Prevention of Motor Neuron Degeneration by Novel Iron Chelators in SOD1G93A Transgenic Mice of Amyotrophic Lateral Sclerosis

Abstract

Background: The causes of amyotrophic lateral sclerosis (ALS) are largely unknown. Oxidative stress is considered to play a major role in motor neuron degeneration associated with iron homeostasis disturbance. Objective: Iron chelation treatment might be a potential therapeutic approach on the basis of its ability to reduce the oxygen free radical generation caused by iron accumulation. Methods and Results: In the present study, we applied the brain-permeable iron chelators VK-28 and M30 in a G93A mutant superoxide dismutase 1 transgenic (SOD1^G93A) mouse model of ALS and found that VK-28 and M30 significantly delayed disease onset, extended the life span and reduced spinal cord motor neuron loss. Furthermore, we documented that both iron chelators significantly attenuated the elevated iron level and transferrin receptor expression, decreased oxygen free radicals and suppressed microglial and astrocytic activation in the spinal cords of the SOD1^G93A mice. Moreover, we demonstrated that both iron chelators were able to decrease TDP-43 protein aggregation and the proapoptotic molecule Bax, and to enhance antiapoptotic protein Bcl-2 expression, in the ALS mice. Conclusions: These results provide evidence that iron is involved in the pathogenesis of ALS and iron chelation therapy may have the potential for the prevention and treatment of ALS.