Overfeeding during development induces temporally-dependent changes in areas controlling food intake in the brains of male Wistar rats.

AIMS: We sought to evaluate the effects of overfeeding during lactation on the feeding behavior and expression of specific regulatory genes in brain areas associated with food intake in 22- and 60-day old male rats. METHODS: We evaluated body weight, food intake of standard and palatable diet, and mRNA expression of dopamine receptor D1 (DDR1), dopamine receptor (DDR2), melanocortin 4 receptor (MC4R), the µ-opioid receptor (MOR), neuropeptide Y (NPY), agouti-related protein (AGRP), proopiomelanocortin (POMC), cocaine-and amphetamine-regulated transcript (CART), serotonin (5-hydroxytryptamine; 5-HT) transporter (SERT), 5-hydroxytryptamine receptor 1B (5-HT1B), 5-hydroxytryptamine receptor 2C receptor (5-HT2C), Clock (CLOK), cryptochrome protein 1 (Cry1) and period circadian protein homolog 2 (Per2) in the striatum, hypothalamus and brainstem of male rats at post-natal days (PND) 22 and 60. KEY FINDINGS: Overfeeding resulted in significantly increased body weight through PND60, and a 2-fold increase in palatable food intake at PND22, but not at PND60. We observed significant increases in DDR1, DDR2, and MC4R gene expression in the striatum and brainstem and POMC/CART in the hypothalamus of the OF group at PND22 that were reversed by PND60. Hypothalamic levels of 5-HT1B, 5-HT2C and NPY/AGRP on the other hand were decreased at PND22 and increased at PND60 in OF animals. Clock genes were unaffected by OF at PND22, but were significantly elevated at PND60. SIGNIFICANCE: Overfeeding during early development of the rat brain results in obesity and altered feeding behavior in early adulthood. The altered behavior might be the consequence of the changes in food intake and reward gene expression.

Early life fluoxetine treatment causes long-term lean phenotype in skeletal muscle of rats exposed to maternal lard-based high-fat diet.

There is a concern about early life exposure to Selective Serotonin Reuptake Inhibitors (SSRI) in child development and motor system maturation. Little is known, however, about the interaction of environmental factors, such as maternal nutrition, associated with early exposure to SSRI. The increased maternal consumption of high-fat diets is worrisome and affects serotonin system development with repercussions in body phenotype. This study aimed to assess the short- and long-term effects of neonatal fluoxetine treatment on the body and skeletal muscle phenotype of rats exposed to a maternal lard-based high-fat (H) diet during the perinatal period. A maternal lard-based high-fat diet causes reduced birth weight, a short-term reduction in type IIA fibers in the soleus muscle, and in type IIB fibers in the Extensor Digitorum Longus (EDL) muscle, reducing Lactate Dehydrogenase (LDH) activity in both muscles. In the long-term, the soleus showed reduced muscle weight, smaller area and perimeter of muscle fibers, while the EDL muscle showed reduced Citrate Synthase (CS) activity in offspring from the rats on the maternal lard-based high-fat diet. Early-life exposure to fluoxetine reduced body weight and growth and reduced soleus weight and enzymatic activity in young rats. Exposure to neonatal fluoxetine in adult rats caused a decreased body mass index, less food intake, and reduced muscle weight with reduced CS and LDH activity. Neonatal fluoxetine in young rats exposed to a maternal lard-based high-fat diet caused reduced body weight and growth, reduced soleus weight as well as area and perimeter of type I muscle fibers. In adulthood, there was a reduction in food intake, increased proportion of IIA type fibers, reduced area and perimeter of type IIB, and reduction in levels of CS activity in EDL muscle. Neonatal fluoxetine treatment in rats exposed to a maternal lard-based, high-fat diet induces a reduction in muscle weight, an increase in the proportion of oxidative fibers and greater oxidative enzymatic activity in adulthood.

Fluoxetine administration in juvenile overfed rats improves hypothalamic mitochondrial respiration and REDOX status and induces mitochondrial biogenesis transcriptional expression.

Nutritional imbalance in early life may disrupt the hypothalamic control of energy homeostasis and increase the risk of metabolic disease. The hypothalamic serotonin (5-hydroxytryptamine; 5-HT) system based in the hypothalamus plays an important role in the homeostatic control of energy balance, however the mechanisms underlying the regulation of energy metabolism by 5-HT remain poorly described. Several crucial mitochondrial functions are altered by mitochondrial stress. Adaptations to this stress include changes in mitochondrial multiplication (i.e, mitochondrial biogenesis). Due to the scarcity of evidence regarding the effects of serotonin reuptake inhibitors (SSRI) such as fluoxetine (FLX) on mitochondrial function, we sought to investigate the potential contribution of FLX on changes in mitochondrial function and biogenesis occurring in overfed rats. Using a neonatal overfeeding model, male Wistar rats were divided into 4 groups between 39 and 59 days of age based on nutrition and FLX administration: normofed + vehicle (NV), normofed + FLX (NF), overfed + vehicle (OV) and overfed + FLX (OF). We found that neonatal overfeeding impaired mitochondrial respiration and increased oxidative stress biomarkers in the hypothalamus. FLX administration in overfed rats reestablished mitochondrial oxygen consumption, increased mitochondrial uncoupling protein 2 (Ucp2) expression, reduced total reactive species (RS) production and oxidative stress biomarkers, and up-regulated mitochondrial biogenesis-related genes. Taken together our results suggest that FLX administration in overfed rats improves mitochondrial respiratory chain activity and oxidative balance and increases the transcription of genes employed in mitochondrial biogenesis favoring mitochondrial energy efficiency in response to early nutritional imbalance.

Influence of maternal protein malnutrition on oxidative stress and regulators of mitochondrial biogenesis in female rat hearts over succeeding generations.

AIMS: We sought to evaluate the effects of maternal protein restriction (LP) on oxidative balance and transcription factors for mitochondrial biogenesis in the hearts of young female rats of both the first (F1) and second (F2) generation. MAIN METHODS: We evaluated oxidative stress biomarkers (lipid peroxidation and protein oxidation), enzymatic antioxidant defense (activity of superoxide dismutase-SOD, catalase, and glutathione-S-transferase-GST), nonenzymatic antioxidant defense (reduced glutathione-GSH and sulfhydryl groups) and gene expression of AMPK, PGC-1α and TFAM. KEY FINDINGS: Interestingly, lipid peroxidation was decreased (49%, p < 0.001) in the LP-F1 group and 59% (p < 0.001) in LP-F2. In enzymatic defense, we observed increases in SOD activity in the LP-F1 group (79%, p = 0.036) and in CAT activity (approximately 40%, p = 0.041). GSH was increased in F2 in both groups (LP 546%, p < 0.0001 and in NP 491.7%, p < 0.0001). With respect to mitochondrial biogenesis gene transcription, we observed a decrease in AMPK (60%, p < 0. 0001) and an increase in PGC-1α (340%, p < 0.001) in LP compared to NP in the F1 generation. TFAM was decreased in LP-F2L compared to NP-F2L (42%, p = 0.0069) and increased in LP-F2 compared to LP-F1 (160%, p = 0.0037). SIGNIFICANCE: Our study contributes to knowledge of inheritance, showing that despite the potential mitochondrial 'inheritance' of cardiovascular damage caused by maternal malnutrition, that damage is not cross-generational and can be eliminated with proper nutrition in the F1 generation.

Mitochondrial impairment following neonatal overfeeding: A comparison between normal and ischemic-reperfused hearts.

Overweight and obesity are established factors underpin several metabolic impairments, including the cardiovascular. Although the diversity of factors involved in overweight/obesity-induced cardiovascular diseases, mitochondria has been highlighted due to its role in cardiac metabolism. As obesity can be originated in early postnatal life, the current study evaluates the effects of neonatal overfeeding on the cardiac mitochondrial bioenergetics and oxidative balance in rats that underwent an ischemia-reperfusion insult. Seventy-two hours after delivery, Wistar rat litters were randomly assigned into the control (C; nine pups per mother) and the Overfed (OF; three pups per mother) groups throughout the lactation period. At weaning, male offspring were fed with laboratory chow ad libitum until sacrifice at 30 and 60 days of life. Mitochondrial heart bioenergetics and oxidative balance showed to be deeply affected by neonatal overfeeding at both ages. Interestingly, after ischemia-reperfusion insult I/R (Langendorff or mineral oil incubation), most parameters evaluated in OF animals were not influenced by additional ischemic-reperfusion injury. Our findings demonstrated that suckling overfeeding deregulates cardiac mitochondrial alike to ischemia-reperfusion insult by disengaging electrical mitochondrial coupling and potentiate oxidative stress, wherein the neonatal overfeeding shows to be so detrimental as I/R. Our findings support the concept that nutritional insults in the critical development periods increase the risk for cardiovascular disease and mitochondria impairments throughout life while oxidative damage change between molecular targets.

Serotonin transporter inhibition during neonatal period induces sex-dependent effects on mitochondrial bioenergetics in the rat brainstem.

The serotonin reuptake is mainly regulated by the serotonin transporters (SERTs), which are abundantly found in the raphe nuclei, located in the brainstem. Previous studies have shown that dysfunction in the SERT has been associated with several disorders, including depression and cardiovascular diseases. In this manuscript, we aimed to investigate how gender and the treatment with a serotonin selective reuptake inhibitor (SSRI) could affect mitochondrial bioenergetics and oxidative stress in the brainstem of male and female rats. Fluoxetine, our chosen SSRI, was used during the neonatal period (i.e., from postnatal Day 1 to postnatal Day 21-PND1 to PND21) in both male and female animals. Thereafter, experiments were conducted in adult rats (60 days old). Our results demonstrate that, during lactation, fluoxetine treatment modulates the mitochondrial bioenergetics in a sex-dependent manner, such as improving male mitochondrial function and female antioxidant capacity.

Anacardic Acids from Cashew Nuts Prevent Behavioral Changes and Oxidative Stress Induced by Rotenone in a Rat Model of Parkinson's Disease.

Anacardic acids (AAs) are alkyl phenols mainly presenting in cashew nuts. The antioxidant effects of these compounds have been an area of interest in recent research, with findings suggesting potential therapeutic use for certain diseases. Nevertheless, none of these studies were performed in order to test the hypothesis of whether anacardic acids are capable of preventing behavioral changes and oxidative stress induced by the pesticide rotenone in experimental model of Parkinson's disease. In our research, adult male rats were treated orally with AAs (1, 3, 10, 25, 50, or 100 mg/kg/day) 1 h before rotenone (3 mg/kg; s.c.) for five consecutive days. The behavioral testing strategies, including tests for general locomotor activity (open field), motor coordination (rotarod), and spatial memory performance (elevated T-maze), were carried out. Lipoperoxidation levels and total superoxide dismutase (t-SOD) activity, as well as cytoplasmic and mitochondrial SOD gene expression, were assessed in the substantia nigra (SN), striatum, and cerebral cortex. The results showed that AAs dose-dependently prevented the rotenone-induced learning and motor impairment from 10 mg/kg/day. AAs also precluded rotenone-induced lipoperoxidation in all doses, acting directly on the mitochondria, and improved the t-SOD activity in the doses 25-100 mg/kg/day. AAs per se (100 mg/kg/day) increased SOD gene expression and t-SOD activity. Our findings indicate that the oral administration of AAs prevents rotenone-induced behavioral changes and oxidative stress, in part due to a modulatory action on the mitochondria and SOD gene expression. These data suggest that AAs have promising neuroprotective action against degenerative changes in Parkinson's disease.

Mitochondrial bioenergetics and oxidative status disruption in brainstem of weaned rats: Immediate response to maternal protein restriction.

Mitochondrial bioenergetics dysfunction has been postulated as an important mechanism associated to a number of cardiovascular diseases in adulthood. One of the hypotheses is that this is caused by the metabolic challenge generated by the mismatch between prenatal predicted and postnatal reality. Perinatal low-protein diet produces several effects that are manifested in the adult animal, including altered sympathetic tone, increased arterial blood pressure and oxidative stress in the brainstem. The majority of the studies related to nutritional programming postulates that the increased risk levels for non-communicable diseases are associated with the incompatibility between prenatal and postnatal environment. However, little is known about the immediate effects of maternal protein restriction on the offspring's brainstem. The present study aimed to test the hypothesis that a maternal low-protein diet causes tissue damage immediately after exposure to the nutritional insult that can be assessed in the brainstem of weaned offspring. In this regard, a series of assays was conducted to measure the mitochondrial bioenergetics and oxidative stress biomarkers in the brainstem, which is the brain structure responsible for the autonomic cardiovascular control. Pregnant Wistar rats were fed ad libitum with normoprotein (NP; 17% casein) or low-protein (LP; 8% casein) diet throughout pregnancy and lactation periods. At weaning, the male offsprings were euthanized and the brainstem was quickly removed to assess the mitochondria function, reactive oxygen species (ROS) production, mitochondrial membrane electric potential (ΔΨm), oxidative biomarkers, antioxidant defense and redox status. Our data demonstrated that perinatal LP diet induces an immediate mitochondrial dysfunction. Furthermore, the protein restriction induced a marked increase in ROS production, with a decrease in antioxidant defense and redox status. Altogether, our findings suggest that LP-fed animals may be at a higher risk for oxidative metabolism impairment throughout life than NP-fed rats, due to the immediate disruption of the mitochondrial bioenergetics and oxidative status caused by the LP diet.

Effect of fluoxetine treatment on mitochondrial bioenergetics in central and peripheral rat tissues.

Recent investigations have focused on the mitochondrion as a direct drug target in the treatment of metabolic diseases (obesity, metabolic syndrome). Relatively few studies, however, have explicitly investigated whether drug therapies aimed at changing behavior by altering central nervous system (CNS) function affect mitochondrial bioenergetics, and none has explored their effect during early neonatal development. The present study was designed to evaluate the effects of chronic treatment of newborn male rats with the selective serotonin reuptake inhibitor fluoxetine on the mitochondrial bioenergetics of the hypothalamus and skeletal muscle during the critical nursing period of development. Male Wistar rat pups received either fluoxetine (Fx group) or vehicle solution (Ct group) from the day of birth until 21 days of age. At 60 days of age, mitochondrial bioenergetics were evaluated. The Fx group showed increased oxygen consumption in several different respiratory states and reduced production of reactive oxygen species, but there was no change in mitochondrial permeability transition pore opening or oxidative stress in either the hypothalamus or skeletal muscle. We observed an increase in glutathione S-transferase activity only in the hypothalamus of the Fx group. Taken together, our results suggest that chronic exposure to fluoxetine during the nursing phase of early rat development results in a positive modulation of mitochondrial respiration in the hypothalamus and skeletal muscle that persists into adulthood. Such long-lasting alterations in mitochondrial activity in the CNS, especially in areas regulating appetite, may contribute to permanent changes in energy balance in treated animals.