Institution: University of California Berkeley
Poster Title: Transcriptomic Analysis of Lens Epithelium Heterogeneity Associated with Lens Growth and Homeostasis
Abstract:
Background: The lens epithelial cells (LECs) maintain the overall growth and homeostasis of the eye lens. In prior research, connexin 50 knockout (Cx50KO) mice display microphthalmia and smaller lenses with mild cataracts while mitogen-activated protein kinase kinase1 transgenic (Mek1TG) mice show macrophthalmia and enlarged lenses with severe cataracts, and Cx50KO/Mek1TG double mutant mice develop normal size lenses with severe cataracts.
Purpose: The study aims to investigate the heterogeneity of lens epithelium and to identify the transcriptional changes across different epithelial cell subpopulations using single-cell RNA sequencing (scRNA-seq). Moreover, gene candidates that play important roles in epithelial cell proliferation, differentiation and/or homeostasis are investigated.
Methods: Postnatal day 30 (P30) LECs were collected for scRNA-seq. 10x Genomics pipeline was used to align and preprocess raw scRNA-seq data. Seurat was utilized to process the data and integrate matrices for various genotypes. Monocle3 was employed to predict the pseudotime trajectory of lens epithelium. GO analysis was performed to explore the signaling pathways.
Results: The integrated scRNA-seq datasets reveal seven clusters among wild-type control, Cx50KO, Mek1TG and Cx50KO/Mek1KO, with variable distribution of cells in each cluster. The expression of crystallins, transcription regulatory genes, and metabolic genes varied across LEC subclusters and total cells of different genotypes, indicating different LEC heterogeneity and suggesting candidate genes involved in the regulation of LEC proliferation, differentiation and lens homeostasis.
Conclusions: scRNA-seq and GO analysis provide some molecular insights into the heterogeneity and transcriptomics of lens epithelium in different mutant lenses with different sizes. The scRNA-seq results reveal changes of LECs subpopulations associated with the distinct lens phenotypes of Cx50KO and Mek1TG. Identified specific genes, such as Tob1, Eid1 and Prox1, are likely involved in lens size control, while both Cx50 and Aqp1 are important for water homeostasis in lens epithelial cells.