Project description:A robust set of CNS transcript changes was defined by comparing microarray data that describe the injury response of the rat retina [Vazquez-Chona et al., IOVS 2004; GSE1001], brain [Matzilevich et al., J Neurosci Res 2002; GSE1911], and spinal cord [Di Giovanni et al., Ann Neurol 2003; GDS63]. We determined the CNS injury genes that were expressed in cultured astrocytes from rat cortex [GSM34300] and from human optic nerve head [Yang et al., Physiol Genomics 2004; GDS532]. Keywords: other
Project description:Recent developments in animal models (Morris et al., 2004; Tumbar et al., 2004) as well as the discovery of cell surface markers (Jones and Watt, 1993; Tani et al., 2000; Trempus et al., 2003; Nijhof et al., 2006) have made it possible to isolate living epidermal hair follicle stem cells (HFSCs) from mouse skin, facilitating the study of the biological and molecular features inherent to HFSCs. A complexity of stem and progenitor cell populations within the hair follicle has been revealed. Here, we report comprehensive profiling of mouse CD34-expressing HFSCs using the Agilent mouse oligo microarray platform in order to extend and enrich the existing HFSC databases. Keywords: gene expression, cell characterization
Project description:Leber congenital amaurosis (LCA) includes congenital or early-onset blinding diseases, characterized by vision loss together with nystagmus and nonrecordable electroretinogram (ERG). At least 19 genes are associated with LCA. While most LCA is recessive, mutations in the homeodomain transcription factor gene CRX lead to autosomal dominant LCA. The mechanism of CRX-LCA is not understood. Here, we report a new spontaneous mouse mutant carrying a frameshift mutation in Crx (CrxRip). We show that, unlike Crx-/- mouse retina, the dominant Crx c.763del1 mutation in CrxRip results in congenital blindness with complete loss of ERG, yet the photoreceptors do not degenerate. Dominant CRX frameshift mutations associated with LCA mimic the CrxRip phenotype that can be rescued by Crx. RNA-Seq profiling reveals progressive and complete loss of rod differentiation factor Nrl in CrxRip, while residual Nrl remains in Crx-/- retina. Moreover, Nrl partially restores the rod phenotype in CrxRip/+ mice. We show that the binding of Otx2 to Nrl promoter is obliterated in CrxRip mutant, and ectopic Otx2 can rescue the rod phenotype. Therefore, Otx2 is required to maintain Nrl expression in developing rods to consolidate rod fate. Our studies provide the mechanism of congenital blindness caused by dominant CRX mutations and should assist in therapeutic design. Retinal samples were harvested from WT, CrxRip/+, CrxRip/Rip, Crx-/- and Nrl-/- retina at postnatal days 2 and 21 for whole transcriptome sequencing (RNAseq). Each sample included 2 independent frozen retina and experiments were performed in duplicates. RNA-seq transcriptome libraries were constructed from 1 ?g of total RNA.
Project description:The basic motif-leucine zipper (bZIP) transcription factor NRL determines rod photoreceptor cell fate during retinal development, and its loss leads to cone-only retina in mice. NRL works synergistically with homeodomain protein Cone-Rod Homeobox and other regulatory factors to control the transcription of most genes associated with rod morphogenesis and functional maturation, which span over a period of several weeks in the mammalian retina. We predicted that NRL gradually establishes rod cell identity and function by temporal and dynamic regulation of stage-specific transcriptional targets. Therefore, we mapped the genomic occupancy of NRL at four stages of mouse photoreceptor differentiation by CUT&RUN analysis. Dynamics of NRL binding revealed concordance with the corresponding changes in transcriptome of the developing rods. Notably, we identified c-Jun proto-oncogene as one of the targets of NRL, which could bind to specific cis-elements in the c-Jun promoter and modulate its activity in HEK293 cells. Coimmunoprecipitation studies showed the association of NRL with c-Jun, also a bZIP protein, in transfected cells as well as in developing mouse retina. Additionally, shRNA-mediated knockdown of c-Jun in the mouse retina in vivo resulted in altered expression of almost 1000 genes, with reduced expression of phototransduction genes and many direct targets of NRL in rod photoreceptors. We propose that c-Jun-NRL heterodimers prime the NRL-directed transcriptional program in neonatal rod photoreceptors before high NRL expression suppresses c-Jun at later stages. Our study highlights a broader cooperation among cell-type restricted and widely expressed bZIP proteins, such as c-Jun, in specific spatiotemporal contexts during cellular differentiation.
Project description:The basic motif-leucine zipper (bZIP) transcription factor NRL determines rod photoreceptor cell fate during retinal development, and its loss leads to cone-only retina in mice. NRL works synergistically with homeodomain protein Cone-Rod Homeobox and other regulatory factors to control the transcription of most genes associated with rod morphogenesis and functional maturation, which span over a period of several weeks in the mammalian retina. We predicted that NRL gradually establishes rod cell identity and function by temporal and dynamic regulation of stage-specific transcriptional targets. Therefore, we mapped the genomic occupancy of NRL at four stages of mouse photoreceptor differentiation by CUT&RUN analysis. Dynamics of NRL binding revealed concordance with the corresponding changes in transcriptome of the developing rods. Notably, we identified c-Jun proto-oncogene as one of the targets of NRL, which could bind to specific cis-elements in the c-Jun promoter and modulate its activity in HEK293 cells. Coimmunoprecipitation studies showed the association of NRL with c-Jun, also a bZIP protein, in transfected cells as well as in developing mouse retina. Additionally, shRNA-mediated knockdown of c-Jun in the mouse retina in vivo resulted in altered expression of almost 1000 genes, with reduced expression of phototransduction genes and many direct targets of NRL in rod photoreceptors. We propose that c-Jun-NRL heterodimers prime the NRL-directed transcriptional program in neonatal rod photoreceptors before high NRL expression suppresses c-Jun at later stages. Our study highlights a broader cooperation among cell-type restricted and widely expressed bZIP proteins, such as c-Jun, in specific spatiotemporal contexts during cellular differentiation.
Project description:Nrl acts as a molecular toggle switch during retinal development: if a photoreceptor precursor turns on Nrl, it differentiates as a rod, otherwise it differentiates as a cone. In contrast, acute Nrl knockout transforms mature rods into cells with features intermediate between those of normal rods and cones (‘cods’). We used microarray to comprehensively evaluate the transcriptomic changes that occur upon acute knockout of Nrl in mouse retina.
Project description:The rod photoreceptor-specific neural retina leucine zipper protein Nrl is essential for rod differentiation and plays a critical role in regulating gene expression. In the mouse retina, rods account for 97% of the photoreceptors; however, in the absence of Nrl (Nrl-/-), no rods are present and a concomitant increase in cones is observed. Using mouse GeneChips (Affymetrix), we have generated expression profiles of the wild-type and Nrl-/- retina at three time-points representing distinct stages of photoreceptor differentiation. Experiment Overall Design: Both the Nrl-/- mice and wild type controls were of a matched mixed genetic background (R1 and C57BL/6 strains).
Project description:We performed mRNA transcriptional profiling of mouse retina in the wild-type and Nrl-null context to determine Nrl-dependent gene expression We sequenced cDNA libraries made from polyA+ selected RNA from retinas of litter-matched WT and Nrl-/- adult mice at postnatal day 21 (P21) (WT vs Nrl-/-, n=5 and n= 6 resp.)
Project description:We performed non-coding transcriptional profiling to identify Nrl-dependent ncRNAs by deep sequencing non-polyadenylated RNA from the same control and Nrl-/- retinal samples. non-coding RNA profiling is a robust method for the identification of cell-type specific functional enhancer elements in the mouse retina