Successfully cultured retina from versatile stem cells

The human eye is often likened to a camera and although it has a fairly basic design, the detailed structure of the eye is more complex than most advanced electronic devices today. This means that unlike other simple organs, research on retinopathy depends heavily on animal tests and it is extremely difficult to treat these diseases. However, a hope has surfaced when researchers from the John Hopkins Institute have recently recreated part of the function of the human retina with stem cells and it can react to light like real eyes. .

The retina is a complex link in the eyes of a person who plays a role similar to a film or image sensor in a camera. It is made up of 10 layers of tissue including structural membranes, nerve nodes, photoreceptors, and black-and-white rod-shaped cells - works very well in low light and The cones recognize colors. If scientists can replicate this structure in the laboratory, this will be an important finding in the treatment of eye diseases.

Rod-shaped receptor cells (green) inside the mini retina are cultured from stem cells in the laboratory.

The team's approach comes from the Johns Hopkins Institute, which uses human pluripotent stem cells (iPS) . In other words, adult cells have been converted back into stem cells and from these cells, they can metabolize more than 200 different types of cells. The John Hopkins team programmed stem cells so they could develop into retinal cells on a petri dish. These cells develop into retinal cells in the same manner and proportion as in human embryos. As they develop, they differentiate into seven different cell types that make up the retina and organize themselves into three-dimensional outer structures necessary for the action of receptors.

M Valeria Canto-Soler - Associate Professor of Ophthalmology at Johns Hopkins Institute said: "We already know that 3D cell structures are essential to reproduce the functional properties of the retina. However, when caught "At the beginning of this study, we did not think that stem cells could make the retina themselves. In our system, cells somehow know what they need to do."

The cultivation of the retina component was previously done by the University of Wisconsin-Madison but the Johns Hopkins study is different because of the practical ability of mini retinas to actually work. When the retina reached 28 weeks of age, the researchers connected sensory cells to light with the electrode and transmitted light pulses to them. According to the team, the cells exhibited the same photochemical reactions as normal retina, especially rod - shaped cells - the key components that make up light receptors.

The results of the Johns Hopkins study are a mini retina that can respond to light but is unable to reproduce images. The structure is still incomplete and there is no way the artificial retina can connect to the visual cortex. However, the ability to create complex retinal structures promises to open new methods for studying eye diseases as well as finding therapies.

According to Canto-Soler, the technique will allow doctors to grow hundreds of mini retinas from patients' cells so that they can study further and offer drug treatments for individual fish. multiply. In addition, technology will also allow scientists to study eye diseases without the need for animal tests. Finally, it may hold the hope of recovering sight for patients with retinopathy with lab-made retinas.