Original Research
Exp. Biol. Med.
Sec. Translational Research
Volume 250 - 2025 | doi: 10.3389/ebm.2025.10559
This article is part of the Issue2024 International Conference on Neuroprotective Agents Conference ProceedingsView all 8 articles
A double-edged effect of hypoxia on astrocyte-derived exosome releases
- 1College of Pharmaceutical Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
- 2Taipei Veterans General Hospital, Taipei, Taipei County, Taiwan
- 3Institue of Physiology, National Yang Ming Chiao Tung University, Taipei, Taiwan
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Exosomes are the smallest extracellular vesicles secreted from cells, carrying different cargos, including nucleic acids, proteins and others which transfer from cells to cells. The properties of exosomes depend on the donor cells. Hypoxia, referring to a sublethal and insufficient oxygen supply, reportedly influences exosome secretion of hypoxic cells. In the present study, we focused on the effects of hypoxia on exosomes obtained from CTX-TNA2 astrocyte cells exposed to different durations of hypoxia followed by normoxia as a model of hypoxic preconditioning. To evaluate the functions of exosomes, primary cultured cortical neurons were treated with hemin, a potent neurotoxin. Our sulforhodamine B assay showed that incubation of hemin (30 μM) consistently induced neuronal death. Co-incubation of exosomes from CTX-TNA2 cells subjected to 2 hr-hypoxia plus 6 hr-renormoxia (2H/6R exosomes), but not 12 hr-hypoxia plus 24 hr-renormoxia (12H/24R exosomes), attenuated hemin-induced cell death and reduction in growth associated protein 43 level (a biomarker of neurite outgrowth). Western blot assay demonstrated that 2H/6R exosomes attenuated hemin-induced elevations in inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) levels (two proinflammatory biomarkers) as well as heme oxygenase-1 (HO-1). In contrast, 12H/24R exosomes did not alter hemin-induced elevation in HO-1 but further augmented hemin-induced increases in iNOS and COX-2. Moreover, 2H/6R exosomes attenuated hemin-induced reduction in glutathione hydroperoxidase 4 (a biomarker of ferroptosis) and elevation in active caspase 3 (a biomarker of apoptosis) while 12H/24R exosomes did not effectively alter hemin-induced programed cell death. In conclusion, our study showed that 2H/6R exosomes possessed neuroprotective activities while 12H/24R exosomes had mild pro-inflammatory activities, suggesting that different hypoxic preconditionings influenced CTX-TNA2 cells which then secreted exosomes with differential biological activities. These findings highlight a double-edged role of hypoxia on exosome functions.
Keywords: hypoxic preconditioning, double-edged role, exosomes, Hemin, CTX-TNA2
Received: 02 Mar 2025; Accepted: 02 May 2025.
Copyright: © 2025 Tseng, Huang, Lin and Maan-Yuh Lin. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Anya Maan-Yuh Lin, College of Pharmaceutical Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
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