Horscs

We obtained human bone marrow-derived mesenchymal stem cells (Catholic MASTER Cells from the Catholic Institute of Cell Therapy (CIC, Seoul, Korea). We purchased human outer root sheath cells (hORSCs) from ScienCell (San Diego, CA, USA) and cultured them, as previously described [49 (link)]. hORSCs (1 × 10⁵ cells per well) were seeded into six-well culture plates in Dulbecco’s Modified Eagle Medium (DMEM high glucose, Gibco BRL, Life Technology, Karlsruhe, Germany) containing 10% fetal bovine serum (FBS; Gibco BRL, Life Technology, Karlsruhe, Germany) and 1% penicillin/streptomycin (Gibco, BRL) for 24 h. hORSCs at passage three to five were used for the experiments. Then, hORSCs were seeded on culture dish plates with serum-free DMEM, and the plates were co-cultured with upper chamber containing hHMSCs.

hDPCs were purchased from Promocell (Heidelberg, Germany) and hORSCs were purchased from ScienCell research laboratories (Carlsbad, CA, USA). hDPCs were cultured in a basal medium supplemented with Supplement Mix, which contains 4% fetal calf serum, 0.4% bovine pituitary extract, 1 ng/mL of basic fibroblast growth factor, and 5 μg/mL of insulin. hORSCs were cultured in a mesenchymal stem cell medium containing 5% FBS, 1% penicillin streptomycin and 1% MSCGS (Mesenchymal Stem Cell Growth Supplement) which is provided by the manufacturer. Cells were maintained in a humidified incubator at 37 °C with 5% CO₂. hDPCs under the passage number 5 were used for experiments.