RAW264 cells were seeded in
24-well plates (Falcon) at 5 × 10 3 cells/well. On the following day (day 0), RANK Ligand, Soluble, Murine, Recombinant (
sRANKL; Pepro Tech, Rocky Hill, CT, USA) was added to
α-MEM (Sigma Aldrich) at 100 ng/mL. The medium was replaced with medium containing
sRANKL every 2nd day. On day 8, TRAP staining was performed using a
TRAP/ALP staining kit (Wako, Tokyo, Japan) to confirm differentiation into osteoclasts, and cells were observed with a
DMi1 microscope (Leica, Wetzlar, Germany).
Next, MSCs were seeded into
6-well plates (Falcon) at 1 × 10 4 cells/well, and RAW264 cells were seeded at In other
6-well plates (Falcon), RAW264 cells were cultured alone at 5 × 10 3 cells/well. On the following day (day 0), the culture medium was replaced with medium containing
sRANKL (Pepro Tech) (
sRANKL was added to both RAW264 only cultures and RAW264/MSC co-cultures), and the medium was replaced with fresh medium every 2nd day.
From day 0 (at the start of
sRANKL addition), using the number of actin ring-forming cells with five or more nuclei to represent the number of mature osteoclasts, osteoclast counts among RAW264 cells cultured alone and in RAW264 cell/MSC co-cultures were compared.
Abe T., Sumi K., Kunimatsu R., Oki N., Tsuka Y., Nakajima K., Ando K, & Tanimoto K. (2019). The effect of mesenchymal stem cells on osteoclast precursor cell differentiation. Journal of oral science, 61(1).