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The NLRP3 inflammasome has emerged as an important regulator of metabolic disorders and age-related diseases in NLRP3-deficient mice. In this article, we determine whether, in old mice C57BL6J, the NLRP3 inflammasome inhibitor MCC950 is able to attenuate age-related metabolic syndrome to providing health benefits. We report that MCC950 attenuates metabolic and hepatic dysfunction in aged mice. In addition, MCC950 inhibited the Pi3K/AKT/mTOR pathway, enhanced autophagy, and activated peroxisome proliferator-activated receptor-α in vivo and in vitro. The data suggest that MCC950 mediates the protective effects by the mammalian target of rapamycin inhibition, thus activating autophagy and peroxisome proliferator-activated receptor-α. In conclusion, pharmacological inhibition of NLRP3 in aged mice has a significant impact on health. Thus, NLRP3 may be a therapeutic target of human age-related metabolic syndrome., (© The Author(s) 2019. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aging is the major risk factor for many metabolic chronic diseases. Several metabolic pathways suffer a progressive impairment during aging including body composition and insulin resistance which are associated to autophagy dysfunction and increased inflammation. Many of these alterations are aggravated by non-healthy lifestyle such as obesity and hypercaloric diet which have been shown to accelerate aging. Here, we show that the deleterious effect of hypercaloric diets is reverted by the NLRP3 inflammasome inhibition. NLRP3 deficiency extends mean lifespan of adult mice fed a high-fat diet. This lifespan extension is accompanied by metabolic health benefits including reduced liver steatosis and cardiac damage, improved glucose and lipid metabolism, and improved protein expression profiles of SIRT-1, mTOR, autophagic flux, and apoptosis. These findings suggest that the suppression of NLRP3 prevented many age-associated changes in metabolism impaired by the effect of hypercaloric diets.

While NLRP3-inflammasome has been implicated in cardiovascular diseases, its role in physiological cardiac aging is largely unknown. During aging, many alterations occur in the organism, which are associated with progressive impairment of metabolic pathways related to insulin resistance, autophagy dysfunction, and inflammation. Here, we investigated the molecular mechanisms through which NLRP3 inhibition may attenuate cardiac aging. Ablation of NLRP3-inflammasome protected mice from age-related increased insulin sensitivity, reduced IGF-1 and leptin/adiponectin ratio levels, and reduced cardiac damage with protection of the prolongation of the age-dependent PR interval, which is associated with atrial fibrillation by cardiovascular aging and reduced telomere shortening. Furthermore, old NLRP3 KO mice showed an inhibition of the PI3K/AKT/mTOR pathway and autophagy improvement, compared with old wild mice and preserved Nampt-mediated NAD + levels with increased SIRT1 protein expression. These findings suggest that suppression of NLRP3 prevented many age-associated changes in the heart, preserved cardiac function of aged mice and increased lifespan., (© 2019 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.)

The inflammasomes are innate immune system sensors that control the activation of caspase-1 and induce inflammation in response to infectious microbes and molecules originating from host proteins, leading to the release of pro-inflammatory cytokines, Il1b and IL18, and a particular inflammatory type of cell death termed pyroptosis. It is broadly considered that chronic inflammation may be a common link in age-related diseases, aging being the greatest risk factor for the development of chronic diseases. In this sense, we discuss the role of inflammasomes in non-infectious inflammation and their interest in aging and age-related diseases.

Conventional cardiovascular risk factors (CVRFs) are accepted to identify asymptomatic individuals with high risk of acute myocardial infarction (AMI). However, AMI affects many patients previously classified at low risk. New biomarkers are needed to improve risk prediction. We propose to evaluate the NLRP3-inflammasome complex as a potential conventional cardiovascular risk (CVR) indicator in healthy males and post-AMI patients and compare both groups by known CVRFs. We included 109 men with no history of cardiovascular disease (controls) and 150 AMI patients attending a cardiac rehabilitation program. AMI patients had higher mean of body mass index (BMI) and waist circumference than the controls. However, high percentages of the controls had a high BMI and a waist circumference >95 cm. The controls also had higher systolic blood pressure (p > 0.001), total and low-density lipoprotein cholesterol, dietary nutrient, and calorific intake. Fuster BEWAT score (FBS) correlated more closely than Framingham risk score (FRS) with most CVRF, groups. However, only the FBS showed a correlation with inflammasome cytokine interleukin 1β (IL-1β). Several CVRFs were significantly better in AMI patients; however, this group also had higher mRNA expression of the inflammasome gene NLRP3 and lower expression of the autophagy gene MAP-LC3. The controls had high levels of CVRF, probably reflecting unhealthy lifestyle. FBS reflects the efficiency of strategies to induce lifestyle changes such as cardiac rehabilitation programs, and could provide a sensitive evaluation CVR. These results lead to the hypothesis that NLRP3-inflammasome and associated IL-1β release have potential as CVR biomarkers, particularly in post-AMI patients with otherwise low risk scores. Antioxid. Redox Signal. 27, 269-275.

Depression is a major public health concern in modern society, yet little is known about the molecular link between this condition and neuroinflammation. The inflammasome complex was recently shown to be implicated in depression. The present study shows the implication of NLRP3 inflammasome in animal model of stress-induced depression. Accordingly, we show here that in the absence of a NLRP3 inflammasome, prolonged stress does not provoke depressive behaviors or microglial activation in mice or dampen hippocampal neurogenesis. Indeed, NLRP3 deletion or inhibition of microglial activation impairs the stress-induced alterations associated with depression. According to these findings in animal model, the inflammasome could be a target for new therapeutic interventions to prevent depression in patients.

Aims: Impairment in adenosine monophosphate-activated protein kinase (AMPK) activity and NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation are associated with several metabolic and inflammatory diseases. In this study, we investigated the role of AMPK/NLRP3 inflammasome axis in the molecular mechanism underlying pain perception., Results: Impairment in AMPK activation induced by compound C or sunitinib, two AMPK inhibitors, provoked hyperalgesia in mice (p<0.001) associated with marked NLRP3 inflammasome protein activation and increased serum levels of interleukin-1β (IL-1β) (24.56±0.82 pg/ml) and IL-18 (23.83±1.882 pg/ml) compared with vehicle groups (IL-1β: 8.15±0.44; IL-18: 4.92±0.4). This effect was rescued by increasing AMPK phosphorylation via metformin treatment (p<0.001), caloric restriction diet (p<0.001), or NLRP3 inflammasome genetic inactivation using NLRP3 knockout (nlrp3(-/-)) mice (p<0.001). Deficient AMPK activation and overactivation of NLRP3 inflammasome axis were also observed in blood cells from patients with fibromyalgia (FM), a prevalent human chronic pain disease. In addition, metformin treatment (200 mg/daily), which increased AMPK activation, restored all biochemical alterations examined by us in blood cells and significantly improved clinical symptoms, such as, pain, fatigue, depression, disturbed sleep, and tender points, in patients with FM., Innovation and Conclusions: These data suggest that AMPK/NLRP3 inflammasome axis participates in chronic pain and that NLRP3 inflammasome inhibition by AMPK modulation may be a novel therapeutic target to fight against chronic pain and inflammatory diseases as FM.