Metabolic mitochondrial alterations prevail in the female rat heart 8 weeks after exercise cessation.

BACKGROUND: The consumption of high-caloric diets strongly contributes to the development of non-communicable diseases (NCDs), including cardiovascular disease, the leading cause of mortality worldwide. Exercise (along with diet intervention) is one of the primary non-pharmacological approaches to promote a healthier lifestyle and counteract the rampant prevalence of NCDs. The present study evaluated the effects of exercise cessation after a short period training on the cardiac metabolic and mitochondrial function of female rats. METHODS: Seven-week-old female Sprague-Dawley rats were fed a control or a high-fat, high-sugar (HFHS) diet and, after 7 weeks, the animals were kept on a sedentary lifestyle or submitted to endurance exercise for 3 weeks (6 days per week, 20-60 min/day). The cardiac samples were analysed 8 weeks after exercise cessation. RESULTS: The consumption of the HFHS diet triggered impaired glucose tolerance, whereas the HFHS diet and physical exercise resulted in different responses in plasma adiponectin and leptin levels. Cardiac mitochondrial respiration efficiency was decreased by the HFHS diet consumption, which led to reduced ATP and increased NAD(P)H mitochondrial levels, which remained prevented by exercise 8 weeks after cessation. Exercise training-induced cardiac adaptations in redox balance, namely increased relative expression of Nrf2 and downstream antioxidant enzymes persist after an eight-week exercise cessation period. CONCLUSIONS: Endurance exercise modulated cardiac redox balance and mitochondrial efficiency in female rats fed a HFHS diet. These findings suggest that exercise may elicit cardiac adaptations crucial for its role as a non-pharmacological intervention for individuals at risk of developing NCDs.

Gestational Exercise Antagonises the Impact of Maternal High-Fat High-Sucrose Diet on Liver Mitochondrial Alterations and Quality Control Signalling in Male Offspring.

Maternal high-caloric nutrition and related gestational diabetes mellitus (GDM) are relevant modulators of the intrauterine environment, increasing the risk of liver metabolic alterations in mothers and offspring. In contrast, as a non-pharmacological approach against metabolic disorders, exercise is highly recommended in GDM treatment. We analysed whether gestational exercise (GE) protects mothers from diet-induced GDM metabolic consequences and mitigates liver mitochondrial deleterious alterations in their 6-week-old male offspring. Female Sprague Dawley rats were fed with control or high-fat high-sucrose (HFHS) diet and kept sedentary or submitted to GE. Male offspring were sedentary and fed with control diet. Sedentary HFHS mothers and their offspring showed impaired hepatic mitochondrial biogenesis and morphological evidence of mitochondrial remodelling. In contrast, GE-related beneficial effects were demonstrated by upregulation of mitochondrial biogenesis signalling markers and mitochondrial fusion proteins and downregulation of mitochondrial fission protein. Alterations in miR-34a, miR-130b, and miR-494, associated with epigenetic regulation of mitochondrial biogenesis, suggested that GE is a more critical modulator of intergenerational changes in miRs expression than the maternal diet. Our data showed that GE positively modulated the altered hepatic mitochondrial biogenesis and dynamics markers and quality control signalling associated with maternal HFHS-diet-related GDM in mothers and offspring.

Exercise performed during pregnancy positively modulates liver metabolism and promotes mitochondrial biogenesis of female offspring in a rat model of diet-induced gestational diabetes.

Gestational diabetes mellitus (GDM) is associated with a high-risk for metabolic complications in offspring. However, exercise is recognized as a non-pharmacological strategy against metabolic disorders and is recommended in GDM treatment. This study aimed to investigate whether gestational exercise (GE) could modulate maternal high-fat high-sucrose (HFHS) diet-related hepatic metabolic and mitochondrial outcomes in female offspring of mothers with HFHS-induced GDM. Female Sprague-Dawley rats were fed with control or HFHS diet and kept sedentary or submitted to GE. Their female offspring were fed with control diet and kept sedentary. Hepatic lipid accumulation, lipid metabolism regulators, mitochondrial biogenesis and dynamics markers, and microRNAs associated to the regulation of these markers were evaluated. Female offspring of GDM mothers showed increased body weight at early age, whereas GE prevented this effect of maternal HFHS-feeding and reduced hepatic lipid accumulation. GE stimulated hepatic mRNA transcription and protein expression of mitochondrial biogenesis markers (peroxisome proliferator-activated receptor-gamma co-activator-1alpha and mitochondrial transcription factor A) and mRNA transcription of mitochondrial dynamics markers (mitofusin-1, mitofusin-2, and dynamin-related protein-1) that were altered by maternal GDM, while mitochondrial dynamics markers protein expression was not affected by maternal diet/GE except for optic atrophy-1. MicroRNAs associated with these processes (miR-122, miR-34a, miR-130b, miR-494), and the expression of auto/mitophagy- and apoptosis-related proteins were not substantially influenced by altered intrauterine environment. Our findings suggest that GE is an important regulator of the intrauterine environment positively affecting liver metabolism and promoting liver mitochondrial biogenesis in female offspring despite eventual effects of maternal HFHS-feeding and related GDM.

Gestational Exercise Increases Male Offspring's Maximal Workload Capacity Early in Life.

Mothers' antenatal strategies to improve the intrauterine environment can positively decrease pregnancy-derived intercurrences. By challenging the mother-fetus unit, gestational exercise (GE) favorably modulates deleterious stimuli, such as high-fat, high-sucrose (HFHS) diet-induced adverse consequences for offspring. We aimed to analyze whether GE alters maternal HFHS-consumption effects on male offspring's maximal workload performance (MWP) and in some skeletal muscle (the soleus-SOL and the tibialis anterior-TA) biomarkers associated with mitochondrial biogenesis and oxidative fitness. Infant male Sprague-Dawley rats were divided into experimental groups according to mothers' dietary and/or exercise conditions: offspring of sedentary control diet-fed or HFHS-fed mothers (C-S or HFHS-S, respectively) and of exercised HFHS-fed mothers (HFHS-E). Although maternal HFHS did not significantly alter MWP, offspring from GE dams exhibited increased MWP. Lower SOL AMPk levels in HFHS-S were reverted by GE. SOL PGC-1α, OXPHOS C-I and C-IV subunits remained unaltered by maternal diet, although increased in HFHS-E offspring. Additionally, GE prevented maternal diet-related SOL miR-378a overexpression, while upregulated miR-34a expression. Decreased TA C-IV subunit expression in HFHS-S was reverted in HFHS-E, concomitantly with the downregulation of miR-338. In conclusion, GE in HFHS-fed dams increases the offspring's MWP, which seems to be associated with the intrauterine modulation of SM mitochondrial density and functional markers.

Fit mothers for a healthy future: Breaking the intergenerational cycle of non-alcoholic fatty liver disease with maternal exercise.

SPECIAL ISSUE: 'FOIEGRAS-Bioenergetic Remodelling in the Pathophysiology and Treatment of Non-Alcoholic Fatty Liver Disease'. BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) emerges as significant health burden worldwide. Lifestyle changes, unhealthy dietary habits and physical inactivity, can trigger NAFLD development. Persisting on these habits during pregnancy affects in utero environment and prompts a specific metabolic response in foetus resulting in offspring metabolic maladjustments potentially critical for developing NAFLD later in life. The increasing prevalence of NAFLD, particularly in children, has shifted the research focus towards preventive and therapeutic strategies. Yet, designing effective approaches that can break the NAFLD intergenerational cycle becomes even more complicated. Regular physical exercise (PE) is a powerful non-pharmacological strategy known to counteract deleterious metabolic outcomes. In this narrative review, we aimed to briefly describe NAFLD pathogenesis focusing on maternal nutritional challenge and foetal programming, and to provide potential mechanisms behind the putative intergenerational effect of PE against metabolic diseases, including liver diseases. METHODS: Following detailed electronic database search, recent existing evidence about NAFLD development, intergenerational programming and gestational exercise effects was critically analysed and discussed. RESULTS: PE during pregnancy could have a great potential to counteract intergenerational transmission of metabolic burden. The interplay between different PE roles-metabolic, endocrine and epigenetic-could offer a more stable in utero environment to the foetus, thus rescuing offspring vulnerability to metabolic disturbances. CONCLUSIONS: The better understanding of maternal PE beneficial consequences on offspring metabolism could reinforce the importance of PE during pregnancy as an indispensable strategy in improving offspring health.

Building-up fit muscles for the future: Transgenerational programming of skeletal muscle through physical exercise.

'Special issue - In Utero and Early Life Programming of Aging and Disease'. Skeletal muscle (SM) adaptations to physical exercise (PE) have been extensively studied due, not only to the relevance of its in situ plasticity, but also to the SM endocrine-like effects in noncontractile tissues, such as brain, liver or adipocytes. Regular PE has been considered a pleiotropic nonpharmacological strategy to prevent and counteract the deleterious consequences of several metabolic, cardiovascular, oncological and neurodegenerative disorders. Additionally, PE performed by parents seems to have a direct impact in the offspring through the transgenerational programming of different tissues, such as SM. In fact, SM offspring programming mechanisms seems to be orchestrated, at least in part, by epigenetic machinery conditioning transcriptional or post-transcriptional processes. Ultimately, PE performed in the early in life is also a critical window of opportunity to positively modulate the juvenile and adult phenotype. Parental PE has a positive impact in several health-related offspring outcomes, such as SM metabolism, differentiation, morphology and ultimately in offspring exercise volition and endurance. Also, early-life PE counteracts conceptional-related adverse effects and induces long-lasting healthy benefits throughout adulthood. Additionally, epigenetics mechanisms seem to play a key role in the PE-induced SM adaptations. Despite the undoubtedly positive role of parental and early-life PE on SM phenotype, a strong research effort is still needed to better understand the mechanisms that positively regulate PE-induced SM programming.

Maternal high-fat high-sucrose diet and gestational exercise modulate hepatic fat accumulation and liver mitochondrial respiratory capacity in mothers and male offspring.

BACKGROUND: Maternal high-caloric nutrition and related gestational diabetes mellitus (GDM) are associated with a high-risk for developing metabolic complications later in life and in their offspring. In contrast, exercise is recognized as a non-pharmacological strategy against metabolic dysfunctions associated to lifestyle disorders. Therefore, we investigated whether gestational exercise delays the development of metabolic alterations in GDM mothers later in life, but also protects 6-week-old male offspring from adverse effects of maternal diet. METHODS: Female Sprague-Dawley rats were fed with either control (C) or high-fat high-sucrose (HFHS) diet to induce GDM and submitted to gestational exercise during the 3 weeks of pregnancy. Male offspring were sedentary and fed with C-diet. RESULTS: Sedentary HFHS-fed dams exhibited increased gestational body weight gain (p < 0.01) and glucose intolerance (p < 0.01), characteristic of GDM. Their offspring had normal glucose metabolism, but increased early-age body weight, which was reverted by gestational exercise. Gestational exercise also reduced offspring hepatic triglycerides accumulation (p < 0.05) and improved liver mitochondrial respiration capacity (p < 0.05), contributing to the recovery of liver bioenergetics compromised by maternal HFHS diet. Interestingly, liver mitochondrial respiration remained increased by gestational exercise in HFHS-fed dams despite prolonged HFHS consumption and exercise cessation. CONCLUSIONS: Gestational exercise can result in liver mitochondrial adaptations in GDM animals, which can be preserved even after the exercise program cessation. Exposure to maternal GDM programs liver metabolic setting of male offspring, whereas gestational exercise appears as an important preventive tool against maternal diet-induced metabolic alterations.

Preventive and Therapeutic Potential of Physical Exercise in Neurodegenerative Diseases.

Significance: The prevalence and incidence of age-related neurodegenerative diseases (NDDs) tend to increase along with the enhanced average of the world life expectancy. NDDs are a major cause of morbidity and disability, affecting the health care, social and economic systems with a significant impact. Critical Issues and Recent Advances: Despite the worldwide burden of NDDs and the ongoing research efforts to increase the underlying molecular mechanisms involved in NDD pathophysiologies, pharmacological therapies have been presenting merely narrow benefits. On the contrary, absent of detrimental side effects but growing merits, regular physical exercise (PE) has been considered a prone pleiotropic nonpharmacological alternative able to modulate brain structure and function, thereby stimulating a healthier and "fitness" neurological phenotype. Future Directions: This review summarizes the state of the art of some peripheral and central-related mechanisms that underlie the impact of PE on brain plasticity as well as its relevance for the prevention and/or treatment of NDDs. Nevertheless, further studies are needed to better clarify the molecular signaling pathways associated with muscle contractions-related myokines release and its plausible positive effects in the brain. In addition, particular focus of research should address the role of PE in the modulation of mitochondrial metabolism and oxidative stress in the context of NDDs.

Physical exercise and liver "fitness": Role of mitochondrial function and epigenetics-related mechanisms in non-alcoholic fatty liver disease.

BACKGROUND: Modern lifestyles, especially high-caloric intake and physical inactivity, contribute to the increased prevalence of non-alcoholic fatty liver disease (NAFLD), which becomes a significant health problem worldwide. Lifestyle changes, however, affect not only parental generation, but also their offspring, reinforcing the need for efficient preventive approaches to deal with this disease. This transgenerational influence of phenotypes dependent on parents (particularly maternal) behaviours may open additional research avenues. Despite persistent attempts to design an effective pharmacological therapy against NAFLD, physical activity, as a non-pharmacological approach, emerges as an exciting strategy. SCOPE OF REVIEW: Here we briefly review the effect of physical exercise on liver mitochondria adaptations in NAFLD, highlighting the importance of mitochondrial metabolism and transgenerational and epigenetic mechanisms in liver diseases. MAJOR CONCLUSIONS: A deeper look into cellular mechanisms sheds a light on possible effects of physical activity in the prevention and treatment of NAFLD through modulation of function and structure of particular organelles, namely mitochondria. Additionally, despite of increasing evidence regarding the contribution of epigenetic mechanisms in the pathogenesis of different diseases, the role of microRNAs, DNA methylation, and histone modification in NAFLD pathogenesis still needs to be elucidated.

Physical exercise positively modulates DOX-induced hepatic oxidative stress, mitochondrial dysfunction and quality control signaling.

Doxorubicin (DOX), a widely used and efficient antineoplastic agent, is mainly limited by cardiotoxicity, although other tissues including liver are also affected. The effects of exercise to cope with DOX side-effects has already been studied in the heart and brain, demonstrating successful results. However, the benefits of this non-pharmacological strategy have not been so extensively checked in the liver. We here aimed to ascertain whether exercise could mitigate DOX-induced liver harmful effects using mitochondria as a model for evaluating toxicity. Twenty-four male rats were divided into four groups: SED + SAL (sedentary with saline administration), SED + DOX (sedentary with DOX administration), ET + DOX (endurance-trained with DOX administration) and VPA + DOX (voluntary physical activity with DOX administration). Isolated liver mitochondria were obtained for evaluation of their respiratory activity and transmembrane electrical potential endpoints. Molecular markers of oxidative damage (carbonyls, MDA, aconitase, MnSOD), mitochondrial dynamics (PGC-1α, TFAM, OPA1, DRP1, MFN1) and auto(mito)phagy signaling (p62, LC3, Beclin1, Bcl-2, PINK, Parkin) were measured. Transmission electron microscopy evaluation was used to analyze mitochondrial morphological alterations. When compared to SED + SAL, respiratory function of SED + DOX was compromised. Decreased SOD and aconitase activities and increased MDA content, decreases in PGC-1α, TFAM, OPA1 and MFN1 expressions, and increases in DRP1 and LC3II/LC3I ratio were also observed after DOX administration. However, these alterations were reverted or mitigated in the ET + DOX group. Semi-quantitative and qualitative analyses from microphotographs showed that liver mitochondria of SED + DOX animals were more circular and had lower density, whereas the animals with exercise showed a tendency to revert this phenotype and increase the mitochondrial density. Taken together, our results suggest that physical exercise, particularly ET, positively reversed the deleterious effects caused by DOX administration, such as oxidative damage, mitochondrial dysfunction, and altered mitochondrial dynamics toward fission, thus contributing to increase liver resistance against DOX administration.

Exercise mitigates diclofenac-induced liver mitochondrial dysfunction.

BACKGROUND: Several strategies have been developed to counteract liver injury as a consequence of nonsteroid anti-inflammatory drugs toxicity. Here, we aimed to determine whether physical exercise results in liver mitochondrial protection against in vitro diclofenac toxicity. MATERIAL AND METHODS: Male adult Sprague-Dawley rats were divided into sedentary, 12-week endurance training (ET) and voluntary activity (VPA). In vitro liver mitochondrial function as assessed by oxygen consumption, transmembrane electric potential (ΔΨ) and susceptibility to the mitochondrial permeability transition pore (MPTP) was evaluated in the absence and presence of diclofenac. Mitochondrial oxidative stress markers [MnSOD, aconitase, -SH and MDA, SIRT3, p66shc(Ser36)/p66shc ratio] and apoptotic signalling (caspases 3, 8 and 9, Bax, Bcl-2 and CypD) were assessed. Content of OXPHOS components and qualitative liver morphological evaluation were assessed. RESULTS: Despite no effects of ET and VPA on basal liver mitochondrial oxygen consumption or ΔΨ endpoints, exercised animals showed lower susceptibility to MPTP. Diclofenac-induced decrease in ΔΨ, increased state 4 respiration and susceptibility to MPTP opening were all prevented by exercise. Under untreated conditions, VPA group showed higher aconitase activity, while ET decreased MDA and increased Bax content. VPA decreased p66shc(Ser36), complex III and V OXPHOS subunits. Both ET and VPA increased complex IV OXPHOS subunit, and SIRT3 and Bcl-2 content and decreased caspase 9 activity. Unexpectedly, ET and VPA decreased ANT. CONCLUSIONS: Both chronic physical exercise models augmented the resistance to in vitro diclofenac-induced mitochondrial alterations, including increased MPTP susceptibility, possibly by modulating oxidative stress and MPTP regulators.

Combined effects of aging and in vitro non-steroid anti-inflammatory drugs on kidney and liver mitochondrial physiology.

AIMS: Aging and drug-induced side effects may contribute to deteriorate mitochondrial bioenergetics in many tissues, including kidney and liver. One possibility is that the combination of both aging and drug toxicity accelerates the process of mitochondrial degradation, leading to progressive bioenergetic disruption. We therefore analyzed in vitro kidney (KM) and liver (LM) mitochondrial response to salicylate and diclofenac in old and adult animals. MAIN METHODS: Male-Wistar adult (19-wks) and aged (106-wks) rats were used. In vitro endpoints of oxygen consumption and membrane potential were evaluated in non-treated conditions (vehicle) and in the presence of salicylate (0.5mM) and diclofenac (50µM). The susceptibility to calcium-induced permeability transition pore (MPTP) was assessed. Aconitase and C, -SH and MDA contents were measured. Apoptotic signaling was followed by measuring caspase 3, 8 and 9 activities, Bax, Bcl2 and CypD expression. ANT content was semi-quantified. KEY FINDINGS: In general, animal age alone compromised KM state 3 and LM ADP lag phase while resulting in decreased resistance to the MPTP. Aging decreased LM CypD and increased Mn-SOD. Kidney caspase 9-like activity was lower in aged group. Salicylate and diclofenac induced KM and LM dysfunction. ADP lag phase in KM was further increased in the aged group in the presence of diclofenac. No further impairments were observed regarding drug toxicity adding to the aging process. SIGNIFICANCE: Aging impaired KM and LM function despite no detected alterations on oxidative stress and apoptosis. However, aging did not further exacerbate KM and LM frailty induced by salicylate and diclofenac.

Bile acids are toxic for isolated cardiac mitochondria: a possible cause for hepatic-derived cardiomyopathies?

Cholestasis and other liver diseases may affect the heart through the toxic effects of the retained bile acids on cardiac mitochondria, which could explain the origin of hepatic-derived cardiomyopathies. The objective of this work was to test the hypothesis that bile acids are toxic to heart mitochondria for concentrations that are relevant for cholestasis. Heart mitochondria were isolated from rat and subjected to incubation with selected bile acids (litocholic acid [LCA], deoxycholic acid [DCA], chenodeoxycholic acid [CDCA], glycochenodeoxycholic acid [GCDC], taurodeoxycholic acid [TDCA], and glycoursodeoxycholic acid [GUDC]). We observed that the most toxic bile acids were also the most lipophilic ones (LCA, DCA, and CDCA), inducing a decrease on state 3 respiration, respiratory control ratio, and membrane potential and causing the induction of the mitochondrial permeability transition. GUDC was the bile acid with lower indexes of toxicity on isolated heart mitochondria. The results of this research indicate that at toxicologically relevant concentrations, most bile acids (mainly the most lipophilic) alter mitochondrial bioenergetics. The impairment of cardiac mitochondrial function may be an important cause for the observed cardiac alterations during cholestasis.

Enhanced permeability transition explains the reduced calcium uptake in cardiac mitochondria from streptozotocin-induced diabetic rats.

Cardiac dysfunction is associated with diabetes. It was previously shown that heart mitochondria from diabetic rats have a reduced calcium accumulation capacity. The objective of this work was to determine whether the reduction in calcium accumulation by cardiac mitochondria from diabetic rats is related to an enhanced susceptibility to induction of the mitochondrial permeability transition. Streptozotocin-induced diabetic rats were used as a model to study the alterations caused by diabetes in the permeability transition, 21 days after streptozotocin administration. Heart mitochondria were isolated to evaluate respiratory parameters and susceptibility to the calcium-dependent permeability transition. Our results show that streptozotocin diabetes facilitates the mitochondrial permeability transition in cardiac mitochondria, resulting in decreased mitochondrial calcium accumulation. We also observed that heart mitochondria from diabetic rats had depressed oxygen consumption during the phosphorylative state. The reduced mitochondrial calcium uptake observed in heart mitochondria from diabetic rats is related to an enhanced susceptibility to the permeability transition rather than to damage to the calcium uptake machinery.

Diabetes induces metabolic adaptations in rat liver mitochondria: role of coenzyme Q and cardiolipin contents.

Several studies have been carried out to evaluate the alterations in mitochondrial functions of diabetic rats. However, results are sometimes controversial, since experimental conditions diverge, including age and strain of used animals. The purpose of this study was to evaluate the metabolic modifications in liver mitochondria, both in the presence of severe (STZ-treated rats) and mild hyperglycaemia [Goto-Kakizaki (GK) rats], when compared with control animals of similar age. Moreover, metabolic alterations were evaluated also at initial and advanced stages of the disease. We observed that both models of diabetes (type 1 and type 2) presented a decreased susceptibility of liver mitochondria to the induction of permeability transition (MPT). Apparently, there is a positive correlation between the severity of diabetes mellitus (and duration of the disease) and the decline in the susceptibility to MPT induction. We also found that liver mitochondria isolated from diabetic rats presented some metabolic adaptations, such as an increase in coenzyme Q and cardiolipin contents, that can be responsible for the observed decrease in the susceptibility to multiprotein pore (MPTP) opening.