Ependymal cell lineage reprogramming as a potential therapeutic intervention for hydrocephalus.

Hydrocephalus is a common neurological condition, characterized by the excessive accumulation of cerebrospinal fluid in the cerebral ventricles. Primary treatments for hydrocephalus mainly involve neurosurgical cerebrospinal fluid diversion, which hold high morbidity and failure rates, highlighting the necessity for the discovery of novel therapeutic approaches. Although the pathophysiology of hydrocephalus is highly multifactorial, impaired function of the brain ependymal cells plays a fundamental role in hydrocephalus. Here we show that GemC1 and McIdas, key regulators of multiciliated ependymal cell fate determination, induce direct cellular reprogramming towards ependyma. Our study reveals that ectopic expression of GemC1 and McIdas reprograms cortical astrocytes and programs mouse embryonic stem cells into ependyma. McIdas is sufficient to establish functional activity in the reprogrammed astrocytes. Furthermore, we show that McIdas' expression promotes ependymal cell regeneration in two different postnatal hydrocephalus mouse models: an intracranial hemorrhage and a genetic form of hydrocephalus and ameliorates the cytoarchitecture of the neurogenic niche. Our study provides evidence on the restoration of ependyma in animal models mimicking hydrocephalus that could be exploited towards future therapeutic interventions.