Expression Of NLRP3 Inflammasome Research Articles

Effects of TABATA Exercise Volume and Royal Jelly Supplementation on NLRP3 Inflammasome and lncRNA-H19 Expression in Obese Men

Background: Both coding and long non-coding RNAs (lncRNAs) have emerged as vital regulators in almost every cellular process, and their expression can be modulated by external stimuli, such as physical exercise. Objectives: The current research aimed to investigate the effects of different volumes of TABATA-high-intensity interval training (HIIT) exercises combined with royal jelly (RJ) supplementation on the NLRP3 inflammasome and lncRNA-H19 expression in obese males. Methods: Forty-two healthy men [Body Mass Index (BMI) = 30 kg/m², waist-to-hip ratio = 0.95, age range: 40 - 60 years] volunteered to participate in the study. The individuals were randomly divided into five experimental groups (N = 35) and one control + placebo group (N = 7). The high-volume (HV) or low-volume (LV) TABATA exercise programs were performed twice a week for 8 weeks. Participants in the RJ supplementation groups received a 1000 mg capsule once a day for 8 weeks. The expression of NLRP3 and lncRNA-H19 genes was evaluated using the real-time PCR method. Results: The NLRP3 gene expression in the Bruce test, measured before and after the 8-week exercise interventions and RJ supplementation, showed insignificant changes across the different groups. However, the H19 gene expression in the Bruce test showed a significant reduction in the HV-TABATA HIIT intervention groups, which was more pronounced than in the LV groups after 8 weeks: HV group (P = 0.004), RJ group (P = 0.001), HV + RJ group (P = 0.007), and LV + RJ group (P = 0.002). After 8 weeks of non-pharmacological interventions involving exercise training and supplementation, a significant decrease in NLRP3 and a significant increase in H19 gene expression were detected in the HV group compared to the LV group (P = 0.05 and P = 0.010). Significant improvement was also found in the resting H19 levels between the RJ and LV groups (P = 0.011) and the LV + RJ group (P = 0.44). Moreover, a significant reduction in resting NLRP3 gene expression was observed between the RJ + LV and LV groups (P = 0.038). Conclusions: Chronic HV TABATA HIIT exercise, when combined with RJ supplementation, is effective in attenuating inflammatory responses to acute stress.

TXNIP regulates pulmonary inflammation induced by Asian sand dust

Asian sand dust (ASD), a seasonal dust storm originating from the deserts of China and Mongolia, affects Korea and Japan during the spring, carrying soil particles and a variety of biochemical components. Exposure to ASD has been associated with the onset and exacerbation of respiratory disorders, although the underlying mechanisms remain unclear. This study investigates ASD-induced pulmonary toxicity and its mechanistic pathways, focusing on the role of thioredoxin-interacting protein (TXNIP). Using TXNIP knock-out (KO) mice and adeno-associated virus (AAV)-mediated TXNIP overexpression transgenic mice, we explored how TXNIP modulates ASD-induced pulmonary inflammation. Mice were exposed to ASD via intranasal administration on days 1, 3, and 5 to induce inflammation. ASD exposure led to significant pulmonary inflammation, evidenced by increased inflammatory cell counts and elevated cytokine levels in bronchoalveolar lavage fluid, as well as heightened protein expression of the TXNIP/NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome. TXNIP KO mice exhibited attenuated airway inflammation and downregulation of the NLRP3 inflammasome compared to wild-type controls, while AAV-mediated TXNIP overexpression mice showed exacerbated inflammatory responses, including elevated NLRP3 inflammasome expression, compared to AAV-GFP controls. These findings suggest that TXNIP is a key regulator of ASD-induced pulmonary inflammation.

BA6b9, a novel sk4 K + channel blocker, attenuates atrial fibrillation substrate in rats with reduced ejection fraction

Abstract Background Atrial fibrillation (AF), the most common cardiac arrhythmia, is strongly associated with several comorbidities including heart failure (HF). AF in general, and specifically in the context of HF, is progressive in nature and associated with poor clinical outcomes. Current therapies for AF are limited in number and efficacy and do not target the underlying causes of atrial remodeling such as inflammation or fibrosis. We previously identified the calcium-activated SK4 K+ channels, which are preferentially expressed in the atria relative to the ventricles in both rat and human hearts, as novel druggable targets for efforts to treat AF. Methods and Findings We examined the ability of BA6b9, a novel allosteric inhibitor of SK4 channels that targets the specific calmodulin-PIP2 binding domain, to alter AF susceptibility and atrial remodeling in a systolic HF rat post-myocardial infarction (post-MI) model. Daily BA6b9 injection (20 mg/kg/day) for 3 weeks starting 1-week post-MI prolonged the atrial effective refractory period, reduced AF induction and duration, and dramatically prevented atrial structural remodeling. In the post-MI left atrium (LA), pronounced upregulation of the SK4 K+ channel was observed, with corresponding increases in collagen deposition, α-SMA levels, and NLRP3 inflammasome expression. Strikingly, BA6b9 treatment reversed these changes while also significantly reducing the lateralization of the atrial connexin Cx43 in the LA of post-MI rats. Interpretation Our findings indicate that the blockade of SK4 K+ channels using BA6b9 not only favors rhythm control but also remarkably reduces atrial structural remodeling, a property that is highly desirable for novel AF therapies, particularly in patients with comorbid HF.

Pinocembrin alleviates LPS-induced depressive-like behavior in mice via the NLRP3/DCC signaling pathway

ObjectiveDepression, a prevalent and severe mental disorder, continues to be a significant area of research concerning its pathogenesis and therapeutic approaches. Conventional antidepressants are often limited by delayed therapeutic effects and notable adverse reactions, necessitating the development of innovative and efficacious treatment modalities. Multiple lines of evidence suggest that peripheral and central inflammation play a role in depression, and that anti-inflammatory drugs can ameliorate depressive symptoms in patients with inflammation-related depression. Pinocembrin (PB), a natural bioactive compound, is renowned for its anti-inflammatory and antioxidant properties, while the effect and mechanism of PB are still unclear. Consequently, this study employs PB as an intervention to investigate its effects on depression in mice model, with the objective of establishing a novel therapeutic strategy and foundational data for the treatment of depression. Methods(1) The acute inflammation model used lipopolysaccharide (LPS) to induce depression-like behavior in mice by injecting LPS intraperitoneally at a dose of 0.83 mg/kg. The effects of PB (20 mg/kg, i.p.) and the NLRP3 inflammasome inhibitor MCC950 (10 mg/kg, i.p.) on improving depression behavior in mice were evaluated. (2) To explore the specific mechanism of PB in improving depression-like behavior in LPS mice by regulating NLRP3 and Netrin-1/DCC pathway. ResultsThe results showed that after intraperitoneal injection of LPS, the mice exhibited a significant decrease in body weight, sucrose preference score, and a significant increase in tail suspension immobility time. Treatment with PB and MCC950 increased the sucrose preference score and decreased the tail suspension immobility time. Besides, PB and MCC950 could inhibit the expression of NLRP3 related neuroinflammation, down-regulated the Netrin-1/DCC signaling pathway, and improved hippocampal neuroplasticity in mice. ConclusionIn conclusion, PB significantly improved LPS-induced depression-like behavior in mice by reducing the expression of hippocampal NLRP3 inflammasome and down-regulating the Netrin-1/DCC signaling pathway. Additionally, PB was found to regulate α-amino-3-hydroxy-5-methyl-4 isoxazole receptor (AMPAR) and postsynaptic density 95 (PSD95), protecting excitatory synaptic transmission and enhancing synaptic plasticity. This study demonstrates the effectiveness of PB in improving depressive symptoms induced by LPS and provides a new strategy for the clinical treatment of depression.

Discovery of novel substituted (Z)-N′-hydroxy-3-(3-phenylureido)benzimidamide derivatives as multifunctional molecules targeting pathological hallmarks of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder marked by significant loss of central cholinergic neurons. This progressive deterioration leads to cognitive dysfunction and impaired motor activity, culminating in the brain cell's death at the later stages of the disease. The approved drugs for AD are limited to providing symptomatic relief for an initial period due to the multifaceted etiology of the disease. Several studies have demonstrated that rivastigmine (RIV) is a selectively potent inhibitor of butyrylcholinesterase and devoid of antioxidant, Aβ, and tau protein aggregation inhibition and anti-inflammatory properties. Therefore, to address these issues associated with RIV, novel rivastigmine-based molecules were rationally designed, synthesized, and evaluated in various in-vitro and in-vivo AD models. In in-vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition studies revealed that 3q &6e as promising leads (AChE, IC50 1.72 ± 0.15, 0.91 ± 0.016 μM, BChE, IC50 6.69 ± 0.28 μM, 1.19 ± 0.026 μM, for 3q &6e, respectively). The computational studies (molecular docking and dynamics) further corroborated the in-vitro studies. Further, 3q and 6e were found to be potent antioxidants in the DPPH assay (IC50 16.15 ± 1.05 & 15.17 ± 0.07 μM, for 3q &6e, respectively). Interestingly, 3q, and 6e could effectively inhibit self-induced full-length tau and Aβ1-42 aggregation. Treatment with 3q &6e inhibited microglial activation by attenuating ROS release and mitochondrial damage. Further, 3q &6e also suppressed NLRP3 inflammasome and NF-κB expression levels in microglial cells and halted the release of pro-inflammatory cytokines in human microglial cells. Finally, 3q &6e were found to be efficacious in reversing the scopolamine-induced memory impairment in the Morris water maze test. The expression of various neuroprotection markers, such as BDNF and TRKB, was significantly overexpressed compared to the disease control group.

A carbamazepine metabolite activates NLRP3 and controls skin homing of CD8+ T-cells in SJS/TEN

BackgroundStevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe adverse drug reactions with extensive keratinocyte death. Carbamazepine (CBZ), the most commonly implicated drug in SJS/TEN, is metabolized by the cytochrome P450 enzyme 3A4 (CYP3A4) into carbamazepine-10,11-epoxide (CBZE) in the liver. While CD8+ cytotoxic T cells play an important role in SJS/TEN, the underlying mechanism of exuberant immune response by CD8+ T cells in these conditions remains incompletely understood. ObjectivesTo examine the expression of NLRP3 inflammasome and their skin migration in CBZE-induced SJS/TEN. MethodsThe expression of the NLRP3 inflammasome complex in skin lesions, sera, and blister fluids of SJS/TEN patients were analyzed by immunohistochemistry and enzyme-linked immunosorbent assay. NLRP3 formation and CD8+ T cell activation status and their functions were examined by immunoblotting, immunofluorescence, and chemotaxis assays. ResultsThe expression of the NLRP3 inflammasome complex was greatly increased in skin lesions of SJS/TEN patients. Moreover, IL-1β and IL-18 levels in sera and blister fluids of SJS/TEN patients were approximately 3-fold higher than those in healthy individuals, with a linear correlation between IL-1β levels and disease activity. CBZE induced NLRP3 inflammasome formation, upregulated CXCL9/CXCL10 levels, and activated CD8+ cytotoxic T cell functions via IL-1β/IL-1R or IL-18/IL-18R signaling in SJS/TEN keratinocytes, which promoted CD8+ cytotoxic T cell migration in SJS/TEN patients. ConclusionThis study showed that CBZE promoted NLRP3 inflammasome formation and strengthened the activation and function of CD8+ cytotoxic T cells in the skin, which contributed to the initiation and progression of SJS/TEN.

Inhibiting endoplasmic reticulum stress alleviates perioperative neurocognitive disorders by reducing neuroinflammation mediated by NLRP3 inflammasome activation.

The aim of this study is to explore the key mechanisms of perioperative neurocognitive dysfunction (PND) after anesthesia/surgery (A/S) by screening hub genes. Transcriptome sequencing was conducted on hippocampal samples obtained from 18-month-old C57BL/6 mice assigned to control (Ctrl) and A/S groups. The functionality of differentially expressed genes (DEGs) was investigated using Metascape. Hub genes associated with changes between the two groups were screened by combining weighted gene coexpression network analysis within CytoHubba. Reverse transcription PCR and western blotting were used to validate changes in mRNA and protein expression, respectively. NLRP3 inflammasome activation was detected by western blotting and ELISA. Tauroursodeoxycholic acid (TUDCA), an inhibitor of endoplasmic reticulum (ER) stress, was administrated preoperatively to explore its effects on the occurrence of PND. Immunofluorescence analysis was performed to evaluate the activation of astrocytes and microglia in the hippocampus, and hippocampus-dependent learning and memory were assessed using behavioral experiments. In total, 521 DEGs were detected between the control and A/S groups. These DEGs were significantly enriched in biological processes related to metabolic processes and their regulation. Four hub genes (Hspa5, Igf1r, Sfpq, and Xbp1) were identified. Animal experiments have shown that mice in the A/S group exhibited cognitive impairments accompanied by increased Hspa5 and Xbp1 expression, ER stress, and activation of NLRP3 inflammasome. Inhibiting ER stress alleviated cognitive impairment in A/S mice; particularly, ER stress induced by A/S results in NLRP3 inflammasome activation and neuroinflammation. Moreover, the preoperative administration of TUDCA inhibited ER stress, NLRP3 inflammasome activation, and neuroinflammation.

The impact of alternate-day fasting on the salivary gland stem cell compartments in non-obese diabetic mice with newly established Sjögren's syndrome.

Intermittent fasting exerts a profound beneficial influence on a spectrum of diseases through various mechanisms including regulation of immune responses, elimination of senescent- and pathogenic cells and improvement of stem cell-based tissue regeneration in a disease- and tissue-dependent manner. Our previous study demonstrated that alternate-day fasting (ADF) led to alleviation of xerostomia and sialadenitis in non-obese diabetic (NOD) mice, a well-defined model of Sjögren's syndrome (SS). This present study delved into the previously unexplored impacts of ADF in this disease setting and revealed that ADF increases the proportion of salivary gland stem cells (SGSCs), defined as the EpCAMhi cell population among the lineage marker negative submandibular gland (SMG) cells. Furthermore, ADF downregulated the expression of p16INK4a, a cellular senescence marker, which was concomitant with increased apoptosis and decreased expression and activity of NLRP3 inflammasomes in the SMGs, particularly in the SGSC-residing ductal compartments. RNA-sequencing analysis of purified SGSCs from NOD mice revealed that the significantly downregulated genes by ADF were mainly associated with sugar metabolism, amino acid biosynthetic process and MAPK signaling pathway, whereas the significantly upregulated genes related to fatty acid metabolic processes, among others. Collectively, these findings indicate that ADF increases the SGSC proportion, accompanied by a modulation of the SGSC property and a switch from sugar- to fatty acid-based metabolism. These findings lay the foundation for further investigation into the functionality of SGSCs influenced by ADF and shed light on the cellular and molecular mechanisms by which ADF exerts beneficial actions on salivary gland restoration in SS.

Application of a modified multifunctional short peptide in the treatment of periodontitis

Periodontitis is a chronic inflammatory disease involving plaque biofilm as a pathogenic factor. Potassium ion plays an important role in cellular homeostasis; a large outflow of potassium may lead to local inflammation progression. In this work, the multifunctional short peptide molecule BmKTX-33 was designed by modifying the BmKTX, a Kv1.3 potassium channel inhibitor. This was to explore its antibacterial properties, capability of maintaining cell ion homeostasis, and bone-forming capacity. The results showed that BmKTX-33 had inhibitory effects on S. gordonii, F. nucleatum, and P. gingivalis. Moreover, BmKTX-33 also inhibited excessive potassium outflow in inflammatory environments. Finally, BmKTX-33 promoted MC3T3-E1 early osteogenesis while suppressing the NLRP3 inflammasome's production. In conclusion, BmKTX-33 not only has antibacterial properties, but also can inhibit the expression of NLRP3 inflammasome and play an anti-inflammatory role.

The AGEs/RAGE Signaling Pathway Regulates NLRP3-Mediated Neuronal Pyroptosis After MCAO Injury in Lepr-/- Obese Rats.

Obesity is recognized as a primary risk factor for cerebral ischemia, which has shown a significant increase in its incidence among obese patients. The exact mechanism by which obesity exacerbates cerebral ischemic injury is not fully understood though. The present study validated the hypothesis that obesity mediates pyroptosis by the AGEs/RAGE signaling pathway to exacerbate cerebral ischemic injury. Leptin receptor knockout (Lepr-/- ) rats were used in this study to construct an obesity model, and the middle cerebral artery occlusion (MCAO) models of ischemic stroke were established in Lepr-/- obese rats and their wild-type (WT) littermates respectively. Zea-Longa score, TTC and H&E staining were utilized to evaluate the neurological impairment. Western Blot, immunohistochemistry, and immunofluorescence were used to detect protein expressions. Transmission electron microscopy was used to observe the pores in the neuronal cell membrane in the ischemic penumbra cortex. Compared with WT littermates, Lepr-/- obese rats exhibited exacerbated neuronal injury after MCAO, with higher expressions of NLRP3 inflammasome and pyroptosis-related proteins in the cortical tissue of the penumbra. Moreover, more GSDMD pores were observed on the neuronal cell membranes of Lepr-/- obese rats according to the electron microscopy. Inhibition of NLRP3 inflammasome expression with MCC950 inhibited neuronal pyroptosis after cerebral ischemia in Lepr-/- obese rats, thus reducing neuronal injury. We also found that compared with WT littermates, the levels of AGEs and RAGE in the cortex of Lepr-/- obese rats are significantly higher, with further increase after cerebral ischemia. Inhibition of AGEs/RAGE signaling pathway with FPS-ZM1 reduced the NLRP3 inflammasome-mediated neuronal pyroptosis in Lepr-/- obese rats, thereby mitigating the neuronal damage after cerebral ischemia. The AGEs/RAGE signaling pathway is involved in the exacerbation of cerebral ischemic injury in Lepr-/- obese rats via regulating NLRP3-mediated neuronal pyroptosis.

Regulation of NLRP3 Inflammasome Expression through Inhibition of Podocyte-Specific Lysyl Oxidase-Like 2 as a New Therapeutic Target for AKI on CKD

Regulation of NLRP3 Inflammasome Expression through Inhibition of Podocyte-Specific Lysyl Oxidase-Like 2 as a New Therapeutic Target for AKI on CKD

Plasma Zinc Levels in Patients with Diabetic Nephropathy: Is there a Relationship with NLRP3 Inflammasome Activation and Renal Prognosis?

Zinc is an essential trace element, and impaired zinc homeostasis may be associated with inflammation in patients with diabetic nephropathy (DN). We investigated the influence of zinc level on nod-like receptor nucleotide-binding domain and leucine-rich repeat pyrin-3 domain (NLRP3) inflammasome expression and renal prognosis in patients with DN. We recruited 90 patients definitively diagnosed with DN by renal biopsy and 40 healthy controls. Zinc, NLRP3, interleukin (IL)-1β, and IL-18 levels were detected in blood samples, and the correlations between these parameters were assessed. Receiver operating characteristic (ROC) curve and decision curve analysis (DCA) evaluated the predictive value of zinc and the NLRP3 inflammasome for DN. Furthermore, patients with DN were divided into low- and normal-zinc groups to observe differences in clinical indicators and identify expression of inflammatory-related factors in renal tissue. Kaplan-Meier survival curves predicted the impact of zinc levels on renal prognosis. We found thatthe plasma zinc concentration in patients with DN was lower, while NLRP3, IL-1β, and IL-18 levels were higher than were those in patients without DN (P < 0.05). Zinc level was negatively correlated with NLRP3, IL-1β, and IL-18 levels (P < 0.01). Zinc and the NLRP3 inflammasome were predictive of DN, but their combination improved the diagnostic value. The DCA curve demonstrated a good positive net benefit in the combined model. Compared to patients with low zinc levels, patients with normal zinc levels had lower expression of NLRP3 inflammasome and a better prognosis. Zinc has a protective effect on DN and may affect NLRP3 inflammasome activation.

Deacetylation of HnRNP U mediated by sirtuin1 ameliorates aged rat with liver fibrosis via inhibiting p53-related senescence and NLRP3-related inflammation

Senescence represents a major risk factor promoting liver fibrosis progression. Sirtuin 1 (SIRT1), an essential regulator of cellular senescence, may be involved in developing liver fibrosis. However, the role and mechanism of SIRT1 in liver fibrosis development were largely unknown. We constructed the liver fibrosis in aged rats induced by carbon tetrachloride (CCl4) and then transfected with GFP-SIRT1 adenoviral vectors. After that, we performed acetylomic analysis of liver tissue in aged rats to identify potential substrates of SIRT1. Furthermore, replicative senescent rat hepatocytes were pretreated with siRNA HnRNP U, SIRT1 adenoviral vectors, resveratrol, and siRNA SIRT1, following stimulation with H2O2. We found that the protein levels of SIRT1 and HnRNP U were down-regulation in aged rat liver fibrotic tissues, with an accumulation of NLRP3 inflammasome and activation of the p53/p21 pathway in liver tissue, as well as an increased level of plasma IL-1β secretion. In comparison, these effects were reversed by overexpressing SIRT1 with adenoviral vectors. Acetylation of HnRNP U and its sites at K28 and K787 might be potential targets for SIRT1-mediated liver fibrosis in aged rats. Silencing HnRNP U reduced H2O2-induced up-regulation expression of p53, p21, and NLRP3 inflammasome at protein levels. Additionally, H2O2 induced high acetylation of HnRNP U in senescent hepatocytes, whereas overexpressing SIRT1 with adenoviral vectors and resveratrol deacetylate HnRNP U to inhibit NLRP3 inflammasome and the p53/p21 pathway. Besides, the silence of SIRT1 aggravated H2O2-induced p53-related senescence and NLRP3-related inflammation in senescent hepatocytes. Our findings suggested that deacetylation of HnRNPU mediated by SIRT1 attenuated liver fibrosis in the elderly by inhibiting p53/p21 pathway and NLRP3-related inflammation.

Matrine Suppresses Arsenic-Induced Malignant Transformation of SV-HUC-1 Cells via NOX2.

Arsenic (As) has been classified as a carcinogen for humans. There is abundant evidence indicating that arsenic increases the risk of bladder cancer among human populations. However, the underlying mechanisms have yet to be fully understood and elucidated. NADPH oxidases (NOXs) are the main enzymes for ROS production in the body. NADPH Oxidase 2 (NOX2), which is the most distinctive and ubiquitously expressed subunit of NOXs, can promote the formation and development of tumors. The utilization of NOX2 as a therapeutic target has been proposed to modulate diseases resulting from the activation of NOD-like receptor thermal protein domain associated protein 3 (NLRP3). Matrine has been reported to exhibit various pharmacological effects, including anti-inflammatory, antifibrotic, antitumor, and analgesic properties. However, it has not been reported whether matrine can inhibit malignant transformation induced by arsenic in uroepithelial cells through NOX2. We have conducted a series of experiments using both a sub-chronic NaAsO2 exposure rat model and a long-term NaAsO2 exposure cell model. Our findings indicate that arsenic significantly increases cell proliferation, migration, and angiogenesis in vivo and in vitro. Arsenic exposure resulted in an upregulation of reactive oxygen species (ROS), NOX2, and NLRP3 inflammasome expression. Remarkably, both in vivo and in vitro, the administration of matrine demonstrated a significant improvement in the detrimental impact of arsenic on bladder epithelial cells. This was evidenced by the downregulation of proliferation, migration, and angiogenesis, as well as the expression of the NOX2 and NLRP3 inflammasomes. Collectively, these findings indicate that matrine possesses the ability to reduce NOX2 levels and inhibit the transformation of bladder epithelial cells.

Radix Isatidis polysaccharide (RIP) alleviates QX-genotype infectious bronchitis virus-induced interstitial nephritis through the Nrf2/NLRP3/Caspase-3 signaling pathway

Interstitial nephritis is the primary cause of mortality in IBV-infected chickens. Our previous research has demonstrated that Radix Isatidis polysaccharide (RIP) could alleviate this form of interstitial nephritis. To explore the mechanism, SPF chickens and chicken embryonic kidney cells (CEKs) were pre-treated with RIP and subsequently infected with QX-genotype IBV strain. Kidneys were sampled for transcriptomic and metabolomic analyses, and the cecum contents were collected for 16S rRNA gene sequencing. Results showed that pre-treatment with RIP led to a 50 % morbidity reduction in infected-chickens, along with decreased tissue lesion and viral load in the kidneys. Multi-omics analysis indicated three possible pathways (including antioxidant, anti-inflammatory and anti-apoptosis) which associated with RIP's efficacy against interstitial nephritis. Following further validation both in vivo and in vitro, the results showed that pre-treatment with RIP could activate the antioxidant transcription factor Nrf2, stimulate antioxidant enzyme expression, and consequently inhibit oxidative stress. Pre-treatment with RIP could also significantly reduce the expression of NLRP3 inflammasome and apoptosis-associated proteins (including Bax, Caspase-3, and Caspase-9). Additionally, RIP was also observed to promote the growth of beneficial bacteria in the intestine. Overall, pretreatment with RIP can alleviate QX-genotype IBV-induced interstitial nephritis via the Nrf2/NLRP3/Caspase-3 signaling pathway. This study lays the groundwork for the potential use of RIP in controlling avian infectious bronchitis (IB).

Apigenin and inflammation in the brain: can apigenin inhibit neuroinflammation in preclinical models?

Apigenin is a flavone-kind of flavonoid present in fruits and vegetables. Apigenin exhibits biological activities including neuropharmacological effects against different neurological disorders. In this study, we summarize and discuss the molecular mechanisms of the anti-neuroinflammatory effects of apigenin in neurological disorders. A systematic review was conducted by searching Google Scholar, Web of Science, Scopus and PubMed. A total of 461 records were retrieved from the search. After screening of the records based on the inclusion criteria, 16 articles were selected and discussed in this study. The results from the selected studies showed that apigenin exhibited anti-neuroinflammatory effect in preclinical studies. The anti-neuroinflammatory mechanisms exhibited by apigenin include inhibition of overproduction of pro-inflammatory cytokines, attenuation of microglia activation via reduction of CD-11b-positive cells, inhibition of ROCK-1 expression and upregulation of miR-15a, p-ERK1/2, p-CREB, and BDNF, downregulation of NLRP3 inflammasome, iNOS and COX-2 expression, reduction of Toll-like receptor-4 expression and inhibition of nuclear factor-kappa B (NF-kB) activation. Overall, apigenin inhibited neuroinflammation which suggests it confers neuroprotective effect against neuronal degeneration in some neurodegenerative conditions. This review provides important neuropharmacological information on the neuroprotective mechanisms of apigenin against neuroinflammation which may be useful for future preclinical and clinical studies.

MiR-21 attenuated inflammation targeting MyD88 in human chondrocytes stimulated with Hyaluronan oligosaccharides

Inflammation is the body's response to injuries, which depends on numerous regulatory factors. Among them, miRNAs have gained much attention for their role in regulating inflammatory gene expression at multiple levels. In particular, miR-21 is up-regulated during the inflammatory response and reported to be involved in the resolution of inflammation by down-regulating pro-inflammatory mediators, including MyD88. Herein, we evaluated the regulatory effects of miR-21 on the TLR-4/MyD88 pathway in an in vitro model of 6-mer HA oligosaccharides-induced inflammation in human chondrocytes.The exposition of chondrocytes to 6-mer HA induced the activation of the TLR4/MyD88 pathway, which culminates in NF-kB activation. Changes in miR-21, TLR-4, MyD88, NLRP3 inflammasome, IL-29, Caspase1, MMP-9, iNOS, and COX-2 mRNA expression of 6-mer HA-stimulated chondrocytes were examined by qRT-PCR. Protein amounts of TLR-4, MyD88, NLRP3 inflammasome, p-ERK1/2, p-AKT, IL-29, caspase1, MMP-9, p-NK-kB p65 subunit, and IKB-a have been evaluated by ELISA kits. NO and PGE2 levels have been assayed by colorimetric and ELISA kits, respectively.HA oligosaccharides induced a significant increase in the expression of the above parameters, including NF-kB activity. The use of a miR-21 mimic attenuated MyD88 expression levels and the downstream effectors. On the contrary, treatment with a miR-21 inhibitor induced opposite effects. Interestingly, the use of a MyD88 siRNA confirmed MyD88 as the target of miR-21 action.Our results suggest that miR-21 expression could increase in an attempt to reduce the inflammatory response, targeting MyD88.

Acupuncture ameliorates depression-like behavior of poststroke depression model rats through the regulation of gut microbiota and NLRP3 inflammasome in the colon.

This study was conducted to examine the effects of acupuncture on gut microbiota and expression of NLRP3 inflammasome in the colon in poststroke depression (PSD) model rats. Sprague-Dawley male rats were randomized into four groups: sham surgery group, poststroke depression group, acupuncture group, and probiotics group. Acupuncture therapy at Baihui (GV20), Shenting (GV24), bilateral Zusanli (ST36) acupoints in the acupuncture group and probiotic gavage therapy in the probiotics group were performed once per day for 2 weeks. Behaviors of depression were assessed by using weight measurements, sucrose preference test, open field test, and forced swimming test. Histopathological alterations in the colon were determined by hematoxylin-eosin staining, the expression of NLRP3/ASC/caspase-1 pathway-related proteins was analyzed by western blotting. Serum levels of IL-1β and IL-18 were derived from ELISA. The 16S rRNA gene sequencing was performed to examine and analyze the differences of gut microbiota of rats among all groups. Acupuncture was effective to increase weight and ameliorate depressive-like behaviors in PSD rats. Acupuncture increased the diversity of gut microbiota, upregulated the abundance of Bifidobacteriaceae and Lactobacillaceae, and decreased the relative abundance of Peptostreptococcaceae, Rikenellaceae, Eggerthellaceae, and Streptococcaceae at family level. Acupuncture effectively improved the pathological changes in the colon. Meanwhile, acupuncture reduced NLRP3, ASC, caspase-1 protein expressions in the colon, and serum levels of IL-18 and IL-1β. Acupuncture may reduce depressive-like behaviors of PSD by regulating the gut microbiota and suppressing hyperactivation of NLRP3 inflammasome in the colon. Microbiota-gut-brain axis may be an effective target pathway for acupuncture treatment of PSD.

HMGB1/TLR4 axis promotes pyroptosis after ICH by activating the NLRP3 inflammasome

BackgroundWe previously reported that the HMGB1/TLR4 axis promoted inflammation during the acute phase of intracerebral hemorrhage. Given that this phase is known to involve neuronal pyroptosis and neuroinflammation, here we explore whether HMGB1/TLR signaling activate inflammasome and pyroptosis after intracerebral hemorrhage. MethodsAutologous blood was injected into Sprague–Dawley rats to induce intracerebral hemorrhage. Neurological deficits were assessed using a modified neurological severity score. These expression and localization of NLRP1 and NLRP3 inflammasomes, as well as the levels of pyroptosis and pyroptosis-associated proteins were assessed using Western blot or immunocytochemistry. These experiments were repeated in animals that received treatment with short interfering RNAs against NLRP1 or NLRP3, with HMGB1 inhibitor ethyl pyruvate or TLR4 inhibitor TAK-242. ResultsIntracerebral hemorrhage upregulated NLRP1 and NLRP3 in the ipsilateral striatum and increased the proportions of these cells that were pyroptosis-positive. Additionally, the levels of caspase protein family (e.g., pro-caspase-1 and caspase-1), apoptosis-associated speck-like protein (ASC), pro-interleukin-1β (IL-1β), and IL-1β were also elevated. These effects on pyroptosis and associated neurological deficit, were partially reversed by knockdown of NLRP1 or NLRP3, or by inhibition of HMGB1 or TLR4. Inhibition of HMGB1 or TLR4 resulted in the downregulation NLRP3 but not NLRP1. ConclusionsThe HMGB1/TLR4 signaling may activate the NLRP3 inflammasome during the acute phase of intracerebral hemorrhage, resulting in the inflammatory process known as pyroptosis. These insights suggest potential therapeutic targets for the mitigation tissue injury and associated neurological deficits following hemorrhagic stroke.

Metformin improves cognitive dysfunction through SIRT1/NLRP3 pathway-mediated neuroinflammation in db/db mice.

Diabetes mellitus (DM), an important public health problem, aggravates the global economic burden. Diabetic encephalopathy (DE) is a serious complication of DM in the central nervous system. Metformin has been proven to improve DE. However, the mechanism is still unclear. In this study, the db/db mice, a common model used for DE, were employed to explore and study the neuroprotective effect of metformin and related mechanisms. Behavioral tests indicated that metformin (100 or 200 mg/kg/day) could significantly improve the learning and memory abilities of db/db mice. The outcomes from the oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) demonstrate that metformin effectively modulates glucose and insulin signaling pathways in db/db mice. The results of body weight and blood lipid panel (total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol) show that metformin promotes the level of lipid metabolism in db/db mice. Furthermore, data from oxidative stress assays, which measured levels of malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase, suggest that metformin suppresses oxidative stress-induced brain damage in db/db mice. In addition, western blot, Nissl staining, and immunofluorescence results showed that metformin increased the expressions of nerve growth factor and postsynaptic density 95 and repaired neuronal structural damage. For the mechanism study, metformin activated SIRT1 and inhibited the expression of NLRP3 inflammasome (NLRP3, ASC, caspase-1, IL-1β, and IL-18) and inflammatory cytokines (TNFα and IL-6). In conclusion, metformin could ameliorate cognitive dysfunction through the SIRT1/NLRP3 pathway, which might be a promising mechanism for DE treatment.