Background: Studies in our laboratory have shown that transforming growth factor beta (TGF beta) induces rodent lens epithelial cells to undergo aberrant growth and differentiation that reproduces morphological and molecular features of human anterior subcapsular cataract and posterior capsule opacification. In addition, features of apoptosis have been described in some forms of human cataract. In the present study we investigated apoptotic changes induced by TGF beta in our rodent models.
Methods: Lens epithelial explants and whole lenses from rats were cultured with TGF beta. Morphological analysis and TUNEL were used to detect apoptotic changes. Transgenic mice expressing a self-activating form of human TGF beta 1 in the lens were included in the analysis.
Results: TGF beta-induced cell loss in epithelial explants coincided with increased numbers of pyknotic nuclei. Some of these nuclei were TUNEL-positive. Studies on lenses cultured with TGF beta and lenses from transgenic mice showed that the subcapsular plaques that developed contained pyknotic nuclei and that many of these were TUNEL-positive.
Discussion: This study shows that cells develop morphological and molecular features of apoptosis in TGF beta-induced cataract models. This confirms that apoptosis can be included as another TGF beta-induced cellular change that mimics events in human cataract.