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Schoknecht K, Hirrlinger J, Eilers J. Transient astrocytic accumulation of fluorescein during spreading depolarizations. Neurobiol Dis 2023; 178:106026. [PMID: 36731681 DOI: 10.1016/j.nbd.2023.106026] [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: 08/23/2022] [Revised: 01/16/2023] [Accepted: 01/29/2023] [Indexed: 02/01/2023] Open
Abstract
Spreading depolarizations (SDs) occur frequently in acute cerebral injuries. They are characterized by a breakdown of transmembrane ion gradients resulting in a reduced extracellular sodium ([Na+]o) and increased extracellular potassium concentration ([K+]o). Elevated [K+]o induces astrocytic swelling, another feature of SD; however, the solutes that drive astrocytic swelling remain incompletely understood. We incidentally found astrocytic accumulation of fluorescein (Fluo) - a low molecular weight anionic dye - during SDs induced by elevated [K+]o. Herein, we aimed to explore the properties of astrocytic Fluo accumulation during SDs, electrical stimulation, [K+]o and glutamate elevation and elucidate underlying mechanisms and its relation to swelling. Experiments were performed in acute neocortical slices from adult male C57Bl6 mice and transgenic mice expressing tdTomato in parvalbumin (PV)-positive neurons. We labeled astrocytes with sulforhodamine-101 (SR-101), measured Fluo kinetics using 2-photon laser scanning microscopy and recorded local field potentials (LFP) to detect SDs. Elevations of [K+]o lead to an increase of the astrocytic Fluo intensity in parallel with astrocytic swelling. Pharmacological inhibitors of sodium‑potassium ATPase (Na/K-ATPase), secondary-active transporters and channels were used to address the underlying mechanisms. Fluo accumulation as well as swelling were only prevented by inhibition of the sodium‑potassium ATPase. Application of glutamate or hypoosmolar solution induced astrocytic swelling independent of Fluo accumulation and glutamate opposed Fluo accumulation when co-administered with high [K+]o. Astrocytes accumulated Fluo and swelled during electrical stimulation and even more during SDs. Taken together, Fluo imaging can be used as a tool to visualize yet unidentified anion fluxes during [K+]o- but not glutamate- or hypoosmolarity induced astrocytic swelling. Fluo imaging may thereby help to elucidate mechanisms of astrocytic swelling and associated fluid movements between brain compartments during physiological and pathological conditions, e.g. SDs.
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Affiliation(s)
- Karl Schoknecht
- Carl-Ludwig-Institute of Physiology, Medical Faculty, Leipzig University, Leipzig, Germany.
| | - Johannes Hirrlinger
- Carl-Ludwig-Institute of Physiology, Medical Faculty, Leipzig University, Leipzig, Germany; Department of Neurogenetics, Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Jens Eilers
- Carl-Ludwig-Institute of Physiology, Medical Faculty, Leipzig University, Leipzig, Germany
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Wen Q, Zhou J, Sun X, Ma T, Liu Y, Xie Y, Wang L, Cheng J, Wen J, Wu J, Zou J, Liu S, Liu J. Urine metabolomics analysis of sleep quality in deep-underground miners: A pilot study. Front Public Health 2022; 10:969113. [PMID: 36062104 PMCID: PMC9437423 DOI: 10.3389/fpubh.2022.969113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 08/01/2022] [Indexed: 01/25/2023] Open
Abstract
Background In previous questionnaire surveys of miners, sleep disorders were found among underground workers. The influence of the special deep-underground environment and its potential mechanism are still unclear. Therefore, this study intends to utilize LC-MS metabolomics to study the potential differences between different environments and different sleep qualities. Methods Twenty-seven miners working at 645-1,500 m deep wells were investigated in this study, and 12 local ground volunteers were recruited as the control group. The Pittsburgh Sleep Quality Index (PSQI) was used to examine and evaluate the sleep status of the subjects in the past month, and valuable basic information about the participants was collected. PSQI scores were obtained according to specific calculation rules, and the corresponding sleep grouping and subsequent analysis were carried out. Through liquid chromatography-mass spectrometry (LC-MS) non-targeted metabolomics analysis, differences in metabolism were found by bioinformatics analysis in different environments. Results Between the deep-underground and ground (DUvsG) group, 316 differential metabolites were identified and 125 differential metabolites were identified in the good sleep quality vs. poor sleep quality (GSQvsPSQ) group. The metabolic pathways of Phenylalanine, tyrosine and tryptophan biosynthesis (p = 0.0102) and D-Glutamine and D-glutamate metabolism (p = 0.0241) were significantly enriched in DUvsG. For GSQvsPSQ group, Butanoate metabolism was statistically significant (p = 0.0276). L-Phenylalanine, L-Tyrosine and L-Glutamine were highly expressed in the deep-underground group. Acetoacetic acid was poorly expressed, and 2-hydroxyglutaric acid was highly expressed in good sleep quality. Conclusions The influence of the underground environment on the human body is more likely to induce specific amino acid metabolism processes, and regulate the sleep-wake state by promoting the production of excitatory neurotransmitters. The difference in sleep quality may be related to the enhancement of glycolytic metabolism, the increase in excitatory neurotransmitters and the activation of proinflammation. L-phenylalanine, L-tyrosine and L-glutamine, Acetoacetic acid and 2-hydroxyglutaric acid may be potential biomarkers correspondingly.
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Affiliation(s)
- Qiao Wen
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Zhou
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaoru Sun
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Tengfei Ma
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yilin Liu
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China,Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Yike Xie
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Ling Wang
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Juan Cheng
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jirui Wen
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jiang Wu
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jian Zou
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Shixi Liu
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China,Shixi Liu
| | - Jifeng Liu
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China,*Correspondence: Jifeng Liu
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