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Shakhmantsir I, Dooley SJ, Kishore S, Chen D, Pierce E, Bennett J, Sehgal A. RNA Splicing Factor Mutations That Cause Retinitis Pigmentosa Result in Circadian Dysregulation. J Biol Rhythms 2019; 35:72-83. [PMID: 31726916 DOI: 10.1177/0748730419887876] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Circadian clocks regulate multiple physiological processes in the eye, but their requirement for retinal health remains unclear. We previously showed that Drosophila homologs of spliceosome proteins implicated in human retinitis pigmentosa (RP), the most common genetically inherited cause of blindness, have a role in the brain circadian clock. In this study, we report circadian phenotypes in murine models of RP. We found that mice carrying a homozygous H2309P mutation in Pre-mRNA splicing factor 8 (Prpf8) display a lengthened period of the circadian wheel-running activity rhythm. We show also that the daily cycling of circadian gene expression is dampened in the retina of Prpf8-H2309P mice. Surprisingly, molecular rhythms are intact in the eye cup, which includes the retinal pigment epithelium (RPE), even though the RPE is thought to be the primary tissue affected in this form of RP. Downregulation of Prp31, another RNA splicing factor implicated in RP, leads to period lengthening in a human cell culture model. The period of circadian bioluminescence in primary fibroblasts of human RP patients is not significantly altered. Together, these studies link a prominent retinal disorder to circadian deficits, which could contribute to disease pathology.
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Affiliation(s)
- Iryna Shakhmantsir
- Chronobiology and Sleep institute (CSI) and Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Graduate Program in Cell and Molecular Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Scott J Dooley
- Graduate Program in Cell and Molecular Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Center for Advanced Retinal and Ocular Therapeutics, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Siddharth Kishore
- Graduate Program in Cell and Molecular Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Dechun Chen
- Chronobiology and Sleep institute (CSI) and Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Eric Pierce
- Ocular Genomics Institute, Mass Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Amita Sehgal
- Chronobiology and Sleep institute (CSI) and Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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Verra DM, Sajdak BS, Merriman DK, Hicks D. Diurnal rodents as pertinent animal models of human retinal physiology and pathology. Prog Retin Eye Res 2019; 74:100776. [PMID: 31499165 DOI: 10.1016/j.preteyeres.2019.100776] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/27/2019] [Accepted: 08/31/2019] [Indexed: 12/12/2022]
Abstract
This presentation will survey the retinal architecture, advantages, and limitations of several lesser-known rodent species that provide a useful diurnal complement to rats and mice. These diurnal rodents also possess unusually cone-rich photoreceptor mosaics that facilitate the study of cone cells and pathways. Species to be presented include principally the Sudanian Unstriped Grass Rat and Nile Rat (Arvicanthis spp.), the Fat Sand Rat (Psammomys obesus), the degu (Octodon degus) and the 13-lined ground squirrel (Ictidomys tridecemlineatus). The retina and optic nerve in several of these species demonstrate unusual resilience in the face of neuronal injury, itself an interesting phenomenon with potential translational value.
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Affiliation(s)
- Daniela M Verra
- Department of Neurobiology of Rhythms, Institut des Neurosciences Cellulaires et Intégratives (INCI), CNRS UPR 3212, Strasbourg, France
| | | | - Dana K Merriman
- Department of Biology, University of Wisconsin Oshkosh, Oshkosh, WI, USA
| | - David Hicks
- Department of Neurobiology of Rhythms, Institut des Neurosciences Cellulaires et Intégratives (INCI), CNRS UPR 3212, Strasbourg, France.
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Ribelayga C, Mangel SC. Circadian clock regulation of cone to horizontal cell synaptic transfer in the goldfish retina. PLoS One 2019; 14:e0218818. [PMID: 31461464 PMCID: PMC6713326 DOI: 10.1371/journal.pone.0218818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/10/2019] [Indexed: 11/19/2022] Open
Abstract
Although it is well established that the vertebrate retina contains endogenous circadian clocks that regulate retinal physiology and function during day and night, the processes that the clocks affect and the means by which the clocks control these processes remain unresolved. We previously demonstrated that a circadian clock in the goldfish retina regulates rod-cone electrical coupling so that coupling is weak during the day and robust at night. The increase in rod-cone coupling at night introduces rod signals into cones so that the light responses of both cones and cone horizontal cells, which are post-synaptic to cones, become dominated by rod input. By comparing the light responses of cones, cone horizontal cells and rod horizontal cells, which are post-synaptic to rods, under dark-adapted conditions during day and night, we determined whether the daily changes in the strength of rod-cone coupling could account entirely for rhythmic changes in the light response properties of cones and cone horizontal cells. We report that although some aspects of the day/night changes in cone and cone horizontal cell light responses, such as response threshold and spectral tuning, are consistent with modulation of rod-cone coupling, other properties cannot be solely explained by this phenomenon. Specifically, we found that at night compared to the day the time course of spectrally-isolated cone photoresponses was slower, cone-to-cone horizontal cell synaptic transfer was highly non-linear and of lower gain, and the delay in cone-to-cone horizontal cell synaptic transmission was longer. However, under bright light-adapted conditions in both day and night, cone-to-cone horizontal cell synaptic transfer was linear and of high gain, and no additional delay was observed at the cone-to-cone horizontal cell synapse. These findings suggest that in addition to controlling rod-cone coupling, retinal clocks shape the light responses of cone horizontal cells by modulating cone-to-cone horizontal cell synaptic transmission.
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Affiliation(s)
- Christophe Ribelayga
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, United States of America
- MD Anderson/UTHealth Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Stuart C. Mangel
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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Hagen LA, Arnegard S, Kuchenbecker JA, Gilson SJ, Neitz M, Neitz J, Baraas RC. The association between L:M cone ratio, cone opsin genes and myopia susceptibility. Vision Res 2019; 162:20-28. [PMID: 31254532 PMCID: PMC7122956 DOI: 10.1016/j.visres.2019.06.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/12/2019] [Accepted: 06/13/2019] [Indexed: 11/16/2022]
Abstract
In syndromic forms of myopia caused by long (L) to middle (M) wavelength (L/M) interchange mutations, erroneous contrast signals from ON-bipolar cells activated by cones with different levels of opsin expression are suggested to make the eye susceptible to increased growth. This susceptibility is modulated by the L:M cone ratio. Here, we examined L and M opsin genes, L:M cone ratios and their association with common refractive errors in a population with low myopia prevalence. Cycloplegic autorefraction and ocular biometry were obtained for Norwegian genetically-confirmed normal trichromats. L:M cone ratios were estimated from spectral sensitivity functions measured with full-field ERG, after adjusting for individual differences in the wavelength of peak absorption deduced from cone opsin genetics. Mean L:M cone ratios and the frequency of alanine at L opsin position 180 were higher in males than what has been reported in males in populations with high myopia prevalence. High L:M cone ratios in females were associated with lower degree of myopia, and myopia was more frequent in females who were heterozygous for L opsin exon 3 haplotypes than in those who were homozygous. The results suggest that the L:M cone ratio, combined with milder versions of L opsin gene polymorphisms, may play a role in common myopia. This may in part explain the low myopia prevalence in Norwegian adolescents and why myopia prevalence was higher in females who were heterozygous for the L opsin exon 3 haplotype, since females are twice as likely to have genetic polymorphisms carried on the X-chromosome.
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Affiliation(s)
- Lene A Hagen
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University of South-Eastern Norway, Hasbergs vei 36, 3616 Kongsberg, Norway.
| | - Solveig Arnegard
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University of South-Eastern Norway, Hasbergs vei 36, 3616 Kongsberg, Norway.
| | - James A Kuchenbecker
- Department of Ophthalmology, University of Washington Medical School, Box 358058, 750 Republican Street, Building E Room, Seattle, WA 98109, United States
| | - Stuart J Gilson
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University of South-Eastern Norway, Hasbergs vei 36, 3616 Kongsberg, Norway.
| | - Maureen Neitz
- Department of Ophthalmology, University of Washington Medical School, Box 358058, 750 Republican Street, Building E Room, Seattle, WA 98109, United States.
| | - Jay Neitz
- Department of Ophthalmology, University of Washington Medical School, Box 358058, 750 Republican Street, Building E Room, Seattle, WA 98109, United States.
| | - Rigmor C Baraas
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University of South-Eastern Norway, Hasbergs vei 36, 3616 Kongsberg, Norway.
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DeVera C, Baba K, Tosini G. Retinal Circadian Clocks are Major Players in the Modulation of Retinal Functions and Photoreceptor Viability. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2019; 92:233-240. [PMID: 31249484 PMCID: PMC6585523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Circadian rhythms control many biochemical and physiological functions within the body of an organism. These circadian rhythms are generated by a molecular clock that is located in almost every cell of the body. Accumulating data indicate that dysfunction of the circadian clock negatively affects the health status of the tissue in which the circadian clock has been disabled. The eye also contains a complex circadian system that regulates many important functions such as the processing of light information, the release of neurotransmitters, and phagocytic activity by the retinal pigment epithelium, to name just a few. Emerging experimental evidence indicates that dysfunction of the circadian clock within the retina has severe consequence for retinal function and photoreceptor viability. The aim of this review is to provide the reader with a summary of current knowledge about the eye circadian system and what effects emerge with a disruption of this system.
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Affiliation(s)
| | | | - Gianluca Tosini
- To whom all correspondence should be addressed: Gianluca Tosini, PhD, Mailing address: 720 Westview Dr. SW, Atlanta, GA, 30310-1495; Tel: 404-756-5214, Fax: 404-752-1041,
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Steady-State Pupil Size Varies with Circadian Phase and Sleep Homeostasis in Healthy Young Men. Clocks Sleep 2019; 1:240-258. [PMID: 33089167 PMCID: PMC7445830 DOI: 10.3390/clockssleep1020021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/07/2019] [Indexed: 11/16/2022] Open
Abstract
Pupil size informs about sympathovagal balance as well as cognitive and affective processes, and perception. It is also directly linked to phasic activity of the brainstem locus coeruleus, so that pupil measures have gained recent attention. Steady-state pupil size and its variability have been directly linked to sleep homeostasis and circadian phase, but results have been inconsistent. Here, we report robust changes in steady-state pupil size during 29 h of continuous wakefulness in healthy young men (N = 20; 18–30 years old) maintained in dim-light in strictly controlled constant routine conditions. These variations were associated with variations in motivation and sustained attention performance. Pupil size variability did not significantly change during the protocol. Yet, pupil size variability was linearly associated with subjective fatigue, sociability, and anguish. No associations were found between neither steady-state pupil size nor pupil size variability, and objective EEG measure of alertness and subjective sleepiness. Our data support therefore the notion that, compared with its variability, steady-state pupil size is strongly influenced by the concomitant changes in sleep need and circadian phase. In addition, steady-state pupil size appears to be related to motivation and attention, while its variability may be related to separate affective dimensions and subjective fatigue.
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