Retbindin: A riboflavin Binding Protein, Is Critical for Photoreceptor Homeostasis and Survival in Models of Retinal Degeneration

The large number of inherited retinal disease genes (IRD), including the photopigment rhodopsin and the photoreceptor outer segment (OS) structural component peripherin 2 (PRPH2), has prompted interest in identifying common cellular mechanisms involved in degeneration. Although metabolic dysregulati...

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Main Authors: Ayse M. Genc, Mustafa S. Makia, Tirthankar Sinha, Shannon M. Conley, Muayyad R. Al-Ubaidi, Muna I. Naash
Format: Article
Language:English
Published: MDPI AG 2020-10-01
Series:International Journal of Molecular Sciences
Subjects:
Online Access:https://www.mdpi.com/1422-0067/21/21/8083
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author Ayse M. Genc
Mustafa S. Makia
Tirthankar Sinha
Shannon M. Conley
Muayyad R. Al-Ubaidi
Muna I. Naash
author_facet Ayse M. Genc
Mustafa S. Makia
Tirthankar Sinha
Shannon M. Conley
Muayyad R. Al-Ubaidi
Muna I. Naash
author_sort Ayse M. Genc
collection DOAJ
description The large number of inherited retinal disease genes (IRD), including the photopigment rhodopsin and the photoreceptor outer segment (OS) structural component peripherin 2 (PRPH2), has prompted interest in identifying common cellular mechanisms involved in degeneration. Although metabolic dysregulation has been shown to play an important role in the progression of the disease etiology, identifying a common regulator that can preserve the metabolic ecosystem is needed for future development of neuroprotective treatments. Here, we investigated whether retbindin (RTBDN), a rod-specific protein with riboflavin binding capability, and a regulator of riboflavin-derived cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is protective to the retina in different IRD models; one carrying the P23H mutation in rhodopsin (which causes retinitis pigmentosa) and one carrying the Y141C mutation in <i>Prph2</i> (which causes a blended cone-rod dystrophy). RTBDN levels are significantly upregulated in both the rhodopsin (<i>Rho</i>)<i><sup>P23H/+</sup></i> and <i>Prph2<sup>Y141C/+</sup></i> retinas. Rod and cone structural and functional degeneration worsened in models lacking RTBDN. In addition, removing <i>Rtbdn</i> worsened other phenotypes, such as fundus flecking. Retinal flavin levels were reduced in <i>Rho<sup>P23H/+</sup>/Rtbdn<sup>−/−</sup></i> and <i>Prph2<sup>Y141C/+</sup>/Rtbdn<sup>−/−</sup></i> retinas. Overall, these findings suggest that RTBDN may play a protective role during retinal degenerations that occur at varying rates and due to varying disease mechanisms.
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spelling doaj.art-436459834f8b45faba7bab634b3c66422023-11-20T19:04:58ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672020-10-012121808310.3390/ijms21218083Retbindin: A riboflavin Binding Protein, Is Critical for Photoreceptor Homeostasis and Survival in Models of Retinal DegenerationAyse M. Genc0Mustafa S. Makia1Tirthankar Sinha2Shannon M. Conley3Muayyad R. Al-Ubaidi4Muna I. Naash5Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USADepartment of Biomedical Engineering, University of Houston, Houston, TX 77204, USADepartment of Biomedical Engineering, University of Houston, Houston, TX 77204, USADepartment of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USADepartment of Biomedical Engineering, University of Houston, Houston, TX 77204, USADepartment of Biomedical Engineering, University of Houston, Houston, TX 77204, USAThe large number of inherited retinal disease genes (IRD), including the photopigment rhodopsin and the photoreceptor outer segment (OS) structural component peripherin 2 (PRPH2), has prompted interest in identifying common cellular mechanisms involved in degeneration. Although metabolic dysregulation has been shown to play an important role in the progression of the disease etiology, identifying a common regulator that can preserve the metabolic ecosystem is needed for future development of neuroprotective treatments. Here, we investigated whether retbindin (RTBDN), a rod-specific protein with riboflavin binding capability, and a regulator of riboflavin-derived cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is protective to the retina in different IRD models; one carrying the P23H mutation in rhodopsin (which causes retinitis pigmentosa) and one carrying the Y141C mutation in <i>Prph2</i> (which causes a blended cone-rod dystrophy). RTBDN levels are significantly upregulated in both the rhodopsin (<i>Rho</i>)<i><sup>P23H/+</sup></i> and <i>Prph2<sup>Y141C/+</sup></i> retinas. Rod and cone structural and functional degeneration worsened in models lacking RTBDN. In addition, removing <i>Rtbdn</i> worsened other phenotypes, such as fundus flecking. Retinal flavin levels were reduced in <i>Rho<sup>P23H/+</sup>/Rtbdn<sup>−/−</sup></i> and <i>Prph2<sup>Y141C/+</sup>/Rtbdn<sup>−/−</sup></i> retinas. Overall, these findings suggest that RTBDN may play a protective role during retinal degenerations that occur at varying rates and due to varying disease mechanisms.https://www.mdpi.com/1422-0067/21/21/8083<i>Prph2</i>retinal degenerationinherited retinal degenerationriboflavinmetabolismflavoproteins
spellingShingle Ayse M. Genc
Mustafa S. Makia
Tirthankar Sinha
Shannon M. Conley
Muayyad R. Al-Ubaidi
Muna I. Naash
Retbindin: A riboflavin Binding Protein, Is Critical for Photoreceptor Homeostasis and Survival in Models of Retinal Degeneration
International Journal of Molecular Sciences
<i>Prph2</i>
retinal degeneration
inherited retinal degeneration
riboflavin
metabolism
flavoproteins
title Retbindin: A riboflavin Binding Protein, Is Critical for Photoreceptor Homeostasis and Survival in Models of Retinal Degeneration
title_full Retbindin: A riboflavin Binding Protein, Is Critical for Photoreceptor Homeostasis and Survival in Models of Retinal Degeneration
title_fullStr Retbindin: A riboflavin Binding Protein, Is Critical for Photoreceptor Homeostasis and Survival in Models of Retinal Degeneration
title_full_unstemmed Retbindin: A riboflavin Binding Protein, Is Critical for Photoreceptor Homeostasis and Survival in Models of Retinal Degeneration
title_short Retbindin: A riboflavin Binding Protein, Is Critical for Photoreceptor Homeostasis and Survival in Models of Retinal Degeneration
title_sort retbindin a riboflavin binding protein is critical for photoreceptor homeostasis and survival in models of retinal degeneration
topic <i>Prph2</i>
retinal degeneration
inherited retinal degeneration
riboflavin
metabolism
flavoproteins
url https://www.mdpi.com/1422-0067/21/21/8083
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