Optic cup morphogenesis is a complex process involving cellular behaviors such as epithelial folding, cell shape changes, proliferation, and tissue fusion. Disruptions to these processes can lead to an ocular coloboma, a congenital defect where the optic fissure fails to close. This study investigates the role of Shroom3, a protein implicated in epithelial morphogenesis, in mouse embryos during optic cup development. It was observed that Shroom3 is apically localized in the neural retina and retinal pigmented epithelium, and its deficiency leads to a both a conventional coloboma phenotype characterized by a gap in pigmented tissue as well as a unique type of coloboma where an ectopic ventral fold of neural tissue is present. Increased apical areas of both neural retina and retinal pigmented epithelial cells are present in the absence of Shroom3 leading to a greater apical surface area and disruption of optic fissure alignment. Neural retina specific gene ablation revealed that Shroom3 function in the RPE is likely sufficient to facilitate tissue alignment and permit fusion. However, the fusion process is ultimately disturbed due to a failure of the neural tissue to reestablish apical-basal polarity. Furthermore, it is demonstrated that Shroom3 deficiency also affects other epithelial fusion events in the embryo that rely on polarity reestablishment, such as lens vesicle separation, eyelid formation, and secondary palate closure. These findings highlight the importance of Shroom3 during optic cup morphogenesis, aid our understanding of optic fissure closure and coloboma formation, and implicates a role for Shroom3 in regulating apical-basal polarity.

• MeSH
• kolobom embryologie   genetika   MeSH
• morfogeneze MeSH
• myši MeSH
• polarita buněk * fyziologie   MeSH
• retina embryologie   metabolismus   MeSH
• retinální pigmentový epitel embryologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• mikrofilamentové proteiny MeSH
• Shrm protein, mouse MeSH Prohlížeč

PURPOSE: Interphotoreceptor retinoid-binding protein's (IRBP) role in eye growth and its involvement in cell homeostasis remain poorly understood. One hypothesis proposes early conditional deletion of the IRBP gene could lead to a myopic response with retinal degeneration, whereas late conditional deletion (after eye size is determined) could cause retinal degeneration without myopia. Here, we sought to understand if prior myopia was required for subsequent retinal degeneration in the absence of IRBP. This study investigates if any cell type or developmental stage is more important in myopia or retinal degeneration. METHODS: IBRPfl/fl mice were bred with 5 Cre-driver lines: HRGP-Cre, Chx10-Cre, Rho-iCre75, HRGP-Cre Rho-iCre75, and Rx-Cre. Mice were analyzed for IRBP gene expression through digital droplet PCR (ddPCR). Young adult (P30) mice were tested for retinal degeneration and morphology using spectral-domain optical coherence tomography (SD-OCT) and hematoxylin and eosin (H&E) staining. Function was analyzed using electroretinograms (ERGs). Eye sizes and axial lengths were compared through external eye measurements and whole eye biometry. RESULTS: Across all outcome measures, when bred to IRBPfl/fl, HRGP-Cre and Chx10-Cre lines showed no differences from IRBPfl/fl alone. With the Rho-iCre75 line, small but significant reductions were seen in retinal thickness with SD-OCT imaging and postmortem H&E staining without increased axial length. Both the HRGP-Cre+Rho-iCre75 and the Rx-Cre lines showed significant decreases in retinal thickness and outer nuclear layer cell counts. Using external eye measurements and SD-OCT imaging, both lines showed an increase in eye size. Finally, function in both lines was roughly halved across scotopic, photopic, and flicker ERGs. CONCLUSIONS: Our studies support hypotheses that for both eye size determination and retinal homeostasis, there are two critical timing windows when IRBP must be expressed in rods or cones to prevent myopia (P7-P12) and degeneration (P21 and later). The rod-specific IRBP knockout (Rho-iCre75) showed significant retinal functional losses without myopia, indicating that the two phenotypes are independent. IRBP is needed for early development of photoreceptors and eye size, whereas Rho-iCre75 IRBPfl/fl knockout results in retinal degeneration without myopia.

• MeSH
• degenerace retiny * genetika   metabolismus   patofyziologie   MeSH
• elektroretinografie * MeSH
• modely nemocí na zvířatech * MeSH
• myopie * genetika   metabolismus   patofyziologie   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované * MeSH
• myši MeSH
• oční proteiny * genetika   metabolismus   MeSH
• optická koherentní tomografie * MeSH
• proteiny vázající retinol * genetika   MeSH
• retina metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• interstitial retinol-binding protein MeSH Prohlížeč
• oční proteiny * MeSH
• proteiny vázající retinol * MeSH

Chromatin remodeling complexes are required for many distinct nuclear processes such as transcription, DNA replication, and DNA repair. However, the contribution of these complexes to the development of complex tissues within an organism is poorly characterized. Imitation switch (ISWI) proteins are among the most evolutionarily conserved ATP-dependent chromatin remodeling factors and are represented by yeast Isw1/Isw2, and their vertebrate counterparts Snf2h (Smarca5) and Snf2l (Smarca1). In this study, we focused on the role of the Snf2h gene during the development of the mammalian retina. We show that Snf2h is expressed in both retinal progenitors and post-mitotic retinal cells. Using Snf2h conditional knockout mice (Snf2h cKO), we found that when Snf2h is deleted, the laminar structure of the adult retina is not retained, the overall thickness of the retina is significantly reduced compared with controls, and the outer nuclear layer (ONL) is completely missing. The depletion of Snf2h did not influence the ability of retinal progenitors to generate all the differentiated retinal cell types. Instead, the Snf2h function is critical for the proliferation of retinal progenitor cells. Cells lacking Snf2h have a defective S-phase, leading to the entire cell division process impairments. Although all retinal cell types appear to be specified in the absence of the Snf2h function, cell-cycle defects and concomitantly increased apoptosis in Snf2h cKO result in abnormal retina lamination, complete destruction of the photoreceptor layer, and consequently, a physiologically non-functional retina.

• Klíčová slova
• Smarca5, Snf2h, apoptosis, cell cycle, photoreceptors, retina,
• MeSH
• adenosintrifosfatasy * metabolismus   MeSH
• buněčné jádro metabolismus   MeSH
• chromatin * metabolismus   MeSH
• chromozomální proteiny, nehistonové * metabolismus   MeSH
• myši knockoutované MeSH
• myši MeSH
• proliferace buněk MeSH
• restrukturace chromatinu * MeSH
• retina MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• adenosintrifosfatasy * MeSH
• chromatin * MeSH
• chromozomální proteiny, nehistonové * MeSH
• Smarca5 protein, mouse MeSH Prohlížeč

Iron accumulation has been implicated in degenerative retinal diseases. It can catalyze the production of damaging reactive oxygen species. Previous work has demonstrated iron accumulation in multiple retinal diseases, including age-related macular degeneration and diabetic retinopathy. In mice, systemic knockout of the ferroxidases ceruloplasmin (Cp) and hephaestin (Heph), which oxidize iron, results in retinal iron accumulation and iron-induced degeneration. To determine the role of Heph in the retina, we generated a neural retina-specific Heph knockout on a background of systemic Cp knockout. This resulted in elevated neural retina iron. Conversely, retinal ganglion cells had elevated transferrin receptor and decreased ferritin, suggesting diminished iron levels. The retinal degeneration observed in systemic Cp-/-, Heph-/- mice did not occur. These findings indicate that Heph has a local role in regulating neural retina iron homeostasis, but also suggest that preserved Heph function in either the RPE or systemically mitigates the degeneration phenotype observed in the systemic Cp-/-, Heph-/- mice.

• Klíčová slova
• Age-related macular degeneration, Ceruloplasmin, Ferrous, Hephaestin, Iron, Retina,
• MeSH
• ceruloplasmin genetika   metabolismus   MeSH
• homeostáza MeSH
• makulární degenerace * genetika   MeSH
• membránové proteiny * genetika   MeSH
• myši knockoutované MeSH
• myši MeSH
• retina metabolismus   MeSH
• železo metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• ceruloplasmin MeSH
• membránové proteiny * MeSH
• železo MeSH

Iron-induced oxidative stress can cause or exacerbate retinal degenerative diseases. Retinal iron overload has been reported in several mouse disease models with systemic or neural retina-specific knockout (KO) of homologous ferroxidases ceruloplasmin (Cp) and hephaestin (Heph). Cp and Heph can potentiate ferroportin (Fpn) mediated cellular iron export. Here, we used retina-specific Fpn KO mice to test the hypothesis that retinal iron overload in Cp/Heph DKO mice is caused by impaired iron export from neurons and glia. Surprisingly, there was no indication of retinal iron overload in retina-specific Fpn KO mice: the mRNA levels of transferrin receptor in the retina were not altered at 7-10-months age. Consistent with this, levels and localization of ferritin light chain were unchanged. To "stress the system", we injected iron intraperitoneally into Fpn KO mice with or without Cp KO. Only mice with both retina-specific Fpn KO and Cp KO had modestly elevated retinal iron levels. These results suggest that impaired iron export through Fpn is not sufficient to explain the retinal iron overload in Cp/Heph DKO mice. An increase in the levels of retinal ferrous iron caused by the absence of these ferroxidases, followed by uptake into cells by ferrous iron importers, is most likely necessary.

• Klíčová slova
• Age-related macular degeneration, Ceruloplasmin, Ferroportin, Ferrous, Iron, Retina,
• MeSH
• ceruloplasmin genetika   metabolismus   MeSH
• ferroportin MeSH
• myši knockoutované MeSH
• myši MeSH
• přetížení železem * MeSH
• proteiny přenášející kationty * genetika   MeSH
• retina metabolismus   MeSH
• železo metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• ceruloplasmin MeSH
• ferroportin MeSH
• proteiny přenášející kationty * MeSH
• železo MeSH

Retinal progenitor cells (RPCs) divide in limited numbers to generate the cells comprising vertebrate retina. The molecular mechanism that leads RPC to the division limit, however, remains elusive. Here, we find that the hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) in an RPC subset by deletion of tuberous sclerosis complex 1 (Tsc1) makes the RPCs arrive at the division limit precociously and produce Müller glia (MG) that degenerate from senescence-associated cell death. We further show the hyperproliferation of Tsc1-deficient RPCs and the degeneration of MG in the mouse retina disappear by concomitant deletion of hypoxia-induced factor 1-alpha (Hif1a), which induces glycolytic gene expression to support mTORC1-induced RPC proliferation. Collectively, our results suggest that, by having mTORC1 constitutively active, an RPC divides and exhausts mitotic capacity faster than neighboring RPCs, and thus produces retinal cells that degenerate with aging-related changes.

• Klíčová slova
• mTORC1, Hif1a, clonal expansion, developmental biology, glycolysis, hypoxia-induced factor 1-alpha, mechanistic target of rapamycin complex 1, mitotic division limit, mouse, retinal progenitor cell,
• MeSH
• ependymální buňky patologie   MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa genetika   metabolismus   MeSH
• hamartin genetika   metabolismus   MeSH
• kmenové buňky patologie   MeSH
• mitóza MeSH
• mTORC1 genetika   metabolismus   MeSH
• myši MeSH
• retina patologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• faktor 1 indukovatelný hypoxií - podjednotka alfa MeSH
• hamartin MeSH
• Hif1a protein, mouse MeSH Prohlížeč
• mTORC1 MeSH
• Tsc1 protein, mouse MeSH Prohlížeč

Members of the POU4F/Brn3 transcription factor family have an established role in the development of retinal ganglion cell (RGCs) types, the main transducers of visual information from the mammalian eye to the brain. Our previous work using sparse random recombination of a conditional knock-in reporter allele expressing alkaline phosphatase (AP) and intersectional genetics had identified three types of Brn3c positive (Brn3c+ ) RGCs. Here, we describe a novel Brn3cCre mouse allele generated by serial Dre to Cre recombination and use it to explore the expression overlap of Brn3c with Brn3a and Brn3b and the dendritic arbor morphologies and visual stimulus response properties of Brn3c+ RGC types. Furthermore, we explore brain nuclei that express Brn3c or receive input from Brn3c+ neurons. Our analysis reveals a much larger number of Brn3c+ RGCs and more diverse set of RGC types than previously reported. Most RGCs expressing Brn3c during development are still Brn3c positive in the adult, and all express Brn3a while only about half express Brn3b. Genetic Brn3c-Brn3b intersection reveals an area of increased RGC density, extending from dorsotemporal to ventrolateral across the retina and overlapping with the mouse binocular field of view. In addition, we report a Brn3c+ RGC projection to the thalamic reticular nucleus, a visual nucleus that was not previously shown to receive retinal input. Furthermore, Brn3c+ neurons highlight a previously unknown subdivision of the deep mesencephalic nucleus. Thus, our newly generated allele provides novel biological insights into RGC type classification, brain connectivity, and cytoarchitectonic.

• Klíčová slova
• Brn3c, Cre recombinase, Pou4f3, deep mesencephalic nucleus, periaqueductal gray, retinal ganglion cells, superior colliculus, thalamic reticular nucleus, transcription factor,
• MeSH
• alely MeSH
• genový knockin metody   MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• integrasy MeSH
• mozek cytologie   metabolismus   MeSH
• myši MeSH
• retinální gangliové buňky cytologie   metabolismus   MeSH
• transkripční faktor Brn-3C genetika   metabolismus   MeSH
• zrakové dráhy cytologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• Cre recombinase MeSH Prohlížeč
• homeodoménové proteiny MeSH
• integrasy MeSH
• Pou4f3 protein, mouse MeSH Prohlížeč
• transkripční faktor Brn-3C MeSH

The vertebrate eye is derived from the neuroepithelium, surface ectoderm, and extracellular mesenchyme. The neuroepithelium forms an optic cup in which the spatial separation of three domains is established, namely, the region of multipotent retinal progenitor cells (RPCs), the ciliary margin zone (CMZ)-which possesses both a neurogenic and nonneurogenic potential-and the optic disk (OD), the interface between the optic stalk and the neuroretina. Here, we show by genetic ablation in the developing optic cup that Meis1 and Meis2 homeobox genes function redundantly to maintain the retinal progenitor pool while they simultaneously suppress the expression of genes characteristic of CMZ and OD fates. Furthermore, we demonstrate that Meis transcription factors bind regulatory regions of RPC-, CMZ-, and OD-specific genes, thus providing a mechanistic insight into the Meis-dependent gene regulatory network. Our work uncovers the essential role of Meis1 and Meis2 as regulators of cell fate competence, which organize spatial territories in the vertebrate eye.

• Klíčová slova
• Meis, development, retina,
• MeSH
• buněčná diferenciace genetika   MeSH
• genový knockdown MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• kmenové buňky cytologie   metabolismus   MeSH
• obratlovci MeSH
• retina cytologie   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• homeodoménové proteiny MeSH
• transkripční faktory MeSH

Genome duplication leads to an emergence of gene paralogs that are essentially free to undergo the process of neofunctionalization, subfunctionalization or degeneration (gene loss). Onecut1 (Oc1) and Onecut2 (Oc2) transcription factors, encoded by paralogous genes in mammals, are expressed in precursors of horizontal cells (HCs), retinal ganglion cells and cone photoreceptors. Previous studies have shown that ablation of either Oc1 or Oc2 gene in the mouse retina results in a decreased number of HCs, while simultaneous deletion of Oc1 and Oc2 leads to a complete loss of HCs. Here we study the genetic redundancy between Oc1 and Oc2 paralogs and focus on how the dose of Onecut transcription factors influences abundance of individual retinal cell types and overall retina physiology. Our data show that reducing the number of functional Oc alleles in the developing retina leads to a gradual decrease in the number of HCs, progressive thinning of the outer plexiform layer and diminished electrophysiology responses. Taken together, these observations indicate that in the context of HC population, the alleles of Oc1/Oc2 paralogous genes are mutually interchangeable, function additively to support proper retinal function and their molecular evolution does not follow one of the typical routes after gene duplication.

• MeSH
• alely MeSH
• amakrinní buňky metabolismus   patologie   MeSH
• bipolární buňky sítnice metabolismus   patologie   MeSH
• čípky retiny metabolismus   patologie   MeSH
• ependymální buňky metabolismus   patologie   MeSH
• genetické lokusy MeSH
• genotyp MeSH
• hepatocytární jaderný faktor 6 genetika   metabolismus   MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• myši transgenní MeSH
• myši MeSH
• oči růst a vývoj   patologie   MeSH
• retina cytologie   patologie   fyziologie   MeSH
• retinální gangliové buňky cytologie   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hepatocytární jaderný faktor 6 MeSH
• homeodoménové proteiny MeSH
• Onecut1 protein, mouse MeSH Prohlížeč
• ONECUT2 protein, mouse MeSH Prohlížeč
• transkripční faktory MeSH

The liver secretes hepcidin (Hepc) into the bloodstream to reduce blood iron levels. Hepc accomplishes this by triggering degradation of the only known cellular iron exporter ferroportin in the gut, macrophages, and liver. We previously demonstrated that systemic Hepc knockout (HepcKO) mice, which have high serum iron, develop retinal iron overload and degeneration. However, it was unclear whether this is caused by high blood iron levels or, alternatively, retinal iron influx that would normally be regulated by retina-produced Hepc. To address this question, retinas of liver-specific and retina-specific HepcKO mice were studied. Liver-specific HepcKO mice had elevated blood and retinal pigment epithelium (RPE) iron levels and increased free (labile) iron levels in the retina, despite an intact blood-retinal barrier. This led to RPE hypertrophy associated with lipofuscin-laden lysosome accumulation. Photoreceptors also degenerated focally. In contrast, there was no change in retinal or RPE iron levels or degeneration in the retina-specific HepcKO mice. These data indicate that high blood iron levels can lead to retinal iron accumulation and degeneration. High blood iron levels can occur in patients with hereditary hemochromatosis or result from use of iron supplements or multiple blood transfusions. Our results suggest that high blood iron levels may cause or exacerbate retinal disease.

• MeSH
• degenerace retiny etiologie   metabolismus   patologie   MeSH
• hematoretinální bariéra MeSH
• hepcidiny fyziologie   MeSH
• játra metabolismus   patologie   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• přetížení železem etiologie   metabolismus   patologie   MeSH
• retina metabolismus   patologie   MeSH
• železo metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• Hamp protein, mouse MeSH Prohlížeč
• hepcidiny MeSH
• železo MeSH