Newly identified chemicals preserve mitochondrial capacity and
decelerate loss of photoreceptor cells in murine retinal degeneration
models
Abstract
Metabolic stress and associated mitochondrial dysfunction are implicated
in retinal degeneration irrespective of the underlying cause. We
identified seven unique chemicals from a screen of the Chembridge
DiverSET and tested their protection against calcium ionophore and
IBMX-induced loss of mitochondrial capacity, as measured by viability
and respirometry, in mouse retinal photoreceptor-derived 661W cells. Six
of the agents (CB1, 2, 6, 10 11, 12) were protective. Cheminformatic
analyses identified a unique pharmacophore with 6 physico-chemical
features based on two of the compounds (CB11 and CB12). The protective
efficacy of CB11 was further shown by a decrease in the loss of rod
photoreceptor cells in retinal explants from two retinitis pigmentosa
rodent models, the rd1 mouse and the S334ter-line-3 rat exposed to CB11
in the media. Using eye drops, CB11 biodistribution was confirmed in the
retina of the pig eye. The same eye drops decreased photoreceptor cell
loss in Balb/c mouse exposed to constant light, a model of age-related
macular degeneration. Our studies have identified new chemicals that
protect from mitochondrial damage and leads to improved mitochondrial
function. Using ex vivo and in vivo models, CB11 decreased the loss of
photoreceptor cells in murine models of retinal degeneration and may be
effective in the treatment of a wide variety of retinal dystrophies.