Acute administration of a dopamine D2/D3 receptor agonist alters behavioral and neural parameters in adult zebrafish.

The dopaminergic neurotransmitter system is implicated in several brain functions and behavioral processes. Alterations in it are associated with the pathogenesis of several human neurological disorders. Pharmacological agents that interact with the dopaminergic system allow the investigation of dopamine-mediated cellular and molecular responses and may elucidate the biological bases of such disorders. Zebrafish, a translationally relevant biomedical research organism, has been successfully employed in prior psychopharmacology studies. Here, we evaluated the effects of quinpirole (dopamine D2/D3 receptor agonist) in adult zebrafish on behavioral parameters, brain-derived neurotrophic factor (BDNF) and neurotransmitter levels. Zebrafish received intraperitoneal injections of 0.5, 1.0, or 2.0 mg/kg quinpirole or saline (control group) twice with an inter-injection interval of 48 h. All tests were performed 24 h after the second injection. After this acute quinpirole administration, zebrafish exhibited decreased locomotor activity, increased anxiety-like behaviors and memory impairment. However, quinpirole did not affect social and aggressive behavior. Quinpirole-treated fish exhibited stereotypic swimming, characterized by repetitive behavior followed by immobile episodes. Moreover, quinpirole treatment also decreased the number of BDNF-immunoreactive cells in the zebrafish brain. Analysis of neurotransmitter levels demonstrated a significant increase in glutamate and a decrease in serotonin, while no alterations were observed in dopamine. These findings demonstrate that dopaminergic signaling altered by quinpirole administration results in significant behavioral and neuroplastic changes in the central nervous system of zebrafish. Thus, we conclude that the use of quinpirole administration in adult zebrafish may be an appropriate tool for the analysis of mechanisms underlying neurological disorders related to the dopaminergic system.

Tmem65 is critical for the structure and function of the intercalated discs in mouse hearts.

The intercalated disc (ICD) is a unique membrane structure that is indispensable to normal heart function, yet its structural organization is not completely understood. Previously, we showed that the ICD-bound transmembrane protein 65 (Tmem65) was required for connexin43 (Cx43) localization and function in cultured mouse neonatal cardiomyocytes. Here, we investigate the functional and cellular effects of Tmem65 reductions on the myocardium in a mouse model by injecting CD1 mouse pups (3-7 days after birth) with recombinant adeno-associated virus 9 (rAAV9) harboring Tmem65 shRNA, which reduces Tmem65 expression by 90% in mouse ventricles compared to scrambled shRNA injection. Tmem65 knockdown (KD) results in increased mortality which is accompanied by eccentric hypertrophic cardiomyopathy within 3 weeks of injection and progression to dilated cardiomyopathy with severe cardiac fibrosis by 7 weeks post-injection. Tmem65 KD hearts display depressed hemodynamics as measured echocardiographically as well as slowed conduction in optical recording accompanied by prolonged PR intervals and QRS duration in electrocardiograms. Immunoprecipitation and super-resolution microscopy demonstrate a physical interaction between Tmem65 and sodium channel ß subunit (ß1) in mouse hearts and this interaction appears to be required for both the establishment of perinexal nanodomain structure and the localization of both voltage-gated sodium channel 1.5 (NaV1.5) and Cx43 to ICDs. Despite the loss of NaV1.5 at ICDs, whole-cell patch clamp electrophysiology did not reveal reductions in Na+ currents but did show reduced Ca2+ and K+ currents in Tmem65 KD cardiomyocytes in comparison to control cells. We conclude that disrupting Tmem65 function results in impaired ICD structure, abnormal cardiac electrophysiology, and ultimately cardiomyopathy.

Inflammatory Pain Alters Dopaminergic Modulation of Excitatory Synapses in the Anterior Cingulate Cortex of Mice.

Pain modulation of dopamine-producing nuclei is known to contribute to the affective component of chronic pain. However, pain modulation of pain-related cortical regions receiving dopaminergic inputs is understudied. The present study demonstrates that mice with chronic inflammatory injury of the hind paws develop persistent mechanical hypersensitivity and transient anxiety. Peripheral inflammation induced by injection of complete Freund's Adjuvant (CFA) induced potentiation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic receptor (AMPAR) currents with a presynaptic component in layer II/III of the ACC. After four days of inflammatory pain, the dopamine-mediated inhibition of AMPAR currents was significantly reduced in the ACC. Furthermore, dopamine enhanced presynaptic modulation of excitatory transmission, but only in mice with inflammatory pain. High-performance liquid chromatography (HPLC) analysis of dopamine tissue concentration revealed that dopamine neurotransmitter concentration in the ACC was reduced three days following CFA. Our results demonstrate that inflammatory pain induces activity-dependent changes in excitatory synaptic transmission and alters dopaminergic homeostasis in the ACC.

PPA2-associated sudden cardiac death: extending the clinical and allelic spectrum in 20 new families.

PURPOSE: Biallelic hypomorphic variants in PPA2, encoding the mitochondrial inorganic pyrophosphatase 2 protein, have been recently identified in individuals presenting with sudden cardiac death, occasionally triggered by alcohol intake or a viral infection. Here we report 20 new families harboring PPA2 variants. METHODS: Synthesis of clinical and molecular data concerning 34 individuals harboring five previously reported PPA2 variants and 12 novel variants, 11 of which were functionally characterized. RESULTS: Among the 34 individuals, only 6 remain alive. Twenty-three died before the age of 2 years while five died between 14 and 16 years. Within these 28 cases, 15 died of sudden cardiac arrest and 13 of acute heart failure. One case was diagnosed prenatally with cardiomyopathy. Four teenagers drank alcohol before sudden cardiac arrest. Progressive neurological signs were observed in 2/6 surviving individuals. For 11 variants, recombinant PPA2 enzyme activities were significantly decreased and sensitive to temperature, compared to wild-type PPA2 enzyme activity. CONCLUSION: We expand the clinical and mutational spectrum associated with PPA2 dysfunction. Heart failure and sudden cardiac arrest occur at various ages with inter- and intrafamilial phenotypic variability, and presentation can include progressive neurological disease. Alcohol intake can trigger cardiac arrest and should be strictly avoided.

Lasting effects of mild embryonic ethanol exposure on voltage-gated ion channels in adult zebrafish brain.

The zebrafish is increasingly well utilized in alcohol research, particularly in modeling human fetal alcohol spectrum disorders (FASD). FASD results from alcohol reaching the developing fetus intra utero, a completely preventable yet prevalent and devastating life-long disorder. The hope with animal models, including the zebrafish, is to discover the mechanisms underlying this disease, which may aid treatment and diagnosis. In the past, we developed an embryonic alcohol exposure regimen that is aimed at mimicking the milder, and most prevalent, forms of FASD in zebrafish. We have found numerous lasting alterations in behavior, neurochemistry, neuronal markers and glial cell phenotypes in this zebrafish FASD model. Using the same model (2 h long bath immersion of 24 h post-fertilization old zebrafish eggs into 1% vol/vol ethanol), here we conduct a proof of concept analysis of voltage-gated cation channels, investigating potential embryonic alcohol induced changes in L-, T- and N- type Ca++ and the SCN1A Na+ channels using Western blot followed by immunohistochemical analysis of the same channels in the pallium and cerebellum of the zebrafish brain. We report significant reduction of expression in all four channel proteins using both methods. We conclude that reduced voltage-gated cation channel expression induced by short and low dose exposure to alcohol during embryonic development of zebrafish may contribute to the previously demonstrated lasting behavioral and neurobiological changes.

The role of interindividual licking received and dopamine genotype on later-life licking provisioning in female rat offspring.

INTRODUCTION: Rat mothers exhibit natural variations in care that propagate between generations of female offspring. However, there is limited information on genetic variation that could influence this propagation. METHODS: We assessed early-life maternal care received by individual female rat offspring, later-life maternal care provisioning, and dopaminergic activity in the maternal brain in relation to naturally occurring genetic polymorphisms linked to the dopaminergic system. We also conducted a systematic analysis of other genetic variants potentially related to maternal behavior in our Long-Evans rat population. RESULTS: While we did not find a direct relationship between early-life licking received and later-life licking provisioning, this relationship was indirectly affected by dopamine levels in the nucleus accumbens and dependent on variation in the dopamine receptor 2 gene (rs107017253). More specifically, female rat offspring with the A/G genotype showed a positive relationship between average licking received and dopamine levels in the nucleus accumbens of the maternal brain; there was no relationship with female rat offspring with the A/A genotype. The higher dopamine levels in the nucleus accumbens corresponded with higher maternal licking provisioning from postnatal days 2-9. We also discovered and validated several new variants that were predicted by our systematic analysis. CONCLUSION: Our findings suggest that genetic variation influences the relationship between early-life maternal care received and the dopaminergic system of the maternal brain, which can indirectly influence later-life maternal care provisioning.

Effect of MTHFR (rs1801133) and FTO (rs9939609) genetic polymorphisms and obesity in T2DM: a study among Bengalee Hindu caste population of West Bengal, India.

Type 2 diabetes mellitus (T2DM) susceptibility has increased due to the independent risks of genetic polymorphism and obesity as well as combinations of these. Despite recent advancements in T2DM management and diagnosis, the challenges of susceptibility and prognosis still remain. The present work is attempted to understand the association of methylenetetrahydrofolate reductase (MTHFR) (rs1801133) and FTO (rs9939609) genetic polymorphisms and obesity with T2DM among the Bengalee Hindu caste population of West Bengal, India. One hundred and four clinically diagnosed T2DM male patients and 176 healthy males, without family history of T2DM, (control group) of the endogamous linguistic group (Bengalee Hindu caste) participated. Genotyping was performed using the PCR-RFLP method following the isolation of genomic DNA. MTHFR (rs1801133) genetic polymorphism with CT genotype revealed significantly higher risk (OR = 3.44; p = .01) of T2DM compared to the CC genotype. The attenuation of MTHFR-T2DM risk after adjustment for age and waist circumference revealed obesity and age effects in progression of T2DM. T2DM patients also had significantly (p < .05) higher overall obesity, central obesity, and SBP compared to the controls. However, FTO (rs9939609) genetic polymorphism demonstrated no significant (p= .854) effect on T2DM and obesity. The present study identified that MTHFR genetic polymorphism and obesity might be used as screening tools for early prognosis of T2DM.

Lasting alterations induced in glial cell phenotypes by short exposure to alcohol during embryonic development in zebrafish.

Despite the known teratogenic effects of alcohol (ethanol) on the developing human fetus, the prevalence of fetal alcohol spectrum disorder (FASD) is not decreasing. Appropriate treatment for this life-long disease has not been developed, and even diagnostic biomarkers are unavailable. FASD remains a large unmet medical need. Numerous animal models have been developed to mimic FASD and study potential underlying biological mechanisms. However, most of these models focused on neuronal phenotypes. Given that glial cells represent the majority of cells in the vertebrate brain, and given the increasingly appreciated roles they play in a myriad of neuronal functions as well as CNS disorders, we decided to investigate potential embryonic alcohol exposure induced changes in them. Building upon a previously introduced zebrafish model of milder and most prevalent forms of FASD, we investigated the effect of a 2-hour-long exposure to alcohol (1% vol/vol bath concentration) employed at the 24th hour postfertilization stage of development of zebrafish on a number of glial cell-related phenotypes. We studied oligodendrocyte, astrocyte as well as microglia-related phenotypes using immunohistochemistry, lipid, and enzyme activity analyses. We report significant changes in wide-spread glial cell phenotypes induced by embryonic alcohol exposure in the zebrafish brain and conclude that the zebrafish will advance our understanding of the mechanisms of this devastating disorder.

A Novel Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Biomarker-Anti-DSG2-Is Absent in Athletes With Right Ventricular Enlargement.

BACKGROUND: Right ventricular (RV) enlargement is common in endurance athletes. It is usually considered to be physiological, but it is possible that this remodelling is adverse, manifesting as a variant of arrhythmogenic right ventricular cardiomyopathy (ARVC), termed "exercise-induced ARVC." A novel biomarker (anti-desmoglein-2 [anti-DSG2] antibody) has been shown to indicate ARVC with high sensitivity and specificity and may be an immune response to breakdown of RV desmosomes. It is not known if this antibody is present in endurance athletes with RV enlargement but without clinical ARVC. METHODS: Middle-aged, healthy endurance athletes with RV enlargement on cardiac magnetic resonance imaging had serum tested for the presence of the anti-DSG2 antibody. All athletes also underwent Holter monitoring, a signal-averaged electrocardiogram, and an exercise questionnaire. RESULTS: A total of 30 athletes (20 men, 10 women, average age 53 ± 6 years) were enrolled in this study with median RV end-diastolic volume indexes of 117.1 mL/m2 (men) and 103.5 mL/m2 (women). Athletes demonstrated other characteristics of endurance training, including depolarization abnormalities (abnormal signal-averaged electrocardiogram, 19 of 30) and incomplete right bundle branch block (8 of 30). No athlete met criteria for definite or probable ARVC. None of the athletes tested positive for anti-DSG2 antibody. CONCLUSIONS: Among middle-aged endurance athletes with RV enlargement, the anti-DSG2 antibody, a suggested ARVC biomarker, is absent in all and is highly specific in this cohort (95% confidence interval, 88%-100%). Despite significant RV remodelling, these athletes did not express a previously characterized pathologic biomarker known to be sensitive for ARVC. Physiological exercise remodelling and pathologic ARVC remodelling are likely separate processes.

INTRODUCTION: L'augmentation du volume du ventricule droit (VD) est fréquente chez les sportifs d'endurance. On considère habituellement que ce remodelage est physiologique, mais il est possible qu'il soit indésirable, c'est-à-dire qu'il révèle une variante de la cardiomyopathie arythmogène du ventricule droit (CAVD), appelée « CAVD induite par l'exercice ¼. Il a été démontré qu'un nouveau biomarqueur (l'anticorps anti-desmogléine 2 [anti-DSG2]) présente une sensibilité et une spécificité élevées pour dépister la CAVD et qu'il peut être une réponse immunitaire à la dégradation des desmosomes du VD. On ne sait pas si cet anticorps est présent chez les sportifs d'endurance qui ont une augmentation du volume du VD, sans CAVD clinique. MÉTHODES: Les sportifs d'endurance d'âge moyen en bonne santé qui ont une augmentation du volume du VD à l'imagerie cardiaque par résonance magnétique ont subi une épreuve pour vérifier la présence de l'anticorps anti-DSG2 dans le sérum. Tous les athlètes ont également eu une surveillance par la méthode de Holter, un électrocardiogramme à signaux moyennés et un questionnaire sur l'exercice. RÉSULTATS: Nous avons inscrit à cette étude un total de 30 athlètes (20 hommes, 10 femmes, âge moyen de 53 ± 6 ans) dont les indices volumiques télédiastoliques médians du VD des hommes étaient de 117,1 ml/m2 et des femmes, de 103,5 ml/m2. Les athlètes ont démontré d'autres caractéristiques de l'entraînement en endurance, notamment des anomalies de la dépolarisation (électrocardiogramme à signaux moyennés anormal, 19 sur 30) et un bloc de branche droit incomplet (8 sur 30). Aucun athlète n'a répondu aux critères de CAVD définie ou probable. Aucun des athlètes n'a eu de résultats positifs au test de dépistage des anticorps anti-DSG2. CONCLUSIONS: Chez tous les sportifs d'endurance d'âge moyen qui ont une augmentation du volume du VD, l'anticorps anti-DSG2, un biomarqueur proposé pour dépister la CAVD, est absent et est hautement spécifique dans cette cohorte (intervalle de confiance à 95 %, 88 %-100 %). En dépit d'un remodelage important du VD, les athlètes n'ont pas exprimé le biomarqueur pathologique, auparavant caractérisé, connu pour être sensible au dépistage de la CAVD. Le remodelage physiologique induit par l'exercice et le remodelage pathologique associé à la CAVD sont des processus probablement distincts.

An autoantibody profile detects Brugada syndrome and identifies abnormally expressed myocardial proteins.

AIMS: Brugada syndrome (BrS) is characterized by a unique electrocardiogram (ECG) pattern and life-threatening arrhythmias. However, the Type 1 Brugada ECG pattern is often transient, and a genetic cause is only identified in <25% of patients. We sought to identify an additional biomarker for this rare condition. As myocardial inflammation may be present in BrS, we evaluated whether myocardial autoantibodies can be detected in these patients. METHODS AND RESULTS: For antibody (Ab) discovery, normal human ventricular myocardial proteins were solubilized and separated by isoelectric focusing (IEF) and molecular weight on two-dimensional (2D) gels and used to discover Abs by plating with sera from patients with BrS and control subjects. Target proteins were identified by mass spectrometry (MS). Brugada syndrome subjects were defined based on a consensus clinical scoring system. We assessed discovery and validation cohorts by 2D gels, western blots, and ELISA. We performed immunohistochemistry on myocardium from BrS subjects (vs. control). All (3/3) 2D gels exposed to sera from BrS patients demonstrated specific Abs to four proteins, confirmed by MS to be α-cardiac actin, α-skeletal actin, keratin, and connexin-43, vs. 0/8 control subjects. All (18/18) BrS subjects from our validation cohorts demonstrated the same Abs, confirmed by western blots, vs. 0/24 additional controls. ELISA optical densities for all Abs were elevated in all BrS subjects compared to controls. In myocardium obtained from BrS subjects, each protein, as well as SCN5A, demonstrated abnormal protein expression in aggregates. CONCLUSION: A biomarker profile of autoantibodies against four cardiac proteins, namely α-cardiac actin, α-skeletal actin, keratin, and connexin-43, can be identified from sera of BrS patients and is highly sensitive and specific, irrespective of genetic cause for BrS. The four involved proteins, along with the SCN5A-encoded Nav1.5 alpha subunit are expressed abnormally in the myocardium of patients with BrS.

Folic acid content of diet during pregnancy determines post-birth re-set of metabolism in Wistar rat dams.

Maternal metabolism begins to return to homeostasis (re-set) following birth and is accelerated by lactation. Delay in metabolic re-set may contribute to postpartum weight retention and later-life metabolic consequences. Folic acid (FA) is essential during pregnancy but inadequate intakes may alter 1-carbon metabolism, consequently affecting energy homeostatic systems. Our objectives were to examine the effects of FA content 1)below and 2)above requirements during pregnancy on the re-set of body weight, markers of hepatic 1-carbon metabolism and central and peripheral energy metabolic pathways in Wistar rat mothers early post-weaning (PW) compared to pregnant controls. Pregnant Wistar rats were fed an AIN-93G diet with FA at 0X, 1X (control, 2 mg FA/kg) or a range above requirements at 2.5X, 5X or 10X recommended levels then the control diet during lactation up to 1 week PW. Dams fed below (0X) or above (5X and 10X) FA requirements had delayed weight-loss from weaning up to 1 week PW, higher plasma insulin and HOMA-IR and changes in glucose and lipid metabolism-regulating genes in muscle, but not liver or adipose tissue compared to controls. Expression of folate-related genes in liver were lower in high FA fed dams. Central food intake neurons were not affected by FA diets. In conclusion, intakes of FA below (0X) or above (5X, 10X) requirements during pregnancy delayed weight-loss, dysregulated 1-carbon pathways in the liver and peripheral energy metabolic pathways in the Wistar rat mother up to 4 weeks after dietary exposure; potentially programming long-term negative metabolic effects and that of her future offspring.

Maternal Choline Intake Programs Hypothalamic Energy Regulation and Later-Life Phenotype of Male Wistar Rat Offspring.

SCOPE: High-folic-acid diets during pregnancy result in obesity in the offspring, associated with altered DNA-methylation of hypothalamic food intake neurons. Like folic acid, the methyl-donor choline modulates foetal brain development, but its long-term programing effects on energy regulation remain undefined. This study aims to describe the effect of choline intake during pregnancy on offspring phenotype and hypothalamic energy-regulatory mechanisms. METHODS AND RESULTS: Wistar rat dams are fed an AIN-93G diet with recommended choline (RC, 1 g kg-1 diet), low choline (LC, 0.5-fold), or high choline (HC, 2.5-fold) during pregnancy. Male pups are terminated at birth and 17 weeks post-weaning. Brain 1-carbon metabolites, body weight, food intake, energy expenditure, plasma hormones, and protein expression of hypothalamic neuropeptides are measured. HC pups have higher expression of the orexigenic neuropeptide-Y neurons at birth, consistent with higher cumulative food intake and body weight gain post-weaning compared to RC and LC offspring. LC pups have lower leptin receptor expression at birth and lower energy expenditure and activity during adulthood. CONCLUSION: Choline content of diets that are consumed by rats during pregnancy affects the later-life phenotype of offspring, associated with altered in utero programing of hypothalamic food intake regulation.

Developmental stage-dependent deficits induced by embryonic ethanol exposure in zebrafish: A neurochemical analysis.

FASD results from the developing fetus being exposed to alcohol, and is characterized by morphological, behavioural and cognitive deficits. However, the expression, severity and age of onset of these symptoms has been found to show variation. This variation may partly be due to the developmental stage at which alcohol reached the developing fetus. Previously, alcohol was shown to lead to significant concentration dependent behavioural as well as neurochemical changes detected in adult zebrafish when this substance was administered at 24 h post-fertilization (hpf) for 2 h. This alcohol exposure method arguably mimicked the milder, and more prevalent, forms of human FASD. However, whether the observed changes depended upon the developmental stage, i.e., the timing, of alcohol exposure has not been systematically analyzed. Here, we employ the same alcohol dosing regimen, where zebrafish eggs are immersed into 0% or 1% (vol/vol) alcohol for 2 h, but we perform the immersion at 5, 10, 16, 24, 36, or 48 hpf. We previously developed a sensitive HPLC method to quantify neurochemicals, and found levels of dopamine, serotonin and their metabolites DOPAC and 5-HIAA to be affected by embryonic alcohol treatment. Here, using the same method, we compare whole-brain levels of these neurochemicals in the embryonic alcohol exposed and control zebrafish at their age of 30 days post-fertilization (dpf). Consistent with previous reports, we found significant reduction of levels of dopamine, serotonin and their metabolites in the fish exposed to alcohol at 24 hpf. However, we also found significant dependency on the developmental stage at which alcohol was administered with particularly robust impairments when the exposure was at the early or middle of the developmental periods probed. Our results now demonstrate that one can detect functional abnormalities in the zebrafish brain induced by embryonic alcohol as early as 30 dpf and that the neurochemical deficits are dependent upon the developmental stage at which alcohol is administered.

Gestational folic acid content alters the development and function of hypothalamic food intake regulating neurons in Wistar rat offspring post-weaning.

Background: Folic acid plays an important role in early brain development of offspring, including proliferation and differentiation of neural stem cells known to impact the function of food intake regulatory pathways. Excess (10-fold) intakes of folic acid in the gestational diet have been linked to increased food intake and obesity in male rat offspring post-weaning.Objective: The present study examined the effects of folic acid content in gestational diets on the development and function of two hypothalamic neuronal populations, neuropeptide Y (NPY) and pro-opiomelanocortin (POMC), within food intake regulatory pathways of male Wistar rat offspring at birth and post-weaning.Results: Folic acid fed at 5.0-fold above recommended levels (5RF) to Wistar dams during pregnancy increased the number of mature NPY-positive neurons in the hypothalamus of male offspring, compared to control (RF), 0RF, 2.5RF, and 10RF at birth. Folic acid content had no effect on expression and maturation of POMC-positive neurons. Body weight and food intake were higher in all treatment groups (2.5-, 5.0-, and 10.0-fold folic acid) from birth to 9 weeks post-weaning compared to control. Increased body weight and food intake at 9-weeks post-weaning were accompanied by a reduced activation of POMC neurons in the arcuate nucleus (ARC).Conclusion: Gestational folic acid content modulates expression of mature hypothalamic NPY-positive neurons at birth and activation of POMC-positive neurons at 9-weeks post-weaning in the ARC of male Wistar rat offspring which may contribute to higher body weight and food intake later in life.

Acute decrease in plasma testosterone and appetite after either glucose or protein beverages in adolescent males.

OBJECTIVE: Chronic testosterone blood concentrations associate with food intake (FI), but acute effects of testosterone on appetite and effect of protein and glucose consumption on testosterone response have had little examination. METHODS: In a randomized, crossover study, twenty-three adolescent (12-18 years old) males were given beverages containing either: (a) whey protein (1 g/kg body weight), (b) glucose (1 g/kg body weight) or (c) a calorie-free control (C). Plasma testosterone, luteinizing hormone (LH), GLP-1 (active), ghrelin (acylated), glucose, insulin and subjective appetite were measured prior (0) and at 20, 35 and 65 minutes after the consumption of the beverage. FI at an ad libitum pizza meal was assessed at 85 minutes. RESULTS: Testosterone decreased acutely to 20 minutes after both protein and glucose with the decrease continuing after protein but not glucose to 65 minutes (P = 0.0382). LH was also decreased by both protein and glucose, but glucose had no effect at 20 minutes in contrast to protein (P < 0.001). Plasma testosterone concentration correlated positively with LH (r = 0.58762, P < 0.0001) and negatively with GLP-1 (r = -0.50656, P = 0.0003). No associations with appetite, ghrelin or glycaemic markers were found. Food intake was not affected by treatments. CONCLUSION: Protein or glucose ingestion results in acute decreases in both plasma testosterone and LH in adolescent males. The physiological significance of this response remains to be determined as no support for testosterone's role in acute regulation of food intake was found.

Inter-individual maternal care received and genotype interactions affect dopaminergic phenotypes in female rat offspring.

Rat mothers exhibit natural variations in care and can shape offspring adult behaviour and their maternal care by affecting the dopaminergic system. We explored whether genotype and gene × environment interactions are involved in these processes in nulliparous female offspring. We assessed maternal licking/grooming toward individual female pups during the first week postpartum and dopamine-related behaviour of the offspring in adulthood. Behaviours explored included strategy shifting, impulsive action and sucrose preference. Single nucleotide polymorphisms in the dopamine receptor 2, dopamine transporter and catechol-O-methyltransferase genes were examined in relation to offspring behaviour and baseline dopamine turnover in select brain regions. Dopamine receptor 2 (RS107017253) variation moderated, or interacted with, the relationship between early-life licking received and behaviour. Specifically, offspring with the A/A genotype showed a significant correlation between early-life licking received and behaviour. Offspring with the A/G and G/G genotypes did not show this relationship. Dopamine transporter gene variation affected offspring behaviour regardless of early-life licking received. Our findings suggest that genotype can directly affect dopamine-related behaviours and alter the sensitivity of offspring to the maternal environment. This could be informative on how maternal care is transmitted between generations of female offspring.

An autoantibody identifies arrhythmogenic right ventricular cardiomyopathy and participates in its pathogenesis.

Aims: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by right ventricular myocardial replacement and life-threatening ventricular arrhythmias. Desmosomal gene mutations are sometimes identified, but clinical and genetic diagnosis remains challenging. Desmosomal skin disorders can be caused by desmosomal gene mutations or autoantibodies. We sought to determine if anti-desmosome antibodies are present in subjects with ARVC. Methods and results: We evaluated ARVC subjects and controls for antibodies to cardiac desmosomal cadherin proteins. Desmoglein-2 (DSG2), desmocollin-2, and N-cadherin proteins on western blots were exposed to sera, in primary and validation cohorts of subjects and controls, as well as the naturally occurring Boxer dog model of ARVC. We identified anti-DSG2 antibodies in 12/12 and 25/25 definite ARVC cohorts and 7/8 borderline subjects. Antibody was absent in 11/12, faint in 1/12, and absent in 20/20 of two control cohorts. Anti-DSG2 antibodies were present in 10/10 Boxer dogs with ARVC, and absent in 18/18 without. In humans, the level of anti-DSG2 antibodies correlated with the burden of premature ventricular contractions (r = 0.70), and antibodies caused gap junction dysfunction, a common feature of ARVC, in vitro. Anti-DSG2 antibodies were present in ARVC subjects regardless of whether an underlying mutation was identified, or which mutation was present. A disease-specific DSG2 epitope was identified. Conclusion: Anti-DSG2 antibodies are a sensitive and specific biomarker for ARVC. The development of autoimmunity as a result of target-related mutations is unique. Anti-DSG2 antibodies likely explain the cardiac inflammation that is frequently identified in ARVC and may represent a new therapeutic target.

Short exposure to low concentrations of alcohol during embryonic development has only subtle and strain- dependent effect on the levels of five amino acid neurotransmitters in zebrafish.

The zebrafish has been successfully employed to model and study the effects of embryonic alcohol exposure. Short exposure to low alcohol concentrations during embryonic development has been shown to significantly disrupt social behavior as well as the dopaminergic and serotoninergic systems in zebrafish. However, analysis of potential effects of embryonic alcohol exposure on other amino acid neurotransmitter systems has not been performed. Here we analyzed neurochemicals obtained from adult AB and TU strain zebrafish that were immersed in 0.00% (control), 0.25%, 0.50%, 0.75% or 1.00% alcohol solution (vol/vol%) at 24 h post-fertilization for 2 h. From whole brain extracts, we quantified glutamate, aspartate, glycine, taurine and GABA levels using high performance liquid chromatography (HPLC). We found embryonic alcohol exposure not to have any significant effect on the levels of glutamate, aspartate, glycine and GABA in both AB and TU zebrafish. AB zebrafish showed a significant elevation of taurine levels, but only in the highest alcohol dose group compared to control. These results, albeit mainly negative, together with prior findings suggest that behavioral abnormalities resulting from embryonic alcohol exposure described before for AB zebrafish may primarily be due to altered dopaminergic and serotoninergic mechanisms. Furthermore, a Principal Component Analysis conducted with all neurochemicals tested in this and in our prior study, found a strain-dependent correlation structure response to embryonic alcohol treatment, confirming that embryonic alcohol effects may be genotype dependent.