A role for miR-4488 in conditional suppression of ER stress-associated pro-inflammatory responses

We have metabolically perturbed normal fibroblasts in order to study the biological roles of microRNAs (miRs) under mild and extended ER stress. We now report that miR-4488 quenches inflammation-associated gene expression in such metabolically perturbed cells.

Furthermore, we define miR-4488 as a non-canonical miRNA derived from the expansion segment ES7L of the 28S ribosomal RNA. Generation of miR-4488 requires Dicer, but not Drosha. Moreover, its generation involves the autophagy-lysosome route and is inhibited when this pathway is blocked, thus unveiling an anti-inflammatory role for lysosomes engaged at the onset of stress.