new insights

Little regulatory molecules called microRNAs are essential for proper maturation, composition, and function in the postnatal retina.

In our recent study published in iScience, we show that dysregulation of microRNAs (miRNAs) results in delays of retinal cell maturation in the developing eye after birth. Specifically, we removed a molecule called Dicer, which produces many small genetic regulators known as microRNAs. These regulators help cells to develop into the right cell types at the right time. When Dicer was removed from these developing retinal cells, the retina did not form properly. In adult eyes, the light-sensing rod cells did not function well, and there were fewer support cells (Müller glia). Interestingly, there was an overproduction of another neuron type called amacrine cells. They are normally born a little earlier, and it appears that their development is regulated by the miRNAs miR-25/20. We also found that some young retinal cells never fully matured and stayed “immature”, i.e., remained stuck in an early developmental stage, even into adulthood. This shows that Dicer and microRNAs are essential for proper retinal cell maturation, so a healthy, functioning retina can form. Our data also shows that miRNAs play a role in Müller glia maturation, hence they can probably be used to rejuvenate these cells for therapeutic purposes.

Why is it important to know that miRNAs play a role in retinal development? Well, knowing which specific miRNAs play a role in regulating a specific cell type will help to develop better tools for cell reprogramming and other tools in regenerative medicine, including organoid research, which are promising approaches to restoring lost cells in patients.

Kang, S., Larbi, D., Bruns, E., Hahne, K., Khodadadi-Jamayran, A., Sreenivasaiah, C., Lima Carneiro, M., Andrade, M., Batsuuri, K., Chen, S., Jager, J., Viswanathan, S., Clark, B.S., Wohl, S. G. 2025. “Dicer is essential for proper maturation, composition, and function in the postnatal retina.” iScience, 28, 113794.