Gene expression signatures of UV-A induced senescent human corneal endothelial cells.

Abstract

Purpose : We presented that 5J/cm² ultraviolet (UV) -A radiation induced cellular senescence in human corneal endothelial cells (hCEnCs) (Numa et al. ARVO2023 in New Orleans). This study is aimed to determine the full spectrum of RNA expression in UV-A induced senescent hCEnCs via RNA-sequencing (RNA-seq), compared to ionizing irradiation (IR) induced senescent hCEnCs.

Methods : Primary hCEnCs were obtained from donor corneas. HCEnCs were irradiated with 5J/cm² UV-A or 10Gy-IR and were cultured to undergo senescent. Senescent cells were examined by senescence-associated β-galactosidase (SA-β-gal) staining, Ed-U incorporation, the expression level of p16 and p21. RNAs were extracted from UV-A and IR-induced senescent hCEnCs and RNA-seq was performed by sequencing on Illumina HiSeq4000.

Results : Cells exposed to UV-A and to IR exhibited typical senescent phenotypes, including enlargement, increased SA-β-gal activity, decreased cell proliferation and elevated expression of p16 and p21. A total of 3205 genes were found to be differentially expressed, with 1505 genes upregulated and 1700 genes downregulated in UV-A-induced senescent hCEnCs compared to control cells (fold change>2 and adjusted p-value<0.05). RNA-Seq analysis revealed that 83.9% of the genes significantly upregulated and 82.6% of the genes significantly downregulated in UV-A-induced senescent hCEnCs overlapped with the genes regulated in IR-induced senescent hCEnCs. Gene ontology analysis revealed that the genes related to extracellular matrix organization were most enriched in the both UV-A and IR-induced senescent hCEnCs.

Conclusions : In this study, where senescence was induced by UV-A, a more physiological stress for hCEnCs compared to IR, we determined that UV-A modulated the expression of many genes typically altered upon IR treatment, a more conventional method of senescence induction.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.