Radiation-induced brain injury

Brain radiation is a widely used tool to help control brain tumor growth, but leads to significant cognitive deficits, especially in patients who undergo long-term whole-brain radiation. The molecular mechanisms of the cognitive impairment caused by radiation are poorly understood, but prolonged activation of the immune cells of the brain (microglia) has been implicated.

Dr. Burns and colleagues defined the transcriptome of acute and chronic irradiation in microglia and identified chronic changes that were highly reminiscent of changes occurring in natural aging. These results suggest that aging-related changes may be accelerated by irradiation and provide a starting point for understanding the microglial signature of aging-related and radiation-related cognitive decline. Subsequent unpublished work reveals profound enrichment of the microglial signature in human neurodegeneration and a correlation with poor survival rates in patients with glioblastoma.

Given the significant overlap between aging and radiation signatures, research in the Mayo Clinic Regenerative Neurosurgery and Neuro-Oncology Lab is working to harness promising anti-aging strategies, such as heterochronic parabiosis, to discriminate between the beneficial and pathological effects of microglial activation, enabling focused strategies to promote rejuvenation. Additionally, Dr. Burns' lab is actively exploring the use of certain progenitor cells, which also shows promise for repairing radiation-induced brain injury.

Related publications:

• Burns TC, Awad AJ, Li MD , Grant GA. Radiation-induced brain injury: Low-hanging fruit for neuroregeneration. Neurosurgical Focus. 2016; doi:10.3171/2016.2.focus161.
• Li MD, Burns TC, Kumar S, Morgan AA, Sloan SA, Palmer TD. Aging-like changes in the transcriptome of irradiated microglia. Glia. 2015; doi:10.1002/glia.22782.