1
|
Yuan XC, Tao YX. Ligands for Melanocortin Receptors: Beyond Melanocyte-Stimulating Hormones and Adrenocorticotropin. Biomolecules 2022; 12:biom12101407. [PMID: 36291616 PMCID: PMC9599618 DOI: 10.3390/biom12101407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
The discovery of melanocortins in 1916 has resulted in more than 100 years of research focused on these peptides. Extensive studies have elucidated well-established functions of melanocortins mediated by cell surface receptors, including MSHR (melanocyte-stimulating hormone receptor) and ACTHR (adrenocorticotropin receptor). Subsequently, three additional melanocortin receptors (MCRs) were identified. Among these five MCRs, MC3R and MC4R are expressed primarily in the central nervous system, and are therefore referred to as the neural MCRs. Since the central melanocortin system plays important roles in regulating energy homeostasis, targeting neural MCRs is emerging as a therapeutic approach for treating metabolic conditions such as obesity and cachexia. Early efforts modifying endogenous ligands resulted in the development of many potent and selective ligands. This review focuses on the ligands for neural MCRs, including classical ligands (MSH and agouti-related peptide), nonclassical ligands (lipocalin 2, β-defensin, small molecules, and pharmacoperones), and clinically approved ligands (ACTH, setmelanotide, bremelanotide, and several repurposed drugs).
Collapse
Affiliation(s)
- Xiao-Chen Yuan
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230061, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
- Correspondence:
| |
Collapse
|
2
|
Flores-Bastías O, Gómez GI, Orellana JA, Karahanian E. Activation of Melanocortin-4 Receptor by a Synthetic Agonist Inhibits Ethanolinduced Neuroinflammation in Rats. Curr Pharm Des 2020; 25:4799-4805. [PMID: 31840601 DOI: 10.2174/1381612825666191216145153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 12/10/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND High ethanol intake induces a neuroinflammatory response resulting in the subsequent maintenance of chronic alcohol consumption. The melanocortin system plays a pivotal role in the modulation of alcohol consumption. Interestingly, it has been shown that the activation of melanocortin-4 receptor (MC4R) in the brain decreases the neuroinflammatory response in models of brain damage other than alcohol consumption, such as LPS-induced neuroinflammation, cerebral ischemia, glutamate excitotoxicity, and spinal cord injury. OBJECTIVES In this work, we aimed to study whether MC4R activation by a synthetic MC4R-agonist peptide prevents ethanol-induced neuroinflammation, and if alcohol consumption produces changes in MC4R expression in the hippocampus and hypothalamus. METHODS Ethanol-preferring Sprague Dawley rats were selected offering access to 20% ethanol on alternate days for 4 weeks (intermittent access protocol). After this time, animals were i.p. administered an MC4R agonist peptide in the last 2 days of the protocol. Then, the expression of the proinflammatory cytokines interleukin 6 (IL-6), interleukin 1-beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) were measured in the hippocampus, hypothalamus and prefrontal cortex. It was also evaluated if ethanol intake produces alterations in the expression of MC4R in the hippocampus and the hypothalamus. RESULTS Alcohol consumption increased the expression of MC4R in the hippocampus and the hypothalamus. The administration of the MC4R agonist reduced IL-6, IL-1β and TNF-α levels in hippocampus, hypothalamus and prefrontal cortex, to those observed in control rats that did not drink alcohol. CONCLUSION High ethanol consumption produces an increase in the expression of MC4R in the hippocampus and hypothalamus. The administration of a synthetic MC4R-agonist peptide prevents neuroinflammation induced by alcohol consumption in the hippocampus, hypothalamus, and prefrontal cortex. These results could explain the effect of α-MSH and other synthetic MC4R agonists in decreasing alcohol intake through the reduction of the ethanol-induced inflammatory response in the brain.
Collapse
Affiliation(s)
- Osvaldo Flores-Bastías
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Chile.,Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Santiago, Chile
| | - Gonzalo I Gómez
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Chile.,Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Santiago, Chile
| | - Juan A Orellana
- Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Santiago, Chile.,Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo Karahanian
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Chile.,Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Santiago, Chile
| |
Collapse
|
3
|
Hu K, Stewart AJ, Yuen KY, Hinrichsen S, Dryburgh EL, Bertin FR. The effect of freeze-thaw cycles on determination of immunoreactive plasma adrenocorticotrophic hormone concentrations in horses. J Vet Intern Med 2020; 34:1350-1356. [PMID: 32255541 PMCID: PMC7255672 DOI: 10.1111/jvim.15771] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 03/16/2020] [Indexed: 11/28/2022] Open
Abstract
Background Determination of plasma adrenocotrophic hormone (ACTH) concentration (endogenous or thyrotropin‐releasing hormone [TRH] stimulation test) is the most commonly used diagnostic test for pituitary pars intermedia dysfunction (PPID) in horses. Because ACTH is unstable, samples often are frozen to be shipped to laboratories or to allow for batch analysis of research samples. However, the effect of multiple freeze‐thaw cycles on equine ACTH is unknown. Objective To determine the effects of multiple freeze‐thaw cycles on immunoreactive ACTH concentration. Animals Twenty‐eight horses ranging from 10 to 27 years of age were used. Methods Prospective study. Horses were divided into 4 groups: group 1, PPID‐negative, without TRH stimulation; group 2, PPID‐negative, with TRH stimulation; group 3, PPID‐positive, without TRH stimulation; and group 4, PPID‐positive, with TRH stimulation. Whole blood was collected from each horse at baseline or 30 minutes after TRH stimulation. Immunoreactive plasma ACTH concentration was determined using a chemiluminescence assay. Plasma samples then were frozen at −80°C >24 hours, thawed at 4°C and reanalyzed for 5 freeze‐thaw cycles. Changes in plasma ACTH concentration were analyzed using a linear mixed‐effect model. Results Significant effects of freeze‐thaw cycles (P = .001) and PPID status (P = .04) on plasma ACTH concentration were observed, but no significant effect of TRH stimulation was identified. Conclusions and Clinical Importance The plasma ACTH concentration is altered by freeze‐thaw cycles, and the effect is observed sooner in horses with PPID. To diagnose PPID, multiple freeze‐thaw cycles should be avoided when measuring plasma ACTH concentration.
Collapse
Affiliation(s)
- Ke Hu
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - Allison J Stewart
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - Ka Y Yuen
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - Sophia Hinrichsen
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | | | - François-René Bertin
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| |
Collapse
|
4
|
Lisak RP, Nedelkoska L, Benjamins JA. Sigma-1 receptor agonists as potential protective therapies in multiple sclerosis. J Neuroimmunol 2020; 342:577188. [PMID: 32179326 DOI: 10.1016/j.jneuroim.2020.577188] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 01/17/2020] [Accepted: 02/07/2020] [Indexed: 01/25/2023]
Abstract
The sigma-1 receptor (σ-1R) is an endoplasmic reticulum (ER) chaperone upregulated during ER stress, and regulates calcium homeostasis. Agonists of σ-1R are neuroprotective. ANAVEX2-73, a new σ-1R agonist, is undergoing several clinical trials. We show that ANAVEX2-73 protects oligodendroglia (OL) and oligodendroglial precursors (OPC) from apoptosis, excitotoxicity, reactive oxygen species (ROS) and quinolinic acid (QA), associated with inflammation. ANAVEX2-73 stimulates OPC proliferation, but does not alter early maturation to OL. We previously reported that dextromethorphan (DM), another σ-1R agonist with a different structure, had similar effects. We now show that both DM and ANAVEX2-73 protect neurons from the four cytotoxic agents.
Collapse
Affiliation(s)
- Robert P Lisak
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA; Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, USA.
| | - Liljana Nedelkoska
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
| | - Joyce A Benjamins
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA; Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI, USA.
| |
Collapse
|
5
|
Flores-Bastías O, Adriasola-Carrasco A, Karahanian E. Activation of Melanocortin-4 Receptor Inhibits Both Neuroinflammation Induced by Early Exposure to Ethanol and Subsequent Voluntary Alcohol Intake in Adulthood in Animal Models: Is BDNF the Key Mediator? Front Cell Neurosci 2020; 14:5. [PMID: 32063838 PMCID: PMC6997842 DOI: 10.3389/fncel.2020.00005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 01/10/2020] [Indexed: 12/31/2022] Open
Abstract
The concept that neuroinflammation induced by excessive alcohol intake in adolescence triggers brain mechanisms that perpetuate consumption has strengthened in recent years. The melanocortin system, composed of the melanocortin 4 receptor (MC4R) and its ligand α-melanocyte-stimulating hormone (α-MSH), has been implicated both in modulation of alcohol consumption and in ethanol-induced neuroinflammation decrease. Chronic alcohol consumption in adolescent rats causes a decrease in an α-MSH release by the hypothalamus, while the administration of synthetic agonists of MC4R causes a decrease in neuroinflammation and a decrease in voluntary alcohol consumption. However, the mechanism that connects the activation of MC4R with the decrease of both neuroinflammation and voluntary alcohol consumption has not been elucidated. Brain-derived neurotrophic factor (BDNF) has been implicated in alcohol drinking motivation, dependence and withdrawal, and its levels are reduced in alcoholics. Deficiencies in BDNF levels increased ethanol self-administration in rats. Further, BDNF triggers important anti-inflammatory effects in the brain, and this could be one of the mechanisms by which BDNF reduces chronic alcohol intake. Interestingly, MC4R signaling induces BDNF expression through the activation of the cAMP-responsive element-binding protein (CREB). We hypothesize that ethanol exposure during adolescence decreases the expression of α-MSH and hence MC4R signaling in the hippocampus, leading to a lower BDNF activity that causes dramatic changes in the brain (e.g., neuroinflammation and decreased neurogenesis) that predispose to maintain alcohol abuse until adulthood. The activation of MC4R either by α-MSH or by synthetic agonist peptides can induce the expression of BDNF, which would trigger several processes that lead to lower alcohol consumption.
Collapse
Affiliation(s)
- Osvaldo Flores-Bastías
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile.,Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Universidad Autónoma de Chile, Santiago, Chile
| | - Alfredo Adriasola-Carrasco
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| | - Eduardo Karahanian
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile.,Research Center for the Study of Alcohol Drinking Behavior in Adolescents, Universidad Autónoma de Chile, Santiago, Chile
| |
Collapse
|
6
|
Wang W, Guo DY, Lin YJ, Tao YX. Melanocortin Regulation of Inflammation. Front Endocrinol (Lausanne) 2019; 10:683. [PMID: 31649620 PMCID: PMC6794349 DOI: 10.3389/fendo.2019.00683] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/19/2019] [Indexed: 12/18/2022] Open
Abstract
Adrenocorticotropic hormone (ACTH), and α-, β-, and γ-melanocyte-stimulating hormones (α-, β-, γ-MSH), collectively known as melanocortins, together with their receptors (melanocortin receptors), are components of an ancient modulatory system. The clinical use of ACTH in the treatment of rheumatoid arthritis started in 1949, originally thought that the anti-inflammatory action was through hypothalamus-pituitary-adrenal axis and glucocorticoid-dependent. Subsequent decades have witnessed extensive attempts in unraveling the physiology and pharmacology of the melanocortin system. It is now known that ACTH, together with α-, β-, and γ-MSHs, also possess glucocorticoid-independent anti-inflammatory and immunomodulatory effects by activating the melanocortin receptors expressed in the brain or peripheral immune cells. This review will briefly introduce the melanocortin system and highlight the action of melanocortins in the regulation of immune functions from in vitro, in vivo, preclinical, and clinical studies. The potential therapeutic use of melanocortins are also summarized.
Collapse
Affiliation(s)
- Wei Wang
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
| | - Dong-Yu Guo
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
- *Correspondence: Dong-Yu Guo
| | - Yue-Jun Lin
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
- Ya-Xiong Tao
| |
Collapse
|
7
|
Chen S, Zhao L, Sherchan P, Ding Y, Yu J, Nowrangi D, Tang J, Xia Y, Zhang JH. Activation of melanocortin receptor 4 with RO27-3225 attenuates neuroinflammation through AMPK/JNK/p38 MAPK pathway after intracerebral hemorrhage in mice. J Neuroinflammation 2018; 15:106. [PMID: 29642894 PMCID: PMC5896146 DOI: 10.1186/s12974-018-1140-6] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 03/27/2018] [Indexed: 12/25/2022] Open
Abstract
Background Neuroinflammation plays an important role in the pathogenesis of intracerebral hemorrhage (ICH)-induced secondary brain injury. Activation of melanocortin receptor 4 (MC4R) has been shown to elicit anti-inflammatory effects in many diseases. The objective of this study was to explore the role of MC4R activation on neuroinflammation in a mouse ICH model and to investigate the contribution of adenosine monophosphate-activated protein kinase (AMPK)/c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (p38 MAPK) pathway in MC4R-mediated protection. Methods Adult male CD1 mice (n = 189) were subjected to intrastriatal injection of bacterial collagenase or sham surgery. The selective MC4R agonist RO27-3225 was administered by intraperitoneal injection at 1 h after collagenase injection. The specific MC4R antagonist HS024 and selective AMPK inhibitor dorsomorphin were administered prior to RO27-3225 treatment to elucidate potential mechanism. Short- and long-term neurobehavioral assessments, brain water content, immunofluorescence staining, and western blot were performed. Results The expression of MC4R and p-AMPK increased after ICH with a peak at 24 h. MC4R was expressed by microglia, neurons, and astrocytes. Activation of MC4R with RO27-3225 improved the neurobehavioral functions, decreased brain edema, and suppressed microglia/macrophage activation and neutrophil infiltration after ICH. RO27-3225 administration increased the expression of MC4R and p-AMPK while decreasing p-JNK, p-p38 MAPK, TNF-α, and IL-1β expression, which was reversed with inhibition of MC4R and AMPK. Conclusions Our study demonstrated that activation of MC4R with RO27-3225 attenuated neuroinflammation through AMPK-dependent inhibition of JNK and p38 MAPK signaling pathway, thereby reducing brain edema and improving neurobehavioral functions after experimental ICH in mice. Therefore, the activation of MC4R with RO27-3225 may be a potential therapeutic approach for ICH management. Electronic supplementary material The online version of this article (10.1186/s12974-018-1140-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Shengpan Chen
- Department of Neurosurgery, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou, 570208, China.,Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, USA
| | - Lianhua Zhao
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, USA.,Department of Neurology, Tianjin TEDA Hospital, Tianjin, 300457, China
| | - Prativa Sherchan
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, USA
| | - Yan Ding
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, USA
| | - Jing Yu
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, USA
| | - Derek Nowrangi
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, USA
| | - Jiping Tang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, USA
| | - Ying Xia
- Department of Neurosurgery, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou, 570208, China.
| | - John H Zhang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, USA. .,Department of Neurosurgery and Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA, 92354, USA.
| |
Collapse
|
8
|
Flores-Bastías O, Karahanian E. Neuroinflammation produced by heavy alcohol intake is due to loops of interactions between Toll-like 4 and TNF receptors, peroxisome proliferator-activated receptors and the central melanocortin system: A novel hypothesis and new therapeutic avenues. Neuropharmacology 2018; 128:401-407. [DOI: 10.1016/j.neuropharm.2017.11.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/26/2017] [Accepted: 11/03/2017] [Indexed: 02/06/2023]
|
9
|
Gao Y, Vidal-Itriago A, Milanova I, Korpel NL, Kalsbeek MJ, Tom RZ, Kalsbeek A, Hofmann SM, Yi CX. Deficiency of leptin receptor in myeloid cells disrupts hypothalamic metabolic circuits and causes body weight increase. Mol Metab 2017; 7:155-160. [PMID: 29174000 PMCID: PMC5784319 DOI: 10.1016/j.molmet.2017.11.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 10/28/2017] [Accepted: 11/01/2017] [Indexed: 01/16/2023] Open
Abstract
Objective Leptin is a cytokine produced by adipose tissue that acts mainly on the hypothalamus to regulate appetite and energy homeostasis. Previous studies revealed that the leptin receptor is expressed not only in neurons, but also in glial cells. Microglia are resident immune cells in the brain that play an essential role in immune defense and neural network development. Previously we reported that microglial morphology and cytokine production are changed in the leptin receptor deficient db/db mouse, suggesting that leptin's central effects on metabolic control might involve signaling through microglia. In the current study, we aimed to uncover the role of leptin signaling in microglia in systemic metabolic control. Methods We generated a mouse model with leptin receptor deficiency, specifically in the myeloid cells, to determine the role of microglial leptin signaling in the development of metabolic disease and to investigate microglial functions. Results We discovered that these mice have increased body weight with hyperphagia. In the hypothalamus, pro-opiomelanocortin neuron numbers in the arcuate nucleus (ARC) and α-MSH projections from the ARC to the paraventricular nucleus (PVN) decreased, which was accompanied by the presence of less ramified microglia with impaired phagocytic capacity in the PVN. Conclusions Myeloid cell leptin receptor deficient mice partially replicate the db/db phenotype. Leptin signaling in hypothalamic microglia is important for microglial function and a correct formation of the hypothalamic neuronal circuit regulating metabolism. Microglia express functional leptin receptor. Myeloid cell leptin receptor deficient mice partially replicate the db/db phenotype. Microglial leptin signaling is vital for maintaining hypothalamic neuronal circuits.
Collapse
Affiliation(s)
- Yuanqing Gao
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Andrés Vidal-Itriago
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Irina Milanova
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Nikita L Korpel
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Martin J Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Robby Zachariah Tom
- Institute for Diabetes and Regeneration Research & Helmholtz Diabetes Center, Helmholtz Zentrum München, Germany
| | - Andries Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, The Netherlands; Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Susanna M Hofmann
- Institute for Diabetes and Regeneration Research & Helmholtz Diabetes Center, Helmholtz Zentrum München, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany; Medizinische Klinik und Poliklinik IV, Klinikum der LMU, München, Germany
| | - Chun-Xia Yi
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, The Netherlands.
| |
Collapse
|
10
|
Melanocortin receptor subtypes are expressed on cells in the oligodendroglial lineage and signal ACTH protection. J Neurosci Res 2017; 96:427-435. [DOI: 10.1002/jnr.24141] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 07/15/2017] [Accepted: 07/24/2017] [Indexed: 02/06/2023]
|
11
|
Melanocortins, Melanocortin Receptors and Multiple Sclerosis. Brain Sci 2017; 7:brainsci7080104. [PMID: 28805746 PMCID: PMC5575624 DOI: 10.3390/brainsci7080104] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/07/2017] [Accepted: 08/08/2017] [Indexed: 02/07/2023] Open
Abstract
The melanocortins and their receptors have been extensively investigated for their roles in the hypothalamo-pituitary-adrenal axis, but to a lesser extent in immune cells and in the nervous system outside the hypothalamic axis. This review discusses corticosteroid dependent and independent effects of melanocortins on the peripheral immune system, central nervous system (CNS) effects mediated through neuronal regulation of immune system function, and direct effects on endogenous cells in the CNS. We have focused on the expression and function of melanocortin receptors in oligodendroglia (OL), the myelin producing cells of the CNS, with the goal of identifying new therapeutic approaches to decrease CNS damage in multiple sclerosis as well as to promote repair. It is clear that melanocortin signaling through their receptors in the CNS has potential for neuroprotection and repair in diseases like MS. Effects of melanocortins on the immune system by direct effects on the circulating cells (lymphocytes and monocytes) and by signaling through CNS cells in regions lacking a mature blood brain barrier are clear. However, additional studies are needed to develop highly effective MCR targeted therapies that directly affect endogenous cells of the CNS, particularly OL, their progenitors and neurons.
Collapse
|
12
|
Orellana JA, Cerpa W, Carvajal MF, Lerma-Cabrera JM, Karahanian E, Osorio-Fuentealba C, Quintanilla RA. New Implications for the Melanocortin System in Alcohol Drinking Behavior in Adolescents: The Glial Dysfunction Hypothesis. Front Cell Neurosci 2017; 11:90. [PMID: 28424592 PMCID: PMC5380733 DOI: 10.3389/fncel.2017.00090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 03/15/2017] [Indexed: 12/12/2022] Open
Abstract
Alcohol dependence causes physical, social, and moral harms and currently represents an important public health concern. According to the World Health Organization (WHO), alcoholism is the third leading cause of death worldwide, after tobacco consumption and hypertension. Recent epidemiologic studies have shown a growing trend in alcohol abuse among adolescents, characterized by the consumption of large doses of alcohol over a short time period. Since brain development is an ongoing process during adolescence, short- and long-term brain damage associated with drinking behavior could lead to serious consequences for health and wellbeing. Accumulating evidence indicates that alcohol impairs the function of different components of the melanocortin system, a major player involved in the consolidation of addictive behaviors during adolescence and adulthood. Here, we hypothesize the possible implications of melanocortins and glial cells in the onset and progression of alcohol addiction. In particular, we propose that alcohol-induced decrease in α-MSH levels may trigger a cascade of glial inflammatory pathways that culminate in altered gliotransmission in the ventral tegmental area and nucleus accumbens (NAc). The latter might potentiate dopaminergic drive in the NAc, contributing to increase the vulnerability to alcohol dependence and addiction in the adolescence and adulthood.
Collapse
Affiliation(s)
- Juan A Orellana
- Centro de Investigación y Estudio del Consumo de Alcohol en AdolescentesSantiago, Chile.,Laboratorio de Neurociencias, Departamento de Neurología, Escuela de Medicina, Facultad de Medicina, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Waldo Cerpa
- Centro de Investigación y Estudio del Consumo de Alcohol en AdolescentesSantiago, Chile.,Laboratorio de Función y Patología Neuronal, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Maria F Carvajal
- Centro de Investigación y Estudio del Consumo de Alcohol en AdolescentesSantiago, Chile.,Unidad de Neurociencia, Centro de Investigación Biomédica, Universidad Autónoma de ChileSantiago, Chile
| | - José M Lerma-Cabrera
- Centro de Investigación y Estudio del Consumo de Alcohol en AdolescentesSantiago, Chile.,Unidad de Neurociencia, Centro de Investigación Biomédica, Universidad Autónoma de ChileSantiago, Chile
| | - Eduardo Karahanian
- Centro de Investigación y Estudio del Consumo de Alcohol en AdolescentesSantiago, Chile.,Unidad de Neurociencia, Centro de Investigación Biomédica, Universidad Autónoma de ChileSantiago, Chile
| | - Cesar Osorio-Fuentealba
- Centro de Investigación y Estudio del Consumo de Alcohol en AdolescentesSantiago, Chile.,Facultad de Kinesiología, Artes y Educación Física, Universidad Metropolitana de Ciencias de la EducaciónSantiago, Chile
| | - Rodrigo A Quintanilla
- Centro de Investigación y Estudio del Consumo de Alcohol en AdolescentesSantiago, Chile.,Laboratory of Neurodegenerative Diseases, Universidad Autónoma de ChileSantiago, Chile
| |
Collapse
|
13
|
Langner E, Lemieszek MK, Kwiecień JM, Rajtar G, Rzeski W, Turski WA. Kynurenic Acid Induces Impairment of Oligodendrocyte Viability: On the Role of Glutamatergic Mechanisms. Neurochem Res 2016; 42:838-845. [PMID: 27444613 PMCID: PMC5357470 DOI: 10.1007/s11064-016-2009-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/12/2016] [Accepted: 07/15/2016] [Indexed: 01/26/2023]
Abstract
Kynurenic acid (KYNA) is an end stage product of tryptophan metabolism with a variety of functions in the human body, both in the central nervous system (CNS) and in other organs. Although its activity in the human brain has been widely studied and effects on neural cells were emphasized, the effect of KYNA on oligodendroglial cells remains unknown. Present study aims at describing the activity of high concentration of KYNA in OLN-93 cells. The inhibition of OLN-93 oligodendrocytes viability by KYNA in a medium with reduced serum concentration has been demonstrated. Although decreased metabolic activity of KYNA treated OLN-93 cells was shown, the cells proliferation was not altered. KYNA treatment did not alter morphology as well as expression level of cell cycle and proliferation regulating proteins. Furthermore, glutamate receptor antagonists and agonists did not alter the inhibitory effect of KYNA on viability of OLN-93 oligodendrocytes. This study contributes to the elucidation of effects of KYNA on oligodendrocytes in vitro, yet further analyses are necessary to explain the mechanisms behind the damage and loss of myelin sheaths.
Collapse
Affiliation(s)
- Ewa Langner
- Department of Medical Biology, Institute of Rural Health, Lublin, Poland.,Department of Pharmacology, Medical University, Lublin, Poland
| | - Marta K Lemieszek
- Department of Medical Biology, Institute of Rural Health, Lublin, Poland
| | - Jacek M Kwiecień
- Department of Pathology and Molecular Medicine, M. deGroote School of Medicine, McMaster University, Hamilton, Canada.,Department of Clinical Pathomorphology, Medical University, Lublin, Poland
| | - Grażyna Rajtar
- Department of Pharmacology, Medical University, Lublin, Poland
| | - Wojciech Rzeski
- Department of Medical Biology, Institute of Rural Health, Lublin, Poland.,Department of Virology and Immunology, Institute of Microbiology and Biotechnology, Maria Curie-Sklodowska University, Lublin, Poland
| | - Waldemar A Turski
- Department of Experimental and Clinical Pharmacology, Medical University, Lublin, Poland.
| |
Collapse
|
14
|
The melanocortin ACTH 1-39 promotes protection of oligodendrocytes by astroglia. J Neurol Sci 2016; 362:21-6. [DOI: 10.1016/j.jns.2016.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/24/2015] [Accepted: 01/04/2016] [Indexed: 11/18/2022]
|
15
|
Loram LC, Culp ME, Connolly-Strong EC, Sturgill-Koszycki S. Melanocortin peptides: potential targets in systemic lupus erythematosus. Inflammation 2015; 38:260-71. [PMID: 25323206 PMCID: PMC4312383 DOI: 10.1007/s10753-014-0029-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease resulting in loss of self-tolerance with multiple organs, such as the kidney, skin, joints, and the central nervous system (CNS), being targeted. Numerous immunosuppressant therapies are currently being used for the treatment of SLE, but their clinical utility is somewhat variable because of the clinical heterogeneity. Melanocortins are a family of peptides derived from the common precursor protein pro-opiomelanocortin. These multifunctional peptides activate five subtypes of melanocortin receptors expressed on immune, skin, muscle, bone, and kidney cells and cells within the CNS. Melanocortin peptides have demonstrated a variety of biologic actions including immunomodulation, melanogenesis, and renoprotection. This review aims to introduce the melanocortin system and explore the mechanisms by which they may be beneficial in diseases such as SLE.
Collapse
Affiliation(s)
- Lisa Carole Loram
- Mallinckrodt Pharmaceuticals (formerly Questcor), 26118 Research Road, Hayward, CA, 94545, USA
| | | | | | | |
Collapse
|
16
|
Lisak RP, Nedelkoska L, Bealmear B, Benjamins JA. Melanocortin receptor agonist ACTH 1-39 protects rat forebrain neurons from apoptotic, excitotoxic and inflammation-related damage. Exp Neurol 2015; 273:161-7. [PMID: 26300474 DOI: 10.1016/j.expneurol.2015.08.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/12/2015] [Accepted: 08/14/2015] [Indexed: 12/22/2022]
Abstract
Patients with relapsing-remitting multiple sclerosis (RRMS) are commonly treated with high doses of intravenous corticosteroids (CS). ACTH 1-39, a member of the melanocortin family, stimulates production of CS by the adrenals, but melanocortin receptors are also found in the central nervous system (CNS) and on immune cells. ACTH is produced within the CNS and may have direct protective effects on glia and neurons independent of CS. We previously reported that ACTH 1-39 protected oligodendroglia (OL) and their progenitors (OPC) from a panel of excitotoxic and inflammation-related agents. Neurons are the most vulnerable cells in the CNS. They are terminally differentiated, and sensitive to inflammatory and excitotoxic insults. For potential therapeutic protection of gray matter, it is important to investigate the direct effects of ACTH on neurons. Cultures highly enriched in neurons were isolated from 2-3 day old rat brain. After 4-7 days in culture, the neurons were treated for 24h with selected toxic agents with or without ACTH 1-39. ACTH 1-39 protected neurons from death induced by staurosporine, glutamate, NMDA, AMPA, kainate, quinolinic acid, reactive oxygen species and, to a modest extent, from rapidly released NO, but did not protect against kynurenic acid or slowly released nitric oxide. Our results show that ACTH 1-39 protects neurons in vitro from several apoptotic, excitotoxic and inflammation-related insults.
Collapse
Affiliation(s)
- Robert P Lisak
- Department of Neurology, Wayne State University School of Medicine, 8D University Health Center, 4201 St. Antoine St., Detroit, MI 48201, USA.
| | - Liljana Nedelkoska
- Department of Neurology, Wayne State University School of Medicine, 8D University Health Center, 4201 St. Antoine St., Detroit, MI 48201, USA
| | - Beverly Bealmear
- Department of Neurology, Wayne State University School of Medicine, 8D University Health Center, 4201 St. Antoine St., Detroit, MI 48201, USA
| | - Joyce A Benjamins
- Department of Neurology, Wayne State University School of Medicine, 8D University Health Center, 4201 St. Antoine St., Detroit, MI 48201, USA
| |
Collapse
|
17
|
Talaber G, Tuckermann JP, Okret S. ACTH controls thymocyte homeostasis independent of glucocorticoids. FASEB J 2015; 29:2526-34. [PMID: 25733567 DOI: 10.1096/fj.14-268508] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 02/09/2015] [Indexed: 12/22/2022]
Abstract
It has been known for decades that lowering the circulating glucocorticoid (GC) concentration as in Addison's disease or after removing the adrenals results in thymus enlargement, largely due to thymocyte expansion. This has been attributed to the loss of the proapoptotic effects on thymocytes by adrenal GCs. Here, we test this concept and report that ACTH directly controls thymic growth post-adrenalectomy (ADX) independent of the proapoptotic effect of GCs. This was supported by the finding that ADX caused thymus enlargement and a 1.7-fold (P < 0.001) increase in thymocyte number in GR(LckCre) mice resistant to GC-induced thymocyte apoptosis, similar to the increase seen in wild-type mice (2.2-fold; P < 0.01). We show by immunostaining that melanocortin receptor subtype 2, which selectively binds ACTH, is partly expressed on the thymic epithelium. Furthermore, ACTH in comparison to vehicle induced a 2.0-fold (P < 0.01) increase in fetal thymic organ culture thymocyte numbers in vitro and enhanced 2.2-fold (P < 0.05) the expression of delta-like ligand 4, a factor that supports T-cell development. Additionally, adrenalectomized GR(LckCre) mice treated with ACTH under conditions that repressed endogenous ACTH secretion showed increased thymocyte cellularity (1.9-fold; P < 0.01) and splenic naive T-cell numbers (2.5-fold; P < 0.001) compared to when treated with PBS. Altogether, our results show that ACTH directly controls thymocyte homeostasis independent of GCs. These results revise the old paradigm behind compensatory thymus growth following ADX, now demonstrating that ACTH has a central role in regulating thymocyte expansion when systemic GC concentration is low.
Collapse
Affiliation(s)
- Gergely Talaber
- *Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Huddinge, Sweden; and Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Jan Peter Tuckermann
- *Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Huddinge, Sweden; and Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Sam Okret
- *Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Huddinge, Sweden; and Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| |
Collapse
|
18
|
Hashimoto M, Sato EF, Hiramoto K, Kasahara E, Inoue M, Kitagawa S. Role of adrenocorticotropic hormone in the modulation of pollinosis induced by pollen antigens. Neuroimmunomodulation 2015; 22:256-62. [PMID: 25501673 DOI: 10.1159/000368309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 09/05/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND A mild restraint stressor suppressed an increase in the levels of Th2-dependent cytokines and IgE, thereby reducing the symptoms of pollinosis. In the present study, to clarify the mechanism of action of adrenocorticotropic hormone (ACTH) in improving the symptoms of pollinosis, we studied the effects of ACTH on the plasma level of histamine, mast cell number in nasal-associated lymphoid tissue (NALT) and the T cell differentiation in splenocytes. METHODS The role of ACTH in the development of pollen antigen-induced pollinosis was studied in mice. Allergic symptoms and parameters were measured on day 17 after sensitization. To investigate the effects of ACTH on T cell differentiation, we stimulated splenocytes obtained from control mice with ACTH and CD3/CD28 in vitro, and measured the cytokine production in the culture supernatant. RESULTS The plasma levels of IL-10, IgE and histamine and mast cell number in NALT were increased in the sensitized animals in association with a concomitant increase in the incidence of sneezing and nasal rubbing. The intraperitoneal administration of ACTH decreased the IL-10, IgE and histamine levels in the plasma and mast cell number in NALT, while increasing the IFN-γ level and suppressing the incidence of nasal rubbing. Furthermore, the production of IFN-γ increased, while the IL-4 level was suppressed after 2 days in culture. CONCLUSIONS The present findings showed that ACTH directly affects T cell differentiation and promotes Th1-type reactions. The regulation of the Th1/Th2 balance by ACTH may result in a decrease in the pathological features of pollinosis.
Collapse
Affiliation(s)
- Maki Hashimoto
- Department of Physiology, Osaka City University Medical School, Suzuka, Japan
| | | | | | | | | | | |
Collapse
|
19
|
Namekata K, Kimura A, Harada C, Yoshida H, Matsumoto Y, Harada T. Dock3 protects myelin in the cuprizone model for demyelination. Cell Death Dis 2014; 5:e1395. [PMID: 25165881 PMCID: PMC4454328 DOI: 10.1038/cddis.2014.357] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/11/2014] [Accepted: 07/21/2014] [Indexed: 12/18/2022]
Abstract
Dedicator of cytokinesis 3 (Dock3) belongs to an atypical family of the guanine nucleotide exchange factors. It is predominantly expressed in the neural tissues and causes cellular morphological changes by activating the small GTPase Rac1. We previously reported that Dock3 overexpression protects retinal ganglion cells from excitotoxic cell death. Oligodendrocytes are the myelinating cells of axons in the central nervous system and these cells are damaged in demyelinating disorders including multiple sclerosis (MS) and optic neuritis. In this study, we examined if Dock3 is expressed in oligodendrocytes and if increasing Dock3 signals can suppress demyelination in a cuprizone-induced demyelination model, an animal model of MS. We demonstrate that Dock3 is expressed in oligodendrocytes and Dock3 overexpression protects myelin in the corpus callosum following cuprizone treatment. Furthermore, we show that cuprizone demyelinates optic nerves and the extent of demyelination is ameliorated in mice overexpressing Dock3. Cuprizone treatment impairs visual function, which was demonstrated by multifocal electroretinograms, an established non-invasive method, and Dock3 overexpression prevented this effect. In mice overexpressing Dock3, Erk activation is increased, suggesting this may at least partly explain the observed protective effects. Our findings suggest that Dock3 may be a therapeutic target for demyelinating disorders including optic neuritis.
Collapse
Affiliation(s)
- K Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - A Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - C Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - H Yoshida
- Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Y Matsumoto
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - T Harada
- 1] Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan [2] Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| |
Collapse
|
20
|
Skaggs K, Goldman D, Parent JM. Excitotoxic brain injury in adult zebrafish stimulates neurogenesis and long-distance neuronal integration. Glia 2014; 62:2061-79. [PMID: 25043622 DOI: 10.1002/glia.22726] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 06/04/2014] [Accepted: 07/03/2014] [Indexed: 12/28/2022]
Abstract
Zebrafish maintain a greater capacity than mammals for central nervous system repair after injury. Understanding differences in regenerative responses between different vertebrate species may shed light on mechanisms to improve repair in humans. Quinolinic acid is an excitotoxin that has been used to induce brain injury in rodents for modeling Huntington's disease and stroke. When injected into the adult rodent striatum, this toxin stimulates subventricular zone neurogenesis and neuroblast migration to injury. However, most new neurons fail to survive and lesion repair is minimal. We used quinolinic acid to lesion the adult zebrafish telencephalon to study reparative processes. We also used conditional transgenic lineage mapping of adult radial glial stem cells to explore survival and integration of neurons generated after injury. Telencephalic lesioning with quinolinic acid, and to a lesser extent vehicle injection, produced cell death, microglial infiltration, increased cell proliferation, and enhanced neurogenesis in the injured hemisphere. Lesion repair was more complete with quinolinic acid injection than after vehicle injection. Fate mapping of her4-expressing radial glia showed injury-induced expansion of radial glial stem cells that gave rise to neurons which migrated to injury, survived at least 8 weeks and formed long-distance projections that crossed the anterior commissure and synapsed in the contralateral hemisphere. These findings suggest that quinolinic acid lesioning of the zebrafish brain stimulates adult neural stem cells to produce robust regeneration with long-distance integration of new neurons. This model should prove useful for elucidating reparative mechanisms that can be applied to restorative therapies for mammalian brain injury.
Collapse
Affiliation(s)
- Kaia Skaggs
- Departments of Neurology, University of Michigan Medical Center, Ann Arbor, Michigan
| | | | | |
Collapse
|
21
|
Benjamins JA, Nedelkoska L, Lisak RP. Adrenocorticotropin hormone 1-39 promotes proliferation and differentiation of oligodendroglial progenitor cells and protects from excitotoxic and inflammation-related damage. J Neurosci Res 2014; 92:1243-51. [PMID: 24916309 DOI: 10.1002/jnr.23416] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/21/2014] [Accepted: 04/22/2014] [Indexed: 01/20/2023]
Abstract
Oligodendroglia (OL) are highly susceptible to damage and, like neurons, are terminally differentiated. It is important to protect OL precursors (OPC) because they are reservoirs of differentiating cells capable of myelination following perinatal insult and remyelination in white matter diseases, including multiple sclerosis (MS). Patients with relapsing-remitting MS are commonly treated with high-dose corticosteroids (CS) when experiencing an exacerbation. Adrenocorticotropin hormone (ACTH), a primary component of another approved MS exacerbation treatment, is a melanocortin peptide that stimulates production of CS by the adrenals. Melanocortin receptors are also found in the central nervous system (CNS) and on immune cells. ACTH is produced within the CNS and may have CS-independent effects on glia. We found that ACTH 1-39 stimulated proliferation of OPC, and to a lesser extent astroglia (AS) and microglia (MG), in rat glial cultures. ACTH accelerated differentiation of PDGFRα(+) OPC to a later stage marked by galactolipid expression and caused greater expansion of OL myelin-like sheets compared with untreated cells. Protective effects of ACTH on OPC were assessed by treating cultures with selected toxic agents, with or without ACTH. At 200 nM, ACTH protected OPC from death induced by staurosporine, glutamate, NMDA, AMPA, kainate, quinolinic acid, H2 O2 , and slow NO release, but not against kynurenic acid or rapid NO release. These agents and ACTH were not toxic to AS or MG. Our findings indicate that ACTH 1-39 provides benefits by increasing the number of OPC, accelerating their development into mature OL, and reducing OPC death from toxic insults.
Collapse
Affiliation(s)
- Joyce A Benjamins
- Department of Neurology, Wayne State University School of Medicine, Detroit, Michigan; Department of Immunology and Microbiology, Wayne State University School of Medicine Detroit, Michigan
| | | | | |
Collapse
|
22
|
Hernan AE, Alexander A, Lenck-Santini PP, Scott RC, Holmes GL. Attention deficit associated with early life interictal spikes in a rat model is improved with ACTH. PLoS One 2014; 9:e89812. [PMID: 24587054 PMCID: PMC3933669 DOI: 10.1371/journal.pone.0089812] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 01/26/2014] [Indexed: 12/02/2022] Open
Abstract
Children with epilepsy often present with pervasive cognitive and behavioral comorbidities including working memory impairments, attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder. These non-seizure characteristics are severely detrimental to overall quality of life. Some of these children, particularly those with epilepsies classified as Landau-Kleffner Syndrome or continuous spike and wave during sleep, have infrequent seizure activity but frequent focal epileptiform activity. This frequent epileptiform activity is thought to be detrimental to cognitive development; however, it is also possible that these IIS events initiate pathophysiological pathways in the developing brain that may be independently associated with cognitive deficits. These hypotheses are difficult to address due to the previous lack of an appropriate animal model. To this end, we have recently developed a rat model to test the role of frequent focal epileptiform activity in the prefrontal cortex. Using microinjections of a GABA(A) antagonist (bicuculline methiodine) delivered multiple times per day from postnatal day (p) 21 to p25, we showed that rat pups experiencing frequent, focal, recurrent epileptiform activity in the form of interictal spikes during neurodevelopment have significant long-term deficits in attention and sociability that persist into adulthood. To determine if treatment with ACTH, a drug widely used to treat early-life seizures, altered outcome we administered ACTH once per day subcutaneously during the time of the induced interictal spike activity. We show a modest amelioration of the attention deficit seen in animals with a history of early life interictal spikes with ACTH, in the absence of alteration of interictal spike activity. These results suggest that pharmacological intervention that is not targeted to the interictal spike activity is worthy of future study as it may be beneficial for preventing or ameliorating adverse cognitive outcomes.
Collapse
Affiliation(s)
- Amanda E. Hernan
- Department of Neurology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| | - Abigail Alexander
- Department of Neurology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Pierre-Pascal Lenck-Santini
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| | - Rod C. Scott
- Institute of Child Health, University College London, London, United Kingdom
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| | - Gregory L. Holmes
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| |
Collapse
|
23
|
Lisak RP, Nedelkoska L, Benjamins JA. Effects of dextromethorphan on glial cell function: Proliferation, maturation, and protection from cytotoxic molecules. Glia 2014; 62:751-62. [DOI: 10.1002/glia.22639] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/20/2014] [Accepted: 01/22/2014] [Indexed: 12/11/2022]
Affiliation(s)
- Robert P. Lisak
- Department of Neurology; Wayne State University School of Medicine; Detroit Missouri
- Department of Immunology/Microbiology; Wayne State University School of Medicine; Detroit Missouri
| | - Liljana Nedelkoska
- Department of Neurology; Wayne State University School of Medicine; Detroit Missouri
| | - Joyce A. Benjamins
- Department of Neurology; Wayne State University School of Medicine; Detroit Missouri
- Department of Immunology/Microbiology; Wayne State University School of Medicine; Detroit Missouri
| |
Collapse
|