Anti-inflammatory effect of Trichospira verticillata via suppression of the NLRP3 inflammasome in neutrophilic asthma.

Trichospira verticillata is an annual herb that belongs to the family Asteraceae. Trichospira verticillata extract (TVE) elicits anti-plasmodial activity; however, there has been no detailed report about its anti-inflammatory effects and molecular mechanisms. In addition, herbal plants exhibit anti-inflammatory effects by suppressing the NLRP3 inflammasome. Therefore, the primary goal of this study was to examine the effects of TVE on NLRP3 inflammasome activation by measuring interleukin-1ß (IL-1ß) secretion. We treated lipopolysaccharides (LPS)-primed J774A.1 and THP-1 cells with TVE, which attenuated NLRP3 inflammasome activation. Notably, TVE did not affect nuclear factor-kappa B (NF-κB) signalling or intracellular reactive oxygen species (ROS) production and potassium efflux, suggesting that it inactivates the NLRP3 inflammasome via other mechanisms. Moreover, TVE suppressed the formation of apoptosis-associated speck-like protein (ASC) speck and oligomerization. Immunoprecipitation data revealed that TVE reduced the binding of NLRP3 to NIMA-related kinase 7 (NEK7), resulting in reduced ASC oligomerization and speck formation. Moreover, TVE alleviated neutrophilic asthma (NA) symptoms in mice. This study demonstrates that TVE modulates the binding of NLPR3 to NEK7, thereby reporting novel insights into the mechanism by which TVE inhibits NLRP3 inflammasome. These findings suggest TVE as a potential therapeutic of NLRP3 inflammasome-mediated diseases, particularly NA.

Muscle-derived IL-1ß regulates EcSOD expression via the NBR1-p62-Nrf2 pathway in muscle during cancer cachexia.

Oxidative stress contributes to the loss of skeletal muscle mass and function in cancer cachexia. However, this outcome may be mitigated by an improved endogenous antioxidant defence system. Here, using the well-established oxidative stress-inducing muscle atrophy model of Lewis lung carcinoma (LLC) in 13-week-old male C57BL/6J mice, we demonstrate that extracellular superoxide dismutase (EcSOD) levels increase in the cachexia-prone extensor digitorum longus muscle. LLC transplantation significantly increased interleukin-1ß (IL-1ß) expression and release from extensor digitorum longus muscle fibres. Moreover, IL-1ß treatment of C2C12 myotubes increased NBR1, p62 phosphorylation at Ser351, Nrf2 nuclear translocation and EcSOD protein expression. Additional studies in vivo indicated that intramuscular IL-1ß injection is sufficient to stimulate EcSOD expression, which is prevented by muscle-specific knockout of p62 and Nrf2 (i.e. in p62 skmKO and Nrf2 skmKO mice, respectively). Finally, since an increase in circulating IL-1ß may lead to unwanted outcomes, we demonstrate that targeting this pathway at p62 is sufficient to drive muscle EcSOD expression in an Nrf2-dependent manner. In summary, cancer cachexia increases EcSOD expression in extensor digitorum longus muscle via muscle-derived IL-1ß-induced upregulation of p62 phosphorylation and Nrf2 activation. These findings provide further mechanistic evidence for the therapeutic potential of p62 and Nrf2 to mitigate cancer cachexia-induced muscle atrophy. KEY POINTS: Oxidative stress plays an important role in muscle atrophy during cancer cachexia. EcSOD, which mitigates muscle loss during oxidative stress, is upregulated in 13-week-old male C57BL/6J mice of extensor digitorum longus muscles during cancer cachexia. Using mouse and cellular models, we demonstrate that cancer cachexia promotes muscle EcSOD protein expression via muscle-derived IL-1ß-dependent stimulation of the NBR1-p62-Nrf2 signalling pathway. These results provide further evidence for the potential therapeutic targeting of the NBR1-p62-Nrf2 signalling pathway downstream of IL-1ß to mitigate cancer cachexia-induced muscle atrophy.

Colchicine effect on biomarkers of cardiac remodelling and atherosclerosis in ST-elevation myocardial infarction: A randomized controlled trial.

AIMS: Owing to its underlying inflammatory nature, atherosclerotic cardiovascular disease remains the leading global cause of mortality, particularly post-ST-elevation myocardial infarction (STEMI), a condition with significant risk for further cardiovascular events and mortality. This study aimed to investigate colchicine's effect on inflammation, cardiac remodelling and atherosclerotic risk in STEMI patients. METHODS: We conducted a randomized controlled study on 88 STEMI patients undergoing percutaneous coronary intervention. Eligible patients were randomly assigned to 1 of 2 groups. The control group received the guideline-directed medical therapy for STEMI, and the test group received guideline-directed medical therapy and 0.5 mg colchicine twice daily for 3 months. The soluble suppressor of tumorigenicity (sST2), interleukin-1ß, lipid profile parameters, triglyceride (TG)/high-density lipoprotein (HDL-C) ratio levels and left ventricular ejection fraction were evaluated for patients at baseline and the end of the 3 months. RESULTS: No significant effects were reported for colchicine on sST2, interleukin-1ß levels or left ventricular ejection fraction. Colchicine significantly lowered TG levels vs. controls, 134 (46-353) vs. 176 (72-825) respectively, P = .02, as well as TG/HDL-C ratio levels, 4.16 (2.75-5.24) vs. 5.11 (3.51-8.33),` respectively, P = .024. sST2 levels of the studied cohort were positively correlated with their TG/HDL-C ratio levels (R = .459, P < .001) at the end of follow-up. CONCLUSION: Our study highlights a promising impact of colchicine on atherosclerosis and cardiac remodelling factors in STEMI patients. Colchicine significantly reduced TG levels and TG/HDL-C ratio and was safe and well tolerated. Larger long-term studies powered to assess clinical outcomes of remodelling are necessary to confirm its beneficial effects in STEMI. GOV REGISTRATION ID: NCT06054100.

Investigating the role of salivary Interleukin-40 levels in diagnosing periodontal diseases.

BACKGROUND: The present study aimed to analyze IL-40, IL-1ß, and MMP-8 levels in periodontitis as well as gingivitis and periodontal health, and to explore potential correlations between these biomarkers and standard clinical parameters. MATERIALS AND METHODS: We collected saliva samples from 120 systemically healthy, non-smoking individuals aged between 18 and 63 years. These individuals were divided into three groups: healthy controls [S], gingivitis [G], and stage III grade B periodontitis [P]. IL-40, IL-1ß, and MMP-8 levels in saliva samples were analyzed by ELISA. RESULTS: We observed significantly elevated salivary IL-40 levels in the G group compared to the S group (p = 0.003). We found significantly higher salivary IL-1ß levels in the P group compared to both the S and G groups (p = 0.000). Salivary MMP-8 levels were significantly higher in the P group than in the S group (p = 0.016). CONCLUSION: Our study suggests that IL-40 and IL-1ß may serve as effective salivary biomarkers for diagnosing gingivitis, while MMP-8 and IL-1ß may be effective for distinguishing periodontitis. Based on our study's findings, it can be stated that IL-40 may serve as a new and effective biomarker for distinguishing individuals with gingivitis from healthy ones.

A selective inhibitor of the NLRP3 inflammasome as a potential therapeutic approach for neuroprotection in a transgenic mouse model of Huntington's disease.

BACKGROUND: Huntington's disease (HD) is a neurodegenerative disorder caused by the expansion of the CAG repeat in the huntingtin (HTT) gene. When the number of CAG repeats exceeds 36, the translated expanded polyglutamine-containing HTT protein (mutant HTT [mHTT]) interferes with the normal functions of many cellular proteins and subsequently jeopardizes important cellular machineries in major types of brain cells, including neurons, astrocytes, and microglia. The NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome, which comprises NLRP3, ASC, and caspase-1, is involved in the activation of IL-1ß and IL-18 and has been implicated in various biological functions. Although the existence of the NLRP3 inflammasome in the brain has been documented, the roles of the NLRP3 inflammasome in HD remain largely uncharacterized. MCC950 is a highly selective and potent small-molecule inhibitor of NLRP3 that has been used for the treatment of several diseases such as Alzheimer's disease. However, whether MCC950 is also beneficial in HD remains unknown. Therefore, we hypothesized that MCC950 exerts beneficial effects in a transgenic mouse model of HD. METHODS: To evaluate the effects of MCC950 in HD, we used the R6/2 (B6CBA-Tg[HDexon1]62Gpb/1J) transgenic mouse model of HD, which expresses exon 1 of the human HTT gene carrying 120 ± 5 CAG repeats. Male transgenic R6/2 mice were treated daily with MCC950 (10 mg/kg of body weight; oral administration) or water for 5 weeks from the age of 7 weeks. We examined neuronal density, neuroinflammation, and mHTT aggregation in the striatum of R6/2 mice vs. their wild-type littermates. We also evaluated the motor function, body weight, and lifespan of R6/2 mice. RESULTS: Systematic administration of MCC950 to R6/2 mice suppressed the NLRP3 inflammasome, decreased IL-1ß and reactive oxygen species production, and reduced neuronal toxicity, as assessed based on increased neuronal density and upregulation of the NeuN and PSD-95 proteins. Most importantly, oral administration of MCC950 increased neuronal survival, reduced neuroinflammation, extended lifespan, and improved motor dysfunction in R6/2 mice. CONCLUSIONS: Collectively, our findings indicate that MCC950 exerts beneficial effects in a transgenic mouse model of HD and has therapeutic potential for treatment of this devastating neurodegenerative disease.

SUMO1 SUMOylates and SENP3 deSUMOylates NLRP3 to orchestrate the inflammasome activation.

The NLRP3 inflammasome regulates innate immune and inflammatory responses by promoting caspase1-dependent induction of pro-inflammatory cytokines. However, aberrant inflammasome activation causes diverse diseases, and thus inflammasome activity must be tightly controlled. Here, we reveal a molecular mechanism underlying the regulation of NLRP3 inflammasome. NLRP3 interacts with SUMO-conjugating enzyme (UBC9), which subsequently promotes small ubiquitin-like modifier 1 (SUMO1) to catalyze NLRP3 SUMOylation at residue Lys204. SUMO1-catalyzed SUMOylation of NLRP3 facilitates ASC oligomerization, inflammasome activation, and interleukin-1ß secretion. Moreover, this study also reveals that SUMO-specific protease 3 (SENP3) is required for the deSUMOylation of NLRP3. Interestingly, SENP3 deSUMOylates NLRP3 to attenuate ASC recruitment and speck formation, the NLRP3 inflammasome activation, as well as IL-1ß cleavage and secretion. In conclusion, we reveal that SUMO1-catalyzed SUMOylation and SENP3-mediated deSUMOylation of NLRP3 orchestrate the inflammasome activation.

Interleukin-1ß/nuclear factor-κB signaling promotes osteosarcoma cell growth through the microRNA-181b/phosphatase and tensin homolog axis.

So far, microRNA has attracted plenty of interest due to its role in tumorigenesis. Reportedly, miR-181b may be involved in the tumorigenesis of osteosarcoma (OS). In the current study, we attempted to investigate the detailed function and mechanism of miR-181b in OS carcinogenesis. Herein, miR-181a, miR-181b, miR-181c, and miR-181d expressions in OS tissues were higher than that in nontumor tissue samples as examined real-time polymerase chain reaction. Via direct targeting, miR-181b negatively regulated the expression of phosphatase and tensin homolog (PTEN), a well-known tumor suppressor. Furthermore, a small interfering RNA strategy was used to find that interleukin (IL)-1B and nuclear factor-κB (NF-κB) regulate miR-181b and PTEN expression. Consequently, the repression of PTEN by miR-181b promotes OS cell proliferation. In summary, our data support a critical role for NF-κB-dependent upregulation of miR-181b, which further inhibited PTEN expression and promoted the cell proliferation of OS cell lines. The above findings represent a new pathway for the repression of PTEN and the promotion of cell proliferation upon IL-1ß induction.

Inflammatory markers and noncoding-RNAs responses to low and high compressions of HIIT with or without berberine supplementation in middle-aged men with prediabetes.

This study compared the capacity of two different models of HIIT [high-(HC) and low-(LC) compression], with or without the use of berberine (BBR), on NOD-like receptor pyrin domain-containing protein-3 (NLRP3), H19, interleukin (IL)-1ß, high-sensitivity C-reactive protein (hs-CRP), and insulin resistance markers. Fifty-four middle-aged men with overweight or obesity and prediabetes [fasting blood glucose (FBG) 110-180 mg/dL] were randomly and equally assigned to the HC, LC, HC + BBR, LC + BBR, BBR, and non-exercising control (CON) groups. The HC (2:1 work-to-rest) and LC (1:1 work-to-rest) home-based training programs included 2-4 sets of 8 exercises at 80%-95% HRmax, twice a week for 8 weeks. Participants in the berberine groups received approximately 1000 mg daily. All exercise interventions led to a significant reduction in hs-CRP, IL-1ß, insulin, FBG, and insulin resistance index (HOMA-IR) versus CON. Notably, there was a significant reduction in FBG and HOMA-IR with the BBR group compared to the baseline. Both NLRP3 and H19 experienced a significant drop only with LC in comparison to the baseline. While both exercise protocols were beneficial overall, LC uniquely exhibited more anti-inflammatory effects, as indicated by reductions in H19 and NLRP3. However, the addition of berberine to the exercise programs did not demonstrate additional benefits.

NF-κB affected the serum levels of TNF-α and IL-1ß via activation of the MAPK/NF-κB signaling pathway in rat model of acute pulmonary microthromboembolism.

Pulmonary thromboembolism caused by thrombi blocking major pulmonary artery and its branches, is a frequently encountered phenomenon and an important cause of high morbidity and mortality in lung diseases and may develop into persistent pulmonary hypertension (PH). Nuclear factor-κB (NF-κB) signaling pathway had been reported participated in the formation and development of PH by promoting inflammatory response. The aim of this study was to investigate the effects of NF-κB activation on the serum levels of tumor necrosis factor α (TNF-α) and interleukin-1ß (IL-1ß) in acute pulmonary microthromboembolism (APMTE) rats. Rats were randomized into five groups. APMTE group received jugular vein injection of autologous thrombus, while control group rats received normal saline injection. Pulmonary hemodynamic parameters were measured through ECHO-guided transthoracic puncture. Pulmonary vascular morphological changes were analyzed by HE. The expression changes of NF-κB and serum TNF-α、IL-1ß levels were detected by enzyme-linked immunosorbent assay. Protein expression of the MAPK/NF-κB signaling pathway including p-IκBα, p-p38 MAPK, p-NF-κB p65, IκBα, p38 MAPK, and NF-κB p65 was determined using western blot analysis. Compared with control group, the expression of NF-κB in lung tissue and the levels of serum TNF-α and IL-1ß rats were higher, a significant reduction in IκBα and elevation in the phosphorylation of IκBα, p38 MAPK, and NF-κB p65 were found in APMTE group rats. And UK administration reversed the APMTE-induced increase in TNF-α, IL-1ß, p-IκBα, p-MAPK, and p-NF-κB protein. Furthermore, the levels of NF-κB, TNF-α, and IL-1ß were positively correlated with mean pulmonary artery. And the levels of TNF-α and IL-1ß were positively correlated with NF-κB. These findings suggest that the activation of MAPK/NF-κB pathway as a critical driver of increasing TNF-α and IL-1ß level in APMTE rats and UK exerted protective effects against APMTE-induced PH may be related to the downregulation of the MAPK/NF-κB signaling pathway.

Interleukin-1ß Disruption Protects Male Mice From Heart Failure With Preserved Ejection Fraction Pathogenesis.

Background Heart failure with preserved ejection fraction (HFpEF) is a significant unmet need in cardiovascular medicine and remains an untreatable cardiovascular disease. The role and mechanism of interleukin-1ß in HFpEF pathogenesis are poorly understood. Methods and Results C57/Bl6J and interleukin-1ß-/- male mice were randomly divided into 4 groups. Groups 1 and 2: C57/Bl6J and interleukin-1ß-/- mice were fed a regular diet for 4 months and considered controls. Groups 3 and 4: C57/Bl6 and interleukin-1ß-/- mice were fed a high-fat diet with N[w]-nitro-l-arginine methyl ester (endothelial nitric oxide synthase inhibitor, 0.5 g/L) in the drinking water for 4 months. We measured body weight, blood pressure, diabetes status, cardiac function/hypertrophy/inflammation, fibrosis, vascular endothelial function, and signaling. C57/Bl6 fed a high-fat diet and N[w]-nitro-l-arginine methyl ester in the drinking water for 4 months developed HFpEF pathogenesis characterized by obesity, diabetes, hypertension, cardiac hypertrophy, lung edema, low running performance, macrovascular and microvascular endothelial dysfunction, and diastolic cardiac dysfunction but no change in cardiac ejection fraction compared with control mice. Interestingly, the genetic disruption of interleukin-1ß protected mice from HFpEF pathogenesis through the modulation of the inflammation and endoplasmic reticulum stress mechanisms. Conclusions Our data suggest that interleukin-1ß is a critical driver in the development of HFpEF pathogenesis, likely through regulating inflammation and endoplasmic reticulum stress pathways. Our findings provide a potential therapeutic target for HFpEF treatment.

Inhibition of LPS­induced NLRP3 inflammasome activation by stem cell­conditioned culture media in human gingival epithelial cells.

Interleukin (IL)­1ß is a pathogenic factor associated with the destruction of periodontal tissue in periodontitis. IL­1ß processing is regulated by cytosolic machinery known as the inflammasome. Porphyromonas gingivalis infection and lipopolysaccharide (LPS) have an important role in the destruction of periodontal tissue in periodontitis. P. gingivalis infection and LPS have been reported to activate the NOD­like receptor family pyrin domain­containing protein 3 (NLRP3) inflammasome in human oral cells. Stem cell therapy exhibits anti­inflammatory effects and stem cell­conditioned culture media (SCM) shows similar beneficial effects. The present study tested the hypothesis that SCM inhibits activation of the inflammasome and protects human gingival epithelial cells (GECs) against LPS­induced inflammatory damage. Human GECs were treated with or without LPS plus SCM or control cell media. NLPR3 inflammasome components and inflammatory factors were measured by western blotting and immunofluorescence. The present study revealed that LPS induced an increase in the expression of inflammasome components, NLRP3, apoptosis­associated speck­like protein containing a caspase recruitment domain (ASC) and caspase­1. Co­immunoprecipitation revealed increased binding of NLRP3 and ASC, and immunofluorescence showed an increased co­localization of ASC and caspase­1, suggesting that LPS stimulated assembly of the NLRP3 inflammasome. SCM inhibited the overexpression and assembly of NLRP3 inflammasome components induced by LPS. Furthermore, SCM blocked the increase in IL­1ß production induced by LPS and inhibited the translocation of the inflammatory factor, NF­κB, into the nuclei. Consequently, SCM protected cells against LPS­induced damage, as suggested by the recovery of disturbed E­cadherin staining pattern, which indicates a disruption in epithelial integrity. In conclusion, treatment with SCM may attenuate LPS­induced inflammatory damage in human GECs via inhibition of NLRP3 inflammasome activation, suggesting a potential therapeutic use for SCM.

Macrophages facilitate tumor cell PD-L1 expression via an IL-1ß-centered loop to attenuate immune checkpoint blockade.

Tumor-associated macrophages (TAMs) play critical roles in reprogramming other immune cells and orchestrating antitumor immunity. However, the interplay between TAMs and tumor cells responsible for enhancing immune evasion remains insufficiently understood. Here, we revealed that interleukin (IL)-1ß was among the most abundant cytokines within the in vitro tumor-macrophage coculture system, and enhanced IL-1ß expression was associated with impaired cytotoxicity of CD8+ T cells in human ovarian cancer, indicating the possibility that IL-1ß mediated immunosuppression during tumor-TAMs crosstalk. Mechanistically, we demonstrated that IL-1ß significantly boosted programmed death-ligand 1 (PD-L1) expression in tumor cells via the activation of the nuclear factor-κb signaling cascade. Specifically, IL-1ß released from TAMs was triggered by lactate, the anaerobic metabolite of tumor cells, in an inflammasome activation-dependent manner. IL-1ß sustained and intensified immunosuppression by promoting C-C motif chemokine ligand 2 secretion in tumor cells to fuel TAMs recruitment. Importantly, IL-1ß neutralizing antibody significantly curbed tumor growth and displayed synergistic antitumor efficacies with anti-PD-L1 antibody in tumor-bearing mouse models. Together, this study presents an IL-1ß-centered immunosuppressive loop between TAMs and tumor cells, highlighting IL-1ß as a candidate therapeutic target to reverse immunosuppression and potentiate immune checkpoint blockade.

Pulmonary alveolar proteinosis after lung transplantation.

We report the case of a 69-year-old man five-month post double lung transplant for idiopathic pulmonary fibrosis (IPF) who presented with progressive breathlessness, loss of lung function, and diffuse ground glass shadowing on the chest computed tomography. Transbronchial lung biopsy revealed foamy macrophages, hyperplasia of type II pneumocytes, and eosinophilic material in the alveolar space. Video thoracic lung biopsy was performed, and histology confirmed pulmonary alveolar proteinosis. Anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies were negative. Bilateral sequential whole lung lavage (WLL) was performed. Lavage fluid recovered during WLL was notably dark brown in colour and upon analysis was shown to contain heavily oxidized protein (lipofuscin), giant lipofuscin-engorged macrophages, and a highly pro-inflammatory gene expression profile. Following WLL, the patient's symptoms, lung function, and radiology appearance improved. His repeat bronchoalveolar lavage (BAL) fluid analysis showed reduced lipofuscin and normalized macrophage size and gene expression.

High salivary levels of JP2 genotype of Aggregatibacter actinomycetemcomitans is associated with clinical attachment loss in Moroccan adolescents.

It has previously been shown that the presence of Aggregatibacter actinomycetemcomitans in subgingival plaque is significantly associated with increased risk for clinical attachment loss. The highly leukotoxic JP2 genotype of this bacterium is frequently detected in adolescents with aggressive forms of periodontitis. The aims of the study were to quantify the levels of JP2 and non-JP2 genotypes of A. actinomycetemcomitans in saliva of Moroccan adolescents with the JP2 genotype earlier detected in the subgingival plaque. The salivary concentrations of inflammatory proteins were quantified and linked to the clinical parameters and microbial findings. Finally, a mouth rinse with leukotoxin-neutralizing effect was administrated and its effect on the levels the biomarkers and A. actinomycetemcomitans examined. The study population consisted of 22 adolescents that previously were found to be positive for the JP2 genotype in subgingival plaque. Periodontal registration and sampling of stimulated saliva was performed at baseline. A mouth rinse (active/placebo) was administrated, and saliva sampling repeated after 2 and 4 weeks rinse. The salivary levels of JP2 and non-JP2 were analyzed by quantitative PCR and inflammatory proteins by ELISA. Both the JP2 and the non-JP2 genotype were detected in all individuals with significantly higher levels of the non-JP2. Enhanced levels of the JP2 genotype of A. actinomycetemcomitans was significantly correlated to the presence of attachment loss (≥3 mm). Salivary concentrations of inflammatory biomarkers did not correlate to periodontal condition or levels of A. actinomycetemcomitans. The use of active or placebo leukotoxin-neutralizing mouth rinse did not significantly interfered with the levels of these biomarkers. Saliva is an excellent source for detection of A. actinomycetemcomitans on individual basis, and high levels of the JP2 genotype were significantly associated with the presence of clinical attachment loss.

Transcriptional regulation of human amelotin gene by interleukin-1ß.

One of the major causes of tooth loss is chronic inflammation of the periodontium, the tissues surrounding the tooth. Amelotin (AMTN) is a tooth enamel protein which is expressed in maturation-stage ameloblasts and also in the internal basal lamina of junctional epithelium, a unique epithelial structure attached to the tooth surface which protects against the constant microbiological challenge to the periodontium. Localization of AMTN suggests that its function could be involved in the dentogingival attachment. The purpose of this study was to investigate the effect of interleukin-1ß (IL-1ß) on AMTN gene transcription in human gingival epithelial Ca9-22 cells. IL-1ß increased AMTN mRNA and protein levels at 3 h, and the levels reached maximum at 6 and 12 h. IL-1ß induced luciferase activities of human AMTN gene promoter constructs (-211, -353, -501, -769, and -950AMTN), but these activities were partially inhibited in -353AMTN constructs that included 3-bp mutations in CCAAT/enhancer binding protein 1 (C/EBP1), C/EBP2, and Ying Yang 1 (YY1) elements. Transcriptional activities induced by IL-1ß were abrogated by protein kinase A (PKA), tyrosine kinase, mitogen-activated protein kinase kinase (MEK1/2), and phosphatidylinositol 3-kinase (PI3K) inhibitors. Gel shift and ChIP assays showed that IL-1ß increased C/EBPß binding to C/EBP1 and C/EBP2, and YY1 binding to YY1 elements after 3 h, and that these DNA-protein interactions were inhibited by PKA, tyrosine kinase, MEK1/2, and PI3K inhibitors. These results demonstrated that IL-1ß increases AMTN gene transcription in human gingival epithelial cells mediated through C/EBP1, C/EBP2, and YY1 elements in the human AMTN gene promoter.

NLRP3 Inflammasome Expression and Activation in Human Atherosclerosis.

BACKGROUND: The NLR family, pyrin domain containing 3 (NLRP3) inflammasome is an interleukin (IL)-1ß and IL-18 cytokine processing complex that is activated in inflammatory conditions. The role of the NLRP3 inflammasome in the pathogenesis of atherosclerosis and myocardial infarction is not fully understood. METHODS AND RESULTS: Atherosclerotic plaques were analyzed for transcripts of the NLRP3 inflammasome, and for IL-1ß release. The Swedish First-ever myocardial Infarction study in Ac-county (FIA) cohort consisting of DNA from 555 myocardial infarction patients and 1016 healthy individuals was used to determine the frequency of 4 single nucleotide polymorphisms (SNPs) from the downstream regulatory region of NLRP3. Expression of NLRP3, Apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1 (CASP1), IL1B, and IL18 mRNA was significantly increased in atherosclerotic plaques compared to normal arteries. The expression of NLRP3 mRNA was significantly higher in plaques of symptomatic patients when compared to asymptomatic ones. CD68-positive macrophages were observed in the same areas of atherosclerotic lesions as NLRP3 and ASC expression. Occasionally, expression of NLRP3 and ASC was also present in smooth muscle cells. Cholesterol crystals and ATP induced IL-1ß release from lipopolysaccharide-primed human atherosclerotic lesion plaques. The minor alleles of the variants rs4266924, rs6672995, and rs10733113 were associated with NLRP3 mRNA levels in peripheral blood mononuclear cells but not with the risk of myocardial infarction. CONCLUSIONS: Our results indicate a possible role of the NLRP3 inflammasome and its genetic variants in the pathogenesis of atherosclerosis.