Food-intake regulation during stress by the hypothalamo-pituitary-adrenal axis. Brain Res Bull. 2013;95:46-53. [PMID: 23590931 DOI: 10.1016/j.brainresbull.2013.04.002]

Association of single nucleotide polymorphisms in Neuropeptide Y (NPY) and Phosphoglycerate Mutase 2 (PGAM2) genes with growth traits in rabbits

Genetic improvement of local rabbit breeds using modern approaches such as marker-assisted selection requires accurate and precise information about marker‒trait associations in animals with different genetic backgrounds. Therefore, this study was designed to estimate the association between two mutations located in the Neuropeptide Y (NPY, g.1778G > C) and Phosphoglycerate Mutase 2 (PGAM2, c.195 C > T) genes in New Zealand White (NZW), Baladi (BR), and V-line rabbits. The first mutation was genotyped using high-resolution melting, and the second mutation was genotyped using the PCR-RFLP method. The results revealed significant associations between the NPY mutation and body weight at 10 (V-line) and 12 weeks of age (NZW, BR, and V-line), body weight gain (BWG) from 10 to 12 weeks of age (BR), BWG from 6 to 12 weeks of age (NZW, BR, and V-line), average daily gain (NZW, BR, and V-line, and BR), growth rate (GR) from 8 to10 weeks (V-line), 10 to 12 weeks (BR), and GR from 6 to 12 weeks of age (BR, and V-line). The PGAM2 mutation was associated with body weight at 10 (V-line) and 12 (NZW, and V-line) weeks of age, with significant positive additive effects at 12 weeks of age in all breeds, and was associated with BWG from 8 to 10 and 10 to 12 in BR, and BWG from 6 to 12 weeks of age (NZW, and BR), and average daily gain (NZW, and BR), and was associated with GR form 8 to 10 weeks (BR), from10 to 12 weeks (BR, and V-line) and from 6 to 12 weeks (BR). The results highlighted the importance of the two mutations in growth development, and the possibility of considering them as candidate genes for late growth in rabbits.

Treating chronic stress and chronic pain by manipulating gut microbiota with diet: can we kill two birds with one stone?

Background: Chronic stress and chronic pain are closely linked by the capacity to exacerbate each other, sharing common roots in the brain and in the gut. The strict intersection between these two neurological diseases makes important to have a therapeutic strategy aimed at preventing both to maintain mental health in patients. Diet is an modifiable lifestyle factor associated with gut-brain axis diseases and there is growing interest in its use as adjuvant to main therapies. Several evidence attest the impact of specific diets or nutrients on chronic stress-related disorders and pain with a good degree of certainty. A daily adequate intake of foods containing micronutrients such as amino acids, minerals and vitamins, as well as the reduction in the consumption of processed food products can have a positive impact on microbiota and gut health. Many nutrients are endowed of prebiotic, anti-inflammatory, immunomodulatory and neuroprotective potential which make them useful tools helping the management of chronic stress and pain in patients. Dietary regimes, as intermittent fasting or caloric restriction, are promising, although further studies are needed to optimize protocols according to patient's medical history, age and sex. Moreover, by supporting gut microbiota health with diet is possible to attenuate comorbidities such as obesity, gastrointestinal dysfunction and mood disorders, thus reducing healthcare costs related to chronic stress or pain.Objective: This review summarize the most recent evidence on the microbiota-mediated beneficial effects of macro- and micronutrients, dietary-related factors, specific nutritional regimens and dietary intervention on these pathological conditions.

Circadian Synchronization of Feeding Attenuates Rats' Food Restriction-Induced Anxiety and Amygdalar Thyrotropin-Releasing Hormone Downregulation

Anxiety is a common comorbidity of obesity, resulting from prescribing long-term caloric restriction diets (CRDs); patients with a reduced food intake lose weight but present anxious behaviors, poor treatment adherence, and weight regain in the subsequent 5 years. Intermittent fasting (IF) restricts feeding time to 8 h during the activity phase, reducing patients' weight even with no caloric restriction; it is unknown whether an IF regime with ad libitum feeding avoids stress and anxiety development. We compared the corticosterone blood concentration between male Wistar rats fed ad libitum or calorie-restricted with all-day or IF food access after 4 weeks, along with their anxiety parameters when performing the elevated plus maze (EPM). As the amygdalar thyrotropin-releasing hormone (TRH) is believed to have anxiolytic properties, we evaluated its expression changes in association with anxiety levels. The groups formed were the following: a control which was offered food ad libitum (C-adlib) or 30% of C-adlib's energy requirements (C-CRD) all day, and IF groups provided food ad libitum (IF-adlib) or 30% of C-adlib's requirements (IF-CRD) with access from 9:00 to 17:00 h. On day 28, the rats performed the EPM and, after 30 min, were decapitated to analyze their amygdalar TRH mRNA expression by in situ hybridization and corticosterone serum levels. Interestingly, circadian feeding synchronization reduced the body weight, food intake, and animal anxiety levels in both IF groups, with ad libitum (IF-adlib) or restricted (IF-CRD) food access. The anxiety levels of the experimental groups resulted to be negatively associated with TRH expression, which supported its anxiolytic role. Therefore, the low anxiety levels induced by synchronizing feeding with the activity phase would help patients who are dieting to improve their diet therapy adherence.

A missense SNP in the proopiomelanocortin (POMC) gene is associated with growth traits in Awassi and Karakul sheep

This study was conducted to assess the association between proopiomelanocortin (POMC) gene and growth traits in Awassi and Karakul sheep. PCR-single strand conformation polymorphism (SSCP) method was utilized to assess the polymorphism of POMC PCR amplicons with body weight and length, wither and rump height, chest and abdominal circumference measured at birth, 3, 6, 9, and 12 months intervals. Only one missense SNP (rs424417456:C > A) was detected in exon-2, in which glycine was converted to cysteine in the 65th position in POMC (p.65Gly > Cys). rs424417456 SNP showed significant associations with all growth traits in the third, sixth, ninth, and twelfth months. At the age of 3 months onward, lambs with CC genotype showed higher body weight, body length, wither and rump heights, and chest and abdominal circumferences than lambs with CA and AA genotypes, respectively. Prediction analyses indicated a deleterious effect of p.65Gly > Cys on POMC structure, function, and stability. Owing to the strong correlation between rs424417456:CC and better growth characteristics, this genotype is proposed as a promising marker to enhance growth traits in Awassi and Karakul sheep. The predicted damaging effects caused by rs424417456:CA and rs424417456:AA genotypes may entail a putative mechanism through which lambs with these genotypes exhibit lower growth traits.

Emotional eating: elusive or evident? Integrating laboratory, psychometric and daily life measures

PURPOSE

Emotional eating (EE) refers to eating in response to (negative) emotions. Evidence for the validity of EE is mixed: some meta-analyses find EE only in eating disordered patients, others only in restrained eaters, which suggest that only certain subgroups show EE. Furthermore, EE measures from lab-based assessments, ecological momentary assessment (EMA), and psychometric measures often diverge. This paper tested whether the covariance of these three different EE methods can be modeled through a single latent variable (factorial validity), and if so, how this variable would relate to restrained eating (construct validity), Body-Mass-Index (BMI), and subclinical eating disorder symptomatology (concurrent validity).

METHODS

102 non-eating disordered female participants with a wide BMI range completed EE measures from three methods: psychometric questionnaires, a laboratory experiment (craving ratings of food images in induced neutral vs. negative emotion) and EMA questionnaires (within-participant correlations of momentary negative emotions and momentary food cravings across 9 days). Two measures for each method were extracted and submitted to confirmatory factor analysis.

RESULTS

A one-factor model provided a good fit. The resulting EElat factor correlated positively with subclinical eating disorder symptoms and BMI but not with restrained eating.

CONCLUSIONS

The one-factor solution shows that the EE construct can validly be assessed with three different methods. Individual differences in EE are supported by the data and are related to eating and weight problem symptomatology but not to restrained eating. This supports learning accounts of EE and underscores the relevance of the EE construct to physical and mental health.

LEVEL OF EVIDENCE

II (Evidence obtained from well-designed controlled trials without randomization).

Genetic Obesity in Pregnant Ay Mice Does Not Affect Susceptibility to Obesity and Food Choice in Offspring

Maternal diet and obesity (MO) may influence taste preferences and increase the susceptibility to obesity in offspring, but the impact of MO per se to these influences is poorly understood. We evaluated the influence of MO on food choice and susceptibility to obesity in offspring when mothers consumed a standard diet (SD). Mice with the Lethal yellow mutation (Ay/a) develop obesity consuming an SD. Metabolic parameters were assessed in pregnant and lactating Ay/a (obesity) and a/a (control) mothers. Metabolic response to the consumption of a sweet–fat diet (SFD: SD, lard, and sweet biscuits) and the choice of components of this diet were evaluated in their male and female offspring. Compared to control mothers, pregnant obese mothers had higher levels of insulin, leptin, and FGF21. MO increased food intake and liver expression of lipogenesis genes in male offspring consuming the SD. SFD consumption caused obesity development and insulin resistance, increased liver expression of glycolytic and lipogenesis genes, and affected hypothalamic expression of anorexigenic and orexigenic genes. In offspring of both sexes, MO had no effect on food choice and metabolic response to SFD intake. Therefore, when obese mothers consume a balanced diet, MO does not affect food choice and development of diet-induced obesity in offspring.

Pre-Test Manipulation by Intraperitoneal Saline Injection with or without Isoflurane Pre-Treatment Does Not Influence the Outcome of Social Test in Male Mice

Preclinical studies on rodents should follow the 3R principle minimising the suffering of the animals. To do so, some researchers use inhalation anaesthetic induction even before intraperitoneal injection. However, several studies suggested that both interventions might influence the behaviour of the animals. We aimed to test whether intraperitoneal injection alone or in combination with isoflurane anaesthesia is a preferable treatment method 30 min before a social test. Male C57BL/6 mice were studied using a behavioural test battery comparing three groups (one control group and intraperitoneal saline-treated groups with or without short isoflurane inhalation). Our results confirmed that both interventions had no profound influence on the conventionally measured parameters of social tests (interest in sociability, social discrimination memory, social interaction as well as resident–intruder test) and were not acutely stressful (measured by similar ACTH levels between the groups) not even after repeated administration (similar body weight gain during the one-week observation period). Taking into consideration the possible long-term harmful effect of isoflurane inhalation, we recommend using intraperitoneal injection without it as saline injection did not violate the 3R principle inducing only mild stress.

The Role of Metabolic Phenotype in the Capacity to Balance Competing Energetic Demands

AbstractGiven the critical role of metabolism in the life history of all organisms, there is particular interest in understanding the relationship between individual metabolic phenotypes and the capacity to partition energy into competing life history traits. Such relationships could be predictive of individual phenotypic performances throughout life. Here, we were specifically interested in whether an individual fish's metabolic phenotype can shape its propensity to feed following a significant stressor (2-min exhaustive exercise challenge). Such a relationship would provide insight into previous intraspecific observations linking high metabolism with faster growth. Using a teleost fish, the barramundi (Lates calcarifer), we predicted that individuals with high standard metabolic rates (SMRs) and maximal metabolic rates (MMRs) would be faster to recover and resume feeding after exercise. Contrary to our prediction, neither SMR nor MMR was correlated with latency to feed after exercise (food was offered at 0.5, 1.5, 3, and 18 h after exercise). Only time after exercise and individual fish ID were significant predictors of latency to feed. Measurements of MMR from the same individuals (three measurements spaced 8-12 d apart) revealed a moderate degree of repeatability (R=0.319). We propose that interindividual differences in biochemical and endocrine processes may be more influential than whole-organism metabolic phenotype in mediating feeding latency after exercise.

Comparative evaluation of natural neuroprotectives and their combinations on chronic immobilization stress-induced depression in experimental mice

The present study evaluates the potential of neuroprotective phytochemicals-rutin (R), resveratrol (Res), 17β-estradiol (17β-E2), and their different combinations against chronic immobilization stress (CIS)-induced depression-like behaviour in male albino mice. Here, the mice were exposed to stress via immobilization of their four limbs under a restrainer for 6 h daily until 7 days of the induction after 30 min of respective drug treatment in different mice groups. The result found the protective effect of these phytoconstituents and their combinations against CIS-induced depression due to their ability to suppress oxidative stress, restore mitochondria, HPA-axis modulation, neurotransmitter level, stress hormones, and inflammatory markers. Also, the combination drug regimens of these phytoconstituents showed synergistic results in managing the physiological and biochemical features of depression. Thus, these neuroprotective could be utilized well in combination to manage depression-like symptoms during episodic stress. Furthermore, such results could be well justified when administered in polyherbal formulation with these neuroprotective as major components. In addition, an advanced study can be designed at the molecular and epigenetics level using a formulation based on these neuroprotective.

Evidence for Neuropeptide W Acting as a Physiological Corticotropin-releasing Inhibitory Factor in Male Chickens

In vertebrates, adrenocorticotropin (ACTH), released by the pituitary gland, is a critical part of the stress axis and stress response. Generally, the biosynthesis and secretion of ACTH are controlled by both hypothalamic stimulatory factors and inhibitory factors [eg, ACTH-releasing inhibitory factor (CRIF)], but the identity of this CRIF remains unrevealed. We characterized the neuropeptide B (NPB)/neuropeptide W (NPW) system in chickens and found that NPW could directly target the pituitary to inhibit growth hormone (GH) and prolactin (PRL) secretion via neuropeptide B/W receptor 2 (NPBWR2), which is completely different from the mechanism in mammals. The present study first carried out a series of assays to investigate the possibility that NPW acts as a physiological CRIF in chickens. The results showed that (1) NPW could inhibit ACTH synthesis and secretion by inhibiting the 3',5'-cyclic adenosine 5'-monophosphate/protein kinase A signaling cascade in vitro and in vivo; (2) NPBWR2 was expressed abundantly in corticotrophs (ACTH-producing cells), which are located mainly in cephalic lobe of chicken pituitary, as demonstrated by single-cell RNA-sequencing, immunofluorescent staining, and fluorescence in situ hybridization; (3) dexamethasone could stimulate pituitary NPBWR2 and hypothalamic NPW expression in chicks, which was accompanied by the decease of POMC messenger RNA levels, as revealed by in vitro and subcutaneous injection assays; and (4) the temporal expression profiles of NPW-NPBWR2 pair in hypothalamus-pituitary axis and POMC in pituitary were almost unanimous in chicken. Collectively, these findings provide comprehensive evidence for the first time that NPW is a potent physiological CRIF in chickens that plays a core role in suppressing the activity of the stress axis.

Growth Curves and Body Condition of Young Cats and Their Relation to Maternal Body Condition

The aim of the present study was to assess factors like litter, individual and maternal effects on kitten overweight at 8 months of age, defined as body condition score (BCS) ≥ 6, in an intact cat family. To minimize confounding, a homogenized cat population was used. After categorization of the life weight data according to the kittens’ sex, BCS and maternal non-pregnant phenotype (overweight (OM), lean (LM), variable (VM)), analyses including Pearson’s correlation coefficients, two-way ANOVA, linear, linear broken-line regression and repeated measures mixed model analyses were performed. Overweight and OM kittens gained weight most quickly, and females reached their peak weight earlier than males (6.2 ± 0.6 vs. 7.4 ± 0.2 months). In females but not in males the age to reach peak weight differed markedly according to category. Male (5.82 ± 0.09, p < 0.01) and OM kittens’ (5.80 ± 0.11, p = 0.07) BCS at 8 months was higher and they were heavier than their counterparts, from 3 and 5 months onwards, respectively. Litter size negatively correlated with overweight (r = −0.30, p < 0.01) and birthweight showed a positive correlation to live weight (R2 = 0.05, p = 0.05) and monthly weight gain (R2 = 0.18, p < 0.01) over time. This study supports routine monitoring of birthweight, growth rate and maternal phenotype prior to pregnancy to identify kittens at risk for becoming overweight.

Crosstalk of hepatocyte nuclear factor 4a and glucocorticoid receptor in the regulation of lipid metabolism in mice fed a high-fat-high-sugar diet

Background

Hepatocyte nuclear factor 4α (HNF4α) and glucocorticoid receptor (GR), master regulators of liver metabolism, are down-regulated in fatty liver diseases. The present study aimed to elucidate the role of down-regulation of HNF4α and GR in fatty liver and hyperlipidemia.

Methods

Adult mice with liver-specific heterozygote (HET) and knockout (KO) of HNF4α or GR were fed a high-fat-high-sugar diet (HFHS) for 15 days. Alterations in hepatic and circulating lipids were determined with analytical kits, and changes in hepatic mRNA and protein expression in these mice were quantified by real-time PCR and Western blotting. Serum and hepatic levels of bile acids were quantified by LC-MS/MS. The roles of HNF4α and GR in regulating hepatic gene expression were determined using luciferase reporter assays.

Results

Compared to HFHS-fed wildtype mice, HNF4α HET mice had down-regulation of lipid catabolic genes, induction of lipogenic genes, and increased hepatic and blood levels of lipids, whereas HNF4α KO mice had fatty liver but mild hypolipidemia, down-regulation of lipid-efflux genes, and induction of genes for uptake, synthesis, and storage of lipids. Serum levels of chenodeoxycholic acid and deoxycholic acid tended to be decreased in the HNF4α HET mice but dramatically increased in the HNF4α KO mice, which was associated with marked down-regulation of cytochrome P450 7a1, the rate-limiting enzyme for bile acid synthesis. Hepatic mRNA and protein expression of sterol-regulatory-element-binding protein-1 (SREBP-1), a master lipogenic regulator, was induced in HFHS-fed HNF4α HET mice. In reporter assays, HNF4α cooperated with the corepressor small heterodimer partner to potently inhibit the transactivation of mouse and human SREBP-1C promoter by liver X receptor. Hepatic nuclear GR proteins tended to be decreased in the HNF4α KO mice. HFHS-fed mice with liver-specific KO of GR had increased hepatic lipids and induction of SREBP-1C and PPARγ, which was associated with a marked decrease in hepatic levels of HNF4α proteins in these mice. In reporter assays, GR and HNF4α synergistically/additively induced lipid catabolic genes.

Conclusions

induction of lipid catabolic genes and suppression of lipogenic genes by HNF4α and GR may mediate the early resistance to HFHS-induced fatty liver and hyperlipidemia.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01654-6.

Rescue of Vasopressin Synthesis in Magnocellular Neurons of the Supraoptic Nucleus Normalises Acute Stress-Induced Adrenocorticotropin Secretion and Unmasks an Effect on Social Behaviour in Male Vasopressin-Deficient Brattleboro Rats

The relevance of vasopressin (AVP) of magnocellular origin to the regulation of the endocrine stress axis and related behaviour is still under discussion. We aimed to obtain deeper insight into this process. To rescue magnocellular AVP synthesis, a vasopressin-containing adeno-associated virus vector (AVP-AAV) was injected into the supraoptic nucleus (SON) of AVP-deficient Brattleboro rats (di/di). We compared +/+, di/di, and AVP-AAV treated di/di male rats. The AVP-AAV treatment rescued the AVP synthesis in the SON both morphologically and functionally. It also rescued the peak of adrenocorticotropin release triggered by immune and metabolic challenges without affecting corticosterone levels. The elevated corticotropin-releasing hormone receptor 1 mRNA levels in the anterior pituitary of di/di-rats were diminished by the AVP-AAV-treatment. The altered c-Fos synthesis in di/di-rats in response to a metabolic stressor was normalised by AVP-AAV in both the SON and medial amygdala (MeA), but not in the central and basolateral amygdala or lateral hypothalamus. In vitro electrophysiological recordings showed an AVP-induced inhibition of MeA neurons that was prevented by picrotoxin administration, supporting the possible regulatory role of AVP originating in the SON. A memory deficit in the novel object recognition test seen in di/di animals remained unaffected by AVP-AAV treatment. Interestingly, although di/di rats show intact social investigation and aggression, the SON AVP-AAV treatment resulted in an alteration of these social behaviours. AVP released from the magnocellular SON neurons may stimulate adrenocorticotropin secretion in response to defined stressors and might participate in the fine-tuning of social behaviour with a possible contribution from the MeA.

The Association of Restrained Eating and Overeating during COVID-19: A Cross-Lagged Model

Widespread overeating has been found during the 2019 coronavirus (COVID-19) pandemic. The present study investigated whether pre-pandemic restrained eating (RE) predicted overeating during the pandemic, and further explored the behavioral (mortality threat, negative affect) mechanisms underlying this association. An eight-month longitudinal survey was conducted with a large sample of 616 undergraduates from Southwest university. From September 2019 to April 2020, three measurements were conducted. RE was tested before the pandemic (T1), and data of mortality threat, negative affect, and overeating were collected at the middle (T2) and end of (T3) the COVID-19 crisis in China. The correlation results showed that baseline RE was positively associated with mortality threat, negative affect, and overeating at T2 and T3. Moreover, negative affect and mortality threat were positively correlated with overeating. Results from longitudinal mediation showed that baseline RE would positively predict T3 overeating through T2 negative affect, but not T2 mortality threat. This study supports and extends the counterregulatory eating hypothesis that RE positively predicts future overeating, especially through negative emotions. These findings further reveal the core psychological mechanism underlying this positive RE-overeating relation in the context of COVID-19, indicating that the individuals with higher RE could not cope with negative affect adequately, contributing to more overeating.

Inflammatory dysregulation in women with an eating disorder: Relationships with altered emotional reactivity

BACKGROUND

Some studies suggest that inflammatory signaling dysregulation may contribute to eating disorder (ED) pathophysiology. However, little is known about the influence of inflammatory response on altered processes seen among patients with ED, such as emotional processing and reactivity.

OBJECTIVES

The objectives were: (a) to investigate the systemic inflammatory response in ED women; and (b) to analyze the role of inflammatory markers in emotional reactivity.

METHOD

Concentrations of several intercellular and intracellular inflammatory mediators (cytokines, prostaglandin by-products and enzymes, TBARS, and MAPK proteins) were quantified in plasma and PBMCs from 68 women with an ED (m = 22.01 years, SD = 9.15) and 35 healthy controls (m = 18.54 years, SD = 4.21). Moreover, emotional reactivity to affective pictures (those without either food or thinness content) was studied using the adult (>18 years old) sample (n = 41).

RESULTS

Between-group differences were revealed for most markers (TNF-α, PGE₂ , COX2, and ratio of activated MAPK proteins), pointing to increased inflammatory response in patients (p < .01). Women with ED showed heightened emotional reactivity, regardless of picture valence. Principal components derived from inflammatory markers showed an explanatory loading on patient's emotional reaction, in terms of valence and arousal.

CONCLUSION

This study corroborates the altered systemic inflammatory response in patients with ED. The inflammatory dysregulation may contribute to ED phenotype, as seen by its relationship with heightened emotional reactivity, even though the inflammatory markers were not evaluated throughout the emotional reactivity protocol.

Restriction of food intake by PPP1R17-expressing neurons in the DMH

We set out to identify novel neuronal populations controlling feeding behaviors. Therefore, we focused on identifying novel neuronal populations modulating food intake and body weight. In this article, we report that DMH^Ppp1r17 neurons are activated by increased food intake and that activating them results in decreased food intake and body weight, while inhibiting them leads to increased body weight and food intake. These data suggest that DMH^Ppp1r17 neurons restrict binges of eating. In addition to its basic science importance, these findings could have therapeutic applications, as they suggest that pharmacologic activation of PPP1R17 neurons could potentially reduce weight in settings of obesity and binge-like eating.

Leptin-deficient ob/ob mice eat voraciously, and their food intake is markedly reduced by leptin treatment. In order to identify potentially novel sites of leptin action, we used PhosphoTRAP to molecularly profile leptin-responsive neurons in the hypothalamus and brainstem. In addition to identifying several known leptin responsive populations, we found that neurons in the dorsomedial hypothalamus (DMH) of ob/ob mice expressing protein phosphatase 1 regulatory subunit 17 (PPP1R17) constitutively express cFos and that this is suppressed by leptin treatment. Because ob mice are hyperphagic, we hypothesized that activating PPP1R17 neurons would increase food intake. However, chemogenetic activation of PPP1R17 neurons decreased food intake and body weight of ob/ob mice while inhibition of PPP1R17 neurons increased them. Similarly, in a scheduled feeding protocol that elicits increased consumption, mice also ate more when PPP1R17 neurons were inhibited and ate less when they were activated. Finally, we found that pair-feeding of ob mice reduced cFos expression to a similar extent as leptin and that reducing the amount of food available during scheduled feeding in DMH^Ppp1r17 neurons also decreased cFos in DMH^Ppp1r17 neurons. Finally, these neurons do not express the leptin receptor, suggesting that the effect of leptin on these neurons is indirect and secondary to reduced food intake. In aggregate, these results show that PPP1R17 neurons in the DMH are activated by increased food intake and in turn restrict intake to limit overconsumption, suggesting that they function to constrain binges of eating.

Networks of stress, affect and eating behaviour: anticipated stress coping predicts goal-congruent eating in young adults

BACKGROUND

Many people aim to eat healthily. Yet, affluent food environments encourage consumption of energy dense and nutrient-poor foods, making it difficult to accomplish individual goals such as maintaining a healthy diet and weight. Moreover, goal-congruent eating might be influenced by affects, stress and intense food cravings and might also impinge on these in turn. Directionality and interrelations of these variables are currently unclear, which impedes targeted intervention. Psychological network models offer an exploratory approach that might be helpful to identify unique associations between numerous variables as well as their directionality when based on longitudinal time-series data.

METHODS

Across 14 days, 84 diet-interested participants (age range: 18-38 years, 85.7% female, mostly recruited via universities) reported their momentary states as well as retrospective eating episodes four times a day. We used multilevel vector autoregressive network models based on ecological momentary assessment data of momentary affects, perceived stress and stress coping, hunger, food craving as well as goal-congruent eating behaviour.

RESULTS

Neither of the momentary measures of stress (experience of stress or stress coping), momentary affects or craving uniquely predicted goal-congruent eating. Yet, temporal effects indicated that higher anticipated stress coping predicted subsequent goal-congruent eating. Thus, the more confident participants were in their coping with upcoming challenges, the more they ate in line with their goals.

CONCLUSION

Most eating behaviour interventions focus on hunger and craving alongside negative and positive affect, thereby overlooking additional important variables like stress coping. Furthermore, self-regulation of eating behaviours seems to be represented by how much someone perceives a particular eating episode as matching their individual eating goal. To conclude, stress coping might be a potential novel intervention target for eating related Just-In-Time Adaptive Interventions in the context of intensive longitudinal assessment.

Toxicity of humidifier disinfectant polyhexamethylene guanidine hydrochloride by two-week whole body-inhalation exposure in rats

The use of polyhexamethylene guanidine hydrochloride (PHMG·HCl) as a humidifier disinfectant caused an outbreak of pulmonary disease, leading to the deaths of pregnant women and children in South Korea. However, limited information is available on the inhalation toxicity of PHMG·HCl. Therefore, this study aimed to characterize the subacute inhalation toxicity of PHMG·HCl by whole-body exposure in rats. F344 rats were exposed to 0 mg/m³, 1 mg/m³, 5 mg/m³, or 25 mg/m³ of PHMG·HCl for 6 h/day, 5 days/week for two weeks via whole-body inhalation. Emaciation and rale were observed in rats in the 25 mg/m³ PHMG·HCl group. Significant changes in body weight, hematology, serum chemistry and organ weight were observed in all PHMG·HCl-exposed groups. Gross lesions showed ballooning or red focus in the lungs of rats in the PHMG·HCl-exposed groups. In histopathological examination, most of histological lesions (including degeneration, atrophy, ulcer, inflammatory cell infiltration, inflammation, and fibrosis in nasal cavity, larynx, trachea, and lungs) indicated tissue damage by PHMG·HCl in all PHMG·HCl-exposed groups. Additionally, atrophy of the spleen, thymus, and reproductive organs; immaturity of the testes; and cell debris in the epididymides were affected by the reduction in body weight in PHMG·HCl-exposed groups. In conclusion, two-week repeated whole-body inhalation exposure of rats to PHMG·HCl reveled toxic effects on the respiratory system and secondary effects on other organs. The results of this study indicate that the no observable adverse effect level (NOAEL) for PHMG·HCl is below 1 mg/m³.

Underlying Susceptibility to Eating Disorders and Drug Abuse: Genetic and Pharmacological Aspects of Dopamine D4 Receptors

The dopamine D4 receptor (DRD4) has a predominant expression in the prefrontal cortex (PFC), brain area strictly involved in the modulation of reward processes related to both food and drug consumption. Additionally, the human DRD4 gene is characterized by a variable number of tandem repeats (VNTR) in the exon 3 and, among the polymorphic variants, the 7-repeat (7R) allele appears as a contributing factor in the neurobiological mechanisms underlying drug abuse, aberrant eating behaviors and related comorbidities. The 7R variant encodes for a receptor with a blunted intracellular response to dopamine, and carriers of this polymorphism might be more tempted to enhance dopamine levels in the brain, through the overconsumption of drugs of abuse or palatable food, considering their reinforcing properties. Moreover, the presence of this polymorphism seems to increase the susceptibility of individuals to engage maladaptive eating patterns in response to negative environmental stimuli. This review is focused on the role of DRD4 and DRD4 genetic polymorphism in these neuropsychiatric disorders in both clinical and preclinical studies. However, further research is needed to better clarify the complex DRD4 role, by using validated preclinical models and novel compounds more selective for DRD4.

Does stress eat away at you or make you eat? EMA measures of stress predict day to day food craving and perceived food intake as a function of trait stress-eating

Eating behaviour can be driven by non-homeostatic factors like stress. Both increased and decreased food intake in response to stress has been documented, but it has remained difficult to identify a trait that predicts who shows either pattern. Thus, we collected naturalistic data from Ecological Momentary Assessment in combination with the trait-level Salzburg Stress Eating Scale (SSES). In study 1, 97 individuals completed the SSES and 6 daily reports about stress, food craving and perceived food intake across 8 days, whereas in study 2, 83 diet-interested participants completed the same measures at 4 daily prompts across 14 days. Consistent across both studies, multilevel modelling revealed that participants with high SSES-scores showed relatively more positive intra-day stress-craving relationships than those with low SSES-scores. On the day level, stress also predicted perceived food intake as a function of SSES-scores. Controlling for negative affect did not alter results. Results support an individual difference model of stress-eating where decrease vs increase of eating depends on SSES-scores. In affected individuals stress influences simultaneous food craving but might exhibit cumulative or delayed effects on food intake. Furthermore, the SSES provides a valid instrument for identifying at risk individuals and for tailoring interventions.

Fight, Flight, - Or Grab a Bite! Trait Emotional and Restrained Eating Style Predicts Food Cue Responding Under Negative Emotions

In today's society, obesity rates are rising as food intake is no longer only a response to physiological hunger signals that ensure survival. Eating can represent a reward, a response to boredom, or stress reduction and emotion regulation. While most people decrease food intake in response to stress or negative emotions, some do the opposite. Yet, it is unclear who shows emotional overeating under which circumstances. Emotion regulation theories describe emotional overeating as a learned strategy to down-regulate negative emotions. Cognitive theories, by contrast, attribute emotional overeating to perceived diet breaches in individuals who chronically attempt to diet. After consuming "forbidden foods", they eat more than individuals who do not restrict their food intake. This laboratory study investigated emotional overeating by exposing individuals to a personalized emotion induction while showing images of palatable foods. Outcome variables indexed cue reactivity to food images through picture ratings (valence, desire to eat), facial expressions (electromyography of the corrugator supercilii muscle), and brain reactivity by detecting event-related potentials (ERPs) by means of electroencephalography (EEG). The influence of emotion condition (negative, neutral) and individual differences (self-reported trait emotional and restrained eating) on outcome variables was assessed. Valence ratings and appetitive reactions of the corrugator muscle to food pictures showed a relative increase in the negative condition for individuals with higher emotional eating scores, with the opposite pattern in lower scores. Desire to eat ratings showed a similar pattern in individuals who showed a strong response to the emotion induction manipulation, indicative of a dose-response relationship. Although no differences between conditions were found for ratings or corrugator activity with restrained eating as a predictor, an ERP at P300 showed increased activation when viewing food compared to objects in the negative condition. Findings support emotion regulation theories: Emotional eaters showed an appetitive reaction in rating patterns and corrugator activity. EEG findings (increased P300) suggest a motivated attention toward food in restrained eaters, which supports cognitive theories. However, this did not translate to other variables, which might demonstrate successful restraint. Future studies may follow up on these findings by investigating eating disorders with emotion regulation difficulties.

Workplace bullying and workplace violence as risk factors for cardiovascular disease: a multi-cohort study

AIMS

To assess the associations between bullying and violence at work and cardiovascular disease (CVD).

METHODS AND RESULTS

Participants were 79 201 working men and women, aged 18-65 years and free of CVD and were sourced from three cohort studies from Sweden and Denmark. Exposure to workplace bullying and violence was measured at baseline using self-reports. Participants were linked to nationwide health and death registers to ascertain incident CVD, including coronary heart disease and cerebrovascular disease. Study-specific results were estimated by marginal structural Cox regression and were combined using fixed-effect meta-analysis. Nine percent reported being bullied at work and 13% recorded exposure to workplace violence during the past year. We recorded 3229 incident CVD cases with a mean follow-up of 12.4 years (765 in the first 4 years). After adjustment for age, sex, country of birth, marital status, and educational level, being bullied at work vs. not was associated with a hazard ratio (HR) of 1.59 [95% confidence interval (CI) 1.28-1.98] for CVD. Experiencing workplace violence vs. not was associated with a HR of 1.25 (95% CI 1.12-1.40) for CVD. The population attributable risk was 5.0% for workplace bullying and 3.1% for workplace violence. The excess risk remained similar in analyses with different follow-up lengths, cardiovascular risk stratifications, and after additional adjustments. Dose-response relations were observed for both workplace bullying and violence (Ptrend < 0.001). There was only negligible heterogeneity in study-specific estimates.

CONCLUSION

Bullying and violence are common at workplaces and those exposed to these stressors are at higher risk of CVD.

Oxidative stress, inflammatory reactions and apoptosis mediated the negative effect of chronic stress induced by maternal separation on the reproductive system in male mice

Exposure to severe and long-lasting stressors during early postnatal life negatively affects development of the brain and associated biological networks. Maternal separation (MS) is a valid stressful experience in early life that adversely affects neurobiological circuits. In the present study, we aimed to evaluate the effects of MS on sperm quality and histology of the testis in adult male mice. In this study, male mice were subjected to MS during post-natal days (PND) 2-14. Sperm parameters, histological alterations in the testicular tissue, ROS production (using DCFH-DA assay), gene expression of TLR4, NLRP3, TNFα, BAX, ASC, caspase-1 and BCL-2 (using RT-PCR), protein levels of caspase-3 and caspase-8 (using western blotting), and protein levels of IL-1β, IL-18, GPx and ATP (using ELISA) as well as protein expression of caspase-1 and NLRP3 (using immunocytochemistry) were evaluated. Findings showed that MS decreased count, morphology and viability of spermatozoa. MS decreased the diameter of seminiferous tubules and decreased the thickness of seminiferous epithelium. Furthermore, MS increased the level of ROS production and decreased the concentrations of GPx and ATP. MS led to increased expression of TLR4, NlRP3, TNFα, caspase-1, ASC, IL-1β and IL-18. In addition, MS induced apoptosis as evidenced by increased BAX, caspase-3 and caspase-8 as well as decreased BCL-2 expression. We concluded that early life stress induced by MS has detrimental effects on sperm parameters and testicular tissue. Our results suggest that these effects are mediated by activation of ROS production, and alterations in mitochondrial function, inflammatory processes and apoptosis pathways.

Qualitative Study to Determine Stressors Influencing Dietary and Physical Activity Behaviors of Overweight and Obese Adolescents in Iran

Introduction

Childhood obesity has become a global endemic public health problem. Emotional distress has been proposed to be a strong mediator of unhealthy lifestyle behaviors among youth. The aim of this study was to explore the sources and role of stress on developing unhealthy lifestyle practices pertaining to diet and physical activity among overweight and obese adolescents.

Methods

This qualitative study was conducted in 2016-2017 in two large cities of Iran, Mashhad and Isfahan. Fifty-two overweight and obese adolescents were selected through purposeful sampling. In-depth semi-structured interviews and focus group discussions were conducted to obtain perceptions and experiences regarding underlying factors of obesity and the sources and role of stress in inducing unhealthy lifestyle. Ten parents were also interviewed. Data were analyzed using conventional content analysis with MAXQDA software. Study rigor was verified using criteria proposed by Lincoln and Guba.

Results

After analyzing the data, two main categories which triggered emotional overeating and physical inactivity among adolescents were: "school originated stress" and "family originated stress." Three subcategories of school originated stress were "Too much homework," "Frequent exams" and "Priority for studying at both school and home" and family originated stress subcategories were "Parental destructive conflicts," "Divorce" and "Socio-familial issues.".

Conclusions

Our findings highlighted the sources and role of stress in emerging unhealthy lifestyle practices including emotional overeating and physical inactivity among adolescents which could lead to weight gain. Therefore, to improve lifestyle behaviors of students and prevent childhood obesity, addressing school, and family stressors is a crucial subject.

Preclinical and Clinical Evidence for a Distinct Regulation of Mu Opioid and Type 1 Cannabinoid Receptor Genes Expression in Obesity

Among endogenous signaling networks involved in both rewarding and homeostatic mechanisms of obesity, a relevant role is played by the endocannabinoid (ECS) and the opioid (EOS) systems. We here studied the transcriptional regulation of ECS and EOS genes in the hypothalamus of Diet-induced obesity rats, a preclinical model of obesity, as well as in humans with obesity and healthy controls. A significant and selective increase in type 1 cannabinoid receptor gene (Cnr1) expression was observed at the beginning of obesity development (5 weeks on high fat diet) as well as after 21 weeks of high diet exposure. After 5 weeks on high fat diet, selective up-regulation of mu opioid receptor gene (Oprm1) expression was also observed. Consistently, epigenetic studies showed a selective and significant decrease in DNA methylation at specific CpG sites at both gene promoters in overweight rats, but only after 5 weeks on high fat diet. Moreover, significantly lower levels of DNA methylation were observed at selected CpG sites of both receptor gene promoters, analyzed in peripheral blood mononuclear cells from younger (<30 years old) humans with obesity, as well as in those with shorter time length from disease onset. Taken together, we here provide evidence of selective, synergistic and time-dependent transcriptional regulation of CNR1 and OPRM1 genes in overweight rats, as well as in human subjects. These alterations in genes regulation could contribute to the development of the obese phenotype, and we thus suggest CNR1 and OPRM1 epigenetic modulation as possible biomarkers of obesity development. Due to the reversible nature of the epigenetic hallmark, our data might also open new avenue to early environmental strategies of intervention.

Stress-related hormones affect carbohydrate metabolism in Drosophila females

A highly conservative insulin signaling pathway, stable work of which is indicated by carbohydrates metabolism, is also known to play an important role in the control of stress resistance. Here we demonstrate that exposure to heat stress leads to a rise in the levels of trehalose and glucose in females of Drosophila melanogaster, but does not affect the expression level of the trehalase (Treh) gene. We have shown that the rise in juvenile hormone (JH) and dopamine decreases levels of both carbohydrates under the normal conditions but brings them to values close to normal following the stress exposure. The data obtained suggest that (a) dopamine and JH involved in the neuroendocrine stress reaction in D. melanogaster also take part in the regulation of carbohydrates metabolism, tending to normalize it after stress; (b) the regulation of trehalose content under stress does not occur at the level of transcription of the degrading enzyme.

Transcriptional regulation of the endocannabinoid system in a rat model of binge-eating behavior reveals a selective modulation of the hypothalamic fatty acid amide hydrolase gene

OBJECTIVE

Binge-eating episodes are recurrent and are defining features of several eating disorders. Thus binge-eating episodes might influence eating disorder development of which exact underlying mechanisms are still largely unknown.

METHODS

Here we focused on the transcriptional regulation of the endocannabinoid system, a potent regulator of feeding behavior, in relevant rat brain regions, using a rat model in which a history of intermittent food restriction and a frustration stress induce binge-like palatable food consumption.

RESULTS

We observed a selective down-regulation of fatty acid amide hydrolase (faah) gene expression in the hypothalamus of rats showing the binge-eating behavior with a consistent reduction in histone 3 acetylation at lysine 4 of the gene promoter. No relevant changes were detected for any other endocannabinoid system components in any brain regions under study, as well as for the other epigenetic mechanisms investigated (DNA methylation and histone 3 lysine 27 methylation) at the faah gene promoter.

DISCUSSION

Our findings suggest that faah transcriptional regulation is a potential biomarker of binge-eating episodes, with a relevant role in the homeostatic regulation of food intake.

Effects of Isolation and Social Subchronic Stresses on Food Intake and Levels of Leptin, Ghrelin, and Glucose in Male Rats

Background:

Exposure to psychological stresses can be a reason for obesity. Therefore, identifying the effective nutritional mechanisms such as feeding markers is of high necessity for the psychological stress conditions. Hence, the present study investigates the effects of subchronic isolation and social stresses on food intake, body weight differences (BWD), and levels of leptin, ghrelin, and glucose in rats.

Materials and Methods:

Eighteen male rats were randomly allocated into three groups: control (Co), isolation stress (IS), and social stress (SS) groups. Rats were under stresses for 7 days. The food intake (for three continuous hours after 16–18 h of food deprivation), BWD, levels of ghrelin, leptin, and glucose were measured.

Results:

The results showed that the food intake significantly (P < 0.05) reduced during the 1^st h in the SS group compared to the Co group. At the 2^nd h, the food intake significantly (P < 0.001 and P < 0.01, respectively) decreased in the IS group compared to the Co and SS groups. The cumulative food intake and body weight were significantly (P < 0.05) reduced in the IS group compared to the Co group. The serum ghrelin level significantly reduced in the IS group compared to the Co group.

Conclusions:

The subchronic psychological stresses led to a reduction in food intake by the reduction of serum ghrelin levels. It seems that ghrelin might have a more fundamental role in the food intake with respect to the leptin and glucose levels in subchronic stress condition. Furthermore, the decreased body weight justified the reduction of food intake, particularly in subchronic isolation stress.

Neurohormonal Regulation of Appetite and its Relationship with Stress: A Mini Literature Review

Stress has long been known to affect eating behaviors in humans. Stress-induced hyperphagia is considered a potential cause for the development of obesity. Given the high prevalence of obesity and its association with other cardiovascular and metabolic disorders, the subject of stress-induced eating has become even more important. We reviewed data from past studies to further elucidate the relationship between stress, appetite regulation and eating patterns in humans. Even though it is difficult to say with certainty that a person exposed to stress will undereat or overeat, but certain assumptions can be made. Generally, acute stress results in decreased eating whereas chronic stress results in increased eating. Glucocorticoids, the effector molecules of the stress response, increase the tendency to consume high-calorie, palatable foods. Further studies that can link the biological markers of stress-response with the hormones and neurotransmitters of appetite regulation can broaden our understanding of the subject. These studies can provide a groundwork for the development of effective anti-obesity strategies.

Workplace bullying and violence as risk factors for type 2 diabetes: a multicohort study and meta-analysis

AIMS/HYPOTHESIS

The aim of this multicohort study was to examine whether employees exposed to social stressors at work, such as workplace bullying and violence, have an increased risk of type 2 diabetes.

METHODS

The study included 45,905 men and women (40-65 years of age and free of diabetes at baseline) from four studies in Sweden, Denmark and Finland. Workplace bullying and violence were self-reported at baseline. Incident diabetes was ascertained through national health and medication records and death registers. Marginal structural Cox models adjusted for age, sex, country of birth, marital status and educational level were used for the analyses.

RESULTS

Nine per cent of the population reported being bullied at work and 12% were exposed to workplace violence or threats of violence. Bullied participants had a 1.46 (95% CI 1.23, 1.74) times higher risk of developing diabetes compared with non-bullied participants. Exposure to violence or threats of violence was also associated with a higher risk of diabetes (HR 1.26 [95% CI 1.02, 1.56]). The risk estimates attenuated slightly when taking BMI into account, especially for bullying. The results were similar for men and women, and were consistent across cohorts.

CONCLUSIONS/INTERPRETATION

We found a higher risk of incident type 2 diabetes among employees exposed to bullying or violence in the workplace. Further research is needed to determine whether policies to reduce bullying and violence at work may reduce the incidence of type 2 diabetes in working populations. Research on the mechanisms is also highly warranted.

Epigenome-wide association analysis revealed that SOCS3 methylation influences the effect of cumulative stress on obesity

Chronic stress has a significant impact on obesity. However, how stress influences obesity remains unclear. We conducted an epigenome-wide DNA methylation association analysis of obesity (N=510) and examined whether cumulative stress influenced the DNA methylation on body weight. We identified 20 CpG sites associated with body mass index at the false discovery rate q<0.05, including a novel site, cg18181703, in suppressor of cytokine signaling 3 (SOCS3) gene (coefficient β=-0.0022, FDR q=4.94×10-5). The interaction between cg18181703 and cumulative adverse life stress contributed to variations in body weight (p=0.002). Individuals with at least five major life events and lower methylation of cg1818703 showed a 1.38-fold higher risk of being obese (95%CI: 1.17-1.76). Our findings suggest that aberrant in DNA methylation is associated with body weight and that methylation of SOCS3 moderates the effect of cumulative stress on obesity.

Eating behavior during dexamethasone treatment in children with acute lymphoblastic leukemia

BACKGROUND AND AIM

Large prospective studies on dexamethasone-induced changes in eating behavior, energy, and nutrient intake are lacking in pediatric acute lymphoblastic leukemia (ALL). We prospectively studied eating behavior, energy, nutrient intake, and the effect on leptin and adiponectin levels during dexamethasone administration in children with ALL.

PATIENTS

Parents of patients with ALL (3-16 years) completed a dietary diary for their child during 4 days of dexamethasone (6 mg/m² ) administration. Energy intake and nutrient intake (energy percentage = E%) were assessed and compared with the recommended intake. The Dutch Eating Behavior Questionnaire for Children was completed before start and after 4 days of dexamethasone administration by patients of 7-12 years of age. Fasting leptin and adiponectin levels were also measured before start and after 4 days of dexamethasone administration.

RESULTS

Energy intake per day(kcal) (N = 44) increased significantly during dexamethasone (median day 1: 1,103 (717-1,572) versus day 4: 1,482 (1,176-1,822), P < 0.01), including an increase in total protein, fat, saturated fat, carbohydrate, and sodium intake. Intake of saturated fat (median day 4: 12 E%) and salt (median day 4: 1.9 g/day) exceeded the healthy range for age and gender. With respect to eating behavior, dexamethasone significantly decreased restrained eating (P = 0.04). Leptin levels as well as adiponectin levels increased significantly during the dexamethasone course.

CONCLUSIONS

Four days of dexamethasone treatment significantly increased energy intake, including excessive saturated fat and salt intake, and changed eating behavior in children with ALL. Nutritional and behavioral interventions during dexamethasone treatment are recommended to stimulate a healthy lifestyle.

Mechanisms Linking Interparental Aggression to Child Dental Caries

Research has garnered support for a systemic view of factors affecting child dental caries that accounts for the influence of social factors such as the family environment. Our previous work has demonstrated the association between mother-to-father emotional aggression and child caries. The present study builds on these results by evaluating pathways that might explain this relation. Families (n = 135) completed a multimethod assessment of mother-to-father emotional aggression, child caries, and several hypothesized mediators (i.e., child cariogenic snack and drink intake, child internalizing behaviors, child salivary cortisol and α-amylase reactivity, parental laxness, child oral hygiene maintenance, and parental socialization of child oral hygiene maintenance). Mediation analyses partially supported the role of the child's diet as a mechanism linking mother-to-father emotional aggression and child caries. However, children's neglect of oral hygiene, parental laxness, and child emotional and biological disturbances failed to stand as conduits for this association. Future investigations should expand upon these results to better establish the causal links that could only be suggested by the present cross-sectional findings.

Acute stress is detrimental to heart regeneration in zebrafish

Psychological stress is one of the factors associated with human cardiovascular disease. Here, we demonstrate that acute perceived stress impairs the natural capacity of heart regeneration in zebrafish. Beside physical and chemical disturbances, intermittent crowding triggered an increase in cortisol secretion and blocked the replacement of fibrotic tissue with new myocardium. Pharmacological simulation of stress by pulse treatment with dexamethasone/adrenaline reproduced the regeneration failure, while inhibition of the stress response with anxiolytic drugs partially rescued the regenerative process. Impaired heart regeneration in stressed animals was associated with a reduced cardiomyocyte proliferation and with the downregulation of several genes, including igfbp1b, a modulator of IGF signalling. Notably, daily stress induced a decrease in Igf1r phosphorylation. As cardiomyocyte proliferation was decreased in response to IGF-1 receptor inhibition, we propose that the stress-induced cardiac regenerative failure is partially caused by the attenuation of IGF signalling. These findings indicate that the natural regenerative ability of the zebrafish heart is vulnerable to the systemic paracrine stress response.

Epigenetic regulation of nociceptin/orphanin FQ and corticotropin-releasing factor system genes in frustration stress-induced binge-like palatable food consumption

Evidence suggests that binge eating may be caused by a unique interaction between dieting and stress. We developed a binge-eating model in which female rats with a history of intermittent food restriction show binge-like palatable food consumption after a 15-minute exposure to the sight of the palatable food (frustration stress). The aim of the present study was to investigate the regulation of the stress neurohormone corticotropin-releasing factor (CRF) system and of the nociceptin/orphanin FQ (N/OFQ) system genes in selective rat brain regions, using our animal model. Food restriction by itself seems to be responsible in the hypothalamus for the downregulation on messenger RNA levels of CRF-1 receptor, N/OFQ and its receptor (NOP). For the latter, this alteration might be due to selective histone modification changes. Instead, CRF gene appears to be upregulated in the hypothalamus as well as in the ventral tegmental area only when rats are food restricted and exposed to frustration stress, and, of relevance, these changes appear to be due to a reduction in DNA methylation at gene promoters. Moreover, also CRF-1 receptor gene resulted to be differentially regulated in these two brain regions. Epigenetic changes may be viewed as adaptive mechanisms to environmental perturbations concurring to facilitate food consumption in adverse conditions, that is, in this study, under food restriction and stressful conditions. Our data on N/OFQ and CRF signaling provide insight on the use of this binge-eating model for the study of epigenetic modifications in controlled genetic and environmental backgrounds.

Anorexia is Associated with Stress-Dependent Orexigenic Responses to Exogenous Neuropeptide Y

Chicken lines that have been divergently selected for either low (LWS) or high (HWS) body weight at 56 days of age for more than 57 generations have different feeding behaviours in response to a range of i.c.v. injected neurotransmitters. The LWS have different severities of anorexia, whereas the HWS become obese. Previously, we demonstrated that LWS chicks did not respond, whereas HWS chicks increased food intake, after central injection of neuropeptide Y (NPY). The present study aimed to determine the molecular mechanisms underlying the loss of orexigenic function of NPY in LWS. Chicks were divided into four groups: stressed LWS and HWS on day of hatch, and control LWS and HWS. The stressor was a combination of food deprivation and cold exposure. On day 5 post-hatch, each chick received an i.c.v. injection of vehicle or 0.2 nmol of NPY. Only the LWS stressed group did not increase food intake in response to i.c.v. NPY. Hypothalamic mRNA abundance of appetite-associated factors was measured at 1 h post-injection. Interactions of genetic line, stress and NPY treatment were observed for the mRNA abundance of agouti-related peptide (AgRP) and synaptotagmin 1 (SYT1). Intracerebroventricular injection of NPY decreased and increased AgRP and SYT1 mRNA, respectively, in the stressed LWS and increased AgRP mRNA in stressed HWS chicks. Stress was associated with increased NPY, orexin receptor 2, corticotrophin-releasing factor receptor 1, melanocortin receptor 3 (MC3R) and growth hormone secretagogue receptor expression. In conclusion, the loss of responsiveness to exogenous NPY in stressed LWS chicks may be a result of the decreased and increased hypothalamic expression of AgRP and MC3R, respectively. This may induce an intensification of anorexigenic melanocortin signalling pathways in LWS chicks that block the orexigenic effect of exogenous NPY. These results provide insights onto the anorexic condition across species, and especially for forms of inducible anorexia such as human anorexia nervosa.

Long lasting preventive effects of piperlongumine and a Piper longum extract against stress triggered pathologies in mice

Aim:

To compare doxycycline (DOX) such as oral efficacies of piperlongumine (PL) and a Piper longum fruits extract (PLE) as stress resistance inducers.

Materials and Methods:

Efficacies of oral pretreatments with 5 mg/kg PL or PLE or of 50 mg/kg DOX for 10 consecutive days against stress resistance were compared. Mice in treated groups were subjected to a stress induced hyperthermia on the 1^st, 5^th, 7^th, and 10^thday. Treated mice were then subjected to tail suspension test on the 11^thday. Alteration in body weights, core temperatures, and gastric ulcers triggered by occasional exposures to foot shocks were determined.

Results:

DOX like long-lasting protective effects of PL and PLE against gradual alterations in body weights, basal temperatures and transient hyperthermic responses triggered by foot shocks during the post-treatment days were observed. Altered responses of stressed mice in tail suspension test observed 1 day after the last foot-shock exposures and gastric ulcers and other pathologies quantified 1 day after the test were also suppressed in PL or PLE or DOX pretreated groups.

Conclusion:

PL and crude PLE are DOX like long-acting desensitizers of stress triggered co-morbidities. Reported observations add further experimental evidences justifying traditionally known medicinal uses of P. longum and other plants of the Piperaceae family, and reveal that PL is also another very long acting and orally active inducer of stress resistance. Efforts to confirm stress preventive potentials of low dose plant-derived products enriched in PL or piperine like amide alkaloids in volunteers and patients can be warranted.

Chronic cortisol and the regulation of food intake and the endocrine growth axis in rainbow trout

To gain a better understanding of the mechanisms by which cortisol suppresses growth during chronic stress in fish, we characterized the effects of chronic cortisol on food intake, mass gain, the expression of appetite-regulating factors, and the activity of the GH/IGF axis. Fish given osmotic pumps that maintained plasma cortisol levels at ∼70 or 116 ng/ml for 34 days were sampled 14, 28 and 42 days post-implantation. Relative to shams, the cortisol treatments reduced food intake by 40-60% and elicited marked increases in liver leptin (lep-a1) and brain preoptic area (POA) corticotropin-releasing factor (crf) mRNA levels. The cortisol treatments also elicited 40-80% reductions in mass gain associated with increases in pituitary gh, liver gh receptor (ghr), liver igfI and igf binding protein (igfbp)-1 and -2 mRNA levels, reduced plasma GH and no change in plasma IGF1. During recovery, while plasma GH and pituitary gh, liver ghr and igfI gene expression did not differ between treatments, the high cortisol-treated fish had lower plasma IGF1 and elevated liver igfbp1 mRNA levels. Finally, the cortisol-treated fish had higher plasma glucose levels, reduced liver glycogen and lipid reserves, and muscle lipid content. Thus, our findings suggest that the growth-suppressing effects of chronic cortisol in rainbow trout result from reduced food intake mediated at least in part by increases in liver lep-a1 and POA crf mRNA, from sustained increases in hepatic igfbp1 expression that reduce the growth-promoting actions of the GH/IGF axis, and from a mobilization of energy reserves.

Real-time sampling of reasons for hedonic food consumption: further validation of the Palatable Eating Motives Scale

Highly palatable foods play a salient role in obesity and binge-eating, and if habitually eaten to deal with intrinsic and extrinsic factors unrelated to metabolic need, may compromise adaptive coping and interpersonal skills. This study used event sampling methodology (ESM) to examine whether individuals who report eating palatable foods primarily to cope, to enhance reward, to be social, or to conform, as measured by the Palatable Eating Motives Scale (PEMS), actually eat these foods primarily for the motive(s) they report on the PEMS. Secondly this study examined if the previously reported ability of the PEMS Coping motive to predict BMI would replicate if the real-time (ESM-reported) coping motive was used to predict BMI. A total of 1691 palatable eating events were collected from 169 college students over 4 days. Each event included the day, time, and types of tasty foods or drinks consumed followed by a survey that included an abbreviated version of the PEMS, hunger as an additional possible motive, and a question assessing general perceived stress during the eating event. Two-levels mixed modeling confirmed that ESM-reported motives correlated most strongly with their respective PEMS motives and that all were negatively associated with eating for hunger. While stress surrounding the eating event was strongly associated with the ESM-coping motive, its inclusion in the model as a predictor of this motive did not abolish the significant association between ESM and PEMS Coping scores. Regression models confirmed that scores on the ESM-coping motive predicted BMI. These findings provide ecological validity for the PEMS to identify true-to-life motives for consuming palatable foods. This further adds to the utility of the PEMS in individualizing, and hence improving, treatment strategies for obesity, binge-eating, dietary nutrition, coping, reward acquisition, and psychosocial skills.

Toward a radically embodied neuroscience of attachment and relationships

Attachment theory (Bowlby, 1969/1982) posits the existence of internal working models as a foundational feature of human bonds. Radical embodied approaches instead suggest that cognition requires no computation or representation, favoring a cognition situated in a body in an environmental context with affordances for action (Chemero, 2009; Barrett, 2011; Wilson and Golonka, 2013; Casasanto and Lupyan, 2015). We explore whether embodied approaches to social soothing, interpersonal warmth, separation distress, and support seeking could replace representational constructs such as internal working models with a view of relationship cognition anchored in the resources afforded to the individual by their brain, body, and environment in interaction. We review the neurobiological bases for social attachments and relationships and attempt to delineate how these systems overlap or don’t with more basic physiological systems in ways that support or contradict a radical embodied explanation. We suggest that many effects might be the result of the fact that relationship cognition depends on and emerges out of the action of neural systems that regulate several clearly physically grounded systems. For example, the neuropeptide oxytocin appears to be central to attachment and pair-bond behavior (Carter and Keverne, 2002) and is implicated in social thermoregulation more broadly, being necessary for maintaining a warm body temperature (for a review, see IJzerman et al., 2015b). Finally, we discuss the most challenging issues around taking a radically embodied perspective on social relationships. We find the most crucial challenge in individual differences in support seeking and responses to social contact, which have long been thought to be a function of representational structures in the mind (e.g., Baldwin, 1995). Together we entertain the thought to explain such individual differences without mediating representations or computations, but in the end propose a hybrid model of radical embodiment and internal representations.

Mood disorders: A potential link between ghrelin and leptin on human body?

Leptin and ghrelin are two hormones associated with multiple physiological functions, especially energy balance. Leptin is an adipocyte-secreted hormone discovered in 1950 and ghrelin which was found in 1999, is a peptide hormone produced and secreted in the stomach. A number of previous studies showed that these hormones could be associated with different types of mood disorders. The results of previous studies, nevertheless, are confounded by diverse sample selection and different methodologies. A search for related articles in the PubMed database was attempted. The search covered studies, reports, reviews and editorials published in the last ten years. Older references served as auxiliary sources for comparison purposes. However, due to the different results of the studies, there is a need for more investigation in order to establish the exact biochemical mechanisms that are responsible for these diseases and ghrelin’s and leptin’s effects on mood.

Vasopressin deficiency diminishes acute and long-term consequences of maternal deprivation in male rat pups

Early life events have special importance in the development as postnatal environmental alterations may permanently affect the lifetime vulnerability to diseases. For the interpretation of the long-term consequences it is important to understand the immediate effects. As the role of vasopressin in hypothalamic-pituitary-adrenal axis regulation as well as in affective disorders seem to be important we addressed the question whether the congenital lack of vasopressin will modify the stress reactivity of the pups and will influence the later consequences of single 24h maternal deprivation (MD) on both stress-reactivity and stress-related behavioral changes. Vasopressin-producing (di/+) and deficient (di/di) Brattleboro rat were used. In 10-day-old pups MD induced a remarkable corticosterone rise in both genotypes without adrenocorticotropin (ACTH) increase in di/di rats. Studying the later consequences at around weaning (25-35-day-old rats) we found somatic and hormonal alterations (body weight reduction, dysregulation of the stress axis) which were not that obvious in di/di rats. The more anxious state of MD rats was not detectable in di/di rats both at weaning and in adulthood (7-12-week-old). The lack of vasopressin abolished all chronic stress and anxiety-like tendencies both at weaning and in adulthood probably as a consequence of reduced ACTH rise immediately after MD in pups. This finding suggests that postnatal stress-induced ACTH rise may have long-term developmental consequences.

Restraint stress delays endometrial adaptive remodeling during mouse embryo implantation

In mice, previously, we showed that restraint stress reduces the number of embryo implantation sites in the endometrium. Here, we hypothesized that the uterine microenvironment is altered by restraint stress and consequently is suboptimal for embryo implantation. On embryonic day 1 (E1), 60 of 154 pregnant CD1 mice underwent restraint stress (4 h), repeated daily to E3, E5 or E7 (n = 10 mice per group). Restraint stress decreased food intake and suppressed body weight gain on E3, E5 and E7. Restraint stress decreased the actual and relative weight (percent body weight) of uterus and ovary on E5 (by 14.9%, p = 0.03; 16.1%, p = 0.004) and E7 (by 16.8%, p = 0.03; 20.0%, p = 0.01). Morphologically, restraint stress decreased relative endometrial area (by 8.94-18.8%, p = 0.003-0.021) and uterine gland area (by 30.6%, p < 0.01 on E3 and 44.5%, p < 0.01 on E5). Immunohistochemistry showed that restraint stress decreased microvessel density (by 12.9-70.5%, p < 0.01) and vascular endothelial growth factor expression (by 14.6-45.9%, p = 0.007-0.02). Restraint stress decreased by 32.4-39.8% (p = 0.002-0.01) the mean optical density ratio for proliferating cell nuclear antigen/terminal deoxynucleotidyl transferase dUTP nick end labeling. Methyl thiazolyl tetrazolium assay showed a dose-dependent decrease in proliferative activity of endometrial stromal cells (from 52 of 154 pregnant E5 control mice) incubated with H2O2 (100-1000 μM) in vitro. These findings supported the hypothesis that restraint stress negatively influences endometrial adaptive remodeling via an oxidative stress pathway, which resulted in fewer implantation sites.