Postdoctoral Researcher · TheraFUS Laboratory · University of Rome Tor Vergata
BACKGROUND
Biography
Valentin Beaufils is a postdoctoral researcher in the TheraFUS Laboratory at the University of Rome Tor Vergata. He investigates focused ultrasound and magnetic nanodiscs in experimental models of glioblastoma. His background is in neuroscience, with particular interests in brain injury, neurovascular function and experimental methods for studying ultrasound–tissue interactions.
He trained at the University of Caen and carried out doctoral research at the ISTCT unit, Cyceron, on physical activity and the cerebral effects of radiotherapy. His earlier work examined low-dose ionising radiation in a rat model of vascular cognitive impairment.
Vascular dementia is a leading cause of cognitive decline, with few effective treatment options currently available. Within the framework of hormesis, treatment with low-dose ionizing radiation (LDIR<0.1 Gy) has been proposed as a promising therapy for neurodegenerative diseases. This study investigates the effects of LDIR on cognitive decline, brain damage, blood-brain barrier permeability, and oxidative stress in a rat model of vascular dementia. After chronic cerebral hypoperfusion (CCH), the whole brain was exposed to 0.3 Gy of X rays, delivered in 0.1 Gy fractions over three consecutive days, beginning at day 1 or day 7 after occlusion. LDIR effects were evaluated using behavioral tests, MRI, post-mortem analyses, and in vitro analyses. Early exposure to LDIR attenuated recognition memory deficits induced by CCH. LDIR applied one day after occlusion reduced alterations in brain tissue integrity attributed to CCH and mitigated neuronal loss in the hippocampus. Moreover, LDIR counteracted CCH-induced blood-brain barrier permeabilization and improved survival of epithelial cells subjected to oxygen-glucose deprivation/reoxygenation. LDIR modulated oxidative stress by altering the reactive species interactome and activating antioxidant enzymes. Brain exposure to low-dose ionizing radiation modulates the events triggered by CCH and thus attenuates cognitive decline and brain damage in the rat.
Although radiotherapy improves the prognosis of patients with brain cancer, it induces cognitive deficits. Animal models have been used to address the underlying mechanisms of these radiation-induced deficits. Nonetheless, in most of the animal studies, whole-brain irradiation has been applied, deviating from the clinical practice, where the goal is to reduce the exposure of healthy brain tissue to radiation. Here we analyzed in rats the evolution of brain tissue injury and cognitive impairments induced by irradiation restricted to only one cerebral hemisphere and systematically compared these effects with those observed after whole-brain irradiation. Rats were divided into control, whole-brain-irradiated (WBI) and hemispheric-irradiated (HBI) groups. Multiparametric magnetic resonance imaging, behavioral tests and immunohistology were performed up to 6 months following the irradiation (3 × 10 Gy). Relative to WBI, more restricted irradiation did not induce significant locomotion impairment nor anxiety-like behavior; cognitive deficits and brain atrophy were also reduced after HBI compared with WBI. Magnetic resonance imaging revealed major alterations in the microstructure and the vasculature of brain tissue only in WBI rats. However, immunohistological analyses indicated that HBI induced persistent neuroinflammation confined to the irradiated hemisphere, which appeared more pronounced than that observed after WBI. Overall, the data highlight that restricted brain irradiation mitigates brain damage and induces less cognitive deficits compared with whole-brain irradiation. In the future, refining animal models with targeted cerebral irradiation will be essential for evaluating neuroprotective strategies.