CRH Expression Research Articles

CRH expression in follicular fluid patients with endometriosis

CRH expression in follicular fluid patients with endometriosis

Methamphetamine Induces TET1- and TET3-Dependent DNA Hydroxymethylation of Crh and Avp Genes in the Rat Nucleus Accumbens

Methamphetamine (METH) addiction is a biopsychosocial disorder that is accompanied by multiple relapses even after prolonged abstinence, suggesting the possibilities of long-lasting maladaptive epigenetic changes in the brain. Here, we show that METH administration produced time-dependent increases in the expression of corticotropin-releasing hormone (Crh/Crf), arginine vasopressin (Avp), and cocaine- and amphetamine-regulated transcript prepropeptide (Cartpt) mRNAs in the rat nucleus accumbens (NAc). Chromatin immunoprecipitation (ChIP) assays revealed that METH increased the abundance of phosphorylated CREB (pCREB) at the promoter of Cartpt but not at Avp or Crh DNA sequences. In contrast, METH produced DNA hypomethylation at sites near the Crh transcription start site (TSS) and at intragenic Avp sequences. METH also increased DNA hydroxymethylation at the Crh TSS and at intragenic Avp sites. In addition, METH increased the protein expression of ten-eleven-translocation enzymes that catalyze DNA hydroxymethylation. Importantly, METH increased TET1 binding at the Crh promoter and increased TET3 binding at Avp intragenic regions. We further tested the role of TET enzymes in METH-induced changes in gene expression by using the TET inhibitor, 1,5-isoquinolinediol (IQD), and found that IQD blocked METH-induced increases in Crh and Avp mRNA expression. Together, these results indicate that METH produced changes in neuropeptide transcription by both activation of the cAMP/CREB pathway and stimulation of TET-dependent DNA hydroxymethylation. These results provide molecular evidence for epigenetic controls of METH-induced changes in the expression of neuropeptides.

Sex differences in the effect of chronic mild stress on mouse prefrontal cortical BDNF levels: A role of major ovarian hormones

Depression induced by stress is affected by sex, age and hormonal status of the animal and also by duration and type of the stressors. Moreover, higher prevalence of depression and comorbidities in women than men implies the need to include the sex variable in studies on animal models of depression. The present study was therefore initiated to evaluate the effect of sex and ovarian hormones on depression-like phenotypes in mice exposed to a 21-day Chronic Variable Mild Stress (CVMS) paradigm. Adult male, intact female and, ovariectomized (OVX) female mice exposed to CVMS displayed despair behavior, a depression-like phenotype, in all the groups. However, intact females alone, but not males and OVX females, showed anhedonia, another depression-like phenotype. At the molecular level, the expression of Brain-Derived Neurotrophic Factor (BDNF), a neuropeptide associated with depression, and few other stress-specific genes CRH, NR3C1, CART, and NPY were measured in the Prefrontal Cortex (PFC) region of the reward circuitry. There was a significant decrease in the BDNF protein expression along with an increase in the mRNA expression of CRH, NR3C1, CART, and NPY in intact females, but not in the other two groups of mice. OVX females resembled males in behavioral and molecular responses to CVMS. 17β-Estradiol (E2) administration, not Progesterone (P4), to OVX female stress mice, mitigated despair and enhanced hedonic capacity with an increased expression of BDNF in PFC. This study strengthens the evidence for the beneficial effects of E2 administration in stress condition.

Expression of Inflammatory and Neurogenic Mediators in Adenomyosis.

Adenomyosis is a uterine disorder characterized by dysmenorrhea, dyspareunia, abnormal uterine bleeding, and infertility. Pathogenesis indicates that endometrial cells invade and proliferate within myometrium, and inflammatory mediators participate to the intense painful symptoms. The aim of the present study was to investigate the messenger RNA (mRNA) and protein expression of inflammatory (interleukin 1β [IL-1β], corticotropin-releasing hormone [CRH], urocortin [Ucn]) and neurogenic (nerve growth factors [NGFs], synaptophysin [SYN], microtubule-associated protein 2 [MAP2]) factors in adenomyotic nodules. This prospective study enrolled 16 women, 8 women with nodular adenomyosis and 8 control women undergoing to hysterectomy. Specimens from adenomyotic nodules and eutopic endometrium were collected after surgery. Endometrial tissue was also obtained from the control group and also used for preparing primary culture of human endometrial stromal cells (HESCs). Messenger RNA expression of inflammatory mediators (IL-1β, CRH, and Ucn) and neurogenic factors (NGF, SYN, and MAP2) was analyzed by real-time polymerase chain reaction. The in vitro effects of CRH/Ucn on NGF or SYN mRNA expression were also investigated. Adenomyotic nodules highly expressed IL-1β, CRH, and Ucn mRNAs, as well as NGF, SYN, and MAP2 mRNAs ( P < .001 vs eutopic endometrium and control). Endometrium of women with adenomyosis showed high expression of IL-1β and CRH ( P < .001 vs control). Protein expression of CRH, NGF, and SYN in adenomyotic nodules was confirmed by immunohistochemical and immunofluorescence analyses. Urocortin increased NGF mRNA expression in cultured HESCs. The present study showed that adenomyotic nodules are novel site of expression of inflammatory and neurogenic factors, probably involved in the pathogenesis of adenomyosis.

Late-Onset Cognitive Impairments after Early-Life Stress Are Shaped by Inherited Differences in Stress Reactivity.

Early-life stress (ELS) has been associated with lasting cognitive impairments and with an increased risk for affective disorders. A dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis, the body’s main stress response system, is critically involved in mediating these long-term consequences of adverse early-life experience. It remains unclear to what extent an inherited predisposition for HPA axis sensitivity or resilience influences the relationship between ELS and cognitive impairments, and which neuroendocrine and molecular mechanisms may be involved. To investigate this, we exposed animals of the stress reactivity mouse model, consisting of three independent lines selectively bred for high (HR), intermediate (IR), or low (LR) HPA axis reactivity to a stressor, to ELS and assessed their cognitive performance, neuroendocrine function and hippocampal gene expression in early and in late adulthood. Our results show that HR animals that were exposed to ELS exhibited an HPA axis hyper-reactivity in early and late adulthood, associated with cognitive impairments in hippocampus-dependent tasks, as well as molecular changes in transcript levels involved in the regulation of HPA axis activity (Crh) and in neurotrophic action (Bdnf). In contrast, LR animals showed intact cognitive function across adulthood, with no change in stress reactivity. Intriguingly, LR animals that were exposed to ELS even showed significant signs of enhanced cognitive performance in late adulthood, which may be related to late-onset changes observed in the expression of Crh and Crhr1 in the dorsal hippocampus of these animals. Collectively, our findings demonstrate that the lasting consequences of ELS at the level of cognition differ as a function of inherited predispositions and suggest that an innate tendency for low stress reactivity may be protective against late-onset cognitive impairments after ELS.

The role of glucocorticoids and corticotropin-releasing hormone regulation on anxiety symptoms and response to treatment.

The stress response has been linked to the expression of anxiety and depression, but the mechanisms for these connections are under continued consideration. The activation and expression of glucocorticoids and CRH are variable and may hold important clues to individual experiences of mood disorders. This paper explores the interactions of glucocorticoids and CRH in the presentation of anxiety and depressive disorders in an effort to better describe their differing roles in each of these clinical presentations. In addition, it focuses on ways in which extra-hypothalamic glucocorticoids and CRH, often overlooked, may play important roles in the presentation of clinical disorders.

Life-cycle exposure to BDE-47 results in thyroid endocrine disruption to adults and offsprings of zebrafish (Danio rerio).

2,2,4',4'-Tetrabromodi-phenyl ether (BDE-47) is predominantly concentrated in humans and wildlife and disturbs thyroid hormone homeostasis. The purpose of this study was to characterize the thyroid endocrine disruption induced by life-cycle exposure to BDE-47 in adults and offspring of zebrafish (Danio rerio). We exposed zebrafish embryos at the blastula stage to different concentrations of BDE-47 (1, 5, and 10μg/L). Exposure duration was 180days until fish reached adulthood. In F0 larvae, exposure decreased survival and increased malformations at 4 dpf. Thyroid hormone concentrations did not differ significantly between the F0 larvae and controls. All exposures significantly up-regulated expression of tshß, pa8, ugt1 and tg and down-regulated ttr. Significant up-regulation of dio2 and crh was observed in the 10μg/L BDE-47 group. There was no significant difference in the growth and somatic index between F0 adults and controls. BDE-47 (10μg/L) significantly decreased whole-body content of thyroxine (T4) but significantly increased triiodothyronine (T3) in both sexes. All exposures up-regulated expression of crh, tshß, pa8, ugt1 and tg and down-regulated ttr. Exposure to 10μg/L BDE-47 significantly up-regulated dio2 and ugt1 in both sexes. BDE-47 exposure (5 and 10μg/L) significantly increased the activity of pethoxy-resorufin-O-deethylase and UDP-glucuronosyl transferase. BDE-47 (10μg/L) significantly increased activity of ethoxy- and methoxy-resorufin-O-deethylase. In F1 offspring without continued BDE-47 (10μg/L) treatment, T4 significantly decreased and T3 increased. T4 was further decreased and T3 was further increased with continued BDE-47 treatment. Continued BDE-47 exposure decreased hatching and increased malformation compared with those without BDE-47 exposure. Expression of crh, tshß, dio2, pa8, ugt1 and tg was significantly up-regulated without BDE-47 exposure and with continued exposure. With continued BDE-47 exposure, dio1 was significantly up-regulated and ttr was significantly down-regulated. All the genes showed clear differences between continued exposure to 10μg/L BDE-47 and without BDE-47 exposure. These results suggest that parental exposure to BDE-47 results in thyroid endocrine disruption in adults and offspring.

Loss of hypothalamic corticotropin-releasing hormone markedly reduces anxiety behaviors in mice.

A long-standing paradigm posits that hypothalamic corticotropin-releasing hormone (CRH) regulates neuroendocrine functions such as adrenal glucocorticoid release, while extra-hypothalamic CRH plays a key role in stressor-triggered behaviors. Here we report that hypothalamus-specific Crh knockout mice (Sim1CrhKO mice, created by crossing Crhflox with Sim1Cre mice) have absent Crh mRNA and peptide mainly in the paraventricular nucleus of the hypothalamus (PVH) but preserved Crh expression in other brain regions including amygdala and cerebral cortex. As expected, Sim1CrhKO mice exhibit adrenal atrophy as well as decreased basal, diurnal and stressor-stimulated plasma corticosterone secretion and basal plasma ACTH, but surprisingly, have a profound anxiolytic phenotype when evaluated using multiple stressors including open field, elevated plus maze, holeboard, light-dark box, and novel object recognition task. Restoring plasma corticosterone did not reverse the anxiolytic phenotype of Sim1CrhKO mice. Crh-Cre driver mice revealed that PVHCrh fibers project abundantly to cingulate cortex and the nucleus accumbens shell, and moderately to medial amygdala, locus coeruleus, and solitary tract, consistent with the existence of PVHCrh-dependent behavioral pathways. Although previous, nonselective attenuation of CRH production or action, genetically in mice and pharmacologically in humans, respectively, has not produced the anticipated anxiolytic effects, our data show that targeted interference specifically with hypothalamic Crh expression results in anxiolysis. Our data identify neurons that express both Sim1 and Crh as a cellular entry point into the study of CRH-mediated, anxiety-like behaviors and their therapeutic attenuation.

Ewes With Divergent Cortisol Responses to ACTH Exhibit Functional Differences in the Hypothalamo-Pituitary-Adrenal (HPA) Axis.

Within any population, the cortisol response to ACTH covers a considerable range. High responders (HRs) exhibit a greater cortisol secretory response to stress or ACTH, compared with individuals classified as low cortisol responders (LRs). We administered ACTH (0.2 μg/kg, iv) to 160 female sheep and selected subpopulations of animals as LR and HR. In the present study, we aimed to characterize the hypothalamo-pituitary-adrenal axis in HR and LR and to identify factors that underlie the differing cortisol responses to ACTH. Hypothalami, pituitaries, and adrenals were collected from nonstressed HR and LR ewes. Expression of genes for CRH, arginine vasopressin (AVP), oxytocin, glucocorticoid receptor, and mineralocorticoid receptor were measured by in situ hybridization in the paraventricular nucleus of the hypothalamus, and proopiomelanocortin (POMC) gene expression was measured in the anterior pituitary. Expression of CRH, AVP, and POMC was higher in HR, with no differences in either glucocorticoid receptor or mineralocorticoid receptor expression. Oxytocin expression was greater in LR. In the adrenal gland, real-time PCR analysis indicated that expression of the ACTH receptor and a range of steroidogenic enzymes was similar in HR and LR. Adrenal weights, the cortex to medulla ratio and adrenal cortisol content were also similar in LR and HR. In conclusion, LR and HR display innate differences in the steady-state expression of CRH, AVP, oxytocin, and POMC, indicating that selection for cortisol responsiveness identifies distinct subpopulations that exhibit innate differences in the gene expression/function of hypothalamo-pituitary-adrenal axis markers.

Loss of Mrap2 is associated with Sim1 deficiency and increased circulating cholesterol.

Melanocortin receptor accessory protein 2 (MRAP2) is a transmembrane accessory protein predominantly expressed in the brain. Both global and brain-specific deletion of Mrap2 in mice results in severe obesity. Loss-of-function MRAP2 mutations have also been associated with obesity in humans. Although MRAP2 has been shown to interact with MC4R, a G protein-coupled receptor with an established role in energy homeostasis, appetite regulation and lipid metabolism, the mechanisms through which loss of MRAP2 causes obesity remains uncertain. In this study, we used two independently derived lines of Mrap2 deficient mice (Mrap2tm1a/tm1a) to further study the role of Mrap2 in the regulation of energy balance and peripheral lipid metabolism. Mrap2tm1a/tm1a mice have a significant increase in body weight, with increased fat and lean mass, but without detectable changes in food intake or energy expenditure. Transcriptomic analysis showed significantly decreased expression of Sim1, Trh, Oxt and Crh within the hypothalamic paraventricular nucleus of Mrap2tm1a/tm1a mice. Circulating levels of both high-density lipoprotein and low-density lipoprotein were significantly increased in Mrap2 deficient mice. Taken together, these data corroborate the role of MRAP2 in metabolic regulation and indicate that, at least in part, this may be due to defective central melanocortin signalling.

The Environmental Pollutant Tributyltin Chloride Disrupts the Hypothalamic-Pituitary-Adrenal Axis at Different Levels in Female Rats.

Tributyltin chloride (TBT) is an environmental contaminant that is used as a biocide in antifouling paints. TBT has been shown to induce endocrine-disrupting effects. However, studies evaluating the effects of TBT on the hypothalamus-pituitary-adrenal (HPA) axis are especially rare. The current study demonstrates that exposure to TBT is critically responsible for the improper function of the mammalian HPA axis as well as the development of abnormal morphophysiology in the pituitary and adrenal glands. Female rats were treated with TBT, and their HPA axis morphophysiology was assessed. High CRH and low ACTH expression and high plasma corticosterone levels were detected in TBT rats. In addition, TBT leads to an increased in the inducible nitric oxide synthase protein expression in the hypothalamus of TBT rats. Morphophysiological abnormalities, including increases in inflammation, a disrupted cellular redox balance, apoptosis, and collagen deposition in the pituitary and adrenal glands, were observed in TBT rats. Increases in adiposity and peroxisome proliferator-activated receptor-γ protein expression in the adrenal gland were observed in TBT rats. Together, these data provide in vivo evidence that TBT leads to functional dissociation between CRH, ACTH, and costicosterone, which could be associated an inflammation and increased of inducible nitric oxide synthase expression in hypothalamus. Thus, TBT exerts toxic effects at different levels on the HPA axis function.

Involvement of the Hippocampus in Binge Ethanol-Induced Spleen Atrophy in Adolescent Rats.

Ethanol (EtOH) affects the immune system. Binge drinking of hard liquor initiates a stress response. This form of drinking is popular during adolescence, which involves maturation of the immune system. The spleen is a key immune organ, and spleen atrophy is associated with immunosuppression. While the hypothalamic-pituitary-adrenal (HPA) axis plays a key role in the initial stress response, the hippocampus may be involved in stress beyond the HPA axis. Blood ethanol concentration (BEC), blood endotoxin levels, and plasma corticosterone levels were measured following binge EtOH treatment. Absolute and relative spleen sizes were analyzed, and stress-related gene expression was compared in the hypothalamus and hippocampus. Polymerase chain reaction array was performed to analyze the expression profile of EtOH metabolism and immune regulation-related genes in the spleen. Relationships among variables were analyzed using the Pearson correlation. At 24hours following a 3-day EtOH treatment, no significant difference in BEC was detected between EtOH-treated and control rats. Average plasma endotoxin levels in EtOH-treated animals were significantly higher than in controls, and spleen size was significantly lower. Spleen size did not correlate with plasma endotoxin levels; however, it did significantly negatively correlate with plasma corticosterone levels. Spleen size significantly negatively correlated with hippocampal CRH expression and significantly positively correlated with hippocampal MR expression. No correlation was observed in the hypothalamus. Significantly higher hippocampal CRH and significantly lower MR expression was seen in low spleen/body weight (sp-wt) ratio rats. No gene was found to decrease expression ≥1.5-fold (p<0.05) in the spleen of high sp-wt group, whereas expression of several genes, including Gabra1, Gabra5, Ifnb1, Irf9, Il12b, and Cx3cr1, decreased significantly in the low sp-wt group. Our findings suggest that binge EtOH exposure causes lower spleen size in adolescents and that the hippocampus and stress may be associated with alterations in spleen structure and gene expression.

Environmental enrichment imparts disease-modifying and transgenerational effects on genetically-determined epilepsy and anxiety

IntroductionThe absence epilepsies are presumed to be caused by genetic factors, but the influence of environmental exposures on epilepsy development and severity, and whether this influence is transmitted to subsequent generations, is not well known. We assessed the effects of environmental enrichment on epilepsy and anxiety outcomes in multiple generations of GAERS – a genetic rat model of absence epilepsy that manifests comorbid elevated anxiety-like behaviour. MethodsGAERS were exposed to environmental enrichment or standard housing beginning either prior to, or after epilepsy onset, and underwent EEG recordings and anxiety testing. Then, we exposed male GAERS to early enrichment or standard housing and generated F1 progeny, which also underwent EEG recordings. Hippocampal CRH mRNA expression and DNA methylation were assessed using RT-PCR and pyrosequencing, respectively. ResultsEarly environmental enrichment delayed the onset of epilepsy in GAERS, and resulted in fewer seizures in adulthood, compared with standard housed GAERS. Enrichment also reduced the frequency of seizures when initiated in adulthood. Anxiety levels were reduced by enrichment, and these anti-epileptogenic and anxiolytic effects were heritable into the next generation. We also found reduced expression of CRH mRNA in GAERS exposed to enrichment, but this was not due to changes in DNA methylation. ConclusionsEnvironmental enrichment produces disease-modifying effects on genetically determined absence epilepsy and anxiety, and these beneficial effects are transferable to the subsequent generation. Reduced CRH expression was associated with these phenotypic improvements. Environmental stimulation holds promise as a naturalistic therapy for genetically determined epilepsy which may benefit subsequent generations.

Temperature dependence of the control of energy homeostasis requires CART signaling

Cocaine- and amphetamine-regulated transcript (CART) is a key neuropeptide with predominant expression in the hypothalamus central to the regulation of diverse biological processes, including food intake and energy expenditure. While there is considerable information on CART's role in the control of feeding, little is known about its thermoregulatory potential. Here we show the consequences of lack of CART signaling on major parameters of energy homeostasis in CART−/− mice under standard ambient housing (RT, 22°C), which is considered a mild cold exposure for mice, and thermoneutral conditions (TN, 30°C). WT mice kept at RT showed an increase in food intake, energy expenditure, BAT UCP-1 expression, and physical activity compared with TN condition, reflecting the augmented energy demand for thermogenesis at RT. On the molecular level, RT housing led to upregulated mRNA expression of TH, CRH, and TRH at the PVN, while NPY, AgRP and CART mRNA levels in the Arc were downregulated. CART−/− mice displayed elevated adiposity and diminished lean mass across both RT and TN. At RT, CART−/− mice showed unchanged food consumption yet greater body weight gain. In addition, an increase in energy expenditure and heightened BAT thermogenesis marked by UCP-1 protein expression was observed in the CART−/− mice. In contrast, TN-housed CART−/− mice exhibited lower weight gain than WT mice accompanied with pronounced reduction in basal feeding. These findings were correlated with reduced BAT temperature, but unchanged energy expenditure and UCP-1 levels. Interestingly, the respiratory exchange ratio for CART−/− mice, which shifted from lower at RT to higher at TN with respect to WT controls, indicates a transition of relative fuel source preference from fat to carbohydrate in the absence of CART signaling. Taken together, these results demonstrate that CART is a critical regulator of energy expenditure, energy partitioning and utilization dependent on the thermal environment.

Identification of a novel interaction between corticotropin releasing hormone (Crh) and macroautophagy.

In inflammatory bowel disease (IBD), compromised restitution of the epithelial barrier contributes to disease severity. Owing to the complexity in the pathogenesis of IBD, a variety of factors have been implicated in its progress. In this study, we report a functional interaction between macroautophagy and Corticotropin Releasing Hormone (Crh) in the gut. For this purpose we used DSS colitis model on Crh −/− or wild-type (wt) with pharmacological inhibition of autophagy. We uncovered sustained basal autophagy in the gut of Crh −/− mice, which persisted over the course of DSS administration. Autophagy inhibition resulted in partial rescue of Crh −/− mice, while it increased the expression of Crh in the wt gut. Similarly, Crh deficiency was associated with sustained activation of base line autophagy. In vitro models of amino acid deprivation- and LPS-induced autophagy confirmed the in vivo findings. Our results indicate a novel role for Crh in the intestinal epithelium that involves regulation of autophagy, while suggesting the complementary action of the two pathways. These data suggest the intriguing possibility that targeting Crh stimulation in the intestine may provide a novel therapeutic approach to support the integrity of the epithelial barrier and to protect from chronic colitis.

Exposure to aflatoxin B1 in late gestation alters protein kinase C and apoptotic protein expression in murine placenta.

Mycotoxins are chemicals with diverse toxicities that are produced by fungi. Aflatoxin B1 is commonly found in plant food, and is generally regarded as one of the most toxic mycotoxins. In the present study, pregnant ICR mice were given p.o. daily doses of aflatoxin B1 at 0, 0.05, 0.5, 5mg/kg for 4days (from E13.5 to E16.5). Compared to the control group, time of delivery was shortened and low birth weight was induced in mice treated with 0.5 and 5mg aflatoxin B1/kg, respectively. Placental tissue isolated from pregnant mice at E17.5 showed that the mRNA expression of crh was increased in aflatoxin-treated groups. This upregulation might signify premature delivery. Further analysis indicated that Pkc proteins were activated and Bcl-2 was reduced in the placental tissue of the aflatoxin-treated groups. Reduction of the anti-apoptotic proteins, on the other hand, might affect the morphorgenesis and maintenance of the placenta.

Pregnancy-induced adaptations of the central circadian clock and maternal glucocorticoids.

Maternal physiological adaptations, such as changes to the hypothalamic-pituitary-adrenal (HPA) axis, are central to pregnancy success. Circadian variation of the HPA axis is dependent on clock gene rhythms in the hypothalamus, but it is not known whether pregnancy-induced changes in maternal glucocorticoid levels are mediated via this central clock. We hypothesized that hypothalamic expression of clock genes changes across mouse pregnancy and this is linked to altered HPA activity. The anterior hypothalamus and maternal plasma were collected from C57Bl/6J mice prior to pregnancy and on days 6, 10, 14 and 18 of gestation (term=d19), across a 24-h period (0800, 1200, 1600, 2000, 0000, 0400 h). Hypothalamic expression of clock genes and Crh was determined by qPCR, plasma ACTH concentration measured by Milliplex assay and plasma corticosterone concentration by LC-MS/MS. Expression of all clock genes varied markedly across gestation, most notably at mid-gestation when levels of each gene were elevated. The pregnancy-induced increase in maternal corticosterone levels (by up to 14-fold on day 14) was not accompanied by a parallel shift in plasma ACTH (28% lower on day 14 compared with non-pregnant levels). Moreover, while circadian rhythmicity in corticosterone was maintained up to day 14 of gestation, this was effectively lost by day 18. Overall, our data show that the central circadian clock undergoes marked adaptations throughout mouse pregnancy, changes that are likely to contribute to maternal physiological adaptations. Importantly, however, neither hypothalamic clock genes nor plasma ACTH levels appear to drive the marked increase in maternal corticosterone after mid-gestation.

HPA Axis Gene Expression and DNA Methylation Profiles in Rats Exposed to Early Life Stress, Adult Voluntary Ethanol Drinking and Single Housing.

The neurobiological basis of early life stress (ELS) impact on vulnerability to alcohol use disorder is not fully understood. The effect of ELS, adult ethanol consumption and single housing, on expression of stress and DNA methylation regulatory genes as well as blood corticosterone levels was investigated in the hypothalamus and pituitary of adult out-bred Wistar rats subjected to different rearing conditions. A prolonged maternal separation (MS) of 360 min (MS360) was used to study the effect of ELS, and a short MS of 15 min (MS15) was used as a control. Voluntary ethanol drinking was assessed using a two-bottle free choice paradigm to simulate human episodic drinking. The effects of single housing and ethanol were assessed in conventional animal facility rearing (AFR) conditions. Single housing in adulthood was associated with lower Crhr1 and higher Pomc expression in the pituitary, whereas ethanol drinking was associated with higher expression of Crh in the hypothalamus and Crhr1 in the pituitary, accompanied by lower corticosterone levels. As compared to controls with similar early life handling, rats exposed to ELS displayed lower expression of Pomc in the hypothalamus, and higher Dnmt1 expression in the pituitary. Voluntary ethanol drinking resulted in lower Fkbp5 expression in the pituitary and higher Crh expression in the hypothalamus, independently of rearing conditions. In rats exposed to ELS, water and ethanol drinking was associated with higher and lower corticosterone levels, respectively. The use of conventionally reared rats as control group yielded more significant results than the use of rats exposed to short MS. Positive correlations, restricted to the hypothalamus and ELS group, were observed between the expression of the hypothalamus-pituitary-adrenal receptor and the methylation-related genes. Promoter DNA methylation and expression of respective genes did not correlate suggesting that other loci are involved in transcriptional regulation. Concluding, single housing is a confounding factor to be considered in voluntary ethanol drinking paradigms. ELS and ethanol drinking in adulthood exert independent effects on hypothalamic and pituitary related genes, however, in a manner dependent on the control group used.

Environmental enrichment delays limbic epileptogenesis and restricts pathologic synaptic plasticity.

Environmental exposures impart powerful effects on vulnerability to many brain diseases, including epilepsy. Mesial temporal lobe epilepsy (MTLE) is a common form of epilepsy, and it is often accompanied by neuropsychiatric comorbidities. This study tests the hypothesis that environmental enrichment (EE) confers antiepileptogenic, psychoprotective, and neuroprotective effects in the amygdala kindling model of MTLE, and explores potential neurobiologic mechanisms. At weaning, male Wistar rats were allocated into either EE (large cages containing running wheels and toys; n = 43) or standard housing (SH; standard laboratory cages; n = 39) conditions. At P56, a bipolar electrode was implanted into the left amygdala, and rats underwent rapid amygdala kindling until experiencing five class V seizures (Racine scale, fully kindled). The elevated plus maze was used to assess anxiety. Postmortem histologic and molecular analyses investigated potential biologic mediators of effects. EE significantly delayed kindling epileptogenesis, with EE rats requiring a significantly greater number of kindling stimulations to reach a fully kindled state compared to SH rats (p < 0.05). EE and kindling both reduced anxiety (p < 0.05). Timm's staining revealed significant reductions in aberrant mossy fiber sprouting in EE rats (p < 0.05), and these effects of EE were accompanied by reduced expression of TrkB and CRH genes. We identify beneficial effects of EE on vulnerability to limbic epileptogenesis and anxiety, and identify reduced pathologic neuroplasticity and plasticity-related gene expression as potential underlying mechanisms. Enhanced environmental stimulation represents a potential antiepileptogenic strategy that might also mitigate the common psychiatric comorbidities of MTLE.

Differential expression of feeding-related hypothalamic neuropeptides in the first generation of quails divergently selected for low or high feed efficiency

Livestock and poultry sectors are facing a combination of challenges, including a substantial increase in global demand for high quality animal protein, general droughts and steady rise in animal feed cost. Thus feed efficiency (FE), which defines the animal's ability to convert feed into body weight, is a vital economic and agricultural trait. Genetic selection for FE has been largely used in chickens and has been applied without knowledge of the underlying molecular mechanisms. Although it has made tremendous progress (breast yield, growth rate, egg production), there have been a number of undesirable changes such as metabolic disorders.In the present study we divergently selected male and female quail for high and low FE and we aimed to characterize the molecular basis of these differences at the central level, with the long-term goal of maximizing FE and avoiding the unfavorable consequences.The FE phenotype in first generation quails seemed to be achieved by reduced feed intake in female and increased body weight gain in males. At the molecular level, we found that the expression of feeding-related hypothalamic genes is gender- and line-dependent. Indeed, the expression of NPY, POMC, CART, CRH, melanocortin system (MC1R, MC2R, MC4R, MC5R), ORX, mTOR and ACCα was significantly decreased, however ORXR1/2, AMPKα1, S6K1 and STAT1, 5 and 6 were increased in high compared to low FE males (P<0.05). These genes did not differ between the two female lines. ADPN gene expression was higher and its receptor Adip-R1 was lower in LFE compared to HFE females (P<0.05). In male however, although there was no difference in ADPN gene expression between the genotypes, Adip-R1 and Adip-R2 mRNA abundances were higher in the LFE compared to HFE line (P<0.05).This study identified several key central feeding-related genes that are differentially expressed between low and high FE male and female quails which might explain the differences in feed intake/body weight gain observed between the two lines. Of particular interest, we provided novel insights into central AMPK–mTOR–ACC transcriptional differences between low and high FE quail which may open new research avenues on their roles in the regulation of energy balance and FE in poultry and livestock species.