An international consortium of researchers including Stefan Kempf (University of Southern Denmark, Denmark) has demonstrated that ionizing radiation is a potential contributor to Alzheimer’s disease.
Exposure to ionizing radiation is becoming increasingly common in the modern world through likes of nuclear technologies, airline travel, medical diagnostics and therapeutic radiology, amongst others. Recent data has suggested then at even relatively low doses, exposure to this type of radiation could induce molecular alterations associated with cognitive dysfunction.
The consortium therefore studied the effect of chronic low-dose-rate ionizing radiation treatment in the murine hippocampus at two dose rates. ApoE-deficient C57BL/6 mice used as AD models were treated at rates of either 1mGy or 20mGy per day, over 300 days.
At both dose rates, the ApoE knockout mice presented with radiation-induced alterations in molecular features, particularly on the phosphoproteome level, similar to those observed in AD neuropathology. In fact, a number of the proteins that demonstrated a radiation-induced change in their phosphorylation status were associated with synaptic plasticity.
This study highlights chronic low-dose-rate radiation as a potential risk factor in AD etiology and that ionizing radiation may accelerate AD symptoms.
“When you compare these figures you will find that we exposed the mice to a more than 1000 times smaller cumulative dose than what a patient gets from a single CT scan in the same time interval. And even then we could see changes in the synapses within the hippocampus that resemble Alzheimer´s pathology,” stated Kempf.
Sources: Kempf SJ, Janik D, Barjaktarovic Z et al. Chronic low-dose-rate ionising radiation affects the hippocampal phosphoproteome in the ApoE−/− Alzheimer’s mouse model. Oncotarget. doi: 10.18632/oncotarget.12376 (2016) (Epub ahead of print);
The University of Southern Denmark press release.