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Massa MG, Scott RL, Cara AL, Cortes LR, Vander PB, Sandoval NP, Park JW, Ali SL, Velez LM, Wang HB, Ati SS, Tesfaye B, Reue K, van Veen JE, Seldin MM, Correa SM. Feeding neurons integrate metabolic and reproductive states in mice. iScience 2023; 26:107918. [PMID: 37817932 PMCID: PMC10561062 DOI: 10.1016/j.isci.2023.107918] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 07/27/2023] [Accepted: 09/12/2023] [Indexed: 10/12/2023] Open
Abstract
Balance between metabolic and reproductive processes is important for survival, particularly in mammals that gestate their young. How the nervous system coordinates this balance is an active area of study. Herein, we demonstrate that somatostatin (SST) neurons of the tuberal hypothalamus alter feeding in a manner sensitive to metabolic and reproductive states in mice. Whereas chemogenetic activation of SST neurons increased food intake across sexes, ablation decreased food intake only in female mice during proestrus. This ablation effect was only apparent in animals with low body mass. Fat transplantation and bioinformatics analysis of SST neuronal transcriptomes revealed white adipose as a key modulator of these effects. These studies indicate that SST hypothalamic neurons integrate metabolic and reproductive cues by responding to varying levels of circulating estrogens to modulate feeding differentially based on energy stores. Thus, gonadal steroid modulation of neuronal circuits can be context dependent and gated by metabolic status.
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Affiliation(s)
- Megan G. Massa
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
- Neuroscience Interdepartmental Doctoral Program, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Rachel L. Scott
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Alexandra L. Cara
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Laura R. Cortes
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Paul B. Vander
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Norma P. Sandoval
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Jae W. Park
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Sahara L. Ali
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Leandro M. Velez
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Huei-Bin Wang
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Shomik S. Ati
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Bethlehem Tesfaye
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Karen Reue
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - J. Edward van Veen
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
| | - Marcus M. Seldin
- Department of Biological Chemistry, School of Medicine, University of California – Irvine, Irvine, CA 92697, USA
| | - Stephanie M. Correa
- Department of Integrative Biology and Physiology, University of California – Los Angeles, Los Angeles, CA 90095, USA
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Huang C, Rosencrans RF, Bugescu R, Vieira CP, Hu P, Adu-Agyeiwaah Y, Gamble KL, Longhini ALF, Fuller PM, Leinninger GM, Grant MB. Depleting hypothalamic somatostatinergic neurons recapitulates diabetic phenotypes in mouse brain, bone marrow, adipose and retina. Diabetologia 2021; 64:2575-2588. [PMID: 34430981 PMCID: PMC9004546 DOI: 10.1007/s00125-021-05549-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/11/2021] [Indexed: 12/01/2022]
Abstract
AIMS/HYPOTHESIS Hypothalamic inflammation and sympathetic nervous system hyperactivity are hallmark features of the metabolic syndrome and type 2 diabetes. Hypothalamic inflammation may aggravate metabolic and immunological pathologies due to extensive sympathetic activation of peripheral tissues. Loss of somatostatinergic (SST) neurons may contribute to enhanced hypothalamic inflammation. METHODS The present data show that leptin receptor-deficient (db/db) mice exhibit reduced hypothalamic SST neurons, particularly in the periventricular nucleus. We model this finding, using adeno-associated virus delivery of diphtheria toxin subunit A (DTA) driven by an SST-cre system to deplete these neurons in Sstcre/gfp mice (SST-DTA). RESULTS SST-DTA mice exhibit enhanced hypothalamic c-Fos expression and brain inflammation as demonstrated by microglial and astrocytic activation. Bone marrow from SST-DTA mice undergoes skewed haematopoiesis, generating excess granulocyte-monocyte progenitors and increased proinflammatory (C-C chemokine receptor type 2; CCR2hi) monocytes. SST-DTA mice exhibited a 'diabetic retinopathy-like' phenotype: reduced visual function by optokinetic response (0.4 vs 0.25 cycles/degree; SST-DTA vs control mice); delayed electroretinogram oscillatory potentials; and increased percentages of retinal monocytes. Finally, mesenteric visceral adipose tissue from SST-DTA mice was resistant to catecholamine-induced lipolysis, displaying 50% reduction in isoprenaline (isoproterenol)-induced lipolysis compared with control littermates. Importantly, hyperglycaemia was not observed in SST-DTA mice. CONCLUSIONS/INTERPRETATION The isolated reduction in hypothalamic SST neurons was able to recapitulate several hallmark features of type 2 diabetes in disease-relevant tissues.
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Affiliation(s)
- Chao Huang
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Robert F Rosencrans
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Raluca Bugescu
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Cristiano P Vieira
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ping Hu
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yvonne Adu-Agyeiwaah
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Karen L Gamble
- Department of Psychiatry and Neurobehavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ana Leda F Longhini
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Patrick M Fuller
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Gina M Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Maria B Grant
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, USA.
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Protective Role of Somatostatin in Sepsis-Induced Intestinal Barrier Dysfunction through Inhibiting the Activation of NF- κB Pathway. Gastroenterol Res Pract 2020; 2020:2549486. [PMID: 33376482 PMCID: PMC7746440 DOI: 10.1155/2020/2549486] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 11/10/2020] [Accepted: 11/16/2020] [Indexed: 12/14/2022] Open
Abstract
Somatostatin (SST) has a protective role in intestinal injury, inflammatory response, and intestinal mucosal barrier in rats with acute pancreatitis. However, its function in sepsis-induced intestinal barrier dysfunction remains largely unknown. A mouse sepsis model was constructed, and SST was injected into the tail vein. Then, hematoxylin and eosin staining (HE) was used to detect the intestinal barrier dysfunction. Enzyme-linked immunosorbent assay was used to detect the level of tumor necrosis factor α- (TNF-) α, interleukin- (IL-) 6, and interleukin- (IL-) 10 in the ileum. Expressions of tight junction proteins, zonula occludens- (ZO-) 1 and Claudin-1, and NF-κB p65 in the ileum were detected using western blot and immunohistochemistry as needed. Furthermore, JSH-23 as an inhibitor of the NF-κB pathway was injected into sepsis mice with SST or not. Mice with sepsis showed an obvious intestinal barrier dysfunction with decreasing specific somatostatin receptor subtype (SSTRs), and increasing TNF-α, IL-6, and IL-10 in the ileum. SST could relieve the injury, the decrease of SSTRs, and the increase of TNF-α and IL-6 induced by sepsis and also further enhanced the expression of IL-10. Further analysis showed that ZO-1 and Claudin-1 were reduced in the ileum by sepsis but enhanced by SST. NF-κB p65 was promoted in the ileum by sepsis but inhibited by SST. Further experiments confirmed that NF-κB inhibitor JSH-23 could repair the intestinal barrier dysfunction and enhance the protective effect of SST on the intestinal barrier. SST, with a protective effect on intestinal barrier dysfunction through suppression of NF-κB, could be a potential therapeutic drug for sepsis-induced intestinal barrier dysfunction.
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Characterization of Neurons Expressing the Novel Analgesic Drug Target Somatostatin Receptor 4 in Mouse and Human Brains. Int J Mol Sci 2020; 21:ijms21207788. [PMID: 33096776 PMCID: PMC7589422 DOI: 10.3390/ijms21207788] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/08/2020] [Accepted: 10/16/2020] [Indexed: 12/13/2022] Open
Abstract
Somatostatin is an important mood and pain-regulating neuropeptide, which exerts analgesic, anti-inflammatory, and antidepressant effects via its Gi protein-coupled receptor subtype 4 (SST4) without endocrine actions. SST4 is suggested to be a unique novel drug target for chronic neuropathic pain, and depression, as a common comorbidity. However, its neuronal expression and cellular mechanism are poorly understood. Therefore, our goals were (i) to elucidate the expression pattern of Sstr4/SSTR4 mRNA, (ii) to characterize neurochemically, and (iii) electrophysiologically the Sstr4/SSTR4-expressing neuronal populations in the mouse and human brains. Here, we describe SST4 expression pattern in the nuclei of the mouse nociceptive and anti-nociceptive pathways as well as in human brain regions, and provide neurochemical and electrophysiological characterization of the SST4-expressing neurons. Intense or moderate SST4 expression was demonstrated predominantly in glutamatergic neurons in the major components of the pain matrix mostly also involved in mood regulation. The SST4 agonist J-2156 significantly decreased the firing rate of layer V pyramidal neurons by augmenting the depolarization-activated, non-inactivating K+ current (M-current) leading to remarkable inhibition. These are the first translational results explaining the mechanisms of action of SST4 agonists as novel analgesic and antidepressant candidates.
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Ketchesin KD, Huang NS, Seasholtz AF. Cell Type-Specific Expression of Corticotropin-Releasing Hormone-Binding Protein in GABAergic Interneurons in the Prefrontal Cortex. Front Neuroanat 2017; 11:90. [PMID: 29066956 PMCID: PMC5641307 DOI: 10.3389/fnana.2017.00090] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 09/25/2017] [Indexed: 01/31/2023] Open
Abstract
Corticotropin-releasing hormone-binding protein (CRH-BP) is a secreted glycoprotein that binds CRH with very high affinity to modulate CRH receptor activity. CRH-BP is widely expressed throughout the brain, with particularly high expression in regions such as the amygdala, hippocampus, ventral tegmental area and prefrontal cortex (PFC). Recent studies suggest a role for CRH-BP in stress-related psychiatric disorders and addiction, with the PFC being a potential site of interest. However, the molecular phenotype of CRH-BP-expressing cells in this region has not been well-characterized. In the current study, we sought to determine the cell type-specific expression of CRH-BP in the PFC to begin to define the neural circuits in which this key regulator is acting. To characterize the expression of CRH-BP in excitatory and/or inhibitory neurons, we utilized dual in situ hybridization to examine the cellular colocalization of CRH-BP mRNA with vesicular glutamate transporter (VGLUT) or glutamic acid decarboxylase (GAD) mRNA in different subregions of the PFC. We show that CRH-BP is expressed predominantly in GABAergic interneurons of the PFC, as revealed by the high degree of colocalization (>85%) between CRH-BP and GAD. To further characterize the expression of CRH-BP in this heterogenous group of inhibitory neurons, we examined the colocalization of CRH-BP with various molecular markers of GABAergic interneurons, including parvalbumin (PV), somatostatin (SST), vasoactive intestinal peptide (VIP) and cholecystokinin (CCK). We demonstrate that CRH-BP is colocalized predominantly with SST in the PFC, with lower levels of colocalization in PV- and CCK-expressing neurons. Our results provide a more comprehensive characterization of the cell type-specific expression of CRH-BP and begin to define its potential role within circuits of the PFC. These results will serve as the basis for future in vivo studies to manipulate CRH-BP in a cell type-specific manner to better understand its role in stress-related psychiatric disorders, including anxiety, depression and addiction.
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Affiliation(s)
- Kyle D Ketchesin
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States.,Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States
| | - Nicholas S Huang
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, United States
| | - Audrey F Seasholtz
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States.,Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States.,Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, United States
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Somatostatin, neuronal vulnerability and behavioral emotionality. Mol Psychiatry 2015; 20:377-87. [PMID: 25600109 PMCID: PMC4355106 DOI: 10.1038/mp.2014.184] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/13/2014] [Accepted: 11/17/2014] [Indexed: 12/16/2022]
Abstract
Somatostatin (SST) deficits are common pathological features in depression and other neurological disorders with mood disturbances, but little is known about the contribution of SST deficits to mood symptoms or causes of these deficits. Here we show that mice lacking SST (Sst(KO)) exhibit elevated behavioral emotionality, high basal plasma corticosterone and reduced gene expression of Bdnf, Cortistatin and Gad67, together recapitulating behavioral, neuroendocrine and molecular features of human depression. Studies in Sst(KO) and heterozygous (Sst(HZ)) mice show that elevated corticosterone is not sufficient to reproduce the behavioral phenotype, suggesting a putative role for Sst cell-specific molecular changes. Using laser capture microdissection, we show that cortical SST-positive interneurons display significantly greater transcriptome deregulations after chronic stress compared with pyramidal neurons. Protein translation through eukaryotic initiation factor 2 (EIF2) signaling, a pathway previously implicated in neurodegenerative diseases, was most affected and suppressed in stress-exposed SST neurons. We then show that activating EIF2 signaling through EIF2 kinase inhibition mitigated stress-induced behavioral emotionality in mice. Taken together, our data suggest that (1) low SST has a causal role in mood-related phenotypes, (2) deregulated EIF2-mediated protein translation may represent a mechanism for vulnerability of SST neurons and (3) that global EIF2 signaling has antidepressant/anxiolytic potential.
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Reubi JC, Schonbrunn A. Illuminating somatostatin analog action at neuroendocrine tumor receptors. Trends Pharmacol Sci 2013; 34:676-88. [PMID: 24183675 DOI: 10.1016/j.tips.2013.10.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/26/2013] [Accepted: 10/03/2013] [Indexed: 02/08/2023]
Abstract
Somatostatin analogs for the diagnosis and therapy of neuroendocrine tumors (NETs) have been used in clinical applications for more than two decades. Five somatostatin receptor subtypes have been identified and molecular mechanisms of somatostatin receptor signaling and regulation have been elucidated. These advances increased understanding of the biological role of each somatostatin receptor subtype, their distribution in NETs, as well as agonist-specific regulation of receptor signaling, internalization, and phosphorylation, particularly for the sst2 receptor subtype, which is the primary target of current somatostatin analog therapy for NETs. Various hypotheses exist to explain differences in patient responsiveness to somatostatin analog inhibition of tumor secretion and growth as well as differences in the development of tumor resistance to therapy. In addition, we now have a better understanding of the action of both first generation (octreotide, lanreotide, Octreoscan) and second generation (pasireotide) FDA-approved somatostatin analogs, including the biased agonistic character of some agonists. The increased understanding of somatostatin receptor pharmacology provides new opportunities to design more sophisticated assays to aid the future development of somatostatin analogs with increased efficacy.
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Affiliation(s)
- Jean Claude Reubi
- Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Berne, Switzerland.
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The functional state of hormone-sensitive adenylyl cyclase signaling system in diabetes mellitus. JOURNAL OF SIGNAL TRANSDUCTION 2013; 2013:594213. [PMID: 24191197 PMCID: PMC3804439 DOI: 10.1155/2013/594213] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 09/05/2013] [Indexed: 12/18/2022]
Abstract
Diabetes mellitus (DM) induces a large number of diseases of the nervous, cardiovascular, and some other systems of the organism. One of the main causes of the diseases is the changes in the functional activity of hormonal signaling systems which lead to the alterations and abnormalities of the cellular processes and contribute to triggering and developing many DM complications. The key role in the control of physiological and biochemical processes belongs to the adenylyl cyclase (AC) signaling system, sensitive to biogenic amines and polypeptide hormones. The review is devoted to the changes in the GPCR-G protein-AC system in the brain, heart, skeletal muscles, liver, and the adipose tissue in experimental and human DM of the types 1 and 2 and also to the role of the changes in AC signaling in the pathogenesis and etiology of DM and its complications. It is shown that the changes of the functional state of hormone-sensitive AC system are dependent to a large extent on the type and duration of DM and in experimental DM on the model of the disease. The degree of alterations and abnormalities of AC signaling pathways correlates very well with the severity of DM and its complications.
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