PT  - JOURNAL ARTICLE
AU  - Manoj Kumar Jaiswal
AU  - Bernhard U. Keller
TI  - Cu/Zn Superoxide Dismutase Typical for Familial Amyotrophic Lateral Sclerosis Increases the Vulnerability of Mitochondria and Perturbs Ca<sup>2+</sup> Homeostasis in SOD1<sup>G93A</sup> Mice
AID  - 10.1124/mol.108.050831
DP  - 2009 Mar 01
TA  - Molecular Pharmacology
PG  - 478--489
VI  - 75
IP  - 3
4099  - http://molpharm.aspetjournals.org/content/75/3/478.short
4100  - http://molpharm.aspetjournals.org/content/75/3/478.full
SO  - Mol Pharmacol2009 Mar 01; 75
AB  - Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the selective loss of defined motoneuron populations in the brainstem and spinal cord. Although low cytosolic calcium ([Ca2+]i) buffering and a strong interaction between metabolic mechanisms and [Ca2+]i have been associated with selective motoneuron vulnerability, the underlying cellular mechanisms are barely understood. To elucidate the underlying molecular events, we used rapid charge-cooled device imaging to evaluate Ca2+ signaling and metabolic signatures in the brainstem slices of SOD1G93A mice, the mouse model of human ALS, at 8 to 9 and 14 to 15 weeks of age, corresponding to the presymptomatic and symptomatic stages of motor dysfunction, respectively, and compared the results with corresponding age-matched wild-type littermates. We also monitored the mitochondrial membrane potential (ΔΨm) of brainstem motoneurons, a valuable tool for characterizing the metabolic signature of intrinsic energy profiles and considered to be a good experimental measure for monitoring energy metabolism in cells. We found that different pharmacological interventions substantially disrupt ΔΨm in SOD1G93A motoneurons during the symptomatic stage. Furthermore, we investigated the impact of impaired mitochondrial mechanisms on [Ca2+]i regulation by using the membrane-permeable indicator fura-acetoxy methyl ester. Taken together, the results indicate that mitochondrial disruptions are critical elements of SOD1G93A-mediated motoneuron degeneration in which selective motoneuron vulnerability results from a synergistic accumulation of risk factors, including the disruption of electrochemical potential, low Ca2+ buffering, and strong mitochondrial control of [Ca2+]i. The stabilization of mitochondria-related signal cascades may represent a useful strategy for clinical neuroprotection in ALS. The American Society for Pharmacology and Experimental Therapeutics