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Updated: Aug 23, 2025
Retinal Organoid Induction System for Derivation of 3D Retinal Tissues from Human Pluripotent Stem Cells
Published on: April 12, 2021
Single-Cell Transcriptomic Profiling of Human Retinal Organoids Revealed a Role of IGF1-PHLDA1 Axis in Photoreceptor
Yuhua Xiao1, Xiying Mao2, Xing Hu1
1State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
Purpose:
Cone and rod photoreceptors in the retina convert light to electrical signals which are transmitted to the visual cortex of the brain. Abnormal photoreceptor development and degeneration results in blindness. So far, the mechanism that controls photoreceptor specification and its subsequent fate bifurcation remain elusive.
Methods:
To trace and enrich the human photoreceptor lineage, we first engineered H9 human embryonic stem cell (hESC) reporter line by fusing EGFP to endogenous BLIMP1 using CRISPR/CAS9 gene-editing technology, and then used the cell line to generate 3D retinal organoids. Following EGFP-based cell sorting, single-cell RNA-sequencing was conducted via 10x Genomics Chromium system, and the data were analyzed using Seurat. Immunofluorescence combined with lentivirus-mediated knockdown and overexpression experiments were used as validation approaches.
Results:
Single-cell transcriptomic profiling revealed that retinal progenitor cells were temporally programmed to differentiate to cone and rod sequentially. We identified PHLDA1 as a novel regulator of photoreceptor specification. PHLDA1 mediated the effects of IGF1 through IGF1R, and inhibited AKT phosphorylation during photoreceptor development.
Conclusions:
Our data established a transcriptomic cell atlas of the human photoreceptor lineage, and identified IGF1-PHLDA1 axis to regulate human photoreceptor development.
Insights
Researchers mapped human photoreceptor development using single-cell sequencing. They identified the IGF1-PHLDA1 pathway as crucial for regulating photoreceptor specification and development, offering insights into preventing blindness.
Area of Science:
- Retinal biology
- Developmental biology
- Genetics
Background:
- Photoreceptors (cones and rods) in the retina convert light into electrical signals for vision.
- Dysfunctional photoreceptor development or degeneration leads to blindness.
- Mechanisms governing photoreceptor specification and fate remain unclear.
Purpose of the Study:
- To map the human photoreceptor lineage and identify key regulatory factors.
- To understand the molecular mechanisms controlling photoreceptor development.
Main Methods:
- Engineered a human embryonic stem cell (hESC) reporter line using CRISPR/CAS9.
- Generated 3D retinal organoids and performed single-cell RNA-sequencing.
- Utilized EGFP-based cell sorting, Seurat analysis, and immunofluorescence.
Main Results:
- Identified sequential differentiation of retinal progenitor cells into cone and rod photoreceptors.
- Discovered PHLDA1 as a novel regulator of photoreceptor specification.
- Showed PHLDA1 mediates IGF1 effects via IGF1R, inhibiting AKT phosphorylation.
Conclusions:
- Established a transcriptomic cell atlas of the human photoreceptor lineage.
- Identified the IGF1-PHLDA1 axis as a key regulator of human photoreceptor development.
