Aspirin alleviates endothelial gap junction dysfunction through inhibition of NLRP3 inflammasome activation in LPS-induced vascular injury

The loss of endothelial connective integrity and endothelial barrier dysfunction can lead to increased vascular injury, which is related to the activation of endothelial inflammasomes. There are evidences that low concentrations of aspirin can effectively prevent cardiovascular diseases. We hypothesized that low-dose aspirin could ameliorate endothelial injury by inhibiting the activation of NLRP3 inflammasomes and ultimately prevent cardiovascular diseases. Microvascular endothelial cells were stimulated by lipopolysaccharide (2 μg/mL) and administrated by 0.1-2 mmol/L aspirin. The wild type mice were stimulated with LPS (100 μg/kg/day), and 1 h later treated with aspirin (12.5, 62.5, or 125 mg/kg/day) and dexamethasone (0.0182 mg/kg/day) for 7 days. Plasma and heart were harvested for measurement of ELISA and immunofluorescence analyses. We found that aspirin could inhibit NLRP3 inflammasome formation and activation in dose-dependent manner and has correlation between the NLRP3 inflammasome and the ROS/TXNIP pathway. We also found that low-concentration aspirin could inhibit the formation and activation of NLRP3 inflammasome and restore the expression of the endothelial tight junction protein zonula occludens-1/2 (ZO1/2). We assume that aspirin can ameliorate the endothelial layer dysfunction by suppressing the activation of NLRP3 inflammasome.

Effect of Dihydromyricetin on High Glucose-induced Glomerular Mesangial Cell Proliferation and Fibro-nectin Accumulation / 中国药房

OBJECTIVE:To study the effect of dihydromyricetin(DMY)on high glucose(HG)-induced glomerular mesangial cell(MCs)proliferation and fibronectin(FN)accumulation,and explore its mechanism for diabetic nephropathy glomerulosclero-sis. METHODS:Cells were divided into normal group(5.5 mmol/L glucose),HG group(30 mmol/L glucose),DMY low-concen-tration,medium-concentration,high-concentration groups (30 mmol/L glucose+22.5,45,90 μmol/L DMY). After incubating 48 h,MTT was used to detect the proliferative activity [reflected by the optical density(OD)value] of cells;molecular docking meth-od was adopted to conduct simulation analysis for DMY binding state with Smad2. Cells were divided into normal group(5.5 mmol/L glucose),HG group (30 mmol/L glucose),DMY group (30 mmol/L glucose+45 μmol/L DMY) and DMY control group (5.5 mmol/L glucose+45 μmol/L DMY). After incubating 5 h,Western blot was used to detect the expression levels of phosphorylated Smad2 (p-Smad2) and extracellular matrix protein FN. RESULTS:Results of MTT detection showed,compared with normal group,OD values in HG group were significantly increased(P<0.05);compared with HG group,OD values in DMY each con-centration group were significantly reduced(P<0.05). The Gibbs free energy(ΔG)of DMY and Smad2 protein was -5.64 kJ/mol, Ki was 73.53 μmol/L,and there were hydrogen bond donor and receptor binding in No. 465,464,461,458 amino acid residues. Results of Western blot showed,compared with normal group,expression levels of p-Smad2 and extracellular matrix protein FN in HG group were significantly increased (P<0.05);compared with HG group,expression levels of p-Smad2 and extracellular ma-trix protein FN in DMY group were significantly decreased(P<0.05). CONCLUSIONS:DMY inhibits HG-induced MCs prolifera-tion and improves diabetic nephropathy glomerulosclerosis by combining with Smad2 and inhibiting Smad2 phosphorylation to re-duce the extracellular matrix protein FN expression.