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Zhao C, Sun L, Zhang Y, Shu X, Hu Y, Chen D, Zhang Z, Xia S, Yang H, Bao X, Li J, Xu Y. Thymol improves ischemic brain injury by inhibiting microglia-mediated neuroinflammation. Brain Res Bull 2024; 215:111029. [PMID: 39009094 DOI: 10.1016/j.brainresbull.2024.111029] [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: 01/18/2024] [Revised: 06/20/2024] [Accepted: 07/04/2024] [Indexed: 07/17/2024]
Abstract
BACKGROUND Microglia-mediated inflammation is a critical factor in the progression of ischemic stroke. Consequently, mitigating excessive microglial activation represents a potential therapeutic strategy for ischemic injury. Thymol, a monophenol derived from plant essential oils, exhibits diverse beneficial biological activities, including anti-inflammatory and antioxidant properties, with demonstrated protective effects in various disease models. However, its specific effects on ischemic stroke and microglial inflammation remain unexplored. METHODS Rodent transient middle cerebral artery occlusion (tMCAO) model was established to simulate ischemic stroke. TTC staining, modified neurological function score (mNSS), and behavioral tests were used to assess the severity of neurological damage. Then immunofluorescence staining and cytoskeleton analysis were used to determine activation of microglia. Lipopolysaccharide (LPS) was utilized to induce the inflammatory response of primary microglia in vitro. Quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and enzyme-linked immunosorbent assay (ELISA) were performed to exam the expression of inflammatory cytokines. And western blot was used to investigate the mechanism of the anti-inflammatory effect of thymol. RESULTS In this study, we found that thymol treatment could ameliorate post-stroke neurological impairment and reduce infarct volume by mitigating microglial activation and pro-inflammatory response (IL-1β, IL-6, and TNF-α). Mechanically, thymol could inhibit the phosphorylation of phosphatidylinositol-3-kinase (PI3K), sink serine/threonine kinase (Akt), and mammalian target of rapamycin (mTOR), thereby suppressing the activation of nuclear factor-κB (NF-κB). CONCLUSIONS Our study demonstrated that thymol could reduce the microglial inflammation by targeting PI3K/Akt/mTOR/NF-κB signaling pathway, ultimately alleviating ischemic brain injury. These findings suggest that thymol is a promising candidate as a neuroprotective agent against ischemic stroke.
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Affiliation(s)
- Chenchen Zhao
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China
| | - Liang Sun
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China
| | - Yuxin Zhang
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China
| | - Xin Shu
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China
| | - Yujie Hu
- Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases, Nanjing University, Nanjing 210008, China
| | - Duo Chen
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China
| | - Zhi Zhang
- Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases, Nanjing University, Nanjing 210008, China
| | - Shengnan Xia
- Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases, Nanjing University, Nanjing 210008, China
| | - Haiyan Yang
- Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China
| | - Xinyu Bao
- Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases, Nanjing University, Nanjing 210008, China
| | - Jingwei Li
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China
| | - Yun Xu
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China; Department of Neurology, Nanjing Drum Tower Hospital, State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases, Nanjing University, Nanjing 210008, China; Nanjing Neurology Medical Center, Nanjing 210008, China; Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing 210008, China.
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Ma L, Mi N, Wang Z, Bao R, Fang J, Ren Y, Xu X, Zhang H, Tang Y. Knockdown of IRF8 alleviates neuroinflammation through regulating microglial activation in Parkinson's disease. J Chem Neuroanat 2024; 138:102424. [PMID: 38670441 DOI: 10.1016/j.jchemneu.2024.102424] [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: 02/03/2024] [Revised: 04/08/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024]
Abstract
Neuroinflammation associated with microglial activation plays a role in the development of Parkinson's disease (PD). The upregulation of interferon regulatory factor 8 (IRF8) in microglia following peripheral nerve injury has been observed to induce microglial activation. This suggests the potential therapeutic significance of IRF8 in PD. This research aims to explore the effects of IRF8 on the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model and lipopolysaccharide (LPS)-induced neuroinflammation, along with its underlying mechanisms. The study examines the differential expression of IRF8 and its effects on neuropathological changes using a PD mouse model and a PD model established from BV2 cells in vitro. IRF8 was found to be prominently expressed in the substantia nigra pars compacta (SNpc) region of PD mice and LPS-stimulated BV2 cells, while the expression of tyrosine hydroxylase (TH) and dopamine (DA) content in the SNpc region of PD mice was notably reduced. MPTP treatment and LPS stimulation intensified microglial activation, inflammation, and activation of the AMPK/mTOR signaling pathway in vivo and in vitro, respectively. Upon IRF8 silencing in the PD mouse and cell models, the knockdown of IRF8 ameliorated MPTP-induced behavioral deficits, increased the counts of TH and Nissl-positive neurons and DA content, reduced the number of Iba-1-positive microglia, and reduced the content of inflammatory factors, possibly by inhibiting the AMPK/mTOR signaling pathway. Similar outcomes were observed in the PD cell model. In conclusion, the suppression of IRF8 alleviates neuroinflammation through regulating microglial activation in PD models in vivo and in vitro by the AMPK/mTOR signaling pathway.
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Affiliation(s)
- Lili Ma
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China; Department of Neurology, Jilin City Hospital of Chemical Industry, Jilin City, Jilin, China
| | - Na Mi
- Department of Neurology, Chifeng Municipal Hospital, Chifeng, Inner Mongolia Autonomous Region, China
| | - Zhi Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Rui Bao
- Department of Rehabilitation, The Third Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang, China
| | - Jing Fang
- Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Yajing Ren
- School of Medical and Life Sciences, Chengdu University of TCM, Chengdu, Sichuan, China
| | - Xiuzhi Xu
- General Medical Department, Heilongjiang Provincial Hospital, Harbin, Heilongjiang, China
| | - Hongjia Zhang
- Department of Neurology, Jilin City Hospital of Chemical Industry, Jilin City, Jilin, China.
| | - Ying Tang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
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Ravizza T, Scheper M, Di Sapia R, Gorter J, Aronica E, Vezzani A. mTOR and neuroinflammation in epilepsy: implications for disease progression and treatment. Nat Rev Neurosci 2024; 25:334-350. [PMID: 38531962 DOI: 10.1038/s41583-024-00805-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2024] [Indexed: 03/28/2024]
Abstract
Epilepsy remains a major health concern as anti-seizure medications frequently fail, and there is currently no treatment to stop or prevent epileptogenesis, the process underlying the onset and progression of epilepsy. The identification of the pathological processes underlying epileptogenesis is instrumental to the development of drugs that may prevent the generation of seizures or control pharmaco-resistant seizures, which affect about 30% of patients. mTOR signalling and neuroinflammation have been recognized as critical pathways that are activated in brain cells in epilepsy. They represent a potential node of biological convergence in structural epilepsies with either a genetic or an acquired aetiology. Interventional studies in animal models and clinical studies give strong support to the involvement of each pathway in epilepsy. In this Review, we focus on available knowledge about the pathophysiological features of mTOR signalling and the neuroinflammatory brain response, and their interactions, in epilepsy. We discuss mitigation strategies for each pathway that display therapeutic effects in experimental and clinical epilepsy. A deeper understanding of these interconnected molecular cascades could enhance our strategies for managing epilepsy. This could pave the way for new treatments to fill the gaps in the development of preventative or disease-modifying drugs, thus overcoming the limitations of current symptomatic medications.
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Affiliation(s)
- Teresa Ravizza
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy
| | - Mirte Scheper
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Rossella Di Sapia
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy
| | - Jan Gorter
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands.
| | - Annamaria Vezzani
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy.
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Balistreri CR, Monastero R. Neuroinflammation and Neurodegenerative Diseases: How Much Do We Still Not Know? Brain Sci 2023; 14:19. [PMID: 38248234 PMCID: PMC10812964 DOI: 10.3390/brainsci14010019] [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: 11/27/2023] [Revised: 12/12/2023] [Accepted: 12/21/2023] [Indexed: 01/23/2024] Open
Abstract
The term "neuroinflammation" defines the typical inflammatory response of the brain closely related to the onset of many neurodegenerative diseases (NDs). Neuroinflammation is well known, but its mechanisms and pathways are not entirely comprehended. Some progresses have been achieved through many efforts and research. Consequently, new cellular and molecular mechanisms, diverse and conventional, are emerging. In listing some of those that will be the subject of our description and discussion, essential are the important roles of peripheral and infiltrated monocytes and clonotypic cells, alterations in the gut-brain axis, dysregulation of the apelinergic system, alterations in the endothelial glycocalyx of the endothelial component of neuronal vascular units, variations in expression of some genes and levels of the encoding molecules by the action of microRNAs (miRNAs), or other epigenetic factors and distinctive transcriptional factors, as well as the role of autophagy, ferroptosis, sex differences, and modifications in the circadian cycle. Such mechanisms can add significantly to understanding the complex etiological puzzle of neuroinflammation and ND. In addition, they could represent biomarkers and targets of ND, which is increasing in the elderly.
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Affiliation(s)
- Carmela Rita Balistreri
- Cellular and Molecular Laboratory, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90134 Palermo, Italy
| | - Roberto Monastero
- Unit of Neurology & Neuro-Physiopathology, Department of Biomedicine, Neuroscience, and Advanced Diagnostics (Bi.N.D), University of Palermo, Via La Loggia 1, 90129 Palermo, Italy;
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