Brain Cleanup as a Potential Target for Poststroke Recovery: The Role of RXR (Retinoic X Receptor) in Phagocytes
| Autor: | Lidiya Obertas, Shun-Ming Ting, Mercedes Ricote, Guanghua Sun, Xiurong Zhao, Jaroslaw Aronowski |
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| Přispěvatelé: | National Institutes of Health (United States), Ministerio de Ciencia, Innovación y Universidades (España), Instituto de Salud Carlos III, Fundación ProCNIC |
| Rok vydání: | 2020 |
| Předmět: |
Phagocytosis
Retinoid X receptors Inflammation Retinoid X receptor Brain Ischemia 03 medical and health sciences Mice 0302 clinical medicine medicine Animals Receptor 030304 developmental biology Advanced and Specialized Nursing Mice Knockout 0303 health sciences Phagocytes Retinoid X Receptor alpha Microglia business.industry Macrophages Brain Stroke medicine.anatomical_structure Gene Expression Regulation Bexarotene Cancer research Neurology (clinical) medicine.symptom Cardiology and Cardiovascular Medicine business 030217 neurology & neurosurgery |
| Zdroj: | Repisalud Instituto de Salud Carlos III (ISCIII) |
| ISSN: | 1524-4628 |
| Popis: | Background and Purpose— Phagocytic cells, such as microglia and blood-derived macrophages, are a key biological modality responsible for phagocytosis-mediated clearance of damaged, dead, or displaced cells that are compromised during senescence or pathological processes, including after stroke. This process of clearance is essential to eliminate the source of inflammation and to allow for optimal brain repair and functional recovery. Transcription factor, RXR (retinoic-X-receptor) is strongly implicated in phagocytic functions regulation, and as such could represent a novel target for brain recovery after stroke. Methods— Primary cultured microglia and bone marrow macrophages were used for phagocytic study. Mice with deleted RXR-α in myeloid phagocytes (Mac-RXR-α −/− ) were subjected to transient middle cerebral artery occlusion to mimic ischemic stroke and then treated with RXR agonist bexarotene. RNA-sequencing and long-term recovery were evaluated. Results— Using cultured microglia, we demonstrated that the RXR-α promotes the phagocytic functions of microglia toward apoptotic neurons. Using mice with deleted RXR-α in myeloid phagocytes (Mac-RXR-α −/− ), we have shown that despite behaving similarly to the control at early time points (up to 3 days, damage established histologically and behaviorally), these Mac-RXR-α −/− mice demonstrated worsened late functional recovery and developed brain atrophy that was larger in size than that seen in control mice. The RXR-α deficiency was associated with reduced expression of genes known to be under control of the prominent transcriptional RXR partner, PPAR (peroxisome proliferator-activated receptor)-γ, as well as genes encoding for scavenger receptors and genes that signify microglia/macrophages polarization to a reparative phenotype. Finally, we demonstrated that the RXR agonist, bexarotene, administered as late as 1 day after middle cerebral artery occlusion, improved neurological recovery, and reduced the atrophy volume as assessed 28 days after stroke. Bexarotene did not improve outcome in Mac-RXR-α −/− mice. Conclusions— Altogether, these data suggest that phagocytic cells control poststroke recovery and that RXR in these cells represents an attractive target with exceptionally long therapeutic window. |
| Databáze: | OpenAIRE |
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