Abstract
Purpose :
We have earlier confirmed the presence of lens epithelial stem cells (SOX-2+ Cx-43－) in the central zone. This study aims to quantify and functionally characterize the adult stem cells with aging and in cataract.
Methods :
Donor lens of both normal and cataract were obtained from eye banks of Aravind Eye Care System. The whole mount of anterior lens epithelium was immunostained for SOX2 (stem cell marker) and Cx-43 (differentiation marker). Sequential confocal images were acquired and the percentage of stem cells were quantified. Lens epithelial explant cultures were established from central+germinative, transitional and equatorial zones. The functional properties of adult stem cells was analysed using label retaining cell (LRC) assay and sphere forming ability.
Results :
With aging there was no change in the proportion of SOX2+Cx-43－stem cells in the central zone: <30 years - 2.2±1.3% and 30-60 years - 2.3±1.1%. Upon culturing, LRCs (BrdU+) expressing SOX-2 were observed to be located in central (>30 years - 21.8±12.7%, 30-60years - 12.9±3.7%), transitional (>30 years - 6.56±2.4%, 30-60years - 12±3.9%) and equatorial (>30 years - 18.9±24.6%, 30-60years - 13.7±5.1%) zones of normal donor lens. In contrast, cells with the ability to form spheres were identified only in the central zone. In cataractous donor lens (age: 54.3±2.08 years), the BrdU+ SOX-2+ cells were restricted to the central zone and were reduced in number (1.73±0.87%).
Conclusions :
The mean percentage of lens epithelial stem cells in the central zone remained the same with ageing. The absence of SOX-2+ cells in native tissue and the reduction in the percentage of LRCs in cultured lens epithelial cells in cataractous lens indicates a probable association of these stem cells with the cataract development.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.