scholarly journals Contribution of Autophagy-Notch1-Mediated NLRP3 Inflammasome Activation to Chronic Inflammation and Fibrosis in Keloid Fibroblasts

2020 ◽  
Vol 21 (21) ◽  
pp. 8050
Author(s):  
Seongju Lee ◽  
Sun Kyeon Kim ◽  
Hyungsun Park ◽  
Yu Jin Lee ◽  
Song Hee Park ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Chronic Inflammation ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Myofibroblast Differentiation ◽  
Expression Levels ◽  
Notch1 Signaling ◽  
Nlrp3 Inflammasome Activation ◽  
Keloid Fibroblasts

Keloid is a representative chronic fibroproliferative condition that occurs after tissue injury. Emerging evidence showed that activation of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome is involved in the pro-inflammatory response in injured tissues. However, the role of NLRP3 inflammasome in keloid progression remains unclear. Notch signaling, which activates NLRP3 inflammasome, is known to contribute to scar formation in keloid, but the cause of enhanced Notch signaling in keloid is not clear. We sought to investigate whether autophagy regulates Notch1 signaling in keloid fibroblasts and determine whether Notch1 signaling might regulate NLRP3 inflammasomes and myofibroblast differentiation. An in vitro model of keloid was established by culturing primary keloid fibroblasts from patients. Expression levels of Notch1, NLRP3 inflammasome proteins, pro-inflammatory cytokines, and myofibroblast markers in keloid fibroblasts were examined and compared with those in normal fibroblasts. Autophagy known to mediate Notch1 degradation was also monitored in fibroblasts. Small interfering RNA (siRNA) targeting Notch1 was used to transfect keloid fibroblasts to further examine the role of Notch signaling in NLRP3 inflammasome activation. Expression levels of Notch1 and NLRP3 inflammasome in keloid fibroblasts increased compared to those in normal fibroblasts. Such increases were accompanied by increased LC3 levels and reduced autophagic flux. Notch1 silencing in keloid fibroblasts by siRNA transfection significantly suppressed increased levels of overall NLRP3 inflammasome complex proteins, NF-kB, and α-smooth muscle actin. Autophagy induction by rapamycin treatment in keloid fibroblasts effectively suppressed expression levels of Notch1 and NLRP3 inflammasome proteins. Decreased autophagy activity in keloid can result in Notch1-mediated myofibroblast activation and NLRP3 inflammasome signaling activation which is critical for chronic inflammation. Collectively, these results identify Notch1 as a novel activator of NLRP3 inflammasome signaling leading to chronic tissue damage and myofibroblast differentiation in keloid progression.

scholarly journals The NLRP3 Inflammasome as a Novel Player of the Intercellular Crosstalk in Metabolic Disorders

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Elisa Benetti ◽  
Fausto Chiazza ◽  
Nimesh S. A. Patel ◽  
Massimo Collino
Keyword(s):  
Chronic Inflammation ◽  
Nlrp3 Inflammasome ◽  
Metabolic Disorders ◽  
Inflammasome Activation ◽  
Nucleotide Binding Domain ◽  
Metabolic Inflammation ◽  
Nlrp3 Inflammasome Activation ◽  
Leucine Rich Repeat Protein

The combination of obesity and type 2 diabetes is a serious health problem, which is projected to afflict 300 million people worldwide by 2020. Both clinical and translational laboratory studies have demonstrated that chronic inflammation is associated with obesity and obesity-related conditions such as insulin resistance. However, the precise etiopathogenetic mechanisms linking obesity to diabetes remain to be elucidated, and the pathways that mediate this phenomenon are not fully characterized. One of the most recently identified signaling pathways, whose activation seems to affect many metabolic disorders, is the “inflammasome,” a multiprotein complex composed of NLRP3 (nucleotide-binding domain and leucine-rich repeat protein 3), ASC (apoptosis-associated speck-like protein containing a CARD), and procaspase-1. NLRP3 inflammasome activation leads to the processing and secretion of the proinflammatory cytokines interleukin- (IL-) 1βand IL-18. The goal of this paper is to review new insights on the effects of the NLRP3 inflammasome activation in the complex mechanisms of crosstalk between different organs, for a better understanding of the role of chronic inflammation in metabolic disease pathogenesis. We will provide here a perspective on the current research on NLRP3 inflammasome, which may represent an innovative therapeutic target to reverse the detrimental metabolic consequences of the metabolic inflammation.

scholarly journals Eplerenone prevented obesity-induced inflammasome activation and glucose intolerance

2017 ◽  
Vol 235 (3) ◽  
pp. 179-191 ◽  
Author(s):  
Tsutomu Wada ◽  
Akari Ishikawa ◽  
Eri Watanabe ◽  
Yuto Nakamura ◽  
Yusuke Aruga ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Glucose Intolerance ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
M2 Macrophage ◽  
Expression Levels ◽  
Nlrp3 Inflammasome Activation ◽  
M1 Macrophage ◽  
Anti Inflammatory

Obesity-associated activation of the renin-angiotensin-aldosterone system is implicated in the pathogenesis of insulin resistance; however, influences of mineralocorticoid receptor (MR) inhibition remain unclear. Therefore, we aimed to clarify the anti-inflammatory mechanisms of MR inhibition using eplerenone, a selective MR antagonist, in C57BL/6 mice fed a high-fat diet (HFD) for 12 weeks. Eplerenone prevented excessive body weight gain and fat accumulation, ameliorated glucose intolerance and insulin resistance and enhanced energy metabolism. In the epididymal white adipose tissue (eWAT), eplerenone prevented obesity-induced accumulation of F4/80+CD11c+CD206−-M1-adipose tissue macrophage (ATM) and reduction of F4/80+CD11c−CD206+-M2-ATM. Interestingly, M1-macrophage exhibited lower expression levels of MR, compared with M2-macrophage, in the ATM of eWAT and in vitro-polarized bone marrow-derived macrophages (BMDM). Importantly, eplerenone and MR knockdown attenuated the increase in the expression levels of proIl1b, Il6 and Tnfa, in the eWAT and liver of HFD-fed mice and LPS-stimulated BMDM. Moreover, eplerenone suppressed IL1b secretion from eWAT of HFD-fed mice. To reveal the anti-inflammatory mechanism, we investigated the involvement of NLRP3-inflammasome activation, a key process of IL1b overproduction. Eplerenone suppressed the expression of the inflammasome components, Nlrp3 and Caspase1, in the eWAT and liver. Concerning the second triggering factors, ROS production and ATP- and nigericin-induced IL1b secretion were suppressed by eplerenone in the LPS-primed BMDM. These results indicate that eplerenone inhibited both the priming and triggering signals that promote NLRP3-inflammasome activation. Therefore, we consider MR to be a crucial target to prevent metabolic disorders by suppressing inflammasome-mediated chronic inflammation in the adipose tissue and liver under obese conditions.

scholarly journals The role of NLRP3 inflammasome activation in radiation damage

2019 ◽  
Vol 118 ◽  
pp. 109217 ◽  
Author(s):  
Jinlong Wei ◽  
Heru Wang ◽  
Huanhuan Wang ◽  
Bin Wang ◽  
Lingbin Meng ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

scholarly journals NADPH Oxidase 2 Regulates NLRP3 Inflammasome Activation in the Brain after Traumatic Brain Injury

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Merry W. Ma ◽  
Jing Wang ◽  
Krishnan M. Dhandapani ◽  
Darrell W. Brann
Keyword(s):  
Oxidative Stress ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Nadph Oxidase ◽  
Nlrp3 Inflammasome ◽  
Healing Process ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Nadph Oxidase 2

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. After the initial primary mechanical injury, a complex secondary injury cascade involving oxidative stress and neuroinflammation follows, which may exacerbate the injury and complicate the healing process. NADPH oxidase 2 (NOX2) is a major contributor to oxidative stress in TBI pathology, and inhibition of NOX2 is neuroprotective. The NLRP3 inflammasome can become activated in response to oxidative stress, but little is known about the role of NOX2 in regulating NLRP3 inflammasome activation following TBI. In this study, we utilized NOX2 knockout mice to study the role of NOX2 in mediating NLRP3 inflammasome expression and activation following a controlled cortical impact. Expression of NLRP3 inflammasome components NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC), as well as its downstream products cleaved caspase-1 and interleukin-1β (IL-1β), was robustly increased in the injured cerebral cortex following TBI. Deletion of NOX2 attenuated the expression, assembly, and activity of the NLRP3 inflammasome via a mechanism that was associated with TXNIP, a sensor of oxidative stress. The results support the notion that NOX2-dependent inflammasome activation contributes to TBI pathology.

The role of HIF-1α in regulating NLRP3 inflammasome activation in bladder cancer.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e17028-e17028 ◽  
Author(s):  
Yuan-Ru Chen ◽  
Hsin-Chih Yeh ◽  
Fang-Yen Chiu ◽  
Hsin-En Wu ◽  
Huei-Chen Fang ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Urothelial Carcinoma ◽  
Cancer Cells ◽  
Nlrp3 Inflammasome ◽  
Migration And Invasion ◽  
Inflammasome Activation ◽  
T24 Cells ◽  
Nlrp3 Inflammasome Activation ◽  
Bladder Cancer Cells

e17028 Background: Bladder cancer is one of the most common malignancies of urinary system with the forth incidence rate and the eighth leading mortality rate in male genitourinary tumors. Hypoxia environment activates the hypoxia‐signalling pathway, principally via hypoxia‐inducible transcription factors (HIF) to activate numerous target genes which mediate embryonic vascularization, metabolism, tumor angiogenesis and the other processes to supply tissues with blood and oxygen. Inflammasomes are multiprotein signal responsible for the maturation of proinflammatory cytokines IL-1β and IL-18 as well as trigger the inflammatory cell pyroptosis. Recent study showed that HIF-1α promotes NLRP3 inflammasome activation in bleomycin-induced acute lung injury. However, the role of HIF1α in regulating the progression of bladder cancer has not been examined so far. The present study aimed to investigate the effect of HIF-1α on NLRP3 inflammasome activation in urothelial carcinoma. Methods: In this research, urothelial carcinoma cell lines were treated with NLRP3 inflammasome inducers, LPS/ATP, to induce NLRP3 inflammasome activation. Results: Our preliminary results showed that both T24 and 5637 bladder cancer cells can be induced NLRP3 inflammasome activation and IL-1β secretion. In addition, hypoxia also induces the secretion of IL-1β in T24 cells. We further investigated the effect of NLRP3 inflammasome activation in modulating EMT-related protein levels, migration and invasion in bladder cancer T24 cells. Our results demonstrated that NLRP3 inflammasome activation promotes tumor growth and metastasis in bladder cancer cells. Furthermore, knockdown of HIF1α reduces both inflammatory response and migratory activity in bladder cancer. Conclusions: Collectively, these results suggest that targeting NLRP3 inflammasome might offer potential to treat hypoxic malignant tumor in bladder carcinoma.

The purinergic 2X7receptor participates in renal inflammation and injury induced by high-fat diet: possible role of NLRP3 inflammasome activation

2013 ◽  
Vol 231 (3) ◽  
pp. 342-353 ◽  
Author(s):  
Anna Solini ◽  
Stefano Menini ◽  
Chiara Rossi ◽  
Carlo Ricci ◽  
Eleonora Santini ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
High Fat Diet ◽  
Inflammasome Activation ◽  
High Fat ◽  
Renal Inflammation ◽  
Nlrp3 Inflammasome Activation

scholarly journals Inhibitory Role of Berberine, an Isoquinoline Alkaloid, on NLRP3 Inflammasome Activation for the Treatment of Inflammatory Diseases

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6238
Author(s):  
Paromita Sarbadhikary ◽  
Blassan P. George ◽  
Heidi Abrahamse
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammatory Diseases ◽  
In Vivo Studies ◽  
Inflammasome Activation ◽  
Inflammatory Disorders ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory

The pyrin domain-containing multiprotein complex NLRP3 inflammasome, consisting of the NLRP3 protein, ASC adaptor, and procaspase-1, plays a vital role in the pathophysiology of several inflammatory disorders, including neurological and metabolic disorders, chronic inflammatory diseases, and cancer. Several phytochemicals act as promising anti-inflammatory agents and are usually regarded to have potential applications as complementary or alternative therapeutic agents against chronic inflammatory disorders. Various in vitro and in vivo studies have reported the anti-inflammatory role of berberine (BRB), an organic heteropentacyclic phytochemical and natural isoquinoline, in inhibiting NLRP3 inflammasome-dependent inflammation against many disorders. This review summarizes the mechanism and regulation of NLRP3 inflammasome activation and its involvement in inflammatory diseases, and discusses the current scientific evidence on the repressive role of BRB on NLRP3 inflammasome pathways along with the possible mechanism(s) and their potential in counteracting various inflammatory diseases.

scholarly journals Role of the mitochondrial Na+/Ca2+ exchanger in NLRP3 inflammasome activation.

IBJ Plus ◽  
2018 ◽  
Author(s):  
◽  
◽  
Paloma Narros Fernández ◽  
Alejandra Palomino Antolín ◽  
Víctor Farré Alins ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation
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