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Pena-Leon V, Perez-Lois R, Villalon M, Prida E, Muñoz-Moreno D, Fernø J, Quiñones M, Al-Massadi O, Seoane LM. Novel mechanisms involved in leptin sensitization in obesity. Biochem Pharmacol 2024; 223:116129. [PMID: 38490517 DOI: 10.1016/j.bcp.2024.116129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/21/2024] [Accepted: 03/12/2024] [Indexed: 03/17/2024]
Abstract
Leptin is a hormone that is secreted by adipocytes in proportion to adipose tissue size, and that informs the brain about the energy status of the body. Leptin acts through its receptor LepRb, expressed mainly in the hypothalamus, and induces a negative energy balance by potent inhibition of feeding and activation of energy expenditure. These actions have led to huge expectations for the development of therapeutic targets for metabolic complications based on leptin-derived compounds. However, the majority of patients with obesity presents elevated leptin production, suggesting that in this setting leptin is ineffective in the regulation of energy balance. This resistance to the action of leptin in obesity has led to the development of "leptin sensitizers," which have been tested in preclinical studies. Much research has focused on generating combined treatments that act on multiple levels of the gastrointestinal-brain axis. The gastrointestinal-brain axis secretes a variety of different anorexigenic signals, such as uroguanylin, glucagon-like peptide-1, amylin, or cholecystokinin, which can alleviate the resistance to leptin action. Moreover, alternative mechanism such as pharmacokinetics, proteostasis, the role of specific kinases, chaperones, ER stress and neonatal feeding modifications are also implicated in leptin resistance. This review will cover the current knowledge regarding the interaction of leptin with different endocrine factors from the gastrointestinal-brain axis and other novel mechanisms that improve leptin sensitivity in obesity.
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Affiliation(s)
- Veronica Pena-Leon
- Grupo Fisiopatología Endocrina, Departamento de Endocrinología, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (CHUS/SERGAS), Santiago de Compostela, Travesía da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Raquel Perez-Lois
- Grupo Fisiopatología Endocrina, Departamento de Endocrinología, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (CHUS/SERGAS), Santiago de Compostela, Travesía da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Maria Villalon
- Grupo Fisiopatología Endocrina, Departamento de Endocrinología, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (CHUS/SERGAS), Santiago de Compostela, Travesía da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Eva Prida
- Translational Endocrinology group, Endocrinology Section, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (IDIS/CHUS), Santiago de Compostela, Travesía da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Diego Muñoz-Moreno
- Translational Endocrinology group, Endocrinology Section, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (IDIS/CHUS), Santiago de Compostela, Travesía da Choupana s/n, 15706 Santiago de Compostela, Spain
| | - Johan Fernø
- Hormone Laboratory, Department of Biochemistry and Pharmacology, Haukeland University Hospital, 5201 Bergen, Norway
| | - Mar Quiñones
- Grupo Fisiopatología Endocrina, Departamento de Endocrinología, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (CHUS/SERGAS), Santiago de Compostela, Travesía da Choupana s/n, 15706 Santiago de Compostela, Spain; CIBER de Fisiopatología de la Obesidad y la Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Omar Al-Massadi
- Translational Endocrinology group, Endocrinology Section, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (IDIS/CHUS), Santiago de Compostela, Travesía da Choupana s/n, 15706 Santiago de Compostela, Spain; CIBER de Fisiopatología de la Obesidad y la Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
| | - Luisa M Seoane
- Grupo Fisiopatología Endocrina, Departamento de Endocrinología, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (CHUS/SERGAS), Santiago de Compostela, Travesía da Choupana s/n, 15706 Santiago de Compostela, Spain; CIBER de Fisiopatología de la Obesidad y la Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
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LA Padula D, Zavaglia L, Hamad T, Nocito MC, Aquila S, Avena P, Rago V. Leptin effects: focusing on the relationship between obesity and male infertility. Minerva Endocrinol (Torino) 2024; 49:100-110. [PMID: 36251021 DOI: 10.23736/s2724-6507.22.03901-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The human male infertility has several causes interconnected to improper lifestyles such as smoking, sedentarism, environmental factors, toxins accumulation and energy imbalances. All these factors contribute to the obesity accompanied metabolic syndrome and hormonal alterations in the leptin-ghrelin axis. The leptin (Lep) has many pleiotropic effects in several biological systems, directly on the peripheral tissues or through the central nervous system. Many studies suggest that Lep is a key player in gonadal functions beside its documented role in reproductive regulation; however, further investigations are still necessary to elucidate all the molecular pathways involved in these mechanisms. Keeping into account that increased Lep levels in obese men are positively correlated with altered sperm parameters and testicular oxidative stress, evidence refers to Lep as a potential link between obesity and male infertility. This review represents an updated version on the concept of the Lep roles in mediating the male reproductive functions in obese patients.
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Affiliation(s)
- Davide LA Padula
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Lucia Zavaglia
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Tarig Hamad
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Marta C Nocito
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Saveria Aquila
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Paola Avena
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Vittoria Rago
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy -
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Ghasemzadeh-Hasankolaei M, Elcombe CS, Powls S, Lea RG, Sinclair KD, Padmanabhan V, Evans NP, Bellingham M. Preconceptional and in utero exposure of sheep to a real-life environmental chemical mixture disrupts key markers of energy metabolism in male offspring. J Neuroendocrinol 2024; 36:e13358. [PMID: 38087451 PMCID: PMC10841670 DOI: 10.1111/jne.13358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 01/12/2024]
Abstract
Over recent decades, an extensive array of anthropogenic chemicals have entered the environment and have been implicated in the increased incidence of an array of diseases, including metabolic syndrome. The ubiquitous presence of these environmental chemicals (ECs) necessitates the use of real-life exposure models to the assess cumulative risk burden to metabolic health. Sheep that graze on biosolids-treated pastures are exposed to a real-life mixture of ECs such as phthalates, per- and polyfluoroalkyl substances, heavy metals, pharmaceuticals, pesticides, and metabolites thereof, and this EC exposure can result in metabolic disorders in their offspring. Using this model, we evaluated the effects of gestational exposure to a complex EC mixture on plasma triglyceride (TG) concentrations and metabolic and epigenetic regulatory genes in tissues key to energy regulation and storage, including the hypothalamus, liver, and adipose depots of 11-month-old male offspring. Our results demonstrated a binary effect of EC exposure on gene expression particularly in the hypothalamus. Principal component analysis revealed two subsets (B-S1 [n = 6] and B-S2 [n = 4]) within the biosolids group (B, n = 10), relative to the controls (C, n = 11). Changes in body weight, TG levels, and in gene expression in the hypothalamus, and visceral and subcutaneous fat were apparent between biosolid and control and the two subgroups of biosolids animals. These findings demonstrate that gestational exposure to an EC mixture results in differential regulation of metabolic processes in adult male offspring. Binary effects on hypothalamic gene expression and altered expression of lipid metabolism genes in visceral and subcutaneous fat, coupled with phenotypic outcomes, point to differences in individual susceptibility to EC exposure that could predispose vulnerable individuals to later metabolic dysfunction.
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Affiliation(s)
- Mohammad Ghasemzadeh-Hasankolaei
- School of Biodiversity One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Chris S Elcombe
- School of Biodiversity One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Samantha Powls
- School of Biodiversity One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Richard G Lea
- University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | - Kevin D Sinclair
- University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | | | - Neil P Evans
- School of Biodiversity One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Michelle Bellingham
- School of Biodiversity One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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DeMars KM, Ross MR, Starr A, McIntyre JC. Neuronal primary cilia integrate peripheral signals with metabolic drives. Front Physiol 2023; 14:1150232. [PMID: 37064917 PMCID: PMC10090425 DOI: 10.3389/fphys.2023.1150232] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
Neuronal primary cilia have recently emerged as important contributors to the central regulation of energy homeostasis. As non-motile, microtubule-based organelles, primary cilia serve as signaling antennae for metabolic status. The impairment of ciliary structure or function can produce ciliopathies for which obesity is a hallmark phenotype and global ablation of cilia induces non-syndromic adiposity in mouse models. This organelle is not only a hub for metabolic signaling, but also for catecholamine neuromodulation that shapes neuronal circuitry in response to sensory input. The objective of this review is to highlight current research investigating the mechanisms of primary cilium-regulated metabolic drives for maintaining energy homeostasis.
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Affiliation(s)
- Kelly M. DeMars
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Madeleine R. Ross
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
- Summer Neuroscience Internship Program, University of Florida, Gainesville, FL, United States
| | - Alana Starr
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Jeremy C. McIntyre
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
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You J, Juhng S, Song J, Park J, Jang M, Kang G, Yang H, Min HS, Shin J, Lee S, Ko HW, Jung H. Egg Microneedle for Transdermal Delivery of Active Liraglutide. Adv Healthc Mater 2023; 12:e2202473. [PMID: 36617627 DOI: 10.1002/adhm.202202473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/20/2022] [Indexed: 01/10/2023]
Abstract
Liraglutide, a human glucagon-like peptide-1 (GLP-1) analog, is promising for safely treating type 2 diabetes mellitus (T2DM), compared to insulin, by significantly reducing the risk of glucose-dependent hypoglycemia. Concerns related to injection prevent T2DM patients from taking liraglutide regularly, even though once-a-day subcutaneous (SC) injections. Dissolving microneedles (DMNs) are promising substitutes for SC injection and for improving patient convenience. However, there are two fundamental limitations: the low drug delivery due to incomplete insertion and loss of drug activity during DMN fabrication. Here, it is shown that an egg microneedle (EMN) designed with three functional layered structures can maintain the maximum activity of the loaded compound during DMN fabrication and deliver it completely into the skin, with the base layer allowing the complete delivery of liraglutide, and the shell layer maintaining the drug activity by mimicking the role of albumin in eggs. In a diabetic mouse model, liraglutide administration via EMN exhibited similar effect when compared to that of injection. Therefore, EMN-mediated liraglutide administration is a good potential option for replacing liraglutide injections in T2DM treatment.
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Affiliation(s)
- Jeongyun You
- Department of Biotechnology, Yonsei University, Building 123, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Seorin Juhng
- Department of Biotechnology, Yonsei University, Building 123, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Jieun Song
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Jihyun Park
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Mingyu Jang
- Juvic Inc, 272 Digital-ro, Guro-gu, Seoul, 08389, Korea
| | - Geonwoo Kang
- Department of Biotechnology, Yonsei University, Building 123, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Huisuk Yang
- Juvic Inc, 272 Digital-ro, Guro-gu, Seoul, 08389, Korea
| | - Hye Su Min
- Department of Biotechnology, Yonsei University, Building 123, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Jiwoo Shin
- Department of Biotechnology, Yonsei University, Building 123, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Seri Lee
- Department of Biotechnology, Yonsei University, Building 123, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Hyuk Wan Ko
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Hyungil Jung
- Department of Biotechnology, Yonsei University, Building 123, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea
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Cabrera Zapata LE, Cambiasso MJ, Arevalo MA. Epigenetic modifier Kdm6a/Utx controls the specification of hypothalamic neuronal subtypes in a sex-dependent manner. Front Cell Dev Biol 2022; 10:937875. [PMID: 36268511 PMCID: PMC9577230 DOI: 10.3389/fcell.2022.937875] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/07/2022] [Indexed: 11/23/2022] Open
Abstract
Kdm6a is an X-chromosome-linked H3K27me2/3 demethylase that promotes chromatin accessibility and gene transcription and is critical for tissue/cell-specific differentiation. Previous results showed higher Kdm6a levels in XX than in XY hypothalamic neurons and a female-specific requirement for Kdm6a in mediating increased axogenesis before brain masculinization. Here, we explored the sex-specific role of Kdm6a in the specification of neuronal subtypes in the developing hypothalamus. Hypothalamic neuronal cultures were established from sex-segregated E14 mouse embryos and transfected with siRNAs to knockdown Kdm6a expression (Kdm6a-KD). We evaluated the effect of Kdm6a-KD on Ngn3 expression, a bHLH transcription factor regulating neuronal sub-specification in hypothalamus. Kdm6a-KD decreased Ngn3 expression in females but not in males, abolishing basal sex differences. Then, we analyzed Kdm6a-KD effect on Ascl1, Pomc, Npy, Sf1, Gad1, and Th expression by RT-qPCR. While Kdm6a-KD downregulated Ascl1 in both sexes equally, we found sex-specific effects for Pomc, Npy, and Th. Pomc and Th expressed higher in female than in male neurons, and Kdm6a-KD reduced their levels only in females, while Npy expressed higher in male than in female neurons, and Kdm6a-KD upregulated its expression only in females. Identical results were found by immunofluorescence for Pomc and Npy neuropeptides. Finally, using ChIP-qPCR, we found higher H3K27me3 levels at Ngn3, Pomc, and Npy promoters in male neurons, in line with Kdm6a higher expression and demethylase activity in females. At all three promoters, Kdm6a-KD induced an enrichment of H3K27me3 only in females. These results indicate that Kdm6a plays a sex-specific role in controlling the expression of transcription factors and neuropeptides critical for the differentiation of hypothalamic neuronal populations regulating food intake and energy homeostasis.
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Affiliation(s)
| | - María Julia Cambiasso
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
- Facultad de Odontología, Universidad Nacional de Córdoba, Córdoba, Argentina
- *Correspondence: María Julia Cambiasso, , Maria Angeles Arevalo,
| | - Maria Angeles Arevalo
- Instituto Cajal (IC), CSIC, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- *Correspondence: María Julia Cambiasso, , Maria Angeles Arevalo,
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Claflin KE, Sullivan AI, Naber MC, Flippo KH, Morgan DA, Neff TJ, Jensen-Cody SO, Zhu Z, Zingman LV, Rahmouni K, Potthoff MJ. Pharmacological FGF21 signals to glutamatergic neurons to enhance leptin action and lower body weight during obesity. Mol Metab 2022; 64:101564. [PMID: 35944896 PMCID: PMC9403559 DOI: 10.1016/j.molmet.2022.101564] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/21/2022] [Accepted: 07/26/2022] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE Fibroblast growth factor 21 (FGF21) is a peripherally-derived endocrine hormone that acts on the central nervous system (CNS) to regulate whole body energy homeostasis. Pharmacological administration of FGF21 promotes weight loss in obese animal models and human subjects with obesity. However, the central targets mediating these effects are incompletely defined. METHODS To explore the mechanism for FGF21's effects to lower body weight, we pharmacologically administer FGF21 to genetic animal models lacking the obligate FGF21 co-receptor, β-klotho (KLB), in either glutamatergic (Vglut2-Cre) or GABAergic (Vgat-Cre) neurons. In addition, we abolish FGF21 signaling to leptin receptor (LepR-Cre) positive cells. Finally, we examine the synergistic effects of FGF21 and leptin to lower body weight and explore the importance of physiological leptin levels in FGF21-mediated regulation of body weight. RESULTS Here we show that FGF21 signaling to glutamatergic neurons is required for FGF21 to modulate energy expenditure and promote weight loss. In addition, we demonstrate that FGF21 signals to leptin receptor-expressing cells to regulate body weight, and that central leptin signaling is required for FGF21 to fully stimulate body weight loss during obesity. Interestingly, co-administration of FGF21 and leptin synergistically leads to robust weight loss. CONCLUSIONS These data reveal an important endocrine crosstalk between liver- and adipose-derived signals which integrate in the CNS to modulate energy homeostasis and body weight regulation.
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Affiliation(s)
- Kristin E Claflin
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Andrew I Sullivan
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Meghan C Naber
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Kyle H Flippo
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Donald A Morgan
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Tate J Neff
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Sharon O Jensen-Cody
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Zhiyong Zhu
- Department of Internal Medicine, Iowa City, IA 52242, USA
| | | | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Veterans Affairs Health Care System, Iowa City, IA 52242, USA; Department of Internal Medicine, Iowa City, IA 52242, USA
| | - Matthew J Potthoff
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Veterans Affairs Health Care System, Iowa City, IA 52242, USA.
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Balbuena E, Cheng J, Eroglu A. Carotenoids in orange carrots mitigate non-alcoholic fatty liver disease progression. Front Nutr 2022; 9:987103. [PMID: 36225879 PMCID: PMC9549209 DOI: 10.3389/fnut.2022.987103] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/02/2022] [Indexed: 11/23/2022] Open
Abstract
Background Carotenoids are abundant in colored fruits and vegetables. Non-alcoholic fatty liver disease (NAFLD) is a global burden and risk factor for end-stage hepatic diseases. This study aims to compare the anti-NAFLD efficacy between carotenoid-rich and carotenoid-deficient vegetables. Materials and methods Male C57BL/6J mice were randomized to one of four experimental diets for 15 weeks (n = 12 animals/group): Low-fat diet (LFD, 10% calories from fat), high-fat diet (HFD, 60% calories from fat), HFD with 20% white carrot powders (HFD + WC), or with 20% orange carrot powders (HFD + OC). Results We observed that carotenoids in the orange carrots reduced HFD-induced weight gain, better than white carrots. Histological and triglyceride (TG) analyses revealed significantly decreased HFD-induced hepatic lipid deposition and TG content in the HFD + WC group, which was further reduced in the HFD + OC group. Western blot analysis demonstrated inconsistent changes of fatty acid synthesis-related proteins but significantly improved ACOX-1 and CPT-II, indicating that orange carrot carotenoids had the potential to inhibit NAFLD by improving β-oxidation. Further investigation showed significantly higher mRNA and protein levels of PPARα and its transcription factor activity. Conclusion Carotenoid-rich foods may display more potent efficacy in mitigating NAFLD than those with low carotenoid levels.
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Affiliation(s)
- Emilio Balbuena
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States
- Department of Molecular and Structural Biochemistry, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, NC, United States
| | - Junrui Cheng
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States
| | - Abdulkerim Eroglu
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States
- Department of Molecular and Structural Biochemistry, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, NC, United States
- *Correspondence: Abdulkerim Eroglu,
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Ahn W, Latremouille J, Harris RBS. Leptin receptor-expressing cells in the ventromedial nucleus of the hypothalamus contribute to enhanced CCK-induced satiety following central leptin injection. Am J Physiol Endocrinol Metab 2022; 323:E267-E280. [PMID: 35830689 PMCID: PMC9448279 DOI: 10.1152/ajpendo.00088.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/15/2022] [Accepted: 07/08/2022] [Indexed: 01/27/2023]
Abstract
Others have shown that leptin and cholecystokinin (CCK) act synergistically to suppress food intake. Experiments described here tested whether leptin in the ventromedial hypothalamus (VMH) contributes to the synergy with peripheral CCK in male Sprague Dawley rats. A subthreshold injection of 50-ng leptin into the VMH 1 h before a peripheral injection of 1 µg/kg CCK did not change the response to CCK in rats offered chow or low-fat purified diet, but did exaggerate the reduction in intake of high-fat diet 30 min and 1 h after injection in rats that had been food deprived for 8 h. By contrast, deletion of leptin receptor-expressing cells in the VMH using leptin-conjugated saporin (Lep-Sap) abolished the response to peripheral CCK in chow-fed rats. Lateral ventricle injection of 2-µg leptin combined with peripheral CCK exaggerated the inhibition of chow intake for up to 6 h in control rats treated with Blank-saporin, but not in Lep-Sap rats. Blank-Saporin rats offered low- or high-fat purified diet also demonstrated a dose-response inhibition of intake that reached significance with 1 µg/kg of CCK for both diets. CCK did not inhibit intake of Lep-Sap rats in either low- or high-fat-fed rats. Thus, although basal activation of VMH leptin receptors makes a significant contribution to the synergy with CCK, increased leptin activity in the VMH does not exaggerate the response to CCK in intact rats offered low-fat diets, but does enhance the response in those offered high-fat diet.NEW & NOTEWORTHY Leptin is a feedback signal in the control of energy balance, whereas cholecystokinin (CCK) is a short-term satiety signal that inhibits meal size. The two hormones synergize to promote satiety. We tested whether leptin receptors in the ventromedial nucleus of the hypothalamus (VMH) contribute to the synergy. The results suggest that there is a requirement for a baseline level of activation of leptin receptors in the VMH in order for CCK to promote satiety.
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Affiliation(s)
- WonMo Ahn
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - John Latremouille
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ruth B S Harris
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
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10
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Speakman JR, Elmquist JK. Obesity: an evolutionary context. LIFE METABOLISM 2022; 1:10-24. [PMID: 36394061 PMCID: PMC9642988 DOI: 10.1093/lifemeta/loac002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/21/2022] [Accepted: 03/09/2022] [Indexed: 05/07/2023]
Abstract
People completely lacking body fat (lipodystrophy/lipoatrophy) and those with severe obesity both show profound metabolic and other health issues. Regulating levels of body fat somewhere between these limits would, therefore, appear to be adaptive. Two different models might be contemplated. More traditional is a set point (SP) where the levels are regulated around a fixed level. Alternatively, dual-intervention point (DIP) is a system that tolerates fairly wide variation but is activated when critically high or low levels are breached. The DIP system seems to fit our experience much better than an SP, and models suggest that it is more likely to have evolved. A DIP system may have evolved because of two contrasting selection pressures. At the lower end, we may have been selected to avoid low levels of fat as a buffer against starvation, to avoid disease-induced anorexia, and to support reproduction. At the upper end, we may have been selected to avoid excess storage because of the elevated risks of predation. This upper limit of control seems to have malfunctioned because some of us deposit large fat stores, with important negative health effects. Why has evolution not protected us against this problem? One possibility is that the protective system slowly fell apart due to random mutations after we dramatically reduced the risk of being predated during our evolutionary history. By chance, it fell apart more in some people than others, and these people are now unable to effectively manage their weight in the face of the modern food glut. To understand the evolutionary context of obesity, it is important to separate the adaptive reason for storing some fat (i.e. the lower intervention point), from the nonadaptive reason for storing lots of fat (a broken upper intervention point). The DIP model has several consequences, showing how we understand the obesity problem and what happens when we attempt to treat it.
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Affiliation(s)
- John R Speakman
- Corresponding author. John R Speakman, Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen, China. E-mail:
| | - Joel K Elmquist
- Joel K. Elmquist, Departments of Internal Medicine and Pharmacology, Center for Hypothalamic Research, University of Texas Southwestern, 5323 Harry Hines blvd., Dallas, TX 75390, USA. E-mail:
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11
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Tu L, Fukuda M, Tong Q, Xu Y. The ventromedial hypothalamic nucleus: watchdog of whole-body glucose homeostasis. Cell Biosci 2022; 12:71. [PMID: 35619170 PMCID: PMC9134642 DOI: 10.1186/s13578-022-00799-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 04/25/2022] [Indexed: 02/06/2023] Open
Abstract
The brain, particularly the ventromedial hypothalamic nucleus (VMH), has been long known for its involvement in glucose sensing and whole-body glucose homeostasis. However, it is still not fully understood how the brain detects and responds to the changes in the circulating glucose levels, as well as brain-body coordinated control of glucose homeostasis. In this review, we address the growing evidence implicating the brain in glucose homeostasis, especially in the contexts of hypoglycemia and diabetes. In addition to neurons, we emphasize the potential roles played by non-neuronal cells, as well as extracellular matrix in the hypothalamus in whole-body glucose homeostasis. Further, we review the ionic mechanisms by which glucose-sensing neurons sense fluctuations of ambient glucose levels. We also introduce the significant implications of heterogeneous neurons in the VMH upon glucose sensing and whole-body glucose homeostasis, in which sex difference is also addressed. Meanwhile, research gaps have also been identified, which necessities further mechanistic studies in future.
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Affiliation(s)
- Longlong Tu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA
| | - Makoto Fukuda
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
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12
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Ameroso D, Meng A, Chen S, Felsted J, Dulla CG, Rios M. Astrocytic BDNF signaling within the ventromedial hypothalamus regulates energy homeostasis. Nat Metab 2022; 4:627-643. [PMID: 35501599 PMCID: PMC9177635 DOI: 10.1038/s42255-022-00566-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/28/2022] [Indexed: 11/12/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is essential for maintaining energy and glucose balance within the central nervous system. Because the study of its metabolic actions has been limited to effects in neuronal cells, its role in other cell types within the brain remains poorly understood. Here we show that astrocytic BDNF signaling within the ventromedial hypothalamus (VMH) modulates neuronal activity in response to changes in energy status. This occurs via the truncated TrkB.T1 receptor. Accordingly, either fasting or central BDNF depletion enhances astrocytic synaptic glutamate clearance, thereby decreasing neuronal activity in mice. Notably, selective depletion of TrkB.T1 in VMH astrocytes blunts the effects of energy status on excitatory transmission, as well as on responses to leptin, glucose and lipids. These effects are driven by increased astrocytic invasion of excitatory synapses, enhanced glutamate reuptake and decreased neuronal activity. We thus identify BDNF/TrkB.T1 signaling in VMH astrocytes as an essential mechanism that participates in energy and glucose homeostasis.
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Affiliation(s)
- Dominique Ameroso
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Alice Meng
- Graduate Program in Cell, Molecular and Developmental Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Stella Chen
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Jennifer Felsted
- Graduate Program in Biochemical and Molecular Nutrition, Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | - Chris G Dulla
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
- Graduate Program in Cell, Molecular and Developmental Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Maribel Rios
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA.
- Graduate Program in Cell, Molecular and Developmental Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA.
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA.
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13
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Tran LT, Park S, Kim SK, Lee JS, Kim KW, Kwon O. Hypothalamic control of energy expenditure and thermogenesis. Exp Mol Med 2022; 54:358-369. [PMID: 35301430 PMCID: PMC9076616 DOI: 10.1038/s12276-022-00741-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 12/05/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Energy expenditure and energy intake need to be balanced to maintain proper energy homeostasis. Energy homeostasis is tightly regulated by the central nervous system, and the hypothalamus is the primary center for the regulation of energy balance. The hypothalamus exerts its effect through both humoral and neuronal mechanisms, and each hypothalamic area has a distinct role in the regulation of energy expenditure. Recent studies have advanced the understanding of the molecular regulation of energy expenditure and thermogenesis in the hypothalamus with targeted manipulation techniques of the mouse genome and neuronal function. In this review, we elucidate recent progress in understanding the mechanism of how the hypothalamus affects basal metabolism, modulates physical activity, and adapts to environmental temperature and food intake changes. The hypothalamus is a key regulator of metabolism, controlling resting metabolism, activity levels, and responses to external temperature and food intake. The balance between energy intake and expenditure must be tightly controlled, with imbalances resulting in metabolic disorders such as obesity or diabetes. Obin Kwon at Seoul National University College of Medicine and Ki Woo Kim at Yonsei University College of Dentistry, Seoul, both in South Korea, and coworkers reviewed how metabolism is regulated by the hypothalamus, a small hormone-producing brain region. They report that hormonal and neuronal signals from the hypothalamus influence the ratio of lean to fatty tissue, gender-based differences in metabolism, activity levels, and weight gain in response to food intake. They note that further studies to untangle cause-and-effect relationships and other genetic factors will improve our understanding of metabolic regulation.
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Affiliation(s)
- Le Trung Tran
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Sohee Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Seul Ki Kim
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Jin Sun Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Ki Woo Kim
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea.
| | - Obin Kwon
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea. .,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.
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14
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Le N, Sayers S, Mata-Pacheco V, Wagner EJ. The PACAP Paradox: Dynamic and Surprisingly Pleiotropic Actions in the Central Regulation of Energy Homeostasis. Front Endocrinol (Lausanne) 2022; 13:877647. [PMID: 35721722 PMCID: PMC9198406 DOI: 10.3389/fendo.2022.877647] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/30/2022] [Indexed: 12/11/2022] Open
Abstract
Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP), a pleiotropic neuropeptide, is widely distributed throughout the body. The abundance of PACAP expression in the central and peripheral nervous systems, and years of accompanying experimental evidence, indicates that PACAP plays crucial roles in diverse biological processes ranging from autonomic regulation to neuroprotection. In addition, PACAP is also abundantly expressed in the hypothalamic areas like the ventromedial and arcuate nuclei (VMN and ARC, respectively), as well as other brain regions such as the nucleus accumbens (NAc), bed nucleus of stria terminalis (BNST), and ventral tegmental area (VTA) - suggesting that PACAP is capable of regulating energy homeostasis via both the homeostatic and hedonic energy balance circuitries. The evidence gathered over the years has increased our appreciation for its function in controlling energy balance. Therefore, this review aims to further probe how the pleiotropic actions of PACAP in regulating energy homeostasis is influenced by sex and dynamic changes in energy status. We start with a general overview of energy homeostasis, and then introduce the integral components of the homeostatic and hedonic energy balance circuitries. Next, we discuss sex differences inherent to the regulation of energy homeostasis via these two circuitries, as well as the activational effects of sex steroid hormones that bring about these intrinsic disparities between males and females. Finally, we explore the multifaceted role of PACAP in regulating homeostatic and hedonic feeding through its actions in regions like the NAc, BNST, and in particular the ARC, VMN and VTA that occur in sex- and energy status-dependent ways.
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Affiliation(s)
- Nikki Le
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Sarah Sayers
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Veronica Mata-Pacheco
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Edward J. Wagner
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
- *Correspondence: Edward J. Wagner, ; www.westernu.edu
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15
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Yan YL, Titus T, Desvignes T, BreMiller R, Batzel P, Sydes J, Farnsworth D, Dillon D, Wegner J, Phillips JB, Peirce J, Dowd J, Buck CL, Miller A, Westerfield M, Postlethwait JH. A fish with no sex: gonadal and adrenal functions partition between zebrafish NR5A1 co-orthologs. Genetics 2021; 217:6043928. [PMID: 33724412 DOI: 10.1093/genetics/iyaa030] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 11/16/2020] [Indexed: 02/06/2023] Open
Abstract
People with NR5A1 mutations experience testicular dysgenesis, ovotestes, or adrenal insufficiency, but we do not completely understand the origin of this phenotypic diversity. NR5A1 is expressed in gonadal soma precursor cells before expression of the sex-determining gene SRY. Many fish have two co-orthologs of NR5A1 that likely partitioned ancestral gene subfunctions between them. To explore ancestral roles of NR5A1, we knocked out nr5a1a and nr5a1b in zebrafish. Single-cell RNA-seq identified nr5a1a-expressing cells that co-expressed genes for steroid biosynthesis and the chemokine receptor Cxcl12a in 1-day postfertilization (dpf) embryos, as does the mammalian adrenal-gonadal (interrenal-gonadal) primordium. In 2dpf embryos, nr5a1a was expressed stronger in the interrenal-gonadal primordium than in the early hypothalamus but nr5a1b showed the reverse. Adult Leydig cells expressed both ohnologs and granulosa cells expressed nr5a1a stronger than nr5a1b. Mutants for nr5a1a lacked the interrenal, formed incompletely differentiated testes, had no Leydig cells, and grew far larger than normal fish. Mutants for nr5a1b formed a disorganized interrenal and their gonads completely disappeared. All homozygous mutant genotypes lacked secondary sex characteristics, including male breeding tubercles and female sex papillae, and had exceedingly low levels of estradiol, 11-ketotestosterone, and cortisol. RNA-seq showed that at 21dpf, some animals were developing as females and others were not, independent of nr5a1 genotype. By 35dpf, all mutant genotypes greatly under-expressed ovary-biased genes. Because adult nr5a1a mutants form gonads but lack an interrenal and conversely, adult nr5a1b mutants lack a gonad but have an interrenal, the adrenal, and gonadal functions of the ancestral nr5a1 gene partitioned between ohnologs after the teleost genome duplication, likely owing to reciprocal loss of ancestral tissue-specific regulatory elements. Identifying such elements could provide hints to otherwise unexplained cases of Differences in Sex Development.
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Affiliation(s)
- Yi-Lin Yan
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Tom Titus
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Thomas Desvignes
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Ruth BreMiller
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Peter Batzel
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Jason Sydes
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Dylan Farnsworth
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Danielle Dillon
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Jeremy Wegner
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | | | - Judy Peirce
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - John Dowd
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | | | - Charles Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Adam Miller
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Monte Westerfield
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
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16
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Multiple Leptin Signalling Pathways in the Control of Metabolism and Fertility: A Means to Different Ends? Int J Mol Sci 2021; 22:ijms22179210. [PMID: 34502119 PMCID: PMC8430761 DOI: 10.3390/ijms22179210] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/13/2021] [Accepted: 08/23/2021] [Indexed: 01/20/2023] Open
Abstract
The adipocyte-derived ‘satiety promoting’ hormone, leptin, has been identified as a key central regulator of body weight and fertility, such that its absence leads to obesity and infertility. Plasma leptin levels reflect body adiposity, and therefore act as an ‘adipostat’, whereby low leptin levels reflect a state of low body adiposity (under-nutrition/starvation) and elevated leptin levels reflect a state of high body adiposity (over-nutrition/obesity). While genetic leptin deficiency is rare, obesity-related leptin resistance is becoming increasingly common. In the absence of adequate leptin sensitivity, leptin is unable to exert its ‘anti-obesity’ effects, thereby exacerbating obesity. Furthermore, extreme leptin resistance and consequent low or absent leptin signalling resembles a state of starvation and can thus lead to infertility. However, leptin resistance occurs on a spectrum, and it is possible to be resistant to leptin’s metabolic effects while retaining leptin’s permissive effects on fertility. This may be because leptin exerts its modulatory effects on energy homeostasis and reproductive function through discrete intracellular signalling pathways, and these pathways are differentially affected by the molecules that promote leptin resistance. This review discusses the potential mechanisms that enable leptin to exert differential control over metabolic and reproductive function in the contexts of healthy leptin signalling and of diet-induced leptin resistance.
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17
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Berger C, Heyne HO, Heiland T, Dommel S, Höfling C, Guiu-Jurado E, Roßner S, Dannemann M, Kelso J, Kovacs P, Blüher M, Klöting N. A novel compound heterozygous leptin receptor mutation causes more severe obesity than in Lepr db/db mice. J Lipid Res 2021; 62:100105. [PMID: 34390703 PMCID: PMC8450258 DOI: 10.1016/j.jlr.2021.100105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 01/04/2023] Open
Abstract
The leptin receptor (Lepr) pathway is important for food intake regulation, energy expenditure, and body weight. Mutations in leptin and the Lepr have been shown to cause early-onset severe obesity in mice and humans. In studies with C57BL/6NCrl mice, we found a mouse with extreme obesity. To identify a putative spontaneous new form of monogenic obesity, we performed backcross studies with this mouse followed by a quantitative trait locus (QTL) analysis and sequencing of the selected chromosomal QTL region. We thereby identified a novel Lepr mutation (C57BL/6N-LeprL536Hfs*6-1NKB), which is located at chromosome 4, exon 11 within the CRH2-leptin-binding site. Compared with C57BL/6N mice, LeprL536Hfs*6 develop early onset obesity and their body weight exceeds that of Leprdb/db mice at an age of 30 weeks. Similar to Leprdb/db mice, the LeprL536Hfs*6 model is characterized by hyperphagia, obesity, lower energy expenditure and activity, hyperglycemia, and hyperinsulinemia compared with C57BL/6N mice. Crossing Leprdb/wt with LeprL536Hfs*6/wt mice results in compound heterozygous LeprL536Hfs*6/db mice, which develop even higher body weight and fat mass than both homozygous Leprdb/db and LeprL536Hfs*6 mice. Compound heterozygous Lepr deficiency affecting functionally different regions of the Lepr causes more severe obesity than the parental homozygous mutations.
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Affiliation(s)
- Claudia Berger
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany
| | - Henrike O Heyne
- Medical Department, Institute for Human Genetics, University of Leipzig Medical Center, Leipzig, Germany; Institute for Molecular Medicine Finland: FIMM, Helsinki, Finland; Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Tina Heiland
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Sebastian Dommel
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany
| | - Corinna Höfling
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Esther Guiu-Jurado
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany; Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig, Leipzig, Germany
| | - Steffen Roßner
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Michael Dannemann
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Janet Kelso
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Peter Kovacs
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany
| | - Matthias Blüher
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany; Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig, Leipzig, Germany
| | - Nora Klöting
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany; Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig, Leipzig, Germany.
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18
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Gonçalves GHM, Tristão SM, Volpi RE, Almeida-Pereira G, de Carvalho Borges B, Donato J, de Castro M, Antunes-Rodrigues J, Elias LLK. STAT3 but Not ERK2 Is a Crucial Mediator Against Diet-Induced Obesity via VMH Neurons. Diabetes 2021; 70:1498-1507. [PMID: 33883215 DOI: 10.2337/db20-0658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 04/18/2021] [Indexed: 11/13/2022]
Abstract
Leptin plays an important role in the protection against diet-induced obesity (DIO) by its actions in ventromedial hypothalamic (VMH) neurons. However, little is known about the intracellular mechanisms involved in these effects. To assess the role of the STAT3 and ERK2 signaling in neurons that express the steroidogenic factor 1 (SF1) in the VMH in energy homeostasis, we used cre-lox technology to generate male and female mice with specific disruption of STAT3 or ERK2 in SF1 neurons of the VMH. We demonstrated that the conditional knockout of STAT3 in SF1 neurons of the VMH did not affect body weight, food intake, energy expenditure, or glucose homeostasis in animals on regular chow. However, with high-fat diet (HFD) challenge, loss of STAT3 in SF1 neurons caused a significant increase in body weight, food intake, and energy efficiency that was more remarkable in females, which also showed a decrease in energy expenditure. In contrast, deletion of ERK2 in SF1 neurons of VMH did not have any impact on energy homeostasis in both regular diet and HFD conditions. In conclusion, STAT3 but not ERK2 signaling in SF1 neurons of VMH plays a crucial role in protection against DIO in a sex-specific pattern.
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Affiliation(s)
- Gabriel Henrique Marques Gonçalves
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Sabrina Mara Tristão
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Rafaella Eduarda Volpi
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Gislaine Almeida-Pereira
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Beatriz de Carvalho Borges
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - Margaret de Castro
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - José Antunes-Rodrigues
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Lucila Leico Kagohara Elias
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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19
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Harris RBS. Phosphorylation of STAT3 in hypothalamic nuclei is stimulated by lower doses of leptin than are needed to inhibit food intake. Am J Physiol Endocrinol Metab 2021; 321:E190-E201. [PMID: 34121448 PMCID: PMC8321824 DOI: 10.1152/ajpendo.00143.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This experiment investigated which hypothalamic nuclei were activated by a dose of leptin that inhibited food intake. Foodnot intake, energy expenditure, respiratory exchange ratio (RER), and intrascapular brown adipose tissue (IBAT) temperature were measured in male and female Sprague Dawley rats for 36 h following an intraperitoneal injection of 0, 50, 200, 500, or 1,000 µg leptin/kg with each rat tested with each dose of leptin in random order. In both males and females, RER and 12-h food intake were inhibited only by 1,000 µg leptin/kg, but there was no effect on energy expenditure or IBAT temperature. At the end of the experiment, phosphorylated signal transducer and activator of transcription 3 (pSTAT3) immunoreactivity was measured 1 h after injection of 0, 50, 500, or 1,000 µg leptin/kg. In male rats, the lowest dose of leptin produced a maximal activation of STAT3 in the Arc and nucleus of the solitary tract (NTS). There was no response in the dorsomedial hypothalamus, but there was a progressive increase in ventromedial nucleus of the hypothalamus (VMH) pSTAT3 with increasing doses of leptin. In female rats, there was no significant change in Arc and pSTAT3 NTS activation was maximal with 500 mg leptin/kg, but only the highest dose of leptin increased VMH pSTAT3. These results suggest that the VMH plays an important role in the energetic response to elevations of circulating leptin but do not exclude the possibility that multiple nuclei provide the appropriate integrated response to hyperleptinemia.NEW & NOTEWORTHY The results of this experiment show that doses of leptin too small to inhibit food intake produce a maximal response to leptin in the arcuate nucleus. By contrast the VMH shows a robust response that correlates with inhibition of food intake. This suggests that the VMH plays an important role in the energetic response to hyperleptinemia.
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Affiliation(s)
- Ruth B S Harris
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia
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20
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Rouabhi M, Guo DF, Morgan DA, Zhu Z, López M, Zingman L, Grobe JL, Rahmouni K. BBSome ablation in SF1 neurons causes obesity without comorbidities. Mol Metab 2021; 48:101211. [PMID: 33722691 PMCID: PMC8065214 DOI: 10.1016/j.molmet.2021.101211] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/25/2021] [Accepted: 03/08/2021] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVES The hypothalamic ventromedial nucleus (VMH) plays a major role in metabolic control, but the molecular mechanisms involved remain poorly defined. We analyzed the relevance of the BBSome, a protein complex composed of 8 Bardet-Biedl syndrome (BBS) proteins including BBS1, in VMH steroidogenic factor 1 (SF1) neurons for the control of energy homeostasis and related physiological processes. METHODS We generated mice bearing selective BBSome disruption, through Bbs1 gene deletion, in SF1 neurons (SF1Cre/Bbs1fl/fl). We analyzed the consequence on body weight, glucose homeostasis, and cardiovascular autonomic function of BBSome loss in SF1 neurons. RESULTS SF1Cre/Bbs1fl/fl mice had increased body weight and adiposity under normal chow conditions. Food intake, energy absorption, and digestive efficiency were not altered by Bbs1 gene deletion in SF1 neurons. SF1Cre/Bbs1fl/fl mice exhibited lower energy expenditure, particularly during the dark cycle. Consistent with this finding, SF1Cre/Bbs1fl/fl mice displayed reduced sympathetic nerve traffic and expression of markers of thermogenesis in brown adipose tissue. SF1Cre/Bbs1fl/fl mice also had lower sympathetic nerve activity to subcutaneous white adipose tissue that was associated with a protein expression profile that promotes lipid accumulation. Notably, despite obesity and hyperinsulinemia, SF1Cre/Bbs1fl/fl mice did not exhibit significant changes in glucose metabolism, insulin sensitivity, blood pressure, and baroreflex sensitivity. CONCLUSIONS Our findings demonstrate that the SF1 neuron BBSome is necessary for the regulation of energy homeostasis through modulation of the activity of the sympathetic nervous system and that the SF1 neuron BBSome is required for the development of obesity-related comorbidities.
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Affiliation(s)
- Mohamed Rouabhi
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Deng-Fu Guo
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Veterans Affairs Health Care System, Iowa City, IA, USA
| | - Donald A Morgan
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Veterans Affairs Health Care System, Iowa City, IA, USA
| | - Zhiyong Zhu
- Veterans Affairs Health Care System, Iowa City, IA, USA; Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Miguel López
- NeurObesity Group, Department of Physiology, CiMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Leonid Zingman
- Veterans Affairs Health Care System, Iowa City, IA, USA; Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Obesity Research and Education Initiative, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Justin L Grobe
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Obesity Research and Education Initiative, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Veterans Affairs Health Care System, Iowa City, IA, USA; Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Obesity Research and Education Initiative, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, IA, USA.
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21
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Sabatini PV, Wang J, Rupp AC, Affinati AH, Flak JN, Li C, Olson DP, Myers MG. tTARGIT AAVs mediate the sensitive and flexible manipulation of intersectional neuronal populations in mice. eLife 2021; 10:66835. [PMID: 33704065 PMCID: PMC8026215 DOI: 10.7554/elife.66835] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 03/10/2021] [Indexed: 12/20/2022] Open
Abstract
While Cre-dependent viral systems permit the manipulation of many neuron types, some cell populations cannot be targeted by a single DNA recombinase. Although the combined use of Flp and Cre recombinases can overcome this limitation, insufficient recombinase activity can reduce the efficacy of existing Cre+Flp-dependent viral systems. We developed a sensitive dual recombinase-activated viral approach: tTA-driven Recombinase-Guided Intersectional Targeting (tTARGIT) adeno-associated viruses (AAVs). tTARGIT AAVs utilize a Flp-dependent tetracycline transactivator (tTA) ‘Driver’ AAV and a tetracycline response element-driven, Cre-dependent ‘Payload’ AAV to express the transgene of interest. We employed this system in Slc17a6FlpO;LeprCre mice to manipulate LepRb neurons of the ventromedial hypothalamus (VMH; LepRbVMH neurons) while omitting neighboring LepRb populations. We defined the circuitry of LepRbVMH neurons and roles for these cells in the control of food intake and energy expenditure. Thus, the tTARGIT system mediates robust recombinase-sensitive transgene expression, permitting the precise manipulation of previously intractable neural populations. The brain contains hundreds of types of neurons, which differ in size, shape and behavior. But neuroscientists often wish to study individual neuronal types in isolation. They are able to do this with the aid of a toolkit made up of two parts: viral vectors and genetically modified mice. Viral vectors are viruses that have been modified so that they are no longer harmful and can instead be used to introduce genetic material into cells on demand. To create a viral vector, the virus’ own genetic material is replaced with a ‘cargo’ gene, such as the gene for a fluorescent protein. The virus is then introduced into a new host such as a mouse. Importantly, the virus only produces the protein encoded by its ‘cargo’ gene if it is inside a cell that also contains one of two specific enzymes. These enzymes are called Cre and Flp. This is where the second part of the toolkit comes in. Mice can be genetically engineered to produce either Cre or Flp exclusively in specific cell types. By introducing a viral vector into mice that produce either Cre or Flp only in one particular type of neuron, researchers can limit the activity of the cargo gene to that neuronal type. But sometimes even this approach is not selective enough. Researchers may wish to limit the activity of the cargo gene to a subpopulation of cells that produce Cre or Flp. Or they may wish to target only Cre- or Flp-producing cells in a small area of the brain, while leaving cells in neighboring areas unaffected. Sabatini et al. have now overcome this limitation by developing and testing a new set of viral vectors that are active only in neurons that produce both Cre and Flp. The vectors are called tTARGIT AAVs and allow researchers to target cells more precisely than was possible with the previous version of the toolkit. Sabatini et al. show tTARGIT AAVs in action by using them to identify a group of neurons that control how much energy mice use and how much food they eat. As well as applying the vectors to their own research on obesity, Sabatini et al. have also made them freely available for other researchers to use in their own projects.
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Affiliation(s)
- Paul V Sabatini
- Department of Internal Medicine, University of Michigan, Ann Arbor, United States
| | - Jine Wang
- Department of Internal Medicine, University of Michigan, Ann Arbor, United States.,Chinese academy, College of Medical Science, China Three Gorges University, Yichang, China
| | - Alan C Rupp
- Department of Internal Medicine, University of Michigan, Ann Arbor, United States
| | - Alison H Affinati
- Department of Internal Medicine, University of Michigan, Ann Arbor, United States
| | - Jonathan N Flak
- Indiana Biosciences Research Institute, Indianapolis, United States
| | - Chien Li
- Novo Nordisk Research Center, Seattle, United States
| | - David P Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, United States.,Department of Molecular and Integrative Physiology, Ann Arbor, United States
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, United States.,Department of Molecular and Integrative Physiology, Ann Arbor, United States
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22
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Pereira S, Cline DL, Glavas MM, Covey SD, Kieffer TJ. Tissue-Specific Effects of Leptin on Glucose and Lipid Metabolism. Endocr Rev 2021; 42:1-28. [PMID: 33150398 PMCID: PMC7846142 DOI: 10.1210/endrev/bnaa027] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Indexed: 12/18/2022]
Abstract
The discovery of leptin was intrinsically associated with its ability to regulate body weight. However, the effects of leptin are more far-reaching and include profound glucose-lowering and anti-lipogenic effects, independent of leptin's regulation of body weight. Regulation of glucose metabolism by leptin is mediated both centrally and via peripheral tissues and is influenced by the activation status of insulin signaling pathways. Ectopic fat accumulation is diminished by both central and peripheral leptin, an effect that is beneficial in obesity-associated disorders. The magnitude of leptin action depends upon the tissue, sex, and context being examined. Peripheral tissues that are of particular relevance include the endocrine pancreas, liver, skeletal muscle, adipose tissues, immune cells, and the cardiovascular system. As a result of its potent metabolic activity, leptin is used to control hyperglycemia in patients with lipodystrophy and is being explored as an adjunct to insulin in patients with type 1 diabetes. To fully understand the role of leptin in physiology and to maximize its therapeutic potential, the mechanisms of leptin action in these tissues needs to be further explored.
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Affiliation(s)
- Sandra Pereira
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Daemon L Cline
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Maria M Glavas
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Scott D Covey
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada.,Department of Surgery, University of British Columbia, Vancouver, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
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23
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Bravo Durán DA, Barreda Guzmán SJ, Trujillo Hernández A, Silva Gómez AB. Obese female Zucker rats (fa/fa) exhibit dendritic retraction in neurons in the ventromedial hypothalamic nucleus. J Chem Neuroanat 2021; 113:101919. [PMID: 33497806 DOI: 10.1016/j.jchemneu.2021.101919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/21/2020] [Accepted: 01/16/2021] [Indexed: 11/17/2022]
Abstract
The ventromedial hypothalamic nucleus (VMH) is located in the tuberal region of the hypothalamus and is traditionally considered the satiety center. In obese Zucker rats, which express a mutation in the leptin receptor gene and exhibit obesity from the first weeks of life, the morphology of VMH neurons is unknown. In the present study, we found that the dendritic length of VMH neurons in obese Zucker rats was significantly shorter than that in Long Evans rats. This finding allows us to suggest that obese Zucker rats exhibit both neuronal metabolic alterations related to leptin and a reduction in the flow of information within the neuronal circuits in which the VMH nucleus participates to regulate foraging.
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Affiliation(s)
- Dolores Adriana Bravo Durán
- Laboratorio de Neurofisiología Experimental, Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Puebla, CP, 72520, Mexico
| | - Selina Jocelyn Barreda Guzmán
- Laboratorio de Neurofisiología Experimental, Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Puebla, CP, 72520, Mexico
| | - Angélica Trujillo Hernández
- Laboratorio de Neuroendocrinología, Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Puebla, CP, 72520, Mexico
| | - Adriana Berenice Silva Gómez
- Laboratorio de Neurofisiología Experimental, Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Puebla, CP, 72520, Mexico.
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24
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Luo S, Ezrokhi M, Cominos N, Tsai TH, Stoelzel CR, Trubitsyna Y, Cincotta AH. Experimental dopaminergic neuron lesion at the area of the biological clock pacemaker, suprachiasmatic nuclei (SCN) induces metabolic syndrome in rats. Diabetol Metab Syndr 2021; 13:11. [PMID: 33485386 PMCID: PMC7825247 DOI: 10.1186/s13098-021-00630-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The daily peak in dopaminergic neuronal activity at the area of the biological clock (hypothalamic suprachiasmatic nuclei [SCN]) is diminished in obese/insulin resistant vs lean/insulin sensitive animals. The impact of targeted lesioning of dopamine (DA) neurons specifically at the area surrounding (and that communicate with) the SCN (but not within the SCN itself) upon glucose metabolism, adipose and liver lipid gene expression, and cardiovascular biology in normal laboratory animals has not been investigated and was the focus of this study. METHODS Female Sprague-Dawley rats received either DA neuron neurotoxic lesion by bilateral intra-cannula injection of 6-hydroxydopamine (2-4 μg/side) or vehicle treatment at the area surrounding the SCN at 20 min post protriptyline ip injection (20 mg/kg) to protect against damage to noradrenergic and serotonergic neurons. RESULTS At 16 weeks post-lesion relative to vehicle treatment, peri-SCN area DA neuron lesioning increased weight gain (34.8%, P < 0.005), parametrial and retroperitoneal fat weight (45% and 90% respectively, P < 0.05), fasting plasma insulin, leptin and norepinephrine levels (180%, 71%, and 40% respectively, P < 0.05), glucose tolerance test area under the curve (AUC) insulin (112.5%, P < 0.05), and insulin resistance (44%-Matsuda Index, P < 0.05) without altering food consumption during the test period. Such lesion also induced the expression of several lipid synthesis genes in adipose and liver and the adipose lipolytic gene, hormone sensitive lipase in adipose (P < 0.05 for all). Liver monocyte chemoattractant protein 1 (a proinflammatory protein associated with metabolic syndrome) gene expression was also significantly elevated in peri-SCN area dopaminergic lesioned rats. Peri-SCN area dopaminergic neuron lesioned rats were also hypertensive (systolic BP rose from 157 ± 5 to 175 ± 5 mmHg, P < 0.01; diastolic BP rose from 109 ± 4 to 120 ± 3 mmHg, P < 0.05 and heart rate increase from 368 ± 12 to 406 ± 12 BPM, P < 0.05) and had elevated plasma norepinephrine levels (40% increased, P < 0.05) relative to controls. CONCLUSIONS These findings indicate that reduced dopaminergic neuronal activity in neurons at the area of and communicating with the SCN contributes significantly to increased sympathetic tone and the development of metabolic syndrome, without effect on feeding.
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Affiliation(s)
- Shuqin Luo
- VeroScience LLC, 1334 Main Road, Tiverton, RI, 02878, USA
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25
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Takefusa M, Kubo Y, Ohno M, Segi-Nishida E. Electroconvulsive seizures lead to lipolytic-induced gene expression changes in mediobasal hypothalamus and decreased white adipose tissue mass. Neuropsychopharmacol Rep 2021; 41:56-64. [PMID: 33426813 PMCID: PMC8182960 DOI: 10.1002/npr2.12156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/25/2020] [Accepted: 12/10/2020] [Indexed: 12/17/2022] Open
Abstract
Aims Electroconvulsive seizure (ECS) therapy is highly effective in the treatment of several psychiatric disorders, including depression. Past studies have shown that the rodent model of ECS reveals the activation of multiple brain regions including the hypothalamus, suggesting that this method of brain stimulation broadly regulates central neuronal function, which results in peripheral function. The ventromedial nucleus of the hypothalamus (VMH) plays an important role in feeding and energy homeostasis. Our previous study showed that ECS increases the expression of anorexigenic factors in the VMH and has an anorexigenic effect in a mouse model. Since the VMH is also suggested to play a critical role in the peripheral lipid metabolism of white adipose tissue (WAT), we hypothesized that ECS alters lipid metabolism via activation of the VMH. Methods and Results Here, we demonstrate that repeated ECS suppresses the fat mass of epididymal WAT and significantly increases the expression levels of lipolytic and brown adipose tissue markers such as Adrb3, Hsl/Lipe, and Ppargc1a. In the VMH, ECS increased the expression of multiple genes, notably Bdnf, Adcyap1, and Crhr2, which are not only anorexigenic factors but are also modulators of lipid metabolism. Furthermore, gold‐thioglucose‐induced hypothalamic lesions affecting the VMH abolished the effect of ECS on the WAT, indicating that hypothalamus activation is required for the phenotypic changes seen in the epididymal WAT. Conclusion Our data demonstrates a new effect of ECS on the lipid metabolism of WAT via induction of hypothalamic activity involving the VMH. In the present study, we demonstrated that ECS exerts effects on adipose tissue and suggest the requirement of the hypothalamus, including the VMH, for the lipolytic effect of ECS.![]()
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Affiliation(s)
- Marika Takefusa
- Department of Biological Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Katsushika-ku, Japan
| | - Yuki Kubo
- Department of Biological Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Katsushika-ku, Japan
| | - Marie Ohno
- Department of Biological Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Katsushika-ku, Japan
| | - Eri Segi-Nishida
- Department of Biological Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Katsushika-ku, Japan
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26
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McMillan TR, Forster MAM, Short LI, Rudecki AP, Cline DL, Gray SL. Melanotan II, a melanocortin agonist, partially rescues the impaired thermogenic capacity of pituitary adenylate cyclase-activating polypeptide deficient mice. Exp Physiol 2020; 106:427-437. [PMID: 33332767 DOI: 10.1113/ep088838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 11/27/2020] [Indexed: 12/16/2022]
Abstract
NEW FINDINGS What is the central question of this study? Can chronic treatment of pituitary adenylate cyclase-activating polypeptide (PACAP) deficient mice with the melanocortin agonist melanotan II during cold acclimation rescue the impaired thermogenic capacity previously observed in PACAP deficient mice? What is the main finding and its importance? Using a genetic model of PACAP deficiency, this study provides evidence that PACAP acts upstream of the melanocortin system in regulating sympathetic nerve activity to brown adipose tissue in mice. ABSTRACT Impaired adipose tissue function in obesity, including reduced thermogenic potential, has detrimental consequences for metabolic health. Hormonal regulation of adaptive thermogenesis is being explored as a potential therapeutic target for human obesity. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide expressed in nuclei of the hypothalamus known to regulate energy expenditure, and functional studies reveal a role for PACAP in the central regulation of thermogenesis, although mechanisms are not well understood. We hypothesized that PACAP acts upstream of the melanocortin system to regulate sympathetic nerve activity to stimulate thermogenesis. To assess this, female PACAP-/- and PACAP+/+ mice were given daily peripheral injections of a melanocortin receptor agonist, melanotan II (MTII), for 3 weeks during cold acclimation, and the effect of MTII on thermogenic capacity and adipose tissue remodelling was examined by physiological and histological analyses. MTII partially rescued the impaired thermogenic capacity in PACAP-/- mice as compared to PACAP+/+ mice as determined by measuring noradrenaline-induced metabolic rate. In addition, MTII treatment during cold acclimation corrected the previously identified deficit in lipid utilization in response to adrenergic stimulation in PACAP-/- null mice, suggesting impaired lipid mobilization may contribute to the impaired thermogenic capacity of PACAP-/- mice. Results presented here provide physiological evidence to suggest that PACAP acts upstream of melanocortin receptors to facilitate sympathetically induced mechanisms of adaptive thermogenesis in response to cold acclimation.
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Affiliation(s)
- Thecla Rae McMillan
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Maeghan A M Forster
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Landon I Short
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Alexander P Rudecki
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Daemon L Cline
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Sarah L Gray
- Northern Medical Program, University of Northern British Columbia, Prince George, British Columbia, Canada
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27
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Li X, Wang H. Multiple organs involved in the pathogenesis of non-alcoholic fatty liver disease. Cell Biosci 2020; 10:140. [PMID: 33372630 PMCID: PMC7720519 DOI: 10.1186/s13578-020-00507-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/27/2020] [Indexed: 02/08/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) represents the leading cause of chronic liver disease worldwide and the anticipated health burden is huge. There are limited therapeutic approaches for NAFLD now. It’s imperative to get a better understanding of the disease pathogenesis if new treatments are to be discovered. As the hepatic manifestation of metabolic syndrome, this disease involves complex interactions between different organs and regulatory pathways. It’s increasingly clear that brain, gut and adipose tissue all contribute to NAFLD pathogenesis and development, in view of their roles in energy homeostasis. In the present review, we try to summarize currently available data regarding NAFLD pathogenesis and to lay a particular emphasis on the inter-organ crosstalk evidence.
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Affiliation(s)
- Xiaoyan Li
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China
| | - Hua Wang
- Department of Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China. .,Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Hefei, 230032, China.
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28
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Harris RBS. Consuming sucrose solution promotes leptin resistance and site specifically modifies hypothalamic leptin signaling in rats. Am J Physiol Regul Integr Comp Physiol 2020; 320:R182-R194. [PMID: 33206557 DOI: 10.1152/ajpregu.00238.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rats consuming 30% sucrose solution and a sucrose-free diet (LiqS) become leptin resistant, whereas rats consuming sucrose from a formulated diet (HS) remain leptin responsive. This study tested whether leptin resistance in LiqS rats extended beyond a failure to inhibit food intake and examined leptin responsiveness in the hypothalamus and hindbrain of rats offered HS, LiqS, or a sucrose-free diet (NS). Female LiqS Sprague-Dawley rats initially only partially compensated for the calories consumed as sucrose, but energy intake matched that of HS and NS rats when they were transferred to calorimetry cages. There was no effect of diet on energy expenditure, intrascapular brown fat tissue (IBAT) temperature, or fat pad weight. A peripheral injection of 2 mg of leptin/kg on day 23 or day 26 inhibited energy intake of HS and NS but not LiqS rats. Inhibition occurred earlier in HS rats than in NS rats and was associated with a smaller meal size. Leptin had no effect on energy expenditure but caused a transient rise in IBAT temperature of HS rats. Leptin increased the phosphorylation of signal transducer and activator of transcription 3 (pSTAT3) in the hindbrain and ventromedial hypothalamus of all rats. There was a minimal effect of leptin in the arcuate nucleus, and only the dorsomedial hypothalamus showed a correlation between pSTAT3 and leptin responsiveness. These data suggest that the primary response to leptin is inhibition of food intake and the pattern of sucrose consumption, rather than calories consumed as sucrose, causes leptin resistance associated with site-specific differences in hypothalamic leptin signaling.
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Affiliation(s)
- Ruth B S Harris
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
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29
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Abstract
Since the discovery of functionally competent, energy-consuming brown adipose tissue (BAT) in adult humans, much effort has been devoted to exploring this tissue as a means for increasing energy expenditure to counteract obesity. However, despite promising effects on metabolic rate and insulin sensitivity, no convincing evidence for weight-loss effects of cold-activated human BAT exists to date. Indeed, increasing energy expenditure would naturally induce compensatory feedback mechanisms to defend body weight. Interestingly, BAT is regulated by multiple interactions with the hypothalamus from regions overlapping with centers for feeding behavior and metabolic control. Therefore, in the further exploration of BAT as a potential source of novel drug targets, we discuss the hypothalamic orchestration of BAT activity and the relatively unexplored BAT feedback mechanisms on neuronal regulation. With a holistic view on hypothalamic-BAT interactions, we aim to raise ideas and provide a new perspective on this circuit and highlight its clinical relevance.
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Affiliation(s)
- Jo B Henningsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark;
| | - Camilla Scheele
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark;
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30
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Li Q, Wen H, Li Y, Zhang Z, Wang L, Mao X, Li J, Qi X. FOXO1A promotes neuropeptide FF transcription subsequently regulating the expression of feeding-related genes in spotted sea bass (Lateolabrax maculatus). Mol Cell Endocrinol 2020; 517:110871. [PMID: 32450284 DOI: 10.1016/j.mce.2020.110871] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 05/05/2020] [Accepted: 05/13/2020] [Indexed: 01/13/2023]
Abstract
FOXOs belong to the forkhead transcription factor superfamily, several of which are suggested to be involved in the control of food intake. Previously, we proved that the neuropeptide FF (NPFF) peptide was involved in feeding regulation in spotted sea bass. In the present study, seven members of the foxo family were identified in the whole genome of spotted sea bass. The distributions of these genes in different tissues were analyzed by qRT-PCR. Variations in the foxo1a and npff expression profiles during short-term starvation showed similar expression patterns. The colocalization of foxo1a and npff in the telencephalon, hypothalamus, stomach and intestine further provided evidence that foxo1a may act directly to promote the transcription of npff. Thirteen predicted FOXO1 binding sites were found in the 5' upstream region of npff. Luciferase assay results showed that FOXO1A was able to activate npff transcriptional responses by directly binding DNA response elements, and the key regulatory areas and sites of FOXO1A on the npff promoter were confirmed by deletion and site-directed mutagenesis analyses. These findings may help to elucidate the role of FOXO1 in the regulation of feeding processes in teleosts.
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Affiliation(s)
- Qing Li
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Haishen Wen
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Yun Li
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Zhanxiong Zhang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Lingyu Wang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Xuebin Mao
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Junjie Li
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Xin Qi
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China.
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31
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Intracellular interplay between cholecystokinin and leptin signalling for satiety control in rats. Sci Rep 2020; 10:12000. [PMID: 32686770 PMCID: PMC7371863 DOI: 10.1038/s41598-020-69035-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 06/29/2020] [Indexed: 11/09/2022] Open
Abstract
Cholecystokinin (CCK) and leptin are satiety-controlling peptides, yet their interactive roles remain unclear. Here, we addressed this issue using in vitro and in vivo models. In rat C6 glioma cells, leptin pre-treatment enhanced Ca2+ mobilization by a CCK agonist (CCK-8s). This leptin action was reduced by Janus kinase inhibitor (AG490) or PI3-kinase inhibitor (LY294002). Meanwhile, leptin stimulation alone failed to mobilize Ca2+ even in cells overexpressing leptin receptors (C6-ObRb). Leptin increased nuclear immunoreactivity against phosphorylated STAT3 (pSTAT3) whereas CCK-8s reduced leptin-induced nuclear pSTAT3 accumulation in these cells. In the rat ventromedial hypothalamus (VMH), leptin-induced action potential firing was enhanced, whereas nuclear pSTAT3 was reduced by co-stimulation with CCK-8s. To further analyse in vivo signalling interplay, a CCK-1 antagonist (lorglumide) was intraperitoneally injected in rats following 1-h restricted feeding. Food access was increased 3-h after lorglumide injection. At this timepoint, nuclear pSTAT3 was increased whereas c-Fos was decreased in the VMH. Taken together, these results suggest that leptin and CCK receptors may both contribute to short-term satiety, and leptin could positively modulate CCK signalling. Notably, nuclear pSTAT3 levels in this experimental paradigm were negatively correlated with satiety levels, contrary to the generally described transcriptional regulation for long-term satiety via leptin receptors.
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Jagannathan L, Socks E, Balasubramanian P, McGowan R, Herdt TM, Kianian R, MohanKumar SMJ, MohanKumar PS. Oleic acid stimulates monoamine efflux through PPAR-α: Differential effects in diet-induced obesity. Life Sci 2020; 255:117867. [PMID: 32479954 DOI: 10.1016/j.lfs.2020.117867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/20/2020] [Accepted: 05/26/2020] [Indexed: 01/13/2023]
Abstract
Obesity continues to be a growing health concern around the world, and elevated levels of free fatty acids as a result of high-fat intake might play a role in neuroendocrine alterations leading to obesity. However, it is unclear how fatty acids affect neuroendocrine functions and energy metabolism. Since hypothalamic monoamines play a crucial role in regulating neuroendocrine functions relating to energy balance, we investigated the direct effects of oleic acid on hypothalamic monoamines and hypothesized that oleic acid would activate peroxisome proliferator-activated receptor alpha (PPAR-α), a nuclear transcription factor involved with fatty acid metabolism, to affect monoamines. We also hypothesized that this response would be subdued in diet-induced obesity (DIO). To test these hypotheses, hypothalami from Sprague Dawley and DIO rats were incubated with 0 (Control), 0.00132 mM, 0.132 mM, 1.32 mM oleic acid, 50 μM MK 886 (a selective PPAR- α antagonist), or oleic acid + MK 886 in Krebs Ringers Henseleit (KRH) solution. HPLC-EC was used to measure monoamine levels in perfusates. Oleic acid produced a significant increase in norepinephrine, dopamine, and serotonin levels in a dose-dependent manner, and incubation with MK886 blocked these effects. The effect of oleic acid on hypothalamic monoamines was attenuated in DIO rats. These findings suggest that PPARα probably plays an essential role in fatty acid sensing in the hypothalamus, by affecting monoamine efflux and DIO rats are resistant to the effects of oleic acid.
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Affiliation(s)
- Lakshmikripa Jagannathan
- Neuroendocrine Research Laboratory, Departments of Pathobiology and Diagnostic Investigation, USA
| | - Emily Socks
- Neuroendocrine Research Laboratory, Departments of Pathobiology and Diagnostic Investigation, USA
| | | | - Robert McGowan
- Neuroendocrine Research Laboratory, Departments of Pathobiology and Diagnostic Investigation, USA
| | - Thomas M Herdt
- Diagnostic Center for Population and Animal Health, Michigan State University, E. Lansing, MI 48824, USA
| | - Reza Kianian
- Neuroendocrine Research Laboratory, Department of Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA 30606, USA
| | - Sheba M J MohanKumar
- Neuroendocrine Research Laboratory, Department of Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA 30606, USA
| | - P S MohanKumar
- Neuroendocrine Research Laboratory, Department of Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA 30606, USA.
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Aslanpour S, Rosin JM, Balakrishnan A, Klenin N, Blot F, Gradwohl G, Schuurmans C, Kurrasch DM. Ascl1 is required to specify a subset of ventromedial hypothalamic neurons. Development 2020; 147:dev180067. [PMID: 32253239 DOI: 10.1242/dev.180067] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 03/23/2020] [Indexed: 03/01/2024]
Abstract
Despite clear physiological roles, the ventromedial hypothalamus (VMH) developmental programs are poorly understood. Here, we asked whether the proneural gene achaete-scute homolog 1 (Ascl1) contributes to VMH development. Ascl1 transcripts were detected in embryonic day (E) 10.5 to postnatal day 0 VMH neural progenitors. The elimination of Ascl1 reduced the number of VMH neurons at E12.5 and E15.5, particularly within the VMH-central (VMHC) and -dorsomedial (VMHDM) subdomains, and resulted in a VMH cell fate change from glutamatergic to GABAergic. We observed a loss of Neurog3 expression in Ascl1-/- hypothalamic progenitors and an upregulation of Neurog3 when Ascl1 was overexpressed. We also demonstrated a glutamatergic to GABAergic fate switch in Neurog3-null mutant mice, suggesting that Ascl1 might act via Neurog3 to drive VMH cell fate decisions. We also showed a concomitant increase in expression of the central GABAergic fate determinant Dlx1/2 in the Ascl1-null hypothalamus. However, Ascl1 was not sufficient to induce an ectopic VMH fate when overexpressed outside the normal window of competency. Combined, Ascl1 is required but not sufficient to specify the neurotransmitter identity of VMH neurons, acting in a transcriptional cascade with Neurog3.
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Affiliation(s)
- Shaghayegh Aslanpour
- Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jessica M Rosin
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Anjali Balakrishnan
- Sunnybrook Research Institute, Department of Biochemistry, University of Toronto, ON M4N 3M5, Canada
| | - Natalia Klenin
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Florence Blot
- Department of Development and Stem Cells, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM, Universite de Strasbourg, Illkirch 67400, France
| | - Gerard Gradwohl
- Department of Development and Stem Cells, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM, Universite de Strasbourg, Illkirch 67400, France
| | - Carol Schuurmans
- Sunnybrook Research Institute, Department of Biochemistry, University of Toronto, ON M4N 3M5, Canada
| | - Deborah M Kurrasch
- Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
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Harris RBS. Loss of leptin receptor-expressing cells in the hindbrain decreases forebrain leptin sensitivity. Am J Physiol Endocrinol Metab 2020; 318:E806-E816. [PMID: 32228323 PMCID: PMC7272723 DOI: 10.1152/ajpendo.00020.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Previous studies indicate that inhibition of food intake by leptin is mediated by an integrated response to activation of hypothalamic and hindbrain receptors. This study tested whether loss of hindbrain leptin receptor signaling changed sensitivity to forebrain leptin. Injections of leptin-conjugated saporin (Lep-Sap) into the medial nucleus of the solitary tract (NTS) were used to destroy hindbrain leptin receptor-expressing neurons of male Sprague-Dawley rats. Controls were injected with saporin conjugated with a nonsense peptide (Blk-Sap). Lep-Sap had no effect on daily food intake or body weight, but expression of phosphorylated signal transducer and activator of transcription 3 (pSTAT3) in the NTS following a peripheral injection of leptin was abolished 26 days after Lep-Sap injections. To test forebrain leptin sensitivity, Lep-Sap and Blk-Sap rats received third-ventricle injections of 0, 0.05, 0.1, 0.25, or 0.5 μg leptin. Food intake was inhibited by 0.25 and 0.5 μg leptin in Blk-Sap rats, but there was no significant effect of leptin on food intake of Lep-Sap rats. There was no difference in hypothalamic pSTAT3 in unstimulated conditions, but pSTAT3 was lower in the dorsomedial region of the ventromedial nucleus of the hypothalamus (VMH) of Lep-Sap rats compared with Blk-Sap rats following a third-ventricle injection of 0.25 μg leptin. These results are consistent with previous data showing that loss of VMH leptin receptor-expressing cells prevents weight loss caused by fourth-ventricle leptin infusion and show that the integrated response between the hindbrain and forebrain is heavily dependent on leptin activity in the VMH.
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Affiliation(s)
- Ruth B S Harris
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
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Glendining KA, Fisher LC, Jasoni CL. Maternal Obesity Modulates Expression of Satb2 in Hypothalamic VMN of Female Offspring. Life (Basel) 2020; 10:life10040048. [PMID: 32344561 PMCID: PMC7235991 DOI: 10.3390/life10040048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/16/2020] [Accepted: 04/21/2020] [Indexed: 01/24/2023] Open
Abstract
Maternal obesity during pregnancy is associated with a greater risk of poor health outcomes in offspring, including obesity, metabolic disorders, and anxiety, however the incidence of these diseases differs for males and females. Similarly, animal models of maternal obesity have reported sex differences in offspring, for both metabolic outcomes and anxiety-like behaviors. The ventromedial nucleus of the hypothalamus (VMN) is a brain region known to be involved in the regulation of both metabolism and anxiety, and is well documented to be sexually dimorphic. As the VMN is largely composed of glutamatergic neurons, which are important for its functions in modulating metabolism and anxiety, we hypothesized that maternal obesity may alter the number of glutamatergic neurons in the offspring VMN. We used a mouse model of a maternal high-fat diet (mHFD), to examine mRNA expression of the glutamatergic neuronal marker Satb2 in the mediobasal hypothalamus of control and mHFD offspring at GD17.5. We found sex differences in Satb2 expression, with mHFD-induced upregulation of Satb2 mRNA in the mediobasal hypothalamus of female offspring, compared to controls, but not males. Using immunohistochemistry, we found an increase in the number of SATB2-positive cells in female mHFD offspring VMN, compared to controls, which was localized to the rostral region of the nucleus. These data provide evidence that maternal nutrition during gestation alters the developing VMN, possibly increasing its glutamatergic drive of offspring in a sex-specific manner, which may contribute to sexual dimorphism in offspring health outcomes later in life.
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Sims ED, Jennings WJ, Empringham B, Fleming A, Portwine C, Johnston DL, Zelcer SM, Rassekh SR, Burrow S, Thabane L, Samaan MC. Circulating leptin levels are associated with adiposity in survivors of childhood brain tumors. Sci Rep 2020; 10:4711. [PMID: 32170116 PMCID: PMC7070034 DOI: 10.1038/s41598-020-61520-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 02/28/2020] [Indexed: 11/16/2022] Open
Abstract
Survivors of Childhood Brain Tumors (SCBT) are at a higher risk of developing cardiovascular disease and type 2 diabetes compared to the general population. Adiposity is an important risk factor for the development of these outcomes, and identifying biomarkers of adiposity may help the stratification of survivors based on their cardiovascular risk or allow for early screening and interventions to improve cardiometabolic outcomes. Leptin is an adipokine that positively correlates with the adipose mass in the general population and is a predictor of adverse cardiometabolic outcomes, yet its association with adiposity in SCBT has not been studied. The aim of this study was to determine if leptin levels are associated with the adipose mass in SCBT, and to define its predictors. This cross-sectional study included 74 SCBT (n = 32 females) with 126 non-cancer controls (n = 59 females). Total adiposity was measured using Bioelectrical Impendence Analysis (BIA) and central adiposity was measured using waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR). We used multivariable linear regression analysis to determine if leptin predicts adiposity in SCBT and adjusted for age, sex, puberty, and cancer status. Leptin correlated strongly with total (p < 0.001) and central (WHR p = 0.001; WHtR p < 0.001) adiposity in SCBT and non-cancer controls. In conclusion, leptin is a potential biomarker for adiposity in SCBT, and further investigation is needed to clarify if leptin is a predictor of future cardiometabolic risk in SCBT.
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Affiliation(s)
- E Danielle Sims
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.,Division of Pediatric Endocrinology, McMaster Children's Hospital, Hamilton, Ontario, Canada
| | - William J Jennings
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.,Division of Pediatric Endocrinology, McMaster Children's Hospital, Hamilton, Ontario, Canada
| | - Brianna Empringham
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.,Division of Pediatric Endocrinology, McMaster Children's Hospital, Hamilton, Ontario, Canada
| | - Adam Fleming
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.,Division of Pediatric Hematology/Oncology, McMaster Children's Hospital, Hamilton, Ontario, Canada
| | - Carol Portwine
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.,Division of Pediatric Hematology/Oncology, McMaster Children's Hospital, Hamilton, Ontario, Canada
| | - Donna L Johnston
- Division of Pediatric Hematology/Oncology, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Shayna M Zelcer
- Pediatric Hematology Oncology, Children's Hospital, London Health Sciences Center, London, Ontario, Canada
| | - Shahrad Rod Rassekh
- Division of Pediatric Hematology/Oncology/BMT, Department of Pediatrics, British Columbia Children's Hospital, Vancouver, BC, Canada
| | - Sarah Burrow
- Division of Orthopedic Surgery, Department of Surgery, McMaster University Medical Centre, Hamilton, Ontario, Canada
| | - Lehana Thabane
- Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada.,Department of Anesthesia, McMaster University, Hamilton, Ontario, Canada.,Centre for Evaluation of Medicines, St. Joseph's Health Care, Hamilton, Ontario, Canada.,Biostatistics Unit, St Joseph's Healthcare-Hamilton, Hamilton, Ontario, Canada
| | - M Constantine Samaan
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada. .,Division of Pediatric Endocrinology, McMaster Children's Hospital, Hamilton, Ontario, Canada. .,Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada.
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Hanna L, Kawalek TJ, Beall C, Ellacott KLJ. Changes in neuronal activity across the mouse ventromedial nucleus of the hypothalamus in response to low glucose: Evaluation using an extracellular multi-electrode array approach. J Neuroendocrinol 2020; 32:e12824. [PMID: 31880369 PMCID: PMC7064989 DOI: 10.1111/jne.12824] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/04/2019] [Accepted: 12/23/2019] [Indexed: 01/01/2023]
Abstract
The hypothalamic ventromedial nucleus (VMN) is involved in maintaining systemic glucose homeostasis. Neurophysiological studies in rodent brain slices have identified populations of VMN glucose-sensing neurones: glucose-excited (GE) neurones, cells which increased their firing rate in response to increases in glucose concentration, and glucose-inhibited (GI) neurones, which show a reduced firing frequency in response to increasing glucose concentrations. To date, most slice electrophysiological studies characterising VMN glucose-sensing neurones in rodents have utilised the patch clamp technique. Multi-electrode arrays (MEAs) are a state-of-the-art electrophysiological tool enabling the electrical activity of many cells to be recorded across multiple electrode sites (channels) simultaneously. We used a perforated MEA (pMEA) system to evaluate electrical activity changes across the dorsal-ventral extent of the mouse VMN region in response to alterations in glucose concentration. Because intrinsic (ie, direct postsynaptic sensing) and extrinsic (ie, presynaptically modulated) glucosensation were not discriminated, we use the terminology 'GE/presynaptically excited by an increase (PER)' and 'GI/presynaptically excited by a decrease (PED)' in the present study to describe responsiveness to changes in extracellular glucose across the mouse VMN. We observed that 15%-60% of channels were GE/PER, whereas 2%-7% were GI/PED channels. Within the dorsomedial portion of the VMN (DM-VMN), significantly more channels were GE/PER compared to the ventrolateral portion of the VMN (VL-VMN). However, GE/PER channels within the VL-VMN showed a significantly higher basal firing rate in 2.5 mmol l-1 glucose than DM-VMN GE/PER channels. No significant difference in the distribution of GI/PED channels was observed between the VMN subregions. The results of the present study demonstrate the utility of the pMEA approach for evaluating glucose responsivity across the mouse VMN. pMEA studies could be used to refine our understanding of other neuroendocrine systems by examining population level changes in electrical activity across brain nuclei, thus providing key functional neuroanatomical information to complement and inform the design of single-cell neurophysiological studies.
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Affiliation(s)
- Lydia Hanna
- Reading School of PharmacyUniversity of ReadingReadingUK
- Institute of Biomedical & Clinical SciencesUniversity of Exeter Medical SchoolExeterUK
- Present address:
Department of Biological SciencesCentre for Biomedical SciencesRoyal Holloway University of LondonEghamUK
| | - Tristan J. Kawalek
- Institute of Biomedical & Clinical SciencesUniversity of Exeter Medical SchoolExeterUK
| | - Craig Beall
- Institute of Biomedical & Clinical SciencesUniversity of Exeter Medical SchoolExeterUK
| | - Kate L. J. Ellacott
- Institute of Biomedical & Clinical SciencesUniversity of Exeter Medical SchoolExeterUK
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Liu H, Xu Y, Hu F. AMPK in the Ventromedial Nucleus of the Hypothalamus: A Key Regulator for Thermogenesis. Front Endocrinol (Lausanne) 2020; 11:578830. [PMID: 33071984 PMCID: PMC7538541 DOI: 10.3389/fendo.2020.578830] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/24/2020] [Indexed: 12/19/2022] Open
Abstract
Obesity has become a global health issue, but effective therapies remain very limited. Adaptive thermogenesis promotes weight loss by dissipating energy in the form of heat, thereby representing a promising target to counteract obesity. Notably, the regulation of thermogenesis is tightly orchestrated by complex neuronal networks, especially those in the hypothalamus. Recent evidence highlights the importance of adenosine monophosphate-activated protein kinase (AMPK) within the ventromedial nucleus of the hypothalamus (VMH) in modulating thermogenesis. Various molecules, such as GLP-1, leptin, estradiol, and thyroid hormones, have been reported to act on the VMH to inhibit AMPK, which subsequently increases thermogenesis through the activation of the sympathetic nervous system (SNS). In this review, we summarize the critical role of AMPK within the VMH in the control of energy balance, focusing on its contribution to thermogenesis and the associated mechanisms.
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Affiliation(s)
- Hailan Liu
- Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, China
- Department of Pediatrics, Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, United States
| | - Yong Xu
- Department of Pediatrics, Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, United States
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States
| | - Fang Hu
- Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, China
- *Correspondence: Fang Hu
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Seamon M, Ahn W, Li AJ, Ritter S, Harris RBS. Leptin receptor-expressing neurons in ventromedial nucleus of the hypothalamus contribute to weight loss caused by fourth ventricle leptin infusions. Am J Physiol Endocrinol Metab 2019; 317:E586-E596. [PMID: 31361549 PMCID: PMC6842917 DOI: 10.1152/ajpendo.00205.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/11/2019] [Accepted: 07/22/2019] [Indexed: 12/24/2022]
Abstract
Leptin administration into the hindbrain, and specifically the nucleus of the solitary tract, increases phosphorylated signal transducer and activator of transcription 3 (pSTAT3), a marker of leptin receptor activation, in hypothalamic nuclei known to express leptin receptors. The ventromedial nucleus of the hypothalamus (VMH) shows the greatest response, with a threefold increase in pSTAT3. This experiment tested the importance of VMH leptin receptor-expressing neurons in mediating weight loss caused by fourth ventricle (4V) leptin infusion. Male Sprague-Dawley rats received bilateral VMH 75-nL injections of 260 ng/μL of leptin-conjugated saporin (Lep-Sap) or blank-saporin (Blk-Sap). After 23 days they were fitted with 4V infusion cannulas and 1 wk later adapted to housing in a calorimeter before they were infused with 0.9 μg leptin/day for 14 days. There was no effect of VMH Lep-Sap on weight gain or glucose clearance before leptin infusion. Leptin inhibited food intake and respiratory exchange ratio in Blk-Sap but not Lep-Sap rats. Leptin had no effect on energy expenditure or brown adipose tissue temperature of either group. Inguinal and epididymal fat were significantly reduced in leptin-treated Blk-Sap rats, but the response was greatly attenuated in Lep-Sap rats. VMH pSTAT3 was increased in leptin-treated Blk-Sap but not Lep-Sap rats. These results support the concept that leptin-induced weight loss results from an integrated response across different brain areas. They also support previous reports that VMH leptin receptors do not play a significant role in maintaining energy balance in basal conditions but limit weight gain during positive energy balance.
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Affiliation(s)
- Marissa Seamon
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - WonMo Ahn
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Ai-Jun Li
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, Washington
| | - Sue Ritter
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, Washington
| | - Ruth B S Harris
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia
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Senn SS, Le Foll C, Whiting L, Tarasco E, Duffy S, Lutz TA, Boyle CN. Unsilencing of native LepRs in hypothalamic SF1 neurons does not rescue obese phenotype in LepR-deficient mice. Am J Physiol Regul Integr Comp Physiol 2019; 317:R451-R460. [PMID: 31314542 DOI: 10.1152/ajpregu.00111.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Leptin receptor (LepR) signaling in neurons of the ventromedial nucleus of the hypothalamus (VMH), specifically those expressing steroidogenic factor-1 (SF1), have been proposed to play a key role in controlling energy balance. By crossing LepR-silenced (LepRloxTB) mice with those expressing SF1-Cre, we unsilenced native LepR specifically in the VMH and tested whether SF1 neurons in the VMH are critical mediators of leptin's effect on energy homeostasis. LepRloxTB × SF1-Cre [knockout (KO)/Tg+] mice were metabolically phenotyped and compared with littermate controls that either expressed or were deficient in LepRs. Leptin-induced phosphorylated STAT3 was present in the VMH of KO/Tg+ mice and absent in other hypothalamic nuclei. VMH leptin signaling did not ameliorate obesity resulting from LepR deficiency in chow-fed mice. There was no change in food intake or energy expenditure when comparing complete LepR-null mice with KO/Tg+ mice, nor did KO/Tg+ mice show improved glucose tolerance. The presence of functional LepRs in the VMH mildly enhanced sensitivity to the pancreatic hormone amylin. When maintained on a high-fat diet (HFD), there was no reduction in diet-induced obesity in KO/Tg+ mice, but KO/Tg+ mice had improved glucose tolerance after 7 wk on an HFD compared with LepR-null mice. We conclude that LepR signaling in the VMH alone is not sufficient to correct metabolic dysfunction observed in LepR-null mice.
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Affiliation(s)
- Seraina S Senn
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Christelle Le Foll
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Lynda Whiting
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Erika Tarasco
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Sonya Duffy
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Thomas A Lutz
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Christina Neuner Boyle
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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Carcinoembryonic Cell Adhesion-Related Molecule 2 Regulates Insulin Secretion and Energy Balance. Int J Mol Sci 2019; 20:ijms20133231. [PMID: 31266142 PMCID: PMC6651791 DOI: 10.3390/ijms20133231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/12/2019] [Accepted: 06/25/2019] [Indexed: 12/13/2022] Open
Abstract
The Carcinoembryonic Antigen-Related Cell Adhesion Molecule (CEACAM) family of proteins plays a significant role in regulating peripheral insulin action by participating in the regulation of insulin metabolism and energy balance. In light of their differential expression, CEACAM1 regulates chiefly insulin extraction, whereas CEACAM2 appears to play a more important role in regulating insulin secretion and overall energy balance, including food intake, energy expenditure and spontaneous physical activity. We will focus this review on the role of CEACAM2 in regulating insulin metabolism and energy balance with an overarching goal to emphasize the importance of the coordinated regulatory effect of these related plasma membrane glycoproteins on insulin metabolism and action.
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Hurley MM, Anderson EM, Chen C, Maunze B, Hess EM, Block ME, Patel N, Cooper Z, McCoy R, Dabra T, Conley W, Reilly MJ, Hearing M, Choi S. Acute Blockade of PACAP-Dependent Activity in the Ventromedial Nucleus of the Hypothalamus Disrupts Leptin-Induced Behavioral and Molecular Changes in Rats. Neuroendocrinology 2019; 110:271-281. [PMID: 31167202 PMCID: PMC6895395 DOI: 10.1159/000501337] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 06/05/2019] [Indexed: 12/18/2022]
Abstract
Leptin signaling pathways, stemming primarily from the hypothalamus, are necessary for maintaining normal energy homeostasis and body weight. In both rodents and humans, dysregulation of leptin signaling leads to morbid obesity and diabetes. Since leptin resistance is considered a primary factor underlying obesity, understanding the regulation of leptin signaling could lead to therapeutic tools and provide insights into the causality of obesity. While leptin actions in some hypothalamic regions such as the arcuate nuclei have been characterized, less is known about leptin activity in the hypothalamic ventromedial nuclei (VMN). Recently, pituitary adenylate cyclase-activating polypeptide (PACAP) has been shown to reduce feeding behavior and alter metabolism when administered into the VMN in a pattern similar to that of leptin. In the current study, we examined whether leptin and PACAP actions in the VMN share overlapping pathways in the regulation of energy balance. Interestingly, PACAP administration into the VMN increased STAT3 phosphorylation and SOCS3 mRNA expression, both of which are hallmarks of leptin receptor activation. In addition, BDNF mRNA expression in the VMN was increased by both leptin and PACAP administration. Moreover, antagonizing PACAP receptors fully reversed the behavioral and cellular effects of leptin injections into the VMN. Electrophysiological studies further illustrated that leptin-induced effects on VMN neurons were blocked by antagonizing PACAP receptors. We conclude that leptin dependency on PACAP signaling in the VMN suggests a potential common signaling cascade, allowing a tonically and systemically secreted neuropeptide to be more precisely regulated by central neuropeptides.
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Affiliation(s)
- Matthew M Hurley
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Eden M Anderson
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Christopher Chen
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Brian Maunze
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Evan M Hess
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Megan E Block
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Neerali Patel
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Zane Cooper
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Riley McCoy
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Tanya Dabra
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - William Conley
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Michael J Reilly
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Matthew Hearing
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - SuJean Choi
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA,
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43
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Fujikawa T, Choi YH, Yang DJ, Shin DM, Donato J, Kohno D, Lee CE, Elias CF, Lee S, Kim KW. P110β in the ventromedial hypothalamus regulates glucose and energy metabolism. Exp Mol Med 2019; 51:1-9. [PMID: 31028248 PMCID: PMC6486607 DOI: 10.1038/s12276-019-0249-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/10/2019] [Accepted: 01/23/2019] [Indexed: 12/29/2022] Open
Abstract
Phosphoinositide 3-kinase (PI3K) signaling in hypothalamic neurons integrates peripheral metabolic cues, including leptin and insulin, to coordinate systemic glucose and energy homeostasis. PI3K is composed of different subunits, each of which has several unique isoforms. However, the role of the PI3K subunits and isoforms in the ventromedial hypothalamus (VMH), a prominent site for the regulation of glucose and energy homeostasis, is unclear. Here we investigated the role of subunit p110β in steroidogenic factor-1 (SF-1) neurons of the VMH in the regulation of metabolism. Our data demonstrate that the deletion of p110β in SF-1 neurons disrupts glucose metabolism, rendering the mice insulin resistant. In addition, the deletion of p110β in SF-1 neurons leads to the whitening of brown adipose tissues and increased susceptibility to diet-induced obesity due to blunted energy expenditure. These results highlight a critical role for p110β in the regulation of glucose and energy homeostasis via VMH neurons. A particular subunit of a critical signaling enzyme is needed for neurons inside the brain’s hypothalamus to properly regulate energy metabolism. Ki Woo Kim from Yonsei University College of Dentistry, Seoul, South Korea, and colleagues explored the role that the PI3K enzyme plays in neurons of the ventromedial area toward the front of the hypothalamus, a region involved in regulating hunger and metabolism. Deleting a subunit of PI3K called p110β, which is needed for enzymatic function, made mice less responsive to insulin, the hormone that keeps blood sugar levels at healthy levels. As well as having abnormal glucose metabolism, the mice converted more brown fat, which burns energy, into white fat, which stores energy. They were also more susceptible to diet-induced obesity. The findings point toward p110β as a potential drug target for treating diabetes.
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Affiliation(s)
- Teppei Fujikawa
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Cellular and Integrative Physiology, Long School of Medicine, UT Health San Antonio, San Antonio, TX, USA
| | - Yun-Hee Choi
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Dong Joo Yang
- Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Dong Min Shin
- Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Jose Donato
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508000, Brazil
| | - Daisuke Kohno
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, 371-8512, Japan
| | - Charlotte E Lee
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Carol F Elias
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Syann Lee
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ki Woo Kim
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA. .,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, 75390, USA. .,Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul, 03722, Korea.
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44
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Piattini F, Le Foll C, Kisielow J, Rosenwald E, Nielsen P, Lutz T, Schneider C, Kopf M. A spontaneous leptin receptor point mutation causes obesity and differentially affects leptin signaling in hypothalamic nuclei resulting in metabolic dysfunctions distinct from db/db mice. Mol Metab 2019; 25:131-141. [PMID: 31076350 PMCID: PMC6601129 DOI: 10.1016/j.molmet.2019.04.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/18/2019] [Accepted: 04/22/2019] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE Leptin (Lep) plays a crucial role in controlling food intake and energy expenditure. Defective Lep/LepRb-signaling leads to fat accumulation, massive obesity, and the development of diabetes. We serendipitously noticed spontaneous development of obesity similar to LepR-deficient (db/db) mice in offspring from a C57BL/6J breeding and transmittance of the phenotype in a Mendelian manner. Candidate gene sequencing revealed a spontaneous point mutation in the LepRb gene. We investigated leptin responsiveness, leptin receptor signaling and metabolic phenotype of this novel LepRb mutant mouse variant. METHODS Overexpression and functional tests of the mutant LepRb in 3T3 cells. Measurement of leptin responsiveness in hypothalamic nuclei, glucose tolerance, food uptake and energy expenditure in the mutant mice. RESULTS The mutation results in the exchange of a glycine for serine (G506S) and introduces an alternative splice acceptor which, when used, encodes for a protein with a 40aa deletion that is retained in the cytoplasm. LepRb signaling was abrogated in the hypothalamic ventromedial nucleus (VMN) and dorsomedial nucleus (DMN), but only partially reduced in the hypothalamic arcuate nucleus (ARC) of LepRbG506S/G506S mice, most likely due to differential splicing in neurons located in the respective regions of the hypothalamus. Extensive metabolic characterization of these mice revealed interesting differences in the control of food intake, glucose tolerance, energy expenditure, and fat accumulation in LepRbG506S/G506S compared with LepRb-deficient db/db mice. CONCLUSIONS This study provides further insight into differences of the leptin responsiveness in VMN, DMN, and ARC and its metabolic consequences.
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Affiliation(s)
- Federica Piattini
- Institute of Molecular Biomedicine, Department Biology, ETH Zürich, Switzerland
| | - Christelle Le Foll
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Switzerland
| | - Jan Kisielow
- Institute of Molecular Biomedicine, Department Biology, ETH Zürich, Switzerland
| | - Esther Rosenwald
- Institute of Molecular Biomedicine, Department Biology, ETH Zürich, Switzerland
| | - Peter Nielsen
- Institute of Molecular Biomedicine, Department Biology, ETH Zürich, Switzerland
| | - Thomas Lutz
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Switzerland
| | - Christoph Schneider
- Institute of Molecular Biomedicine, Department Biology, ETH Zürich, Switzerland
| | - Manfred Kopf
- Institute of Molecular Biomedicine, Department Biology, ETH Zürich, Switzerland.
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Abstract
The hypothalamus is the brain region responsible for the maintenance of energetic homeostasis. The regulation of this process arises from the ability of the hypothalamus to orchestrate complex physiological responses such as food intake and energy expenditure, circadian rhythm, stress response, and fertility. Metabolic alterations such as obesity can compromise these hypothalamic regulatory functions. Alterations in circadian rhythm, stress response, and fertility further contribute to aggravate the metabolic dysfunction of obesity and contribute to the development of chronic disorders such as depression and infertility.At cellular level, obesity caused by overnutrition can damage the hypothalamus promoting inflammation and impairing hypothalamic neurogenesis. Furthermore, hypothalamic neurons suffer apoptosis and impairment in synaptic plasticity that can compromise the proper functioning of the hypothalamus. Several factors contribute to these phenomena such as ER stress, oxidative stress, and impairments in autophagy. All these observations occur at the same time and it is still difficult to discern whether inflammatory processes are the main drivers of these cellular dysfunctions or if the hypothalamic hormone resistance (insulin, leptin, and ghrelin) can be pinpointed as the source of several of these events.Understanding the mechanisms that underlie the pathophysiology of obesity in the hypothalamus is crucial for the development of strategies that can prevent or attenuate the deleterious effects of obesity.
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Evans MC, Anderson GM. Integration of Circadian and Metabolic Control of Reproductive Function. Endocrinology 2018; 159:3661-3673. [PMID: 30304391 DOI: 10.1210/en.2018-00691] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/03/2018] [Indexed: 12/11/2022]
Abstract
Optimal fertility in humans and animals relies on the availability of sufficient metabolic fuels, information about which is communicated to the brain via levels of the hormones leptin and insulin. The circadian clock system is also critical; this input is especially evident in the precise timing of the female-specific surge of GnRH and LH secretion that triggers ovulation the next day. Chronodisruption and metabolic imbalance can both impair reproductive activity, and these two disruptions exacerbate each other, such that they often occur simultaneously. Kisspeptin neurons located in the anteroventral periventricular nucleus of the hypothalamus are able to integrate both circadian and metabolic afferent inputs and use this information to modulate the timing and magnitude of the preovulatory GnRH/LH surge. In an environment in which exposure to high caloric diets and chronodisruptors such as artificial night lighting, shift work, and transmeridian travel have become the norm, the implications of these factors for couples struggling to conceive deserve closer attention and more public education.
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Affiliation(s)
- Maggie C Evans
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Greg M Anderson
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
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47
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Alvarsson A, Stanley SA. Remote control of glucose-sensing neurons to analyze glucose metabolism. Am J Physiol Endocrinol Metab 2018; 315:E327-E339. [PMID: 29812985 PMCID: PMC6171010 DOI: 10.1152/ajpendo.00469.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/25/2018] [Accepted: 05/23/2018] [Indexed: 12/13/2022]
Abstract
The central nervous system relies on a continual supply of glucose, and must be able to detect glucose levels and regulate peripheral organ functions to ensure that its energy requirements are met. Specialized glucose-sensing neurons, first described half a century ago, use glucose as a signal and modulate their firing rates as glucose levels change. Glucose-excited neurons are activated by increasing glucose concentrations, while glucose-inhibited neurons increase their firing rate as glucose concentrations fall and decrease their firing rate as glucose concentrations rise. Glucose-sensing neurons are present in multiple brain regions and are highly expressed in hypothalamic regions, where they are involved in functions related to glucose homeostasis. However, the roles of glucose-sensing neurons in healthy and disease states remain poorly understood. Technologies that can rapidly and reversibly activate or inhibit defined neural populations provide invaluable tools to investigate how specific neural populations regulate metabolism and other physiological roles. Optogenetics has high temporal and spatial resolutions, requires implants for neural stimulation, and is suitable for modulating local neural populations. Chemogenetics, which requires injection of a synthetic ligand, can target both local and widespread populations. Radio- and magnetogenetics offer rapid neural activation in localized or widespread neural populations without the need for implants or injections. These tools will allow us to better understand glucose-sensing neurons and their metabolism-regulating circuits.
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Affiliation(s)
- Alexandra Alvarsson
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai , New York, New York
| | - Sarah A Stanley
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai , New York, New York
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai , New York, New York
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48
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Güemes A, Georgiou P. Review of the role of the nervous system in glucose homoeostasis and future perspectives towards the management of diabetes. Bioelectron Med 2018; 4:9. [PMID: 32232085 PMCID: PMC7098234 DOI: 10.1186/s42234-018-0009-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/10/2018] [Indexed: 12/16/2022] Open
Abstract
Diabetes is a disease caused by a breakdown in the glucose metabolic process resulting in abnormal blood glucose fluctuations. Traditionally, control has involved external insulin injection in response to elevated blood glucose to substitute the role of the beta cells in the pancreas which would otherwise perform this function in a healthy individual. The central nervous system (CNS), however, also plays a vital role in glucose homoeostasis through the control of pancreatic secretion and insulin sensitivity which could potentially be used as a pathway for enhancing glucose control. In this review, we present an overview of the brain regions, peripheral nerves and molecular mechanisms by which the CNS regulates glucose metabolism and the potential benefits of modulating them for diabetes management. Development of technologies to interface to the nervous system will soon become a reality through bioelectronic medicine and we present the emerging opportunities for the treatment of type 1 and type 2 diabetes.
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Affiliation(s)
- Amparo Güemes
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Imperial College London, South Kensington Campus, London, UK
| | - Pantelis Georgiou
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Imperial College London, South Kensington Campus, London, UK
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49
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Ye Z, Liu G, Guo J, Su Z. Hypothalamic endoplasmic reticulum stress as a key mediator of obesity-induced leptin resistance. Obes Rev 2018. [PMID: 29514392 DOI: 10.1111/obr.12673] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Obesity is an epidemic disease that is increasing worldwide and is a major risk factor for many metabolic diseases. However, effective agents for the prevention or treatment of obesity remain limited. Therefore, it is urgent to clarify the pathophysiological mechanisms underlying the development and progression of obesity and exploit potential agents to cure and prevent this disease. According to a recent study series, obesity is associated with the development of endoplasmic reticulum stress and the activation of its stress responses (unfolded protein response) in metabolically active tissues, which contribute to the development of obesity-related insulin and leptin resistance, inflammation and energy imbalance. Hypothalamic endoplasmic reticulum stress is the central mechanism underlying the development of obesity-associated leptin resistance and disruption of energy homeostasis; thus, targeting endoplasmic reticulum stress offers a promising therapeutic strategy for improving leptin sensitivity, increasing energy expenditure and ultimately combating obesity. In this review, we highlight the relationship between and mechanism underlying hypothalamic endoplasmic reticulum stress and obesity-associated leptin resistance and energy imbalance and provide new insight regarding strategies for the treatment of obesity.
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Affiliation(s)
- Z Ye
- Guangdong Metabolic Disease Research Center of Integrated Chinese and Western Medicine, Key Unit of Modulating Liver to Treat Hyperlipemia SATCM (State Administration of Traditional Chinese Medicine), Guangdong Pharmaceutical University, Guangzhou, China.,Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Pharmaceutical University, Guangzhou, China
| | - G Liu
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - J Guo
- Guangdong Metabolic Disease Research Center of Integrated Chinese and Western Medicine, Key Unit of Modulating Liver to Treat Hyperlipemia SATCM (State Administration of Traditional Chinese Medicine), Guangdong Pharmaceutical University, Guangzhou, China
| | - Z Su
- Guangdong Metabolic Disease Research Center of Integrated Chinese and Western Medicine, Key Unit of Modulating Liver to Treat Hyperlipemia SATCM (State Administration of Traditional Chinese Medicine), Guangdong Pharmaceutical University, Guangzhou, China.,Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Pharmaceutical University, Guangzhou, China
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50
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Abstract
Interactions between the brain and distinct adipose depots have a key role in maintaining energy balance, thereby promoting survival in response to metabolic challenges such as cold exposure and starvation. Recently, there has been renewed interest in the specific central neuronal circuits that regulate adipose depots. Here, we review anatomical, genetic and pharmacological studies on the neural regulation of adipose function, including lipolysis, non-shivering thermogenesis, browning and leptin secretion. In particular, we emphasize the role of leptin-sensitive neurons and the sympathetic nervous system in modulating the activity of brown, white and beige adipose tissues. We provide an overview of advances in the understanding of the heterogeneity of the brain regulation of adipose tissues and offer a perspective on the challenges and paradoxes that the community is facing regarding the actions of leptin on this system.
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Affiliation(s)
- Alexandre Caron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Syann Lee
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K. Elmquist
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Laurent Gautron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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