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Sáenz de Miera C, Bellefontaine N, Allen SJ, Myers MG, Elias CF. Glutamate neurotransmission from leptin receptor cells is required for typical puberty and reproductive function in female mice. eLife 2024; 13:RP93204. [PMID: 39007235 PMCID: PMC11249761 DOI: 10.7554/elife.93204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/16/2024] Open
Abstract
The hypothalamic ventral premammillary nucleus (PMv) is a glutamatergic nucleus essential for the metabolic control of reproduction. However, conditional deletion of leptin receptor long form (LepRb) in vesicular glutamate transporter 2 (Vglut2) expressing neurons results in virtually no reproductive deficits. In this study, we determined the role of glutamatergic neurotransmission from leptin responsive PMv neurons on puberty and fertility. We first assessed if stimulation of PMv neurons induces luteinizing hormone (LH) release in fed adult females. We used the stimulatory form of designer receptor exclusively activated by designer drugs (DREADDs) in LeprCre (LepRb-Cre) mice. We collected blood sequentially before and for 1 hr after intravenous clozapine-N-oxide injection. LH level increased in animals correctly targeted to the PMv, and LH level was correlated to the number of Fos immunoreactive neurons in the PMv. Next, females with deletion of Slc17a6 (Vglut2) in LepRb neurons (LeprΔVGlut2) showed delayed age of puberty, disrupted estrous cycles, increased gonadotropin-releasing hormone (GnRH) concentration in the axon terminals, and disrupted LH secretion, suggesting impaired GnRH release. To assess if glutamate is required for PMv actions in pubertal development, we generated a Cre-induced reexpression of endogenous LepRb (LeprloxTB) with concomitant deletion of Slc17a6 (Vglut2flox) mice. Rescue of Lepr and deletion of Slc17a6 in the PMv was obtained by stereotaxic injection of an adeno-associated virus vector expressing Cre recombinase. Control LeprloxTB mice with PMv LepRb rescue showed vaginal opening, follicle maturation, and became pregnant, while LeprloxTB;Vglut2flox mice showed no pubertal development. Our results indicate that glutamatergic neurotransmission from leptin sensitive neurons regulates the reproductive axis, and that leptin action on pubertal development via PMv neurons requires Vglut2.
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Affiliation(s)
- Cristina Sáenz de Miera
- Department of Molecular and Integrative Physiology, University of Michigan–Ann ArborAnn ArborUnited States
| | - Nicole Bellefontaine
- Department of Molecular and Integrative Physiology, University of Michigan–Ann ArborAnn ArborUnited States
| | - Susan J Allen
- Department of Molecular and Integrative Physiology, University of Michigan–Ann ArborAnn ArborUnited States
| | - Martin G Myers
- Department of Molecular and Integrative Physiology, University of Michigan–Ann ArborAnn ArborUnited States
- Elizabeth W. Caswell Diabetes Institute, University of Michigan–Ann ArborAnn ArborUnited States
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan–Ann ArborAnn ArborUnited States
| | - Carol F Elias
- Department of Molecular and Integrative Physiology, University of Michigan–Ann ArborAnn ArborUnited States
- Elizabeth W. Caswell Diabetes Institute, University of Michigan–Ann ArborAnn ArborUnited States
- Department of Obstetrics and Gynecology, University of Michigan–Ann ArborAnn ArborUnited States
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2
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de Miera CS, Bellefontaine N, Allen SJ, Myers MG, Elias CF. Glutamate neurotransmission from leptin receptor cells is required for typical puberty and reproductive function in female mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.21.558865. [PMID: 37790549 PMCID: PMC10542178 DOI: 10.1101/2023.09.21.558865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The hypothalamic ventral premammillary nucleus (PMv) is a glutamatergic nucleus essential for the metabolic control of reproduction. However, conditional deletion of leptin receptor (LepRb) in vesicular glutamate transporter 2 (Vglut2) expressing neurons results in virtually no reproductive deficits. In this study, we determine the role of glutamatergic signaling from leptin responsive PMv neurons on puberty and fertility. We first assessed if stimulation of PMv neurons induces LH release in fed adult females. We used the stimulatory form of designer receptor exclusively activated by designer drugs (DREADDs) in LepRb-Cre mice. We collected blood sequentially before and for 1h after iv. clozapine-N-oxide injection. LH level increased in animals correctly targeted to the PMv, and LH level was correlated to the number of cFos immunoreactive neurons in the PMv. Next, females with deletion of Vglut2 in LepRb neurons (LepR∆VGlut2) showed delayed age of puberty, disrupted estrous cycles, increased GnRH concentration in the axon terminals and disrupted LH responses, suggesting impaired GnRH release. To assess if glutamate is required for PMv actions in pubertal development, we generated a Cre-induced reexpression of endogenous LepRb (LepRloxTB) with concomitant deletion of Vglut2 (Vglut2-floxed) mice. Rescue of Lepr and deletion of Vglut2 in the PMv was obtained by stereotaxic injection of an adeno-associated virus vector expressing Cre recombinase. Control LepRloxTB mice with PMv LepRb rescue showed vaginal opening, follicle maturation and became pregnant, while LepRloxTB;Vglut2flox mice showed no pubertal development. Our results indicate that glutamatergic signaling from leptin sensitive neurons regulates the reproductive axis, and that leptin action on pubertal development via PMv neurons requires Vglut2.
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Affiliation(s)
- Cristina Sáenz de Miera
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109-5622, USA
| | - Nicole Bellefontaine
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109-5622, USA
| | - Susan J. Allen
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109-5622, USA
| | - Martin G. Myers
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109-5622, USA
- Elizabeth W. Caswell Diabetes Institute, University of Michigan, Ann Arbor, MI, 48109-5622, USA
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, MI, 48109-5622, USA
| | - Carol F. Elias
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109-5622, USA
- Elizabeth W. Caswell Diabetes Institute, University of Michigan, Ann Arbor, MI, 48109-5622, USA
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, 48109-5622, USA
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3
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Liu Z, Xiao T, Liu H. Leptin signaling and its central role in energy homeostasis. Front Neurosci 2023; 17:1238528. [PMID: 38027481 PMCID: PMC10644276 DOI: 10.3389/fnins.2023.1238528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Leptin plays a critical role in regulating appetite, energy expenditure and body weight, making it a key factor in maintaining a healthy balance. Despite numerous efforts to develop therapeutic interventions targeting leptin signaling, their effectiveness has been limited, underscoring the importance of gaining a better understanding of the mechanisms through which leptin exerts its functions. While the hypothalamus is widely recognized as the primary site responsible for the appetite-suppressing and weight-reducing effects of leptin, other brain regions have also been increasingly investigated for their involvement in mediating leptin's action. In this review, we summarize leptin signaling pathways and the neural networks that mediate the effects of leptin, with a specific emphasis on energy homeostasis.
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Affiliation(s)
- Zhaoxun Liu
- Nursing Department, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Emergency, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Tao Xiao
- Nursing Department, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hailan Liu
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
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4
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Palus-Chramiec K, Sanetra AM, Lewandowski MH. Day/night Changes in the Dorsomedial Hypothalamus Firing Responses to Ghrelin are Modulated by High-fat Diet. Neuroscience 2022; 494:167-177. [PMID: 35569641 DOI: 10.1016/j.neuroscience.2022.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 02/06/2023]
Abstract
Dorsomedial hypothalamus (DMH) is a part of the feeding center involved in food intake and regulation of the metabolism. DMH neurons express many receptors for different metabolic cues which can modulate its network and influence animals' behaviour. One of the metabolic peptides deliveredto this structure is ghrelin, the only well-known hunger signal, produced mainly in the stomach. Diet-induced obesity is a physiological model of obesity widely used in research. Here we investigated how time-of-day and high-fat diet (HFD) affect neuronal networks and the sensitivity to the metabolic information received by the DMH. Our results indicate that even a short period of HFD (2-3 weeks) consumption can cause dysregulation of the DMH neuronal network, manifested as a disruption of the day/night pattern of basal activity and altered sensitivity to incoming information. We showed for the first time a day/night pattern of sensitivity to ghrelin in the DMH, with a higher level during the behaviorally active phase of animals. This day/night rhythm of sensitivity to ghrelin was reversed in HFD group, causing a stronger effect during the non-active phase. After prolongation of the HFD consumption to 7-8 weeks we observed an increase in the responsiveness to ghrelin, than during the short-term diet.
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Affiliation(s)
- K Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland.
| | - A M Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland.
| | - M H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland.
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5
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Quaresma PGF, Wasinski F, Mansano NS, Furigo IC, Teixeira PDS, Gusmao DO, Frazao R, Donato J. Leptin Receptor Expression in GABAergic Cells is Not Sufficient to Normalize Metabolism and Reproduction in Mice. Endocrinology 2021; 162:6353267. [PMID: 34402859 DOI: 10.1210/endocr/bqab168] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Indexed: 12/12/2022]
Abstract
Previous studies indicate that leptin receptor (LepR) expression in GABAergic neurons is necessary for the biological effects of leptin. However, it is not clear whether LepR expression only in GABAergic neurons is sufficient to prevent the metabolic and neuroendocrine imbalances caused by LepR deficiency. In the present study, we produced mice that express the LepR exclusively in GABAergic cells (LepRVGAT mice) and compared them with wild-type (LepR+/+) and LepR-deficient (LepRNull/Null) mice. Although LepRVGAT mice showed a pronounced reduction in body weight and fat mass, as compared with LepRNull/Null mice, male and female LepRVGAT mice exhibited an obese phenotype relative to LepR+/+ mice. Food intake was normalized in LepRVGAT mice; however, LepRVGAT mice still exhibited lower energy expenditure in both sexes and reduced ambulatory activity in the females, compared with LepR+/+ mice. The acute anorexigenic effect of leptin and hedonic feeding were normalized in LepRVGAT mice despite the hyperleptinemia they present. Although LepRVGAT mice showed improved glucose homeostasis compared with LepRNull/Null mice, both male and female LepRVGAT mice exhibited insulin resistance. In contrast, LepR expression only in GABAergic cells was sufficient to normalize the density of agouti-related peptide (AgRP) and α-MSH immunoreactive fibers in the paraventricular nucleus of the hypothalamus. However, LepRVGAT mice exhibited reproductive dysfunctions, including subfertility in males and alterations in the estrous cycle of females. Taken together, our findings indicate that LepR expression in GABAergic cells, although critical to the physiology of leptin, is insufficient to normalize several metabolic aspects and the reproductive function in mice.
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Affiliation(s)
- Paula G F Quaresma
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Frederick Wasinski
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Naira S Mansano
- Departamento de Anatomia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, SP, 05508-900, Brazil
| | - Isadora C Furigo
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Pryscila D S Teixeira
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Daniela O Gusmao
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
| | - Renata Frazao
- Departamento de Anatomia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, SP, 05508-900, Brazil
| | - Jose Donato
- Universidade de São Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, São Paulo, SP, 05508-000, Brazil
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6
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Navarro VM. Metabolic regulation of kisspeptin - the link between energy balance and reproduction. Nat Rev Endocrinol 2020; 16:407-420. [PMID: 32427949 PMCID: PMC8852368 DOI: 10.1038/s41574-020-0363-7] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/16/2020] [Indexed: 12/17/2022]
Abstract
Hypothalamic kisspeptin neurons serve as the nodal regulatory centre of reproductive function. These neurons are subjected to a plethora of regulatory factors that ultimately affect the release of kisspeptin, which modulates gonadotropin-releasing hormone (GnRH) release from GnRH neurons to control the reproductive axis. The presence of sufficient energy reserves is critical to achieve successful reproduction. Consequently, metabolic factors impose a very tight control over kisspeptin synthesis and release. This Review offers a synoptic overview of the different steps in which kisspeptin neurons are subjected to metabolic regulation, from early developmental stages to adulthood. We cover an ample array of known mechanisms that underlie the metabolic regulation of KISS1 expression and kisspeptin release. Furthermore, the novel role of kisspeptin neurons as active players within the neuronal circuits that govern energy balance is discussed, offering evidence of a bidirectional role of these neurons as a nexus between metabolism and reproduction.
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Affiliation(s)
- Víctor M Navarro
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
- Harvard Graduate Program in Neuroscience, Boston, MA, USA.
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7
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Giri AK, Prasad G, Bandesh K, Parekatt V, Mahajan A, Banerjee P, Kauser Y, Chakraborty S, Rajashekar D, Sharma A, Mathur SK, Basu A, McCarthy MI, Tandon N, Bharadwaj D. Multifaceted genome-wide study identifies novel regulatory loci in SLC22A11 and ZNF45 for body mass index in Indians. Mol Genet Genomics 2020; 295:1013-1026. [PMID: 32363570 DOI: 10.1007/s00438-020-01678-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 04/11/2020] [Indexed: 12/22/2022]
Abstract
Obesity, a risk factor for multiple diseases (e.g. diabetes, hypertension, cancers) originates through complex interactions between genes and prevailing environment (food habit and lifestyle) that varies across populations. Indians exhibit a unique obesity phenotype with high abdominal adiposity for a given body weight compared to matched white populations suggesting presence of population-specific genetic and environmental factors influencing obesity. However, Indian population-specific genetic contributors for obesity have not been explored yet. Therefore, to identify potential genetic contributors, we performed a two-staged genome-wide association study (GWAS) for body mass index (BMI), a common measure to evaluate obesity in 5973 Indian adults and the lead findings were further replicated in 1286 Indian adolescents. Our study revealed novel association of variants-rs6913677 in BAI3 gene (p = 1.08 × 10-8) and rs2078267 in SLC22A11 gene (p = 4.62 × 10-8) at GWAS significance, and of rs8100011 in ZNF45 gene (p = 1.04 × 10-7) with near GWAS significance. As genetic loci may dictate the phenotype through modulation of epigenetic processes, we overlapped genetic data of identified signals with their DNA methylation patterns in 236 Indian individuals and performed methylation quantitative trait loci (meth-QTL) analysis. Further, functional roles of discovered variants and underlying genes were speculated using publicly available gene regulatory databases (ENCODE, JASPAR, GeneHancer, GTEx). The identified variants in BAI3 and SLC22A11 genes were found to dictate methylation patterns at unique CpGs harboring critical cis-regulatory elements. Further, BAI3, SLC22A11 and ZNF45 variants were located in repressive chromatin, active enhancer, and active chromatin regions, respectively, in human subcutaneous adipose tissue in ENCODE database. Additionally, these genomic regions represented potential binding sites for key transcription factors implicated in obesity and/or metabolic disorders. Interestingly, GTEx portal identify rs8100011 as a robust cis-expression quantitative trait locus (cis-eQTL) in subcutaneous adipose tissue (p = 1.6 × 10-7), and ZNF45 gene expression in skeletal muscle of Indian subjects showed an inverse correlation with BMI indicating its possible role in obesity. In conclusion, our study discovered 3 novel population-specific functional genetic variants (rs6913677, rs2078267, rs8100011) in 2 novel (SLC22A11 and ZNF45) and 1 earlier reported gene (BAI3) for BMI in Indians. Our study decodes key genomic loci underlying obesity phenotype in Indians that may serve as prospective drug targets in future.
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Affiliation(s)
- Anil K Giri
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, CSIR-Institute of Genomics and Integrative Biology Campus, New Delhi, India
| | - Gauri Prasad
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, CSIR-Institute of Genomics and Integrative Biology Campus, New Delhi, India
| | - Khushdeep Bandesh
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, CSIR-Institute of Genomics and Integrative Biology Campus, New Delhi, India
| | - Vaisak Parekatt
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Anubha Mahajan
- Wellcome Trust Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Priyanka Banerjee
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Yasmeen Kauser
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, CSIR-Institute of Genomics and Integrative Biology Campus, New Delhi, India
| | - Shraddha Chakraborty
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, CSIR-Institute of Genomics and Integrative Biology Campus, New Delhi, India
| | - Donaka Rajashekar
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | | | - Abhay Sharma
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, CSIR-Institute of Genomics and Integrative Biology Campus, New Delhi, India
| | - Sandeep Kumar Mathur
- Department of Endocrinology, Sawai Man Singh Medical College, Jaipur, Rajasthan, India
| | - Analabha Basu
- National Institute of Biomedical Genomics, Kalyani, West Bengal, India
| | - Mark I McCarthy
- Wellcome Trust Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nikhil Tandon
- Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, India.
| | - Dwaipayan Bharadwaj
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics and Integrative Biology Campus, New Delhi, India. .,Systems Genomics Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.
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8
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Expression of lysine-mediated neuropeptide hormones controlling satiety and appetite in broiler chickens. Poult Sci 2019; 99:1409-1420. [PMID: 32115028 PMCID: PMC7587822 DOI: 10.1016/j.psj.2019.10.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/18/2019] [Accepted: 10/19/2019] [Indexed: 11/21/2022] Open
Abstract
Lysine is the second most limiting amino acid after methionine and is considered the most limiting amino acid for growth in poultry. Lysine requirement for broiler chickens has changed over the years. Leptin and adiponectin represent 2 adipokines that mediate metabolism by eliciting satiety effects whereas ghrelin peptide hormone influences appetite. We hypothesize that this affects growth performance of chicks. This study evaluates the effect of varying dietary lysine homeostasis on performance of broiler chickens through satiety- and appetite-mediating hormones. In 3 replications, 270 one-day-old chicks were reared for 8 wk feeding on diets comprising 0.85, 1.14, and 1.42% lysine during the starter period and 0.75, 1.00, and 1.25% lysine during the grower period. These concentrations of lysine represent 75% (low lysine), 100% (control), and 125% (high lysine) of National Research Council recommendation for broiler chickens. Feed and water were provided for ad libitum consumption. At 8 wk of age, liver, pancreas, brain, and hypothalamus tissues were collected from 18 birds randomly selected from each treatment, snap frozen in liquid nitrogen, and stored at -80°C until use. Total RNA was extracted, and cDNA was synthesized for quantitative real-time PCR assays. Low lysine concentration caused slow growth and high mortality. There was significant upregulation of ghrelin in the hypothalamus and pancreas, and leptin and adiponectin in the hypothalamus and liver, and downregulation of ghrelin in the intestines. At low lysine concentrations, adiponectin was not expressed in both pancreas and intestines. High lysine concentration exhibited increased growth, upregulation of ghrelin in the liver, and downregulation of ghrelin in the intestines, and both adiponectin and leptin in the liver. The expression of ghrelin was negatively correlated with the expression of adiponectin and leptin (P < 0.05) in the liver, hypothalamus, and pancreas. Expression of leptin was positively correlated with adiponectin in the hypothalamus and liver (P < 0.05), exhibiting satiety effects when the concentrations of lysine were low.
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9
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Fujita Y, Yamashita T. The Effects of Leptin on Glial Cells in Neurological Diseases. Front Neurosci 2019; 13:828. [PMID: 31447640 PMCID: PMC6692660 DOI: 10.3389/fnins.2019.00828] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 07/25/2019] [Indexed: 12/11/2022] Open
Abstract
It is known that various endocrine modulators, including leptin and ghrelin, have neuroprotective roles in neurological diseases. Leptin is a hormone produced by adipocytes and was originally identified as a gene related to obesity in mice. The leptin receptors in the hypothalamus are the main target for the homeostatic regulation of body weight. Recent studies have demonstrated that leptin receptors are also expressed in other regions of the central nervous system (CNS), such as the hippocampus, cerebral cortex, and spinal cord. Accordingly, these studies identified the involvement of leptin in the regulation of neuronal survival and neural development. Furthermore, leptin has been shown to have neuroprotective functions in animal models of neurological diseases and demyelination. These observations also suggest that dysregulation of leptin signaling may be involved in the association between neurodegeneration and obesity. In this review, we summarize novel functions of leptin in animal models of neurodegenerative diseases. Specifically, we focus on the emerging evidence for the role of leptin in non-neuronal cells in the CNS, including astrocytes, microglia, and oligodendrocytes. Understanding leptin-mediated neuroprotective signals and molecular mechanisms underlying remyelination will be helpful to establish therapeutic strategies against neurological diseases.
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Affiliation(s)
- Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.,Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.,Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Osaka, Japan
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10
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Abstract
Interactions between the brain and distinct adipose depots have a key role in maintaining energy balance, thereby promoting survival in response to metabolic challenges such as cold exposure and starvation. Recently, there has been renewed interest in the specific central neuronal circuits that regulate adipose depots. Here, we review anatomical, genetic and pharmacological studies on the neural regulation of adipose function, including lipolysis, non-shivering thermogenesis, browning and leptin secretion. In particular, we emphasize the role of leptin-sensitive neurons and the sympathetic nervous system in modulating the activity of brown, white and beige adipose tissues. We provide an overview of advances in the understanding of the heterogeneity of the brain regulation of adipose tissues and offer a perspective on the challenges and paradoxes that the community is facing regarding the actions of leptin on this system.
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Affiliation(s)
- Alexandre Caron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Syann Lee
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K. Elmquist
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Laurent Gautron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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11
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A neural basis for antagonistic control of feeding and compulsive behaviors. Nat Commun 2018; 9:52. [PMID: 29302029 PMCID: PMC5754347 DOI: 10.1038/s41467-017-02534-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 12/07/2017] [Indexed: 02/06/2023] Open
Abstract
Abnormal feeding often co-exists with compulsive behaviors, but the underlying neural basis remains unknown. Excessive self-grooming in rodents is associated with compulsivity. Here, we show that optogenetically manipulating the activity of lateral hypothalamus (LH) projections targeting the paraventricular hypothalamus (PVH) differentially promotes either feeding or repetitive self-grooming. Whereas selective activation of GABAergic LH→PVH inputs induces feeding, activation of glutamatergic inputs promotes self-grooming. Strikingly, targeted stimulation of GABAergic LH→PVH leads to rapid and reversible transitions to feeding from induced intense self-grooming, while activating glutamatergic LH→PVH or PVH neurons causes rapid and reversible transitions to self-grooming from voracious feeding induced by fasting. Further, specific inhibition of either LH→PVH GABAergic action or PVH neurons reduces self-grooming induced by stress. Thus, we have uncovered a parallel LH→PVH projection circuit for antagonistic control of feeding and self-grooming through dynamic modulation of PVH neuron activity, revealing a common neural pathway that underlies feeding and compulsive behaviors.
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12
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Xu J, Bartolome CL, Kong D. Synaptic Regulation of Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1090:49-77. [PMID: 30390285 DOI: 10.1007/978-981-13-1286-1_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Neurons in the brain, particularly those in the hypothalamus, are essential for the maintenance of whole-body metabolic homeostasis. Dysfunctions or dysregulations of them can result in various metabolic diseases, including eating disorders, obesity, and diabetes. In addition to hormonal and peptidergic regulation, accumulating evidence has shown that these neurons are subject to synaptic regulation, which has been largely overlooked. In this chapter, we focus on synaptic neurotransmission of hypothalamic neurons and summarize current knowledge of synaptic plasticity in the maintenance of energy balance. Synaptic modulation engaged by circulating hormones is also discussed.
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Affiliation(s)
- Jie Xu
- Department of Neuroscience, Tufts University School of Medicine, Tufts University, Boston, MA, USA.,Program of Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, USA
| | - Christopher L Bartolome
- Department of Neuroscience, Tufts University School of Medicine, Tufts University, Boston, MA, USA.,Program of Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, USA
| | - Dong Kong
- Department of Neuroscience, Tufts University School of Medicine, Tufts University, Boston, MA, USA. .,Program of Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, USA.
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Wahab F, Atika B, Ullah F, Shahab M, Behr R. Metabolic Impact on the Hypothalamic Kisspeptin-Kiss1r Signaling Pathway. Front Endocrinol (Lausanne) 2018; 9:123. [PMID: 29643834 PMCID: PMC5882778 DOI: 10.3389/fendo.2018.00123] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/12/2018] [Indexed: 12/12/2022] Open
Abstract
A large body of data has established the hypothalamic kisspeptin (KP) and its receptor, KISS1R, as major players in the activation of the neuroendocrine reproductive axis at the time of puberty and maintenance of reproductive capacity in the adult. Due to its strategic location, this ligand-receptor pair acts as an integrator of cues from gonadal steroids as well as of circadian and seasonal variation-related information on the reproductive axis. Besides these cues, the activity of the hypothalamic KP signaling is very sensitive to the current metabolic status of the body. In conditions of energy imbalance, either positive or negative, a number of alterations in the hypothalamic KP signaling pathway have been documented in different mammalian models including nonhuman primates and human. Deficiency of metabolic fuels during fasting causes a marked reduction of Kiss1 gene transcript levels in the hypothalamus and, hence, decreases the output of KP-containing neurons. Food intake or exogenous supply of metabolic cues, such as leptin, reverses metabolic insufficiency-related changes in the hypothalamic KP signaling. Likewise, alterations in Kiss1 expression have also been reported in other situations of energy imbalance like diabetes and obesity. Information related to the body's current metabolic status reaches to KP neurons both directly as well as indirectly via a complex network of other neurons. In this review article, we have provided an updated summary of the available literature on the regulation of the hypothalamic KP-Kiss1r signaling by metabolic cues. In particular, the potential mechanisms of metabolic impact on the hypothalamic KP-Kiss1r signaling, in light of available evidence, are discussed.
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Affiliation(s)
- Fazal Wahab
- Platform Degenerative Diseases, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
- *Correspondence: Fazal Wahab,
| | - Bibi Atika
- Department of Developmental Biology, Faculty of Biology, University of Göttingen, Göttingen, Germany
| | - Farhad Ullah
- Department of Zoology, Islamia College University, Peshawar, Pakistan
| | - Muhammad Shahab
- Laboratory of Reproductive Neuroendocrinology, Department of Animal Sciences, Faculty of Biological Sciences, Quiad-i-Azam University, Islamabad, Pakistan
| | - Rüdiger Behr
- Platform Degenerative Diseases, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
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Presynaptic Regulation of Leptin in a Defined Lateral Hypothalamus-Ventral Tegmental Area Neurocircuitry Depends on Energy State. J Neurosci 2017; 37:11854-11866. [PMID: 29089444 DOI: 10.1523/jneurosci.1942-17.2017] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/30/2017] [Accepted: 10/16/2017] [Indexed: 12/16/2022] Open
Abstract
Synaptic transmission controls brain activity and behaviors, including food intake. Leptin, an adipocyte-derived hormone, acts on neurons located in the lateral hypothalamic area (LHA) to maintain energy homeostasis and regulate food intake behavior. The specific synaptic mechanisms, cell types, and neural projections mediating this effect remain unclear. In male mice, using pathway-specific retrograde tracing, whole-cell patch-clamp recordings and post hoc cell type identification, we found that leptin reduces excitatory synaptic strength onto both melanin-concentrating hormone- and orexin-expressing neurons projecting from the LHA to the ventral tegmental area (VTA), which may affect dopamine signaling and motivation for feeding. A presynaptic mechanism mediated by distinct intracellular signaling mechanisms may account for this regulation by leptin. The regulatory effects of leptin depend on intact leptin receptor signaling. Interestingly, the synaptic regulatory function of leptin in the LHA-to-VTA neuronal pathway is highly sensitive to energy states: both energy deficiency (acute fasting) and excessive energy storage (high-fat diet-induced obesity) blunt the effect of leptin. These data revealed that leptin may regulate synaptic transmission in the LHA-to-VTA neurocircuitry in an inverted "U-shape" fashion dependent on plasma glucose levels and related to metabolic states.SIGNIFICANCE STATEMENT The lateral hypothalamic area (LHA) to ventral tegmental area (VTA) projection is an important neural pathway involved in balancing whole-body energy states and reward. We found that the excitatory synaptic inputs to both orexin- and melanin-concentrating hormone expressing LHA neurons projecting to the VTA were suppressed by leptin, a peptide hormone derived from adipocytes that signals peripheral energy status to the brain. Interestingly, energy states seem to affect how leptin regulates synaptic transmission since both the depletion of energy induced by acute food deprivation and excessive storage of energy by high-fat diet feeding dampen the suppressive effect of leptin on synaptic transmission. Together, these data show that leptin regulates synaptic transmission and might be important for maintaining energy homeostasis.
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Glutamatergic Preoptic Area Neurons That Express Leptin Receptors Drive Temperature-Dependent Body Weight Homeostasis. J Neurosci 2017; 36:5034-46. [PMID: 27147656 DOI: 10.1523/jneurosci.0213-16.2016] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/21/2016] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED The preoptic area (POA) regulates body temperature, but is not considered a site for body weight control. A subpopulation of POA neurons express leptin receptors (LepRb(POA) neurons) and modulate reproductive function. However, LepRb(POA) neurons project to sympathetic premotor neurons that control brown adipose tissue (BAT) thermogenesis, suggesting an additional role in energy homeostasis and body weight regulation. We determined the role of LepRb(POA) neurons in energy homeostasis using cre-dependent viral vectors to selectively activate these neurons and analyzed functional outcomes in mice. We show that LepRb(POA) neurons mediate homeostatic adaptations to ambient temperature changes, and their pharmacogenetic activation drives robust suppression of energy expenditure and food intake, which lowers body temperature and body weight. Surprisingly, our data show that hypothermia-inducing LepRb(POA) neurons are glutamatergic, while GABAergic POA neurons, originally thought to mediate warm-induced inhibition of sympathetic premotor neurons, have no effect on energy expenditure. Our data suggest a new view into the neurochemical and functional properties of BAT-related POA circuits and highlight their additional role in modulating food intake and body weight. SIGNIFICANCE STATEMENT Brown adipose tissue (BAT)-induced thermogenesis is a promising therapeutic target to treat obesity and metabolic diseases. The preoptic area (POA) controls body temperature by modulating BAT activity, but its role in body weight homeostasis has not been addressed. LepRb(POA) neurons are BAT-related neurons and we show that they are sufficient to inhibit energy expenditure. We further show that LepRb(POA) neurons modulate food intake and body weight, which is mediated by temperature-dependent homeostatic responses. We further found that LepRb(POA) neurons are stimulatory glutamatergic neurons, contrary to prevalent models, providing a new view on thermoregulatory neural circuits. In summary, our study significantly expands our current understanding of central circuits and mechanisms that modulate energy homeostasis.
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VMAT2-Mediated Neurotransmission from Midbrain Leptin Receptor Neurons in Feeding Regulation. eNeuro 2017; 4:eN-NWR-0083-17. [PMID: 28560316 PMCID: PMC5446488 DOI: 10.1523/eneuro.0083-17.2017] [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: 03/10/2017] [Revised: 04/22/2017] [Accepted: 05/10/2017] [Indexed: 02/08/2023] Open
Abstract
Leptin receptors (LepRs) expressed in the midbrain contribute to the action of leptin on feeding regulation. The midbrain neurons release a variety of neurotransmitters including dopamine (DA), glutamate and GABA. However, which neurotransmitter mediates midbrain leptin action on feeding remains unclear. Here, we showed that midbrain LepR neurons overlap with a subset of dopaminergic, GABAergic and glutamatergic neurons. Specific removal of vesicular monoamine transporter 2 (VMAT2) in midbrain LepR neurons (KO mice) disrupted DA accumulation in vesicles, but failed to cause a significant change in the evoked release of either glutamate or GABA to downstream neurons. While KO mice showed no differences on chow, they presented a reduced high-fat diet (HFD) intake and resisted to HFD-induced obesity. Specific activation of midbrain LepR neurons promoted VMAT2-dependent feeding on chow and HFD. When tested with an intermittent access to HFD where first 2.5-h HFD eating (binge-like) and 24-h HFD feeding were measured, KO mice exhibited more binge-like, but less 24-h HFD feeding. Interestingly, leptin inhibited 24-h HFD feeding in controls but not in KO mice. Thus, VMAT2-mediated neurotransmission from midbrain LepR neurons contributes to both binge-like eating and HFD feeding regulation.
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Melanocortin neurons: Multiple routes to regulation of metabolism. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2477-2485. [PMID: 28499988 DOI: 10.1016/j.bbadis.2017.05.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/31/2017] [Accepted: 05/05/2017] [Indexed: 01/07/2023]
Abstract
The burden of disability, premature death, escalating health care costs and lost economic productivity due to obesity and its associated complications including hypertension, stroke, cardiovascular disease and type 2 diabetes is staggering [1,2]. A better understanding of metabolic homeostatic pathways will provide us with insights into the biological mechanisms of obesity and how to fundamentally address this epidemic [3-6]. In mammals, energy balance is maintained via a homeostatic system involving both peripheral and central melanocortin systems; changes in body weight reflect an unbalance of the energetic state [7-9]. Although the primary cause of obesity is unknown, there is significant effort to understand the role of the central melanocortin pathway in the brain as it has been shown that deficiency of proopiomelanocortin (POMC) [10,11] and melanocortin 4 receptors (MC4R) [12-15] in both rodents and humans results in severe hyperphagia and obesity [16-23]. In this review, we will summarize how the central melanocortin pathway helps regulate body mass and adiposity within a 'healthy' range through the 'nutrient sensing' network [24-28]. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.
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Mela V, Vargas A, Meza C, Kachani M, Wagner EJ. Modulatory influences of estradiol and other anorexigenic hormones on metabotropic, Gi/o-coupled receptor function in the hypothalamic control of energy homeostasis. J Steroid Biochem Mol Biol 2016; 160:15-26. [PMID: 26232394 PMCID: PMC4732935 DOI: 10.1016/j.jsbmb.2015.07.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 07/22/2015] [Accepted: 07/26/2015] [Indexed: 11/22/2022]
Abstract
The appetite suppressant actions of estradiol are due to its ability to attenuate orexigenic signals and potentiate anorexigenic signals. The work from my laboratory has shown that male guinea pigs are more sensitive to the hyperphagic and hypothermic effects of cannabinoids than their female counterparts. Cannabinoid sensitivity is further dampened by the activational effects of estradiol. This occurs via the hypothalamic feeding circuitry, where estradiol rapidly attenuates the cannabinoid CB1 receptor-mediated presynaptic inhibition of glutamatergic input onto anorexigenic proopiomelanocortin (POMC) neurons in the arcuate nucleus. This disruption is blocked by the estrogen receptor antagonist ICI 182,780, and associated with increased expression of phosphatidylinositol-3-kinase (PI3K). Moreover, the ability of estradiol to reduce both the cannabinoid-induced hyperphagia and glutamate release onto POMC neurons is abrogated by the PI3K inhibitor PI 828. The peptide orphanin FQ/nociceptin (OFQ/N) activates opioid receptor-like (ORL)1 receptors to hyperpolarize and inhibit POMC neurons via the activation of postsynaptic G protein-gated, inwardly-rectifying (GIRK) channels. We have demonstrated that the fasting-induced hyperphagia observed in ORL1-null mice is blunted compared to wild type controls. In addition, the ORL1 receptor-mediated activation of GIRK channels in POMC neurons from ovariectomized female rats is markedly impaired by estradiol. The estrogenic attenuation of presynaptic CB1 and postsynaptic ORL1 receptor function may be part of a more generalized mechanism through which anorexigenic hormones suppress orexigenic signaling. Indeed, we have found that leptin robustly suppresses the OFQ/N-induced activation of GIRK channels in POMC neurons. Furthermore, its ability to augment excitatory input onto POMC neurons is blocked by PI 828. Thus, estradiol and other hormones like leptin reduce energy intake at least partly by activating PI3K to disrupt the pleiotropic functions of Gi/o-coupled receptors that inhibit anorexigenic POMC neurons.
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Affiliation(s)
- Virginia Mela
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Amanda Vargas
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Cecilia Meza
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Malika Kachani
- College of Veterinary Medicine, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Edward J Wagner
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States.
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Xu Y, Chang JT, Myers MG, Xu Y, Tong Q. Euglycemia Restoration by Central Leptin in Type 1 Diabetes Requires STAT3 Signaling but Not Fast-Acting Neurotransmitter Release. Diabetes 2016; 65:1040-9. [PMID: 26822087 PMCID: PMC4806656 DOI: 10.2337/db15-1160] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 01/13/2016] [Indexed: 12/21/2022]
Abstract
Central leptin action is sufficient to restore euglycemia in insulinopenic type 1 diabetes (T1D); however, the underlying mechanism remains poorly understood. To examine the role of intracellular signal transducer and activator of transcription 3 (STAT3) pathways, we used LepRs/s mice with disrupted leptin-phosphorylated STAT3 signaling to test the effect of central leptin on euglycemia restoration. These mice developed streptozocin-induced T1D, which was surprisingly not associated with hyperglucagonemia, a typical manifestation in T1D. Further, leptin action on euglycemia restoration was abrogated in these mice, which was associated with refractory hypercorticosteronemia. To examine the role of fast-acting neurotransmitters glutamate and γ-aminobutyric acid (GABA), two major neurotransmitters in the brain, from leptin receptor (LepR) neurons, we used mice with disrupted release of glutamate, GABA, or both from LepR neurons. Surprisingly, all mice responded normally to leptin-mediated euglycemia restoration, which was associated with expected correction from hyperglucagonemia and hyperphagia. In contrast, mice with loss of glutamate and GABA appeared to develop an additive obesity effect over those with loss of single neurotransmitter release. Thus, our study reveals that STAT3 signaling, but not fast-acting neurotransmitter release, is required for leptin action on euglycemia restoration and that hyperglucagonemia is not required for T1D.
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Affiliation(s)
- Yuanzhong Xu
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX
| | - Jeffrey T Chang
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX Department of Integrative Biology and Pharmacology of McGovern Medical School and School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX
| | - Martin G Myers
- Departments of Internal Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX
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Parimisetty A, Dorsemans AC, Awada R, Ravanan P, Diotel N, Lefebvre d’Hellencourt C. Secret talk between adipose tissue and central nervous system via secreted factors-an emerging frontier in the neurodegenerative research. J Neuroinflammation 2016; 13:67. [PMID: 27012931 PMCID: PMC4806498 DOI: 10.1186/s12974-016-0530-x] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 03/15/2016] [Indexed: 02/06/2023] Open
Abstract
First seen as a storage organ, the white adipose tissue (WAT) is now considered as an endocrine organ. WAT can produce an array of bioactive factors known as adipokines acting at physiological level and playing a vital role in energy metabolism as well as in immune response. The global effect of adipokines in metabolic activities is well established, but their impact on the physiology and the pathophysiology of the central nervous system (CNS) remains poorly defined. Adipokines are not only produced by the WAT but can also be expressed in the CNS where receptors for these factors are present. When produced in periphery and to affect the CNS, these factors may either cross the blood brain barrier (BBB) or modify the BBB physiology by acting on cells forming the BBB. Adipokines could regulate neuroinflammation and oxidative stress which are two major physiological processes involved in neurodegeneration and are associated with many chronic neurodegenerative diseases. In this review, we focus on four important adipokines (leptin, resistin, adiponectin, and TNFα) and one lipokine (lysophosphatidic acid-LPA) associated with autotaxin, its producing enzyme. Their potential effects on neurodegeneration and brain repair (neurogenesis) will be discussed. Understanding and regulating these adipokines could be an interesting lead to novel therapeutic strategy in order to counteract neurodegenerative disorders and/or promote brain repair.
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Affiliation(s)
- Avinash Parimisetty
- />Université de La Réunion, UMR 1188, Sainte-Clotilde, F-97490 France
- />Inserm, UMR 1188 Diabète athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, Sainte-Clotilde, F-97490 France
| | - Anne-Claire Dorsemans
- />Université de La Réunion, UMR 1188, Sainte-Clotilde, F-97490 France
- />Inserm, UMR 1188 Diabète athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, Sainte-Clotilde, F-97490 France
| | - Rana Awada
- />Lebanese University, Faculty of Sciences, Beirut, Lebanon
| | - Palaniyandi Ravanan
- />Apoptosis and Cell Death Research Lab, School of Biosciences and Technology, Vellore Institute of Technology University, Vellore, India
| | - Nicolas Diotel
- />Université de La Réunion, UMR 1188, Sainte-Clotilde, F-97490 France
- />Inserm, UMR 1188 Diabète athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, Sainte-Clotilde, F-97490 France
| | - Christian Lefebvre d’Hellencourt
- />Université de La Réunion, UMR 1188, Sainte-Clotilde, F-97490 France
- />Inserm, UMR 1188 Diabète athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, Sainte-Clotilde, F-97490 France
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Payne A, Wang X, Ivy M, Stewart A, Nelson K, Darris C, Nahashon S. Lysine mediation of neuroendocrine food regulation in guinea fowl. Poult Sci 2016; 95:276-86. [DOI: 10.3382/ps/pev326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/15/2015] [Indexed: 01/12/2023] Open
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An Indirect Action Contributes to C-Fos Induction in Paraventricular Hypothalamic Nucleus by Neuropeptide Y. Sci Rep 2016; 6:19980. [PMID: 26813148 PMCID: PMC4728490 DOI: 10.1038/srep19980] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 12/17/2015] [Indexed: 12/03/2022] Open
Abstract
Neuropeptide Y (NPY) is a well-established orexigenic peptide and hypothalamic paraventricular nucleus (PVH) is one major brain site that mediates the orexigenic action of NPY. NPY induces abundant expression of C-Fos, an indicator for neuronal activation, in the PVH, which has been used extensively to examine the underlying NPY orexigenic neural pathways. However, PVH C-Fos induction is in discordance with the abundant expression of NPY receptors, a group of inhibitory Gi protein coupled receptors in the PVH, and with the overall role of PVH neurons in feeding inhibition, suggesting a mechanism of indirect action. Here we showed that the ability of NPY on C-Fos induction in the PVH was blunted in conditions of insulin deficiency and fasting, a condition associated with a high level of NPY and a low level of insulin. Moreover, insulin insufficiency blunted C-Fos induction in the PVH by fasting-induced re-feeding, and insulin and NPY induced c-Fos induction in the same group of PVH neurons. Finally, NPY produced normal C-Fos induction in the PVH with disruption of GABA-A receptors. Thus, our results revealed that PVH C-Fos induction by NPY is mediated by an indirect action, which is at least partially mediated by insulin action, but not GABA-A receptors.
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Abstract
The continuous rise in obesity is a major concern for future healthcare management. Many strategies to control body weight focus on a permanent modification of food intake with limited success in the long term. Metabolism or energy expenditure is the other side of the coin for the regulation of body weight, and strategies to enhance energy expenditure are a current focus for obesity treatment, especially since the (re)-discovery of the energy depleting brown adipose tissue in adult humans. Conversely, several human illnesses like neurodegenerative diseases, cancer, or autoimmune deficiency syndrome suffer from increased energy expenditure and severe weight loss. Thus, strategies to modulate energy expenditure to target weight gain or loss would improve life expectancies and quality of life in many human patients. The aim of this book chapter is to give an overview of our current understanding and recent progress in energy expenditure control with specific emphasis on central control mechanisms.
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Xu Y, Kim ER, Fan S, Xia Y, Xu Y, Huang C, Tong Q. Profound and rapid reduction in body temperature induced by the melanocortin receptor agonists. Biochem Biophys Res Commun 2014; 451:184-9. [PMID: 25065745 DOI: 10.1016/j.bbrc.2014.07.079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 07/17/2014] [Indexed: 01/05/2023]
Abstract
The melanocortin receptor 4 (MC4R) plays a major role in body weight regulation and its agonist MTII has been widely used to study the role of MC4Rs in energy expenditure promotion and feeding reduction. Unexpectedly, we observed that intraperitoneal (i.p.) administration of MTII induced a rapid reduction in both body temperature and energy expenditure, which was independent of its effect on feeding and followed by a prolonged increase in energy expenditure. The rapid reduction was at least partly mediated by brain neurons since intracerebroventricular (icv) administration of alpha melanocyte-stimulating hormone, an endogenous melanocortin receptor agonist, produced a similar response. In addition, the body temperature-lowering effect of MTII was independent of the presence of MC4Rs, but in a similar fashion to the previously shown effect on body temperature by 5'AMP. Moreover, β-adrenergic receptors (β-ARs) were required for the recovery from low body temperature induced by MTII and further pharmacological studies showed that the MTII's effect on body temperature may be partially mediated by the vasopressin V1a receptors. Collectively, our results reveal a previously unappreciated role for the melanocortin pathway in rapidly lowering body temperature.
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Affiliation(s)
- Yuanzhong Xu
- Brown Foundation Institute of Molecular Medicine, University of Texas Medical School at Houston, TX 77030, USA
| | - Eun Ran Kim
- Brown Foundation Institute of Molecular Medicine, University of Texas Medical School at Houston, TX 77030, USA
| | - Shengjie Fan
- Brown Foundation Institute of Molecular Medicine, University of Texas Medical School at Houston, TX 77030, USA; School of Pharmacy, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China
| | - Yan Xia
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Cheng Huang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine, University of Texas Medical School at Houston, TX 77030, USA; Programs in Neuroscience and Biochemistry, Graduate School of Biological Sciences, University of Texas Medical School at Houston, TX 77030, USA.
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Resch JM, Maunze B, Phillips KA, Choi S. Inhibition of food intake by PACAP in the hypothalamic ventromedial nuclei is mediated by NMDA receptors. Physiol Behav 2014; 133:230-5. [PMID: 24878316 DOI: 10.1016/j.physbeh.2014.05.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 11/17/2022]
Abstract
Central injections of pituitary adenylate cyclase-activating polypeptide (PACAP) into the ventromedial nuclei (VMN) of the hypothalamus produce hypophagia that is dependent upon the PAC1 receptor; however, the signaling downstream of this receptor in the VMN is unknown. Though PACAP signaling has many targets, this neuropeptide has been shown to influence glutamate signaling in several brain regions through mechanisms involving NMDA receptor potentiation via activation of the Src family of protein tyrosine kinases. With this in mind, we examined the Src-NMDA receptor signaling pathway as a target for PACAP signaling in the VMN that may mediate its effects on feeding behavior. Under nocturnal feeding conditions, NMDA receptor antagonism prior to PACAP administration into the VMN attenuated PACAP-mediated decreases in feeding suggesting that glutamatergic signaling via NMDA receptors is necessary for PACAP-induced hypophagia. Furthermore, PACAP administration into the VMN resulted in increased tyrosine phosphorylation of the GluN2B subunit of the NMDA receptor, and inhibition of Src kinase activity also blocked the effects of PACAP administration into the VMN on feeding behavior. These results indicate that PACAP neurotransmission in the VMN likely augments glutamate signaling by potentiating NMDA receptors activity through the tyrosine phosphorylation events mediated by the Src kinase family, and modulation of NMDA receptor activity by PACAP in the hypothalamus may be a primary mechanism for its regulation of food intake.
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Affiliation(s)
- Jon M Resch
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201, USA
| | - Brian Maunze
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201, USA
| | - Kailynn A Phillips
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201, USA
| | - SuJean Choi
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53201, USA.
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Yu F, Hao S, Zhao Y, Ren Y, Yang J, Sun X, Chen J. Mild maternal iron deficiency anemia induces DPOAE suppression and cochlear hair cell apoptosis by caspase activation in young guinea pigs. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:291-299. [PMID: 24378594 DOI: 10.1016/j.etap.2013.11.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Revised: 11/22/2013] [Accepted: 11/28/2013] [Indexed: 06/03/2023]
Abstract
Iron deficiency (ID) anemia (IDA) alters auditory neural normal development in the mammalian cochlea. Previous results suggest that mild maternal IDA during pregnancy and lactation altered the hearing and nervous system development of the young offspring, but the mechanisms underlying the association are incompletely understood. The objective of this study was to evaluate the role of apoptosis in the development of sensory hair cells following mild maternal IDA during pregnancy and lactation. We established a maternal anemia model in female guinea pigs by using a mild iron deficient diet. The offspring were weaned on postnatal day (PND) 9 and then was given the iron sufficient diet. Maternal blood samples were collected on gestational day (GD) 21, GD 42, GD 63 and PND 9, serum level of iron (SI) or hemoglobin (Hb) was measured. Blood samples of pups were collected on PND 9 for SI measurement. On PND 24, pups were examined the distortion product otoacoustic emission (DPOAE) task, and then the cochleae were harvested for assessment of apoptosis by immunohistochemistry of cysteine-aspartic acid proteases 3/9 (caspase-3/9) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, and by double immunofluorescence for the colocalization of TUNEL and caspase-3. Blood samples of pups were collected on PND 24 for SI and Hb measurements. Here we show that mild maternal IDA during pregnancy and lactation resulted in hearing impairment, decreased hair cell number, caspase-3/9 activation and increased apoptotic cell number of young guinea pigs. These results indicate a key role for apoptosis in inhibition of hair cell development, caused by mild maternal IDA during pregnancy and lactation.
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Affiliation(s)
- Fei Yu
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, 92 North 2nd Road, Heping District, Shenyang, China.
| | - Shuai Hao
- Department of Otolaryngology, First Affiliated Hospital of China Medical University, Shenyang, China
| | - Yue Zhao
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, 92 North 2nd Road, Heping District, Shenyang, China
| | - Yahao Ren
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, 92 North 2nd Road, Heping District, Shenyang, China
| | - Jun Yang
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, 92 North 2nd Road, Heping District, Shenyang, China
| | - Xiance Sun
- Department of Occupational and Environmental of Health, Dalian Medical University, No. 9 Western Section of Lushun South Road, Dalian, Liaoning, China.
| | - Jie Chen
- Department of Occupational and Environmental of Health, School of Public Health, China Medical University, Shenyang, China.
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Xu Y, Wu Z, Sun H, Zhu Y, Kim ER, Lowell BB, Arenkiel BR, Xu Y, Tong Q. Glutamate mediates the function of melanocortin receptor 4 on Sim1 neurons in body weight regulation. Cell Metab 2013; 18:860-70. [PMID: 24315371 PMCID: PMC3880549 DOI: 10.1016/j.cmet.2013.11.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 08/26/2013] [Accepted: 10/25/2013] [Indexed: 11/16/2022]
Abstract
The melanocortin receptor 4 (MC4R) is a well-established mediator of body weight homeostasis. However, the neurotransmitter(s) that mediate MC4R function remain largely unknown; as a result, little is known about the second-order neurons of the MC4R neural pathway. Single-minded 1 (Sim1)-expressing brain regions, which include the paraventricular nucleus of hypothalamus (PVH), represent key brain sites that mediate melanocortin action. We conditionally restored MC4R expression in Sim1 neurons in the background of Mc4r-null mice. The restoration dramatically reduced obesity in Mc4r-null mice. The anti-obesity effect was completely reversed by selective disruption of glutamate release from those same Sim1 neurons. The reversal was caused by lower energy expenditure and hyperphagia. Corroboratively, selective disruption of glutamate release from adult PVH neurons led to rapid obesity development via reduced energy expenditure and hyperphagia. Thus, this study establishes glutamate as the primary neurotransmitter that mediates MC4Rs on Sim1 neurons in body weight regulation.
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Affiliation(s)
- Yuanzhong Xu
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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28
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Yi CX, Meyer CW, Jastroch M. Leptin action in the brain: How (and when) it makes fat burn. Mol Metab 2013; 2:63-4. [PMID: 24199151 DOI: 10.1016/j.molmet.2013.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Accepted: 03/05/2013] [Indexed: 11/25/2022] Open
Affiliation(s)
- Chun-Xia Yi
- Institute for Diabetes and Obesity, Helmholtz Zentrum Munich, Munich, Germany
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