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Kuwasako K, Kitamura K, Nagata S, Sekiguchi T, Danfeng J, Murakami M, Hattori Y, Kato J. β-arrestins negatively control human adrenomedullin type 1-receptor internalization. Biochem Biophys Res Commun 2017; 487:438-443. [PMID: 28427767 DOI: 10.1016/j.bbrc.2017.04.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 04/16/2017] [Indexed: 02/08/2023]
Abstract
Adrenomedullin (AM) is a potent hypotensive peptide that exerts a powerful variety of protective effects against multiorgan damage through the AM type 1 receptor (AM1 receptor), which consists of the calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 2 (RAMP2). Two β-arrestin (β-arr) isoforms, β-arr-1 and β-arr-2, play a central role in the agonist-induced internalization of many receptors for receptor resensitization. Notably, β-arr-biased agonists are now being tested in phase II clinical trials, targeting acute pain and acute heart failure. Here, we examined the effects of β-arr-1 and β-arr-2 on human AM1 receptor internalization. We constructed a V5-tagged chimera in which the cytoplasmic C-terminal tail (C-tail) of CLR was replaced with that of the β2-adrenergic receptor (β2-AR), and it was transiently transfected into HEK-293 cells that stably expressed RAMP2. The cell-surface expression and internalization of the wild-type or chimeric receptor were quantified by flow cytometric analysis. The [125I]AM binding and the AM-induced cAMP production of these receptors were also determined. Surprisingly, the coexpression of β-arr-1 or -2 resulted in significant decreases in AM1 receptor internalization without affecting AM binding and signaling prior to receptor internalization. Dominant-negative (DN) β-arr-1 or -2 also significantly decreased AM-induced AM1 receptor internalization. In contrast, the AM-induced internalization of the chimeric AM1 receptor was markedly augmented by the cotransfection of β-arr-1 or -2 and significantly reduced by the coexpression of DN-β-arr-1 or -2. These results were consistent with those seen for β2-AR. Thus, both β-arrs negatively control AM1 receptor internalization, which depends on the C-tail of CLR.
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Affiliation(s)
- Kenji Kuwasako
- Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan.
| | - Kazuo Kitamura
- Division of Circulation and Body Fluid Regulation, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Sayaka Nagata
- Division of Circulation and Body Fluid Regulation, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Toshio Sekiguchi
- Noto Marine Laboratory, Institute of Nature and Environmental Technology, Division of Marine Environmental Studies, Kanazawa University, Ishikawa 927-0553, Japan
| | - Jiang Danfeng
- Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Manabu Murakami
- Department of Pharmacology, Hirosaki University, Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Yuichi Hattori
- Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Johji Kato
- Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan
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Pace M, Adamantidis A, Facchin L, Bassetti C. Role of REM Sleep, Melanin Concentrating Hormone and Orexin/Hypocretin Systems in the Sleep Deprivation Pre-Ischemia. PLoS One 2017; 12:e0168430. [PMID: 28061506 PMCID: PMC5218733 DOI: 10.1371/journal.pone.0168430] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 12/01/2016] [Indexed: 12/19/2022] Open
Abstract
STUDY OBJECTIVES Sleep reduction after stroke is linked to poor recovery in patients. Conversely, a neuroprotective effect is observed in animals subjected to acute sleep deprivation (SD) before ischemia. This neuroprotection is associated with an increase of the sleep, melanin concentrating hormone (MCH) and orexin/hypocretin (OX) systems. This study aims to 1) assess the relationship between sleep and recovery; 2) test the association between MCH and OX systems with the pathological mechanisms of stroke. METHODS Sprague-Dawley rats were assigned to four experimental groups: (i) SD_IS: SD performed before ischemia; (ii) IS: ischemia; (iii) SD_Sham: SD performed before sham surgery; (iv) Sham: sham surgery. EEG and EMG were recorded. The time-course of the MCH and OX gene expression was measured at 4, 12, 24 hours and 3, 4, 7 days following ischemic surgery by qRT-PCR. RESULTS A reduction of infarct volume was observed in the SD_IS group, which correlated with an increase of REM sleep observed during the acute phase of stroke. Conversely, the IS group showed a reduction of REM sleep. Furthermore, ischemia induces an increase of MCH and OX systems during the acute phase of stroke, although, both systems were still increased for a long period of time only in the SD_IS group. CONCLUSIONS Our data indicates that REM sleep may be involved in the neuroprotective effect of SD pre-ischemia, and that both MCH and OX systems were increased during the acute phase of stroke. Future studies should assess the role of REM sleep as a prognostic marker, and test MCH and OXA agonists as new treatment options in the acute phase of stroke.
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Affiliation(s)
- Marta Pace
- Center for Experimental Neurology (ZEN), Department of Neurology, Bern University Hospital, Bern, Switzerland
- Department of Neuroscience and Brain Technologies, Italian Institute of Technology (IIT), Genova, Italy
- * E-mail:
| | - Antoine Adamantidis
- Center for Experimental Neurology (ZEN), Department of Neurology, Bern University Hospital, Bern, Switzerland
| | - Laura Facchin
- Center for Experimental Neurology (ZEN), Department of Neurology, Bern University Hospital, Bern, Switzerland
| | - Claudio Bassetti
- Center for Experimental Neurology (ZEN), Department of Neurology, Bern University Hospital, Bern, Switzerland
- Sleep-Wake-Epilepsy-Center, Department of Neurology, Bern University Hospital, Bern, Switzerland
- Division of Cognitive and Restorative Neurology, Department of Neurology, Bern University Hospital, Bern, Switzerland
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Ogawa Y, Irukayama-Tomobe Y, Murakoshi N, Kiyama M, Ishikawa Y, Hosokawa N, Tominaga H, Uchida S, Kimura S, Kanuka M, Morita M, Hamada M, Takahashi S, Hayashi Y, Yanagisawa M. Peripherally administered orexin improves survival of mice with endotoxin shock. eLife 2016; 5. [PMID: 28035899 PMCID: PMC5245965 DOI: 10.7554/elife.21055] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 12/29/2016] [Indexed: 12/22/2022] Open
Abstract
Sepsis is a systemic inflammatory response to infection, accounting for the most common cause of death in intensive care units. Here, we report that peripheral administration of the hypothalamic neuropeptide orexin improves the survival of mice with lipopolysaccharide (LPS) induced endotoxin shock, a well-studied septic shock model. The effect is accompanied by a suppression of excessive cytokine production and an increase of catecholamines and corticosterone. We found that peripherally administered orexin penetrates the blood-brain barrier under endotoxin shock, and that central administration of orexin also suppresses the cytokine production and improves the survival, indicating orexin's direct action in the central nervous system (CNS). Orexin helps restore body temperature and potentiates cardiovascular function in LPS-injected mice. Pleiotropic modulation of inflammatory response by orexin through the CNS may constitute a novel therapeutic approach for septic shock.
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Affiliation(s)
- Yasuhiro Ogawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Yoko Irukayama-Tomobe
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Nobuyuki Murakoshi
- Department of Cardiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Maiko Kiyama
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Yui Ishikawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Naoto Hosokawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Hiromu Tominaga
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Shuntaro Uchida
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Saki Kimura
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Mika Kanuka
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Miho Morita
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Michito Hamada
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Satoru Takahashi
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Yu Hayashi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan.,Department of Molecular Genetics and Howard Hughes Medical Institute, Unversity of Texas Southwestern Medical Center, Dallas, United States
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Orexin-A promotes Glu uptake by OX1R/PKCα/ERK1/2/GLT-1 pathway in astrocytes and protects co-cultured astrocytes and neurons against apoptosis in anoxia/hypoglycemic injury in vitro. Mol Cell Biochem 2016; 425:103-112. [DOI: 10.1007/s11010-016-2866-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 11/02/2016] [Indexed: 12/31/2022]
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Application of the Co-culture Membrane System Pointed to a Protective Role of Catestatin on Hippocampal Plus Hypothalamic Neurons Exposed to Oxygen and Glucose Deprivation. Mol Neurobiol 2016; 54:7369-7381. [PMID: 27815840 DOI: 10.1007/s12035-016-0240-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 10/17/2016] [Indexed: 12/30/2022]
Abstract
Depletion of oxygen and glucose even for brief periods is sufficient to cause cerebral ischemia, which is a predominant worldwide cause of motor deficits with the reduction of life quality and subsequently death. Hence, more insights regarding protective measures against ischemic events are becoming a major research goal. Among the many neuronal factors, N-methyl-D-aspartate receptors (NMDAR), orexinergic neuroreceptors (ORXR), and sympatho-inhibitory neuropeptide catestatin (CST) are widely involved with ischemic episodes. In this study, it was possible to induce in vitro ischemic conditions of the hamster (Mesocricetus auratus) hippocampal and hypothalamic neuronal cultures, grown on a newly compartmentalized membrane system, via oxygen and glucose deprivation (OGD). These cultures displayed notably differentiated NMDARergic and ORXergic receptor expression activities along with evident brain-derived neurotrophic factor (BDNF) plus orexin A (ORX-A) secretion, especially under co-cultured conditions. Interestingly, addition of CST in OGD-insulted hippocampal cells accounted for upregulated GluN1 and ORX1R transcripts that in the case of the latter neuroreceptor was very strongly (p < 0.001) increased when co-cultured with hypothalamic cells. Similarly, hypothalamic neurons supplied very evident upregulations of GluN1, ORX1R, and above all of GluN2A transcripts along with increased BDNF and ORX-A secretion in the presence of hippocampal cells. Overall, the preferential CST effects on BDNF plus ORX-A production together with altered NMDAR and ORXR levels, especially in co-cultured hypothalamic cells pointed to ORX-containing neurons as major protective constituents against ischemic damages thus opening new scenarios on the cross-talking roles of CST during ischemic disorders.
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Tanaka S, Takizawa N, Honda Y, Koike T, Oe S, Toyoda H, Kodama T, Yamada H. Hypocretin/orexin loss changes the hypothalamic immune response. Brain Behav Immun 2016; 57:58-67. [PMID: 27318095 DOI: 10.1016/j.bbi.2016.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 12/26/2022] Open
Abstract
Hypocretin, also known as orexin, maintains the vigilance state and regulates various physiological processes, such as arousal, sleep, food intake, energy expenditure, and reward. Previously, we found that when wild-type mice and hypocretin/ataxin-3 littermates (which are depleted of hypothalamic hypocretin-expressing neurons postnatally) were administered lipopolysaccharide (LPS), the two genotypes exhibited significant differences in their sleep/wake cycle, including differences in the degree of increase in sleep periods and in recovery from sickness behaviour. In the present study, we examined changes in the hypothalamic vigilance system and in the hypothalamic expression of inflammatory factors in response to LPS in hypocretin/ataxin-3 mice. Peripheral immune challenge with LPS affected the hypothalamic immune response and vigilance states. This response was altered by the loss of hypocretin. Hypocretin expression was inhibited after LPS injection in both hypocretin/ataxin-3 mice and their wild-type littermates, but expression was completely abolished only in hypocretin/ataxin-3 mice. Increases in the number of histidine decarboxylase (HDC)-positive cells and in Hdc mRNA expression were found in hypocretin/ataxin-3 mice, and this increase was suppressed by LPS. Hypocretin loss did not impact the change in expression of hypothalamic inflammatory factors in response to LPS, except for interferon gamma and colony stimulating factor 3. The number of c-Fos-positive/HDC-positive cells in hypocretin/ataxin-3 mice administered LPS injections was elevated, even during the rest period, in all areas, suggesting that there is an increase in the activity of histaminergic neurons in hypocretin/ataxin-3 mice following LPS injection. Taken together, our results suggest a novel role for hypocretin in the hypothalamic response to peripheral immune challenge. Our findings contribute to the understanding of the pathophysiology of narcolepsy.
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Affiliation(s)
- Susumu Tanaka
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan; SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
| | - Nae Takizawa
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Yoshiko Honda
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Taro Koike
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Souichi Oe
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Hiromi Toyoda
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tohru Kodama
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hisao Yamada
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
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57
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Qu W, Liu NK, Xie XMS, Li R, Xu XM. Automated monitoring of early neurobehavioral changes in mice following traumatic brain injury. Neural Regen Res 2016; 11:248-56. [PMID: 27073377 PMCID: PMC4810988 DOI: 10.4103/1673-5374.177732] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Traumatic brain injury often causes a variety of behavioral and emotional impairments that can develop into chronic disorders. Therefore, there is a need to shift towards identifying early symptoms that can aid in the prediction of traumatic brain injury outcomes and behavioral endpoints in patients with traumatic brain injury after early interventions. In this study, we used the SmartCage system, an automated quantitative approach to assess behavior alterations in mice during an early phase of traumatic brain injury in their home cages. Female C57BL/6 adult mice were subjected to moderate controlled cortical impact (CCI) injury. The mice then received a battery of behavioral assessments including neurological score, locomotor activity, sleep/wake states, and anxiety-like behaviors on days 1, 2, and 7 after CCI. Histological analysis was performed on day 7 after the last assessment. Spontaneous activities on days 1 and 2 after injury were significantly decreased in the CCI group. The average percentage of sleep time spent in both dark and light cycles were significantly higher in the CCI group than in the sham group. For anxiety-like behaviors, the time spent in a light compartment and the number of transitions between the dark/light compartments were all significantly reduced in the CCI group than in the sham group. In addition, the mice suffering from CCI exhibited a preference of staying in the dark compartment of a dark/light cage. The CCI mice showed reduced neurological score and histological abnormalities, which are well correlated to the automated behavioral assessments. Our findings demonstrate that the automated SmartCage system provides sensitive and objective measures for early behavior changes in mice following traumatic brain injury.
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Affiliation(s)
- Wenrui Qu
- Hand & Foot Surgery and Reparative & Reconstructive Surgery Center, Orthopaedic Hospital of the Second Hospital of Jilin University, Changchun, Jilin Province, China; Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Goodman Campbell Brain and Spine, Indianapolis, IN, USA
| | - Nai-Kui Liu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Goodman Campbell Brain and Spine, Indianapolis, IN, USA
| | | | - Rui Li
- Hand & Foot Surgery and Reparative & Reconstructive Surgery Center, Orthopaedic Hospital of the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Xiao-Ming Xu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Goodman Campbell Brain and Spine, Indianapolis, IN, USA
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58
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Systematic review of survival time in experimental mouse stroke with impact on reliability of infarct estimation. J Neurosci Methods 2016; 261:10-8. [PMID: 26620203 DOI: 10.1016/j.jneumeth.2015.11.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/24/2015] [Accepted: 11/17/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND Stroke is the second most common cause of death worldwide. Only one treatment for acute ischemic stroke is currently available, thrombolysis with rt-PA, but it is limited in its use. Many efforts have been invested in order to find additive treatments, without success. A multitude of reasons for the translational problems from mouse experimental stroke to clinical trials probably exists, including infarct size estimations around the peak time of edema formation. Furthermore, edema is a more prominent feature of stroke in mice than in humans, because of the tendency to produce larger infarcts with more substantial edema. PURPOSE This paper will give an overview of previous studies of experimental mouse stroke, and correlate survival time to peak time of edema formation. Furthermore, investigations of whether the included studies corrected the infarct measurements for edema and a comparison of correction methods will be discussed. METHOD Relevant terms were searched in the National Library of Medicine PubMed database. A method for classification of infarct measurement methods was made using a naming convention. CONCLUSION Our study shows that infarct size estimations are often performed around the peak time of edema, with a median of 24h. Most studies do consider edema formation, however, there is no consensus on what method to use to correct for edema. Furthermore, investigations into neuroprotective drugs should use longer survival times to ensure completion of the investigated process. Our findings indicate a need for more research in this area, and establishment of common correction methodology.
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Wang CP, Shi YW, Tang M, Zhang XC, Gu Y, Liang XM, Wang ZW, Ding F. Isoquercetin Ameliorates Cerebral Impairment in Focal Ischemia Through Anti-Oxidative, Anti-Inflammatory, and Anti-Apoptotic Effects in Primary Culture of Rat Hippocampal Neurons and Hippocampal CA1 Region of Rats. Mol Neurobiol 2016; 54:2126-2142. [PMID: 26924319 DOI: 10.1007/s12035-016-9806-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/17/2016] [Indexed: 01/29/2023]
Abstract
Ischemic stroke is a major disability and cause of death worldwide due to its narrow therapeutic time window. Neuroprotective agent is a promising strategy to salvage acutely ischemic brain tissue and extend the therapeutic time window for stroke treatment. In this study, we aimed to evaluate the neuroprotective effects of isoquercetin in (1) primary culture of rat hippocampal neurons exposure on oxygen and glucose deprivation and reperfusion (OGD/R) injury and (2) rats subjected to transient middle cerebral artery occlusion and reperfusion (MCAO/R) injury. The results showed that isoquercetin post-treatment reduced the infarct size, number of apoptotic cells, oxidative stress, and inflammatory response after ischemia and reperfusion injury. The underlying mechanism study indicated that the neuroprotective effects of isoquercetin were elicited via suppressing the activation of toll-like receptor 4 (TLR4), nuclear factor-kappa B (NF-κB) and caspase-1; the phosphorylation of ERK1/2, JNK1/2, and p38 mitogen-activated protein kinase (MAPK); and the secretion of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6. In addition, isoquercetin also effectively alleviated hippocampus neuron apoptosis by regulation of cyclic AMP responsive element-binding protein (CREB), Bax, Bcl-2, and caspase-3. Our report provided new considerations into the therapeutic action and the underlying mechanisms of isoquercetin to improve brain injury in individuals who have suffered from ischemic stroke. As a potent anti-inflammatory and anti-oxidative compound with neuroprotective capacities, the beneficial effects of isoquercetin when used to treat ischemic stroke and related diseases in humans warrant further studies.
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Affiliation(s)
- Cai-Ping Wang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, No. 19, Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Yun-Wei Shi
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, No. 19, Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Miao Tang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, No. 19, Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Xiao-Chuan Zhang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, No. 19, Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Yun Gu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, No. 19, Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Xin-Miao Liang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, No. 19, Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China. .,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China. .,Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, Liaoning, 116023, People's Republic of China.
| | - Zhi-Wei Wang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, No. 19, Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China. .,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China. .,Department of Pharmacology, University of California, Irvine, CA, 92697, USA.
| | - Fei Ding
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, No. 19, Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China. .,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China.
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Fatemi I, Shamsizadeh A, Ayoobi F, Taghipour Z, Sanati MH, Roohbakhsh A, Motevalian M. Role of orexin-A in experimental autoimmune encephalomyelitis. J Neuroimmunol 2016; 291:101-9. [PMID: 26857503 DOI: 10.1016/j.jneuroim.2016.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/27/2015] [Accepted: 01/04/2016] [Indexed: 12/25/2022]
Abstract
The aim of this study was to evaluate the effects of orexin-A (OX-A) on behavioral and pathological parameters and on gene expression of some multiple sclerosis-related peptides in a model of experimental autoimmune encephalomyelitis (EAE). EAE was induced by subcutaneous administration of MOG 35-55. Following immunization, the treatment was initiated by using SB.334867 (orexin-1 receptor antagonist) and/or OX-A. Locomotor activity and exploratory behaviors were monitored using open field and T-maze continuous alternation task (T-CAT) respectively. Pain sensitivity was assessed by hot-plate test. Histopathological assessments were performed by H&E staining. The expression of TGF-β, MBP, MMP-9, IL-12, iNOS and MCP-1 were measured using real-time PCR method in lumbar spinal cord. OX-A administration in EAE mice remarkably attenuated the clinical symptoms, increased latency response in hot plate test, inhibited infiltration of inflammatory cells, up-regulated mRNA expression of TGF-β as well as MBP and down-regulated mRNA expression of iNOS, MMP-9 and IL-12. In contrast SB.334867 administration in EAE mice deteriorated the clinical symptoms, decreased the alternation in T-CAT, increased infiltration of inflammatory cells, down-regulated mRNA expression of TGF-β and MBP and up-regulated mRNA expression of iNOS. Results of this study suggest that the orexinergic system might be involved in pathological development of EAE. These findings suggest orexinergic system as a potential target for treatment of multiple sclerosis.
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Affiliation(s)
- Iman Fatemi
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Ali Shamsizadeh
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Fatemeh Ayoobi
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Zahra Taghipour
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Mohammad Hossein Sanati
- Department of Medical Genetics, National Institute for Genetic Engineering and Biotechnology, Tehran, Iran
| | - Ali Roohbakhsh
- Pharmacutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Manijeh Motevalian
- Department of Pharmacology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran; Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran.
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61
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Duffy CM, Yuan C, Wisdorf LE, Billington CJ, Kotz CM, Nixon JP, Butterick TA. Role of orexin A signaling in dietary palmitic acid-activated microglial cells. Neurosci Lett 2015; 606:140-4. [PMID: 26306651 DOI: 10.1016/j.neulet.2015.08.033] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/05/2015] [Accepted: 08/19/2015] [Indexed: 12/23/2022]
Abstract
Excess dietary saturated fatty acids such as palmitic acid (PA) induce peripheral and hypothalamic inflammation. Hypothalamic inflammation, mediated in part by microglial activation, contributes to metabolic dysregulation. In rodents, high fat diet-induced microglial activation results in nuclear translocation of nuclear factor-kappa B (NFκB), and increased central pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). The hypothalamic neuropeptide orexin A (OXA, hypocretin 1) is neuroprotective in brain. In cortex, OXA can also reduce inflammation and neurodegeneration through a microglial-mediated pathway. Whether hypothalamic orexin neuroprotection mechanisms depend upon microglia is unknown. To address this issue, we evaluated effects of OXA and PA on inflammatory response in immortalized murine microglial and hypothalamic neuronal cell lines. We demonstrate for the first time in microglial cells that exposure to PA increases gene expression of orexin-1 receptor but not orexin-2 receptor. Pro-inflammatory markers IL-6, TNF-α, and inducible nitric oxide synthase in microglial cells are increased following PA exposure, but are reduced by pretreatment with OXA. The anti-inflammatory marker arginase-1 is increased by OXA. Finally, we show hypothalamic neurons exposed to conditioned media from PA-challenged microglia have increased cell survival only when microglia were pretreated with OXA. These data support the concept that OXA may act as an immunomodulatory regulator of microglia, reducing pro-inflammatory cytokines and increasing anti-inflammatory factors to promote a favorable neuronal microenvironment.
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Affiliation(s)
- Cayla M Duffy
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
| | - Ce Yuan
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
| | - Lauren E Wisdorf
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
| | - Charles J Billington
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Minnesota Obesity Center, St Paul, MN USA
| | - Catherine M Kotz
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA; Minnesota Obesity Center, St Paul, MN USA
| | - Joshua P Nixon
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
| | - Tammy A Butterick
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA.
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62
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Song J, Kim E, Kim CH, Song HT, Lee JE. The role of orexin in post-stroke inflammation, cognitive decline, and depression. Mol Brain 2015; 8:16. [PMID: 25884812 PMCID: PMC4357085 DOI: 10.1186/s13041-015-0106-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 02/23/2015] [Indexed: 01/02/2023] Open
Abstract
Ischemic stroke results in diverse pathophysiologies, including cerebral inflammation, neuronal loss, cognitive dysfunction, and depression. Studies aimed at identifying therapeutic solutions to alleviate these outcomes are important due to the increase in the number of stroke patients annually. Recently, many studies have reported that orexin, commonly known as a neuropeptide regulator of sleep/wakefulness and appetite, is associated with neuronal cell apoptosis, memory function, and depressive symptoms. Here, we briefly summarize recent studies regarding the role and future perspectives of orexin in post-ischemic stroke. This review advances our understanding of the role of orexin in post-stroke pathologies, focusing on its possible function as a therapeutic regulator in the post-ischemic brain. Ultimately, we suggest the clinical potential of orexin to regulate post-stroke pathologies.
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Affiliation(s)
- Juhyun Song
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 120-752, South Korea.
| | - Eosu Kim
- Department of Pharmacology, Yonsei University College of Medicine, 120-752, Seoul, South Korea.
| | - Chul-Hoon Kim
- Department of Psychiatry, Yonsei University College of Medicine, 120-752, Seoul, South Korea.
| | - Ho-Taek Song
- Department of Diagnostic Radiology, Yonsei University College of Medicine, 120-752, Seoul, South Korea.
| | - Jong Eun Lee
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 120-752, South Korea. .,BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University, College of Medicine, Seoul, 120-752, South Korea.
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63
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Xie XS. The neuronal circuit between nociceptin/orphanin FQ and hypocretins/orexins coordinately modulates stress-induced analgesia and anxiety-related behavior. VITAMINS AND HORMONES 2015; 97:295-321. [PMID: 25677777 DOI: 10.1016/bs.vh.2014.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The neuropeptide nociceptin/orphanin FQ (N/OFQ), acting on its receptors (NOP), modulates a variety of biological functions and neurobehavior including nociception, stress responses, water and food-intake, locomotor activity, and spatial attention. N/OFQ is conventionally regarded as an "antiopiate" peptide in the brain because central administration of N/OFQ attenuates stress-induced analgesia (SIA) and produces anxiolytic effects. However, naloxone-irreversible SIA and anxiolytic action are unlikely to be mediated by the opiate system. Both N/OFQ and NOP receptors are expressed most abundantly in the hypothalamus, where two other neuropeptides, the hypocretins/orexins (Hcrts), are exclusively synthesized in the lateral hypothalamic area. N/OFQ and Hcrt regulate most cellular physiological responses in opposite directions (e.g., ion channel modulation and second messenger coupling), and produce differential modulations for almost all neurobehavior assessed, including sleep/wake, locomotion, and rewarding behaviors. This chapter focuses on recent studies that provide evidence at a neuroanatomical level showing that a local neuronal circuit linking N/OFQ to Hcrt neurons exists. Functionally, N/OFQ depresses Hcrt neuronal activity at the cellular level, and modulates stress responses, especially SIA and anxiety-related behavior in the whole organism. N/OFQ exerts its attenuation of SIA and anxiolytic action on fear-induced anxiety through direct modulation of Hcrt neuronal activity. The information obtained from these studies has provided insights into how interaction between the Hcrt and N/OFQ systems positively and negatively modulates the complex and integrated stress responses.
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Affiliation(s)
- Xinmin Simon Xie
- AfaSci Research Laboratories, Redwood City, California, USA; Department of Anesthesia, Stanford University School of Medicine, Stanford, California, USA.
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64
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Feng Y, Liu T, Li XQ, Liu Y, Zhu XY, Jankovic J, Pan TH, Wu YC. Neuroprotection by Orexin-A via HIF-1α induction in a cellular model of Parkinson's disease. Neurosci Lett 2014; 579:35-40. [PMID: 25038418 DOI: 10.1016/j.neulet.2014.07.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/01/2014] [Accepted: 07/08/2014] [Indexed: 01/20/2023]
Abstract
Orexin-A, a neuropeptide secreted by hypothalamic neurons, may be neuroprotective in many neurological conditions such as cerebral ischaemia. One mechanism postulated to be involved in the neuroprotection by Orexin-A is the induction of hypoxia inducible factor 1 alpha (HIF-1α). Parkinson's disease (PD) is a progressive neurodegenerative disorder and mitochondrial dysfunction has been demonstrated to play a role in its pathogenesis. Mitochondrial dysfunction may cause reduction of O2 consumption and subsequently activate prolyl hydroxylase, which leads to decreased level of HIF-1α. In this study, we used MPP(+)-treated SH-SY5Y cells as an in vitro cellular model of PD to test the role of Orexin-A as an inducer of HIF-1α. Our results showed that Orexin-A not only induced HIF-1α but also activated downstream targets of HIF-1α, such as vascular endothelial growth factor and erythropoietin. Thus, Orexin-A treatment attenuated MPP(+)-induced cell injury and this effect was blocked when HIF-1α was suppressed. Hence, we conclude that induction of HIF-1α is one of the mechanisms involved in the neuroprotection by Orexin-A.
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Affiliation(s)
- Ya Feng
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, PR China
| | - Te Liu
- Shanghai Geriatric Institute of Chinese Medicine, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, PR China
| | - Xin-Qun Li
- Department of Experimental Therapeutics, M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Ye Liu
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, PR China
| | - Xiao-Ying Zhu
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, PR China
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tian-Hong Pan
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Yun-Cheng Wu
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, PR China.
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65
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Liesz A, Bauer A, Hoheisel JD, Veltkamp R. Intracerebral interleukin-10 injection modulates post-ischemic neuroinflammation: an experimental microarray study. Neurosci Lett 2014; 579:18-23. [PMID: 25019688 DOI: 10.1016/j.neulet.2014.07.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/20/2014] [Accepted: 07/01/2014] [Indexed: 11/25/2022]
Abstract
Stroke induces a profound neuroinflammatory reaction that leads to secondary cerebral tissue injury. Interleukin-10 (IL-10) is a key anti-inflammatory cytokine that is endogenously produced by immune cells and limits this inflammatory reaction. Previously, therapeutic administration of IL-10 has been shown to be neuroprotective in experimental stroke. However, the signaling pathways affected by this approach are largely unknown. The aim of this study was to verify the neuroprotective effects of IL-10 in an experimental mouse stroke model and to analyze the pathways modulated by this approach. Therefore, we performed a whole genome microarray analysis comparing the cerebral gene expression profile at two time points after cortical stroke in IL-10-treated and control C57Bl/6J mice. We administered IL-10 locally by intracerebroventricular injection. We were able to validate a reduction of infarct volume by IL-10 administration and characterized the kinetics of endogenous cerebral IL-10 expression after stroke. The microarray analysis revealed that IL-10 treatment effectively downregulated pro-inflammatory signaling cascades which were upregulated by the ischemic lesion in the acute phase after the stroke. This is the first study characterizing the global gene regulation profile of IL-10 immunotherapy for ischemic stroke. Our results emphasize the key role of IL-10 as a neuroprotective cytokine and suggest several novel downstream pathways for further investigation to better understand the mechanisms of post-stroke neuroinflammation.
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Affiliation(s)
- Arthur Liesz
- Department of Neurology, University Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; Institute for Stroke and Dementia Research, Klinikum der Universität München, Max-Lebsche-Platz 30, 81377 Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| | - Andrea Bauer
- Division of Functional Genome Analysis, German Cancer Research Center, Im Neuenheimer Feld 580, Heidelberg, Germany
| | - Jörg D Hoheisel
- Division of Functional Genome Analysis, German Cancer Research Center, Im Neuenheimer Feld 580, Heidelberg, Germany
| | - Roland Veltkamp
- Department of Neurology, University Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; Division of Brain Sciences, Imperial College London, Fulham Palace Road, London W6 RF, UK
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66
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Lourbopoulos A, Mourouzis I, Karapanayiotides T, Nousiopoulou E, Chatzigeorgiou S, Mavridis T, Kokkinakis I, Touloumi O, Irinopoulou T, Chouliaras K, Pantos C, Karacostas D, Grigoriadis N. Changes in thyroid hormone receptors after permanent cerebral ischemia in male rats. J Mol Neurosci 2014; 54:78-91. [PMID: 24577884 DOI: 10.1007/s12031-014-0253-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 02/04/2014] [Indexed: 11/25/2022]
Abstract
Thyroid hormones (TH) and receptors (TRs) may play an important role in the pathophysiology of acute cerebral ischemia. In the present study, we sought to determine whether serum triodothyronine (T3)/thyroxine (T4) and brain TRs (TRα1, TRβ1) might change after experimental stroke. Male adult Wistar rats were subjected to permanent middle cerebral artery occlusion (group P) and compared to sham-operated controls (group S). Animals were followed clinically for 14 days until brain collection for Western blot (WB) or neuropathological analysis of TRs in three different brain areas (infarcted tissue, E1; noninfarcted ipsilateral hemisphere, E2; and contralateral hemisphere, E3). Analysis of serum TH levels showed a reduction of T4 in group P (p = 0.002) at days 2 to 14, while half of the animals also displayed "low T3" values (p = 0.012) on day 14. This T4 reduction was inversely correlated to the clinical severity of stroke and the concomitant body weight loss (p < 0.005). WB analysis of TRα1 and TRβ1 protein expression showed heterogenic responses at day 14: total and nuclear TRα1 were similar between the two groups, while total TRβ1 decreased 7.5-fold within E1 (p ≤ 0.001) with a concomitant 1.8-fold increase of nuclear TRβ1 in E2 area (p = 0.03); TRβ1 expression did not differ in E3. Neuropathological analysis revealed that activated macrophages/microglia exclusively expressed nuclear TRα1 within the infarct core. Astrocytes mildly expressed nuclear TRα1 in and around the infarct, along with a prominent TRβ nuclear signal restricted in the astrocytic scar. Neurons around the infarct expressed mainly TRα1 and, to a milder degree, TRβ. Surprisingly enough, we detected for the first time a TRβ expression in the paranodal region of Ranvier nodes, of unknown significance so far. Our data support that cerebral ischemia induces a low TH response, associated with significant and heterogenic changes in brain TR expression. These findings could imply an important role of TH signaling in cerebral ischemia.
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Affiliation(s)
- Athanasios Lourbopoulos
- B' Department of Neurology, Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Stilponos Kiriakides str. 1, 54636, Thessaloniki, Macedonia, Greece
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67
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Yao ZA, Xu L, Wu HG. Immunomodulatory function of κ-carrageenan oligosaccharides acting on LPS-activated microglial cells. Neurochem Res 2013; 39:333-43. [PMID: 24357352 DOI: 10.1007/s11064-013-1228-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 10/22/2013] [Accepted: 12/11/2013] [Indexed: 01/08/2023]
Abstract
The major neurodegenerative diseases are characterized by increasing of activated-microglial cells and inflammatory cytokines in the central nervous system. Carrageenan extracted from red algae is a kind of polysaccharide with sulfate groups. The oligosaccharides were obtained from carrageenan by enzymatic degradation. To detect the immunomodulatory activity of κ-carrageenan oligosaccharides (KOS) on microglial cells and the relationship to the sulfate group content, the desulfated derivatives of KOS (DSK) were obtained by dimethyl sulfoxide-methanol-pyridine method. KOS was labeled with fluorescein isothiocyanate. The effect of KOS and DSK on lipopolysaccharide (LPS)-activated microglial cells was detected. Hematoxylin-eosin staining and flow cytometric were used to detect the cell viability. The "scratch" migration assay, ornithine analysis and RT-PCR were used to determine the cell migration, arginase and TNF-α released by microglial cells, respectively. The effect of LPS and KOS on microglial cells was determined by flow cytometry and laser scanning confocal microscopy. The results showed that KOS and DSK could inhibit the cell viability, arginase and TNF-α released by LPS-activated microglia cell with concentration dependent manner. But the effect of DSK was weaker than that of KOS. KOS aggregated on the cell surface firstly, and then they enter into the cell to the nucleus, spread over the entire cell finally. But the exist of LPS could prevent the entrance of KOS. It could be concluded that KOS could protect microglial cells from being activated by LPS, and its inhibition function had relationship to the sulfate group content of KOS, while there were competition between LPS and KOS.
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Affiliation(s)
- Zi-Ang Yao
- College of Life Science and Technology, Dalian University, Dalian, 116622, China
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68
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Xiong XX, Gu LJ, Shen J, Kang XH, Zheng YY, Yue SB, Zhu SM. Probenecid protects against transient focal cerebral ischemic injury by inhibiting HMGB1 release and attenuating AQP4 expression in mice. Neurochem Res 2013; 39:216-24. [PMID: 24317635 DOI: 10.1007/s11064-013-1212-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 10/31/2013] [Accepted: 11/25/2013] [Indexed: 12/11/2022]
Abstract
Stroke results in inflammation, brain edema, and neuronal death. However, effective neuroprotectants are not available. Recent studies have shown that high mobility group box-1 (HMGB1), a proinflammatory cytokine, contributes to ischemic brain injury. Aquaporin 4 (AQP4), a water channel protein, is considered to play a pivotal role in ischemia-induced brain edema. More recently, studies have shown that pannexin 1 channels are involved in cerebral ischemic injury and the cellular inflammatory response. Here, we examined whether the pannexin 1 channel inhibitor probenecid could reduce focal ischemic brain injury by inhibiting cerebral inflammation and edema. Transient focal ischemia was induced in C57BL/6J mice by middle cerebral artery occlusion (MCAO) for 1 h. Infarct volume, neurological score and cerebral water content were evaluated 48 h after MCAO. Immunostaining, western blot analysis and ELISA were used to assess the effects of probenecid on the cellular inflammatory response, HMGB1 release and AQP4 expression. Administration of probenecid reduced infarct size, decreased cerebral water content, inhibited neuronal death, and reduced inflammation in the brain 48 h after stroke. In addition, HMGB1 release from neurons was significantly diminished and serum HMGB1 levels were substantially reduced following probenecid treatment. Moreover, AQP4 protein expression was downregulated in the cortical penumbra following post-stroke treatment with probenecid. These results suggest that probenecid, a powerful pannexin 1 channel inhibitor, protects against ischemic brain injury by inhibiting cerebral inflammation and edema.
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Affiliation(s)
- Xiao-Xing Xiong
- Department of Anesthesia, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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Machaalani R, Hunt NJ, Waters KA. Effects of changes in energy homeostasis and exposure of noxious insults on the expression of orexin (hypocretin) and its receptors in the brain. Brain Res 2013; 1526:102-22. [PMID: 23830852 DOI: 10.1016/j.brainres.2013.06.035] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/19/2013] [Accepted: 06/25/2013] [Indexed: 12/23/2022]
Abstract
This review summarizes data regarding the brain expression of the orexin (hypocretin) system including: prepro-orexin (PPO), orexin A (OxA), orexin B (OxB) and the two orexin receptors 1 and 2 (OxR1, OxR2). Clinical data is limited to OxA and OxB in cerebral spinal fluid and serum/plasma, thus necessitating the development of animal models to undertake mechanistic studies. We focus on changes in animal models that were either exposed to a regime of altered sleep, metabolic energy homeostasis, exposed to drugs and noxious insults. Many more expressional studies are available for PPO, OxA and OxB levels, compared to studies of the receptors. Interestingly, the direction and pattern of change for PPO, OxA and OxB is inconsistent amongst studies, whereas for the receptors, there tends to be increased expression for both OxR1 and OxR2 after alterations in energy homeostasis, and an increased expression after noxious insults or exposure to some drugs. The clinical implications of these results from animal models are discussed in light of the findings from human studies, and future research directions are suggested to fill knowledge gaps with regard to the orexin system, particularly during early brain development.
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Affiliation(s)
- Rita Machaalani
- Department of Medicine, Blackburn Building, DO6, University of Sydney, NSW 2006, Australia.
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Hypocretin/orexin neurons contribute to hippocampus-dependent social memory and synaptic plasticity in mice. J Neurosci 2013; 33:5275-84. [PMID: 23516292 DOI: 10.1523/jneurosci.3200-12.2013] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Hypocretin/orexin (Hcrt)-producing neurons in the lateral hypothalamus project throughout the brain, including to the hippocampus, where Hcrt receptors are widely expressed. Hcrt neurons activate these targets to orchestrate global arousal state, wake-sleep architecture, energy homeostasis, stress adaptation, and reward behaviors. Recently, Hcrt has been implicated in cognitive functions and social interaction. In the present study, we tested the hypothesis that Hcrt neurons are critical to social interaction, particularly social memory, using neurobehavioral assessment and electrophysiological approaches. The validated "two-enclosure homecage test" devices and procedure were used to test sociability, preference for social novelty (social novelty), and recognition memory. A conventional direct contact social test was conducted to corroborate the findings. We found that adult orexin/ataxin-3-transgenic (AT) mice, in which Hcrt neurons degenerate by 3 months of age, displayed normal sociability and social novelty with respect to their wild-type littermates. However, AT mice displayed deficits in long-term social memory. Nasal administration of exogenous Hcrt-1 restored social memory to an extent in AT mice. Hippocampal slices taken from AT mice exhibited decreases in degree of paired-pulse facilitation and magnitude of long-term potentiation, despite displaying normal basal synaptic neurotransmission in the CA1 area compared to wild-type hippocampal slices. AT hippocampi had lower levels of phosphorylated cAMP response element-binding protein (pCREB), an activity-dependent transcription factor important for synaptic plasticity and long-term memory storage. Our studies demonstrate that Hcrt neurons play an important role in the consolidation of social recognition memory, at least in part through enhancements of hippocampal synaptic plasticity and cAMP response element-binding protein phosphorylation.
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