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Jansson JO, Anesten F, Hägg D, Zlatkovic J, Dickson SL, Jansson PA, Schéle E, Bellman J, Ohlsson C. The dual hypothesis of homeostatic body weight regulation, including gravity-dependent and leptin-dependent actions. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220219. [PMID: 37661748 PMCID: PMC10475867 DOI: 10.1098/rstb.2022.0219] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 06/27/2023] [Indexed: 09/05/2023] Open
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)'.
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Affiliation(s)
- John-Olov Jansson
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
| | - Frederik Anesten
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
| | - Daniel Hägg
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
| | - Jovana Zlatkovic
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
| | - Suzanne L. Dickson
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
| | - Per-Anders Jansson
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
| | - Erik Schéle
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
| | - Jakob Bellman
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
| | - Claes Ohlsson
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-41390 Göteborg, Västra Götaland, Sweden
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Veie CHB, Nielsen IMT, Frisk NLS, Dalgaard LT. Extracellular microRNAs in Relation to Weight Loss-A Systematic Review and Meta-Analysis. Noncoding RNA 2023; 9:53. [PMID: 37736899 PMCID: PMC10514795 DOI: 10.3390/ncrna9050053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/10/2023] [Accepted: 09/12/2023] [Indexed: 09/23/2023] Open
Abstract
Obesity is an important risk factor for cardiovascular disease and type 2 diabetes mellitus. Even a modest weight loss of 5-15% improves metabolic health, but circulating markers to indicate weight loss efficiency are lacking. MicroRNAs, small non-coding post-transcriptional regulators of gene expression, are secreted from tissues into the circulation and may be potential biomarkers for metabolic health. However, it is not known which specific microRNA species are reproducibly changed in levels by weight loss. In this study, we performed a systematic review and meta-analysis to investigate the microRNAs associated with weight loss by comparing baseline to follow-up levels following intervention-driven weight loss. This systematic review was performed according to the PRISMA guidelines with searches in PubMed and SCOPUS. The primary search resulted in a total of 697 articles, which were screened according to the prior established inclusion and exclusion criteria. Following the screening of articles, the review was based on the inclusion of 27 full-text articles, which were evaluated for quality and the risk of bias. We performed systematic data extraction, whereafter the relative values for miRNAs were calculated. A meta-analysis was performed for the miRNA species investigated in three or more studies: miR-26a, miR-126, and miR-223 were overall significantly increased following weight loss, while miR-142 was significantly decreased after weight loss. miR-221, miR-140, miR-122, and miR-146 were not significantly changed by intervention-driven weight loss. These results indicate that few miRNAs are significantly changed during weight loss.
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Affiliation(s)
| | | | | | - Louise T. Dalgaard
- Department of Science and Environment, Roskilde University, Universitetsvej 1, 4000 Roskilde, Denmark (N.L.S.F.)
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Kesić M, Baković P, Farkaš V, Bagarić R, Kolarić D, Štefulj J, Čičin-Šain L. Constitutive Serotonin Tone as a Modulator of Brown Adipose Tissue Thermogenesis: A Rat Study. Life (Basel) 2023; 13:1436. [PMID: 37511811 PMCID: PMC10381595 DOI: 10.3390/life13071436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/30/2023] Open
Abstract
Brown adipose tissue (BAT), an important regulator of thermogenic and metabolic processes, is considered a promising target to combat metabolic disorders. The neurotransmitter and hormone serotonin (5HT) is a major modulator of energy homeostasis, with its central and peripheral pools acting in opposing ways. To better understand how individual variations in 5HT homeostasis influence the thermogenic functionality of BAT, we used a rat model consisting of two sublines with constitutively increased (high-5HT) or decreased (low-5HT) whole-body 5HT tone, developed by selective breeding for platelet 5HT parameters. We have shown that animals with constitutively low 5HT activity maintained at a standard housing temperature (22 °C) have greater interscapular BAT (iBAT) mass and higher iBAT metabolic activity (as evidenced by measurements of iBAT temperature and glucose uptake), accompanied by increased iBAT mRNA expression of key thermogenic genes, compared to animals with high 5HT tone. In response to further thermogenic challenges-intermittent cold exposure or treatment with a β3-adrenergic agonist-5HT sublines show several functional and molecular differences linking constitutively low endogenous 5HT tone to higher BAT activity/capacity. Overall, the results support a role of 5-HT in the control of BAT thermogenesis They also suggest that individuals with lower 5HT activity may be more sensitive to β3-adrenergic drugs.
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Affiliation(s)
- Maja Kesić
- Department of Molecular Biology, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
| | - Petra Baković
- Department of Molecular Biology, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
| | - Vladimir Farkaš
- Department of Experimental Physics, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
| | - Robert Bagarić
- Department of Experimental Physics, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
| | - Darko Kolarić
- Centre for Informatics and Computing, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
| | - Jasminka Štefulj
- Department of Molecular Biology, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
| | - Lipa Čičin-Šain
- Department of Molecular Biology, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
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Freeman AK, Glendining KA, Jasoni CL. Developmental genes controlling neural circuit formation are expressed in the early postnatal hypothalamus and cellular lining of the third ventricle. J Neuroendocrinol 2021; 33:e13020. [PMID: 34423876 DOI: 10.1111/jne.13020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 07/20/2021] [Accepted: 07/27/2021] [Indexed: 02/07/2023]
Abstract
The arcuate nucleus of the hypothalamus is central in the regulation of body weight homeostasis through its ability to sense peripheral metabolic signals and relay them, through neural circuits, to other brain areas, ultimately affecting physiological and behavioural changes. The early postnatal development of these neural circuits is critical for normal body weight homeostasis, such that perturbations during this critical period can lead to obesity. The role for peripheral regulators of body weight homeostasis, including leptin, insulin and ghrelin, in this postnatal development is well described, yet some of the fundamental processes underpinning axonal and dendritic growth remain unclear. Here, we hypothesised that molecules known to regulate axonal and dendritic growth processes in other areas of the developing brain would be expressed in the postnatal arcuate nucleus and/or target nuclei where they would function to mediate the development of this circuitry. Using state-of-the-art RNAscope® technology, we have revealed the expression patterns of genes encoding Dcc/Netrin-1, Robo1/Slit1 and Fzd5/Wnt5a receptor/ligand pairs in the early postnatal mouse hypothalamus. We found that individual genes had unique expression patterns across developmental time in the arcuate nucleus, paraventricular nucleus of the hypothalamus, ventromedial nucleus of the hypothalamus, dorsomedial nucleus of the hypothalamus, median eminence and, somewhat unexpectedly, the third ventricle epithelium. These observations indicate a number of new molecular players in the development of neural circuits regulating body weight homeostasis, as well as novel molecular markers of tanycyte heterogeneity.
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Affiliation(s)
- Alice Katherine Freeman
- Centre for Neuroendocrinology, Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Kelly A Glendining
- Centre for Neuroendocrinology, Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Christine L Jasoni
- Centre for Neuroendocrinology, Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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Kesić M, Baković P, Horvatiček M, Proust BLJ, Štefulj J, Čičin-Šain L. Constitutionally High Serotonin Tone Favors Obesity: Study on Rat Sublines With Altered Serotonin Homeostasis. Front Neurosci 2020; 14:219. [PMID: 32269507 PMCID: PMC7109468 DOI: 10.3389/fnins.2020.00219] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/27/2020] [Indexed: 01/08/2023] Open
Abstract
Central and peripheral pools of biogenic monoamine serotonin (5-hydroxytryptamine [5HT]) exert opposite effects on the body weight regulation: increase in brain 5HT activity is expected to decrease body weight, whereas increase in peripheral 5HT activity will increase body weight and adiposity. In a genetic model of rats with constitutionally high- or low-5HT homeostasis (hyperserotonergic/hyposerotonergic rats), we have studied how individual differences in endogenous 5HT tone modulate net energy balance of the organism. The high-5HT and low-5HT sublines of the model were developed by selective breeding toward extreme platelet activities of 5HT transporter, a key molecule determining 5HT bioavailability/activity. In animals from high-5HT and low-5HT sublines, we assessed physiological characteristics associated with body weight homeostasis and expression profile of a large scale of body weight–regulating genes in hypothalamus, a major brain region controlling energy balance. Results showed that under standard chow diet animals from the high-5HT subline, as compared to low-5HT animals, have lifelong increased body weight (by 12%), higher absolute daily food intake (by 9%), and different pattern of fat distribution (larger amount of white adipose tissue and lower amount of brown adipose tissue). A large number of body weight–regulating hypothalamic genes were analyzed for their mRNA expression: 24 genes by reverse transcription–quantitative polymerase chain reaction (n = 9–10 rats/subline) including neuropeptides and their receptors, growth factors, transcriptional factors, and receptors for peripheral signals, and a total of 84 genes of various classes by polymerase chain reaction array (pools of six rats/subline). Only few genes showed significant differences in mRNA expression levels between 5HT sublines (e.g. neuropeptide Y receptor, fibroblast growth factor 10), but high-5HT animals displayed a clear trend to upregulation of mRNAs for a number of orexigenic signaling peptides, their receptors, and other molecules with orexigenic activity. Receptors for peripheral signals (leptin, insulin) and molecules in their downstream signaling were not altered, indicating no changes in central insulin/leptin resistance. At the protein level, there were no differences in the content of hypothalamic leptin receptor between 5HT sublines, but significant sex and age effects were observed. Results show that higher constitutive/individual 5HT tone favors higher body weight and adiposity probably due to concurrent upregulation of several hypothalamic orexigenic pathways.
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Affiliation(s)
- Maja Kesić
- Laboratory of Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Petra Baković
- Laboratory of Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Marina Horvatiček
- Laboratory of Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Bastien Lucien Jean Proust
- Laboratory of Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Jasminka Štefulj
- Laboratory of Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Lipa Čičin-Šain
- Laboratory of Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
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Abstract
Presently, control of body weight is assumed to exist, but there is no consensus framework of body weight homeostasis. Three different models have been proposed, with a "set point" suggesting (i) a more or less tight and (ii) symmetric or asymmetric biological control of body weight resulting from feedback loops from peripheral organs and tissues (e.g. leptin secreted from adipose tissue) to a central control system within the hypothalamus. Alternatively, a "settling point" rather than a set point reflects metabolic adaptations to energy imbalance without any need for feedback control. Finally, the "dual intervention point" model combines both paradigms with two set points and a settling point between them. In humans, observational studies on large populations do not provide consistent evidence for a biological control of body weight, which, if it exists, may be overridden by the influences of the obesogenic environment and culture on personal behavior and experiences. To re-address the issue of body weight homeostasis, there is a need for targeted protocols based on sound concepts, e.g. lean rather than overweight subjects should be investigated before, during, and after weight loss and weight regain. In addition, improved methods and a multi-level-multi-systemic approach are needed to address the associations (i) between masses of individual body components and (ii) between masses and metabolic functions in the contexts of neurohumoral control and systemic effects. In the future, simplifications and the use of crude and non-biological phenotypes (i.e. body mass index and waist circumference) should be avoided. Since changes in body weight follow the mismatch between tightly controlled energy expenditure at loosely controlled energy intake, control (or even a set point) is more likely to be about energy expenditure rather than about body weight itself.
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Affiliation(s)
- Manfred J Müller
- Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Corinna Geisler
- Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | | | - Anja Bosy-Westphal
- Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
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