Alcohol suppresses cardiovascular diurnal variations in male normotensive rats: Role of reduced PER2 expression and CYP2E1 hyperactivity in the heart

Ethanol-induced lung and cardiac right ventricular inflammation and remodeling underlie progression to pulmonary arterial hypertension

BACKGROUND

Current research on ethanol-induced cardiovascular anomalies has focused on left ventricular (LV) function and blood pressure. To extend this area of research, we sought to determine whether ethanol-induced alterations in the structure and function of the right cardiac ventricle (RV) and pulmonary artery (PA) lead to pulmonary arterial hypertension (PAH).

METHODS

Two groups of male Sprague-Dawley rats received a balanced liquid diet containing 5% ethanol (w/v) or a pair-fed isocaloric liquid diet for 8 weeks. Weekly echocardiography was conducted to evaluate cardiopulmonary function, and lung and RV tissues were collected for ex vivo histological and molecular studies.

RESULTS

The ethanol-treated rats exhibited: (1) Elevated mean pulmonary arterial pressure and decreased pulmonary artery acceleration time/ejection time; (2) Pulmonary vascular remodeling comprising intrapulmonary artery medial layer thickening; and (3) RV hypertrophy along with increased RV/LV + septum, RV diameter, RV cardiomyocyte cross-sectional area, and LV mass/body weight ratio. These responses were associated with increased lung and RV pro-inflammatory markers, endothelin-1 (ET-1), TNF-α, and IL-6 levels and higher ET-1, ET-1 type A/B receptor ratio, and downregulation of the cytoprotective protein, bone morphogenetic protein receptor 2 (BMPR2), in the lungs.

CONCLUSION

These findings show that moderate ethanol-induced cardiopulmonary changes underlie progression to PAH via an upregulated proinflammatory ET1-TNFα-IL6 pathway and suppression of the anti-inflammatory BMPR2.

Estrogen-mediated mitigation of cardiac oxidative stress in ovariectomized rats is associated with upregulated cardiac circadian clock Per2 and heart-specific miRNAs

AIM

Estrogen (E2) confers cardioprotection in premenopausal women and in models of menopause and its effects, mostly studied in female reproductive organs, vary on a circadian rhythm basis in relation to the circadian clock genes. However, it remains unknown if a similar circadian pattern exists in the female heart in a manner that explains, at least partly, the cardioprotective effect of E2. The aim of the present investigation was to determine if upregulation of the circadian clock Per2 and its regulated heart-specific miRNAs, and redox enzymes contribute to the E2-mediated cardioprotection in ovariectomized rats.

MAIN METHODS

Rats were subjected to ovariectomy (OVX) 2-weeks prior to a 2-week E2 treatment. On the last treatment day, hearts were collected every 4 h. for ex-vivo biochemical measurements. In parallel studies, telemetric mean arterial pressure (MAP) was obtained at the tissue collection times.

KEY FINDINGS

OVX + E2 rats exhibited lower body weight during daytime and MAP during day and night times, and their hearts exhibited: (1) higher Per2 protein abundance, cardioprotective miRNAs (miRNA1, miRNA133a, miRNA208a, miRNA499), mALDH2, and catalase; (2) lower reactive oxygen species, cardio-detrimental miRNA652, carbonyl, MDA and HO-1 levels. The reciprocal Per2/HO-1 relationship was more evident during the daytime and correlated with the upregulated cardioprotective miRNAs in OVX + E2 rats. Finally, cardiac Per2, heart-specific miRNAs and reactive oxygen species levels and redox enzymes activities were similar in normal female and OVX + E2 rats.

SIGNIFICANCE

Enhancement of cardiac Per2, redox enzymes and heart-specific miRNAs likely contribute to E2-mediated mitigation of cardiac oxidative stress in OVX rats.

Cyp2e1 knockdown attenuates high glucose-induced apoptosis and oxidative stress of cardiomyocytes by activating PI3K/Akt signaling

AIMS

Cyp2e1 is a crucial CYP450 enzyme participating in diabetes and cardiovascular disorder. However, the role of Cyp2e1 in diabetic cardiomyopathy (DCM) has never been reported. Thus, we intended to identify the effects of Cyp2e1 on cardiomyocytes under high glucose (HG) conditions.

METHODS

Identification of differentially expressed genes in DCM and control rats was performed using bioinformatics analysis based on GEO database. The Cyp2e1-knockdown H9c2 and HL-1 cells were established through transfection with si-Cyp2e1. Western blot analysis was performed to determine the expression levels of Cyp2e1, apoptosis-related proteins and PI3K/Akt signaling-associated proteins. TUNEL assay was performed to assess apoptotic rate. Reactive oxygen species (ROS) generation was examined by DCFH2-DA staining assay.

RESULTS

From the bioinformatics analysis, Cyp2e1 was confirmed as an upregulated gene in DCM tissues. In vitro assays proved that Cyp2e1 expression was markedly increased in HG-induced H9c2 and HL-1 cells. Cyp2e1 knockdown attenuated HG-induced apoptosis in both H9c2 and HL-1 cells, as proved by deceased apoptotic rate, relative cleaved caspase-3/caspase-3 level, and caspase-3 activity. Cyp2e1 knockdown reduced ROS generation and elevated the expression level of nuclear Nrf2 in HG-induced H9c2 and HL-1 cells. Increased relative levels of p-PI3K/PI3K and p-Akt/Akt were found in Cyp2e1-knockdown H9c2 and HL-1 cells. Inhibition of PI3K/Akt using LY294002 reversed the inhibitory effects of Cyp2e1 knockdown on cell apoptosis and ROS generation on cardiomyocytes.

CONCLUSIONS

Cyp2e1 knockdown attenuated HG-induced apoptosis and oxidative stress by activating PI3K/Akt signaling in cardiomyocytes. These findings suggested that Cyp2e1 might be potentially used as an effective therapeutic strategy for DCM.

Binge drinking during the adolescence period causes oxidative damage-induced cardiometabolic disorders: A possible ameliorative approach with selenium supplementation

Binge drinking (BD) is the most common alcohol consumption model among adolescents. BD exposure during adolescence disrupts the nervous system function, being involved in the major mortality causes at this age: motor vehicle accidents, homicides and suicides. Recent studies have also shown that BD consumption during adolescence affects liver, renal and cardiovascular physiology, predisposing adolescents to future adult cardiometabolic damage. BD is a particularly pro-oxidant alcohol consumption pattern, because it leads to the production of a great source of reactive oxygen species (ROS) via the microsomal ethanol oxidizing system, also decreasing the antioxidant activity of glutathione peroxidase (GPx). Selenium (Se) is a mineral which plays a pivotal role against oxidation; it forms part of the catalytic center of different antioxidant selenoproteins such as GPxs (GPx1, GPx4, GPx3) and selenoprotein P (SelP). Specifically, GPx4 has an essential role in mitochondria, preventing their oxidation, apoptosis and NFkB-inflamative response, being this function even more relevant in heart's tissue. Se serum levels are decreased in acute and chronic alcoholic adult patients, being correlated to the severity of oxidation, liver damage and metabolic profile. Experimental studies have described that Se supplementation to alcohol exposed mice clearly decreases oxidative and liver damage. However, clinical BD effects on Se homeostasis and selenoproteins' tissue distribution related to oxidation during adolescence are not yet studied. In this narrative review we will describe the use of sodium selenite supplementation as an antioxidant therapy in adolescent BD rats in order to analyze Se homeostasis implication during BD exposure, oxidative balance, apoptosis and inflammation, mainly in liver, kidney, and heart. These biomolecular changes and the cardiovascular function will be analyzed. Se supplementation therapies could be a good strategy to prevent the oxidation, inflammation and apoptosis generated in tissues by BD during adolescence, such as liver, kidney and heart, improving cardiovascular functioning.

Transcriptomic-based toxicological investigations of ethanol to human umbilical vein endothelial cells

Ethanol has a complex effect on the cardiovascular system in humans, but the systemic effects of ethanol to endothelial cells were rarely investigated. In this study, we exposed human umbilical vein endothelial cells (HUVECs) to 5- or 50-mM ethanol and performed transcriptomics to investigate the systemic effects of ethanol. While these concentrations of ethanol did not significantly affect HUVEC viability, 5-mM ethanol significantly upregulated and downregulated 59 and 73 genes, respectively, whereas 50-mM ethanol significantly upregulated and downregulated 50 and 80 genes, respectively. Totally, 37 genes were shared by the two concentrations of ethanol. The most significantly altered gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway after 5-mM ethanol treatment were nucleic acid binding (GO:0003676) and Herpes simplex virus 1 infection (ko05168), respectively, whereas the most significantly altered GO term and KEGG pathway by 50-mM ethanol treatment were aryl sulfotransferase activity (GO:0004062) and chemical carcinogenesis (ko05204). We further verified that ethanol treatment downregulated the mRNA levels of CD38 molecule (CD38), ORAI calcium release-activated calcium modulator 2 (ORAI2), cysteinyl leukotriene receptor 2 (CYSLTR2), key genes involved in calcium signaling pathway (ko04020), as well as integrin subunit alpha 2 (ITGA2), and cAMP responsive element binding protein 3 like 2 (CREB3L2), key genes involved in PI3K-Akt signaling pathway (ko04151). The results from this study suggested that ethanol could induce systemic effects and alter signaling pathways in HUVECs.