| First Author | Tidyman WE | Year | 2022 |
| Journal | Dis Model Mech | Volume | 15 |
| Issue | 2 | PubMed ID | 34553752 |
| Mgi Jnum | J:314851 | Mgi Id | MGI:6827475 |
| Doi | 10.1242/dmm.049166 | Citation | Tidyman WE, et al. (2022) MEK-inhibitor-mediated rescue of skeletal myopathy caused by activating Hras mutation in a Costello syndrome mouse model. Dis Model Mech 15(2):dmm049166 |
| abstractText | Costello syndrome (CS) is a congenital disorder caused by heterozygous activating germline HRAS mutations in the canonical Ras/mitogen-activated protein kinase (Ras/MAPK) pathway. CS is one of the RASopathies, a large group of syndromes caused by mutations within various components of the Ras/MAPK pathway. An important part of the phenotype that greatly impacts quality of life is hypotonia. To gain a better understanding of the mechanisms underlying hypotonia in CS, a mouse model with an activating HrasG12V allele was utilized. We identified a skeletal myopathy that was due, in part, to inhibition of embryonic myogenesis and myofiber formation, resulting in a reduction in myofiber size and number that led to reduced muscle mass and strength. In addition to hyperactivation of the Ras/MAPK and PI3K/AKT pathways, there was a significant reduction in p38 signaling, as well as global transcriptional alterations consistent with the myopathic phenotype. Inhibition of Ras/MAPK pathway signaling using a MEK inhibitor rescued the HrasG12V myopathy phenotype both in vitro and in vivo, demonstrating that increased MAPK signaling is the main cause of the muscle phenotype in CS. |
