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Updated: Jan 16, 2026
Monitoring Astrocyte Reactivity and Proliferation in Vitro Under Ischemic-Like Conditions
Published on: October 21, 2017
Inhibition of Astrocyte Reactivity by Mdivi-1 After Status Epilepticus in Rats Exacerbates Microglia-Mediated
Francisca Gómez-Oliver1,2,3, Rubén Fernández de la Rosa1,4, Mirjam Brackhan1,3
1Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Abstract:
The lithium-pilocarpine rat model of status epilepticus (SE) is a well-established paradigm for studying epileptogenesis. Astrocyte reactivity has been implicated in modulating seizure susceptibility and neuroinflammation, yet its functional role in early epileptogenesis remains unclear. Herein, we evaluated the effects of Mdivi-1, a pharmacological inhibitor of mitochondrial fission protein Drp1, for its ability to modulate astrocytic mitochondrial dynamics and for its reported preventive neuroprotective properties. Mdivi-1 was administered shortly after SE onset, and we assessed brain glucose metabolism using [18F]FDG PET, alongside histological markers of neurodegeneration, astrocyte reactivity, and microglial activation, at 3 days post-SE. As expected, SE induced widespread brain hypometabolism measured by a VOI analysis, hippocampal neurodegeneration, and glial activation. Post-SE Mdivi-1 administration reduced hippocampal astrogliosis but neither conferred neuroprotection nor rescued glucose metabolism. On the contrary, Mdivi-1 exacerbated limbic-cortical hypometabolism when evaluated by SPM and normalized to whole brain tracer uptake and microglia-mediated neuroinflammation. These findings challenge the assumption that early astrocyte inhibition confers neuroprotection. Furthermore, early suppression of astrocyte reactivity after the damage has occurred may shift the neuroinflammatory response toward maladaptive microglial activation. Thus, while Mdivi-1 holds promise as a preventive neuroprotective agent, its use post-SE may have unintended adverse effects on the brain's response to SE.
Insights
Mitochondrial fission inhibitor Mdivi-1 did not prevent neuroprotection or improve brain metabolism after status epilepticus (SE) in rats. Early Mdivi-1 treatment worsened brain hypometabolism and neuroinflammation, challenging its use post-SE.
Area of Science:
- Neuroscience
- Epileptology
- Mitochondrial Biology
Background:
- Status epilepticus (SE) is a critical condition leading to epileptogenesis.
- Astrocyte reactivity plays a role in neuroinflammation and seizure susceptibility, but its function in early epileptogenesis is not fully understood.
- Mitochondrial dynamics, specifically fission regulated by Drp1, are implicated in cellular stress responses.
Purpose of the Study:
- To investigate the effects of Mdivi-1, a Drp1 inhibitor, on astrocytic mitochondrial dynamics and neuroprotection post-SE.
- To evaluate Mdivi-1's impact on brain glucose metabolism, neurodegeneration, and glial activation in the lithium-pilocarpine rat model of SE.
Main Methods:
- Administration of Mdivi-1 shortly after SE onset in the lithium-pilocarpine rat model.
- Assessment of brain glucose metabolism using [18F]FDG PET at 3 days post-SE.
- Histological analysis of neurodegeneration, astrocyte reactivity (astrogliosis), and microglial activation.
Main Results:
- SE induced significant brain hypometabolism, hippocampal neurodegeneration, and glial activation.
- Post-SE Mdivi-1 treatment reduced hippocampal astrogliosis but did not provide neuroprotection or rescue glucose metabolism.
- Mdivi-1 exacerbated limbic-cortical hypometabolism and increased microglia-mediated neuroinflammation.
Conclusions:
- Early Mdivi-1 administration after SE onset does not confer neuroprotection and may worsen brain metabolic deficits.
- Inhibiting astrocyte reactivity post-SE might promote maladaptive microglial activation, suggesting potential adverse effects of Mdivi-1 in this context.
- The use of Mdivi-1 as a post-SE therapeutic agent requires careful consideration due to its potential unintended consequences on neuroinflammation and brain metabolism.
