Potential canditates on optimization of osteogenic differentiation of amniotic fluid derived stem cells: TGF-ß3, 17ß-estradiol and osteoprotegerin

Bone is a complex tissue which comprises of both organic and inorganic substances. There are numerous factors known to effect the tissue like hormones, growth factors, cytokins, trace elements, etc. and over 100 diseases and syndroms had been identified related with the the tissue. These pathological states which require comlex and unique treatments, have the potential to stimuate severe adverse effects in innovative cellular therapy approaches. In the study, production of osteoprotegerin (OPG), a very important protein for bone metabolism, is promoted in osteoblast cell line hfOB cells under the influence of TGF-ß3 and 17ß-estradiol and the condition mediums (CM) were collected as OPG rich CM. Amniotic fluid derived stem cells (AFSCs) were differentiated into osteogenic lineage using OPG rich CM, TGF-ß3, 17ß-estradiol and standart hfOB CM. The cells were analysed with real-time PCR after 14 and 21 day differentiations for gene expressions of osteogenic markers SPP1, RUNX2, COL1 and DCN. Furthermore, Alizarin Red S quantification were performed on differentiated cells to determine their calcium deposition levels. The data suggested that, 17ß-estradiol hastens the osteogenic differentiation progress and helps cells to reach late osteogenesis rather quickly while also augmenting the mineralisation of cells. In other respects, TGF-ß3 and OPG assists cells to stay in early osteoblastogenesis stage for a longer period and keeps mineralisation in low levels. In circumstances that enhanced bone formation and greater mineralisation is intended, 17ß-estradiol offers promising results while TGF-ß3 and OPG seems to be more prefferable in situations which extensive mineralisation is undesirable and use of early osteoblastogenic cells would be beneficiary. Data from the study should be further expanded with other early and late osteogenic markers and it also should be determined how long the cells remain in which stage of osteogenesis by setting different time intervals. Finally, the results of those studies should be tested with in vivo studies.