One of the most complex organs of the human anatomy is the eye. The eye controls the entire visual of an individual, with complex structures and components such as the retina. The retina is a complicated mix of cells and layers that help the eye focus and observe every detail in the field of eyesight.
Any infliction to the retina can result in severe outcomes, potentially leading to retinal diseases. Even the best medications currently like cell therapy can involve a lot of effort and time which the patients cannot give.
However, researchers at the North Texas Eye Research Institute looked into the matter and developed a fast and easier method to rebuild the damaged retina in eye diseases. The method involves a few chemicals that lead to the generation of cells which ultimately restore eyesight.
Stem cell therapy
Macular degeneration is a typical reason for loss of eyesight in individuals aged over 60. In this case, the cells which sense light in the retina, primarily known as photoreceptors, begin to deteriorate. Traditionally, doctors have opted for medications for the last surgery to fix this.
However, recently, researchers discovered stem cell therapy. This therapy is the method by which loss or degenerated cells are replaced with healthier cells. For the replenishment of these cells, researchers changed the type of specialized cells with the help of specific proteins known as “Yamanaka factors”.
“Reprogramming” of specialized cells
This is a big revolution in stem cell therapy. This method can “reprogram” or restore the generalization of specialized cells such as the heart and immune cells. Basic cells are called pluripotent stem cells. These cells possess the ability to further develop into several types of cells with the inclusion of photoreceptors that are lost in eye diseases.
However, there are rooms for improvements with the struggles in this method. The skin is usually a more typical origin for the “reprogramming” of cells. The usual time needed is 25 days for the conversion to stem cells. However, further conversion to photoreceptors might take 65-70 extra days, before they are ready to begin cell therapy.
Skipping the reprogramming
With 5 small chemicals, researchers at the North Texas Eye Research Institute have overcome these complications. After publishing their research, they explained that they used these chemicals called small molecule drugs which created photoreceptors straight from skin cells known as fibroblasts, and eliminated the reprogramming step altogether, with no involvement of stem cells.
The 5 chemicals were tested individually and as a combination. Results concluded that the combination showed the most promising results, transforming skin cells into cells that behaved like photoreceptors,
However, the similarity of the “photoreceptor-like-cells” and the actual photoreceptors, was studied. Hence, they studied the transcriptome of the two, which is an integral part of the cell’s identity. The results showed sufficient similarity. However, stem cell therapy is a very intricate process with a lot of complications.
The cells have to persist the transplant and change of environment while making the proper connections with the target cells for optimal functionality as a photoreceptor. The real experiment was to test the functionality of these chemically-generated photoreceptors in animal models of eye diseases.
Transplanting the chemically-generated photoreceptors
The transplant was performed in mice with retinal damage. Researchers concluded that almost half of the mice with retinal damage who received the transplant showed pupil reflexes which were similar to mice without retinal damage. This concluded visual response improvement.
The transplant also provided an improved vision, with better pupil reflexes. While these photoreceptors restored vision in the mice with retinal damage, it also helped researchers better understand the cell’s chemical machinery for the restoration of sight, which lays a foundation for different methods to improve vision.