In a study, the Cognitive Disorder Research unit examined samples from 16 deceased donors, half of whom had Alzheimer’s disease.
“We profiled paired retinal and hippocampal tissue from the same postmortem donors."
“We profiled paired retinal and hippocampal tissue from the same postmortem donors,” explains Jessica Santiago, first author of the article.
They used a sequential dual-extraction protocol to capture proteins across different solubility states. And their analysis revealed that a majority of all detected proteins were present in both the retina and hippocampus.
“We identified 372 differentially abundant retinal proteins in patients with Alzheimer’s, compared with controls. Of these, 64 were also differently abundant in the hippocampus,” summarizes Jessica Santiago.
Several retinal proteins also correlated with neuropathological disease stage. Further analysis showed that both tissues had similar changes in pathways related to synaptic function, mitochondria and the processing of APP – a precursor protein involved in Alzheimer’s disease.
The shared changes between retina and hippocampus support the idea that the retina may reflect brain pathology. This lends weight to its potential as an accessible site to track disease progression in living patients. Malin Wennström, the senior author of the study, sees this as an interesting and promising window for assessing Alzheimer’s, even though she stresses that there is still a long road to that point, as their findings must be confirmed in larger cohorts spanning earlier disease stages.
Nevertheless, their discoveries also hold important clues to preventing visual dysfunction from arising in Alzheimer’s patients.
Our findings offer a molecular explanation for retinal alterations seen in Alzheimer's disease"
“Our findings offer a molecular explanation for retinal alterations seen in Alzheimer's disease, which is necessary to understand for future work on vision-preserving treatments in these patients,” concludes Malin Wennström.
