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Kaiser S, Henrich L, Kiessling I, Loy B, Schallner N. Neuroprotection via Carbon Monoxide Depends on the Circadian Regulation of CD36-Mediated Microglial Erythrophagocytosis in Hemorrhagic Stroke. Int J Mol Sci 2024; 25:1680. [PMID: 38338958 PMCID: PMC10855856 DOI: 10.3390/ijms25031680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/19/2024] [Accepted: 01/27/2024] [Indexed: 02/12/2024] Open
Abstract
The molecular basis for circadian dependency in stroke due to subarachnoid hemorrhagic stroke (SAH) remains unclear. We reasoned that microglial erythrophagocytosis, crucial for SAH response, follows a circadian pattern involving carbon monoxide (CO) and CD36 surface expression. The microglial BV-2 cell line and primary microglia (PMG) under a clocked medium change were exposed to blood ± CO (250 ppm, 1 h) in vitro. Circadian dependency and the involvement of CD36 were analyzed in PMG isolated from control mice and CD36-/- mice and by RNA interference targeting Per-2. In vivo investigations, including phagocytosis, vasospasm, microglia activation and spatial memory, were conducted in an SAH model using control and CD36-/- mice at different zeitgeber times (ZT). In vitro, the surface expression of CD36 and its dependency on CO and phagocytosis occurred with changed circadian gene expression. CD36-/- PMG exhibited altered circadian gene expression, phagocytosis and impaired responsiveness to CO. In vivo, control mice with SAH demonstrated circadian dependency in microglia activation, erythrophagocytosis and CO-mediated protection at ZT2, in contrast to CD36-/- mice. Our study indicates that circadian rhythmicity modulates microglial activation and subsequent CD36-dependent phagocytosis. CO altered circadian-dependent neuroprotection and CD36 induction, determining the functional outcome in a hemorrhagic stroke model. This study emphasizes how circadian rhythmicity influences neuronal damage after neurovascular events.
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Affiliation(s)
- Sandra Kaiser
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany (N.S.)
- Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Luise Henrich
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany (N.S.)
- Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Iva Kiessling
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany (N.S.)
- Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Benedikt Loy
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany (N.S.)
- Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Nils Schallner
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany (N.S.)
- Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
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2
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Ma S, Zhou L, Ma Y, Zhao H, Li L, Wang M, Diao H, Li X, Zhang C, Liu W. Hemicyanine-based sensor for mitochondrial viscosity imaging in BV2 cells. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 302:123132. [PMID: 37478757 DOI: 10.1016/j.saa.2023.123132] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/18/2023] [Accepted: 07/10/2023] [Indexed: 07/23/2023]
Abstract
Mitochondrial viscosity is a critical factor affecting numerous physiological processes, including phagocytosis. Abnormal viscosity in mitochondria is related to some pathological activities and diseases. Evaluating and detecting the changes in mitochondrial viscosity in vivo is crucial. Thus, a mitochondria-targeted red-emitting fluorescent probe (VP) was prepared, and can be used to detect viscosity with high selectivity and sensitivity. The synthesis of probe VP was as simple as two steps and the cost was low. In addition, the fluorescence intensity (log I615) exhibited an excellent relationship with viscosity (log η) in the range of 0.5 - 2.5 (R2 = 0.9985) in water/glycerol mixture. It is noteworthy that the probe VP displayed the highest signal-to-noise ratio (about 50-fold) for viscosity in water and glycerol system. The probe VP can visualize the mitochondrial viscosity change in living cells. More importantly, phagocytic test for BV2 cells further demonstrated that phagocytosis decreased with increased viscosity. Furthermore, VP was successfully used for monitoring the mitophagy process induced by starvation, and mitochondrial viscosity exhibited enhancement during mitophagy. The probe was a potential tool for studying viscosity and phagocytosis.
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Affiliation(s)
- Sufang Ma
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China
| | - Liang Zhou
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China
| | - Yingyu Ma
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China
| | - Huanhuan Zhao
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China
| | - Leyan Li
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China
| | - Meiling Wang
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China
| | - Haipeng Diao
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China; Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan 030001, PR China.
| | - Xiaowan Li
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China
| | - Chengwu Zhang
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China.
| | - Wen Liu
- College of Basic Medical Science, Shanxi Medical University, Taiyuan 030001, PR China; Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan 030001, PR China.
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3
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Microglia in Alzheimer’s Disease: A Favorable Cellular Target to Ameliorate Alzheimer’s Pathogenesis. Mediators Inflamm 2022; 2022:6052932. [PMID: 35693110 PMCID: PMC9184163 DOI: 10.1155/2022/6052932] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 05/09/2022] [Indexed: 11/18/2022] Open
Abstract
Microglial cells serve as molecular sensors of the brain that play a role in physiological and pathological conditions. Under normal physiology, microglia are primarily responsible for regulating central nervous system homeostasis through the phagocytic clearance of redundant protein aggregates, apoptotic cells, damaged neurons, and synapses. Furthermore, microglial cells can promote and mitigate amyloid β phagocytosis and tau phosphorylation. Dysregulation of the microglial programming alters cellular morphology, molecular signaling, and secretory inflammatory molecules that contribute to various neurodegenerative disorders especially Alzheimer’s disease (AD). Furthermore, microglia are considered primary sources of inflammatory molecules and can induce or regulate a broad spectrum of cellular responses. Interestingly, in AD, microglia play a double-edged role in disease progression; for instance, the detrimental microglial effects increase in AD while microglial beneficiary mechanisms are jeopardized. Depending on the disease stages, microglial cells are expressed differently, which may open new avenues for AD therapy. However, the disease-related role of microglial cells and their receptors in the AD brain remain unclear. Therefore, this review represents the role of microglial cells and their involvement in AD pathogenesis.
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4
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Abstract
The innate immune system plays key roles in controlling Alzheimer's disease (AD), while secreting cytokines to eliminate pathogens and regulating brain homeostasis. Recent research in the field of AD has shown that the innate immune-sensing ability of pattern recognition receptors on brain-resident macrophages, known as microglia, initiates neuroinflammation, Aβ accumulation, neuronal loss, and memory decline in patients with AD. Advancements in understanding the role of innate immunity in AD have laid a strong foundation to elucidate AD pathology and devise therapeutic strategies for AD in the future. In this review, we highlight the present understanding of innate immune responses, inflammasome activation, inflammatory cell death pathways, and cytokine secretion in AD. We also discuss how the AD pathology influences these biological processes.
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Affiliation(s)
- SangJoon Lee
- Department of Infection Biology, Faculty of Medicine, 38515University of Tsukuba, Tsukuba, Japan
| | - Hyun-Jeong Cho
- Department of Biomedical Laboratory Science, College of Medical Science, 34966Konyang University, Daejeon, South Korea
| | - Jin-Hyeob Ryu
- BIORCHESTRA Co. Ltd., 17, Techno 4-ro, Yuseong-gu, Daejeon, Republic of Korea.,BIORCHESTRA Co. Ltd., 245 Main St, Cambridge, MA 02142, USA
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5
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Rojas A, Amaradhi R, Banik A, Jiang C, Abreu-Melon J, Wang S, Dingledine R, Ganesh T. A Novel Second-Generation EP2 Receptor Antagonist Reduces Neuroinflammation and Gliosis After Status Epilepticus in Rats. Neurotherapeutics 2021; 18:1207-1225. [PMID: 33410110 PMCID: PMC8423966 DOI: 10.1007/s13311-020-00969-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2020] [Indexed: 02/07/2023] Open
Abstract
Prostaglandin-E2 (PGE2), an important mediator of inflammation, achieves its functions via four different G protein-coupled receptors (EP1, EP2, EP3, and EP4). We previously demonstrated that the EP2 receptor plays a proinflammatory and neurodegenerative role after status epilepticus (SE). We recently developed TG8-260 as a second-generation highly potent and selective EP2 antagonist. Here, we investigate whether TG8-260 is anti-inflammatory and combats neuropathology caused by pilocarpine-induced SE in rats. Adult male Sprague-Dawley rats were injected subcutaneously with pilocarpine (380-400 mg/kg) to induce SE. Following 60 min of SE, the rats were administered three doses of TG8-260 or vehicle and were allowed to recover. Neurodegeneration, neuroinflammation, gliosis, and blood-brain barrier (BBB) integrity were examined 4 days after SE. The results confirmed that pilocarpine-induced SE results in hippocampal neurodegeneration and a robust inflammatory response that persists days after SE. Furthermore, inhibition of the EP2 receptor by TG8-260 administered beginning 2 h after SE significantly reduced hippocampal neuroinflammation and gliosis but, in distinction to the earlier generation EP2 antagonist, did not mitigate neuronal injury or BBB breakdown. Thus, attenuation of neuroinflammation and gliosis is a common feature of EP2 inhibition following SE.
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Affiliation(s)
- Asheebo Rojas
- Department of Pharmacology and Chemical Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA, 30322, USA.
| | - Radhika Amaradhi
- Department of Pharmacology and Chemical Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA, 30322, USA
| | - Avijit Banik
- Department of Pharmacology and Chemical Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA, 30322, USA
| | - Chunxiang Jiang
- Department of Pharmacology and Chemical Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA, 30322, USA
| | - JuanMartin Abreu-Melon
- Department of Pharmacology and Chemical Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA, 30322, USA
| | - Sarah Wang
- Department of Pharmacology and Chemical Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA, 30322, USA
| | - Raymond Dingledine
- Department of Pharmacology and Chemical Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA, 30322, USA
| | - Thota Ganesh
- Department of Pharmacology and Chemical Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA, 30322, USA.
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6
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Shi AC, Rohlwink U, Scafidi S, Kannan S. Microglial Metabolism After Pediatric Traumatic Brain Injury - Overlooked Bystanders or Active Participants? Front Neurol 2021; 11:626999. [PMID: 33569038 PMCID: PMC7868439 DOI: 10.3389/fneur.2020.626999] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 12/23/2020] [Indexed: 12/14/2022] Open
Abstract
Microglia play an integral role in brain development but are also crucial for repair and recovery after traumatic brain injury (TBI). TBI induces an intense innate immune response in the immature, developing brain that is associated with acute and chronic changes in microglial function. These changes contribute to long-lasting consequences on development, neurologic function, and behavior. Although alterations in glucose metabolism are well-described after TBI, the bulk of the data is focused on metabolic alterations in astrocytes and neurons. To date, the interplay between alterations in intracellular metabolic pathways in microglia and the innate immune response in the brain following an injury is not well-studied. In this review, we broadly discuss the microglial responses after TBI. In addition, we highlight reported metabolic alterations in microglia and macrophages, and provide perspective on how changes in glucose, fatty acid, and amino acid metabolism can influence and modulate the microglial phenotype and response to injury.
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Affiliation(s)
- Aria C Shi
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Ursula Rohlwink
- Neuroscience Institute and Division of Neurosurgery, University of Cape Town, Cape Town, South Africa.,The Francis Crick Institute, London, United Kingdom
| | - Susanna Scafidi
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Sujatha Kannan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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7
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Zhou Y, Chen Y, Xu C, Zhang H, Lin C. TLR4 Targeting as a Promising Therapeutic Strategy for Alzheimer Disease Treatment. Front Neurosci 2020; 14:602508. [PMID: 33390886 PMCID: PMC7775514 DOI: 10.3389/fnins.2020.602508] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/16/2020] [Indexed: 12/30/2022] Open
Abstract
Alzheimer disease (AD) is a devastating neurodegenerative disorder characterized by extracellular accumulation of amyloid-beta and formation of intracellular neurofibrillary tangles. Microglia activation and neuroinflammation play important roles in the pathogenesis of AD; Toll-like receptor 4 (TLR4)-a key component of the innate immune system-in microglia is also thought to be involved based on the observed association between TLR gene polymorphisms and AD risk. TLR4 has been shown to exert both detrimental and beneficial effects on AD-related pathologies. In preclinical models, experimental manipulations targeting TLR4 were shown to improve learning and memory, which was related to inhibition of pro-inflammatory cytokine release and reduction of oxidative stress. In this review, we summarize the key evidence supporting TLR4 as a promising therapeutic target in AD treatment.
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Affiliation(s)
- Yongji Zhou
- Department of Neurology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yanxing Chen
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Congcong Xu
- The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hao Zhang
- Department of Neurology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Caixiu Lin
- Department of Neurology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
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8
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Dobri AM, Dudău M, Enciu AM, Hinescu ME. CD36 in Alzheimer's Disease: An Overview of Molecular Mechanisms and Therapeutic Targeting. Neuroscience 2020; 453:301-311. [PMID: 33212223 DOI: 10.1016/j.neuroscience.2020.11.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/17/2020] [Accepted: 11/03/2020] [Indexed: 12/11/2022]
Abstract
CD36 is a membrane protein with wide distribution in the human body, is enriched in the monocyte-macrophage system and endothelial cells, and is involved in the cellular uptake of long chain fatty acids (LCFA) and oxidized low-density lipoproteins. It is also a scavenger receptor, binding hydrophobic amyloid fibrils found in the Alzheimer's disease (AD) brain. In neurobiology research, it has been mostly studied in relationship with chronic ischemia and stroke, but it was also related to amyloid clearance by microglial phagocytosis. In AD animal models, amyloid binding to CD36 has been consistently correlated with a pro-inflammatory response. Therapeutic approaches have two main focuses: CD36 blockade with monoclonal antibodies or small molecules, which is beneficial in terms of the inflammatory milieu, and upregulation of CD36 for increased amyloid clearance. The balance of the two approaches, centered on microglia, is poorly understood. Furthermore, CD36 evaluation in AD clinical studies is still at a very early stage and there is a gap in the knowledge regarding the impact of LCFA on AD progression and CD36 expression and genetic phenotype. This review summarizes the role played by CD36 in the pathogenic amyloid cascade and explore the translatability of preclinical data towards clinical research.
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Affiliation(s)
- Ana-Maria Dobri
- "Victor Babes" National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania; "Carol Davila" University of Medicine and Pharmacy, 5 Eroilor Sanitari Blvd, 050047 Bucharest, Romania.
| | - Maria Dudău
- "Victor Babes" National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania; "Carol Davila" University of Medicine and Pharmacy, 5 Eroilor Sanitari Blvd, 050047 Bucharest, Romania.
| | - Ana-Maria Enciu
- "Victor Babes" National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania; "Carol Davila" University of Medicine and Pharmacy, 5 Eroilor Sanitari Blvd, 050047 Bucharest, Romania.
| | - Mihail Eugen Hinescu
- "Victor Babes" National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania; "Carol Davila" University of Medicine and Pharmacy, 5 Eroilor Sanitari Blvd, 050047 Bucharest, Romania
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9
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Kaiser S, Selzner L, Weber J, Schallner N. Carbon monoxide controls microglial erythrophagocytosis by regulating CD36 surface expression to reduce the severity of hemorrhagic injury. Glia 2020; 68:2427-2445. [PMID: 32476210 DOI: 10.1002/glia.23864] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 04/22/2020] [Accepted: 05/15/2020] [Indexed: 12/27/2022]
Abstract
Microglial erythrophagocytosis is crucial in injury response to hemorrhagic stroke. We hypothesized that regulation of microglial erythrophagocytosis via HO-1/CO depends on a pathway involving reactive oxygen species (ROS) and CD36 surface-expression. The microglial BV-2 cell line and primary microglia (PMG) were incubated +/-blood and +/-CO-exposure. PMG isolated from tissue-specific HO-1-deficient (LyzM-Cre-Hmox1 fl/fl ) and CD36 -/- mice or siRNA against AMPK (AMP-activated protein kinase) were used to test our hypothesis. In a murine subarachnoid hemorrhage (SAH) model, we compared neuronal injury in wild-type and CD36 -/- mice. Readouts included vasospasm, microglia activation, neuronal apoptosis, and spatial memory. We observed increased microglial HO-1-expression after blood-exposure. A burst in ROS-production was seen after CO-exposure, which led to increased amounts of phosphorylated AMPK with subsequently enhanced CD36 surface-expression. Naïve PMG from LyzM-Cre-Hmox1 fl/fl mice showed reduced ROS-production and CD36 surface-expression and failed to respond to CO with increased CD36 surface-expression. Lack of HO-1 and CD36 resulted in reduced erythrophagocytosis that could not be rescued with CO. Erythrophagocytosis was enhanced in BV-2 cells in the presence of exogenous CO, which was abolished in cells treated with siRNA to AMPK. CD36 -/- mice subjected to SAH showed enhanced neuronal cell death, which resulted in impaired spatial memory function. We demonstrate that microglial phagocytic function partly depends on a pathway involving HO-1 with changes in ROS-production, phosphorylated AMPK, and surface expression of CD36. CD36 was identified as a crucial component in blood clearance after hemorrhage that ultimately determines neuronal outcome. These results demand further investigations studying the potential neuroprotective properties of CO.
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Affiliation(s)
- Sandra Kaiser
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Lisa Selzner
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Janick Weber
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Nils Schallner
- Department of Anesthesiology & Critical Care Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
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10
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Rojas A, Ganesh T, Wang W, Wang J, Dingledine R. A rat model of organophosphate-induced status epilepticus and the beneficial effects of EP2 receptor inhibition. Neurobiol Dis 2020; 133:104399. [PMID: 30818067 PMCID: PMC6708729 DOI: 10.1016/j.nbd.2019.02.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/29/2019] [Accepted: 02/20/2019] [Indexed: 02/06/2023] Open
Abstract
This review describes an adult rat model of status epilepticus (SE) induced by diisopropyl fluorophosphate (DFP), and the beneficial outcomes of transient inhibition of the prostaglandin-E2 receptor EP2 with a small molecule antagonist, delayed by 2-4 h after SE onset. Administration of six doses of the selective EP2 antagonist TG6-10-1 over a 2-3 day period accelerates functional recovery, attenuates hippocampal neurodegeneration, neuroinflammation, gliosis and blood-brain barrier leakage, and prevents long-term cognitive deficits without blocking SE itself or altering acute seizure characteristics. This work has provided important information regarding organophosphate-induced seizure related pathologies in adults and revealed the effectiveness of delayed EP2 inhibition to combat these pathologies.
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Affiliation(s)
- Asheebo Rojas
- Department of Pharmacology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA.
| | - Thota Ganesh
- Department of Pharmacology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Wenyi Wang
- Department of Pharmacology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Jennifer Wang
- Department of Pharmacology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Raymond Dingledine
- Department of Pharmacology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA
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11
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Madadi S, Schwarzenbach H, Saidijam M, Mahjub R, Soleimani M. Potential microRNA-related targets in clearance pathways of amyloid-β: novel therapeutic approach for the treatment of Alzheimer's disease. Cell Biosci 2019; 9:91. [PMID: 31749959 PMCID: PMC6852943 DOI: 10.1186/s13578-019-0354-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/01/2019] [Indexed: 02/07/2023] Open
Abstract
Imbalance between amyloid-beta (Aβ) peptide synthesis and clearance results in Aβ deregulation. Failure to clear these peptides appears to cause the development of Alzheimer's disease (AD). In recent years, microRNAs have become established key regulators of biological processes that relate among others to the development and progression of neurodegenerative diseases, such as AD. This review article gives an overview on microRNAs that are involved in the Aβ cascade and discusses their inhibitory impact on their target mRNAs whose products participate in Aβ clearance. Understanding of the mechanism of microRNA in the associated signal pathways could identify novel therapeutic targets for the treatment of AD.
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Affiliation(s)
- Soheil Madadi
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Heidi Schwarzenbach
- Department of Tumor Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Massoud Saidijam
- Department of Genetics and Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Reza Mahjub
- Department of Pharmaceutics, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Meysam Soleimani
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran
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12
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da Rocha GHO, Loiola RA, Pantaleão LDN, Reutelingsperger C, Solito E, Farsky SHP. Control of expression and activity of peroxisome proliferated-activated receptor γ by Annexin A1 on microglia during efferocytosis. Cell Biochem Funct 2019; 37:560-568. [PMID: 31479167 DOI: 10.1002/cbf.3433] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 08/13/2019] [Accepted: 08/22/2019] [Indexed: 12/18/2022]
Abstract
Annexin A1 (AnxA1) is a protein secreted by phagocytic cells which plays a pivotal role on the resolution of inflammation by enhancing phagocytosis carried out by phagocytes. Which factors and intracellular mechanisms are linked to such actions exerted by AnxA1 are yet to be completely understood. In order to investigate such, BV2 microglial cells were transfected with plasmids aimed at down-modulating AnxA1 expression and also treated with exogenous recombinant rAnxA1; gene and protein expression of proliferated-activated receptor γ (PPARγ) and CD36, STAT6 phosphorylation and phagocytosis of apoptotic neurons were investigated. Down-modulating AnxA1 in BV2 cells impaired gene and protein expression of PPARγ, effects reversed by treatment with recombinant AnxA1 (rAnxA1). Lower levels of CD36 were also verified in AnxA1 down-modulated BV2 cells. AnxA1-mediated phagocytosis of apoptotic cells was abrogated due to blockade of PPARγ activation, and in AnxA1 down-modulated cells exogenous AnxA1 failed to exert any effects on phagocytosis. Lower levels of STAT6/pSTAT6 in AnxA1 down-modulated BV2 cells suggest the involvement of this transcription factor with PPARγ and CD36 synthesis and actions. Data here shown suggest that there is a probable connection between AnxA1, PPARγ, and CD36, which must all act in association in order for efferocytosis to occur properly. AnxA1-mediated phosphorylation of STAT6 is probably involved with intracellular pathways involving PPARγ and CD36 actions. These data evidence that PPARγ/CD36 play a role on AnxA1-mediated efferocytosis in microglial cells. SIGNIFICANCE OF THE STUDY: The findings of this work provide evidence that the glucocorticoid-mediated protein annexin A1 modulates PPARγ expression and that PPARγ is important for annexin A1-mediated efferocytosis. Only recently the interaction between these two factors has begun to be explored, and knowledge on associated cell mechanisms are still scarce. Elucidating how annexin A1 and PPARγ interact with one another provides basis for further research aimed at understanding molecular pathways and cell signaling events involved with these factors, expanding existing knowledge on the anti-inflammatory effects of such factors.
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Affiliation(s)
| | - Rodrigo Azevedo Loiola
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Lorena do Nascimento Pantaleão
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Chris Reutelingsperger
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Egle Solito
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University, London, United Kingdom
| | - Sandra Helena Poliselli Farsky
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
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13
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Gut Microbiota Disorder, Gut Epithelial and Blood-Brain Barrier Dysfunctions in Etiopathogenesis of Dementia: Molecular Mechanisms and Signaling Pathways. Neuromolecular Med 2019; 21:205-226. [PMID: 31115795 DOI: 10.1007/s12017-019-08547-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 05/17/2019] [Indexed: 12/12/2022]
Abstract
Emerging evidences indicate a critical role of the gut microbiota in etiopathogenesis of dementia, a debilitating multifactorial disorder characterized by progressive deterioration of cognition and behavior that interferes with the social and professional functions of the sufferer. Available data suggest that gut microbiota disorder that triggers development of dementia is characterized by substantial reduction in specific species belonging to the Firmicutes and Bacteroidetes phyla and presence of pathogenic species, predominantly, pro-inflammatory bacteria of the Proteobacteria phylum. These changes in gut microbiota microecology promote the production of toxic metabolites and pro-inflammatory cytokines, and reduction in beneficial substances such as short chain fatty acids and other anti-inflammatory factors, thereby, enhancing destruction of the gut epithelial barrier with concomitant activation of local and distant immune cells as well as dysregulation of enteric neurons and glia. This subsequently leads to blood-brain barrier dysfunctions that trigger neuroinflammatory reactions and predisposes to apoptotic neuronal and glial cell death, particularly in the hippocampus and cerebral cortex, which underlie the development of dementia. However, the molecular switches that control these processes in the histo-hematic barriers of the gut and brain are not exactly known. This review integrates very recent data on the molecular mechanisms that link gut microbiota disorder to gut epithelial and blood-brain barrier dysfunctions, underlying the development of dementia. The signaling pathways that link gut microbiota disorder with impairment in cognition and behavior are also discussed. The review also highlights potential therapeutic options for dementia.
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Zhu H, Wang Z, Yu J, Yang X, He F, Liu Z, Che F, Chen X, Ren H, Hong M, Wang J. Role and mechanisms of cytokines in the secondary brain injury after intracerebral hemorrhage. Prog Neurobiol 2019; 178:101610. [PMID: 30923023 DOI: 10.1016/j.pneurobio.2019.03.003] [Citation(s) in RCA: 184] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 03/07/2019] [Accepted: 03/16/2019] [Indexed: 12/18/2022]
Abstract
Intracerebral hemorrhage (ICH) is a common and severe cerebrovascular disease that has high mortality. Few survivors achieve self-care. Currently, patients receive only symptomatic treatment for ICH and benefit poorly from this regimen. Inflammatory cytokines are important participants in secondary injury after ICH. Increases in proinflammatory cytokines may aggravate the tissue injury, whereas increases in anti-inflammatory cytokines might be protective in the ICH brain. Inflammatory cytokines have been studied as therapeutic targets in a variety of acute and chronic brain diseases; however, studies on ICH are limited. This review summarizes the roles and functions of various pro- and anti-inflammatory cytokines in secondary brain injury after ICH and discusses pathogenic mechanisms and emerging therapeutic strategies and directions for treatment of ICH.
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Affiliation(s)
- Huimin Zhu
- Department of Neurology, Linyi People's Hospital, Linyi, Shandong 276003, China
| | - Zhiqiang Wang
- Central laboratory, Linyi People's Hospital, Linyi, Shandong 276003, China
| | - Jixu Yu
- Department of Neurology, Linyi People's Hospital, Linyi, Shandong 276003, China; Central laboratory, Linyi People's Hospital, Linyi, Shandong 276003, China; Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Boston, MA 02129, USA
| | - Xiuli Yang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Feng He
- Department of Neurology, Linyi People's Hospital, Linyi, Shandong 276003, China
| | - Zhenchuan Liu
- Department of Neurology, Linyi People's Hospital, Linyi, Shandong 276003, China.
| | - Fengyuan Che
- Department of Neurology, Linyi People's Hospital, Linyi, Shandong 276003, China; Central laboratory, Linyi People's Hospital, Linyi, Shandong 276003, China.
| | - Xuemei Chen
- Department of Anatomy, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450000, Henan, China
| | - Honglei Ren
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael Hong
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jian Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Fiebich BL, Batista CRA, Saliba SW, Yousif NM, de Oliveira ACP. Role of Microglia TLRs in Neurodegeneration. Front Cell Neurosci 2018; 12:329. [PMID: 30333729 PMCID: PMC6176466 DOI: 10.3389/fncel.2018.00329] [Citation(s) in RCA: 182] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/10/2018] [Indexed: 12/13/2022] Open
Abstract
Toll-like receptors (TLRs) are a group of receptors widely distributed in the organism. In the central nervous system, they are expressed in neurons, astrocytes and microglia. Although their involvement in immunity is notorious, different articles have demonstrated their roles in physiological and pathological conditions, including neurodegeneration. There is increasing evidence of an involvement of TLRs, especially TLR2, 4 and 9 in neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS). In this sense, their expression in microglia might modulate the activity of these cells, which in turn, lead to protective or deleterious effects over neurons and other cells. Therefore, TLRs might mediate the link between inflammation and neurodegenerative diseases. However, further studies have to be performed to elucidate the role of the other TLRs in these diseases and to further prove and confirm the pathophysiological role of all TLRs in neurodegeneration. In this article, we revise and summarize the current knowledge regarding the role of TLRs in neurodegeneration with the focus on the possible functions of these receptors in microglia.
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Affiliation(s)
- Bernd L Fiebich
- Neuroimmunology and Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | - Soraya Wilke Saliba
- Neuroimmunology and Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Nizar M Yousif
- Neuroimmunology and Neurochemistry Research Group, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
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Welcome MO. Current Perspectives and Mechanisms of Relationship between Intestinal Microbiota Dysfunction and Dementia: A Review. Dement Geriatr Cogn Dis Extra 2018; 8:360-381. [PMID: 30483303 PMCID: PMC6244112 DOI: 10.1159/000492491] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/26/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Accumulating data suggest a crucial role of the intestinal microbiota in the development and progression of neurodegenerative diseases. More recently, emerging reports have revealed an association between intestinal microbiota dysfunctions and dementia, a debilitating multifactorial disorder, characterized by progressive deterioration of cognition and behavior that interferes with the social and professional life of the sufferer. However, the mechanisms of this association are not fully understood. SUMMARY In this review, I discuss recent data that suggest mechanisms of cross-talk between intestinal microbiota dysfunction and the brain that underlie the development of dementia. Potential therapeutic options for dementia are also discussed. The pleiotropic signaling of the metabolic products of the intestinal microbiota together with their specific roles in the maintenance of both the intestinal and blood-brain barriers as well as regulation of local, distant, and circulating immunocytes, and enteric, visceral, and central neural functions are integral to a healthy gut and brain. KEY MESSAGES Research investigating the effect of intestinal microbiota dysfunctions on brain health should focus on multiple interrelated systems involving local and central neuroendocrine, immunocyte, and neural signaling of microbial products and transmitters and neurohumoral cells that not only maintain intestinal, but also blood brain-barrier integrity. The change in intestinal microbiome/dysbiome repertoire is crucial to the development of dementia.
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Affiliation(s)
- Menizibeya O. Welcome
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, Abuja, Nigeria
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17
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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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Amos PJ, Fung S, Case A, Kifelew J, Osnis L, Smith CL, Green K, Naydenov A, Aloi M, Hubbard JJ, Ramakrishnan A, Garden GA, Jayadev S. Modulation of Hematopoietic Lineage Specification Impacts TREM2 Expression in Microglia-Like Cells Derived From Human Stem Cells. ASN Neuro 2017; 9:1759091417716610. [PMID: 28683563 PMCID: PMC5548325 DOI: 10.1177/1759091417716610] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Microglia are the primary innate immune cell type in the brain, and their dysfunction has been linked to a variety of central nervous system disorders. Human microglia are extraordinarily difficult to obtain for experimental investigation, limiting our ability to study the impact of human genetic variants on microglia functions. Previous studies have reported that microglia-like cells can be derived from human monocytes or pluripotent stem cells. Here, we describe a reproducible relatively simple method for generating microglia-like cells by first deriving embryoid body mesoderm followed by exposure to microglia relevant cytokines. Our approach is based on recent studies demonstrating that microglia originate from primitive yolk sac mesoderm distinct from peripheral macrophages that arise during definitive hematopoiesis. We hypothesized that functional microglia could be derived from human stem cells by employing BMP-4 mesodermal specification followed by exposure to microglia-relevant cytokines, M-CSF, GM-CSF, IL-34, and TGF-β. Using immunofluorescence microscopy, flow cytometry, and reverse transcription polymerase chain reaction, we observed cells with microglia morphology expressing a repertoire of markers associated with microglia: Iba1, CX3CR1, CD11b, TREM2, HexB, and P2RY12. These microglia-like cells maintain myeloid functional phenotypes including Aβ peptide phagocytosis and induction of pro-inflammatory gene expression in response to lipopolysaccharide stimulation. Addition of small molecules BIO and SB431542, previously demonstrated to drive definitive hematopoiesis, resulted in decreased surface expression of TREM2. Together, these data suggest that mesodermal lineage specification followed by cytokine exposure produces microglia-like cells in vitro from human pluripotent stem cells and that this phenotype can be modulated by factors influencing hematopoietic lineage in vitro.
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Affiliation(s)
- Peter J Amos
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
| | - Susan Fung
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
| | - Amanda Case
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
| | - Jerusalem Kifelew
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
| | - Leah Osnis
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
| | - Carole L Smith
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
| | - Kevin Green
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
| | - Alipi Naydenov
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
| | - Macarena Aloi
- 2 Department of Pathology, University of Washington, Seattle, WA, USA
| | | | | | - Gwenn A Garden
- 1 Department of Neurology, University of Washington, Seattle, WA, USA.,2 Department of Pathology, University of Washington, Seattle, WA, USA
| | - Suman Jayadev
- 1 Department of Neurology, University of Washington, Seattle, WA, USA
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Cai W, Yang T, Liu H, Han L, Zhang K, Hu X, Zhang X, Yin KJ, Gao Y, Bennett MVL, Leak RK, Chen J. Peroxisome proliferator-activated receptor γ (PPARγ): A master gatekeeper in CNS injury and repair. Prog Neurobiol 2017; 163-164:27-58. [PMID: 29032144 DOI: 10.1016/j.pneurobio.2017.10.002] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/06/2017] [Accepted: 10/08/2017] [Indexed: 01/06/2023]
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) is a widely expressed ligand-modulated transcription factor that governs the expression of genes involved in inflammation, redox equilibrium, trophic factor production, insulin sensitivity, and the metabolism of lipids and glucose. Synthetic PPARγ agonists (e.g. thiazolidinediones) are used to treat Type II diabetes and have the potential to limit the risk of developing brain injuries such as stroke by mitigating the influence of comorbidities. If brain injury develops, PPARγ serves as a master gatekeeper of cytoprotective stress responses, improving the chances of cellular survival and recovery of homeostatic equilibrium. In the acute injury phase, PPARγ directly restricts tissue damage by inhibiting the NFκB pathway to mitigate inflammation and stimulating the Nrf2/ARE axis to neutralize oxidative stress. During the chronic phase of acute brain injuries, PPARγ activation in injured cells culminates in the repair of gray and white matter, preservation of the blood-brain barrier, reconstruction of the neurovascular unit, resolution of inflammation, and long-term functional recovery. Thus, PPARγ lies at the apex of cell fate decisions and exerts profound effects on the chronic progression of acute injury conditions. Here, we review the therapeutic potential of PPARγ in stroke and brain trauma and highlight the novel role of PPARγ in long-term tissue repair. We describe its structure and function and identify the genes that it targets. PPARγ regulation of inflammation, metabolism, cell fate (proliferation/differentiation/maturation/survival), and many other processes also has relevance to other neurological diseases. Therefore, PPARγ is an attractive target for therapies against a number of progressive neurological disorders.
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Affiliation(s)
- Wei Cai
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Tuo Yang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Huan Liu
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Lijuan Han
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kai Zhang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Xiaoming Hu
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Fudan University, Shanghai 200032, China; Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh PA, USA
| | - Xuejing Zhang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ke-Jie Yin
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Yanqin Gao
- State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Michael V L Bennett
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rehana K Leak
- Division of Pharmaceutical Sciences, School of Pharmacy, Duquesne University, Pittsburgh, PA 15282, USA.
| | - Jun Chen
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Fudan University, Shanghai 200032, China; Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh PA, USA.
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20
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Kang X, Qiu J, Li Q, Bell KA, Du Y, Jung DW, Lee JY, Hao J, Jiang J. Cyclooxygenase-2 contributes to oxidopamine-mediated neuronal inflammation and injury via the prostaglandin E2 receptor EP2 subtype. Sci Rep 2017; 7:9459. [PMID: 28842681 PMCID: PMC5573328 DOI: 10.1038/s41598-017-09528-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/17/2017] [Indexed: 01/10/2023] Open
Abstract
Cyclooxygenase-2 (COX-2) triggers pro-inflammatory processes that can aggravate neuronal degeneration and functional impairments in many neurological conditions, mainly via producing prostaglandin E2 (PGE2) that activates four membrane receptors, EP1-EP4. However, which EP receptor is the culprit of COX-2/PGE2-mediated neuronal inflammation and degeneration remains largely unclear and presumably depends on the insult types and responding components. Herein, we demonstrated that COX-2 was induced and showed nuclear translocation in two neuronal cell lines – mouse Neuro-2a and human SH-SY5Y – after treatment with neurotoxin 6-hydroxydopamine (6-OHDA), leading to the biosynthesis of PGE2 and upregulation of pro-inflammatory cytokine interleukin-1β. Inhibiting COX-2 or microsomal prostaglandin E synthase-1 suppressed the 6-OHDA-triggered PGE2 production in these cells. Treatment with PGE2 or EP2 selective agonist butaprost, but not EP4 agonist CAY10598, increased cAMP response in both cell lines. PGE2-initiated cAMP production in these cells was blocked by our recently developed novel selective EP2 antagonists – TG4-155 and TG6-10-1, but not by EP4 selective antagonist GW627368X. The 6-OHDA-promoted cytotoxicity was largely blocked by TG4-155, TG6-10-1 or COX-2 selective inhibitor celecoxib, but not by GW627368X. Our results suggest that PGE2 receptor EP2 is a key mediator of COX-2 activity-initiated cAMP signaling in Neuro-2a and SH-SY5Y cells following 6-OHDA treatment, and contributes to oxidopamine-mediated neurotoxicity.
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Affiliation(s)
- Xu Kang
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, Ohio, 45267-0514, USA
| | - Jiange Qiu
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, Ohio, 45267-0514, USA.,Department of Cell Biology and Institute of Biomedicine, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Qianqian Li
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, Ohio, 45267-0514, USA
| | - Katherine A Bell
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, Ohio, 45267-0514, USA
| | - Yifeng Du
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, Ohio, 45267-0514, USA
| | - Da Woon Jung
- Research Institute for Basic Sciences and Department of Chemistry, College of Sciences, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Jae Yeol Lee
- Research Institute for Basic Sciences and Department of Chemistry, College of Sciences, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Jiukuan Hao
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, Ohio, 45267-0514, USA
| | - Jianxiong Jiang
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, Ohio, 45267-0514, USA.
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Lan X, Han X, Li Q, Yang QW, Wang J. Modulators of microglial activation and polarization after intracerebral haemorrhage. Nat Rev Neurol 2017; 13:420-433. [PMID: 28524175 PMCID: PMC5575938 DOI: 10.1038/nrneurol.2017.69] [Citation(s) in RCA: 522] [Impact Index Per Article: 74.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intracerebral haemorrhage (ICH) is the most lethal subtype of stroke but currently lacks effective treatment. Microglia are among the first non-neuronal cells on the scene during the innate immune response to ICH. Microglia respond to acute brain injury by becoming activated and developing classic M1-like (proinflammatory) or alternative M2-like (anti-inflammatory) phenotypes. This polarization implies as yet unrecognized actions of microglia in ICH pathology and recovery, perhaps involving microglial production of proinflammatory or anti-inflammatory cytokines and chemokines. Furthermore, alternatively activated M2-like microglia might promote phagocytosis of red blood cells and tissue debris, a major contribution to haematoma clearance. Interactions between microglia and other cells modulate microglial activation and function, and are also important in ICH pathology. This Review summarizes key studies on modulators of microglial activation and polarization after ICH, including M1-like and M2-like microglial phenotype markers, transcription factors and key signalling pathways. Microglial phagocytosis, haematoma resolution, and the potential crosstalk between microglia and T lymphocytes, neurons, astrocytes, and oligodendrocytes in the ICH brain are described. Finally, the clinical and translational implications of microglial polarization in ICH are presented, including the evidence that therapeutic approaches aimed at modulating microglial function might mitigate ICH injury and improve brain repair.
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Affiliation(s)
- Xi Lan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building 370B, Baltimore, Maryland 21205, USA
| | - Xiaoning Han
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building 370B, Baltimore, Maryland 21205, USA
| | - Qian Li
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building 370B, Baltimore, Maryland 21205, USA
| | - Qing-Wu Yang
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, 183 Xinqiao Main Street, Shapingba District, Chongqing 400037, China
| | - Jian Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building 370B, Baltimore, Maryland 21205, USA
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22
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Wang J, Wang G, Yi J, Xu Y, Duan S, Li T, Sun XG, Dong L. The effect of monascin on hematoma clearance and edema after intracerebral hemorrhage in rats. Brain Res Bull 2017; 134:24-29. [PMID: 28655601 DOI: 10.1016/j.brainresbull.2017.06.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/24/2017] [Accepted: 06/21/2017] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND PURPOSE Intracerebral hemorrhage (ICH) is a particularly devastating form of stroke with high mortality and morbidity. Hematomas are the primary cause of neurologic deficits associated with ICH. The products of hematoma are recognized as neurotoxins and the main contributors to edema formation and tissue damage after ICH. Finding a means to efficiently promote absorption of hematoma is a novel clinical challenge for ICH. Peroxisome proliferator-activated receptor gamma (PPARγ) and nuclear factor erythroid 2-related factor 2 (Nrf2), had been shown that, can take potential roles in the endogenous hematoma clearance. However, monascin, a novel natural Nrf2 activator with PPARγ agonist, has not been reported to play a role in ICH. This study was designed to evaluate the effect of monascin on neurological deficits, hematoma clearance and edema extinction in a model of ICH in rats. METHODS 164 adult male Sprague-Dawley (SD) rats were randomly divided into sham; vehicle; monascin groups with low dosages (1mg/kg/day), middle dosages (5mg/kg/day) and high dosages (10mg/kg/day) respectively. Animals were euthanized at 1, 3 and 7days following neurological evaluation after surgery. We examined the effect of monascin on the brain water contents, blood brain barrier (BBB) permeability and hemoglobin levels, meanwhile reassessed the volume of hematoma and edema around the hematoma by Magnetic Resonance Imaging (MRI) in each group. RESULTS The high dosage of monascin significantly improved neurological deficits, reduced the volume of hematoma in 1-7days after ICH, decreased BBB permeability and edema formation in 1-3days following ICH. CONCLUSION Our study demonstrated that the high dosage of monascin played a neuroprotective role in ICH through reducing BBB permeability, edema and hematoma volume.
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Affiliation(s)
- Juan Wang
- Department of Neurology, Shanxi Medical University, 56 Xinjian S Rd, Yingze, Taiyuan, Shanxi, 030001, China
| | - Gaiqing Wang
- Department of Neurology, Shanxi Medical University, 56 Xinjian S Rd, Yingze, Taiyuan, Shanxi, 030001, China; Department of Neurology, The Second Hospital, Shanxi Medical University, 382 WuYi Avenue, Taiyuan, Shanxi, 030001, China.
| | - Jinying Yi
- Department of Neurology, Shanxi Medical University, 56 Xinjian S Rd, Yingze, Taiyuan, Shanxi, 030001, China
| | - Yi Xu
- Department of Radiology, The Second Hospital, Shanxi Medical University, 382 WuYi Avenue, Taiyuan, Shanxi, 030001, China
| | - Shuna Duan
- Department of Neurology, Shanxi Medical University, 56 Xinjian S Rd, Yingze, Taiyuan, Shanxi, 030001, China
| | - Tong Li
- Department of Neurology, Shanxi Medical University, 56 Xinjian S Rd, Yingze, Taiyuan, Shanxi, 030001, China
| | - Xin-Gang Sun
- Department of Neurology, The Second Hospital, Shanxi Medical University, 382 WuYi Avenue, Taiyuan, Shanxi, 030001, China
| | - Liang Dong
- Department of Neurology, Shanxi Medical University, 56 Xinjian S Rd, Yingze, Taiyuan, Shanxi, 030001, China
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Ano Y, Dohata A, Taniguchi Y, Hoshi A, Uchida K, Takashima A, Nakayama H. Iso-α-acids, Bitter Components of Beer, Prevent Inflammation and Cognitive Decline Induced in a Mouse Model of Alzheimer's Disease. J Biol Chem 2017; 292:3720-3728. [PMID: 28087694 DOI: 10.1074/jbc.m116.763813] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 01/04/2017] [Indexed: 12/31/2022] Open
Abstract
Alongside the rapid growth in aging populations worldwide, prevention and therapy for age-related memory decline and dementia are in great demand to maintain a long, healthy life. Here we found that iso-α-acids, hop-derived bitter compounds in beer, enhance microglial phagocytosis and suppress inflammation via activation of the peroxisome proliferator-activated receptor γ. In normal mice, oral administration of iso-α-acids led to a significant increase both in CD11b and CD206 double-positive anti-inflammatory type microglia (p < 0.05) and in microglial phagocytosis in the brain. In Alzheimer's model 5xFAD mice, oral administration of iso-α-acids resulted in a 21% reduction in amyloid β in the cerebral cortex as observed by immunohistochemical analysis, a significant reduction in inflammatory cytokines such as IL-1β and chemokines including macrophage inflammatory protein-1α in the cerebral cortex (p < 0.05) and a significant improvement in a novel object recognition test (p < 0.05), as compared with control-fed 5xFAD mice. The differences in iso-α-acid-fed mice were due to the induction of microglia to an anti-inflammatory phenotype. The present study is the first to report that amyloid β deposition and inflammation are suppressed in a mouse model of Alzheimer's disease by a single component, iso-α-acids, via the regulation of microglial activation. The suppression of neuroinflammation and improvement in cognitive function suggests that iso-α-acids contained in beer may be useful for the prevention of dementia.
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Affiliation(s)
- Yasuhisa Ano
- From the Research Laboratories for Health Science & Food Technologies and
| | - Atsushi Dohata
- the Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo 113-8657, Japan, and
| | - Yoshimasa Taniguchi
- the Central Laboratories for Key Technologies, Kirin Company Ltd., Kanagawa 236-0004, Japan
| | - Ayaka Hoshi
- the Central Laboratories for Key Technologies, Kirin Company Ltd., Kanagawa 236-0004, Japan
| | - Kazuyuki Uchida
- the Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo 113-8657, Japan, and
| | - Akihiko Takashima
- the Department of Neurobiology, National Center for Geriatrics and Gerontology, Obu 474-8511, Japan
| | - Hiroyuki Nakayama
- the Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo 113-8657, Japan, and
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24
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Ravari A, Mirzaei T, Kennedy D, Kazemi Arababadi M. Chronoinflammaging in Alzheimer; A systematic review on the roles of toll like receptor 2. Life Sci 2017; 171:16-20. [PMID: 28087373 DOI: 10.1016/j.lfs.2017.01.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 12/24/2016] [Accepted: 01/06/2017] [Indexed: 12/23/2022]
Abstract
Aging is associated with a range of chronic low-grade inflammation (Chronoinflammaging) which may play a significant role in some chronic inflammatory based diseases, such as Alzheimer disease (AD). However, the events which lead to the induction of chronoinflammaging in AD are yet to be clarified. It has been proposed that the recognition of endogenous ligands by pathogen recognition receptors (PRRs) may be involved in the induction of chronoinflammaging. Toll like receptors (TLRs) are a family of PRRs which recognize endogenous damage associated molecular patterns (DAMPs) and subsequently induce inflammation. Therefore, TLRs are worthy of investigation to elucidate their roles in chronoinflammaging associated AD. This review article explores the main roles played by TLR2 in the pathogenesis of chronoinflammaging in patients suffering from AD.
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Affiliation(s)
- Ali Ravari
- Geriatric Care Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Dept. of Medical Surgical Nursing, Faculty of Nursing and Midwifery, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Tayebeh Mirzaei
- Geriatric Care Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Dept. of Medical Surgical Nursing, Faculty of Nursing and Midwifery, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
| | - Derek Kennedy
- School of Natural Sciences, Eskitis Institute for Drug Discovery, Griffith University Nathan, Queensland, Australia
| | - Mohammad Kazemi Arababadi
- Immunology of Infectious Diseases Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Dept. of Laboratory Sciences, Faculty of Paramedicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
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25
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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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26
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Su F, Bai F, Zhou H, Zhang Z. Reprint of: Microglial toll-like receptors and Alzheimer's disease. Brain Behav Immun 2016; 55:166-178. [PMID: 27255539 DOI: 10.1016/j.bbi.2016.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 10/09/2015] [Accepted: 10/15/2015] [Indexed: 01/04/2023] Open
Abstract
Microglial activation represents an important pathological hallmark of Alzheimer's disease (AD), and emerging data highlight the involvement of microglial toll-like receptors (TLRs) in the course of AD. TLRs have been observed to exert both beneficial and detrimental effects on AD-related pathologies, and transgenic animal models have provided direct and credible evidence for an association between TLRs and AD. Moreover, analyses of genetic polymorphisms have suggested interactions between genetic polymorphisms in TLRs and AD risk, further supporting the hypothesis that TLRs are involved in AD. In this review, we summarize the key evidence in this field. Future studies should focus on exploring the mechanisms underlying the potential roles of TLRs in AD.
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Affiliation(s)
- Fan Su
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China
| | - Feng Bai
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
| | - Hong Zhou
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China
| | - Zhijun Zhang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China
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27
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Fiala M, Terrando N, Dalli J. Specialized Pro-Resolving Mediators from Omega-3 Fatty Acids Improve Amyloid-β Phagocytosis and Regulate Inflammation in Patients with Minor Cognitive Impairment. J Alzheimers Dis 2016; 48:293-301. [PMID: 26401996 DOI: 10.3233/jad-150367] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this review we discuss the immunopathology of Alzheimer's disease (AD) and recent advances in the prevention of minor cognitive impairment (MCI) by nutritional supplementation with omega-3 fatty acids. Defective phagocytosis of amyloid-β (Aβ) and abnormal inflammatory activation of peripheral blood mononuclear cells (PBMCs) are the two key immune pathologies of MCI and AD patients. The phagocytosis of Aβ by PBMCs of MCI and AD patients is universally defective and the inflammatory gene transcription is heterogeneously deregulated in comparison to normal subjects. Recent studies have discovered a cornucopia of beneficial anti-inflammatory and pro-resolving effects of the specialized proresolving mediators (SPMs) resolvins, protectins, maresins, and their metabolic precursors. Resolvin D1 and other mediators switch macrophages from an inflammatory to a tissue protective/pro-resolving phenotype and increase phagocytosis of Aβ. In a recent study of AD and MCI patients, nutritional supplementation by omega-3 fatty acids individually increased resolvin D1, improved Aβ phagocytosis, and regulated inflammatory genes toward a physiological state, but only in MCI patients. Our studies are beginning to dissect positive factors (adherence to Mediterranean diet with omega-3 and exercise) and negative factors (high fat diet, infections, cancer, and surgeries) in each patient. The in vitro and in vivo effects of omega-3 fatty acids and SPMs suggest that defective phagocytosis and chronic inflammation are related to defective production and/or defective signaling by SPMs in immune cells.
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Affiliation(s)
- Milan Fiala
- Department of Surgery, UCLA School of Medicine, Los Angeles, California, USA
| | - Niccolo Terrando
- Departments of Anesthesiology, Basic Science Division, Duke University Medical Center, Durham, North Carolina, USA
| | - Jesmond Dalli
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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28
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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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29
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Su F, Bai F, Zhou H, Zhang Z. Microglial toll-like receptors and Alzheimer's disease. Brain Behav Immun 2016; 52:187-198. [PMID: 26526648 DOI: 10.1016/j.bbi.2015.10.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 10/09/2015] [Accepted: 10/15/2015] [Indexed: 02/08/2023] Open
Abstract
Microglial activation represents an important pathological hallmark of Alzheimer's disease (AD), and emerging data highlight the involvement of microglial toll-like receptors (TLRs) in the course of AD. TLRs have been observed to exert both beneficial and detrimental effects on AD-related pathologies, and transgenic animal models have provided direct and credible evidence for an association between TLRs and AD. Moreover, analyses of genetic polymorphisms have suggested interactions between genetic polymorphisms in TLRs and AD risk, further supporting the hypothesis that TLRs are involved in AD. In this review, we summarize the key evidence in this field. Future studies should focus on exploring the mechanisms underlying the potential roles of TLRs in AD.
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Affiliation(s)
- Fan Su
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
| | - Feng Bai
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
| | - Hong Zhou
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
| | - Zhijun Zhang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
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30
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Teng E, Taylor K, Bilousova T, Weiland D, Pham T, Zuo X, Yang F, Chen PP, Glabe CG, Takacs A, Hoffman DR, Frautschy SA, Cole GM. Dietary DHA supplementation in an APP/PS1 transgenic rat model of AD reduces behavioral and Aβ pathology and modulates Aβ oligomerization. Neurobiol Dis 2015; 82:552-560. [PMID: 26369878 DOI: 10.1016/j.nbd.2015.09.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 08/22/2015] [Accepted: 09/07/2015] [Indexed: 12/18/2022] Open
Abstract
Increased dietary consumption of docosahexaenoic acid (DHA) is associated with decreased risk for Alzheimer's disease (AD). These effects have been postulated to arise from DHA's pleiotropic effects on AD pathophysiology, including its effects on β-amyloid (Aβ) production, aggregation, and toxicity. While in vitro studies suggest that DHA may inhibit and reverse the formation of toxic Aβ oligomers, it remains uncertain whether these mechanisms operate in vivo at the physiological concentrations of DHA attainable through dietary supplementation. We sought to clarify the effects of dietary DHA supplementation on Aβ indices in a transgenic APP/PS1 rat model of AD. Animals maintained on a DHA-supplemented diet exhibited reductions in hippocampal Aβ plaque density and modest improvements on behavioral testing relative to those maintained on a DHA-depleted diet. However, DHA supplementation also increased overall soluble Aβ oligomer levels in the hippocampus. Further quantification of specific conformational populations of Aβ oligomers indicated that DHA supplementation increased fibrillar (i.e. putatively less toxic) Aβ oligomers and decreased prefibrillar (i.e. putatively more toxic) Aβ oligomers. These results provide in vivo evidence suggesting that DHA can modulate Aβ aggregation by stabilizing soluble fibrillar Aβ oligomers and thus reduce the formation of both Aβ plaques and prefibrillar Aβ oligomers. However, since fibrillar Aβ oligomers still retain inherent neurotoxicity, DHA may need to be combined with other interventions that can additionally reduce fibrillar Aβ oligomer levels for more effective prevention of AD in clinical settings.
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Affiliation(s)
- Edmond Teng
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
| | - Karen Taylor
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Tina Bilousova
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - David Weiland
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Thaidan Pham
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Xiaohong Zuo
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA; Department of Neurobiology and Neurology, Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Fusheng Yang
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Ping-Ping Chen
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Charles G Glabe
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA; Biochemistry Department and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Dennis R Hoffman
- Retina Foundation of the Southwest, Dallas, TX, USA; Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sally A Frautschy
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Gregory M Cole
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
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