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Ganesh T. Targeting EP2 Receptor for Drug Discovery: Strengths, Weaknesses, Opportunities, and Threats (SWOT) Analysis. J Med Chem 2023; 66:9313-9324. [PMID: 37458373 PMCID: PMC10388357 DOI: 10.1021/acs.jmedchem.3c00655] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Indexed: 07/28/2023]
Abstract
Cyclooxygenase-1 and -2 (COX1 and COX2) derived endogenous ligand prostaglandin-E2 (PGE2) triggers several physiological and pathological conditions. It mediates signaling through four G-protein coupled receptors, EP1, EP2, EP3, and EP4. Among these, EP2 is expressed throughout the body including the brain and uterus. The functional role of EP2 has been extensively studied using EP2 gene knockout mice, cellular models, and selective small molecule agonists and antagonists for this receptor. The efficacy data from in vitro and in vivo animal models indicate that EP2 receptor is a major proinflammatory mediator with deleterious functions in a variety of diseases suggesting a path forward for EP2 inhibitors as the next generation of selective anti-inflammatory and antiproliferative agents. Interestingly in certain diseases, EP2 action is beneficial; therefore, EP2 agonists seem to be clinically useful. Here, we highlight the strengths, weaknesses, opportunities, and potential threats (SWOT analysis) for targeting EP2 receptor for therapeutic development for a variety of unmet clinical needs.
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Affiliation(s)
- Thota Ganesh
- Department of Pharmacology and Chemical
Biology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
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2
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Qin YR, Ma CQ, Jiang JH, Wang DP, Zhang QQ, Liu MR, Zhao HR, Fang Q, Liu Y. Artesunate restores mitochondrial fusion-fission dynamics and alleviates neuronal injury in Alzheimer's disease models. J Neurochem 2022; 162:290-304. [PMID: 35598091 DOI: 10.1111/jnc.15620] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 04/01/2022] [Accepted: 04/26/2022] [Indexed: 11/29/2022]
Abstract
Alzheimer's disease (AD) remains a leading cause of dementia and no therapy that reverses underlying neurodegeneration is available. Recent studies suggest the protective role of artemisinin, an antimalarial drug, in neurological disorders. In this study, we investigated the therapeutic potential of artesunate, a water-soluble derivative of artemisinin, on amyloid-beta (Aβ)-treated challenged microglial BV-2, neuronal N2a cells, and the amyloid precursor protein/presenilin (APP/PS1) mice model. We found that Aβ significantly induced multiple AD-related phenotypes, including increased expression/production of pro-inflammatory cytokines from microglial cells, enhanced cellular and mitochondrial production of reactive oxygen species, promoted mitochondrial fission, inhibited mitochondrial fusion, suppressed mitophagy or biogenesis in both cell types, stimulated apoptosis of neuronal cells, and microglia-induced killing of neurons. All these in vitro phenotypes were attenuated by artesunate. In addition, the over-expression of the mitochondrial fission protein Drp-1, or down-regulation of the mitochondrial fusion protein OPA-1 both reduced the therapeutic benefits of artesunate. Artesunate also alleviated AD phenotypes in APP/PS1 mice, reducing Aβ deposition, and reversing deficits in memory and learning. Artesunate protects neuronal and microglial cells from AD pathology, both in vitro and in vivo. Maintaining mitochondrial dynamics and simultaneously targeting multiple AD pathogenic mechanisms are associated with the protective effects of artesunate. Consequently, artesunate may become a promising therapeutic for AD.
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Affiliation(s)
- Yi-Ren Qin
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Chi-Qian Ma
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jian-Hua Jiang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Da-Peng Wang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Quan-Quan Zhang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Mei-Rong Liu
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Hong-Ru Zhao
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Qi Fang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yang Liu
- Department of Neurology, Saarland University, Homburg, Germany
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Rawat V, Banik A, Amaradhi R, Rojas A, Taval S, Nagy T, Dingledine R, Ganesh T. Pharmacological antagonism of EP2 receptor does not modify basal cardiovascular and respiratory function, blood cell counts, and bone morphology in animal models. Biomed Pharmacother 2022; 147:112646. [PMID: 35091236 PMCID: PMC8854338 DOI: 10.1016/j.biopha.2022.112646] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/31/2021] [Accepted: 01/12/2022] [Indexed: 01/12/2023] Open
Abstract
The EP2 receptor has emerged as a therapeutic target with exacerbating role in disease pathology for a variety of peripheral and central nervous system disorders. We and others have recently demonstrated beneficial effects of EP2 antagonists in preclinical models of neuroinflammation and peripheral inflammation. However, it was earlier reported that mice with global EP2 knockout (KO) display adverse phenotypes on fertility and blood pressure. Other studies indicated that EP2 activation with an agonist has a beneficial effect of healing fractured bone in animal models. These results impeded the development of EP2 antagonists, and EP2 antagonism as therapeutic strategy. To determine whether treatment with EP2 antagonist mimics the adverse phenotypes of the EP2 global KO mouse, we tested two EP2 antagonists TG11-77. HCl and TG6-10-1 in mice and rats while they are on normal or high-salt diet, and by two different administration protocols (acute and chronic). There were no adverse effects of the antagonists on systolic and diastolic blood pressure, heart rate, respiratory function in mice and rats regardless of rodents being on a regular or high salt diet. Furthermore, chronic exposure to TG11-77. HCl produced no adverse effects on blood cell counts, bone-volume and bone-mineral density in mice. Our findings argue against adverse effects on cardiovascular and respiratory systems, blood counts and bone structure in healthy rodents from the use of small molecule reversible antagonists for EP2, in contrast to the genetic ablation model. This study paves the way for advancing therapeutic applications of EP2 antagonists against diseases involving EP2 dysfunction.
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Affiliation(s)
- Varun Rawat
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Avijit Banik
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Radhika Amaradhi
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Asheebo Rojas
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | | | - Tamas Nagy
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens GA 30602
| | - Raymond Dingledine
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Thota Ganesh
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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4
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Nagano T, Tsuda N, Fujimura K, Ikezawa Y, Higashi Y, Kimura SH. Prostaglandin E 2 increases the expression of cyclooxygenase-2 in cultured rat microglia. J Neuroimmunol 2021; 361:577724. [PMID: 34610503 DOI: 10.1016/j.jneuroim.2021.577724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 12/21/2022]
Abstract
Prostaglandin E2 (PGE2) plays pivotal roles in controlling microglial activation with the EP2 receptor, a PGE2 receptor subtype. Activated microglia are often reported to increase cyclooxygenase (COX)-2 expression, followed by PGE2 production, but it is unclear whether extracellular PGE2 is involved in microglial PGE2 synthesis. In the present study, we report that PGE2 increases COX-2 protein in microglia. In a culture system, PGE2 at 10-6 M for 3 h increased COX-2 and microsomal PGE synthase (mPGES)-1 mRNA levels, and reduced mPGES-2, but did not affect COX-1 or cytosolic PGE synthase (cPGES) in microglia. PGE2 at 10-6 M for 3 h also increased the COX-2 protein level, but did not affect COX-1, mPGES-1, mPGES-2, or cPGES. An EP2 agonist, ONO-AE1-259-01, also increased COX-2 and mPGES-1 mRNA levels, and reduced mPGES-2, but did not affect COX-1 or cPGES, whereas an EP1 agonist, ONO-DI-004, an EP3 agonist, ONO-AE-248, and an EP4 agonist, ONO-AE1-329, had no effect. Similar to PGE2, ONO-AE1-259-01 increased the COX-2 protein level, but did not affect COX-1, mPGES-1, mPGES-2, or cPGES. In addition, the effects of PGE2 were inhibited by an EP2 antagonist, PF-04418948, but not by an EP1 antagonist, ONO-8713, an EP3 antagonist, ONO-AE3-240, or an EP4 antagonist, ONO-AE3-208, at 10-6 M. On the other hand, lipopolysaccharide (LPS) increased PGE2 production, but the LPS-induced PGE2 production was not affected by ONO-8713, PF-04418948, ONO-AE3-240, or ONO-AE3-208. These results indicate that PGE2 increases COX-2 protein in microglia through the EP2 receptor supporting the idea that extracellular PGE2 has a triggering aspect for microglial activation.
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Affiliation(s)
- Takayuki Nagano
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
| | - Naohiko Tsuda
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Kenichi Fujimura
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Yuji Ikezawa
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Yuki Higashi
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Shinya H Kimura
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
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Vitaliti G, Falsaperla R. Chorioamnionitis, Inflammation and Neonatal Apnea: Effects on Preterm Neonatal Brainstem and on Peripheral Airways: Chorioamnionitis and Neonatal Respiratory Functions. CHILDREN-BASEL 2021; 8:children8100917. [PMID: 34682182 PMCID: PMC8534519 DOI: 10.3390/children8100917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/01/2021] [Accepted: 10/13/2021] [Indexed: 11/16/2022]
Abstract
Background: The present manuscript aims to be a narrative review evaluating the association between inflammation in chorioamnionitis and damage on respiratory centers, peripheral airways, and lungs, explaining the pathways responsible for apnea in preterm babies born by delivery after chorioamnionitis. Methods: A combination of keywords and MESH words was used, including: "inflammation", "chorioamnionitis", "brainstem", "cytokines storm", "preterm birth", "neonatal apnea", and "apnea physiopathology". All identified papers were screened for title and abstracts by the two authors to verify whether they met the proper criteria to write the topic. Results: Chorioamnionitis is usually associated with Fetal Inflammatory Response Syndrome (FIRS), resulting in injury of brain and lungs. Literature data have shown that infections causing chorioamnionitis are mostly associated with inflammation and consequent hypoxia-mediated brain injury. Moreover, inflammation and infection induce apneic episodes in neonates, as well as in animal samples. Chorioamnionitis-induced inflammation favors the systemic secretion of pro-inflammatory cytokines that are involved in abnormal development of the respiratory centers in the brainstem and in alterations of peripheral airways and lungs. Conclusions: Preterm birth shows a suboptimal development of the brainstem and abnormalities and altered development of peripheral airways and lungs. These alterations are responsible for reduced respiratory control and apnea. To date, mostly animal studies have been published. Therefore, more clinical studies on the role of chorioamninitis-induced inflammation on prematurity and neonatal apnea are necessary.
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Affiliation(s)
- Giovanna Vitaliti
- Unit of Pediatrics, Department of Medical Sciences, Section of Pediatrics, University of Ferrara, 44121 Ferrara, Italy
- Correspondence: ; Tel.: +39-34-0471-0614
| | - Raffaele Falsaperla
- Pediatrics and Pediatric Emergency Operative Unit, Azienda Ospedaliero Universitaria Policlinico G.Rodolico-San Marco, San Marco Hospital, University of Catania, 95124 Catania, Italy;
- Neonatal Intensive Care Unit, Azienda Ospedaliero Universitaria Policlinico G.Rodolico-San Marco, San Marco Hospital, San Marco Hospital, University of Catania, 95124 Catania, Italy
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Peripheral Myeloid Cell EP2 Activation Contributes to the Deleterious Consequences of Status Epilepticus. J Neurosci 2020; 41:1105-1117. [PMID: 33293358 DOI: 10.1523/jneurosci.2040-20.2020] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/06/2020] [Accepted: 11/23/2020] [Indexed: 12/20/2022] Open
Abstract
A multidimensional inflammatory response ensues after status epilepticus (SE), driven partly by cyclooxygenase-2-mediated activation of prostaglandin EP2 receptors. The inflammatory response is typified by astrocytosis, microgliosis, erosion of the blood-brain barrier (BBB), formation of inflammatory cytokines, and brain infiltration of blood-borne monocytes. Our previous studies have shown that inhibition of monocyte brain invasion or systemic administration of an EP2 receptor antagonist relieves multiple deleterious consequences of SE. Here we identify those effects of EP2 antagonism that are reproduced by conditional ablation of EP2 receptors in immune myeloid cells and show that systemic EP2 antagonism blocks monocyte brain entry in male mice. The induction of hippocampal IL-6 after pilocarpine SE was nearly abolished in EP2 conditional KO mice. Serum albumin levels in the cortex, a measure of BBB breakdown, were significantly higher after SE in EP2-sufficient mice but not in EP2 conditional KOs. EP2 deficiency in innate immune cells accelerated the recovery from sickness behaviors following SE. Surprisingly, neurodegeneration was not alleviated in myeloid conditional KOs. Systemic EP2 antagonism prevented monocyte brain infiltration and provided broader rescue of SE-induced effects than myeloid EP2 ablation, including neuroprotection and broader suppression of inflammatory mediators. Reporter expression indicated that the cellular target of CD11b-driven Cre was circulating myeloid cells but, unexpectedly, not microglia. These findings indicate that activation of EP2 receptors on immune myeloid cells drives substantial deficits in behavior and disrupts the BBB after SE. The benefits of systemic EP2 antagonism can be attributed, in part, to blocking brain recruitment of blood-borne monocytes.SIGNIFICANCE STATEMENT Unabated seizures reduce quality of life, promote the development of epilepsy, and can be fatal. We previously identified activation of prostaglandin EP2 receptors as a driver of undesirable consequences of seizures. However, the relevant EP2-expressing cell types remain unclear. Here we identify peripheral innate immune cells as a driver of the EP2-related negative consequences of seizures. Removal of EP2 from peripheral immune cells was beneficial, abolishing production of a key inflammatory cytokine, accelerating weight regain, and limiting behavioral deficits. These findings provide evidence that EP2 engagement on peripheral immune and brain endothelia contributes to the deleterious effects of SE, and will assist in the development of beneficial therapies to enhance quality of life in individuals who suffer prolonged seizures.
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Jiang C, Caskurlu A, Ganesh T, Dingledine R. Inhibition of the prostaglandin EP2 receptor prevents long-term cognitive impairment in a model of systemic inflammation. Brain Behav Immun Health 2020; 8:100132. [PMID: 34589882 PMCID: PMC8474496 DOI: 10.1016/j.bbih.2020.100132] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/19/2020] [Accepted: 08/19/2020] [Indexed: 12/19/2022] Open
Abstract
Long-term cognitive and affective impairments are common problems in the survivors of sepsis, which weakens their vocational and daily life ability. Neuroinflammation has been reported to exert a key role in the development of cognitive deficit in different disorders including epilepsy, Alzheimer's disease (AD) and stroke. Mice treated with lipopolysaccharide (LPS), an endotoxin produced by gram-negative bacteria, show a robust but short-lived neuroinflammation and develop long-term memory and affective problems. In this study, we test the hypothesis that pharmacological blockade of the EP2 receptor for prostaglandin E2 reduces neuroinflammation and prevents long-term affective and memory deficits in a mouse model of LPS-induced, sepsis-associated encephalopathy (SAE). Our results show that an EP2 antagonist, TG6-10-1, promotes the recovery of body weight, mitigates neuroinflammation as judged by inflammatory cytokines and microgliosis, prevents the loss of synaptic proteins, and ameliorates depression-like behavior in the sucrose preference test as well as memory loss in the novel object recognition test. Our results point to a new avenue to ameliorate neuroinflammation and long-term affective and cognition problems of sepsis survivors.
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Affiliation(s)
- Chunxiang Jiang
- Department of Pharmacology and Chemical Biology, School of Medicine, Emory University, Atlanta, 30322, Georgia
- Department of Neurology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
| | - Aysegul Caskurlu
- Department of Pharmacology and Chemical Biology, School of Medicine, Emory University, Atlanta, 30322, Georgia
| | - Thota Ganesh
- Department of Pharmacology and Chemical Biology, School of Medicine, Emory University, Atlanta, 30322, Georgia
| | - Ray Dingledine
- Department of Pharmacology and Chemical Biology, School of Medicine, Emory University, Atlanta, 30322, Georgia
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8
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Chibaatar E, Le K, Abdoulaye IA, Wu S, Guo Y. Melatonin Ameliorates Lipopolysaccharide-Induced Microglial Inflammation via Triggering SIRT1/HMGB1 Signaling Axis. J Mol Neurosci 2020; 71:691-701. [PMID: 32910356 DOI: 10.1007/s12031-020-01699-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/03/2020] [Indexed: 12/12/2022]
Abstract
Stroke is one of the highest incidence neurological disorder with great morbidity and mortality rate. The secondary neuroinflammation contributed by microglial activation is a consequential response observed in the pathogenesis of stroke. High-mobility group box 1, a non-histone nuclear protein, interacts with immune cells, such as microglia, and leads to a cascade amplification of the secondary neuroinflammatory responses, which are related to neuronal damage later. Melatonin is a neurohormone, well-known as its anti-oxidative and anti-inflammatory effects. However, until now, more findings are required for better understanding about anti-inflammatory effect of melatonin on HMGB1 and HMGB1-triggered pathway in LPS-induced microglial activation. Melatonin effect on the viability of BV2 microglial cells was measured by CCK-8 assay; mRNA levels of HMGB1 and other inflammatory cytokines were determined by quantitative real-time polymerase chain reaction assay or enzyme-linked immunosorbent assays; the protein expression levels of TLR4/MyD88/NF-κB and SIRT1 were detected by Western blot, and HMGB1 translocation and release from BV2 microglial cells were examined by immunofluorescence assay. The results of this study demonstrated that melatonin suppressed LPS-triggered BV2 microglial activation-mediated inflammation by inhibiting high expression and release of HMGB1 and moderating the activation of subsequent TLR4/MyD88/NF-κB signaling pathway, which was activated by SIRT1 elevation. Furthermore, LPS-induced expression of pro-inflammatory cytokines (i.e., TNF-α, IL-6, and IL-1β) was notably reversed by melatonin pre-treatment. In summary, our findings suggest that melatonin may act as a promising therapeutic agent for reducing post-stroke neuroinflammation by targeting HMGB1 and the subsequent signaling axis.
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Affiliation(s)
- Enkhmurun Chibaatar
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, 210009, Jiangsu Province, China.,School of Medicine, Southeast University, Nanjing, 210009, Jiangsu Province, China
| | - Kai Le
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, China
| | - Idriss Ali Abdoulaye
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, 210009, Jiangsu Province, China.,School of Medicine, Southeast University, Nanjing, 210009, Jiangsu Province, China
| | - Shanshan Wu
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, 210009, Jiangsu Province, China.,School of Medicine, Southeast University, Nanjing, 210009, Jiangsu Province, China
| | - Yijing Guo
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, 210009, Jiangsu Province, China.
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Feng X, Fan Y, Chung CY. Mefenamic acid can attenuate depressive symptoms by suppressing microglia activation induced upon chronic stress. Brain Res 2020; 1740:146846. [PMID: 32325074 DOI: 10.1016/j.brainres.2020.146846] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 04/17/2020] [Accepted: 04/19/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Depression is the most debilitating neuropsychiatric disorder, and psychosocial stressors are major risk factors for the onset of depression. Depression is closely associated with chronic inflammation and microglia are the principal mediators of inflammation in the central nervous system (CNS). Mefenamic acid (MA) and celecoxib are nonselective and selective inhibitors of cyclooxygenase (COX), respectively. COX is a key enzyme in mediating inflammatory response in microglia. In this study, we examine the effects of inhibiting COX by MA on depressive-like behaviors and microglia activation in the hippocampus. METHODS We evaluate the effect of MA on chronic mild stress (CMS) induced depressive-like behavior by sucrose preference and forced swimming tests. Effect of MA on microglia activation in dentate gyrus (DG) of hippocampus was examined by immunohistochemistry. In vitro experiments including western blotting and phagocytosis assay were used to investigate the effect of MA on microglia activation. RESULTS Behavioral assays reveal MA and celecoxib ameliorate CMS-induced depressive-like behavior. Compared to the stressed mice, the number of activated/phagocytic microglia (Iba1+/CD68+) in DG of hippocampus significantly decreases in stressed mice treated with MA or celecoxib. MA and celecoxib play a role in inhibiting microglia activation by inhibiting of ERK1/2 and P38 MAPK activation and iNOS expression. MA or celecoxib also reduce the high phagocytic activity of activated microglia. CONCLUSION MA inhibits microglia activation/phagocytosis induced upon chronic stress in the hippocampus, which might result in the improvement of depressive symptoms.
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Affiliation(s)
- Xiaoye Feng
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Yang Fan
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Chang Y Chung
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, China; Division of Natural Science, Duke Kunshan University, Kunshan 215316, China.
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Zhang C, Wang L, Li T, Mao W, Liu B, Cao J. EP2/4 Receptors Promote the Synthesis of PGE 2 Increasing Tissue Damage in Bovine Endometrial Explants Induced by Escherichia coli. J Pharmacol Exp Ther 2019; 372:175-184. [PMID: 31732699 DOI: 10.1124/jpet.119.262444] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/11/2019] [Indexed: 12/17/2022] Open
Abstract
The bovine uterine is easily contaminated with bacteria during coitus or parturition. A previous study suggested that prostaglandin E2 (PGE2) promoted Escherichia coli-infected bovine endometrial tissue inflammatory damage via cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1). However, it remains unclear which PGE2 receptors regulate the proinflammatory effect of PGE2 In this study, we evaluated the effect of PGE2 and its mediated receptors on E. coli-infected endometrium explants isolated from the bovine uterus. The E. coli-infected bovine endometrial explants were cultured in vitro, and the study used EP2/4 receptor agonists to investigate the responses of COX-2, mPGES-1, PGE2, proinflammatory factors, and damage-associated molecular patterns (DAMPs). The expression of COX-2, mPGES-1, PGE2, proinflammatory factors, and DAMPs was significantly increased after infection with E. coli; however, the high expression levels caused by E. coli were reduced following treatment with COX-2 and mPGES-1 inhibitors. In addition, the expression levels of COX-2, mPGES-1, PGE2, proinflammatory factors, and DAMPs were higher in treatment with EP2/4 receptor agonists in E. coli-infected endometrium explants, and their promotable effects were effectively blocked by EP2/4 receptor antagonists. These findings provide evidence that PGE2 may promote the progress of inflammation in endometrial explants infected with E. coli in bovines. Furthermore, EP2/4 may be involved in a positive feedback loop for COX-2 and mPGES-1 expression, and this may be responsible for the proinflammatory reaction of PGE2 in E. coli-infected uteri of bovines. SIGNIFICANCE STATEMENT: PGE2 promoted E. coli-infected bovine endometrial tissue damage via COX-2 and mPGES-1. However, this proinflammatory effect of PGE2 depends on which receptors are affected by PGE2, and this remains unclear. In this study, it was investigated that EP2 and EP4 may be involved in a positive feedback loop for COX-2 and mPGES-1 expression, and this may be responsible for the proinflammatory reaction of PGE2 in E. coli-infected uteri of bovines.
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Affiliation(s)
- Chao Zhang
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine (C.Z., L.W., T.L., W.M., B.L., J.C.), and Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture (C.Z., L.W., T.L., W.M., B.L., J.C.), Inner Mongolia Agricultural University, Huhhot, China
| | - Lingrui Wang
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine (C.Z., L.W., T.L., W.M., B.L., J.C.), and Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture (C.Z., L.W., T.L., W.M., B.L., J.C.), Inner Mongolia Agricultural University, Huhhot, China
| | - Tingting Li
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine (C.Z., L.W., T.L., W.M., B.L., J.C.), and Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture (C.Z., L.W., T.L., W.M., B.L., J.C.), Inner Mongolia Agricultural University, Huhhot, China
| | - Wei Mao
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine (C.Z., L.W., T.L., W.M., B.L., J.C.), and Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture (C.Z., L.W., T.L., W.M., B.L., J.C.), Inner Mongolia Agricultural University, Huhhot, China
| | - Bo Liu
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine (C.Z., L.W., T.L., W.M., B.L., J.C.), and Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture (C.Z., L.W., T.L., W.M., B.L., J.C.), Inner Mongolia Agricultural University, Huhhot, China
| | - Jinshan Cao
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine (C.Z., L.W., T.L., W.M., B.L., J.C.), and Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture (C.Z., L.W., T.L., W.M., B.L., J.C.), Inner Mongolia Agricultural University, Huhhot, China
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Bai XY, Wang XF, Zhang LS, Du PC, Cao Z, Hou Y. Tetramethylpyrazine ameliorates experimental autoimmune encephalomyelitis by modulating the inflammatory response. Biochem Biophys Res Commun 2018; 503:1968-1972. [PMID: 30078676 DOI: 10.1016/j.bbrc.2018.07.143] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 07/28/2018] [Indexed: 12/26/2022]
Abstract
Multiple sclerosis (MS) is a disabling inflammatory and demyelinating disorder of the central nervous system. Tetramethylpyrazine (TMP) has been demonstrated to ameliorate cerebral ischemic injury and spinal cord injury by inhibiting inflammatory cell activation and pro-inflammatory cytokine production. However, the effects of TMP on MS have not been studied. In this study, we evaluated the effects of TMP on the inflammatory response in experimental autoimmune encephalomyelitis (EAE), which is an animal model of MS. TMP (30 mg/kg) treatment significantly reduced the expression levels of NLR Family, Pyrin Domain-Containing 3 Protein inflammasome and caspase-1and decreased inflammatory infiltration and glial activation. Moreover, TMP (30 mg/kg) suppressed the expression of pro-inflammatory cytokines (interleukin-18 [IL-18] and IL-17) and promoted the expression of an anti-inflammatory cytokine (IL-10). The reduced inflammatory response resulted in improvement in clinical scores and decreased demyelination in EAE mice. Therefore, our results demonstrate that TMP (30 mg/kg) improved functional recovery in part by reducing inflammation in EAE mice. TMP may be a potential therapeutic agent for MS therapy.
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Affiliation(s)
- Xian-Yong Bai
- Department of Histology and Embryology, Binzhou Medical University, Yantai, PR China
| | - Xi-Feng Wang
- Department of Critical Care Medicine, Yu Huang Ding Hospital, Qingdao University, Yantai, PR China
| | - Lian-Shuang Zhang
- Department of Histology and Embryology, Binzhou Medical University, Yantai, PR China
| | - Peng-Chao Du
- Department of Pathology, Binzhou Medical University, Yantai, PR China
| | - Zhang Cao
- Department of Pathology, Binzhou Medical University, Yantai, PR China
| | - Yun Hou
- Department of Histology and Embryology, Binzhou Medical University, Yantai, PR China.
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12
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Abstract
Elevated levels of cyclooxygenase-2 (COX-2) and prostaglandins (PGs) are involved in the pathogenesis of Alzheimer's disease (AD), which is characterized by the accumulation of β-amyloid protein (Aβ) and tau hyperphosphorylation. However, the gaps in our knowledge of the roles of COX-2 and PGs in AD have not been filled. Here, we summarized the literature showing that COX-2 dysregulation obviously influences abnormal cleavage of β-amyloid precursor protein, aggregation and deposition of Aβ in β-amyloid plaques and the inclusion of phosphorylated tau in neurofibrillary tangles. Neuroinflammation, oxidative stress, synaptic plasticity, neurotoxicity, autophagy, and apoptosis have been assessed to elucidate the mechanisms of COX-2 regulation of AD. Notably, an imbalance of these factors ultimately produces cognitive decline. The current review substantiates our understanding of the mechanisms of COX-2-induced AD and establishes foundations for the design of feasible therapeutic strategies to treat AD.-Guan, P.-P., Wang, P. Integrated communications between cyclooxygenase-2 and Alzheimer's disease.
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Affiliation(s)
- Pei-Pei Guan
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Pu Wang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
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13
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Fricker M, Tolkovsky AM, Borutaite V, Coleman M, Brown GC. Neuronal Cell Death. Physiol Rev 2018; 98:813-880. [PMID: 29488822 PMCID: PMC5966715 DOI: 10.1152/physrev.00011.2017] [Citation(s) in RCA: 655] [Impact Index Per Article: 109.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/23/2017] [Accepted: 07/10/2017] [Indexed: 02/07/2023] Open
Abstract
Neuronal cell death occurs extensively during development and pathology, where it is especially important because of the limited capacity of adult neurons to proliferate or be replaced. The concept of cell death used to be simple as there were just two or three types, so we just had to work out which type was involved in our particular pathology and then block it. However, we now know that there are at least a dozen ways for neurons to die, that blocking a particular mechanism of cell death may not prevent the cell from dying, and that non-neuronal cells also contribute to neuronal death. We review here the mechanisms of neuronal death by intrinsic and extrinsic apoptosis, oncosis, necroptosis, parthanatos, ferroptosis, sarmoptosis, autophagic cell death, autosis, autolysis, paraptosis, pyroptosis, phagoptosis, and mitochondrial permeability transition. We next explore the mechanisms of neuronal death during development, and those induced by axotomy, aberrant cell-cycle reentry, glutamate (excitoxicity and oxytosis), loss of connected neurons, aggregated proteins and the unfolded protein response, oxidants, inflammation, and microglia. We then reassess which forms of cell death occur in stroke and Alzheimer's disease, two of the most important pathologies involving neuronal cell death. We also discuss why it has been so difficult to pinpoint the type of neuronal death involved, if and why the mechanism of neuronal death matters, the molecular overlap and interplay between death subroutines, and the therapeutic implications of these multiple overlapping forms of neuronal death.
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Affiliation(s)
- Michael Fricker
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
| | - Aviva M Tolkovsky
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
| | - Vilmante Borutaite
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
| | - Michael Coleman
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
| | - Guy C Brown
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
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14
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Stojanovska V, Miller SL, Hooper SB, Polglase GR. The Consequences of Preterm Birth and Chorioamnionitis on Brainstem Respiratory Centers: Implications for Neurochemical Development and Altered Functions by Inflammation and Prostaglandins. Front Cell Neurosci 2018; 12:26. [PMID: 29449803 PMCID: PMC5799271 DOI: 10.3389/fncel.2018.00026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/17/2018] [Indexed: 11/16/2022] Open
Abstract
Preterm birth is a major cause for neonatal morbidity and mortality, and is frequently associated with adverse neurological outcomes. The transition from intrauterine to extrauterine life at birth is particularly challenging for preterm infants. The main physiological driver for extrauterine transition is the establishment of spontaneous breathing. However, preterm infants have difficulty clearing lung liquid, have insufficient surfactant levels, and underdeveloped lungs. Further, preterm infants have an underdeveloped brainstem, resulting in reduced respiratory drive. These factors facilitate the increased requirement for respiratory support. A principal cause of preterm birth is intrauterine infection/inflammation (chorioamnionitis), and infants with chorioamnionitis have an increased risk and severity of neurological damage, but also demonstrate impaired autoresuscitation capacity and prevalent apnoeic episodes. The brainstem contains vital respiratory centers which provide the neural drive for breathing, but the impact of preterm birth and/or chorioamnionitis on this brain region is not well understood. The aim of this review is to provide an overview of the role and function of the brainstem respiratory centers, and to highlight the proposed mechanisms of how preterm birth and chorioamnionitis may affect central respiratory functions.
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Affiliation(s)
- Vanesa Stojanovska
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Suzanne L Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
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15
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Yousif NM, de Oliveira ACP, Brioschi S, Huell M, Biber K, Fiebich BL. Activation of EP 2 receptor suppresses poly(I: C) and LPS-mediated inflammation in primary microglia and organotypic hippocampal slice cultures: Contributing role for MAPKs. Glia 2017; 66:708-724. [PMID: 29226424 DOI: 10.1002/glia.23276] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/08/2017] [Accepted: 11/17/2017] [Indexed: 12/26/2022]
Abstract
Brain inflammation is a critical factor involved in neurodegeneration. Recently, the prostaglandin E2 (PGE2 ) downstream members were suggested to modulate neuroinflammatory responses accompanying neurodegenerative diseases. In this study, we investigated the protective effects of prostaglandin E2 receptor 2 (EP2 ) during TLR3 and TLR4-driven inflammatory response using in vitro primary microglia and ex vivo organotypic hippocampal slice cultures (OHSCs). Depletion of microglia from OHSCs differentially affected TLR3 and TLR4 receptor expression. Poly(I:C) induced the production of prostaglandin E2 in OHSCs by increasing cyclooxygenase (COX-2) and microsomal prostaglandin E synthase (mPGES)-1. Besides, stimulation of OHSCs and microglia with Poly(I:C) upregulated EP2 receptor expression. Co-stimulation of OHSCs and microglia with the EP2 agonist butaprost reduced inflammatory mediators induced by LPS and Poly(I:C). In Poly(I:C) challenged OHSCs, butaprost almost restored microglia ramified morphology and reduced Iba1 immunoreactivity. Importantly, microglia depletion prevented the induction of inflammatory mediators following Poly(I:C) or LPS challenge in OHSCs. Activation of EP2 receptor reversed the Poly(I:C)/LPS-induced phosphorylation of the mitogen activated protein kinases (MAPKs) ERK, p38 MAPK and c-Jun N-terminal kinase (JNK) in microglia. Collectively, these data identify an anti-inflammatory function for EP2 signaling in diverse innate immune responses, through a mechanism that involves the mitogen-activated protein kinases pathway.
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Affiliation(s)
- Nizar M Yousif
- Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, Freiburg, D-79104, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Simone Brioschi
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, Freiburg, D-79104, Germany
| | - Michael Huell
- Zentrum für Psychiatrie Emmendingen, Neubronnstr. 25, Emmendingen, 79312
| | - Knut Biber
- Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, Freiburg, D-79104, Germany
| | - Bernd L Fiebich
- Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, Freiburg, D-79104, Germany
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16
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Santos LE, Ferreira ST. Crosstalk between endoplasmic reticulum stress and brain inflammation in Alzheimer's disease. Neuropharmacology 2017; 136:350-360. [PMID: 29129774 DOI: 10.1016/j.neuropharm.2017.11.016] [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: 09/29/2017] [Accepted: 11/08/2017] [Indexed: 02/07/2023]
Abstract
While most often noted for its cognitive symptoms, Alzheimer's disease (AD) is, at its core, a disease of protein misfolding/aggregation, with an intriguing inflammatory component. Defective clearance and/or abnormal production of the amyloid-β peptide (Aβ), and its ensuing accumulation and aggregation, underlie two hallmark features of AD: brain accumulation of insoluble protein deposits known as amyloid or senile plaques, and buildup of soluble Aβ oligomers (AβOs), diffusible toxins linked to synapse dysfunction and memory impairment. In neurons, as in typical eukaryotic cells, the endoplasmic reticulum (ER) serves as a main compartment for the folding, maturation, trafficking and quality control of newly synthesized proteins. The ER lumen, a calcium-rich, oxidizing environment, provides favorable conditions for these physiological functions to occur. These conditions, however, also favor protein aggregation. Several stressors, including metabolic/nutrient stress and certain pathologies, may upset the ER homeostasis, e.g., by affecting calcium levels or by causing the accumulation of unfolded or misfolded proteins. Whatever the underlying cause, the result is what is commonly known as "ER stress". This, in turn, triggers a conserved cellular response mechanism known as the "unfolded protein response" (UPR). The UPR comprises three pathways involving transcriptional or translational regulators aimed at normalizing ER function, and each of them results in pro-inflammatory signaling. A positive feedback loop exists between ER stress and inflammation, with clear implications for neurodegeneration and AD. Here, we explore recent findings on the role of ER stress and the UPR in inflammatory processes leading to synapse failure and memory impairment in AD. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'
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Affiliation(s)
- Luis E Santos
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21944-590, Brazil
| | - Sergio T Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21944-590, Brazil; Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21944-590, Brazil.
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17
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Stucky EC, Erndt-Marino J, Schloss RS, Yarmush ML, Shreiber DI. Prostaglandin E 2 Produced by Alginate-Encapsulated Mesenchymal Stromal Cells Modulates the Astrocyte Inflammatory Response. NANO LIFE 2017; 7:1750005. [PMID: 29682085 PMCID: PMC5903452 DOI: 10.1142/s1793984417500052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Astroglia are well known for their role in propagating secondary injury following brain trauma. Modulation of this injury cascade, including inflammation, is essential to repair and recovery. Mesenchymal stromal cells (MSCs) have been demonstrated as trophic mediators in several models of secondary CNS injury, however, there has been varied success with the use of direct implantation due to a failure to persist at the injury site. To achieve sustained therapeutic benefit, we have encapsulated MSCs in alginate microspheres and evaluated the ability of these encapsulated MSCs to attenuate neuro-inflammation. In this study, astroglial cultures were administered lipopolysaccharide (LPS) to induce inflammation and immediately co-cultured with encapsulated or monolayer human MSCs. Cultures were assayed for the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) produced by astroglia, MSC-produced prostaglandin E2, and expression of neurotrophin-associated genes. We found that encapsulated MSCs significantly reduced TNF-α produced by LPS-stimulated astrocytes, more effectively than monolayer MSCs, and this enhanced benefit commences earlier than that of monolayer MSCs. Furthermore, in support of previous findings, encapsulated MSCs constitutively produced high levels of PGE2, while monolayer MSCs required the presence of inflammatory stimuli to induce PGE2 production. The early, constitutive presence of PGE2 significantly reduced astrocyte-produced TNF-α, while delayed administration had no effect. Finally, MSC-produced PGE2 was not only capable of modulating inflammation, but appears to have an additional role in stimulating astrocyte neurotrophin production. Overall, these results support the enhanced benefit of encapsulated MSC treatment, both in modulating the inflammatory response and providing neuroprotection.
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Affiliation(s)
- Elizabeth C Stucky
- Department of Chemical and Biochemical Engineering, Rutgers University, 599 Taylor Road, Piscataway, New Jersey 08854, USA
| | - Joshua Erndt-Marino
- Department of Biomedical Engineering, The College of New Jersey, 2000 Pennington Road, Ewing, New Jersey 08628, USA
| | - Rene S Schloss
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, New Jersey 08854, USA
| | - Martin L Yarmush
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, New Jersey 08854, USA
| | - David I Shreiber
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, New Jersey 08854, USA
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18
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Huang C, Dong D, Jiao Q, Pan H, Ma L, Wang R. Sarsasapogenin-AA13 ameliorates Aβ-induced cognitive deficits via improving neuroglial capacity on Aβ clearance and antiinflammation. CNS Neurosci Ther 2017; 23:498-509. [PMID: 28466999 DOI: 10.1111/cns.12697] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/11/2017] [Accepted: 03/17/2017] [Indexed: 01/14/2023] Open
Abstract
AIMS Sarsasapogenin has been reported to improve dementia symptoms somehow, probably through modulating the function of cholinergic system, suppressing neurofibrillary tangles, and inhibiting inflammation. However, the role of sarsasapogenin in response to beta-amyloid (Aβ) remains to be delineated. This study aimed to determine the therapeutic effect of sarsasapogenin-13 (AA13, a sarsasapogenin derivative) on learning and memory impairments in Aβ-injected mice, as well as the role of AA13 in neuroglia-mediated antiinflammation and Aβ clearance. METHODS Focusing on the role of AA13 in regulating glial responses to Aβ, we conducted behavioral, morphological, and protein expression studies to explore the effects of AA13 on Aβ clearance and inflammatory regulation. RESULTS The results indicated that oral administration of AA13 attenuated the memory deficits of intracerebroventricular (i.c.v.) Aβ-injected mice; also, AA13 protected neuroglial cells against Aβ-induced cytotoxicity. The further mechanical studies demonstrated that AA13 reversed the upregulation of proinflammatory M1 markers and increased the expression of antiinflammatory M2 markers in Aβ-treated cells. Furthermore, AA13 facilitated Aβ clearance through promoting Aβ phagocytosis and degradation. AA13 modulated the expression of fatty acid translocase (CD36), insulin-degrading enzyme (IDE), neprilysin (NEP), and endothelin-converting enzyme (ECE) in neuroglia. CONCLUSION The present study indicated that the neuroprotective effect of AA13 might relate to its modulatory effects on microglia activation state, phagocytic ability, and expression of Aβ-degrading enzymes, which makes it a promising therapeutic agent in the early stage of Alzheimer's disease (AD).
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Affiliation(s)
- Cui Huang
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Dong Dong
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Qian Jiao
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Hui Pan
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Lei Ma
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Rui Wang
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
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19
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Nagano T, Nishiyama R, Sanada A, Mutaguchi Y, Ioku A, Umeki H, Kishimoto S, Yamanaka D, Kimura SH, Takemura M. Prostaglandin E 2 potentiates interferon-γ-induced nitric oxide production in cultured rat microglia. J Neurochem 2017; 140:605-612. [PMID: 27973680 DOI: 10.1111/jnc.13926] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/30/2016] [Accepted: 12/06/2016] [Indexed: 12/26/2022]
Abstract
Prostaglandin E2 (PGE2 ) plays crucial roles in managing microglial activation through the prostanoid EP2 receptor, a PGE2 receptor subtype. In this study, we report that PGE2 enhances interferon-γ (IFN-γ)-induced nitric oxide production in microglia. IFN-γ increased the release of nitrite, a metabolite of nitric oxide, which was augmented by PGE2 , although PGE2 by itself slightly affects nitrite release. The potentiating effect of PGE2 was positively associated with increased expression of inducible nitric oxide synthase. In contrast to nitrite release induced by IFN-γ, lipopolysaccharide-induced nitrite release was not affected by PGE2 . An EP2 agonist, ONO-AE1-259-01 also augmented IFN-γ-induced nitrite release, while an EP1 agonist, ONO-DI-004, an EP3 agonist, ONO-AE-248, or an EP4 agonist, ONO-AE1-329, did not. In addition, the potentiating effect of PGE2 was inhibited by an EP2 antagonist, PF-04418948, but not by an EP1 antagonist, ONO-8713, an EP3 antagonist, ONO-AE3-240, or an EP4 antagonist, ONO-AE3-208, at 10-6 M. Among the EP agonists, ONO-AE1-259-01 alone was able to accumulate cyclic adenosine monophosphate (AMP), and among the EP antagonists, PF-04418948 was the only one able to inhibit PGE2 -increased intracellular cyclic AMP accumulation. On the other hand, IFN-γ promoted phosphorylation of signal transducer and activator of transcription 1, which was not affected by PGE2 . Furthermore, other prostanoid receptor agonists, PGD2 , PGF2α , iloprost, and U-46119, slightly affected IFN-γ-induced nitrite release. These results indicate that PGE2 potentiates IFN-γ-induced nitric oxide production in microglia through the EP2 receptor, which may shed light on one of the pro-inflammatory aspects of PGE2 .
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Affiliation(s)
- Takayuki Nagano
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Ryo Nishiyama
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Ayaka Sanada
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Yukiko Mutaguchi
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Anna Ioku
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Hirohisa Umeki
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Satoshi Kishimoto
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Daisuke Yamanaka
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Shinya H Kimura
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Motohiko Takemura
- Department of Pharmacology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
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20
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Bonfill-Teixidor E, Otxoa-de-Amezaga A, Font-Nieves M, Sans-Fons MG, Planas AM. Differential expression of E-type prostanoid receptors 2 and 4 in microglia stimulated with lipopolysaccharide. J Neuroinflammation 2017; 14:3. [PMID: 28086956 PMCID: PMC5234110 DOI: 10.1186/s12974-016-0780-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 12/15/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cyclooxygenase-2 (COX-2) is induced under inflammatory conditions, and prostaglandin E2 (PGE2) is one of the products of COX activity. PGE2 has pleiotropic actions depending on the activation of specific E-type prostanoid EP1-4 receptors. We investigated the involvement of PGE2 and EP receptors in glial activation in response to an inflammatory challenge induced by LPS. METHODS Cultures of mouse microglia or astroglia cells were treated with LPS in the presence or absence of COX-2 inhibitors, and the production of PGE2 was measured by ELISA. Cells were treated with PGE2, and the effect on LPS-induced expression of TNF-α messenger RNA (mRNA) and protein was studied in the presence or absence of drug antagonists of the four EP receptors. EP receptor expression and the effects of EP2 and EP4 agonists and antagonists were studied at different time points after LPS. RESULTS PGE2 production after LPS was COX-2-dependent. PGE2 reduced the glial production of TNF-α after LPS. Microglia expressed higher levels of EP4 and EP2 mRNA than astroglia. Activation of EP4 or EP2 receptors with selective drug agonists attenuated LPS-induced TNF-α in microglia. However, only antagonizing EP4 prevented the PGE2 effect demonstrating that EP4 was the main target of PGE2 in naïve microglia. Moreover, the relative expression of EP receptors changed during the course of classical microglial activation since EP4 expression was strongly depressed while EP2 increased 24 h after LPS and was detected in nuclear/peri-nuclear locations. EP2 regulated the expression of iNOS, NADPH oxidase-2, and vascular endothelial growth factor. NADPH oxidase-2 and iNOS activities require the oxidation of NADPH, and the pentose phosphate pathway is a main source of NADPH. LPS increased the mRNA expression of the rate-limiting enzyme of the pentose pathway glucose-6-phosphate dehydrogenase, and EP2 activity was involved in this effect. CONCLUSIONS These results show that while selective activation of EP4 or EP2 exerts anti-inflammatory actions, EP4 is the main target of PGE2 in naïve microglia. The level of EP receptor expression changes from naïve to primed microglia where the COX-2/PGE2/EP2 axis modulates important adaptive metabolic changes.
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Affiliation(s)
- Ester Bonfill-Teixidor
- Departament d'Isquèmia Cerebral i Neurodegeneració, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Amaia Otxoa-de-Amezaga
- Departament d'Isquèmia Cerebral i Neurodegeneració, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Miriam Font-Nieves
- Departament d'Isquèmia Cerebral i Neurodegeneració, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
| | - M Glòria Sans-Fons
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Anna M Planas
- Departament d'Isquèmia Cerebral i Neurodegeneració, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain. .,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain. .,Department of Brain Ischemia and Neurodegeneration, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Rosselló 161 planta 6, 08036, Barcelona, Spain.
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21
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Andreasson KI, Bachstetter AD, Colonna M, Ginhoux F, Holmes C, Lamb B, Landreth G, Lee DC, Low D, Lynch MA, Monsonego A, O’Banion MK, Pekny M, Puschmann T, Russek-Blum N, Sandusky LA, Selenica MLB, Takata K, Teeling J, Town T, Van Eldik LJ, Russek-Blum N, Monsonego A, Low D, Takata K, Ginhoux F, Town T, O’Banion MK, Lamb B, Colonna M, Landreth G, Andreasson KI, Sandusky LA, Selenica MLB, Lee DC, Holmes C, Teeling J, Lynch MA, Van Eldik LJ, Bachstetter AD, Pekny M, Puschmann T. Targeting innate immunity for neurodegenerative disorders of the central nervous system. J Neurochem 2016; 138:653-93. [PMID: 27248001 PMCID: PMC5433264 DOI: 10.1111/jnc.13667] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/01/2016] [Accepted: 04/30/2016] [Indexed: 12/21/2022]
Abstract
Neuroinflammation is critically involved in numerous neurodegenerative diseases, and key signaling steps of innate immune activation hence represent promising therapeutic targets. This mini review series originated from the 4th Venusberg Meeting on Neuroinflammation held in Bonn, Germany, 7-9th May 2015, presenting updates on innate immunity in acute brain injury and chronic neurodegenerative disorders, such as traumatic brain injury and Alzheimer disease, on the role of astrocytes and microglia, as well as technical developments that may help elucidate neuroinflammatory mechanisms and establish clinical relevance. In this meeting report, a brief overview of physiological and pathological microglia morphology is followed by a synopsis on PGE2 receptors, insights into the role of arginine metabolism and further relevant aspects of neuroinflammation in various clinical settings, and concluded by a presentation of technical challenges and solutions when working with microglia and astrocyte cultures. Microglial ontogeny and induced pluripotent stem cell-derived microglia, advances of TREM2 signaling, and the cytokine paradox in Alzheimer's disease are further contributions to this article. Neuroinflammation is critically involved in numerous neurodegenerative diseases, and key signaling steps of innate immune activation hence represent promising therapeutic targets. This mini review series originated from the 4th Venusberg Meeting on Neuroinflammation held in Bonn, Germany, 7-9th May 2015, presenting updates on innate immunity in acute brain injury and chronic neurodegenerative disorders, such as traumatic brain injury and Alzheimer's disease, on the role of astrocytes and microglia, as well as technical developments that may help elucidate neuroinflammatory mechanisms and establish clinical relevance. In this meeting report, a brief overview on physiological and pathological microglia morphology is followed by a synopsis on PGE2 receptors, insights into the role of arginine metabolism and further relevant aspects of neuroinflammation in various clinical settings, and concluded by a presentation of technical challenges and solutions when working with microglia cultures. Microglial ontogeny and induced pluripotent stem cell-derived microglia, advances of TREM2 signaling, and the cytokine paradox in Alzheimer's disease are further contributions to this article.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Niva Russek-Blum
- The Dead Sea and Arava Science Center, Central Arava Branch, Yair Station, Hazeva, Israel
| | - Alon Monsonego
- The Shraga Segal Dept. of Microbiology, Immunology and Genetics, The Faculty of Health Sciences: The National Institute of Biotechnology in the Negev, and Zlotowski Center for Neuroscience, Ben-Gurion University, Beer-Sheva 84105, Israel
| | - Donovan Low
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore
| | - Kazuyuki Takata
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore
- Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Florent Ginhoux
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore
| | - Terrence Town
- Departments of Physiology and Biophysics, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089,
| | - M. Kerry O’Banion
- Departments of Neuroscience and Neurology, Del Monte Neuromedicine Institute, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642,
| | - Bruce Lamb
- Department of Neurosciences, Cleveland Clinic, Cleveland, OH 44106
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Gary Landreth
- Department of Neurosciences, Case Western Reserve University 44106
| | - Katrin I. Andreasson
- Department of Neurology and Neurological Sciences, Stanford Neuroscience Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Leslie A. Sandusky
- USF Health Byrd Alzheimer’s Institute, Tampa, FL 33613
- College of Pharmacy & Pharmaceutical Sciences, Tampa, FL 33613
| | - Maj-Linda B. Selenica
- USF Health Byrd Alzheimer’s Institute, Tampa, FL 33613
- College of Pharmacy & Pharmaceutical Sciences, Tampa, FL 33613
| | - Daniel C. Lee
- USF Health Byrd Alzheimer’s Institute, Tampa, FL 33613
- College of Pharmacy & Pharmaceutical Sciences, Tampa, FL 33613
| | - Clive Holmes
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Tremona Road, Southampton, SO16 7YD, United Kingdom
| | - Jessica Teeling
- Centre for Biological Sciences, University of Southampton, Southampton General Hospital, Tremona Road, Southampton, SO16 7YD, United Kingdom
| | | | | | | | - Milos Pekny
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, SE-405 30 Gothenburg, Sweden
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Hunter Medical Research Institute, University of Newcastle, New South Wales, Australia
| | - Till Puschmann
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, SE-405 30 Gothenburg, Sweden
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22
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Woodling NS, Andreasson KI. Untangling the Web: Toxic and Protective Effects of Neuroinflammation and PGE2 Signaling in Alzheimer's Disease. ACS Chem Neurosci 2016; 7:454-63. [PMID: 26979823 DOI: 10.1021/acschemneuro.6b00016] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The neuroinflammatory response has received increasing attention as a key factor in the pathogenesis of Alzheimer's disease (AD). Microglia, the innate immune cells and resident phagocytes of the brain, respond to accumulating Aβ peptides by generating a nonresolving inflammatory response. While this response can clear Aβ peptides from the nervous system in some settings, its failure to do so in AD accelerates synaptic injury, neuronal loss, and cognitive decline. The complex molecular components of this response are beginning to be unraveled, with identification of both damaging and protective roles for individual components of the neuroinflammatory response. Even within one molecular pathway, contrasting effects are often present. As one example, recent studies of the inflammatory cyclooxygenase-prostaglandin pathway have revealed both beneficial and detrimental effects dependent on the disease context, cell type, and downstream signaling pathway. Nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit cyclooxygenases, are associated with reduced AD risk when taken by cognitively normal populations, but additional clinical and mouse model studies have added complexities and caveats to this finding. Downstream of cyclooxygenase activity, prostaglandin E2 signaling exerts both damaging pro-inflammatory and protective anti-inflammatory effects through actions of specific E-prostanoid G-protein coupled receptors on specific cell types. These complexities underscore the need for careful study of individual components of the neuroinflammatory response to better understand their contribution to AD pathogenesis and progression.
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Affiliation(s)
- Nathaniel S. Woodling
- Department of Neurology and
Neurological Sciences, Stanford University School of Medicine, 1201
Welch Road, Stanford, California 94305, United States
| | - Katrin I. Andreasson
- Department of Neurology and
Neurological Sciences, Stanford University School of Medicine, 1201
Welch Road, Stanford, California 94305, United States
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23
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Brown GC, Vilalta A. How microglia kill neurons. Brain Res 2015; 1628:288-297. [PMID: 26341532 DOI: 10.1016/j.brainres.2015.08.031] [Citation(s) in RCA: 201] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 08/03/2015] [Accepted: 08/24/2015] [Indexed: 12/11/2022]
Abstract
Microglia are resident brain macrophages that become inflammatory activated in most brain pathologies. Microglia normally protect neurons, but may accidentally kill neurons when attempting to limit infections or damage, and this may be more common with degenerative disease as there was no significant selection pressure on the aged brain in the past. A number of mechanisms by which activated microglia kill neurons have been identified, including: (i) stimulation of the phagocyte NADPH oxidase (PHOX) to produce superoxide and derivative oxidants, (ii) expression of inducible nitric oxide synthase (iNOS) producing NO and derivative oxidants, (iii) release of glutamate and glutaminase, (iv) release of TNFα, (v) release of cathepsin B, (vi) phagocytosis of stressed neurons, and (vii) decreased release of nutritive BDNF and IGF-1. PHOX stimulation contributes to microglial activation, but is not directly neurotoxic unless NO is present. NO is normally neuroprotective, but can react with superoxide to produce neurotoxic peroxynitrite, or in the presence of hypoxia inhibit mitochondrial respiration. Glutamate can be released by glia or neurons, but is neurotoxic only if the neurons are depolarised, for example as a result of mitochondrial inhibition. TNFα is normally neuroprotective, but can become toxic if caspase-8 or NF-κB activation are inhibited. If the above mechanisms do not kill neurons, they may still stress the neurons sufficiently to make them susceptible to phagocytosis by activated microglia. We review here whether microglial killing of neurons is an artefact, makes evolutionary sense or contributes in common neuropathologies and by what mechanisms. This article is part of a Special Issue entitled SI: Neuroprotection.
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Affiliation(s)
- Guy C Brown
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
| | - Anna Vilalta
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
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24
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Johansson JU, Woodling NS, Shi J, Andreasson KI. Inflammatory Cyclooxygenase Activity and PGE 2 Signaling in Models of Alzheimer's Disease. ACTA ACUST UNITED AC 2015; 11:125-131. [PMID: 28413375 PMCID: PMC5384338 DOI: 10.2174/1573395511666150707181414] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/03/2015] [Accepted: 04/19/2015] [Indexed: 11/28/2022]
Abstract
The inflammatory response is a fundamental driving force in the pathogenesis of Alzheimer’s disease (AD). In the setting of accumulating immunogenic Aß peptide assemblies, microglia, the innate immune cells of the brain, generate a non-resolving immune response and fail to adequately clear accumulating Aß peptides, accelerating neuronal and synaptic injury. Pathological, biomarker, and imaging studies point to a prominent role of the innate immune response in AD development, and the molecular components of this response are beginning to be unraveled. The inflammatory cyclooxygenase-PGE2 pathway is implicated in pre-clinical development of AD, both in epidemiology of normal aging populations and in transgenic mouse models of Familial AD. The cyclooxygenase-PGE2 pathway modulates the inflammatory response to accumulating Aß peptides through actions of specific E-prostanoid G-protein coupled receptors.
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Affiliation(s)
- Jenny U Johansson
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Present address: SRI International, Menlo Park, CA, USA
| | - Nathaniel S Woodling
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Present address: Institute of Healthy Ageing, University College London, London, UK
| | - Ju Shi
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Present address: True North Therapeutics, South San Francisco, CA, USA
| | - Katrin I Andreasson
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
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25
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Sickness: From the focus on cytokines, prostaglandins, and complement factors to the perspectives of neurons. Neurosci Biobehav Rev 2015; 57:30-45. [PMID: 26363665 DOI: 10.1016/j.neubiorev.2015.07.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 07/06/2015] [Accepted: 07/31/2015] [Indexed: 12/29/2022]
Abstract
Systemic inflammation leads to a variety of physiological (e.g. fever) and behavioral (e.g. anorexia, immobility, social withdrawal, depressed mood, disturbed sleep) responses that are collectively known as sickness. While these phenomena have been studied for the past few decades, the neurobiological mechanisms by which sickness occurs remain unclear. In this review, we first revisit how the body senses and responds to infections and injuries by eliciting systemic inflammation. Next, we focus on how peripheral inflammatory molecules such as cytokines, prostaglandins, and activated complement factors communicate with the brain to trigger neuroinflammation and sickness. Since depression also involves inflammation, we further elaborate on the interrelationship between sickness and depression. Finally, we discuss how immune activation can modulate neurons in the brain, and suggest future perspectives to help unravel how changes in neuronal functions relate to sickness responses.
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26
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Fox BM, Beck HP, Roveto PM, Kayser F, Cheng Q, Dou H, Williamson T, Treanor J, Liu H, Jin L, Xu G, Ma J, Wang S, Olson SH. A Selective Prostaglandin E2 Receptor Subtype 2 (EP2) Antagonist Increases the Macrophage-Mediated Clearance of Amyloid-Beta Plaques. J Med Chem 2015; 58:5256-73. [DOI: 10.1021/acs.jmedchem.5b00567] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Brian M. Fox
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Hilary P. Beck
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Philip M. Roveto
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Frank Kayser
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Qingwen Cheng
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Hannah Dou
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Toni Williamson
- Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - James Treanor
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Hantao Liu
- Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Lixia Jin
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Guifen Xu
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Ji Ma
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Songli Wang
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
| | - Steven H. Olson
- Amgen South San Francisco, Amgen Inc., 1120 Veterans
Boulevard, South San Francisco, California 94080, United States
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27
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Sugimoto Y. [Mechanisms of prostaglandin actions in the nervous system]. Nihon Yakurigaku Zasshi 2015; 145:237-42. [PMID: 25958911 DOI: 10.1254/fpj.145.237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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28
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Leclerc JL, Lampert AS, Diller MA, Immergluck JB, Doré S. Prostaglandin E2 EP2 receptor deletion attenuates intracerebral hemorrhage-induced brain injury and improves functional recovery. ASN Neuro 2015; 7:7/2/1759091415578713. [PMID: 25873308 PMCID: PMC4720177 DOI: 10.1177/1759091415578713] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Intracerebral hemorrhage (ICH) is a devastating type of stroke characterized by bleeding into the brain parenchyma and secondary brain injury resulting from strong neuroinflammatory responses to blood components. Production of prostaglandin E2 (PGE2) is significantly upregulated following ICH and contributes to this inflammatory response in part through its E prostanoid receptor subtype 2 (EP2). Signaling through the EP2 receptor has been shown to affect outcomes of many acute and chronic neurological disorders; although, not yet explored in the context of ICH. Wildtype (WT) and EP2 receptor knockout (EP2−/−) mice were subjected to ICH, and various anatomical and functional outcomes were assessed by histology and neurobehavioral testing, respectively. When compared with age-matched WT controls, EP2−/− mice had 41.9 ± 4.7% smaller ICH-induced brain lesions and displayed significantly less ipsilateral hemispheric enlargement and incidence of intraventricular hemorrhage. Anatomical outcomes correlated with improved functional recovery as identified by neurological deficit scoring. Histological staining was performed to begin investigating the mechanisms involved in EP2-mediated neurotoxicity after ICH. EP2−/− mice exhibited 45.5 ± 5.8% and 41.4 ± 8.1% less blood and ferric iron accumulation, respectively. Furthermore, significantly less striatal and cortical microgliosis, striatal and cortical astrogliosis, blood–brain barrier breakdown, and peripheral neutrophil infiltration were seen in EP2−/− mice. This study is the first to suggest a deleterious role for the PGE2-EP2 signaling axis in modulating brain injury, inflammation, and functional recovery following ICH. Targeting the EP2 G protein-coupled receptor may represent a new therapeutic avenue for the treatment of hemorrhagic stroke.
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Affiliation(s)
- Jenna L Leclerc
- Department of Anesthesiology, University of Florida, Gainesville, FL, USA Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Andrew S Lampert
- Department of Anesthesiology, University of Florida, Gainesville, FL, USA
| | - Matthew A Diller
- Department of Anesthesiology, University of Florida, Gainesville, FL, USA
| | | | - Sylvain Doré
- Department of Anesthesiology, University of Florida, Gainesville, FL, USA Department of Neuroscience, University of Florida, Gainesville, FL, USA Departments of Neurology, Psychiatry, and Pharmaceutics, University of Florida, Gainesville, FL, USA
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29
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Ganesh T. Evaluation of WO 2012/177618 A1 and US-2014/0179750 A1: novel small molecule antagonists of prostaglandin-E2 receptor EP2. Expert Opin Ther Pat 2015; 25:837-44. [PMID: 25772215 DOI: 10.1517/13543776.2015.1025752] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recent studies underscore that prostaglandin-E2 exerts mostly proinflammatory effects in chronic CNS and peripheral disease models, mainly through a specific prostanoid receptor EP2. However, very few highly characterized EP2 receptor antagonists have been reported until recently, when Pfizer and Emory University published two distinct classes of EP2 antagonists with good potency, selectivity and pharmacokinetics. The purpose of this article is to evaluate recently published patents WO 2012/177618 A1 and US-2014/0179750 A1 from Emory, which describe a number of cinnamic amide- and amide-derivatives as a potent antagonists of EP2 receptor, and their neuroprotective effects in in vitro and in an in vivo model. A selected compound from this patent(s) also attenuates prostate cancer cell growth and invasion in vitro, suggesting these compounds should be developed for therapeutic use.
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Affiliation(s)
- Thota Ganesh
- Emory University School of Medicine, Department of Pharmacology , 1510 Clifton Rd, Atlanta, GA 30322 , USA +1 404 727 7393 ; +1 404 727 0365 ;
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30
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Zhang T, Gong X, Hu G, Wang X. EP2-PKA signaling is suppressed by triptolide in lipopolysaccharide-induced microglia activation. J Neuroinflammation 2015; 12:50. [PMID: 25880276 PMCID: PMC4364339 DOI: 10.1186/s12974-015-0275-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 03/02/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Microglia are key players for the inflammatory responses in the central nervous system. Suppression of microglial activation and the resulting production of proinflammatory molecules are considered a promising strategy to alleviate the progression of neurodegenerative disorders. Triptolide was demonstrated as a potent anti-inflammatory compound both in vitro and in vivo. The present study explored potential signal pathways of triptolide in the lipopolysaccharide (LPS)-induced inflammatory response using primary rat microglial cells. FINDINGS Microglial cells were pretreated with triptolide and stimulated with LPS. To investigate the anti-inflammatory effect of triptolide, we used Griess reagent and Western blot for NO release and iNOS expression, respectively. Moreover, we applied microglia-conditioned medium to neuronal cells and used the MTS assay to test cell viability. We found that triptolide inhibited LPS-induced NO and iNOS synthesis in microglial cells, which in turn protected neurons. To evaluate the involvement of the EP2 pathway, we used real-time PCR and Western blot to determine EP2 expression. We found that LPS induced a large increase in EP2 expression in microglia, and triptolide almost completely inhibited LPS-induced EP2 expression. Using the selective EP2 agonist butaprost and the EP2 antagonist AH6809, we determined that triptolide inhibited LPS-stimulated NO production in microglia mainly through the EP2 pathway. Additionally, by further treating triptolide-treated microglia with the downstream PKA-specific activator 6-Bnz-cAMP or the Epac-specific activator 8-pCPT-2-O-Me-cAMP, we found that 6-Bnz-cAMP but not 8-pCPT-2-O-Me-cAMP increased NO production in triptolide-LPS treated microglia. These results indicate that the EP2-PKA pathway is very important for triptolide's effects. CONCLUSIONS Triptolide inhibits LPS-stimulated NO production in microglia via a signaling mechanism involving EP2 and PKA. This finding may help establish the pharmacological function of triptolide in neurodegenerative disorders. Moreover, the observation of inflammatory EP2 signaling in primary microglia provides important evidence that EP2 regulates innate immunity in the central nervous system.
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Affiliation(s)
- Ting Zhang
- Department of Neurobiology, Capital Medical University, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disorder, Ministry of Education, No. 10 Xitoutiao, Youanmenwai, Fengtai District, Beijing, 100069, China.
| | - Xiaoli Gong
- Department of Physiology, Capital Medical University, No. 10 Xitoutiao, Youanmenwai, Fengtai District, Beijing, 100069, China.
| | - Guanzheng Hu
- Department of Neurobiology, Capital Medical University, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disorder, Ministry of Education, No. 10 Xitoutiao, Youanmenwai, Fengtai District, Beijing, 100069, China.
| | - Xiaomin Wang
- Department of Neurobiology, Capital Medical University, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disorder, Ministry of Education, No. 10 Xitoutiao, Youanmenwai, Fengtai District, Beijing, 100069, China.
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31
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Lee YH, Lin CH, Hsu PC, Sun YY, Huang YJ, Zhuo JH, Wang CY, Gan YL, Hung CC, Kuan CY, Shie FS. Aryl hydrocarbon receptor mediates both proinflammatory and anti-inflammatory effects in lipopolysaccharide-activated microglia. Glia 2015; 63:1138-54. [PMID: 25690886 DOI: 10.1002/glia.22805] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 01/21/2015] [Indexed: 12/27/2022]
Abstract
The aryl hydrocarbon receptor (AhR) regulates peripheral immunity; but its role in microglia-mediated neuroinflammation in the brain remains unknown. Here, we demonstrate that AhR mediates both anti-inflammatory and proinflammatory effects in lipopolysaccharide (LPS)-activated microglia. Activation of AhR by its ligands, formylindolo[3,2-b]carbazole (FICZ) or 3-methylcholanthrene (3MC), attenuated LPS-induced microglial immune responses. AhR also showed proinflammatory effects, as evidenced by the findings that genetic silence of AhR ameliorated the LPS-induced microglial immune responses and LPS-activated microglia-mediated neurotoxicity. Similarly, LPS-induced expressions of tumor necrosis factor α (TNFα) and inducible nitric oxide synthase (iNOS) were reduced in the cerebral cortex of AhR-deficient mice. Intriguingly, LPS upregulated and activated AhR in the absence of AhR ligands via the MEK1/2 signaling pathway, which effects were associated with a transient inhibition of cytochrome P450 1A1 (CYP1A1). Although AhR ligands synergistically enhance LPS-induced AhR activation, leading to suppression of LPS-induced microglial immune responses, they cannot do so on their own in microglia. Chromatin immunoprecipitation results further revealed that LPS-FICZ co-treatment, but not LPS alone, not only resulted in co-recruitment of both AhR and NFκB onto the κB site of TNFα gene promoter but also reduced LPS-induced AhR binding to the DRE site of iNOS gene promoter. Together, we provide evidence showing that microglial AhR, which can be activated by LPS, exerts bi-directional effects on the regulation of LPS-induced neuroinflammation, depending on the availability of external AhR ligands. These findings confer further insights into the potential link between environmental factors and the inflammatory brain disorders.
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Affiliation(s)
- Yi-Hsuan Lee
- Institute of Physiology, National Yang-Ming University, Taipei, Taiwan; Brain Research Center, National Yang-Ming University, Taipei, Taiwan
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32
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Li X, Melief E, Postupna N, Montine KS, Keene CD, Montine TJ. Prostaglandin E2 receptor subtype 2 regulation of scavenger receptor CD36 modulates microglial Aβ42 phagocytosis. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 185:230-9. [PMID: 25452117 DOI: 10.1016/j.ajpath.2014.09.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 09/14/2014] [Accepted: 09/18/2014] [Indexed: 12/18/2022]
Abstract
Recent studies underline the potential relevance of microglial innate immune activation in Alzheimer disease. Primary mouse microglia that lack prostaglandin E2 receptor subtype 2 (EP2) show decreased innate immune-mediated neurotoxicity and increased amyloid β (Aβ) peptide phagocytosis, features that were replicated in vivo. Here, we tested the hypothesis that scavenger receptor CD36 is an effector of EP2-regulated Aβ phagocytosis. CD36 expression was 143-fold greater in mouse primary microglia than in primary astrocytes. Three different means of suppressing EP2 signaling increased and an agonist of EP2 decreased CD36 expression in primary wild-type microglia. Activation of Toll-like receptor (TLR) 3, TLR4, and TLR7, but not TLR2 or TLR9, reduced primary microglial CD36 transcription and cell surface CD36 protein and reduced Aβ42 phagocytosis as well. At each step, the effects of innate immune activation on CD36 were reversed by at least 50% by an EP2 antagonist, and this partial rescue of microglia Aβ42 phagocytosis was largely mediated by CD36 activity. Finally, we showed in hippocampus of wild-type mice that innate immune activation suppressed CD36 expression by an EP2-dependent mechanism. Taken together with results of others that found brain clearance of Aβ peptides and behavioral improvements mediated by CD36 in mice, regulation of CD36-mediated Aβ phagocytosis by suppression of EP2 signaling may provide a new approach to suppressing some aspects of Alzheimer disease pathogenesis.
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Affiliation(s)
- Xianwu Li
- Department of Pathology, University of Washington, Seattle, Washington.
| | - Erica Melief
- Department of Pathology, University of Washington, Seattle, Washington
| | - Nadia Postupna
- Department of Pathology, University of Washington, Seattle, Washington
| | | | - C Dirk Keene
- Department of Pathology, University of Washington, Seattle, Washington
| | - Thomas J Montine
- Department of Pathology, University of Washington, Seattle, Washington
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33
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Fathali N, Ostrowski RP, Hasegawa Y, Lekic T, Tang J, Zhang JH. Splenic immune cells in experimental neonatal hypoxia-ischemia. Transl Stroke Res 2014; 4:208-19. [PMID: 23626659 DOI: 10.1007/s12975-012-0239-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Neuroimmune processes contribute to hypoxic-ischemic damage in the immature brain and may play a role in the progression of particular variants of neonatal encephalopathy. The present study was designed to elucidate molecular mediators of interactions between astrocytes, neurons and infiltrating peripheral immune cells after experimental neonatal hypoxia-ischemia (HI). Splenectomy was performed on postnatal day-7 Sprague-Dawley rats 3 days prior to HI surgery; in which the right common carotid artery was permanently ligated followed by 2 hours of hypoxia (8% O2). Quantitative analysis showed that natural killer (NK) and T cell expression was reduced in spleen but increased in the brain following HI. Elevations in cyclooxygenase-2 (COX-2) expression after HI by immune cells promoted interleukin-15 expression in astrocytes and infiltration of inflammatory cells to site of injury; additionally, down-regulated the pro-survival protein, phosphoinositide-3-kinase, resulting in caspase-3 mediated neuronal death. The removal of the largest pool of peripheral immune cells in the body by splenectomy, COX-2 inhibitors, as well as rendering NK cells inactive by CD161 knockdown, significantly ameliorated cerebral infarct volume at 72 hours, diminished body weight loss and brain and systemic organ atrophy, and reduced neurobehavioral deficits at 3 weeks. Herein we demonstrate with the use of surgical approach (splenectomy), with pharmacological loss-gain function approach using COX-2 inhibitors/agonists, as well as with NK cell-type specific siRNA that after neonatal HI, the infiltrating peripheral immune cells may modulate downstream targets of cell death and neuroinflammation by COX-2 regulated signals.
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Affiliation(s)
- Nancy Fathali
- Department of Human Anatomy and Pathology, Loma Linda University, Loma Linda, California, USA
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Suppression of Alzheimer-associated inflammation by microglial prostaglandin-E2 EP4 receptor signaling. J Neurosci 2014; 34:5882-94. [PMID: 24760848 DOI: 10.1523/jneurosci.0410-14.2014] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A persistent and nonresolving inflammatory response to accumulating Aβ peptide species is a cardinal feature in the development of Alzheimer's disease (AD). In response to accumulating Aβ peptide species, microglia, the innate immune cells of the brain, generate a toxic inflammatory response that accelerates synaptic and neuronal injury. Many proinflammatory signaling pathways are linked to progression of neurodegeneration. However, endogenous anti-inflammatory pathways capable of suppressing Aβ-induced inflammation represent a relatively unexplored area. Here we report that signaling through the prostaglandin-E2 (PGE2) EP4 receptor potently suppresses microglial inflammatory responses to Aβ42 peptides. In cultured microglial cells, EP4 stimulation attenuated levels of Aβ42-induced inflammatory factors and potentiated phagocytosis of Aβ42. Microarray analysis demonstrated that EP4 stimulation broadly opposed Aβ42-driven gene expression changes in microglia, with enrichment for targets of IRF1, IRF7, and NF-κB transcription factors. In vivo, conditional deletion of microglial EP4 in APPSwe-PS1ΔE9 (APP-PS1) mice conversely increased inflammatory gene expression, oxidative protein modification, and Aβ deposition in brain at early stages of pathology, but not at later stages, suggesting an early anti-inflammatory function of microglial EP4 signaling in the APP-PS1 model. Finally, EP4 receptor levels decreased significantly in human cortex with progression from normal to AD states, suggesting that early loss of this beneficial signaling system in preclinical AD development may contribute to subsequent progression of pathology.
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Fattahi MJ, Mirshafiey A. Positive and negative effects of prostaglandins in Alzheimer's disease. Psychiatry Clin Neurosci 2014; 68:50-60. [PMID: 23992456 DOI: 10.1111/pcn.12092] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 05/23/2013] [Accepted: 05/29/2013] [Indexed: 01/21/2023]
Abstract
The aim of this review was to clarify the role of prostaglandins and prostaglandin receptors in the immunopathology of Alzheimer's disease. A PubMed search was done using the key word, 'Alzheimer's disease' in combination with the term 'prostaglandins'. Articles from the past 10 years were preferentially selected but important ones from the past 20 years were also included according to the authors' judgment. Alzheimer's disease is characterized by pathological hallmarks such as extracellular deposition of the amyloid β-peptide, the appearance of intracellular neurofibrillary tangles, extensive neuronal loss and synaptic changes in the cerebral cortex and hippocampus. These processes induce inflammatory pathways by activating microglia, astrocytes and infiltrating leukocytes that produce inflammatory mediators including cytokines and prostaglandins.Prostaglandins are small lipid mediators derived from arachidonic acid by multi-enzymatic pathways in which cyclooxygenases and phospholipases are the rate-limiting enzymes. In the central nervous system, prostaglandins exhibit either neurotoxic or neuroprotective effects by acting on specific G-protein-coupled receptors that have different subfamilies and differences in their selective agonists, tissue distribution and signal transduction cascades. Further studies on the role of prostaglandins in Alzheimer's disease may contribute to clarification of their neuroprotective actions, which may lead to the development of successful therapeutic strategies.
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Affiliation(s)
- Mohammad Javad Fattahi
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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Abstract
Cycoloxygenase-2 (COX-2) induction is prevalent in a variety of (brain and peripheral) injury models where COX-2 levels correlate with disease progression. Thus, COX-2 has been widely explored for anti-inflammatory therapy with COX-2 inhibitors, which proved to be effective in reducing the pain and inflammation in patients with arthritis and menstrual cramps, but they have not provided any benefit to patients with chronic inflammatory neurodegenerative disease. Recently, two COX-2 drugs, rofecoxib and valdecoxib, were withdrawn from the United States market due to cardiovascular side effects. Thus, future anti-inflammatory therapy could be targeted through a specific prostanoid receptor downstream of COX-2. The PGE2 receptor EP2 is emerging as a pro-inflammatory target in a variety of CNS and peripheral diseases. Here we highlight the latest developments on the role of EP2 in diseases, mechanism of activation, and small molecule discovery targeted either to enhance or to block the function of this receptor.
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Affiliation(s)
- Thota Ganesh
- Department of Pharmacology, Emory University School of Medicine , 1510 Clifton Road, Atlanta, Georgia, 30322, United States
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Suppression of inflammation with conditional deletion of the prostaglandin E2 EP2 receptor in macrophages and brain microglia. J Neurosci 2013; 33:16016-32. [PMID: 24089506 DOI: 10.1523/jneurosci.2203-13.2013] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Prostaglandin E2 (PGE2), a potent lipid signaling molecule, modulates inflammatory responses through activation of downstream G-protein coupled EP(1-4) receptors. Here, we investigated the cell-specific in vivo function of PGE2 signaling through its E-prostanoid 2 (EP2) receptor in murine innate immune responses systemically and in the CNS. In vivo, systemic administration of lipopolysaccharide (LPS) resulted in a broad induction of cytokines and chemokines in plasma that was significantly attenuated in EP2-deficient mice. Ex vivo stimulation of peritoneal macrophages with LPS elicited proinflammatory responses that were dependent on EP2 signaling and that overlapped with in vivo plasma findings, suggesting that myeloid-lineage EP2 signaling is a major effector of innate immune responses. Conditional deletion of the EP2 receptor in myeloid lineage cells in Cd11bCre;EP2(lox/lox) mice attenuated plasma inflammatory responses and transmission of systemic inflammation to the brain was inhibited, with decreased hippocampal inflammatory gene expression and cerebral cortical levels of IL-6. Conditional deletion of EP2 significantly blunted microglial and astrocytic inflammatory responses to the neurotoxin MPTP and reduced striatal dopamine turnover. Suppression of microglial EP2 signaling also increased numbers of dopaminergic (DA) neurons in the substantia nigra independent of MPTP treatment, suggesting that microglial EP2 may influence development or survival of DA neurons. Unbiased microarray analysis of microglia isolated from adult Cd11bCre;EP2(lox/lox) and control mice demonstrated a broad downregulation of inflammatory pathways with ablation of microglial EP2 receptor. Together, these data identify a cell-specific proinflammatory role for macrophage/microglial EP2 signaling in innate immune responses systemically and in brain.
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Shin JW, Moon JY, Seong JW, Song SH, Cheong YJ, Kang C, Sohn NW. Effects of Tetramethylpyrazine on Microglia Activation in Spinal Cord Compression Injury of Mice. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2013; 41:1361-76. [PMID: 24228606 DOI: 10.1142/s0192415x13500912] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Secondary mechanisms, including inflammation and microglia activation, serve as targets for the development and application of pharmacological strategies in the management of spinal cord injury (SCI). Tetramethylpyrazine (TMP), an active ingredient of Ligusticum wallichii (chuanxiong), has shown anti-inflammatory and neuroprotective effects against SCI. However, it remains uncertain whether the inflammation-suppressive effects of TMP play a modulatory role over microglia activation in SCI. The present study investigated the effects of TMP on microglia activation and pro-inflammatory cytokines in spinal cord compression injury in mice. For a real-time PCR measurement of pro-inflammatory cytokines, SCI was induced in mice by the clip compression method (30 g force, 1 min) and TMP (15 or 30 mg/kg, i.p.) was administered once, 30 minutes before the SCI induction. For immunohistochemistry, TMP (30 mg/kg, i.p.) treatment was given three times during the first 48 hours after the SCI. 30 mg/kg of TMP treatment reduced the up-regulation of TNF-α, IL-1β and COX-2 mRNA in the spinal tissue at four hours after the SCI induction. TMP also significantly attenuated microglia activation and neutrophil infiltration at 48 hours after the SCI induction. In addition, iNOS expression in the spinal tissue was attenuated with TMP treatment. These results suggest that TMP plays a modulatory role in microglia activation and may protect the spinal cord from or potentially delay secondary spinal cord injury.
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Affiliation(s)
- Jung-Won Shin
- Department of Oriental Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, South Korea
| | - Ja-Young Moon
- Department of Oriental Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, South Korea
| | - Ju-Won Seong
- Department of Oriental Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, South Korea
| | - Sang-Hoon Song
- Department of Oriental Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, South Korea
| | - Young-Jin Cheong
- Department of Oriental Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, South Korea
| | - Chulhun Kang
- Department of Oriental Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, South Korea
| | - Nak-Won Sohn
- Department of Oriental Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, South Korea
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Lee SH, Lee JH, Oh EY, Kim GY, Choi BT, Kim C, Choi YH. Ethanol extract of Cnidium officinale exhibits anti-inflammatory effects in BV2 microglial cells by suppressing NF-κB nuclear translocation and the activation of the PI3K/Akt signaling pathway. Int J Mol Med 2013; 32:876-82. [PMID: 23864034 DOI: 10.3892/ijmm.2013.1447] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 07/09/2013] [Indexed: 11/05/2022] Open
Abstract
Chronic microglial activation endangers neuronal survival through the release of various toxic pro-inflammatory molecules; thus, negative regulators of microglial activation have been identified as potential therapeutic candidates for several neurological diseases. In this study, we investigated the inhibitory effects of an ethanol extract of Cnidium officinale rhizomes (EECO), which has been used as a herbal drug in Oriental medicine, on the production of lipopolysaccharide (LPS)-induced pro-inflammatory mediators, such as nitric oxide (NO) and prostaglandin E₂ (PGE₂), as well as that of pro-inflammatory cytokines in BV2 microglia cells. EECO significantly inhibited the excess production of NO and PGE₂ in LPS-stimulated BV2 microglia cells. It also attenuated the expression of inducible NO synthase, cyclooxygenase-2, as well as that of pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α. Moreover, EECO exhibited anti-inflammatory properties by suppressing nuclear factor-κB (NF-κB) translocation and the activation of the phosphoinositide 3-kinase/Akt pathway in LPS-stimulated BV2 cells. These results indicate that EECO exerts anti-inflammatory effects in LPS-stimulated BV2 microglial cells by inhibiting pro-inflammatory mediators and cytokine production by blocking the NF-κB pathway. These findings suggest that EECO has substantial therapeutic potential for the treatment of neurodegenerative diseases accompanied by microglial activation.
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Affiliation(s)
- Shin Hwa Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
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40
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Jiang J, Dingledine R. Prostaglandin receptor EP2 in the crosshairs of anti-inflammation, anti-cancer, and neuroprotection. Trends Pharmacol Sci 2013; 34:413-23. [PMID: 23796953 DOI: 10.1016/j.tips.2013.05.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 05/05/2013] [Accepted: 05/10/2013] [Indexed: 10/26/2022]
Abstract
Modulation of a specific prostanoid synthase or receptor provides therapeutic alternatives to nonsteroidal anti-inflammatory drugs (NSAIDs) for treating pathological conditions governed by cyclooxygenase-2 (COX-2 or PTGS2). Among the COX-2 downstream signaling pathways, the prostaglandin E2 (PGE2) receptor EP2 subtype (PTGER2) is emerging as a crucial mediator of many physiological and pathological events. Genetic ablation strategies and recent advances in chemical biology provide tools for a better understanding of EP2 signaling. In the brain, the EP2 receptor modulates some beneficial effects, including neuroprotection, in acute models of excitotoxicity, neuroplasticity, and spatial learning via cAMP-PKA signaling. Conversely, EP2 activation accentuates chronic inflammation mainly through the cAMP-Epac pathway, likely contributing to delayed neurotoxicity. EP2 receptor activation also engages β-arrestin in a G-protein-independent pathway that promotes tumor cell growth and migration. Understanding the conditions under which multiple EP2 signaling pathways are engaged might suggest novel therapeutic strategies to target this key inflammatory prostaglandin receptor.
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Affiliation(s)
- Jianxiong Jiang
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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41
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Quan Y, Jiang J, Dingledine R. EP2 receptor signaling pathways regulate classical activation of microglia. J Biol Chem 2013; 288:9293-302. [PMID: 23404506 DOI: 10.1074/jbc.m113.455816] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activation of EP2 receptors by prostaglandin E2 (PGE2) promotes brain inflammation in neurodegenerative diseases, but the pathways responsible are unclear. EP2 receptors couple to Gαs and increase cAMP, which associates with protein kinase A (PKA) and cAMP-regulated guanine nucleotide exchange factors (Epacs). Here, we studied EP2 function and its signaling pathways in rat microglia in their resting state or undergoing classical activation in vitro following treatment with low concentrations of lipopolysaccharide and interferon-γ. Real time PCR showed that PGE2 had no effect on expression of CXCL10, TGF-β1, and IL-11 and exacerbated the rapid up-regulation of mRNAs encoding cyclooxygenase-2, inducible NOS, IL-6, and IL-1β but blunted the production of mRNAs encoding TNF-α, IL-10, CCL3, and CCL4. These effects were mimicked fully by the EP2 agonist butaprost but only weakly by the EP1/EP3 agonist 17-phenyl trinor PGE2 or the EP4 agonist CAY10598 and not at all by the EP3/EP1 agonist sulprostone and confirmed by protein measurements of cyclooxygenase-2, IL-6, IL-10, and TNF-α. In resting microglia, butaprost induced cAMP formation and altered the mRNA expression of inflammatory mediators, but protein expression was unchanged. The PKA inhibitor H89 had little or no effect on inflammatory mediators modulated by EP2, whereas the Epac activator 8-(4-chlorophenylthio)-2'-O-methyladenosine 3',5'-cyclic monophosphate acetoxymethyl ester mimicked all butaprost effects. These results indicate that EP2 activation plays a complex immune regulatory role during classical activation of microglia and that Epac pathways are prominent in this role.
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Affiliation(s)
- Yi Quan
- Department of Pharmacology, Emory University, Atlanta, GA 30322, USA
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42
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Inhibition of the prostaglandin receptor EP2 following status epilepticus reduces delayed mortality and brain inflammation. Proc Natl Acad Sci U S A 2013; 110:3591-6. [PMID: 23401547 DOI: 10.1073/pnas.1218498110] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Prostaglandin E2 is now widely recognized to play critical roles in brain inflammation and injury, although the responsible prostaglandin receptors have not been fully identified. We developed a potent and selective antagonist for the prostaglandin E2 receptor subtype EP2, TG6-10-1, with a sufficient pharmacokinetic profile to be used in vivo. We found that in the mouse pilocarpine model of status epilepticus (SE), systemic administration of TG6-10-1 completely recapitulates the effects of conditional ablation of cyclooxygenase-2 from principal forebrain neurons, namely reduced delayed mortality, accelerated recovery from weight loss, reduced brain inflammation, prevention of blood-brain barrier opening, and neuroprotection in the hippocampus, without modifying seizures acutely. Prolonged SE in humans causes high mortality and morbidity that are associated with brain inflammation and injury, but currently the only effective treatment is to stop the seizures quickly enough with anticonvulsants to prevent brain damage. Our results suggest that the prostaglandin receptor EP2 is critically involved in neuroinflammation and neurodegeneration, and point to EP2 receptor antagonism as an adjunctive therapeutic strategy to treat SE.
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Cimino PJ, Yang Y, Li X, Hemingway JF, Cherne MK, Khademi SB, Fukui Y, Montine KS, Montine TJ, Keene CD. Ablation of the microglial protein DOCK2 reduces amyloid burden in a mouse model of Alzheimer's disease. Exp Mol Pathol 2013; 94:366-71. [PMID: 23318649 DOI: 10.1016/j.yexmp.2013.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 01/04/2013] [Indexed: 11/24/2022]
Abstract
Alzheimer's disease (AD) neuropathology is characterized by innate immune activation primarily through prostaglandin E2 (PGE2) signaling. Dedicator of cytokinesis 2 (DOCK2) is a guanyl nucleotide exchange factor expressed exclusively in microglia in the brain and is regulated by PGE2 receptor EP2. DOCK2 modulates microglia cytokine secretion, phagocytosis, and paracrine neurotoxicity. EP2 ablation in experimental AD results in reduced oxidative damage and amyloid beta (Aβ) burden. This discovery led us to hypothesize that genetic ablation of DOCK2 would replicate the anti-Aβ effects of loss of EP2 in experimental AD. To test this hypothesis, we crossed mice that lacked DOCK2 (DOCK2-/-), were hemizygous for DOCK2 (DOCK2+/-), or that expressed two DOCK2 genes (DOCK2+/+) with APPswe-PS1Δe9 mice (a model of AD). While we found no DOCK2-dependent differences in cortex or in hippocampal microglia density or morphology in APPswe-PS1Δe9 mice, cerebral cortical and hippocampal Aβ plaque area and size were significantly reduced in 10-month-old APPswe-PS1Δe9/DOCK2-/- mice compared with APPswe-PS1Δe9/DOCK2+/+ controls. DOCK2 hemizygous APPswe-PS1Δe9 mice had intermediate Aβ plaque levels. Interestingly, soluble Aβ42 was not significantly different among the three genotypes, suggesting the effects were mediated specifically in fibrillar Aβ. In combination with earlier cell culture results, our in vivo results presented here suggest DOCK2 contributes to Aβ plaque burden via regulation of microglial innate immune function and may represent a novel therapeutic target for AD.
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Affiliation(s)
- Patrick J Cimino
- Department of Pathology, University of Washington, Seattle, WA 63110-1093, USA.
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Abstract
The enzyme cyclooxygenase-2 (COX-2), responsible for the first committed step in the synthesis of several important mediators which are involved in both initiation and resolution of inflammation, and the subsequent generation of prostaglandins (PGs) upon activation has been shown to participate in the neurodegenerative processes of a variety of diseases. This review looks particular at the role of COX-2 in the pathogenesis of Parkinson's disease, involving the generation of PGs and the role of the two different parts of the cyclooxygenase-cyclooxygenase and peroxidase activity.
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Affiliation(s)
- Peter Teismann
- School of Medical Sciences, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK.
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45
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Prostaglandin E2 and the suppression of phagocyte innate immune responses in different organs. Mediators Inflamm 2012; 2012:327568. [PMID: 23024463 PMCID: PMC3449139 DOI: 10.1155/2012/327568] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/19/2012] [Accepted: 05/03/2012] [Indexed: 12/15/2022] Open
Abstract
The local and systemic production of prostaglandin E2 (PGE2) and its actions in phagocytes lead to immunosuppressive conditions. PGE2 is produced at high levels during inflammation, and its suppressive effects are caused by the ligation of the E prostanoid receptors EP2 and EP4, which results in the production of cyclic AMP. However, PGE2 also exhibits immunostimulatory properties due to binding to EP3, which results in decreased cAMP levels. The various guanine nucleotide-binding proteins (G proteins) that are coupled to the different EP receptors account for the pleiotropic roles of PGE2 in different disease states. Here, we discuss the production of PGE2 and the actions of this prostanoid in phagocytes from different tissues, the relative contribution of PGE2 to the modulation of innate immune responses, and the novel therapeutic opportunities that can be used to control inflammatory responses.
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Li X, Rose SE, Montine KS, Keene CD, Montine TJ. Antagonism of neuronal prostaglandin E(2) receptor subtype 1 mitigates amyloid β neurotoxicity in vitro. J Neuroimmune Pharmacol 2012; 8:87-93. [PMID: 22718277 DOI: 10.1007/s11481-012-9380-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 06/04/2012] [Indexed: 01/28/2023]
Abstract
Multiple lines of evidence indicate that regional brain eicosanoid signaling is important in initiation and progression of neurodegenerative conditions that have neuroinflammatory pathologic component, such as AD. We hypothesized that PGE(2) receptor subtype 1 (EP1) signaling (linked to intracellular Ca(2+) release) regulates Aβ peptide neurotoxicity and tested this in two complementary in vitro models: a human neuroblastoma cell line (MC65) producing Aβ(1-40) through conditional expression of the APP C-terminal portion, and murine primary cortical neuron cultures exposed to Aβ(1-42). In MC65 cells, EP1 receptor antagonist SC-51089 reduced Aβ neurotoxicity ~50 % without altering high molecular weight Aβ immunoreactive species formation. Inositol-3-phosphate receptor antagonist 2-aminoethoxy-diphenyl borate offered similar protection. SC-51089 largely protected the neuron cultures from synthetic Aβ(1-42) neurotoxicity. Nimodipine, a Ca(2+) channel blocker, was completely neuroprotective in both models. Based on these data, we conclude that suppressing neuronal EP1 signaling may represent a promising therapeutic approach to ameliorate Aβ peptide neurotoxicity.
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Affiliation(s)
- Xianwu Li
- Department of Pathology, University of Washington, Box 359645, Seattle, WA 98104, USA.
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Li X, Cudaback E, Breyer RM, Montine KS, Keene CD, Montine TJ. Eicosanoid receptor subtype-mediated opposing regulation of TLR-stimulated expression of astrocyte glial-derived neurotrophic factor. FASEB J 2012; 26:3075-83. [PMID: 22499581 DOI: 10.1096/fj.11-200279] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A major therapeutic target for Parkinson's disease (PD) is providing increased glial-derived neurotrophic factor (GDNF) to dopaminergic neurons. We tested the hypothesis that innate immune activation increases astrocyte GDNF production and that this is regulated by specific eicosanoid receptors. Innate immune-activated primary murine astrocytes were assayed for GDNF expression and secretion. Controls were agent vehicle exposure and wild-type mice. Rank order for up to 10-fold selectively increased GDNF expression was activators of TLR3 > TLR2 or TLR4 > TLR9. TLR3 activator-stimulated GDNF expression was selectively JNK-dependent, followed cyclooxygenase (COX)-2, was coincident with membranous PGE(2) synthase, and was not significantly altered by a nonspecific COX- or a COX-2-selective inhibitor. Specific eicosanoid receptors had opposing effects on TLR3 activator-induced GDNF expression: ∼60% enhancement by blocking or ablating of PGE(2) receptor subtype 1 (EP1), ∼30% enhancement by activating PGF(2α) receptor or thromboxane receptor, or ∼15% enhancement by activating EP4. These results demonstrate functionally antagonistic eicosanoid receptor subtype regulation of innate immunity-induced astrocyte GDNF expression and suggest that selective inhibition of EP1 signaling might be a means to augment astrocyte GDNF secretion in the context of innate immune activation in diseased regions of brain in PD.
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Affiliation(s)
- Xianwu Li
- Department of Pathology, University of Washington, Box 359645, Seattle, WA 98104, USA.
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Rezai-Zadeh K, Gate D, Gowing G, Town T. How to get from here to there: macrophage recruitment in Alzheimer's disease. Curr Alzheimer Res 2011; 8:156-63. [PMID: 21345166 DOI: 10.2174/156720511795256017] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 12/03/2010] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is pathologically defined by presence of intracellular neurofibrillary tangles and extracellular amyloid plaques comprised of amyoid-β (Aβ) peptides. Despite local recruitment of brain microglia to sites of amyloid deposition, these mononuclear phagocytes ultimately fail at restricting β-amyloid plaque formation. On the other hand, it is becoming increasingly clear that professional phagocytes from the periphery possess Aβ clearance aptitude. Yet, in order to harness this beneficial innate immune response, effective strategies must be developed to coax monocytes/macrophages from the periphery into the brain. It has previously been suggested that Aβ 'immunotherapy' clears cerebral Aβ deposits via mononuclear phagocytes, and recent evidence suggests that targeting transforming growth factor-β-Smad 2/3 signaling and chemokine pathways such as Ccr2 impacts blood-to-brain trafficking of these cells in transgenic mouse models of AD. It has also been shown that the fractalkine receptor (Cx3cr1) pathway plays a critical role in chemotaxis of mononuclear phagocytes toward neurons destined for death in AD model mice. In order to translate these basic science findings into AD treatments, a key challenge will be to develop a new generation of pharmacotherapeutics that safely and effectively promote recruitment of peripheral amyloid phagocytes into the AD brain.
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Affiliation(s)
- K Rezai-Zadeh
- Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., SSB3 Room 361, Los Angeles, CA 90048, USA
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Affiliation(s)
- Takako Hirata
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Shuh Narumiya
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
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50
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Woodward DF, Jones RL, Narumiya S. International Union of Basic and Clinical Pharmacology. LXXXIII: classification of prostanoid receptors, updating 15 years of progress. Pharmacol Rev 2011; 63:471-538. [PMID: 21752876 DOI: 10.1124/pr.110.003517] [Citation(s) in RCA: 321] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
It is now more than 15 years since the molecular structures of the major prostanoid receptors were elucidated. Since then, substantial progress has been achieved with respect to distribution and function, signal transduction mechanisms, and the design of agonists and antagonists (http://www.iuphar-db.org/DATABASE/FamilyIntroductionForward?familyId=58). This review systematically details these advances. More recent developments in prostanoid receptor research are included. The DP(2) receptor, also termed CRTH2, has little structural resemblance to DP(1) and other receptors described in the original prostanoid receptor classification. DP(2) receptors are more closely related to chemoattractant receptors. Prostanoid receptors have also been found to heterodimerize with other prostanoid receptor subtypes and nonprostanoids. This may extend signal transduction pathways and create new ligand recognition sites: prostacyclin/thromboxane A(2) heterodimeric receptors for 8-epi-prostaglandin E(2), wild-type/alternative (alt4) heterodimers for the prostaglandin FP receptor for bimatoprost and the prostamides. It is anticipated that the 15 years of research progress described herein will lead to novel therapeutic entities.
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Affiliation(s)
- D F Woodward
- Dept. of Biological Sciences RD3-2B, Allergan, Inc., 2525 Dupont Dr., Irvine, CA 92612, USA.
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