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Yu M, Sun F, Xiang G, Zhang Y, Wang X, Liu X, Huang B, Li X, Zhang D. Liver kinase B-1 modulates the activity of dopamine neurons in the ventral tegmental area and regulates social memory formation. Front Mol Neurosci 2024; 17:1289476. [PMID: 38646099 PMCID: PMC11026561 DOI: 10.3389/fnmol.2024.1289476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 03/19/2024] [Indexed: 04/23/2024] Open
Abstract
Social memory is the ability to discriminate between familiar and unknown conspecifics. It is an important component of social cognition and is therefore essential for the establishment of social relationships. Although the neural circuit mechanisms underlying social memory encoding have been well investigated, little focus has been placed on the regulatory mechanisms of social memory processing. The dopaminergic system, originating from the midbrain ventral tegmental area (VTA), is a key modulator of cognitive function. This study aimed to illustrate its role in modulating social memory and explore the possible molecular mechanisms. Here, we show that the activation of VTA dopamine (DA) neurons is required for the formation, but not the retrieval, of social memory. Inhibition of VTA DA neurons before social interaction, but not 24 h after social interaction, significantly impaired social discrimination the following day. In addition, we showed that the activation of VTA DA neurons was regulated by the serine/threonine protein kinase liver kinase B1 (Lkb1). Deletion of Lkb1 in VTA DA neurons reduced the frequency of burst firing of dopaminergic neurons. Furthermore, Lkb1 plays an important role in regulating social behaviors. Both genetic and virus-mediated deletions of Lkb1 in the VTA of adult mice impaired social memory and subsequently attenuated social familiarization. Altogether, our results provide direct evidence linking social memory formation to the activation of VTA DA neurons in mice and illustrate the crucial role of Lkb1 in regulating VTA DA neuron function.
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Affiliation(s)
- Meng Yu
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
- Jinan Microecological Biomedicine Shandong Laboratory and Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| | - Fengjiao Sun
- Institute of Metabolic and Neuropsychiatric Disorders, Binzhou Medical University Hospital, Binzhou, China
| | - Guo Xiang
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
| | - Yuhan Zhang
- Jinan Microecological Biomedicine Shandong Laboratory and Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| | - Xuejun Wang
- Jinan Microecological Biomedicine Shandong Laboratory and Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| | - Xia Liu
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
| | - Bin Huang
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
- Jinan Microecological Biomedicine Shandong Laboratory and Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| | - Xingang Li
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
- Jinan Microecological Biomedicine Shandong Laboratory and Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| | - Di Zhang
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China
- Jinan Microecological Biomedicine Shandong Laboratory and Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
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2
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Zhang Y, Zhu W, Wang M, Xi P, Wang H, Tian D. Nicotinamide mononucleotide alters body composition and ameliorates metabolic disorders induced by a high-fat diet. IUBMB Life 2023; 75:548-562. [PMID: 36785893 DOI: 10.1002/iub.2707] [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: 11/02/2022] [Accepted: 01/17/2023] [Indexed: 02/15/2023]
Abstract
Obesity is caused by an imbalance between calorie intake and energy expenditure, leading to excessive adipose tissue accumulation. Nicotinamide adenine dinucleotide (NAD+ ) is an important molecule in energy and signal transduction, and NAD+ supplementation therapy is a new treatment for obesity in recent years. Liver kinase B1 (LKB1) is an energy metabolism regulator. The relationship between NAD+ and LKB1 has only been studied in the heart and has not yet been reported in obesity. Nicotinamide mononucleotide (NMN), as a direct precursor of NAD+ , can effectively enhance the level of NAD+ . In the current study, we showed that NMN intervention altered body composition in obese mice, characterized by a reduction in fat mass and an increase in lean mass. NMN reversed high-fat diet-induced blood lipid levels then contributed to reducing hepatic steatosis. NMN also improved glucose tolerance and alleviated adipose tissue inflammation. Moreover, our data suggested that NMN supplementation may be depends on the NAD+ /SIRT6/LKB1 pathway to regulate brown adipose metabolism. These results provided new evidence for NMN in obesity treatment.
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Affiliation(s)
- Yan Zhang
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin, China
| | - Wenjuan Zhu
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin, China
| | - Meng Wang
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin, China
| | - Pengjiao Xi
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin, China
| | - Haomin Wang
- Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin, China
| | - Derun Tian
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin, China.,Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin, China
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3
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Arioglu-Inan E, Kayki-Mutlu G. Sex Differences in Glucose Homeostasis. Handb Exp Pharmacol 2023; 282:219-239. [PMID: 37439847 DOI: 10.1007/164_2023_664] [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] [Indexed: 07/14/2023]
Abstract
Sexual dimorphism has been demonstrated to have an effect on various physiological functions. In this regard, researchers have investigated its impact on glucose homeostasis in both preclinical and clinical studies. Sex differences mainly arise from physiological factors such as sex hormones, body fat and muscle distribution, and sex chromosomes. The sexual dimorphism has also been studied in the context of diabetes. Reflecting the prevalence of the disease among the population, studies focusing on the sex difference in type 1 diabetes (T1D) are not common as the ones in type 2 diabetes (T2D). T1D is reported as the only major specific autoimmune disease that exhibits a male predominance. Clinical studies have demonstrated that impaired fasting glucose is more frequent in men whereas women more commonly exhibit impaired glucose tolerance. Understanding the sex difference in glucose homeostasis becomes more attractive when focusing on the findings that highlight sexual dimorphism on the efficacy or adverse effect profile of antidiabetic medications. Thus, in this chapter, we aimed to discuss the impact of sex on the glucose homeostasis both in health and in diabetes.
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Affiliation(s)
- Ebru Arioglu-Inan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey.
| | - Gizem Kayki-Mutlu
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
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4
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Yu M, Bean JC, Liu H, He Y, Yang Y, Cai X, Yu K, Pei Z, Liu H, Tu L, Conde KM, Wang M, Li Y, Yin N, Zhang N, Han J, Scarcelli NA, Xu P, He Y, Xu Y, Wang C. SK3 in POMC neurons plays a sexually dimorphic role in energy and glucose homeostasis. Cell Biosci 2022; 12:170. [PMID: 36210455 PMCID: PMC9549684 DOI: 10.1186/s13578-022-00907-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/27/2022] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Pro-opiomelanocortin (POMC) neurons play a sexually dimorphic role in body weight and glucose balance. However, the mechanisms for the sex differences in POMC neuron functions are not fully understood. RESULTS We detected small conductance calcium-activated potassium (SK) current in POMC neurons. Secondary analysis of published single-cell RNA-Seq data showed that POMC neurons abundantly express SK3, one SK channel subunit. To test whether SK3 in POMC neurons regulates POMC neuron functions on energy and glucose homeostasis, we used a Cre-loxP strategy to delete SK3 specifically from mature POMC neurons. POMC-specific deletion of SK3 did not affect body weight in either male or female mice. Interestingly, male mutant mice showed not only decreased food intake but also decreased physical activity, resulting in unchanged body weight. Further, POMC-specific SK3 deficiency impaired glucose balance specifically in female mice but not in male mice. Finally, no sex differences were detected in the expression of SK3 and SK current in total POMC neurons. However, we found higher SK current but lower SK3 positive neuron population in male POMC neurons co-expressing estrogen receptor α (ERα) compared to that in females. CONCLUSION These results revealed a sexually dimorphic role of SK3 in POMC neurons in both energy and glucose homeostasis independent of body weight control, which was associated with the sex difference of SK current in a subpopulation of POMC + ERα + neurons.
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Affiliation(s)
- Meng Yu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Jonathan C. Bean
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Hailan Liu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Yang He
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Yongjie Yang
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Xing Cai
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Kaifan Yu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Zhou Pei
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Hesong Liu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Longlong Tu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Kristine M. Conde
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Mengjie Wang
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Yongxiang Li
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Na Yin
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Nan Zhang
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Junying Han
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Nikolas A. Scarcelli
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Pingwen Xu
- grid.185648.60000 0001 2175 0319Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL 60612 USA
| | - Yanlin He
- grid.64337.350000 0001 0662 7451Pennington Biomedical Research Center, Brain glycemic and metabolism control department, Louisiana State University, Baton Rouge, LA 70808 USA
| | - Yong Xu
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA ,grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
| | - Chunmei Wang
- grid.39382.330000 0001 2160 926XChildren’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 USA
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Dos Santos Neves L, Oliveira RKG, Dos Santos LS, Ribeiro IO, Medeiros JMB, de Matos RJB. Modulation of hypothalamic AMPK and hypothalamic neuropeptides in the control of eating behavior: A systematic review. Life Sci 2022; 309:120947. [PMID: 36096244 DOI: 10.1016/j.lfs.2022.120947] [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: 06/27/2022] [Revised: 09/03/2022] [Accepted: 09/07/2022] [Indexed: 12/09/2022]
Abstract
Eating behavior is regulated by central and peripheral signals, which interact to modulate the response to nutrient intake. Central control is mediated by the hypothalamus through neuropeptides that activate the orexigenic and anorexigenic pathways. Energy homeostasis depends on the efficiency of these regulatory mechanisms. This neuroendocrine regulation of hunger and appetite can be modulated by nutritional sensors such as adenosine monophosphate-activated protein kinase (AMPK). Thus, this systematic review discusses the literature on correlations between AMPK and hypothalamic neuropeptides regarding control of eating behavior. Lilacs, PubMed/Medline, ScienceDirect, and Web of Science were searched for articles published from 2009 to 2021 containing combinations of the following descriptors: "eating behavior," "hypothalamus," "neuropeptide," and "AMPK." Of the 1330 articles found initially, 27 were selected after application of the inclusion and exclusion criteria. Of the selected articles, 15 reported decreased AMPK activity, due to interventions using angiotensin II infusion, fructose, glucose, cholecystokinin, leptin, or lipopolysaccharide (LPS) injection; dietary control through a low-protein diet or a high-fat diet (60 % fat); induction of hyperthyroidism; or injection of AMPK inhibitors. Seven studies showed a decrease in neuropeptide Y (NPY) through CV4 AICAR administration; fructose, glucose, leptin, or angiotensin II injections; or infusion of LPS from Escherichia coli and liver kinase B1 (LKB1) overexpression. Eleven studies reported a decrease in food consumption due to a decrease in AMPK activity and/or hypothalamic neuropeptides such as NPY. The results indicate that there is a relationship between AMPK and the control of eating behavior: a decrease in AMPK activity due to a dietary or non-dietary stimulus is associated with a consequent decrease in food intake. Furthermore, AMPK activity can be modulated by glucose, thyroid hormones, estradiol, leptin, and ghrelin.
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Affiliation(s)
- Letycia Dos Santos Neves
- Vitoria Academic Center, Federal University of Pernambuco, Rua do Alto do Reservoir, S/N, Bela Vista, CEP 55608-680 Vitória de Santo Antão, PE, Brazil
| | - Renata Kelly Gomes Oliveira
- Vitoria Academic Center, Federal University of Pernambuco, Rua do Alto do Reservoir, S/N, Bela Vista, CEP 55608-680 Vitória de Santo Antão, PE, Brazil
| | - Lucimeire Santana Dos Santos
- Federal University of Bahia, School of Nutrition, Rua Basilio da Gama, s/n, Campus Canela, CEP: 40.110-907 Salvador, BA, Brazil
| | - Ingrid Oliveira Ribeiro
- Federal University of Bahia, School of Nutrition, Rua Basilio da Gama, s/n, Campus Canela, CEP: 40.110-907 Salvador, BA, Brazil
| | - Jairza Maria Barreto Medeiros
- Federal University of Bahia, School of Nutrition, Rua Basilio da Gama, s/n, Campus Canela, CEP: 40.110-907 Salvador, BA, Brazil
| | - Rhowena Jane Barbosa de Matos
- Health Sciences Center, Federal University of Recôncavo of Bahia, Avenida Carlos Amaral, 1015, Cajueiro, CEP 44574-490 Santo Antônio de Jesus, BA, Brazil.
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6
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Pei Z, He Y, Bean JC, Yang Y, Liu H, Yu M, Yu K, Hyseni I, Cai X, Liu H, Qu N, Tu L, Conde KM, Wang M, Li Y, Yin N, Zhang N, Han J, Potts CHS, Scarcelli NA, Yan Z, Xu P, Wu Q, He Y, Xu Y, Wang C. Gabra5 plays a sexually dimorphic role in POMC neuron activity and glucose balance. Front Endocrinol (Lausanne) 2022; 13:889122. [PMID: 36120438 PMCID: PMC9471380 DOI: 10.3389/fendo.2022.889122] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 03/03/2022] [Accepted: 08/15/2022] [Indexed: 11/25/2022] Open
Abstract
Pro-opiomelanocortin (POMC) neurons are important for the regulation of body weight and glucose balance. The inhibitory tone to POMC neurons is mediated primarily by the GABA receptors. However, the detailed mechanisms and functions of GABA receptors are not well understood. The α5 subunit of GABAA receptor, Gabra5, is reported to regulate feeding, and we found that Gabra5 is highly expressed in POMC neurons. To explore the function of Gabra5 in POMC neurons, we knocked down Gabra5 specifically from mature hypothalamic POMC neurons using the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 strategy. This POMC-specific knock-down of Gabra5 did not affect body weight or food intake in either male or female mice. Interestingly, the loss of Gabra5 caused significant increases in the firing frequency and resting membrane potential, and a decrease in the amplitude of the miniature inhibitory postsynaptic current (mIPSC) in male POMC neurons. However, the loss of Gabra5 only modestly decreased the frequency of mIPSC in female POMC neurons. Consistently, POMC-specific knock-down of Gabra5 significantly improved glucose tolerance in male mice but not in female mice. These results revealed a sexually dimorphic role of Gabra5 in POMC neuron activity and glucose balance, independent of body weight control.
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Affiliation(s)
- Zhou Pei
- Department of Endocrinology and Inherited Metabolic Diseases, Children’s Hospital of Fudan University, Shanghai, China
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Yang He
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Jonathan C. Bean
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Yongjie Yang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Hailan Liu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Meng Yu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Kaifan Yu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Ilirjana Hyseni
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Xing Cai
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Hesong Liu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Na Qu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Longlong Tu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Kristine M. Conde
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Mengjie Wang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Yongxiang Li
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Na Yin
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Nan Zhang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Junying Han
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Camille HS. Potts
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Nikolas A. Scarcelli
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Zili Yan
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Pingwen Xu
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL, United States
| | - Qi Wu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Yanlin He
- Pennington Biomedical Research Center, Brain Glycemic and Metabolism Control Department, Louisiana State University, Baton Rouge, LA, United States
| | - Yong Xu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States
| | - Chunmei Wang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
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7
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He Z, Xu Y, Ma Q, Zhou C, Yang L, Lin M, Deng P, Yang Z, Gong M, Zhang H, Lu M, Li Y, Gao P, Lu Y, He M, Zhang L, Pi H, Zhang K, Qin S, Yu Z, Zhou Z, Chen C. SOX2 modulated astrocytic process plasticity is involved in arsenic-induced metabolic disorders. JOURNAL OF HAZARDOUS MATERIALS 2022; 435:128942. [PMID: 35468398 DOI: 10.1016/j.jhazmat.2022.128942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/02/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Metabolic disorders induced by arsenic exposure have attracted great public concern. However, it remains unclear whether hypothalamus-based central regulation mechanisms are involved in this process. Here, we exposed mice to 100 μg/L arsenic in drinking water and established a chronic arsenic exposure model. Our study revealed that chronic arsenic exposure caused metabolic disorders in mice including impaired glucose metabolism and decreased energy expenditure. Arsenic exposure also impaired glucose sensing and the activation of proopiomelanocortin (POMC) neurons in the hypothalamus. In particular, arsenic exposure damaged the plasticity of hypothalamic astrocytic process. Further research revealed that arsenic exposure inhibited the expression of sex-determining region Y-Box 2 (SOX2), which decreased the expression level of insulin receptors (INSRs) and the phosphorylation of AKT. The conditional deletion of astrocytic SOX2 exacerbated arsenic-induced effects on metabolic disorders, the impairment of hypothalamic astrocytic processes, and the inhibition of INSR/AKT signaling. Furthermore, the arsenic-induced impairment of astrocytic processes and inhibitory effects on INSR/AKT signaling were reversed by SOX2 overexpression in primary hypothalamic astrocytes. Together, we demonstrated here that chronic arsenic exposure caused metabolic disorders by impairing SOX2-modulated hypothalamic astrocytic process plasticity in mice. Our study provides evidence of novel central regulatory mechanisms underlying arsenic-induced metabolic disorders and emphasizes the crucial role of SOX2 in regulating the process plasticity of adult astrocytes.
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Affiliation(s)
- Zhixin He
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Yudong Xu
- Department of Environmental Medicine, School of Public Health, and Department of Emergency Medicine, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Qinlong Ma
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Chao Zhou
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China; Army 953 Hospital, Shigatse Branch of Xinqiao Hospital, Third Military Medical University, Shigatse 857099, China
| | - Lingling Yang
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Min Lin
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Ping Deng
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Zhiqi Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing 400038, China
| | - Mingyue Gong
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing 400038, China
| | - Huijie Zhang
- School of Medicine, Guangxi University, Nanning 530004, Guangxi Zhuang Autonomous Region, China
| | - Muxue Lu
- School of Medicine, Guangxi University, Nanning 530004, Guangxi Zhuang Autonomous Region, China
| | - Yanqi Li
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Peng Gao
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Yonghui Lu
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Mindi He
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Lei Zhang
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Huifeng Pi
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Kuan Zhang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing 400038, China
| | - Song Qin
- Department of Anatomy, Histology and Embryology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Zhengping Yu
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China
| | - Zhou Zhou
- Department of Environmental Medicine, School of Public Health, and Department of Emergency Medicine, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China; Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing 400030, China.
| | - Chunhai Chen
- Department of Occupational Health (Key Laboratory of Electromagnetic Radiation Protection, Ministry of Education), Third Military Medical University, Chongqing 400038, China.
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8
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Garner KM, Burton MD. The sex-specific role of sensory neuron LKB1 on metabolic stress-induced mechanical hypersensitivity and mitochondrial respiration. Am J Physiol Regul Integr Comp Physiol 2022; 323:R227-R243. [PMID: 35503781 PMCID: PMC9306793 DOI: 10.1152/ajpregu.00279.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pain disorders induce metabolic stress in peripheral sensory neurons by reducing mitochondrial output, shifting cellular metabolism, and altering energy use. These processes implicate neuronal metabolism as an avenue for creating novel therapeutics. Liver kinase B1 (LKB1) mediates the cellular response to metabolic stress by inducing the AMPK pathway. The LKB1-AMPK pathway increases energy producing processes, including mitochondrial output. These processes inhibit pain by directly or indirectly restoring energetic balance within a cell. Although the LKB1-AMPK pathway has been linked to pain relief, it is not yet known which cell is responsible for this property, as well any direct ties to cellular metabolism. To elucidate this, we developed a genetic mouse model where LKB1 is selectively removed from Nav1.8-pain sensory neurons and metabolically stressed them by fasting for 24 hours. We found females, but not males, had neuron-specific, LKB1-dependent restoration of metabolic stress-induced mitochondrial metabolism. This was reflected in mechanical hypersensitivity, where the absence of LKB1 led to hypersensitivity in female, but not male, animals. This discrepancy suggests a sex- and cell-specific contribution to LKB1-depdendent fasting-induced mechanical hypersensitivity. While our data represent a potential role for LKB1 in anti-pain pathways in a metabolic-specific manner, more must be done to investigate these sex differences.
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Affiliation(s)
- Katherine Marie Garner
- Neuroimmunology and Behavior Laboratory, Department of Neuroscience, School of Behavioral and Brain Sciences, Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, United States
| | - Michael D Burton
- Neuroimmunology and Behavior Laboratory, Department of Neuroscience, School of Behavioral and Brain Sciences, Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, United States
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9
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Cavalcanti-de-Albuquerque JP, Donato J. Rolling out physical exercise and energy homeostasis: Focus on hypothalamic circuitries. Front Neuroendocrinol 2021; 63:100944. [PMID: 34425188 DOI: 10.1016/j.yfrne.2021.100944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 08/11/2021] [Accepted: 08/18/2021] [Indexed: 01/17/2023]
Abstract
Energy balance is the fine regulation of energy expenditure and energy intake. Negative energy balance causes body weight loss, while positive energy balance promotes weight gain. Modern societies offer a maladapted way of life, where easy access to palatable foods and the lack of opportunities to perform physical activity are considered the roots of the obesity pandemic. Physical exercise increases energy expenditure and, consequently, is supposed to promote weight loss. Paradoxically, physical exercise acutely drives anorexigenic-like effects, but the mechanisms are still poorly understood. Using an evolutionary background, this review aims to highlight the potential involvement of the melanocortin system and other hypothalamic neural circuitries regulating energy balance during and after physical exercise. The physiological significance of these changes will be explored, and possible signalling agents will be addressed. The knowledge discussed here might be important for clarifying obesity aetiology as well as new therapeutic approaches for body weight loss.
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Affiliation(s)
| | - José Donato
- Department of Physiology and Biophysics, University of São Paulo, São Paulo 05508-900, Brazil.
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10
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Myers MG, Affinati AH, Richardson N, Schwartz MW. Central nervous system regulation of organismal energy and glucose homeostasis. Nat Metab 2021; 3:737-750. [PMID: 34158655 DOI: 10.1038/s42255-021-00408-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/12/2021] [Indexed: 02/05/2023]
Abstract
Growing evidence implicates the brain in the regulation of both immediate fuel availability (for example, circulating glucose) and long-term energy stores (that is, adipose tissue mass). Rather than viewing the adipose tissue and glucose control systems separately, we suggest that the brain systems that control them are components of a larger, highly integrated, 'fuel homeostasis' control system. This conceptual framework, along with new insights into the organization and function of distinct neuronal systems, provides a context within which to understand how metabolic homeostasis is achieved in both basal and postprandial states. We also review evidence that dysfunction of the central fuel homeostasis system contributes to the close association between obesity and type 2 diabetes, with the goal of identifying more effective treatment options for these common metabolic disorders.
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Affiliation(s)
- Martin G Myers
- Departments of Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Alison H Affinati
- Departments of Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Nicole Richardson
- UW Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Michael W Schwartz
- UW Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA, USA.
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11
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Wu Z, Xi P, Zhang Y, Wang H, Xue J, Sun X, Tian D. LKB1 up-regulation inhibits hypothalamic inflammation and attenuates diet-induced obesity in mice. Metabolism 2021; 116:154694. [PMID: 33358943 DOI: 10.1016/j.metabol.2020.154694] [Citation(s) in RCA: 9] [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: 09/07/2020] [Revised: 12/11/2020] [Accepted: 12/15/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Diet-induced obesity (DIO) is associated with chronic, low-grade inflammation in the hypothalamus. The inflammatory pathway of the hypothalamus is activated during obesity, and inhibition of activation of the inflammatory pathway can partially reverse obesity. Therefore, exploring new targets for inhibiting hypothalamic inflammation will provide new ideas for the prevention and treatment of obesity. Liver kinase B1 (LKB1), a serine/threonine kinase, is a tumor suppressor and metabolic regulator. Recent studies have shown that LKB1 has a certain anti-inflammatory effect. However, a role of LKB1 in the regulation of hypothalamic inflammation remains unclear. Therefore, we examined whether LKB1 overexpression in the hypothalamus could weaken the hypothalamic inflammation and inhibit the development of obesity. METHODS LKB1 overexpressing adeno-associated virus (AAV) particles were injected stereotactically into the third ventricle (3 V) of C57BL/6 mice fed with HFD. We assessed changes in body mass and adiposity, food intake, hypothalamic inflammatory markers, and energy and glucose metabolism. RESULTS LKB1 up-regulation in hypothalamus attenuated diet-induced hypothalamic inflammation, reduced food intake and body weight gain. In addition, the overexpression of hypothalamic LKB1 increased the insulin sensitivity and improved whole-body lipid metabolism, which attenuated hepatic fat accumulation and serum lipid levels. CONCLUSION Hypothalamic LKB1 up-regulation attenuates hypothalamic inflammation, and protects against hypothalamic inflammation induced damage to melanocortin system, resulting in lower food intake and lower fat mass accumulation, which consequently protects mice from the development of obesity. Our data suggest LKB1 as a novel negative regulator of hypothalamic inflammation, and also a potentially important target for treating other inflammatory diseases.
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Affiliation(s)
- Zhaoxia Wu
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China
| | - Pengjiao Xi
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China
| | - Yan Zhang
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China
| | - Haomin Wang
- Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China
| | - Jie Xue
- Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China
| | - Xuguo Sun
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China
| | - Derun Tian
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China; Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China.
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12
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Optogenetic stimulation of the liver-projecting melanocortinergic pathway promotes hepatic glucose production. Nat Commun 2020; 11:6295. [PMID: 33293550 PMCID: PMC7722761 DOI: 10.1038/s41467-020-20160-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 11/18/2020] [Indexed: 12/18/2022] Open
Abstract
The central melanocortin system plays a fundamental role in the control of feeding and body weight. Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) also regulate overall glucose homeostasis via insulin-dependent and -independent pathways. Here, we report that a subset of ARC POMC neurons innervate the liver via preganglionic parasympathetic acetylcholine (ACh) neurons in the dorsal motor nucleus of the vagus (DMV). Optogenetic stimulation of this liver-projecting melanocortinergic pathway elevates blood glucose levels that is associated with increased expression of hepatic gluconeogenic enzymes in female and male mice. Pharmacological blockade and knockdown of the melanocortin-4 receptor gene in the DMV abolish this stimulation-induced effect. Activation of melanocortin-4 receptors inhibits DMV cholinergic neurons and optogenetic inhibition of liver-projecting parasympathetic cholinergic fibers increases blood glucose levels. This elevated blood glucose is not due to altered pancreatic hormone release. Interestingly, insulin-induced hypoglycemia increases ARC POMC neuron activity. Hence, this liver-projecting melanocortinergic circuit that we identified may play a critical role in the counterregulatory response to hypoglycemia. Hypothalamic melanocortin neurons regulate systemic glucose homeostasis through incompletely understood pathways. Here, the authors show that a subset of pro-opiomelanocortin neurons innervate the liver via preganglionic parasympathetic cholinergic neurons in the dorsal motor nucleus of the vagus and that stimulation of this pathway elevates blood glucose levels
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13
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Levitan D, Liu C, Yang T, Shima Y, Lin JY, Wachutka J, Marrero Y, Ali Marandi Ghoddousi R, da Veiga Beltrame E, Richter TA, Katz DB, Nelson SB. Deletion of Stk11 and Fos in mouse BLA projection neurons alters intrinsic excitability and impairs formation of long-term aversive memory. eLife 2020; 9:e61036. [PMID: 32779566 PMCID: PMC7445010 DOI: 10.7554/elife.61036] [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] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 08/04/2020] [Indexed: 12/14/2022] Open
Abstract
Conditioned taste aversion (CTA) is a form of one-trial learning dependent on basolateral amygdala projection neurons (BLApn). Its underlying cellular and molecular mechanisms remain poorly understood. RNAseq from BLApn identified changes in multiple candidate learning-related transcripts including the expected immediate early gene Fos and Stk11, a master kinase of the AMP-related kinase pathway with important roles in growth, metabolism and development, but not previously implicated in learning. Deletion of Stk11 in BLApn blocked memory prior to training, but not following it and increased neuronal excitability. Conversely, BLApn had reduced excitability following CTA. BLApn knockout of a second learning-related gene, Fos, also increased excitability and impaired learning. Independently increasing BLApn excitability chemogenetically during CTA also impaired memory. STK11 and C-FOS activation were independent of one another. These data suggest key roles for Stk11 and Fos in CTA long-term memory formation, dependent at least partly through convergent action on BLApn intrinsic excitability.
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Affiliation(s)
- David Levitan
- Departments of Biology, Brandeis UniversityWalthamUnited States
| | - Chenghao Liu
- Departments of Biology, Brandeis UniversityWalthamUnited States
| | - Tracy Yang
- Departments of Biology, Brandeis UniversityWalthamUnited States
| | - Yasuyuki Shima
- Departments of Biology, Brandeis UniversityWalthamUnited States
| | - Jian-You Lin
- Departments of Psychology, Brandeis UniversityWalthamUnited States
- Volen Center for Complex Systems, Brandeis UniversityWalthamUnited States
| | - Joseph Wachutka
- Departments of Psychology, Brandeis UniversityWalthamUnited States
| | - Yasmin Marrero
- Departments of Psychology, Brandeis UniversityWalthamUnited States
| | | | | | - Troy A Richter
- Departments of Biology, Brandeis UniversityWalthamUnited States
| | - Donald B Katz
- Departments of Psychology, Brandeis UniversityWalthamUnited States
- Volen Center for Complex Systems, Brandeis UniversityWalthamUnited States
| | - Sacha B Nelson
- Departments of Biology, Brandeis UniversityWalthamUnited States
- Volen Center for Complex Systems, Brandeis UniversityWalthamUnited States
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14
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Wu Z, Han J, Xue J, Xi P, Wang H, He L, Wang Q, Liang H, Sun X, Tian D. Deletion of liver kinase B1 in POMC neurons predisposes to diet-induced obesity. Life Sci 2020; 258:118204. [PMID: 32763296 DOI: 10.1016/j.lfs.2020.118204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/27/2020] [Accepted: 08/01/2020] [Indexed: 01/10/2023]
Abstract
AIMS Liver kinase B1 (LKB1) is a serine/threonine kinase. Although many biological functions of LKB1 have been identified, the role of hypothalamic LKB1 in the regulation of central energy metabolism and susceptibility to obesity is unknown. Therefore, we constructed POMC neuron-specific LKB1 knockout mice (PomcLkb1 KO) and studied it at the physiological, morphological, and molecular biology levels. MAIN METHODS Eight-week-old male PomcLkb1 KO mice and their littermates were fed a standard chow fat diet (CFD) or a high-fat diet (HFD) for 3 months. Body weight and food intake were monitored. Dual-energy X-ray absorptiometry was used to measure the fat mass and lean mass. Glucose and insulin tolerance tests and serum biochemical markers were evaluated in the experimental mice. In addition, the levels of peripheral lipogenesis genes and central energy metabolism were measured. KEY FINDINGS PomcLkb1 KO mice did not exhibit impairments under normal physiological conditions. After HFD intervention, the metabolic phenotype of the PomcLkb1 KO mice changed, manifesting as increased food intake and an enhanced obesity phenotype. More seriously, PomcLkb1 KO mice showed increased leptin resistance, worsened hypothalamic inflammation and reduced POMC neuronal expression. SIGNIFICANCE We provide evidence that LKB1 in POMC neurons plays a significant role in regulating energy homeostasis. LKB1 in POMC neurons emerges as a target for therapeutic intervention against HFD-induced obesity and metabolic diseases.
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Affiliation(s)
- Zhaoxia Wu
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China
| | - Jie Han
- Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China
| | - Jie Xue
- Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China
| | - Pengjiao Xi
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China
| | - Haomin Wang
- Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China
| | - Lu He
- Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China
| | - Qiming Wang
- Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China
| | - Huimin Liang
- Department of School of Nursing, Tianjin Medical University, Tianjin 300070, China
| | - Xuguo Sun
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China.
| | - Derun Tian
- Department of Clinical Laboratory Diagnostics, Tianjin Medical University, Tianjin 300203, China; Department of Human Anatomy and Histology, Tianjin Medical University, Tianjin 300070, China.
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15
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Interaction of glucose sensing and leptin action in the brain. Mol Metab 2020; 39:101011. [PMID: 32416314 PMCID: PMC7267726 DOI: 10.1016/j.molmet.2020.101011] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/27/2020] [Accepted: 05/05/2020] [Indexed: 01/10/2023] Open
Abstract
Background In response to energy abundant or deprived conditions, nutrients and hormones activate hypothalamic pathways to maintain energy and glucose homeostasis. The underlying CNS mechanisms, however, remain elusive in rodents and humans. Scope of review Here, we first discuss brain glucose sensing mechanisms in the presence of a rise or fall of plasma glucose levels, and highlight defects in hypothalamic glucose sensing disrupt in vivo glucose homeostasis in high-fat fed, obese, and/or diabetic conditions. Second, we discuss brain leptin signalling pathways that impact glucose homeostasis in glucose-deprived and excessed conditions, and propose that leptin enhances hypothalamic glucose sensing and restores glucose homeostasis in short-term high-fat fed and/or uncontrolled diabetic conditions. Major conclusions In conclusion, we believe basic studies that investigate the interaction of glucose sensing and leptin action in the brain will address the translational impact of hypothalamic glucose sensing in diabetes and obesity.
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16
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Stanley S, Moheet A, Seaquist ER. Central Mechanisms of Glucose Sensing and Counterregulation in Defense of Hypoglycemia. Endocr Rev 2019; 40:768-788. [PMID: 30689785 PMCID: PMC6505456 DOI: 10.1210/er.2018-00226] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/17/2019] [Indexed: 12/12/2022]
Abstract
Glucose homeostasis requires an organism to rapidly respond to changes in plasma glucose concentrations. Iatrogenic hypoglycemia as a result of treatment with insulin or sulfonylureas is the most common cause of hypoglycemia in humans and is generally only seen in patients with diabetes who take these medications. The first response to a fall in glucose is the detection of impending hypoglycemia by hypoglycemia-detecting sensors, including glucose-sensing neurons in the hypothalamus and other regions. This detection is then linked to a series of neural and hormonal responses that serve to prevent the fall in blood glucose and restore euglycemia. In this review, we discuss the current state of knowledge about central glucose sensing and how detection of a fall in glucose leads to the stimulation of counterregulatory hormone and behavior responses. We also review how diabetes and recurrent hypoglycemia impact glucose sensing and counterregulation, leading to development of impaired awareness of hypoglycemia in diabetes.
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Affiliation(s)
- Sarah Stanley
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Amir Moheet
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Elizabeth R Seaquist
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
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17
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Differential Role of Hypothalamic AMPKα Isoforms in Fish: an Evolutive Perspective. Mol Neurobiol 2018; 56:5051-5066. [PMID: 30460617 DOI: 10.1007/s12035-018-1434-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/15/2018] [Indexed: 12/11/2022]
Abstract
In mammals, hypothalamic AMP-activated protein kinase (AMPK) α1 and α2 isoforms mainly relate to regulation of thermogenesis/liver metabolism and food intake, respectively. Since both isoforms are present in fish, which do not thermoregulate, we assessed their role(s) in hypothalamus regarding control of food intake and energy homeostasis. Since many fish species are carnivorous and mostly mammals are omnivorous, assessing if the role of hypothalamic AMPK is different is also an open question. Using the rainbow trout as a fish model, we first observed that food deprivation for 5 days did not significantly increase phosphorylation status of AMPKα in hypothalamus. Then, we administered adenoviral vectors that express dominant negative (DN) AMPKα1 or AMPKα2 isoforms. The inhibition of AMPKα2 (but not AMPKα1) led to decreased food intake. The central inhibition of AMPKα2 resulted in liver with decreased capacity of use and synthesis of glucose, lipids, and amino acids suggesting that a signal of nutrient abundance flows from hypothalamus to the liver, thus suggesting a role for central AMPKα2 in the regulation of peripheral metabolism in fishes. The central inhibition of AMPKα1 induced comparable changes in liver metabolism though at a lower extent. From an evolutionary point of view, it is of interest that the function of central AMPKα2 remained similar throughout the vertebrate lineage. In contrast, the function of central AMPKα1 in fish relates to modulation of liver metabolism whereas in mammals modulates not only liver metabolism but also brown adipose tissue and thermogenesis.
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18
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Kuwako KI, Okano H. Versatile Roles of LKB1 Kinase Signaling in Neural Development and Homeostasis. Front Mol Neurosci 2018; 11:354. [PMID: 30333724 PMCID: PMC6176002 DOI: 10.3389/fnmol.2018.00354] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/11/2018] [Indexed: 01/01/2023] Open
Abstract
Kinase signaling pathways orchestrate a majority of cellular structures and functions across species. Liver kinase B1 (LKB1, also known as STK11 or Par-4) is a ubiquitously expressed master serine/threonine kinase that plays crucial roles in numerous cellular events, such as polarity control, proliferation, differentiation and energy homeostasis, in many types of cells by activating downstream kinases of the AMP-activated protein kinase (AMPK) subfamily members. In contrast to the accumulating evidence for LKB1 functions in nonneuronal tissues, its functions in the nervous system have been relatively less understood until recently. In the brain, LKB1 initially emerged as a principal regulator of axon/dendrite polarity in forebrain neurons. Thereafter, recent investigations have rapidly uncovered diverse and essential functions of LKB1 in the developing and mature nervous system, such as migration, neurite morphogenesis, myelination and the maintenance of neural integrity, demonstrating that LKB1 is also a multifunctional master kinase in the nervous system. In this review article, we summarize the expanding knowledge about the functional aspects of LKB1 signaling in neural development and homeostasis.
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Affiliation(s)
- Ken-Ichiro Kuwako
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
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19
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Leon S, Velasco I, Vázquez MJ, Barroso A, Beiroa D, Heras V, Ruiz-Pino F, Manfredi-Lozano M, Romero-Ruiz A, Sanchez-Garrido MA, Dieguez C, Pinilla L, Roa J, Nogueiras R, Tena-Sempere M. Sex-Biased Physiological Roles of NPFF1R, the Canonical Receptor of RFRP-3, in Food Intake and Metabolic Homeostasis Revealed by its Congenital Ablation in mice. Metabolism 2018; 87:87-97. [PMID: 30075164 DOI: 10.1016/j.metabol.2018.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/28/2018] [Accepted: 07/28/2018] [Indexed: 01/08/2023]
Abstract
BACKGROUND RF-amide-related peptide-3 (RFRP-3), the mammalian ortholog of gonadotropin-inhibiting hormone, operates as inhibitory signal for the reproductive axis. Recently, RFRP-3 has been also suggested to stimulate feeding, and therefore might contribute to the control of body weight and its alterations. Yet, characterization of the metabolic actions of RFRP-3 has been so far superficial and mostly pharmacological. Here, we aim to investigate the physiological roles of RFRP-3 signaling in the control of feeding and metabolic homeostasis using a novel mouse model of genetic ablation of its canonical receptor, NPFF1R. METHODS Food intake, body weight gain and composition, and key metabolic parameters, including glucose tolerance and insulin sensitivity, were monitored in mice with constitutive inactivation of NPFF1R. RESULTS Congenital elimination of NPFF1R in male mice resulted in changes in feeding patterns, with a decrease in spontaneous food intake and altered responses to leptin and ghrelin: leptin-induced feeding suppression was exaggerated in NPFF1R null mice, whereas orexigenic responses to ghrelin were partially blunted. Concordant with this pro-anorectic phenotype, hypothalamic expression of Pomc was increased in NPFF1R null mice. In contrast, spontaneous feeding and neuropeptide expression remained unaltered in NPFF1R KO female mice. Despite propensity for reduced feeding, ablation of NPFF1R signaling in male mice did not cause overt alterations in body weight (BW) gain or composition, neither it affected BW responses to high fat diet (HFD), total energy expenditure or RQ ratios. Yet, NPFF1R KO males showed a decrease in locomotor activity. Conversely, NPFF1R null female mice tended to be heavier and displayed exaggerated BW increases in response to obesogenic insults, such as HFD or ovariectomy. These were associated to increased fat mass, decreased total energy expenditure in HFD, and unaltered RQ ratios or spontaneous locomotor activity. Finally, lack of NPFF1R signaling worsened the metabolic impact of HFD on glycemic homeostasis in males, as revealed by impaired glucose tolerance and insulin sensitivity, while female mice remained unaffected. CONCLUSION Our data support a discernible orexigenic role of NPFF1R signaling selectively in males, which might modulate the effects of leptin and ghrelin on food intake. In addition, our study is the first to disclose the sex-biased, deleterious impact of the lack of NPFF1R signaling on body weight and fat composition, energy expenditure, locomotor activity and glucose balance, which exaggerates some of the metabolic consequences of concurrent obesogenic insults, such as HFD, in a sexually dimorphic manner. SUMMARY OF TRANSLATIONAL RELEVANCE Our data are the first to document the nature and magnitude of the regulatory actions of RFRP-3/NPFF1R signaling in the control of feeding and metabolic homeostasis in a physiological setting. Our results not only suggest an orexigenic action of endogenous RFRP-3, specifically in males, but reveal also the detrimental impact of ablation of NPFF1R signaling on body composition, energy expenditure, locomotor activity or glucose balance, especially when concurrent with other obesogenic insults, as HFD, thereby providing the first evidence for additional metabolic effects of RFRP-3, other that the mere control of feeding. Interestingly, alterations of such key metabolic parameters occurred in a sex-biased manner, with males being more sensitive to deregulation of locomotor activity and glycemic control, while females displayed clearer obesogenic responses and deregulated energy expenditure. While our study cannot discard the possibility of RFRP-3 actions via alternative pathways, such as NPFF2R, our data pave the way for future analyses addressing the eventual contribution of altered RFRP-3/NPFF1R signaling in the development of metabolic alterations (including obesity and its comorbidities), especially in conditions associated to reproductive dysfunction.
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Affiliation(s)
- Silvia Leon
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Inmaculada Velasco
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Maria J Vázquez
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Alexia Barroso
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Daniel Beiroa
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain; Department of Physiology, Faculty of Medicine and CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782 Santiago de Compostela, Spain
| | - Violeta Heras
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Francisco Ruiz-Pino
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Maria Manfredi-Lozano
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Antonio Romero-Ruiz
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Miguel A Sanchez-Garrido
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Carlos Dieguez
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain; Department of Physiology, Faculty of Medicine and CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782 Santiago de Compostela, Spain
| | - Leonor Pinilla
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Juan Roa
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain
| | - Ruben Nogueiras
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain; Department of Physiology, Faculty of Medicine and CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782 Santiago de Compostela, Spain
| | - Manuel Tena-Sempere
- Instituto Maimónides de Investigación Biomédica de Cordoba (IMIBIC), University of Cordoba, 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Hospital Universitario Reina Sofia, Instituto de Salud Carlos III, 14004 Cordoba, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 14004 Cordoba, Spain; FiDiPro Program, Institute of Biomedicine, University of Turku, Turku, Finland.
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20
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Neurobiological characteristics underlying metabolic differences between males and females. Prog Neurobiol 2018; 176:18-32. [PMID: 30194984 DOI: 10.1016/j.pneurobio.2018.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/22/2018] [Accepted: 09/01/2018] [Indexed: 12/24/2022]
Abstract
The hypothalamus is the main integrating center for metabolic control. Our understanding of how hypothalamic circuits function to control appetite and energy expenditure has increased dramatically in recent years, due to the rapid rise in the incidence of obesity and the search for effective treatments. Increasing evidence indicates that these treatments will most likely differ between males and females. Indeed, sex differences in metabolism have been demonstrated at various levels, including in two of the most studied neuronal populations involved in metabolic control: the anorexigenic proopiomelanocortin neurons and the orexigenic neuropeptide Y/Agouti-related protein neurons. Here we review what is known to date regarding the sex differences in these two neuronal populations, as well as other neuronal populations involved in metabolic control and glial cells.
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21
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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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22
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p53 in AgRP neurons is required for protection against diet-induced obesity via JNK1. Nat Commun 2018; 9:3432. [PMID: 30143607 PMCID: PMC6109113 DOI: 10.1038/s41467-018-05711-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/19/2018] [Indexed: 12/13/2022] Open
Abstract
p53 is a well-known tumor suppressor that has emerged as an important player in energy balance. However, its metabolic role in the hypothalamus remains unknown. Herein, we show that mice lacking p53 in agouti-related peptide (AgRP), but not proopiomelanocortin (POMC) or steroidogenic factor-1 (SF1) neurons, are more prone to develop diet-induced obesity and show reduced brown adipose tissue (BAT) thermogenic activity. AgRP-specific ablation of p53 resulted in increased hypothalamic c-Jun N-terminal kinase (JNK) activity before the mice developed obesity, and central inhibition of JNK reversed the obese phenotype of these mice. The overexpression of p53 in the ARC or specifically in AgRP neurons of obese mice decreased body weight and stimulated BAT thermogenesis, resulting in body weight loss. Finally, p53 in AgRP neurons regulates the ghrelin-induced food intake and body weight. Overall, our findings provide evidence that p53 in AgRP neurons is required for normal adaptations against diet-induced obesity. Emerging studies suggest that p53 is an important regulator of energy metabolism, yet there is little known about the metabolic function of this tumor suppressor in the hypothalamus. Here, authors illustrate that p53, specifically in AgRP neurons, is required for adaptation to diet-induced obesity.
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23
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Augmented Insulin and Leptin Resistance of High Fat Diet-Fed APPswe/PS1dE9 Transgenic Mice Exacerbate Obesity and Glycemic Dysregulation. Int J Mol Sci 2018; 19:ijms19082333. [PMID: 30096853 PMCID: PMC6121904 DOI: 10.3390/ijms19082333] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/02/2018] [Accepted: 08/03/2018] [Indexed: 11/16/2022] Open
Abstract
Alzheimer’s disease (AD), a progressive neurodegenerative disease is highly associated with metabolic syndromes. We previously demonstrated that glycemic dysregulation and obesity are augmented in high fat diet (HFD)-treated APPswe/PS1dE9 (APP/PS1) transgenic mice. In the current study, the underlying mechanism mediating exacerbated metabolic stresses in HFD APP/PS1 transgenic mice was further examined. APP/PS1 mice developed insulin resistance and, consequently, impaired glucose homeostasis after 10 weeks on HFD. [18F]-2-fluoro-2-deoxy-d-glucose ([18F]-FDG) positron emission tomography showed that interscapular brown adipose tissue is vulnerable to HFD and AD-related pathology. Chronic HFD induced hyperphagia, with limited effects on basal metabolic rates in APP/PS1 transgenic mice. Excessive food intake may be caused by impairment of leptin signaling in the hypothalamus because leptin failed to suppress the food intake of HFD APP/PS1 transgenic mice. Leptin-induced pSTAT3 signaling in the arcuate nucleus was attenuated. Dysregulated energy homeostasis including hyperphagia and exacerbated obesity was elicited prior to the presence of the amyloid pathology in the hypothalamus of HFD APP/PS1 transgenic mice; nevertheless, cortical neuroinflammation and the level of serum Aβ and IL-6 were significantly elevated. Our study demonstrates the pivotal role of AD-related pathology in augmenting HFD-induced insulin and leptin resistance and impairing hypothalamic regulation of energy homeostasis.
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24
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Emerging Concepts in Brain Glucose Metabolic Functions: From Glucose Sensing to How the Sweet Taste of Glucose Regulates Its Own Metabolism in Astrocytes and Neurons. Neuromolecular Med 2018; 20:281-300. [DOI: 10.1007/s12017-018-8503-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 07/13/2018] [Indexed: 12/16/2022]
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25
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Wang C, He Y, Xu P, Yang Y, Saito K, Xia Y, Yan X, Hinton A, Yan C, Ding H, Yu L, Shu G, Gupta R, Wu Q, Tong Q, Lagor WR, Flores ER, Xu Y. TAp63 contributes to sexual dimorphism in POMC neuron functions and energy homeostasis. Nat Commun 2018; 9:1544. [PMID: 29670083 PMCID: PMC5906443 DOI: 10.1038/s41467-018-03796-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 03/13/2018] [Indexed: 01/09/2023] Open
Abstract
Sexual dimorphism exists in energy balance, but the underlying mechanisms remain unclear. Here we show that the female mice have more pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of hypothalamus than males, and female POMC neurons display higher neural activities, compared to male counterparts. Strikingly, deletion of the transcription factor, TAp63, in POMC neurons confers "male-like" diet-induced obesity (DIO) in female mice associated with decreased POMC neural activities; but the same deletion does not affect male mice. Our results indicate that TAp63 in female POMC neurons contributes to the enhanced POMC neuron functions and resistance to obesity in females. Thus, TAp63 in POMC neurons is one key molecular driver for the sexual dimorphism in energy homeostasis.
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Affiliation(s)
- Chunmei Wang
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yanlin He
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Pingwen Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yongjie Yang
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kenji Saito
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yan Xia
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Xiaofeng Yan
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Antentor Hinton
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Chunling Yan
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Hongfang Ding
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Likai Yu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Gang Shu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Rajat Gupta
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Qi Wu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - William R Lagor
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Elsa R Flores
- Department of Molecular Oncology, Cancer Biology and Evolution Program, Department of Cutaneous Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, 33612, USA
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
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26
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Xiao Y, Xia T, Yu J, Deng Y, Liu H, Liu B, Chen S, Liu Y, Guo F. Knockout of inositol-requiring enzyme 1α in pro-opiomelanocortin neurons decreases fat mass via increasing energy expenditure. Open Biol 2017; 6:rsob.160131. [PMID: 27558934 PMCID: PMC5008012 DOI: 10.1098/rsob.160131] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 07/15/2016] [Indexed: 01/21/2023] Open
Abstract
Although numerous functions of inositol-requiring enzyme 1α (IRE1α) have been identified, a role of IRE1α in pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus is largely unknown. Here, we showed that mice lacking IRE1α specifically in POMC neurons (PIKO) are lean and resistant to high-fat diet-induced obesity and obesity-related insulin resistance, liver steatosis and leptin resistance. Furthermore, PIKO mice had higher energy expenditure, probably due to increased thermogenesis in brown adipose tissue. Additionally, α-melanocyte-stimulating hormone production was increased in the hypothalamus of PIKO mice. These results demonstrate that IRE1α in POMC neurons plays a critical role in the regulation of obesity and obesity-related metabolic disorders. Our results also suggest that IRE1α is not only an endoplasmic reticulum stress sensor, but also a new potential therapeutic target for obesity and obesity-related metabolic diseases.
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Affiliation(s)
- Yuzhong Xiao
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
| | - Tingting Xia
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
| | - Junjie Yu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
| | - Yalan Deng
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
| | - Hao Liu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
| | - Bin Liu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
| | - Shanghai Chen
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
| | - Yong Liu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
| | - Feifan Guo
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, The Graduate School of the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, People's Republic of China
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27
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Molecular mechanisms of appetite and obesity: a role for brain AMPK. Clin Sci (Lond) 2017; 130:1697-709. [PMID: 27555613 DOI: 10.1042/cs20160048] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 07/07/2016] [Indexed: 01/15/2023]
Abstract
Feeding behaviour and energy storage are both crucial aspects of survival. Thus, it is of fundamental importance to understand the molecular mechanisms regulating these basic processes. The AMP-activated protein kinase (AMPK) has been revealed as one of the key molecules modulating energy homoeostasis. Indeed, AMPK appears to be essential for translating nutritional and energy requirements into generation of an adequate neuronal response, particularly in two areas of the brain, the hypothalamus and the hindbrain. Failure of this physiological response can lead to energy imbalance, ultimately with extreme consequences, such as leanness or obesity. Here, we will review the data that put brain AMPK in the spotlight as a regulator of appetite.
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28
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Dorfman MD, Krull JE, Scarlett JM, Guyenet SJ, Sajan MP, Damian V, Nguyen HT, Leitges M, Morton GJ, Farese RV, Schwartz MW, Thaler JP. Deletion of Protein Kinase C λ in POMC Neurons Predisposes to Diet-Induced Obesity. Diabetes 2017; 66:920-934. [PMID: 28073831 PMCID: PMC5360303 DOI: 10.2337/db16-0482] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 01/02/2017] [Indexed: 12/16/2022]
Abstract
Effectors of the phosphoinositide 3-kinase (PI3K) signal transduction pathway contribute to the hypothalamic regulation of energy and glucose homeostasis in divergent ways. Here we show that central nervous system (CNS) action of the PI3K signaling intermediate atypical protein kinase C (aPKC) constrains food intake, weight gain, and glucose intolerance in both rats and mice. Pharmacological inhibition of CNS aPKC activity acutely increases food intake and worsens glucose tolerance in chow-fed rodents and causes excess weight gain during high-fat diet (HFD) feeding. Similarly, selective deletion of the aPKC isoform Pkc-λ in proopiomelanocortin (POMC) neurons disrupts leptin action, reduces melanocortin content in the paraventricular nucleus, and markedly increases susceptibility to obesity, glucose intolerance, and insulin resistance specifically in HFD-fed male mice. These data implicate aPKC as a novel regulator of energy and glucose homeostasis downstream of the leptin-PI3K pathway in POMC neurons.
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Affiliation(s)
- Mauricio D Dorfman
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Jordan E Krull
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Jarrad M Scarlett
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Stephan J Guyenet
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Mini P Sajan
- Department of Internal Medicine, University of South Florida College of Medicine, Tampa, FL
- Research & Internal Medicine Services, James A. Haley VA Medical Center, Tampa, FL
| | - Vincent Damian
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Hong T Nguyen
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Michael Leitges
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
| | - Gregory J Morton
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Robert V Farese
- Department of Internal Medicine, University of South Florida College of Medicine, Tampa, FL
- Research & Internal Medicine Services, James A. Haley VA Medical Center, Tampa, FL
| | - Michael W Schwartz
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Joshua P Thaler
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
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29
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Hypothalamic AMPK as a Regulator of Energy Homeostasis. Neural Plast 2016; 2016:2754078. [PMID: 27547453 PMCID: PMC4980534 DOI: 10.1155/2016/2754078] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/10/2016] [Indexed: 12/16/2022] Open
Abstract
Activated in energy depletion conditions, AMP-activated protein kinase (AMPK) acts as a cellular energy sensor and regulator in both central nervous system and peripheral organs. Hypothalamic AMPK restores energy balance by promoting feeding behavior to increase energy intake, increasing glucose production, and reducing thermogenesis to decrease energy output. Besides energy state, many hormones have been shown to act in concert with AMPK to mediate their anorexigenic and orexigenic central effects as well as thermogenic influences. Here we explore the factors that affect hypothalamic AMPK activity and give the underlying mechanisms for the role of central AMPK in energy homeostasis together with the physiological effects of hypothalamic AMPK on energy balance restoration.
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30
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López M, Nogueiras R, Tena-Sempere M, Diéguez C. Hypothalamic AMPK: a canonical regulator of whole-body energy balance. Nat Rev Endocrinol 2016; 12:421-32. [PMID: 27199291 DOI: 10.1038/nrendo.2016.67] [Citation(s) in RCA: 211] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
AMP-activated protein kinase (AMPK) has a major role in the modulation of energy balance. AMPK is activated in conditions of low energy, increasing energy production and reducing energy consumption. The AMPK pathway is a canonical route regulating energy homeostasis by integrating peripheral signals, such as hormones and metabolites, with neuronal networks. Current evidence has implicated AMPK in the hypothalamus and hindbrain with feeding, brown adipose tissue thermogenesis and browning of white adipose tissue, through modulation of the sympathetic nervous system, as well as glucose homeostasis. Interestingly, several potential antiobesity and/or antidiabetic agents, some of which are currently in clinical use such as metformin and liraglutide, exert some of their actions by acting on AMPK. Furthermore, the orexigenic and weight-gain effects of commonly used antipsychotic drugs are also mediated by hypothalamic AMPK. Overall, this evidence suggests that hypothalamic AMPK signalling is an interesting target for drug development, but is this approach feasible? In this Review we discuss the current understanding of hypothalamic AMPK and its role in the central regulation of energy balance and metabolism.
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Affiliation(s)
- Miguel López
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain
| | - Rubén Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain
| | - Manuel Tena-Sempere
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain
- Department of Cell Biology, Physiology and Immunology, University of Córdoba; Instituto Maimónides de Investigación Biomédica (IMIBIC)/Hospital Reina Sofía, 14004 Córdoba, Spain
- FiDiPro Program, Department of Physiology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland
| | - Carlos Diéguez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain
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31
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Burgos-Ramos E, Canelles S, Rodríguez A, Gómez-Ambrosi J, Frago LM, Chowen JA, Frühbeck G, Argente J, Barrios V. Chronic central leptin infusion modulates the glycemia response to insulin administration in male rats through regulation of hepatic glucose metabolism. Mol Cell Endocrinol 2015; 415:157-72. [PMID: 26296906 DOI: 10.1016/j.mce.2015.08.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 08/06/2015] [Accepted: 08/09/2015] [Indexed: 10/23/2022]
Abstract
Leptin and insulin use overlapping signaling mechanisms to modify hepatic glucose metabolism, which is critical in maintaining normal glycemia. We examined the effect of an increase in central leptin and insulin on hepatic glucose metabolism and its influence on serum glucose levels. Chronic leptin infusion increased serum leptin and reduced hepatic SH-phosphotyrosine phosphatase 1, the association of suppressor of cytokine signaling 3 to the insulin receptor in liver and the rise in glycemia induced by central insulin. Leptin also decreased hepatic phosphoenolpyruvate carboxykinase levels and increased insulin's ability to phosphorylate insulin receptor substrate-1, Akt and glycogen synthase kinase on Ser9 and to stimulate glucose transporter 2 and glycogen levels. Peripheral leptin treatment reproduced some of these changes, but to a lesser extent. Our data indicate that leptin increases the hepatic response to a rise in insulin, suggesting that pharmacological manipulation of leptin targets may be of interest for controlling glycemia.
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Affiliation(s)
- Emma Burgos-Ramos
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, E-28009, Spain; IMDEA Food, CEI UAM+CSIC, Carretera de Cantoblanco 8, Madrid, E-28049, Spain
| | - Sandra Canelles
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, E-28009, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, E-28009, Spain
| | - Amaia Rodríguez
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, E-28009, Spain; Metabolic Research Laboratory, Clínica Universidad de Navarra, IdiSNA, Pamplona, E-31008, Spain
| | - Javier Gómez-Ambrosi
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, E-28009, Spain; Metabolic Research Laboratory, Clínica Universidad de Navarra, IdiSNA, Pamplona, E-31008, Spain
| | - Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, E-28009, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, E-28009, Spain
| | - Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, E-28009, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, E-28009, Spain
| | - Gema Frühbeck
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, E-28009, Spain; Metabolic Research Laboratory, Clínica Universidad de Navarra, IdiSNA, Pamplona, E-31008, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, E-28009, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, E-28009, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, E-28009, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, E-28009, Spain.
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Reduced α-MSH Underlies Hypothalamic ER-Stress-Induced Hepatic Gluconeogenesis. Cell Rep 2015; 12:361-70. [DOI: 10.1016/j.celrep.2015.06.041] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 05/04/2015] [Accepted: 06/10/2015] [Indexed: 11/18/2022] Open
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Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice. Cell Rep 2015; 11:335-43. [PMID: 25865886 PMCID: PMC4410943 DOI: 10.1016/j.celrep.2015.03.029] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/11/2015] [Accepted: 03/11/2015] [Indexed: 11/23/2022] Open
Abstract
Hypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons.
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Schneeberger M, Gomis R, Claret M. Hypothalamic and brainstem neuronal circuits controlling homeostatic energy balance. J Endocrinol 2014; 220:T25-46. [PMID: 24222039 DOI: 10.1530/joe-13-0398] [Citation(s) in RCA: 192] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Alterations in adequate energy balance maintenance result in serious metabolic disturbances such as obesity. In mammals, this complex process is orchestrated by multiple and distributed neuronal circuits. Hypothalamic and brainstem neuronal circuits are critically involved in the sensing of circulating and local factors conveying information about the energy status of the organism. The integration of these signals culminates in the generation of specific and coordinated physiological responses aimed at regulating energy balance through the modulation of appetite and energy expenditure. In this article, we review current knowledge on the homeostatic regulation of energy balance, emphasizing recent advances in mouse genetics, electrophysiology, and optogenetic techniques that have greatly contributed to improving our understanding of this central process.
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Affiliation(s)
- Marc Schneeberger
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain Department of Endocrinology and Nutrition, School of Medicine, Hospital Clínic, University of Barcelona, 08036 Barcelona, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain
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Abstract
Body weight is determined by a balance between food intake and energy expenditure. Multiple neural circuits in the brain have evolved to process information about food, food-related cues and food consumption to control feeding behavior. Numerous gastrointestinal endocrine cells produce and secrete satiety hormones in response to food consumption and digestion. These hormones suppress hunger and promote satiation and satiety mainly through hindbrain circuits, thus governing meal-by-meal eating behavior. In contrast, the hypothalamus integrates adiposity signals to regulate long-term energy balance and body weight. Distinct hypothalamic areas and various orexigenic and anorexigenic neurons have been identified to homeostatically regulate food intake. The hypothalamic circuits regulate food intake in part by modulating the sensitivity of the hindbrain to short-term satiety hormones. The hedonic and incentive properties of foods and food-related cues are processed by the corticolimbic reward circuits. The mesolimbic dopamine system encodes subjective "liking" and "wanting" of palatable foods, which is subjected to modulation by the hindbrain and the hypothalamic homeostatic circuits and by satiety and adiposity hormones. Satiety and adiposity hormones also promote energy expenditure by stimulating brown adipose tissue (BAT) activity. They stimulate BAT thermogenesis mainly by increasing the sympathetic outflow to BAT. Many defects in satiety and/or adiposity hormone signaling and in the hindbrain and the hypothalamic circuits have been described and are believed to contribute to the pathogenesis of energy imbalance and obesity.
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Affiliation(s)
- Liangyou Rui
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48109-0622, USA,
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36
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Schneeberger M, Dietrich MO, Sebastián D, Imbernón M, Castaño C, Garcia A, Esteban Y, Gonzalez-Franquesa A, Rodríguez IC, Bortolozzi A, Garcia-Roves PM, Gomis R, Nogueiras R, Horvath TL, Zorzano A, Claret M. Mitofusin 2 in POMC neurons connects ER stress with leptin resistance and energy imbalance. Cell 2013; 155:172-87. [PMID: 24074867 DOI: 10.1016/j.cell.2013.09.003] [Citation(s) in RCA: 398] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 07/09/2013] [Accepted: 08/22/2013] [Indexed: 11/26/2022]
Abstract
Mitofusin 2 (MFN2) plays critical roles in both mitochondrial fusion and the establishment of mitochondria-endoplasmic reticulum (ER) interactions. Hypothalamic ER stress has emerged as a causative factor for the development of leptin resistance, but the underlying mechanisms are largely unknown. Here, we show that mitochondria-ER contacts in anorexigenic pro-opiomelanocortin (POMC) neurons in the hypothalamus are decreased in diet-induced obesity. POMC-specific ablation of Mfn2 resulted in loss of mitochondria-ER contacts, defective POMC processing, ER stress-induced leptin resistance, hyperphagia, reduced energy expenditure, and obesity. Pharmacological relieve of hypothalamic ER stress reversed these metabolic alterations. Our data establish MFN2 in POMC neurons as an essential regulator of systemic energy balance by fine-tuning the mitochondrial-ER axis homeostasis and function. This previously unrecognized role for MFN2 argues for a crucial involvement in mediating ER stress-induced leptin resistance.
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Affiliation(s)
- Marc Schneeberger
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; Department of Endocrinology and Nutrition, Hospital Clínic. School of Medicine, University of Barcelona, 08036 Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08036 Barcelona, Spain
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Stanley S, Domingos AI, Kelly L, Garfield A, Damanpour S, Heisler L, Friedman J. Profiling of Glucose-Sensing Neurons Reveals that GHRH Neurons Are Activated by Hypoglycemia. Cell Metab 2013; 18:596-607. [PMID: 24093682 DOI: 10.1016/j.cmet.2013.09.002] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 07/29/2013] [Accepted: 08/22/2013] [Indexed: 12/17/2022]
Abstract
Comprehensive transcriptional profiling of glucose-sensing neurons is challenging because of low expression levels of glucokinase (Gck) and other key proteins that transduce a glucose signal. To overcome this, we generated and validated transgenic mice with a neuronal/endocrine-specific Gck promoter driving cre expression and mated them to mice with cre-dependent expression of an EGFP-tagged ribosomal protein construct (EEF1A1-LSL.EGFPL10) that can be used to map and profile cells. We found significant Gck expression in hypothalamic and limbic regions in cells that are activated following administration of glucose or 2-deoxyglucose. Transcriptional profiling from Gck-cre/EEF1A1-LSL.EGFPL10 mice enriched known and previously unknown glucose-sensing populations including neurons expressing growth hormone releasing hormone (GHRH). Electrophysiological recordings show that hypoglycemia activates GHRH neurons, suggesting a mechanistic link between hypoglycemia and growth hormone release. These studies provide a means for mapping glucose-sensitive neurons and for generating transcriptional profiles from other cell types expressing cre in a cell-specific manner.
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Affiliation(s)
- Sarah Stanley
- Laboratory of Molecular Genetics, Rockefeller University, New York, NY 10065, USA
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Gyengesi E, Paxinos G, Andrews ZB. Oxidative Stress in the Hypothalamus: the Importance of Calcium Signaling and Mitochondrial ROS in Body Weight Regulation. Curr Neuropharmacol 2013; 10:344-53. [PMID: 23730258 PMCID: PMC3520044 DOI: 10.2174/157015912804143496] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 07/12/2012] [Accepted: 08/02/2012] [Indexed: 12/25/2022] Open
Abstract
A considerable amount of evidence shows that reactive oxygen species (ROS) in the mammalian brain are directly responsible for cell and tissue function and dysfunction. Excessive reactive oxygen species contribute to various conditions including inflammation, diabetes mellitus, neurodegenerative diseases, tumor formation, and mental disorders such as depression. Increased intracellular calcium levels have toxic roles leading to cell death. However, the exact connection between reactive oxygen production and high calcium stress is not yet fully understood. In this review, we focus on the role of reactive oxygen species and calcium stress in hypothalamic arcuate neurons controlling feeding. We revisit the role of NPY and POMC neurons in the regulation of appetite and energy homeostasis, and consider how ROS and intracellular calcium levels affect these neurons. These novel insights give a new direction to research on hypothalamic mechanisms regulating energy homeostasis and may offer novel treatment strategies for obesity and type-2 diabetes.
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Affiliation(s)
- Erika Gyengesi
- Neuroscience Research Australia, Barker Street, Randwick, New South Wales, Australia
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Santos GA, Pereira VD, Roman EAFR, Ignacio-Souza L, Vitorino DC, de Moura RF, Razolli DS, Torsoni AS, Velloso LA, Torsoni MA. Hypothalamic inhibition of acetyl-CoA carboxylase stimulates hepatic counter-regulatory response independent of AMPK activation in rats. PLoS One 2013; 8:e62669. [PMID: 23626844 PMCID: PMC3633841 DOI: 10.1371/journal.pone.0062669] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 03/22/2013] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Hypothalamic AMPK acts as a cell energy sensor and can modulate food intake, glucose homeostasis, and fatty acid biosynthesis. Intrahypothalamic fatty acid injection is known to suppress liver glucose production, mainly by activation of hypothalamic ATP-sensitive potassium (K(ATP)) channels. Since all models employed seem to involve malonyl-CoA biosynthesis, we hypothesized that acetyl-CoA carboxylase can modulate the counter-regulatory response independent of nutrient availability. METHODOLOGY/PRINCIPAL FINDINGS In this study employing immunoblot, real-time PCR, ELISA, and biochemical measurements, we showed that reduction of the hypothalamic expression of acetyl-CoA carboxylase by antisense oligonucleotide after intraventricular injection increased food intake and NPY mRNA, and diminished the expression of CART, CRH, and TRH mRNA. Additionally, as in fasted rats, in antisense oligonucleotide-treated rats, serum glucagon and ketone bodies increased, while the levels of serum insulin and hepatic glycogen diminished. The reduction of hypothalamic acetyl-CoA carboxylase also increased PEPCK expression, AMPK phosphorylation, and glucose production in the liver. Interestingly, these effects were observed without modification of hypothalamic AMPK phosphorylation. CONCLUSION/SIGNIFICANCE Hypothalamic ACC inhibition can activate hepatic counter-regulatory response independent of hypothalamic AMPK activation.
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Affiliation(s)
- Gustavo A. Santos
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Vinícius D. Pereira
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Erika A. F. R. Roman
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Leticia Ignacio-Souza
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Daniele C. Vitorino
- Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | | | - Daniela S. Razolli
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Adriana S. Torsoni
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Limeira, São Paulo, Brazil
| | - Licio A. Velloso
- Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Marcio A. Torsoni
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Limeira, São Paulo, Brazil
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Pimentel GD, Ropelle ER, Rocha GZ, Carvalheira JBC. The role of neuronal AMPK as a mediator of nutritional regulation of food intake and energy homeostasis. Metabolism 2013; 62:171-8. [PMID: 22898253 DOI: 10.1016/j.metabol.2012.07.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 07/01/2012] [Accepted: 07/06/2012] [Indexed: 02/07/2023]
Abstract
Hypothalamic 5'-adenosine monophosphate-activated protein kinase (AMPK) senses intracellular metabolic stress, i.e., an increase in the cellular AMP:ATP ratio, and integrates diverse hormonal and nutritional signals to restore energy balance. Recent evidence suggests that different nutrients can modulate AMPK activity in the hypothalamus, thereby controlling weight gain through a leptin-independent mechanism. Understanding the mechanisms by which nutrients control hypothalamic AMPK activity is crucial to the development of effective nutritional interventions for the treatment of food intake-related disorders, such as anorexia and obesity. This article highlights the current evidence for the intricate relationship between nutrients and hypothalamic AMPK activity.
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Affiliation(s)
- Gustavo D Pimentel
- Department of Internal Medicine, State University of Campinas, Campinas/São Paulo, Brazil
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Schneeberger M, Claret M. Recent Insights into the Role of Hypothalamic AMPK Signaling Cascade upon Metabolic Control. Front Neurosci 2012; 6:185. [PMID: 23267314 PMCID: PMC3526739 DOI: 10.3389/fnins.2012.00185] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 12/04/2012] [Indexed: 12/31/2022] Open
Abstract
In 2004, two seminal papers focused on the role of AMP-activated protein kinase (AMPK) in the hypothalamus opened new avenues of research in the field of the central regulation of energy homeostasis. Over the following 8 years, hundreds of studies have firmly established hypothalamic AMPK as a key sensor and integrator of hormonal and nutritional signals with neurochemical and neurophysiological responses to regulate whole-body energy balance. In this review article we aim to discuss the most recent findings in this particular area of research, highlighting the function of hypothalamic AMPK in appetite, thermogenesis, and peripheral glucose metabolism. The diversity of mechanisms by which hypothalamic AMPK regulates energy homeostasis illustrates the importance of this evolutionary-conserved energy signaling cascade in the control of this complex and fundamental biological process.
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Affiliation(s)
- Marc Schneeberger
- Diabetes and Obesity Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain ; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas Barcelona, Spain ; Department of Endocrinology and Nutrition, Hospital Clínic, School of Medicine, University of Barcelona Barcelona, Spain
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Schneeberger M, Altirriba J, García A, Esteban Y, Castaño C, García-Lavandeira M, Alvarez CV, Gomis R, Claret M. Deletion of miRNA processing enzyme Dicer in POMC-expressing cells leads to pituitary dysfunction, neurodegeneration and development of obesity. Mol Metab 2012; 2:74-85. [PMID: 24199146 DOI: 10.1016/j.molmet.2012.10.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/05/2012] [Accepted: 10/07/2012] [Indexed: 10/27/2022] Open
Abstract
MicroRNAs (miRNAs) have recently emerged as key regulators of metabolism. However, their potential role in the central regulation of whole-body energy homeostasis is still unknown. In this study we show that the expression of Dicer, an essential endoribonuclease for miRNA maturation, is modulated by nutrient availability and excess in the hypothalamus. Conditional deletion of Dicer in POMC-expressing cells resulted in obesity, characterized by hyperphagia, increased adiposity, hyperleptinemia, defective glucose metabolism and alterations in the pituitary-adrenal axis. The development of the obese phenotype was paralleled by a POMC neuron degenerative process that started around 3 weeks of age. Hypothalamic transcriptomic analysis in presymptomatic POMCDicerKO mice revealed the downregulation of genes implicated in biological pathways associated with classical neurodegenerative disorders, such as MAPK signaling, ubiquitin-proteosome system, autophagy and ribosome biosynthesis. Collectively, our results highlight a key role for miRNAs in POMC neuron survival and the consequent development of neurodegenerative obesity.
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Key Words
- 3V, third ventricle
- ACTH, adrenocorticotropic hormone
- AP, adenopituitary
- ARC, arcuate nucleus of the hypothalamus
- AUC, area under the curve
- Acp2, acid phosphatase 2, lysosomal
- AgRP, agouti-related protein
- Ago2, Argonaute 2
- CART, cocaine and amphetamine-related transcript
- CNS, central nervous system
- CRH, corticotropin releasing hormone
- Crhr1, corticotrophin releasing hormone receptor 1
- Cx, Cortex
- DIO, diet-induced obesity
- Dicer
- Fa, Fascicular zone
- GFP, green fluorescent protein
- Gapdh, Glyceraldehyde 3-phosphate dehydrogenase
- Gh, growth hormone
- Gl, Glomerular zone
- Hprt, Hypoxanthine guanine phosphoribosyl transferase
- Hypothalamus
- IL, intermediate lobe
- IP, intraperitoneal
- LH, lateral hypothalamus
- MC3R, melanocortin receptor 3
- MC4R, melanocortin receptor 4
- MZ, Marginal Zone
- Me, Medula
- Myc, myelocytomatosis oncogene
- NP, neurohypophysis
- NPY, neuropeptide Y
- NS, not significant
- Naglu, alpha-N-acetylglucosaminidase
- Neurodegeneration
- Nhlrc1, NHL repeat containing 1
- Ntrk2, Neurotrophic tyrosine kinase, receptor, type 2
- Obesity
- POMC
- POMC, pro-opiomelanocortin
- POMCDicerKO, mice lacking Dicer in POMC-expressing cells
- PVN, paraventricular nucleus
- Park2, Parkin
- Pit1, pituitary-specific transcription factor 1
- Re, Reticular zone
- Rps24, ribosomal protein S24
- Rps9, ribosomal protein S9
- Tpit, T box transcription factor
- Tshβ, thyroid-stimulating hormone β chain
- UD, undetectable
- UPS, ubiquitin proteosome system
- UTR, untranslated region
- VMH, ventromedial hypothalamus
- YFP, yellow fluorescent protein.
- miRISC, miRNA-induced silencing complexes
- miRNA, microRNA
- microRNA
- qPCR, quantitative real-time PCR
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Affiliation(s)
- Marc Schneeberger
- Diabetes and Obesity Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain ; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain ; Department of Endocrinology and Nutrition, Hospital Clínic, School of Medicine, University of Barcelona, Barcelona, Spain
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Yang SB, Tien AC, Boddupalli G, Xu AW, Jan YN, Jan LY. Rapamycin ameliorates age-dependent obesity associated with increased mTOR signaling in hypothalamic POMC neurons. Neuron 2012; 75:425-36. [PMID: 22884327 DOI: 10.1016/j.neuron.2012.03.043] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2012] [Indexed: 01/08/2023]
Abstract
VIDEO ABSTRACT The prevalence of obesity in older people is the leading cause of metabolic syndromes. Central neurons serving as homeostatic sensors for body-weight control include hypothalamic neurons that express pro-opiomelanocortin (POMC) or neuropeptide-Y (NPY) and agouti-related protein (AgRP). Here, we report an age-dependent increase of mammalian target of rapamycin (mTOR) signaling in POMC neurons that elevates the ATP-sensitive potassium (K(ATP)) channel activity cell-autonomously to silence POMC neurons. Systemic or intracerebral administration of the mTOR inhibitor rapamycin causes weight loss in old mice. Intracerebral rapamycin infusion into old mice enhances the excitability and neurite projection of POMC neurons, thereby causing a reduction of food intake and body weight. Conversely, young mice lacking the mTOR-negative regulator TSC1 in POMC neurons, but not those lacking TSC1 in NPY/AgRP neurons, were obese. Our study reveals that an increase in mTOR signaling in hypothalamic POMC neurons contributes to age-dependent obesity.
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Affiliation(s)
- Shi-Bing Yang
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
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Kawashima J, Alquier T, Tsuji Y, Peroni OD, Kahn BB. Ca2+/calmodulin-dependent protein kinase kinase is not involved in hypothalamic AMP-activated protein kinase activation by neuroglucopenia. PLoS One 2012; 7:e36335. [PMID: 22590531 PMCID: PMC3349669 DOI: 10.1371/journal.pone.0036335] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 04/03/2012] [Indexed: 11/18/2022] Open
Abstract
Hypoglycemia and neuroglucopenia stimulate AMP-activated protein kinase (AMPK) activity in the hypothalamus and this plays an important role in the counterregulatory responses, i.e. increased food intake and secretion of glucagon, corticosterone and catecholamines. Several upstream kinases that activate AMPK have been identified including Ca2+/Calmodulin-dependent protein kinase kinase (CaMKK), which is highly expressed in neurons. However, the involvement of CaMKK in neuroglucopenia-induced activation of AMPK in the hypothalamus has not been tested. To determine whether neuroglucopenia-induced AMPK activation is mediated by CaMKK, we tested whether STO-609 (STO), a CaMKK inhibitor, would block the effects of 2-deoxy-D-glucose (2DG)-induced neuroglucopenia both ex vivo on brain sections and in vivo. Preincubation of rat brain sections with STO blocked KCl-induced α1 and α2-AMPK activation but did not affect AMPK activation by 2DG in the medio-basal hypothalamus. To confirm these findings in vivo, STO was pre-administrated intracerebroventricularly (ICV) in rats 30 min before 2DG ICV injection (40 µmol) to induce neuroglucopenia. 2DG-induced neuroglucopenia lead to a significant increase in glycemia and food intake compared to saline-injected control rats. ICV pre-administration of STO (5, 20 or 50 nmol) did not affect 2DG-induced hyperglycemia and food intake. Importantly, activation of hypothalamic α1 and α2-AMPK by 2DG was not affected by ICV pre-administration of STO. In conclusion, activation of hypothalamic AMPK by 2DG-induced neuroglucopenia is not mediated by CaMKK.
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Affiliation(s)
- Junji Kawashima
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Thierry Alquier
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Youki Tsuji
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Odile D. Peroni
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Barbara B. Kahn
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Abstract
The hypothalamus is one of the master regulators of various physiological processes, including energy balance and nutrient metabolism. These regulatory functions are mediated by discrete hypothalamic regions that integrate metabolic sensing with neuroendocrine and neural controls of systemic physiology. Neurons and nonneuronal cells in these hypothalamic regions act supportively to execute metabolic regulations. Under conditions of brain and hypothalamic inflammation, which may result from overnutrition-induced intracellular stresses or disease-associated systemic inflammatory factors, extracellular and intracellular environments of hypothalamic cells are disrupted, leading to central metabolic dysregulations and various diseases. Recent research has begun to elucidate the effects of hypothalamic inflammation in causing diverse components of metabolic syndrome leading to diabetes and cardiovascular disease. These new understandings have provocatively expanded previous knowledge on the cachectic roles of brain inflammatory response in diseases, such as infections and cancers. This review describes the molecular and cellular characteristics of hypothalamic inflammation in metabolic syndrome and related diseases as opposed to cachectic diseases, and also discusses concepts and potential applications of inhibiting central/hypothalamic inflammation to treat nutritional diseases.
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Affiliation(s)
- Dongsheng Cai
- Department of Molecular Pharmacology, Diabetes Research Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Dailey MJ, Kim S. Inositol polyphosphate multikinase: an emerging player for the central action of AMP-activated protein kinase. Biochem Biophys Res Commun 2012; 421:1-3. [PMID: 22503973 DOI: 10.1016/j.bbrc.2012.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 04/01/2012] [Indexed: 01/10/2023]
Abstract
AMP-activated protein kinase (AMPK) is an essential enzyme indispensable for energy sensing and metabolic homeostasis at both the cellular and whole-body levels. Phosphorylation of AMPK, a key step for its activation, is known to be regulated by upstream kinases such as liver kinase B1 (LKB1) and calmodulin-dependent protein kinase kinase-beta (CaMKKβ). Recent evidence shows that inositol polyphosphate multikinase (IPMK), which possesses both inositol phosphate kinase and lipid inositol kinase activities, can physiologically regulate AMPK signaling in cultured cells and in the arcuate nucleus. IPMK-mediated regulation of AMPK occurs through the dynamic protein interactions of IPMK with AMPK in response to glucose availability. Here we review and discuss a novel role for the hypothalamic IPMK signaling in the control of AMPK and central energy homeostasis.
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Affiliation(s)
- Megan J Dailey
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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