Neuropeptide Y acts directly in the periphery on fat tissue and mediates stress-induced obesity and metabolic syndrome

Mechanisms Involved in the Link between Depression, Antidepressant Treatment, and Associated Weight Change

Major depressive disorder is a severe mood disorder associated with a marked decrease in quality of life and social functioning, accompanied by a risk of suicidal behavior. Therefore, seeking out and adhering to effective treatment is of great personal and society-wide importance. Weight changes associated with antidepressant therapy are often cited as the reason for treatment withdrawal and thus are an important topic of interest. There indeed exists a significant mechanistic overlap between depression, antidepressant treatment, and the regulation of appetite and body weight. The suggested pathomechanisms include the abnormal functioning of the homeostatic (mostly humoral) and hedonic (mostly dopaminergic) circuits of appetite regulation, as well as causing neuromorphological and neurophysiological changes underlying the development of depressive disorder. However, this issue is still extensively discussed. This review aims to summarize mechanisms linked to depression and antidepressant therapy in the context of weight change.

Mindfulness meditation modulates stress-eating and its neural correlates

Stress-related overeating can lead to excessive weight gain, increasing the risk of metabolic and cardiovascular disease. Mindfulness meditation has been demonstrated to reduce stress and increase interoceptive awareness and could, therefore, be an effective intervention for stress-related overeating behavior. To investigate the effects of mindfulness meditation on stress-eating behavior, meditation-naïve individuals with a tendency to stress-eat (N = 66) participated in either a 31-day, web-based mindfulness meditation training or a health training condition. Behavioral and resting-state fMRI data were acquired before and after the intervention. Mindfulness meditation training, in comparison to health training, was found to significantly increase mindfulness while simultaneously reducing stress- and emotional-eating tendencies as well as food cravings. These behavioral results were accompanied by functional connectivity changes between the hypothalamus, reward regions, and several areas of the default mode network in addition to changes observed between the insula and somatosensory areas. Additional changes between seed regions (i.e., hypothalamus and insula) and brain areas attributed to emotion regulation, awareness, attention, and sensory integration were observed. Notably, these changes in functional connectivity correlated with behavioral changes, thereby providing insight into the underlying neural mechanisms of the effects of mindfulness on stress-eating.Clinical trial on the ISRCTN registry: trial ID ISRCTN12901054.

Gut microbes consume host energy and reciprocally provide beneficial factors to sustain a symbiotic relationship with the host

The gut microbes thrive by utilizing host energy and, in return, provide valuable benefits, akin to the symbiotic relationship. To study the mutualistic association between the gut microbiota and host, a range of gut microbe populations (85 %, 66 %, 45 % and 38 % at the normal level) with comparable structures were constructed in broiler model. The results revealed that reductions in gut microbial population led to decreased energy consumption, resulting in increased host weight (10.26 %, 30.88 %, 17.65 % and - 12.77 %, respectively). Fecal metabolome revealed that among 85 % and 66 % of the normal population level, the gut microbes downregulated the immune-associated pathways of tryptophan metabolism and catecholamine biosynthesis, while the level of fatty acid oxidation was upregulated at 45 %. In the host, the concentration of gut microbes contributed to regulate functions related to lipid biosynthesis (from glycerophosphoserines to glycerophosphoethanolamines (9.63 %, 12.20 %, 6.66 % and 47.75 %) and glycerophosphocholines (10.78 %, 36.51 %, 2.00 % and 87.11 %)) and inflammation responses (methionine and betaine metabolism). From 85 % to 45 % of gut microbes, broiler showed an inhibited immunity (thymus gland, spleen, SIgG and IgA) and increased low-level inflammation response (ALT and T-SOD). However, at 38 %, the immune indexes exhibited an increase (thymus gland, spleen, SIgG, and IgA increased by 8.67 %, 8.50 %, 20.87 %, and 29.43 %, respectively), indicating the host lipid accumulation and inflammation response were negatively correlated with the immune reaction. Collectively, the gut microbiota maintains a symbiotic relationship with the host through the secretion of beneficial substances to interact with the host.

Unloading-Induced Skeletal Interoception Alters Hypothalamic Signaling to Promote Bone Loss and Fat Metabolism

Microgravity is the primary factor that affects human physiology in spaceflight, particularly bone loss and disturbances of the central nervous system. However, little is known about the cellular and molecular mechanisms of these effects. Here, it is reported that in mice hindlimb unloading stimulates expression of neuropeptide Y (NPY) and tyrosine hydroxylase (TH) in the hypothalamus, resulting in bone loss and altered fat metabolism. Enhanced expression of TH and NPY in the hypothalamus occurs downstream of a reduced prostaglandin E2 (PGE2)-mediated ascending interoceptive signaling of the skeletal interoception. Sympathetic antagonist propranolol or deletion of Adrb2 in osteocytes rescue bone loss in the unloading model. Moreover, depletion of TH+ sympathetic nerves or inhibition of norepinephrine release ameliorated bone resorption. Stereotactic inhibition of NPY expression in the hypothalamic neurons reduces the food intake with altered energy expenditure with a limited effect on bone, indicating hypothalamic neuroendocrine factor NPY in the facilitation of bone formation by sympathetic TH activity. These findings suggest that reduced PGE2-mediated interoceptive signaling in response to microgravity or unloading has impacts on the skeletal and central nervous systems that are reciprocally regulated.

The evolving functions of the vasculature in regulating adipose tissue biology in health and obesity

Adipose tissue is an endocrine organ and a crucial regulator of energy storage and systemic metabolic homeostasis. Additionally, adipose tissue is a pivotal regulator of cardiovascular health and disease, mediated in part by the endocrine and paracrine secretion of several bioactive products, such as adipokines. Adipose vasculature has an instrumental role in the modulation of adipose tissue expansion, homeostasis and metabolism. The role of the adipose vasculature has been extensively explored in the context of obesity, which is recognized as a global health problem. Obesity-induced accumulation of fat, in combination with vascular rarefaction, promotes adipocyte dysfunction and induces oxidative stress, hypoxia and inflammation. It is now recognized that obesity-associated endothelial dysfunction often precedes the development of cardiovascular diseases. Investigations have revealed heterogeneity within the vascular niche and dynamic reciprocity between vascular and adipose cells, which can become dysregulated in obesity. Here we provide a comprehensive overview of the evolving functions of the vasculature in regulating adipose tissue biology in health and obesity.

Neuropeptide Y receptor Y2 (npy2r) deficiency reduces anxiety and increases food intake in Japanese medaka (Oryzias latipes)

Neuropeptide Y receptor Y2 (npy2r) is an important receptor gene involved in anxiety and feeding regulation in mammals. Since NPY receptors have different receptor gene deletions in mammals and teleost fish, it is not clear whether npy2r has the similar function in fish as in mammals. In this study, we used the CRISPR/Cas9 system to establish npy2r-deficient medaka (Oryzias latipes). Unexpectedly, the deletion of npy2r resulted in the npy2r +/- medaka were all-male, therefore, npy2r homozygous mutant lines could not be established. The deletion of npy2r increased the food intake in medaka, and the expression levels of appetite stimulating genes (agrp, npy) increased significantly, while the expression levels of anorexia factors (cck, pomc) decreased significantly. Moreover, the absence of npy2r significantly increased the total length and body weight of medaka. The mirror test and open field test showed that npy2r +/- medaka improved sociability and reduced anxiety-like behavior, qRT-PCR analysis showed that the expression levels of anxiety related genes (th1, th2, gr1, gr2, and mr) in npy2r +/- medaka were significantly decreased. So far, this is the first npy2r gene knockout model established in fish and demonstrates that npy2r plays an important role in the regulation of reproduction, feeding and anxiety in fish.

The nervous system and adipose tissues: a tale of dialogues

White, beige, and brown adipose tissues play a crucial role in maintaining energy homeostasis. Due to the heterogeneous and diffuse nature of fat pads, this balance requires a fine and coordinated control of many actors and therefore permanent dialogues between these tissues and the central nervous system. For about two decades, many studies have been devoted to describe the neuro-anatomical and functional complexity involved to ensure this dialogue. Thus, if it is now clearly demonstrated that there is an efferent sympathetic innervation of different fat depots controlling plasticity as well as metabolic functions of the fat pad, the crucial role of sensory innervation capable of detecting local signals informing the central nervous system of the metabolic state of the relevant pads is much more recent. The purpose of this review is to provide the current state of knowledge on this subject.

Four-and-a-Half LIM-Domain Protein 2 (FHL2) Induces Neuropeptide Y (NPY) in Macrophages in Visceral Adipose Tissue and Promotes Diet-Induced Obesity

Obesity is characterized by the expansion of the adipose tissue, usually accompanied by inflammation, with a prominent role of macrophages infiltrating the visceral adipose tissue (VAT). This chronic inflammation is a major driver of obesity-associated comorbidities. Four-and-a-half LIM-domain protein 2 (FHL2) is a multifunctional adaptor protein that is involved in the regulation of various biological functions and the maintenance of the homeostasis of different tissues. In this study, we aimed to gain new insights into the expression and functional role of FHL2 in VAT in diet-induced obesity. We found enhanced FHL2 expression in the VAT of mice with Western-type diet (WTD)-induced obesity and obese humans and identified macrophages as the cellular source of enhanced FHL2 expression in VAT. In mice with FHL2 deficiency (FHL2KO), WTD feeding resulted in reduced body weight gain paralleled by enhanced energy expenditure and uncoupling protein 1 (UCP1) expression, indicative of activated thermogenesis. In human VAT, FHL2 was inversely correlated with UCP1 expression. Furthermore, macrophage infiltration and the expression of the chemokine MCP-1, a known promotor of macrophage accumulation, was significantly reduced in WTD-fed FHL2KO mice compared with wild-type (wt) littermates. While FHL2 depletion did not affect the differentiation or lipid metabolism of adipocytes in vitro, FHL2 depletion in macrophages resulted in reduced expressions of MCP-1 and the neuropeptide Y (NPY). Furthermore, WTD-fed FHL2KO mice showed reduced NPY expression in VAT compared with wt littermates, and NPY expression was enhanced in VAT resident macrophages of obese individuals. Stimulation with recombinant NPY induced not only UCP1 expression and lipid accumulation but also MCP-1 expression in adipocytes. Collectively, these findings indicate that FHL2 is a positive regulator of NPY and MCP-1 expression in macrophages and herewith closely linked to the mechanism of obesity-associated lipid accumulation and inflammation in VAT. Thus, FHL2 appears as a potential novel target to interfere with the macrophage-adipocyte crosstalk in VAT for treating obesity and related metabolic disorders.

Neuropeptide Y directly reduced apoptosis of granulosa cells, and the expression of NPY and its receptors in PCOS subjects

BACKGROUND

Most women with anovulatory infertility show polycystic ovarian syndrome (PCOS), and androgen excess is known as a key factor involved in pathogenicity of PCOS. However, the mechanism of follicular developmental arrest in PCOS is not completely understood. The reproductive function of Neuropeptide Y (NPY) in the ovary during folliculogenesis was previously reported; NPY function in apoptosis and proliferation of granulosa cells (GCs) is follicular-stage dependent. The objective of this study was to investigate the role of NPY in ovarian follicular development and the pathogenesis of PCOS.

METHODS

To simulate the PCOS phenotype using a rat model, 21-day old Sprague Dawley rats were implanted with dihydrotestosterone (DHT) capsule (83 µg/day) and euthanized after 28 days. mRNA and protein content of NPY and its receptors were assessed in GCs from DHT treated rats using RT-qPCR and Western blot, respectively. Proliferation and apoptosis of GCs was assessed using Ki67- and TUNEL assays. Finally, NPY levels were measured in human follicular fluid (FF) from matched PCOS and non-PCOS patients using ELISA.

RESULTS

GCs from DHT treated rats (PCOS-GCs) contained significantly less NPY protein and Npy mRNA by 0.16- and 0.56-fold, respectively, and more NPY receptor type 2 and 5 protein by 2.21- and 3.17-fold, respectively, when compared to sham control. Addition of recombinant NPY to PCOS-GCs culture did not alter Ki67-positive but significantly decreased TUNEL-positive cells by 0.65-fold, but not to baseline levels. There was no significant difference in NPY levels in FF between PCOS and non-PCOS subjects.

CONCLUSIONS

These results indicate that DHT modulates expression of NPY and its receptors, NPY decreases DHT-induced GCs apoptosis. That alterations in NPY's function might be involved in follicular developmental failure of PCOS.

Critical role of lateral habenula circuits in the control of stress-induced palatable food consumption

Chronic stress fuels the consumption of palatable food and can enhance obesity development. While stress- and feeding-controlling pathways have been identified, how stress-induced feeding is orchestrated remains unknown. Here, we identify lateral habenula (LHb) Npy1r-expressing neurons as the critical node for promoting hedonic feeding under stress, since lack of Npy1r in these neurons alleviates the obesifying effects caused by combined stress and high fat feeding (HFDS) in mice. Mechanistically, this is due to a circuit originating from central amygdala NPY neurons, with the upregulation of NPY induced by HFDS initiating a dual inhibitory effect via Npy1r signaling onto LHb and lateral hypothalamus neurons, thereby reducing the homeostatic satiety effect through action on the downstream ventral tegmental area. Together, these results identify LHb-Npy1r neurons as a critical node to adapt the response to chronic stress by driving palatable food intake in an attempt to overcome the negative valence of stress.

Adipose Tissue Denervation Blunted the Decrease in Bone Formation Promoted by Obesity in Rats

The impact of obesity upon bone metabolism is controversial since both beneficial or harmful effects have been reported. Bone remodeling is modulated by the central nervous system through cytokines, hormones and neuromodulators. The present study aimed to evaluate the effects evoked by bilateral retroperitoneal white adipose tissue (rWAT) denervation (Dnx) upon bone mineral metabolism and remodeling in an experimental model of obesity in rats. Male Wistar rats were fed during 18 weeks with high-fat diet (HFD) or standard diet (SD) as controls, and rWAT Dnx or Sham surgery was performed at the 14th week. Biochemical and hormonal parameters, bone histomorphometry, rWAT and hypothalamus protein and gene expression were analyzed. The HFD group presented decreased bone formation parameters, increased serum and bone leptin and FGF23, increased serum and hypothalamic neuropeptide Y (NPY) and decreased serum 1,25-dihydroxyvitamin D3 and PTH. After rWAT Dnx, bone markers and histomorphometry showed restoration of bone formation, and serum and hypothalamic NPY decreased, without alteration in leptin levels. The present study shows that the denervation of rWAT improved bone formation in obese rats mediated by a preferential reduction in neurohormonal actions of NPY, emphasizing the relevance of the adipose tissue-brain-bone axis in the control of bone metabolism in obesity.

The rocky road to freedom: number of countries transited during defection and risk of metabolic syndrome among North Korean Refugees in South Korea

OBJECTIVES

North Korean Refugees (NKRs) undergo defection, and this has been shown to impact their current health status in South Korea. However, little is understood about how the defection process is related to metabolic syndrome (MetS). This study regarded the defection process to be a quasi-measurement of traumatic experience and investigated whether defection was a risk factor for MetS among NKRs living in South Korea.

STUDY DESIGN

This cross-sectional study obtained data from the Korea University Anam Hospital in Seoul. NKRs (N = 847) voluntarily completed questionnaires and underwent at least one medical examination between October 2008 and July 2021.

METHODS

Multivariable logistic regression models were used to evaluate whether the number of countries transited by NKRs was associated with MetS by controlling for covariates.

RESULTS

The prevalence of MetS among male and female NKRs in South Korea was 12.3% and 13.3%, respectively. The highest prevalence of MetS (33.4%) was among NKRs who had transited two countries. The number of months in transit countries (mean: 49.9 ± 51.7) and period of residence in South Korea (mean: 40.9 ± 40.9 months) were also considered. NKRs who transited three countries had a higher probability of MetS (odds ratio [OR] 2.660, 95% confidence interval [CI] 1.161-6.097) than those who travelled directly to South Korea. NKRs who transited three countries and had only resided in South Korea for a short period had a higher probability of MetS (OR 3.424, 95% CI 1.149-10.208) than those who have lived in South Korea for a longer period.

CONCLUSIONS

Considering the social vulnerability of NKRs and consequential health problems, there is an urgent need for appropriate support from the government and society.

Neuro-Vulnerability in Energy Metabolism Regulation: A Comprehensive Narrative Review

This comprehensive narrative review explores the concept of neuro-vulnerability in energy metabolism regulation and its implications for metabolic disorders. The review highlights the complex interactions among the neural, hormonal, and metabolic pathways involved in the regulation of energy metabolism. The key topics discussed include the role of organs, hormones, and neural circuits in maintaining metabolic balance. The review investigates the association between neuro-vulnerability and metabolic disorders, such as obesity, insulin resistance, and eating disorders, considering genetic, epigenetic, and environmental factors that influence neuro-vulnerability and subsequent metabolic dysregulation. Neuroendocrine interactions and the neural regulation of food intake and energy expenditure are examined, with a focus on the impact of neuro-vulnerability on appetite dysregulation and altered energy expenditure. The role of neuroinflammation in metabolic health and neuro-vulnerability is discussed, emphasizing the bidirectional relationship between metabolic dysregulation and neuroinflammatory processes. This review also evaluates the use of neuroimaging techniques in studying neuro-vulnerability and their potential applications in clinical settings. Furthermore, the association between neuro-vulnerability and eating disorders, as well as its contribution to obesity, is examined. Potential therapeutic interventions targeting neuro-vulnerability, including pharmacological treatments and lifestyle modifications, are reviewed. In conclusion, understanding the concept of neuro-vulnerability in energy metabolism regulation is crucial for addressing metabolic disorders. This review provides valuable insights into the underlying neurobiological mechanisms and their implications for metabolic health. Targeting neuro-vulnerability holds promise for developing innovative strategies in the prevention and treatment of metabolic disorders, ultimately improving metabolic health outcomes.

Neuroendocrine Effects on the Risk of Metabolic Syndrome in Children

The endocrine and nervous systems reciprocally interact to manage physiological individual functions and homeostasis. The nervous system modulates hormone release through the hypothalamus, the main cerebrally specialized structure of the neuroendocrine system. The hypothalamus is involved in various metabolic processes, administering hormone and neuropeptide release at different levels. This complex activity is affected by the neurons of various cerebral areas, environmental factors, peripheral organs, and mediators through feedback mechanisms. Therefore, neuroendocrine pathways play a key role in metabolic homeostasis control, and their abnormalities are associated with the development of metabolic syndrome (MetS) in children. The impaired functioning of the genes, hormones, and neuropeptides of various neuroendocrine pathways involved in several metabolic processes is related to an increased risk of dyslipidaemia, visceral obesity, insulin resistance, type 2 diabetes mellitus, and hypertension. This review examines the neuroendocrine effects on the risk of MetS in children, identifying and underlying several conditions associated with neuroendocrine pathway disruption. Neuroendocrine systems should be considered in the complex pathophysiology of MetS, and, when genetic or epigenetic mutations in "hot" pathways occur, they could be studied for new potential target therapies in severe and drug-resistant paediatric forms of MetS.

Somatosensory innervation of adipose tissues

The increasing prevalence of obesity and type 2 diabetes has led to a greater interest in adipose tissue physiology. Adipose tissue is now understood as an organ with endocrine and thermogenic capacities in addition to its role in fat storage. It plays a critical role in systemic metabolism and energy regulation, and its activity is tightly regulated by the nervous system. Fat is now recognized to receive sympathetic innervation, which transmits information from the brain, as well as sensory innervation, which sends information into the brain. The role of sympathetic innervation in adipose tissue has been extensively studied. However, the extent and the functional significance of sensory innervation have long been unclear. Recent studies have started to reveal that sensory neurons robustly innervate adipose tissue and play an important role in regulating fat activity. This brief review will discuss both historical evidence and recent advances, as well as important remaining questions about the sensory innervation of adipose tissue.

Estrés percibido en mujeres con síndrome metabólico: un estudio transversal

Introducción: El estrés percibido ha sido sugerido como un factor de riesgo para el desarrollo del Síndrome Metabólico (SM). Sin embargo, poco se sabe sobre esta asociación entre las mujeres. Objetivo: evaluar el estrés percibido en mujeres con Síndrome Metabólico (SM). Materiales y Métodos: estudio transversal, basado en un ensayo clínico no aleatorizado, con pacientes de un centro de salud pública (RBR-43K52N). La variable resultada fue SM, utilizando los criterios NCEP/ATPIII. Se recogieron datos sociodemográficos, antropométricos, bioquímicos, hemodinámicos y aplicación de PSS. Resultados: La muestra estuvo compuesta por 75 mujeres afectadas por SMet (47,69± 8,15 años; 155,65±0,07 cm; 82,43±17,79 kg; IMC de 33,96±6,42). Se encontraron valores altos de WHR entre mujeres estresadas y no estresadas. La puntuación media de PSS fue de 27,73±9,17. En los grupos, hubo una diferencia significativa para PSS entre mujeres estresadas y no estresadas (35,24±5,22 y 20,42±5,53, respectivamente; p=0,001). También se observó que las mujeres estresadas tenían niveles más altos de triglicéridos y niveles más bajos de HDL-c en comparación con las mujeres no estresadas, aunque sin diferencia estadística. Discusiones: Los hallazgos sugieren que las mujeres categorizadas como estresadas tenían puntajes PSS más altos, niveles más altos de triglicéridos y niveles más bajos de HDL-c en comparación con mujeres no estresadas. Conclusiones: la puntuación de PSS fue significativamente mayor entre las mujeres con parámetros lipídicos de SM alterados, con niveles de HDL más bajos y triglicéridos elevados. Como citar este artículo: Barros, Vinicius Santos; de Araújo, Wilkslam Alves; de Jesus, Marcos Vinicius Santos; Damaceno, Taynnan de Oliveira; Rocha, Roseanne Montargil; Fernandes, Josicélia Dumêt; Rosa, Randson Souza; Santos, Isleide Santana Cardoso.  Estresse percebido em mulheres com síndrome metabólica: um estudo transversal. Revista Cuidarte. 2023;14(1):e2634. http://dx.doi.org/10.15649/cuidarte.2634

Exposure to Obesogenic Environments during Perinatal Development Modulates Offspring Energy Balance Pathways in Adipose Tissue and Liver of Rodent Models

Obesogenic environments such as Westernized diets, overnutrition, and exposure to glycation during gestation and lactation can alter peripheral neuroendocrine factors in offspring, predisposing for metabolic diseases in adulthood. Thus, we hypothesized that exposure to obesogenic environments during the perinatal period reprograms offspring energy balance mechanisms. Four rat obesogenic models were studied: maternal diet-induced obesity (DIO); early-life obesity induced by postnatal overfeeding; maternal glycation; and postnatal overfeeding combined with maternal glycation. Metabolic parameters, energy expenditure, and storage pathways in visceral adipose tissue (VAT) and the liver were analyzed. Maternal DIO increased VAT lipogenic [NPY receptor-1 (NPY1R), NPY receptor-2 (NPY2R), and ghrelin receptor], but also lipolytic/catabolic mechanisms [dopamine-1 receptor (D1R) and p-AMP-activated protein kinase (AMPK)] in male offspring, while reducing NPY1R in females. Postnatally overfed male animals only exhibited higher NPY2R levels in VAT, while females also presented NPY1R and NPY2R downregulation. Maternal glycation reduces VAT expandability by decreasing NPY2R in overfed animals. Regarding the liver, D1R was decreased in all obesogenic models, while overfeeding induced fat accumulation in both sexes and glycation the inflammatory infiltration. The VAT response to maternal DIO and overfeeding showed a sexual dysmorphism, and exposure to glycotoxins led to a thin-outside-fat-inside phenotype in overfeeding conditions and impaired energy balance, increasing the metabolic risk in adulthood.

Glucocorticoids, stress and eating: The mediating role of appetite-regulating hormones

Disrupted hormonal appetite signaling plays a crucial role in obesity as it may lead to uncontrolled reward-related eating. Such disturbances can be induced not only by weight gain itself but also by glucocorticoid overexposure, for example, due to chronic stress, disease, or medication use. However, the exact pathways are just starting to be understood. Here, we present a conceptual framework of how glucocorticoid excess may impair hormonal appetite signaling and, consequently, eating control in the context of obesity. The evidence we present suggests that counteracting glucocorticoid excess can lead to improvements in appetite signaling and may therefore pose a crucial target for obesity prevention and treatment. In turn, targeting hormonal appetite signals may not only improve weight management and eating behavior but may also decrease detrimental effects of glucocorticoid excess on cardio-metabolic outcomes and mood. We conclude that gaining a better understanding of the relationship between glucocorticoid excess and circulating appetite signals will contribute greatly to improvements in personalized obesity prevention and treatment.

The Bidirectional Relationship of NPY and Mitochondria in Energy Balance Regulation

Energy balance is regulated by several hormones and peptides, and neuropeptide Y is one of the most crucial in feeding and energy expenditure control. NPY is regulated by a series of peripheral nervous and humoral signals that are responsive to nutrient sensing, but its role in the energy balance is also intricately related to the energetic status, namely mitochondrial function. During fasting, mitochondrial dynamics and activity are activated in orexigenic neurons, increasing the levels of neuropeptide Y. By acting on the sympathetic nervous system, neuropeptide Y modulates thermogenesis and lipolysis, while in the peripheral sites, it triggers adipogenesis and lipogenesis instead. Moreover, both central and peripheral neuropeptide Y reduces mitochondrial activity by decreasing oxidative phosphorylation proteins and other mediators important to the uptake of fatty acids into the mitochondrial matrix, inhibiting lipid oxidation and energy expenditure. Dysregulation of the neuropeptide Y system, as occurs in metabolic diseases like obesity, may lead to mitochondrial dysfunction and, consequently, to oxidative stress and to the white adipose tissue inflammatory environment, contributing to the development of a metabolically unhealthy profile. This review focuses on the interconnection between mitochondrial function and dynamics with central and peripheral neuropeptide Y actions and discusses possible therapeutical modulations of the neuropeptide Y system as an anti-obesity tool.

Link between emotional and external eating behaviors, peripheral neuropeptide Y, and β-hydroxybutyrate in participants with obesity on 12-week ketogenic diet

Objective: Understanding the impact of stress on emotional and external eating behaviors and the psychological and the associated metabolic factors can help in designing subsequent interventions to protect health. In particular, psychological trait-like construct related to eating has been shown to be an important target for intervention. Methods and measures: This study aimed to investigate the biochemical variables associated with a decrease in emotional and external eating behaviors due to 12-week ketogenic diet (12KD) in 35 adult participants (12 males) with obesity. Results: Absolute changes in emotional and external eating were independent of changes in body mass, nutritional intake, and Δ cortisol, but were predicted with increases in serum β-hydroxybutyrate (BHB) and decreases in serum peripheral neuropeptide Y (pNPY) (all p's < 0.050). Decrease in pNPY was also associated with an increase in BHB but was independent of anthropometrical changes, Δ fasting glucose, and Δ insulin. Conclusion: The reductions in emotional and external eating behaviors in participants with obesity were uniquely predicted by an increase in BHB and a decrease in pNPY after 12KD. In ketosis, emotional and external eating dropped independently of body mass change. Change in pNPY predicted changes in emotional and external eating. The role of BHB in modulating eating behavior should be further explored.

Neuropeptide Y Promotes mTORC1 to Regulate Chondrocyte Proliferation and Hypertrophy

Peripheral neuropeptide Y (NPY) has been reported to regulate bone metabolism and homeostasis; however, its potential roles in growth plate chondrogenesis remain unclear. Here, we found that NPY expression decreased during chondrocyte differentiation in vitro and in vivo. NPY was required for chondrocyte proliferation; in contrast, knockdown of NPY facilitated chondrocyte hypertrophic differentiation. Administration of recombinant NPY in rat chondrocytes and metatarsal bones uncoupled normal proliferation and hypertrophic differentiation during chondrogenesis and thereby inhibited growth plate chondrogenesis and longitudinal bone growth. Remarkably, NPY activated the mTORC1 pathway in chondrocytes, whereas attenuation of mTORC1 activity by administration of rapamycin in vitro partially abrogated NPY-mediated effects on chondrocyte proliferation and hypertrophic differentiation. In addition, a combination of Y2R antagonist but not Y1R antagonist with NPY abolished NPY-mediated inhibition of metatarsal growth and growth plate chondrogenesis. Mechanistically, NPY activated Erk1/2 by NPY2R, then phosphorylated ERK1/2 activated mTORC1 to initiate PTHrP expression, which in turn promoted chondrocyte proliferation and inhibited chondrocyte hypertrophic differentiation. In conclusion, our data identified NPY as a crucial regulator of chondrogenesis and may provide a promising therapeutic strategy for skeletal diseases.

The sex-dependent response to psychosocial stress and ischaemic heart disease

Stress is an important risk factor for modern chronic diseases, with distinct influences in males and females. The sex specificity of the mammalian stress response contributes to the sex-dependent development and impacts of coronary artery disease (CAD). Compared to men, women appear to have greater susceptibility to chronic forms of psychosocial stress, extending beyond an increased incidence of mood disorders to include a 2- to 4-fold higher risk of stress-dependent myocardial infarction in women, and up to 10-fold higher risk of Takotsubo syndrome-a stress-dependent coronary-myocardial disorder most prevalent in post-menopausal women. Sex differences arise at all levels of the stress response: from initial perception of stress to behavioural, cognitive, and affective responses and longer-term disease outcomes. These fundamental differences involve interactions between chromosomal and gonadal determinants, (mal)adaptive epigenetic modulation across the lifespan (particularly in early life), and the extrinsic influences of socio-cultural, economic, and environmental factors. Pre-clinical investigations of biological mechanisms support distinct early life programming and a heightened corticolimbic-noradrenaline-neuroinflammatory reactivity in females vs. males, among implicated determinants of the chronic stress response. Unravelling the intrinsic molecular, cellular and systems biological basis of these differences, and their interactions with external lifestyle/socio-cultural determinants, can guide preventative and therapeutic strategies to better target coronary heart disease in a tailored sex-specific manner.

Adipokines: Deciphering the cardiovascular signature of adipose tissue

Obesity and hypertension are intimately linked due to the various ways that the important cell types such as vascular smooth muscle cells (VSMC), endothelial cells (EC), immune cells, and adipocytes, communicate with one another to contribute to these two pathologies. Adipose tissue is a very dynamic organ comprised primarily of adipocytes, which are well known for their role in energy storage. More recently adipose tissue has been recognized as the largest endocrine organ because of its ability to produce a vast number of signaling molecules called adipokines. These signaling molecules stimulate specific types of cells or tissues with many adipokines acting as indicators of adipocyte healthy function, such as adiponectin, omentin, and FGF21, which show anti-inflammatory or cardioprotective effects, acting as regulators of healthy physiological function. Others, like visfatin, chemerin, resistin, and leptin are often altered during pathophysiological circumstances like obesity and lipodystrophy, demonstrating negative cardiovascular outcomes when produced in excess. This review aims to explore the role of adipocytes and their derived products as well as the impacts of these adipokines on blood pressure regulation and cardiovascular homeostasis.

Alterations in mouse visceral adipose tissue mRNA expression of islet G-protein-coupled receptor ligands in obesity

BACKGROUND

Adipose tissue mass expansion in obesity leads to alterations in expression and secretion of adipokines, some of which may alter islet function by binding to G-protein-coupled receptors (GPCRs) expressed by islets. We have therefore quantified expression of mRNAs encoding islet GPCR ligands in visceral adipose tissue retrieved from lean and diet-induced obese mice to determine alterations in islet GPCR ligand mRNAs in obesity.

METHODS

Epididymal adipose tissue was retrieved from C57BL/6 mice that had been maintained on a control-fat diet (10% fat) or high-fat diet (60% fat) for 16 weeks and RT-qPCR was used to quantify mRNAs encoding ligands for islet GPCRs.

RESULTS

Of the 155 genes that encode ligands for islet GPCRs, 45 and 40 were expressed in visceral adipose tissue retrieved from lean and obese mice respectively. The remaining mRNAs were either expressed at trace level (0.0001% to 0.001% relative to Actb expression) or absent (<0.0001%). Obesity was associated with significant alterations in GPCR ligand mRNA expression in visceral adipose tissue, some of which encode for peptides with established effects on islet function (e.g. neuropeptide Y), or for GPCR ligands that have not previously been investigated for their effects on islets (e.g. (C-C motif) ligand 4; Ccl4).

CONCLUSION

Mouse visceral adipose tissue showed significant alterations in expression of mRNAs encoding islet GPCR ligands in obesity. Our data point to ligands of interest for future research on adipose-islet crosstalk via secreted ligands acting at islet GPCRs. Such research may identify islet GPCRs with therapeutic potential for T2D.

Ferroptosis increases obesity: Crosstalk between adipocytes and the neuroimmune system

Ferroptosis requires not only the accumulation of iron ions, but also changes in many ferroptosis-related regulators, including a decrease in GPX4 and inhibition of SLC7A11 for classical ferroptosis, a deletion of FSP1 or GCH1. Surprisingly, adipose tissue (AT) in the obesity conditions is also accompanied by iron buildup, decreased GSH, and increased ROS. On the neurological side, the pro-inflammatory factor released by AT may have first caused ferroptosis in the vagus nerve by inhibiting of the NRF2-GPX4 pathway, resulting in disorders of the autonomic nervous system. On the immune side, obesity may cause M2 macrophages ferroptosis due to damage to iron-rich ATMs (MFe^hi) and antioxidant ATMs (Mox), and lead to Treg cells ferroptosis through reductions in NRF2, GPX4, and GCH1 levels. At the same time, the reduction in GPX4 may also trigger the ferroptosis of B1 cells. In addition, some studies have also found the role of GPX4 in neutrophil autophagy, which is also worth pondering whether there is a connection with ferroptosis. In conclusion, this review summarizes the associations between neuroimmune regulation associated with obesity and ferroptosis, and on the basis of this, highlights their potential molecular mechanisms, proposing that ferroptosis in one or more cells in a multicellular tissue changes the fate of that tissue.

Identification of MRAP protein family as broad-spectrum GPCR modulators

BACKGROUND

The melanocortin receptor accessory proteins (MRAP1 and MRAP2) are well-known endocrine regulators for the trafficking and signalling of all five melanocortin receptors (MC1R-MC5R). The observation of MRAP2 on regulating several non-melanocortin G protein-coupled receptors (GPCRs) has been sporadically reported, whereas other endogenous GPCR partners of the MRAP protein family are largely unknown.

METHODS

Here, we performed single-cell transcriptome analysis and drew a fine GPCR blueprint and MRAPs-associated network of two major endocrine organs, the hypothalamus and adrenal gland at single-cell resolution. We also integrated multiple bulk RNA-seq profiles and single-cell datasets of human and mouse tissues, and narrowed down a list of 48 GPCRs with strong endogenous co-expression correlation with MRAPs.

RESULTS

36 and 46 metabolic-related GPCRs were consequently identified as novel interacting partners of MRAP1 or MRAP2, respectively. MRAPs exhibited protein-protein interactions and varying pharmacological properties on the surface translocation, constitutive activities and ligand-stimulated downstream signalling of these GPCRs. Knockdown of MRAP2 expression by hypothalamic administration of adeno-associated virus (AAV) packed shRNA stimulated body weight gain in mouse model. Co-injection of corticotropinreleasing factor (CRF), the agonist of corticotropin releasing hormone receptor 1 (CRHR1), suppressed feeding behaviour in a MRAP2-dependent manner.

CONCLUSIONS

Collectively, our study has comprehensively elucidated the complex GPCR networks in two major endocrine organs and redefined the MRAP protein family as broad-spectrum GPCR modulators. MRAP proteins not only serve as a vital endocrine pivot on the regulation of global GPCR activities in vivo that could explain the composite physiological phenotypes of the MRAP2 null murine model but also provide us with new insights of the phenotyping investigation of GPCR-MRAP functional complexes.

Cannabinoid CB1 Receptor Deletion from Catecholaminergic Neurons Protects from Diet-Induced Obesity

High-calorie diets and chronic stress are major contributors to the development of obesity and metabolic disorders. These two risk factors regulate the activity of the sympathetic nervous system (SNS). The present study showed a key role of the cannabinoid type 1 receptor (CB1) in dopamine β-hydroxylase (dbh)-expressing cells in the regulation of SNS activity. In a diet-induced obesity model, CB1 deletion from these cells protected mice from diet-induced weight gain by increasing sympathetic drive, resulting in reduced adipogenesis in white adipose tissue and enhanced thermogenesis in brown adipose tissue. The deletion of CB1 from catecholaminergic neurons increased the plasma norepinephrine levels, norepinephrine turnover, and sympathetic activity in the visceral fat, which coincided with lowered neuropeptide Y (NPY) levels in the visceral fat of the mutant mice compared with the controls. Furthermore, the mutant mice showed decreased plasma corticosterone levels. Our study provided new insight into the mechanisms underlying the roles of the endocannabinoid system in regulating energy balance, where the CB1 deletion in dbh-positive cells protected from diet-induced weight gain via multiple mechanisms, such as increased SNS activity, reduced NPY activity, and decreased basal hypothalamic-pituitary-adrenal (HPA) axis activity.

The principle of 'brain energy on demand' and its predictive power for stress, sleep, stroke, obesity and diabetes

Does the brain actively draw energy from the body when needed? There are different schools of thought regarding energy metabolism. In this study, the various theoretical models are classified into one of two categories: (1) conceptualizations of the brain as being purely passively supplied, which we call 'P-models,' and (2) models understanding the brain as not only passively receiving energy but also actively procuring energy for itself on demand, which we call 'A-models.' One prominent example of such theories making use of an A-model is the selfish-brain theory. The ability to make predictions was compared between the A- and P-models. A-models were able to predict and coherently explain all data examined, which included stress, sleep, caloric restriction, stroke, type-1-diabetes mellitus, obesity, and type-2-diabetes, whereas the predictions of P-models failed in most cases. The strength of the evidence supporting A-models is based on the coherence of accurate predictions across a spectrum of metabolic states. The theory test conducted here speaks to a brain that pulls its energy from the body on-demand.

Reciprocal signaling between adipose tissue depots and the central nervous system

In humans, various dietary and social factors led to the development of increased brain sizes alongside large adipose tissue stores. Complex reciprocal signaling mechanisms allow for a fine-tuned interaction between the two organs to regulate energy homeostasis of the organism. As an endocrine organ, adipose tissue secretes various hormones, cytokines, and metabolites that signal energy availability to the central nervous system (CNS). Vice versa, the CNS is a critical regulator of adipose tissue function through neural networks that integrate information from the periphery and regulate sympathetic nerve outflow. This review discusses the various reciprocal signaling mechanisms in the CNS and adipose tissue to maintain organismal energy homeostasis. We are focusing on the integration of afferent signals from the periphery in neuronal populations of the mediobasal hypothalamus as well as the efferent signals from the CNS to adipose tissue and its implications for adipose tissue function. Furthermore, we are discussing central mechanisms that fine-tune the immune system in adipose tissue depots and contribute to organ homeostasis. Elucidating this complex signaling network that integrates peripheral signals to generate physiological outputs to maintain the optimal energy balance of the organism is crucial for understanding the pathophysiology of obesity and metabolic diseases such as type 2 diabetes.

Zinc Supplementation Improved Neuropeptide Y, Nesfatin-1, Leptin, C-reactive protein, and HOMA-IR of Diet-Induced Obese Rats

Obesity is a mild chronic inflammation that causes many metabolic diseases. It was aimed to investigate some parameters affective on the energy metabolism by adding zinc (Zn, ZnSO4) to drinking water of diet-induced obese rats. Five-week aged, male Sprague Dawley rats divided into as control group, consuming standard rat diet, and high-fat diet (HFD) group. After obesity induced by feeding HFD for 8 weeks, the obese rats were divided into Zn-supplemented obese group (HFD + obese + Zn; 150 mg Zn/L (for 6 weeks), 235 mg Zn/L (7th week), 250 mg Zn/L (8th week) in drinking water) and obese group (HFD + obese). Mean body weight, serum concentrations of C-reactive protein, neuropeptide-Y, leptin, insulin fasting blood glucose, and HOMA-IR were statistically decreased by given Zn in HFD + obese + Zn group compared to HFD + obese rats. It was observed that the total cholesterol, LDL, and HDL cholesterol levels of HFD + obese + Zn group became closer to the control group level, and Zn supplementation caused a statistically significant decrease in cholesterol profile than HFD + obese rats. Also, increased mean serum nesfatin-1 level, an effective protein for the formation of satiety, was analyzed in HFD + obese + Zn group when compared to HFD + obese ones. Serum triglyceride concentration tended to decrease with the effect of Zn in obese rats. In conclusion, it can be said that oral use of Zn could improve energy balance and prevent the occurrence of metabolic diseases related to obesity depending on the anti-inflammatory effect of Zn.

Obesity and Type 2 Diabetes Mellitus Explained by the Free Energy Principle

According to the free energy principle, all sentient beings strive to minimize surprise or, in other words, an information-theoretical quantity called variational free energy. Consequently, psychosocial “stress” can be redefined as a state of “heightened expected free energy,” that is, a state of “expected surprise” or “uncertainty.” Individuals experiencing stress primarily attempt to reduce uncertainty, or expected free energy, with the help of what is called an uncertainty resolution program (URP). The URP consists of three subroutines: First, an arousal state is induced that increases cerebral information transmission and processing to reduce uncertainty as quickly as possible. Second, these additional computations cost the brain additional energy, which it demands from the body. Third, the program controls which stress reduction measures are learned for future use and which are not. We refer to an episode as “good” stress, when the URP has successfully reduced uncertainty. Failure of the URP to adequately reduce uncertainty results in either stress habituation or prolonged toxic stress. Stress habituation reduces uncertainty by flattening/broadening individual goal beliefs so that outcomes previously considered as untenable become acceptable. Habituated individuals experience so-called “tolerable” stress. Referring to the Selfish Brain theory and the experimental evidence supporting it, we show that habituated people, who lack stress arousals and therefore have decreased average brain energy consumption, tend to develop an obese type 2 diabetes mellitus phenotype. People, for whom habituation is not the free-energy-optimal solution, do not reduce their uncertainty by changing their goal preferences, and are left with nothing but “toxic” stress. Toxic stress leads to recurrent or persistent arousal states and thus increased average brain energy consumption, which in turn promotes the development of a lean type 2 diabetes mellitus phenotype. In conclusion, we anchor the psychosomatic concept of stress in the information-theoretical concept of uncertainty as defined by the free energy principle. In addition, we detail the neurobiological mechanisms underlying uncertainty reduction and illustrate how uncertainty can lead to psychosomatic illness.

Counteracting Health Risks by Modulating Homeostatic Signaling

Homeostasis was initially conceptualized by Bernard and Cannon around a century ago as a steady state of physiological parameters that vary within a certain range, such as blood pH, body temperature, and heart rate^1,2. The underlying mechanisms that maintain homeostasis are explained by negative feedbacks that are executed by the neuronal, endocrine, and immune systems. At the cellular level, homeostasis, such as that of redox and energy steady state, also exists and is regulated by various cell signaling pathways. The induction of homeostatic mechanism is critical for human to adapt to various disruptive insults (stressors); while on the other hand, adaptation occurs at the expense of other physiological processes and thus runs the risk of collateral damages, particularly under conditions of chronic stress. Conceivably, anti-stress protection can be achieved by stressor-mimicking medicinals that elicit adaptive responses prior to an insult and thereby serve as health risk countermeasures; and in situations where maladaptation may occur, downregulating medicinals could be used to suppress the responses and prevent subsequent pathogenesis. Both strategies are preemptive interventions particularly suited for individuals who carry certain lifestyle, environmental, or genetic risk factors. In this article, we will define and characterize a new modality of prophylactic intervention that forestalls diseases via modulating homeostatic signaling. Moreover, we will provide evidence from the literature that support this concept and distinguish it from other homeostasis-related interventions such as adaptogen, hormesis, and xenohormesis.

Investigation of Behavior and Plasma Levels of Corticosterone in Restrictive- and Ad Libitum-Fed Diet-Induced Obese Mice

Diet-induced obesity (DIO) mice models are commonly used to investigate obesity-related health problems. Until now, only sparse data exist on the influence of DIO on behavior and stress hormones in mice. The present study investigates high-fat DIO with two different feeding regimes on behavioral parameters in mice. Various behavioral tests (open field, elevated plus maze, social interaction, hotplate) were performed with female BALB/c and male C57BL/6 mice after a feeding period of twelve weeks (restrictive vs. ad libitum and normal-fat diet vs. high-fat diet) to investigate levels of anxiety and aggression. BALB/c mice were DIO-resistant and therefore the prerequisite for the behavior analyses was not attained. C57BL/6 mice fed a high-fat diet had a significantly higher body weight and fat mass compared to C57BL/6 mice fed a control diet. Interestingly, the DIO C57BL/6 mice showed no changes in their aggression- or anxiety-related behavior but showed a significant change in the anxiety index. This was probably due to a lower activity level, as other ethological parameters did not show an altered anxiety-related behavior. In the ad libitum-fed DIO group, the highest corticosterone level was detected. Changes due to the feeding regime (restrictive vs. ad libitum) were not observed. These results provide a possible hint to a bias in the investigation of DIO-related health problems in laboratory animal experiments, which may be influenced by the lower activity level.

Avian Neuropeptide Y: Beyond Feed Intake Regulation

Neuropeptide Y (NPY) is one of the most abundant and ubiquitously expressed neuropeptides in both the central and peripheral nervous systems, and its regulatory effects on feed intake and appetite- have been extensively studied in a wide variety of animals, including mammalian and non-mammalian species. Indeed, NPY has been shown to be involved in the regulation of feed intake and energy homeostasis by exerting stimulatory effects on appetite and feeding behavior in several species including chickens, rabbits, rats and mouse. More recent studies have shown that this neuropeptide and its receptors are expressed in various peripheral tissues, including the thyroid, heart, spleen, adrenal glands, white adipose tissue, muscle and bone. Although well researched centrally, studies investigating the distribution and function of peripherally expressed NPY in avian (non-mammalian vertebrates) species are very limited. Thus, peripherally expressed NPY merits more consideration and further in-depth exploration to fully elucidate its functions, especially in non-mammalian species. The aim of the current review is to provide an integrated synopsis of both centrally and peripherally expressed NPY, with a special focus on the distribution and function of the latter.

NPY1R exerts inhibitory action on estradiol-stimulated growth and predicts endocrine sensitivity and better survival in ER-positive breast cancer

G Protein-Coupled Receptors (GPCRs) represent the largest superfamily of cell-surface proteins. However, the expression and function of majority of GPCRs remain unexplored in breast cancer (BC). We interrogated the expression and phosphorylation status of 398 non-sensory GPCRs using the landmark BC proteogenomics and phosphoproteomic dataset from The Cancer Genome Atlas. Neuropeptide Y Receptor Y1 (NPY1R) gene and protein expression were significantly higher in Luminal A tumors versus other BC subtypes. The trend of NPY1R gene, protein, and phosphosite (NPY1R-S368s) expression was decreasing in the order of Luminal A, Luminal B, Basal, and human epidermal growth factor receptor 2 (HER2) subtypes. NPY1R gene expression increased in response to estrogen and reduced with endocrine therapy in estrogen receptor-positive (ER+) BC cells and xenograft models. Conversely, NPY1R expression decreased in ER+ BC cells resistant to endocrine therapies (estrogen deprivation, tamoxifen, and fulvestrant) in vitro and in vivo. NPY treatment reduced estradiol-stimulated cell growth, which was reversed by NPY1R antagonist (BIBP-3226) in ER+ BC cells. Higher NPY1R gene expression predicted better relapse-free survival and overall survival in ER+ BC. Our study demonstrates that NPY1R mediates the inhibitory action of NPY on estradiol-stimulated growth of ER+ BC cells, and its expression serves as a biomarker to predict endocrine sensitivity and survival in ER+ BC patients.

Fibroblast activation protein alpha: Comprehensive detection methods for drug target and tumor marker

Fibroblast activation protein alpha (FAP-α, EC3.4.2. B28), a type II transmembrane proteolytic enzyme for the serine protease peptidase family. It is underexpressed in normal tissues but increased significantly in disease states, especially in neoplasm, which is a potential biomarker to turmor diagnosis. The inhibition of FAP-α activity will retard tumor formation, which is expected to be a promising tumor therapeutic target. At present, although the FAP-α expression detection methods has diversification, a superlative detection means is necessary for the clinical diagnosis. This review covers the discovery and the latest advances in FAP-α, as well as the future research prospects. The tissue distribution, structural characteristics, small-molecule ligands and structure-activity relationship of major inhibitors of FAP-α were summarized in this review. Furthermore, a variety of detection methods including traditional detection methods and emerging probes detection were classified and compared, and the design strategy and kinetic parameters of these FAP-α probe substrates were summarized. In addition, these comprehensive information provides a series of practical and reliable assays for the optimal design principles of FAP-α probes, promoting the application of FAP-α as a disease marker in diagnosis, and a drug target in drug design.

Childhood Violence Exposure, Inflammation, and Cardiometabolic Health

Exposure to interpersonal violence during childhood, a severe and often traumatic form of social stress, is an enduring problem that an emerging body of work suggests may be relevant to cardiometabolic health and the progression of cardiovascular disease (CVD) across the life course. Less is known about this association causally, and consequently, the biological mechanisms that may confer risk for, and resilience to, poor health outcomes in the aftermath of violence are not well understood. Drawing on recent theoretical insights and empirical research in both humans and non-human animal models, the current paper articulates a hypothesis for one way that childhood violence could get "under the skin" to influence CVD. Based on this emerging literature, one plausible way that childhood violence exposure could increase susceptibility to CVD in later life is by sensitizing stress-response neurobiology and immune processes that regulate and promote inflammation, which is a key pathogenic mechanism in CVD. This is inherently a developmental process that begins in early life and that unfolds across the life course, although less is known about the specific mechanisms through which this occurs. The goal of this paper is to articulate some of these plausible mechanisms and to suggest areas for future research that aims to reduce the burden of disease among individuals who are exposed to violence.

Current Insights Into the Role of Neuropeptide Y in Skin Physiology and Pathology

Neuropeptide Y is widely distributed within the body and has long been implicated as a contributor to skin disease based on the correlative clinical data. However, until recently, there have been few empirical investigations to determine whether NPY has a pathophysiological role in the skin. Due to appearance-altering phenotypes of atopic dermatitis, psoriasis, and vitiligo, those suffering from these diseases often face multiple forms of negative social attention. This often results in psychological stress, which has been shown to exacerbate inflammatory skin diseases - creating a vicious cycle that perpetuates disease. This has been shown to drive severe depression, which has resulted in suicidal ideation being a comorbidity of these diseases. Herein, we review what is currently known about the associations of NPY with skin diseases and stress. We also review and provide educated guessing what the effects NPY can have in the skin. Inflammatory skin diseases can affect physical appearance to have significant, negative impacts on quality of life. No cure exists for these conditions, highlighting the need for identification of novel proteins/neuropetides, like NPY, that can be targeted therapeutically. This review sets the stage for future investigations into the role of NPY in skin biology and pathology to stimulate research on therapeutic targeting NPY signaling in order to combat inflammatory skin diseases.

Nutrigenetic variants and response to diet/lifestyle intervention in obese subjects: a pilot study

AIMS

Nutritional and lifestyle interventions can contribute to prevent and treat obesity and its complications; however, genetic background may influence the success of a therapy. The aim of this pilot study is to evaluate the effects of the interaction between nutrigenetic variants and nutritional intervention, as well as the changes in clinical parameters and the adherence to Mediterranean diet (MedDiet) and to physical activity, of 18 overweight or obese subjects affected by T2D or dysglycemia included in a nutritional program.

METHODS

The subjects' clinical parameters as well as their PREDIMED score and physical activity levels were recorded and compared at baseline, at 6 months and at the end of the intervention. Rs9939609 in FTO, rs17782313 near MC4R, rs326 in LPL, rs16147 in NPY, rs2943641 near IRS-1 were genotyped.

RESULTS

The subjects carrying the A allele in FTO lost less weight (p = 0.022) and had a lower BMI decrease from baseline to 12 months (p-interaction = 0.047) than TT carriers. In addition, there was a significant PREDIMED score modification over time, according to genotypes for FTO rs9939609 (p = 0.025) and NPY rs16147 (p = 0.039), respectively.

CONCLUSIONS

These preliminary findings show a significant interaction between genetic variants and the PREDIMED score, suggesting that individuals carrying the FTO variant may lose less weight than non-carriers through diet/lifestyle intervention.

Heterozygous Genetic Variants in Autosomal Recessive Genes of the Leptin-Melanocortin Signalling Pathway Are Associated With the Development of Childhood Obesity

Monogenic obesity is a severe, genetically determined disorder that affects up to 1/1000 newborns. Recent reports on potential new therapeutics and innovative clinical approaches have highlighted the need for early identification of individuals with rare genetic variants that can alter the functioning of the leptin-melanocortin signalling pathway, in order to speed up clinical intervention and reduce the risk of chronic complications. Therefore, next-generation DNA sequencing of central genes in the leptin-melanocortin pathway was performed in 1508 children and adolescents with and without obesity, aged 2-19 years. The recruited cohort comprised approximately 5% of the national paediatric population with obesity. The model-estimated effect size of rare variants in the leptin-melanocortin signalling pathway on longitudinal weight gain between carriers and non-carriers was derived. In total, 21 (1.4%) participants had known disease-causing heterozygous variants (DCVs) in the genes under investigation, and 62 (4.1%) participants were carriers of rare variants of unknown clinical significance (VUS). The estimated frequency of potential genetic variants associated with obesity (including rare VUS) ranged between 1/150 (VUS and DCV) and 1/850 (DCV) and differed significantly between participants with and without obesity. On average, the variants identified would result in approximately 7.6 kg (7.0-12.9 kg at the 95th percentile of body weight) (girls) and 8.4 kg (8.2-14.4 kg) (boys) of additional weight gain in carriers at age 18 years compared with subjects without obesity. In conclusion, children with a genetic predisposition to obesity can be promptly identified and may account for more than 6% of obesity cases. Early identification of genetic variants in the LEPR, PCSK1, POMC, MC3R and MC4R genes could reduce the societal burden and improve the clinical management of early severe childhood obesity and its implementation should be further investigated.

Coping Strategies Influence Cardiometabolic Risk Factors in Chronic Psychological Stress: A Post Hoc Analysis of A Randomized Pilot Study

Chronic psychological stress can result in physiological and mental health risks via the activation of the hypothalamic–pituitary–adrenal (HPA) axis, sympathoadrenal activity and emotion-focused coping strategies. The impact of different stress loads on cardiometabolic risk is poorly understood. This post hoc analysis of a randomized pilot study was conducted on 61 participants (18–65 years of age) with perceived chronic stress. The Perceived Stress Questionnaire (PSQ₃₀), Psychological Neurological Questionnaire (PNF), anthropometric, clinical and blood parameters were assessed. Subjects were assigned to ‘high stress’ (HS; PSQ₃₀ score: 0.573 ± 0.057) and ‘very high stress’ (VHS; PSQ₃₀ score: 0.771 ± 0.069) groups based on the PSQ₃₀. Morning salivary cortisol and CRP were elevated in both groups. Visceral adiposity, elevated blood pressure and metabolic syndrome were significantly more frequent in the HS group vs. the VHS group. The fatty liver index (FLI) was higher (p = 0.045), while the PNF score was lower (p < 0.001) in the HS group. The HS group was comprised of more smokers (p = 0.016). Energy intake and physical activity levels were similar in both groups. Thus, high chronic stress was related to visceral adiposity, FLI, elevated blood pressure and metabolic syndrome in the HS group, while very high chronic stress was associated with psychological–neurological symptoms and a lower cardiometabolic risk in the VHS group, probably due to different coping strategies.

Regulatory Peptides in Asthma

Numerous regulatory peptides play a critical role in the pathogenesis of airway inflammation, airflow obstruction and hyperresponsiveness, which are hallmarks of asthma. Some of them exacerbate asthma symptoms, such as neuropeptide Y and tachykinins, while others have ameliorating properties, such as nociception, neurotensin or β-defensin 2. Interacting with peptide receptors located in the lungs or on immune cells opens up new therapeutic possibilities for the treatment of asthma, especially when it is resistant to available therapies. This article provides a concise review of the most important and current findings regarding the involvement of regulatory peptides in asthma pathology.

Neuronal Induction of Bone-Fat Imbalance through Osteocyte Neuropeptide Y

A differentiation switch of bone marrow mesenchymal stem/stromal cells (BMSCs) from osteoblasts to adipocytes contributes to age- and menopause-associated bone loss and marrow adiposity. Here it is found that osteocytes, the most abundant bone cells, promote adipogenesis and inhibit osteogenesis of BMSCs by secreting neuropeptide Y (NPY), whose expression increases with aging and osteoporosis. Deletion of NPY in osteocytes generates a high bone mass phenotype, and attenuates aging- and ovariectomy (OVX)-induced bone-fat imbalance in mice. Osteocyte NPY production is under the control of autonomic nervous system (ANS) and osteocyte NPY deletion blocks the ANS-induced regulation of BMSC fate and bone-fat balance. γ-Oryzanol, a clinically used ANS regulator, significantly increases bone formation and reverses aging- and OVX-induced osteocyte NPY overproduction and marrow adiposity in control mice, but not in mice lacking osteocyte NPY. The study suggests a new mode of neuronal control of bone metabolism through the ANS-induced regulation of osteocyte NPY.

Altered regional grey matter volume and appetite-related hormone levels in adolescent obesity with or without binge-eating disorder

PURPOSE

Binge eating disorder (BED) is characterized by frequent and persistent overeating episodes of binge eating without compensatory behaviors. The aim was to evaluate regional gray matter volume (GMV) abnormalities and appetite-regulating hormone levels (NPY and Leptin) in obese subjects either with or without BED compared to healthy controls (HC).

METHODS

Twenty-six obese patients with BED, 25 obese patients without BED and 27 healthy subjects as an age-matched control group with neuroimaging and appetite-regulating hormone levels were found eligible for regional GMV abnormalities. A structural magnetic resonance scan and timely blood samples were drawn to assess the appetite-regulating hormone levels.

RESULTS

The BED obese patients had a greater GMVs of the right medial orbitofrontal cortex (OFC) and the left medial OFC compared to the non-BED obese patients. BED patients were characterized by greater GMV of the left medial OFC than HCs. Relative to the HCs, higher serum NPY levels were found in BED obese and non-BED obese groups. Serum leptin levels (pg/mL) had positively correlations with GMV in right medial OFC, left medial OFC, right lateral OFC, and left anterior cingulate cortex.

CONCLUSION

Among the reward processing network, which is largely associated with feeding behaviours in individuals with obesity and binge eating disorder, the OFC volumes was correlated with serum leptin concentrations. The results of our study may provide a rationale for exploring the link between regional grey matter volumes and appetite-related hormone levels in people with BED.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

Obesity-An Update on the Basic Pathophysiology and Review of Recent Therapeutic Advances

Obesity represents a major public health problem with a prevalence increasing at an alarming rate worldwide. Continuous intensive efforts to elucidate the complex pathophysiology and improve clinical management have led to a better understanding of biomolecules like gut hormones, antagonists of orexigenic signals, stimulants of fat utilization, and/or inhibitors of fat absorption. In this article, we will review the pathophysiology and pharmacotherapy of obesity including intersection points to the new generation of antidiabetic drugs. We provide insight into the effectiveness of currently approved anti-obesity drugs and other therapeutic avenues that can be explored.

Effect of Cold Stress on Neurobehavioral and Physiological Parameters in Rats

Objective: Cold stress is an important current issue and implementing control strategies to limit its sometimes harmful effects is crucial. Cold is a common stressor that can occur in our work and our occupational or leisure time activities every day. There are substantial studies on the effects of chronic stress on memory and behavior, although, the cognitive changes and anxiety disorders that can occur after exposure to chronic intermittent cold stress are not completely characterized. Therefore, the present study was undertaken with an aim to investigate the effects of chronic intermittent cold stress on body weight, food intake and working memory, and to elucidate cold stress related anxiety disorders using cognitive and behavioral test batteries. Methods: We generated a cold stress model by exposing rats to chronic intermittent cold stress for 5 consecutive days and in order to test for the potential presence of sex differences, a comparable number of male and female rats were tested in the current study. Then, we measured the body weights, food intake and the adrenal glands weight. Working memory and recognition memory were assessed using the Y maze and the Novel Object Recognition (NOR) tasks. While, sex differences in the effects of chronic stress on behavior were evaluated by the elevated plus maze (EPM), open field maze (OF), and Marble burying (MB) tests. Results: We found that 2 h exposure to cold (4°C) resulted in an increase in the relative weight of the adrenal glands in male rats. Given the same chronic stress 5 days of cold exposure (2 h per day), increased weight gain in male rats, while females showed decreased food intake and no change in body weight. Both sexes successfully performed the Y maze and object recognition (OR) tasks, indicating intact spatial working memory performance and object recognition abilities in both male and female rats. In addition, we have shown that stress caused an increase in the level of anxiety in male rats. In contrast, the behavior of the female rats was not affected by cold exposure. Conclusion: Overall, the current results provide preliminary evidence that chronic intermittent cold stress model may not be an efficient stressor to female rats. Females exhibit resilience to cold exposure that causes an increase in the level of anxiety in male rats, which demonstrates that they are affected differently by stress and the gender is an important consideration in experimental design.

Neuropeptide Y: An Update on the Mechanism Underlying Chronic Intermittent Hypoxia-Induced Endothelial Dysfunction

Endothelial dysfunction (ED) is a core pathophysiological process. The abnormal response of vascular endothelial (VE) cells to risk factors can lead to systemic consequences. ED caused by intermittent hypoxia (IH) has also been recognized. Neuropeptide Y (NPY) is an important peripheral neurotransmitter that binds to different receptors on endothelial cells, thereby causing ED. Additionally, hypoxia can induce the release of peripheral NPY; however, the involvement of NPY and its receptor in IH-induced ED has not been determined. This review explains the definition of chronic IH and VE function, including the relationship between ED and chronic IH-related vascular diseases. The results showed that that the effect of IH on VE injury is mediated by the VE-barrier structure and endothelial cell dysfunction. These findings offer new ideas for the prevention and treatment of obstructive sleep apnea syndrome and its complications.

Transcriptional Landscaping Identifies a Beige Adipocyte Depot in the Newborn Mouse

The present study sought to identify gene networks that are hallmarks of the developing inguinal subcutaneous adipose tissue (iWAT) and the interscapular brown adipose tissue (BAT) in the mouse. RNA profiling revealed that the iWAT of postnatal (P) day 6 mice expressed thermogenic and lipid catabolism transcripts, along with the abundance of transcripts associated with the beige adipogenesis program. This was an unexpected finding, as thermogenic BAT was believed to be the only site of nonshivering thermogenesis in the young mouse. However, the transcriptional landscape of BAT in P6 mice suggests that it is still undergoing differentiation and maturation, and that the iWAT temporally adopts thermogenic and lipolytic potential. Moreover, P6 iWAT and adult (P56) BAT were similar in their expression of immune gene networks, but P6 iWAT was unique in the abundant expression of antimicrobial proteins and virus entry factors, including a possible receptor for SARS-CoV-2. In summary, postnatal iWAT development is associated with a metabolic shift from thermogenesis and lipolysis towards fat storage. However, transcripts of beige-inducing signal pathways including β-adrenergic receptors and interleukin-4 signaling were underrepresented in young iWAT, suggesting that the signals for thermogenic fat differentiation may be different in early postnatal life and in adulthood.

Lactobacillus plantarum Reduces Low-Grade Inflammation and Glucose Levels in a Mouse Model of Chronic Stress and Diabetes

This study aimed to examine the effects of Lactobacillus plantarum, a lactic acid bacteria strain isolated from kimchi, on the development of low-grade inflammation and type 2 diabetes mellitus (T2DM) exacerbated by chronic stress. C57BL/6 mice were fed either a high-fat diet (HFD) and randomized into an HFD group or a group that was fed an HFD and subjected to chronic cold exposure-related stress (HFDS), or mice were fed a normal diet (ND) and randomized into an ND group or a group that was fed an ND and subjected to chronic cold exposure-related stress (NDS). Lactobacillus plantarum LRCC5310 (10⁸, 10¹⁰ CFU) and LRCC5314 (10⁸, 10¹⁰ CFU) as well as L. gasseri BNR17 (10⁸ CFU), as a positive control, were administered orally twice every day to all the mice for 12 weeks. The expression of Glut4 and adiponectin, main glucose transporter-related genes, was upregulated in the LRCC5310- and LRCC5314-treated groups. Levels of serum proinflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6]) and of mRNAs of proinflammatory genes (Tnf-α, Il-6, Ccl2, leptin) were elevated in HFDS mice. The expression of proinflammatory genes was downregulated in LRCC5310- and LRCC5314-treated groups; this was not the case for Tnf-α expression in HFDS mice. Levels of serum corticosterone and mRNA levels of stress-related genes (Npy, Y2r) were decreased in lactic acid bacteria (LAB)-fed groups, with only LRCC5314 downregulating Npy expression in HFDS mice. These results suggest that the LAB strains can normalize the expression of metabolic genes, inhibit inflammatory responses, and suppress stress in HFDS mice.