Regenerating Retinal Ganglion Cells

■ In glaucoma, degeneration of retinal ganglion cells (RGCs) leads to permanent blindness; there is currently no effective treatment for RGC degeneration. Now, University of Nebraska Medical Center researcher Iqbal Ahmad, PhD, and colleagues have shown that human RGCs can be regenerated in an in vitro setting helped by lessons learned in rodent models. The discovery was reported in the journal Development.

“This finding could lead to new methods of screening for drugs and genes impacted by glaucoma to help treat and possibly reverse vision loss in people suffering from the disease,” said Dr. Ahmad, a professor in the department of ophthalmology and visual sciences at UNMC, in a news release. Dr. Ahmad and his team of investigators found that when the mTOR signaling pathway, which is present in all cell types and essential for cell survival, is activated in RGCs, the cells begin to regenerate and thrive. The researchers used a microfluidic chamber system to see how axons regenerated after axotomy.

The significance of this work, Dr. Ahmad said, is that it is done using human adult pluripotent stem cells, whereas previous work was done only in rats and mice. While those animal models provided insight into better understanding of the disease progression of glaucoma, research using human RGCs will translate more readily when it comes to potential drug and gene therapies, he said. His lab has already applied for a patent on the technology that shows how RGCs can be regenerated.