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Shi Y, Lu S, Zhou X, Wang X, Zhang C, Wu N, Dong T, Xing S, Wang Y, Xiao W, Yao M. Systematic metabolic engineering enables highly efficient production of vitamin A in Saccharomyces cerevisiae. Synth Syst Biotechnol 2024; 10:58-67. [PMID: 39247801 PMCID: PMC11380465 DOI: 10.1016/j.synbio.2024.08.004] [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: 05/11/2024] [Revised: 08/14/2024] [Accepted: 08/14/2024] [Indexed: 09/10/2024] Open
Abstract
Vitamin A is a micronutrient critical for versatile biological functions and has been widely used in the food, cosmetics, pharmaceutical, and nutraceutical industries. Synthetic biology and metabolic engineering enable microbes, especially the model organism Saccharomyces cerevisiae (generally recognised as safe) to possess great potential for the production of vitamin A. Herein, we first generated a vitamin A-producing strain by mining β-carotene 15,15'-mono(di)oxygenase from different sources and identified two isoenzymes Mbblh and Ssbco with comparable catalytic properties but different catalytic mechanisms. Combinational expression of isoenzymes increased the flux from β-carotene to vitamin A metabolism. To modulate the vitamin A components, retinol dehydrogenase 12 from Homo sapiens was introduced to achieve more than 90 % retinol purity using shake flask fermentation. Overexpressing POS5Δ17 enhanced the reduced nicotinamide adenine dinucleotide phosphate pool, and the titer of vitamin A was elevated by almost 46 %. Multi-copy integration of the key rate-limiting step gene Mbblh further improved the synthesis of vitamin A. Consequently, the titer of vitamin A in the strain harbouring the Ura3 marker was increased to 588 mg/L at the shake-flask level. Eventually, the highest reported titer of 5.21 g/L vitamin A in S. cerevisiae was achieved in a 1-L bioreactor. This study unlocked the potential of S. cerevisiae for synthesising vitamin A in a sustainable and economical way, laying the foundation for the commercial-scale production of bio-based vitamin A.
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Affiliation(s)
- Yi Shi
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Shuhuan Lu
- CABIO Bioengineering (Wuhan) Co., Ltd, Wuhan, 430075, China
| | - Xiao Zhou
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Xinhui Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Chenglong Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Nan Wu
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Tianyu Dong
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Shilong Xing
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Ying Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
| | - Wenhai Xiao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
- School of Life Sciences, Faculty of Medicine, Tianjin University, China
- Georgia Tech Shenzhen Institute, Tianjin University, Shenzhen, 518071, China
| | - Mingdong Yao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Frontier Research Institute for Synthetic Biology, Tianjin University, China
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Arshavsky VY. Vision: A specialized pathway for pigment regeneration in cones. Curr Biol 2024; 34:R726-R728. [PMID: 39106828 DOI: 10.1016/j.cub.2024.06.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2024]
Abstract
Vision relies on two types of photoreceptor cells, rods and cones. Rods outnumber cones in the retinas of humans and most other vertebrate species, yet the contribution of cones to our vision is far more impactful than rods. A new study reveals an elegant enzymatic mechanism that favors light perception by cones under daylight conditions when rods are saturated by light and contribute little to useful vision.
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Affiliation(s)
- Vadim Y Arshavsky
- Departments of Ophthalmology and Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA.
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Kaylor JJ, Frederiksen R, Bedrosian CK, Huang M, Stennis-Weatherspoon D, Huynh T, Ngan T, Mulamreddy V, Sampath AP, Fain GL, Travis GH. RDH12 allows cone photoreceptors to regenerate opsin visual pigments from a chromophore precursor to escape competition with rods. Curr Biol 2024; 34:3342-3353.e6. [PMID: 38981477 PMCID: PMC11303097 DOI: 10.1016/j.cub.2024.06.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 05/11/2024] [Accepted: 06/10/2024] [Indexed: 07/11/2024]
Abstract
Capture of a photon by an opsin visual pigment isomerizes its 11-cis-retinaldehyde (11cRAL) chromophore to all-trans-retinaldehyde (atRAL), which subsequently dissociates. To restore light sensitivity, the unliganded apo-opsin combines with another 11cRAL to make a new visual pigment. Two enzyme pathways supply chromophore to photoreceptors. The canonical visual cycle in retinal pigment epithelial cells supplies 11cRAL at low rates. The photic visual cycle in Müller cells supplies cones with 11-cis-retinol (11cROL) chromophore precursor at high rates. Although rods can only use 11cRAL to regenerate rhodopsin, cones can use 11cRAL or 11cROL to regenerate cone visual pigments. We performed a screen in zebrafish retinas and identified ZCRDH as a candidate for the enzyme that converts 11cROL to 11cRAL in cone inner segments. Retinoid analysis of eyes from Zcrdh-mutant zebrafish showed reduced 11cRAL and increased 11cROL levels, suggesting impaired conversion of 11cROL to 11cRAL. By microspectrophotometry, isolated Zcrdh-mutant cones lost the capacity to regenerate visual pigments from 11cROL. ZCRDH therefore possesses all predicted properties of the cone 11cROL dehydrogenase. The human protein most similar to ZCRDH is RDH12. By immunocytochemistry, ZCRDH was abundantly present in cone inner segments, similar to the reported distribution of RDH12. Finally, RDH12 was the only mammalian candidate protein to exhibit 11cROL-oxidase catalytic activity. These observations suggest that RDH12 in mammals is the functional ortholog of ZCRDH, which allows cones, but not rods, to regenerate visual pigments from 11cROL provided by Müller cells. This capacity permits cones to escape competition from rods for visual chromophore in daylight-exposed retinas.
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Affiliation(s)
- Joanna J Kaylor
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Rikard Frederiksen
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Christina K Bedrosian
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Melody Huang
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - David Stennis-Weatherspoon
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Theodore Huynh
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Tiffany Ngan
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Varsha Mulamreddy
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Alapakkam P Sampath
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Gordon L Fain
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
| | - Gabriel H Travis
- University of California, Los Angeles, David Geffen School of Medicine, Department of Ophthalmology, 405 Hilgard Avenue, Los Angeles, CA 90095, USA; University of California Los Angeles, Department of Biological Chemistry, 405 Hilgard Avenue, Los Angeles, CA 90095, USA.
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Zhang L, Cavallini M, Wang J, Xin R, Zhang Q, Feng G, Sanes JR, Peng YR. Evolutionary and developmental specialization of foveal cell types in the marmoset. Proc Natl Acad Sci U S A 2024; 121:e2313820121. [PMID: 38598343 PMCID: PMC11032471 DOI: 10.1073/pnas.2313820121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 03/13/2024] [Indexed: 04/12/2024] Open
Abstract
In primates, high-acuity vision is mediated by the fovea, a small specialized central region of the retina. The fovea, unique to the anthropoid lineage among mammals, undergoes notable neuronal morphological changes during postnatal maturation. However, the extent of cellular similarity across anthropoid foveas and the molecular underpinnings of foveal maturation remain unclear. Here, we used high-throughput single-cell RNA sequencing to profile retinal cells of the common marmoset (Callithrix jacchus), an early divergent in anthropoid evolution from humans, apes, and macaques. We generated atlases of the marmoset fovea and peripheral retina for both neonates and adults. Our comparative analysis revealed that marmosets share almost all their foveal types with both humans and macaques, highlighting a conserved cellular structure among primate foveas. Furthermore, by tracing the developmental trajectory of cell types in the foveal and peripheral retina, we found distinct maturation paths for each. In-depth analysis of gene expression differences demonstrated that cone photoreceptors and Müller glia (MG), among others, show the greatest molecular divergence between these two regions. Utilizing single-cell ATAC-seq and gene-regulatory network inference, we uncovered distinct transcriptional regulations differentiating foveal cones from their peripheral counterparts. Further analysis of predicted ligand-receptor interactions suggested a potential role for MG in supporting the maturation of foveal cones. Together, these results provide valuable insights into foveal development, structure, and evolution.
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Affiliation(s)
- Lin Zhang
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA90095
| | - Martina Cavallini
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA90095
| | - Junqiang Wang
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA90095
| | - Ruiqi Xin
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA90095
| | - Qiangge Zhang
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Guoping Feng
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Joshua R. Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA02138
| | - Yi-Rong Peng
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA90095
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Hua QQH, Kültz D, Wiltshire K, Doubleday ZA, Gillanders BM. Projected ocean temperatures impair key proteins used in vision of octopus hatchlings. GLOBAL CHANGE BIOLOGY 2024; 30:e17255. [PMID: 38572638 DOI: 10.1111/gcb.17255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/27/2024] [Accepted: 03/02/2024] [Indexed: 04/05/2024]
Abstract
Global warming is one of the most significant and widespread effects of climate change. While early life stages are particularly vulnerable to increasing temperatures, little is known about the molecular processes that underpin their capacity to adapt to temperature change during early development. Using a quantitative proteomics approach, we investigated the effects of thermal stress on octopus embryos. We exposed Octopus berrima embryos to different temperature treatments (control 19°C, current summer temperature 22°C, or future projected summer temperature 25°C) until hatching. By comparing their protein expression levels, we found that future projected temperatures significantly reduced levels of key eye proteins such as S-crystallin and retinol dehydrogenase 12, suggesting the embryonic octopuses had impaired vision at elevated temperature. We also found that this was coupled with a cellular stress response that included a significant elevation of proteins involved in molecular chaperoning and redox regulation. Energy resources were also redirected away from non-essential processes such as growth and digestion. These findings, taken together with the high embryonic mortality observed under the highest temperature, identify critical physiological functions of embryonic octopuses that may be impaired under future warming conditions. Our findings demonstrate the severity of the thermal impacts on the early life stages of octopuses as demonstrated by quantitative proteome changes that affect vision, protein chaperoning, redox regulation and energy metabolism as critical physiological functions that underlie the responses to thermal stress.
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Affiliation(s)
- Qiaz Q H Hua
- Environment Institute, School of Biological Sciences, The University of Adelaide, South Australia, Australia
| | - Dietmar Kültz
- Department of Animal Sciences and Genome Centre, University of California, Davis, USA
| | - Kathryn Wiltshire
- Environment Institute, School of Biological Sciences, The University of Adelaide, South Australia, Australia
- South Australian Research and Development Institute, West Beach, South Australia
| | - Zoe A Doubleday
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia
| | - Bronwyn M Gillanders
- Environment Institute, School of Biological Sciences, The University of Adelaide, South Australia, Australia
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Zhang L, Cavallini M, Wang J, Xin R, Zhang Q, Feng G, Sanes JR, Peng YR. Evolutionary and Developmental Specialization of Foveal Cell Types in the Marmoset. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.10.570996. [PMID: 38106142 PMCID: PMC10723441 DOI: 10.1101/2023.12.10.570996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
In primates, high-acuity vision is mediated by the fovea, a small specialized central region of the retina. The fovea, unique to the anthropoid lineage among mammals, undergoes notable neuronal morphological changes during postnatal maturation. However, the extent of cellular similarity across anthropoid foveas and the molecular underpinnings of foveal maturation remain unclear. Here, we used high throughput single cell RNA sequencing to profile retinal cells of the common marmoset ( Callithrix jacchus ), an early divergent in anthropoid evolution from humans, apes, and macaques. We generated atlases of the marmoset fovea and peripheral retina for both neonates and adults. Our comparative analysis revealed that marmosets share almost all its foveal types with both humans and macaques, highlighting a conserved cellular structure among primate foveas. Furthermore, by tracing the developmental trajectory of cell types in the foveal and peripheral retina, we found distinct maturation paths for each. In-depth analysis of gene expression differences demonstrated that cone photoreceptors and Müller glia, among others, show the greatest molecular divergence between these two regions. Utilizing single-cell ATAC-seq and gene-regulatory network inference, we uncovered distinct transcriptional regulations differentiating foveal cones from their peripheral counterparts. Further analysis of predicted ligand-receptor interactions suggested a potential role for Müller glia in supporting the maturation of foveal cones. Together, these results provide valuable insights into foveal development, structure, and evolution. Significance statement The sharpness of our eyesight hinges on a tiny retinal region known as the fovea. The fovea is pivotal for primate vision and is susceptible to diseases like age-related macular degeneration. We studied the fovea in the marmoset-a primate with ancient evolutionary ties. Our data illustrated the cellular and molecular composition of its fovea across different developmental ages. Our findings highlighted a profound cellular consistency among marmosets, humans, and macaques, emphasizing the value of marmosets in visual research and the study of visual diseases.
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Gao H, Gu Z, Xing D, Yang Q, Li J, Zhou X, Zhao T, Li C. Identification of differentially expressed genes based on antennae RNA-seq analyses in Culex quinquefasciatus and Culex pipiens molestus. Parasit Vectors 2022; 15:353. [PMID: 36182902 PMCID: PMC9526932 DOI: 10.1186/s13071-022-05482-6] [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: 06/22/2022] [Accepted: 09/13/2022] [Indexed: 11/30/2022] Open
Abstract
Background Both Culex quinquefasciatus and Cx. pipiens molestus are sibling species within Cx. pipiens complex. Even though they are hard to distinguish morphologically, they have different physiological behaviors. However, the molecular mechanisms underlying these differences remain poorly understood. Methods Transcriptome sequencing was conducted on antennae of two sibling species. The identification of the differentially expressed genes (DEGs) was performed by the software DESeq2. Database for Annotation, Visualization and Integrated Discovery was used to perform GO pathway enrichment analysis. The protein–protein interaction (PPI) network was constructed with Cytoscape software. The hub genes were screened by the CytoHubba plugin and Degree algorithms. The identified genes were verified by quantitative real-time PCR. Results Most annotated transcripts (14,687/16,005) were expressed in both sibling species. Among 15 identified odorant-related DEGs, OBP10 was expressed 17.17 fold higher in Cx. pipiens molestus than Cx. quinquefasciatus. Eighteen resistance-related DEGs were identified, including 15 from CYP gene family and three from acetylcholinesterase, in which CYP4d1 was 86.59 fold more highly expressed in C. quinquefasciatus. Three reproductive DEGs were indentified with the expression from 5.01 to 6.55 fold. Among eight vision-related DEGs, retinoic acid receptor RXR-gamma in Cx. pipiens molestus group was more expressed with 214.08 fold. Among the 30 hub genes, there are 10 olfactory-related DEGs, 16 resistance-related DEGs, and four vision-related DEGs, with the highest score hub genes being OBP lush (6041148), CYP4C21 (6044704), and Rdh12 (6043932). The RT-qPCR results were consistent with the transcriptomic data with the correlation coefficient R = 0.78. Conclusion The study provided clues that antennae might play special roles in reproduction, drug resistance, and vision, not only the traditional olfactory function. OBP lush, CYP4C21, and Rdh12 may be key hints to the potential molecular mechanisms behind the two sibling species' biological differences. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05482-6.
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Affiliation(s)
- Heting Gao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Key Laboratory of Vector Borne and Natural Focus Infectious Disease, Beijing, 100071, China
| | - Zhenyu Gu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Key Laboratory of Vector Borne and Natural Focus Infectious Disease, Beijing, 100071, China
| | - Dan Xing
- State Key Laboratory of Pathogen and Biosecurity, Beijing Key Laboratory of Vector Borne and Natural Focus Infectious Disease, Beijing, 100071, China
| | - Qiaojiang Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Key Laboratory of Vector Borne and Natural Focus Infectious Disease, Beijing, 100071, China
| | - Jianhang Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Key Laboratory of Vector Borne and Natural Focus Infectious Disease, Beijing, 100071, China
| | - Xinyu Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Key Laboratory of Vector Borne and Natural Focus Infectious Disease, Beijing, 100071, China
| | - Teng Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Key Laboratory of Vector Borne and Natural Focus Infectious Disease, Beijing, 100071, China.
| | - Chunxiao Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Key Laboratory of Vector Borne and Natural Focus Infectious Disease, Beijing, 100071, China.
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Wang J, Wang Y, Li S, Xiao X, Yi Z, Jiang Y, Li X, Jia X, Wang P, Jin C, Sun W, Zhang Q. Clinical and Genetic Analysis of RDH12-Associated Retinopathy in 27 Chinese Families: A Hypomorphic Allele Leads to Cone-Rod Dystrophy. Invest Ophthalmol Vis Sci 2022; 63:24. [PMID: 35994252 PMCID: PMC9419460 DOI: 10.1167/iovs.63.9.24] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to elucidate the genetic basis of 2 distinct phenotypes associated with biallelic variants in RDH12. Methods Patients with biallelic variants in RDH12 were recruited from our genetic eye clinic. Ocular phenotypes were evaluated. Genotype-phenotype correlations were further clarified using in-house and existing databases. Results In total, 22 biallelic RDH12 variants, including 5 novel variants, were identified in 29 patients from 27 families. Two distinct phenotypes were observed: early-onset and generalized retinal dystrophy with severe impairment of rods and cones in 24 patients (82.8%, 24/29), and late-onset cone-rod dystrophy (CORD) with central macular atrophy in 5 patients from 5 unrelated families (17.2%, 5/29), in which a hypomorphic allele (c.806C>G/p.Ala269Gly) was shared by all 5 patients. During follow-up, patients with late-onset CORD were relatively stable and did not progress to the severe form, which was considered to be an independent manifestation of RDH12-associated retinopathy caused by specific genotypes. Conclusions The hypomorphic allele is responsible for the unique late-onset CORD in 5 families with recessive RDH12-associated retinopathy, in contrast to the well-known severe and generalized retinopathy. Determining the therapeutic value of interventions may depend on understanding the molecular mechanisms underlying manifestation of this hypomorphic variant only in the central macular region, with relative preservation of the peripheral retina.
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Affiliation(s)
- Junwen Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yingwei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Zhen Yi
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yi Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Xueqing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Panfeng Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Chenjin Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Wenmin Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
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Associations Between Fundus Types and Clinical Manifestations in Patients with RDH12 Gene Mutations. Brain Topogr 2022; 35:525-535. [PMID: 35006499 DOI: 10.1007/s10548-021-00885-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/27/2021] [Indexed: 12/27/2022]
Abstract
To study the associations between RDH12 gene mutations, fundus types, and clinical manifestations. In total, 46 patients with inherited eye diseases caused by RDH12 gene mutations were included in this study. High-throughput chip capture sequencing, Sanger sequencing, and gene panel detection were used to determine that RDH12 was the pathogenic gene. All patients underwent the following detailed ophthalmic examinations: visual acuity, visual field, intraocular pressure, fundus photography, electroretinography, and optical coherence tomography (OCT). Statistical analysis was used to evaluate the clinical phenotype. A total of 32 mutations were identified in 46 patients. The most common mutations were c.437T > A, c.184C > T, and c.524C > T; the corresponding amino acid changes were p.Val146Asp, p.Arg62Ter, and p.Ser175Leu. Of the 46 patients, retinitis pigmentosa (RP) was found in 31 (68.9%); leber congenital amaurosis (LVA) was found in 11 (24.4%); early onset of severe retinal dystrophy (EOSRD) was found in one (2.2%); cone rod dystrophy (CORD) was found in one (2.2%); and Stargardt disease was found in one (2.2%). There was a significant difference in best-corrected visual acuity among patients based on fundus type (p = 0.0124). Linear trend analysis showed that best-corrected visual acuity gradually decreased as the fundus type increased in severity. In addition, there was a significant difference in the incidence of night blindness among patients with different fundus types (p = 0.0429): types I and IV fundi were associated with the highest incidences of night blindness. RDH12 gene mutation can cause serious inherited retinal diseases, which primarily include RP and LCA. Combined with clinical symptoms and fundus types, the progression of the disease can be characterized and used to guide genetic diagnosis and gene therapy.
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Sarkar H, Toms M, Moosajee M. Involvement of Oxidative and Endoplasmic Reticulum Stress in RDH12-Related Retinopathies. Int J Mol Sci 2021; 22:ijms22168863. [PMID: 34445569 PMCID: PMC8396253 DOI: 10.3390/ijms22168863] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 12/16/2022] Open
Abstract
Retinol dehydrogenase 12 (RDH12) is expressed in photoreceptor inner segments and catalyses the reduction of all-trans retinal (atRAL) to all-trans retinol (atROL), as part of the visual cycle. Mutations in RDH12 are primarily associated with autosomal recessive Leber congenital amaurosis. To further our understanding of the disease mechanisms, HEK-293 cell lines expressing wildtype (WT) and mutant RDH12 were created. The WT cells afforded protection from atRAL-induced toxicity and oxidative stress. Mutant RDH12 cells displayed reduced protein expression and activity, with an inability to protect cells from atRAL toxicity, inducing oxidative and endoplasmic reticulum (ER) stress, with upregulation of sXBP1, CHOP, and ATF4. Pregabalin, a retinal scavenger, attenuated atRAL-induced ER stress in the mutant RDH12 cell lines. A zebrafish rdh12 mutant model (rdh12u533 c.17_23del; p.(Val6AlafsTer5)) was generated through CRISPR-Cas9 gene editing. Mutant fish showed disrupted phagocytosis through transmission electron microscopy, with increased phagosome size at 12 months post-fertilisation. Rhodopsin mislocalisation and reduced expression of atg12 and sod2 indicated early signs of a rod-predominant degeneration. A lack of functional RDH12 results in ER and oxidative stress representing key pathways to be targeted for potential therapeutics.
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Affiliation(s)
- Hajrah Sarkar
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (H.S.); (M.T.)
- The Francis Crick Institute, London NW1 1AT, UK
| | - Maria Toms
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (H.S.); (M.T.)
- The Francis Crick Institute, London NW1 1AT, UK
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (H.S.); (M.T.)
- The Francis Crick Institute, London NW1 1AT, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
- Correspondence:
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Sarkar H, Méjécase C, Harding P, Eintracht J, Toualbi L, Cunha DL, Moosajee M. Generation of two human iPSC lines from patients with autosomal dominant retinitis pigmentosa (UCLi014-A) and autosomal recessive Leber congenital amaurosis (UCLi015-A), associated with RDH12 variants. Stem Cell Res 2021; 54:102449. [PMID: 34216980 PMCID: PMC8363920 DOI: 10.1016/j.scr.2021.102449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/14/2021] [Accepted: 06/21/2021] [Indexed: 11/30/2022] Open
Abstract
Induced pluripotent stem cell (iPSC) lines were generated from two patients with RDH12 variants. UCLi014-A is from a patient with heterozygous frameshift mutation c.759del p.(Phe254Leufs*24), associated with autosomal dominant retinitis pigmentosa. UCLi015-A is from a patient with homozygous missense mutation c.619A > G p.(Asn207Asp), associated with Leber congenital amaurosis. Fibroblasts were derived from skin biopsies and reprogrammed using integration free episomal reprogramming plasmids. The iPSC lines expressed pluripotency markers, exhibited differentiation potential in vitro and displayed normal karyotypes. These cell lines will act as a tool for disease modelling, enabling comparison of disease mechanisms, identification of therapeutic targets and drug screening.
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Affiliation(s)
- Hajrah Sarkar
- UCL Institute of Ophthalmology, London, UK; The Francis Crick Institute, London, UK
| | - Cécile Méjécase
- UCL Institute of Ophthalmology, London, UK; The Francis Crick Institute, London, UK
| | | | | | - Lyes Toualbi
- UCL Institute of Ophthalmology, London, UK; The Francis Crick Institute, London, UK
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK; The Francis Crick Institute, London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK; Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.
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Lin B, McLelland BT, Aramant RB, Thomas BB, Nistor G, Keirstead HS, Seiler MJ. Retina Organoid Transplants Develop Photoreceptors and Improve Visual Function in RCS Rats With RPE Dysfunction. Invest Ophthalmol Vis Sci 2020; 61:34. [PMID: 32945842 PMCID: PMC7509771 DOI: 10.1167/iovs.61.11.34] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 08/17/2020] [Indexed: 01/01/2023] Open
Abstract
Purpose To study if human embryonic stem cell-derived photoreceptors could survive and function without the support of retinal pigment epithelium (RPE) after transplantation into Royal College of Surgeons rats, a rat model of retinal degeneration caused by RPE dysfunction. Methods CSC14 human embryonic stem cells were differentiated into primordial eye structures called retinal organoids. Retinal organoids were analyzed by quantitative PCR and immunofluorescence and compared with human fetal retina. Retinal organoid sheets (30-70 day of differentiation) were transplanted into immunodeficient RCS rats, aged 44 to 56 days. The development of transplant organoids in vivo in relation to the host was examined by optical coherence tomography. Visual function was assessed by optokinetic testing, electroretinogram, and superior colliculus electrophysiologic recording. Cryostat sections were analyzed for various retinal, synaptic, and donor markers. Results Retinal organoids showed similar gene expression to human fetal retina transplanted rats demonstrated significant improvement in visual function compared with RCS nonsurgery and sham surgery controls by ERGs at 2 months after surgery (but not later), optokinetic testing (up to 6 months after surgery) and electrophysiologic superior colliculus recordings (6-8 months after surgery). The transplanted organoids survived more than 7 months; developed photoreceptors with inner and outer segments, and other retinal cells; and were well-integrated within the host. Conclusions This study, to our knowledge, is the first to show that transplanted photoreceptors survive and function even with host's dysfunctional RPE. Our findings suggest that transplantation of organoid sheets from stem cells may be a promising approach/therapeutic for blinding diseases.
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Affiliation(s)
- Bin Lin
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, School of Medicine, Irvine, California, United States
| | - Bryce T. McLelland
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, School of Medicine, Irvine, California, United States
| | - Robert B. Aramant
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, School of Medicine, Irvine, California, United States
| | - Biju B. Thomas
- USC Roski Eye Institute, Department of Ophthalmology, University of Southern California, Los Angeles, California, United States
| | - Gabriel Nistor
- AIVITA Biomedical Inc., Irvine, California, United States
| | | | - Magdalene J. Seiler
- Physical Medicine & Rehabilitation, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, School of Medicine, Irvine, California, United States
- Ophthalmology, University of California at Irvine, School of Medicine, Irvine, California, United States
- Anatomy & Neurobiology, University of California at Irvine School of Medicine, Irvine, California, United States
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Sallum JMF, Motta FL, Arno G, Porto FBO, Resende RG, Belfort R. Clinical and molecular findings in a cohort of 152 Brazilian severe early onset inherited retinal dystrophy patients. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:728-752. [PMID: 32865313 DOI: 10.1002/ajmg.c.31828] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/25/2020] [Accepted: 07/28/2020] [Indexed: 12/17/2022]
Abstract
Leber congenital amaurosis (LCA) and early-onset retinal dystrophy (EORD) are severe inherited retinal dystrophy that can cause deep blindness childhood. They represent 5% of all retinal dystrophies in the world population and about 10% in Brazil. Clinical findings and molecular basis of syndromic and nonsyndromic LCA/EORD in a Brazilian sample (152 patients/137 families) were studied. In this population, 15 genes were found to be related to the phenotype, 38 new variants were detected and four new complex alleles were discovered. Among 123 variants found, the most common were CEP290: c.2991+1655A>G, CRB1: p.Cys948Tyr, and RPGRIP1: exon10-18 deletion.
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Affiliation(s)
- Juliana Maria Ferraz Sallum
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil.,Instituto de Genética Ocular, Sao Paulo, Brazil
| | - Fabiana Louise Motta
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil.,Instituto de Genética Ocular, Sao Paulo, Brazil
| | - Gavin Arno
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital, London, UK
| | - Fernanda Belga Ottoni Porto
- INRET Clínica e Centro de Pesquisa, Belo Horizonte, Minas Gerais, Brazil.,Centro Oftalmológico de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Rubens Belfort
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil
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Roberts C. Regulating Retinoic Acid Availability during Development and Regeneration: The Role of the CYP26 Enzymes. J Dev Biol 2020; 8:jdb8010006. [PMID: 32151018 PMCID: PMC7151129 DOI: 10.3390/jdb8010006] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 12/16/2022] Open
Abstract
This review focuses on the role of the Cytochrome p450 subfamily 26 (CYP26) retinoic acid (RA) degrading enzymes during development and regeneration. Cyp26 enzymes, along with retinoic acid synthesising enzymes, are absolutely required for RA homeostasis in these processes by regulating availability of RA for receptor binding and signalling. Cyp26 enzymes are necessary to generate RA gradients and to protect specific tissues from RA signalling. Disruption of RA homeostasis leads to a wide variety of embryonic defects affecting many tissues. Here, the function of CYP26 enzymes is discussed in the context of the RA signalling pathway, enzymatic structure and biochemistry, human genetic disease, and function in development and regeneration as elucidated from animal model studies.
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Affiliation(s)
- Catherine Roberts
- Developmental Biology of Birth Defects, UCL-GOS Institute of Child Health, 30 Guilford St, London WC1N 1EH, UK;
- Institute of Medical and Biomedical Education St George’s, University of London, Cranmer Terrace, Tooting, London SW17 0RE, UK
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