Project description:By removing MLL1 from mouse retinal progenitors, we discovered that MLL1 plays multiplex roles in retinal development by regulating: 1) progenitor cell proliferation and cell cycle progression; 2) retinal cell composition; 3) maintenance of horizontal neurons; 4) formation of functional synapses between neuronal layers; and 5) visual function development. Altogether, our results suggest that MLL1 is an indispensable regulator for the development of retinal structure and function.
Project description:Purpose: The retinal pigment epithelium (RPE) forms the outer blood-retinal barrier. Primary cultures of RPE can model the barrier, but are very sensitive to culture conditions. We examined how the neural retina regulates the RPE transcriptome in a culture model of embryonic development. Attention focused on the tight junctional genes essential for barrier function. Methods: Chick RPE from embryonic day 7 (E7) or embryonic day 14 (E14) was cultured on filters in a serum free medium. Media conditioned by organ culture of neural retinas was applied to the apical surface of the cultured RPE. Fetal bovine serum (2%) was included in some experiments. When the transepithelial electrical resistance (TER) reached a plateau, total RNA was isolated to probe the chick genome on Affymetrix microarrays. The expression tight junctional mRNAs was confirmed by real-time PCR and immunoblotting the protein. Results: The TER was slightly increased by serum, but increased 2-3X by retinal conditioned medium. Serum diminished the effect of retinal conditioned medium. In basal conditions, 86% of the transcriptome expressed during development in vivo was also expressed in culture. Approximately 5% of the transcriptome expressed in culture was absent in vivo. E14 retinal conditioned medium affected 15% of the transcriptome in E7 cultures (24% if serum was included), but only 1.9% in E14 cultures (12% with serum). Examination of 610 genes important for RPE function revealed that mRNAs for 17% were regulated by retinal conditioned medium alone in E7 cultures, compared to 6.2% for E14. For tight junctions, retinal conditioned medium had the most affect on members of the claudin family. These results were confirmed by quantitative real-time PCR. Besides regulating mRNA levels, immunoblotting and immunocytochemistry suggested additional mechanisms whereby retinal secretions regulated protein expression and localization. Conclusions: Gene expression in primary cultures of embryonic RPE resembled the native tissue, but expression, and differentiation, is improved when elements of the normal extracellular environment are replicated in culture. For a small group of proteins, retinal secretions were required to maintain in vivo-like expression in culture. Albeit insufficient, retinal secretions promoted differentiation of immature RPE and helped maintain the properties of more mature RPE. Keywords: Tissue interactions, retina, retinal pigment epithelium, blood-retinal barrier, tight junctions
Project description:In order to provide multi-omic resolution to human retinal organoid developmental dynamics, we performed scRNA-seq and scATAC-seq from the same cell suspension across a time course (6-46 weeks) of human retinal organoid development. This data set covers all the retinal organoid scRNA-seq data generated from IMR90 and409B2-iCas9 cell lines.
Project description:PAX6 is essential for eye and forebrain development but how PAX6 instructs retinal versus neuroectoderm specification remains unknown. We found that the paired-less PAX6, PAX6D, is uniquely expressed in retinal cells during human eye development and along human embryonic stem cell (hESC) differentiation to retinal cells. HESCs with deletion of PAX6D failed to enter retinal differentiation. Induced expression of PAX6D but not PAX6A under the PAX6-null background restored the retinal differentiation capacity. ChIP-Seq, confirmed by functional assays, revealed a set of retinal genes and neural genes that are targets of PAX6D, including WNT8B. Inhibition of WNTs restored the retinal differentiation capacity of neuroepithelia with PAX6D knockout whereas activation of WNTs blocks retinal differentiation even when PAX6D is induced. Thus, PAX6D specifies neuroepithelia to retinal cells, partly via regulation of WNTs.
Project description:To begin to understand how TFs regulate retinal cell type identity in human tissues, we established a pooled loss of function (LOF) experiment based on the CROP-seq protocol in developed retinal organoids. We targeted five TFs (OTX2, NRL, CRX, VSX2, and PAX6) that are important for retinal development and expressed dynamically over the organoid developmental time course.
Project description:In order to provide multi-omic resolution to human retinal organoid developmental dynamics, we performed scRNA-seq and scATAC-seq from the same cell suspension across a time course (6-46 weeks) of human retinal organoid development. This data set covers all the retinal organoid scATAC-seq data generated from IMR90 and 409B2-iCas9 cell lines.
Project description:Retinal microvascularization can provide important informations to systemic vascular phenomena. The non-invasive quantitative description of the retinal vascularization is now possible by performing OCT-angiography and their image analysis software (vascular density and retinal perfusion). Systemic microvacular changes during the establishment of oncological treatment by targeted antiangiogenic therapy are little described in the literature. The objective of this pilot study is to describe the evolution of the retinal vascular density of patients with antiangiogenic drugs. In addition, the evolution of the retinal vascular density of patients on antiangiogenic drugs will study as a function of the response to the treatment and the toxicity of these treatments.
Project description:Purpose: The retinal pigment epithelium (RPE) forms the outer blood-retinal barrier. Primary cultures of RPE can model the barrier, but are very sensitive to culture conditions. We examined how the neural retina regulates the RPE transcriptome in a culture model of embryonic development. Attention focused on the tight junctional genes essential for barrier function. Methods: Chick RPE from embryonic day 7 (E7) or embryonic day 14 (E14) was cultured on filters in a serum free medium. Media conditioned by organ culture of neural retinas was applied to the apical surface of the cultured RPE. Fetal bovine serum (2%) was included in some experiments. When the transepithelial electrical resistance (TER) reached a plateau, total RNA was isolated to probe the chick genome on Affymetrix microarrays. The expression tight junctional mRNAs was confirmed by real-time PCR and immunoblotting the protein. Results: The TER was slightly increased by serum, but increased 2-3X by retinal conditioned medium. Serum diminished the effect of retinal conditioned medium. In basal conditions, 86% of the transcriptome expressed during development in vivo was also expressed in culture. Approximately 5% of the transcriptome expressed in culture was absent in vivo. E14 retinal conditioned medium affected 15% of the transcriptome in E7 cultures (24% if serum was included), but only 1.9% in E14 cultures (12% with serum). Examination of 610 genes important for RPE function revealed that mRNAs for 17% were regulated by retinal conditioned medium alone in E7 cultures, compared to 6.2% for E14. For tight junctions, retinal conditioned medium had the most affect on members of the claudin family. These results were confirmed by quantitative real-time PCR. Besides regulating mRNA levels, immunoblotting and immunocytochemistry suggested additional mechanisms whereby retinal secretions regulated protein expression and localization. Conclusions: Gene expression in primary cultures of embryonic RPE resembled the native tissue, but expression, and differentiation, is improved when elements of the normal extracellular environment are replicated in culture. For a small group of proteins, retinal secretions were required to maintain in vivo-like expression in culture. Albeit insufficient, retinal secretions promoted differentiation of immature RPE and helped maintain the properties of more mature RPE. Experiment Overall Design: RPE were isolated from chicken embryos on embryonic day 7 or 14 and cultured, as described <Rahner C, Fukuhara M, Peng S, Kojima S, Rizzolo LJ. The apical and basal environments of the retinal pigment epithelium regulate the maturation of tight junctions during development. J Cell Sci. 2004;117:3307-18>. E7 is when tight junctions of the RPE begin to form; E14 is when tight junctions achieve their mature morphological appearance in vivo. The cells were cultured in medium that contains or lacks E14 retinal conditioned medium. Because serum inhibits the effect of retinal conditioned medium, serum was added to some cultures, resulting in 4 culture conditions for each age. To isolate total RNA, the RNeasy Protect kit (Qiagen) was used according to the manufacturer's protocols. For each culture, 3 independent preparations were used for analysis on Affymetrix microarrays of the chicken genome (Santa Clara, CA). The quality of the total RNA was assessed by the Keck Center, Yale University using formamide gels and a 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA)