Recent advances in the mechanisms of NLRP3 inflammasome activation and its inhibitors. Cell Death Dis. 2019;10:128. [PMID: 30755589 PMCID: PMC6372664 DOI: 10.1038/s41419-019-1413-8]

Plant-derived compounds and neurodegenerative diseases: Different mechanisms of action with therapeutic potential

Neurodegenerative diseases are a group of disorders characterized by progressive degeneration of discrete groups of neurons causing severe disability. The main risk factor is age, hence their incidence is rapidly increasing worldwide due to the rise in life expectancy. Although the causes of the disease are not identified in about 90% of the cases, in the last decades there has been great progress in understanding the basis for neurodegeneration. Different pathological mechanisms including oxidative stress, mitochondrial dysfunction, alteration in proteostasis and inflammation have been addressed as important contributors to neuronal death. Despite our better understanding of the pathophysiology of these diseases, there is still no cure and available therapies only provide symptomatic relief. In an effort to discover new therapeutic approaches, natural products have aroused interest among researchers given their structural diversity and wide range of biological activities. In this review, we focus on three plant-derived compounds with promising neuroprotective potential that have been traditionally used by folk medicine: the flavonoid quercetin (QCT), the phytocannabinoid cannabidiol (CBD)and the tryptamine N,N-dimethyltryptamine (DMT). These compounds exert neuroprotective effects through different mechanisms of action, some overlapping, but each demonstrating a principal biological activity: QCT as an antioxidant, CBD as an anti-inflammatory, and DMT as a promoter of neuroplasticity. This review summarizes current knowledge on these activities, potential therapeutic benefits of these compounds and their limitations as candidates for neuroprotective therapies. We envision that treatments with QCT, CBD, and DMT could be effective either when combined or when targeting different stages of these diseases.

Triptolide attenuates LPS-induced chondrocyte inflammation by inhibiting inflammasome activation via the Wnt/β-catenin and NF-κB signaling pathways

Osteoarthritis (OA) is a common form of arthritis characterized by subchondral bone proliferation and articular cartilage degeneration. Recently, the Nod-like receptor pyrin domain 3 (NLRP3) inflammasome has gained attention due to its association with synovial inflammation in OA. Triptolide (TP), known for its immunosuppressive and anti-inflammatory effects, has been studied in various diseases. However, the specific impact of TP on OA and its underlying mechanism remains largely unexplored. In this study, chondrocytes were treated with a specific concentration of TP, and subsequent analysis through Western blotting and immunofluorescence staining revealed decreased expression levels of MMP-13, NLRP3, Caspase-1, ASC, β-catenin, p-p65, and IκB compared to the model group. ELISA results demonstrated significantly lower levels of IL-1β, IL-18, and TNF-α in the TP treatment group compared to the model group. In addition, triptolide ameliorates the degradation of the extracellular matrix (ECM) by enhancing the expression of collagen-II. In conclusion, our findings suggest that TP exhibits anti-inflammatory effects on chondrocytes in the presence of LPS-induced inflammation by inhibiting the activation of the NLRP3 inflammasome via the Wnt/β-catenin and NF-κB pathway. These results contribute to a better understanding of TP's potential therapeutic benefits in managing OA.

Brain-derived textiloma post glioblastoma resection and application of oxidized regenerated cellulose: A pilot, bedside-to-bench, translational study

Oxidized regenerated cellulose (ORC; marketed as Surgicel® and Tabotamp®) is routinely used as an intraoperative hemostatic agent. Rarely, residual ORC has been associated with a foreign body reaction generating cystic or granulomatous lesions (i.e., textilomas) at the surgical site. Here, we report a bedside-to-bench, translational report of an intracranial mass after neurosurgical resection of glioblastoma with ORC application. As part of patient care, we performed magnetic resonance imaging and histopathological analysis of the mass. We then performed in vitro studies to evaluate the effect of ORC on cytokine production and viability of BV-2 murine microglial cells by using quantitative PCR along with live cell microscopy and crystal violet staining, respectively. Magnetic resonance imaging demonstrated a recurrent mass pressing on the adjacent right ventricle, which was removed in a second surgery for diagnostic and therapeutic purposes. Unexpectedly, histopathological examination of the resected mass revealed abundant ORC arising from the site with inflammation, microglial activation, and collagenization. Mechanistically, we show an ORC-induced modest increase in inflammatory cytokines with a subsequent decrease in microglial cell viability. These findings suggest that ORC may mediate microglial immune response and viability, and serve to raise awareness and guide interpretation of post-treatment surveillance imaging findings in the instance of foreign body reaction.

The Tan-Re-Qing Capsule mitigates acute lung injury by suppressing the NLRP3 inflammasome and MAPK/NF-κB signaling pathways

OBJECTIVE

The Tan-Re-Qing Capsule (TRQC), a traditional Chinese medicine (TCM) preparation, has been historically utilized in treating acute lung injury (ALI) and COVID-19-induced pulmonary diseases. This study aimed to explore the effect and underlying mechanisms of TRQC in lipopolysaccharide (LPS)-induced ALI models.

METHODS

The changes of acute lung injury and inflammatory response were observed after TRQC treatment of the LPS-induced ALI mouse model. Based on active compounds in TRQC and network pharmacology analysis, potential targeting signals were identified. The effects of TRQC on signaling in LPS-stimulated BMDMs were investigated. Additionally, the defecatory status of mice and the mechanism of Cl- secretion in HBE cells and T84 colonic epithelial cells were examined.

RESULTS

TRQC exhibited a notable amelioration of inflammatory injuries in ALI mice. Utilizing a systems-pharmacology approach based on active chemical compounds, TRQC was found to regulate inflammation-related pathways, including NF-κB, NOD-like signaling, and MAPK signaling. In vitro experiments demonstrated that TRQC effectively suppressed LPS-induced activation of macrophages and the assembly of the NLRP3 inflammasome induced by LPS and Nigericin. These effects were attributed to the suppression of NF-κB and NOD-like signaling pathways. Furthermore, TRQC blocked MAPK signaling, thereby mitigating the inhibitory effects of LPS and Nigericin on Ca2+-dependent Cl- efflux across colonic epithelial cells. This mechanism generated a cathartic effect, potentially aiding in the removal of harmful substances and pathogenic bacteria.

CONCLUSION

Our study demonstrates that TRQC significantly mitigates ALI by effectively suppressing the NLRP3 inflammasome and MAPK/NF-κB signaling pathways. These findings suggest that TRQC could serve as a promising therapeutic candidate for inflammatory lung diseases, offering a novel approach to managing conditions like ALI and potentially extending to other inflammatory diseases.

Lipopolysaccharide-Neutralizing Peptide Modulates P2X7 Receptor-Mediated Interleukin-1β Release

Lipopolysaccharide (LPS)-neutralizing peptides are emerging as new potential therapeutic modalities to treat sepsis and skin infections. Purinergic ligand-gated ion channels (P2X receptors) play a critical role in various biological processes, including inflammation. Recent drug development efforts have significantly focused on the modulation of P2X receptors. Here, we investigated the effects of the synthetic LPS-neutralizing peptide Pep19-2.5 on human P2X receptors in cells of the innate immune system. Pep19-2.5 concentration-dependently triggered Ca2+ influx, interleukin (IL)-1β, and lactate dehydrogenase (LDH) release in Toll-like receptor-stimulated human macrophages and monocytes. Ca2+ influx was mediated at least partially by P2X7 receptors, and IL-1β and LDH release by P2X7 receptors, respectively. Confocal microscopy confirmed the colocalization of Pep19-2.5 with P2X7 receptors. Pep19-2.5-induced IL-1β release in primed cells was dependent on K+ efflux, caspase-1, and the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 inflammasome. In the presence of the P2X7 receptor agonist 2'(3')-O-(4-benzoylbenzoyl)adenosine-5'-triphosphate, Pep19-2.5 reduced IL-1β and LDH release. In 1321N1, astrocytoma cells stably transfected with human P2X receptors, Pep19-2.5 potently modulated P2X7 and P2X4 receptors (IC50 values of 0.346 and 0.146 μM, respectively) but showed less (P2X1, P2X3) or no activity (P2X2) at other P2X receptor subtypes. Our findings underline the potential of LPS-neutralizing peptides as modulators of P2X receptors, thus expanding their applicability beyond the treatment of sepsis to the treatment of inflammatory diseases.

Gut-liver axis in sepsis-associated liver injury: Epidemiology, challenges and clinical practice

Although the liver has a remarkable regenerative capacity, sepsis-associated liver injury (SLI) is a complication often seen in intensive care units. Due to its role in immune and inflammatory regulation, the liver is particularly vulnerable during severe infections. Understanding the global prevalence, causes, and management of SLI is essential to improve outcomes and reduce healthcare costs. This paper aims to explore these factors, with an emphasis on identifying effective strategies for clinical management. Zhang et al's bibliometric analysis of 787 publications (745 original articles and 42 reviews, mostly in animal models) from 2000 to 2023 highlights the growing interest in SLI, focusing on oxidative stress, gut microbiota, and inflammatory processes. Key components such as nuclear factor-kappa B and the NOD-like receptor thermal protein domain associated protein 3 inflammasome pathway, along with their links to gut microbiota imbalance and oxidative stress, are crucial for understanding SLI pathogenesis. The gut-liver axis, particularly the role of intestinal permeability and bacterial translocation in liver inflammation, is emphasized. In this context, bacterial translocation is especially relevant for critically ill patients, as it can exacerbate liver inflammation. The findings underscore the need for integrated care in intensive care units, prioritizing gut health and careful antibiotic use to prevent dysbiosis. Despite extensive research, there remains a lack of clinical trials to validate therapeutic approaches. The abundance of experimental studies highlights potential therapeutic targets, stressing the need for high-quality randomized clinical trials to translate these findings into clinical practice.

Immunometabolic Effect of Nitric Oxide on Human Macrophages Challenged With the SARS-CoV2-Induced Cytokine Storm. A Fluxomic Approach

The cytokine storm associated with SARS-CoV-2 infection is one of the most distinctive pathological signatures in COVID-19 patients. Macrophages respond to this pro-inflammatory challenge by reprogramming their functional and metabolic phenotypes. Interestingly, human macrophages fail to express the inducible form of the NO synthase (NOS2) in response to pro-inflammatory activation and, therefore, NO is not synthesized by these cells. The contribution of exogenously added NO, via a chemical NO-donor, on the immunometabolic changes associated with the cytokine storm is investigated. By using metabolic, transcriptomic, and functional assays the effect of NO in human macrophages is evaluated and found specific responses. Moreover, through integrative fluxomic analysis, pathways modified by NO that contribute to the expression of a particular phenotype in human macrophages are identified, which includes a decrease in mitochondrial respiration and TCA with a slight increase in the glycolytic flux. A significant ROS increase and preserved cell viability are observed in the presence of NO, which may ease the inflammatory response and host defense. Also, NO reverses the cytokine storm-induced itaconate accumulation. These changes offer additional clues to understanding the potential crosstalk between NO and the COVID-19 cytokine storm-dependent signaling pathways.

Berberine chloride loaded nano-PEGylated liposomes attenuates imidacloprid-induced neurotoxicity by inhibiting NLRP3/Caspase-1/GSDMD-mediated pyroptosis

Concerns have been expressed about imidacloprid (IMI), one of the most often used pesticides, and its potential neurotoxicity to non-target organisms. Chronic neuroinflammation is central to the pathology of several neurodegenerative disorders. Hence, exploring the molecular mechanism by which IMI would trigger neuroinflammation is particularly important. This study examined the neurotoxic effects of oral administration of IMI (45 mg/kg/day for 30 days) and the potential neuroprotective effect of berberine (Ber) chloride loaded nano-PEGylated liposomes (Ber-Lip) (10 mg/kg, intravenously every other day for 30 days) using laboratory rat. The histopathological changes, anti-oxidant and oxidative stress markers (GSH, SOD, and MDA), proinflammatory cytokines (IL1β and TNF-α), microglia phenotype markers (CD86 and iNOS for M1; CD163 for M2), the canonical pyroptotic pathway markers (NLRP3, caspase-1, GSDMD, and IL-18) and Alzheimer's disease markers (Neprilysin and beta amyloid [Aβ] deposits) were assessed. Oral administration of IMI resulted in apparent cerebellar histopathological alterations, oxidative stress, predominance of M1 microglia phenotype, significantly upregulated NLRP3, caspase-1, GSDMD, IL-18 and Aβ deposits and significantly decreased Neprilysin expression. Berberine reduced the IMI-induced aberrations in the measured parameters and improved the IMI-induced histopathological and ultrastructure alterations brought on by IMI. This study highlights the IMI neurotoxic effect and its potential contribution to the development of Alzheimer's disease and displayed the neuroprotective effect of Ber-Lip.

Baicalein inhibits NLRP3 inflammasome activation and mitigates placental inflammation and oxidative stress in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a common metabolic disorder during pregnancy characterized by glucose intolerance, which poses risks to both maternal and fetal health. Baicalein, a flavonoid derived from the roots of Scutellaria baicalensis Georgi, exhibits various biological functions and has been implicated in the modulation of several diseases. However, the regulatory effects and underlying mechanisms of Baicalein in GDM progression remain unclear. In this study, we found that Baicalein ameliorates metabolic disturbances in GDM mice by improving glucose tolerance, insulin sensitivity, fasting blood glucose levels, and plasma insulin levels. Additionally, Baicalein treatment positively impacted litter size and birth weight. GDM mice exhibited increased inflammation and oxidative stress, which were mitigated following Baicalein administration (40 mg/kg). Furthermore, elevated protein levels of NLRP3, IL-1β, and IL-18 observed in GDM mice were reduced by Baicalein treatment. In conclusion, Baicalein inhibits the NLRP3 inflammasome and alleviates placental inflammation and oxidative stress associated with GDM. These findings provide valuable insights into the potential therapeutic role of Baicalein in managing GDM.

Inflammasomes in neurodegenerative diseases

Inflammasomes represent a crucial component of the innate immune system, which respond to threats by recognizing different molecules. These are known as pathogen-associated molecular patterns (PAMPs) or host-derived damage-associated molecular patterns (DAMPs). In neurodegenerative diseases and neuroinflammation, the accumulation of misfolded proteins, such as beta-amyloid and alpha-synuclein, can lead to inflammasome activation, resulting in the release of interleukin (IL)-1β and IL-18. This activation also induces pyroptosis, the release of inflammatory mediators, and exacerbates neuroinflammation. Increasing evidence suggests that inflammasomes play a pivotal role in neurodegenerative diseases. Therefore, elucidating and investigating the activation and regulation of inflammasomes in these diseases is of paramount importance. This review is primarily focused on evidence indicating that inflammasomes are activated through the canonical pathway in these diseases. Inflammasomes as potential targets for treating neurodegenerative diseases are also discussed.

The design, synthesis, and biological evaluation of 5,6,7,8-tetrahydropteridines as anti-inflammatory compounds

The NLRP3 inflammasome is implicated in the pathogenesis of a wide array of inflammatory diseases including cancer, type II diabetes, atherosclerosis, gout, and neurodegenerative disease. Research has shown that Bruton's tyrosine kinase (BTK) is a critical regulator of the NLRP3 inflammasome and that the pharmacological inhibition of BTK using the FDA-approved inhibitor ibrutinib diminishes NLRP3-dependent inflammatory response. Herein, we describe our pursuit towards novel anti-inflammatory compounds using a scaffold-hopping approach. In our drug discovery efforts, we identified 5,6,7,8-tetrahydropteridines as underutilized scaffolds in medicinal chemistry. We report the synthesis of 5,6,7,8-tetrahydropteridines with potential as anti-inflammatory compounds.

Hypocrellin A from an ethnic medicinal fungus protects against NLRP3-driven gout in mice by suppressing inflammasome activation

Abnormal activation of NLRP3 inflammasome causes the progression of gout, and no small-molecule inhibitor of NLRP3 has been approved yet for clinical use. In this study we established a nigericin-induced inflammasome activation cell model for screening of a natural product library by measuring IL-1β secretion in cell supernatants. Among 432 compounds tested, we found that hypocrellin A (HA), one of the major active components of a traditional ethnic medicinal fungus Hypocrella bambusea in the Northwest Yunnan of China, exhibited the highest inhibition on IL-1β production (IC50 = 0.103 μM). In PMA-primed THP-1 cells or bone marrow derived macrophages (BMDMs) treated with multiple stimuli (nigericin, ATP or MSU), HA dose-dependently suppressed the activation of NLRP3 inflammasome, reducing the subsequent release of inflammatory cytokines and LDH. Furthermore, the suppression of inflammasome activation by HA was specific to NLRP3, but not to AIM2 or NLRC4. In LPS-primed BMDMs treated with nigericin, HA inhibited ASC oligomerization and speckle formation, and blocked the NLRP3-NEK7 interaction during inflammasome assembly without influencing the priming stage. Moreover, we demonstrated that HA directly bound to the NACHT domain of NLRP3, and that Arg578 and Glu629 were the critical residues for HA binding to NLRP3. In MSU-induced peritonitis and acute gouty arthritis mouse models, administration of HA (10 mg/kg, i.p., once or twice daily) effectively suppressed the inflammatory responses mediated by NLRP3 inflammasome. We conclude that HA is a broad-spectrum and specific NLRP3 inhibitor, and a valuable lead compound to develop novel therapeutic inhibitors against NLRP3-driven diseases. This study also elucidates the anti-inflammation mechanisms and molecular targets of HA, a major active component in medicinal fungus Hypocrella bambusea that has been long used by Chinese ethnic groups.

Tranilast alleviates skin inflammation and fibrosis in rosacea-like mice induced by long-term exposure to LL-37

Rosacea, a prevalent chronic facial inflammatory condition, afflicts millions worldwide. Its multifaceted pathogenesis poses challenges for effective treatment. Tranilast (TR), an analog of a tryptophan metabolite, has demonstrated anti-inflammatory and anti-fibrotic properties across various diseases. Yet, its potential in rosacea treatment remains understudied. Here, we induced rosacea-like symptoms in mice via prolonged LL-37 injections and administered TR intervention. Our findings reveal that TR mitigated skin lesions, reduced skin thickness, and suppressed inflammatory cell infiltration within the dermis of LL-37 mice. Notably, TR downregulated the expression of rosacea-associated inflammatory cytokines (TNF-α, IL-6, IL-1β, and IL-18) and the antimicrobial peptide CAMP, while also inhibiting NLRP3 inflammasome activation and the TLR4 signaling pathway. Furthermore, TR attenuated LL-37-induced fibrosis and hindered the transforming growth factor-β1 (TGF-β1)/Smad2/3 pathway. In summary, our study underscores TR's therapeutic potential in rosacea by mitigating both skin inflammation and fibrosis, thereby offering a promising treatment avenue for this condition.

Exploring the role of NLRP3 infalmmasome in diabetes: a literature review and bibliometric analysis

Background

Diabetes has emerged as the foremost public health challenge of the 21st century, with a notable shift towards managing it through an inflammatory lens. This study seeks to investigate the role of NLRP3 infalmmasome in diabetes over the past ten years, leveraging bibliometric analysis to pinpoint prevailing trends, underscore critical focal points, and establish a roadmap for subsequent research endeavors.

Method

A literature search was conducted based on the SCI-E database, and all recorded results were downloaded in plain text format for subsequent analysis. The analysis was carried out using Vosviewer1.6.18, citespace6.3R1, and Microsoft Excel 2021 software, focusing on the following terms: country, institution, author, journal, references, and keywords.

Results

From January 1, 2014, to December 31, 2023, a total of 1373 articles were retrieved, with China, the United States, and Italy contributing the majority of records. Harbin Medical University, Nanjing Medical University, and Central South University stand as the top three most productive institutions. "International Journal of Molecular Sciences" leads the way with the highest number of publications, closely followed by "Frontiers in Immunology" and "Frontiers in Pharmacology." Authors Wang Wei boast the most publications, closely followed by Li Xiang and Wang Yan. Within the superimposed keyword network, four primary clusters emerge: (1) exploring the link between NLRP3 infalmmasome and inflammatory diseases like diabetes; (2) investigating the cellular-level pathogenesis of diabetes-related conditions; (3) examining diabetes characteristics and associated suppression techniques; (4) studying cell morphology alterations, including pyroptosis. Over the past five years, key topics in this field have revolved around the "heart", "damage", "caspase 1 activation", "NLRP3", and "diabetic kidney disease".

Conclusion

This paper has identified the hot spots and trends concerning the role of NLRP3 infalmmasome in diabetes, thereby providing a valuable reference for future research. Furthermore, it is anticipated that pyroptosis and diabetes-related diseases will become frontier research topics that may garner significant attention in the coming years.

NLRP3 deficiency improves bone healing of tooth extraction sockets through SMAD2/3-RUNX2-mediated osteoblast differentiation

Impaired bone healing following tooth extraction poses a significant challenge for implantation. As a crucial component of the natural immune system, the NLRP3 inflammasome is one of the most extensively studied pattern-recognition receptors, and is involved in multiple diseases. Yet, the role of NLRP3 in bone healing remains to be clarified. Here, to investigate the effect of NLRP3 on bone healing, we established a maxillary first molar extraction model in wild-type and NLRP3KO mice using minimally invasive techniques. We observed that NLRP3 was activated during the bone repair phase, and its depletion enhanced socket bone formation and osteoblast differentiation. Moreover, NLRP3 inflammasome activation was found to inhibit osteogenic differentiation in alveolar bone-derived mesenchymal stem cells (aBMSCs), an effect mitigated by NLRP3 deficiency. Mechanistically, we established that the SMAD2/3-RUNX2 signaling pathway is a downstream target of NLRP3 inflammasome activation, and SMAD2/3 knockdown partially reversed the significant decrease in expression of RUNX2, OSX, and ALP induced by NLRP3. Thus, our findings demonstrate that NLRP3 negatively modulates alveolar socket bone healing and contributes to the understanding of the NLRP3-induced signaling pathways involved in osteogenesis regulation.

Short- and long-term pathologic responses to quartz are induced by nearly free silanols formed during crystal fracturing

BACKGROUND

Inhalation of respirable crystalline silica particles, including quartz, is associated with an increased risk of developing pathologies, including persistent lung inflammation, fibrosis, cancer, and systemic autoimmunity. We demonstrated that the nearly free silanols (NFS) generated upon quartz fracturing trigger the early molecular events determining quartz toxicity. Here, we address the involvement of NFS in driving short- and long-term pathogenic responses, including lung inflammation, fibrosis, cancer, and autoimmunity in multiple mouse models.

RESULTS

In vivo pulmonary responses to as-grown NFS-poor quartz (gQ) and fractured NFS-rich quartz (gQ-f) of synthetic origin were compared to two NFS-rich reference quartz dusts (Min-U-Sil 5, mQ-f). Acute and persistent inflammation, as well as fibrosis, were assessed 3 and 60 days, respectively, after administering one dose of particles (2 mg) via oropharyngeal aspiration (o.p.a.) to C57BL/6 mice. The carcinogenic potential was assessed in a co-carcinogenicity study using A/J mice, which were pre-treated with 3-methylcholanthrene (3-MC) and administered four doses of quartz particles (4 × 1 mg, o.p.a.), then sacrificed after 10 months. Autoimmunity was evaluated in autoimmune-prone 129/Sv mice 4 months after particle administration (2 × 1.25 mg, o.p.a). Mice exposed to NFS-rich quartz exhibited a strong acute lung inflammatory response, characterized by pro-inflammatory cytokine release and leukocyte accumulation, which persisted for up to 60 days. No inflammatory effect was observed in mice treated with NFS-poor gQ. Fibrosis onset (i.e., increased levels of pro-fibrotic factors, hydroxyproline, and collagen) was prominent in mice exposed to NFS-rich but not to NFS-poor quartz. Additionally, lung cancer development (tumour numbers) and autoimmune responses (elevated IgG and anti-dsDNA autoantibody levels) were only observed after exposure to NFS-rich quartz.

CONCLUSIONS

Collectively, the results indicate that NFS, which occur upon fracturing of quartz particles, play a crucial role in the short- and long-term local and systemic responses to quartz. The assessment of NFS on amorphous or crystalline silica particles may help create a predictive model of silica pathogenicity.

From mitochondrial dysfunction to neuroinflammation in Parkinson's disease: Pathogenesis and mitochondrial therapeutic approaches

Parkinson's disease (PD) is a prevalent and intricate neurological condition resulting from a combination of several factors, such as genetics, environment, and the natural process of aging. Degeneration of neurons in the substantia nigra pars compacta (SN) can cause motor and non-motor impairments in patients with PD. In PD's etiology, inflammation and mitochondrial dysfunction play significant roles in the disease's development. Studies of individuals with PD have revealed increased inflammation in various brain areas. Furthermore, mitochondrial dysfunction is an essential part of PD pathophysiology. Defects in the components of the mitochondrial nucleus, its membrane or internal signaling pathways, mitochondrial homeostasis, and morphological alterations in peripheral cells have been extensively documented in PD patients. According to these studies, neuroinflammation and mitochondrial dysfunction are closely connected as pathogenic conditions in neurodegenerative diseases like PD. Given the mitochondria's role in cellular homeostasis maintenance in response to membrane structural flaws or mutations in mitochondrial DNA, their dynamic nature may present therapeutic prospects in this area. Recent research investigates mitochondrial transplantation as a potential treatment for Parkinson's disease in damaged neurons. This review delves into the impact of inflammation and mitochondrial dysfunction on PD occurrence, treatment approaches, and the latest developments in mitochondrial transplantation, highlighting the potential consequences of these discoveries.

The role of Gαq in regulating NLRP3 inflammasome activation

BACKGROUND

G proteins are a class of important signal transducers in mammalians. G proteins can corpoarated with G proteincoupled receptors (GPCRs) and transmit signals from extracellular stimuli into intracellular response, which will regulate a series of biological functions. G-proteins are heterotrimeric proteins composed of Gα, Gβ, and Gγ subunits. Based on structural and functional similarity of their α-subunits, G proteins are typically grouped into four classes (Gi, Gs, Gq/11, and G12/13). The Gq/11 subfamily consists of Gq, G11, G14, and G15/16 proteins. Gαq is the α-subunit of Gq protein and encoded by GNAQ. Our previous studies revealed that Gαq play an important role in regulating T cell survival and T cell differentiation. Inflammasomes are multiprotein complexes that play a critical role in modulating innate inflammatory response. NLRP3 inflammasome is currently the most extensively studied inflammasome.

METHODS

We found that Gαq suppressed NLRP3 inflammasome activation in macrophage, Gαq also suppressed NLRP3 inflammasome activation in a LPS-induced sepsis mouse model. Gαq can locate to mitochondria and Gαq was required for the maintenance of mitochondrial homeostasis. Gαq regulated NLRP3 inflammasome activation by modulating mitochondrial reactive oxygen species (mtROS).

RESULTS

We found that Gαq suppressed NLRP3 inflammasome activation in macrophage, Gαq also suppressed NLRP3 inflammasome activation in a LPS-induced sepsis mouse model. Gαq can locate to mitochondria and Gαq was required for the maintenance of mitochondrial homeostasis. Gαq regulated NLRP3 inflammasome activation by modulating mitochondrial reactive oxygen species (mtROS).

CONCLUSION

Our results indicate that Gαq regulates NLRP3 inflammasome activation by modulating mitochondrial ROS production. Our research provides new mechanistic insight into the activation of NLRP3 inflammasome. As it has been proved that NLRP3 inflammasome plays an important role in the pathogenesis many diseases such as Alzheimer's disease, cancer, and inflammatory bowel disease, Gαq might become a novel drug target for these diseases in future.

Non-cyclic nucleotide EPAC1 activators suppress lipopolysaccharide-regulated gene expression, signalling and intracellular communication in differentiated macrophage-like THP-1 cells

This study explores the anti-inflammatory effects of non-cyclic nucleotide EPAC1 activators, PW0577 and SY007, on lipopolysaccharide (LPS)-induced responses in differentiated THP-1 macrophage-like cells. Both activators were found to selectively activate EPAC1 in THP-1 macrophages, leading to the activation of the key down-stream effector, Rap1. RNA sequencing analysis of LPS-stimulated THP-1 macrophages, revealed that treatment with PW0577 or SY007 significantly modulates gene expression related to fibrosis and inflammation, including the suppression of NLRP3, IL-1β, and caspase 1 protein expression in LPS-stimulated cells. Notably, these effects were independent of p65 NFκB phosphorylation at Serine 536, indicating a distinct mechanism of action. The study further identified a shared influence of both activators on LPS signalling pathways, particularly impacting extracellular matrix (ECM) components and NFκB-regulated genes. Additionally, in a co-culture model involving THP-1 macrophages, vascular smooth muscle cells, and human coronary artery endothelial cells, EPAC1 activators modulated immune-vascular interactions, suggesting a broader role in regulating cellular communication between macrophages and endothelial cells. These findings enhance our understanding of EPAC1's role in inflammation and propose EPAC1 activators as potential therapeutic agents for treating inflammatory and fibrotic conditions through targeted modulation of Rap1 and associated signalling pathways.

Erxian decoction ameliorates myocardial tissue damage through activating PI3K/AKT signaling pathway in ovariectomized rats

BACKGROUND

Erxian decoction (EXD) is an empirical formula for treating cardiovascular disease, our previous work has shown that EXD could improve the cardiovascular structure and function in ovariectomized (OVX) rats, but its pharmacological mechanism is still unclear.

MATERIALS AND METHODS

Network pharmacology was utilized to assess the key active components and central targets of EXD in treating postmenopausal cardiovascular disease. Then, an OVX rat model was established, HE staining and transmission electron microscope were utilized to observe myocardial tissue morphology, TUNEL staining was utilized to detect cardiomyocyte apoptosis, western blot, and ELISA were used to confirm efficacy and pathway of EXD.

RESULTS

The network pharmacology prediction results showed that 129 common targets were identified by intersecting EXD targets and postmenopausal cardiovascular disease targets, including AKT1, TNF, IL-6, IL-1β, PTGS2 and other core targets, apoptosis, PI3K/AKT, and other signaling pathways may be closely related to postmenopausal cardiovascular disease. After ovariectomy, the myocardial tissue of rats was damaged, the expression level of PI3K/AKT pathway-related molecules in the myocardial tissue were decreased, the apoptosis index of cardiomyocytes was increased, and the levels of inflammatory factors (TNF-α, IL-6, and IL-1β) were enhanced. EXD intervention could improve myocardial tissue injury, EXD could up-regulate the protein expression of PI3K and p-AKT in myocardial tissue, and thereby prevent myocardial cell apoptosis. At the same time, EXD downregulated the levels of inflammatory factors in serum of ovariectomized rats.

CONCLUSION

EXD may prevent myocardial tissue damage through induction of the PI3K/AKT signaling pathway, thereby reducing cardiomyocyte apoptosis and inflammation. EXD may be a potential drug for the treatment of postmenopausal cardiovascular disease.

Therapeutic role of NLRP3 inflammasome inhibitors against Alzheimer's disease

The NLRP3 inflammasome is a multiprotein complex that plays a vital role in regulating inflammatory signaling and the innate immune system. Activation of NLRP3 by accumulation of Aβ leads to its oligomerization and the activation of caspase-1, resulting in the secretion of pro-cytokines such as IL-18 and IL-1β. These pro-cytokines can contribute to cognitive impairment and neurodegeneration. The activation of NLRP3 is associated with neuroinflammation in animal models of Alzheimer's disease (AD). Therefore, the NLRP3 inflammasome is considered a potential therapeutic target for AD. Various natural and synthetic molecules have gained attention as NLRP3 inhibitors against AD. In this review, we will summarize the sources, chemical structures, synthesis, and biological activity of NLRP3 inhibitors as anti-Alzheimer's agents. Additionally, we will critically analyze the structure-activity relationship (SAR) of NLRP3 inhibitors. This detailed examination of the SAR-based investigation of NLRP3 inhibitors and their derivatives offers insights into the design and development of novel NLRP3 inhibitors as anti-Alzheimer's agents. It is expected that this review will assist researchers in developing innovative and effective NLRP3 inhibitors for the treatment of AD.

Nicotine-Induced Transient Activation of Monocytes Facilitates Immunosuppressive Macrophage Polarization that Restrains T Helper 17 Cell Expansion

Macrophages in smoking environment exhibit a distinct immunosuppressive phenotype, but the mechanisms that allow nicotine to "educate" macrophages are incompletely understood. Here, we identified that nicotine transiently activates and subsequently deactivates monocytes, leading to reduced anti-infective capability of macrophages. This deactivation results in a suppression of IL-17-producing cell expansion through decreased IL-1β production. Mechanistically, nicotine induces the expression of IRAK-M in macrophages, which inhibits NF-κB signaling and restrains NLRP3 inflammasome-mediated IL-1β production. Moreover, the induction of IRAK-M by nicotine is mediated through α7 nAChR binding, which activates downstream STAT3 and AKT signaling pathways. Targeting the interaction between nicotine and α7 nAChR can decrease IRAK-M expression and restore LPS-mediated NLRP3 inflammasome-driven IL-1β production. Collectively, these findings elucidate how nicotine modulates macrophage function through complex signaling mechanisms, ultimately impacting their anti-infective responses and inflammatory processes.

Gut Microbiome Implication and Modulation in the Management of Recurrent Urinary Tract Infection

Urinary tract infections (UTIs) are one of the most common bacterial infections, affecting more than 150 million people each year in the world. UTIs have grown exponentially in the last few years. They represent a major load for both individuals and society. The highest incidence (about 55-60%) concerns women. Many pathogens are involved in UTIs, most of which are derived from the gut. Recent studies, together with recent diagnostic techniques (such as quantitative culture of urine or next-generation sequencing), have improved the knowledge of microbial communities in the urinary tract. It turned out that gut dysbiosis is strictly involved in the pathogenesis of UTIs. In particular, the human gut is the natural habitat for Escherichia coli (E. coli), the main bacterium responsible for UTIs. The overgrowth of E. coli pathogenic strains represents a risk factor for them. Furthermore, the human gut microbiota acts as a "global reservoir" for genes conferring resistance to clinically relevant antibiotics, thus influencing the treatment of UTIs. In addition, differently from the past, the idea of a sterile urinary environment has been replaced by the characterization of a urinary microbiome. The aim of our review is to explore recent studies on the association between gut microbiota and urinary microbiome and to summarize the current knowledge about the effects of interactions between gut and urinary microbial communities in the pathogenesis of UTIs, considering UTIs more as a "gut disease" and not only a urinary disease and providing new insight into the therapeutic options such as the use of probiotics.

Stress-experienced monocytes/macrophages lose anti-inflammatory function via β2-adrenergic receptor in skin allergic inflammation

BACKGROUND

Psychological stress can exacerbate the development of allergies; however, the underlying mechanisms remain poorly understood. IgE-mediated cutaneous allergic inflammation (IgE-CAI) is a basophil-dependent skin allergy with eosinophil infiltration at inflammatory sites. Its resolution involves anti-inflammatory programmed death ligand 2 (PD-L2)-positive macrophages.

OBJECTIVE

This study sought to elucidate the cellular and molecular mechanisms by which psychological stress exacerbates IgE-CAI.

METHODS

Neural tissue involved in stress-induced IgE-CAI exacerbation was identified by performing denervation and brain destruction experiments in mice. Immune cell transplantation, RNA sequencing, flow cytometry, and ELISA were used to identify and characterize immune cells with stress-altered functioning, followed by identification of key factors involved in IgE-CAI exacerbation.

RESULTS

Stress-induced exacerbation of IgE-CAI was found to be sympathetic and β2-adrenergic receptor (Adrb2)-dependent. Adoptive transfer experiments revealed that stress diminished the anti-inflammatory functions of PD-L2-positive macrophages through Adrb2, exacerbating the inflammation. RNA sequencing analysis indicated that PD-L2-positive macrophages in stressed mice exhibit reduced expression of efferocytosis-related genes, including Gas6 and MerTK. Consequently, the efferocytic capacity of these macrophages decreased, resulting in increased numbers of dead cells in the lesions. The exacerbation and upregulation of Ccl24 expression in IgE-CAI skin lesions were countered by a Caspase-1 inhibitor.

CONCLUSIONS

Psychological stress diminishes the efferocytotic capacity of PD-L2-positive macrophages, causing an accumulation of dead cells. This, in turn, heightens eosinophil infiltration through Caspase-1-dependent production of CCL24, exacerbating IgE-CAI.

Understanding the Role of NLRP3 Inflammasome in Acute Pancreatitis

Acute pancreatitis (AP) remains a serious clinical condition, with current treatment options being largely supportive. The discovery of inflammasomes, particularly the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, has significantly advanced our knowledge regarding many inflammatory diseases' pathogenesis, including AP. The NLRP3 inflammasome is central in mediating the inflammatory process in AP through its diverse activation mechanisms and its involvement in multiple signal transduction pathways. This has made NLRP3 an appealing target for novel therapeutic strategies aimed at modulating inflammation in AP. Despite the growing interest in NLRP3 as a therapeutic target, there remains a notable gap in clinical research, with few clinical trials exploring the efficacy of NLRP3 inhibitors in AP. Results of several preclinical studies and animal models are promising and suggest that the use of NLRP3 inhibitors could result in reduced inflammation and improved patient outcomes in AP. Further research is urgently needed to assess their potential benefits, safety, and applicability in human patients and address the underlying inflammatory processes driving AP.

How PPAR-alpha mediated inflammation may affect the pathophysiology of chronic kidney disease

Chronic kidney disease (CKD) is a major risk factor for death in adults. Inflammation plays a role in the pathogenesis of CKD, but the mechanisms are poorly understood. Peroxisome proliferator-activated receptor alpha (PPAR-α) is a nuclear receptor and one of the three members (PPARα, PPARβ/δ, and PPARγ) of the PPARs that plays an important role in ameliorating pathological processes that accelerate acute and chronic kidney disease. Although other PPARs members are well studied, the role of PPAR-α is not well described and its role in inflammation-mediated chronic disease is not clear. Herein, we review the role of PPAR-α in chronic kidney disease with implications for the immune system.

Kirenol Ameliorates Myocardial Ischemia-Reperfusion Injury by Promoting Mitochondrial Function and Inhibiting Inflammasome Activation

PURPOSE

Macrophage-mediated inflammation plays a crucial role in the pathophysiological process of myocardial ischemia/reperfusion (I/R) injury. Recent studies have highlighted the importance of mitochondrial function and inflammasome activation in the inflammatory process. Kirenol, a well-known natural compound, has been shown to regulate inflammation in various diseases. This study investigated whether Kirenol could exert anti-inflammatory effects on macrophages during myocardial I/R injury.

METHODS

Mouse myocardial I/R models were established by 45 min of ischemia followed by 24 h of reperfusion. Saline or Kirenol treatment was administered. In vivo assessments included the evaluation of cardiac function, infarcted area, and immune cell infiltration. Subsequently, bone marrow-derived macrophages (BMDMs) were isolated, and mitochondrial function and pyroptosis were assessed. Furthermore, the study compared the cardioprotective effects of Kirenol with a specific NOX1/NOX4 inhibitor, GKT137831.

RESULTS

Kirenol gavage improved cardiac function, decreased infarct area, and alleviated inflammatory infiltration in mice subjected to myocardial I/R injury. Mechanistically, Kirenol inhibited NOX1 and NOX4 and enhanced mitochondrial function, ultimately attenuating the pyroptosis of macrophages. The therapeutic effects of Kirenol and GKT137831 were not significantly different.

CONCLUSION

This study demonstrates that Kirenol mitigates myocardial I/R injury by inhibiting NOX1 and NOX4, restoring mitochondrial function, and ameliorating macrophage pyroptosis.

Role of purinoreceptors in the release of extracellular vesicles and consequences on immune response and cancer progression

Cell-to-cell communication is a major process for accommodating cell functioning to changes in the environments and to preserve tissue and organism homeostasis. It is achieved by different mechanisms characterized by the origin of the message, the molecular nature of the messenger, its speed of action and its reach. Purinergic signalling is a powerful mechanism initiated by extracellular nucleotides, such as ATP, acting on plasma membrane purinoreceptors. Purinergic signalling is tightly controlled in time and space by the action of ectonucleotidases. Recent studies have highlighted the critical role of purinergic signalling in controlling the generation, release and fate of extracellular vesicles and, in this way, mediating long-distance responses. Most of these discoveries have been made in immune and cancer cells. This review is aimed at establishing the current knowledge on the way which purinoreceptors control extracellular vesicle-mediated communications and consequences for recipient cells.

Stapled peptides as potential therapeutics for diabetes and other metabolic diseases

The field of peptide drug research has experienced notable progress, with stapled peptides featuring stabilized α-helical conformation, emerging as a promising field. These peptides offer enhanced stability, cellular permeability, and binding affinity and exhibit potential in the treatment of diabetes and metabolic disorders. Stapled peptides, through the disruption of protein-protein interactions, present varied functionalities encompassing agonism, antagonism, and dual-agonism. This comprehensive review offers insight into the technology of peptide stapling and targeting of crucial molecular pathways associated with glucose metabolism, insulin secretion, and food intake. Additionally, we address the challenges in developing stapled peptides, including concerns pertaining to structural stability, peptide helicity, isomer mixture, and potential side effects.

Hesperetin protects against rotenone-induced motor disability and neurotoxicity via the regulation of SIRT1/NLRP3 signaling

Rotenone is a pesticide that causes complex I inhibition and is widely known to induce motor disability and experimental Parkinson's disease (PD) in rodents. Evidence suggests a crucial role for sirtuin/nuclear factor-kappaB/nod-like receptor family, pyrin domain-containing 3 (SIRT1/NFκB/NLRP3) signaling and inflammation in PD and rotenone neurotoxicity. Hesperetin (C16H14O6) is a citrus flavonoid with documented anti-inflammatory activity. We investigated the value of hesperetin in delaying rotenone-induced PD in mice and the possible modulation of inflammatory burden. PD was induced in mice via rotenone injections. Groups were assigned as a vehicle, PD, or PD + hesperetin (50 or 100 mg/kg) and compared for the motor function, protein level (by ELISA), and gene expression (by real-time PCR) of the target proteins, histopathology, and immunohistochemistry for tyrosine hydroxylase enzyme. Hesperetin (50 or 100 mg/kg) alleviated the motor disability and the striatal dopamine level and decreased the expression of NLRP3 and NF-κB but increased SIRT1 expression (p < 0.05). Further, it enhanced the neural viability and significantly decreased neural degeneration in the substantia nigra, hippocampus, and cerebral cortex (p < 0.05). Taken together, we propose that hesperetin mediates its neuroprotective function via alleviating modulation of the SIRT1/NFκB/NLRP3 pathway. Therefore, hesperetin might delay the PD progression.

Maltol, a compound in Korean Red Ginseng, attenuates the Staphylococcus aureus-induced inflammasome activation in the skin

Background

Staphylococcus aureus can cause local or systemic infections as an opportunistic pathogen and induce the activation of inflammasomes, leading to the secretion of interleukin (IL)-1β. Since S. aureus is part of the normal flora, it is essential to control it using safe, non-antibiotic substances like Korean Red Ginseng Extract (RGE). This study investigated the effects of maltol, a non-saponin compound found in RGE, on S. aureus-mediated inflammasome signaling.

Methods

Human keratinocytes (HaCaT) and macrophages were infected with S. aureus and treated with RGE and maltol. The secretion of IL-1β, an indicator of inflammasome activation, was analyzed. For the mechanistic studies, the HaCaT cells were infected with S. aureus in the presence of maltol or inflammasome inhibitors, and the generation of mitochondrial reactive oxygen species (mitROS) and IL-1β production were measured. The effect of maltol was also evaluated in S. aureus-injected mice.

Results

RGE and maltol inhibited S. aureus-mediated IL-1β secretion in HaCaT, but not in macrophages. In the mechanistic studies, maltol suppressed the production of mitROS and the priming step of inflammasome signaling resulting in attenuated S. aureus-mediated inflammasome activation in HaCaT. In mice, maltol inhibited the production of peritoneal IL-1β and IL-6 in response to the S. aureus injection.

Conclusion

Maltol selectively regulated skin inflammasome activation by inhibiting mitROS generation and the inflammasome priming step.

Increased inflammasome protein expression identified in microglia from postmortem brains with schizophrenia

Schizophrenia (SCZ) is a complex psychiatric disorder that involves an inflammatory response thought to be characterized by microglial activation. The inflammasome complex may play critical roles in the pathomechanism of neuroinflammation but how this relates to SCZ remains unclear. In this study, we performed an immunohistochemical (IHC) analysis to compare the expression of inflammasome proteins in brain tissue from donors with SCZ (n = 16) and non-psychiatric donors (NP; n = 13) isolated from the superior frontal cortex (SFC), superior temporal cortex, and anterior cingulate cortex brain regions. To assess changes in the cell populations that express key inflammasome proteins, we performed IHC analyses of apoptosis-associated speck-like protein containing a CARD (ASC), nod-like receptor protein 3 (NLRP3), and interleukin (IL)-18 to determine if these proteins are expressed in microglia, astrocytes, oligodendrocytes, or neurons. Inflammasome proteins were expressed mainly in microglia from SCZ and NP brains. Increased numbers of microglia were present in the SFC of SCZ brains and exhibited higher inflammasome protein expression of ASC, NLRP3, and IL-18 compared to NPs. These findings suggest that increased inflammasome signaling may contribute to the pathology underlying SCZ.

Mitochondrial Mechanisms in Immunity and Inflammatory Conditions: Beyond Energy Management

Significance: The growing importance of mitochondria in the immune response and inflammation is multifaceted. Unraveling the different mechanisms by which mitochondria have a relevant role in the inflammatory response beyond the energy management of the process is necessary for improving our understanding of the host immune defense and the pathogenesis of various inflammatory diseases and syndromes. Critical Issues: Mitochondria are relevant in the immune response at different levels, including releasing activation molecules, changing its structure and function to accompany the immune response, and serving as a structural base for activating intermediates as NLRP3 inflammasome. In this scientific journey of dissecting mitochondrial mechanisms, new questions and interesting aspects arise, such as the involvement of mitochondrial-derived vesicles in the immune response with the putative role of preventing uncontrolled situations. Recent Advances: Researchers are continuously rethinking the role of mitochondria in acute and chronic inflammation and related disorders. As such, mitochondria have important roles as centrally positioned signaling hubs in regulating inflammatory and immune responses. In this review, we present the current understanding of mitochondrial mechanisms involved, beyond the largely known mitochondrial dysfunction, in the onset and development of inflammatory situations. Future Directions: Mitochondria emerge as an interesting and multifaceted platform for studying and developing pharmaceutical and therapeutic approaches. There are many ongoing studies aimed to describe the effects of specific mitochondrial targeted molecules and treatments to ameliorate the consequences of exacerbated inflammatory components of pathologies and syndromes, resulting in an open area of increasing research interest.

Alzheimer's Disease, Obesity, and Type 2 Diabetes: Focus on Common Neuroglial Dysfunctions (Critical Review and New Data on Human Brain and Models)

BACKGROUND/OBJECTIVES

Obesity, type 2 diabetes (T2D), and Alzheimer's disease (AD) are pathologies that affect millions of people worldwide. They have no effective therapy and are difficult to prevent and control when they develop. It has been known for many years that these diseases have many pathogenic aspects in common. We highlight in this review that neuroglial cells (astroglia, oligodendroglia, and microglia) play a vital role in the origin, clinical-pathological development, and course of brain neurodegeneration. Moreover, we include the new results of a T2D-AD mouse model (APP+PS1 mice on a high-calorie diet) that we are investigating.

METHODS

Critical bibliographic revision and biochemical neuropathological study of neuroglia in a T2D-AD model.

RESULTS

T2D and AD are not only "connected" by producing complex pathologies in the same individual (obesity, T2D, and AD), but they also have many common pathogenic mechanisms. These include insulin resistance, hyperinsulinemia, hyperglycemia, oxidative stress, mitochondrial dysfunction, and inflammation (both peripheral and central-or neuroinflammation). Cognitive impairment and AD are the maximum exponents of brain neurodegeneration in these pathological processes. both due to the dysfunctions induced by metabolic changes in peripheral tissues and inadequate neurotoxic responses to changes in the brain. In this review, we first analyze the common pathogenic mechanisms of obesity, T2D, and AD (and/or cerebral vascular dementia) that induce transcendental changes and responses in neuroglia. The relationships between T2D and AD discussed mainly focus on neuroglial responses. Next, we present neuroglial changes within their neuropathological context in diverse scenarios: (a) aging involution and neurodegenerative disorders, (b) human obesity and diabetes and obesity/diabetes models, (c) human AD and in AD models, and (d) human AD-T2D and AD-T2D models. An important part of the data presented comes from our own studies on humans and experimental models over the past few years. In the T2D-AD section, we included the results of a T2D-AD mouse model (APP+PS1 mice on a high-calorie diet) that we investigated, which showed that neuroglial dysfunctions (astrocytosis and microgliosis) manifest before the appearance of amyloid neuropathology, and that the amyloid pathology is greater than that presented by mice fed a normal, non-high-caloric diet A broad review is finally included on pharmacological, cellular, genic, and non-pharmacological (especially diet and lifestyle) neuroglial-related treatments, as well as clinical trials in a comparative way between T2D and AD. These neuroglial treatments need to be included in the multimodal/integral treatments of T2D and AD to achieve greater therapeutic efficacy in many millions of patients.

CONCLUSIONS

Neuroglial alterations (especially in astroglia and microglia, cornerstones of neuroinflammation) are markedly defining brain neurodegeneration in T2D and A, although there are some not significant differences between each of the studied pathologies. Neuroglial therapies are a very important and p. promising tool that are being developed to prevent and/or treat brain dysfunction in T2D-AD. The need for further research in two very different directions is evident: (a) characterization of the phenotypic changes of astrocytes and microglial cells in each region of the brain and in each phase of development of each isolated and associated pathology (single-cell studies are mandatory) to better understand the pathologies and define new therapeutic targets; (b) studying new therapeutic avenues to normalize the function of neuroglial cells (preventing neurotoxic responses and/or reversing them) in these pathologies, as well as the phenotypic characteristics in each moment of the course and place of the neurodegenerative process.

Parkinson's disease models and death signaling: what do we know until now?

Parkinson's disease (PD) is the second neurodegenerative disorder most prevalent in the world, characterized by the loss of dopaminergic neurons in the Substantia Nigra (SN). It is well known for its motor and non-motor symptoms including bradykinesia, resting tremor, psychiatric, cardiorespiratory, and other dysfunctions. Pathological apoptosis contributes to a wide variety of diseases including PD. Various insults and/or cellular phenotypes have been shown to trigger distinct signaling events leading to cell death in neurons affected by PD. The intrinsic or mitochondrial pathway, inflammatory or oxidative stress-induced extrinsic pathways are the main events associated with apoptosis in PD-related neuronal loss. Although SN is the main brain area studied so far, other brain nuclei are also affected by the disease leading to non-classical motor symptoms as well as non-motor symptoms. Among these, the respiratory symptoms are often overlooked, yet they can cause discomfort and may contribute to patients shortened lifespan after disease diagnosis. While animal and in vitro models are frequently used to investigate the mechanisms involved in the pathogenesis of PD in both the SN and other brain regions, these models provide only a limited understanding of the disease's actual progression. This review offers a comprehensive overview of some of the most studied forms of cell death, including recent research on potential treatment targets for these pathways. It highlights key findings and milestones in the field, shedding light on the potential role of understanding cell death in the prevention and treatment of the PD. Therefore, unraveling the connection between these pathways and the notable pathological mechanisms observed during PD progression could enhance our comprehension of the disease's origin and provide valuable insights into potential molecular targets for the developing therapeutic interventions.

Transcutaneous auricular vagus nerve stimulation mitigates gouty inflammation by reducing neutrophil infiltration in BALB/c mice

Gouty inflammation, caused by uric acid crystal deposition, primarily affects tissues around the toe joints and triggers potent inflammatory responses. Current treatments focus on alleviating inflammation and pain using pharmaceutical agents, which can lead to side effects and complications. This has generated interest in non-pharmacological interventions, such as non-invasive vagus nerve stimulation (VNS). In this study, we explored the anti-inflammatory mechanisms of transcutaneous auricular vagus nerve stimulation (taVNS) in a mouse model of acute gout. Gouty inflammation was induced by injecting monosodium urate (MSU) crystals into the ankle joints of BALB/c mice. The effects of taVNS on the expression of inflammatory cytokines and chemokines in the ankle joint tissue were assessed using real-time quantitative PCR (qPCR), western blotting, histological assessments (H&E staining), and immunohistochemistry (IHC). The role of α7 nicotinic acetylcholine receptors (α7nAChR) was also evaluated by signal blocking. Our findings revealed that MSU significantly elevated gout-associated inflammatory cascades and mediators in the ankle joint. Notably, taVNS at 200 µA and 25 Hz effectively reduced these inflammatory responses, decreasing neutrophil infiltration and chemoattraction within the tissue. taVNS showed significant anti-inflammatory properties by suppressing neutrophil activity, offering a novel therapeutic approach for gout beyond conventional pharmacological methods. Additionally, taVNS holds potential for managing various chronic joint diseases. These results highlight taVNS as a promising non-pharmacological therapy for chronic inflammation.

Potential Roles of IP3 Receptors and Calcium in Programmed Cell Death and Implications in Cardiovascular Diseases

Inositol 1,4,5-trisphosphate receptors (IP3Rs) play a crucial role in maintaining intracellular/cytosolic calcium ion (Ca2+i) homeostasis. The release of Ca2+ from IP3Rs serves as a second messenger and a modulatory factor influencing various intracellular and interorganelle communications during both physiological and pathological processes. Accumulating evidence from in vitro, in vivo, and clinical studies supports the notion that the overactivation of IP3Rs is linked to the pathogenesis of various cardiac conditions. The overactivation of IP3Rs results in the dysregulation of Ca2+ concentration ([Ca2+]) within cytosolic, mitochondrial, and nucleoplasmic cellular compartments. In cardiovascular pathologies, two isoforms of IP3Rs, i.e., IP3R1 and IP3R2, have been identified. Notably, IP3R1 plays a pivotal role in cardiac ischemia and diabetes-induced arrhythmias, while IP3R2 is implicated in sepsis-induced cardiomyopathy and cardiac hypertrophy. Furthermore, IP3Rs have been reported to be involved in various programmed cell death (PCD) pathways, such as apoptosis, pyroptosis, and ferroptosis underscoring their multifaceted roles in cardiac pathophysiology. Based on these findings, it is evident that exploring potential therapeutic avenues becomes crucial. Both genetic ablation and pharmacological intervention using IP3R antagonists have emerged as promising strategies against IP3R-related pathologies suggesting their potential therapeutic potency. This review summarizes the roles of IP3Rs in cardiac physiology and pathology and establishes a foundational understanding with a particular focus on their involvement in the various PCD pathways within the context of cardiovascular diseases.

Sprayable inflammasome-inhibiting lipid nanorods in a polymeric scaffold for psoriasis therapy

Localized delivery of inflammasome inhibitors in phagocytic macrophages could be promising for psoriasis treatment. The present work demonstrates the development of non-spherical lipid nanoparticles, mimicking pathogen-like shapes, consisting of an anti-inflammatory inflammasome inhibiting lipid (pyridoxine dipalmitate) as a trojan horse. The nanorods inhibit inflammasome by 3.8- and 4.5-fold compared with nanoellipses and nanospheres, respectively. Nanorods reduce apoptosis-associated speck-like protein and lysosomal rupture, restrain calcium influx, and mitochondrial reactive oxygen species. Dual inflammasome inhibitor (NLRP3/AIM-2-IN-3) loaded nanorods cause synergistic inhibition by 21.5- and 59-folds compared with nanorods and free drug, respectively alongside caspase-1 inhibition. The NLRP3/AIM-2-IN-3 nanorod when transformed into a polymeric scaffold, simultaneously and effectively inhibits RNA levels of NLRP3, AIM2, caspase-1, chemokine ligand-2, gasdermin-D, interleukin-1β, toll-like receptor 7/ 8, and IL-17A by 6.4-, 1.6-, 2.0-, 13.0-, 4.2-, 24.4-, 4.3-, and 1.82-fold, respectively in psoriatic skin in comparison to Imiquimod positive control group in an in-vivo psoriasis-like mice model.

Inflammasomes: emerging therapeutic targets in hidradenitis suppurativa?

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by recurrent inflammatory lesions, which affect skin and hair follicles in intertriginous areas. HS has a multifactorial aetiology resulting in barrier dysfunction associated with aberrant immune activation. There is increased evidence for the role of inflammasomes in the pathophysiology of inflammatory skin diseases, including HS. Inflammasomes are multiprotein complexes activated following exposure to danger signals, including microbial ligands and components of damaged host cells. Inflammasome activation induces many signalling cascades and subsequent cleavage of proinflammatory cytokines - most notably interleukin (IL)-1β - which have a role in HS pathogenesis. Limited immunotherapies are approved for treating moderate-to-severe HS, with variable response rates influenced by disease heterogeneity. Inflammasomes represent attractive targets to suppress multiple inflammatory pathways in HS, including IL-1β and IL-17. This review aims to summarize the role of inflammasomes in HS and to evaluate evidence for inflammasomes as therapeutic targets for HS treatment.

Loureirin B Reduces Insulin Resistance and Chronic Inflammation in a Rat Model of Polycystic Ovary Syndrome by Upregulating GPR120 and Activating the LKB1/AMPK Signaling Pathway

Polycystic ovary yndrome (PCOS) is a common metabolic disorder in women, which is usually associated with insulin resistance (IR) and chronic inflammation. Loureirin B (LrB) can effectively improve insulin resistance and alleviate chronic inflammation, and in order to investigate the therapeutic effect of LrB on polycystic ovary syndrome with insulin resistance (PCOS-IR), we conducted animal experiments. A PCOS-IR rat model was established by feeding a high-fat diet combined with letrozole (1 mg/kg·d for 21 days). The rats were treated with the GPR120 agonists TUG-891 and LrB for 4 weeks. Biochemical parameters (fasting blood glucose, total cholesterol, triglycerides, high- and low-density lipoprotein), hormone levels (serum insulin, E2, T, LH, and FSH), and inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-18) were analyzed. Histopathological analyses of ovaries were performed using hematoxylin/eosin (H&E) staining. Real-time PCR and western blotting were used to assess GPR120, NLRP3, and caspase-1 expression in ovaries, and immunohistochemistry was used to evaluate LKB1 and AMPK protein expression. LrB reduced body weight, Lee's index, ovarian index, ovarian area, and volume in PCOS-IR rats. It lowered fasting blood glucose, serum insulin, and HOMA-IR. LrB decreased total serum cholesterol, triglyceride, and LDL levels and increased HDL levels. It reduced serum T, LH, and LH/FSH and raised serum E2 and FSH levels. LrB downregulated the mRNA and protein expression levels of NLRP3 and Caspase-1, increased the protein and mRNA expression levels of GPR120 in rat ovaries, and increased LKB1 and AMPK protein expression in ovaries, ameliorating ovarian histopathological changes in PCOS-IR rats. Taken together, LrB upregulated GPR120, LKB1, and AMPK protein expression, downregulated NLRP3 and Caspase-1 protein expression, reduced insulin resistance and chronic inflammation, and ameliorated histopathological changes in ovarian tissues in PCOS rats, suggesting its potential as a treatment for PCOS.

The colonic polyphenol catabolite dihydroferulic acid (DHFA) regulates macrophages activated by oxidized LDL, 7-ketocholesterol, and LPS switching from pro- to anti-inflammatory mediators

Macrophage activation plays a central role in the development of atherosclerotic plaques. Interaction with oxidized low-density lipoprotein (oxLDL) leads to macrophage differentiation into foam cells and oxylipin production, contributing to plaque formation. 7-Ketocholesterol (7KC) is an oxidative byproduct of cholesterol found in oxLDL particles and is considered a factor contributing to plaque progression. During atherosclerotic lesion regression or stabilization, macrophages undergo a transformation from a pro-inflammatory phenotype to a reparative anti-inflammatory state. Interleukin-10 (IL-10) and PGE1 appear to be crucial in resolving both acute and chronic inflammatory processes. After coffee consumption, the gut microbiota processes non-absorbed chlorogenic acids producing various lower size phenolic acids. These colonic catabolites, including dihydroferulic acid (DHFA), may exert various local and systemic effects. We focused on DHFA's impact on inflammation and oxidative stress in THP-1 macrophages exposed to oxLDL, 7KC, and lipopolysaccharides (LPS). Our findings reveal that DHFA inhibits the release of several pro-inflammatory mediators induced by LPS in macrophages, such as CCL-2, CCL-3, CCL-5, TNF-α, IL-6, and IL-17. Furthermore, DHFA reduces IL-18 and IL-1β secretion in an inflammasome-like model. DHFA demonstrated additional benefits: it decreased oxLDL uptake and CD36 expression induced by oxLDL, regulated reactive oxygen species (ROS) and 8-isoprostane secretion (indicating oxidative stress modulation), and selectively increased IL-10 and PGE1 levels in the presence of inflammatory stimuli (LPS and 7KC). Finally, our study highlights the pivotal role of PGE1 in foam cell inhibition and inflammation regulation within activated macrophages. This study highlights DHFA's potential as an antioxidant and anti-inflammatory agent, particularly due to its ability to induce PGE1 and IL-10.

Estrogen-stimulated uropathogenic E. coli mediate enhanced neutrophil responses

Urinary tract infection (UTI) is one of the most common bacterial infections worldwide and the most common cause is uropathogenic Escherichia coli (UPEC). Current research is mostly focused on how UPEC affects host factors, whereas the effect of host factors on UPEC is less studied. Our previous studies have shown that estrogen alters UPEC virulence. However, the effect of this altered UPEC virulence on neutrophils is unknown. The aim of the present study was to investigate how the altered UPEC virulence mediated by estrogen modulates neutrophil responses. We found that estradiol-stimulated CFT073 increased neutrophil phagocytosis, NETs formation and intracellular ROS production. We observed that the total ROS production from neutrophils was reduced by estradiol-stimulated CFT073. We also found that estradiol-stimulated CFT073 induced less cytotoxicity in neutrophils. Additionally, we found that several cytokines and chemokines like IL-8, IL-1β, CXCL6, MCP-1 and MCP-4 were increased upon estradiol-stimulated CFT073 infection. In conclusion, this study demonstrates that the estrogen-mediated alterations to UPEC virulence modulates neutrophil responses, most likely in a host-beneficial manner.

Role of Pyroptosis in Endometrial Cancer and Its Therapeutic Regulation

Pyroptosis is an inflammatory cell death induced by inflammasomes that release several pro-inflammatory mediators such as interleukin-18 (IL-18) and interleukin-1β (IL-1β). Pyroptosis, a type of programmed cell death, has recently received increased interest both as a therapeutic and immunological mechanism. Numerous studies have provided substantial evidence supporting the involvement of inflammasomes and pyroptosis in a variety of pathological conditions including cancers, nerve damage, inflammatory diseases and metabolic conditions. Researchers have demonstrated that dysregulation of pyroptosis and inflammasomes contribute to the progression of endometriosis and gynecological malignancies. Current research also indicates that inflammasome and pyroptosis-dependent signaling pathways may further induce the progression of endometrial cancer (EC). More specifically, dysregulation of NLR family pyrin domain 3 (NLRP3) and caspase-1-dependent pyroptosis play a contributory role in the pathogenesis and development of EC. Therefore, pyroptosis-regulated protein gasdermin D (GSDMD) may be an independent prognostic biomarker for the detection of EC. This review presents the molecular mechanisms of pyroptosis-dependent signaling pathways and their contributory role and function in advancing EC. Moreover, this review offers new insights into potential future applications and innovative approaches in utilizing pyroptosis to develop effective anti-cancer therapies.

Immunomodulatory Effects and Regulatory Mechanisms of (R)-6-HITC, an Isothiocyanate from Wasabi (Eutrema japonicum), in an Ex Vivo Mouse Model of LPS-Induced Inflammation

The present study aimed to investigate the effects of (R)-(-)-1-isothiocyanato-6-(methylsulfinyl)-hexane [(R)-6-HITC], the major isothiocyanate present in wasabi, in an ex vivo model of inflammation using lipopolysaccharide-stimulated murine peritoneal macrophages. (R)-6-HITC improved the immune response and mitigated oxidative stress, which involved suppression of reactive oxygen species, nitric oxide, and pro-inflammatory cytokines (IL-1β, IL-6, IL-17, IL-18, and TNF-α) production and downregulation of pro-inflammatory enzymes such as inducible nitric oxide synthase, COX-2, and mPGES-1. In addition, (R)-6-HITC was able to activate the Nrf2/HO-1 axis while simultaneously inhibiting key signaling pathways, including JAK2/STAT3, mitogen-activated protein kinases, and canonical and noncanonical inflammasome pathways, orchestrating its potent immunomodulatory effects. Collectively, these findings demonstrate the potential of (R)-6-HITC as a promising nutraceutical for the management of immuno-inflammatory diseases and justify the need for further in vivo validation studies.

SGLT2 inhibitors and NLRP3 inflammasome: potential target in diabetic kidney disease

Diabetic kidney disease (DKD) remains the leading cause of chronic kidney disease (CKD) worldwide. The pathogenesis of DKD is influenced by functional, histopathological, and immune mechanisms, including NLRP3 inflammasome activity and oxidative stress. The sodium-glucose cotransporter 2 inhibitors (SGLT2i) have shown metabolic benefits and the ability to slow the progression of DKD in several clinical studies over the years. Recent studies suggest that the antidiabetic activity also extends to inhibition of the inflammatory response, including modulation of the NLRP3 inflammasome, reduction of pro-inflammatory markers and reduction of oxidative stress. Here we review the efficacy of SGLT2i in the treatment of CKD and discuss the role of the inflammatory response in the development of DKD, including its relationship to the NLRP3 inflammasome and oxidative stress.

Traditional approaches and recent tools for studying inflammasome activity

Inflammasomes play a major role in the immune response to infection, development of autoimmune disease, and control of cancer. Western blots were originally used in the early 2000s to characterize inflammasome activation. Since then, a panoply of techniques has been developed to characterize and visualize inflammasome activation in cells, tissues, and animals. This review article describes the most common techniques used by researchers in the inflammasome field and proposes that cell-specific characterization of inflammasome activation in tissues or animals may soon be commonly reported.

Protective effects of pioglitazone in renal ischemia-reperfusion injury (RIRI): focus on oxidative stress and inflammation

BACKGROUND

Renal ischemia-reperfusion injury (RIRI) is a critical phenomenon that compromises renal function and is the most serious health concern related to acute kidney injury (AKI). Pioglitazone (Pio) is a known agonist of peroxisome proliferator-activated receptor-gamma (PPAR-γ). PPAR-γ is a nuclear receptor that regulates genes involved in inflammation, metabolism, and cellular differentiation. Activation of PPAR-γ is associated with antiinflammatory and antioxidant effects, which are relevant to the pathophysiology of RIRI. This study aimed to investigate the protective effects of Pio in RIRI, focusing on oxidative stress and inflammation.

METHODS

We conducted a comprehensive literature search using electronic databases, including PubMed, ScienceDirect, Web of Science, Scopus, and Google Scholar.

RESULTS

The results of this study demonstrated that Pio has antioxidant, anti-inflammatory, and anti-apoptotic activities that counteract the consequences of RIRI. The study also discussed the underlying mechanisms, including the modulation of various pathways such as TNF-α, NF-κB signaling systems, STAT3 pathway, KIM-1 and NGAL pathways, AMPK phosphorylation, and autophagy flux. Additionally, the study presented a summary of various animal studies that support the potential protective effects of Pio in RIRI.

CONCLUSION

Our findings suggest that Pio could protect the kidneys from RIRI by improving antioxidant capacity and decreasing inflammation. Therefore, these findings support the potential of Pio as a therapeutic strategy for preventing RIRI in different clinical conditions.

Assessment of NLRP3 inflammasome activation in patients with chronic obstructive pulmonary disease before and after lung transplantation

The interplay between purinergic receptors as well as pattern recognition receptors like Toll-like receptors (TLRs) and NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) might have a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). The aim of this study was to determine and compare the concentrations of the damage-associated molecular patterns (DAMPs) heat shock protein 70 (Hsp70) and adenosine triphosphate (ATP), and gene expression of their respective receptors as well as NLRP3 inflammasome-related molecules in the peripheral blood of patients with end-stage COPD before and 1 year after lung transplantation (LT). Lung function was assessed by spirometry and diffusion capacity for carbon monoxide (DLCO). Quantitative polymerase chain reaction (qPCR) was applied for detection of TLR2, TLR4, P2X7R, P2Y2R, IL1B, CASP1, and NLRP3 expression. High-sensitivity ELISA kits were used for extracellular (e) Hsp70 and IL-1β, and luminescence assay for eATP measurements. Concentrations of eHsp70 and eATP as well as IL-1β were significantly increased in the plasma of end-stage COPD patients and significantly decreased after LT. In addition, TLR4, P2Y2R, IL1B, CASP1, and NLRP3 expression was up-regulated in COPD patients before LT, while it was significantly suppressed after LT. In conclusion, it could be assumed that NLRP3 inflammasome is activated in the peripheral blood of end-stage COPD patients and that eHsp70 and eATP could be responsible for its activation through triggering their receptors. On the other hand, previously enhanced pro-inflammatory reactions seem to be suppressed to the healthy population levels in lung recipients without allograft rejection.

Recent advances in the treatment of gout with NLRP3 inflammasome inhibitors

Gout is an autoinflammatory disorder characterized by the accumulation of monosodium urate crystals in joints and other tissues, representing the predominant type of inflammatory arthritis with a notable prevalence and propensity for severe outcomes. The NLRP3 inflammasome, a member of the pyrin domain-containing NOD-like receptor family, exerts a substantial impact on both innate and adaptive immune responses and serves as a pivotal factor in the pathogenesis of gout. In recent years, there has been significant academic and industrial interest in the development of NLRP3-targeted small molecule inhibitors as a promising therapeutic approach for gout. To assess the advancements in NLRP3 inflammasome inhibitors for gout treatment, this review offers a comprehensive analysis and evaluation of current clinical candidates and other inhibitors targeting NLRP3 inflammasome from a chemical structure standpoint, with the goal of identifying more efficacious options for clinical management of gout.

Isatidis Folium Represses Dextran Sulfate Sodium-Induced Colitis and Suppresses the Inflammatory Response by Inhibiting Inflammasome Activation

BACKGROUND/OBJECTIVES

Isatidis Folium (IF) has been used in traditional medicine for various ailments, and recent research highlights its anti-inflammatory, antiviral, and detoxifying properties. This study investigated the anti-inflammatory effects of a hydroethanolic extract of IF (EIF) on inflammasomes and colitis.

METHODS

Dextran sulfate sodium (DSS)-induced colitis model C57BL/6 mice were treated with DSS, mesalamine, or EIF (200 mg/kg). Parameters such as daily disease activity index (DAI), spleen weight, colon length, and histopathology were evaluated. Intestinal fibrosis, mucin, and tight junction proteins were assessed using Masson's trichrome, periodic acid-Schiff, and immunohistochemistry staining. RAW264.7 and J774a.1 macrophages were treated with EIF and lipopolysaccharide, with cell viability assessed via the cell counting kit-8 assay, nitric oxide (NO) production with Griess reagent, and cytokine levels with the enzyme-linked immunosorbent assay. NF-κB inhibition was analyzed using the luciferase assay, and phytochemical analysis was performed using UPLC-MS/MS.

RESULTS

EIF mitigated weight loss, reduced DAI scores, prevented colon shortening, and attenuated mucosal damage, fibrosis, and goblet cell loss while enhancing the tight junction protein occludin. The anti-inflammatory effects of EIF in RAW264.7 cells included reduced NO production, pro-inflammatory cytokines, and NF-κB activity, along with inhibition of NLRP3 inflammasome responses in J774a.1 cells. The key constituents identified were tryptanthrin, indigo, and indirubin.

CONCLUSIONS

Animal studies demonstrated the efficacy of EIF in alleviating colitis, suggesting its potential for treating inflammatory diseases.