scholarly journals Ginsenoside Rb1 and compound K improve insulin signaling and inhibit ER stress-associated NLRP3 inflammasome activation in adipose tissue

2016 ◽  
Vol 40 (4) ◽  
pp. 351-358 ◽  
Author(s):  
Weijie Chen ◽  
Junlian Wang ◽  
Yong Luo ◽  
Tao Wang ◽  
Xiaochun Li ◽  
...  
2017 ◽  
Vol 235 (3) ◽  
pp. 179-191 ◽  
Author(s):  
Tsutomu Wada ◽  
Akari Ishikawa ◽  
Eri Watanabe ◽  
Yuto Nakamura ◽  
Yusuke Aruga ◽  
...  

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.


2020 ◽  
Vol 21 (11) ◽  
pp. 4184 ◽  
Author(s):  
Kelvin Ka-Lok Wu ◽  
Samson Wing-Ming Cheung ◽  
Kenneth King-Yip Cheng

Adipose tissue is an active endocrine and immune organ that controls systemic immunometabolism via multiple pathways. Diverse immune cell populations reside in adipose tissue, and their composition and immune responses vary with nutritional and environmental conditions. Adipose tissue dysfunction, characterized by sterile low-grade chronic inflammation and excessive immune cell infiltration, is a hallmark of obesity, as well as an important link to cardiometabolic diseases. Amongst the pro-inflammatory factors secreted by the dysfunctional adipose tissue, interleukin (IL)-1β, induced by the NLR family pyrin domain-containing 3 (NLRP3) inflammasome, not only impairs peripheral insulin sensitivity, but it also interferes with the endocrine and immune functions of adipose tissue in a paracrine manner. Human studies indicated that NLRP3 activity in adipose tissues positively correlates with obesity and its metabolic complications, and treatment with the IL-1β antibody improves glycaemia control in type 2 diabetic patients. In mouse models, genetic or pharmacological inhibition of NLRP3 activation pathways or IL-1β prevents adipose tissue dysfunction, including inflammation, fibrosis, defective lipid handling and adipogenesis, which in turn alleviates obesity and its related metabolic disorders. In this review, we summarize both the negative and positive regulators of NLRP3 inflammasome activation, and its pathophysiological consequences on immunometabolism. We also discuss the potential therapeutic approaches to targeting adipose tissue inflammasome for the treatment of obesity and its related metabolic disorders.


2021 ◽  
Author(s):  
Zheng Liu ◽  
Juan Chen ◽  
Lili Sun ◽  
Jianzhong Li ◽  
Hong Sun

Abstract Background: Advanced glycation end products (AGEs) are pathogenic factors of renal tubular lipid accumulation and play a negative role in diabetic kidney disease (DKD). Glucose cotransporter (SGLT) 2 inhibition offers strong renoprotection in the progression of DKD. The aim of the current study was to investigate the effects of empagliflozin (EMPA, a potent and selective SGLT2 inhibitor) on AGEs-induced renal tubular lipid accumulation in both diabetic mice fed with a high-AGEs diet and AGEs-treated cultured human renal proximal tubular epithelial (HK-2) cells. Methods: In vivo, EMPA was used to treat db/db mice fed a high-AGEs diet or an AIN-76 basal diet. In an in vitro study, HK-2 cells were treated with AGEs-bovine serum albumin (BSA) and/or EMPA. Sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) translocation was detected by confocal microscopy. Results: EMPA reduced tubular lipid droplets and intracellular cholesterol content, as well as the expression of proteins involved in the synthesis and absorption of cholesterol in the kidneys of basal diet-fed db/db mice, high-AGEs diet-fed db/db mice and AGEs-BSA-treated HK-2 cells. AGEs-BSA loading promoted the formation of SCAP-SREBP-2 complexes and enhanced the transport of the complexes to the Golgi, but these effects were markedly inhibited by EMPA in HK-2 cells. EMPA reduced renal inflammation both in basal diet-fed db/db mice and high-AGEs diet-fed db/db mice, and suppressed NLRP3 inflammasome activation in AGEs-BSA-treated HK-2 cells. In addition, EMPA reduced the serum AGEs level in vivo and inhibited renal tubular endoplasmic reticulum (ER) stress and receptor of AGEs (RAGE) expression both in vivo and in vitro. Conclusions: EMPA attenuated AGEs synthesis and inhibited the AGEs-RAGE signaling pathway, thereby suppressing ER stress and inhibiting abnormal cholesterol metabolism and release of inflammatory cytokines, thus alleviating renal tubular lipid accumulation and inflammation.


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