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Planas AM. Role of microglia in stroke. Glia 2024; 72:1016-1053. [PMID: 38173414 DOI: 10.1002/glia.24501] [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: 08/29/2023] [Revised: 12/07/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024]
Abstract
Microglia play key roles in the post-ischemic inflammatory response and damaged tissue removal reacting rapidly to the disturbances caused by ischemia and working to restore the lost homeostasis. However, the modified environment, encompassing ionic imbalances, disruption of crucial neuron-microglia interactions, spreading depolarization, and generation of danger signals from necrotic neurons, induce morphological and phenotypic shifts in microglia. This leads them to adopt a proinflammatory profile and heighten their phagocytic activity. From day three post-ischemia, macrophages infiltrate the necrotic core while microglia amass at the periphery. Further, inflammation prompts a metabolic shift favoring glycolysis, the pentose-phosphate shunt, and lipid synthesis. These shifts, combined with phagocytic lipid intake, drive lipid droplet biogenesis, fuel anabolism, and enable microglia proliferation. Proliferating microglia release trophic factors contributing to protection and repair. However, some microglia accumulate lipids persistently and transform into dysfunctional and potentially harmful foam cells. Studies also showed microglia that either display impaired apoptotic cell clearance, or eliminate synapses, viable neurons, or endothelial cells. Yet, it will be essential to elucidate the viability of engulfed cells, the features of the local environment, the extent of tissue damage, and the temporal sequence. Ischemia provides a rich variety of region- and injury-dependent stimuli for microglia, evolving with time and generating distinct microglia phenotypes including those exhibiting proinflammatory or dysfunctional traits and others showing pro-repair features. Accurate profiling of microglia phenotypes, alongside with a more precise understanding of the associated post-ischemic tissue conditions, is a necessary step to serve as the potential foundation for focused interventions in human stroke.
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Affiliation(s)
- Anna M Planas
- Cerebrovascular Research Laboratory, Department of Neuroscience and Experimental Therapeutics, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
- Cerebrovascular Diseases, Area of Clinical and Experimental Neuroscience, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-Hospital Clínic, Barcelona, Spain
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Wang K, Wen Y, Fu X, Wei S, Liu S, Chen M. mtDNA regulates cGAS-STING signaling pathway in adenomyosis. Free Radic Biol Med 2024; 216:80-88. [PMID: 38494142 DOI: 10.1016/j.freeradbiomed.2024.03.012] [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: 12/25/2023] [Revised: 03/07/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
In various hyperproliferative disorders, damaged mitochondria can release mitochondrial DNA (mtDNA) into the cytoplasm, activating the cGAS-STING signaling pathway and subsequent immune imbalances. Our previous research has demonstrated that hypoxia plays a role in the development of adenomyosis (AM) by inducing mitochondrial dysfunction. However, the precise involvement of the cGAS-STING signaling pathway and mtDNA in AM remains unclear. Therefore, this study aims to investigate the relationship between mtDNA secretion, changes in the cGAS-STING signaling pathway, and the abnormal cellular proliferation observed in AM. We found the cGAS, STING, TBK1, p-TBK1, IRF3, and p-IRF3 proteins levels were significantly elevated in the tissues of patients with AM compared to the control group. Additionally, there was an increase in the expression of the pro-inflammatory cytokines IL-6 and IFN-α in the AM tissues. Hypoxia-induced an increase in the proliferation and migration abilities of endometrial stromal cells (ESCs), accompanied by the activation of the cGAS-STING signaling pathway and elevated levels of IFN-α. Furthermore, hypoxia promoted the leakage of mtDNA into the cytoplasm in AM ESCs, and the deletion of mtDNA reduced the activation of the cGAS-STING pathway. Moreover, knockdown of the STING gene inhibited the expression of TBK1, p-TBK1, IRF3, and p-IRF3 and suppressed the secretion of the inflammatory cytokines IL-6 and IFN-α. Furthermore, the migration and invasion abilities of AM ESCs were significantly diminished after STING knockdown. These findings provide valuable insights into the role of mtDNA release and the cGAS-STING signaling pathway in the pathogenesis of AM.
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Affiliation(s)
- Kun Wang
- Third-grade Pharmacological Laboratory on Traditional Chinese Medicine, State Administration of Traditional Chinese Medicine, China Three Gorges University, Yi Chang, 443000, China; College of Medicine and Health Sciences, China Three Gorges University, Yi Chang, 443000, China
| | - Yi Wen
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610000, China; Department of Gynecology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610000, China
| | - Xianyun Fu
- Third-grade Pharmacological Laboratory on Traditional Chinese Medicine, State Administration of Traditional Chinese Medicine, China Three Gorges University, Yi Chang, 443000, China; College of Medicine and Health Sciences, China Three Gorges University, Yi Chang, 443000, China.
| | - Shaobin Wei
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610000, China; Department of Gynecology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610000, China.
| | - Shidan Liu
- Third-grade Pharmacological Laboratory on Traditional Chinese Medicine, State Administration of Traditional Chinese Medicine, China Three Gorges University, Yi Chang, 443000, China; College of Medicine and Health Sciences, China Three Gorges University, Yi Chang, 443000, China
| | - Minmin Chen
- Third-grade Pharmacological Laboratory on Traditional Chinese Medicine, State Administration of Traditional Chinese Medicine, China Three Gorges University, Yi Chang, 443000, China; College of Medicine and Health Sciences, China Three Gorges University, Yi Chang, 443000, China
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