title: Molecular and Genetic Analyses of Collagen Type IV Mutant Mouse Models of Spontaneous Intracerebral Hemorrhage Identify Mechanisms for Stroke Prevention.
abstract: BACKGROUND
  Collagen type IV alpha1 (COL4A1) and alpha2 (COL4A2) form heterotrimers critical for vascular basement membrane stability and function. Patients with COL4A1 or COL4A2 mutations suffer from diverse cerebrovascular diseases, including cerebral microbleeds, porencephaly, and fatal intracerebral hemorrhage (ICH). However, the pathogenic mechanisms remain unknown, and there is a lack of effective treatment.
  
  
  RESULTS
  Using Col4a1 and Col4a2 mutant mouse models, we investigated the genetic complexity and cellular mechanisms underlying the disease. We found that Col4a1 mutations cause abnormal vascular development, which triggers small-vessel disease, recurrent hemorrhagic strokes, and age-related macroangiopathy. We showed that allelic heterogeneity, genetic context, and environmental factors such as intense exercise or anticoagulant medication modulated disease severity and contributed to phenotypic heterogeneity. We found that intracellular accumulation of mutant collagen in vascular endothelial cells and pericytes was a key triggering factor of ICH. Finally, we showed that treatment of mutant mice with a US Food and Drug Administration-approved chemical chaperone resulted in a decreased collagen intracellular accumulation and a significant reduction in ICH severity.
  
  
  CONCLUSIONS
  Our data are the first to show therapeutic prevention in vivo of ICH resulting from Col4a1 mutation and imply that a mechanism-based therapy promoting protein folding might also prevent ICH in patients with COL4A1 and COL4A2 mutations.
authors.affiliation: From Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco (UCSF).
authors.forename: Marion
authors.initials: M
authors.lastname: Jeanne
authors.affiliation: From Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco (UCSF).
authors.forename: Jeff
authors.initials: J
authors.lastname: Jorgensen
authors.affiliation: From Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco (UCSF). GouldD@vision.ucsf.edu.
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Gould
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000002:abnormalities / Q000196:embryology; D001812:Blood-Brain Barrier; D001921:Brain / Q000098:blood supply / Q000196:embryology; D002543:Cerebral Hemorrhage / Q000235:genetics / Q000517:prevention & control*; D003094:Collagen / Q000378:metabolism; D024141:Collagen Type IV / Q000172:deficiency / Q000235:genetics* / Q000502:physiology; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D059647:Gene-Environment Interaction; D018740:Genetic Heterogeneity; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D009154:Mutation; D018919:Neovascularization, Physiologic / Q000235:genetics; D010446:Peptide Fragments / Q000172:deficiency / Q000235:genetics* / Q000502:physiology; D020286:Pericytes / Q000378:metabolism; D010641:Phenotype; D010805:Physical Conditioning, Animal; D065708:Porencephaly / Q000235:genetics; D012171:Retinal Vessels / Q000196:embryology
chemical_list: C502624:Col4a2 protein, mouse; D024141:Collagen Type IV; D010446:Peptide Fragments; D003094:Collagen
keywords: cerebrovascular disorders; collagen; genetics; hemorrhage; stroke