MG400 profile of spinal cord microglia during disease progression in SOD mice

Amyotrophic lateral sclerosis (ALS) is a paralytic degenerative disease of the nervous system. In the SOD1 mouse model of ALS we found loss of the molecular and functional microglia signature associated with pronounced expression of miR-155 in SOD1 mice. We also found increased expression of miR-155 in the spinal cord of ALS subjects. Genetic ablation of miR-155 increased survival in SOD1 mice and reversed the abnormal microglial and monocyte molecular signature. In addition, dysregulated proteins in the spinal cord of SOD1 mice that we identified in human ALS spinal cords and CSF were restored in SOD1G93A/miR155-/- mice. Treatment of SOD1 mice with anti-miR-155 SOD1 mice injected systemically or into the cerebrospinal fluid prolonged survival and restored the microglial unique genetic and microRNA profiles. Our findings provide a new avenue for immune based therapy of ALS by targeting miR-155. Total RNA was isolated from FACS sorted adult FCRLS+ microglia from spinal cords of Non-Tg and SOD1G93A mice from 30d, 60d, 90d, 120d and 140d of age. Total RNA was extracted using mirVanaTM miRNA isolation kit (Ambion) according to the manufacturer’s protocol. nCounter Nansotring custom-made MG400 chip was used for gene expression profile