Stem Cells Form Light-Sensitive 3-D Retinal Tissue
News Jun 24, 2014
When we view a sunset or a soccer game, an intricate, orchestrated series of events takes place in our eyes. Light passes through the front part of each eye and is refracted and focused on the retina, a thin, delicate tissue at the back of our eyes. The retina contains many specialized cells, including photoreceptor cells, which convert light into electrical signals. These signals are then processed and sent to the brain. If the photoreceptor cells malfunction or die, vision loss and blindness can occur.
Researchers have previously shown that induced pluripotent stem (iPS) cells can grow into a type of retinal cell under certain cell culture conditions. These types of stem cells are adult cells that have been genetically reprogrammed to take on the characteristics of embryonic stem cells. They can grow indefinitely in the laboratory and can theoretically change, or differentiate, into all cell types found in the body.
Previous work showed that mouse and human embryonic stem cells can develop into a 3-D optic cup in culture that resembles the embryonic vertebrate eye. A team led by Drs. Xiufeng Zhong and M. Valeria Canto-Soler at Johns Hopkins University set out to determine to what extent iPS cells could be prompted to differentiate and acquire structural and functional features similar to a human retina. The work was funded in part by NIH’s National Eye Institute (NEI) and National Heart, Lung, and Blood Institute (NHLBI).
The scientists grew human iPS cells in culture dishes in the lab. They reported online on June 10, 2014, in Nature Communications that they were able to coax the cells to gradually take on the characteristics of retinal cells without adding many of the chemicals typically used to induce the cells to mature.
Over time, the iPS cells spontaneously formed cup-like 3-D structures in a sequence of events that mimicked what occurs during human development. The structures developed layers containing all the major cell types that are normally present in the retina, including photoreceptor cells.
To determine whether the photoreceptor cells were sensitive to light, the researchers subjected cells to a flash of light and measured the electrical responses in individual cells. A few cells responded, indicating they had reached a fairly advanced stage of development under the culture conditions.
“We have basically created a miniature human retina in a dish that not only has the architectural organization of the retina but also has the ability to sense light,” Canto-Soler says. “When we began this work, we didn't think stem cells would be able to build up a retina almost on their own. In our system, somehow the cells knew what to do.”
The accomplishment may lead to better tissue culture models to study human eye diseases and explore new therapies.
Switch Discovered to Convert Blood Vessels to Blood Stem Cells During Embryonic DevelopmentNews
Findings could aid research into creating new blood cells for transplants and understanding cancer metastasis.READ MORE
Unraveling How Mesenchymal Stem Cells From Gum Tissue Accelerate Wound HealingNews
To assist with wound healing, mesenchymal stem cells from the gum tissue secrete extracellular vesicles that contain the anti-inflammatory signaling molecule IL-1RA.READ MORE
Mending Broken Hearts with Cardiomyocyte MoldsNews
A team of researchers at Michigan Technological University in collaboration with Harvard Medical School, shows how cardiomyocytes grown in a heart-like environment mature more quickly, have improved functionality and are less likely to be rejected by patients’ bodies.READ MORE
Comments | 0 ADD COMMENT
World Congress on Advanced Pharmacy and Clinical Research
Jul 16 - Jul 17, 2018
6th Annual Congress on Biology and Medicine of Molecules
Sep 17 - Sep 18, 2018
International Conference on Molecular Biology and Stem Cells
Aug 13 - Aug 15, 2018
World Congress on Plant Science and Molecular Biology
Sep 12 - Sep 13, 2018