Long Noncoding RNA Fos Downstream Transcript Is Developmentally Dispensable but Vital for Shaping the Poststroke Functional Outcome

Abstract

Background and Purpose: Stroke induces the expression of several long noncoding RNAs in the brain. However, their functional significance in poststroke outcome is poorly understood. We recently observed that a brain-specific long noncoding RNA called Fos downstream transcript (FosDT) is induced rapidly in the rodent brain following focal ischemia. Using FosDT knockout rats, we presently evaluated the role of FosDT in poststroke brain damage. Methods: FosDT knockout rats were generated using CRISPR-Cas9 genome editing on a Sprague-Dawley background. Male and female FosDT −/− and FosDT +/+ cohorts were subjected to transient middle cerebral artery occlusion. Postischemic sensorimotor deficits were evaluated between days 1 and 7 and lesion volume on day 7 of reperfusion. The developmental expression profile of FosDT was determined with real-time polymerase chain reaction and mechanistic implications of FosDT in the ischemic brain were conducted with RNA-sequencing analysis and immunostaining of pathological markers. Results: FosDT expression is developmentally regulated, with the adult cerebral cortex showing significantly higher FosDT expression than neonates. FosDT −/− rats did not show any anomalies in growth and development, fertility, brain cytoarchitecture, and cerebral vasculature. However, when subjected to transient focal ischemia, FosDT −/− rats of both sexes showed enhanced sensorimotor recovery and reduced brain damage. RNA-sequencing analysis showed that improved poststroke functional outcome in FosDT −/− rats is partially associated with curtailed induction of inflammatory genes, reduced apoptosis, mitochondrial dysfunction, and oxidative stress. Conclusions: Our study shows that FosDT is developmentally dispensable, mechanistically important, and a functionally promising target to reduce ischemic brain damage and facilitate neurological recovery.

CDR1as regulates α-synuclein-mediated ischemic brain damage by controlling miR-7 availability

“…Stroke is also known to trigger many overlapping pathological mechanisms, including mitochondrial fragmentation and inflammation, all of which contribute to secondary brain damage. 7 , 18 , 20 Post-ischemic induction of mitochondrial fragmentation (pDrp1 immunostaining) is significantly decreased by CDR1as overexpression ( Figure 6 A). Post-ischemic induction of inflammation was evaluated by constraining IL-1β and Iba1 (microglia).…”

“… 1 , 2 , 3 , 4 They can affect the post-ischemic functional outcome by influencing chromatin architecture, RNA/protein scaffolding, enhancer function, alternative splicing, RNA stability, transcription, and translation. 5 , 6 , 7 , 8 , 9 , 10 The ncRNAs regulate each other, which is critical for their functionality and stability in the cellular milieu. 11 , 12 , 13 The circRNAs formed by back-splicing and covalent linkage of the 5' and 3′ ends are resistant to exonucleases that digest linear RNAs.…”

A systematic review of the research progress of non-coding RNA in neuroinflammation and immune regulation in cerebral infarction/ischemia-reperfusion injury

“…Studies have shown that a brain-specific long noncoding RNA called Fos downstream transcript (FosDT) is rapidly induced in rodent brains after focal ischemia (319). Using FosDT knockout rats, Suresh et al assessed the role of FosDT in brain injury after stroke (320). They used CRISPR-Cas9 genome editing in the Sprague-Dawley context to generate FosDT knockout rats.…”

Epigenetic mechanisms and potential therapeutic targets in stroke

“…104 Similarly, FosDT knockout rats showed decreased sensorimotor deficits and brain damage after transient MCAO, suggesting that FosDT promotes post-stroke brain damage by epigenetic mechanisms. 105…”

“…104 Similarly, FosDT knockout rats showed decreased sensorimotor deficits and brain damage after transient MCAO, suggesting that FosDT promotes post-stroke brain damage by epigenetic mechanisms. 105 Another lncRNA called Hox transcript antisense intergenic RNA (HOTAIR) acts as a scaffold to tether Polycomb Repressive Complex 2 (PRC2) comprised of H3K27 methylase EZH2 on its 5 0 domain and LSD1/CoREST/REST protein complex on its 3 0 domain. 106 The HOTAIR/PRC2/LSD1 complex promotes histone H3 lysine 27 methylation and lysine 4 demethylation to epigenetically repress homeobox D cluster (HOXD) genes.…”