Retinal cells discovered that could repair vision loss

A previously unreported population of human stem-like cells capable of regenerating retinal tissue and potentially promoting vision recovery has beed identified.

Retinal degeneration is the leading cause of blindness worldwide. Retinal degenerative diseases, characterised by the irreversible loss of light-sensitive neural cells in the retina, affect millions of patients globally. Current treatment options only slow the progression of the disease, but cannot replace the damaged retinal tissue. Now, a team led by Professor Jianzhong Su from Wenzhou Medical University, China, has identified human neural retinal stem-like cells (hNRSCs) with the capability to regenerate retinal tissue and the potential to assist in vision recovery.

'Overall, our work identifies and characterises a distinct category of retinal stem cells from human retinas, underscoring their regenerative potential and promise for transplantation therapy,' said Professor Su in the conclusion to his paper. He added, 'These cells exhibit capabilities for self-renewal and differentiation into all types of retinal cells... the significance of this research not only deepens our understanding of retinal biology but also holds immense potential for advancing therapeutic interventions in retinal degeneration diseases.'

The study, published in Science Translational Medicine, reported a population of hNRSCs, distinct from conventional retinal progenitor cells and retinal pigment epithelium stem-like cells. These cells exhibited substantial self-renewal and differentiation potential – the ability to become a specialised cell type. Single-cell multiomics and spatial transcriptomics were conducted to study gene expression in human retinal organoids – a three-dimensional organisation of stem cells which have been differentiated to form a distinct group of tissue, in this case closely mimicking the retina of the eye. From these analyses, it was determined that the retinal organoids contain a population of hNRSCs with similar transcriptional capabilities and developmental trajectories to hNRSCs in the fetal retina – potentially capable of regenerating all retinal cells.

Transcription factors known to be involved in cell development were also identified – managing the hNRSCs' propensity to differentiate and mature into retinal cells and regulate the repair processes within the retinal organoids. When the organoid-derived hNRSCs were transplanted into a mouse model exhibiting the early stage of a retinal degenerative disease called retinitis pigmentosa, these stem-cell-like cells differentiated and became integrated into the retina of the mouse. This restored retinal structure and enhanced visual function within this mouse line.

Previously, research teams in Korea and the USA have successfully transplanted retinal cells derived from human embryonic stem cells into patients with retinal degenerative disease (see BioNews 800 and 776).

This discovery could pave the way for future translational and regenerative therapies targeting retinal degenerative diseases such as retinitis pigmentosa, congenital retinal dystrophies and age-related macular degeneration. However, the work is at an early stage, and further studies are needed to uncover the exact mechanisms of retinal repair and the efficacy of the organoid-based technique in later-stage retinal degeneration.