The use of DOX (doxorubicin), an antibiotic used in oncological treatments, is limited by a dose-related cardiotoxicity against which acute exercise is protective. However, the mitochondrial-related mechanisms of this protection remain unknown. Therefore the present study aimed to determine the effects of an acute endurance exercise bout performed 24 h before DOX treatment on heart and liver mitochondrial function. A total of 20 adult male Wistar rats were divided into groups as follows: non-exercised with saline (NE + SAL), non-exercised DOX-treated (NE + DOX), exercised with saline (EX + SAL) and exercised DOX-treated (EX + DOX). The animals performed a 60 min exercise bout on a treadmill or remained sedentary 24 h before receiving either a DOX bolus (20 mg/kg of body weight) or saline. Heart and liver mitochondrial function [oxygen consumption, membrane potential (DeltaPsi) and cyclosporin-A-sensitive calcium-induced MPTP (mitochondrial permeability transition pore) opening] were evaluated. The activities of the respiratory complex, Mn-SOD (superoxide dismutase), caspases 3 and 9, as well as the levels of ANT (adenine nucleotide translocase), VDAC (voltage-dependent anion channel), CypD (cyclophilin D), Bax and Bcl-2, were measured. Acute exercise prevented the decreased cardiac mitochondrial function (state 3, phosphorylative lagphase; maximal DeltaPsi generated both with complex I- and II-linked substrates and calcium-induced MPTP opening) induced by DOX treatment. Exercise also prevented the DOX-induced decreased activity of cardiac mitochondrial chain complexes I and V, and increased caspase 3 and 9 activities. DOX administration and exercise caused increased cardiac mitochondrial SOD activity. Exercise ameliorated liver mitochondrial complex activities. No alterations were observed in the measured MPTP and apoptosis-related proteins in heart and liver mitochondria. The results demonstrate that acute exercise protects against cardiac mitochondrial dysfunction, preserving mitochondrial phosphorylation capacity and attenuating DOX-induced decreased tolerance to MPTP opening.

Mitochondrial quality control and apoptosis have been described as key components in the pathogenesis of nonalcoholic steatohepatitis (NASH); exercise is recognized as a nonpharmacological strategy to counteract NASH-associated consequences. We aimed to analyze the effect of voluntary physical activity (VPA) and endurance training (ET) against NASH-induced mitochondrial permeability transition pore (mPTP) opening and mitochondrial and cellular quality control deleterious alterations. Forty-eight male Sprague-Dawley rats were divided into standard-diet sedentary (SS, n = 16), standard-diet VPA (n = 8), high-fat diet sedentary (HS, n = 16), and high-fat diet VPA (n = 8). After 9 weeks of diet treatment, half of the SS and HS groups were engaged in an ET program for 8 weeks, 5 days/week, 1 h/day. Liver mPTP susceptibility through osmotic swelling, mPTP-related proteins (cyclophilin D, Sirtuin3, Cofilin-1), markers of mitochondrial biogenesis ((mitochondrial transcription factor A (Tfam) and peroxisome proliferator-activated receptor gamma co-activator protein (PGC-1α)), dynamics (Mitofusin 1 (Mfn1), Mitofusin 2 (Mfn2), Dynamin related protein 1, and Optic atrophy 1)), auto/mitophagy (Beclin-1, microtubule-associated protein 1 light chain 3, p62, PINK1, and Parkin), and apoptotic signaling (Bax, Bcl-2) and caspases-like activities were assessed. HS animals showed an increased susceptibility to mPTP, compromised expression of Tfam, Mfn1, PINK1, and Parkin and an increase in Bax content (HS vs. SS). ET and VPA improved biogenesis-related proteins (PGC-1α) and autophagy signaling (Beclin-1 and Beclin-1/Bcl-2 ratio) and decreased apoptotic signaling (caspases 8 activity, Bax content, and Bax/Bcl-2 ratio). However, only ET decreased mPTP susceptibility and positively modulated Bcl-2, Tfam, Mfn1, Mfn2, PINK1, and Parkin content. In conclusion, exercise reduces the increased susceptibility to mPTP induced by NASH and promotes the increase of auto/mitophagy and mitochondrial fusion towards a protective phenotype.

No abstract

Several vegetation indices (VI) derived from handheld spectroradiometer reflectance data in the visible spectral region were tested for modelling grapevine water status estimated by the predawn leaf water potential (Ψpd). The experimental trial was carried out in a vineyard in Douro wine region, Portugal. A statistical approach was used to evaluate which VI and which combination of wavelengths per VI allows the best correlation between VIs and Ψpd. A linear regression was defined using a parameterization dataset. The correlation analysis between Ψpd and the VIs computed with the standard formulation showed relatively poor results, with values for squared Pearson correlation coefficient (r 2 ) smaller than 0.67. However, the results of r 2 highly improved for all VIs when computed with the selected best combination of wavelengths (optimal VIs). The optimal Visible Atmospherically Resistant Index (VARI) and Normalized Difference Greenness Vegetation Index (NDGI) showed the higher r 2 and stability index results. The equations obtained through the regression between measured Ψpd (Ψpd_obs) and optimal VARI and between Ψpd_obs and optimal NDGI when using the parameterization dataset were adopted for predicting Ψpd using a testing dataset. The comparison of Ψpd_obs with Ψpd predicted based on VARI led to R 2 = 0.79 and a regression coefficient b = 0.96. Similar R 2 was achieved for the prediction based on NDGI, but b was smaller (b = 0.93). Results obtained allow the future use of optimal VARI and NDGI for estimating Ψpd, supporting vineyards irrigation management.

Knowledge about short-term climate change adaptation strategies for Mediterranean vineyards is needed in order to improve grapevine physiology and yield-quality attributes. We investigated effects of kaolin-particle film suspension on water relations, photosynthesis and oxidative stress of field-grown grapevines in the Douro region (northern Portugal) in 2012 and 2013. Kaolin suspension decreased leaf temperature by 18% and increased leaf water potential (up to 40.7% in 2013). Maximum photochemical quantum efficiency of PSII was higher and the minimal chlorophyll fluorescence was lower in the plants sprayed by kaolin. Two months after application, net photosynthesis and stomatal conductance at midday increased by 58.7 and 28.4%, respectively, in treated plants. In the same period, kaolin treatment increased photochemical reflectance, photosynthetic pigments, soluble proteins, soluble sugars, and starch concentrations, while decreased total phenols and thiobarbituric acid-reactive substances. Kaolin application can be an operational tool to alleviate summer stresses, which ameliorates grapevine physiology and consequently leads to a higher yield.