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Chien HY, Chen SM, Li WC. Dopamine receptor agonists mechanism of actions on glucose lowering and their connections with prolactin actions. FRONTIERS IN CLINICAL DIABETES AND HEALTHCARE 2023; 4:935872. [PMID: 36993818 PMCID: PMC10012161 DOI: 10.3389/fcdhc.2023.935872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 01/20/2023] [Indexed: 03/12/2023]
Abstract
Robust experiment evidence suggests that prolactin can enhance beta-cell proliferation and increase insulin secretion and sensitivity. Apart from acting as an endocrine hormone, it also function as an adipokine and act on adipocytes to modulate adipogenesis, lipid metabolism and inflammation. Several cross-sectional epidemiologic studies consistently showed that circulating prolactin levels positive correlated with increased insulin sensitivity, lower glucose and lipid levels, and lower prevalence of T2D and metabolic syndrome. Bromocriptine, a dopamine receptor agonist used to treat prolactinoma, is approved by Food and Drug Administration for treatment in type 2 diabetes mellitus since 2009. Prolactin lowering suppress insulin secretion and decrease insulin sensitivity, therefore dopamine receptor agonists which act at the pituitary to lower serum prolactin levels are expected to impair glucose tolerance. Making it more complicating, studies exploring the glucose-lowering mechanism of bromocriptine and cabergoline have resulted in contradictory results; while some demonstrated actions independently on prolactin status, others showed glucose lowering partly explained by prolactin level. Previous studies showed that a moderate increase in central intraventricular prolactin levels stimulates hypothalamic dopamine with a decreased serum prolactin level and improved glucose metabolism. Additionally, sharp wave-ripples from the hippocampus modulates peripheral glucose level within 10 minutes, providing evidence for a mechanistic link between hypothalamus and blood glucose control. Central insulin in the mesolimbic system have been shown to suppress dopamine levels thus comprising a feedback control loop. Central dopamine and prolactin levels plays a key role in the glucose homeostasis control, and their dysregulation could lead to the pathognomonic central insulin resistance depicted in the “ominous octet”. This review aims to provide an in-depth discussion on the glucose-lowering mechanism of dopamine receptor agonists and on the diverse prolactin and dopamine actions on metabolism targets.
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Affiliation(s)
- Hung-Yu Chien
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taipei City Hospital, Taipei, Taiwan
| | - Su-Mei Chen
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taipei City Hospital, Taipei, Taiwan
- Division of Nuclear Medicine, Department of Internal Medicine, Taipei City Hospital, Taipei, Taiwan
| | - Wan-Chun Li
- Institute of Oral Biology, School of Dentistry, National Yang Ming Chiao Tung University, Taipei, Taiwan
- *Correspondence: Wan-Chun Li,
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Anhê GF, Bordin S. The adaptation of maternal energy metabolism to lactation and its underlying mechanisms. Mol Cell Endocrinol 2022; 553:111697. [PMID: 35690287 DOI: 10.1016/j.mce.2022.111697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/15/2022] [Accepted: 06/01/2022] [Indexed: 11/29/2022]
Abstract
Maternal energy metabolism undergoes a singular adaptation during lactation that allows for the caloric enrichment of milk. Changes in the mammary gland, changes in the white adipose tissue, brown adipose tissue, liver, skeletal muscles and endocrine pancreas are pivotal for this adaptation. The present review details the landmark studies describing the enzymatic modulation and the endocrine signals behind these metabolic changes. We will also update this perspective with data from recent studies showing transcriptional and post-transcriptional mechanisms that mediate the adaptation of the maternal metabolism to lactation. The present text will also bring experimental and observational data that describe the long-term consequences that short periods of lactation impose to maternal metabolism.
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Affiliation(s)
- Gabriel Forato Anhê
- Department of Translational Medicine, School of Medical Sciences, State University of Campinas, Campinas, Brazil.
| | - Silvana Bordin
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
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Zheng H, Han L, Shi W, Fang X, Hong Y, Cao Y. Research Advances in Lotus Leaf as Chinese Dietary Herbal Medicine. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2022; 50:1423-1445. [PMID: 35770727 DOI: 10.1142/s0192415x22500616] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Lotus leaf (Heye), the dry foliage of Nelumbo nucifera Gaertn, has been valuable as a dietary herbal medicine for thousands of years. Phytochemical studies indicated that alkaloids and flavonoids are the main components of Heye. Polysaccharides, terpenes, and amino acids are also active ingredients. The drug properties of Heye are mild and bitter. Meridian tropism is mainly distributed in the liver, spleen, and stomach meridian. In the Traditional Chinese medicine (TCM) theoretical system, it is in many formulas for the therapy of various symptoms, including wasting-thirst induced by summer heat, diarrhea caused by summer heat-dampness and spleen deficiency, hematochezia, flooding and spotting, among others. Nowadays, the extracts and active components of Heye demonstrate multiple bioactivities, for instance anti-obesity, anti-inflammatory, anti-oxidant, cardiovascular protective, anticancer, hepatoprotective, hypoglycemic, antiviral, antimicrobial, as well as hemostatic activities. This review will provide an overview of Heye serving as a typical plant with functions of both medicine and food, including its practical applications in terms of TCM and healthy diet, phytochemistry, pharmacological activity, together with its toxicity. Besides, the new points and prospects of Heye in the overview are also outlined straightforwardly.
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Affiliation(s)
- Haoxue Zheng
- Department of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, Hubei, P. R. China
| | - Lintao Han
- Department of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, Hubei, P. R. China
| | - Wenfeng Shi
- Department of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, Hubei, P. R. China
| | - Xiaoping Fang
- Department of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, Hubei, P. R. China
| | - Yi Hong
- Department of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, Hubei, P. R. China
| | - Yan Cao
- Department of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, Hubei, P. R. China
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Loos CMM, Urschel KL, Vanzant ES, Oberhaus EL, Bohannan AD, Klotz JL, McLeod KR. Effects of Bromocriptine on Glucose and Insulin Dynamics in Normal and Insulin Dysregulated Horses. Front Vet Sci 2022; 9:889888. [PMID: 35711802 PMCID: PMC9194999 DOI: 10.3389/fvets.2022.889888] [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: 03/04/2022] [Accepted: 05/09/2022] [Indexed: 12/04/2022] Open
Abstract
The objectives of the study were to study the effects of the synthetic ergot alkaloid (EA), bromocriptine, on glucose and lipid metabolism in insulin dysregulated (ID, n = 7) and non-ID (n = 8) mares. Horses were individually housed and fed timothy grass hay and two daily concentrate meals so that the total diet provided 120% of daily DE requirements for maintenance. All horses were given intramuscular bromocriptine injections (0.1 mg/kg BW) every 3 days for 14 days. Before and after 14 days of treatment horses underwent a combined glucose-insulin tolerance test (CGIT) to assess insulin sensitivity and a feed challenge (1 g starch/kg BW from whole oats) to evaluate postprandial glycemic and insulinemic responses. ID horses had higher basal plasma concentrations of insulin (P = 0.01) and triglycerides (P = 0.02), and lower concentrations of adiponectin (P = 0.05) compared with non-ID horses. The CGIT response curve showed that ID horses had slower glucose clearance rates (P = 0.02) resulting in a longer time in positive phase (P = 0.03) and had higher insulin concentrations at 75 min (P = 0.0002) compared with non-ID horses. Glucose (P = 0.02) and insulin (P = 0.04) responses to the feeding challenge were lower in non-ID compared to ID horses. Regardless of insulin status, bromocriptine administration increased hay intake (P = 0.03) and decreased grain (P < 0.0001) and total DE (P = 0.0002) intake. Bromocriptine treatment decreased plasma prolactin (P = 0.0002) and cholesterol (P = 0.10) and increased (P = 0.02) adiponectin concentrations in all horses. Moreover, in both groups of horses, bromocriptine decreased glucose clearance rates (P = 0.02), increased time in positive phase (P = 0.04) of the CGIT and increased insulin concentrations at 75 min (P = 0.001). The postprandial glycemic (P = 0.01) and insulinemic (P = 0.001) response following the oats meal was lower after bromocriptine treatment in all horses. In conclusion, in contrast to data in humans and rodents, bromocriptine treatment reduced insulin sensitivity in all horses, regardless of their insulin status. These results indicate that the physiological effects of EA might be different in horses compared to other species. Moreover, because bromocriptine shares a high degree of homology with natural EA, further investigation is warranted in horses grazing endophyte-infected grasses.
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Affiliation(s)
- Caroline M M Loos
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | - Kristine L Urschel
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | - Eric S Vanzant
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | - Erin L Oberhaus
- School of Animal Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Adam D Bohannan
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
| | - James L Klotz
- Forage-Animal Production Research Unit, Agricultural Research Service, United States Department of Agriculture, Lexington, KY, United States
| | - Kyle R McLeod
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY, United States
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Suzuki MF, Almeida LA, Pomin SA, Silva FD, Freire RP, Oliveira JE, Affonso R, Soares CRJ, Bartolini P. Periplasmic synthesis and purification of the human prolactin antagonist Δ 1-11-G129R-hPRL. AMB Express 2021; 11:62. [PMID: 33905023 PMCID: PMC8079533 DOI: 10.1186/s13568-021-01209-5] [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: 03/11/2021] [Accepted: 03/16/2021] [Indexed: 11/30/2022] Open
Abstract
The human prolactin antagonist Δ1-11-G129R-hPRL is a 21.9 kDa recombinant protein with 188 amino acids that downregulates the proliferation of a variety of cells expressing prolactin receptors. Periplasmic expression of recombinant proteins in E. coli has been considered an option for obtaining a soluble and correctly folded protein, as an alternative to cytoplasmic production. The aim of this work was, therefore, to synthesize for the first time, the Δ1-11-G129R-hPRL antagonist, testing different activation temperatures and purifying it by classical chromatographic techniques. E. coli BL21(DE3) strain was transformed with a plasmid based on the pET25b( +) vector, DsbA signal sequence and the antagonist cDNA sequence. Different doses of IPTG were added, activating under different temperatures, and extracting the periplasmic fluid via osmotic shock. The best conditions were achieved by activating at 35 °C for 5 h using 0.4 mM IPTG, which gave a specific expression of 0.157 ± 0.015 μg/mL/A600 at a final optical density of 3.43 ± 0.13 A600. Purification was carried out by nickel-affinity chromatography followed by size-exclusion chromatography, quantification being performed via high-performance size-exclusion chromatography (HPSEC). The prolactin antagonist was characterized by SDS-PAGE, Western blotting, reversed-phase high-performance liquid chromatography (RP-HPLC) and MALDI-TOF–MS. The final product presented > 95% purity and its antagonistic effects were evaluated in vitro in view of potential clinical applications, including inhibition of the proliferation of cancer cells overexpressing the prolactin receptor and specific antidiabetic properties, taking also advantage of the fact that this antagonist was obtained in a soluble and correctly folded form and without an initial methionine.
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Wasinski F, Chaves FM, Pedroso JA, Mansano NS, Camporez JP, Gusmão DO, List EO, Kopchick JJ, Frazão R, Szawka RE, Donato J. Growth hormone receptor in dopaminergic neurones regulates stress-induced prolactin release in male mice. J Neuroendocrinol 2021; 33:e12957. [PMID: 33769619 PMCID: PMC9670090 DOI: 10.1111/jne.12957] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 02/03/2021] [Accepted: 02/10/2021] [Indexed: 12/15/2022]
Abstract
Arcuate nucleus (ARH) dopaminergic neurones regulate several biological functions, including prolactin secretion and metabolism. These cells are responsive to growth hormone (GH), although it is still unknown whether GH action on ARH dopaminergic neurones is required to regulate different physiological aspects. Mice carrying specific deletion of GH receptor (GHR) in tyrosine hydroxylase (TH)- or dopamine transporter (DAT)-expressing cells were produced. We investigated possible changes in energy balance, glucose homeostasis, fertility, pup survival and restraint stress-induced prolactin release. GHR deletion in DAT- or TH-expressing cells did not cause changes in food intake, energy expenditure, ambulatory activity, nutrient oxidation, glucose tolerance, insulin sensitivity and counter-regulatory response to hypoglycaemia in male and female mice. In addition, GHR deletion in dopaminergic cells caused no gross effects on reproduction and pup survival. However, restraint stress-induced prolactin release was significantly impaired in DAT- and TH-specific GHR knockout male mice, as well as in pegvisomant-treated wild-type males, whereas an intact response was observed in females. Patch clamp recordings were performed in ARH DAT neurones and, in contrast to prolactin, GH did not cause acute changes in the electrical activity of DAT neurones. Furthermore, TH phosphorylation at Ser40 in ARH neurones and median eminence axonal terminals was not altered in DAT-specific GHR knockout male mice during restraint stress. In conclusion, GH action in dopaminergic neurones is required for stress-induced prolactin release in male mice, suggesting the existence of sex differences in the capacity of GHR signalling to affect prolactin secretion. The mechanism behind this regulation still needs to be identified.
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Affiliation(s)
- Frederick Wasinski
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil
| | - Fernanda M. Chaves
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil
| | - João A.B. Pedroso
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil
| | - Naira S. Mansano
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Anatomia, Sao Paulo, Brazil
| | - João Paulo Camporez
- Universidade de Sao Paulo, Faculdade de Medicina de Ribeirao Preto, Departamento de Fisiologia, Ribeirao Preto, Brazil
| | - Daniela O. Gusmão
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Edward O. List
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - John J. Kopchick
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Renata Frazão
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Anatomia, Sao Paulo, Brazil
| | - Raphael E. Szawka
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Jose Donato
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil
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Whole-brain activation signatures of weight-lowering drugs. Mol Metab 2021; 47:101171. [PMID: 33529728 PMCID: PMC7895844 DOI: 10.1016/j.molmet.2021.101171] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/21/2021] [Accepted: 01/21/2021] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE The development of effective anti-obesity therapeutics relies heavily on the ability to target specific brain homeostatic and hedonic mechanisms controlling body weight. To obtain further insight into neurocircuits recruited by anti-obesity drug treatment, the present study aimed to determine whole-brain activation signatures of six different weight-lowering drug classes. METHODS Chow-fed C57BL/6J mice (n = 8 per group) received acute treatment with lorcaserin (7 mg/kg; i.p.), rimonabant (10 mg/kg; i.p.), bromocriptine (10 mg/kg; i.p.), sibutramine (10 mg/kg; p.o.), semaglutide (0.04 mg/kg; s.c.) or setmelanotide (4 mg/kg; s.c.). Brains were sampled two hours post-dosing and whole-brain neuronal activation patterns were analysed at single-cell resolution using c-Fos immunohistochemistry and automated quantitative three-dimensional (3D) imaging. RESULTS The whole-brain analysis comprised 308 atlas-defined mouse brain areas. To enable fast and efficient data mining, a web-based 3D imaging data viewer was developed. All weight-lowering drugs demonstrated brain-wide responses with notable similarities in c-Fos expression signatures. Overlapping c-Fos responses were detected in discrete homeostatic and non-homeostatic feeding centres located in the dorsal vagal complex and hypothalamus with concurrent activation of several limbic structures as well as the dopaminergic system. CONCLUSIONS Whole-brain c-Fos expression signatures of various weight-lowering drug classes point to a discrete set of brain regions and neurocircuits which could represent key neuroanatomical targets for future anti-obesity therapeutics.
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Wasinski F, Klein MO, Bittencourt JC, Metzger M, Donato J. Distribution of growth hormone-responsive cells in the brain of rats and mice. Brain Res 2020; 1751:147189. [PMID: 33152340 DOI: 10.1016/j.brainres.2020.147189] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/25/2020] [Accepted: 10/28/2020] [Indexed: 02/07/2023]
Abstract
A growth hormone (GH) injection is able to induce the phosphorylated form of the signal transducer and activator of transcription 5 (pSTAT5) in a large number of cells throughout the mouse brain. The present study had the objective to map the distribution of GH-responsive cells in the brain of rats that received an intracerebroventricular injection of GH and compare it to the pattern found in mice. We observed that rats and mice exhibited a similar distribution of GH-induced pSTAT5 in the majority of areas of the telencephalon, hypothalamus and brainstem. However, rats exhibited a higher density of GH-responsive cells than mice in the horizontal limb of the diagonal band of Broca (HDB), supraoptic and suprachiasmatic nuclei, whereas mice displayed more GH-responsive cells than rats in the hippocampus, lateral hypothalamic area and dorsal motor nucleus of the vagus (DMX). Since both HDB and DMX contain acetylcholine-producing neurons, pSTAT5 was co-localized with choline acetyltransferase in GH-injected animals. We found that 50.0 ± 4.5% of cholinergic neurons in the rat HDB coexpressed GH-induced pSTAT5, whereas very few co-localizations were observed in the mouse HDB. In contrast, rats displayed fewer cholinergic neurons responsive to GH in the DMX at the level of the area postrema. In summary, pSTAT5 can be used as a marker of GH-responsive cells in the rat brain. Although rats and mice exhibit a relatively similar distribution of GH-responsive neurons, some species-specific differences exist, as exemplified for the responsiveness to GH in distinct populations of cholinergic neurons.
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Affiliation(s)
- Frederick Wasinski
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil
| | - Marianne O Klein
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil
| | - Jackson C Bittencourt
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil
| | - Martin Metzger
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil
| | - Jose Donato
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, Sao Paulo, Brazil.
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Quaresma PGF, Teixeira PDS, Wasinski F, Campos AMP, List EO, Kopchick JJ, Donato J. Cholinergic neurons in the hypothalamus and dorsal motor nucleus of the vagus are directly responsive to growth hormone. Life Sci 2020; 259:118229. [PMID: 32781065 DOI: 10.1016/j.lfs.2020.118229] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/31/2020] [Accepted: 08/04/2020] [Indexed: 02/07/2023]
Abstract
AIMS Cholinergic neurons are distributed in brain areas containing growth hormone (GH)-responsive cells. We determined if cholinergic neurons are directly responsive to GH and the metabolic consequences of deleting the GH receptor (GHR) specifically in choline acetyltransferase (ChAT)-expressing cells. MAIN METHODS Mice received an acute injection of GH to detect neurons co-expressing ChAT and phosphorylated STAT5 (pSTAT5), a well-established marker of GH-responsive cells. For the physiological studies, mice carrying ablation of GHR exclusively in ChAT-expressing cells were produced and possible changes in energy and glucose homeostasis were determined when consuming regular chow or high-fat diet (HFD). KEY FINDINGS The majority of cholinergic neurons in the arcuate nucleus (60%) and dorsomedial nucleus (84%) of the hypothalamus are directly responsive to GH. Approximately 34% of pre-ganglionic parasympathetic neurons in the dorsal motor nucleus of the vagus also exhibited GH-induced pSTAT5. GH-induced pSTAT5 in these ChAT neurons was absent in GHR ChAT knockout mice. Mice carrying ChAT-specific GHR deletion, either in chow or HFD, did not exhibit significant changes in body weight, body adiposity, lean body mass, food intake, energy expenditure, respiratory quotient, ambulatory activity, serum leptin levels, glucose tolerance, insulin sensitivity and metabolic responses to 2-deoxy-d-glucose. However, GHR deletion in ChAT neurons caused decreased hypothalamic Pomc mRNA levels in HFD mice. SIGNIFICANCE Cholinergic neurons that regulate the metabolism are directly responsive to GH, although GHR signaling in these cells is not required for energy and glucose homeostasis. Thus, the physiological importance of GH action on cholinergic neurons still needs to be identified.
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Affiliation(s)
- Paula G F Quaresma
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, Sao Paulo 05508-000, Brazil
| | - Pryscila D S Teixeira
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, Sao Paulo 05508-000, Brazil
| | - Frederick Wasinski
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, Sao Paulo 05508-000, Brazil
| | - Ana M P Campos
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, Sao Paulo 05508-000, Brazil
| | - Edward O List
- Edison Biotechnology Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - John J Kopchick
- Edison Biotechnology Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Jose Donato
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofisica, Sao Paulo 05508-000, Brazil.
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Moore MC, Smith MS, Swift LL, Cincotta AH, Ezrokhi M, Cominos N, Zhang Y, Farmer B, Cherrington AD. Bromocriptine mesylate improves glucose tolerance and disposal in a high-fat-fed canine model. Am J Physiol Endocrinol Metab 2020; 319:E133-E145. [PMID: 32459527 PMCID: PMC7468784 DOI: 10.1152/ajpendo.00479.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bromocriptine mesylate treatment was examined in dogs fed a high fat diet (HFD) for 8 wk. After 4 wk on HFD, daily bromocriptine (Bromo; n = 6) or vehicle (CTR; n = 5) injections were administered. Oral glucose tolerance tests were performed before beginning HFD (OGTT1), 4 wk after HFD began (Bromo only), and after 7.5 wk on HFD (OGTT3). After 8 wk on HFD, clamp studies were performed, with infusion of somatostatin and intraportal replacement of insulin (4× basal) and glucagon (basal). From 0 to 90 min (P1), glucose was infused via peripheral vein to double the hepatic glucose load; and from 90 to 180 min (P2), glucose was infused via the hepatic portal vein at 4 mg·kg-1·min-1, with the HGL maintained at 2× basal. Bromo decreased the OGTT glucose ΔAUC0-30 and ΔAUC0-120 by 62 and 27%, respectively, P < 0.05 for both) without significantly altering the insulin response. Bromo dogs exhibited enhanced net hepatic glucose uptake (NHGU) compared with CTR (~33 and 21% greater, P1 and P2, respectively, P < 0.05). Nonhepatic glucose uptake (non-HGU) was increased ~38% in Bromo in P2 (P < 0.05). Bromo vs. CTR had higher (P < 0.05) rates of glucose infusion (36 and 30%) and non-HGU (~40 and 27%) than CTR during P1 and P2, respectively. In Bromo vs. CTR, hepatic 18:0/16:0 and 16:1/16:0 ratios tended to be elevated in triglycerides and were higher (P < 0.05) in phospholipids, consistent with a beneficial effect of bromocriptine on liver fat accumulation. Thus, bromocriptine treatment improved glucose disposal in a glucose-intolerant model, enhancing both NHGU and non-HGU.
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Affiliation(s)
- Mary Courtney Moore
- Department of Metabolic Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Marta S Smith
- Department of Metabolic Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Larry L Swift
- Vanderbilt Diabetes Research and Training Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | | | | | | | | | - Ben Farmer
- Department of Metabolic Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
- Vanderbilt Diabetes Research and Training Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Alan D Cherrington
- Department of Metabolic Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
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Macotela Y, Triebel J, Clapp C. Time for a New Perspective on Prolactin in Metabolism. Trends Endocrinol Metab 2020; 31:276-286. [PMID: 32044206 DOI: 10.1016/j.tem.2020.01.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/09/2019] [Accepted: 01/09/2020] [Indexed: 12/13/2022]
Abstract
The pituitary hormone prolactin (PRL) regulates a variety of functions beyond reproduction. The association between physiological (pregnancy) and pathological (prolactinoma) hyperprolactinemia and metabolic alterations led to the concept of this hormone being diabetogenic. However, large cohort clinical studies have recently shown that low circulating PRL levels are associated with metabolic disease and represent a risk factor for type 2 diabetes (T2D), whereas high PRL levels are beneficial. Moreover, PRL acts on the pancreas, liver, adipose tissue, and hypothalamus to maintain and promote metabolic homeostasis. By integrating basic and clinical evidence, we hypothesize that upregulation of PRL levels is a mechanism to maintain metabolic homeostasis and, thus, propose that the range of PRL levels considered physiological should be expanded to higher values.
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Affiliation(s)
- Yazmín Macotela
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, 76230 Querétaro, México.
| | - Jakob Triebel
- Institute for Clinical Chemistry, Laboratory Medicine, and Transfusion Medicine, Nuremberg General Hospital, Paracelsus Medical University, 90419 Nuremberg, Germany
| | - Carmen Clapp
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, 76230 Querétaro, México
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Leite F, Ribeiro L. Dopaminergic Pathways in Obesity-Associated Inflammation. J Neuroimmune Pharmacol 2019; 15:93-113. [DOI: 10.1007/s11481-019-09863-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 07/02/2019] [Indexed: 12/11/2022]
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