome pathway molecules were examined using real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. By using enzyme-linked immunosorbent assay (ELISA), we tested interleukin (IL)-1β levels in bronchoalveolar lavage fluid. An in vitro study was conducted to determine how AGP impacts the NLRP3 inflammasome in THP-1 derived macrophages. The levels of molecules involved in the pathway were measured. Furthermore, molecular docking analyses were carried out to investigate the interactions between AGP and pathway targets.

Results

In the in vivo study, NLRP3 inflammasome activation was observed in mice experiencing AECOPD. The administration of high-dose AGP demonstrated a mitigating effect on inflammatory cells infiltration in the lungs. Moreover, AGP administration effectively suppressed the expression of NLRP3, apoptosis associated speck-like protein that contains a CARD (PYCARD), cysteinyl aspartate-specific protease-1 (Caspase-1), IL-1β, and IL-18 at both the genetic and protein levels. In the in vitro experiment, IL-1β levels were significantly elevated in THP-1 derived macrophages with activated inflammasome compared to the control group. Furthermore, the downregulation of NLRP3, CASP1, and IL1B genes was observed upon the inhibition of NLRP3 expression through small interfering RNA (siRNA). AGP demonstrated inhibitory effects on the gene expression and protein levels of NLRP3, Caspase-1, and IL-1β. Additionally, molecular docking analysis confirmed that AGP exhibited a favorable binding affinity with all five targets of the pathway.

Conclusion

AGP effectively inhibited NLRP3 inflammasome activation and mitigated the inflammatory reaction of AECOPD both in animal models and in vitro experiments, highlighting the potential of AGP as a treatment for AECOPD with anti-inflammatory properties.

Research on the signaling pathways related to the intervention of traditional Chinese medicine in Parkinson's disease:A literature review

ETHNOPHARMACOLOGICAL RELEVANCE

Parkinson's disease (PD) is the most common progressive neurodegenerative disorder affecting more than 10 million people worldwide and is characterized by the progressive loss of Daergic (DA) neurons in the substantia nigra pars compacta. It has been reported that signaling pathways play a crucial role in the pathogenesis of PD, while the active ingredients of traditional Chinese medicine (TCM) have been found to possess a protective effect against PD. TCM has demonstrated significant potential in mitigating oxidative stress (OS), neuroinflammation, and apoptosis of DA neurons via the regulation of signaling pathways associated with PD.

AIM OF THE REVIEW

This study discussed and analyzed the signaling pathways involved in the occurrence and development of PD and the mechanism of active ingredients of TCM regulating PD via signaling pathways, with the aim of providing a basis for the development and clinical application of therapeutic strategies for TCM in PD.

MATERIALS AND METHODS

With "Parkinson's disease", "Idiopathic Parkinson's Disease", "Lewy Body Parkinson's Disease", "Parkinson's Disease, Idiopathic", "Parkinson Disease, Idiopathic", "Parkinson's disorders", "Parkinsonism syndrome", "Traditional Chinese medicine", "Chinese herbal medicine", "active ingredients", "medicinal plants" as the main keywords, PubMed, Web of Science and other online search engines were used for literature retrieval.

RESULTS

PD exhibits a close association with various signaling pathways, including but not limited to MAPKs, NF-κB, PI3K/Akt, Nrf2/ARE, Wnt/β-catenin, TLR/TRIF, NLRP3, Notch. The therapeutic potential of TCM lies in its ability to regulate these signaling pathways. In addition, the active ingredients of TCM have shown significant effects in improving OS, neuroinflammation, and DA neuron apoptosis in PD.

CONCLUSION

The active ingredients of TCM have unique advantages in regulating PD-related signaling pathways. It is suggested to combine network pharmacology and bioinformatics to study the specific targets of TCM. This not only provides a new way for the prevention and treatment of PD with the active ingredients of TCM, but also provides a scientific basis for the selection and development of TCM preparations.

USP5 negatively regulates the activation of NLRP3 inflammasomes and participates in the pathological and physiological processes of Sjogren's syndrome

OBJECTIVE

The current treatment and mechanism of Sjogren's syndrome (SS) are unclear. The purpose of the present study was to potential molecular mechanisms of SS.

METHODS

Immunohistochemical and immunofluorescence techniques reveal the targets and therapeutic approaches of SS.

RESULTS

We found through molecular biology techniques such as immunoblotting and immunoprecipitation that USP5 is a novel regulator of NLRP3 involvement in the pathological process of SS. USP5 was significantly downregulated in submandibular gland tissue of SS. Meanwhile, it was found that USP5 is a negative regulator of NLRP3 via ubiquitination NLRP3. In addition, SalvianolicacidB (SaB), a natural USP5 agonist, can alleviate ss by regulating the USP5/NLRP3 signaling pathway.

CONCLUSION

Therefore, this study provides a new mechanism for SS and also provides new therapeutic targets for treating SS.

Design, synthesis and biological evaluation of tanshinone IIA derivatives as NLRP3 inflammasome inhibitors

Natural product structures have long provided valuable pharmacophores and even candidates for drug discovery. Tanshinone scaffold showed moderately inhibitory activity in NLRP3 inflammasome/IL-1β pathway. Herein, we designed a series of derivatives on different regions of Tanshinone IIA (TNA) scaffold. The biological evaluation identified compound T10, a scaffold hybrid of TNA and salicylic acid, as a potent NLRP3 inflammasome inhibitor. Mechanistically, T10 inhibits the production of ROS and prevents NLRP3 inflammasome-dependent IL-1β production. In addition, treatment with T10 significantly attenuated inflammatory response in DSS-induced peritonitis. Our work describes a potential tanshinone-based derivative, which needs to be further structurally optimized as NLRP3 inflammasome inhibitors for treating inflammatory disorders.

Inhibition of SPARC signal by aerobic exercise to ameliorate atherosclerosis

BACKGROUND AND AIMS

Inflammation and atherosclerosis (AS) are closely associated to Secreted Protein Acidic and Rich in Cysteine (SPARC) and its related factors. This study attempted to define the role and the potential mechanism of SPARC and its related factors in ameliorating hyperlipidemia and AS by aerobic exercise intervention.

METHODS

The AS rat model was established with a high-fat diet plus vitamin D3 intraperitoneal injection. Treadmill exercises training (5 days/week at 14 m/min for 60 min/day) for 6 weeks was carried out for AS rat intervention method. Western blotting and qRT-PCR were used to analyze the mRNA and protein expression of SPARC and its related factors, respectively. H&E staining was applied to evaluate the morphological changes and inflammation damage. Von Kossa staining was used to measure the degree of vascular calcification. Fluorescence immunohistochemistry staining was used to detect the expression and distribution of SPARC signal molecules.

RESULTS

SPARC was highly expressed and co-localization with the smooth muscle marker α-SMC in the AS rat. And its downstream factors, NF-κB, Caspase-1, IL-1β and IL-18 were upregulated (P < 0.05 or P < 0.01), FNDC5 expression was downregulated in AS rat model. However, slight declined body weight, delayed AS progression, decreased hyperlipidemia and favorable morphology of skeletal muscle and blood vessels have been detected in AS rat with aerobic exercise intervention. Moreover, the expression of SPARC and its downstream factors were decreased (P < 0.05 or P < 0.01), while elevated the expression of FNDC5 (P < 0.01) was observed after aerobic exercise intervention.

CONCLUSIONS

This study suggested that aerobic exercise ameliorated hyperlipidemia and AS by effectively inhibiting SPARC signal, and vascular smooth muscle cells may contribute greatly to the protection of AS.

A Hybrid Approach Combining Shape-Based and Docking Methods to Identify Novel Potential P2X7 Antagonists from Natural Product Databases

P2X7 is an ATP-activated purinergic receptor implicated in pro-inflammatory responses. It is associated with the development of several diseases, including inflammatory and neurodegenerative conditions. Although several P2X7 receptor antagonists have recently been reported in the literature, none of them is approved for clinical use. However, the structure of the known antagonists can serve as a scaffold for discovering effective compounds in clinical therapy. This study aimed to propose an improved virtual screening methodology for the identification of novel potential P2X7 receptor antagonists from natural products through the combination of shape-based and docking approaches. First, a shape-based screening was performed based on the structure of JNJ-47965567, a P2X7 antagonist, using two natural product compound databases, MEGx (~5.8 × 103 compounds) and NATx (~32 × 103 compounds). Then, the compounds selected by the proposed shape-based model, with Shape-Tanimoto score values ranging between 0.624 and 0.799, were filtered for drug-like properties. Finally, the compounds that met the drug-like filter criteria were docked into the P2X7 allosteric binding site, using the docking programs GOLD and DockThor. The docking poses with the best score values were submitted to careful visual inspection of the P2X7 allosteric binding site. Based on our established visual inspection criteria, four compounds from the MEGx database and four from the NATx database were finally selected as potential P2X7 receptor antagonists. The selected compounds are structurally different from known P2X7 antagonists, have drug-like properties, and are predicted to interact with key P2X7 allosteric binding pocket residues, including F88, F92, F95, F103, M105, F108, Y295, Y298, and I310. Therefore, the combination of shape-based screening and docking approaches proposed in our study has proven useful in selecting potential novel P2X7 antagonist candidates from natural-product-derived compounds databases. This approach could also be useful for selecting potential inhibitors/antagonists of other receptors and/or biological targets.

SLC25A3 negatively regulates NLRP3 inflammasome activation by restricting the function of NLRP3

The NACHT, leucine-rich repeat, and pyrin domains-containing protein 3 (collectively known as NLRP3) inflammasome activation plays a critical role in innate immune and pathogenic microorganism infections. However, excessive activation of NLRP3 inflammasome will lead to cellular inflammation and tissue damage, and naturally it must be precisely controlled in the host. Here, we discovered that solute carrier family 25 member 3 (SLC25A3), a mitochondrial phosphate carrier protein, plays an important role in negatively regulating NLRP3 inflammasome activation. We found that SLC25A3 could interact with NLRP3, overexpression of SLC25A3 and knockdown of SLC25A3 could regulate NLRP3 inflammasome activation, and the interaction of NLRP3 and SLC25A3 is significantly boosted in the mitochondria when the NLRP3 inflammasome is activated. Our detailed investigation demonstrated that the interaction between NLRP3 and SLC25A3 disrupted the interaction of NLRP3-NEK7, promoted ubiquitination of NLRP3, and negatively regulated NLRP3 inflammasome activation. Thus, these findings uncovered a new regulatory mechanism of NLRP3 inflammasome activation, which provides a new perspective for the therapy of NLRP3 inflammasome-associated inflammatory diseases.

Discovery of novel biphenyl-sulfonamide analogues as NLRP3 inflammasome inhibitors

The aberrant activation of NLRP3 inflammasome has been observed in various human diseases. Targeting the NLRP3 protein with small molecule inhibitors shows immense potential as an effective strategy for disease intervention. Herein, a series of novel biphenyl-sulfonamide NLRP3 inflammasome inhibitors were designed and synthesized. The representative compound H28 was identified as potent and specific NLRP3 inflammasome inhibitor with IC50 values of 0.57 μM. Preliminary mechanistic studies have revealed that compound H28 exhibits direct binding to the NLRP3 protein (KD: 1.15 μM), effectively inhibiting the assembly and activation of the NLRP3 inflammasome. The results in a mouse acute peritonitis model revealed that H28 effectively inhibit the NLRP3 inflammasome pathway, demonstrating their anti-inflammatory properties. Our findings strongly support the further development of H28 as potential lead compound for treating NLRP3-related diseases.

The Impact of NLRP3 Inflammasome on Osteoblasts and Osteogenic Differentiation: A Literature Review

Osteoblasts (OBs), which are a crucial type of bone cells, derive from bone marrow mesenchymal stem cells (MSCs). Accumulating evidence suggests inflammatory cytokines can inhibit the differentiation and proliferation of OBs, as well as interfere with their ability to synthesize bone matrix, under inflammatory conditions. NLRP3 inflammasome is closely associated with cellular pyroptosis, which can lead to excessive release of pro-inflammatory cytokines, causing tissue damage and inflammatory responses, however, the comprehensive roles of NLRP3 inflammasome in OBs and their differentiation have not been fully elucidated, making targeting NLRP3 inflammasome approaches to treat diseases related to OBs uncertain. In this review, we provide a summary of NLRP3 inflammasome activation and its impact on OBs. We highlight the significant roles of NLRP3 inflammasome in regulating OBs differentiation and function. Furthermore, current available strategies to affect OBs function and osteogenic differentiation targeting NLRP3 inflammasome are listed and analyzed. Finally, through the prospective discussion, we seek to provide novel insights into the crucial role of NLRP3 inflammasome in diseases related to OBs and offer valuable information for devising treatment strategies.

Fine particulate matter aggravates smoking induced lung injury via NLRP3/caspase-1 pathway in COPD

BACKGROUND

Exposure to noxious particles, including cigarette smoke and fine particulate matter (PM2.5), is a risk factor for chronic obstructive pulmonary disease (COPD) and promotes inflammation and cell death in the lungs. We investigated the combined effects of cigarette smoking and PM2.5 exposure in patients with COPD, mice, and human bronchial epithelial cells.

METHODS

The relationship between PM2.5 exposure and clinical parameters was investigated in patients with COPD based on smoking status. Alveolar destruction, inflammatory cell infiltration, and pro-inflammatory cytokines were monitored in the smoking-exposed emphysema mouse model. To investigate the mechanisms, cell viability and death and pyroptosis-related changes in BEAS-2B cells were assessed following the exposure to cigarette smoke extract (CSE) and PM2.5.

RESULTS

High levels of ambient PM2.5 were more strongly associated with high Saint George's respiratory questionnaire specific for COPD (SGRQ-C) scores in currently smoking patients with COPD. Combined exposure to cigarette smoke and PM2.5 increased mean linear intercept and TUNEL-positive cells in lung tissue, which was associated with increased inflammatory cell infiltration and inflammatory cytokine release in mice. Exposure to a combination of CSE and PM2.5 reduced cell viability and upregulated NLRP3, caspase-1, IL-1β, and IL-18 transcription in BEAS-2B cells. NLRP3 silencing with siRNA reduced pyroptosis and restored cell viability.

CONCLUSIONS

PM2.5 aggravates smoking-induced airway inflammation and cell death via pyroptosis. Clinically, PM2.5 deteriorates quality of life and may worsen prognosis in currently smoking patients with COPD.

Detrimental Roles of Hypoxia-Inducible Factor-1α in Severe Hypoxic Brain Diseases

Hypoxia stabilizes hypoxia-inducible factors (HIFs), facilitating adaptation to hypoxic conditions. Appropriate hypoxia is pivotal for neurovascular regeneration and immune cell mobilization. However, in central nervous system (CNS) injury, prolonged and severe hypoxia harms the brain by triggering neurovascular inflammation, oxidative stress, glial activation, vascular damage, mitochondrial dysfunction, and cell death. Diminished hypoxia in the brain improves cognitive function in individuals with CNS injuries. This review discusses the current evidence regarding the contribution of severe hypoxia to CNS injuries, with an emphasis on HIF-1α-mediated pathways. During severe hypoxia in the CNS, HIF-1α facilitates inflammasome formation, mitochondrial dysfunction, and cell death. This review presents the molecular mechanisms by which HIF-1α is involved in the pathogenesis of CNS injuries, such as stroke, traumatic brain injury, and Alzheimer's disease. Deciphering the molecular mechanisms of HIF-1α will contribute to the development of therapeutic strategies for severe hypoxic brain diseases.

Inflammasome Molecular Insights in Autoimmune Diseases

Autoimmune diseases (AIDs) emerge due to an irregular immune response towards self- and non-self-antigens. Inflammation commonly accompanies these conditions, with inflammatory factors and inflammasomes playing pivotal roles in their progression. Key concepts in molecular biology, inflammation, and molecular mimicry are crucial to understanding AID development. Exposure to foreign antigens can cause inflammation, potentially leading to AIDs through molecular mimicry triggered by cross-reactive epitopes. Molecular mimicry emerges as a key mechanism by which infectious or chemical agents trigger autoimmunity. In certain susceptible individuals, autoreactive T or B cells may be activated by a foreign antigen due to resemblances between foreign and self-peptides. Chronic inflammation, typically driven by abnormal immune responses, is strongly associated with AID pathogenesis. Inflammasomes, which are vital cytosolic multiprotein complexes assembled in response to infections and stress, are crucial to activating inflammatory processes in macrophages. Chronic inflammation, characterized by prolonged tissue injury and repair cycles, can significantly damage tissues, thereby increasing the risk of AIDs. Inhibiting inflammasomes, particularly in autoinflammatory disorders, has garnered significant interest, with pharmaceutical advancements targeting cytokines and inflammasomes showing promise in AID management.

Nod-like receptor protein 3 inflammasome-mediated pyroptosis contributes to chronic NaAsO2 exposure-induced fibrotic changes and dysfunction in the liver of SD rats

The metalloid arsenic, known for its toxic properties, is widespread presence in the environment. Our previous research has confirmed that prolonged exposure to arsenic can lead to liver fibrosis injury in rats, while the precise pathogenic mechanism still requires further investigation. In the past few years, the Nod-like receptor protein 3 (NLRP3) inflammasome has been found to play a pivotal role in the occurrence and development of liver injury. In this study, we administered varying doses of sodium arsenite (NaAsO2) and 10 mg/kg.bw MCC950 (a particular tiny molecular inhibitor targeting NLRP3) to Sprague-Dawley (SD) rats for 36 weeks to explore the involvement of NLRP3 inflammasome in NaAsO2-induced liver injury. The findings suggested that prolonged exposure to NaAsO2 resulted in pyroptosis in liver tissue of SD rats, accompanied by the fibrotic injury, extracellular matrix (ECM) deposition and liver dysfunction. Moreover, long-term NaAsO2 exposure activated NLRP3 inflammasome, leading to the release of pro-inflammatory cytokines in liver tissue. After treatment with MCC950, the induction of NLRP3-mediated pyroptosis and release of pro-inflammatory cytokines were significantly attenuated, leading to a decrease in the severity of liver fibrosis and an improvement in liver function. To summarize, those results clearly indicate that hepatic fibrosis and liver dysfunction induced by NaAsO2 occur through the activation of NLRP3 inflammasome-mediated pyroptosis, shedding new light on the potential mechanisms underlying arsenic-induced liver damage.

The medulla oblongata shows a sex-specific inflammatory response to systemic neonatal lipopolysaccharide

Early life inflammation has been linked to long-term modulation of behavioural outcomes due to the central nervous system, but it is now becoming apparent it is also linked to dysfunction of visceral physiology. The medulla oblongata contains a number of nuclei critical for homeostasis, therefore we utilised the well-established model of neonatal lipopolysaccharide (LPS) exposure to examine the immediate and long-term impacts of systemic inflammation on the medulla oblongata. Wistar rats were injected with LPS or saline on postnatal days 3 and 5, with tissues collected on postnatal days 7 or 90 in order to assess expression of inflammatory mediators and microglial morphology in autonomic regions of the medulla oblongata. We observed a distinct sex-specific response of all measured inflammatory mediators at both ages, as well as significant neonatal sex differences in inflammatory mediators within saline groups. At both ages, microglial morphology had significant changes in branch length and soma size in a sex-specific manner in response to LPS exposure. This data not only highlights the strong sex-specific response of neonates to LPS administration, but also the significant life-long impact on the medulla oblongata and the potential altered control of visceral organs.

Myeloid-derived suppressor cells in cancer: therapeutic targets to overcome tumor immune evasion

Paradoxically, tumor development and progression can be inhibited and promoted by the immune system. After three stages of immune editing, namely, elimination, homeostasis and escape, tumor cells are no longer restricted by immune surveillance and thus develop into clinical tumors. The mechanisms of immune escape include abnormalities in antitumor-associated immune cells, selection for immune resistance to tumor cells, impaired transport of T cells, and the formation of an immunosuppressive tumor microenvironment. A population of distinct immature myeloid cells, myeloid-derived suppressor cells (MDSCs), mediate immune escape primarily by exerting immunosuppressive effects and participating in the constitution of an immunosuppressive microtumor environment. Clinical trials have found that the levels of MDSCs in the peripheral blood of cancer patients are strongly correlated with tumor stage, metastasis and prognosis. Moreover, animal experiments have confirmed that elimination of MDSCs inhibits tumor growth and metastasis to some extent. Therefore, MDSCs may become the target of immunotherapy for many cancers, and eliminating MDSCs can help improve the response rate to cancer treatment and patient survival. However, a clear definition of MDSCs and the specific mechanism involved in immune escape are lacking. In this paper, we review the role of the MDSCs population in tumor development and the mechanisms involved in immune escape in different tumor contexts. In addition, we discuss the use of these cells as targets for tumor immunotherapy. This review not only contributes to a systematic and comprehensive understanding of the essential role of MDSCs in immune system reactions against tumors but also provides information to guide the development of cancer therapies targeting MDSCs.

Berberine Effects in Pre-Fibrotic Stages of Non-Alcoholic Fatty Liver Disease-Clinical and Pre-Clinical Overview and Systematic Review of the Literature

Non-alcoholic fatty liver disease (NAFLD) is the predominant cause of chronic liver conditions, and its progression is marked by evolution to non-alcoholic steatosis, steatohepatitis, cirrhosis related to non-alcoholic steatohepatitis, and the potential occurrence of hepatocellular carcinoma. In our systematic review, we searched two databases, Medline (via Pubmed Central) and Scopus, from inception to 5 February 2024, and included 73 types of research (nine clinical studies and 64 pre-clinical studies) from 2854 published papers. Our extensive research highlights the impact of Berberine on NAFLD pathophysiology mechanisms, such as Adenosine Monophosphate-Activated Protein Kinase (AMPK), gut dysbiosis, peroxisome proliferator-activated receptor (PPAR), Sirtuins, and inflammasome. Studies involving human subjects showed a measurable reduction of liver fat in addition to improved profiles of serum lipids and hepatic enzymes. While current drugs for NAFLD treatment are either scarce or still in development or launch phases, Berberine presents a promising profile. However, improvements in its formulation are necessary to enhance the bioavailability of this natural substance.