inducing 3d neural retina formation from cultured h9-embryonic stem cells for stem-cell based therapies

Enhanced 3D Neural Retina Differentiation from Human Embryonic Stem Cells

The eye serves as the primary source of information among human sensory organs, with the retina being the principal visual sensory tissue in mammalian eyes1. Retinopathy stands as one of the primary global causes of eye diseases, leading to blindness2. Approximately 2.85 million people worldwide suffer from varying degrees of vision impairment due to retinopathy3. Consequently, investigating its pathogenesis is crucial for early diagnosis and timely treatment. Most studies on human retinopathy have primarily focused on animal models4,5,6. However, the human retina is a complex, multi-layered tissue comprising various cell types. Traditional two-dimensional (2D) cell culture and animal model systems typically fail to faithfully recapitulate the normal spatiotemporal development and drug metabolism of the native human retina7,8.
Recently, 3D culture techniques have evolved to generate tissue-like organs from pluripotent stem cells (PSCs)9,10. Retinal organoids (ROs) generated from human PSCs in a 3D suspension culture system not only contain seven retinal cell types but also exhibit a distinct stratified structure similar to the human retina in vivo11,12,13. Human PSC-derived ROs have gained popularity and widespread availability and are currently the best in vitro models for studying the development and disease of the human retina14,15. Over the past few decades, numerous researchers have demonstrated that human PSCs, including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), can differentiate into ROs using various induction protocols. These advancements hold enormous potential in retinopathy for disease modeling, drug screening, and stem cell-based therapies16,17,18.
However, the generation of neural retina (NR) from human pluripotent stem cells (PSCs) is a complex, cumbersome, and time-consuming process. Furthermore, batch-to-batch variations in tissue organoids may lead to lower reproducibility of results19,20. Numerous intrinsic and extrinsic factors can influence the yield of retinal organoids (ROs), such as the number or species of starting cells and the use of transcription factors and small-molecule compounds21,22,23. Since the first human RO was generated by the Sasai laboratory11, multiple modifications have been proposed over the years to enhance the ease and effectiveness of the induction process13,21,24,25. Unfortunately, to date, no gold standard protocol has been established for generating ROs in all laboratories. Indeed, there is a certain degree of discrepancy in ROs resulting from different induction methods, as well as wide variation in the expression of retinal markers and the robustness of their structure22,26. These issues may severely complicate sample collection and the interpretation of study findings. Therefore, a more consolidated and robust differentiation protocol is needed to maximize efficiency with minimal heterogeneity of RO generation.
This study describes an optimized induction protocol based on a combination of Kuwahara et al.12 and D&#246;pper et al.27 with detailed instructions. The new method significantly reduces the probability of organoid vesiculation and fusion, increasing the success rate of generating NR. This development holds great promise for disease modeling, drug screening, and cell therapy applications for retinal disorders.

Author Spotlight: Simple and Efficient Neural Retina Organoid Production for Disease Modeling

Generating Neural Retina from Human Pluripotent Stem Cells

Our group focuses on understanding the pathogenesis and the treatment of human retinal diseases. Our protocol describes a optimized induction technique to generate a neural retina that significantly reduce the probability of vasculation and fusion to increase the success rate of retinal production until day 60. The modified method is simpler and more efficient in generating neural retina, which can prove to be a better disease model for drug screening and cell therapy.In the future, we aim to study the effects of physicochemical factors on retinal development and underlying mechanism using our retinal organoid model.

Inducing 3D Neural Retina Formation from Cultured H9-Embryonic Stem Cells for Stem-Cell Based Therapies

To begin, thaw and culture H9-embryonic stem cells in maintenance medium containing Y-27632. On day zero, once the colonies become 70%confluent, wash them with 2 milliliters of DPBS, then incubate the cells with 0.5 milliliters of cell dissociation solution containing 20 micromoles per liter Y-27632. To abort the digestion, add 3 milliliters of maintenance medium containing 20 micromoles per liter Y-27632.To pellet the cells, centrifuge the tube at 190 G for five minutes and discard the supernatant. Resuspend the pellet in one milliliter of growth factor-free chemically-defined medium with Y-27632. After counting the cells, add 1.2 million cells to 10 milliliters of growth factor-free chemically-defined medium and mix well.Then dispense 100 microliters of cell suspension to each well of a 96 well conical bottom plate. Incubate in a humidified 5%carbon dioxide atmosphere. To induce retina formation on day six, add medium containing BMP4 to each well of a 96 well V-bottom plate and incubate again.On day nine, 12, and 15, replace half of the spent medium with fresh medium without BMP4. On day 18, carefully transfer the formed embryoid bodies to a 15 milliliter centrifuge tube. After the natural precipitation of the embryoid bodies, gently remove the supernatant and rinse them with the neural retina differentiation medium.Then place the embryoid bodies in a low absorption six well plate and incubate the plate again. On day 21, Brightfield images showed continuous neuroepithelial structure in the neural retina generated using this method. The retinal induction success rate was significantly higher and retinal organoids generated using this protocol were similar in size and morphology compared to other methods.

Research

JoVE Journal

Developmental Biology

Retinopathy is one of the main causes of blindness worldwide. Investigating its pathogenesis is essential for the early diagnosis and timely treatment of ...