ABSTRACT
Objective Neonatal stroke affects 1 in 2800 live births and is a major cause of neurological injury. The Sonic Hedgehog (Shh) signaling pathway is critical for central nervous system (CNS) development and has neuroprotective and reparative effects in different CNS injury models. Previous studies have demonstrated beneficial effects of small molecule Shh-Smoothened-agonist (SAG) against neonatal cerebellar injury and it improves Down syndrome-related brain structural deficits in mice. Here, we investigated SAG neuroprotection in rat models of neonatal ischemia-reperfusion (stroke) and adult focal white matter injury.
Methods We used transient middle cerebral artery occlusion at P10 and ethidium bromide injection in adult rats to induce damage. Following surgery and SAG or vehicle treatment we analyzed tissue loss, cell proliferation and fate, and behavioral outcome.
Results We report that a single dose of SAG administered following neonatal stroke preserved brain volume, reduced inflammation, enhanced oligodendrocyte progenitor cell (OPC) and EC proliferation, and resulted in long-term cognitive improvement. Single-dose SAG also promoted proliferation of OPCs following focal demyelination in the adult rat.
Conclusion These findings indicate benefit of one-time SAG treatment post-insult in reducing brain injury and improving behavioral outcome after experimental neonatal stroke.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Financial Support: M.C. acknowledges fellowship awards from the American Heart Association and The Children’s Heart Foundation and funding support from a Career Development Grant awarded by Cerebral Palsy Alliance Research Foundation. This work was supported by funding from the Harrington Discovery Institute (to D.H.R.), UK MS Society (R.J.M.F.), the Adelson Medical Research Foundation (D.H.R., R.J.M.F.), and the National Institutes of Health, NINDS (P01-NS083513 to D.H.R., K99-NS117804 to M.C., R01-NS107039 and U01-NS092764 to F.G.).
Patient consent. Patient consent was not required for this study.
Disclosure. The authors report no conflict of interest.
Impact:
A one-time dose of small molecule Sonic hedgehog agonist protected against neonatal stroke and improved long-term behavioral outcomes in a rat model
This study extends the use of Sonic hedgehog in treating developing brain injury, previously shown in animal models of Down syndrome and cerebellar injury
Sonic hedgehog agonist is one of the most promising therapies in treating neonatal stroke thanks to its safety profile and low dosage
