Ang-(1-7) improved liver fibrosis by regulating NLRP3 inflammasome activation induced by Ang II-mediated ROS via redox balance modulation. Antioxid. Redox Signal. 24, 795-812.

BackgroundCognitive impairment is one of common complications of acute respiratory distress syndrome (ARDS). Increasing evidence suggests that interleukin-1 beta (IL-1β) plays a role in inducing neuronal apoptosis in cognitive dysfunction. The lung protective ventilatory strategies, which serve to reduce pulmonary morbidity for ARDS patients, almost always lead to hypercapnia. Some studies have reported that hypercapnia contributes to the risk of cognitive impairment and IL-1β secretion outside the central nervous system (CNS). However, the underlying mechanism of hypercapnia aggravating cognitive impairment under hypoxia has remained uncertain. This study was aimed to explore whether hypercapnia would partake in increasing IL-1β secretion via activating the NLRP3 (NLR family, pyrin domain-containing 3) inflammasome in the hypoxic CNS and in aggravating cognitive impairment.MethodsThe Sprague-Dawley (SD) rats that underwent hypercapnia/hypoxemia were used for assessment of NLRP3, caspase-1, IL-1β, Bcl-2, Bax, and caspase-3 expression by Western blotting or double immunofluorescence, and the model was also used for Morris water maze test. In addition, Z-YVAD-FMK, a caspase-1 inhibitor, was used to treat BV-2 microglia to determine whether activation of NLRP3 inflammasome was required for the enhancing effect of hypercapnia on expressing IL-1β by Western blotting or double immunofluorescence. The interaction effects were analyzed by factorial ANOVA. Simple effects analyses were performed when an interaction was observed.ResultsThere were interaction effects on cognitive impairment, apoptosis of hippocampal neurons, activation of NLRP3 inflammasome, and upregulation of IL-1β between hypercapnia treatment and hypoxia treatment. Hypercapnia + hypoxia treatment caused more serious damage to the learning and memory of rats than those subjected to hypoxia treatment alone. Expression levels of Bcl-2 were reduced, while that of Bax and caspase-3 were increased by hypercapnia in hypoxic hippocampus. Hypercapnia markedly increased the expression of NLRP3, caspase-1, and IL-1β in hypoxia-activated microglia both in vivo and in vitro. Pharmacological inhibition of NLRP3 inflammasome activation and release of IL-1β might ameliorate apoptosis of neurons.ConclusionsThe present results suggest that hypercapnia-induced IL-1β overproduction via activating the NLRP3 inflammasome by hypoxia-activated microglia may augment neuroinflammation, increase neuronal cell death, and contribute to the pathogenesis of cognitive impairments.

ZFAS1 is one of cardiac-specific or cardiac-related lncRNAs. This study was to explore the functional involvement of ZFAS1 and its regulatory role in AMI. In this study, the models of AMI rat and myocardial cell cultured under hypoxia were made. The expression of ZFAS1 and miR-150 of myocardial infarction tissue or cardiac myocytes was determined by quantitative real time PCR. The regulatory role of ZFAS1 on miR-150 was examined by RNA pull down assay. The effect of miR-150 or ZFAS1 expression on cell viability was analyzed by MTT assay. The relative expression of ZFAS1 in the myocardium infracted zone and border zone was significantly upregulated at 1-48 h of AMI rats, but it downregulated at 1 week and 2 weeks; miR-150 was significantly downregulated at AMI-1-48 h and upregulated at 1 and 2 weeks after model establishment. The result of RNA pull down assay indicated that ZFAS1 could interact directly with miR-150. C-reactive protein (CRP) was regulated by ZFAS1/miR-150 axis and negatively targeted by miR-150. Hypoxia caused the decrease of cell viability and the upregulation of CRP at mRNA and protein levels; whereas this upregulation could be attenuated by miR-150 mimic or si-ZFAS1 in H9C2 cells and cardiomyocytes. Knockdown of ZFAS1 or miR-150 overexpression effectively relieved AMI-induced myocardial infarction in AMI-1 week rats. The ZFAS1/miR-150 axis was involved in the molecular mechanism of AMI induced cardiomyocytes apoptosis via regulating CRP. J. Cell. Biochem. 118: 3281-3289, 2017. © 2017 Wiley Periodicals, Inc.