1
|
McRae SA, Richards CM, Da Silva DE, Riar I, Yang SS, Zurfluh NE, Gibon J, Klegeris A. Pro-neuroinflammatory and neurotoxic potential of extracellular histones H1 and H3. Neurosci Res 2024; 204:34-45. [PMID: 38278218 DOI: 10.1016/j.neures.2024.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 12/23/2023] [Accepted: 01/17/2024] [Indexed: 01/28/2024]
Abstract
Histones organize DNA within cellular nuclei, but they can be released from damaged cells. In peripheral tissues extracellular histones act as damage-associated molecular patterns (DAMPs) inducing pro-inflammatory activation of immune cells. Limited studies have considered DAMP-like activity of histones in the central nervous system (CNS); therefore, we studied the effects of extracellular histones on microglia, the CNS immunocytes, and on neuronal cells. Both the linker histone H1 and the core histone H3 induced pro-inflammatory activation of microglia-like cells by upregulating their secretion of NO and cytokines, including interferon-γ-inducible protein 10 (IP-10) and tumor necrosis factor-α (TNF). The selective inhibitors MMG-11 and TAK-242 were used to demonstrate involvement of toll-like receptors (TLR) 2 and 4, respectively, in H1-induced NO secretion by BV-2 microglia. H1, but not H3, downregulated the phagocytic activity of BV-2 microglia. H1 was also directly toxic to all neuronal cell types studied. We conclude that H1, and to a lesser extent H3, when released extracellularly, have the potential to act as a CNS DAMPs. Inhibition of the DAMP-like effects of extracellular histones on microglia and their neurotoxic activity represents a potential strategy for combating neurodegenerative diseases that are characterized by the adverse activation of microglia and neuronal death.
Collapse
Affiliation(s)
- Seamus A McRae
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Christy M Richards
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Dylan E Da Silva
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Ishvin Riar
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Sijie Shirley Yang
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Noah E Zurfluh
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Julien Gibon
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada.
| |
Collapse
|
2
|
Da Silva DE, Richards CM, McRae SA, Riar I, Yang S(S, Zurfluh NE, Gibon J, Klegeris A. Extracellular mixed histones are neurotoxic and modulate select neuroimmune responses of glial cells. PLoS One 2024; 19:e0298748. [PMID: 38630734 PMCID: PMC11023449 DOI: 10.1371/journal.pone.0298748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 01/29/2024] [Indexed: 04/19/2024] Open
Abstract
Although histone proteins are widely known for their intranuclear functions where they organize DNA, all five histone types can also be released into the extracellular space from damaged cells. Extracellular histones can interact with pattern recognition receptors of peripheral immune cells, including toll-like receptor 4 (TLR4), causing pro-inflammatory activation, which indicates they may act as damage-associated molecular patterns (DAMPs) in peripheral tissues. Very limited information is available about functions of extracellular histones in the central nervous system (CNS). To address this knowledge gap, we applied mixed histones (MH) to cultured cells modeling neurons, microglia, and astrocytes. Microglia are the professional CNS immunocytes, while astrocytes are the main support cells for neurons. Both these cell types are critical for neuroimmune responses and their dysregulated activity contributes to neurodegenerative diseases. We measured effects of extracellular MH on cell viability and select neuroimmune functions of microglia and astrocytes. MH were toxic to cultured primary murine neurons and also reduced viability of NSC-34 murine and SH-SY5Y human neuron-like cells in TLR4-dependent manner. MH did not affect the viability of resting or immune-stimulated BV-2 murine microglia or U118 MG human astrocytic cells. When applied to BV-2 cells, MH enhanced secretion of the potential neurotoxin glutamate, but did not modulate the release of nitric oxide (NO), tumor necrosis factor-α (TNF), C-X-C motif chemokine ligand 10 (CXCL10), or the overall cytotoxicity of lipopolysaccharide (LPS)- and/or interferon (IFN)-γ-stimulated BV-2 microglial cells towards NSC-34 neuron-like cells. We demonstrated, for the first time, that MH downregulated phagocytic activity of LPS-stimulated BV-2 microglia. However, MH also exhibited protective effect by ameliorating the cytotoxicity of LPS-stimulated U118 MG astrocytic cells towards SH-SY5Y neuron-like cells. Our data demonstrate extracellular MH could both damage neurons and alter neuroimmune functions of glial cells. These actions of MH could be targeted for treatment of neurodegenerative diseases.
Collapse
Affiliation(s)
- Dylan E. Da Silva
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Christy M. Richards
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Seamus A. McRae
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Ishvin Riar
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Sijie (Shirley) Yang
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Noah E. Zurfluh
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Julien Gibon
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| |
Collapse
|
3
|
Peggion C, Calì T, Brini M. Mitochondria Dysfunction and Neuroinflammation in Neurodegeneration: Who Comes First? Antioxidants (Basel) 2024; 13:240. [PMID: 38397838 PMCID: PMC10885966 DOI: 10.3390/antiox13020240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 02/13/2024] [Accepted: 02/14/2024] [Indexed: 02/25/2024] Open
Abstract
Neurodegenerative diseases (NDs) encompass an assorted array of disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, each characterised by distinct clinical manifestations and underlying pathological mechanisms. While some cases have a genetic basis, many NDs occur sporadically. Despite their differences, these diseases commonly feature chronic neuroinflammation as a hallmark. Consensus has recently been reached on the possibility that mitochondria dysfunction and protein aggregation can mutually contribute to the activation of neuroinflammatory response and thus to the onset and progression of these disorders. In the present review, we discuss the contribution of mitochondria dysfunction and neuroinflammation to the aetiology and progression of NDs, highlighting the possibility that new potential therapeutic targets can be identified to tackle neurodegenerative processes and alleviate the progression of these pathologies.
Collapse
Affiliation(s)
- Caterina Peggion
- Department of Biology, University of Padova, 35131 Padova, Italy;
| | - Tito Calì
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy;
| | - Marisa Brini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy
| |
Collapse
|
4
|
Wang Y, Wang J, Tao SY, Liang Z, Xie R, Liu NN, Deng R, Zhang Y, Deng D, Jiang G. Mitochondrial damage-associated molecular patterns: A new insight into metabolic inflammation in type 2 diabetes mellitus. Diabetes Metab Res Rev 2024; 40:e3733. [PMID: 37823338 DOI: 10.1002/dmrr.3733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/18/2023] [Accepted: 09/08/2023] [Indexed: 10/13/2023]
Abstract
The pathogenesis of diabetes is accompanied by increased levels of inflammatory factors, also known as "metabolic inflammation", which runs through the whole process of the occurrence and development of the disease. Mitochondria, as the key site of glucose and lipid metabolism, is often accompanied by mitochondrial function damage in type 2 diabetes mellitus (T2DM). Damaged mitochondria release pro-inflammatory factors through damage-related molecular patterns that activate inflammation pathways and reactions to oxidative stress, further aggravate metabolic disorders, and form a vicious circle. Currently, the pathogenesis of diabetes is still unclear, and clinical treatment focuses primarily on symptomatic intervention of the internal environment of disorders of glucose and lipid metabolism with limited clinical efficacy. The proinflammatory effect of mitochondrial damage-associated molecular pattern (mtDAMP) in T2DM provides a new research direction for exploring the pathogenesis and intervention targets of T2DM. Therefore, this review covers the most recent findings on the molecular mechanism and related signalling cascades of inflammation caused by mtDAMP in T2DM and discusses its pathogenic role of it in the pathological process of T2DM to search potential intervention targets.
Collapse
Affiliation(s)
- Yan Wang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Jingwu Wang
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Si-Yu Tao
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | | | - Rong Xie
- Xinjiang Medical University, Urumqi, China
| | - Nan-Nan Liu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Ruxue Deng
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Yuelin Zhang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Deqiang Deng
- Department of Endocrinology, Urumqi Hospital of Traditional Chinese Medicine, Urumqi, China
| | - Guangjian Jiang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| |
Collapse
|
5
|
Garg M, Johri S, Chakraborty K. Immunomodulatory role of mitochondrial DAMPs: a missing link in pathology? FEBS J 2023; 290:4395-4418. [PMID: 35731715 DOI: 10.1111/febs.16563] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/18/2022] [Accepted: 06/21/2022] [Indexed: 12/01/2022]
Abstract
In accordance with the endosymbiotic theory, mitochondrial components bear characteristic prokaryotic signatures, which act as immunomodulatory molecules when released into the extramitochondrial compartment. These endogenous immune triggers, called mitochondrial damage-associated molecular patterns (mtDAMPs), have been implicated in the pathogenesis of various diseases, yet their role remains largely unexplored. In this review, we summarise the available literature on mtDAMPs in diseases, with a special focus on respiratory diseases. We highlight the need to bolster mtDAMP research using a multipronged approach, to study their effect on specific cell types, receptors and machinery in pathologies. We emphasise the lacunae in the current understanding of mtDAMPs, particularly in their cellular release and the chemical modifications they undergo. Finally, we conclude by proposing additional effects of mtDAMPs in diseases, specifically their role in modulating the immune system.
Collapse
Affiliation(s)
- Mayank Garg
- Cardio-Respiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Saumya Johri
- Cardio-Respiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Krishnendu Chakraborty
- Cardio-Respiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| |
Collapse
|
6
|
He J, Chen Y, Dai S, Chen F, Wang Y, Shi T, Chen L, Liu Y, Chen J, Xie P. First insights into region-specific lipidome alterations of prefrontal cortex and hippocampus of mice exposed chronically to microcystins. ENVIRONMENT INTERNATIONAL 2023; 177:108018. [PMID: 37329758 DOI: 10.1016/j.envint.2023.108018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 06/19/2023]
Abstract
Microcystins (MCs), a group of most widespread freshwater cyanotoxins that possess strong neurotoxicity, can adversely affect brain structures and functions and are linked to neurodegenerative diseases. Despite the essential role of lipids in brain structures and functions, the brain lipidome profile of mammals exposed to MCs remains unexplored, hindering a clear understanding of the neurotoxic effects of MCs and underlying mechanisms. In this study, we performed untargeted lipidomic profiling using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) on the prefrontal cortex and hippocampus of mice orally exposed to 30 and 300 μg/kg body mass/day of microcystin-leucine arginine (MC-LR) for 180 days to evaluate the impacts of MC-LR on the brain lipidome profile and functions. Our results show that MC-LR resulted in a decline in cognitive parameters, as assessed by the Morris water maze test. Interestingly, apparent neurodegenerative changes were observed in the prefrontal cortex, but not in the hippocampus. Comprehensive lipidomic analyses uncovered profound, region-specific changes in the phospholipid and sphingolipid profile at the levels of lipid subclasses, lipid species, and fatty acyl composition. These changes showed overall decrease trends of lipid content in the prefrontal cortex yet increasing trends in the hippocampus. We identified distinct transcriptional regulations of lipid metabolism and apoptosis by MC-LR in the two regions, which appeared to underlie the neurodegenerative changes. Collectively, this study uncovers region-specific changes in the brain lipidome profile and functions induced by MCs, shedding light on the role of lipid dysfunction in neurotoxicity mechanism of MCs.
Collapse
Affiliation(s)
- Jun He
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
| | - Yang Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
| | - Shiming Dai
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
| | - Feng Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
| | - Yeke Wang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
| | - Ting Shi
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
| | - Liang Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China
| | - Ying Liu
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China
| | - Jun Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China.
| | - Ping Xie
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China.
| |
Collapse
|
7
|
Di Mambro T, Pellielo G, Agyapong ED, Carinci M, Chianese D, Giorgi C, Morciano G, Patergnani S, Pinton P, Rimessi A. The Tricky Connection between Extracellular Vesicles and Mitochondria in Inflammatory-Related Diseases. Int J Mol Sci 2023; 24:ijms24098181. [PMID: 37175888 PMCID: PMC10179665 DOI: 10.3390/ijms24098181] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/21/2023] [Accepted: 05/01/2023] [Indexed: 05/15/2023] Open
Abstract
Mitochondria are organelles present in almost all eukaryotic cells, where they represent the main site of energy production. Mitochondria are involved in several important cell processes, such as calcium homeostasis, OXPHOS, autophagy, and apoptosis. Moreover, they play a pivotal role also in inflammation through the inter-organelle and inter-cellular communications, mediated by the release of mitochondrial damage-associated molecular patterns (mtDAMPs). It is currently well-documented that in addition to traditional endocrine and paracrine communication, the cells converse via extracellular vesicles (EVs). These small membrane-bound particles are released from cells in the extracellular milieu under physio-pathological conditions. Importantly, EVs have gained much attention for their crucial role in inter-cellular communication, translating inflammatory signals into recipient cells. EVs cargo includes plasma membrane and endosomal proteins, but EVs also contain material from other cellular compartments, including mitochondria. Studies have shown that EVs may transport mitochondrial portions, proteins, and/or mtDAMPs to modulate the metabolic and inflammatory responses of recipient cells. Overall, the relationship between EVs and mitochondria in inflammation is an active area of research, although further studies are needed to fully understand the mechanisms involved and how they may be targeted for therapeutic purposes. Here, we have reported and discussed the latest studies focused on this fascinating and recent area of research, discussing of tricky connection between mitochondria and EVs in inflammatory-related diseases.
Collapse
Affiliation(s)
- Tommaso Di Mambro
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Giulia Pellielo
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Esther Densu Agyapong
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Marianna Carinci
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Diego Chianese
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Carlotta Giorgi
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Giampaolo Morciano
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Simone Patergnani
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
- Center of Research for Innovative Therapies in Cystic Fibrosis, University of Ferrara, 44121 Ferrara, Italy
| | - Alessandro Rimessi
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy
- Center of Research for Innovative Therapies in Cystic Fibrosis, University of Ferrara, 44121 Ferrara, Italy
| |
Collapse
|
8
|
Microglia secrete distinct sets of neurotoxins in a stimulus-dependent manner. Brain Res 2023; 1807:148315. [PMID: 36878343 DOI: 10.1016/j.brainres.2023.148315] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/07/2023] [Accepted: 03/02/2023] [Indexed: 03/07/2023]
Abstract
Microglia are the resident immune cells of the brain which regulate both the innate and adaptive neuroimmune responses in health and disease. In response to specific endogenous and exogenous stimuli, microglia transition to one of their reactive states characterized by altered morphology and function, including their secretory profile. A component of the microglial secretome is cytotoxic molecules capable of causing damage and death to nearby host cells, thus contributing to the pathogenesis of neurodegenerative disorders. Indirect evidence from secretome studies and measurements of mRNA expression using diverse microglial cell types suggest different stimuli may induce microglia to secrete distinct subsets of cytotoxins. We demonstrate the accuracy of this hypothesis directly by challenging murine BV-2 microglia-like cells with eight different immune stimuli and assessing secretion of four potentially cytotoxic molecules, including nitric oxide (NO), tumor necrosis factor α (TNF), C-X-C motif chemokine ligand 10 (CXCL10), and glutamate. Lipopolysaccharide (LPS) and a combination of interferon (IFN)-γ plus LPS induced secretion of all toxins studied. IFN-β, IFN-γ, polyinosinic:polycytidylic acid (poly I:C), and zymosan A upregulated secretion of subsets of these four cytotoxins. LPS and IFN-γ, alone or in combination, as well as IFN-β induced toxicity of BV-2 cells towards murine NSC-34 neuronal cells, while ATP, N-formylmethionine-leucyl-phenylalanine (fMLP), and phorbol 12-myristate 13-acetate (PMA) did not affect any parameters studied. Our observations contribute to a growing body of knowledge on the regulation of the microglial secretome, which may inform future development of novel therapeutics for neurodegenerative diseases, where dysregulated microglia are key contributors to pathogenesis.
Collapse
|
9
|
Wenzel TJ, Murray TE, Noyovitz B, Narayana K, Gray TE, Le J, He J, Simtchouk S, Gibon J, Alcorn J, Mousseau DD, Zandberg WF, Klegeris A. Cardiolipin released by microglia can act on neighboring glial cells to facilitate the uptake of amyloid-β (1-42). Mol Cell Neurosci 2023; 124:103804. [PMID: 36592800 DOI: 10.1016/j.mcn.2022.103804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 11/16/2022] [Accepted: 12/24/2022] [Indexed: 12/31/2022] Open
Abstract
Cardiolipin is a mitochondrial phospholipid that is also detected in serum inferring its extracellular release; however, this process has not been directly demonstrated for any of the brain cell types. Nevertheless, extracellular cardiolipin has been shown to modulate several neuroimmune functions of microglia and astrocytes, including upregulation of their endocytic activity. Low cardiolipin levels are associated with brain aging, and may thus hinder uptake of amyloid-β (Αβ) in Alzheimer's disease. We hypothesized that glial cells are one of the sources of extracellular cardiolipin in the brain parenchyma where this phospholipid interacts with neighboring cells to upregulate the endocytosis of Αβ. Liquid chromatography-mass spectrophotometry identified 31 different species of cardiolipin released from murine BV-2 microglial cells and revealed this process was accelerated by exposure to Aβ42. Extracellular cardiolipin upregulated internalization of fluorescently-labeled Aβ42 by primary murine astrocytes, human U118 MG astrocytic cells, and murine BV-2 microglia. Increased endocytic activity in the presence of extracellular cardiolipin was also demonstrated by studying uptake of Aβ42 and pHrodo™ Bioparticles™ by human induced pluripotent stem cells (iPSCs)-derived microglia, as well as iPSC-derived human brain organoids containing microglia, astrocytes, oligodendrocytes and neurons. Our observations indicate that Aβ42 augments the release of cardiolipin from microglia into the extracellular space, where it can act on microglia and astrocytes to enhance their endocytosis of Aβ42. Our observations suggest that the reduced glial uptake of Aβ due to the decreased levels of cardiolipin could be at least partially responsible for the extracellular accumulation of Aβ in aging and Alzheimer's disease.
Collapse
Affiliation(s)
- Tyler J Wenzel
- Cell Signalling Laboratory, Department of Psychiatry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada; College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Taryn E Murray
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Benjamin Noyovitz
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Kamal Narayana
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Taylor E Gray
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Jennifer Le
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Jim He
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Svetlana Simtchouk
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Julien Gibon
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Jane Alcorn
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Darrell D Mousseau
- Cell Signalling Laboratory, Department of Psychiatry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Wesley F Zandberg
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada.
| |
Collapse
|
10
|
Nouduri S, Padmanabhan R, Hicks R, Abbott MA, O'Brien D, Schlaug G. Case report: MELAS and concomitant presumed antiphospholipid antibody syndrome in an adult woman. Front Neurol 2022; 13:1043695. [PMID: 36588908 PMCID: PMC9794603 DOI: 10.3389/fneur.2022.1043695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes, and other features (short stature, headaches, seizures, and sensorineural hearing loss) constitute characteristics of MELAS syndrome. MELAS is a rare condition due to mutations in maternally inherited mitochondrial DNA with levels of heteroplasmy possibly related to late adulthood presentation. A previously reported MELAS case coexisted with presumed Antiphospholipid Antibody Syndrome (APLAS), but the connection between MELAS and a potential APLAS is unclear. A 29-year-old woman presented with mild right-sided sensorimotor symptoms and mixed aphasia in November 2021. She presented again in May 2022 for unrelenting headaches and was found to have a new right hemisphere syndrome with mild left-sided sensorimotor symptoms, hemineglect, and anosognosia. Characteristic lab and imaging studies were obtained. During the first presentation (October 2021), the discovery of anticardiolipin IgM antibodies (aCL) (and their replication 3 months later) led to a diagnosis of APLAS, and Warfarin was initiated. During the second admission (May 2022), a new stroke-like lesion on the right hemisphere with characteristic features not suggestive of ischemia was detected, which led to a diagnosis of MELAS (m3243A > G mutation). Although MELAS and APLAS could co-exist, alternatively, it is possible that antiphospholipid antibodies might be generated when the strongly anionic Cardiolipin-Hydroperoxide from the inner mitochondrial membrane is exposed to immune component cells upon cell lysis. Thus, the presence of aCL in patients with stroke-like lesions might masquerade as an APLAS, but should probably be questioned if only aCL are repeatedly found and imaging findings are not characteristic for ischemic lesions.
Collapse
Affiliation(s)
- Sirisha Nouduri
- Department of Neurology, Baystate Medical Center, University of Massachusetts Chan Medical School—Baystate, Springfield, MA, United States
| | - Rajiv Padmanabhan
- Department of Neurology, Baystate Medical Center, University of Massachusetts Chan Medical School—Baystate, Springfield, MA, United States
| | - Richard Hicks
- Department of Radiology, Baystate Medical Center, University of Massachusetts Chan Medical School—Baystate, Springfield, MA, United States
| | - Mary-Alice Abbott
- Department of Pediatrics, Baystate Medical Center, University of Massachusetts Chan Medical School—Baystate, Springfield, MA, United States
| | - Dennis O'Brien
- Department of Neurology, Baystate Medical Center, University of Massachusetts Chan Medical School—Baystate, Springfield, MA, United States
| | - Gottfried Schlaug
- Department of Neurology, Baystate Medical Center, University of Massachusetts Chan Medical School—Baystate, Springfield, MA, United States,*Correspondence: Gottfried Schlaug
| |
Collapse
|
11
|
Tremblay MÈ, Almsherqi ZA, Deng Y. Plasmalogens and platelet-activating factor roles in chronic inflammatory diseases. Biofactors 2022; 48:1203-1216. [PMID: 36370412 DOI: 10.1002/biof.1916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022]
Abstract
Fatty acids and phospholipid molecules are essential for determining the structure and function of cell membranes, and they hence participate in many biological processes. Platelet activating factor (PAF) and its precursor plasmalogen, which represent two subclasses of ether phospholipids, have attracted increasing research attention recently due to their association with multiple chronic inflammatory, neurodegenerative, and metabolic disorders. These pathophysiological conditions commonly involve inflammatory processes linked to an excess presence of PAF and/or decreased levels of plasmalogens. However, the molecular mechanisms underlying the roles of plasmalogens in inflammation have remained largely elusive. While anti-inflammatory responses most likely involve the plasmalogen signal pathway; pro-inflammatory responses recruit arachidonic acid, a precursor of pro-inflammatory lipid mediators which is released from membrane phospholipids, notably derived from the hydrolysis of plasmalogens. Plasmalogens per se are vital membrane phospholipids in humans. Changes in their homeostatic levels may alter cell membrane properties, thus affecting key signaling pathways that mediate inflammatory cascades and immune responses. The plasmalogen analogs of PAF are also potentially important, considering that anti-PAF activity has strong anti-inflammatory effects. Plasmalogen replacement therapy was further identified as a promising anti-inflammatory strategy allowing for the relief of pathological hallmarks in patients affected by chronic diseases with an inflammatory component. The aim of this Short Review is to highlight the emerging roles and implications of plasmalogens in chronic inflammatory disorders, along with the promising outcomes of plasmalogen replacement therapy for the treatment of various PAF-related chronic inflammatory pathologies.
Collapse
Affiliation(s)
- Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec City, Canada
- Department of Molecular Medicine, Université de Laval, Québec City, Canada
- Neurology and Neurosurgery Department, McGill University, Montréal, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, British Columbia, Canada
| | - Zakaria A Almsherqi
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yuru Deng
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, China
| |
Collapse
|
12
|
Lin MM, Liu N, Qin ZH, Wang Y. Mitochondrial-derived damage-associated molecular patterns amplify neuroinflammation in neurodegenerative diseases. Acta Pharmacol Sin 2022; 43:2439-2447. [PMID: 35233090 PMCID: PMC9525705 DOI: 10.1038/s41401-022-00879-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 01/23/2022] [Indexed: 12/12/2022] Open
Abstract
Both mitochondrial dysfunction and neuroinflammation are implicated in neurodegeneration and neurodegenerative diseases. Accumulating evidence shows multiple links between mitochondrial dysfunction and neuroinflammation. Mitochondrial-derived damage-associated molecular patterns (DAMPs) are recognized by immune receptors of microglia and aggravate neuroinflammation. On the other hand, inflammatory factors released by activated glial cells trigger an intracellular cascade, which regulates mitochondrial metabolism and function. The crosstalk between mitochondrial dysfunction and neuroinflammatory activation is a complex and dynamic process. There is strong evidence that mitochondrial dysfunction precedes neuroinflammation during the progression of diseases. Thus, an in-depth understanding of the specific molecular mechanisms associated with mitochondrial dysfunction and the progression of neuroinflammation in neurodegenerative diseases may contribute to the identification of new targets for the treatment of diseases. In this review, we describe in detail the DAMPs that induce or aggravate neuroinflammation in neurodegenerative diseases including mtDNA, mitochondrial unfolded protein response (mtUPR), mitochondrial reactive oxygen species (mtROS), adenosine triphosphate (ATP), transcription factor A mitochondria (TFAM), cardiolipin, cytochrome c, mitochondrial Ca2+ and iron.
Collapse
Affiliation(s)
- Miao-Miao Lin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases and Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China
| | - Na Liu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases and Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China
| | - Zheng-Hong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases and Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China
| | - Yan Wang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases and Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China.
| |
Collapse
|
13
|
Mitochondrial Damage-Associated Molecular Patterns Content in Extracellular Vesicles Promotes Early Inflammation in Neurodegenerative Disorders. Cells 2022; 11:cells11152364. [PMID: 35954208 PMCID: PMC9367540 DOI: 10.3390/cells11152364] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 02/06/2023] Open
Abstract
Neuroinflammation is a common hallmark in different neurodegenerative conditions that share neuronal dysfunction and a progressive loss of a selectively vulnerable brain cell population. Alongside ageing and genetics, inflammation, oxidative stress and mitochondrial dysfunction are considered key risk factors. Microglia are considered immune sentinels of the central nervous system capable of initiating an innate and adaptive immune response. Nevertheless, the pathological mechanisms underlying the initiation and spread of inflammation in the brain are still poorly described. Recently, a new mechanism of intercellular signalling mediated by small extracellular vesicles (EVs) has been identified. EVs are nanosized particles (30–150 nm) with a bilipid membrane that carries cell-specific bioactive cargos that participate in physiological or pathological processes. Damage-associated molecular patterns (DAMPs) are cellular components recognised by the immune receptors of microglia, inducing or aggravating neuroinflammation in neurodegenerative disorders. Diverse evidence links mitochondrial dysfunction and inflammation mediated by mitochondrial-DAMPs (mtDAMPs) such as mitochondrial DNA, mitochondrial transcription factor A (TFAM) and cardiolipin, among others. Mitochondrial-derived vesicles (MDVs) are a subtype of EVs produced after mild damage to mitochondria and, upon fusion with multivesicular bodies are released as EVs to the extracellular space. MDVs are particularly enriched in mtDAMPs which can induce an immune response and the release of pro-inflammatory cytokines. Importantly, growing evidence supports the association between mitochondrial dysfunction, EV release and inflammation. Here, we describe the role of extracellular vesicles-associated mtDAMPS in physiological conditions and as neuroinflammation activators contributing to neurodegenerative disorders.
Collapse
|
14
|
Yang TX, Zhu YF, Wang CC, Yang JY, Xue CH, Huang QR, Wang YM, Zhang TT. EPA-enriched plasmalogen attenuates the cytotoxic effects of LPS-stimulated microglia on the SH-SY5Y neuronal cell line. Brain Res Bull 2022; 186:143-152. [PMID: 35728742 DOI: 10.1016/j.brainresbull.2022.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/29/2022] [Accepted: 06/05/2022] [Indexed: 11/25/2022]
Abstract
Microglia plays an important role in the production of inflammation in the central nervous system. Excessive nerve inflammation can cause neuronal damage and neurodegenerative disease. It has been shown that EPA-enriched ethanolamine plasmalogen (EPA-PlsEtn) significantly inhibited the expressions of inflammatory factors and suppressed neuronal loss in a rat model of Alzheimer's disease. However, whether EPA-PlsEtn protects against neuronal loss by inhibiting the activation of microglia is still not clear. Therefore, we examined the effect of PlsEtn on SH-SY5Y cells incubated by conditioned medium from LPS-induced BV2 cells as a neuroinflammation model. Results showed that pre-incubation of LPS-induced BV2 cells with PlsEtn significantly improved the viability of SH-SY5Y cells by reducing the early apoptosis. The increasing production of NO and TNF-α in BV2 cells was reversed by PlsEtn treatment, while the decreasing level of IL-10 was raised. Polarization toward M1 phenotype and activation of NLRP3 inflammasome pathways are attenuated significantly by pre-treatment of PlsEtn in LPS-induced BV2 cells. The study provides evidence for a positive effect of PlsEtn on neuroprotection and the inhibition of neuroinflammation, and PlsEtn may be explored as a potential functional ingredient with neuroprotection effects.
Collapse
Affiliation(s)
- Tian-Xin Yang
- College of Food Science and Engineering, Ocean University of China, No.5 Yushan Road, Qingdao 266003, PR China
| | - Yun-Fang Zhu
- College of Food Science and Engineering, Ocean University of China, No.5 Yushan Road, Qingdao 266003, PR China
| | - Cheng-Cheng Wang
- College of Food Science and Engineering, Ocean University of China, No.5 Yushan Road, Qingdao 266003, PR China
| | - Jin-Yue Yang
- College of Food Science and Engineering, Ocean University of China, No.5 Yushan Road, Qingdao 266003, PR China
| | - Chang-Hu Xue
- College of Food Science and Engineering, Ocean University of China, No.5 Yushan Road, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, Shandong Province, PR China
| | - Qing-Rong Huang
- Rutgers State Univ, Dept Food Sci, 65 Dudley Rd, New Brunswick, NJ 08901, USA
| | - Yu-Ming Wang
- College of Food Science and Engineering, Ocean University of China, No.5 Yushan Road, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, Shandong Province, PR China.
| | - Tian-Tian Zhang
- College of Food Science and Engineering, Ocean University of China, No.5 Yushan Road, Qingdao 266003, PR China.
| |
Collapse
|
15
|
Extracellular Cardiolipin Modulates Select Immune Functions of Astrocytes in Toll-Like Receptor (TLR) 4-Dependent Manner. Mediators Inflamm 2022; 2022:9946439. [PMID: 35369030 PMCID: PMC8975658 DOI: 10.1155/2022/9946439] [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: 07/19/2021] [Revised: 01/11/2022] [Accepted: 02/16/2022] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by chronic neuroinflammation, which is partially mediated by dysregulated functions of glial cells. Cardiolipin (CL) is a phospholipid normally confined to the inner mitochondrial membrane; however, it has been detected in human sera, indicating that it can exist in the extracellular space where it may interact with nearby cells. Although CL has been shown to modulate several functions of microglia in a toll-like receptor (TLR) 4-dependent manner, the effects of extracellular CL on astrocytes are unknown. In addition to their homeostatic functions, astrocytes participate in neuroimmune responses of the brain and express TLR 4. Therefore, we hypothesized that extracellular CL (1) modulates the secretion of cytokines and cytotoxins by astrocytes, as well as their phagocytic activity, and (2) acts by interacting with astrocyte TLR 4. We demonstrate that CL inhibits the lipopolysaccharide- (LPS-) induced secretion of cytotoxins and expression of glial fibrillary acidic protein (GFAP) by human U118 MG astrocytic cells. CL alone upregulates the phagocytic activity of human astrocytic cells and primary murine astrocytes. CL in combination with LPS upregulates secretion of interleukin (IL)-1β by astrocytic cells. Furthermore, CL alone increases the secretion of monocyte chemoattractant protein (MCP)-1 by astrocytic cells, which is blocked by the TLR 4-specific antagonist TAK-242. We demonstrate that CL upregulates MCP-1 secretion in the absence of its natural carrier protein, β2-glycoprotein 1, indicating that CL may be bioactive in the brain where this protein is not present. Lastly, we show that CL downregulates the expression of astrocytic TLR 4, implying that CL engages this receptor, as its activation has been shown to lead to its degradation. Overall, our study extends the list of cell type functions of which CL modulates and provides evidence that CL, or liposomes containing this phospholipid can be used to modulate specific neuroimmune functions of astrocytes.
Collapse
|
16
|
Wenzel TJ, Haskey N, Kwong E, Greuel BK, Gates EJ, Gibson DL, Klegeris A. Dietary fats modulate neuroinflammation in mucin 2 knock out mice model of spontaneous colitis. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166336. [PMID: 34973372 DOI: 10.1016/j.bbadis.2021.166336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 12/17/2021] [Accepted: 12/20/2021] [Indexed: 02/07/2023]
Abstract
Specific diets regulate neuroimmune responses and modify risk of inflammatory bowel diseases, including ulcerative colitis. A link between gut and brain inflammation is also emerging. We hypothesized that adjusting dietary fatty acid composition modulates the neuroimmune responses in the mucin 2 knock out mice model of spontaneous colitis. Mice were randomly divided into three groups and fed isocaloric diets that only differed in their fatty acid composition. Diets enriched with anhydrous milk fat, corn oil, or Mediterranean diet fats were used. After nine weeks, brain and serum concentrations of ten inflammatory cytokines were measured. Three of these cytokines, including interleukin (IL)-2, IL-12 p70 and interferon-γ, were differentially expressed in the brains of animals from the three diet groups while there were no differences in the serum concentrations of these cytokines. Since only limited information is available about the functions of IL-2 in the central nervous system, in vitro experiments were performed to assess its effects on microglia. IL-2 had no effect on the secretion of neurotoxins and nitric oxide by microglia-like cells, but it selectively regulated phagocytic activity and reactive oxygen species production by stimulated microglia-like cells. Modulation of microglial reactive oxygen species through altered brain IL-2 concentrations could be one of the mechanisms linking diets with modified risk of neuroimmune disorders including Parkinson's disease.
Collapse
Affiliation(s)
- Tyler J Wenzel
- Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, British Columbia, Canada
| | - Natasha Haskey
- Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, British Columbia, Canada
| | - Evan Kwong
- Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, British Columbia, Canada
| | - Bridget K Greuel
- Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, British Columbia, Canada
| | - Ellen J Gates
- Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, British Columbia, Canada
| | - Deanna L Gibson
- Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, British Columbia, Canada; Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
| | - Andis Klegeris
- Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, British Columbia, Canada.
| |
Collapse
|
17
|
Falabella M, Vernon HJ, Hanna MG, Claypool SM, Pitceathly RDS. Cardiolipin, Mitochondria, and Neurological Disease. Trends Endocrinol Metab 2021; 32:224-237. [PMID: 33640250 PMCID: PMC8277580 DOI: 10.1016/j.tem.2021.01.006] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 02/07/2023]
Abstract
Over the past decade, it has become clear that lipid homeostasis is central to cellular metabolism. Lipids are particularly abundant in the central nervous system (CNS) where they modulate membrane fluidity, electric signal transduction, and synaptic stabilization. Abnormal lipid profiles reported in Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and traumatic brain injury (TBI), are further support for the importance of lipid metablism in the nervous system. Cardiolipin (CL), a mitochondria-exclusive phospholipid, has recently emerged as a focus of neurodegenerative disease research. Aberrant CL content, structure, and localization are linked to impaired neurogenesis and neuronal dysfunction, contributing to aging and the pathogenesis of several neurodegenerative diseases, such as AD and PD. Furthermore, the highly tissue-specific acyl chain composition of CL confers it significant potential as a biomarker to diagnose and monitor the progression in several neurological diseases. CL also represents a potential target for pharmacological strategies aimed at treating neurodegeneration. Given the equipoise that currently exists between CL metabolism, mitochondrial function, and neurological disease, we review the role of CL in nervous system physiology and monogenic and neurodegenerative disease pathophysiology, in addition to its potential application as a biomarker and pharmacological target.
Collapse
Affiliation(s)
- Micol Falabella
- Department of Neuromuscular Diseases, University College London Queen Square Institute of Neurology, London, UK
| | - Hilary J Vernon
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael G Hanna
- Department of Neuromuscular Diseases, University College London Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, University College London Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK.
| |
Collapse
|
18
|
de Oliveira LG, Angelo YDS, Iglesias AH, Peron JPS. Unraveling the Link Between Mitochondrial Dynamics and Neuroinflammation. Front Immunol 2021; 12:624919. [PMID: 33796100 PMCID: PMC8007920 DOI: 10.3389/fimmu.2021.624919] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 02/25/2021] [Indexed: 12/13/2022] Open
Abstract
Neuroinflammatory and neurodegenerative diseases are a major public health problem worldwide, especially with the increase of life-expectancy observed during the last decades. For many of these diseases, we still lack a full understanding of their etiology and pathophysiology. Nonetheless their association with mitochondrial dysfunction highlights this organelle as an important player during CNS homeostasis and disease. Markers of Parkinson (PD) and Alzheimer (AD) diseases are able to induce innate immune pathways induced by alterations in mitochondrial Ca2+ homeostasis leading to neuroinflammation. Additionally, exacerbated type I IFN responses triggered by mitochondrial DNA (mtDNA), failures in mitophagy, ER-mitochondria communication and mtROS production promote neurodegeneration. On the other hand, regulation of mitochondrial dynamics is essential for CNS health maintenance and leading to the induction of IL-10 and reduction of TNF-α secretion, increased cell viability and diminished cell injury in addition to reduced oxidative stress. Thus, although previously solely seen as power suppliers to organelles and molecular processes, it is now well established that mitochondria have many other important roles, including during immune responses. Here, we discuss the importance of these mitochondrial dynamics during neuroinflammation, and how they correlate either with the amelioration or worsening of CNS disease.
Collapse
Affiliation(s)
- Lilian Gomes de Oliveira
- Neuroimmune Interactions Laboratory, Immunology Department - Institute of Biomedical Sciences (ICB) IV, University of São Paulo (USP), São Paulo, Brazil
- Neuroimmunology of Arboviruses Laboratory, Scientific Platform Pasteur-USP, University of São Paulo (USP), São Paulo, Brazil
| | - Yan de Souza Angelo
- Neuroimmune Interactions Laboratory, Immunology Department - Institute of Biomedical Sciences (ICB) IV, University of São Paulo (USP), São Paulo, Brazil
- Neuroimmunology of Arboviruses Laboratory, Scientific Platform Pasteur-USP, University of São Paulo (USP), São Paulo, Brazil
| | - Antonio H Iglesias
- Loyola University Medical Center, Stritch School of Medicine, Loyola University Chicago, Chicago, IL, United States
| | - Jean Pierre Schatzmann Peron
- Neuroimmune Interactions Laboratory, Immunology Department - Institute of Biomedical Sciences (ICB) IV, University of São Paulo (USP), São Paulo, Brazil
- Neuroimmunology of Arboviruses Laboratory, Scientific Platform Pasteur-USP, University of São Paulo (USP), São Paulo, Brazil
- Loyola University Medical Center, Stritch School of Medicine, Loyola University Chicago, Chicago, IL, United States
| |
Collapse
|
19
|
Extracellular cardiolipin modulates microglial phagocytosis and cytokine secretion in a toll-like receptor (TLR) 4-dependent manner. J Neuroimmunol 2021; 353:577496. [PMID: 33517251 DOI: 10.1016/j.jneuroim.2021.577496] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 12/22/2020] [Accepted: 01/21/2021] [Indexed: 02/06/2023]
Abstract
Microglia-driven neuroinflammation contributes to neurodegenerative diseases. Mitochondrial phospholipid cardiolipin acts as a signaling molecule when released from damaged cells. We demonstrate that extracellular cardiolipin induces the secretion of monocyte chemoattractant protein-1 and interferon gamma-induced protein 10 by resting microglia while inhibiting secretion of cytokines by microglia stimulated with lipopolysaccharide, amyloid Aβ42 peptides, or α-synuclein. Extracellular cardiolipin also induces nitric oxide secretion by microglia-like cells and upregulates microglial phagocytosis. By using blocking antibodies, we determine that toll-like receptor 4 mediates the latter effect. Under physiological and pathological conditions characterized by cell death, extracellularly released cardiolipin may regulate immune responses of microglia.
Collapse
|
20
|
Klegeris A. Regulation of neuroimmune processes by damage- and resolution-associated molecular patterns. Neural Regen Res 2021; 16:423-429. [PMID: 32985460 PMCID: PMC7996015 DOI: 10.4103/1673-5374.293134] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Sterile inflammatory processes are essential for the maintenance of central nervous system homeostasis, but they also contribute to various neurological disorders, including neurotrauma, stroke, and demyelinating or neurodegenerative diseases. Immune mechanisms in the central nervous system and periphery are regulated by a diverse group of endogenous proteins, which can be broadly divided into the pro-inflammatory damage-associated molecular patterns (DAMPs) and anti-inflammatory resolution-associated molecular patterns (RAMPs), even though there is notable overlap between the DAMP- and RAMP-like activities for some of these molecules. Both groups of molecular patterns were initially described in peripheral immune processes and pathologies; however, it is now evident that at least some, if not all, of these immunomodulators also regulate neuroimmune processes and contribute to neuroinflammation in diverse central nervous system disorders. The review of recent literature demonstrates that studies on DAMPs and RAMPs of the central nervous system still lag behind the much broader research effort focused on their peripheral counterparts. Nevertheless, this review also reveals that over the last five years, significant advances have been made in our understanding of the neuroimmune functions of several well-established DAMPs, including high-mobility group box 1 protein and interleukin 33. Novel neuroimmune functions have been demonstrated for other DAMPs that previously were considered almost exclusively as peripheral immune regulators; they include mitochondrial transcription factor A and cytochrome C. RAMPs of the central nervous system are an emerging area of neuroimmunology with very high translational potential since some of these molecules have already been used in preclinical and clinical studies as candidate therapeutic agents for inflammatory conditions, such as multiple sclerosis and rheumatoid arthritis. The therapeutic potential of DAMP antagonists and neutralizing antibodies in central nervous system neuroinflammatory diseases is also supported by several of the identified studies. It can be concluded that further studies of DAMPs and RAMPs of the central nervous system will continue to be an important and productive field of neuroimmunology.
Collapse
Affiliation(s)
- Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC, Canada
| |
Collapse
|
21
|
Hashioka S, Wu Z, Klegeris A. Glia-Driven Neuroinflammation and Systemic Inflammation in Alzheimer's Disease. Curr Neuropharmacol 2021; 19:908-924. [PMID: 33176652 PMCID: PMC8686312 DOI: 10.2174/1570159x18666201111104509] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/28/2020] [Accepted: 11/06/2020] [Indexed: 11/29/2022] Open
Abstract
The neuroinflammatory hypothesis of Alzheimer's disease (AD) was proposed more than 30 years ago. The involvement of the two main types of glial cells microglia and astrocytes, in neuroinflammation, was suggested early on. In this review, we highlight that the exact contributions of reactive glia to AD pathogenesis remain difficult to define, likely due to the heterogeneity of glia populations and alterations in their activation states through the stages of AD progression. In the case of microglia, it is becoming apparent that both beneficially and adversely activated cell populations can be identified at various stages of AD, which could be selectively targeted to either limit their damaging actions or enhance beneficial functions. In the case of astrocytes, less information is available about potential subpopulations of reactive cells; it also remains elusive whether astrocytes contribute to the neuropathology of AD by mainly gaining neurotoxic functions or losing their ability to support neurons due to astrocyte damage. We identify L-type calcium channel blocker, nimodipine, as a candidate drug for AD, which potentially targets both astrocytes and microglia. It has already shown consistent beneficial effects in basic experimental and clinical studies. We also highlight the recent evidence linking peripheral inflammation and neuroinflammation. Several chronic systemic inflammatory diseases, such as obesity, type 2 diabetes mellitus, and periodontitis, can cause immune priming or adverse activation of glia, thus exacerbating neuroinflammation and increasing risk or facilitating the progression of AD. Therefore, reducing peripheral inflammation is a potentially effective strategy for lowering AD prevalence.
Collapse
Affiliation(s)
- Sadayuki Hashioka
- Address correspondence to these authors at the Department of Psychiatry, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan;, E-mail: and Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, BC, V1V 1V7, Canada; E-mail:
| | | | - Andis Klegeris
- Address correspondence to these authors at the Department of Psychiatry, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan;, E-mail: and Department of Biology, Faculty of Science, University of British Columbia Okanagan Campus, Kelowna, BC, V1V 1V7, Canada; E-mail:
| |
Collapse
|
22
|
Wenzel TJ, Kwong E, Bajwa E, Klegeris A. Resolution-Associated Molecular Patterns (RAMPs) as Endogenous Regulators of Glia Functions in Neuroinflammatory Disease. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2020; 19:483-494. [DOI: 10.2174/1871527319666200702143719] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/17/2020] [Accepted: 04/20/2020] [Indexed: 01/01/2023]
Abstract
Glial cells, including microglia and astrocytes, facilitate the survival and health of all cells
within the Central Nervous System (CNS) by secreting a range of growth factors and contributing to
tissue and synaptic remodeling. Microglia and astrocytes can also secrete cytotoxins in response to
specific stimuli, such as exogenous Pathogen-Associated Molecular Patterns (PAMPs), or endogenous
Damage-Associated Molecular Patterns (DAMPs). Excessive cytotoxic secretions can induce the death
of neurons and contribute to the progression of neurodegenerative disorders, such as Alzheimer’s disease
(AD). The transition between various activation states of glia, which include beneficial and detrimental
modes, is regulated by endogenous molecules that include DAMPs, cytokines, neurotransmitters,
and bioactive lipids, as well as a diverse group of mediators sometimes collectively referred to as
Resolution-Associated Molecular Patterns (RAMPs). RAMPs are released by damaged or dying CNS
cells into the extracellular space where they can induce signals in autocrine and paracrine fashions by
interacting with glial cell receptors. While the complete range of their effects on glia has not been described
yet, it is believed that their overall function is to inhibit adverse CNS inflammatory responses,
facilitate tissue remodeling and cellular debris removal. This article summarizes the available evidence
implicating the following RAMPs in CNS physiological processes and neurodegenerative diseases:
cardiolipin (CL), prothymosin α (ProTα), binding immunoglobulin protein (BiP), heat shock protein
(HSP) 10, HSP 27, and αB-crystallin. Studies on the molecular mechanisms engaged by RAMPs could
identify novel glial targets for development of therapeutic agents that effectively slow down neuroinflammatory
disorders including AD.
Collapse
Affiliation(s)
- Tyler J. Wenzel
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia, V1V 1V7, Canada
| | - Evan Kwong
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia, V1V 1V7, Canada
| | - Ekta Bajwa
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia, V1V 1V7, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia, V1V 1V7, Canada
| |
Collapse
|
23
|
Lowry JR, Marshall N, Wenzel TJ, Murray TE, Klegeris A. The dietary fatty acids α-linolenic acid (ALA) and linoleic acid (LA) selectively inhibit microglial nitric oxide production. Mol Cell Neurosci 2020; 109:103569. [PMID: 33161065 DOI: 10.1016/j.mcn.2020.103569] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 10/27/2020] [Accepted: 10/31/2020] [Indexed: 12/19/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder without a known cure or effective treatment. Research has identified several modifiable risk factors and suggested preventative measures to reduce the risk of developing AD, including alterations in diet. Polyunsaturated fatty acids (PUFAs) have been shown to regulate inflammatory responses in the central nervous system (CNS), the main site of inflammation in AD. In the CNS, microglia are immune cells responsible for the maintenance of homeostasis. However, in AD, microglia can become adversely activated, causing them to release increased levels of cytotoxins and inflammatory mediators, including nitric oxide (NO) and monocyte-chemoattractant protein (MCP)-1. We assessed the effects of two PUFAs, α-linolenic acid (ALA) and linoleic acid (LA), on select microglial immune functions, since the effects of these dietary fatty acids on neuroimmune responses are not well characterized. In BV-2 mouse microglia activated with lipopolysaccharide (LPS), exposure to LA reduced NO secretion and inducible nitric oxide synthase (iNOS) levels, whereas exposure to ALA reduced NO without a corresponding reduction of iNOS. Neither ALA nor LA altered MCP-1 levels or cytotoxins released by THP-1 human microglia-like cells stimulated with a combination of LPS and interferon (IFN)-γ. Specific receptor antagonists were used to demonstrate that the inhibitory effect of LA on NO secretion did not depend on the free fatty acid receptor (FFAR) 1 or FFAR4. Furthermore, gas chromatography with a flame ionization detector (GC-FID) revealed that exposure to LA or ALA did not alter the fatty acid composition of BV-2 microglia. Our data indicate that regulation of select microglial immune functions by ALA and LA could be one of the mechanisms underlying the observed link between certain dietary patterns and AD, such as reduced risk of cognitive decline and dementia associated with the Mediterranean diet.
Collapse
Affiliation(s)
- Jessica R Lowry
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada
| | - Nick Marshall
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada
| | - Tyler J Wenzel
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada
| | - Taryn E Murray
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada.
| |
Collapse
|
24
|
Mitochondria Regulate Inflammatory Paracrine Signalling in Neurodegeneration. J Neuroimmune Pharmacol 2020; 15:565-566. [PMID: 32915348 DOI: 10.1007/s11481-020-09952-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/17/2020] [Indexed: 10/23/2022]
Abstract
Mitochondrial dysfunction occurs in most neurodegenerative diseases, contributing to both their onset and progression. A recent breakthrough unveiled that propagation of the inflammatory response and subsequent neuronal injury are also mediated extracellularly by damaged mitochondria, which are released from active microglial cells into the brain milieu. These extracellular fragmented mitochondria can therefore generate sufficient toxicity to trigger neuronal death and widespread brain damage through activation of naïve astrocytes. Besides suggesting potential new pharmacological strategies of therapeutic intervention in neurodegeneration, this original work indicates that mitochondria might act as bioactive ligands exerting paracrine functions. This is an interesting, novel and impactful concept that deserves consideration by the scientific community, as the attention should now be focused on the identification of the specific receptors through which mitochondria mediate such an important extracellular signalling mechanism in neurological conditions.
Collapse
|
25
|
Short-chain fatty acids (SCFAs) alone or in combination regulate select immune functions of microglia-like cells. Mol Cell Neurosci 2020; 105:103493. [DOI: 10.1016/j.mcn.2020.103493] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 03/31/2020] [Accepted: 04/04/2020] [Indexed: 01/04/2023] Open
|
26
|
Acaz-Fonseca E, Ortiz-Rodriguez A, Garcia-Segura LM, Astiz M. Sex differences and gonadal hormone regulation of brain cardiolipin, a key mitochondrial phospholipid. J Neuroendocrinol 2020; 32:e12774. [PMID: 31323169 DOI: 10.1111/jne.12774] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 06/14/2019] [Accepted: 07/15/2019] [Indexed: 12/14/2022]
Abstract
Cardiolipin (CL) is a phospholipid that is almost exclusively located in the inner mitochondrial membrane of eukaryotic cells. As a result of its unique structure and distribution, CL establishes non-covalent bonds with a long list of proteins involved in ATP production, mitochondria biogenesis, mitophagy and apoptosis. Thus, the amount of CL, as well as its fatty acid composition and location, strongly impacts upon mitochondrial-dependent functions and therefore the metabolic homeostasis of different tissues. The brain is particularly sensitive to mitochondrial dysfunction as a result of its high metabolic demand. Several mitochondrial related-neurodegenerative disorders, as well as physiological ageing, show altered CL metabolism. Furthermore, mice lacking enzymes involved in CL synthesis show cognitive impairments. CL content and metabolism are regulated by gonadal hormones in the developing and adult brain. In neuronal cultures, oestradiol increases CL content, whereas adult ovariectomy decreases CL content and alters CL metabolism in the hippocampal mitochondria. Transient sex differences in brain CL metabolism have been detected during development. At birth, brain CL has a higher proportion of unsaturated fatty acids in the brain of male mice than in the brain of females. In addition, the expression of enzymes involved in CL de novo and recycling synthetic pathways is higher in males. Most of these sex differences are abolished by the neonatal androgenisation of females, suggesting a role for testosterone in the generation of sex differences in brain CL. The regulation of brain CL by gonadal hormones may be linked to their homeostatic and protective actions in neural cells, as well as the manifestation of sex differences in neurodegenerative disorders.
Collapse
Affiliation(s)
- Estefania Acaz-Fonseca
- Instituto Cajal-CSIC, Madrid, Spain
- Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Luis Miguel Garcia-Segura
- Instituto Cajal-CSIC, Madrid, Spain
- Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Mariana Astiz
- Institute of Neurobiology, Center of Brain Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| |
Collapse
|
27
|
Benhuri B, ELJack A, Kahaleh B, Chakravarti R. Mechanism and biomarkers in aortitis--a review. J Mol Med (Berl) 2019; 98:11-23. [PMID: 31664480 DOI: 10.1007/s00109-019-01838-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 09/11/2019] [Accepted: 09/22/2019] [Indexed: 12/26/2022]
Abstract
Aortitis can be the manifestation of an underlying infectious or noninfectious disease process. An autoimmune cause is suggested in a large proportion of noninfectious causes. Similar to other autoimmune diseases, the pathophysiology of aortitis has been investigated in detail, but the etiology remains unknown. Most cases of aortitis often go undetected for a long time and are often identified at late stages of the disease. Recent advances in imaging techniques have significantly improved the diagnosis of aortitis. However, significant challenges associated with the imaging techniques limit their use. Several routine inflammation-based markers, such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and inflammatory cytokines, are nonspecific and, therefore, have limited use in the diagnosis of aortitis. The search for more specific serum biomarkers, which can facilitate detection and progression is under progress. Several autoantibodies have been identified, but assigning their role in the pathogenesis as well as their specificity remains a challenge. The current review addresses some of these issues in detail. KEY MESSAGES: • Noninfectious aortitis is an autoimmune disease. • Several biomarkers, including cytokines and autoantibodies, are increased in aortitis. • Imaging techniques, commonly used to detect aortitis, are associated with the high cost and technical challenges. • There is a need to develop low-cost biomarker-based detection tools. • The knowledge of biomarkers in aortitis detection is discussed.
Collapse
Affiliation(s)
- Benjamin Benhuri
- Department of Physiology & Pharmacology, College of Medical & Life Sciences, University of Toledo College of Medicine, 3000 Arlington Ave, Toledo, OH, 43614, USA.,Department of Internal Medicine, Mount Sinai Beth Israel, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ammar ELJack
- Department of Physiology & Pharmacology, College of Medical & Life Sciences, University of Toledo College of Medicine, 3000 Arlington Ave, Toledo, OH, 43614, USA.,Depatment of Intenal Medicine, Beaumont Hospital, Dearborn, MI, 48124, USA
| | - Bashar Kahaleh
- Division of Rheumatology, University of Toledo College of Medicine, 3000 Arlington Ave, Toledo, OH, 43614, USA
| | - Ritu Chakravarti
- Department of Physiology & Pharmacology, College of Medical & Life Sciences, University of Toledo College of Medicine, 3000 Arlington Ave, Toledo, OH, 43614, USA.
| |
Collapse
|
28
|
Wenzel TJ, Bajwa E, Klegeris A. Cytochrome c can be released into extracellular space and modulate functions of human astrocytes in a toll-like receptor 4-dependent manner. Biochim Biophys Acta Gen Subj 2019; 1863:129400. [PMID: 31344401 DOI: 10.1016/j.bbagen.2019.07.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/23/2019] [Accepted: 07/18/2019] [Indexed: 11/16/2022]
Abstract
BACKGROUND Chronic activation of glial cells contributes to neurodegenerative diseases. Cytochrome c (CytC) is a soluble mitochondrial protein that can act as a damage-associated molecular pattern (DAMP) when released into the extracellular space from damaged cells. CytC causes immune activation of microglia in a toll-like receptor (TLR) 4-dependent manner. The effects of extracellular CytC on astrocytes are unknown. Astrocytes, which are the most abundant glial cell type in the brain, express TLR 4 and secrete inflammatory mediators; therefore, we hypothesized that extracellular CytC can interact with the TLR 4 of astrocytes inducing their release of inflammatory molecules and cytotoxins. METHOD Experiments were conducted using primary human astrocytes, U118 MG human astrocytic cells, BV-2 murine microglia, and SH-SY5Y human neuronal cells. RESULTS Extracellularly applied CytC increased the secretion of interleukin (IL)-1β, granulocyte-macrophage colony stimulating factor (GM-CSF) and IL-12 p70 by cultured primary human astrocytes. Anti-TLR 4 antibodies blocked the CytC-induced secretion of IL-1β and GM-CSF by astrocytes. Supernatants from CytC-activated astrocytes were toxic to human SH-SY5Y neuronal cells. We also demonstrated CytC release from damaged glial cells by measuring CytC in the supernatants of BV-2 microglia after their exposure to cytotoxic concentrations of staurosporine, amyloid-β peptides (Aβ42) and tumor necrosis factor-α. CONCLUSION CytC can be released into the extracellular space from damaged glial cells causing immune activation of astrocytes in a TLR 4-dependent manner. GENERAL SIGNIFICANCE Astrocyte activation by CytC may contribute to neuroinflammation and neuronal death in neurodegenerative diseases. Astrocyte TLR 4 could be a potential therapeutic target in these diseases.
Collapse
Affiliation(s)
- Tyler J Wenzel
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Ekta Bajwa
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada.
| |
Collapse
|
29
|
Bajwa E, Pointer CB, Klegeris A. The Role of Mitochondrial Damage-Associated Molecular Patterns in Chronic Neuroinflammation. Mediators Inflamm 2019; 2019:4050796. [PMID: 31065234 PMCID: PMC6466851 DOI: 10.1155/2019/4050796] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 03/01/2019] [Accepted: 03/06/2019] [Indexed: 01/05/2023] Open
Abstract
Mitochondrial dysfunction has been established as a common feature of neurodegenerative disorders that contributes to disease pathology by causing impaired cellular energy production. Mitochondrial molecules released into the extracellular space following neuronal damage or death may also play a role in these diseases by acting as signaling molecules called damage-associated molecular patterns (DAMPs). Mitochondrial DAMPs have been shown to initiate proinflammatory immune responses from nonneuronal glial cells, including microglia and astrocytes; thereby, they have the potential to contribute to the chronic neuroinflammation present in these disorders accelerating the degeneration of neurons. In this review, we highlight the mitochondrial DAMPs cytochrome c (CytC), mitochondrial transcription factor A (TFAM), and cardiolipin and explore their potential role in the central nervous system disorders including Alzheimer's disease and Parkinson's disease, which are characterized by neurodegeneration and chronic neuroinflammation.
Collapse
Affiliation(s)
- Ekta Bajwa
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC, Canada
| | - Caitlin B. Pointer
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC, Canada
| |
Collapse
|