An increase in apoptosis and reduction in αB-crystallin expression levels in the lens underlie the cataractogenesis of Morioka cataract (MCT) mice.

We examined the morphological changes in fibers, localization of apoptotic cells, and protein expression of αB-crystallin in the lens of Morioka cataract (MCT) mice, a novel cataract model. Using a scanning electron microscope, swollen lens fibers and enlarged spaces between lens fibers were observed in the lens of 3-week-old MCT mice. At 2 weeks of age (before cataract), the single-strand DNA (ssDNA)-positive (indicating apoptosis) cell ratio of the lens epithelium was significantly higher in MCT than in wild-type ddY mice. At 2 and 4 weeks of age, αB-crystallin protein expression of the lens in MCT mice was significantly lower than that in wild-type ddY mice. These findings suggest that increase in apoptosis and reduction in αBcrystallin level are involved in the cataractogenesis of MCT mice.