The following is a summary of “Signatures for viral infection and inflammation in the proximal olfactory system in familial Alzheimer’s disease,” published in the March 2023 issue of the Neurobiology of Aging by Bubak et al.
Dementia is a common symptom of Alzheimer’s disease (AD); however, olfactory dysfunction and olfactory pathology are often present long before the diagnosis of AD. Therefore, differential gene and protein expression in the olfactory bulb (OB) and olfactory tract (OT) of autosomal dominant presenilin 1 E280A mutant carriers with familial Alzheimer’s disease (FAD) was examined.
In both highly and poorly myelinated areas, immunostaining for beta-amyloid (A) and CD68 was elevated in the FAD OT group compared to the control group. Moreover, increased immunostaining for Iba1 in the highly myelinated area was seen in the FAD OT group. The olfactory bulb (OB) was found to be infected with a virus, the olfactory tract (OT), which is responsible for relaying information from the OB to the hippocampus via the entorhinal cortex, was found to be inflamed, and oligodendrocyte deconvolved transcripts were found to be reduced in the FAD tissue samples sequenced.
The spatial proteomic study has confirmed aberrant myelination in the OT of FAD patients, which is fascinating. These results indicate a problem in the OB and hippocampus pathways. These results show that viral infections can cause inflammation and myelin disruption in the olfactory system, which may affect hippocampus function. A faster rate of FAD progression may result from this.
Source: sciencedirect.com/science/article/abs/pii/S0197458022002585
