SwePub - sökning: WFRF:(Schele Erik)

Numrering	Referens	Omslagsbild	Hitta
1.	Anesten, Fredrik, et al. (författare) Functional interleukin-6 receptor- is located in tanycytes at the base of the third ventricle 2017 Ingår i: Journal of Neuroendocrinology. - : Wiley. - 0953-8194 .- 1365-2826. ; 29:12 Tidskriftsartikel (refereegranskat)abstract Interleukin (IL)-6(-)/(-) mice develop mature onset obesity, whereas i.c.v. injection of IL-6 decreases obesity in rodents. Moreover, levels of IL-6 in cerebrospinal fluid (CSF) were reported to be inversely correlated with obesity in humans. Tanycytes lining the base of the third ventricle (3V) in the hypothalamus have recently been reported to be of importance for metabolism. In the present study, we investigated whether tanycytes could respond to IL-6 in the CSF. With immunohistochemistry using a well characterised antibody directed against the ligand binding receptor for IL-6, IL-6 receptor (IL-6R), it was found that tanycytes, identified by the two markers, vimentin and dopamine- and cAMP-regulated phosphoprotein of 32 kDa, contained IL-6R. There were fewer IL-6R on another type of ventricle-lining cells, ependymal cells, as identified by the marker glucose transporter-1. To demonstrate that the immunoreactive IL-6R were responsive to IL-6, we injected IL-6 i.c.v. This treatment increased immunoreactive phosphorylated signal transducer and activator of transcription-3 (pSTAT3) in tanycytes after 5minutes and in cells in the medial part of the arcuate nucleus after 5 and 15 minutes. Intracerebroventricular injection of leptin exerted similar effects. As expected, i.p. injection of leptin also induced pSTAT3 staining in the hypothalamus, whereas i.p. IL-6 injection had little effect on this parameter. Intracerebroventricular or i.p. injection of vehicle only had no effect on pSTAT3-immunoreactivity. In summary, there are functional IL-6R on tanycytes at the bottom of the 3V, in agreement with the possibility that ventricular administration of IL-6 decreases obesity in mice via an effect on this cell type.
2.	Anesten, Fredrik, et al. (författare) Preproglucagon neurons in the hindbrain have IL-6 receptor-α and show Ca2+ influx in response to IL-6 2016 Ingår i: American Journal of Physiology. Regulatory Integrative and Comparative Physiology. - : American Physiological Society. - 0363-6119 .- 1522-1490. ; 311:1 Tidskriftsartikel (refereegranskat)abstract Neuronal circuits in the hypothalamus and hindbrain are of importance for control of food intake, energy expenditure, and fat mass. We have recently shown that treatment with exendin-4 (Ex-4), an analog of the proglucagonderived molecule glucagon-like peptide 1 (GLP-1), markedly increases mRNA expression of the cytokine interleukin-6 (IL-6) in the hypothalamus and hindbrain and that this increase partly mediates the suppression of food intake and body weight by Ex-4. Endogenous GLP-1 in the central nervous system (CNS) is produced by preproglucagon (PPG) neurons of the nucleus of the solitary tract (NTS) in the hindbrain. These neurons project to various parts of the brain, including the hypothalamus. Outside the brain, IL-6 stimulates GLP-1 secretion from the gut and pancreas. In this study, we aim to investigate whether IL-6 can affect GLP-1-producing PPG neurons in the nucleus of the solitary tract (NTS) in mouse hindbrain via the ligand binding part of the IL-6 receptor, IL-6 receptor-α (IL-6Rα). Using immunohistochemistry, we found that IL-6Rα was localized on PPG neurons of the NTS. Recordings of these neurons in GCaMP3/GLP-1 reporter mice showed that IL-6 enhances cytosolic Ca2+ concentration in neurons capable of expressing PPG. We also show that the Ca2+ increase originates from the extracellular space. Furthermore, we found that IL-6Rα was localized on cells in the caudal hindbrain expressing immunoreactive NeuN (a neuronal marker) or CNP:ase (an oligodendrocyte marker). In summary, IL-6Rα is present on PPG neurons in the NTS, and IL-6 can stimulate these cells by increasing influx of Ca2+ to the cytosol from the extracellular space. © 2016 the American Physiological Society.
3.	Benrick, Anna, 1979, et al. (författare) Interleukin-6 gene knockout influences energy balance regulating peptides in the hypothalamic paraventricular and supraoptic nuclei. 2009 Ingår i: Journal of neuroendocrinology. - : Wiley. - 1365-2826 .- 0953-8194. ; 21:7, s. 620-8 Tidskriftsartikel (refereegranskat)abstract Interleukin (IL)-6 is a pro-inflammatory cytokine that also affects metabolic function because IL-6 depleted (IL-6(-/-)) mice develop late-onset obesity. IL-6 appears to act in the central nervous system, presumably in the hypothalamus, to increase energy expenditure that appears to involve stimulation of the sympathetic nervous system. In the present study, we explored possible central mechanisms for the effects exerted by IL-6 on body fat. Therefore, we measured the effects of IL-6 depletion in IL-6(-/-) mice on expression of key hypothalamic peptide genes involved in energy balance by the real time polymerase chain reaction. Additionally, co-localisation between such peptides and IL-6 receptor alpha was investigated by immunohistochemistry. IL-6 deficiency decreased the expression of several peptides found in the paraventricular nucleus (PVN), which is a nucleus that has been attributed an adipostatic function. For example, corticotrophin-releasing hormone (CRH), which is reported to stimulate the sympathetic nervous system, was decreased by 40% in older IL-6(-/-) mice. Oxytocin, which is reported to prevent obesity, was also decreased in older IL-6(-/-) animals, as was arginine vasopressin (AVP). The IL-6 receptor alpha was abundantly expressed in the PVN, but also in the supraoptic nucleus, and was shown to be co-expressed to a high extent with CRH, AVP, oxytocin and thyrotrophin-releasing hormone. These data indicate that depletion of endogenous IL-6, a body fat suppressing cytokine, is associated with the decreased expression of CRH and oxytocin (i.e. energy balance regulating peptides) as well as AVP in the PVN. Because IL-6 receptor alpha is co-expressed with CRH, oxytocin and AVP, IL-6 could stimulate the expression of these peptides directly.
4.	de Git, K. C. G., et al. (författare) Rats that are predisposed to excessive obesity show reduced (leptin-induced) thermoregulation even in the preobese state 2019 Ingår i: Physiological Reports. - : Wiley. - 2051-817X. ; 7:14 Tidskriftsartikel (refereegranskat)abstract Both feeding behavior and thermogenesis are regulated by leptin. The sensitivity to leptin's anorexigenic effects on chow diet was previously shown to predict the development of diet-induced obesity. In this study, we determined whether the sensitivity to leptin's anorexigenic effects correlates with leptin's thermogenic response, and if this response is exerted at the level of the dorsomedial hypothalamus (DMH), a brain area that plays an important role in thermoregulation. Based on the feeding response to injected leptin on a chow diet, rats were divided into leptin-sensitive (LS) and leptin-resistant (LR) groups. The effects of leptin on core body, brown adipose tissue (BAT) and tail temperature were compared after intravenous versus intra-DMH leptin administration. After intravenous leptin injection, LS rats increased their BAT thermogenesis and reduced heat loss via the tail, resulting in a modest increase in core body temperature. The induction of these thermoregulatory mechanisms with intra-DMH leptin was smaller, but in the same direction as with intravenous leptin administration. In contrast, LR rats did not show any thermogenic response to either intravenous or intra-DMH leptin. These differences in the thermogenic response to leptin were associated with a 1°C lower BAT temperature and reduced UCP1 expression in LR rats under adlibitum feeding. The preexisting sensitivity to the anorexigenic effects of leptin, a predictor for obesity, correlates with the sensitivity to the thermoregulatory effects of leptin, which appears to be exerted, at least in part, at the level of the DMH. © 2019 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.
5.	de Git, K. C. G., et al. (författare) Zona incerta neurons projecting to the ventral tegmental area promote action initiation towards feeding 2021 Ingår i: Journal of Physiology-London. - : Wiley. - 0022-3751 .- 1469-7793. ; 559:2, s. 709-724 Tidskriftsartikel (refereegranskat)abstract Key points The zona incerta (ZI) and ventral tegmental area (VTA) are brain areas that are both implicated in feeding behaviour. The ZI projects to the VTA, although it has not yet been investigated whether this projection regulates feeding. We experimentally (in)activated the ZI to VTA projection by using dual viral vector technology, and studied the effects on feeding microstructure, the willingness to work for food, general activity and body temperature. Activity of the ZI to VTA projection promotes feeding by facilitating action initiation towards food, as reflected in meal frequency and the willingness to work for food reward, without affecting general activity or directly modulating body temperature. We show for the first time that activity of the ZI to VTA projection promotes feeding, which improves the understanding of the neurobiology of feeding behaviour and body weight regulation. Both the zona incerta (ZI) and the ventral tegmental area (VTA) have been implicated in feeding behaviour. The ZI provides prominent input to the VTA, although it has not yet been investigated whether this projection regulates feeding. Therefore, we investigated the role of ZI to VTA projection neurons in the regulation of several aspects of feeding behaviour. We determined the effects of (in)activation of ZI to VTA projection neurons on feeding microstructure, food-motivated behaviour under a progressive ratio schedule of reinforcement, locomotor activity and core body temperature. To activate or inactivate ZI neurons projecting to the VTA, we used a combination of canine adenovirus-2 in the VTA, as well as Cre-dependent designer receptors exclusively activated by designer drugs (DREADD) or tetanus toxin (TetTox) light chain in the ZI. TetTox-mediated inactivation of ZI to VTA projection neurons reduced food-motivated behaviour and feeding by reducing meal frequency. Conversely, DREADD-mediated chemogenetic activation of ZI to VTA projection neurons promoted food-motivated behaviour and feeding. (In)activation of ZI to VTA projection neurons did not affect locomotor activity or directly regulate core body temperature. Taken together, ZI neurons projecting to the VTA exert bidirectional control overfeeding behaviour. More specifically, activity of ZI to VTA projection neurons facilitate action initiation towards feeding, as reflected in both food-motivated behaviour and meal initiation, without affecting general activity.
6.	Egecioglu, Emil, 1977, et al. (författare) Interleukin-6 is important for regulation of core body temperature during long-term cold exposure in mice 2018 Ingår i: Biomedical Reports. - : Spandidos Publications. - 2049-9434 .- 2049-9442. ; 9:3, s. 206-212 Tidskriftsartikel (refereegranskat)abstract Interleukin-6 (IL6) is a cytokine important for inducing the fever response during infection and has been reported to uphold core body temperature during acute cold exposure. Recently it has also been indicated that IL6 in serum increases in cold-exposed mice. The aim of the present study was to investigate if IL6 is important for core body temperature regulation following a long-term cold exposure in mice. Experiments were performed with global IL6 deficient (-/-) mice, mice with conditional IL6 receptor α (IL6Rα) knockdown in the central nervous system (CNS; IL6RαNesCre) and appropriate wild-type (Wt) controls. All mice were placed in a cold environment (4˚C) for 6 days. Core body temperature and oxygen consumption were measured by telemetry probes and indirect calorimetry at room temperature (20˚C), and during the first and last day of cold exposure. Brain stem, hypothalamus and white and brown adipose tissues from the cold-exposed mice were subjected to gene expression analysis. After 6 days in 4˚C, the IL6-/- mice exhibited significantly lower body temperature and oxygen consumption compared with Wt mice (P<0.05). The IL6RαNesCre mice also exhibited lower body temperature compared with WtNesCre controls during the last day of cold exposure (P<0.05). Furthermore, an increase in the mRNA level of brain-derived neurotrophic factor (Bdnf) was detected in the brain stem of both IL6-/- and IL6RαNesCre mice compared with the Wt groups (P<0.05). The finding that body temperature was decreased in IL6-/- and IL6RαNesCre mice indicates a decrease in thermogenesis in these animals. Bdnf has previously been indicated to increase body temperature and could in the present study be a mechanistic factor involved in counteracting the low body temperature in IL6-/- and IL6RαNesCre mice. These results suggest that IL6 is not only involved in body temperature regulation during infection, but also during long-term cold exposure, probably through mechanisms in the CNS.
7.	Farman, Helen H., 1983, et al. (författare) Female Mice Lacking Estrogen Receptor-alpha in Hypothalamic Proopiomelanocortin (POMC) Neurons Display Enhanced Estrogenic Response on Cortical Bone Mass 2016 Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 157:8, s. 3242-3252 Tidskriftsartikel (refereegranskat)abstract Estrogens are important regulators of bone mass and their effects are mainly mediated via estrogen receptor(ER)alpha. Central ER alpha exerts an inhibitory role on bone mass. ER alpha is highly expressed in the arcuate (ARC) and the ventromedial (VMN) nuclei in the hypothalamus. To test whether ER alpha in proopiomelanocortin (POMC) neurons, located in ARC, is involved in the regulation of bone mass, we used mice lacking ER alpha expression specifically in POMC neurons (POMC-ER alpha(-/-)). Female POMC-ER alpha(-/-) and control mice were ovariectomized (OVX) and treated with vehicle or estradiol (0.5 mu g/d) for 6 weeks. As expected, estradiol treatment increased the cortical bone thickness in femur, the cortical bone mechanical strength in tibia and the trabecular bone volume fraction in both femur and vertebrae in OVX control mice. Importantly, the estrogenic responses were substantially increased in OVX POMC-ER alpha(-/-) mice compared with the estrogenic responses in OVX control mice for cortical bone thickness (+ 126 +/- 34%, P < .01) and mechanical strength (+ 193 +/- 38%, P <.01). To test whether ER alpha in VMN is involved in the regulation of bone mass, ER alpha was silenced using an adeno-associated viral vector. Silencing of ER alpha in hypothalamic VMN resulted in unchanged bone mass. In conclusion, mice lacking ER alpha in POMC neurons display enhanced estrogenic response on cortical bone mass and mechanical strength. We propose that the balance between inhibitory effects of central ER alpha activity in hypothalamic POMC neuronsin ARC and stimulatory peripheral ER alpha-mediated effects in bone determines cortical bone mass in female mice.
8.	Gummesson, Anders, 1973, et al. (författare) Relations of Adipose Tissue Cell Death-Inducing DFFA-like Effector A Gene Expression to Basal Metabolic Rate, Energy Restriction and Obesity: Population-based and Dietary Intervention Studies. 2007 Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 92:12, s. 4759-65 Tidskriftsartikel (refereegranskat)abstract Context: Cell death-inducing DFFA-like effector A (CIDEA) could be a potential target for the treatment of obesity via the modulation of metabolic rate, based on the findings that CIDEA inhibits the brown adipose tissue uncoupling process in rodents. Objective: To investigate the putative link between CIDEA and basal metabolic rate in humans, and to further elucidate the role of CIDEA in human obesity. Design: We have explored CIDEA gene expression in adipose tissue in two different human studies: A cross-sectional and population-based study assessing body composition and metabolic rate (Mölndal Metabolic study, n=92), and a longitudinal intervention-study of obese subjects treated with a very low calorie diet (VLCD study, n=24). Results: The CIDEA gene was predominantly expressed in adipocytes as compared to other human tissues. CIDEA gene expression in adipose tissue was inversely associated with basal metabolic rate independently of body composition, age and gender (p=0.014). VLCD induced an increase in adipose tissue CIDEA expression (p<0.0001) with a subsequent decrease in response to refeeding (p<0.0001). Reduced CIDEA gene expression was associated with a high body fat content (p<0.0001) and with high insulin levels (p<0.01). No dysregulation of CIDEA expression was observed in individuals with the metabolic syndrome when compared with BMI-matched controls. In a separate sample of VLCD-treated subjects (n=10), uncoupling protein 1 expression was reduced during diet (p=0.0026) and inversely associated with CIDEA expression (p=0.0014). Conclusion: The findings are consistent with the concept that CIDEA plays a role in adipose tissue energy expenditure.
9.	Jansson, John-Olov, 1954, et al. (författare) A Body Weight Sensor Regulates Prepubertal Growth via the Somatotropic Axis in Male Rats 2021 Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 162:6 Tidskriftsartikel (refereegranskat)abstract In healthy conditions, prepubertal growth follows an individual specific growth channel. Growth hormone (GH) is undoubtedly the major regulator of growth. However, the homeostatic regulation to maintain the individual specific growth channel during growth is unclear. We recently hypothesized a body weight sensing homeostatic regulation of body weight during adulthood, the gravitostat. We now investigated if sensing of body weight also contributes to the strict homeostatic regulation to maintain the individual specific growth channel during prepubertal growth. To evaluate the effect of increased artificial loading on prepubertal growth, we implanted heavy (20% of body weight) or light (2% of the body weight) capsules into the abdomen of 26-day-old male rats. The body growth, as determined by change in biological body weight and growth of the long bones and the axial skeleton, was reduced in rats bearing a heavy load compared with light load. Removal of the increased load resulted in a catch-up growth and a normalization of body weight. Loading decreased hypothalamic growth hormone releasing hormone mRNA, liver insulin-like growth factor (IGF)-1 mRNA, and serum IGF-1, suggesting that the reduced body growth was caused by a negative feedback regulation on the somatotropic axis and this notion was supported by the fact that increased loading did not reduce body growth in GH-treated rats. Based on these data, we propose the gravitostat hypothesis for the regulation of prepubertal growth. This states that there is a homeostatic regulation to maintain the individual specific growth channel via body weight sensing, regulating the somatotropic axis and explaining catch-up growth.
10.	Jansson, John-Olov, 1954, et al. (författare) Body weight homeostat that regulates fat mass independently of leptin in rats and mice. 2018 Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490. ; 115:2, s. 427-432 Tidskriftsartikel (refereegranskat)abstract Subjects spending much time sitting have increased risk of obesity but the mechanism for the antiobesity effect of standing is unknown. We hypothesized that there is a homeostatic regulation of body weight. We demonstrate that increased loading of rodents, achieved using capsules with different weights implanted in the abdomen or s.c. on the back, reversibly decreases the biological body weight via reduced food intake. Importantly, loading relieves diet-induced obesity and improves glucose tolerance. The identified homeostat for body weight regulates body fat mass independently of fat-derived leptin, revealing two independent negative feedback systems for fat mass regulation. It is known that osteocytes can sense changes in bone strain. In this study, the body weight-reducing effect of increased loading was lost in mice depleted of osteocytes. We propose that increased body weight activates a sensor dependent on osteocytes of the weight-bearing bones. This induces an afferent signal, which reduces body weight. These findings demonstrate a leptin-independent body weight homeostat ("gravitostat") that regulates fat mass.
11.	Jansson, John-Olov, 1954, et al. (författare) The dual hypothesis of homeostatic body weight regulation, including gravity-dependent and leptin-dependent actions. 2023 Ingår i: Philosophical transactions of the Royal Society of London. Series B, Biological sciences. - 1471-2970. ; 378:1888 Forskningsöversikt (refereegranskat)abstract Body weight is tightly regulated when outside the normal range. It has been proposed that there are individual-specific lower and upper intervention points for when the homeostatic regulation of body weight is initiated. The nature of the homeostatic mechanisms regulating body weight at the lower and upper ends of the body weight spectrum might differ. Previous studies demonstrate that leptin is the main regulator of body weight at the lower end of the body weight spectrum. We have proposed that land-living animals use gravity to regulate their body weight. We named this homeostatic system the gravitostat and proposed that there are two components of the gravitostat. First, an obvious mechanism involves increased energy consumption in relation to body weight when working against gravity on land. In addition, we propose that there exists a component, involving sensing of the body weight by osteocytes in the weight-bearing bones, resulting in a feedback regulation of energy metabolism and body weight. The gravity-dependent homeostatic regulation is mainly active in obese mice. We, herein, propose the dual hypothesis of body weight regulation, including gravity-dependent actions (= gravitostat) at the upper end and leptin-dependent actions at the lower end of the body weight spectrum. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.
12.	Lager, Susanne, 1978, et al. (författare) Perinatal lack of maternal IL-6 promotes increased adiposity during adulthood in mice. 2011 Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 152:4, s. 1336-46 Tidskriftsartikel (refereegranskat)abstract The perinatal environment appears important in establishing metabolic phenotypes in adulthood. Mice deficient in IL-6 (IL-6(-/-)) tend to develop mature-onset obesity, but it is unknown whether perinatal exposure to IL-6 produced by the dam influences the metabolism of adult offspring. To address this issue, we monitored IL-6(-/-) offspring of IL-6(-/-) or IL-6(+/-) dams, as well as wild-type (WT) mice. At adult age, IL-6(-/-) mice weighed significantly more and had more body fat than WT mice, regardless of maternal genotype, and had lower insulin sensitivity. This phenotype was more pronounced in IL-6(-/-) offspring of IL-6(-/-) dams, because they gained weight significantly faster than IL-6(-/-) offspring of IL-6(+/-) dams and had more body fat and higher serum leptin levels at an earlier age. The leptin content was 2-fold higher in milk from IL-6(-/-) than WT dams. However, cross-fostering IL-6(-/-) mice with WT dams did not alter body weight, body composition, or adipocyte size at adult age compared with IL-6(-/-) mice fostered by IL-6(-/-) dams. Conversely, WT mice fostered by IL-6(-/-) dams weighed significantly more than those fostered by WT dams and had more body fat, larger adipocytes, and altered hypothalamic gene expression. We conclude that body fat of adult mice can be increased by perinatal exposure to factors affected by lack of maternal IL-6.
13.	Le May, Marie, et al. (författare) Activation of the rat hypothalamic supramammillary nucleus by food anticipation, food restriction or ghrelin administration 2019 Ingår i: Journal of Neuroendocrinology. - : Wiley. - 0953-8194 .- 1365-2826. ; 31:7 Tidskriftsartikel (refereegranskat)abstract The circulating orexigenic hormone ghrelin targets many brain areas involved in feeding control and signals via a dedicated receptor, the growth hormone secretagogue receptor 1A. One unexplored target area for ghrelin is the supramammillary nucleus (SuM), a hypothalamic area involved in motivation and reinforcement and also recently linked to metabolic control. Given that ghrelin binds to the SuM, we explored whether SuM cells respond to ghrelin and/or are activated when endogenous ghrelin levels are elevated. We found that peripheral ghrelin injection activates SuM cells in rats, reflected by an increase in the number of cells expressing c-Fos protein in this area, as welll as by the predominantly excitatory response of single SuM cells recorded in in vivo electrophysiological studies. Further c-Fos mapping studies reveal that this area is also activated in rats in situations when circulating ghrelin levels are known to be elevated: in food-restricted rats anticipating the consumption of food and in fed rats anticipating the consumption of an energy-dense food. We also show that intra-SuM injection of ghrelin induces a feeding response in rats suggesting that, if peripheral ghrelin is able to access the SuM, it may have direct effects on this brain region. Collectively, our data demonstrate that the SuM is activated when peripheral ghrelin levels are high, further supporting the emerging role for this brain area in metabolic and feeding control. © 2018 The Authors. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology
14.	Le May, Marie, et al. (författare) Functional and Neurochemical Identification of Ghrelin Receptor (GHSR)-Expressing Cells of the Lateral Parabrachial Nucleus in Mice 2021 Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-453X. ; 15 Tidskriftsartikel (refereegranskat)abstract The lateral parabrachial nucleus (lPBN), located in the pons, is a well-recognized anorexigenic center harboring, amongst others, the calcitonin gene-related peptide (CGRP)-expressing neurons that play a key role. The receptor for the orexigenic hormone ghrelin (the growth hormone secretagogue receptor, GHSR) is also abundantly expressed in the lPBN and ghrelin delivery to this site has recently been shown to increase food intake and alter food choice. Here we sought to explore whether GHSR-expressing cells in the lPBN (GHSR(lPBN) cells) contribute to feeding control, food choice and body weight gain in mice offered an obesogenic diet, involving studies in which GHSR(lPBN) cells were silenced. We also explored the neurochemical identity of GHSR(lPBN) cells. To silence GHSR(lPBN) cells, Ghsr-IRES-Cre male mice were bilaterally injected intra-lPBN with a Cre-dependent viral vector expressing tetanus toxin-light chain. Unlike control wild-type littermates that significantly increased in body weight on the obesogenic diet (i.e., high-fat high-sugar free choice diet comprising chow, lard and 9% sucrose solution), the heterozygous mice with silenced GHSR(lPBN) cells were resistant to diet-induced weight gain with significantly lower food intake and fat weight. The lean phenotype appeared to result from a decreased food intake compared to controls and caloric efficiency was unaltered. Additionally, silencing the GHSR(lPBN) cells altered food choice, significantly reducing palatable food consumption. RNAscope and immunohistochemical studies of the lPBN revealed considerable co-expression of GHSR with glutamate and pituitary adenylate cyclase-activating peptide (PACAP), and much less with neurotensin, substance P and CGRP. Thus, the GHSR(lPBN) cells are important for diet-induced weight gain and adiposity, as well as in the regulation of food intake and food choice. Most GHSR(lPBN) cells were found to be glutamatergic and the majority (76%) do not belong to the well-characterized anorexigenic CGRP cell population.
15.	Mulders, R. J., et al. (författare) Microbiota in obesity: interactions with enteroendocrine, immune and central nervous systems 2018 Ingår i: Obesity Reviews. - : Wiley. - 1467-7881. ; 19:4, s. 435-451 Tidskriftsartikel (refereegranskat)abstract Western diets, with high consumption of simple sugars and saturated fats, contribute to the rise in the prevalence of obesity. It now seems clear that high-fat diets cause obesity, at least in part, by modifying the composition and function of the microorganisms that colonize in the gastrointestinal tract, the microbiota. The exact pathways by which intestinal microbiota contribute to obesity remain largely unknown. High-fat diet-induced alterations in intestinal microbiota have been suggested to increase energy extraction, intestinal permeability and systemic inflammation while decreasing the capability to generate obesity-suppressing short-chain fatty acids. Moreover, by increasing systemic inflammation, microglial activation and affecting vagal nerve activity, obese microbiota' indirectly influence hypothalamic gene expression and promote overeating. Because the potential of intestinal microbiota to induce obesity has been recognized, multiple ways to modify its composition and function are being investigated to provide novel preventive and therapeutic strategies against diet-induced obesity.
16.	Peris-Sampedro, Fiona, et al. (författare) A skeleton in the cupboard in ghrelin research: Where are the skinny dwarfs? 2021 Ingår i: Journal of Neuroendocrinology. - : Wiley. - 0953-8194 .- 1365-2826. ; 33:11 Tidskriftsartikel (refereegranskat)abstract Based on studies delivering ghrelin or ghrelin receptor agonists, we have learned a great deal about the importance of the brain ghrelin signalling system for a wide range of physiological processes that include feeding behaviours, growth hormone secretion and glucose homeostasis. Because these processes can be considered as essential to life, the question arises as to why mouse models of depleted ghrelin signalling are not all skinny dwarfs with a host of behavioural and metabolic problems. Here, we provide a systematic detailed review of the phenotype of mice with deficient ghrelin signalling to help better understand the relevance and importance of the brain ghrelin signalling system, with a particular emphasis on those questions that remain unanswered.
17.	Peris-Sampedro, Fiona, et al. (författare) Impact of Free-Choice Diets High in Fat and Different Sugars on Metabolic Outcome and Anxiety-Like Behavior in Rats 2019 Ingår i: Obesity. - : Wiley. - 1930-7381. ; 27:3, s. 409-419 Tidskriftsartikel (refereegranskat)abstract Objective Rats were exposed to free-choice diets (fat plus one of two different sugar solutions, glucose or sucrose), and the metabolic consequences and impact on locomotor activity and anxiety-like behavior were explored. Methods For 3 weeks, 7-week-old male rats were offered either chow only or free-choice high-fat diets differing in their added sugar: no sugar, sucrose, or glucose. In a second experiment, after 2 weeks on the diets, rats were switched from high sucrose to high glucose for two additional weeks. Metabolic end points included body weight, food intake, food choice, glycemic control, metabolic hormones, fat pad weight, brown adipose tissue weight, and gene expression. Behavioral analysis included locomotor and anxiety-like activity in the open field and elevated plus maze. Results Both sugar diets enhanced adiposity and induced hyperphagia, favoring unhealthier dietary selection above that of the control diets (chow or free-choice high-fat with no sugar). Despite isocaloric intake in the sugar-containing diets, offering glucose instead of sucrose was associated with improved insulin sensitivity. The sugar-containing diets reduced activity (but with movements of increased velocity) and induced an anxiety-like phenotype. Conclusions Although free-choice diets negatively impacted on metabolism and anxiety-like behavior, replacing sucrose with glucose improved insulin sensitivity and may therefore be better for health.
18.	Peters, T., et al. (författare) The association of serum leptin levels with food addiction is moderated by weight status in adolescent psychiatric inpatients 2018 Ingår i: European Eating Disorders Review. - : Wiley. - 1072-4133. ; 26:6, s. 618-628 Tidskriftsartikel (refereegranskat)abstract Leptin is essential for the control of energy homeostasis and eating behaviour. We investigated potential associations between serum leptin levels and food addiction in adolescent psychiatric inpatients (n = 228). The most frequent psychiatric diagnoses were mood disorders, anxiety disorders, and substance use disorders. More than three quarters of the study group suffered from more than one psychiatric disorder. Food addiction was assessed with the Yale Food Addiction Scale. Leptin was determined in serum. Analyses were conducted for the whole body weight range and for distinct weight categories to evaluate a potential impact of known nonlinearity between leptin levels and satiety due to leptin resistance in obese. A weak negative association between food addiction and leptin in normal weight patients (ss = -0.11, p = .022) was detected. In contrast, food addiction was associated with a significantly higher serum leptin (ss = 0.16. p = .038) in overweight patients. Food addiction in normal weight patients might be associated with restrained eating, previously shown to involve reduced leptin levels. The small positive association of food addiction with higher serum leptin in overweight patients might reflect leptin resistance and overeating.
19.	Pfabigan, D. M., et al. (författare) Ghrelin is related to lower brain reward activation during touch 2024 Ingår i: PSYCHOPHYSIOLOGY. - 0048-5772 .- 1469-8986. ; 61:2 Tidskriftsartikel (refereegranskat)abstract The gut hormone ghrelin drives food motivation and increases food intake, but it is also involved in the anticipation of and response to rewards other than food. This pre-registered study investigated how naturally varying ghrelin concentrations affect the processing of touch as a social reward in humans. Sixty-seven volunteers received slow caressing touch (so-called CT-targeted touch) as a social reward and control touch on their shins during 3T functional imaging on two test days. On one occasion, participants were fasted, and on another, they received a meal. On each occasion, plasma ghrelin was measured at three time points. All touch was rated as more pleasant after the meal, but there was no association between ghrelin concentrations and pleasantness. CT-targeted touch was rated as the most pleasant and activated somatosensory and reward networks (whole brain). A region-of-interest in the right medial orbitofrontal cortex (mOFC) showed lower activation during all touches, the higher the ghrelin concentrations were. During CT-targeted touch, a larger satiety response (ghrelin decrease after the meal) was associated with higher mOFC activation, and this mOFC activation was associated with higher experienced pleasantness. Overall, higher ghrelin concentrations appear to be related to a lower reward value for touch. Ghrelin may reduce the value of social stimuli, such as touch, to promote food search and intake in a state of low energy. This suggests that the role of ghrelin goes beyond assigning value to food reward.
20.	Rabasa-Papio, Cristina, et al. (författare) Divergent Metabolic Effects of Acute Versus Chronic Repeated Forced Swim Stress in the Rat 2019 Ingår i: Obesity. - : Wiley. - 1930-7381. ; 27:3, s. 427-433 Tidskriftsartikel (refereegranskat)abstract Objective This study sought to examine divergence regarding the impact of acute versus chronic repeated stress on energy balance. Methods Rats were exposed to either chronic repeated forced swim (FS) stress for 7 days or an acute stress (a single FS). Body weight and food intake were measured daily. Metabolic parameters explored included brown adipose tissue (BAT) weight and activity. Results Chronic repeated FS stress decreased body weight and caloric efficiency. It also increased the relative weight of BAT. The same stressor delivered only once did not alter adrenal or BAT weight, but it did increase the metabolic activity of BAT. In stress-naive rats, acute FS stress induced an anorexigenic response during the first day after the stressor that caused a reduction in body weight (that persisted for 4 days). By contrast, the chronic FS rats did not show an anorexigenic response after the final stressor, and there was no change in body weight during the following 4 days. Conclusions Rats exposed to chronic repeated FS stress adapt to the stressor over time; they become less sensitive to its anorexigenic effects and its metabolic effects in BAT, adaptations that ultimately reduce sensitivity to the weight-lowering effects of an acute stressor.
21.	Schéle, Erik, 1980 (författare) Body fat regulating neuropeptides: relation to interleukines and gut microbiota 2012 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Previous studies have shown that mice lacking interleukin-6 (IL-6), an important cytokine in the immune system, develop obesity, and that central, but not peripheral, administration of IL-6 induces energy expenditure. These findings suggest that IL-6 suppresses fat mass through the central nervous system. The mechanism behind this, however, is not understood. The aim of this thesis was to investigate possible neurobiological mechanisms, by which IL-6, during health, could exert its fat suppressing effect. Using immunohistochemistry, we aimed to map the distribution of the IL-6 receptor α (IL-6Rα) in human and mouse hypothalamus. In IL-6 knockout mice, we measured the gene expression of key hypothalamic neuropeptides known to regulate energy homeostasis. In mice, IL-6Rα was present mainly on neurons, and was widely distributed throughout the hypothalamus. IL-6Rα was found in a large number of neurons in the fat suppressing arcuate nucleus (ARC) and paraventricular nucleus (PVN), as well as in the fat promoting lateral hypothalamic area (LHA). We also found the IL-6Rα to be co-localized with several energy balance regulating neuropeptides in these hypothalamic sites, for instance with orexin and melanin concentrating hormone (MCH) in the LHA. In humans, IL-6Rα was only found in MCH neurons, but virtually all MCH neurons contained IL-6Rα. Depletion of IL-6 reduced the expression of the fat suppressing neuropeptides corticotrophin-releasing hormone (CRH) and oxytocin, as well as of arginine-vasopressin (AVP). In addition, we found IL-6Rα on neurons that produce these neuropeptides. This indicates that IL-6 could directly act on these neurons to increase the expression of CRH, oxytocin and AVP. Depletion of IL-6 induced the expression of the fat suppressing cytokine IL-1. In addition, IL-6 expression was reduced in mice with IL-1 receptor 1 knockout. This indicates that, in the hypothalamus, IL-1 receptor 1 signaling increase IL-6 expression, while IL-6 decreases IL-1 expression. Based on our findings in this thesis we speculate that IL-6 could act on several hypothalamic neurons and sites involved in energy homeostasis to increase energy expenditure and eventually weight loss in mice, while a similar effect could by exerted via the pro-obesity neuropeptide MCH in humans. Previous studies show that gut microbiota contributes to obesity, in part by facilitating nutritional uptake, but probably also through other mechanisms. We aimed to investigate possible effects of gut microbiota on central energy balance regulation. We measured the gene expression of several important energy balance regulating neuropeptides in the hypothalamus and brainstem of germ free mice. The fat suppressing neuropeptides glucagon-like peptide-1(GLP-1) and brain-derived neurotrophic factor (BDNF) was downregulated in the presence of gut microbiota, which could explain the elevated fat mass. In addition, we found that mice with gut microbiota were less sensitive to leptin, providing another mechanism by which gut microbiota could increase fat mass. In conclution, our findings are in line the assumption that components of the immune system and the commensal gut microbiota can affect fat mass in part via energy balance-regulating circuits in the brain.
22.	Schéle, Erik, 1980, et al. (författare) Central administration of ghrelin induces conditioned avoidance in rodents 2017 Ingår i: European Neuropsychopharmacology. - : Elsevier BV. - 0924-977X. ; 27:8, s. 809-815 Tidskriftsartikel (refereegranskat)abstract Feelings of hunger carry a negative-valence (emotion) signal that appears to be conveyed through agouti-related peptide (AgRP) neurons in the hypothalamic arcuate nucleus. The circulating hunger hormone, ghrelin, activates these neurons although it remains unclear whether it also carries a negative-valence signal. Given that ghrelin also activates pathways in the midbrain that are important for reward, it remains possible that ghrelin could act as a positive reinforcer and hence, carry a positive-valence signal. Here we used condition preference/avoidance tests to explore the reinforcing/aversive properties of ghrelin, delivered by intracerebroventricular (ICV) injection (2 mu g/injection once a day for 4 days). We found that ICV ghrelin produces conditioned avoidance, both in a conditioned place preference/avoidance test (CPP/CPA, in which the animals avoid a chamber previously paired to ghrelin injection) and in a conditioned flavor preference/avoidance test (CFP/CFA, in which the animals consume/avoid a taste previously paired to ghrelin injection). These effects of ghrelin to induce a CPA were observed when conditioning to ghrelin occurred in the absence or presence of food. We did not find evidence, however, that brain ghrelin delivery to rats induces malaise (in the pica test). Our data indicate that ICV ghrelin carries a negative-valence signal consistent with its role as a circulating hunger hormone and with its effects to activate AgRP neurones.
23.	Schéle, Erik, 1980, et al. (författare) Centrally Administered Ghrelin Acutely Influences Food Choice in Rodents 2016 Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:2 Tidskriftsartikel (refereegranskat)abstract We sought to determine whether the orexigenic hormone, ghrelin, is involved in the intrinsic regulation of food choice in rats. Ghrelin would seem suited to serve such a role given that it signals hunger information from the stomach to brain areas important for feeding control, including the hypothalamus and reward system (e. g. ventral tegmental area, VTA). Thus, in rats offered a choice of palatable foods (sucrose pellets and lard) superimposed on regular chow for 2 weeks, we explored whether acute central delivery of ghrelin (intracerebroventricular (ICV) or intra-VTA) is able to redirect their dietary choice. The major unexpected finding is that, in rats with high baseline lard intake, acute ICV ghrelin injection increased their chow intake over 3-fold, relative to vehicle-injected controls, measured at both 3 hr and 6 hr after injection. Similar effects were observed when ghrelin was delivered to the VTA, thereby identifying the VTA as a likely contributing neurobiological substrate for these effects. We also explored food choice after an overnight fast, when endogenous ghrelin levels are elevated, and found similar effects of dietary choice to those described for ghrelin. These effects of fasting on food choice were suppressed in models of suppressed ghrelin signaling (i. e. peripheral injection of a ghrelin receptor antagonist to rats and ghrelin receptor (GHSR) knock-out mice), implicating a role for endogenous ghrelin in the changes in food choice that occur after an overnight fast. Thus, in line with its role as a gut-brain hunger hormone, ghrelin appears to be able to acutely alter food choice, with notable effects to promote "healthy" chow intake, and identify the VTA as a likely contributing neurobiological substrate for these effects.
24.	Schele, Erik, et al. (författare) Engagement of the brain orexin system in activity-based anorexia behaviour in mice 2023 Ingår i: European Neuropsychopharmacology. - : Elsevier BV. - 0924-977X. ; 70, s. 63-71 Tidskriftsartikel (refereegranskat)abstract While excessive physical activity is common amongst anorexia nervosa (AN) patients, contributing to their low body weight, little is known about the underlying biology and effective treatments targeting the hyperactivity are lacking. Given the role of orexin in arousal, physical activity and energy expenditure, we sought to investigate i) the extent to which orexin neurons are activated during severe anorectic state in the activity-based anorexia (ABA) mouse model, and ii) if the dual orexin receptor antagonist suvorexant can reduce physical activity during ABA. The Fos-TRAP2 technique enable us to visually capture active neurons (Fos expressing) during severe anorectic state in the ABA mouse model, and by immunohistochemistry, determine the extent to which these active neurons are orexin positive. In addition, suvorexant was administered peripherally to ABA mice and running activity was monitored. We found that a large population of orexin neurons in the hypothalamus are activated by ABA and that peripheral administration of suvorexant decreases food anticipatory activity in these mice. We conclude that orexin may be a suitable target to treat hyperactivity in AN and recommend further studies to examine the efficacy of suvorexant in aiding AN patients to control their drive for hyperactivity. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
25.	Schéle, Erik, 1980, et al. (författare) Ghrelin Induces Place Preference for Social Interaction in the Larger Peer of a Male Rat Pair. 2020 Ingår i: Neuroscience. - : Elsevier BV. - 1873-7544 .- 0306-4522. Tidskriftsartikel (refereegranskat)abstract Social interaction is important for survival in most social species including humans. To ensure social activities, individuals experience reward from social interaction, generating a powerfully reinforcing process. Here we hypothesized that reward from social interaction in a juvenile male rat pair may be enhanced by ghrelin, a circulating hormone that has been shown to enhance reward from other natural (e.g. food, sex) as well as artificial reinforcers (e.g. alcohol and other drugs of abuse). To this end, we assessed the impact of ghrelin and a ghrelin antagonist on preference for a chamber previously paired to the presence of a social partner in a conditioned place preference paradigm. We found that ghrelin increased and a ghrelin antagonist decreased preference for social interaction but only in the heavier partner in a social pair. In addition, we found that administered ghrelin induced a positive association between preference for social interaction and body weight difference within socially interacting pairs, where larger ghrelin treated rats preferred social interaction, and whereas smaller ghrelin treated rats avoided it, which raises the question if ghrelin could have a role in implementing social hierarchies in rats. In summary, we conclude that ghrelin signaling increases the reward from social interaction in a manner that reflects the degree of divergence in body weight between the social pair.
26.	Schéle, Erik, 1980, et al. (författare) Interleukin-6 Receptor alpha is Co-localised with Melanin-Concentrating Hormone in Human and Mouse Hypothalamus 2012 Ingår i: Journal of Neuroendocrinology. - : Wiley. - 0953-8194. ; 24:6, s. 930-943 Tidskriftsartikel (refereegranskat)abstract Interleukin (IL)-6 deficient mice develop mature-onset obesity. Furthermore, i.c.v. administration of IL-6 increases energy expenditure, suggesting that IL-6 centrally regulates energy homeostasis. To investigate whether it would be possible for IL-6 to directly influence the energy homeostasis via hypothalamic regulation in humans and rodents, we mapped the distribution of the ligand binding IL-6 receptor a (IL-6Ra) in this brain region. In the human hypothalamus, IL-6Ra-immunoreactivity was detected in perikarya and first-order dendrites of neurones. The IL-6Ra-immunoreactive (-IR) neurones were observed posterior to the level of the interventricular foramen. There, IL-6Ra-IR neurones were located in the lateral hypothalamic, perifornical, dorsal and posterior hypothalamic areas, the hypothalamic dorsomedial nucleus and in the zona incerta. In the caudal part of the hypothalamus, the density of the IL-6Ra-IR neurones gradually increased. Double-labelling immunofluorescent studies demonstrated that IL-6Ra immunoreactivity was localised in the same neurones as the orexigenic neuropeptide, melanin-concentrating hormone (MCH). By contrast, IL-6Ra-immunoreactivity was not observed in the orexin B-IR neurones. To determine whether the observed expression of IL-6Ra is evolutionary conserved, we studied the co-localisation of IL-6Ra with MCH and orexin in the mouse hypothalamus, where IL-6Ra-immunoreactivity was present in numerous MCH-IR and orexin-IR neurones. Our data demonstrate that the MCH neurones of the human hypothalamus, as well as the MCH and orexin neurones of the mouse hypothalamus, contain IL-6Ra. This opens up the possibility that IL-6 influences the energy balance through the MCH neurones in humans, and both MCH and orexin neurones in mice.
27.	Schéle, Erik, 1980, et al. (författare) Interrelation between interleukin-1 (IL-1), IL-6 and body fat regulating circuits of the hypothalamic arcuate nucleus. 2013 Ingår i: Journal of neuroendocrinology. - : Wiley. - 1365-2826 .- 0953-8194. ; 25:6, s. 580-589 Tidskriftsartikel (refereegranskat)abstract Interleukin-1 (IL-1) and interleukin-6 (IL-6) are immune modulating cytokines that also affect metabolic functions, as both IL-1 receptor I deficient (IL1RI -/-) and IL-6 deficient (IL-6 -/-) mice develop late-onset obesity and leptin resistance. Both IL-1 and IL-6 appear to target the central nervous system (CNS) to increase energy expenditure. The hypothalamic arcuate nucleus (ARC) is a major relay between the periphery and CNS in body fat regulation, e g by being a target of leptin. We aimed to investigate possible mechanisms for the effects exerted by endogenous IL-1 and IL-6 on body fat at the level of the ARC, as well as possible interactions between IL-1 and IL-6. Therefore, we measured the gene expression of neuropeptides of the ARC involved in energy balance in IL-1RI -/- and IL-6-/- mice. We also investigated the interactions between expression of IL-1 and IL-6 in these mice, and mapped IL-6 receptor α (IL-6Rα) in the ARC The expression of the obesity promoting peptide neuropeptide Y (NPY), found in ARC, was increased in IL-1RI -/- mice. The expression of NPY and agouti-related peptide (AgRP), known to be co-expressed with NPY in ARC neurons, was increased in cold exposed IL-6 -/- mice. IL-6Rα immunoreactivity was densely localized in the ARC, especially in the medial part, and there partly found in NPY positive cell bodies and also α-MSH positive cell bodies. The expression of hypothalamic IL-6 was decreased in IL-1RI -/- mice, while IL-1ß expression was increased in IL-6 -/- mice. The present results indicate that depletion of the activity of the fat suppressing cytokines IL-1 and IL-6 in knockout mice can increase the expression of the obesity promoting neuropeptide NPY in the ARC. Depletion of IL-1 activity suppresses IL-6 expression, and IL-6Rα -like immunoreactivity is present in neurons in the medial ARC including neurons containing NPY. Therefore, IL-6, IL-1 and NPY/AgRP could interact at the level of the hypothalamic ARC in regulation of body fat. © 2013 British Society for Neuroendocrinology.
28.	Schéle, Erik, 1980, et al. (författare) Regulation of body fat mass by the gut microbiota: Possible mediation by the brain. 2016 Ingår i: Peptides. - : Elsevier BV. - 1873-5169 .- 0196-9781. ; 77, s. 54-59 Forskningsöversikt (refereegranskat)abstract New insight suggests gut microbiota as a component in energy balance. However, the underlying mechanisms by which gut microbiota can impact metabolic regulation is unclear. A recent study from our lab shows, for the first time, a link between gut microbiota and energy balance circuitries in the hypothalamus and brainstem. In this article we will review this study further.
29.	Schéle, Erik, 1980, et al. (författare) The gut microbiota reduces leptin sensitivity and the expression of the obesity-suppressing neuropeptides proglucagon (Gcg) and brain-derived neurotrophic factor (Bdnf) in the central nervous system. 2013 Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 154:10, s. 3643-51 Tidskriftsartikel (refereegranskat)abstract The gut microbiota contributes to fat mass and the susceptibility to obesity. However, the underlying mechanisms are not completely understood. To investigate whether the gut microbiota affects hypothalamic and brainstem body fat-regulating circuits, we compared gene expression of food intake-regulating neuropeptides between germ-free and conventionally raised (CONV-R) mice. We found that CONV-R mice had decreased expression of the antiobesity neuropeptide glucagon-like peptide-1 (GLP-1) precursor proglucagon (Gcg) in the brainstem. Moreover, in both the hypothalamus and the brainstem, CONV-R mice had decreased expression of the antiobesity neuropeptide brain-derived neurotrophic factor (Bdnf). CONV-R mice had reduced expression of the pro-obesity peptides neuropeptide-Y (Npy) and agouti-related protein (Agrp), and increased expression of the antiobesity peptides proopiomelanocortin (Pomc) and cocaine- and amphetamine-regulated transcript (Cart) in the hypothalamus. The latter changes in neuropeptide expression could be secondary to elevated fat mass in CONV-R mice. Leptin treatment caused less weight reduction and less suppression of orexigenic Npy and Agrp expression in CONV-R mice compared with germ-free mice. The hypothalamic expression of leptin resistance-associated suppressor of cytokine signaling 3 (Socs-3) was increased in CONV-R mice. In conclusion, the gut microbiota reduces the expression of 2 genes coding for body fat-suppressing neuropeptides, Gcg and Bdnf, an alteration that may contribute to fat mass induction by the gut microbiota. Moreover, the presence of body fat-inducing gut microbiota is associated with hypothalamic signs of Socs-3-mediated leptin resistance, which may be linked to failed compensatory body fat reduction.
30.	Schéle, Ingrid, et al. (författare) The interrelationships between individual, contextual and processual constructs and stress and wellbeing among psychologists 2014 Konferensbidrag (refereegranskat)
31.	Stoltenborg, Iris, et al. (författare) TRAPing Ghrelin-Activated Circuits: A Novel Tool to Identify, Target and Control Hormone-Responsive Populations in TRAP2 Mice 2022 Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 23:1 Tidskriftsartikel (refereegranskat)abstract The availability of Cre-based mouse lines for visualizing and targeting populations of hormone-sensitive cells has helped identify the neural circuitry driving hormone effects. However, these mice have limitations and may not even be available. For instance, the development of the first ghrelin receptor (Ghsr)-IRES-Cre model paved the way for using the Cre-lox system to identify and selectively manipulate ghrelin-responsive populations. The insertion of the IRES-Cre cassette, however, interfered with Ghsr expression, resulting in defective GHSR signaling and a pronounced phenotype in the homozygotes. As an alternative strategy to target ghrelin-responsive cells, we hereby utilize TRAP2 (targeted recombination in active populations) mice in which it is possible to gain genetic access to ghrelin-activated populations. In TRAP2 mice crossed with a reporter strain, we visualized ghrelin-activated cells and found, as expected, much activation in the arcuate nucleus (Arc). We then stimulated this population using a chemogenetic approach and found that this was sufficient to induce an orexigenic response of similar magnitude to that induced by peripheral ghrelin injection. The stimulation of this population also impacted food choice. Thus, the TRAPing of hormone-activated neurons (here exemplified by ghrelin-activated pathways) provides a complimentary/alternative technique to visualize, access and control discrete pathways, linking hormone action to circuit function.

Skapa referenser, mejla, bekava och länka

Länka till träfflistan

Träfflista för sökning "WFRF:(Schele Erik) "

Avgränsa träffmängd

År