Epifluorescence at day 5 post-treatment with the factors. (A-D) Immunolabeling for osteopontin (OPN, red fluorescence) was mainly cytoplasmic, in perinuclear area and in punctate deposits. Cell-associated green fluorescence reveals actin cytoskeleton (Alexa Fluor 488-conjugated phalloidin), whereas blue fluorescence indicates cell nuclei (DAPI - DNA staining). No major differences were noticed among groups in terms of labeling pattern and fluorescence intensity for OPN. (E-H) Immunolabeling for alkaline phosphatase (ALP, red fluorescence) was more intense for the positive control compared to the treated groups.