New AMD study uses light-sensitive retinal organoids

Choroidal neovascularization (CNV) is the creation of new, abnormal blood vessels that originate in the choroid, a vessel-containing layer under the retina, and is a hallmark of wet age-related macular degeneration (AMD). A partnership between ophthalmology researchers at the University of Colorado School of Medicine and Johns Hopkins University expands the understanding of how oxidative stress contributes to the development of CNV in patients with AMD.

To study the roles oxidative stress, a condition in which the body lacks antioxidants, and hypoxia, low levels of oxygen in body tissues, play in the progression of AMD, Johns Hopkins University researchers turned to CellSight, the ocular stem cell and regeneration research program in the CU Department of Ophthalmology, for tools that allow researchers to explore specific conditions relevant to AMD. Using human-induced pluripotent stem cells, a type of stem cells that are generated or induced from cells obtained from an adult person’s skin or blood, CellSight investigators can recreate human retinal tissue in the lab. “We generate retinal organoids, which can be described as mini retinas in a petri dish, that mimic the cellular organization of the human retina and are capable of responding to light,” explains CellSight researcher Miguel Flores-Bellver, Ph.D., assistant professor of ophthalmology. “We also have another tool, retinal pigment epithelium tissue, also derived from stem cells. By subjecting these retinal organoids and the retinal pigment epithelium tissues to oxidative stress and hypoxia, we can mimic pathological conditions that promote the development of AMD and contribute to the research our colleagues at Johns Hopkins are conducting.”

The research, published in Proceedings of the National Academy of Sciences, marks a step forward in better understanding AMD, a leading cause of vision impairment across the world, and highlights the vital role retinal organoids can play in finding a treatment for millions of people who are diagnosed with the debilitating disease. The study concludes that “a careful balance of hypoxia-inducible factor levels must be maintained to prevent vision loss in the eyes of patients with AMD” and that modulation of hypoxia-inducible factor may be an effective therapeutic approach for the treatment or prevention of AMD. (Hypoxia-inducible factor is a protein that plays an essential role in the cellular response to low oxygen.)

Source: CU Anschutz Medical Campus, Medical Xpress, December 7, 2023; see source article