Amelioration of Inflammatory Cytokines Mix Stimulation: A Pretreatment of CD137 Signaling Study on VSMC

Arsenic exposure promotes the emergence of cardiovascular diseases

A large number of studies conducted in the past decade 2010-2020 refer to the impact of arsenic (As) exposure on cardiovascular risk factors. The arsenic effect on humans is complex and mainly depends on the varying individual susceptibilities, its numerous toxic expressions and the variation in arsenic metabolism between individuals. In this review we present relevant data from studies which document the association of arsenic exposure with various biomarkers, the effect of several genome polymorphisms on arsenic methylation and the underling molecular mechanisms influencing the cardiovascular pathology. The corresponding results provide strong evidence that high and moderate-high As intake induce oxidative stress, inflammation and vessel endothelial dysfunction that are associated with increased risk for cardiovascular diseases (CVDs) and in particular hypertension, myocardial infarction, carotid intima-media thickness and stroke, ventricular arrhythmias and peripheral arterial disease. In addition, As exposure during pregnancy implies risks for blood pressure abnormalities among infants and increased mortality rates from acute myocardial infarction during early adulthood. Low water As concentrations are associated with increased systolic, diastolic and pulse pressure, coronary heart disease and incident stroke. For very low As concentrations the relevant studies are few. They predict a risk for myocardial infarction, stroke and ischemic stroke and incident CVD, but they are not in agreement regarding the risk magnitude.

CD137-CD137L Aggravates Calcification of Vascular Smooth Muscle Cell and Vasculature of ApoE-/- Mice Via Rab7-Mediated Autophagy

Vascular calcification is an independent risk factor for acute cardiovascular events and a predictor of adverse prognosis; the abnormal fusion and degradation of autophagosomes and lysosomes are closely related to the calcification of VSMC and aortic AS plaque in ApoE-/- mice. Rab7 is a member of the Ras protein family and acts as a molecular switch in the fusion between autophagosomes and lysosomes. In this study, we found that the activation of the CD137-CD137L signal promoted calcification by inhibiting the expression and activity of Rab7, which regulates the degradation of autophagic cargo in vascular smooth muscle cells (VSMCs) and aortic atherosclerosis (AS) plaques in ApoE-/- mice. Knockdown of Rab7 impaired its tethering with the downstream molecule FYVE and coiled-coil containing 1 (FYCO1), which transports autophagosomes to lysosomes through microtubule motor kinesins and fuses with lysosomes to degrade the autophagic content. Overexpression of Rab7-alleviated calcification caused by the activation of the CD137 signaling pathway. In addition, FYCO1 knockdown promoted calcification even though the expression and activity of Rab7 were normal. Our results suggest that Rab7 is the target of CD137 signaling; Rab7 cannot interact with its downstream molecule FYCO1 when its activity and expression were inhibited by the activation of CD137 signaling pathway, thus inhibiting the autophagic degradation and promoting calcification.

Hypermethylation of the Micro-RNA 145 Promoter Is the Key Regulator for NLRP3 Inflammasome-Induced Activation and Plaque Formation

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miR-145 in vessels decreases with plaque progression.

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DNMT1 and TET2 dynamic imbalance leads to miR-145 promoter hypermethylation.

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Reduction of miR-145 activates NLRP3 inflammasome through CD137/NFATc1 signaling.

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DNMT1 and TET2 could be promising therapeutic candidates for atherosclerosis in the future.

Two major issues are involved in clinical atherosclerosis treatment. First, there are no significant clinical markers for early diagnosis of atherosclerosis. Second, the plaque will not regress once it initiates even if the risk factors are removed. In this paper, the research shows that the hypermethylation level of the microRNA 145 (miR-145) promoter is related to a DNMT1 and TET2 dynamic imbalance. The reduction of miR-145 causes NLRP3 (nucleotide-binding oligomerization domain-like receptor protein 3) inflammasome activation through CD137/NFATc1 signaling. These findings could be a potential target for plaque regression in the future.