scholarly journals Macrophage digesting dysfunction by Angiotensin II through lysosomal cathepsin B‐mediated Nlrp3 inflammasome activation

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Dawei Lian ◽  
Jieqing Lai ◽  
Yanjiao Wu ◽  
Lei Wang ◽  
Lin Yao ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Nlrp3 Inflammasome ◽  
Cathepsin B ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

Abstract P075: Angiotensin II Induces Endothelial Dysfunction And Vascular Remodeling Dependent Of Nlrp3 Inflammasome

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Stefany B Cau ◽  
Marcondes da Silva ◽  
Nathanne d Ferreira ◽  
Rita C Tostes ◽  
Thiago Bruder-Nascimento
Keyword(s):  
Angiotensin Ii ◽  
Endothelial Dysfunction ◽  
Nlrp3 Inflammasome ◽  
Vascular Remodeling ◽  
Vascular Diseases ◽  
Vascular Damage ◽  
Mesenteric Arteries ◽  
Cell Counting ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

The NLRP3 inflammasome is a multimeric protein complex constituted by NLRP3, Asc and Capase-1 (Casp1). It triggers an inflammatory response by releasing the pro-inflammatory cytokines IL-1β and IL-18. NLRP3 inflammasome is expressed in different cells and its activation has been associated with several diseases including atherosclerosis and hypertension. Herein we tested the hypothesis that angiotensin II (AngII) induces vascular damage by activating the NLPR3 inflammasome in the vasculature. C57BL/6J male mice (Ctrl) and Casp-1 deficient mice (Casp1-/-) were treated with AngII (490 ng/min/kg/14 days by osmotic mini pump). In Ctrl mice, AngII treatment impaired the vascular relaxation to acetylcholine in mesenteric arteries, increased aorta media thickness [Ctrl: 49.4 ± 2.5 vs AngII: 62.3 ± 2.3* (μm), *P<0.05] and cross-sectional area [Ctrl: 0.11 ± 0.1 vs AngII: 0.15 ± 0.2* (mm), *P<0.05] and triggered NLRP3 inflammasome activation in aorta and mesenteric arteries, analyzed by caspase-1 cleavage and IL-1B maturation via western blot and casp1 activity - FAM-FLICA assay. Fascinatingly, Casp1-/- mice were protected from AngII-induced endothelial dysfunction and vascular remodeling. Furthermore, AngII (0.1uM) incubation, combined or not with lipopolysaccharide (500 ng.ml –1 ultrapure) or Nigericin (20 μM), elevated Casp1 cleavage and IL-1B maturation in Rat Aortic Smooth Muscle Cells (RASMC). Moreover, AngII elevated PCNA (~2.5-fold) and CyclinD1 (~2.1-fold) protein expression and induced vascular migration and proliferation measured by scratch assay and cell counting kit-8 (CCK-8) assay respectively. Interestingly NLRP3 antagonist incubation (MCC950, 1uM) abolished PCNA expression and attenuated the vascular migration and proliferation produced by AngII incubation. Our data suggest that AngII induces vascular damage by activating NLPR3 inflammasome directly in the vasculature. We place this innate immune receptor as a master regulator of the vascular phenotype and as a target for therapeutic strategies for vascular diseases. Future studies will be helpful providing a better understanding into the molecular mechanism of NLRP3 inflammasome activation and regulation in the control of vascular diseases.

scholarly journals Deoxycholic Acid-Mediated Sphingosine-1-Phosphate Receptor 2 Signaling Exacerbates DSS-Induced Colitis through Promoting Cathepsin B Release

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Shengnan Zhao ◽  
Zizhen Gong ◽  
Xixi Du ◽  
Chunyan Tian ◽  
Lingyu Wang ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
High Fat Diet ◽  
Cathepsin B ◽  
Intestinal Inflammation ◽  
Critical Role ◽  
Inflammasome Activation ◽  
High Fat ◽  
Molecular Pattern ◽  
Nlrp3 Inflammasome Activation ◽  
Sphingosine 1 Phosphate

We recently have proved that excessive fecal DCA caused by high-fat diet may serve as an endogenous danger-associated molecular pattern to activate NLRP3 inflammasome and thus contributes to the development of inflammatory bowel disease (IBD). Moreover, the effect of DCA on inflammasome activation is mainly mediated through bile acid receptor sphingosine-1-phosphate receptor 2 (S1PR2); however, the intermediate process remains unclear. Here, we sought to explore the detailed molecular mechanism involved and examine the effect of S1PR2 blockage in a colitis mouse model. In this study, we found that DCA could dose dependently upregulate S1PR2 expression. Meanwhile, DCA-induced NLRP3 inflammasome activation is at least partially achieved through stimulating extracellular regulated protein kinases (ERK) signaling pathway downstream of S1PR2 followed by promoting of lysosomal cathepsin B release. DCA enema significantly aggravated DSS-induced colitis in mice and S1PR2 inhibitor as well as inflammasome inhibition by cathepsin B antagonist substantially reducing the mature IL-1β production and alleviated colonic inflammation superimposed by DCA. Therefore, our findings suggest that S1PR2/ERK1/2/cathepsin B signaling plays a critical role in triggering inflammasome activation by DCA and S1PR2 may represent a new potential therapeutic target for the management of intestinal inflammation in individuals on a high-fat diet.

scholarly journals Cathepsin B Is Required for NLRP3 Inflammasome Activation in Macrophages, Through NLRP3 Interaction

2020 ◽  
Vol 8 ◽  
Author(s):  
Angélique Chevriaux ◽  
Thomas Pilot ◽  
Valentin Derangère ◽  
Harmonie Simonin ◽  
Pierre Martine ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Cathepsin B ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

scholarly journals Nlrp3 Deficiency Alleviates Angiotensin II-Induced Cardiomyopathy by Inhibiting Mitochondrial Dysfunction

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yu Chen ◽  
Meiying Zeng ◽  
Yang Zhang ◽  
Hui Guo ◽  
Wei Ding ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Function ◽  
Mitochondrial Dysfunction ◽  
Nlrp3 Inflammasome ◽  
Gene Deletion ◽  
Cardiac Fibrosis ◽  
Inflammasome Activation ◽  
Ang Ii ◽  
Nlrp3 Gene ◽  
Nlrp3 Inflammasome Activation

Inflammation has been considered a key component in the pathogenesis and progression of angiotensin II- (Ang II-) induced cardiac hypertrophy and related cardiomyopathy. As a vital mediator of inflammation, the role of the Nlrp3 inflammasome in Ang II-induced cardiomyopathy remains unclear. This study was aimed to determine whether Nlrp3 inflammasome activation and its downstream pathway were involved in Ang II-induced cardiomyopathy. We established an Ang II infusion model in both wild-type and Nlrp3-/- mice to determine the contribution of Nlrp3 to cardiac function. Cardiac fibrosis was determined by Masson’s trichrome staining, real-time PCR, and TUNEL assay; cardiac function was assessed by echocardiography. Nlrp3 inflammasome activation and related downstream cytokines were measured by Western blotting and enzyme-linked immunosorbent assays; mitochondrial dysfunction was examined by transmission electron microscopy and real-time PCR. We found that Ang II-infused mice showed impaired cardiac function, as evidenced by increased cardiac fibrosis, apoptosis, inflammation, and left ventricular dysfunction. However, these alterations were significantly alleviated in the mice with Nlrp3 gene deletion. Moreover, Ang II-infused mice showed increased Nlrp3 inflammasome activity relative to that of the cytokines IL-1β and IL-18, increased reactive oxygen species, mitochondrial abnormalities, and decreased mtDNA copy number and ATP synthase activity. These molecular and pathological alterations were also attenuated in Nlrp3 deficient mice. In conclusion, Nlrp3 inflammasome-induced mitochondrial dysfunction is involved in Ang II-induced cardiomyopathy. Nlrp3 gene deletion attenuated mitochondrial abnormalities, cardiac inflammation, oxidative stress, and fibrosis and thus alleviated heart dysfunction and hypertrophy. Targeting the Nlrp3 inflammasome and/or mitochondria may be a therapeutic approach for Ang II-induced cardiac diseases.

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