2-DE AND MALDI-TOF-MS FOR A COMPARATIVE ANALYSIS OF PROTEINS EXPRESSED IN DIFFERENT CELLULAR MODELS OF AMYOTROPHIC LATERAL SCLEROSIS

Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disorder characterized by
the selective loss of motor neurons from the spinal cord and brain. About 10% of ALS cases
are familial (FALS), and in 20% of these cases the disease has been linked to mutations in
the Cu,Zn-SOD1 gene. Although the molecular mechanisms causing these forms of ALS
are still unclear, evidence has been provided that motor neurons injuries associated with
mutant superoxide dismutase (SOD1)-related FALS result from a toxic gain-in-fuction of
the mutated enzyme. To understand better the role of these mutations in the pathophysiology
of FALS we have compared the pattern of proteins expressed in human neuroblastoma
SH-SY5Ycell line with those of cell lines transfected with plasmids expressing the
wild-type human SOD1 and the H46R and G93A mutants. 2-DE coupled to MALDI-TOFMS
were the proteomic tools used for identification of differentially expressed proteins.
These included cytoskeletal proteins, proteins that regulate energetic metabolism and
intracellular redox conditions, and the ubiquitin proteasome system. The proteomic
approach allowed to expand the knowledge on the pattern of proteins, with altered expression,
which we should focus on, for a better understanding of the possible mechanism
involved in mutated-SOD1 toxicity. The cellular models considered in this work have also
evidenced biochemical characteristics common to other SOD1-mutated cellular lines connected
to the pathogenesis of ALS.