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Mak KWY, He W, Loganathan N, Belsham DD. Bisphenol A Alters the Levels of miRNAs That Directly and/or Indirectly Target Neuropeptide Y in Murine Hypothalamic Neurons. Genes (Basel) 2023; 14:1773. [PMID: 37761913 PMCID: PMC10530511 DOI: 10.3390/genes14091773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/01/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
The hypothalamus is a vital regulator of energy homeostasis. Orexigenic neuropeptide Y (NPY) neurons within the hypothalamus can stimulate feeding and suppress energy expenditure, and dysregulation of these neurons may contribute to obesity. We previously reported that bisphenol A (BPA), an endocrine disruptor with obesogenic properties, alters Npy transcription in hypothalamic neurons by inducing oxidative stress. We hypothesized that hypothalamic microRNAs (miRNAs), a class of small non-coding RNAs, could directly regulate Npy gene expression by binding the 3' untranslated region (UTR). Five predicted Npy-targeting miRNA candidates were uncovered through TargetScan and were detected in Npy-expressing hypothalamic neuronal cell models and hypothalamic neuronal primary cultures. BPA dysregulated the expression of a number of these hypothalamic miRNAs. We examined the effects of putative Npy-targeting miRNAs using miRNA mimics, and we found that miR-143-3p, miR-140-5p, miR-29b-1-5p, and let-7b-3p altered Npy expression in the murine hypothalamic cell lines. Importantly, miR-143-3p targets the mouse Npy 3' UTR, as detected using a luciferase construct containing the potential 3' UTR binding sites. Overall, this study established the first hypothalamic miRNA that directly targets the 3' UTR of mouse Npy, emphasizing the involvement of miRNAs in the NPY system and providing an alternative target for control of NPY levels.
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Affiliation(s)
- Kimberly W. Y. Mak
- Department of Physiology, University of Toronto, Medical Sciences Building 3247A, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada; (K.W.Y.M.); (W.H.); (N.L.)
| | - Wenyuan He
- Department of Physiology, University of Toronto, Medical Sciences Building 3247A, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada; (K.W.Y.M.); (W.H.); (N.L.)
| | - Neruja Loganathan
- Department of Physiology, University of Toronto, Medical Sciences Building 3247A, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada; (K.W.Y.M.); (W.H.); (N.L.)
| | - Denise D. Belsham
- Department of Physiology, University of Toronto, Medical Sciences Building 3247A, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada; (K.W.Y.M.); (W.H.); (N.L.)
- Department of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
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Ormanji MS, Melo MVL, Meca R, Garcia ML, Anauate AC, Muñoz JJAM, Oyama LM, Nishi EE, Bergamaschi CT, Carvalho AB, Heilberg IP. Adipose Tissue Denervation Blunted the Decrease in Bone Formation Promoted by Obesity in Rats. Nutrients 2023; 15:3574. [PMID: 37630764 PMCID: PMC10458609 DOI: 10.3390/nu15163574] [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] [Received: 07/10/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
The impact of obesity upon bone metabolism is controversial since both beneficial or harmful effects have been reported. Bone remodeling is modulated by the central nervous system through cytokines, hormones and neuromodulators. The present study aimed to evaluate the effects evoked by bilateral retroperitoneal white adipose tissue (rWAT) denervation (Dnx) upon bone mineral metabolism and remodeling in an experimental model of obesity in rats. Male Wistar rats were fed during 18 weeks with high-fat diet (HFD) or standard diet (SD) as controls, and rWAT Dnx or Sham surgery was performed at the 14th week. Biochemical and hormonal parameters, bone histomorphometry, rWAT and hypothalamus protein and gene expression were analyzed. The HFD group presented decreased bone formation parameters, increased serum and bone leptin and FGF23, increased serum and hypothalamic neuropeptide Y (NPY) and decreased serum 1,25-dihydroxyvitamin D3 and PTH. After rWAT Dnx, bone markers and histomorphometry showed restoration of bone formation, and serum and hypothalamic NPY decreased, without alteration in leptin levels. The present study shows that the denervation of rWAT improved bone formation in obese rats mediated by a preferential reduction in neurohormonal actions of NPY, emphasizing the relevance of the adipose tissue-brain-bone axis in the control of bone metabolism in obesity.
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Affiliation(s)
- Milene Subtil Ormanji
- Nephrology Division, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.S.O.); (M.V.L.M.); (R.M.); (A.C.A.); (J.J.A.M.M.); (A.B.C.)
| | - Maria Victória Lazarini Melo
- Nephrology Division, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.S.O.); (M.V.L.M.); (R.M.); (A.C.A.); (J.J.A.M.M.); (A.B.C.)
| | - Renata Meca
- Nephrology Division, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.S.O.); (M.V.L.M.); (R.M.); (A.C.A.); (J.J.A.M.M.); (A.B.C.)
| | - Michelle Louvaes Garcia
- Department of Physiology, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.L.G.); (L.M.O.); (E.E.N.); (C.T.B.)
| | - Ana Carolina Anauate
- Nephrology Division, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.S.O.); (M.V.L.M.); (R.M.); (A.C.A.); (J.J.A.M.M.); (A.B.C.)
| | - Juan José Augusto Moyano Muñoz
- Nephrology Division, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.S.O.); (M.V.L.M.); (R.M.); (A.C.A.); (J.J.A.M.M.); (A.B.C.)
| | - Lila Missae Oyama
- Department of Physiology, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.L.G.); (L.M.O.); (E.E.N.); (C.T.B.)
| | - Erika Emy Nishi
- Department of Physiology, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.L.G.); (L.M.O.); (E.E.N.); (C.T.B.)
| | - Cassia Toledo Bergamaschi
- Department of Physiology, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.L.G.); (L.M.O.); (E.E.N.); (C.T.B.)
| | - Aluizio Barbosa Carvalho
- Nephrology Division, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.S.O.); (M.V.L.M.); (R.M.); (A.C.A.); (J.J.A.M.M.); (A.B.C.)
| | - Ita Pfeferman Heilberg
- Nephrology Division, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil; (M.S.O.); (M.V.L.M.); (R.M.); (A.C.A.); (J.J.A.M.M.); (A.B.C.)
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Duquenne M, Folgueira C, Bourouh C, Millet M, Silva A, Clasadonte J, Imbernon M, Fernandois D, Martinez-Corral I, Kusumakshi S, Caron E, Rasika S, Deliglia E, Jouy N, Oishi A, Mazzone M, Trinquet E, Tavernier J, Kim YB, Ory S, Jockers R, Schwaninger M, Boehm U, Nogueiras R, Annicotte JS, Gasman S, Dam J, Prévot V. Leptin brain entry via a tanycytic LepR-EGFR shuttle controls lipid metabolism and pancreas function. Nat Metab 2021; 3:1071-1090. [PMID: 34341568 PMCID: PMC7611554 DOI: 10.1038/s42255-021-00432-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 06/23/2021] [Indexed: 01/14/2023]
Abstract
Metabolic health depends on the brain's ability to control food intake and nutrient use versus storage, processes that require peripheral signals such as the adipocyte-derived hormone, leptin, to cross brain barriers and mobilize regulatory circuits. We have previously shown that hypothalamic tanycytes shuttle leptin into the brain to reach target neurons. Here, using multiple complementary models, we show that tanycytes express functional leptin receptor (LepR), respond to leptin by triggering Ca2+ waves and target protein phosphorylation, and that their transcytotic transport of leptin requires the activation of a LepR-EGFR complex by leptin and EGF sequentially. Selective deletion of LepR in tanycytes blocks leptin entry into the brain, inducing not only increased food intake and lipogenesis but also glucose intolerance through attenuated insulin secretion by pancreatic β-cells, possibly via altered sympathetic nervous tone. Tanycytic LepRb-EGFR-mediated transport of leptin could thus be crucial to the pathophysiology of diabetes in addition to obesity, with therapeutic implications.
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Affiliation(s)
- Manon Duquenne
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Cintia Folgueira
- Universidade de Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Santiago de Compostela, Spain
| | - Cyril Bourouh
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, CNRS, U1283-UMR 8199-EGID, Lille, France
| | - Marion Millet
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Anisia Silva
- Institut Cochin, Inserm U1016, CNRS UMR 8104, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jérôme Clasadonte
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Monica Imbernon
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Daniela Fernandois
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Ines Martinez-Corral
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Soumya Kusumakshi
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - Emilie Caron
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - S Rasika
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Eleonora Deliglia
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Nathalie Jouy
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
- Flow Cytometry Core Facility, BioImaging Center of Lille, Hospital Campus, UMS2014-US41, Lille, France
| | - Asturo Oishi
- Institut Cochin, Inserm U1016, CNRS UMR 8104, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Massimiliano Mazzone
- Laboratory of Tumor Inflammation and Angiogenesis, Center for Cancer Biology, VIB, Department of Oncology, Leuven, Belgium
| | - Eric Trinquet
- Cisbio Bioassays, Parc Technologique Marcel Boiteux, Codolet, France
| | - Jan Tavernier
- VIB-UGent Center for Medical Biotechnology, Gent, Belgium
| | - Young-Bum Kim
- Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Stéphane Ory
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Ralf Jockers
- Institut Cochin, Inserm U1016, CNRS UMR 8104, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Ulrich Boehm
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - Ruben Nogueiras
- Universidade de Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Jean-Sébastien Annicotte
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, CNRS, U1283-UMR 8199-EGID, Lille, France
| | - Stéphane Gasman
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Julie Dam
- Institut Cochin, Inserm U1016, CNRS UMR 8104, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Vincent Prévot
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France.
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McIlwraith EK, Belsham DD. Hypothalamic reproductive neurons communicate through signal transduction to control reproduction. Mol Cell Endocrinol 2020; 518:110971. [PMID: 32750397 DOI: 10.1016/j.mce.2020.110971] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/11/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus coordinate fertility and puberty. In order to achieve successful reproductive capacity, they receive signals from the periphery and from other hypothalamic neurons that coordinate energy homeostasis. Hormones, such as estradiol, insulin, leptin, and adiponectin, act directly or indirectly on GnRH and its associated reproductive neurons. Nutrients like glucose and fatty acids can also affect reproductive neurons to signal nutrient availability. Additionally, acute and chronic inflammation is reported to detrimentally affect GnRH and kisspeptin expression. All of these cues activate signal transduction pathways within neurons that lead to the changes in GnRH neuronal function. The signalling pathways can also be dysregulated by endocrine disrupting chemicals, which impair fertility by misappropriating common signalling pathways. The complex mechanisms controlling the levels of GnRH during the reproductive cycle rely on a carefully orchestrated set of signal transduction events to regulate the positive and negative feedback arms of the hypothalamic-pituitary-gonadal axis. If these signalling events are dysregulated, this will result is a downregulatory event leading to hypogonadal hypogonadism with decreased or absent fertility. Therefore, an understanding of the mechanisms involved in distinct neuronal signalling could provide an advantage to inform therapeutic interventions for infertility and reproductive disorders.
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Affiliation(s)
- Emma K McIlwraith
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Denise D Belsham
- Department of Physiology, University of Toronto, Toronto, ON, Canada; Obstetrics and Gynaecology and Medicine, University of Toronto, Toronto, ON, Canada.
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Lu JW, Chi PJ, Lin YL, Wang CH, Hsu BG. Serum leptin levels are positively associated with aortic stiffness in patients with chronic kidney disease stage 3-5. Adipocyte 2020; 9:206-211. [PMID: 32403968 PMCID: PMC7238868 DOI: 10.1080/21623945.2020.1764799] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Leptin potentially exerts atherogenic effects.This study evaluated the relationship between serum leptin levels and aortic stiffness in patients with stage 3-5 chronic kidney disease (CKD). Totally 205 participants were enrolled. Fasting blood sample were checked and serum leptin were measured by enzyme immunoassay. Aortic stiffness was measured as the carotid-femoral pulse wave velocity (cfPWV). 73 (35.6%) of 205 patients showed cfPWV >10 m/s were defined as aortic stiffness group. Compared with the remaining patients, the aortic stiffness group had high prevalence of diabetes mellitus, older age, higher waist circumference, body fat mass, systolic blood pressure, fasting glucose, and higher serum leptin level. In multivariable logistic regression analysis the independent predictors of cfPWV >10 m/s included leptin levels (odds ratio [OR]: 1.061, 95% confidence interval [CI]: 1.027-1.095, P < 0.001), age (OR: 1.064, 95% CI: 1.033-1.096, P< 0.001), and systolic blood pressure (OR: 1.021, 95% CI: 1.006-1.037, P = 0.006). Multivariable forward stepwise linear regression analysisshowed a positive association between log-transformed leptin levels and log-cfPWV (β = 0.192, adjusted R2 change = 0.042, P = 0.001). Thus, aortic stiffness is positively correlated with serum leptin levels in patients with stage 3-5 CKD.Abbreviations: BUN, blood urea nitrogen; cfPWV, carotid-femoral pulse wave velocity; CI, confidence interval; CKD, chronic kidney disease; Cre, creatinine; DBP, diastolic blood pressure; DM, diabetes mellitus; eGFR, estimated glomerular filtration rate; LDL-C, low-density lipoprotein cholesterol; OR, odds ratio; SBP, systolic blood pressure; TCH, total cholesterol; TG, triglycerides.
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Affiliation(s)
- Jing-Wun Lu
- School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Po-Jui Chi
- Division of Nephrology, E-DA Hospital, E-DA Cancer Hospital, I-Shou University, Kaohsiung, Taiwan
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
| | - Yu-Li Lin
- Division of Nephrology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Chih-Hsien Wang
- School of Medicine, Tzu Chi University, Hualien, Taiwan
- Division of Nephrology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Bang-Gee Hsu
- School of Medicine, Tzu Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
- Division of Nephrology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
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Loganathan N, McIlwraith EK, Belsham DD. BPA Differentially Regulates NPY Expression in Hypothalamic Neurons Through a Mechanism Involving Oxidative Stress. Endocrinology 2020; 161:5910085. [PMID: 32960947 DOI: 10.1210/endocr/bqaa170] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 09/18/2020] [Indexed: 12/13/2022]
Abstract
Bisphenol A (BPA), a ubiquitous endocrine-disrupting chemical, interferes with reproduction and is also considered an obesogen. The neuropeptide Y (NPY) neurons of the hypothalamus control both food intake and reproduction and have emerged as potential targets of BPA. These functionally diverse subpopulations of NPY neurons are differentially regulated by peripheral signals, such as estrogen and leptin. Whether BPA also differentially alters Npy expression in subpopulations of NPY neurons, contributing to BPA-induced endocrine dysfunction is unclear. We investigated the response of 6 immortalized hypothalamic NPY-expressing cell lines to BPA treatment. BPA upregulated Npy mRNA expression in 4 cell lines (mHypoA-59, mHypoE-41, mHypoA-2/12, mHypoE-42), and downregulated Npy in 2 lines (mHypoE-46, mHypoE-44). This differential expression of Npy occurred concurrently with differential expression of estrogen receptor mRNA levels. Inhibition of G-protein coupled estrogen receptor GPR30 or estrogen receptor β prevented the BPA-mediated decrease in Npy, whereas inhibition of energy sensor 5' adenosine monophosphate-activated protein kinase (AMPK) with compound C prevented BPA-induced increase in Npy. BPA also altered neuroinflammatory and oxidative stress markers in both mHypoA-59 and mHypoE-46 cell lines despite the differential regulation of Npy. Remarkably, treatment with BPA in an antioxidant-rich media, Neurobasal A (NBA), or with reactive oxygen species scavenger tauroursodeoxycholic acid mitigated the BPA-induced increase and decrease in Npy. Furthermore, 2 antioxidant species from NBA-N-acetylcysteine and vitamin B6-diminished the induction of Npy in the mHypoA-59 cells, demonstrating these supplements can counteract BPA-induced dysregulation in certain subpopulations. Overall, these results illustrate the differential regulation of Npy by BPA in neuronal subpopulations, and point to oxidative stress as a pathway that can be targeted to block BPA-induced Npy dysregulation in hypothalamic neurons.
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Affiliation(s)
- Neruja Loganathan
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Emma K McIlwraith
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Denise D Belsham
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Obstetrics, University of Toronto, Toronto, Ontario, Canada
- Department of Gynaecology and Medicine, University of Toronto, Toronto, Ontario, Canada
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McIlwraith EK, Loganathan N, Belsham DD. Phoenixin Expression Is Regulated by the Fatty Acids Palmitate, Docosahexaenoic Acid and Oleate, and the Endocrine Disrupting Chemical Bisphenol A in Immortalized Hypothalamic Neurons. Front Neurosci 2018; 12:838. [PMID: 30524225 PMCID: PMC6262291 DOI: 10.3389/fnins.2018.00838] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 10/29/2018] [Indexed: 01/22/2023] Open
Abstract
Phoenixin (PNX) is a newly identified reproductive peptide required for the estrous cycle. It is most highly expressed in the hypothalamus, where it is a positive regulator of gonadotropin-releasing hormone (GnRH) and kisspeptin. However, it is unknown what signals lie upstream of Pnx to coordinate its effects on GnRH and kisspeptin. We investigated the effects of the hormones, estrogen and leptin; the fatty acids, palmitate, docosahexaenoic acid (DHA), oleate and palmitoleate; and the endocrine disrupting chemical BPA on Pnx mRNA levels. We also examined whether the signaling pathways of nitric oxide, lipopolysaccharide, cAMP and protein kinase C could alter Pnx expression. Immortalized hypothalamic neurons were treated from 2 to 24 h with these compounds and Pnx mRNA levels were measured with RT-qPCR. Unexpectedly, only BPA as well as the fatty acids, palmitate, DHA and oleate, could alter Pnx expression; therefore suggesting that Pnx may fulfill a nutrient-sensing role in the hypothalamus. Our study is the first to delineate potential regulators of this novel neuropeptide, and our findings provide some insight into the functional role of PNX in the hypothalamus.
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Affiliation(s)
- Emma K McIlwraith
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Neruja Loganathan
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Denise D Belsham
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, ON, Canada.,Department of Medicine, University of Toronto, Toronto, ON, Canada
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Kim SM, McIlwraith EK, Chalmers JA, Belsham DD. Palmitate Induces an Anti-Inflammatory Response in Immortalized Microglial BV-2 and IMG Cell Lines that Decreases TNFα Levels in mHypoE-46 Hypothalamic Neurons in Co-Culture. Neuroendocrinology 2018; 107:387-399. [PMID: 30352432 DOI: 10.1159/000494759] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 10/23/2018] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Elevated levels of saturated fatty acids (SFA) induce a state of neuroinflammation in the hypothalamus. It has been suggested that microglia sense palmitate, a prevalent circulating SFA, and act as mediators of this inflammatory process by communicating with neurons, particularly those involved in appetite regulation. In this study, we examined the inflammatory response to palmitate in immortalized microglial cell lines, BV-2 and IMG, and the subsequent effects on inflammatory gene expression in a model of NPY/AgRP neurons, mHypoE-46. METHODS The BV-2 cells were treated with 50 µM palmitate for 4 and 24 h, and the transcriptional regulation of markers for inflammation and cellular stress was assessed using an RT2 Profiler PCR Array. Select genes were verified with qRT-PCR. The BV-2 and IMG cells were then co-cultured using 1.0-µm cell culture inserts with an immortalized hypothalamic cell line, mHypoE-46, to investigate potential intercellular communication between microglia and neurons. RESULTS We found that palmitate increased the mRNA levels of specific inflammatory genes, and a general anti-inflammatory profile was revealed in the microglia cells. The mRNA changes in TNFα at 4 and 24 h in BV-2 cells were abrogated with the toll-like receptor 4 (TLR4) inhibitor, TAK-242, indicating the involvement of TLR4. Co-culture of mHypoE-46 neurons with microglia pre-treated with palmitate resulted in repression of TNFα expression in the hypothalamic neurons. As palmitate significantly increased IL-13 expression in microglia, the effect of this cytokine was tested in mHypoE-46 neurons. The addition of IL-13 to neuronal cultures normalized the palmitate-mediated increase in IL-6 and AgRP expression, suggesting that microglia may protect surrounding neurons, at least in part, through the release of IL-13. CONCLUSIONS These results suggest a potential anti-inflammatory role of microglia towards the palmitate-induced neuroinflammation, and potentially energy homeostasis, in hypothalamic neurons.
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Affiliation(s)
- Stephanie M Kim
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Emma K McIlwraith
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jennifer A Chalmers
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Denise D Belsham
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario,
- Departments of Medicine and Obstetrics and Gynaecology, Faculty of Medicine, University of Toronto, Toronto, Ontario,
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Mittelman-Smith MA, Wong AM, Micevych PE. Estrogen and Progesterone Integration in an in vitro Model of RP3V Kisspeptin Neurons. Neuroendocrinology 2017; 106:101-115. [PMID: 28384629 PMCID: PMC5750133 DOI: 10.1159/000471878] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 03/21/2017] [Indexed: 12/18/2022]
Abstract
Positive feedback on gonadotropin release requires not only estrogen but also progesterone to activate neural circuits. In rodents, ovarian estradiol (E2) stimulates progesterone synthesis in hypothalamic astrocytes (neuroP), needed for the luteinizing hormone (LH) surge. Kisspeptin (kiss) neurons are the principal stimulators of gonadotropin-releasing hormone neurons, and disruption of kiss signaling abrogates the LH surge. Similarly, blocking steroid synthesis in the hypothalamus or deleting classical progesterone receptor (PGR) selectively in kiss neurons prevents the LH surge. These results suggest a synergistic action of E2 and progesterone in kiss neurons to affect gonadotropin release. The mHypoA51, immortalized kiss-expressing neuronal cell line derived from adult female mice, is a tractable model for examining integration of steroid signaling underlying estrogen positive feedback. Here, we report that kiss neurons in vitro integrate E2 and progesterone signaling to increase levels of kiss translation and release. mHypoA51 neurons expressed nonclassical membrane progesterone receptors (mPRα and mPRβ) and E2-inducible PGR, required for progesterone-augmentation of E2-induced kiss expression. With astrocyte-conditioned media or in mHypoA51-astrocyte co-culture, neuroP augmented stimulatory effects of E2 on kiss protein. Progesterone activation of classical, membrane-localized PGR led to activation of MAPK and Src kinases. Importantly, progesterone or Src activation induced release of kiss from E2-primed mHypoA51 neurons. Consistent with previous studies, the present results provide compelling evidence that the interaction of E2 and progesterone stimulates kiss expression and release. Further, these results demonstrate a mechanism though which peripheral E2 may prime kiss neurons to respond to neuroP, mediating estrogen positive feedback.
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Molnar MZ, Nagy K, Remport A, Gaipov A, Fülöp T, Czira ME, Kovesdy CP, Mucsi I, Mathe Z. Association Between Serum Leptin Level and Mortality in Kidney Transplant Recipients. J Ren Nutr 2016; 27:53-61. [PMID: 27666945 DOI: 10.1053/j.jrn.2016.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 08/07/2016] [Accepted: 08/08/2016] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVE Leptin is a hormone made by adipocytes and associated with hypertension, inflammation, and coronary artery disease. Low serum leptin level was associated with higher risk of death in patients with advanced chronic kidney disease. Little is known about the association of serum leptin with outcomes in kidney transplant recipients. DESIGN Prospective prevalent cohort. SETTING AND SUBJECT We collected sociodemographic and clinical parameters, medical and transplant history, and laboratory data of 979 prevalent kidney transplant recipients. Associations between serum leptin level and death with a functioning graft, all-cause death, and death-censored graft loss over a 6-year follow-up period were examined in survival models. RESULTS Serum leptin levels showed moderate negative correlation with eGFR (R = -0.21, P < .001) and positive correlations with BMI (R = 0.48, P < .001) and C-reactive protein (R = 0.20, P < .001). Each 10 ng/mL higher serum leptin level was associated with 7% lower risk of death with functioning graft (hazard ratio [HR] (95% confidence interval [CI]), 0.93 (0.87-0.99)), and this association persisted after adjustment for confounders: HR (95% CI), 0.90 (0.82-0.99). Similar associations were found with all-cause death as outcome. The association between serum leptin level and risk of graft loss was nonlinear, and only low serum leptin level was associated with higher risk of graft loss. CONCLUSIONS In prevalent kidney transplant recipients, lower serum leptin was an independent predictor of death.
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Affiliation(s)
- Miklos Z Molnar
- Division of Nephrology, Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee; Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary.
| | - Kristof Nagy
- Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary
| | - Adam Remport
- Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary
| | - Abduzhappar Gaipov
- Department of Extracorporeal Hemocorrection, National Scientific Medical Research Center, Astana, Kazakhstan
| | - Tibor Fülöp
- Department of Internal Medicine, University of Mississippi Medical Center, Jackson, Mississippi
| | - Maria E Czira
- Institute of Epidemiology and Social Medicine, University of Muenster, Muenster, Germany
| | - Csaba P Kovesdy
- Division of Nephrology, Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee; Nephrology Section, Memphis Veterans Affairs Medical Center, Memphis, Tennessee
| | - Istvan Mucsi
- Department of Medicine, Division of Nephrology and Multiorgan Transplant Program, University Health Network, University of Toronto, Toronto, Canada
| | - Zoltan Mathe
- Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary
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11
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Mele P, Zammaretti F, Longo A, Panzica G, Oberto A, Eva C. Sex-dependent regulation of hypothalamic neuropeptide Y-Y1 receptor gene expression in leptin treated obese (ob/ob) or lean mice. Brain Res 2016; 1649:102-109. [PMID: 27425429 DOI: 10.1016/j.brainres.2016.07.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/22/2016] [Accepted: 07/14/2016] [Indexed: 01/05/2023]
Abstract
Pharmacological and genetic studies have shown that the Y1 receptor (Y1R) for Neuropeptide Y (NPY) plays a crucial role in the control of feeding behavior under metabolic conditions of low leptin levels or leptin deficiency. In this study, we investigated the effect of leptin deficiency and leptin replacement on Y1R gene expression in the hypothalamus of lean and obese Y1R/LacZ transgenic mice (TgY1R/LacZ) carrying the murine Y1R promoter linked to the LacZ gene that induces the expression of β-galactosidase. Two daily intraperitoneal injections with leptin (1μg/g of body weight for one week) of male and female lean (TgY1R/LacZ+/+) and obese (TgY1R/LacZob/ob) mice induced a significant decrease of body weight in both sexes and genotypes. In males, leptin administration decreased β-galactosidase activity in the PVN and DMH of lean mice, and increased transgene expression in the same hypothalamic nuclei of obese mice. Sex-related differences were also observed in both genotypes, since leptin treatment failed to affect transgene expression in hypothalamus of lean and obese female mice. These results provide further evidence for a sexual dimorphism of the hypothalamic NPY-Y1R-mediated pathway in response to changes in leptin circulating levels.
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Affiliation(s)
- Paolo Mele
- Department of Neuroscience, University of Turin, C.so Massimo d'Azeglio 52, Torino, Italy; Neuroscience Institute of the Cavalieri-Ottolenghi Foundation (NICO), Regione Gonzole 10, 10043 Orbassano, Torino, Italy
| | - Francesca Zammaretti
- Department of Neuroscience, University of Turin, C.so Massimo d'Azeglio 52, Torino, Italy
| | - Angela Longo
- Department of Neuroscience, University of Turin, C.so Massimo d'Azeglio 52, Torino, Italy; Neuroscience Institute of the Cavalieri-Ottolenghi Foundation (NICO), Regione Gonzole 10, 10043 Orbassano, Torino, Italy
| | - Giancarlo Panzica
- Department of Neuroscience, University of Turin, C.so Massimo d'Azeglio 52, Torino, Italy; Neuroscience Institute of the Cavalieri-Ottolenghi Foundation (NICO), Regione Gonzole 10, 10043 Orbassano, Torino, Italy
| | - Alessandra Oberto
- Department of Neuroscience, University of Turin, C.so Massimo d'Azeglio 52, Torino, Italy; Neuroscience Institute of the Cavalieri-Ottolenghi Foundation (NICO), Regione Gonzole 10, 10043 Orbassano, Torino, Italy
| | - Carola Eva
- Department of Neuroscience, University of Turin, C.so Massimo d'Azeglio 52, Torino, Italy; Neuroscience Institute of the Cavalieri-Ottolenghi Foundation (NICO), Regione Gonzole 10, 10043 Orbassano, Torino, Italy.
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12
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Dwarkasing JT, Witkamp RF, Boekschoten MV, Ter Laak MC, Heins MS, van Norren K. Increased hypothalamic serotonin turnover in inflammation-induced anorexia. BMC Neurosci 2016; 17:26. [PMID: 27207102 PMCID: PMC4875640 DOI: 10.1186/s12868-016-0260-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 05/11/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Anorexia can occur as a serious complication of disease. Increasing evidence suggests that inflammation plays a major role, along with a hypothalamic dysregulation characterized by locally elevated serotonin levels. The present study was undertaken to further explore the connections between peripheral inflammation, anorexia and hypothalamic serotonin metabolism and signaling pathways. First, we investigated the response of two hypothalamic neuronal cell lines to TNFα, IL-6 and LPS. Next, we studied transcriptomic changes and serotonergic activity in the hypothalamus of mice after intraperitoneal injection with TNFα, IL-6 or a combination of TNFα and IL-6. RESULTS In vitro, we showed that hypothalamic neurons responded to inflammatory mediators by releasing cytokines. This inflammatory response was associated with an increased serotonin release. Mice injected with TNFα and IL-6 showed decreased food intake, associated with altered expression of inflammation-related genes in the hypothalamus. In addition, hypothalamic serotonin turnover showed to be elevated in treated mice. CONCLUSIONS Overall, our results underline that peripheral inflammation reaches the hypothalamus where it affects hypothalamic serotoninergic metabolism. These hypothalamic changes in serotonin pathways are associated with decreased food intake, providing evidence for a role of serotonin in inflammation-induced anorexia.
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Affiliation(s)
- J T Dwarkasing
- Nutrition and Pharmacology Group, Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703HD, Wageningen, The Netherlands.
| | - R F Witkamp
- Nutrition and Pharmacology Group, Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703HD, Wageningen, The Netherlands
| | - M V Boekschoten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703HD, Wageningen, The Netherlands
| | - M C Ter Laak
- Nutrition and Pharmacology Group, Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703HD, Wageningen, The Netherlands
| | - M S Heins
- Brains On-line, P.O. Box 4030, 9701 EA, Groningen, The Netherlands
| | - K van Norren
- Nutrition and Pharmacology Group, Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703HD, Wageningen, The Netherlands
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13
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Tsai JP, Wang JH, Chen ML, Yang CF, Chen YC, Hsu BG. Association of serum leptin levels with central arterial stiffness in coronary artery disease patients. BMC Cardiovasc Disord 2016; 16:80. [PMID: 27151106 PMCID: PMC4857286 DOI: 10.1186/s12872-016-0268-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 04/29/2016] [Indexed: 01/05/2023] Open
Abstract
Background Serum adipokines have roles in the development of arterial stiffness. Our aim was to investigate the relationship of leptin and the surrogate marker carotid-femoral pulse wave velocity (cfPWV) in coronary artery disease (CAD) patients. Methods Fasting blood samples were obtained from 105 CAD patients. cfPWV was measured with the SphygmoCor system. A cfPWV > 10 m/s was defined as high arterial stiffness, and ≤ 10 m/s as low arterial stiffness. Results Thirty-seven patients (35.2 %) had high arterial stiffness, and had a higher percentage of diabetes (P = 0.001), hypertension (P = 0.010), older age (P = 0.001), and higher systolic blood pressure (SBP) (P < 0.001), diastolic blood pressure (DBP) (P = 0.021), pulse pressure (P = 0.014), and serum leptin level (P = 0.002) compared to patients with low arterial stiffness. Serum leptin levels correlated with the number of angiographically documented stenotic coronary artery vessels (P < 0.001). After adjusting for factors significantly associated with arterial stiffness, multivariate logistic regression analysis showed that leptin (odds ratio = 1.026, 95 % confidence interval: 1.002–1.051, P = 0.037) was a significant independent predictor of arterial stiffness. Conclusions Increasing serum concentration of leptin correlated positively with the total number of stenotic coronary arteries, and serum leptin level may predict the development of arterial stiffness in CAD patients.
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Affiliation(s)
- Jen-Pi Tsai
- Division of Nephrology, Department of Internal Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Ji-Hung Wang
- School of Medicine, Tzu Chi University, Hualien, Taiwan.,Division of Cardiology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Mei-Ling Chen
- Division of Cardiology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Chiu-Fen Yang
- Division of Cardiology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Yu-Chih Chen
- Division of Cardiology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Bang-Gee Hsu
- School of Medicine, Tzu Chi University, Hualien, Taiwan. .,Division of Nephrology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan.
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14
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Breit A, Wicht K, Boekhoff I, Glas E, Lauffer L, Mückter H, Gudermann T. Glucose Enhances Basal or Melanocortin-Induced cAMP-Response Element Activity in Hypothalamic Cells. Mol Endocrinol 2016; 30:748-62. [PMID: 27144291 DOI: 10.1210/me.2016-1001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Melanocyte-stimulating hormone (MSH)-induced activation of the cAMP-response element (CRE) via the CRE-binding protein in hypothalamic cells promotes expression of TRH and thereby restricts food intake and increases energy expenditure. Glucose also induces central anorexigenic effects by acting on hypothalamic neurons, but the underlying mechanisms are not completely understood. It has been proposed that glucose activates the CRE-binding protein-regulated transcriptional coactivator 2 (CRTC-2) in hypothalamic neurons by inhibition of AMP-activated protein kinases (AMPKs), but whether glucose directly affects hypothalamic CRE activity has not yet been shown. Hence, we dissected effects of glucose on basal and MSH-induced CRE activation in terms of kinetics, affinity, and desensitization in murine, hypothalamic mHypoA-2/10-CRE cells that stably express a CRE-dependent reporter gene construct. Physiologically relevant increases in extracellular glucose enhanced basal or MSH-induced CRE-dependent gene transcription, whereas prolonged elevated glucose concentrations reduced the sensitivity of mHypoA-2/10-CRE cells towards glucose. Glucose also induced CRCT-2 translocation into the nucleus and the AMPK activator metformin decreased basal and glucose-induced CRE activity, suggesting a role for AMPK/CRTC-2 in glucose-induced CRE activation. Accordingly, small interfering RNA-induced down-regulation of CRTC-2 expression decreased glucose-induced CRE-dependent reporter activation. Of note, glucose also induced expression of TRH, suggesting that glucose might affect the hypothalamic-pituitary-thyroid axis via the regulation of hypothalamic CRE activity. These findings significantly advance our knowledge about the impact of glucose on hypothalamic signaling and suggest that TRH release might account for the central anorexigenic effects of glucose and could represent a new molecular link between hyperglycaemia and thyroid dysfunction.
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Affiliation(s)
- Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Kristina Wicht
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Ingrid Boekhoff
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Evi Glas
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Lisa Lauffer
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Harald Mückter
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 Munich, Germany
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15
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Tsai JP, Lee MC, Le MC, Chen YC, Ho GJ, Shih MH, Hsu BG. Hyperleptinemia Is a Risk Factor for the Development of Central Arterial Stiffness in Kidney Transplant Patients. Transplant Proc 2016; 47:1825-30. [PMID: 26293058 DOI: 10.1016/j.transproceed.2015.06.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 05/13/2015] [Accepted: 06/02/2015] [Indexed: 12/23/2022]
Abstract
BACKGROUND Arterial stiffness could cause adverse outcomes in kidney transplant (KT) patients. Leptin has a role in influencing vascular smooth muscle that may contribute to atherosclerosis. The aim of this study was to evaluate the relationship between fasting serum leptin concentration and carotid-femoral pulse wave velocity (cfPWV) in KT patients. MATERIALS AND METHODS Fasting blood samples were obtained from 55 KT patients and 65 subjects from the outpatient department were enrolled as the control group. The cfPWV values of >10 m/s were used to define as the high arterial stiffness group and <10 m/s as the low arterial stiffness group. The predictive ability of leptin for arterial stiffness of KT was assessed using receiver operating characteristic (ROC) curve and multivariate logistic regression analyses. RESULTS Kidney transplant patients had lower hemoglobin, but higher blood urea nitrogen, creatinine, total cholesterol, diastolic blood pressure, intact parathyroid hormone levels, and leptin levels than controls. Although cfPWV levels were higher in KT patients, there is no difference of cfPWV levels between KT patients and control (P = .595). Fifteen KT patients (27.3%) were defined in the high arterial stiffness group, and serum leptin level was higher in the high arterial stiffness group compared with the low arterial stiffness group in KT patients (P < .001). Multivariate logistic regression analysis showed that leptin (odds ratio: 1.044, 95% confidence interval [CI]: 1.016-1.072, P = .002) was an independent predictor of arterial stiffness in KT patients. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve predicting arterial stiffness in KT patients were 73.33%, 87.5%, 68.7%, 89.7%, and 0.828 (95% CI: 0.703-0.917, P < .001), and the leptin cut-off value was 74.14 ng/mL. CONCLUSION Serum fasting leptin level could predict the development of central arterial stiffness of KT patients.
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Affiliation(s)
- J P Tsai
- Division of Nephrology, Buddhist Tzu Chi General Hospital, Dalin Branch, Chiayi, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | | | - M C Le
- School of Medicine, Tzu Chi University, Hualien, Taiwan; Department of Surgery, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Y C Chen
- Department of Surgery, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - G J Ho
- Department of Surgery, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - M H Shih
- Department of Nursing, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - B G Hsu
- School of Medicine, Tzu Chi University, Hualien, Taiwan; Division of Nephrology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan.
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16
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Nagy K, Nagaraju SP, Rhee CM, Mathe Z, Molnar MZ. Adipocytokines in renal transplant recipients. Clin Kidney J 2016; 9:359-73. [PMID: 27274819 PMCID: PMC4886901 DOI: 10.1093/ckj/sfv156] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/18/2015] [Indexed: 02/07/2023] Open
Abstract
In the last two decades, perceptions about the role of body fat have changed. Adipocytes modulate endocrine and immune homeostasis by synthesizing hundreds of hormones, known as adipocytokines. Many studies have been investigating the influences and effects of these adipocytokines and suggest that they are modulated by the nutritional and immunologic milieu. Kidney transplant recipients (KTRs) are a unique and relevant population in which the function of adipocytokines can be examined, given their altered nutritional and immune status and subsequent dysregulation of adipocytokine metabolism. In this review, we summarize the recent findings about four specific adipocytokines and their respective roles in KTRs. We decided to evaluate the most widely described adipocytokines, including leptin, adiponectin, visfatin and resistin. Increasing evidence suggests that these adipocytokines may lead to cardiovascular events and metabolic changes in the general population and may also increase mortality and graft loss rate in KTRs. In addition, we present findings on the interrelationship between serum adipocytokine levels and nutritional and immunologic status, and mechanisms by which adipocytokines modulate morbidity and outcomes in KTRs.
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Affiliation(s)
- Kristof Nagy
- Department of Transplantation and Surgery , Semmelweis University , Budapest , Hungary
| | | | - Connie M Rhee
- Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension , University of California Irvine , Orange, CA , USA
| | - Zoltan Mathe
- Department of Transplantation and Surgery , Semmelweis University , Budapest , Hungary
| | - Miklos Z Molnar
- Division of Nephrology, Department of Medicine , University of Tennessee Health Science Center , Memphis, TN , USA
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17
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Iwakura H, Dote K, Bando M, Koyama H, Hosoda K, Kangawa K, Nakao K. Establishment of Leptin-Responsive Cell Lines from Adult Mouse Hypothalamus. PLoS One 2016; 11:e0148639. [PMID: 26849804 PMCID: PMC4744015 DOI: 10.1371/journal.pone.0148639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 01/21/2016] [Indexed: 12/03/2022] Open
Abstract
Leptin resistance is considered to be the primary cause of obesity. However, the cause of leptin resistance remains incompletely understood, and there is currently no cure for the leptin-resistant state. In order to identify novel drug-target molecules that could overcome leptin resistance, it would be useful to develop in vitro assay systems for evaluating leptin resistance. In this study, we established immortalized adult mouse hypothalamus—derived cell lines, termed adult mouse hypothalamus (AMH) cells, by developing transgenic mice in which SV40 Tag was overexpressed in chromogranin A—positive cells in a tamoxifen-dependent manner. In order to obtain leptin-responsive clones, we selected clones based on the phosphorylation levels of STAT3 induced by leptin. The selected clones were fairly responsive to leptin in terms of STAT3, ERK, and Akt phosphorylation and induction of c-Fos mRNA induction. Pretreatment with leptin, insulin, and palmitate attenuated the c-Fos mRNA response to leptin, suggesting that certain aspects of leptin resistance might be reconstituted in this cellular model. These cell lines are useful tools for understanding the molecular nature of the signal disturbance in the leptin-resistant state and for identifying potential target molecules for drugs that relieve leptin resistance, although they have drawbacks including de-differentiated nature and lack of long-time stability.
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Affiliation(s)
- Hiroshi Iwakura
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
- * E-mail:
| | - Katsuko Dote
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mika Bando
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroyuki Koyama
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Diabetes and Clinical Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kiminori Hosoda
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Human Health Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Kangawa
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
- National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Kazuwa Nakao
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
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18
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Differential expression of hypothalamic, metabolic and inflammatory genes in response to short-term calorie restriction in juvenile obese- and lean-prone JCR rats. Nutr Diabetes 2015; 5:e178. [PMID: 26302065 PMCID: PMC4558559 DOI: 10.1038/nutd.2015.28] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/08/2015] [Accepted: 07/21/2015] [Indexed: 01/02/2023] Open
Abstract
Background: Childhood obesity is an important early predictor of adult obesity and associated comorbidities. Common forms of obesity are underpinned by both environmental and genetic factors. However, the rising prevalence of obesity in genetically stable populations strongly suggests that contemporary lifestyle is a premier factor to the disease. In pediatric population, the current treatment/prevention options for obesity are lifestyle interventions such as caloric restriction (CR) and increase physical activity. In obese individuals, CR improves many metabolic parameters in peripheral tissues. Little is known about the effect of CR on the hypothalamus. This study aimed to assess the effect of CR on hypothalamic metabolic gene expression of young obese- and lean-prone animals. Methods: Male juvenile JCR:LA-cp obese-prone rats were freely fed (Obese-FF) or pair fed (Obese-FR) to lean-prone, free-feeding animals (Lean-FF). A group of lean-prone rats (Lean-FR) were matched for relative average degree of CR to Obese-FR rats. Results: In free-feeding conditions, obese-prone rats consumed more energy than lean-prone rats (P<0.001) and showed greater increases in body weight, fat mass, plasma glucose, insulin and lipids (P<0.01). These metabolic differences were associated with alterations of feeding-related neuropeptides expression in the hypothalamus, as well as pro-inflammatory cytokines and oxidative stress markers. When submitted to the same degree of CR, the two genotypes responded differently; hypothalamic inflammatory and oxidative stress gene expression was improved in Obese-FR, while it was worsened in Lean-FR rats. Conclusions: We demonstrate in JCR rats that the metabolic and inflammatory response of the brain to CR is genotype dependent.
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19
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Taurine supplementation preserves hypothalamic leptin action in normal and protein-restricted mice fed on a high-fat diet. Amino Acids 2015; 47:2419-35. [DOI: 10.1007/s00726-015-2035-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 06/17/2015] [Indexed: 12/19/2022]
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20
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Dwarkasing JT, Boekschoten MV, Argilès JM, van Dijk M, Busquets S, Penna F, Toledo M, Laviano A, Witkamp RF, van Norren K. Differences in food intake of tumour-bearing cachectic mice are associated with hypothalamic serotonin signalling. J Cachexia Sarcopenia Muscle 2015; 6:84-94. [PMID: 26136415 PMCID: PMC4435100 DOI: 10.1002/jcsm.12008] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/11/2014] [Accepted: 10/29/2014] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Anorexia is a common symptom among cancer patients and contributes to malnutrition and strongly impinges on quality of life. Cancer-induced anorexia is thought to be caused by an inability of food intake-regulating systems in the hypothalamus to respond adequately to negative energy balance during tumour growth. Here, we show that this impaired response of food-intake control is likely to be mediated by altered serotonin signalling and by failure in post-transcriptional neuropeptide Y (NPY) regulation. METHODS Two tumour cachectic mouse models with different food intake behaviours were used: a C26-colon adenocarcinoma model with increased food intake and a Lewis lung carcinoma model with decreased food intake. This contrast in food intake behaviour between tumour-bearing (TB) mice in response to growth of the two different tumours was used to distinguish between processes involved in cachexia and mechanisms that might be important in food intake regulation. The hypothalamus was used for transcriptomics (affymetrix chips). RESULTS In both models, hypothalamic expression of orexigenic NPY was significantly higher compared with controls, suggesting that this change does not directly reflect food intake status but might be linked to negative energy balance in cachexia. Expression of genes involved in serotonin signalling showed to be different between C26-TB mice and Lewis lung carcinoma-TB mice and was inversely associated with food intake. In vitro, using hypothalamic cell lines, serotonin repressed neuronal hypothalamic NPY secretion while not affecting messenger NPY expression, suggesting that serotonin signalling can interfere with NPY synthesis, transport, or secretion. CONCLUSIONS Altered serotonin signalling is associated with changes in food intake behaviour in cachectic TB mice. Serotonins' inhibitory effect on food intake under cancer cachectic conditions is probably via affecting the NPY system. Therefore, serotonin regulation might be a therapeutic target to prevent the development of cancer-induced eating disorders.
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Affiliation(s)
- Jvalini T Dwarkasing
- Nutrition and Pharmacology Group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Mark V Boekschoten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Joseph M Argilès
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, University of Barcelona, Barcelona, Spain
| | | | - Silvia Busquets
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, University of Barcelona, Barcelona, Spain
| | - Fabio Penna
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, University of Barcelona, Barcelona, Spain
| | - Miriam Toledo
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, University of Barcelona, Barcelona, Spain
| | | | - R F Witkamp
- Nutrition and Pharmacology Group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Klaske van Norren
- Nutrition and Pharmacology Group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.,Nutricia Research, Utrecht, The Netherlands
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21
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Briffa JF, McAinch AJ, Romano T, Wlodek ME, Hryciw DH. Leptin in pregnancy and development: a contributor to adulthood disease? Am J Physiol Endocrinol Metab 2015; 308:E335-50. [PMID: 25516549 DOI: 10.1152/ajpendo.00312.2014] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Emerging research has highlighted the importance of leptin in fetal growth and development independent of its essential role in the maintenance of hunger and satiety through the modulation of neuropeptide Y and proopiomelanocortin neurons. Alterations in maternal-placental-fetal leptin exchange may modify the development of the fetus and contribute to the increased risk of developing disease in adulthood. In addition, leptin also plays an important role in reproductive functions, with plasma leptin concentrations rising in pregnant women, peaking during the third trimester. Elevated plasma leptin concentrations occur at the completion of organogenesis, and research in animal models has demonstrated that leptin is involved in the development and maturation of a number of organs, including the heart, brain, kidneys, and pancreas. Elevated maternal plasma leptin is associated with maternal obesity, and reduced fetal plasma leptin is correlated with intrauterine growth restriction. Alterations in plasma leptin during development may be associated with an increased risk of developing a number of adulthood diseases, including cardiovascular, metabolic, and renal diseases via altered fetal development and organogenesis. Importantly, research has shown that leptin antagonism after birth significantly reduces maturation of numerous organs. Conversely, restoration of the leptin deficiency after birth in growth-restricted animals restores the offspring's body weight and improves organogenesis. Therefore, leptin appears to play a major role in organogenesis, which may adversely affect the risk of developing a number of diseases in adulthood. Therefore, greater understanding of the role of leptin during development may assist in the prevention and treatment of a number of disease states that occur in adulthood.
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Affiliation(s)
- Jessica F Briffa
- Department of Physiology, University of Melbourne, Parkville, Australia
| | - Andrew J McAinch
- Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine, Victoria University, St. Albans, Australia; and
| | - Tania Romano
- Department of Human Biosciences, Latrobe University, Bundoora, Australia
| | - Mary E Wlodek
- Department of Physiology, University of Melbourne, Parkville, Australia
| | - Deanne H Hryciw
- Department of Physiology, University of Melbourne, Parkville, Australia;
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22
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Wellhauser L, Gojska NM, Belsham DD. Delineating the regulation of energy homeostasis using hypothalamic cell models. Front Neuroendocrinol 2015; 36:130-49. [PMID: 25223866 DOI: 10.1016/j.yfrne.2014.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 08/28/2014] [Accepted: 09/02/2014] [Indexed: 12/27/2022]
Abstract
Attesting to its intimate peripheral connections, hypothalamic neurons integrate nutritional and hormonal cues to effectively manage energy homeostasis according to the overall status of the system. Extensive progress in the identification of essential transcriptional and post-translational mechanisms regulating the controlled expression and actions of hypothalamic neuropeptides has been identified through the use of animal and cell models. This review will introduce the basic techniques of hypothalamic investigation both in vivo and in vitro and will briefly highlight the key advantages and challenges of their use. Further emphasis will be place on the use of immortalized models of hypothalamic neurons for in vitro study of feeding regulation, with a particular focus on cell lines proving themselves most fruitful in deciphering fundamental basics of NPY/AgRP, Proglucagon, and POMC neuropeptide function.
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Affiliation(s)
- Leigh Wellhauser
- Department of Physiology, University of Toronto, Toronto, Ontario M5G 1A8, Canada
| | - Nicole M Gojska
- Department of Physiology, University of Toronto, Toronto, Ontario M5G 1A8, Canada
| | - Denise D Belsham
- Departments of Physiology, Medicine and OB/GYN, University of Toronto, Toronto, Ontario M5G 1A8, Canada; Division of Cellular and Molecular Biology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario M5S 1A8, Canada.
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23
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Abstract
The mouse insulin I promoter (MIP) construct was developed to eliminate the promoter activity detected with the rat insulin II promoter in specific hypothalamic neurons that may have unintended effects on glucose and energy homeostasis in transgenic models. Thus, the specificity of this novel construct must be validated prior to the widespread availability of derived Cre models. Although limited validation efforts have indicated a lack of MIP activity within neuronal tissue, the global immunohistochemical methodology used may not be specific enough to rule out the possibility of specific populations of neurons with MIP activity. To investigate possible MIP activity within the hypothalamus, primary hypothalamic isolates from MIP-green fluorescent protein reporter mice were analyzed after fluorescent-activated cell sorting. Primary hypothalamic neurons isolated from the MIP-green fluorescent protein mice were immortalized. Characterization detected the presence of hypothalamic neuropeptide Y (NPY) and agouti-related peptide, involved in the control of energy homeostasis, as well as confirmed insulin responsiveness in the cell lines. Moreover, because insulin was demonstrated to differentially regulate NPY expression within these MIP neurons, the promoter construct may be active in multiple hypothalamic NPY/agouti-related peptide subpopulations with unique physiological functions. MIP transgenic animals may therefore face similar limitations seen previously with rat insulin II promoter-based models.
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Affiliation(s)
- Zi Chen Wang
- Departments of Physiology (Z.C.W., M.B.W., D.D.B.), Medicine (M.B.W., D.D.B.), and Obstetrics and Gynaecology (D.D.B.), University of Toronto, and Division of Cellular and Molecular Biology (M.B.W., D.D.B.), Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada M5S 1A8
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Briffa JF, McAinch AJ, Poronnik P, Hryciw DH. Adipokines as a link between obesity and chronic kidney disease. Am J Physiol Renal Physiol 2013; 305:F1629-36. [PMID: 24107418 DOI: 10.1152/ajprenal.00263.2013] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Adipocytes secrete a number of bioactive adipokines that activate a variety of cell signaling pathways in central and peripheral tissues. Obesity is associated with the altered production of many adipokines and is linked to a number of pathologies. As an increase in body weight is directly associated with an increased risk for developing chronic kidney disease (CKD), there is significant interest in the link between obesity and renal dysfunction. Altered levels of the adipokines leptin, adiponectin, resistin, and visfatin can decrease the glomerular filtration rate and increase albuminuria, which are pathophysiological changes typical of CKD. Specifically, exposure of the glomerulus to altered adipokine levels can increase its permeability, fuse the podocytes, and cause mesangial cell hypertrophy, all of which alter the glomerular filtration rate. In addition, the adipokines leptin and adiponectin can act on tubular networks. Thus, adipokines can act on multiple cell types in the development of renal pathophysiology. Importantly, most studies have been performed using in vitro models, with future studies in vivo required to further elucidate the specific roles that adipokines play in the development and progression of CKD.
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Affiliation(s)
- Jessica F Briffa
- Dept. of Physiology, The Univ. of Melbourne, Parkville, VIC 3010, Australia.
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25
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Purser MJ, Dalvi PS, Wang ZC, Belsham DD. The cytokine ciliary neurotrophic factor (CNTF) activates hypothalamic urocortin-expressing neurons both in vitro and in vivo. PLoS One 2013; 8:e61616. [PMID: 23626705 PMCID: PMC3633986 DOI: 10.1371/journal.pone.0061616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 03/12/2013] [Indexed: 12/11/2022] Open
Abstract
Ciliary neurotrophic factor (CNTF) induces neurogenesis, reduces feeding, and induces weight loss. However, the central mechanisms by which CNTF acts are vague. We employed the mHypoE-20/2 line that endogenously expresses the CNTF receptor to examine the direct effects of CNTF on mRNA levels of urocortin-1, urocortin-2, agouti-related peptide, brain-derived neurotrophic factor, and neurotensin. We found that treatment of 10 ng/ml CNTF significantly increased only urocortin-1 mRNA by 1.84-fold at 48 h. We then performed intracerebroventricular injections of 0.5 mg/mL CNTF into mice, and examined its effects on urocortin-1 neurons post-exposure. Through double-label immunohistochemistry using specific antibodies against c-Fos and urocortin-1, we showed that central CNTF administration significantly activated urocortin-1 neurons in specific areas of the hypothalamus. Taken together, our studies point to a potential role for CNTF in regulating hypothalamic urocortin-1-expressing neurons to mediate its recognized effects on energy homeostasis, neuronal proliferaton/survival, and/or neurogenesis.
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Affiliation(s)
- Matthew J. Purser
- Department of Physiology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Prasad S. Dalvi
- Department of Physiology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Zi C. Wang
- Department of Physiology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Denise D. Belsham
- Department of Physiology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
- Departments of Obstetrics, Gynaecology and Medicine, University of Toronto and Division of Cellular and Molecular Biology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
- * E-mail:
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26
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Dornelles CTL, Goldani HAS, Wilasco MIA, Maurer RL, Kieling CO, Porowski M, Ferreira CT, Santos JL, Vieira SMG, Silveira TR. Ghrelin, leptin and insulin in cirrhotic children and adolescents: relationship with cirrhosis severity and nutritional status. ACTA ACUST UNITED AC 2012; 180:26-32. [PMID: 23142314 DOI: 10.1016/j.regpep.2012.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 06/29/2012] [Accepted: 10/17/2012] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Ghrelin, leptin, and insulin concentrations are involved in the control of food intake and they seem to be associated with anorexia-cachexia in cirrhotic patients. The present study aimed to investigate the relationship between the nutritional status and fasting ghrelin, leptin and insulin concentrations in pediatric cirrhotic patients. METHODS Thirty-nine patients with cirrhosis and 39 healthy controls aged 0-15 years matched by sex and age were enrolled. Severity of liver disease was assessed by Child-Pugh classification, and Pediatric for End Stage Liver Disease (PELD) or Model for End-stage Liver Disease (MELD) scores. Blood samples were collected from patients and controls to assay total ghrelin, acyl ghrelin, leptin and insulin by using a commercial ELISA kit. Anthropometry parameters used were standard deviation score of height-for-age and triceps skinfold thickness-for-age ratio. A multiple linear regression analysis was used to determine the correlation between dependent and independent variables. RESULTS Acyl ghrelin was significantly lower in cirrhotic patients than in controls [142 (93-278) pg/mL vs 275 (208-481) pg/mL, P=0.001]. After multiple linear regression analysis, total ghrelin and acyl ghrelin showed an inverse correlation with age; acyl ghrelin was associated with the severity of cirrhosis and des-acyl ghrelin with PELD or MELD scores ≥15. Leptin was positively correlated with gender and anthropometric parameters. Insulin was not associated with any variable. CONCLUSION Low acyl ghrelin and high des-acyl ghrelin concentrations were associated with cirrhosis severity, whereas low leptin concentration was associated with undernourishment in children and adolescents with cirrhosis.
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Affiliation(s)
- Cristina T L Dornelles
- Experimental Laboratory of Gastroenterology and Hepatology, Centro de Pesquisas do Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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27
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Dhillon SS, Gingerich S, Virtanen C, Belsham DD. Gene array analysis of embryonic- versus adult-derived hypothalamic NPY-expressing cell lines. Mol Cell Endocrinol 2012; 358:116-26. [PMID: 22476083 DOI: 10.1016/j.mce.2012.03.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 01/24/2012] [Accepted: 03/20/2012] [Indexed: 10/28/2022]
Abstract
Few studies have utilized microarray analysis to understand the genome wide changes involved in the development of the hypothalamus despite its overall importance to basic physiology. Gene expression profiling of immortalized, clonal hypothalamic neurons, embryonic-derived mHypoE-46 and adult-derived mHypoA-2/12, reveals that the expression of 1225 probes was significantly changed between the two neuronal models. Further comparison of the gene expression profiles identified two categories of genes that were confirmed with qRT-PCR: (i) genes implicated in the Wnt signaling pathway; and (ii) transcription factors previously implicated in the development of the central nervous system. Yet, functional analysis of the two cell lines, including hormonal responses and secretion, indicate that they are comparable despite their developmental origin. This study provides a comprehensive analysis of embryonic- and adult-derived hypothalamic neuronal cell models that both express neuropeptide Y, and identifies novel genes as candidates for mediating the development of specific hypothalamic neurons.
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Affiliation(s)
- Sandeep S Dhillon
- Department of Physiology, University Health Network, Toronto, ON, Canada M5S 1A8
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28
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Ghrelin, leptin and insulin in healthy children: Relationship with anthropometry, gender, and age distribution. ACTA ACUST UNITED AC 2012; 173:21-6. [DOI: 10.1016/j.regpep.2011.08.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 08/17/2011] [Accepted: 08/23/2011] [Indexed: 01/12/2023]
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29
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Dhillon SS, McFadden SA, Chalmers JA, Centeno ML, Kim GL, Belsham DD. Cellular leptin resistance impairs the leptin-mediated suppression of neuropeptide Y secretion in hypothalamic neurons. Endocrinology 2011; 152:4138-47. [PMID: 21914774 DOI: 10.1210/en.2011-0178] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Evidence shows that neuropeptide Y (NPY) neurons are involved in mediating the anorexigenic action of leptin via neuronal circuits in the hypothalamus. However, studies have produced limited data on the cellular processes involved and whether hypothalamic NPY neurons are susceptible to cellular leptin resistance. To investigate the direct regulation of NPY secretion by leptin, we used novel NPY-synthesizing, immortalized mHypoA-NPY/green fluorescent protein and mHypoA-59 hypothalamic cell lines derived from adult hypothalamic primary cultures. We report that leptin treatment significantly suppressed NPY secretion in the cells by approximately 20%. We found a decrease in c-fos expression upon leptin exposure, indicating deactivation or hyperpolarization of the neurons. Protein analysis indicated that leptin inhibits AMP-activated protein kinase (AMPK) activity and activates acetyl-coenzyme A carboxylase in NPY neurons, supporting the hypothesis of an AMPK-dependent mechanism. Inhibiting both AMPK with Compound C or phosphatidylinositol 3 kinase (PI3K) with 2-(4-morpholinyl)-8-phenyl-1(4H)-1-benzopyran-4-one hydrochloride prevented the leptin-mediated decrease in NPY secretion, indicating both AMPK- and PI3K-mediated mechanisms. Further, NPY secretion was stimulated by 30% by the AMPK activator, aminoimidazole carboxamide ribonucleotide. Importantly, prolonged leptin exposure in the mHypoA-NPY/green fluorescent protein cells prevented leptin-induced changes in AMPK phosphorylation and suppression of NPY secretion, indicating that NPY neurons are susceptible to leptin resistance. Our studies indicate that AMPK and PI3K pathways are involved in leptin action in NPY neurons and that leptin resistance blocks the feedback response likely required to maintain energy homeostasis.
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Affiliation(s)
- Sandeep S Dhillon
- Department of Physiology, University of Toronto, and Toronto General Hospital Research Institute, University Health Network, Medical Sciences Building 3344, 1 Kings College Circle, Toronto, Ontario, Canada M5S 1A8
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