ATP-sensitive potassium channel opener, Nicorandil, inhibits NF-κB/AIM2/GSDMD pathway activation to protect against neuroinflammation in ischemic stroke.

The Absent in Melanoma 2 (AIM2) inflammasome contributes to ischemic brain injury by inducing cell pyroptosis and inflammatory responses. Our research group has previously demonstrated that ATP-sensitive potassium channels (KATP channels) openers can modulate neuronal synaptic plasticity post-ischemic stroke for neuroprotection. However, the specific mechanisms of KATP channels in the inflammatory response following ischemic stroke remain unclear. Here, we assessed cellular damage by observing changes in BV-2 morphology and viability. TTC staining, mNSS scoring, Nissl staining, and TUNEL staining were used to evaluate behavioral deficits, brain injury severity, and neuronal damage in mice subjected to Middle Cerebral Artery Occlusion (MCAO). Real-time fluorescence quantitative PCR (RT-qPCR) assessed AIM2 expression after oxygen-glucose deprivation/reperfusion (OGD/R), while Western blotting, immunofluorescence, and Enzyme-Linked Immunosorbent Assay (ELISA) measured pyroptosis-related protein expression, Nuclear Factor-kappa B/Inhibitor of κB alpha (NF-κB/IκBα) signaling activation, and inflammatory cytokine secretion during the acute ischemic phase. We observed an increase in NF-κB nuclear translocation and activation of the NF-κB/IκBα inflammatory pathway after OGD/R. Furthermore, AIM2 protein expression was upregulated and localized within the cytoplasm of BV-2 cells. Notably, low-dose Nicorandil treatment reduced pyroptosis-related protein expression, including AIM2, cleaved cysteinyl aspartate-specific protease-1 (cleaved caspase-1), Gasdermin D Full-length (GSDMD-FL), and Gasdermin D N-terminal (GSDMD-NT), reducing the pore-forming rupture rate of BV-2 cells. Further investigations revealed that the KATP channel inhibitor 5-HD upregulated p-NF-κB p65, NF-κB p65, and p-IκBα expression, promoting microglial cell activation, pyroptosis, and inflammatory factor secretion, attenuating Nicorandil's neuroprotective effect in vivo. Overall, our results suggest that opening KATP channels can improve post-ischemic neurological function by inhibiting AIM2 inflammasome-induced microglial pyroptosis and NF-κB/IκBα signaling activation.

The ester-containing prodrug NT-0796 enhances delivery of the NLRP3 inflammasome inhibitor NDT-19795 to monocytic cells expressing carboxylesterase-1.

NT-0796 is an ester prodrug which is metabolized by carboxylesterase-1 (CES1) to yield the carboxylic acid NDT-19795, an inhibitor of the NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome. When applied to human monocytes/macrophages which express CES1, however, NT-0796 is much more potent at inhibiting NLRP3 inflammasome activation than is NDT-19795. Comparison of the binding of NDT-19795 and NT-0796 in a cell-based NLRP3 target engagement assay confirms that NDT-19795 is the active species. Moreover, microsomes expressing CES1 efficiently convert NT-0796 to NDT-19795, confirming CES1-dependent activation. To understand the basis for the enhanced potency of the ester prodrug species in human monocytes, we analyzed the accumulation and de-esterification of NT-0796 in cultured cells. Our studies reveal NT-0796 rapidly accumulates in cells, achieving estimated cellular concentrations above those applied to the medium, with concomitant metabolism to NDT-19795 in CES1-expressing cells. Using cells lacking CES1 or a poorly hydrolysable NT-0796 analog demonstrated that de-esterification is not required for NT-0796 to achieve high cellular levels. As a result of a dynamic equilibrium whereby NDT-19795 formed intracellularly is subsequently released to the medium, concentrations of NT-0796 sufficient to inhibit NLRP3 can be completely metabolized to NDT-19795 resulting in a transient pharmacodynamic response. In contrast, when NDT-19795 is applied directly to cells observed cell-associated levels are below those present in the medium and remain stable over time. Dynamics observed within the context of a closed tissue culture system highlight the utility of NT-0796 as a vehicle for delivering the NDT-19795 acid payload to CES1 expressing cells.

GDF15 regulated by HDAC2 exerts suppressive effects on oxygen-glucose deprivation/reoxygenation-induced neuronal cell pyroptosis via the NLRP3 inflammasome.

Background: Pyroptosis, inflammation-related programed cell death mediated by NLRP3 inflammasome, is involved in the pathogenesis of cerebral hypoxic-ischemic injury. Our study aims to explore the biological role of growth differentiation factor (GDF)15 in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced neuronal pyroptosis. Methods: HT22 neurons were subjected to OGD/R to simulate cerebral hypoxic-ischemic injury. Cells were transfected with plasmids to overexpress GDF15, or lentiviral-based shRNAs constructs to silence GDF15. ELISA assay was used to detect GDF15, IL-1ß, IL-18, and neuron specific enolase (NSE) levels. Cell pyroptosis was measured by flow cytometery. Chromatin immunoprecipitation assay was used to detect interaction of H3K27ac with GDF15 promoter. GDF15, NLRP3, Caspase-1 p20 and GSDMD-N expressions were measured by Western blotting. Results: Patients with malignant middle cerebral artery infarction showed decreased GDF15, but increased IL-1ß, IL-18, and NSE levels in serum compared to healthy controls. OGD/R treatment caused significant increases in the levels of IL-1ß, IL-18 and NSE, percentages of pyroptotic cells, and expressions of NLRP3, Caspase-1 p20, and GSDMD in HT22 cells, which were markedly reversed by GDF15 overexpression. However, GDF15 knockdown resulted in neuronal injury similar to those observed in OGD/R treatment. The GDF15 knockdown-induced effects were counteracted by treatment with NLRP3 inhibitor. OGD/R decreased the enrichment of H3K27ac in the promoter of GDF15 to down-regulate GDF15, but was compromised by co-treatment with HDAC2 inhibitor. Conclusion: Our data demonstrates that GDF15 attenuates OGD/R-induced pyroptosis through NLRP3 inflammasome. HDAC2 is involved in mediating OGD-induced GDF15 down-regulation via H3K27ac modification. GDF15 overexpression and HDAC2 inhibition hold potential as useful therapeutic strategies for neuroprotection.

Successful Treatment With High-Dose Colchicine of a 101-Year-Old Patient Diagnosed With COVID-19 After an Emergency Cholecystectomy.

There are multiple factors associated with increased morbidity and mortality in COVID-19 patients, and advanced age is one such independent prognostic factor. It is well established that the multiorgan failure and death in COVID-19 patients are due to the hyperactivation of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome and the ensuing cytokine storm. Colchicine, a well-known anti-inflammatory drug, has been shown to inhibit the NLRP3 inflammasome in micromolar concentrations potently. It has the unique property of accumulating in leukocytes, which is the primary cause of the abnormal activation of the NLRP3 inflammasome in COVID-19. It has been shown that achieving inhibitory concentrations of colchicine in leucocytes requires treatment with higher doses. Our recent studies showed that treatment with higher doses of colchicine in both outpatient and inpatient settings is safe and results in remarkable cure rates and significantly decreased mortality rates, even in the most severely affected patients with multiple comorbidities and risk factors. The main risk factor for severe COVID-19 is age, especially over 85 years. Here, we present a unique case of a 101-year-old male who underwent two major emergency abdominal surgeries and contracted COVID-19 while in the hospital. Laboratory tests showed increased values of markers for severe COVID-19, including CRP, D-dimer, and ferritin. Increased opacities bilaterally paracardially and moderate right-side pleural effusions were detected on the chest X-ray. We initiated our high-dose colchicine treatment regimen, resulting in the patient's complete recovery and discharge. We are convinced that the administration of high-dose colchicine to high-risk COVID-19 patients should be mandatory.

Molecular mechanisms and therapeutic potential of natural flavonoids in diabetic nephropathy: Modulation of intracellular developmental signaling pathways.

Recognized as a common microvascular complication of diabetes mellitus (DM), diabetic nephropathy (DN) is the principal cause of chronic end-stage renal disease (ESRD). Patients with diabetes have an approximately 25% risk of developing progressive renal disease. The underlying principles of DN control targets the dual outcomes of blood glucose regulation through sodium glucose cotransporter 2 (SGLT 2) blockade and hypertension management through renin-angiotensin-aldosterone inhibition. However, these treatments are ineffective in halting disease progression to kidney failure and cardiovascular comorbidities. Recently, the dysregulation of subcellular signaling pathways has been increasingly implicated in DN pathogenesis. Natural compounds are emerging as effective and side-effect-free therapeutic agents that target intracellular pathways. This narrative review synthesizes recent insights into the dysregulation of maintenance pathways in DN, drawing from animal and human studies. To compile this review, articles reporting DN signaling pathways and their treatment with natural flavonoids were collected from PubMed, Cochrane Library Web of Science, Google Scholar and EMBASE databases since 2000. As therapeutic interventions are frequently based on the results of clinical trials, a brief analysis of data from current phase II and III clinical trials on DN is discussed.

Applying Dynamical Systems Theory to Improve Personalized Medicine Following Mild Traumatic Brain Injury.

A sizable proportion of patients with mild traumatic brain injury (mTBI) have persistent symptoms and functional impairments months to years following injury. This phenomenon is continually observed despite an explosion of research and interest in improving mTBI clinical outcomes over the last two decades. All pharmacological clinical trials to date have failed to demonstrate improved outcomes for mTBI. One possible explanation for these continued failures is an overly myopic approach to treating mTBI (i.e., testing the effect of a single drug with a specific mechanism on a group of people with highly heterogenous injuries). Clinical presentation and prognosis of mTBI vary considerably between patients, and yet we continue to assess group-level effects of a homogenized treatment. We need to utilize an equally complex treatment approach to match the extraordinary complexity of the human brain. Dynamical systems theory has been used to describe systems composed of multiple subsystems who function somewhat independently but are ultimately interconnected. This theory was popularized in the motor control literature as an overarching framework for how the mind and body connect to interact and move through the environment. However, the human body can be viewed as a dynamical system composed of multiple subsystems (i.e., organ systems) who have isolated functions, which are also codependent on the health and performance of other interconnected organ systems. In this perspective piece, we will use the example of mTBI in the obese patient to demonstrate how broadening our approach to treatment of the individual (and not necessarily the injury) may ultimately yield improved outcomes. Furthermore, we will explore clinical and pre-clinical evidence demonstrating multiple system interactions in the context of obesity and TBI and discuss how expanding our understanding of the mechanistic interplay between multiple organ systems may ultimately provide a more personalized treatment approach for this mTBI patient subpopulation.

Constituents from leaves of Macaranga hemsleyana.

Objective: To study constituents of the leaves of Macaranga hemsleyana, and evaluate their inhibitory effects against NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation, and antiproliferative activity. Methods: The constituents were isolated and purified by column chromatography on MCI gel CHP20P/P120, silica gel, Sephadex LH-20, and HPLC. The structures of compounds were determined by 1D, 2D NMR, and HR-ESI-MS data. The inhibitory effect of compounds on inflammasome activation was determined by lactate dehydrogenase (LDH) procedure. The antiproliferative activity was evaluated using MTT assay. Results: The study led to the isolation of 23 compounds, including one new compound, identified as (2Z)-3-[4-(ß-D-glucopyranosyloxy)-2'-hydroxy-5'-methoxyphenyl]-2-propenoic acid (1), together with 22 known compounds recognized as 1,4-dihydro-4-oxo-3-pyridinecarbonitrile (2), methyl 4-methoxynicotinate (3), 4-methoxynicotinonitrile (4), 1-(3-O-ß-D-glucopyranosyl-4,5-dihydroxyphenyl)-ethanone (5), neoisoastilbin (6), isoastilbin (7), aromadendrin (8), neoastilbin (9), astilbin (10), quercitrin (11), neoschaftoside (12), apigenin 6,8-bis-C-α-L-arabinoside (13), vitexin (14), bergenin (15), scopoletin (16), glucopyranoside salicyl (17), koaburside (18), benzyl ß-D-glucoside (19), icariside B5 (20), roseoside (21), loliolide (22), and adenosine (23). The tested compounds did not show LDH inhibition nor antiproliferative activity. Conclusion: Compound 1 was a new glycoside. Compounds 2 and 3 were obtained for the first time from natural source. The 22 known compounds constituted of alkaloids (2-4, 23), phenolics (5, 15, 17, 18), flavonoids (6-14), coumarin (16), benzyl glycoside (19), and norsesquiterpenes (20-22). All the compounds, 1-23, were revealed from M. hemsleyana for the first time. This is the initial uncovering of molecules 1-10, 12, 13, 17-19, and 23 from the genus Macaranga. The isolated compounds, 11, 14-16, and 20-22 established taxonomic classification of M. hemsleyana in Euphorbiaceae family. Flavonoids were outstanding as chemosystematic markers of Macaranga genus.

Release of IL-1ß and IL-18 in human primary bronchial epithelial cells exposed to cigarette smoke is independent of NLRP3.

Cigarette smoke (CS) is a major risk factor for chronic lung diseases and promotes activation of pattern recognition receptors in the bronchial epithelium. NOD-like receptor family, pyrin domain-containing 3 (NLRP3) is a pattern recognition receptor whose activation leads to caspase-1 cleavage, maturation/release of IL-1ß and IL-18, and eventually pyroptosis. Whether the NLRP3 inflammasome participates in CS-induced inflammation in bronchial epithelial cells is still unclear. Herein, we evaluated the involvement of NLRP3 in CS-induced inflammatory responses in human primary bronchial epithelial cells. To this purpose, human primary bronchial epithelial cells were stimulated with CS extracts (CSE) and lytic cell death, caspase activation (-1, -8, -3/7), cytokine release (IL-1ß, IL-18, and IL-8), NLRP3, pro-IL-1ß/pro-IL-18 mRNA, and protein expression were measured. The impact of inhibitors of NLRP3 (MCC950), caspases, and the effect of the antioxidant N-acetyl cysteine were evaluated. We found that CSE increased pro-IL-1ß expression and induced activation of caspase-1 and release of IL-1ß and IL-18. These events were independent of NLRP3 and we found that NLRP3 was not expressed. N-acetyl cysteine reverted CSE-induced caspase-1 activation. Overall, our findings support that the bronchial epithelium may play a central role in the release of IL-1 family cytokines independently of NLRP3 in the lungs of smokers.

Andrographolide Inhibits Expression of NLPR3 Inflammasome in Canine Mononuclear Leukocytes.

Inflammasomes are multiprotein complexes that trigger processes through caspase-1 activation, leading to the maturation of proinflammatory cytokines, such as IL-1ß and IL-18. The gene encoding the inflammasome stimulatory protein NLRP3 is conserved in canines. Caspase-1/4 homologues have been identified in multiple carnivores, including canines, and caspase-1 activity has been shown in humans. The NLRP3 inflammasome has also been described in some canine inflammatory diseases. Andrographolide, a labdane diterpene, is the principal active ingredient in the herb Andrographis paniculate. The objective of this study was to determine the effect of andrographolide on the gene expression of the components of the NLRP3 inflammasome, proinflammatory cytokines, and IL-1ß secretion in canine peripheral blood mononuclear cells. For this, MTT assays and real-time PCR were employed to assess the cytotoxicity and gene expression. Further, an ELISA test was performed to measure the IL-1ß concentration. The findings reveal that andrographolide significantly reduces the expression of NLRP3, caspase-1/4, IL-1ß, and IL-18. Additionally, it decreases the secretion of IL-1ß and other proinflammatory cytokines, including IL-6, IL-8, and TNF-α. The results show that andrographolide decreases the expression of NLRP3, caspase-1/4, IL-1ß, and IL-18. Andrographolide also reduces proinflammatory cytokines expression, and decreases IL-1ß secretion. This indicates that andrographolide can interfere with the activation and function of the inflammasome, resulting in a decrease in the inflammatory response in canines. Research in this area is still budding, and more studies are necessary to fully understand andrographolide's mechanisms of action and its therapeutic potential in relation to the NLRP3 inflammasome in dogs.

Hydroethanolic Extract of Lepidium apetalum Willdenow Alleviates Dextran Sulfate Sodium-Induced Colitis by Enhancing Intestinal Barrier Integrity and Inhibiting Oxidative Stress and Inflammasome Activation.

The prevalence of ulcerative colitis (UC) has surged in Asian nations recently. The limitations of traditional drug treatments, including biologics, have spurred interest in herbal medicines for managing UC. This study aimed to elucidate the protective mechanisms of hydroethanolic extract from Lepidium apetalum Willdenow (LWE) on intestinal integrity and inflammation in a dextran sodium sulfate (DSS)-induced colitis model of inflammatory bowel disease (IBD). Using UPLC-MS/MS analysis, eleven phytochemicals were identified in LWE, including catechin, vicenin-2, and quercetin. LWE restored transepithelial electrical resistance (TEER) and reduced paracellular permeability in IL-6-stimulated Caco-2 cells, increasing the expression of the tight junction proteins ZO-1 and occludin. LWE treatment alleviated DSS-induced colitis symptoms in mice, reducing body weight loss, disease activity index values, and spleen size, while improving colon length and reducing serum FITC-dextran levels, indicating enhanced intestinal barrier function. LWE suppressed NLRP3 inflammasome activation, reducing protein levels of pro-caspase-1, cleaved-caspase-1, ASC, and NLRP3, as well as mRNA levels of IL-1ß, IL-6, and TNF-α. LWE treatment upregulated activity and mRNA levels of the antioxidant enzymes SOD1 and NQO1. Additionally, LWE modulated the Nrf2/Keap1 pathway, increasing p-Nrf2 levels and decreasing Keap1 levels. LWE also restored goblet cell numbers and reduced fibrosis in DSS-induced chronic colitis mice, increasing gene and protein expressions of ZO-1 and occludin. In summary, LWE shows promise as a therapeutic intervention for reducing tissue damage and inflammation by enhancing intestinal barrier function and inhibiting colonic oxidative stress-induced inflammasome activation.

OxInflammatory Responses in the Wound Healing Process: A Systematic Review.

Significant sums are spent every year to find effective treatments to control inflammation and speed up the repair of damaged skin. This study investigated the main mechanisms involved in the skin wound cure. Consequently, it offered guidance to develop new therapies to control OxInflammation and infection and decrease functional loss and cost issues. This systematic review was conducted using the PRISMA guidelines, with a structured search in the MEDLINE (PubMed), Scopus, and Web of Science databases, analyzing 23 original studies. Bias analysis and study quality were assessed using the SYRCLE tool (Prospero number is CRD262 936). Our results highlight the activation of membrane receptors (IFN-δ, TNF-α, toll-like) in phagocytes, especially macrophages, during early wound healing. The STAT1, IP3, and NF-kß pathways are positively regulated, while Ca2+ mobilization correlates with ROS production and NLRP3 inflammasome activation. This pathway activation leads to the proteolytic cleavage of caspase-1, releasing IL-1ß and IL-18, which are responsible for immune modulation and vasodilation. Mediators such as IL-1, iNOS, TNF-α, and TGF-ß are released, influencing pro- and anti-inflammatory cascades, increasing ROS levels, and inducing the oxidation of lipids, proteins, and DNA. During healing, the respiratory burst depletes antioxidant defenses (SOD, CAT, GST), creating a pro-oxidative environment. The IFN-δ pathway, ROS production, and inflammatory markers establish a positive feedback loop, recruiting more polymorphonuclear cells and reinforcing the positive interaction between oxidative stress and inflammation. This process is crucial because, in the immune system, the vicious positive cycle between ROS, the oxidative environment, and, above all, the activation of the NLRP3 inflammasome inappropriately triggers hypoxia, increases ROS levels, activates pro-inflammatory cytokines and inhibits the antioxidant action and resolution of anti-inflammatory cytokines, contributing to the evolution of chronic inflammation and tissue damage.

Elucidating PAR1 as a therapeutic target for delayed traumatic brain injury: Unveiling the PPAR-γ/Nrf2/HO-1/GPX4 axis to suppress ferroptosis and alleviate NLRP3 inflammasome activation in rats.

Repetitive traumatic brain injury (RTBI) is acknowledged as a silent overlooked public health crisis, with an incomplete understanding of its pathomechanistic signaling pathways. Mounting evidence suggests the involvement of thrombin and its receptor, the protease-activated receptor (PAR)1, in the development of secondary injury in TBI; however, the consequences of PAR1 modulation and its impact on ferroptosis-redox signaling, and NLRP3 inflammasome activation in RTBI, remain unclear. Further, the utilitarian function of PAR1 as a therapeutic target in RTBI has not been elucidated. To study this crosstalk, RTBI was induced in Wistar rats by daily weight drops on the right frontal region for five days. Three groups were included: normal control, untreated RTBI, and RTBI+SCH79797 (a PAR1 inhibitor administered post-trauma at 25 µg/kg/day). The concomitant treatment of PAR1 antagonism improved altered behavior function, cortical histoarchitecture, and neuronal cell survival. Moreover, the receptor blockade downregulated mRNA expression of PAR1 but upregulatedthat of the neuroprotective receptor PPAR-γ. The anti-inflammatory impact of SCH79797 was signified by the low immune expression/levels of NF-κB p65,TNF-α, IL-1ß, and IL-18. Consequently, the PAR1 blocker hindered the formation of inflammasome components NLRP3, ASC, and activated caspase-1. Ultimately, SCH79797 treatment abated ferroptosis-dependent iron redox signaling through the activation of the antioxidant Nrf2/HO-1 axis and its subsequent antioxidant machinery (GPX4, SOD) to limit lipid peroxidation, iron accumulation, and transferrin serum increment. Collectively, SCH79797 offered putative preventive mechanisms against secondary RTBI consequences in rats by impeding ferroptosis and NLRP3 inflammasome through activating the PPAR-γ/Nrf2 antioxidant cue.

Pathophysiological role and potential drug target of NLRP3 inflammasome in the metabolic disorders.

NLRP3 plays a role in the development of autoinflammatory diseases. NLRP3, ASC, and Caspases 1 or 8 make up the NLRP3 inflammasome, which is an important part of innate immune system. The NLRP3 inflammasome-mediated inflammatory cytokines may also participate in metabolic disorders, such as diabetes, hyperlipidemia, atherosclerosis, non-alcoholic fatty liver disease, and gout. Hence, an overview of the NLRP3 regulation in these metabolic diseases and the potential drugs targeting NLRP3 is the focus of this review.

Defining PANoptosis: Biochemical and Mechanistic Evaluation of Innate Immune Cell Death Activation.

The innate immune system is the first line of host defense. Innate immune activation utilizes pattern recognition receptors to detect pathogens, pathogen-associated and damage-associated molecular patterns (PAMPs and DAMPs), and homeostatic alterations and drives inflammatory signaling pathways and regulated cell death. Cell death activation is critical to eliminate pathogens and aberrant or damaged cells, while excess activation can be linked to inflammation, tissue damage, and disease. Therefore, there is increasing interest in studying cell death mechanisms to understand the underlying biology and identify therapeutic strategies. However, there are significant technical challenges, as many cell death pathways share key molecules with each other, and genetic models where these cell death molecules are deleted remain the gold standard for evaluation. Furthermore, extensive crosstalk has been identified between the cell death pathways pyroptosis, apoptosis, necroptosis, and the more recently characterized PANoptosis, which is defined as a prominent, unique innate immune, lytic, and inflammatory cell death pathway initiated by innate immune sensors and driven by caspases and RIPKs through PANoptosomes. PANoptosomes are multi-protein complexes assembled by innate immune sensor(s) in response to pathogens, PAMPs, DAMPs, cytokines, and homeostatic changes that drive PANoptosis. In this article, we provide methods for molecularly defining distinct cell death pathways, including PANoptosis, using both genetic and chemical approaches through western blot, LDH assay, and microscopy readouts. This procedure allows for the assessment of cell death on the cell population and single-cell levels even without access to genetic models. Having this comprehensive workflow that is more accessible to all labs will improve our ability as a scientific community to accelerate discovery. Using these protocols will help identify new innate immune sensors that drive PANoptosis and define the molecular mechanisms and regulators involved to establish new targets for clinical translation. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Induction and quantification of cell death using live cell imaging Alternate Protocol 1: Quantification of cell death using LDH Alternate Protocol 2: Assessment of cell death complexes in single cells using immunofluorescence staining Basic Protocol 2: Analysis of cell death mechanisms by immunoblots (western blots).

Irisin preserves mitochondrial integrity and function in tubular epithelial cells after ischemia-reperfusion-induced acute kidney injury.

AIMS: A myokine secreted by skeletal muscles during exercise called irisin mitigates ischemia-reperfusion (I/R) injury in epithelial cells of various organs by limiting damage to mitochondria. We test whether irisin may preserve the mitochondrial integrity and function in renal tubular epithelial cells and protect against ischemia-reperfusion-induced acute kidney injury (AKI). METHODS: We correlated serum irisin levels with serum creatinine and BUN levels from both AKI patients and healthy individuals. In mice with irisin administration, various renal injury markers such as serum creatinine, BUN, kidney injury molecule-1 (Kim-1), and neutrophil gelatinase-associated lipocalin (NGAL), and renal histopathology were assessed after I/R. To identify the potential mechanisms of the protective of irisin's protective effect, we perfused proximal tubules under confocal microscopy and analyzed kidney tissues by qPCR, western blot, and immunohistochemistry. RESULTS: Serum irisin correlated inversely with serum creatinine and BUN levels were significantly lower in AKI patients than in healthy subjects. Administering irisin to mice after I/R decreased biomarker levels for AKI including serum creatinine, BUN, Kim-1, NAGL and lessened histological changes. In kidney tissues of mice, irisin upregulated the mitochondrial autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3), the mitochondrial autophagy pathway-related proteins PTEN-induced putative kinase 1 (PINK1) and Parkinson's disease 2 parkin (PARK2) and downregulated the reactive substrate protein sequestosome 1 (P62) and mitochondrial membrane proteins translocase of outer mitochondrial membrane 20 (TOM20) and translocase of inner mitochondrial membrane 23 (TIM23). CONCLUSION: Irisin protects against renal I/R injury, which may involve the preservation of mitochondrial integrity and function.

The Inflammasome Adaptor Protein ASC in Plasma as a Biomarker of Early Cognitive Changes.

Dementia is a group of symptoms including memory loss, language difficulties, and other types of cognitive and functional impairments that affects 57 million people worldwide, with the incidence expected to double by 2040. Therefore, there is an unmet need to develop reliable biomarkers to diagnose early brain impairments so that emerging interventions can be applied before brain degeneration. Here, we performed biomarker analyses for apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and amyloid-ß 42/40 (Aß42/40) ratio in the plasma of older adults. Participants had blood drawn at baseline and underwent two annual clinical and cognitive evaluations. The groups tested either cognitively normal on both evaluations (NN), cognitively normal year 1 but cognitively impaired year 2 (NI), or cognitively impaired on both evaluations (II). ASC was elevated in the plasma of the NI group compared to the NN and II groups. Additionally, Aß42 was increased in the plasma in the NI and II groups compared to the NN group. Importantly, the area under the curve (AUC) for ASC in participants older than 70 years old in NN vs. NI groups was 0.81, indicating that ASC is a promising plasma biomarker for early detection of cognitive decline.

Colchicine-The Divine Medicine against COVID-19.

Colchicine has a number of effects that suggest it may be useful in the treatment of COVID-19. Myeloid cells are a major source of dysregulated inflammation in COVID-19. The hyperactivation of the NLRP3 inflammasome and the subsequent cytokine storm take place precisely inside them and can lead to multiorgan damage and death. NLRP3 inflammasome inhibition has been assessed at micromolar colchicine concentrations which cannot be achieved in serum. However, colchicine has remarkable ability to accumulate intensively in leukocytes, where the cytokine storm is generated. Over 50 observational studies and randomized clinical trials, small randomized non-controlled trials, and retrospective cohort studies were initiated to test its healing effect in vivo, leading to conflicting, rather disappointing results. The WHO gives a "Strong recommendation against" the use of colchicine for COVID-19 treatment. This is because low doses of colchicine are always used, where the concentrations required to inhibit the NLRP3 inflammasome in leukocytes cannot be reached. Considering this, from March 2020, we started the administration of higher doses of colchicine. Our assumption was that a safe increase in colchicine doses to reach micromolar concentrations in leukocytes will result in NLRP3 inflammasome/cytokine storm inhibition. We demonstrated that in 785 inpatients treated with increasing doses of colchicine, mortality fell between two and seven times. Our data, including a large number of COVID-19 outpatients, showed that nearly 100% of the patients treated with this therapeutic regimen escaped hospitalization. In addition, post-COVID-19 symptoms in those treated with colchicine were significantly rarer. As a large number of viruses can overactivate the NLRP3 inflammasome (like seasonal influenza), we are convinced that higher colchicine doses would be useful in these cases as well.

Host Innate Antiviral Response to Influenza A Virus Infection: From Viral Sensing to Antagonism and Escape.

Influenza virus possesses an RNA genome of single-stranded, negative-sensed, and segmented configuration. Influenza virus causes an acute respiratory disease, commonly known as the "flu" in humans. In some individuals, flu can lead to pneumonia and acute respiratory distress syndrome. Influenza A virus (IAV) is the most significant because it causes recurring seasonal epidemics, occasional pandemics, and zoonotic outbreaks in human populations, globally. The host innate immune response to IAV infection plays a critical role in sensing, preventing, and clearing the infection as well as in flu disease pathology. Host cells sense IAV infection through multiple receptors and mechanisms, which culminate in the induction of a concerted innate antiviral response and the creation of an antiviral state, which inhibits and clears the infection from host cells. However, IAV antagonizes and escapes many steps of the innate antiviral response by different mechanisms. Herein, we review those host and viral mechanisms. This review covers most aspects of the host innate immune response, i.e., (1) the sensing of incoming virus particles, (2) the activation of downstream innate antiviral signaling pathways, (3) the expression of interferon-stimulated genes, (4) and viral antagonism and escape.

The Novel Role of the NLRP3 Inflammasome in Mycotoxin-Induced Toxicological Mechanisms.

Mycotoxins are secondary metabolites produced by several fungi and moulds that exert toxicological effects on animals including immunotoxicity, genotoxicity, hepatotoxicity, teratogenicity, and neurotoxicity. However, the toxicological mechanisms of mycotoxins are complex and unclear. The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome is a multimeric cytosolic protein complex composed of the NLRP3 sensor, ASC adapter protein, and caspase-1 effector. Activation of the NLRP3 inflammasome plays a crucial role in innate immune defence and homeostatic maintenance. Recent studies have revealed that NLRP3 inflammasome activation is linked to tissue damage and inflammation induced by mycotoxin exposure. Thus, this review summarises the latest advancements in research on the roles of NLRP3 inflammasome activation in the pathogenesis of mycotoxin exposure. The effects of exposure to multiple mycotoxins, including deoxynivalenol, aflatoxin B1, zearalenone, T-2 toxin, ochratoxin A, and fumonisim B1, on pyroptosis-related factors and inflammation-related factors in vitro and in vivo and the pharmacological inhibition of specific and nonspecific NLRP3 inhibitors are summarized and examined. This comprehensive review contributes to a better understanding of the role of the NLRP3 inflammasome in toxicity induced by mycotoxin exposure and provides novel insights for pharmacologically targeting NLRP3 as a novel anti-inflammatory agent against mycotoxin exposure.

Resveratrol protects against a high-fat diet-induced neuroinflammation by suppressing mitochondrial fission via targeting SIRT1/PGC-1α.

Various health issues have emerged due to consuming high-fat diets (HFD), particularly the detrimental impact they have on mitochondrial dynamics and subsequet cognition functions. Specially, mitochondrial fission can serve as an upstream signal in the regulation of cortical inflammation and neural pyroptosis. Our study was designed to verify the existence of neuroinflammation in the pathogenesis of HFD-induced cognitive dysfunction and demonstrated that resveratrol (RSV) attenuated neural deficits via regulation of cortical mitochondrial fission. A total of 50 male Sprague Dawley rats were randomly divided into five groups: control (Cont, 26 weeks on normal rodent diet); high-fat diet (HFD); dietary adjustments (HFD + ND); resveratrol intervention (HFD + R); joint intervention (HFD + ND + R) for 26 weeks. The spatial learning and memory function, spine density, NLRP3 inflammasome associated protein, mRNA and protein expression involved in mitochondrial dynamics and SIRT1/PGC-1α signaling pathway in brain were measured. Furthermore, reactive oxygen species (ROS) accumulation and resultant mitochondrial membrane potential (MMP) alteration in PC12 cells exposed to palmitic acid (PA) or Drp1 inhibitor (Mdivi-1) were detected to reflect mitochondrial function. The findings suggested that prolonged treatment of RSV improved cognitive deficits and neuronal damage induced by HFD, potentially attributed to activation of the SIRT1/PGC-1α axis. We further indicated that the activation of the NLRP3 inflammasome in PA (200 µM) treated PC12 cells could be inhibited by Mdivi-1. More importantly, Mdivi-1 (10 µM) reduced intracellular ROS levels and enhanced MMP by reversing Drp1-mediated aberrant mitochondrial fission. To summarize, those results clearly indicated that a HFD inhibited the SIRT1/PGC-1α pathway, which contributed to an imbalance in mitochondrial dynamics and the onset of NLRP3-mediated pyroptosis. This effect was mitigated by the RSV possibly through triggering the SIRT1/PGC-1α axis, prevented aberrant mitochondrial fission and thus inhibited the activation of the NLRP3 inflammatory pathway.