**Author details**

2). The role of astrocytes in the induction of motor neuron death was recently confirmed in astrocytes generated from post-mortem tissue of familial and sporadic ALS patients, addi‐ tionally providing an *in vitro* model system for the study of these mechanisms (Haidet-Phillips

**Figure 2. Model for the role of motor neurons and glia in the ROS-mediated ALS progression.** Different cell types are affected and play a role at different stages of the disease. During the onset and early disease progression, motor neurons undergo degeneration and cell death by cell-autonomous mechanisms. Later in the disease progression, acti‐ vated microglia and astrocytes release ROS, RNS, and toxic factors that magnify the injury (cell death amplification

In summary, the mechanism of mutant SOD1 toxicity is unknown and highly controversial but there is strong evidence suggesting that the mutant SOD1 toxic gain-of-function is related to an alteration of its redox properties and the induction of oxidative stress. In this scenario, the aberrant chemistry of mutant SOD1 turns the enzyme from antioxidant to pro-oxidant. Zn-

et al., 2011).

150 Current Advances in Amyotrophic Lateral Sclerosis

mechanisms).

**6. Conclusion**

María Clara Franco1,2, Cassandra N. Dennys1,2, Fabian H. Rossi1,2 and Alvaro G. Estévez1,2

1 Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, USA

2 Orlando VA Healthcare System, Orlando, USA
