Short communication: Ex-situ conservation in hatcheries is associated with spleen development in Lepidochelys olivacea turtle hatchlings.

Ex-situ conservation in hatcheries is a successful strategy for the recovery of sea turtle populations. However, it alters the ontogenesis of the brain and gonads, as well as body size and locomotor performance at nest emergence. Relocation to hatcheries may alter immune system development, since this depends highly on the nest environment. We hypothesized that ex-situ brooding would negatively associate with immune traits of Lepidochelys olivacea. Splenic cytoarchitecture and leukocyte quantification were used as proxies for the immune configuration. Body size, gonadal sex and sand temperature during incubation were determined. Additionally, the success of nest hatching and emergence was quantified. Linear mixed models of splenic cytoarchitecture, leucocyte proportions and body size, using sex and nest type as explanatory variables, evaluated the effects of ex-situ brooding. Generalized linear mixed models using quasibinomial distributions (log link) analyzed effects on hatching and emergence success. Hatchlings from ex-situ nests were heavier, larger and showed a greater spleen-somatic index. They showed more and better defined splenic periarteriolar lymphoid sheaths, as well as a higher proportion of heterophils but less monocytes. Moreover, ex-situ brooding increased hatching and emergence success. Sand temperatures in hatcheries favored male sex determination, while the opposite occurred for in-situ incubation. Interestingly, the immune configuration and body size were independent of sex but associated with ex-situ conservation. Greater body size promotes early hatchling survival, while better spleen development is related to a greater antibody production and a better immune response to pathogens. Altogether, the results suggest that ex-situ incubation is associated with a better immune configuration and higher survival success.

Microbiota Signals during the Neonatal Period Forge Life-Long Immune Responses.

The microbiota regulates immunological development during early human life, with long-term effects on health and disease. Microbial products include short-chain fatty acids (SCFAs), formyl peptides (FPs), polysaccharide A (PSA), polyamines (PAs), sphingolipids (SLPs) and aryl hydrocarbon receptor (AhR) ligands. Anti-inflammatory SCFAs are produced by Actinobacteria, Bacteroidetes, Firmicutes, Spirochaetes and Verrucomicrobia by undigested-carbohydrate fermentation. Thus, fiber amount and type determine their occurrence. FPs bind receptors from the pattern recognition family, those from commensal bacteria induce a different response than those from pathogens. PSA is a capsular polysaccharide from B. fragilis stimulating immunoregulatory protein expression, promoting IL-2, STAT1 and STAT4 gene expression, affecting cytokine production and response modulation. PAs interact with neonatal immunity, contribute to gut maturation, modulate the gut-brain axis and regulate host immunity. SLPs are composed of a sphingoid attached to a fatty acid. Prokaryotic SLPs are mostly found in anaerobes. SLPs are involved in proliferation, apoptosis and immune regulation as signaling molecules. The AhR is a transcription factor regulating development, reproduction and metabolism. AhR binds many ligands due to its promiscuous binding site. It participates in immune tolerance, involving lymphocytes and antigen-presenting cells during early development in exposed humans.

Metformin Plus Caloric Restriction Show Anti-epileptic Effects Mediated by mTOR Pathway Inhibition.

Caloric restriction (CR) has anti-epileptic effects in different animal models, at least partially due to inhibition of the mechanistic or mammalian target of rapamycin (mTOR) signaling pathway. Adenosine monophosphate-activated protein kinase (AMPK) inhibits mTOR cascade function if energy levels are low. Since hyper-activation of mTOR participates in epilepsy, its inhibition results in beneficial anti-convulsive effects. A way to attain this is to activate AMPK with metformin. The effects of metformin, alone or combined with CR, on the electrical kindling epilepsy model and the mTOR cascade in the hippocampus and the neocortex were studied. Combined metformin plus CR beneficially affected many kindling aspects, especially those relating to generalized convulsive seizures. Therefore, metformin plus CR could decrease measures of epileptic activity in patients with generalized convulsive seizures. Patients that are obese, overweight or that have metabolic syndrome in addition to having an epileptic disease are an ideal population for clinical trials to test the effectiveness of metformin plus CR.

Effect of Nicotine on CYP2B1 Expression in a Glioma Animal Model and Analysis of CYP2B6 Expression in Pediatric Gliomas.

Cyclophosphamide (CPA) is a pro-drug commonly used in the chemotherapeutic schemes for glioma treatment but has high toxicity and the side effects include brain damage and even death. Since CPA is activated mainly by CY2B6, over-expression of the enzyme in the tumor cells has been proposed to enhance CPA activation. In this study, we explored the induction of the Cyp2b1 (homologous to CYP2B6) by nicotine in an animal rat model with glioma. Gene expression and protein levels were analyzed by RT-PCR and Western blot. Nicotine treatment increased CYP2B1 protein levels in the healthy animals' brain tissue. In the brain tissue of animals with glioma, the CYP2B1 showed a high expression, even before nicotine treatment. Nicotine did not increase significantly the CYP2B1 protein expression in the tumor, but increased its expression in the tumor vicinity, especially around blood vessels in the cortex. We also explored CY2B6 expression in glioma samples derived from pediatric patients. Tumor tissue showed a variable expression of the enzyme, which could depend on the tumor malignancy grade. Induction of the CYP2B6 in pediatric gliomas with lower expression of the enzyme, could be an alternative to improve the antitumoral effect of CPA treatment.

Corrigendum to "Sphingolipids as Mediators in the Crosstalk between Microbiota and Intestinal Cells: Implications for Inflammatory Bowel Disease".

[This corrects the article DOI: 10.1155/2016/9890141.].

Selecting, optimizing and externally validating a preexisting machine-learning regression algorithm for estimating waist circumference.

Obesity, typically defined by the body mass index (BMI), has well known negative health effects. However, the BMI has serious deficiencies in predicting the adverse risks associated to obesity. Waist circumference (WC) is an alternative to define obesity and a better disease predictor according to the literature. However, old databases often lack this information, it is inaccurate (collected via self-report) or it is incomplete. Thus, this study accurately assesses WC using machine learning. The novel approaches are: 1) predictor variables (weight, height, age and sex) likely to appear in most data sets are used. 2) Publicly available data (including non-adults) and algorithms are used. 3) Systematic methods for data cleanup, model selection, hyperparameter optimization and external validation are performed. DATA ARE CLEANED: one variable per column, no special codes, missing values or outliers. Preexisting regression algorithms are gaged by cross-validation, using one data set. The hyperparameters of the best performing algorithm are optimized. The tuned algorithm is externally validated with other data sets by cross-validation. In spite of the limited number of features, the tuned algorithm outperforms prior WC approximations, using the same or similar predictor variables. The tuned algorithm enables using data where WC is not measured, is incomplete or is unreliable. A similar approach would be useful to estimate other variables of interest.

Synaptic vesicle protein 2A: basic facts and role in synaptic function.

In recent years, there has been considerable interest in determining the function of synaptic vesicle protein 2A and its role as a target for antiepileptic drugs. Although it is known that synaptic vesicle protein 2A is involved in normal synaptic vesicle function, its participation in synaptic vesicle cycling and neurotransmitter release in normal and pathological conditions is unclear. However, the experimental evidence suggests that synaptic vesicle protein 2A could be a vesicular transporter, regulate synaptic exocytosis as a gel matrix, or modulate synaptotagmin-1 activity. This review describes and discusses the participation of synaptic vesicle protein 2A in synaptic modulation in normal and pathological conditions.

Distribution of estrogen receptors alpha and beta in the brain of male rats with same-sex preference.

Two distinct estrogen receptors (ERs) exist, ERα and ERß. Both receptors participate in sexual differentiation of the rat brain and likely participate in the regulation of adult sexual orientation (i.e. partner preference). This last idea was investigated herein by examining males treated with the aromatase inhibitor, letrozole, administered prenatally (0.56 µg/kg G10-22). This treatment usually provokes same-sex preference in 1-2 males per litter. Vehicle-treated males (with female preference) and females in spontaneous proestrus (with male preference) were included as controls. ERα and ERß expression was analyzed by immunohistochemistry in brain areas known to control masculine sexual behavior and partner preference, like the medial preoptic area (MPOA), bed nucleus of the stria terminalis (BNST), medial amygdala (MeA) and ventromedial hypothalamic nucleus (VMH), as well as other brain regions suspected to participate in these processes. In addition, serum levels of estradiol were determined in all male groups. Letrozole-treated male rats that preferred sexually experienced males (LPM) showed over-expressed ERα in the hippocampal cornu Ammonis (CA 1, 3, 4) and dentate gyrus. The LPM group showed up-regulated ERß expression in the CA2 and reticular thalamic nucleus. The levels of estradiol did not differ between the groups. Higher expression of ERs in these males was different than their expression in females, with male sex-preference. This suggests that males with same-sex preference showed a unique brain, this sui generis steroid receptor expression probably participates in the biological underpinnings of sexual preference.

Incubation in shaded hatcheries biases sex-determination but preserves Lepidochelys olivacea hatchling physiology.

Some studies have associated ex situ conservation with cerebral and gonadal developmental delay, as well as decreased motor performance in Lepidochelys olivacea offspring. Ex situ management is also related to a more mature spleen and a differential leukocyte count in newly emerged Lepidochelys olivacea hatchlings. The physiological relevance of a more mature spleen is unknown in sea turtles, but studies in birds suggest an increased immune response. Because egg relocation to hatcheries is a common conservation practice, it is imperative to know its impact on hatchling physiology. Herein, plasma activity of superoxide dismutase, alkaline phosphatase and the alternative complement pathway, as well as total antioxidant capacity and hydrogen peroxide concentrations were quantified in hatchlings from in situ and ex situ nests under basal conditions at nest emergence. Toll-like receptor 4 (tlr4), heat shock proteins (hsp) 70 and hsp90 expression were quantified in the spleen and liver of the hatchlings. Hepatocyte density and nuclear area were quantified in histological sections of the liver and all turtles were sexed by histological sectioning of the gonads. Total antioxidant capacity and hydrogen peroxide concentrations in plasma were lower in turtles from ex situ nests, while tlr4 and hsp70 mRNA expression was higher in the spleen but not in the liver. Ex situ incubation produced 98% male hatchlings, whereas in situ incubation produced 100% females. There were no other differences in the attributes sampled between hatchlings emerging from ex situ and in situ treatments. The results suggest that ex situ relocated turtles may be less prone to oxidative stress than in situ incubated hatchlings and could have more mature splenic function. Together, the data suggest that ex situ relocation to shaded hatcheries biased sex determination but preserved the general physiological condition of sea turtle hatchlings.

Increased oxidative stress contributes to enhance brain amyloidogenesis and blunts energy metabolism in sucrose-fed rat: effect of AMPK activation.

Metabolic disturbances are linked to neurodegenerative diseases such as Alzheimer disease (AD). However, the cellular mechanisms underlying this connection are unclear. We evaluated the role of oxidative stress (OS), during early metabolic syndrome (MetS), on amyloidogenic processes in a MetS rat model induced by sucrose. MetS caused OS damage as indicated by serum and hypothalamus lipid peroxidation and elevated serum catalase activity. Tissue catalase and superoxide dismutase activity were unchanged by MetS, but gene expression of nuclear factor erythroid-derived 2-like 2 (NFE2L2), which up-regulates expression of antioxidant enzymes, was higher. Expression of amyloid-ß cleaving enzyme 1 (BACE-1) and amyloid precursor protein (APP), key proteins in the amyloidogenesis pathway, were slightly increased by sucrose-intake in the hippocampus and hypothalamus. Activation and expression of protein kinase B (PKB) and AMP-dependent protein kinase (AMPK), pivotal proteins in metabolism and energy signaling, were similarly affected in the hippocampus and hypothalamus of MetS rats. Brain creatine kinase activity decreased in brain tissues from rats with MetS, mainly due to irreversible oxidation. Chronic metformin administration partially reversed oxidative damage in sucrose-fed animals, together with increased AMPK activation; probably by modulating BACE-1 and NFE2L2. AMPK activation may be considered as a preventive therapy for early MetS and associated neurodegenerative diseases.

Synaptic Vesicle Protein 2A Expression in Glutamatergic Terminals Is Associated with the Response to Levetiracetam Treatment.

Synaptic vesicle protein 2A (SV2A), the target of the antiepileptic drug levetiracetam (LEV), is expressed ubiquitously in all synaptic terminals. Its levels decrease in patients and animal models of epilepsy. Thus, changes in SV2A expression could be a critical factor in the response to LEV. Epilepsy is characterized by an imbalance between excitation and inhibition, hence SV2A levels in particular terminals could also influence the LEV response. SV2A expression was analyzed in the epileptic hippocampus of rats which responded or not to LEV, to clarify if changes in SV2A alone or together with glutamatergic or GABAergic markers may predict LEV resistance. Wistar rats were administered saline (control) or pilocarpine to induce epilepsy. These groups were subdivided into untreated or LEV-treated groups. All epileptic rats were video-monitored to assess their number of seizures. Epileptic rats with an important seizure reduction (>50%) were classified as responders. SV2A, vesicular γ-aminobutyric acid transporter and vesicular glutamate transporter (VGLUT) expression were assessed by immunostaining. SV2A expression was not modified during epilepsy. However, responders showed ≈55% SV2A-VGLUT co-expression in comparison with the non-responder group (≈40%). Thus, SV2A expression in glutamatergic terminals may be important for the response to LEV treatment.

Endocrine, neural and pharmacological aspects of sexual satiety in male rats.

Sexual satiety is the inhibition of masculine mating behavior produced by copulation itself. This inhibition is manifested in different ways depending upon the species, the time and the amount of sexual behavior prior to sexual satiety. Pharmacological studies indicate that monoaminergic and opioidergic compounds modify this phenomenon in the rat and other species, possibly via a final dopaminergic pathway involving sexual motivation. Reduced androgen receptor expression and/or increased estrogen receptor alpha expression in specific brain areas are associated with the inhibition of mating behavior that characterizes rat sexual satiety. Androgen receptor over-expression in the same and other brain areas coincides with a partial recovery of rat male copulatory behavior after sexual satiety. The lateral septum, medial amygdala and medial preoptic area may participate in the neuroendocrine regulation of sexual satiety, based on changes in the expression of c-Fos, androgen receptor and estrogen receptor alpha in these cerebral regions. These data suggest that changes in steroid receptors, possibly triggered by modifications in neurotransmitters, underlie at least partly the inhibition of copulatory behavior characteristic of rat sexual satiety.

Anabolic androgens restore mating after sexual satiety in male rats.

Androgen receptors and estrogen receptors importantly participate in the neuroendocrine control of masculine mating behavior. Sexual satiety is the long term inhibition of masculine mating behavior after repeated ejaculations and is associated to changes in both androgen receptor and estrogen receptor-alpha expression. Androgen receptor expression is up-regulated by systemic chronic administration of anabolic androgens, 5alpha-dihydrotestosterone or estradiol benzoate. This study was carried out to investigate the effect of these treatments on sexual satiety development and recovery; additionally flutamide or tamoxifen treatments -- alone or together with anabolic androgens -- were also included. Chronic 15-day treatment with 5alpha-dihydrotestosterone (5 mg/kg) or tamoxifen (15 mg/kg) inhibited, whereas estradiol benzoate treatment (5 mg/kg) facilitated, mating behavior during sexual satiety development. The proportion of animals that ejaculated 48 h after sexual satiety was increased after 17-day treatment with a mixture of anabolic androgens containing 2 mg/kg testosterone propionate, 2 mg/kg nandrolone decanoate and 1 mg/kg boldenone undecylenate. This effect was only blocked by the combined administration of flutamide plus tamoxifen. The data suggest that anabolic androgens metabolites synergize to restore mating behavior after sexual satiety.

Caloric restriction protects against electrical kindling of the amygdala by inhibiting the mTOR signaling pathway.

Caloric restriction (CR) has been shown to possess antiepileptic properties; however its mechanism of action is poorly understood. CR might inhibit the activity of the mammalian or mechanistic target of rapamycin (mTOR) signaling cascade, which seems to participate crucially in the generation of epilepsy. Thus, we investigated the effect of CR on the mTOR pathway and whether CR modified epilepsy generation due to electrical amygdala kindling. The former was studied by analyzing the phosphorylation of adenosine monophosphate-activated protein kinase, protein kinase B and the ribosomal protein S6. The mTOR cascade is regulated by energy and by insulin levels, both of which may be changed by CR; thus we investigated if CR altered the levels of energy substrates in the blood or the level of insulin in plasma. Finally, we studied if CR modified the expression of genes that encode proteins participating in the mTOR pathway. CR increased the after-discharge threshold and tended to reduce the after-discharge duration, indicating an anti-convulsive action. CR diminished the phosphorylation of protein kinase B and ribosomal protein S6, suggesting an inhibition of the mTOR cascade. However, CR did not change glucose, ß-hydroxybutyrate or insulin levels; thus the effects of CR were independent from them. Interestingly, CR also did not modify the expression of any investigated gene. The results suggest that the anti-epileptic effect of CR may be partly due to inhibition of the mTOR pathway.

Identification of the antiepileptic racetam binding site in the synaptic vesicle protein 2A by molecular dynamics and docking simulations.

Synaptic vesicle protein 2A (SV2A) is an integral membrane protein necessary for the proper function of the central nervous system and is associated to the physiopathology of epilepsy. SV2A is the molecular target of the anti-epileptic drug levetiracetam and its racetam analogs. The racetam binding site in SV2A and the non-covalent interactions between racetams and SV2A are currently unknown; therefore, an in silico study was performed to explore these issues. Since SV2A has not been structurally characterized with X-ray crystallography or nuclear magnetic resonance, a three-dimensional (3D) model was built. The model was refined by performing a molecular dynamics simulation (MDS) and the interactions of SV2A with the racetams were determined by docking studies. A reliable 3D model of SV2A was obtained; it reached structural equilibrium during the last 15 ns of the MDS (50 ns) with remaining structural motions in the N-terminus and long cytoplasmic loop. The docking studies revealed that hydrophobic interactions and hydrogen bonds participate importantly in ligand recognition within the binding site. Residues T456, S665, W666, D670 and L689 were important for racetam binding within the trans-membrane hydrophilic core of SV2A. Identifying the racetam binding site within SV2A should facilitate the synthesis of suitable radio-ligands to study treatment response and possibly epilepsy progression.

Ca(2+) mishandling and cardiac dysfunction in obesity and insulin resistance: role of oxidative stress.

Obesity and insulin resistance (IR) are strongly connected to the development of subclinical cardiac dysfunction and eventually can lead to heart failure, which is the main cause of morbidity and death in patients having these metabolic diseases. It has been considered that excessive fat tissue may play a critical role in producing systemic IR and enhancing reactive oxygen species (ROS) generation. This oxidative stress (OS) may elicit or exacerbate IR. On the other hand, evidence suggests that some of the cellular mechanisms involved in the pathophysiology of obesity and IR-related cardiomyopathy are excessive myocardial ROS production and abnormal Ca(2+) homeostasis. In addition, emerging evidence suggests that augmented ROS production may contribute to Ca(2+) mishandling by affecting the redox state of key proteins implicated in this process. In this review, we focus on the role of Ca(2+) mishandling in the development of cardiac dysfunction in obesity and IR and address the evidence suggesting that OS might also contribute to cardiac dysfunction by affecting Ca(2+) handling.

EphB4 is developmentally and differentially regulated in blood vessels throughout the forebrain neurogenic niche in the mouse brain: Implications for vascular remodeling.

Neurogenesis is a process influenced by environmental cues that create highly specific functional niches. Recently, the role of blood vessels in the maintenance and functioning of neurogenic niches during development and in adult life has been hallmarked. In addition to their trophic support for the highly demanding neurogenic process, blood vessels regulate neuroblast differentiation and migration and define functional domains. Since neurogenesis along the forebrain neurogenic niche (FNN) is a multistage process, in which neuroblast proliferation, differentiation and migration are spatially restricted to specific locations; we evaluated the structural features of vascular beds that support these processes during critical time points in their development. Additionally, we studied the molecular identity of the endothelial components of vascular beds using the expression of the venous marker EphB4. Our results show that blood vessels along the FNN: 1) are present very early in development; 2) define the borders of the FNN since early developmental stages; 3) experience constant remodeling until achieving their mature structure; 4) show venous features during perinatal developmental times; and 5) down-regulate their EphB4 expression as development proceeds. Collectively, our results describe the formation of the intricate vascular network that may support neurogenesis along the FNN and show that blood vessels along this neurogenic niche are dynamic entities that experience significant structural and molecular remodeling throughout development.

Relationship between sexual satiety and brain androgen receptors.

Recently we showed that 24 h after copulation to satiety, there is a reduction in androgen receptor density (ARd) in the medial preoptic area (MPOA) and in the ventromedial hypothalamic nucleus (VMH), but not in the bed nucleus of the stria terminalis (BST). The present study was designed to analyze whether the ARd changes in these and other brain areas, such as the medial amygdala (MeA) and lateral septum, ventral part (LSV), were associated with changes in sexual behavior following sexual satiety. Males rats were sacrificed 48 h, 72 h or 7 days after sexual satiety (4 h ad libitum copulation) to determine ARd by immunocytochemistry; additionally, testosterone serum levels were measured in independent groups sacrificed at the same intervals. In another experiment, males were tested for recovery of sexual behavior 48 h, 72 h or 7 days after sexual satiety. The results showed that 48 h after sexual satiety 30% of the males displayed a single ejaculation and the remaining 70% showed a complete inhibition of sexual behavior. This reduction in sexual behavior was accompanied by an ARd decrease exclusively in the MPOA-medial part (MPOM). Seventy-two hours after sexual satiety there was a recovery of sexual activity accompanied by an increase in ARd to control levels in the MPOM and an overexpression of ARd in the LSV, BST, VMH and MeA. Serum testosterone levels were unmodified during the post-satiety period. The results are discussed on the basis of the similarities and discrepancies between ARd in specific brain areas and male sexual behavior.