Impaired RNA metabolism has been implicated in amyotrophic lateral sclerosis (ALS). Xu et al. report that the nonsense-mediated mRNA decay (NMD) pathway is inhibited in C9orf72 hexanucleotide repeat expansion-associated ALS. Reactivation of the NMD pathway protects against neurodegeneration in ALS models, suggesting potential as a therapeutic strategy.

Type 2 helper T cells (T(H)2) are critically involved in allergies and asthma. Here we demonstrate that extracellular matrix protein-1 (ECM1) is highly and selectively expressed in T(H)2 cells. ECM1 deficiency caused impaired T(H)2 responses and reduced allergic airway inflammation in vivo. Functional analysis demonstrated that although the T(H)2 polarization of ECM1-deficient cells was unimpaired, these cells had a defect in migration and were retained in peripheral lymphoid organs. This was associated with reduced expression of KLF2 and S1P(1). We also found that ECM1 could directly bind the interleukin-2 (IL-2) receptor to inhibit IL-2 signaling and activate S1P(1) expression. Our data identify a previously unknown function of ECM1 in regulating T(H)2 cell migration through control of KLF2 and S1P(1) expression.