Project description:Single-cell RNA sequencing (scRNA-seq) was used to assess transcriptional heterogeneity between cells in the postnatal day 2 lens epithelium and identify distinct epithelial cell subtypes.
Project description:Cellular differentiation is marked by temporally and spatially coordinated gene expression regulated at multiple levels within the nucleus. Sequence-specific DNA-binding transcription factor CTCF EDIT. Topologically associated domains (TADs). Using Hi-C, we investigated changes in chromatin organization between newborn (P0.5) mouse lens fiber and epithelium and compared them to embryonic stem (ES) cells. Compartments A and B. Using ChIP-seq, we determined localization of CTCF in both lens tissues Formation of lens-specific TADs is demonstrated via comparative studies of chromatin at Pax6, Prox1, Gata3, Hsf4, and crystallin loci (to be updated) between lens and ES cell nuclei. Our study has generated the first data on nuclear organization in lens epithelium and lens fibers and directly compared these data with ES cells.
Project description:Analysis of gene expression in mouse lens epithelium with or without UVB-irradiation in mouse eye lens. Results provide insight into a role for the respons to UVB-irradiation in lens epithelial cells.
Project description:PurposeThe lens epithelium maintains the overall health of the organ. We used single-cell RNA sequencing (scRNA-seq) technology to assess transcriptional heterogeneity between cells in the postnatal day 2 (P2) epithelium and identify distinct epithelial cell subtypes. Analysis of these data was used to better understand lens growth, differentiation, and homeostasis on P2.MethodsscRNA-seq on P2 mouse lenses was performed using the 10x Genomics Chromium Single Cell 3' Kit (v3.1) and short-read Illumina sequencing. Sequence alignment and preprocessing of data were conducted using 10x Genomics Cell Ranger software. Seurat was employed for preprocessing, quality control, dimensionality reduction, and cell clustering, and Monocle was utilized for trajectory analysis to understand the developmental progression of the lens cells. CellChat and GO analyses were used to explore cell-cell communication networks and signaling interactions.ResultsLens epithelial cells (LECs) were divided into seven subclusters, classified by specific gene markers. The expression of crystallin, cell-cycle, and metabolic genes was not uniform, indicating distinct functional roles of LECs. Trajectory analysis predicted a bifurcation of differentiating and cycling cells from an Igfbp5+ progenitor pool. We also identified heterogeneity in signaling molecules and pathways, suggesting that cycling and progenitor subclusters have prominent roles in coordinating crosstalk.ConclusionsscRNA-seq corroborated many known markers of epithelial differentiation and proliferation while providing further insight into the pathways and genes directing these processes. Interestingly, we demonstrated that the developing epithelium can be divided into distinct subpopulations. These clusters reflect the transcriptionally diverse roles of the epithelium in proliferation, signaling, and maintenance.
Project description:Epithelial cells and differentiated fiber cells represent distinct compartments in the ocular lens. While previous studies have revealed proteins that are preferentially expressed in epithelial vs. fiber cells, a comprehensive proteomics library comparing the molecular composition of epithelial vs. fiber cells is essential for understanding lens formation, function, disease and regenerative potential, and for efficient differentiation of pluripotent stem cells for modeling of lens development and pathology in vitro. To compare protein composition between the lens epithelium and fibers, we employed tandem mass spectrometry (2DLC/ MS) analysis of micro-dissected mouse P0.5 lenses. Functional classifications of the top 525 identified proteins into gene ontology categories by molecular process and subcellular localization, were adapted for lens. Expression levels of both epithelial and fiber proteomes were compared with their temporal and spatial mRNA levels using E14.5, E16.5, E18.5, and P0.5 RNA-Seq data sets. During this developmental time window, multiple complex biosynthetic and catabolic processes generate the molecular and structural foundation for lens transparency. As expected, crystallins showed a high correlation between their mRNA and protein levels. Comprehensive data analysis confirmed and/or predicted roles for transcription factors (TFs), RNA-binding proteins, translational apparatus including ribosomal heterogeneity and initiation factors, microtubules, cytoskeletal and membrane proteins in lens formation and maturation. Our data highlighted many proteins with unknown function in the lens that were preferentially enriched in epithelium or fibers, setting the stage for future studies to further dissect the roles of these proteins in fiber cell differentiation vs. epithelial cell maintenance. In conclusion, the present proteomic datasets established reference mouse lens epithelium and fiber cell proteomes, provided quantitative analyses of protein and RNA-Seq data, and probed the major proteome remodeling required to form the mature lens fiber cells.
Project description:E12.5 mouse lens epithelium and fiber cells were collected using Leica LMD 6000 Laser microdissection system. Total RNA was isolated from epithelium and fiber cells using Qiagen RNeasy kit
Project description:In mouse early organogenic stages, a Mab21l1-null mutation causes severe defects in invagination of the lens placode toward optic cup due to its severe defects in both cell proliferation and survival, which subsequently results in severe microphthalmia after birth. In human, loss of function variants in MAB21L1 have recently been described in Cerebello-Oculo-Facio-Genital syndrome (COFG syndrome). The close similarity between mouse and human phenotypes including microphthalmia indicates the importance of Mab21l1 function in human lens placode. To approach the molecular function of MAB21L1 in eye morphogenesis, we examined single cell transcriptomes in lens placode and its surrounding surface ectoderm at 26 somite stage (E9.25), just prior to the onset of lens defects in Mab21l1-null embryos. Here we demonstrate the identification of several key genes immediately downstream of Mab21l1 function, together with the early lens placode-/surface ectoderm-specific single cell transcriptomes during murine lens placode specification.