Transcriptome profiling of SOD1 mutant ALS model motor neurons.

Recent genetic studies of ALS patients have identified several forms of ALS that are associated with mutations in RNA binding proteins. In animals or cultured cells, such defects broadly affect RNA metabolism. This raises the question of whether all forms of ALS have general effects on RNA metabolism. We tested this hypothesis in a mouse model of ALS that is transgenic for a human disease-causing mutation in the enzyme superoxide dismutase 1 (SOD1). We analyzed RNA from laser-captured spinal cord motor neuron cell bodies of the mutant SOD1 strain, comparing the RNA profile with that from a corresponding wild-type SOD1 transgenic strain. We prepared the samples from animals that were presymptomatic, but which manifested abnormalities at the cellular level that are seen in ALS, including aggregation of the mutant protein in motor neuron cell bodies and defective morphology of neuromuscular junctions, the connections between neuron and muscle. We observed only minor changes in the level and splicing of RNA in the SOD1 mutant animals as compared with wild-type, suggesting that mutant SOD1 produces the toxic effects of ALS by a mechanism that does not involve global RNA disturbance. Overall design: RNA-Seq of laser microdissection of motor neuron bodies from two biological replicates each of SOD1 YFP (wildtype 592) and SOD1 G85R YFP (737) transgenic mice.

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Bandyopadhyay U, Cotney J, Nagy M, Oh S, Leng J, Mahajan M, Mane S, Fenton WA, Noonan JP, Horwich AL