scholarly journals Determinants of Disease Penetrance in PRPF31-Associated Retinopathy

Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1542
Author(s):  
Samuel McLenachan ◽  
Dan Zhang ◽  
Janya Grainok ◽  
Xiao Zhang ◽  
Zhiqin Huang ◽  
...  

Retinitis pigmentosa 11 (RP11) is caused by dominant mutations in PRPF31, however a significant proportion of mutation carriers do not develop retinopathy. Here, we investigated the relationship between CNOT3 polymorphism, MSR1 repeat copy number and disease penetrance in RP11 patients and non-penetrant carriers (NPCs). We further characterized PRPF31 and CNOT3 expression in fibroblasts from eight RP11 patients and one NPC from a family carrying the c.1205C>T variant. Retinal organoids (ROs) and retinal pigment epithelium (RPE) were differentiated from induced pluripotent stem cells derived from RP11 patients, an NPC and a control subject. All RP11 patients were homozygous for the 3-copy MSR1 repeat in the PRPF31 promoter, while 3/5 NPCs carried a 4-copy MSR1 repeat. The CNOT3 rs4806718 genotype did not correlate with disease penetrance. PRFP31 expression declined with age in adult cadaveric retina. PRPF31 and CNOT3 expression was reduced in RP11 fibroblasts, RO and RPE compared with controls. Both RP11 and NPC RPE displayed shortened primary cilia compared with controls, however a subpopulation of cells with normal cilia lengths was present in NPC RPE monolayers. Our results indicate that RP11 non-penetrance is associated with the inheritance of a 4-copy MSR1 repeat, but not with CNOT3 polymorphisms.

2021 ◽  
Vol 22 (3) ◽  
pp. 1345
Author(s):  
Caroline Amalie Brunbjerg Hey ◽  
Lasse Jonsgaard Larsen ◽  
Zeynep Tümer ◽  
Karen Brøndum-Nielsen ◽  
Karen Grønskov ◽  
...  

Bardet-Biedl syndrome (BBS) is a ciliopathy characterized by retinal dystrophy, renal cysts, obesity and polydactyly. BBS genes have been implicated in ciliogenesis, hedgehog signaling and retinal pigment epithelium maturation. BBS1 and BBS5 are members of the BBSome, implicated in cilia transport of proteins, and BBS10 is a member of the chaperonin-complex, mediating BBSome assembly. In this study, involvement of BBS1, BBS5 and BBS10 in ciliogenesis and hedgehog signaling were investigated in BBS-defective patient fibroblasts as well as in RPE-hTERT cells following siRNA-mediated knockdown of the BBS genes. Furthermore, the ability of BBS1-defective induced pluripotent stem-cells (iPSCs) to differentiate into RPE cells was assessed. We report that cells lacking functional BBS5 or BBS10 have a reduced number of primary cilia, whereas cells lacking functional BBS1 display shorter primary cilia compared to wild-type cells. Hedgehog signaling was substantially impaired and Smoothened, a component of hedgehog signaling, was trapped inside the cilia of the BBS-defective cells, even in the absence of Smoothened agonist. Preliminary results demonstrated the ability of BBS1-defective iPSC to differentiate into RPE-65 expressing RPE-like cells. The BBS1−/−-defective RPE-like cells were less pigmented, compared to RPE-like cells differentiated from control iPSCs, indicating an impact of BBS1 on RPE maturation.


2020 ◽  
Author(s):  
Xiaoling Guo ◽  
Deliang Zhu ◽  
Ruiling Lian ◽  
Qiaolang Zeng ◽  
Sanjana Mathew ◽  
...  

Abstract Background: Retinal pigment epithelium (RPE) cells derived from human induced pluripotent stem cells (hiPSCs) exhibit great promise in treating retinal degenerative diseases. Here, we would explore the feasibility of non-colony dissociated hiPSCs to differentiate into functional RPE cells (hiPSC-RPE), and offer an alternative transplantation method based on cell spheroids.Methods: hiPSC-RPE cells were identified using reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence assay, Western blotting, and flow cytometry assay. The functions of hiPSC-RPE cells in vitro and in vivo were assessed by fluorescein leakage test, transepithelial electrical resistance (TEER) assay, atomic force microscopy observation, POS phagocytosis assay, frozen tissue sections, live/dead assay, SA-β-Gal staining, and immunocytochemistry.Results: hiPSC-RPE cells positively expressed biomarkers of RPE cells but not iPSCs, such as CRALBP (97.4%), EMMPRIN (93.8%), Oct4 (2.1%), and Sox2 (2.0%). hiPSC-RPE cells displayed RPE-like characteristics including barrier function, phagocytic activity, and polarized membrane. The cells derived from hiPSC-RPE spheroids positively expressed Nestin and exhibited reduced SA-β-Gal staining. hiPSC-RPE cell spheroids could form monolayer on decellularized corneal matrixes (DCM). After one month of subretinal transplantation, hiPSC-RPE cell spheroids could survive and maintain segmental sheet growth in sodium iodate (NaIO3) induced RPE-degenerated chinchilla rabbits. Conclusion: This study suggested that non-colony dissociated hiPSCs were effectively differentiated into functional RPE cells, and hiPSC-RPE cell spheroids maintained segmental sheet growth in the subretinal of RPE degenerate chinchilla rabbits in vivo, which may lay the foundation for cell spheroid transplantation as an alternative method for RPE degenerative disease therapy in the future.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Helena Isla-Magrané ◽  
Anna Veiga ◽  
José García-Arumí ◽  
Anna Duarri

Abstract Background Recently, great efforts have been made to design protocols for obtaining ocular cells from human stem cells to model diseases or for regenerative purposes. Current protocols generally focus on isolating retinal cells, retinal pigment epithelium (RPE), or corneal cells and fail to recapitulate the complexity of the tissue during eye development. Here, the generation of more advanced in vitro multiocular organoids from human induced pluripotent stem cells (hiPSCs) is demonstrated. Methods A 2-step method was established to first obtain self-organized multizone ocular progenitor cells (mzOPCs) from 2D hiPSC cultures within three weeks. Then, after the cells were manually isolated and grown in suspension, 3D multiocular organoids were generated to model important cellular features of developing eyes. Results In the 2D culture, self-formed mzOPCs spanned the neuroectoderm, surface ectoderm, neural crest, and RPE, mimicking early stages of eye development. After lifting, mzOPCs developed into different 3D multiocular organoids composed of multiple cell lineages including RPE, retina, and cornea, and interactions between the different cell types and regions of the eye system were observed. Within these organoids, the retinal regions exhibited correct layering and contained all major retinal cell subtypes as well as retinal morphological cues, whereas the corneal regions closely resembled the transparent ocular-surface epithelium and contained of corneal, limbal, and conjunctival epithelial cells. The arrangement of RPE cells also formed organoids composed of polarized pigmented epithelial cells at the surface that were completely filled with collagen matrix. Conclusions This approach clearly demonstrated the advantages of the combined 2D-3D construction tissue model as it provided a more ocular native-like cellular environment than that of previous models. In this complex preparations, multiocular organoids may be used to model the crosstalk between different cell types in eye development and disease. Graphical abstract


2018 ◽  
Author(s):  
Marcela Garita-Hernandez ◽  
Maruša Lampič ◽  
Antoine Chaffiol ◽  
Laure Guibbal ◽  
Fiona Routet ◽  
...  

A major challenge in the treatment of retinal degenerative diseases, with the transplantation of replacement photoreceptors, is the difficulty in inducing the grafted cells to grow and maintain light sensitive outer segments (OS) in the host retina, which depends on proper interaction with the underlying retinal pigment epithelium (RPE). For a RPE-independent treatment approach, we introduced a hyperpolarizing microbial opsin into photoreceptor precursors from new-born mice, and transplanted them into blind mice lacking the photoreceptor layer. These optogenetically transformed photoreceptors were light responsive and their transplantation lead to the recovery of visual function, as shown by ganglion cell recordings and behavioral tests. Subsequently, we generated cone photoreceptors from human induced pluripotent stem cells (hiPSCs), expressing the chloride pump Jaws. After transplantation into blind mice, we observed light-driven responses at the photoreceptor and ganglion cell level. These results demonstrate that structural and functional retinal repair is possible by combining stem cell therapy and optogenetics.


2020 ◽  
Author(s):  
Xiaoling Guo ◽  
Deliang Zhu ◽  
Ruiling Lian ◽  
Qiaolang Zeng ◽  
Sanjana Mathew ◽  
...  

Abstract Background Retinal pigment epithelium (RPE) cells derived from human induced pluripotent stem cells (hiPSCs) exhibit great promise in treating retinal degenerative diseases. To develop transplantable and functional hiPSC-RPE cells, here, we used a novel differentiation protocol based on a non-colony-type monolayer (NCM) culture and injectable spheroids. Methods The derived hiPSC-RPE cells were identified using reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence assay, Western blotting, and flow cytometry assay. The functions of transplantable hiPSC-RPE cells in vitro and in vivo were also analyzed by fluorescein leakage test, transepithelial electrical resistance (TEER) assay, atomic force microscopy observation, POS phagocytosis assay, frozen tissue sections, live/dead assay, SA-β-Gal activity assay, and immunocytochemistry. Results The derived hiPSC-RPE cells positively expressed biomarkers of RPE cells but not iPSCs, such as CRALBP (97.4%), EMMPRIN (93.8%), Oct4 (2.1%), and Sox2 (2.0%). hiPSC-RPE cells displayed RPE-like characteristics including barrier function, phagocytic activity, and polarized membrane. hiPSC-RPE cell spheroids positively expressed Nestin and exhibited reduced SA-β-Gal staining. Injectable hiPSC-RPE cell spheroids could form monolayers on decellularized corneal matrixes (DCM). After subretinal transplantation for one month, hiPSC-RPE cell spheroids could survive and maintain segmental sheet growth in RPE-degenerated chinchilla rabbits. Conclusion This study realized that NCM dissociated hiPSCs were effectively differentiated into transplantable and functional RPE through the sequential addition of defined factors but not involving exogenous genes. This study may lay the foundation for the clinical transplantation of hiPSC-RPE cell spheroids as therapy for RPE degenerative diseases in the future.


2015 ◽  
Vol 112 (35) ◽  
pp. 10950-10955 ◽  
Author(s):  
Julien Maruotti ◽  
Srinivas R. Sripathi ◽  
Kapil Bharti ◽  
John Fuller ◽  
Karl J. Wahlin ◽  
...  

Age-related macular degeneration (AMD) is associated with dysfunction and death of retinal pigment epithelial (RPE) cells. Cell-based approaches using RPE-like cells derived from human pluripotent stem cells (hPSCs) are being developed for AMD treatment. However, most efficient RPE differentiation protocols rely on complex, stepwise treatments and addition of growth factors, whereas small-molecule–only approaches developed to date display reduced yields. To identify new compounds that promote RPE differentiation, we developed and performed a high-throughput quantitative PCR screen complemented by a novel orthogonal human induced pluripotent stem cell (hiPSC)-based RPE reporter assay. Chetomin, an inhibitor of hypoxia-inducible factors, was found to strongly increase RPE differentiation; combination with nicotinamide resulted in conversion of over one-half of the differentiating cells into RPE. Single passage of the whole culture yielded a highly pure hPSC-RPE cell population that displayed many of the morphological, molecular, and functional characteristics of native RPE.


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