Transcriptomic profiling of lentoid bodies highlights potential mechanisms of radiation-induced cataracts

The lens of the eye has been recognized as one of the most radiosensitive tissues in the human body. Radiation-induced cataractogenesis is believed to arise through a complex interplay of molecular processes, including crystallin protein oxidation and aggregation, impaired antioxidant defenses, apoptosis of lens epithelial cells, and epithelial-mesenchymal transition. Nonetheless, the precise mechanisms responsible for these changes remain to be fully elucidated. Organoid model systems are an emerging tool that provide a novel approach for investigating disease processes. In this study, we examined transcriptional changes in lentoid bodies, an organoid-like model of the ocular lens, following exposure to ionizing radiation.

Lentoid bodies were generated from human pluripotent stem cells through a three-step differentiation protocol. Mature lentoid bodies were then subjected to an x-ray dose of 0.25 or 2 Gy and RNA was isolated 12, 24, and 48 hours post exposure for whole transcriptome RNA-sequencing. Genes were considered differentially expressed if they exhibited a fold change < -2.0 or >2.0, false discovery rate-corrected p-value <0.05, and a minimum average read count of 30 transcripts per million.

Significant changes in gene expression profiles were observed post-irradiation with both dose and time post-exposure playing critical roles in the extent and nature of gene dysregulation. Differentially expressed genes were identified within key biological pathways implicated in cataract formation, including cell survival and proliferation, differentiation, migration, and epithelial-mesenchymal transition.

These results advance our understanding of the molecular mechanisms underlying radiation-induced cataracts and demonstrate the value of lens organoid models as a physiologically relevant platform, offering insights beyond those achievable with conventional lens cell lines.