Altered Expression of DJ-1 and PINK1 in Sporadic ALS and in the SOD1 super( G93A) ALS Mouse Model

Mitochondrial dysfunction is an important mechanism in the pathogenesis of neurodegenerative diseases such as Parkinson disease and amyotrophic lateral sclerosis (ALS). DJ-1 and PTEN-induced putative kinase 1 (PINK 1) are important proteins for the maintenance of mitochondrial function and protection against cell death. Here, the authors have studied the mRNA and protein expression of PINK 1 and DJ-1 in postmortem brain and spinal cord tissue and muscle biopsy samples, from ALS patients and controls and in brain, spinal cord, and gastroenemius muscle of SOD1 super( G93A) ALS mice at different disease stages. They found significant decreases of PINK 1 and DJ-1 mRNA levels in muscle tissue of SOD1 super( G93A) mice. Together with the significant decrease of PINK 1 mRNA levels in human ALS muscle tissue, statistically nonsignificant reduction of DJ-1 mRNA levels, and reduced immunostaining for PINK 1 in human ALS muscle, the results suggest potential pathophysiologic roles for these proteins in both mutant SOD1 super( G93A) transgenic mice and in sporadic ALS.