Mtesr1 supplement

Amniocyte-derived iPSCs were purchased from Cell Inspire Bio (IPSN-0008, Shenzhen, China). Prior to generating the iPSC-MSCs, iPSCs were plated into a Matrigel-coated six-well plate, and cultured in mTeSR1 basal medium containing 20% mTeSR1 supplement (Stem Cell, MA, USA), 1% penicillin/streptomycin (Gibco, CA, USA). Once 60% confluence was reached, the mTeSR1 medium was replaced with induction medium containing minimum essential medium eagle-α modified (α-MEM), 10% fetal bovine serum (FBS), 1% penicillin/ streptomycin, 200 mM l-glutamine and 10 mM non-essential amino acids (Gibco, CA, USA), sodium pyruvate, 10 mM l-ascorbate-2-phosphate (Sigma, MO, USA) and changed every other day. At 2 weeks later, cells were split with a 1:2 ratio using 0.25% trypsin-ethylenediaminetetraacetic acid (Gibco, CA, USA), plated in a gelatin-coated six-well plate as passage one (P1). After two passages, cells were seeded in an uncoated six-well plate and cultured in iPSC-MSCs growth medium containing high glucose Dulbecco’s modified eagle’s medium (Hyclone, UT, USA), 10% FBS, 5 ng/ml fibroblast growth factor (bFGF), 10 ng/ml epidermal growth factor (Gibco, CA, USA), 1% penicillin/streptomycin. Overall, three human iPSC-MSC clones were generated. Passage 9 to passage 17 iPSC-MSCs were used in this study.