Generation of Human iPSC-derived skeletal myotubes to evaluate DOK7 and COLQ targeted therapeutics

Authors

• BM Jones
• Y Zou
• CG Bönnemann
• C Chen

Abstract

Congenital Myasthenic Syndromes (CMS) are neuromuscular transmission disorders associated with mutations in collagen like tail subunit of asymmetric acetylcholinesterase (COLQ) and downstream of tyrosine kinase 7 (Dok7) genes. ColQ and Dok7 proteins are essential for regulating acetylcholine receptor signaling at the neuromuscular junction. Investigations into loss of function mutations in COLQ and DOK7 genes demonstrate diminished acetylcholinesterase activity along with acetylcholine receptor clustering, which leads to skeletal muscle dysfunction. Whereas over-expression of COLQ and DOK7 drastically increases skeletal muscle acetylcholine receptor signaling. Hence, DOK7 and COLQ deficient CMS patients do not respond to acetylcholinesterase inhibitor drugs, which are the standard of care for most forms of CMS. To generate in vitro disease models, we differentiated KOLF2.1J Dok7_A33 and ColQ_B63 knockout human induced pluripotent stem cells (iPSC) into myogenic progenitor cells. We saw efficient differentiation to myogenic progenitor cells as characterized by pluripotency and myogenic markers, and the ability for further differentiation to skeletal myotubes within 3 days of induction. The myogenic progenitor cells have stable proliferative potential to provide robust and quickly obtainable skeletal myotube model that is transgene free. Future studies will assess in vitro disease phenotypes associated with DOK7 and COLQ deficiencies to develop assays for evaluation of therapeutic candidates for CMS.

Scientific Focus Area: Stem Cell Biology

This page was last updated on Tuesday, August 6, 2024