In a recent study published in PNAS Nexus, a research team from NYU Langone Health performed single cell RNA sequencing (scRNA-seq) on human corneas and cornea organoids to understand the molecular development of corneal cells in the womb as well as evaluate the potential use of these organoids as 3D models for future cell-based therapies.
Give me some background first.
Researchers designed 3D cornea organoids from pluripotent stem cells to determine the codifferentiation of corneal cells.
Interestingly, unlike traditional cell cultures—which contain a flat sheet of a singular type of cell in a dish of nutrients—these organoids were grown from stem cells with particular nutrient adjustments to allow for multiple cell types to develop and eventually organize into three-dimensional structures.
What’s the purpose of these organoids?
The 3D organoids allow for different cell types to interact in layers, more closely replicating the structure and function of corneal tissues than previous models.
Now talk about the study.
Through scRNA-seq, researchers identified cell-specific genes activated in lab-derived human corneal organoids and in human cadaver corneas.
They then determined that the organoids contain cell clusters resembling the cells of the corneal epithelium, stroma, and endothelium, with subpopulations that reflect signatures of early developmental states.
Go on…
Conversely, the adult cadaver corneas were predominantly composed of epithelial, stromal, and—to a lesser degree—endothelial cells.
Unlike the adult cornea, where the largest cell population is stromal, the organoids contain large proportions of epithelial and endothelial-like cells.
These provided a 3D model to study corneal diseases and measure the integrated responses of different cell types.
Anything else?
Ultimately, a third to a fourth of the developing cells in the organoids had an endothelial-activated gene signature, and the activated gene signature of the organoids resembled that of a developing immature cornea.
Expert opinion?
“Our study is the first to examine human corneal organoids at a single-cell resolution,” noted Shukti Chakravarti, PhD, corresponding author. “By reading the genetic code built by active genes in this model, we have found that our organoids behave like actual corneas that are rapidly maturing in the womb.”
Chakravarti added that the organoids provide an opportunity to examine gene expression during development
“With their 3D structures and coexisting cell types, they allow the study of cellular signaling and cell-cell interactions in a more natural environment,” she stated.
Significance?
These organoids offer an experimental approach to modeling human diseases in tissue culture, consequently minimizing the need for animal models.
This technology could lead to the potential for developing cell-based regenerative approaches to treatments for blinding corneal diseases and providing a system for screening potential therapies for genetic diseases in the future—at less cost than traditional mouse model studies.