Isolation of OPMD Patient Muscle Cells

The tissue biopsy was obtained from an OPMD patient undergoing cricopharyngeal myotomy (heterozygous polyalanine expansion mutation resulted in +3 Ala in PABPN1). The tissue was submerged by incubation with collagenase II solution (Merck, C0130). After the incubation, the tissue was transferred using a 5% BSA coated pipette tip into a 5% BSA pre-coated 10 cm plate filled with DMEM supplemented with 2.5% pen-strep-Nystatin (PSN). The tissue was further incubated for 30 min, and the muscle was then repeatedly pipetted to dissociate the myofibers. Using a fire-polished Pasteur pipette coated with 5% BSA, all visible myofibers were transferred to a 6-well plate coated with 5% BSA and filled with DMEM 2.5% PSN and then to another well coated with Matrigel (Corning, 354234) and filled with Bioamf 1% (Sartorius, 01-194-1 A) PSN. The connective tissue was transferred to another well coated with Matrigel and filled with bioamf1% to extract fibroblasts.