Crumbs homolog 1 (CRB1) mutations result in a thick human retina with abnormal lamination
Samuel G Jacobson1, Artur V Cideciyan, Tomas S Aleman
1Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA. jacobsos@mail.med.upenn.edu
Insights
Mutations in CRB1 disrupt normal retinal development, causing inherited blindness. CRB1 mutant retinas show abnormal thickness and organization, resembling immature tissue, suggesting interrupted apoptosis.
Area of Science:
- Ophthalmology
- Genetics
- Developmental Biology
Background:
- CRB1 mutations cause autosomal recessive blinding retinal disorders.
- The precise role of CRB1 in retinal organization and disease is not fully understood.
Purpose of the Study:
- To characterize the in vivo retinal organization in patients with CRB1 mutations.
- To elucidate the pathological mechanisms underlying CRB1-associated retinal degeneration.
Main Methods:
- In vivo characterization of retinal organization in patients with CRB1 mutations.
- Histological analysis of retinal structure.
Main Results:
- CRB1 mutant retinas exhibit abnormal thickness and lack distinct layering compared to normal adult retina.
- The abnormal architecture resembles immature retinal tissue.
- The findings suggest CRB1 plays a critical role in establishing normal retinal lamination.
Conclusions:
- CRB1 mutations lead to a distinct form of inherited retinal degeneration characterized by disrupted retinal development.
- The CRB1 disease pathway may interfere with programmed cell death (apoptosis) during retinal development.
- Understanding CRB1's role is crucial for developing therapies for CRB1-associated blindness.
Abstract:
Mutations in CRB1, the human homolog of Drosophila Crumbs, cause autosomal recessive blinding disorders of the retina. Whereas Crumbs is implicated in apical-basal epithelial polarity and photoreceptor morphogenesis, the role of CRB1 in normal or diseased retina remains unclear. We characterized the retinal organization in vivo of patients with CRB1 mutations and found that, unlike other inherited retinal degenerations studied to date, the CRB1 mutant retinas are remarkably thick in cross-section and lack the distinct layers of normal adult retina. There are coarse outer and inner zones and a thick surface layer around the optic nerve. The abnormal retinal architecture in CRB1 mutations resembles that of immature normal retina. The results suggest that the CRB1 disease pathway disturbs the development of normal human retinal organization by interrupting naturally occurring apoptosis.
