Background and Purpose
Iron chelation therapy is emerging as a novel neuroprotective strategy. The mechanisms of neuroprotection are diverse and include both neuronal and vascular pathways. We sought to examine the effect of iron chelation on cerebrovascular function in healthy aging and to explore whether HIF-1 activation may be temporally correlated with vascular changes
Methods
We assessed cerebrovascular function (autoregulation, vasoreactivity, neurovascular coupling) and serum concentrations of vascular endothelial growth factor (VEGF) and erythropoietin (EPO), as representative measures of HIF-1 activation, during 6 hours of deferoxamine (DFO) infusion in healthy 24 young and 24 older volunteers in a randomized, blinded, placebo-controlled cross-over study design. Cerebrovascular function was assessed using the transcranial Doppler ultrasound. VEGF and EPO serum protein assays were conducted using the Meso Scale Discovery platform.
Results
DFO elicited a strong age- and time-dependent increase in the plasma concentrations of EPO and VEGF, which persisted up to 3 hours post infusion (age effect p=0.04, treatment x time p<0.01). DFO infusion also resulted in a significant time- and age-dependent improvement in cerebral vasoreactivity (treatment x time, p<0.01, age p<0.01) and cerebral autoregulation (gain: age x time x treatment p=0.04).
Conclusions
DFO infusion improved cerebrovascular function, particularly in older individuals. The temporal association between improved cerebrovascular function and increased serum VEGF and EPO concentrations is supportive of shared HIF-1 regulated pathways. Therefore, pharmacological activation of HIF-1 to enhance cerebrovascular function may be a promising neuroprotective strategy in acute and chronic ischemic syndromes, especially in elderly patients.
Clinical Trial Registration
URL: http://www.clinicaltrials.gov. Unique identifier: NCT013655104.