The Roles of the NLRP3 Inflammasome in Neurodegenerative and Metabolic Diseases and in Relevant Advanced Therapeutic Interventions

NLRP3 Inflammasome: A central player in renal pathologies and nephropathy

The cytoplasmic oligomer NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome has been implicated in most inflammatory and autoimmune diseases. Here, we highlight the significance of NLRP3 in diverse renal disorders, demonstrating its activation in macrophages and non-immune tubular epithelial and mesangial cells in response to various stimuli. This activation leads to the release of pro-inflammatory cytokines, contributing to the development of acute kidney injury (AKI), chronic renal injury, or fibrosis. In AKI, NLRP3 inflammasome activation and pyroptotic renal tubular cell death is driven by contrast and chemotherapeutic agents, sepsis, and rhabdomyolysis. Nevertheless, inflammasome is provoked in disorders such as crystal and diabetic nephropathy, obesity-related renal fibrosis, lupus nephritis, and hypertension-induced renal damage that induce chronic kidney injury and/or fibrosis. The mechanisms by which the inflammatory NLRP3/ Apoptosis-associated Speck-like protein containing a Caspase recruitment domain (ASC)/caspase-1/interleukin (IL)-1β & IL-18 pathway can turn on renal fibrosis is also comprehended. This review further outlines the involvement of dopamine and its associated G protein-coupled receptors (GPCRs), including D1-like (D1, D5) and D2-like (D2-D4) subtypes, in regulating this inflammation-linked renal dysfunction pathway. Hence, we identify D-related receptors as promising targets for renal disease management by inhibiting the functionality of the NLRP3 inflammasome.

NLRP3 inflammasome: a key player in the pathogenesis of life-style disorders

Proinflammatory cytokines and chemokines play a crucial role in regulating the inflammatory response, which is essential for the proper functioning of our immune system. When infections or threats to the body's defense mechanisms are detected, the innate immune system takes the lead. However, an excessive inflammatory response can lead to the production of high concentrations of cytotoxic molecules, resulting in tissue damage. Inflammasomes are significant contributors to innate immunity, and one of the most extensively studied inflammasome complexes is NOD-like receptor 3 (NLRP3). NLRP3 has a wide range of recognition mechanisms that streamline immune activation and eliminate pathogens. These cytosolic multiprotein complexes are composed of effector, adaptor, and sensor proteins, which are crucial for identifying intracellular bacterial breakdown products and initiating an innate immune cascade. To understand the diverse behavior of NLRP3 activation and its significance in the development of lifestyle-related diseases, one must delve into the study of the immune response and apoptosis mediated by the release of proinflammatory cytokines. In this review, we briefly explore the immune response in the context of lifestyle associated disorders such as obesity, hyperlipidemia, diabetes, chronic respiratory disease, oral disease, and cardiovascular disease.

Intranasal delivery of mitochondria targeted neuroprotective compounds for traumatic brain injury: screening based on pharmacological and physiological properties

Targeting drugs to the mitochondrial level shows great promise for acute and chronic treatment of traumatic brain injury (TBI) in both military and civilian sectors. Perhaps the greatest obstacle to the successful delivery of drug therapies is the blood brain barrier (BBB). Intracerebroventricular and intraparenchymal routes may provide effective delivery of small and large molecule therapies for preclinical neuroprotection studies. However, clinically these delivery methods are invasive, and risk inadequate exposure to injured brain regions due to the rapid turnover of cerebral spinal fluid. The direct intranasal drug delivery approach to therapeutics holds great promise for the treatment of central nervous system (CNS) disorders, as this route is non-invasive, bypasses the BBB, enhances the bioavailability, facilitates drug dose reduction, and reduces adverse systemic effects. Using the intranasal method in animal models, researchers have successfully reduced stroke damage, reversed Alzheimer's neurodegeneration, reduced anxiety, improved memory, and delivered neurotrophic factors and neural stem cells to the brain. Based on literature spanning the past several decades, this review aims to highlight the advantages of intranasal administration over conventional routes for TBI, and other CNS disorders. More specifically, we have identified and compiled a list of most relevant mitochondria-targeted neuroprotective compounds for intranasal administration based on their mechanisms of action and pharmacological properties. Further, this review also discusses key considerations when selecting and testing future mitochondria-targeted drugs given intranasally for TBI.

Subchronic exposure to di-(2-ethylhexyl) phthalate (DEHP) elicits blood-brain barrier dysfunction and neuroinflammation in male C57BL/6J mice

BACKGROUND

Exposure to di-(2-ethylhexyl) phthalate (DEHP) can cause neurotoxicity but the mechanism is not clear. Blood brain barrier (BBB) is one of the most important tissues to protect the brain. However, whether DEHP can disrupt the BBB or not remains unclear. The objective of this study is to investigate the potential effects of subchronic DEHP exposure on BBB integrity and discuss the role of BBB in DEHP inducible neurotoxicity with an emphasis on neuroinflammatory responses. Male adult C57BL/6J mice were orally administered with vehicle or 200 or 750 mg/kg/day DEHP for 90 days. Subchronic exposure to high-dose DEHP increased water intake but decreased body weight and brain weight. The concentrations of DEHP metabolites increased in serum from all DEHP-exposed groups while increased in brain only from the high-dose group. DEHP induced neurobehavioural alterations and damaged hippocampal neurons. DEHP increased BBB permeability by Evans blue (EB) extravasation and decreased tight junction proteins (ZO-1, occludin, and claudin-5) while presenting a neuroinflammatory feature characterized by the upregulated inflammatory mediators TNF-α and the NLRP3/caspase-1/IL-1β inflammasome pathway. Our data provide new insights into neurotoxicity caused by subchronic DEHP exposure, which is probably involved in BBB dysfunction and neuroinflammatory responses.

Development and validation of a kidney renal clear cell carcinoma prognostic model relying on pyroptosis-related LncRNAs-A multidimensional comprehensive bioinformatics exploration

BACKGROUND

Renal cell carcinoma (RCC) is a malignant tumour that may develop in the kidney. RCC is one of the most common kinds of tumours of this sort, and its most common pathological subtype is kidney renal clear cell carcinoma (KIRC). However, the aetiology and pathogenesis of RCC still need to be clarified. Exploring the internal mechanism of RCC contributes to diagnosing and treating this disease. Pyroptosis is a critical process related to cell death. Recent research has shown that pyroptosis is a critical factor in the initiation and progression of tumour formation. Thus far, researchers have progressively uncovered evidence of the regulatory influence that long noncoding RNAs (lncRNAs) have on pyroptosis.

METHODS

In this work, a comprehensive bioinformatics approach was used to produce a predictive model according to pyroptosis-interrelated lncRNAs for the purpose of predicting the overall survival and molecular immune specialties of patients diagnosed with KIRC. This model was verified from multiple perspectives.

RESULTS

First, we discovered pyroptosis-associated lncRNAs in KIRC patients using the TCGA database and a Sankey diagram. Then, we developed and validated a KIRC patient risk model based on pyroptosis-related lncRNAs. We demonstrated the grouping power of PLnRM through PCA and used PLnRM to assess the tumour immune microenvironment and response to immunotherapy. Immunological and molecular traits of diverse PLnRM subgroups were evaluated, as were clinical KIRC patient characteristics and predictive risk models. On this basis, a predictive nomogram was developed and analyzed, and novel PLnRM candidate compounds were identified. Finally, we investigated possible medications used by KIRC patients.

CONCLUSIONS

The results demonstrate that the model generated has significant value for KIRC in clinical practice.

Dual Role of Mitogen-Activated Protein Kinase 8 Interacting Protein-1 in Inflammasome and Pancreatic β-Cell Function

Inflammasomes have been implicated in the pathogenesis of type 2 diabetes (T2D). However, their expression and functional importance in pancreatic β-cells remain largely unknown. Mitogen-activated protein kinase 8 interacting protein-1 (MAPK8IP1) is a scaffold protein that regulates JNK signaling and is involved in various cellular processes. The precise role of MAPK8IP1 in inflammasome activation in β-cells has not been defined. To address this gap in knowledge, we performed a set of bioinformatics, molecular, and functional experiments in human islets and INS-1 (832/13) cells. Using RNA-seq expression data, we mapped the expression pattern of proinflammatory and inflammasome-related genes (IRGs) in human pancreatic islets. Expression of MAPK8IP1 in human islets was found to correlate positively with key IRGs, including the NOD-like receptor (NLR) family pyrin domain containing 3 (NLRP3), Gasdermin D (GSDMD) and Apoptosis-associated speck-like protein containing a CARD (ASC), but correlate inversely with Nuclear factor kappa β1 (NF-κβ1), Caspase-1 (CASP-1), Interleukin-18 (IL-18), Interleukin-1β (IL-1β) and Interleukin 6 (IL-6). Ablation of Mapk8ip1 by siRNA in INS-1 cells down-regulated the basal expression levels of Nlrp3, NLR family CARD domain containing 4 (Nlrc4), NLR family CARD domain containing 1 (Nlrp1), Casp1, Gsdmd, Il-1β, Il-18, Il-6, Asc, and Nf-κβ1 at the mRNA and/or protein level and decreased palmitic acid (PA)-induced inflammasome activation. Furthermore, Mapk8ip1-silened cells substantially reduced reactive oxygen species (ROS) generation and apoptosis in palmitic acid-stressed INS-1 cells. Nonetheless, silencing of Mapk8ip1 failed to preserve β-cell function against inflammasome response. Taken together, these findings suggest that MAPK8IP1 is involved in regulating β-cells by multiple pathways.

In-vitro inhibition of NLRP3 inflammasome by 3,6-dihydroxyflavone (3,6-DHF): a therapeutic strategy for the treatment of chronic inflammatory and autoimmune diseases

Nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome complex has an important role in immune system and its abnormal activation is associated with the pathogenesis of various inflammatory and auto-immune diseases. The study reveals the anti-inflammatory effects of 3,6-dihydroxyflavone (3,6-DHF). Here, we aimed to determine the inhibitory effects of 3,6-DHF on NLRP3 inflammasome and its associated components, thereby determining the signaling pathways involved in the inhibition. Reactive oxygen species (ROS) and nitric oxide (NO) were quantified by chemiluminescence and Griess methods, respectively. Inflammatory cell model was induced in human leukemic monocytes (THP-1). mRNA levels were estimated through real-time RT-PCR, protein expressions were evaluated by protein slot blot and immunocytochemistry, MTT and alamar blue assays were employed for toxicity studies. The compound 3,6-DHF was found to be the potent inhibitor of NLRP3 inflammasome by targeting the molecules involve in its activation pathway. Anti-inflammatory effects were revealed by inhibition of ROS and NO, reduction in the transcription of caspase-1, ASC, IL-1β and TLR-4 was observed along with the marked inhibition of NLRP3, IL-18, NF-κB and pNF-κB at translational level. 3,6-DHF was non-toxic on normal human fibroblast (BJ) and THP-1 cells and, could be a potential therapeutic agent in NLRP3 inflammasome driven diseases.

A novel sorbicillinoid compound as a potent anti-inflammation agent through inducing NLRP3 protein degradation

BACKGROUND AND PURPOSE

Chronic inflammation is pathogenic and contributes to human diseases, causing a significant threat to public health. The NLR family pyrin domain-containing protein 3 (NLRP3) is the best-characterized factor regulating inflammation. Therefore, targeting NLRP3 has the potential to treat inflammatory diseases and improve human health.

EXPERIMENTAL APPROACH

Lipopolysaccharide was used to induce inflammation in cell cultures. Lipopolysaccharide/d-galactosamine and dextran sulfate sodium salt were used to induce acute liver inflammation and ulcerative colitis respectively in C57BL/6J mice. Western blotting, immunofluorescence, immunoprecipitation, quantitative PCR and enzyme-linked immunosorbent assay (ELISA) were used to evaluate the activation of the inflammatory response in cell cultures and in mice.

KEY RESULTS

JNUTS013, a novel sorbicillinoid compound recently synthesized by us, significantly inhibited inflammation both in cell cultures and in mouse models. Mechanistically, JNUTS013 induced proteasome-dependent degradation of NLRP3. Hence, it suppressed the formation of the NLRP3 inflammasome and the production of downstream inflammatory cytokines and chemokines. The inhibitory effect of JNUTS013 on NLRP3 protein expression was confirmed in mice. Importantly, JNUTS013 failed to ameliorate bowel inflammation in Nlrp3^-/- knockout mice, supporting NLRP3 as the biological target by which JNUTS013 inhibits inflammation. Further studies revealed critical chemical moieties of JNUTS013 required for inducing NLRP3 degradation.

CONCLUSION AND IMPLICATIONS

This study identifies a novel compound JNUTS013 that inhibits inflammation through inducing NLRP3 protein degradation in vitro and in vivo, which not only supports the development of JNUTS013 as an anti-inflammation agent but also creates a new way for the treatment of inflammation by chemically inducing NLRP3 degradation.

In Silico Structural and Functional Analyses of NLRP3 Inflammasomes to Provide Insights for Treating Neurodegenerative Diseases

Inflammasomes are cytoplasmic intracellular multiprotein complexes that control the innate immune system's activation of inflammation in response to derived chemicals. Recent advancements increased our molecular knowledge of activation of NLRP3 inflammasomes. Although several studies have been done to investigate the role of inflammasomes in innate immunity and other diseases, structural, functional, and evolutionary investigations are needed to further understand the clinical consequences of NLRP3 gene. The purpose of this study is to investigate the structural and functional impact of the NLRP3 protein by using a computational analysis to uncover putative protein sites involved in the stabilization of the protein-ligand complexes with inhibitors. This will allow for a deeper understanding of the molecular mechanism underlying these interactions. It was found that human NLRP3 gene coexpresses with PYCARD, NLRC4, CASP1, MAVS, and CTSB based on observed coexpression of homologs in other species. The NACHT, LRR, and PYD domain-containing protein 3 is a key player in innate immunity and inflammation as the sensor subunit of the NLRP3 inflammasome. The inflammasome polymeric complex, consisting of NLRP3, PYCARD, and CASP1, is formed in response to pathogens and other damage-associated signals (and possibly CASP4 and CASP5). Comprehensive structural and functional analyses of NLRP3 inflammasome components offer a fresh approach to the development of new treatments for a wide variety of human disorders.

The NLRP3 Inflammasome in Stress Response: Another Target for the Promiscuous Cannabidiol

Many psychiatric patients do not respond to conventional therapy. There is a vast effort to investigate possible mechanisms involved in treatment resistance, trying to provide better treatment options, and several data points toward a possible involvement of inflammatory mechanisms. Microglia, glial, and resident immune cells are involved in complex responses in the brain, orchestrating homeostatic functions, such as synaptic pruning and maintaining neuronal activity. In contrast, microglia play a major role in neuroinflammation, neurodegeneration, and cell death. Increasing evidence implicate microglia dysfunction in neuropsychiatric disorders. The mechanisms are still unclear, but one pathway in microglia has received increased attention in the last 8 years, i.e., the NLRP3 inflammasome pathway. Stress response and inflammation, including microglia activation, can be attenuated by Cannabidiol (CBD). CBD has antidepressant, anti-stress, antipsychotic, anti-inflammatory, and other properties. CBD effects are mediated by direct or indirect modulation of many receptors, enzymes, and other targets. This review will highlight some findings for neuroinflammation and microglia involvement in stress-related psychiatric disorders, particularly addressing the NLRP3 inflammasome pathway. Moreover, we will discuss evidence and mechanisms for CBD effects in psychiatric disorders and animal models and address its potential effects on stress response via neuroinflammation and NLRP3 inflammasome modulation.

Metformin inhibits cardiometabolic syndrome associated cognitive deficits in high fat diet rats

Objectives

Glucose intolerance and insulin resistance are hallmarks of metabolic syndrome and lead to Alzheimer's disease (AD). The purpose of this study is to elucidate the neuroprotective effect of metformin through insulin regulation with cardiometabolic and neurotransmitter metabolic enzyme regulation in high-fat, high-sucrose diet and streptozotocin (HFHS-STZ)-induced rats.

Methods

Male Wistar rats were treated with metformin (180 mg/kg and 360 mg/kg). STZ (35 mg/kg i.p.) injection was performed on the 14th day of 42 days of HFHS diet treatment. Brain neurotransmitter metabolic enzymes (acetylcholinesterase and monoamine oxidase) were determined along with sodium-potassium ATPase (Na+K+-ATPase). Plasma lipids and homeostasis model assessment of insulin resistance (HOMA-IR) was performed. Mean arterial blood pressure, heart rate and electrocardiogram (QT, QTc and RR intervals) were analysed with PowerLab.

Results

Metformin treatment significantly (p < 0.001) reduced the HOMA-IR index and decreased neurotransmitter metabolic enzymes such as AChE and MAO (p < 0.01 and p < 0.05). The lipid profile was significantly (p < 0.001) controlled with cardiometabolic functions.

Conclusions

Our investigation revealed that metformin has a remarkable role in regulating brain insulin, vascular system with monoaminergic metabolic enzymes and enhancing synaptic plasticity. Metformin may be a selective early therapeutic agent in metabolic syndrome associated with cognitive decline.

Identification of pyroptosis-related long non-coding RNAs with prognosis and therapy in lung squamous cell carcinoma

Pyroptosis is a type of programmed cell death with an intense inflammatory response. Previous studies have shown that pyroptosis plays an important role in the pathogenesis and progression of lung cancer. However, the prognostic value and drug targets of pyroptosis-related lncRNAs in lung squamous cell carcinoma (LSCC) have never been studied. In the present study, we identified 1468 pyroptosis-related lncRNAs in LSCC by performing Pearson correlation analysis between the pyroptosis-related genes and the lncRNAs from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. The whole set was divided into a training and a test set with a 1:1 ratio. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) analyses were conducted to establish an 11 multilncRNA signature in the three sets. The signature divided LSCC patients into the low-risk and the high-risk groups. Kaplan–Meier analysis and receiver operating characteristic (ROC) indicated that the prognostic signature had a promising predictive capability for LSCC patients. Besides, the association of microenvironment and immunotherapy response with signature was also analyzed. Moreover, 28 potential compounds targeting signature were screened as possible drugs to treat LSCC. Finally, a nomogram model was constructed to offer the quantitative prediction and net benefit for the prognosis of LSCC patients. In conclusion, the 11 pyroptosis-related lncRNAs and their signature may be promising prognostic factors and therapeutic targets for patients with LSCC.

The Role of the NLRP3 Inflammasome in HCC Carcinogenesis and Treatment: Harnessing Innate Immunity

Simple Summary

The Hepatocellular Carcinoma (HCC) remains a major concern for the public health. The pandemic of metabolic syndrome in the Western societies and the considerable amounts of viral hepatitis in the underdeveloped countries keep fueling s the development of HCC. The hepatotropic viruses evade the NLRP3 inflammasome in order to sustain the chronicity of infection leading to cirrhosis while in the established tumors the activation of NLRP3 promotes several pro-tumorigenic effects. That leads to substantial economic burden for the societies and alternative therapeutic targets should be investigated. Reviewing past and more recent literature it can be deduced that the NLRP3 inflammasome could be an ideal therapeutic effects and it should be studied in more depth.

Abstract

The HCC constitutes one of the most frequent cancers, with a non-decreasing trend in disease mortality despite advances in systemic therapy and surgery. This trend is fueled by the rise of an obesity wave which is prominent the Western populations and has reshaped the etiologic landscape of HCC. Interest in the nucleotide-binding domain leucine-rich repeat containing (NLR) family member NLRP3 has recently been revived since it would appear that, by generating inflammasomes, it participates in several physiologic processes and its dysfunction leads to disease. The NLRP3 inflammasome has been studied in depth, and its influence in HCC pathogenesis has been extensively documented during the past quinquennial. Since inflammation comprises a major regulator of carcinogenesis, it is of paramount importance an attempt to evaluate the contribution of the NLRP3 inflammasome to the generation and management of HCC. The aim of this review was to examine the literature in order to determine the impact of the NLRP3 inflammasome on, and present a hypothesis about its input in, HCC.

The crosstalk between NLRP3 inflammasome and gut microbiome in atherosclerosis

Atherosclerosis (AS) is chronic pathological process based on the inflammatory reaction associated with factors including vascular endothelial dysfunction, inflammation, and autoimmunity. Inflammasomes are known to be at the core of the inflammatory response. As a pattern recognition receptor of innate immunity, the NLRP3 inflammasome mediates the secretion of inflammatory factors by activating the Caspase-1, which is important for maintaining the immune system and regulating the gut microbiome, and participates in the occurrence and development of AS. The intestinal microecology is composed of a large number of complex structures of gut microbiota and its metabolites, which play an important role in AS. The gut microbiota and its metabolites regulate the activation of the NLRP3 inflammasome. Targeting the NLRP3 inflammasome and regulating intestinal microecology represent a new direction for the treatment of AS. This paper systematically reviews the interaction between the NLRP3 inflammasome and gut microbiome in AS, strategies for targeting the NLRP3 inflammasome and gut microbiome for the treatment of AS, and provides new ideas for the research and development of drugs for the treatment of AS.

The involvement of oxidative stress, neuronal lesions, neurotransmission impairment, and neuroinflammation in acrylamide-induced neurotoxicity in C57/BL6 mice

Acrylamide (ACR) is a typical environmental contaminant, presenting potential health hazards that have been attracting increasing attention. Its neurotoxicity is known to cause significant damage to health. However, the mechanisms of ACR-induced neurotoxicity require further clarification. This study uses a mouse model to explore how ACR-induced oxidative stress, neuronal lesions, neurotransmission impairment, and neuroinflammation mutually contribute to neurotoxicity. A distinct increase in the cellular reactive oxygen species (ROS) levels, malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OHdG) content and a significant decrease in the glutathione (GSH) content after ACR exposure were indicative of oxidative stress. Moreover, ACR caused neurological defects associated with gait abnormality and neuronal loss while suppressing the acetylcholine (ACh) and dopamine (DA) levels and increasing the protein expression of α-synuclein (α-syn), further inhibiting cholinergic and dopaminergic neuronal function. Additionally, ACR treatment caused an inflammatory response via nuclear factor-kappa B (NF-κB) activation and increased the protein expression of NOD-like receptor protein-3 (NLRP3), consequently activating the NLRP3 inflammasome constituents, including cysteinyl aspartate specific proteinase 1 (Caspase-1), apoptosis-associated speck-like protein containing CARD (ASC), N domain gasdermin D (N-GSDMD), interleukin-1β (IL-1β), and IL-18. The results revealed the underlying molecular mechanism of ACR-induced neurotoxicity via oxidative stress, neurotransmission impairment, and neuroinflammation-related signal cascade. This information will further improve the development of an alternative pathway strategy for investigating the risk posed by ACR. The hypothetical mechanism of ACR-induced neurotoxicity in vivo.

A Novel Defined Pyroptosis-Related Gene Signature for Predicting Prognosis and Treatment of Glioma

Pyroptosis, a form of programmed cell death, that plays a significant role in the occurrence and progression of tumors, has been frequently investigated recently. However, the prognostic significance and therapeutic value of pyroptosis in glioma remain undetermined. In this research, we revealed the relationship of pyroptosis-related genes to glioma by analyzing whole transcriptome data from The Cancer Genome Atlas (TCGA) dataset serving as the training set and the Chinese Glioma Genome Atlas (CGGA) dataset serving as the validation set. We identified two subgroups of glioma patients with disparate prognostic and clinical features by performing consensus clustering analysis on nineteen pyroptosis-related genes that were differentially expressed between glioma and normal brain tissues. We further derived a risk signature, using eleven pyroptosis-related genes, that was demonstrated to be an independent prognostic factor for glioma. Furthermore, we used Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) to implement functional analysis of our gene set, and the results were closely related to immune and inflammatory responses in accordance with the characteristics of pyroptosis. Moreover, Gene Set Enrichment Analysis (GSEA) results showed that that the high-risk group exhibited enriched characteristics of malignant tumors in accordance with its poor prognosis. Next, we analyzed different immune cell infiltration between the two risk groups using ssGSEA. Finally, CASP1 was identified as a core gene, so we subsequently selected an inhibitor targeting CASP1 and simulated molecular docking. In addition, the inhibitory effect of belnacasan on glioma was verified at the cellular level. In conclusion, pyroptosis-related genes are of great significance for performing prognostic stratification and developing treatment strategies for glioma.

Potential of nobiletin against Alzheimer's disease through inhibiting neuroinflammation

OBJECTIVE

This study aimed to explore the mechanism of Nobiletin attenuating Alzheimer's disease (AD) by inhibiting neuroinflammation.

METHODS

The expression of inflammatory cytokines and HMGB-1 in serum of AD patients were examined. Microglia (MGs) were treated with different doses of Nobiletin before LPS and Nigericin induction. Cell viability and apoptosis were determined by CCK-8 and TUNEL assays, respectively. APP/PS1 mice were gavaged with Nobiletin, and Morris water maze (MWM) was established to record swimming speed, escape latency, the number of platform crossings, and time spent in the platform quadrant. MGs activation in brain tissues was evaluated by immunofluorescence. The expression of pyroptosis-related proteins, inflammatory cytokines, and HMGB-1 was determined in the hippocampus and MGs.

RESULTS

The levels of inflammatory cytokines and HMGB-1 were high in serum of AD patients. Treatment with different concentrations of Nobiletin prominently enhanced cell viability and reduced apoptosis and the expression of inflammatory cytokine and pyroptosis-related proteins in LPS + Nigericin-induced MGs. Gavage of different doses of Nobiletin into APP/PS1 mice shortened the escape latency in mice, diminished MGs activation in brain tissues, and remarkably elevated the number of platform crossings and the time spent in the platform quadrant without obvious change in swimming speed, suggesting that Nobiletin improved the spatial learning and memory abilities in APP/PS1 mice. The expression of pyroptosis-related proteins, HMGB-1, and inflammatory cytokines was decreased dramatically by Nobiletin in the hippocampus of APP/PS1 mice.

CONCLUSIONS

Nobiletin can inhibit neuroinflammation by inhibiting HMGB-1, pyroptosis-related proteins, and inflammatory cytokines, thus mitigating AD.

A Highly Fluorescent Pyrene-Based Sensor for Selective Detection Of Fe3+ Ion in Aqueous Medium: Computational Investigations

In this work, we introduce a highly selective and sensitive fluorescent sensor based on pyrene derivative for Fe(III) ion sensing in DMSO/water media. 2-(pyrene-2-yl)-1-(pyrene-2-ylmethyl)-1H-benzo[d]imidazole (PEBD) receptor was synthesized via simple condensation reaction and confirmed by spectroscopic techniques. The receptor exhibits fluorescence quenching in the presence of Fe(III) ions at 440 nm. ESI-MS and Job's method were used to confirm the 1:1 molar binding ratio of the receptor PEBD to Fe(III) ions. Using the Benesi-Hildebrand equation the binding constant value was determined as 8.485 × 10³ M^-1. Furthermore, the limit of detection (LOD, 3σ/K) value was found to be 1.81 µM in DMSO/water (95/5, v/v) media. According to the Environmental Protection Agency (EPA) of the United States, it is lower than the acceptable value of Fe³⁺ in drinking water (0.3 mg/L). The presence of 14 other metal ions such Co²⁺, Cr³⁺, Cu²⁺, Fe²⁺, Hg²⁺, Pb²⁺, K⁺, Ni²⁺, Mg²⁺, Cd²⁺, Ca²⁺, Mn²⁺, Al³⁺, and Zn²⁺ did not interfere with the detection of Fe(III) ions. The fluorescence life-time of the receptor PEBD with and without Fe³⁺ ion was found to be 1.097 × 10^-9 s and 0.9202 × 10^-9 s respectively. Similarly, the quantum yield of the receptor PEBD with Fe³⁺ and without Fe³⁺ ion was calculated, and found as 0.05 and 0.25 respectively. Computational studies of the receptor PEBD were carried out with density functional theory (DFT) using B3LYP/ 6-311G (d, p), LANL2DZ level of theory.

The Road to Personalized Medicine in Alzheimer’s Disease: The Use of Artificial Intelligence

Dementia remains an extremely prevalent syndrome among older people and represents a major cause of disability and dependency. Alzheimer’s disease (AD) accounts for the majority of dementia cases and stands as the most common neurodegenerative disease. Since age is the major risk factor for AD, the increase in lifespan not only represents a rise in the prevalence but also adds complexity to the diagnosis. Moreover, the lack of disease-modifying therapies highlights another constraint. A shift from a curative to a preventive approach is imminent and we are moving towards the application of personalized medicine where we can shape the best clinical intervention for an individual patient at a given point. This new step in medicine requires the most recent tools and analysis of enormous amounts of data where the application of artificial intelligence (AI) plays a critical role on the depiction of disease–patient dynamics, crucial in reaching early/optimal diagnosis, monitoring and intervention. Predictive models and algorithms are the key elements in this innovative field. In this review, we present an overview of relevant topics regarding the application of AI in AD, detailing the algorithms and their applications in the fields of drug discovery, and biomarkers.

Inflammasome regulation by adaptor isoforms, ASC and ASCb, via differential self-assembly

ASC is an essential adaptor of the inflammasome, a micrometer-size multiprotein complex that processes proinflammatory cytokines. Inflammasome formation depends on ASC self-association into large assemblies via homotypic interactions of its two death domains, PYD and CARD. ASCb, an alternative splicing isoform, activates the inflammasome to a lesser extent compared with ASC. Thus, it has been postulated that adaptor isoforms differentially regulate inflammasome function. At the amino acid level, ASC and ASCb differ only in the length of the linker connecting the two death domains. To understand inflammasome regulation at the molecular level, we investigated the self-association properties of ASC and ASCb using real-time NMR, dynamic light scattering (DLS), size-exclusion chromatography, and transmission electron microscopy (TEM). The NMR data indicate that ASC self-association is faster than that of ASCb; a kinetic model for this oligomerization results in differing values for both the reaction order and the rate constants. Furthermore, DLS analysis indicates that ASC self-associates into more compact macrostructures compared with ASCb. Finally, TEM data show that ASCb has a reduced tendency to form densely packed filaments relative to ASC. Overall, these differences can only be explained by an effect of the linker length, as the NMR results show structural equivalence of the PYD and CARD in both proteins. The effect of linker length was corroborated by molecular docking with the procaspase-1 CARD domain. Altogether, our results indicate that ASC’s faster and less polydisperse polymerization is more efficient, plausibly explaining inflammasome activation differences by ASC isoforms at the molecular level.

1,2,4-Trimethoxybenzene selectively inhibits NLRP3 inflammasome activation and attenuates experimental autoimmune encephalomyelitis

NOD-like receptor (NLR) family pyrin domain-containing-3 (NLRP3) inflammasome is implicated in inflammation-associated diseases such as multiple sclerosis, Parkinson's disease, and stroke. Targeting the NLRP3 inflammasome is beneficial to these diseases, but few NLRP3 inflammasome-selective inhibitors are identified to date. Essential oils (EOs) are liquid mixtures of volatile and low molecular-weight organic compounds extracted from aromatic plants, which show various pharmacological activities, including antibacterial, antifungal, antiviral, antioxidant, and anti-inflammatory properties. In this study we screened active ingredients from essential oils, and identified 1,2,4-trimethoxybenzene (1,2,4-TTB) as a selective NLRP3 inflammasome inhibitor. We showed that 1,2,4-TTB (1 mM) markedly suppressed nigericin- or ATP-induced NLRP3 inflammasome activation, thus decreased caspase-1 activation and IL-1β secretion in immortalized murine bone marrow-derived macrophages (iBMDMs) and in primary mouse microglia. Moreover, 1,2,4-TTB specifically inhibited the activation of NLRP3 inflammasome without affecting absent in melanoma 2 (AIM2) inflammasome activation. We further demonstrated that 1,2,4-TTB inhibited oligomerization of the apoptosis-associated speck-like protein containing a CARD (ASC) and protein-protein interaction between NLRP3 and ASC, thus blocking NLRP3 inflammasome assembly in iBMDMs and in primary mouse macrophages. In mice with experimental autoimmune encephalomyelitis (EAE), administration of 1,2,4-TTB (200 mg · kg^-1 · d^-1, i.g. for 17 days) significantly ameliorated EAE progression and demyelination. In conclusion, our results demonstrate that 1,2,4-TTB is an NLRP3 inflammasome inhibitor and attenuates the clinical symptom and inflammation of EAE, suggesting that 1,2,4-TTB is a potential candidate compound for treating NLRP3 inflammasome-driven diseases, such as multiple sclerosis.

S1P/S1P2 Signaling Axis Regulates Both NLRP3 Upregulation and NLRP3 Inflammasome Activation in Macrophages Primed with Lipopolysaccharide

The activation of NLRP3 inflammasome is a key factor for various inflammatory diseases. Here, we provide experimental evidence supporting the regulatory role of sphingosine-1-phosphate (S1P) in NLRP3 inflammasome activation in mouse bone-marrow-derived macrophages (BMDMs), along with the S1P receptor subtype involved and underlying regulatory mechanisms. During the priming stage, S1P induced NLRP3 upregulation in BMDMs only when primed with lipopolysaccharide (LPS). In this event, S1P₂, but not S1P₁, was involved based on the attenuated NLRP3 upregulation with JTE013 (S1P₂ antagonist) or S1P₂ knockdown. During the activation stage, S1P induced NLRP3 inflammasome activation in LPS-primed BMDMs via caspase-1 activation, interleukin 1β maturation, apoptosis-associated speck-like protein containing a CARD (ASC) speck formation, and IL-1β secretion. Such NLRP3 inflammasome activation was blocked by either pharmacological inhibition or genetic knockdown of S1P₂. NF-κB, PI3K/Akt, and ERK1/2 were identified as effector pathways underlying S1P/S1P₂ signaling in the regulation of NLRP3 upregulation in LPS-primed BMDMs. Further, reactive oxygen species (ROS) production was dependent on the S1P/S1P₂ signaling axis in these cells, and the ROS generated regulate NLRP3 inflammasome activation, but not NLRP3 priming. Collectively, our findings suggest that S1P promotes NLRP3 upregulation and NLRP3 inflammasome activation in LPS-primed BMDMs via S1P₂ and subsequent effector pathways.

Pyroptosis in the Retinal Neurovascular Unit: New Insights Into Diabetic Retinopathy

Diabetic retinopathy (DR) is prevalent among people with long-term diabetes mellitus (DM) and remains the leading cause of visual impairment in working-aged people. DR is related to chronic low-level inflammatory reactions. Pyroptosis is an emerging type of inflammatory cell death mediated by gasdermin D (GSDMD), NOD-like receptors and inflammatory caspases that promote interleukin-1β (IL-1β) and IL-18 release. In addition, the retinal neurovascular unit (NVU) is the functional basis of the retina. Recent studies have shown that pyroptosis may participate in the destruction of retinal NVU cells in simulated hyperglycemic DR environments. In this review, we will clarify the importance of pyroptosis in the retinal NVU during the development of DR.

Reversing Postcardiopulmonary Bypass Associated Cognitive Dysfunction Using k-Opioid Receptor Agonists to Regulate Microglial Polarization via the NLRP3/Caspase-1 Pathway

Cardiopulmonary bypass (CPB) is mainly used during cardiac surgeries that treat ischemic, valvular, or congenital heart disease and aortic dissections. The disorders of central nervous system (CNS) that occur after cardiopulmonary bypass are attracting considerable interest. Postoperative neurocognitive disorders (PND) have been reported as the leading cause of patients' disability and death following CPB. The k-opioid receptor (KOR) agonists (U50488H) have been suggested to be vital in the treatment of surgically induced CNS neuroinflammatory responses. In this article, the transitions between the M1 and M2 microglial polarization state phenotypes were hypothesized to significantly affect the regulatory mechanisms of KOR agonists on postcardiopulmonary bypass (post-CPB) neuroinflammation. We investigated the effects of U50488H on neuroinflammation and microglia polarization in rats exposed to CPB and explored the method of the NLRP3/caspase-1 pathway. Thirty SD rats were randomly divided into three groups: sham operation group, cardiopulmonary bypass model group, and CPB+ k-opioid receptor agonist (U50488H) group, with ten rats in each group. The Morris water maze was used to evaluate the changes in the cognitive function of CPB rats. Hematoxylin and eosin (HE) staining and TUNEL were performed to assess the rats' hippocampal damage. Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect changes in brain injury markers and inflammatory factors. Furthermore, immunofluorescence was used to observe the expression of microglia polarization and NLRP3 followed by Western blots to detect the expression of the NLRP3/caspase-1 pathway and microglia polarization-related proteins. Rat microglia were cultured in vitro, with LPS stimulation, and treated with U50488H and a caspase-1 antagonist to evaluate the effects and mechanism of action of U50488H. KORs alleviated hippocampal damage caused by CPB and improved PND. CPB activated the NLRP3 inflammasome and upregulated pro-caspase-1 expression which promoted the expression of pro-IL-lβ and pro-IL-18 and resulted in increased inflammation. However, KORs also inhibited NLRP3 and transformed microglia from the M1 to the M2 state. Caspase-1 inhibitor treatment reduced the microglial polarization induced by KORs. The κ-opioid receptor agonists inhibited the inflammation mediated by microglia and improved PND through the NLRP3/caspase-1 signaling pathway.

Etiological Value of Sterile Inflammation in Preeclampsia: Is It a Non-Infectious Pregnancy Complication?

Understanding of sterile inflammation and its associated biological triggers and diseases is still at the elementary stage. This becomes more warranted in cases where infections are not associated with the pathology. Detrimental effects of bacterial and viral infections on the immune responses at the maternal-fetal interface as well as pregnancy outcomes have been well documented. However, an infection-induced etiology is not thought to be a major contributing component to severe pregnancy complications such as preeclampsia (PE) and gestational diabetes. How is then an inflammatory signal thought to be associated with these pregnancy complications? It is not clear what type of inflammation is involved in the onset of PE-like features. We opine that sterile inflammation regulated by the inflammasome-gasdermins-caspase-1 axis is a contributory factor to the onset of PE. We hypothesize that increased production and release of damage-associated molecular patterns (DAMPs) or Alarmins such as high-mobility group box1 (HMGB1), cell-free fetal DNA, uric acid, the NOD-like receptor pyrin-containing receptor 3 (NLRP3) inflammasome, IL-1β and IL-18 occur in the PE placenta. Some of these molecules have already been observed in the placenta from women with PE. Mechanistically, emerging evidence has demonstrated that excessive placental endoplasmic reticulum (ER) stress, impaired autophagy and gasdermine D (GSDMD)-mediated intrinsic pyroptosis are key events that contribute to systemic sterile inflammation in patients with PE, especially early-onset PE (e-PE). In this review, we highlight the advances on the roles of sterile inflammation and inflammatory signaling cascades involving ER stress, autophagy deficiency and pyroptosis in PE pathophysiology. Deciphering the mechanisms underlying these inflammatory pathways may provide potential diagnostic biomarkers and facilitate the development of therapeutic strategies to treat this devastating disease.

Study on caspase-1 and partial cognitive impairment in the comorbidity of type 2 diabetes and MDD

BACKGROUND

Major depressive disorder (MDD) is a major mood disorder characterized by chronic low mood with cognitive impairment. Diabetes mellitus is a group of chronic metabolic diseases, Type 2 diabetes (T2DM) will obviously increase the risk of dementia. People with the the comorbidity of T2DM and MDD have a higher risk of dementia. In this study, we aim to investigate partial cognitive impairment in the comorbidity of T2DM and MDD, and to determine the relationship between changes in caspase-1 expression and cognitive impairment. To further explore the role of caspase-1 in the partial cognitive impairment in the comorbidity of T2DM and MDD.

METHODS

A total of 162 people were enrolled, there were 49 patients in the comorbidity of T2DM and MDD group, 54 patients in the MDD group, and 45 patients in the T2DM group. Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess the cognitive function of these three groups. Serum level of caspase-1 was determined by ELISA, and the level of caspase-1, as well as partial cognitive function, was compared in the three groups.

RESULTS

The cognitive impairment of patients of the comorbidity of T2DM and MDD group was worse than the MDD group and the T2DM group, and the immediate memory, attention, and delayed memory in the comorbidity of T2DM and MDD group were lower than those in the other two groups, and the caspase-1 of the comorbidity of T2DM and MDD is higher than the caspase-1 of the MDD group, all the difference was statistically significant (P < 0.05). Caspase-1 protein was negatively correlated with immediate memory, attention, and delayed memory (r=-0.332, r=-0.182, r=-0.313, P<0.05).

CONCLUSION

The cognitive impairment of patients of the comorbidity of T2DM and MDD group was worse than the MDD group and the T2DM group, and the immediate memory, attention, and delayed memory in the comorbidity of T2DM and MDD group were lower than those in the other two groups. The differences of the caspase-1 in the comorbidity of T2DM and MDD group, the MDD group and the T2DM group were significant, the level of the caspase-1 is higher than the other two groups, the cognitive impairment of three groups is associated with caspase-1, suggesting caspase-1 protein may be involved in the cognitive impairment aggravation mechanism of the comorbidity of T2DM and MDD group.

Long Non-coding RNA MSTRG.24008.1 Regulates the Regeneration of the Sciatic Nerve via the miR-331-3p-NLRP3/MAL Axis

Peripheral nerve injury (PNI) is a common clinical problem, which can cause severe disability and dramatically affect a patient’s quality of life. Neural regeneration after PNI is a complex biological process that involves a variety of signaling pathways and genes. Emerging studies demonstrated that long non-coding RNAs (lncRNAs) were abnormally expressed after PNI and played pivotal roles in peripheral nerve regeneration. Based on the rat sciatic nerve injury model, we found that the expression levels of several lncRNAs were increased significantly in the sciatic nerve after injury. Software prediction prompted us to focus on one up-regulated lncRNA, MSTRG.24008.1. Dual-luciferase reporter assay, RNA pull-down assay and RNA interference approach verified that MSTRG.24008.1 regulated neuroregeneration via the miR-331-3p/nucleotide-binding oligomerization domain-like pyrin domain containing 3 (NLRP3)/myelin and lymphocyte protein (MAL) axis in vitro. Subsequently, we performed gastrocnemius muscle gravity and sciatic functional index experiments to evaluate the recovery of injured sciatic nerves after MSTRG.24008.1 siRNA interference in vivo. In conclusion, knockdown of MSTRG.24008.1 promotes the regeneration of the sciatic nerve via the miR-331-3p/NLRP3/MAL axis, which may provide a new strategy to evaluate and repair injured peripheral nerves clinically.

Molecular prospect of type-2 diabetes: Nanotechnology based diagnostics and therapeutic intervention

About ninety percent of all diabetic conditions account for T2D caused due to abnormal insulin secretion/ action or increased hepatic glucose production. Factors that contribute towards the aetiology of T2D could be well explained through biochemical, molecular, and cellular aspects. In this review, we attempt to explain the recent evolving molecular and cellular advancement associated with T2D pathophysiology. Current progress fabricated in T2D research concerning intracellular signaling cascade, inflammasome, autophagy, genetic and epigenetics changes is discretely explained in simple terms. Present available anti-diabetic therapeutic strategies commercialized and their limitations which are needed to be acknowledged are addressed in the current review. In particular, the pre-eminence of nanotechnology-based approaches to nullify the inadequacy of conventional anti-diabetic therapeutics and heterogeneous nanoparticulated systems exploited in diabetic researches are also discretely mentioned and are also listed in a tabular format in the review. Additionally, as a future prospect of nanotechnology, the review presents several strategic hypotheses to ameliorate the austerity of T2D by an engineered smart targeted nano-delivery system. In detail, an effort has been made to hypothesize novel nanotechnological based therapeutic strategies, which exploits previously described inflammasome, autophagic target points. Utilizing graphical description it is explained how a smart targeted nano-delivery system could promote β-cell growth and development by inducing the Wnt signaling pathway (inhibiting Gsk3β), inhibiting inflammasome (inhibiting NLRP3), and activating autophagic target points (protecting Atg3/Atg7 complex from oxidative stress) thereby might ameliorate the severity of T2D. Additionally, several targeting molecules associated with autophagic and epigenetic factors are also highlighted, which can be exploited in future diabetic research.

An update on the regulatory mechanisms of NLRP3 inflammasome activation

The NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome is a multiprotein complex involved in the release of mature interleukin-1β and triggering of pyroptosis, which is of paramount importance in a variety of physiological and pathological conditions. Over the past decade, considerable advances have been made in elucidating the molecular mechanisms underlying the priming/licensing (Signal 1) and assembly (Signal 2) involved in NLRP3 inflammasome activation. Recently, a number of studies have indicated that the priming/licensing step is regulated by complicated mechanisms at both the transcriptional and posttranslational levels. In this review, we discuss the current understanding of the mechanistic details of NLRP3 inflammasome activation with a particular emphasis on protein-protein interactions, posttranslational modifications, and spatiotemporal regulation of the NLRP3 inflammasome machinery. We also present a detailed summary of multiple positive and/or negative regulatory pathways providing upstream signals that culminate in NLRP3 inflammasome complex assembly. A better understanding of the molecular mechanisms underlying NLRP3 inflammasome activation will provide opportunities for the development of methods for the prevention and treatment of NLRP3 inflammasome-related diseases.

Role of Thioredoxin-Interacting Protein in Diseases and Its Therapeutic Outlook

Thioredoxin-interacting protein (TXNIP), widely known as thioredoxin-binding protein 2 (TBP2), is a major binding mediator in the thioredoxin (TXN) antioxidant system, which involves a reduction-oxidation (redox) signaling complex and is pivotal for the pathophysiology of some diseases. TXNIP increases reactive oxygen species production and oxidative stress and thereby contributes to apoptosis. Recent studies indicate an evolving role of TXNIP in the pathogenesis of complex diseases such as metabolic disorders, neurological disorders, and inflammatory illnesses. In addition, TXNIP has gained significant attention due to its wide range of functions in energy metabolism, insulin sensitivity, improved insulin secretion, and also in the regulation of glucose and tumor suppressor activities in various cancers. This review aims to highlight the roles of TXNIP in the field of diabetology, neurodegenerative diseases, and inflammation. TXNIP is found to be a promising novel therapeutic target in the current review, not only in the aforementioned diseases but also in prolonged microvascular and macrovascular diseases. Therefore, TXNIP inhibitors hold promise for preventing the growing incidence of complications in relevant diseases.

The involvement of NLRP3 inflammasome in the treatment of neurodegenerative diseases

In an ageing society, neurodegenerative diseases have attracted attention because of their high incidence worldwide. Despite extensive research, there is a lack of conclusive insights into the pathogenesis of neurodegenerative diseases, which limit the strategies for symptomatic treatment. Therefore, better elucidation of the molecular mechanisms involved in neurodegenerative diseases can provide an important theoretical basis for the discovery of new and effective prevention and treatment methods. The innate immune system is activated during the ageing process and in response to neurodegenerative diseases. Inflammasomes are multiprotein complexes that play an important role in the activation of the innate immune system. They mediate inflammatory reactions and pyroptosis, which are closely involved in neurodegeneration. There are different types of inflammasomes, although the nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasome is the most common inflammasome; NLRP3 plays an important role in the pathogenesis of neurodegenerative diseases. In this review, we will discuss the mechanisms that are involved in the activation of the NLRP3 inflammasome and its crucial role in the pathology of neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and multiple sclerosis. We will also review various treatments that target the NLRP3 inflammasome pathway and alleviate neuroinflammation. Finally, we will summarize the novel treatment strategies for neurodegenerative disorders.

Induction of Pyroptosis: A Promising Strategy for Cancer Treatment

Pyroptosis, a lytic pro-inflammatory type of programmed cell death, has been widely studied in diverse inflammatory disease models. Membrane perforation and cell swelling induced by cleaved gasdermin family members is the main characteristic of pyroptosis. Emerging evidence has revealed a complicated relationship between pyroptosis and cancer. On the one hand, as inflammatory cell death, pyroptosis provides a comfortable environment for tumor proliferation. On the other hand, excessive activation of pyroptosis can inhibit the development of tumor cells. In this review, we first summarized the latest progress about the molecular mechanism of pyroptosis. Then, members from gasdermin family, the central molecules of pyroptosis which formed pores on the cell membrane, were highlighted. In the second part of this review, we summarized drugs that induced pyroptosis in different tumors and their concrete mechanisms based on recent literature reports. In the final section, we discussed several hotspots in pyroptosis and cancer therapy, which will point out the direction of sequent research. In brief, inducing pyroptosis in cancer cells is a promising strategy for cancer therapy.

Sirtuin 3 deficiency exacerbates diabetic cardiomyopathy via necroptosis enhancement and NLRP3 activation

Sirtuin 3 (SIRT3) is a potential therapeutic target for cardiovascular, metabolic, and other aging-related diseases. In this study, we investigated the role of SIRT3 in diabetic cardiomyopathy (DCM). Mice were injected with streptozotocin (STZ, 60 mg/kg, ip) to induce diabetes mellitus. Our proteomics analysis revealed that SIRT3 expression in the myocardium of diabetic mice was lower than that of control mice, as subsequently confirmed by real-time PCR and Western blotting. To explore the role of SIRT3 in DCM, SIRT3-knockout mice and 129S1/SvImJ wild-type mice were injected with STZ. We found that diabetic mice with SIRT3 deficiency exhibited aggravated cardiac dysfunction, increased lactate dehydrogenase (LDH) level in the serum, decreased adenosine triphosphate (ATP) level in the myocardium, exacerbated myocardial injury, and promoted myocardial reactive oxygen species (ROS) accumulation. Neonatal rat cardiomyocytes were transfected with SIRT3 siRNA, then exposed to high glucose (HG, 25.5 mM). We found that downregulation of SIRT3 further increased LDH release, decreased ATP level, suppressed the mitochondrial membrane potential, and elevated oxidative stress in HG-treated cardiomyocytes. SIRT3 deficiency further raised expression of necroptosis-related proteins including receptor-interacting protein kinase 1 (RIPK1), RIPK3, and cleaved caspase 3, and upregulated the expression of inflammation-related proteins including NLR family pyrin domain-containing protein 3 (NLRP3), caspase 1 p20, and interleukin-1β both in vitro and in vivo. Collectively, SIRT3 deficiency aggravated hyperglycemia-induced mitochondrial damage, increased ROS accumulation, promoted necroptosis, possibly activated the NLRP3 inflammasome, and ultimately exacerbated DCM in the mice. These results suggest that SIRT3 can be a molecular intervention target for the prevention and treatment of DCM.

Elevated levels of NLRP3 inflammasome in serum of patients with chronic inflammatory demyelinating polyradiculoneuropathy are associated with disease severity

This study aims to compare the levels of NLRP3 inflammasome and its related cytokines (IL-1β, IL-6, and IL-17), in serum and cerebrospinal fluid (CSF) of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), non-inflammatory chronic polyneuropathy, and functional neurological disorders. The results showed elevated NLRP3 inflammasome, IL-1β, IL-6, and IL-17 levels in serum but not in CSF of CIDP, compared to the other groups. Moreover, there was a positive correlation between NLRP3 inflammasome level and each cytokine. We also found a positive correlation between serum NLRP3 inflammasome level and disease severity in CIDP patients. Taken together, these results suggested that NLRP3 inflammasome could act as a potential biomarker to diagnose CIDP and assess the severity of the disease.

Schisandrin Inhibits NLRP1 Inflammasome-Mediated Neuronal Pyroptosis in Mouse Models of Alzheimer's Disease

BACKGROUND

In recent years, schisandrin (SCH) was proved to improve Alzheimer's Disease (AD). The aim of our study is to explore the effect of SCH on neuronal pyroptosis in the disease.

METHODS

A Morris water maze test was performed to evaluate the spatial learning and memory retention of AD mouse. ELISA was fulfilled to examine the concentration of Aβ, IL-1β, and IL-18. Western blot was performed to detect the expression of apoptosis- and pyroptosis-related proteins. Besides, the neuronal apoptosis rate was examined using TUNEL assay. Immunohistochemistry was utilized to detect the activation of NLRP1 inflammasome.

RESULTS

Here, AD mice have serious cognitive impairment. Meantime, Aβ was highly expressed in the brains of AD mice. SCH could effectively rescue the cognitive impairment in AD mice and impede the production of Aβ. Subsequently, we further demonstrated that SCH repressed neuronal apoptosis, pyroptosis-related proteins expression, and the activation of NLRP1 inflammasome in the hippocampus of AD mice. We also proved that Aβ induced neuronal apoptosis and pyroptosis in vitro. However, the effects of Aβ on neuronal apoptosis and pyroptosis were partly reversed by SCH treatment.

CONCLUSION

Overall, our data indicated that SCH improved cognitive impairment in AD mice through inhibition of NLRP1 inflammasome-mediated neuronal pyroptosis and neuronal apoptosis. Our works provided new evidence to support SCH acting as a potential treatment method in AD.

Same pollution sources for climate change might be hyperactivating the NLRP3 inflammasome and exacerbating neuroinflammation and SARS mortality

We have reviewed a considerable amount of recent scientific papers relating inflammation caused by air pollution with chronic and severe medical conditions. Furthermore, there are evidences relating organ inflammation caused by not only outdoor long-term but also short-term inhaled radioisotopes contained in high polluted air or in household natural radioactive background aerosols, in addition to SARS-COV-2 attached to bioaerosols, which are related with a worst evolution of severe acute respiratory syndrome patients. Reactive oxygen species (ROS) production induced by the interaction with environmental ionizing radiation contained in pollution is pointed out as a critical mechanism that predispose mainly to elder population, but not excluding young subjects, presenting previous chronic conditions of lung inflammation or neuroinflammation, which can lead to the most serious consequences.

NLR in eXile: Emerging roles of NLRX1 in immunity and human disease

NLRX1 is a member of the NOD-like receptor family, a set of pattern recognition receptors associated with innate immunity. Interestingly, NLRX1 exists in somewhat of an exile from its NLR counterparts with unique features that mediate atypical functions compared with traditional NOD-like receptors (NLRs). Aside from a mitochondrial targeting sequence, the N-terminal region is yet to be characterized. Mitochondrially located, NLRX1 sits within a subgroup of regulatory NLRs responsible for negatively regulating cellular inflammatory signalling. As well as modulating pathogen response, emerging evidence is implicating NLRX1 as a central homeostatic gatekeeper between mitochondrial biology and immunological response. More recently, NLRX1 has been implicated in a wide range of disease, both pathogen-driven and otherwise. Emerging links of NLRX1 in cancer biology, autoimmunity and other inflammatory conditions are raising the potential of targeting NLRX1 therapeutically, with recent studies in inflammatory bowel disease showing great promise. Within this review, we address the unique features of NLRX1, its roles in innate immune signalling and its involvement in a range of inflammatory, metabolic and oncology disease indications with a focus on areas that could benefit from therapeutic targeting of NLRX1.

Nutraceutical Strategies for Suppressing NLRP3 Inflammasome Activation: Pertinence to the Management of COVID-19 and Beyond

Inflammasomes are intracellular protein complexes that form in response to a variety of stress signals and that serve to catalyze the proteolytic conversion of pro-interleukin-1β and pro-interleukin-18 to active interleukin-1β and interleukin-18, central mediators of the inflammatory response; inflammasomes can also promote a type of cell death known as pyroptosis. The NLRP3 inflammasome has received the most study and plays an important pathogenic role in a vast range of pathologies associated with inflammation-including atherosclerosis, myocardial infarction, the complications of diabetes, neurological and autoimmune disorders, dry macular degeneration, gout, and the cytokine storm phase of COVID-19. A consideration of the molecular biology underlying inflammasome priming and activation enables the prediction that a range of nutraceuticals may have clinical potential for suppressing inflammasome activity-antioxidants including phycocyanobilin, phase 2 inducers, melatonin, and N-acetylcysteine, the AMPK activator berberine, glucosamine, zinc, and various nutraceuticals that support generation of hydrogen sulfide. Complex nutraceuticals or functional foods featuring a number of these agents may find utility in the prevention and control of a wide range of medical disorders.

Propofol reduces renal ischemia/reperfusion-induced acute lung injury by stimulating sirtuin 1 and inhibiting pyroptosis

The activation of pyroptosis is an important feature of renal ischemia/reperfusion (rI/R)-induced acute lung injury (ALI). Propofol, a general anesthetic, is known to inhibit inflammation in I/R-induced ALI. We investigated whether propofol could suppress pyroptosis during rI/R-induced ALI by upregulating sirtuin 1 (SIRT1). We generated an in vivo model of rI/R-induced ALI by applying microvascular clamps to the renal pedicles of rats for 45 min. Pathological studies revealed that rI/R provoked substantial lung injury and inflammatory cell infiltration. The rI/R stimulus markedly activated pyroptotic proteins such as NLRP3, ASC, caspase 1, interleukin-1β and interleukin-18 in the lungs, but reduced the mRNA and protein levels of SIRT1. Propofol treatment greatly inhibited rI/R-induced lung injury and pyroptosis, whereas it elevated SIRT1 expression. Treatment with the selective SIRT1 inhibitor nicotinamide reversed the protective effects of propofol during rI/R-induced ALI. Analogous defensive properties of propofol were detected in vitro in rat alveolar macrophages incubated with serum from the rI/R rat model. These findings indicate that propofol attenuates rI/R-induced ALI by suppressing pyroptosis, possibly by upregulating SIRT1 in the lungs.

Past Exposure to Cigarette Smoke Aggravates Cognitive Impairment in a Rat Model of Vascular Dementia via Neuroinflammation

Smoking is a risk factor for dementia. Cognitive function can be partially restored after quitting smoking, but still lower than never smoked group. The underlying mechanisms still remain unclear. The effects of smoking cessation combined with cerebral chronic hypoperfusion (CCH) on cognitive function have never been described. Here, we established a cigarette smoking cessation model, a CCH model, and a cigarette smoking cessation plus CCH model. We investigated cognitive function in these models and the mechanisms of the neuroinflammation, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3(NLRP3)/cysteine aspartate-specific proteinase (caspase-1)/interleukin- 1β (IL-1β) pathway, and eucaryotic initiation factor 2α (eIF2α) /autophagy pathway. We used morris water maze (MWM) and novel object recognition (NOR) test to evaluate cognitive function in rats. Nissl staining was performed to observe cell morphology in the hippocampal CA1 area. A neuroinflammatory marker (glial fibrillary acidic protein, GFAP) was assessed by Western blot analysis and immunohistochemistry staining. IL-1β levels were detected by ELISA. The protein levels of NLRP3/caspase-1/ IL-1β and eIF2α/autophagy pathway were evaluated by Western blot analysis. LC3 was assessed by immunofluorescence staining. CCH can affect cognitive function by influencing neuroinflammation, NLRP3/caspase-1/IL-1β pathway, and eIF2α/autophagy pathway. Past exposure to cigarette smoke can also affect cognitive function by influencing neuroinflammation and NLRP3/caspase-1/IL-1β pathway, which may be induced by smoking and may not be alleviated after smoking cessation. Past exposure to cigarette smoke does not influence autophagy, which may be increased by smoking and then decrease to normal levels after smoking cessation. Past exposure to smoking can further aggravate cognitive impairment and neuroinflammation in VaD animals: cognitive impairment induced by CCH via neuroinflammation, NLRP3/caspase-1/IL-1β, and eIF2α/autophagy pathway and cognitive impairment induced by past exposure to cigarette smoke via neuroinflammation and NLRP3/caspase-1/IL-1β pathway. The combined group had the worst cognitive impairment because of harmful reasons.

Amifostine ameliorates induction of experimental autoimmune encephalomyelitis: Effect on reactive oxygen species/NLRP3 pathway

Multiple sclerosis (MS) is an autoimmune disease for which conventional treatments have limited efficacy or side effects. Free radicals are primarily involved in blood-brain barrier disruption and induce neuronal and axonal damage, thus promoting the development of MS. Amifostine, a radioprotective drug used as a cytoprotective agent, attenuates oxidative stress and improves radiation damage by acting as a direct scavenger of reactive oxygen and nitrogen species. The aim of this study was to evaluate the effects of amifostine on MS in a mouse model of experimental autoimmune encephalomyelitis (EAE), which was developed by immunizing C57BL/6 mice with myelin oligodendrocyte glycoprotein and pertussis toxin. EAE mice received intraperitoneal injections of amifostine prior to onset of clinical symptoms and were monitored up to day 15 post induction. We observed abnormal clinical behavioral scores and a decrease in body weight. Histological analysis showed severe inflammatory infiltration and demyelination in the brain and spinal cord lumbar enlargements where significant upregulation of the mRNA expression of the pro-inflammatory cytokines interleukin-6 and interleukin-8, downregulation of the anti-inflammatory cytokine interleukin-10, and obvious microgliosis were also observed. Amifostine treatment potently reversed these abnormal changes. The anti-inflammatory effect of amifostine was associated with the inhibition of reactive oxygen species generation. Furthermore, the expression of proteins involved in the NLRP3 signaling pathway and pyroptosis was decreased. In conclusion, our study showed that amifostine ameliorates induction of experimental autoimmune encephalomyelitis via anti-inflammatory and anti-pyroptosis effects, providing further insights into the use of amifostine for the treatment of MS.

NLRP3 Inflammasome From Bench to Bedside: New Perspectives for Triple Negative Breast Cancer

The tumor microenvironment (TME) is crucial in cancer onset, progression and response to treatment. It is characterized by an intricate interaction of immune cells and cytokines involved in tumor development. Among these, inflammasomes are oligomeric molecular platforms and play a key role in inflammatory response and immunity. Inflammasome activation is initiated upon triggering of pattern recognition receptors (Toll-like receptors, NOD-like receptors, and Absent in melanoma like receptors), on the surface of immune cells with the recruitment of caspase-1 by an adaptor apoptosis-associated speck-like protein. This structure leads to the activation of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18 and participates in different biological processes exerting its effects. To date, the Nod-Like Receptor Protein 3 (NLRP3) inflammasome has been well studied and its involvement has been established in different cancer diseases. In this review, we discuss the structure, biology and mechanisms of inflammasomes with a special focus on the specific role of NLRP3 in breast cancer (BC) and in the sub-group of triple negative BC. The NLRP3 inflammasome and its down-stream pathways could be considered novel potential tumor biomarkers and could open new frontiers in BC treatment.

Age-induced NLRP3 Inflammasome Over-activation Increases Lethality of SARS-CoV-2 Pneumonia in Elderly Patients

Age is one of the most important prognostic factors associated to lethality in SARS-CoV-2 infection. In multivariate analysis, advanced age was an independent risk factor for death. Recent studies suggest a role for the nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3) inflammasome activation in lung inflammation and fibrosis in SARS-CoV and SARS-CoV-2 infections. Increased NLRP3/ apoptosis-associated speck-like protein (ASC) mRNA expression and increased caspase-1 activity, have been observed in aged lung, provoking increased and heightened expression levels of mature Interleukin (IL)-1β and IL-18 in aged individuals. Aged individuals have a basal predisposition to over-react to infection, displaying an increased hyper-inflammatory cascade, that seems not to be fully physiologically controlled. NLRP3 inflammasome is over-activated in aged individuals, through deficient mitochondrial functioning, increased mitochondrial Reactive Oxigen Species (mtROS) and/or mitochondrial (mt)DNA, leading to a hyper-response of classically activated macrophages and subsequent increases in IL-1 β. This NLRP3 over-activated status in elderly individuals, is also observed in telomere dysfunctional mice models. In our opinion, the NLRP3 inflammasome plays a central role in the increased lethality observed in elderly patients infected by COVID-19. Strategies blocking inflammasome would deserve to be studied.

Cellular Models and Assays to Study NLRP3 Inflammasome Biology

The NLRP3 inflammasome is a multi-protein complex that initiates innate immunity responses when exposed to a wide range of stimuli, including pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). Inflammasome activation leads to the release of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18 and to pyroptotic cell death. Over-activation of NLRP3 inflammasome has been associated with several chronic inflammatory diseases. A deep knowledge of NLRP3 inflammasome biology is required to better exploit its potential as therapeutic target and for the development of new selective drugs. To this purpose, in the past few years, several tools have been developed for the biological characterization of the multimeric inflammasome complex, the identification of the upstream signaling cascade leading to inflammasome activation, and the downstream effects triggered by NLRP3 activation. In this review, we will report cellular models and cellular, biochemical, and biophysical assays that are currently available for studying inflammasome biology. A special focus will be on those models/assays that have been used to identify NLRP3 inhibitors and their mechanism of action.

Nanotargeting of Drug(s) for Delaying Dementia: Relevance of Covid-19 Impact on Dementia

By incorporating appropriate drug(s) into lipid (biobased) nanocarriers, one obtains a combination therapeutic for dementia treatment that targets certain cell-surface scavenger receptors (mainly class B type I, or "SR-BI") and thereby crosses the blood-brain barrier. The cardiovascular risk factors for dementia trigger widespread inflammation -- which lead to neurodegeneration, gradual cognitive/memory decline, and eventually (late-onset) dementia. Accordingly, one useful strategy to delay dementia could be based upon nanotargeting drug(s), using lipid nanocarriers, toward a major receptor class responsible for inflammation-associated (cytokine-mediated) cell signaling events. At the same time, the immune response and excessive inflammation, commonly observed in the very recent human coronavirus (COVID-19) pandemic, may accelerate the progression of brain inflammatory neurodegeneration-which increases the probability of post-infection memory impairment and accelerating progression of Alzheimer's disease. Hence, the proposed multitasking combination therapeutic, using a (biobased) lipid nanocarrier, may also display greater effectiveness at different stages of dementia.