EXCEPTIONAL AGGRESSIVENESS OF CEREBRAL CAVERNOUS MALFORMATION DISEASE ASSOCIATED WITH PDCD10 MUTATIONS

PURPOSE: The phenotypic manifestations of cerebral cavernous malformation (CCM) disease caused by rare PDCD10 mutations have not been systematically examined, and a mechanistic link to Rho kinase (ROCK) mediated hyperpermeability, a potential therapeutic target, has not been established. METHODS: We analyze PDCD10-siRNA treated endothelial cells for stress fibers, ROCK activity and permeability. ROCK activity is assessed in CCM lesions. Brain permeability and CCM lesion burden is quantified, and clinical manifestations are assessed in prospectively enrolled subjects with PDCD10 mutations. RESULTS: We determine that PDCD10 protein suppresses endothelial stress fibers, ROCK activity and permeability in vitro. Pdcd10 heterozygous mice have greater lesion burden than other Ccm genotypes. We demonstrate robust ROCK activity in murine and human CCM vasculature, and increased brain vascular permeability in humans with PDCD10 mutation. Clinical phenotype is exceptionally aggressive compared to the more common KRIT1 and CCM2 familial and sporadic CCM, with greater lesion burden and more frequent hemorrhages earlier in life. We first report other phenotypic features including scoliosis, cognitive disability and skin lesions, unrelated to lesion burden or bleeding. CONCLUSION: These findings define a unique CCM disease with exceptional aggressiveness, and they inform preclinical therapeutic testing, clinical counseling and the design of trials.