101
|
Han B, Li X, Hao J. The cholinergic anti-inflammatory pathway: An innovative treatment strategy for neurological diseases. Neurosci Biobehav Rev 2017; 77:358-368. [PMID: 28392244 DOI: 10.1016/j.neubiorev.2017.04.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 02/28/2017] [Accepted: 04/03/2017] [Indexed: 12/22/2022]
Abstract
Acetylcholine (ACh), as a classical neurotransmitter, regulates the neuronal network in response to internal and external stimuli. In recent decades, the biology of ACh has been endowed with unparalleled new insights, especially with respect to cholinergic anti-inflammatory properties in non-neuronal cells. In fact, a mechanism frequently referred to as the "cholinergic anti-inflammatory pathway" has been termed to describe interactions between the central nervous system (CNS) and the immune system via vagus nerve. As well documented, immune cells express choline acetyltransferase, a direct synthetase for ACh, and other corresponding cholinergic components. Alternatively, the ACh released from immune cells or cholinergic neurons modulates immune function in an autocrine/paracrine manner by acting on its receptors. Moreover, muscarinic or nicotinic ACh receptors on various immune cells and CNS glial cells administer the work of their respective agonists, causing functional and biochemical changes. In this review, we focus on the anti-inflammatory benefits of non-neuronal and neuronal ACh as a means of providing new insights into treating inflammation-related neurological diseases, as exemplified by those described herein.
Collapse
Affiliation(s)
- Bin Han
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.
| | - Xiuping Li
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.
| | - Junwei Hao
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.
| |
Collapse
|
102
|
Reactions of Microglial Cells in the Sensorimotor Cortex of Rats after Transient Ischemia. NEUROPHYSIOLOGY+ 2017. [DOI: 10.1007/s11062-017-9638-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
103
|
EXPRESSION OF Β-TUBULIN IN THE SENSORIMOTOR CORTEX OF THE CEREBRAL HEMATURIA IN THE MODELING OF TRANSIENT ISCHEMIA ON THE BACKGROUND OF SENSITIZATION OF BRAIN ANTIGEN AND IMMUNE CORRECTION OF THE CHANGES. WORLD OF MEDICINE AND BIOLOGY 2017. [DOI: 10.26724/2079-8334-2017-4-62-173-178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
104
|
Cholinergic Protection in Ischemic Brain Injury. SPRINGER SERIES IN TRANSLATIONAL STROKE RESEARCH 2017. [DOI: 10.1007/978-3-319-45345-3_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
105
|
Gu W, Zhang W, Lei Y, Cui Y, Chu S, Gu X, Ma Z. Activation of spinal alpha-7 nicotinic acetylcholine receptor shortens the duration of remifentanil-induced postoperative hyperalgesia by upregulating KCC2 in the spinal dorsal horn in rats. Mol Pain 2017; 13:1744806917704769. [PMID: 28425312 PMCID: PMC6997724 DOI: 10.1177/1744806917704769] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 02/28/2017] [Accepted: 03/15/2017] [Indexed: 12/15/2022] Open
Abstract
Background Accumulating evidence has shown that the signal from spinal brain-derived neurotrophic factor/tyrosine receptor kinase B-K+-Cl- cotransporter-2 plays a critical role in the process of pain hypersensitivity. The activation of alpha-7 nicotinic acetylcholine receptors could have an analgesic effect on remifentanil-induced postoperative hyperalgesia. Nevertheless, whether intrathecal administration of PNU-120596, an alpha-7 nicotinic acetylcholine receptors selective type II positive allosteric modulator, before surgery could affect the duration of remifentanil-induced postoperative hyperalgesia remains unknown, and the effects of alpha-7 nicotinic acetylcholine receptors activation on the brain-derived neurotrophic factor/tyrosine receptor kinase B-K+-Cl- cotransporter-2 signal in the spinal dorsal horn of rats with remifentanil-induced postoperative hyperalgesia is still enigmatic. Results We demonstrated that the brain-derived neurotrophic factor/tyrosine receptor kinase B-K+-Cl- cotransporter-2 signal played a critical role in the development of remifentanil-induced postoperative hyperalgesia. Intrathecal administration of PNU-120596 (8 µg/kg, 15 min before surgery) was associated with earlier signs of recovery from remifentanil-induced postoperative hyperalgesia. Simultaneously, remifentanil-induced postoperative hyperalgesia-induced K+-Cl- cotransporter-2 downregulation was partly reversed and coincided with a decreased expression of brain-derived neurotrophic factor/tyrosine receptor kinase B in the spinal dorsal horn, approximately correlating with the time course of the nociceptive behavior. Moreover, intrathecal administration of the K+-Cl- cotransporter-2 inhibitor VU0240551 significantly reduced the analgesic effect of PNU-120596 on remifentanil-induced postoperative hyperalgesia. Conclusions The activation of alpha-7 nicotinic acetylcholine receptors induced a shorter duration of remifentanil-induced postoperative hyperalgesia by restoring the brain-derived neurotrophic factor/tyrosine receptor kinase B-K+-Cl- cotransporter-2 signal in the spinal dorsal horn of rats, which provides new insight into treatment in clinical postoperative pain management.
Collapse
Affiliation(s)
- Wei Gu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China
| | - Wei Zhang
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China
| | - Yishan Lei
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical School of Nanjing University, Nanjing, China
| | - Yin Cui
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical School of Nanjing University, Nanjing, China
| | - Shuaishuai Chu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical School of Nanjing University, Nanjing, China
| | - Xiaoping Gu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical School of Nanjing University, Nanjing, China
| | - Zhengliang Ma
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China
| |
Collapse
|
106
|
ConBr, A Lectin Purified from the Seeds of Canavalia brasiliensis, Protects Against Ischemia in Organotypic Culture of Rat Hippocampus: Potential Implication of Voltage-Gated Calcium Channels. Neurochem Res 2016; 42:347-359. [DOI: 10.1007/s11064-016-2078-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 09/22/2016] [Accepted: 10/04/2016] [Indexed: 12/13/2022]
|
107
|
Zhang R, Xu M, Wang Y, Xie F, Zhang G, Qin X. Nrf2—a Promising Therapeutic Target for Defensing Against Oxidative Stress in Stroke. Mol Neurobiol 2016; 54:6006-6017. [DOI: 10.1007/s12035-016-0111-0] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 09/06/2016] [Indexed: 12/30/2022]
|
108
|
Bagdas D, Wilkerson JL, Kulkarni A, Toma W, AlSharari S, Gul Z, Lichtman AH, Papke RL, Thakur GA, Damaj MI. The α7 nicotinic receptor dual allosteric agonist and positive allosteric modulator GAT107 reverses nociception in mouse models of inflammatory and neuropathic pain. Br J Pharmacol 2016; 173:2506-20. [PMID: 27243753 DOI: 10.1111/bph.13528] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 05/05/2016] [Accepted: 05/17/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE Orthosteric agonists and positive allosteric modulators (PAMs) of the α7 nicotinic ACh receptor (nAChR) represent novel therapeutic approaches for pain modulation. Moreover, compounds with dual function as allosteric agonists and PAMs, known as ago-PAMs, add further regulation of receptor function. EXPERIMENTAL APPROACH Initial studies examined the α7 ago-PAM, GAT107, in the formalin, complete Freund's adjuvant (CFA), LPS inflammatory pain models, the chronic constriction injury neuropathic pain model and the tail flick and hot plate acute thermal nociceptive assays. Additional studies examined the locus of action of GAT107 and immunohistochemical markers in the dorsal horn of the spinal cord in the CFA model. KEY RESULTS Complementary pharmacological and genetic approaches confirmed that the dose-dependent antinociceptive effects of GAT107 were mediated through α7 nAChR. However, GAT107 was inactive in the tail flick and hot plate assays. In addition, GAT107 blocked conditioned place aversion elicited by acetic acid injection. Furthermore, intrathecal, but not intraplantar, injections of GAT107 reversed nociception in the CFA model, suggesting a spinal component of action. Immunohistochemical evaluation revealed an increase in the expression of astrocyte-specific glial fibrillary acidic protein and phosphorylated p38MAPK within the spinal cords of mice treated with CFA, which was attenuated by intrathecal GAT107 treatment. Importantly, GAT107 did not elicit motor impairment and continued to produce antinociceptive effects after subchronic administration in both phases of the formalin test. CONCLUSIONS AND IMPLICATIONS Collectively, these results provide the first proof of principle that α7 ago-PAMs represent an effective pharmacological strategy for treating inflammatory and neuropathic pain.
Collapse
Affiliation(s)
- Deniz Bagdas
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA.,Experimental Animals Breeding and Research Center, Faculty of Medicine, Uludag University, Bursa, Turkey
| | - Jenny L Wilkerson
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA
| | - Abhijit Kulkarni
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Wisam Toma
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA
| | - Shakir AlSharari
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA.,Department of Pharmacology and Toxicology, King Saud University, Riyadh, Saudi Arabia
| | - Zulfiye Gul
- Department of Pharmacology, Faculty of Medicine, Uludag University, Bursa, Turkey
| | - Aron H Lichtman
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA
| | - Roger L Papke
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Ganesh A Thakur
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - M Imad Damaj
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA
| |
Collapse
|
109
|
Abstract
Macrophages and their counterparts in the central nervous system, the microglia, detect and subsequently clear microbial pathogens and injured tissue. These phagocytic cells alter and adapt their phenotype depending on their prime activity, i.e., whether they participate in acute defence against pathogenic organisms ('M1'-phenotype) or in clearing damaged tissues and performing repair activities ('M2'-phenotype). Stimulation of pattern recognition receptors by viruses (vaccines), bacterial membrane components (e.g., LPS), alcohol, or long-chain saturated fatty acids promotes M1-polarization. Vaccine or LPS administration to healthy human subjects can result in sickness symptoms and low mood. Alcohol abuse and abdominal obesity are recognized as risk factors for depression. In the M1-polarized form, microglia and macrophages generate reactive oxygen and nitrogen radicals to eradicate microbial pathogens. Inadvertently, also tetrahydrobiopterin (BH4) may become oxidized. This is an irreversible reaction that generates neopterin, a recognized biomarker for depression. BH4 is a critical cofactor for the synthesis of dopamine, noradrenaline, and serotonin, and its loss could explain some of the symptoms of depression. Based on these aspects, the suppression of M1-polarization would limit the inadvertent catabolism of BH4. In the current review, we evaluate the evidence that antidepressant treatments (monoamine reuptake inhibitors, PDE4 inhibitors, lithium, valproate, agomelatine, tianeptine, electroconvulsive shock, and vagus nerve stimulation) inhibit LPS-induced microglia/macrophage M1-polarization. Consequently, we propose that supplementation with BH4 could limit the reduction in central monoamine synthesis and might represent an effective treatment for depressed mood.
Collapse
Affiliation(s)
- Hans O Kalkman
- Neuroscience Research, NIBR, Fabrikstrasse 22-3.001.02, Basel 4002, Switzerland.
| | - Dominik Feuerbach
- Neuroscience Research, NIBR, Fabrikstrasse 22-3.001.02, Basel 4002, Switzerland
| |
Collapse
|
110
|
Kalkman HO, Feuerbach D. Modulatory effects of α7 nAChRs on the immune system and its relevance for CNS disorders. Cell Mol Life Sci 2016; 73:2511-30. [PMID: 26979166 PMCID: PMC4894934 DOI: 10.1007/s00018-016-2175-4] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 02/25/2016] [Accepted: 03/01/2016] [Indexed: 02/08/2023]
Abstract
The clinical development of selective alpha-7 nicotinic acetylcholine receptor (α7 nAChR) agonists has hitherto been focused on disorders characterized by cognitive deficits (e.g., Alzheimer's disease, schizophrenia). However, α7 nAChRs are also widely expressed by cells of the immune system and by cells with a secondary role in pathogen defense. Activation of α7 nAChRs leads to an anti-inflammatory effect. Since sterile inflammation is a frequently observed phenomenon in both psychiatric disorders (e.g., schizophrenia, melancholic and bipolar depression) and neurological disorders (e.g., Alzheimer's disease, Parkinson's disease, and multiple sclerosis), α7 nAChR agonists might show beneficial effects in these central nervous system disorders. In the current review, we summarize information on receptor expression, the intracellular signaling pathways they modulate and reasons for receptor dysfunction. Information from tobacco smoking, vagus nerve stimulation, and cholinesterase inhibition is used to evaluate the therapeutic potential of selective α7 nAChR agonists in these inflammation-related disorders.
Collapse
Affiliation(s)
- Hans O Kalkman
- Neuroscience Research, NIBR, Fabrikstrasse 22-3.001.02, 4002, Basel, Switzerland.
- , Gänsbühlgartenweg 7, 4132, Muttenz, Switzerland.
| | - Dominik Feuerbach
- Neuroscience Research, NIBR, Fabrikstrasse 22-3.001.02, 4002, Basel, Switzerland
| |
Collapse
|
111
|
Sadigh-Eteghad S, Majdi A, Mahmoudi J, Golzari SEJ, Talebi M. Astrocytic and microglial nicotinic acetylcholine receptors: an overlooked issue in Alzheimer's disease. J Neural Transm (Vienna) 2016; 123:1359-1367. [PMID: 27262818 DOI: 10.1007/s00702-016-1580-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/27/2016] [Indexed: 02/01/2023]
Abstract
It is increasingly recognized that astrocytes and microglia-associated dysfunction contribute to AD pathology. In addition, glial nicotinic acetylcholine receptors (nAChRs) play a role in AD-related phenomena, such as neuron survival, synaptic plasticity, and memory. From mechanistic point of view, the glial regulation of pro-inflammatory cytokines, as common contributors in AD, is modulated by nAChRs. Astrocytic and microglial nAChRs contribute to Aβ metabolism, including Aβ phagocytosis and degradation as well as Aβ-related oxidative stress and neurotoxicity. These receptors are also involved in neurotransmission and gliotransmission through indirect interaction with N-Methyl-D-aspartate (NMDA) and a-amino-3-hydroxy-5-methyl-4 isoxazolepropionic acid (AMPA) receptors as well as gamma-aminobutyric acid (GABA) and intracellular calcium regulation. In addition, glial nAChRs participate in trophic factors-induced neuroprotection. This review gathers the most recent advances along with the previous data on astrocytic and microglial nAChRs role in AD pathogenesis.
Collapse
Affiliation(s)
- Saeed Sadigh-Eteghad
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Alireza Majdi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Javad Mahmoudi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Samad E J Golzari
- Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahnaz Talebi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
112
|
Corradi J, Bouzat C. Understanding the Bases of Function and Modulation of α7 Nicotinic Receptors: Implications for Drug Discovery. Mol Pharmacol 2016; 90:288-99. [PMID: 27190210 DOI: 10.1124/mol.116.104240] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/05/2016] [Indexed: 01/01/2023] Open
Abstract
The nicotinic acetylcholine receptor (nAChR) belongs to a superfamily of pentameric ligand-gated ion channels involved in many physiologic and pathologic processes. Among nAChRs, receptors comprising the α7 subunit are unique because of their high Ca(2+) permeability and fast desensitization. nAChR agonists elicit a transient ion flux response that is further sustained by the release of calcium from intracellular sources. Owing to the dual ionotropic/metabotropic nature of α7 receptors, signaling pathways are activated. The α7 subunit is highly expressed in the nervous system, mostly in regions implicated in cognition and memory and has therefore attracted attention as a novel drug target. Additionally, its dysfunction is associated with several neuropsychiatric and neurologic disorders, such as schizophrenia and Alzheimer's disease. α7 is also expressed in non-neuronal cells, particularly immune cells, where it plays a role in immunity, inflammation, and neuroprotection. Thus, α7 potentiation has emerged as a therapeutic strategy for several neurologic and inflammatory disorders. With unique activation properties, the receptor is a sensitive drug target carrying different potential binding sites for chemical modulators, particularly agonists and positive allosteric modulators. Although macroscopic and single-channel recordings have provided significant information about the underlying molecular mechanisms and binding sites of modulatory compounds, we know just the tip of the iceberg. Further concerted efforts are necessary to effectively exploit α7 as a drug target for each pathologic situation. In this article, we focus mainly on the molecular basis of activation and drug modulation of α7, key pillars for rational drug design.
Collapse
Affiliation(s)
- Jeremías Corradi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del Sur, CONICET/UNS, Bahía Blanca, Argentina
| | - Cecilia Bouzat
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del Sur, CONICET/UNS, Bahía Blanca, Argentina
| |
Collapse
|
113
|
Zhao T, Ding Q, Hu J, He S, Shi F, Ma L. GPER expressed on microglia mediates the anti-inflammatory effect of estradiol in ischemic stroke. Brain Behav 2016; 6:e00449. [PMID: 27127723 PMCID: PMC4840664 DOI: 10.1002/brb3.449] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Stroke could lead to serious morbidity, of which ischemic stroke counts for majority of the cases. Inflammation plays an important role in the pathogenesis of ischemic stroke, thus drugs targeting inflammation could be potentially neuroprotective. Estradiol was shown to be neuroprotective as well as anti-inflammatory in animal models of ischemic stroke with unclear mechanism. We hypothesize that the anti-inflammatory and neuroprotective effect of estradiol is mediated by the estradiol receptor G protein-coupled estrogen receptor 1 (GPER) expressed on microglia. METHODS We have generated the rat global cerebral ischemic model and the primary microglia culture to study the neuroprotective and anti-inflammatory effect of estradiol. We have further used pharmacological methods and siRNA knockdown approach to study the underlying mechanism. RESULTS We found that estradiol reduced the level of proinflammatory cytokines including IL-1β and TNF-α, both in vivo and in vitro. We also found that the specific GPER agonist G1 could reduce the level of IL-1β (P = 0 P = 0.0017, one-way ANOVA and post hoc test) and TNF-α (P < 0.0001) in the primary microglia culture. Moreover, the specific GPER antagonist G15 was able to abolish the anti-inflammatory effect of estradiol. Estradiol failed to reduce the level of IL-1β (P = 0.4973, unpaired Student's t-test) and TNF-α (P = 0.1627) when GPER was knocked down. CONCLUSIONS Our studies have suggested that GPER expressed on microglia mediated the anti-inflammatory effect of estradiol after ischemic stroke. Our studies could potentially help to develop more specific drugs to manage inflammation postischemic stroke.
Collapse
Affiliation(s)
- Tian‐Zhi Zhao
- Department of NeurosurgeryWuhan General Hospital of Guangzhou Military Command of Chinese PLAWuhan430070Hubei ProvinceChina
- Department of NeurosurgeryTangdu HospitalFourth Military Medical UniversityNo. 569 Xinsi RoadBaqiao DistrictXi'an710038Shanxi ProvinceChina
| | - Qian Ding
- Department of AnesthesiologyTangdu HospitalFourth Military Medical UniversityNo. 569 Xinsi RoadBaqiao DistrictXi'an710038Shanxi ProvinceChina
| | - Jun Hu
- Department of NeurologyChinese PLA No. 451 HospitalXi'an710054Shanxi ProvinceChina
| | - Shi‐Ming He
- Department of NeurosurgeryTangdu HospitalFourth Military Medical UniversityNo. 569 Xinsi RoadBaqiao DistrictXi'an710038Shanxi ProvinceChina
| | - Fei Shi
- Department of Aerospace BiodynamicsFourth Military Medical UniversityXi'an710032Shanxi ProvinceChina
| | - Lian‐Ting Ma
- Department of NeurosurgeryWuhan General Hospital of Guangzhou Military Command of Chinese PLAWuhan430070Hubei ProvinceChina
| |
Collapse
|
114
|
Sun F, Johnson SR, Jin K, Uteshev VV. Boosting Endogenous Resistance of Brain to Ischemia. Mol Neurobiol 2016; 54:2045-2059. [PMID: 26910820 DOI: 10.1007/s12035-016-9796-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 02/16/2016] [Indexed: 12/22/2022]
Abstract
Most survivors of ischemic stroke remain physically disabled and require prolonged rehabilitation. However, some stroke victims achieve a full neurological recovery suggesting that the human brain can defend itself against ischemic injury, but the protective mechanisms are unknown. This study used selective pharmacological agents and a rat model of cerebral ischemic stroke to detect endogenous brain protective mechanisms that require activation of α7 nicotinic acetylcholine receptors (nAChRs). This endogenous protection was found to be (1) limited to less severe injuries; (2) significantly augmented by intranasal administration of a positive allosteric modulator of α7 nAChRs, significantly reducing brain injury and neurological deficits after more severe ischemic injuries; and (3) reduced by inhibition of calcium/calmodulin-dependent kinase-II. The physiological role of α7 nAChRs remains largely unknown. The therapeutic activation of α7 nAChRs after cerebral ischemia may serve as an important physiological responsibility of these ubiquitous receptors and holds a significant translational potential.
Collapse
Affiliation(s)
- Fen Sun
- Institute for Healthy Aging, Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | | | - Kunlin Jin
- Institute for Healthy Aging, Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Victor V Uteshev
- Institute for Healthy Aging, Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA.
| |
Collapse
|
115
|
Ma Y, Wang J, Wang Y, Yang GY. The biphasic function of microglia in ischemic stroke. Prog Neurobiol 2016; 157:247-272. [PMID: 26851161 DOI: 10.1016/j.pneurobio.2016.01.005] [Citation(s) in RCA: 491] [Impact Index Per Article: 61.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 12/22/2015] [Accepted: 01/10/2016] [Indexed: 12/16/2022]
Abstract
Microglia are brain resident macrophages originated from primitive progenitor cells in the yolk sac. Microglia can be activated within hours and recruited to the lesion site. Traditionally, microglia activation is considered to play a deleterious role in ischemic stroke, as inhibition of microglia activation attenuates ischemia induced brain injury. However, increasing evidence show that microglia activation is critical for attenuating neuronal apoptosis, enhancing neurogenesis, and promoting functional recovery after cerebral ischemia. Differential polarization of microglia could likely explain the biphasic role of microglia in ischemia. We comprehensively reviewed the mechanisms involved in regulating microglia activation and polarization. The latest discoveries of microRNAs in modulating microglia function are discussed. In addition, the interaction between microglia and other cells including neurons, astrocytes, oligodendrocytes, and stem cells were also reviewed. Future therapies targeting microglia may not exclusively aim at suppressing microglia activation, but also at modulating microglia polarization at different stages of ischemic stroke. More work is needed to elucidate the cellular and molecular mechanisms of microglia polarization under ischemic environment. The roles of microRNAs and transplanted stem cells in mediating microglia activation and polarization during brain ischemia also need to be further studied.
Collapse
Affiliation(s)
- Yuanyuan Ma
- Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China; Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Jixian Wang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China; Department of Rehabilitation, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Yongting Wang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
| | - Guo-Yuan Yang
- Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China; Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
| |
Collapse
|
116
|
A Non-Canonical Role for β-Secretase in the Retina. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:333-9. [PMID: 26427429 DOI: 10.1007/978-3-319-17121-0_44] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
It has long been established that β-Secretase (BACE) plays a critical role in the formation of amyloid plaques in Alzheimer's Disease patients, but it is only recently that the importance of β-secretases in retinal pathophysiology has been recognized. BACE expression is elevated in response to stress, and downregulation results in lysosomal abnormalities and mitochondrial changes. Inhibition of BACE can lead to reduced retinal function, retinal thinning, lipofuscin accumulation and vascular dysfunction in mice. Furthermore, BACE inhibition accelerates choroidal neovascularization (CNV) in mice. We propose that BACE plays an important role in retinal homeostasis and that BACE upregulation in response to stress is a protective measure.
Collapse
|
117
|
Bodhankar S, Lapato A, Chen Y, Vandenbark AA, Saugstad JA, Offner H. Role for microglia in sex differences after ischemic stroke: importance of M2. Metab Brain Dis 2015; 30:1515-29. [PMID: 26246072 PMCID: PMC4644102 DOI: 10.1007/s11011-015-9714-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 07/20/2015] [Indexed: 01/17/2023]
Abstract
Inflammation plays a critical role in the pathogenesis of ischemic stroke. This process depends, in part, upon proinflammatory factors released by activated resident central nervous system (CNS) microglia (MG). Previous studies demonstrated that transfer of IL-10(+) B-cells reduced infarct volumes in male C57BL/6 J recipient mice when given 24 h prior to or therapeutically at 4 or 24 h after experimental stroke induced by 60 min middle cerebral artery occlusion (MCAO). The present study assesses possible sex differences in immunoregulation by IL-10(+) B-cells on primary male vs. female MG cultured from naïve and ischemic stroke-induced mice. Thus, MG cultures were treated with recombinant (r)IL-10, rIL-4 or IL-10(+) B-cells after lipopolysaccharide (LPS) activation and evaluated by flow cytometry for production of proinflammatory and anti-inflammatory factors. We found that IL-10(+) B-cells significantly reduced MG production of TNF-α, IL-1β and CCL3 post-MCAO and increased their expression of the anti-inflammatory M2 marker, CD206, by cell-cell interactions. Moreover, MG from female vs. male mice had higher expression of IL-4 and IL-10 receptors and increased production of IL-4, especially after treatment with IL-10(+) B-cells. These findings indicate that IL-10-producing B-cells play a crucial role in regulating MG activation, proinflammatory cytokine release and M2 phenotype induction, post-MCAO, with heightened sensitivity of female MG to IL-4 and IL-10. This study, coupled with our previous demonstration of increased numbers of transferred IL-10(+) B-cells in the ischemic hemisphere, provide a mechanistic basis for local regulation by secreted IL-10 and IL-4 as well as direct B-cell/MG interactions that promote M2-MG.
Collapse
Affiliation(s)
- Sheetal Bodhankar
- Neuroimmunology Research, R&D-31, VA Portland Health Care System, 3710 SW U.S. Veterans Hospital Rd., Portland, OR, 97239, USA
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA
| | - Andrew Lapato
- Neuroimmunology Research, R&D-31, VA Portland Health Care System, 3710 SW U.S. Veterans Hospital Rd., Portland, OR, 97239, USA
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA
| | - Yingxin Chen
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA
| | - Arthur A Vandenbark
- Neuroimmunology Research, R&D-31, VA Portland Health Care System, 3710 SW U.S. Veterans Hospital Rd., Portland, OR, 97239, USA
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA
| | - Julie A Saugstad
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA
- Department of Medical and Molecular Genetics, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA
| | - Halina Offner
- Neuroimmunology Research, R&D-31, VA Portland Health Care System, 3710 SW U.S. Veterans Hospital Rd., Portland, OR, 97239, USA.
- Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA.
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, USA.
| |
Collapse
|
118
|
Cuadrado A. Structural and functional characterization of Nrf2 degradation by glycogen synthase kinase 3/β-TrCP. Free Radic Biol Med 2015; 88:147-157. [PMID: 25937177 DOI: 10.1016/j.freeradbiomed.2015.04.029] [Citation(s) in RCA: 183] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 12/30/2022]
Abstract
Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a master regulator of cellular homeostasis that controls the expression of more than 1% of human genes related to biotransformation reactions, redox homeostasis, energetic metabolism, DNA repair, and proteostasis. Its activity has a tremendous impact on physiology and pathology and therefore it is very tightly regulated, mainly at the level of protein stability. In addition to the very well established regulation by the ubiquitin E3 ligase adapter Keap1, recent advances have identified a novel mechanism based on signaling pathways that regulate glycogen synthase kinse-3 (GSK-3). This kinase phosphorylates specific serine residues in the Neh6 domain of Nrf2 to create a degradation domain that is then recognized by the ubiquitin ligase adapter β-TrCP and tagged for proteasome degradation by a Cullin1/Rbx1 complex. Here we review the mechanistic elements and the signaling pathways that participate in this regulation by GSK-3/β-TrCP. These pathways include those activated by ligands of tyrosine kinase, G protein-coupled, metabotropic, and ionotropic receptors that activate phosphatidyl inositol 3-kinase (PI3K)/ATK and by the canonical WNT signaling pathway, where a fraction of Nrf2 interacts with Axin1/GSK-3. Considering that free Nrf2 protein is localized in the nucleus, we propose a model termed "double flux controller" to explain how Keap1 and β-TrCP coordinate the stability of Nrf2 in several scenarios. The GSK-3/β-TrCP axis provides a novel therapeutic strategy to modulate Nrf2 activity.
Collapse
Affiliation(s)
- Antonio Cuadrado
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Investigaciones Biomedicas "Alberto Sols" UAM-CSIC, Instituto de Investigación Sanitaria La Paz (IdiPaz), and Department of Biochemistry, Faculty of Medicine, Autonomous University of Madrid, 28029 Madrid, Spain.
| |
Collapse
|
119
|
McCormick SM, Heller NM. Regulation of Macrophage, Dendritic Cell, and Microglial Phenotype and Function by the SOCS Proteins. Front Immunol 2015; 6:549. [PMID: 26579124 PMCID: PMC4621458 DOI: 10.3389/fimmu.2015.00549] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/13/2015] [Indexed: 12/11/2022] Open
Abstract
Macrophages are innate immune cells of dynamic phenotype that rapidly respond to external stimuli in the microenvironment by altering their phenotype to respond to and to direct the immune response. The ability to dynamically change phenotype must be carefully regulated to prevent uncontrolled inflammatory responses and subsequently to promote resolution of inflammation. The suppressor of cytokine signaling (SOCS) proteins play a key role in regulating macrophage phenotype. In this review, we summarize research to date from mouse and human studies on the role of the SOCS proteins in determining the phenotype and function of macrophages. We will also touch on the influence of the SOCS on dendritic cell (DC) and microglial phenotype and function. The molecular mechanisms of SOCS function in macrophages and DCs are discussed, along with how dysregulation of SOCS expression or function can lead to alterations in macrophage/DC/microglial phenotype and function and to disease. Regulation of SOCS expression by microRNA is discussed. Novel therapies and unanswered questions with regard to SOCS regulation of monocyte-macrophage phenotype and function are highlighted.
Collapse
Affiliation(s)
- Sarah M McCormick
- Anesthesiology and Critical Care Medicine, The Johns Hopkins University , Baltimore, MD , USA
| | - Nicola M Heller
- Anesthesiology and Critical Care Medicine, The Johns Hopkins University , Baltimore, MD , USA ; Anesthesiology and Critical Care Medicine, The Johns Hopkins University , Baltimore, MD , USA
| |
Collapse
|
120
|
Anti-inflammatory role of microglial alpha7 nAChRs and its role in neuroprotection. Biochem Pharmacol 2015; 97:463-472. [DOI: 10.1016/j.bcp.2015.07.032] [Citation(s) in RCA: 213] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/27/2015] [Indexed: 12/15/2022]
|
121
|
Bertrand D, Lee CHL, Flood D, Marger F, Donnelly-Roberts D. Therapeutic Potential of α7 Nicotinic Acetylcholine Receptors. Pharmacol Rev 2015; 67:1025-73. [DOI: 10.1124/pr.113.008581] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
|
122
|
Khalifeh S, Fakhfouri G, Mehr SE, Mousavizadeh K, Dehpour AR, Khodagholi F, Kazmi S, Rahimian R. Beyond the 5-HT3 receptors. Hum Exp Toxicol 2015; 34:922-31. [DOI: 10.1177/0960327114562034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Accumulation of reactive oxygen species, such as hydrogen peroxide (H2O2), generated by inflammatory cells or other pathological conditions, leads to oxidative stress, which may contribute to the neuronal degeneration observed in a wide variety of neurodegenerative disorders such as Alzheimer’s disease. Recent investigations have described effective properties of tropisetron, such as antiphlogistic action or protection against β-amyloid induced-neuroinflammation in rats. Our data revealed that H2O2-induced cell death in rat pheochromocytoma cell line (PC12) can be inhibited by tropisetron, as defined by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide assay, caspase 3 and caspase 12 levels. We further showed that tropisetron exerts its protective effects by upregulation of heme oxygenase-1, glutathione, catalase activity, and nuclear factor-erythroid 2 p45-related factor 2 level. Moreover, tropisetron was recently found to be a partial agonist of α7 nicotinic acetylcholine receptor (α7nAChR). The activation of α7nAChR could inhibit inflammatory and apoptotic signaling pathways in the oxidative stress conditions. In this study, selective α7nAChR antagonists (methyllycaconitine) reversed the effects of tropisetron on caspase 3 level. Our findings indicated that tropisetron can protect PC12 cells against H2O2-induced neurotoxicity through α7nAChR in vitro.
Collapse
Affiliation(s)
- S Khalifeh
- Department of Animal Physiology, Faculty of Biology, Kharazmi University, Tehran, Islamic Republic of Iran
| | - G Fakhfouri
- Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, Québec City, Québec, Canada. Institut universitaire en santé mentale de Québec, Québec City, Québec, Canada
- Institut Universitaire en Sante Mentale de Quebec (IUSMQ) research center, Quebec, Canada
| | - SE Mehr
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
| | - K Mousavizadeh
- Cellular and Molecular Research Center and Department of Molecular Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - AR Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
| | - F Khodagholi
- NeuroBiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran
| | - S Kazmi
- Department of Anatomical Sciences, School of Medicine, Iran University of Medical Sciences, Tehran, Islamic Republic of Iran
| | - R Rahimian
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
| |
Collapse
|
123
|
Minami SS, Shen V, Le D, Krabbe G, Asgarov R, Perez-Celajes L, Lee CH, Li J, Donnelly-Roberts D, Gan L. Reducing inflammation and rescuing FTD-related behavioral deficits in progranulin-deficient mice with α7 nicotinic acetylcholine receptor agonists. Biochem Pharmacol 2015. [PMID: 26206194 DOI: 10.1016/j.bcp.2015.07.016] [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] [Indexed: 01/11/2023]
Abstract
Mutations in the progranulin gene cause frontotemporal dementia (FTD), a debilitating neurodegenerative disease that involves atrophy of the frontal and temporal lobes and affects personality, behavior, and language. Progranulin-deficient mouse models of FTD exhibit deficits in compulsive and social behaviors reminiscent of patients with FTD, and develop excessive microgliosis and increased release of inflammatory cytokines. Activation of nicotinic acetylcholine receptors (nAChRs) by nicotine or specific α7 nAChR agonists reduces neuroinflammation. Here, we investigated whether activation of nAChRs by nicotine or α7 agonists improved the excessive inflammatory and behavioral phenotypes of a progranulin-deficient FTD mouse model. We found that treatment with selective α7 agonists, PHA-568487 or ABT-107, strongly suppressed the activation of NF-κB in progranulin-deficient cells. Treatment with ABT-107 also reduced microgliosis, decreased TNFα levels, and reduced compulsive behavior in progranulin-deficient mice. Collectively, these data suggest that targeting activation of the α7 nAChR pathway may be beneficial in decreasing neuroinflammation and reversing some of the behavioral deficits observed in progranulin-deficient FTD.
Collapse
Affiliation(s)
- S Sakura Minami
- Gladstone Institute of Neurological Diseases, 1650 Owens St., San Francisco, CA 94158, United States; Department of Neurology, University of California, San Francisco, CA 94158, United States
| | - Vivian Shen
- Gladstone Institute of Neurological Diseases, 1650 Owens St., San Francisco, CA 94158, United States
| | - David Le
- Gladstone Institute of Neurological Diseases, 1650 Owens St., San Francisco, CA 94158, United States
| | - Grietje Krabbe
- Gladstone Institute of Neurological Diseases, 1650 Owens St., San Francisco, CA 94158, United States; Department of Neurology, University of California, San Francisco, CA 94158, United States
| | - Rustam Asgarov
- Gladstone Institute of Neurological Diseases, 1650 Owens St., San Francisco, CA 94158, United States; Graduate Program in Neurochemistry and Molecular Neurobiology, Stockholm University, Sweden
| | - Liberty Perez-Celajes
- Gladstone Institute of Neurological Diseases, 1650 Owens St., San Francisco, CA 94158, United States
| | | | - Jinhe Li
- AbbVie Inc., North Chicago, IL 60064, United States
| | | | - Li Gan
- Gladstone Institute of Neurological Diseases, 1650 Owens St., San Francisco, CA 94158, United States; Department of Neurology, University of California, San Francisco, CA 94158, United States.
| |
Collapse
|
124
|
Parada E, Buendia I, Navarro E, Avendaño C, Egea J, López MG. Microglial HO-1 induction by curcumin provides antioxidant, antineuroinflammatory, and glioprotective effects. Mol Nutr Food Res 2015; 59:1690-700. [PMID: 26047311 DOI: 10.1002/mnfr.201500279] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 05/21/2015] [Accepted: 05/21/2015] [Indexed: 12/17/2022]
Abstract
SCOPE We have studied if curcumin can protect glial cells under an oxidative stress and inflammatory environment, which is known to be deleterious in neurodegeneration. METHODS AND RESULTS Primary rat glial cultures exposed to the combination of an oxidative (rotenone/oligomycin A) and a proinflammatory LPS stimuli reduced by 50% glial viability. Under these experimental conditions, curcumin afforded significant glial protection and reduction of reactive oxygen species; these effects were blocked by the HO-1 inhibitor tin protoporphyrin-IX (SnPP). These findings correlate with the observation that curcumin induced the antioxidative protein HO-1. Most interesting was the observation that the glial protective effects related to HO-1 induction were microglial specific as shown in glial cultures from LysM(Cre) Hmox(∆/∆) mice where curcumin lost its protective effect. Under LPS conditions, curcumin reduced the microglial proinflammatory markers iNOS and tumor necrosis factor, but increased the anti-inflammatory cytokine IL4. Analysis of the microglial phenotype showed that curcumin favored a ramified morphology toward a microglial alternative activated state against LPS insult also by a HO-1-dependent mechanism. CONCLUSION The curry constituent curcumin protects glial cells and promotes a microglial anti-inflammatory phenotype by a mechanism that implicates HO-1 induction; these effects may have impact on brain protection under oxidative and inflammatory conditions.
Collapse
Affiliation(s)
- Esther Parada
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa (IIS-IP), Hospital Universitario de la Princesa, Madrid, Spain
| | - Izaskun Buendia
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Elisa Navarro
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Carlos Avendaño
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Javier Egea
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa (IIS-IP), Hospital Universitario de la Princesa, Madrid, Spain
| | - Manuela G López
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa (IIS-IP), Hospital Universitario de la Princesa, Madrid, Spain
| |
Collapse
|
125
|
Dexamethasone acts as a radiosensitizer in three astrocytoma cell lines via oxidative stress. Redox Biol 2015; 5:388-397. [PMID: 26160768 PMCID: PMC4506989 DOI: 10.1016/j.redox.2015.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/13/2015] [Accepted: 06/16/2015] [Indexed: 01/08/2023] Open
Abstract
Glucocorticoids (GCs), which act on stress pathways, are well-established in the co-treatment of different kinds of tumors; however, the underlying mechanisms by which GCs act are not yet well elucidated. As such, this work investigates the role of glucocorticoids, specifically dexamethasone (DEXA), in the processes referred to as DNA damage and DNA damage response (DDR), establishing a new approach in three astrocytomas cell lines (CT2A, APP.PS1 L.1 and APP.PS1 L.3). The results show that DEXA administration increased the basal levels of gamma-H2AX foci, keeping them higher 4 h after irradiation (IR) of the cells, compared to untreated cells. This means that DEXA might cause increased radiosensitivity in these cell lines. On the other hand, DEXA did not have an apparent effect on the formation and disappearance of the 53BP1 foci. Furthermore, it was found that DEXA administered 2 h before IR led to a radical change in DNA repair kinetics, even DEXA does not affect cell cycle. It is important to highlight that DEXA produced cell death in these cell lines compared to untreated cells. Finally and most important, the high levels of gamma-H2AX could be reversed by administration of ascorbic acid, a potent blocker of reactive oxygen species, suggesting that DEXA acts by causing DNA damage via oxidative stress. These exiting findings suggest that DEXA might promote radiosensitivity in brain tumors, specifically in astrocytoma-like tumors. Dexamethasone causes DNA damage by increasing gamma-H2AX levels in three astrocytoma cell lines (CT2A, APP.PS1 L.1 and APP.PS1 L.3) Dexamethasone affects DNA repair kinetics and produces cell death in three astrocytoma cell lines (CT2A, APP.PS1 L.1 and APP.PS1 L.3) even dexamethasone does not affect any cell cycle arrest in any cell line studied. Oxidative stress appears to be one of the mechanisms of dexamethasone action in DNA damage as their effect is reversed with ascorbic acid addition.
Collapse
|
126
|
Schallner N, Pandit R, LeBlanc R, Thomas AJ, Ogilvy CS, Zuckerbraun BS, Gallo D, Otterbein LE, Hanafy KA. Microglia regulate blood clearance in subarachnoid hemorrhage by heme oxygenase-1. J Clin Invest 2015; 125:2609-25. [PMID: 26011640 DOI: 10.1172/jci78443] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 04/27/2015] [Indexed: 12/25/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) carries a 50% mortality rate. The extravasated erythrocytes that surround the brain contain heme, which, when released from damaged red blood cells, functions as a potent danger molecule that induces sterile tissue injury and organ dysfunction. Free heme is metabolized by heme oxygenase (HO), resulting in the generation of carbon monoxide (CO), a bioactive gas with potent immunomodulatory capabilities. Here, using a murine model of SAH, we demonstrated that expression of the inducible HO isoform (HO-1, encoded by Hmox1) in microglia is necessary to attenuate neuronal cell death, vasospasm, impaired cognitive function, and clearance of cerebral blood burden. Initiation of CO inhalation after SAH rescued the absence of microglial HO-1 and reduced injury by enhancing erythrophagocytosis. Evaluation of correlative human data revealed that patients with SAH have markedly higher HO-1 activity in cerebrospinal fluid (CSF) compared with that in patients with unruptured cerebral aneurysms. Furthermore, cisternal hematoma volume correlated with HO-1 activity and cytokine expression in the CSF of these patients. Collectively, we found that microglial HO-1 and the generation of CO are essential for effective elimination of blood and heme after SAH that otherwise leads to neuronal injury and cognitive dysfunction. Administration of CO may have potential as a therapeutic modality in patients with ruptured cerebral aneurysms.
Collapse
|
127
|
Aeinehband S, Lindblom RPF, Al Nimer F, Vijayaraghavan S, Sandholm K, Khademi M, Olsson T, Nilsson B, Ekdahl KN, Darreh-Shori T, Piehl F. Complement component C3 and butyrylcholinesterase activity are associated with neurodegeneration and clinical disability in multiple sclerosis. PLoS One 2015; 10:e0122048. [PMID: 25835709 PMCID: PMC4383591 DOI: 10.1371/journal.pone.0122048] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 02/06/2015] [Indexed: 12/22/2022] Open
Abstract
Dysregulation of the complement system is evident in many CNS diseases but mechanisms regulating complement activation in the CNS remain unclear. In a recent large rat genome-wide expression profiling and linkage analysis we found co-regulation of complement C3 immediately downstream of butyrylcholinesterase (BuChE), an enzyme hydrolyzing acetylcholine (ACh), a classical neurotransmitter with immunoregulatory effects. We here determined levels of neurofilament-light (NFL), a marker for ongoing nerve injury, C3 and activity of the two main ACh hydrolyzing enzymes, acetylcholinesterase (AChE) and BuChE, in cerebrospinal fluid (CSF) from patients with MS (n = 48) and non-inflammatory controls (n = 18). C3 levels were elevated in MS patients compared to controls and correlated both to disability and NFL. C3 levels were not induced by relapses, but were increased in patients with ≥9 cerebral lesions on magnetic resonance imaging and in patients with progressive disease. BuChE activity did not differ at the group level, but was correlated to both C3 and NFL levels in individual samples. In conclusion, we show that CSF C3 correlates both to a marker for ongoing nerve injury and degree of disease disability. Moreover, our results also suggest a potential link between intrathecal cholinergic activity and complement activation. These results motivate further efforts directed at elucidating the regulation and effector functions of the complement system in MS, and its relation to cholinergic tone.
Collapse
Affiliation(s)
- Shahin Aeinehband
- Department of Clinical Neuroscience, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
| | - Rickard P. F. Lindblom
- Department of Clinical Neuroscience, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden
| | - Faiez Al Nimer
- Department of Clinical Neuroscience, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden
| | - Swetha Vijayaraghavan
- Division of Alzheimer Neurobiology Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | | | - Mohsen Khademi
- Department of Clinical Neuroscience, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden
| | - Tomas Olsson
- Department of Clinical Neuroscience, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden
| | - Bo Nilsson
- Division of Clinical Immunology, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Kristina Nilsson Ekdahl
- Division of Clinical Immunology, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- School of Natural Sciences, Linnæus University, Kalmar, Sweden
| | - Taher Darreh-Shori
- Division of Alzheimer Neurobiology Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Fredrik Piehl
- Department of Clinical Neuroscience, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
128
|
Guerra-Álvarez M, Moreno-Ortega AJ, Navarro E, Fernández-Morales JC, Egea J, López MG, Cano-Abad MF. Positive allosteric modulation of alpha-7 nicotinic receptors promotes cell death by inducing Ca(2+) release from the endoplasmic reticulum. J Neurochem 2015; 133:309-19. [PMID: 25650007 DOI: 10.1111/jnc.13049] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 01/15/2015] [Accepted: 01/16/2015] [Indexed: 12/11/2022]
Abstract
Positive allosteric modulation of α7 isoform of nicotinic acetylcholine receptors (α7-nAChRs) is emerging as a promising therapeutic approach for central nervous system disorders such as schizophrenia or Alzheimer's disease. However, its effect on Ca(2+) signaling and cell viability remains controversial. This study focuses on how the type II positive allosteric modulator (PAM II) PNU120596 affects intracellular Ca(2+) signaling and cell viability. We used human SH-SY5Y neuroblastoma cells overexpressing α7-nAChRs (α7-SH) and their control (C-SH). We monitored cytoplasmic and endoplasmic reticulum (ER) Ca(2+) with Fura-2 and the genetically encoded cameleon targeting the ER, respectively. Nicotinic inward currents were measured using patch-clamp techniques. Viability was assessed using methylthiazolyl blue tetrazolium bromide or propidium iodide staining. We observed that in the presence of a nicotinic agonist, PNU120596 (i) reduced viability of α7-SH but not of C-SH cells; (ii) significantly increased inward nicotinic currents and cytosolic Ca(2+) concentration; (iii) released Ca(2+) from the ER by a Ca(2+) -induced Ca(2+) release mechanism only in α7-SH cells; (iv) was cytotoxic in rat organotypic hippocampal slice cultures; and, lastly, all these effects were prevented by selective blockade of α7-nAChRs, ryanodine receptors, or IP3 receptors. In conclusion, positive allosteric modulation of α7-nAChRs with the PAM II PNU120596 can lead to dysregulation of ER Ca(2+) , overloading of intracellular Ca(2+) , and neuronal cell death. This study focuses on how the type II positive allosteric modulator PNU120596 (PAM II PNU12) affects intracellular Ca(2+) signaling and cell viability. Using SH-SY5Y neuroblastoma cells overexpressing α7-nAChRs (α7-SH) and their control (C-SH), we find that PAM of α7-nAChRs with PNU120596: (i) increases inward calcium current (ICa ) and cytosolic Ca(2+) concentration ([Ca(2+) ]cyt ); (ii) releases Ca(2+) from the ER ([Ca(2+) ]ER ) by a Ca(2+) -induced Ca(2+) release mechanism; and (iv) reduces cell viability. These findings were corroborated in rat hippocampal organotypic cultures. [Ca(2+) ]cyt , cytosolic Ca(2+) concentration; [Ca(2+) ]ER , endoplasmic reticulum Ca(2+) concentration; α7 nAChR, α7 isoform of nicotinic acetylcholine receptors; α7-SH, SH-SY5Y stably overexpressing α7 nAChRs cells; C-SH, control SH-SY5Y cells; Nic, nicotine; PNU12, PNU120596.
Collapse
Affiliation(s)
- María Guerra-Álvarez
- Servicio de Farmacología Clínica, Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, Madrid, Spain
| | | | | | | | | | | | | |
Collapse
|
129
|
Buendia I, Egea J, Parada E, Navarro E, León R, Rodríguez-Franco MI, López MG. The melatonin-N,N-dibenzyl(N-methyl)amine hybrid ITH91/IQM157 affords neuroprotection in an in vitro Alzheimer's model via hemo-oxygenase-1 induction. ACS Chem Neurosci 2015; 6:288-96. [PMID: 25393881 DOI: 10.1021/cn5002073] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We have investigated the protective effects of ITH91/IQM157, a hybrid of melatonin and N,N-dibenzyl(N-methyl)amine, in an in vitro model of Alzheimer's disease (AD)-like pathology that combines amyloid beta (Aβ) and tau hyperphosphorylation induced by okadaic acid (OA), in the human neuroblastoma cell line SH-SY5Y. Combination of subtoxic concentrations of Aβ and OA caused a significant toxicity of 40% cell death, which mainly was apoptotic; this effect was accompanied by retraction of the cells' prolongations and accumulation of thioflavin-S stained protein aggregates. In this toxicity model, ITH91/IQM157 (1-1000 nM) reduced cell death measured as MTT reduction; at 100 nM, it prevented apoptosis, retraction of prolongations, and Aβ aggregates. The protective actions of ITH91/IQM157 were blocked by mecamylamine, luzindol, chelerythrine, PD98059, LY294002, and SnPP. We show that the combination of melatonin with a fragment endowed with AChE inhibition in a unique chemical structure, ITH91/IQM157, can reduce neuronal cell death induced by Aβ and OA by a signaling pathway that implicates both nicotinic and melatonin receptors, PKC, Akt, ERK1/2, and induction of hemoxygenase-1.
Collapse
Affiliation(s)
- Izaskun Buendia
- Instituto
Teófilo Hernando (ITH), Universidad Autónoma de Madrid, Madrid 28029, Spain
- Departamento
de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain
- Instituto
de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid 28029, Spain
| | - Javier Egea
- Instituto
Teófilo Hernando (ITH), Universidad Autónoma de Madrid, Madrid 28029, Spain
- Departamento
de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain
- Instituto
de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid 28029, Spain
| | - Esther Parada
- Instituto
Teófilo Hernando (ITH), Universidad Autónoma de Madrid, Madrid 28029, Spain
- Departamento
de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain
| | - Elisa Navarro
- Instituto
Teófilo Hernando (ITH), Universidad Autónoma de Madrid, Madrid 28029, Spain
- Departamento
de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain
| | - Rafael León
- Instituto
Teófilo Hernando (ITH), Universidad Autónoma de Madrid, Madrid 28029, Spain
- Departamento
de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain
- Instituto
de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid 28029, Spain
| | - María Isabel Rodríguez-Franco
- Instituto
de Química Médica, Consejo Superior de Investigaciones Científicas (IQM-CSIC), C/Juan de la Cierva 3, 28006 Madrid, Spain
| | - Manuela G. López
- Instituto
Teófilo Hernando (ITH), Universidad Autónoma de Madrid, Madrid 28029, Spain
- Departamento
de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain
- Instituto
de Investigación Sanitaria, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid 28029, Spain
| |
Collapse
|
130
|
Egea J, Buendia I, Parada E, Navarro E, Rada P, Cuadrado A, López MG, García AG, León R. Melatonin-sulforaphane hybrid ITH12674 induces neuroprotection in oxidative stress conditions by a 'drug-prodrug' mechanism of action. Br J Pharmacol 2015; 172:1807-21. [PMID: 25425158 DOI: 10.1111/bph.13025] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 11/03/2014] [Accepted: 11/19/2014] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND AND PURPOSE Neurodegenerative diseases are a major problem afflicting ageing populations; however, there are no effective treatments to stop their progression. Oxidative stress and neuroinflammation are common factors in their pathogenesis. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the master regulator of oxidative stress, and melatonin is an endogenous hormone with antioxidative properties that reduces its levels with ageing. We have designed a new compound that combines the effects of melatonin with Nrf2 induction properties, with the idea of achieving improved neuroprotective properties. EXPERIMENTAL APPROACH Compound ITH12674 is a hybrid of melatonin and sulforaphane designed to exert a dual drug-prodrug mechanism of action. We obtained the proposed hybrid in a single step. To test its neuroprotective properties, we used different in vitro models of oxidative stress related to neurodegenerative diseases and brain ischaemia. KEY RESULTS ITH12674 showed an improved neuroprotective profile compared to that of melatonin and sulforaphane. ITH12674 (i) mediated a concentration-dependent protective effect in cortical neurons subjected to oxidative stress; (ii) decreased reactive oxygen species production; (iii) augmented GSH concentrations in cortical neurons; (iv) enhanced the Nrf2-antioxidant response element transcriptional response in transfected HEK293T cells; and (v) protected organotypic cultures of hippocampal slices subjected to oxygen and glucose deprivation and re-oxygenation from stress by increasing the expression of haem oxygenase-1 and reducing free radical production. CONCLUSION AND IMPLICATIONS ITH12674 combines the signalling pathways of the parent compounds to improve its neuroprotective properties. This opens a new line of research for such hybrid compounds to treat neurodegenerative diseases.
Collapse
Affiliation(s)
- Javier Egea
- Departamento de Farmacología y Terapéutica, Instituto Teófilo Hernando de I + D del medicamento Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain; Instituto de Investigación Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, Madrid, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
131
|
High therapeutic potential of positive allosteric modulation of α7 nAChRs in a rat model of traumatic brain injury: proof-of-concept. Brain Res Bull 2015; 112:35-41. [PMID: 25647232 DOI: 10.1016/j.brainresbull.2015.01.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/15/2015] [Accepted: 01/23/2015] [Indexed: 12/25/2022]
Abstract
There are currently no clinically efficacious drug therapies to treat brain damage secondary to traumatic brain injury (TBI). In this proof-of-concept study, we used a controlled cortical impact model of TBI in young adult rats to explore a novel promising approach that utilizes PNU-120596, a previously reported highly selective Type-II positive allosteric modulator (α7-PAM) of α7 nicotinic acetylcholine receptors (nAChRs). α7-PAMs enhance and prolong α7 nAChR activation, but do not activate α7 nAChRs when administered without an agonist. The rational basis for the use of an α7-PAM as a post-TBI treatment is tripartite and arises from: (1) the intrinsic ability of brain injury to elevate extracellular levels of choline (a ubiquitous cell membrane-building material and a selective endogenous agonist of α7 nAChRs) due to the breakdown of cell membranes near the site and time of injury; (2) the ubiquitous expression of functional α7 nAChRs in neuronal and glial/immune brain cells; and (3) the potent neuroprotective and anti-inflammatory effects of α7 nAChR activation. Therefore, both neuroprotective and anti-inflammatory effects can be achieved post-TBI by targeting only a single player (i.e., the α7 nAChR) using α7-PAMs to enhance the activation of α7 nAChRs by injury-elevated extracellular choline. Our data support this hypothesis and demonstrate that subcutaneous administration of PNU-120596 post-TBI in young adult rats significantly reduces both brain cell damage and reactive gliosis. Therefore, our results introduce post-TBI systemic administration of α7-PAMs as a promising therapeutic intervention that could significantly restrict brain injury post-TBI and facilitate recovery of TBI patients.
Collapse
|
132
|
Tasca CI, Dal-Cim T, Cimarosti H. In vitro oxygen-glucose deprivation to study ischemic cell death. Methods Mol Biol 2015; 1254:197-210. [PMID: 25431067 DOI: 10.1007/978-1-4939-2152-2_15] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Oxygen-glucose deprivation (OGD ) is widely used as an in vitro model for stroke, showing similarities with the in vivo models of brain ischemia. In order to perform OGD, cell or tissue cultures, such as primary neurons or organotypic slices, and acutely prepared tissue slices are usually incubated in a glucose-free medium under a deoxygenated atmosphere, for example in a hypoxic chamber. Here, we describe the step-by-step procedure to expose cultures and acute slices to OGD, focusing on the most suitable methods for assessing cellular death and/or viability. OGD is a simple yet highly useful technique, not only for the elucidation of the role of key cellular and molecular mechanisms underlying brain ischemia, but also for the development of novel neuroprotective strategies.
Collapse
Affiliation(s)
- Carla I Tasca
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário - Trindade 88040-900, Florianópolis, SC, Brazil
| | | | | |
Collapse
|
133
|
Fakhfouri G, Mousavizadeh K, Mehr SE, Dehpour AR, Zirak MR, Ghia JE, Rahimian R. From Chemotherapy-Induced Emesis to Neuroprotection: Therapeutic Opportunities for 5-HT3 Receptor Antagonists. Mol Neurobiol 2014; 52:1670-1679. [DOI: 10.1007/s12035-014-8957-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 10/21/2014] [Indexed: 01/11/2023]
|
134
|
Chalcones as positive allosteric modulators of α7 nicotinic acetylcholine receptors: A new target for a privileged structure. Eur J Med Chem 2014; 86:724-39. [DOI: 10.1016/j.ejmech.2014.09.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/09/2014] [Accepted: 09/11/2014] [Indexed: 12/26/2022]
|
135
|
Freitas AE, Egea J, Buendía I, Navarro E, Rada P, Cuadrado A, Rodrigues ALS, López MG. Agmatine induces Nrf2 and protects against corticosterone effects in hippocampal neuronal cell line. Mol Neurobiol 2014; 51:1504-19. [PMID: 25084759 DOI: 10.1007/s12035-014-8827-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 07/21/2014] [Indexed: 12/15/2022]
Abstract
Hyperactivation of the hypothalamic-pituitary-adrenal axis is a common finding in major depression; this may lead to increased levels of cortisol, which are known to cause oxidative stress imbalance and apoptotic neuronal cell death, particularly in the hippocampus, a key region implicated in mood regulation. Agmatine, an endogenous metabolite of L-arginine, has been proposed for the treatment of major depression. Corticosterone induced apoptotic cell death and increased ROS production in cultured hippocampal neuronal cells, effects that were abolished in a concentration- and time-dependent manner by agmatine. Interestingly, the combination of sub-effective concentrations of agmatine with fluoxetine or imipramine afforded synergic protection. The neuroprotective effect of agmatine was abolished by yohimbine (α2-adrenoceptor antagonist), ketanserin (5-HT2A receptor antagonist), LY294002 (PI3K inhibitor), PD98059 (MEK1/2 inhibitor), SnPP (HO-1 inhibitor), and cycloheximide (protein synthesis inhibitor). Agmatine increased Akt and ERK phosphorylation and induced the transcription factor Nrf2 and the proteins HO-1 and GCLc; induction of these proteins was prevented by yohimbine, ketanserin, LY294002, and PD98059. In conclusion, agmatine affords neuroprotection against corticosterone effects by a mechanism that implicates Nrf2 induction via α2-adrenergic and 5-HT2A receptors, Akt and ERK pathways, and HO-1 and GCLc expression.
Collapse
Affiliation(s)
- Andiara E Freitas
- Instituto Teofilo Hernando, Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, 4-28029, Madrid, Spain,
| | | | | | | | | | | | | | | |
Collapse
|
136
|
Jiang Y, Li L, Liu B, Zhang Y, Chen Q, Li C. Vagus nerve stimulation attenuates cerebral ischemia and reperfusion injury via endogenous cholinergic pathway in rat. PLoS One 2014; 9:e102342. [PMID: 25036185 PMCID: PMC4103831 DOI: 10.1371/journal.pone.0102342] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/16/2014] [Indexed: 12/02/2022] Open
Abstract
Inflammation and apoptosis play critical roles in the acute progression of ischemic injury pathology. Emerging evidence indicates that vagus nerve stimulation (VNS) following focal cerebral ischemia and reperfusion (I/R) may be neuroprotective by limiting infarct size. However, the underlying molecular mechanisms remain unclear. In this study, we investigated whether the protective effects of VNS in acute cerebral I/R injury were associated with anti-inflammatory and anti-apoptotic processes. Male Sprague-Dawley (SD) rats underwent VNS at 30 min after focal cerebral I/R surgery. Twenty-four h after reperfusion, neurological deficit scores, infarct volume, and neuronal apoptosis were evaluated. In addition, the levels of pro-inflammatory cytokines were detected using enzyme-linked immune sorbent assay (ELISA), and immunofluorescence staining for the endogenous "cholinergic anti-inflammatory pathway" was also performed. The protein expression of a7 nicotinic acetylcholine receptor (a7nAchR), phosphorylated Akt (p-Akt), and cleaved caspase 3 in ischemic penumbra were determined with Western blot analysis. I/R rats treated with VNS (I/R+VNS) had significantly better neurological deficit scores, reduced cerebral infarct volume, and decreased number of TdT mediated dUTP nick end labeling (TUNEL) positive cells. Furthermore, in the ischemic penumbra of the I/R+VNS group, the levels of pro-inflammatory cytokines and cleaved caspase 3 protein were significantly decreased, and the levels of a7nAchR and phosphorylated Akt were significantly increased relative to the I/R alone group. These results indicate that VNS is neuroprotective in acute cerebral I/R injury by suppressing inflammation and apoptosis via activation of cholinergic and a7nAchR/Akt pathways.
Collapse
Affiliation(s)
- Ying Jiang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Longling Li
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Bin Liu
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yanhong Zhang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qian Chen
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Changqing Li
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| |
Collapse
|
137
|
Therapeutically targeting neuroinflammation and microglia after acute ischemic stroke. BIOMED RESEARCH INTERNATIONAL 2014; 2014:297241. [PMID: 25089266 PMCID: PMC4095830 DOI: 10.1155/2014/297241] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 06/10/2014] [Indexed: 12/11/2022]
Abstract
Inflammation has a pivotal role in the pathogenesis of ischemic stroke, and recent studies posit that inflammation acts as a double-edged sword, not only detrimentally augmenting secondary injury, but also potentially promoting recovery. An initial event of inflammation in ischemic stroke is the activation of microglia, leading to production of both pro- and anti-inflammatory mediators acting through multiple receptor signaling pathways. In this review, we discuss the role of microglial mediators in acute ischemic stroke and elaborate on preclinical and clinical studies focused on microglia in stroke models. Understanding how microglia can lead to both pro- and anti-inflammatory responses may be essential to implement therapeutic strategies using immunomodulatory interventions in ischemic stroke.
Collapse
|
138
|
Leite PEC, Gandía L, de Pascual R, Nanclares C, Colmena I, Santos WC, Lagrota-Candido J, Quirico-Santos T. Selective activation of α7 nicotinic acetylcholine receptor (nAChRα7) inhibits muscular degeneration in mdx dystrophic mice. Brain Res 2014; 1573:27-36. [PMID: 24833065 DOI: 10.1016/j.brainres.2014.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 04/30/2014] [Accepted: 05/03/2014] [Indexed: 02/07/2023]
Abstract
Amount evidence indicates that α7 nicotinic acetylcholine receptor (nAChRα7) activation reduces production of inflammatory mediators. This work aimed to verify the influence of endogenous nAChRα7 activation on the regulation of full-blown muscular inflammation in mdx mouse with Duchenne muscular dystrophy. We used mdx mice with 3 weeks-old at the height myonecrosis, and C57 nAChRα7(+/+) wild-type and nAChRα7(-/-) knockout mice with muscular injury induced with 60µL 0.5% bupivacaine (bp) in the gastrocnemius muscle. Pharmacological treatment included selective nAChRα7 agonist PNU282987 (0.3mg/kg and 1.0mg/kg) and the antagonist methyllycaconitine (MLA at 1.0mg/kg) injected intraperitoneally for 7 days. Selective nAChRα7 activation of mdx mice with PNU282987 reduced circulating levels of lactate dehydrogenase (LDH, a marker of cell death by necrosis) and the area of perivascular inflammatory infiltrate, and production of inflammatory mediators TNFα and metalloprotease MMP-9 activity. Conversely, PNU282987 treatment increased MMP-2 activity, an indication of muscular tissue remodeling associated with regeneration, in both mdx mice and WTα7 mice with bp-induced muscular lesion. Treatment with PNU282987 had no effect on α7KO, and MLA abolished the nAChRα7 agonist-induced anti-inflammatory effect in both mdx and WT. In conclusion, nAChRα7 activation inhibits muscular inflammation and activates tissue remodeling by increasing muscular regeneration. These effects were not accompanied with fibrosis and/or deposition of non-functional collagen. The nAChRα7 activation may be considered as a potential target for pharmacological strategies to reduce inflammation and activate mechanisms of muscular regeneration.
Collapse
Affiliation(s)
- Paulo Emílio Correa Leite
- Department of Cellular and Molecular Biology, Fluminense Federal University, Rio de Janeiro, Brazil.
| | - Luís Gandía
- Instituto Teófilo Hernando, Department of Pharmacology and Therapeutics, Autonomous University of Madrid, Madrid, Spain.
| | - Ricardo de Pascual
- Instituto Teófilo Hernando, Department of Pharmacology and Therapeutics, Autonomous University of Madrid, Madrid, Spain.
| | - Carmen Nanclares
- Instituto Teófilo Hernando, Department of Pharmacology and Therapeutics, Autonomous University of Madrid, Madrid, Spain.
| | - Inés Colmena
- Instituto Teófilo Hernando, Department of Pharmacology and Therapeutics, Autonomous University of Madrid, Madrid, Spain.
| | - Wilson C Santos
- Instituto Teófilo Hernando, Department of Pharmacology and Therapeutics, Autonomous University of Madrid, Madrid, Spain; Department of Pharmacy Administration, Fluminense Federal University, Rio de Janeiro, Brazil.
| | | | - Thereza Quirico-Santos
- Department of Cellular and Molecular Biology, Fluminense Federal University, Rio de Janeiro, Brazil.
| |
Collapse
|
139
|
The Yin and Yang of innate immunity in stroke. BIOMED RESEARCH INTERNATIONAL 2014; 2014:807978. [PMID: 24877133 PMCID: PMC4021995 DOI: 10.1155/2014/807978] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/15/2014] [Indexed: 11/18/2022]
Abstract
Immune system plays an elementary role in the pathophysiological progress of ischemic stroke. It consists of innate and adaptive immune system. Activated within minutes after ischemic onset, innate immunity is responsible for the elimination of necrotic cells and tissue repair, while it is critically involved in the initiation and amplification of poststroke inflammation that amplifies ischemic damage to the brain tissue. Innate immune response requires days to be fully developed, providing a considerable time window for therapeutic intervention, suggesting prospect of novel immunomodulatory therapies against poststroke inflammation-induced brain injury. However, obstacles still exist and a comprehensive understanding of ischemic stroke and innate immune reaction is essential. In this review, we highlighted the current experimental and clinical data depicting the innate immune response following ischemic stroke, mainly focusing on the recognition of damage-associated molecular patterns, activation and recruitment of innate immune cells, and involvement of various cytokines. In addition, clinical trials targeting innate immunity were also documented regardless of the outcome, stressing the requirements for further investigation.
Collapse
|
140
|
Involvement of α7 nAChR subtype in rat oxaliplatin-induced neuropathy: Effects of selective activation. Neuropharmacology 2014; 79:37-48. [DOI: 10.1016/j.neuropharm.2013.10.034] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 10/14/2013] [Accepted: 10/28/2013] [Indexed: 12/12/2022]
|
141
|
Perinatal hypoxia-ischemia reduces α 7 nicotinic receptor expression and selective α 7 nicotinic receptor stimulation suppresses inflammation and promotes microglial Mox phenotype. BIOMED RESEARCH INTERNATIONAL 2014; 2014:718769. [PMID: 24757672 PMCID: PMC3976804 DOI: 10.1155/2014/718769] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/30/2014] [Accepted: 01/30/2014] [Indexed: 11/17/2022]
Abstract
Inflammation plays a central role in neonatal brain injury. During brain inflammation the resident macrophages of the brain, the microglia cells, are rapidly activated. In the periphery, α7 nicotinic acetylcholine receptors (α7R) present on macrophages can regulate inflammation by suppressing cytokine release. In the current study we investigated α7R expression in neonatal mice after hypoxia-ischemia (HI). We further examined possible anti-inflammatory role of α7R stimulation in vitro and microglia polarization after α7R agonist treatment. Real-time PCR analysis showed a 33% reduction in α7R expression 72 h after HI. Stimulation of primary microglial cells with LPS in combination with increasing doses of the selective α7R agonist AR-R 17779 significantly attenuated TNFα release and increased α7R transcript in microglial cells. Gene expression of M1 markers CD86 and iNOS, as well as M2 marker CD206 was not influenced by LPS and/or α7R agonist treatment. Further, Mox markers heme oxygenase (Hmox1) and sulforedoxin-1 (Srx1) were significantly increased, suggesting a polarization towards the Mox phenotype after α7R stimulation. Thus, our data suggest a role for the α7R also in the neonatal brain and support the anti-inflammatory role of α7R in microglia, suggesting that α7R stimulation could enhance the polarization towards a reparative Mox phenotype.
Collapse
|
142
|
Parada E, Buendia I, León R, Negredo P, Romero A, Cuadrado A, López MG, Egea J. Neuroprotective effect of melatonin against ischemia is partially mediated by alpha-7 nicotinic receptor modulation and HO-1 overexpression. J Pineal Res 2014; 56:204-12. [PMID: 24350834 DOI: 10.1111/jpi.12113] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 12/13/2013] [Indexed: 01/20/2023]
Abstract
Melatonin has been widely studied as a protective agent against oxidative stress. However, the molecular mechanisms underlying neuroprotection in neurodegeneration and ischemic stroke are not yet well understood. In this study, we evaluated the neuroprotective/antioxidant mechanism of action of melatonin in organotypic hippocampal cultures (OHCs) as well as in photothrombotic stroke model in vivo. Melatonin (0.1, 1, and 10 μM) incubated postoxygen and glucose deprivation (OGD) showed a concentration-dependent protection; maximum protection was achieved at 10 μM (90% protection). Next, OHCs were exposed to 10 μM melatonin at different post-OGD times; the protective effect of melatonin was maintained at 0, 1, and 2 hr post-OGD treatment, but it was lost at 6 hr post-OGD. The protective effect of melatonin and the reduction in OGD-induced ROS were prevented by luzindole (melatonin antagonist) and α-bungarotoxin (α-Bgt, a selective α7 nAChR antagonist). In Nrf2 knockout mice, the protective effect of melatonin was reduced by 40% compared with controls. Melatonin, incubated 0, 1, and 2 hr post-OGD, increased the expression of heme oxygenase-1 (HO-1), and this overexpression was prevented by luzindole and α-bungarotoxin. Finally, administration of 15 mg/kg melatonin following the induction of photothrombotic stroke in vivo, reduced infarct size (50%), and improved motor skills; this effect was partially lost in 0.1 mg/kg methyllycaconitine (MLA, selective α7 nAChR antagonist)-treated mice. Taken together, these results demonstrate that postincubation of melatonin provides a protective effect that, at least in part, depends on nicotinic receptor activation and overexpression of HO-1.
Collapse
Affiliation(s)
- Esther Parada
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Instituto Teófilo Hernando, Universidad Autónoma de Madrid, Madrid, Spain
| | | | | | | | | | | | | | | |
Collapse
|
143
|
Uteshev VV. The therapeutic promise of positive allosteric modulation of nicotinic receptors. Eur J Pharmacol 2014; 727:181-5. [PMID: 24530419 DOI: 10.1016/j.ejphar.2014.01.072] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/17/2014] [Accepted: 01/24/2014] [Indexed: 12/11/2022]
Abstract
In the central nervous system, deficits in cholinergic neurotransmission correlate with decreased attention and cognitive impairment, while stimulation of neuronal nicotinic acetylcholine receptors improves attention, cognitive performance and neuronal resistance to injury as well as produces robust analgesic and anti-inflammatory effects. The rational basis for the therapeutic use of orthosteric agonists and positive allosteric modulators (PAMs) of nicotinic receptors arises from the finding that functional nicotinic receptors are ubiquitously expressed in neuronal and non-neuronal tissues including brain regions highly vulnerable to traumatic and ischemic types of injury (e.g., cortex and hippocampus). Moreover, functional nicotinic receptors do not vanish in age-, disease- and trauma-related neuropathologies, but their expression and/or activation levels decline in a subunit- and brain region-specific manner. Therefore, augmenting the endogenous cholinergic tone by nicotinic agents is possible and may offset neurological impairments associated with cholinergic hypofunction. Importantly, because neuronal damage elevates extracellular levels of choline (a selective agonist of α7 nicotinic acetylcholine receptors) near the site of injury, α7-PAM-based treatments may augment pathology-activated α7-dependent auto-therapies where and when they are most needed (i.e., in the penumbra, post-injury). Thus, nicotinic-PAM-based treatments are expected to augment the endogenous cholinergic tone in a spatially and temporally restricted manner creating the potential for differential efficacy and improved safety as compared to exogenous orthosteric nicotinic agonists that activate nicotinic receptors indiscriminately. In this review, I will summarize the existing trends in therapeutic applications of nicotinic PAMs.
Collapse
Affiliation(s)
- Victor V Uteshev
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
| |
Collapse
|
144
|
Kalappa BI, Sun F, Johnson SR, Jin K, Uteshev VV. A positive allosteric modulator of α7 nAChRs augments neuroprotective effects of endogenous nicotinic agonists in cerebral ischaemia. Br J Pharmacol 2014; 169:1862-78. [PMID: 23713819 DOI: 10.1111/bph.12247] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 05/08/2013] [Accepted: 05/16/2013] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Activation of α7 nicotinic acetylcholine receptors (nAChRs) can be neuroprotective. However, endogenous choline and ACh have not been regarded as potent neuroprotective agents because physiological levels of choline/ACh do not produce neuroprotective levels of α7 activation. This limitation may be overcome by the use of type-II positive allosteric modulators (PAMs-II) of α7 nAChRs, such as 1-(5-chloro-2,4-dimethoxyphenyl)-3-(5-methylisoxazol-3-yl)-urea (PNU-120596). This proof-of-concept study presents a novel neuroprotective paradigm that converts endogenous choline/ACh into potent neuroprotective agents in cerebral ischaemia by inhibiting α7 nAChR desensitization using PNU-120596. EXPERIMENTAL APPROACH An electrophysiological ex vivo cell injury assay (to quantify the susceptibility of hippocampal neurons to acute injury by complete oxygen and glucose deprivation; COGD) and an in vivo middle cerebral artery occlusion model of ischaemia were used in rats. KEY RESULTS Choline (20-200 μM) in the presence, but not absence of 1 μM PNU-120596 significantly delayed anoxic depolarization/injury of hippocampal CA1 pyramidal neurons, but not CA1 stratum radiatum interneurons, subjected to COGD in acute hippocampal slices and these effects were blocked by 20 nM methyllycaconitine, a selective α7 antagonist, thus, activation of α7 nAChRs was required. PNU-120596 alone was ineffective ex vivo. In in vivo experiments, both pre- and post-ischaemia treatments with PNU-120596 (30 mg·kg(-1) , s.c. and 1 mg·kg(-1) , i.v., respectively) significantly reduced the cortical/subcortical infarct volume caused by transient focal cerebral ischaemia. PNU-120596 (1 mg·kg(-1) , i.v., 30 min post-ischaemia) remained neuroprotective in rats subjected to a choline-deficient diet for 14 days prior to experiments. CONCLUSIONS AND IMPLICATIONS PNU-120596 and possibly other PAMs-II significantly improved neuronal survival in cerebral ischaemia by augmenting neuroprotective effects of endogenous choline/ACh.
Collapse
Affiliation(s)
- Bopanna I Kalappa
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | | | | | | | | |
Collapse
|
145
|
Majid A. Neuroprotection in stroke: past, present, and future. ISRN NEUROLOGY 2014; 2014:515716. [PMID: 24579051 PMCID: PMC3918861 DOI: 10.1155/2014/515716] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Accepted: 09/16/2013] [Indexed: 01/05/2023]
Abstract
Stroke is a devastating medical condition, killing millions of people each year and causing serious injury to many more. Despite advances in treatment, there is still little that can be done to prevent stroke-related brain damage. The concept of neuroprotection is a source of considerable interest in the search for novel therapies that have the potential to preserve brain tissue and improve overall outcome. Key points of intervention have been identified in many of the processes that are the source of damage to the brain after stroke, and numerous treatment strategies designed to exploit them have been developed. In this review, potential targets of neuroprotection in stroke are discussed, as well as the various treatments that have been targeted against them. In addition, a summary of recent progress in clinical trials of neuroprotective agents in stroke is provided.
Collapse
Affiliation(s)
- Arshad Majid
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385A Glossop Road, Sheffield S10 2HQ, UK
- Department of Neurology and Manchester Academic Health Sciences Centre, Salford Royal Hospital, Stott Lane, Salford M6 8HD, UK
| |
Collapse
|
146
|
Microglial responses after ischemic stroke and intracerebral hemorrhage. Clin Dev Immunol 2013; 2013:746068. [PMID: 24223607 PMCID: PMC3810327 DOI: 10.1155/2013/746068] [Citation(s) in RCA: 289] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 08/06/2013] [Accepted: 08/28/2013] [Indexed: 12/18/2022]
Abstract
Stroke is a leading cause of death worldwide. Ischemic stroke is caused by blockage of blood vessels in the brain leading to tissue death, while intracerebral hemorrhage (ICH) occurs when a blood vessel ruptures, exposing the brain to blood components. Both are associated with glial toxicity and neuroinflammation. Microglia, as the resident immune cells of the central nervous system (CNS), continually sample the environment for signs of injury and infection. Under homeostatic conditions, they have a ramified morphology and phagocytose debris. After stroke, microglia become activated, obtain an amoeboid morphology, and release inflammatory cytokines (the M1 phenotype). However, microglia can also be alternatively activated, performing crucial roles in limiting inflammation and phagocytosing tissue debris (the M2 phenotype). In rodent models, microglial activation occurs very early after stroke and ICH; however, their specific roles in injury and repair remain unclear. This review summarizes the literature on microglial responses after ischemic stroke and ICH, highlighting the mediators of microglial activation and potential therapeutic targets for each condition.
Collapse
|
147
|
Sun F, Jin K, Uteshev VV. A type-II positive allosteric modulator of α7 nAChRs reduces brain injury and improves neurological function after focal cerebral ischemia in rats. PLoS One 2013; 8:e73581. [PMID: 23951360 PMCID: PMC3739732 DOI: 10.1371/journal.pone.0073581] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 07/26/2013] [Indexed: 11/19/2022] Open
Abstract
In the absence of clinically-efficacious therapies for ischemic stroke there is a critical need for development of new therapeutic concepts and approaches for prevention of brain injury secondary to cerebral ischemia. This study tests the hypothesis that administration of PNU-120596, a type-II positive allosteric modulator (PAM-II) of α7 nicotinic acetylcholine receptors (nAChRs), as long as 6 hours after the onset of focal cerebral ischemia significantly reduces brain injury and neurological deficits in an animal model of ischemic stroke. Focal cerebral ischemia was induced by a transient (90 min) middle cerebral artery occlusion (MCAO). Animals were then subdivided into two groups and injected intravenously (i.v.) 6 hours post-MCAO with either 1 mg/kg PNU-120596 (treated group) or vehicle only (untreated group). Measurements of cerebral infarct volumes and neurological behavioral tests were performed 24 hrs post-MCAO. PNU-120596 significantly reduced cerebral infarct volume and improved neurological function as evidenced by the results of Bederson, rolling cylinder and ladder rung walking tests. These results forecast a high therapeutic potential for PAMs-II as effective recruiters and activators of endogenous α7 nAChR-dependent cholinergic pathways to reduce brain injury and improve neurological function after cerebral ischemic stroke.
Collapse
Affiliation(s)
- Fen Sun
- University of North Texas Health Science Center, Department of Pharmacology and Neuroscience, Fort Worth, TX, United States of America
| | - Kunlin Jin
- University of North Texas Health Science Center, Department of Pharmacology and Neuroscience, Fort Worth, TX, United States of America
| | - Victor V. Uteshev
- University of North Texas Health Science Center, Department of Pharmacology and Neuroscience, Fort Worth, TX, United States of America
- * E-mail:
| |
Collapse
|