Differential effects of mutant SOD1 on protein structure of skeletal muscle and spinal cord of familial amyotrophic lateral sclerosis: role of chaperone network.

Protein misfolding is considered to be a potential contributing factor for motor neuron and muscle loss in diseases like Amyotrophic lateral sclerosis (ALS). Several independent studies have demonstrated using over-expressed mutated Cu/Zn-superoxide dismutase (mSOD1) transgenic mouse models which mimic familial ALS (f-ALS), that both muscle and motor neurons undergo degeneration during disease progression. However, it is unknown whether protein conformation of skeletal muscle and spinal cord is equally or differentially affected by mSOD1-induced toxicity. It is also unclear whether heat shock proteins (Hsp's) differentially modulate skeletal muscle and spinal cord protein structure during ALS disease progression. We report three intriguing observations utilizing the f-ALS mouse model and cell-free in vitro system; (i) muscle proteins are equally sensitive to misfolding as spinal cord proteins despite the presence of low level of soluble and absence of insoluble G93A protein aggregate, unlike in spinal cord, (ii) Hsp's levels are lower in muscle compared to spinal cord at any stage of the disease, and (iii) G93ASOD1 enzyme-induced toxicity selectively affects muscle protein conformation over spinal cord proteins. Together, these findings strongly suggest that differential chaperone levels between skeletal muscle and spinal cord may be a critical determinant for G93A-induced protein misfolding in ALS.

Wei R ，Bhattacharya A ，Hamilton RT ，Jernigan AL ，Chaudhuri AR ... -  《-》

Over-expression of Hsp27 does not influence disease in the mutant SOD1(G93A) mouse model of amyotrophic lateral sclerosis.

Krishnan J ，Vannuvel K ，Andries M ，Waelkens E ，Robberecht W ，Van Den Bosch L ... -  《-》

Histological evidence of protein aggregation in mutant SOD1 transgenic mice and in amyotrophic lateral sclerosis neural tissues.

Watanabe M ，Dykes-Hoberg M ，Culotta VC ，Price DL ，Wong PC ，Rothstein JD ... -  《NEUROBIOLOGY OF DISEASE》

Heat shock factor 1 over-expression protects against exposure of hydrophobic residues on mutant SOD1 and early mortality in a mouse model of amyotrophic lateral sclerosis.

Lin PY ，Simon SM ，Koh WK ，Folorunso O ，Umbaugh CS ，Pierce A ... -  《Molecular Neurodegeneration》

Molecular chaperone mediated late-stage neuroprotection in the SOD1(G93A) mouse model of amyotrophic lateral sclerosis.

Novoselov SS ，Mustill WJ ，Gray AL ，Dick JR ，Kanuga N ，Kalmar B ，Greensmith L ，Cheetham ME ... -  《-》