scholarly journals STS Protects Diabetic Glomerular Vascular Endothelial Barrier by Ameliorating EPC Dysfunction: Targeting RAGE-TXNIP-NLRP3 Inflammasome Pathway

Author(s):  
Yan-Yan Heng ◽  
Xiao-Yan Zhang ◽  
Fei-Fei Wang ◽  
Peng-Fei Zhang ◽  
wei wei

Abstract Background: Glomerular endothelial cell (GEC) injury is one of the crucial causes of diabetic kidney disease (DKD). Endothelial progenitor cell (EPC) is the essential mechanism of vascular endothelial repair, which damages by diabetic pathology. Sodium Tanshinone Sulfonate ⅡA (STS) is known to protect endothelium, but the mechanism and the role in DKD need to be studied. Methods: EPC was treated with high glucose (HG), and thioredoxin interacting protein (TXNIP), NLR family pyrin domain containing 3 (NLRP3) inflammasome, DNA damage, proliferation, differentiation and senescence were detected; STS and EPC were intravenous injected into diabetic nude mice, the urine protein quantitation and urine protein/creatinine were detected; the Dil-labeled EPC was traced and the expression of TXNIP, caspase-1 (p20), p21, Ki67, CD31 were detected by fluorescence co-location in glomerulus.Results: We found that STS inhibited HG-induced TXNIP expression and NLRP3 inflammasome activation, catalase (CAT) inactivation, DNA damage, senescence; STS restored EPC proliferation and differentiation functions; advanced glycation end products (AGEs) produced in HG treated EPC supernatant, the receptor of AGE (RAGE) blocking inhibited TXNIP expression and NLRP3 inflammasome activation, which mimicked by STS. STS protected EPC functions in diabetic glomerular and enhanced EPC renal function amelioration. Conclusions: We concluded that STS watched CAT activity to prevent HG-induced EPC DNA damage, proliferation, differentiation dysfunction, accelerated senescence by inhibiting the RAGE-TXNIP-NLRP3 inflammasome-caspase-1 pathway.

2018 ◽  
Author(s):  
Yong Yang ◽  
Jianxin Li ◽  
Ting-Li Han ◽  
Xiaobo Zhou ◽  
Hongbo Qi ◽  
...  

AbstractPreeclampsia (PE) development is often associated with placental immune and inflammatory dysregulation, as well as endoplasmic reticulum (ER) stress. However, the mechanisms linking ER stress and inflammatory dysregulation to PE have not been clarified. It has been reported that thioredoxin-interacting protein (TXNIP), which can bind with and activate the NLR family pyrin domain containing 3 (NLRP3) inflammasome, plays a critical role in immune regulation. Recent experimental evidence suggests that activated NLRP3 inflammasomes can activate interleukin-1β (IL-1β) production in the placenta of patients with PE. The objective of the current study was to explore if TXNIP plays a critical signaling role linking ER stress with NLRP3 inflammasome activation in PE. We hypothesised that ER stress would induce TXNIP production, which would bind with NLRP3 inflammasomes to activate IL-1β production. HTR8/SVneo cells were subjected to six hours hypoxia followed by six hours reoxygenation (H/R). These cells showed a higher protein level of NLRP3 and IL-1β, as well as a higher enzymatic activity of caspase-1, indicating enhanced inflammatory dysregulation and ER stress. Cells transfected with TXNIP siRNA showed reduced NLRP3 inflammasome activation. Cells treated with 4-phenylbutyric acid, an inhibitor of ER stress, showed a similar result. In addition, the outgrowth of explant with TXNIP lentivirus in H/R or Tunicamycin (inducers of ER stress) was also measured to verify our hypothesis. These findings demonstrated that TXNIP could influence inflammatory dysregulation by mediating ER stress and NLRP3 inflammasome activation in PE. This novel mechanism may further explain the inflammation observed at the maternal-fetal interface, which leads to placental dysfunction in a patient with PE.


Pharmacology ◽  
2018 ◽  
Vol 101 (5-6) ◽  
pp. 236-245 ◽  
Author(s):  
Shiro Nakamura ◽  
Toshio Watanabe ◽  
Tetsuya Tanigawa ◽  
Sunao Shimada ◽  
Yuji Nadatani ◽  
...  

Activation of the NOD-Like Receptor Family, Pyrin Domain-Containing 3 (NLRP3) inflammasome, which consists of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and pro-caspase-1, triggers pro-caspase-1 cleavage promoting the processing of pro-interleukin (IL)-1β into mature IL-1β, which is critical for the development of non-steroidal anti-inflammatory drug (NSAID)-induced enteropathy. We investigated the effects of isoliquiritigenin, a flavonoid derived from the roots of Glycyrrhiza species, on NSAID-induced small intestinal damage and the inflammasome activation. To induce enteropathy, mice were administered indomethacin by gavage with or without isoliquiritigenin pretreatment. Some mice received an intraperitoneal injection of recombinant murine IL-1β in addition to isoliquiritigenin and indomethacin. Indomethacin induced small intestinal damage and increased protein levels of cleaved caspase-1 and mature IL-1β in the small intestine. Treatment with 7.5 and 75 mg/kg isoliquiritigenin inhibited indomethacin-induced small intestinal damage by 40 and 56%, respectively. Isoliquiritigenin also inhibited the indomethacin-induced increase in cleaved caspase-1 and mature IL-1β protein levels, whereas it did not affect the mRNA expression of NLRP3, ASC, caspase-1, and IL-1β. Protection against intestinal damage in isoliquiritigenin-treated mice was completely abolished with exogenous IL-1β. NLRP3–/– and caspase-1–/– mice exhibited resistance to intestinal damage, and isoliquiritigenin treatment failed to inhibit the damage in NLRP3–/– and caspase-1–/– mice. Isoliquiritigenin prevents NSAID-induced small intestinal damage by inhibiting NLRP3 inflammasome activation.


2016 ◽  
Vol 311 (1) ◽  
pp. C83-C100 ◽  
Author(s):  
Michael A. Katsnelson ◽  
Kristen M. Lozada-Soto ◽  
Hana M. Russo ◽  
Barbara A. Miller ◽  
George R. Dubyak

Nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3 (NLRP3) is a cytosolic protein that nucleates assembly of inflammasome signaling platforms, which facilitate caspase-1-mediated IL-1β release and other inflammatory responses in myeloid leukocytes. NLRP3 inflammasomes are assembled in response to multiple pathogen- or environmental stress-induced changes in basic cell physiology, including the destabilization of lysosome integrity and activation of K+-permeable channels/transporters in the plasma membrane (PM). However, the quantitative relationships between lysosome membrane permeabilization (LMP), induction of increased PM K+ permeability, and activation of NLRP3 signaling are incompletely characterized. We used Leu-Leu- O-methyl ester (LLME), a soluble lysosomotropic agent, to quantitatively track the kinetics and extent of LMP in relation to NLRP3 inflammasome signaling responses (ASC oligomerization, caspase-1 activation, IL-1β release) and PM cation fluxes in murine bone marrow-derived dendritic cells (BMDCs). Treatment of BMDCs with submillimolar (≤1 mM) LLME induced slower and partial increases in LMP that correlated with robust NLRP3 inflammasome activation and K+ efflux. In contrast, supramillimolar (≥2 mM) LLME elicited extremely rapid and complete collapse of lysosome integrity that was correlated with suppression of inflammasome signaling. Supramillimolar LLME also induced dominant negative effects on inflammasome activation by the canonical NLRP3 agonist nigericin; this inhibition correlated with an increase in NLRP3 ubiquitination. LMP elicited rapid BMDC death by both inflammasome-dependent pyroptosis and inflammasome-independent necrosis. LMP also triggered Ca2+ influx, which attenuated LLME-stimulated NLRP3 inflammasome signaling but potentiated LLME-induced necrosis. Taken together, these studies reveal a previously unappreciated signaling network that defines the coupling between LMP, changes in PM cation fluxes, cell death, and NLRP3 inflammasome activation.


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