Three Blind Mice? Maybe Not
Author: Jeannette Y. Wick, RPh, MBA, FASCP
Stressing mice with simulated glaucoma by reducing their oxygen intake reduced their rate of vision loss, researchers report.
Researchers at Washington University School of Medicine in St. Louis have discovered a treatment that prevents glaucoma-related optic nerve injury in a mouse model. They reported their results in a study
published online on February 29, 2012, in Molecular Medicine
To simulate glaucoma in mice, the researchers tied off vessels that normally allow fluid to drain from the eye, causing intraocular pressure to increase. The researchers then stressed some of the mice by reducing the level of oxygen available to them several times over 2 weeks, which increased the resistance of their optic nerve cells to damage—a protective response referred to as “tolerance.”
The researchers found that after 10 weeks of simulated glaucoma, normal mice lost an average of 30% of their retinal ganglion cell bodies, compared with 3% for the preconditioned mice. Preconditioned mice also lost significantly fewer retinal ganglion cell axons. Saving retinal ganglion cells can help prevent vision loss and blindness.
“Previous research has shown that there are literally hundreds of survival genes built into our DNA that are normally inactive,” said study senior author Jeffrey M. Gidday, PhD, associate professor of neurological surgery and ophthalmology, in a press release. “When these genes are activated, the proteins they encode can make cells much less vulnerable to a variety of injuries.” Identifying specific survival genes should help scientists develop drugs that can activate them, according to Dr. Gidday.
Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.