Signaling pathways in skeletal muscle of Amyotrophic Lateral Sclerosis mouse model. Signaling pathways in skeletal muscle of Amyotrophic Lateral Sclerosis mouse model

Gene expression analyses through cDNA microarray of fifteen gastrocnemius muscles from transgenic and wild-type SOD1G93A mouse model by the ages of 40 and 80 days old were performed. We used a customized cDNA array containing the cDNA platform comprised of 2352 spots, 326 of them orthologous to mouse, 1384 additional human cDNA sequences, 496 negative controls (DMSO) and 48 positive controls (the Q gene from λ-phage). Gene expression results for SOD1G93A and WT age matched mice pointed to eight up- (LOXL2, PIK4CA, FZD9, CUL1, CTNND1, SNF1LK, PRKX, DNER) and nine down-regulated genes (PIK3C2A, RIPK4, ID2, C1QDC1, EIF2AK2, RAC3, CDS1, INPPL1, TBL1X) at 40 days and also to one up- (PIK3CA) and five down-regulated genes (CD44, EEF2K, FZD2, CREBBP, PIKI3R1) at 80 days. Based on differentially expressed genes, analyses for gene priorization were performed and used to construct a network of protein-protein interaction. The network based on the genes of 40 and 80 days old mice was composed by 251 and 531 genes, respectively. GRB2 and SRC were identified as central genes of both networks. In conclusion, changes in gene expression of skeletal muscle from transgenic ALS mice in pre-symptomatic periods give further evidence of early neuromuscular abnormalities that precede motor neuron death. Overall design: We performed gene expression analyses by customized cDNA array, using reference design, of fifteen gastrocnemius muscles from transgenic and wild-type SOD1G93A mouse model by the ages of 40 and 80 days old. These differentially expressed lists were submitted to analyses for gene priorization and used to construct a network of protein-protein interaction.