Cold exposure aggravates pulmonary arterial hypertension through increased miR-146a-5p, miR-155-5p and cytokines TNF-α, IL-1ß, and IL-6.

BACKGROUND: Cold temperatures can aggravate pulmonary diseases and promote pulmonary arterial hypertension (PAH); however, the underlying mechanism has not been fully explored. AIM: To explore the effect of chronic cold exposure on the production of inflammatory cytokines and microRNAs (miRNAs) in a monocrotaline (MCT)-induced PAH model. METHODS: Male Sprague Dawley rats were divided into a Control (23.5 ± 2 °C), Cold (5.0 ± 1 °C for ten days), MCT (60 mg/kg body weight i.p.), and MCT + Cold (ten days of cold exposure after 3 weeks of MCT injection). Hemodynamic parameters, right ventricle (RV) hypertrophy, and pulmonary arterial medial wall thickness were determined. IL-1ß, IL-6, and TNF-α levels were determined using western blotting. miR-21-5p and -3p, miR-146a-5p and -3p, and miR-155-5p and -3p and plasma extracellular vesicles (EVs) and mRNA expression of Cd68, Cd163, Bmpr2, Smad5, Tgfbr2, and Smad3 were determined using RT-qPCR. RESULTS: The MCT + Cold group had aggravated RV hypertrophy hemodynamic parameters, and pulmonary arterial medial wall thickness. In lungs of the MCT + Cold, group the protein levels of TNF-α, IL-1ß, and IL-6 were higher than those in the MCT group. The mRNA expression of Cd68 and Cd163 were higher in the MCT + Cold group. miR-146a-5p and miR-155-5p levels were higher in the plasma EVs and lungs of the MCT + Cold group. Cold exposure promoted a greater decrease in miR-21-5p, Bmpr2, Smad5, Tgfbr2, and Smad3 mRNA expression in lungs of the MCT + Cold group. CONCLUSION: Cold exposure aggravates MCT-induced PAH with an increase in inflammatory marker and miRNA levels in the plasma EVs and lungs.

Characterization of the cytotoxic effects of the combination of cisplatin and flavanol (-)-epicatechin on human lung cancer cell line A549. An isobolographic approach.

BACKGROUND: Among malignancies, lung cancer is a leading cause of death. Platinum-based therapeutic compounds used to treat lung cancer have not been able to increase the survival of patients and such compounds have a high incidence of adverse and toxic effects. It has been proposed that flavonoids such as catechins may significantly reduce the risk of developing cancer, alongside with other health benefits. The aim of this work was to determine the effect of (-)-epicatechin, the main flavanol found in cocoa, on the proliferation of the lung non-small cell adenocarcinoma cancer cell line A549, and to determine its effects when added simultaneously with cisplatin. MATERIALS AND METHODS: Concentration-response curves for cisplatin and epicatechin were obtained, inhibitory concentrations calculated and an isobolographic analysis was then performed. RESULTS: We found that epicatechin has a concentration-dependent inhibitory effect on proliferation of tumor cells and the isobolographic analysis reveals that the effect of its combination with cisplatin is synergistic. It was also observed that epicatechin promotes cell death by apoptosis. CONCLUSIONS: Epicatechin might be considered for future studies to explore its possible use as coadjuvant in cisplatin-based treatments.

17Beta-estradiol increases intracellular calcium concentration through a short-term and nongenomic mechanism in rat vascular endothelium in culture.

17Beta-estradiol (E2) plays an important role in Ca2+ fluxes in several cell types. It has been proposed that some of its effects are of nongenomic origin E2 at vascular smooth muscle level can block calcium entry through L-type calcium channels, this mechanism cannot include vascular endothelial cells (VECs), in which increases in the intracellular calcium concentration ([Ca2+]i) are necessary to NO synthesis. We used male rat aorta ECs in culture loaded with fura-2 and a fluorescence imaging system to evaluate the short-term effects of E2 on [Ca2+]i kinetics. We explored the participation of the intracellular steroid receptor on the effects induced by E2, using tamoxifen (1 microM) and ICI 182,780 (10 microM). Our results showed that E2 (like bradykinin) induced an increase in [Ca2+]i. Such agonist-like effects showed a biphasic curve behavior. The 17beta-estradiol effects were not modified by the presence of the intracellular estradiol-receptor antagonist tamoxifen, but it is blocked in the presence of the ICI 182,780. The 17beta-estradiol effects were obtained even with restriction of steroid-free diffusion into cells (17beta-estradiol-bovine serum albumin). Phospholipase Cbeta activity is involved in these effects, because U-73122, a PLCbeta inhibitor, blocked E2 effects. All E2 effects were of rapid onset (milliseconds), exerted at the membrane level, and of rapid offset. We conclude that estradiol can influence the endothelium physiologic responses through effects of nongenomic origin.