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Nicolini G, Casini G, Posarelli C, Amato R, Lulli M, Balzan S, Forini F. Thyroid Hormone Signaling in Retinal Development and Function: Implications for Diabetic Retinopathy and Age-Related Macular Degeneration. Int J Mol Sci 2024; 25:7364. [PMID: 39000471 PMCID: PMC11242054 DOI: 10.3390/ijms25137364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 06/27/2024] [Accepted: 07/02/2024] [Indexed: 07/16/2024] Open
Abstract
Thyroid Hormones (THs) play a central role in the development, cell growth, differentiation, and metabolic homeostasis of neurosensory systems, including the retina. The coordinated activity of various components of TH signaling, such as TH receptors (THRs) and the TH processing enzymes deiodinases 2 and 3 (DIO2, DIO3), is required for proper retinal maturation and function of the adult photoreceptors, Müller glial cells, and pigmented epithelial cells. Alterations of TH homeostasis, as observed both in frank or subclinical thyroid disorders, have been associated with sight-threatening diseases leading to irreversible vision loss i.e., diabetic retinopathy (DR), and age-related macular degeneration (AMD). Although observational studies do not allow causal inference, emerging data from preclinical models suggest a possible correlation between TH signaling imbalance and the development of retina disease. In this review, we analyze the most important features of TH signaling relevant to retinal development and function and its possible implication in DR and AMD etiology. A better understanding of TH pathways in these pathological settings might help identify novel targets and therapeutic strategies for the prevention and management of retinal disease.
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Affiliation(s)
| | - Giovanni Casini
- Department of Biology, University of Pisa, 56127 Pisa, Italy
| | - Chiara Posarelli
- Ophthalmology, Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, 56126 Pisa, Italy
| | - Rosario Amato
- Department of Biology, University of Pisa, 56127 Pisa, Italy
| | - Matteo Lulli
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy
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Forini F, Nicolini G, Amato R, Balzan S, Saba A, Bertolini A, Andreucci E, Marracci S, Melecchi A, Terlizzi D, Zucchi R, Iervasi G, Lulli M, Casini G. Local modulation of thyroid hormone signaling in the retina affects the development of diabetic retinopathy. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166892. [PMID: 37758065 DOI: 10.1016/j.bbadis.2023.166892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/05/2023] [Accepted: 09/19/2023] [Indexed: 10/01/2023]
Abstract
Thyroid hormone (TH) dyshomeostasis is associated with poor prognosis in acute and prolonged illness, but its role in diabetic retinopathy (DR) has never been investigated. Here, we characterized the TH system in the retinas of db/db mice and highlighted regulatory processes in MIO-M1 cells. In the db/db retinas, typical functional traits and molecular signatures of DR were paralleled by a tissue-restricted reduction of TH levels. A local condition of low T3 (LT3S) was also demonstrated, which was likely to be induced by deiodinase 3 (DIO3) upregulation, and by decreased expression of DIO2 and of TH receptors. Concurrently, T3-responsive genes, including mitochondrial markers and microRNAs (miR-133-3p, 338-3p and 29c-3p), were downregulated. In MIO-M1 cells, a feedback regulatory circuit was evidenced whereby miR-133-3p triggered the post-transcriptional repression of DIO3 in a T3-dependent manner, while high glucose (HG) led to DIO3 upregulation through a nuclear factor erythroid 2-related factor 2-hypoxia-inducible factor-1 pathway. Finally, an in vitro simulated condition of early LT3S and hyperglycemia correlated with reduced markers of both mitochondrial function and stress response, which was reverted by T3 replacement. Together, the data suggest that, in the early phases of DR, a DIO3-driven LT3S may be protective against retinal stress, while, in the chronic phase, it not only fails to limit HG-induced damage, but also increases cell vulnerability likely due to persistent mitochondrial dysfunction.
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Affiliation(s)
- Francesca Forini
- Institute of Clinical Physiology, National Research Council, Pisa, Italy.
| | | | - Rosario Amato
- Department of Biology, University of Pisa, Pisa, Italy.
| | - Silvana Balzan
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Alessandro Saba
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy; Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy; Center for Instrument Sharing (CISUP), University of Pisa, Pisa, Italy.
| | - Andrea Bertolini
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy.
| | - Elena Andreucci
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy.
| | | | | | - Domiziana Terlizzi
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Riccardo Zucchi
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy.
| | - Giorgio Iervasi
- Department of Biomedical Sciences, National Research Council, Rome, Italy.
| | - Matteo Lulli
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy.
| | - Giovanni Casini
- Department of Biology, University of Pisa, Pisa, Italy; Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy; Center for Instrument Sharing (CISUP), University of Pisa, Pisa, Italy.
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3
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Ludwig J, Sawant OB, Wood J, Singamsetty S, Pan X, Bonilha VL, Rao S, Pshezhetsky AV. Histological characterization of retinal degeneration in mucopolysaccharidosis type IIIC. Exp Eye Res 2023; 229:109433. [PMID: 36858249 PMCID: PMC10103010 DOI: 10.1016/j.exer.2023.109433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/14/2023] [Accepted: 02/25/2023] [Indexed: 03/03/2023]
Abstract
Heparan-α-glucosaminide N-acetyltransferase (HGSNAT) participates in lysosomal degradation of heparan sulfate. Mutations in the gene encoding this enzyme cause mucopolysaccharidosis IIIC (MPS IIIC) or Sanfilippo syndrome type C. MPS IIIC patients exhibit progressive neurodegeneration, leading to dementia and death in early adulthood. Currently there is no approved treatment for MPS IIIC. Incidences of non-syndromic retinitis pigmentosa and early signs of night blindness are reported in some MPS IIIC patients, however the majority of ocular phenotypes are not well characterized. The goal of this study was to investigate retinal degeneration phenotype in the Hgsnat knockout mouse model of MPS IIIC and a cadaveric human MPS IIIC eye. Cone and rod photoreceptors in the eyes of homozygous 6-month-old Hgsnat knockout mice and their wild-type counterparts were analyzed using cone arrestin, S-opsin, M-opsin and rhodopsin antibodies. Histological observation was performed on the eye from a 35-year-old MPS IIIC donor. We observed a nearly 50% reduction in the rod photoreceptors density in the Hgsnat knockout mice compared to the littermate wild-type controls. Cone photoreceptor density was unaltered at this age. Severe retinal degeneration was also observed in the MPS IIIC donor eye. To our knowledge, this is the first report characterizing ocular phenotypes arising from deleterious variants in the Hgsnat gene associated with MPS IIIC clinical phenotype. Our findings indicate retinal manifestations may be present even before behavioral manifestations. Thus, we speculate that ophthalmological evaluations could be used as diagnostic indicators of early disease, progression, and end-point evaluation for future MPS IIIC therapies.
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Affiliation(s)
- Jessica Ludwig
- Center for Vision and Eye Banking Research, Eversight, Cleveland, OH, 44103, USA
| | - Onkar B Sawant
- Center for Vision and Eye Banking Research, Eversight, Cleveland, OH, 44103, USA.
| | | | | | - Xuefang Pan
- Sainte-Justine University Hospital Research Center, University of Montreal, Montreal, Quebec, Canada
| | - Vera L Bonilha
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Sujata Rao
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Alexey V Pshezhetsky
- Sainte-Justine University Hospital Research Center, University of Montreal, Montreal, Quebec, Canada; Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
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4
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Liu Q, Wang Z, Cao J, Dong Y, Chen Y. Insulin ameliorates dim blue light at night-induced apoptosis in hippocampal neurons via the IR/IRS1/AKT/GSK3β/β-catenin signaling pathway. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 250:114488. [PMID: 36586168 DOI: 10.1016/j.ecoenv.2022.114488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/24/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
In recent years, the damaging effects of night light pollution, one of the environmental pollutions, on memory has been attracting attention. However, the underlying molecular mechanisms by which light at night, especially blue light at night, impairs memory remains unclear. Here, a total of 42 C57BL6/J mice that exposed to no light at night, dim white light at night (dLAN-WL), or dim blue light at night (dLAN-BL) for 28 days. Behavioral data indicated that exposure to dLAN-BL resulted in severe recognition memory impairment, as evidenced by the reduced recognition index and discrimination index in the novel object recognition test. At the same time, we observed a decrease in plasma insulin levels. Consistent with these changes, we also observed that dLAN-BL reduced the number of neurons in the CA1, CA3 and DG regions of the hippocampus, up-regulated the mRNA expression levels of Bax, down-regulated the mRNA expression levels of Bcl-2, Bcl-xl and the protein expression level of pIRS1, pAKT, pGSK3β, β-catenin in the hippocampus. In vitro experiments, we found that insulin (10 nM) inhibited apoptosis and up-regulated the protein expression levels of pAKT, pGSK3β, β-catenin of HT22 cells induced by H2O2 (200 μM). However, these changes disappeared when the insulin receptors (IR) in HT22 cells were silenced. Taken together, our findings suggested that the impairment of memory in mice induced by dLAN-BL was mediated by insulin via the IR/IRS1/AKT/GSK3β/β-catenin pathway. DATA AVAILABILITY: All data generated or analyzed during this study are included in this published article.
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Affiliation(s)
- Qi Liu
- College of Veterinary Medicine, China Agricultural University, Haidian, Beijing 100193, China
| | - Zixu Wang
- College of Veterinary Medicine, China Agricultural University, Haidian, Beijing 100193, China
| | - Jing Cao
- College of Veterinary Medicine, China Agricultural University, Haidian, Beijing 100193, China
| | - Yulan Dong
- College of Veterinary Medicine, China Agricultural University, Haidian, Beijing 100193, China
| | - Yaoxing Chen
- College of Veterinary Medicine, China Agricultural University, Haidian, Beijing 100193, China; Department of Nutrition and Health, China Agricultural University, Haidian, Beijing 100193, China.
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Jidigam VK, Sawant OB, Fuller RD, Wilcots K, Singh R, Lang RA, Rao S. Neuronal Bmal1 regulates retinal angiogenesis and neovascularization in mice. Commun Biol 2022; 5:792. [PMID: 35933488 PMCID: PMC9357084 DOI: 10.1038/s42003-022-03774-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/26/2022] [Indexed: 11/20/2022] Open
Abstract
Circadian clocks in the mammalian retina regulate a diverse range of retinal functions that allow the retina to adapt to the light-dark cycle. Emerging evidence suggests a link between the circadian clock and retinopathies though the causality has not been established. Here we report that clock genes are expressed in the mouse embryonic retina, and the embryonic retina requires light cues to maintain robust circadian expression of the core clock gene, Bmal1. Deletion of Bmal1 and Per2 from the retinal neurons results in retinal angiogenic defects similar to when animals are maintained under constant light conditions. Using two different models to assess pathological neovascularization, we show that neuronal Bmal1 deletion reduces neovascularization with reduced vascular leakage, suggesting that a dysregulated circadian clock primarily drives neovascularization. Chromatin immunoprecipitation sequencing analysis suggests that semaphorin signaling is the dominant pathway regulated by Bmal1. Our data indicate that therapeutic silencing of the retinal clock could be a common approach for the treatment of certain retinopathies like diabetic retinopathy and retinopathy of prematurity.
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Affiliation(s)
- Vijay K Jidigam
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Onkar B Sawant
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
- Eversight, Cleveland, OH, 44103, USA
| | - Rebecca D Fuller
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Kenya Wilcots
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
- Department of Chemistry, Cleveland State University, Cleveland, OH, 44115, USA
| | - Rupesh Singh
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Richard A Lang
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, USA
- Department of Ophthalmology, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Sujata Rao
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, 44195, USA.
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Isla-Magrané H, Zufiaurre-Seijo M, García-Arumí J, Duarri A. All-trans retinoic acid modulates pigmentation, neuroretinal maturation, and corneal transparency in human multiocular organoids. Stem Cell Res Ther 2022; 13:376. [PMID: 35902874 PMCID: PMC9330659 DOI: 10.1186/s13287-022-03053-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 07/18/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND All-trans retinoic acid (ATRA) plays an essential role during human eye development, being temporally and spatially adjusted to create gradient concentrations that guide embryonic anterior and posterior axis formation of the eye. Perturbations in ATRA signaling can result in severe ocular developmental diseases. Although it is known that ATRA is essential for correct eye formation, how ATRA influences the different ocular tissues during the embryonic development of the human eye is still not well studied. Here, we investigated the effects of ATRA on the differentiation and the maturation of human ocular tissues using an in vitro model of human-induced pluripotent stem cells-derived multiocular organoids. METHODS Multiocular organoids, consisting of the retina, retinal pigment epithelium (RPE), and cornea, were cultured in a medium containing low (500 nM) or high (10 µM) ATRA concentrations for 60 or 90 days. Furthermore, retinal organoids were cultured with taurine and T3 to further study photoreceptor modulation during maturation. Histology, immunochemistry, qPCR, and western blot were used to study gene and protein differential expression between groups. RESULTS High ATRA levels promote the transparency of corneal organoids and the neuroretinal development in retinal organoids. However, the same high ATRA levels decreased the pigmentation levels of RPE organoids and, in long-term cultures, inhibited the maturation of photoreceptors. By contrast, low ATRA levels enhanced the pigmentation of RPE organoids, induced the opacity of corneal organoids-due to an increase in collagen type IV in the stroma- and allowed the maturation of photoreceptors in retinal organoids. Moreover, T3 promoted rod photoreceptor maturation, whereas taurine promoted red/green cone photoreceptors. CONCLUSION ATRA can modulate corneal epithelial integrity and transparency, photoreceptor development and maturation, and the pigmentation of RPE cells in a dose-dependent manner. These experiments revealed the high relevance of ATRA during ocular tissue development and its use as a potential new strategy to better modulate the development and maturation of ocular tissue through temporal and spatial control of ATRA signaling.
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Affiliation(s)
- Helena Isla-Magrané
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119-129, 08035, Barcelona, Spain
| | - Maddalen Zufiaurre-Seijo
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119-129, 08035, Barcelona, Spain
| | - José García-Arumí
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119-129, 08035, Barcelona, Spain.,Department of Ophthalmology, Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain.,Department of Surgery, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Anna Duarri
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119-129, 08035, Barcelona, Spain.
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7
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Bery A, Bagchi U, Bergen AA, Felder-Schmittbuhl MP. Circadian clocks, retinogenesis and ocular health in vertebrates: new molecular insights. Dev Biol 2022; 484:40-56. [DOI: 10.1016/j.ydbio.2022.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/21/2022] [Accepted: 02/01/2022] [Indexed: 12/22/2022]
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El-Eshmawy MM, Shahin M. Thyroid and Eye: Where They Meet in Clinical Practice. Endocr Metab Immune Disord Drug Targets 2020; 20:39-49. [PMID: 31237221 DOI: 10.2174/1871530319666190618120107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/25/2019] [Accepted: 05/03/2019] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Thyroid Hormones (TH) are essential for normal growth, development and continued optimal function of most of the body organs including the eye. TH signaling plays a central role in the regulation of retinal development and maturation. Deficiency in TH during fetal and early postnatal development impairs growth of the eye and proliferation of all retinal cell types. The present article reviews the most important topics of the different derangements in thyroid function and structure and its relation with eye diseases. METHODS A literature search strategy was conducted for all English-language literature. RESULTS From a clinical practice viewpoint, it should be mentioned that both hypothyroidism and hyperthyroidism are accompanied by ocular diseases i.e. thyroid-associated ophthalmopathy, diabetic retinopathy and age-related macular degeneration. Although the orbit and globe are not common sites for metastatic thyroid cancers, orbital metastasis may be the primary clinical manifestation of thyroid carcinoma. Finally, some medications as amiodarone may be accompanied by both thyroid dysfunction and adverse ocular events. CONCLUSION Thyroid disorders and eye diseases are interrelated through several mechanisms thus, awareness of this relation has a great impact on early diagnosis and treatment.
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Affiliation(s)
- Mervat M El-Eshmawy
- Internal Medicine Department, Mansoura Specialized Medical Hospital, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Maha Shahin
- Ophthalmology Department, Mansoura Ophthalmic Center, Faculty of Medicine, Mansoura University, Mansoura, Egypt
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Sawant OB, Jidigam VK, Wilcots K, Fuller RD, Samuels I, Rao S. Thyroid Activating Enzyme, Deiodinase II Is Required for Photoreceptor Function in the Mouse Model of Retinopathy of Prematurity. Invest Ophthalmol Vis Sci 2020; 61:36. [PMID: 33237298 PMCID: PMC7691789 DOI: 10.1167/iovs.61.13.36] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 10/30/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Retinopathy of prematurity (ROP) is a severe complication of premature infants, leading to vision loss when untreated. Presently, the molecular mechanisms underlying ROP are still far from being clearly understood. This study sought to investigate whether thyroid hormone (TH) signaling contributes to the neuropathology of ROP using the mouse model of ROP to evaluate longitudinal photoreceptor function. Methods Animals were exposed to hyperoxia from P7 to P12 to induce retinopathy, thereafter the animals were returned to room air (normoxia). The thyroid-activating enzyme type 2 deiodinases (Dio2) knockout (KO) mice and the littermate controls that were exposed to hyperoxia or maintained in room air and were then analyzed. The retinal function was evaluated using electroretinograms (ERGs) at three and seven weeks followed by histologic assessments with neuronal markers to detect cellular changes in the retina. Rhodopsin protein levels were measured to validate the results obtained from the immunofluorescence analyses. Results In the ROP group, the photoreceptor ERG responses are considerably lower both in the control and the Dio2 KO animals at P23 compared to the non-ROP group. In agreement with the ERG responses, loss of Dio2 results in mislocalized cone nuclei, and abnormal rod bipolar cell dendrites extending into the outer nuclear layer. The retinal function is compromised in the adult Dio2 KO animals, although the cellular changes are less severe. Despite the reduction in scotopic a-wave amplitudes, rhodopsin levels are similar in the adult mice, across all genotypes irrespective of exposure to hyperoxia. Conclusions Using the mouse model of ROP, we show that loss of Dio2 exacerbates the effects of hyperoxia-induced retinal deficits that persist in the adults. Our data suggest that aberrant Dio2/TH signaling is an important factor in the pathophysiology of the visual dysfunction observed in the oxygen-induced retinopathy model of ROP.
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Affiliation(s)
- Onkar B. Sawant
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
- Eversight, Cleveland, Ohio, United States
| | - Vijay K. Jidigam
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
| | - Kenya Wilcots
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
- Department of Chemistry, Cleveland State University, Cleveland, Ohio, United States
| | - Rebecca D. Fuller
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
| | - Ivy Samuels
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
- Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, United States
| | - Sujata Rao
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, United States
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10
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Kong X, Wang J, Gao G, Tan M, Ding B, Li H, Ma J. Association between Free Thyroxine Levels and Diabetic Retinopathy in Euthyroid Patients with Type 2 Diabetes Mellitus. Endocr Res 2020; 45:111-118. [PMID: 31773995 DOI: 10.1080/07435800.2019.1690504] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Background: This study aimed to evaluate the association between thyroid parameters and diabetic retinopathy (DR) in euthyroid patients with type 2 diabetes mellitus (T2DM).Materials and Methods: In this cross-sectional study, a total of 911 euthyroid patients with T2DM (539 men and 372 women; mean age, 60.81 ± 12.93 years) were enrolled. Clinical factors were assessed and free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels were measured. DR was diagnosed using fundus fluorescein angiography.Results: Compared with patients without DR (n = 718), patients with DR (n = 193) exhibited lower FT3 (4.40 ± 0.58 vs. 4.50 ± 0.51 pmol/L; P = .019) and FT4 (14.86 ± 2.09 vs. 15.91 ± 2.18 pmol/L; P < .001) and higher TSH (1.86 [1.22, 2.66] vs. 1.58 [1.14, 2.34] µIU/mL; P = .015) levels. After adjustment for potential DR risk factors, patients in the highest tertile of plasma FT4 levels had a 0.332-fold likelihood of developing DR compared with those in the lowest tertile of plasma FT4 levels (Ptrend < 0.001). The prevalence of DR showed a significantly decreasing trend across the three tertiles based on FT4 levels (31.35%, 19.08% and 13.16%; Ptrend < 0.001). Similar results were obtained for the presence of proliferative DR.Conclusion: These findings suggest that low-normal FT4 levels are associated with the prevalence of DR in euthyroid patients with T2DM.
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Affiliation(s)
- Xiaocen Kong
- Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Jian Wang
- Department of intensive care unit, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Gu Gao
- Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Mingjuan Tan
- Department of Clinical Laboratory, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Bo Ding
- Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Huiqin Li
- Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Jianhua Ma
- Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
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Chichagova V, Hilgen G, Ghareeb A, Georgiou M, Carter M, Sernagor E, Lako M, Armstrong L. Human iPSC differentiation to retinal organoids in response to IGF1 and BMP4 activation is line- and method-dependent. Stem Cells 2019; 38:195-201. [PMID: 31721366 PMCID: PMC7383896 DOI: 10.1002/stem.3116] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/09/2019] [Indexed: 12/13/2022]
Abstract
Induced pluripotent stem cell (iPSC)‐derived retinal organoids provide a platform to study human retinogenesis, disease modeling, and compound screening. Although retinal organoids may represent tissue structures with greater physiological relevance to the in vivo human retina, their generation is not without limitations. Various protocols have been developed to enable development of organoids with all major retinal cell types; however, variability across iPSC lines is often reported. Modulating signaling pathways important for eye formation, such as those involving bone morphogenetic protein 4 (BMP4) and insulin‐like growth factor 1 (IGF1), is a common approach used for the generation of retinal tissue in vitro. We used three human iPSC lines to generate retinal organoids by activating either BMP4 or IGF1 signaling and assessed differentiation efficiency by monitoring morphological changes, gene and protein expression, and function. Our results showed that the ability of iPSC to give rise to retinal organoids in response to IGF1 and BMP4 activation was line‐ and method‐dependent. This demonstrates that careful consideration is needed when choosing a differentiation approach, which would also depend on overall project aims.
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Affiliation(s)
| | - Gerrit Hilgen
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Ali Ghareeb
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Maria Georgiou
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Madeleine Carter
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Evelyne Sernagor
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Majlinda Lako
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Lyle Armstrong
- Newcells Biotech Ltd, Newcastle upon Tyne, UK.,Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
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12
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Zerti D, Dorgau B, Felemban M, Ghareeb AE, Yu M, Ding Y, Krasnogor N, Lako M. Developing a simple method to enhance the generation of cone and rod photoreceptors in pluripotent stem cell-derived retinal organoids. Stem Cells 2019; 38:45-51. [PMID: 31670434 PMCID: PMC7004057 DOI: 10.1002/stem.3082] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/17/2019] [Accepted: 06/26/2019] [Indexed: 01/05/2023]
Abstract
Cell replacement therapy is a promising treatment for irreversible retinal cell death in diverse diseases such as Stargardt's disease, age-related macular degeneration, and retinitis pigmentosa. The final impact of all retinal dystrophies is the loss of photoreceptors; hence, there is a pressing need for research into replacement. Seminal work has shown that a simple three-dimensional culture system enables differentiation of human pluripotent stem cells to retinal organoids containing large numbers of photoreceptors developing alongside retinal neurons and Müller glia cells in a laminated structure that resembles the native retina. Despite these promising developments, current protocols show different efficiencies across pluripotent stem cells and result in retinal organoids with a mixture of photoreceptor cells at varying maturation states, along with nonphotoreceptor cell types. In this study, we investigated the impact of stage-specific addition of retinoic acid (RA), 9-cis-retinal, 11-cis-retinal, levodopa (l-DOPA), triiodothyronine (T3), and γ-secretase inhibitor ((2S)-N-[(3,5-Difluorophenyl)acetyl]-l-alanyl-2-phenyl]glycine1,1-dimethylethyl ester2L [DAPT]) in the generation of cone and rod photoreceptors. Our results indicate that addition of RA + T3 during days 90 to 120 of differentiation enhanced the generation of rod and S-cone photoreceptor formation, while the combined addition of DAPT from days 28 to 42 with RA during days 30 to 120 of differentiation led to enhanced generation of L/M-cones at the expense of rods. l-DOPA when added together with RA during days 90 to 120 of differentiation also promoted the emergence of S-cones at the expense of rod photoreceptors. Collectively, these data represent an advance in our ability to direct generation of rod and cone photoreceptors in vitro.
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Affiliation(s)
- Darin Zerti
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Birthe Dorgau
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Majed Felemban
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Princess Al-Jawhara Center of Excellence in Research of Hereditary Disorders and Department of Medical Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ali E Ghareeb
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Min Yu
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Yuchun Ding
- Interdisciplinary Computing and Complex Biosystems (ICOS) Research Group, Newcastle University, Newcastle upon Tyne, UK
| | - Natalio Krasnogor
- Interdisciplinary Computing and Complex Biosystems (ICOS) Research Group, Newcastle University, Newcastle upon Tyne, UK
| | - Majlinda Lako
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
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13
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Sawant OB, Jidigam VK, Fuller RD, Zucaro OF, Kpegba C, Yu M, Peachey NS, Rao S. The circadian clock gene Bmal1 is required to control the timing of retinal neurogenesis and lamination of Müller glia in the mouse retina. FASEB J 2019; 33:8745-8758. [PMID: 31002540 PMCID: PMC6662963 DOI: 10.1096/fj.201801832rr] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 04/02/2019] [Indexed: 12/20/2022]
Abstract
A single pool of multipotent retinal progenitor cells give rise to the diverse cell types within the mammalian retina. Such cellular diversity is due to precise control of various cellular processes like cell specification, proliferation, differentiation, and maturation. Circadian clock genes can control the expression of key regulators of cell cycle progression and therefore can synchronize the cell cycle state of a heterogeneous population of cells. Here we show that the protein encoded by the circadian clock gene brain and muscle arnt-like protein-1 (Bmal1) is expressed in the embryonic retina and is required to regulate the timing of cell cycle exit. Accordingly, loss of Bmal1 during retinal neurogenesis results in increased S-phase entry and delayed cell cycle exit. Disruption in cell cycle kinetics affects the timely generation of the appropriate neuronal population thus leading to an overall decrease in the number of retinal ganglion cells, amacrine cells, and an increase in the number of the late-born type II cone bipolar cells as well as the Müller glia. Additionally, the mislocalized Müller cells are observed in the photoreceptor layer in the Bmal1 conditional mutants. These changes affect the functional integrity of the visual circuitry as we report a significant delay in visual evoked potential implicit time in the retina-specific Bmal1 null animals. Our results demonstrate that Bmal1 is required to maintain the balance between the neural and glial cells in the embryonic retina by coordinating the timing of cell cycle entry and exit. Thus, Bmal1 plays an essential role during retinal neurogenesis affecting both development and function of the mature retina.-Sawant, O. B., Jidigam, V. K., Fuller, R. D., Zucaro, O. F., Kpegba, C., Yu, M., Peachey, N. S., Rao, S. The circadian clock gene Bmal1 is required to control the timing of retinal neurogenesis and lamination of Müller glia in the mouse retina.
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Affiliation(s)
- Onkar B. Sawant
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Vijay K. Jidigam
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Rebecca D. Fuller
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Olivia F. Zucaro
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Cristel Kpegba
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
| | - Minzhong Yu
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
| | - Neal S. Peachey
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
- Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, USA
| | - Sujata Rao
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
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14
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Sawant OB, Horton AM, Zucaro OF, Chan R, Bonilha VL, Samuels IS, Rao S. The Circadian Clock Gene Bmal1 Controls Thyroid Hormone-Mediated Spectral Identity and Cone Photoreceptor Function. Cell Rep 2017; 21:692-706. [PMID: 29045837 PMCID: PMC5647869 DOI: 10.1016/j.celrep.2017.09.069] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/15/2017] [Accepted: 09/20/2017] [Indexed: 10/18/2022] Open
Abstract
Circadian clocks regulate various aspects of photoreceptor physiology, but their contribution to photoreceptor development and function is unclear. Cone photoreceptors are critical for color vision. Here, we define the molecular function of circadian activity within cone photoreceptors and reveal a role for the clock genes Bmal1 and Per2 in regulating cone spectral identity. ChIP analysis revealed that BMAL1 binds to the promoter region of the thyroid hormone (TH)-activating enzyme type 2 iodothyronine deiodinase (Dio2) and thus regulates the expression of Dio2. TH treatment resulted in a partial rescue of the phenotype caused by the loss of Bmal1, thus revealing a functional relationship between Bmal1 and Dio2 in establishing cone photoreceptor identity. Furthermore, Bmal1 and Dio2 are required to maintain cone photoreceptor functional integrity. Overall, our results suggest a mechanism by which circadian proteins can locally regulate the availability of TH and influence tissue development and function.
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Affiliation(s)
- Onkar B Sawant
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Amanda M Horton
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Olivia F Zucaro
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Ricky Chan
- Institute for Computational Biology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Vera L Bonilha
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA; Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Ivy S Samuels
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Sujata Rao
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA; Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA.
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15
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Rakshit T, Senapati S, Parmar VM, Sahu B, Maeda A, Park PSH. Adaptations in rod outer segment disc membranes in response to environmental lighting conditions. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017. [PMID: 28645515 DOI: 10.1016/j.bbamcr.2017.06.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The light-sensing rod photoreceptor cell exhibits several adaptations in response to the lighting environment. While adaptations to short-term changes in lighting conditions have been examined in depth, adaptations to long-term changes in lighting conditions are less understood. Atomic force microscopy was used to characterize the structure of rod outer segment disc membranes, the site of photon absorption by the pigment rhodopsin, to better understand how photoreceptor cells respond to long-term lighting changes. Structural properties of the disc membrane changed in response to housing mice in constant dark or light conditions and these adaptive changes required output from the phototransduction cascade initiated by rhodopsin. Among these were changes in the packing density of rhodopsin in the membrane, which was independent of rhodopsin synthesis and specifically affected scotopic visual function as assessed by electroretinography. Studies here support the concept of photostasis, which maintains optimal photoreceptor cell function with implications in retinal degenerations.
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Affiliation(s)
- Tatini Rakshit
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Subhadip Senapati
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Vipul M Parmar
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Bhubanananda Sahu
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Akiko Maeda
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Paul S-H Park
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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16
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Hatsukano T, Kurisu J, Fukumitsu K, Fujishima K, Kengaku M. Thyroid Hormone Induces PGC-1α during Dendritic Outgrowth in Mouse Cerebellar Purkinje Cells. Front Cell Neurosci 2017; 11:133. [PMID: 28536504 PMCID: PMC5422430 DOI: 10.3389/fncel.2017.00133] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 04/20/2017] [Indexed: 11/26/2022] Open
Abstract
Thyroid hormone 3,3′,5-Triiodo-L-thyronine (T3) is essential for proper brain development. Perinatal loss of T3 causes severe growth defects in neurons and glia, including strong inhibition of dendrite formation in Purkinje cells in the cerebellar cortex. Here we show that T3 promotes dendritic outgrowth of Purkinje cells through induction of peroxisome proliferator-activated receptor gamma (PPARγ) co-activator 1α (PGC-1α), a master regulator of mitochondrial biogenesis. PGC-1α expression in Purkinje cells is upregulated during dendritic outgrowth in normal mice, while it is significantly retarded in hypothyroid mice or in cultures depleted of T3. In cultured Purkinje cells, PGC-1α knockdown or molecular perturbation of PGC-1α signaling inhibits enhanced dendritic outgrowth and mitochondrial generation and activation caused by T3 treatment. In contrast, PGC-1α overexpression promotes dendrite extension even in the absence of T3. PGC-1α knockdown also downregulates dendrite formation in Purkinje cells in vivo. Our findings suggest that the growth-promoting activity of T3 is partly mediated by PGC-1α signaling in developing Purkinje cells.
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Affiliation(s)
- Tetsu Hatsukano
- Kengaku Group, Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto UniversityKyoto, Japan.,Kengaku Group, Graduate School of Biostudies, Kyoto UniversityKyoto, Japan
| | - Junko Kurisu
- Kengaku Group, Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto UniversityKyoto, Japan
| | - Kansai Fukumitsu
- Kengaku Group, Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto UniversityKyoto, Japan.,Kengaku Group, Graduate School of Biostudies, Kyoto UniversityKyoto, Japan
| | - Kazuto Fujishima
- Kengaku Group, Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto UniversityKyoto, Japan
| | - Mineko Kengaku
- Kengaku Group, Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto UniversityKyoto, Japan.,Kengaku Group, Graduate School of Biostudies, Kyoto UniversityKyoto, Japan
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17
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Henning Y, Szafranski K. Age-Dependent Changes of Monocarboxylate Transporter 8 Availability in the Postnatal Murine Retina. Front Cell Neurosci 2016; 10:205. [PMID: 27616981 PMCID: PMC4999454 DOI: 10.3389/fncel.2016.00205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/15/2016] [Indexed: 12/12/2022] Open
Abstract
The thyroid hormones (TH) triiodothyronine (T3) and its prohormone thyroxine (T4) are crucial for retinal development and function, and increasing evidence points at TH dysregulation as a cause for retinal degenerative diseases. Thus, precise regulation of retinal TH supply is required for proper retinal function, but knowledge on these mechanisms is still fragmentary. Several transmembrane transporters have been described as key regulators of TH availability in target tissues of which the monocarboxylate transporter 8 (MCT8), a high affinity transporter for T4 and T3, plays an essential role in the central nervous system. Moreover, in the embryonic chicken retina, MCT8 is highly expressed, but the postnatal availability of MCT8 in the mammalian retina was not reported to date. In the present study, spatiotemporal retinal MCT8 availability was examined in mice of different age. For this purpose, we quantified expression levels of Mct8 via Real-Time Reverse-Transcriptase PCR in mouse eyecups (C57BL/6) of juvenile and adult age groups. Additionally, age-dependent MCT8 protein levels were quantified via Western blotting and localized via immunofluorescence confocal microscopy. While no difference in Mct8 expression levels could be detected between age groups, MCT8 protein levels in juvenile animals were about two times higher than in adult animals based on Western blot analyses. Immunohistochemical analyses showed that MCT8 immunoreactivity in the eyecup was restricted to the retina and the retinal pigment epithelium. In juvenile mice, MCT8 was broadly observed along the apical membrane of the retinal pigment epithelium, tightly surrounding photoreceptor outer segments. Distinct immunopositive staining was also detected in the inner nuclear layer and the ganglion cell layer. However, in adult specimens, immunoreactivity visibly declined in all layers, which was in line with Western blot analyses. Since MCT8 was abundantly present in juvenile and about twofold lower in adult retinae, our findings suggest a pivotal role of MCT8 especially during postnatal maturation. The present study provides novel insights into age-dependent retinal TH supply, which might help to understand different aspects regarding retinal development, function, and disorders.
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Affiliation(s)
- Yoshiyuki Henning
- Department of General Zoology, Faculty of Biology, University of Duisburg-Essen Essen, Germany
| | - Karol Szafranski
- Genome Analysis, Leibniz Institute on Aging - Fritz Lipmann Institute Jena, Germany
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