Alternative splicing has emerged as a fundamental mechanism for the spatiotemporal control of development. A better understanding of how this mechanism is regulated has the potential not only to elucidate fundamental biological principles, but also to decipher pathological mechanisms implicated in diseases where normal splicing networks are mis-regulated.
Here, the authors took advantage of human pluripotent stem cells to decipher during human myogenesis the role of MBNL proteins, a family of tissue-specific splicing regulators whose loss of function is associated with Myotonic Dystrophy type 1 (DM1), an inherited neuromuscular disease.
Thanks to the CRISPR/Cas9 technology, they generated human-induced pluripotent stem cells (hiPSCs) depleted in MBNL proteins and evaluated the consequences of their losses on the generation of skeletal muscle cells. Our results suggested that MBNL proteins are required for the late myogenic maturation. In addition, loss of MBNL1 and MBNL2 recapitulated the main features of DM1 observed in hiPSC-derived skeletal muscle cells. Comparative transcriptomic analyses also revealed the muscle-related processes regulated by these proteins that are commonly mis-regulated in DM1. Together, our study reveals the temporal requirement of MBNL proteins in human myogenesis and should facilitate the identification of new therapeutic strategies capable to cope with the loss of function of these MBNL proteins.
Antoine Mérien, Julie Tahraoui-Bories, Michel Cailleret, Jean-Baptiste Dupont, Céline Leteur, Jérôme Polentes, Alexandre Carteron, Hélène Polvèche, Jean-Paul Concordet, Christian Pinset, Margot Jarrige, Denis Furling and Cécile Martinat
DOI (link) : https://doi.org/10.1093/hmg/ddab218