In the latest Nature Molecular Therapy a group of researchers from Tufts University is reporting using non-viral gene transfer therapy to deliver a gene that codes for a photoreceptor protecting protein produced in the eye. Not having to use viruses as a delivery mechanism avoids many potential side effects in developing future gene therapies. More from Tufts press office :
In a model simulating the progression of human retinal degeneration, the researchers treated mice with nanoparticles carrying a gene for GDNF (Glial Cell Line-Derived Neurotrophic Factor), a protein known to protect the photoreceptor cells in the eye. Retinas treated with the GDNF-carrying nanoparticles showed significantly less photoreceptor cell death than controls. Preservation of these cells resulted in significantly better eyesight in the treatment group seven days after treatment, compared to controls.
The protection conferred by the GDNF-carrying nanoparticles was temporary, as tests fourteen days after treatment showed no difference in eyesight between treated mice and controls.
“The next step in this research is to prolong this protection by adding elements to the DNA that permit its retention in the cell. Bringing forth a more potent and enduring result will move us closer to clinical application of non-viral gene therapy,” said Kumar-Singh.
In a previous study, this same team of researchers developed the gene delivery method used in this research. The researchers showed that a peptide called PEG-POD, which compacts DNA into nanoparticles, delivers genes to the retina more efficiently than other non-viral carriers.
Image: Top shows damage (pink) to the retina. Bottom image shows that POD GDNF nanoparticles protected the retina from damage.
Press release: Breakthrough Gene Therapy Prevents Retinal Degeneration…
Abstract in Molecular Therapy: POD Nanoparticles Expressing GDNF Provide Structural and Functional Rescue of Light-induced Retinal Degeneration in an Adult Mouse