[1,25-Dihydroxyvitamin D3 effects on human cultured osteoclast-like multinucleated cells]

This enzyme- and immuno-histochemical study investigated the effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the derivation of multinucleated cells from mononuclear cells of human bone marrow. The mononuclear cells differentiated into multinucleated cells after 3 weeks of culturing in the presence of the 1,25(OH)2D3. The tartrate-resistant acid phosphatase (TRAP) positive multinucleated cells having more than three nuclei were counted and analyzed statistically. The findings were investigated to determine the effects of 1,25(OH)2D3, cellular density of mononuclear marrow cells, and of the age of the bone marrow donor. The main findings were; 1) the phenotypic expression of the cultured multinucleated cells coincided with that of the osteoclast, 2) the multinucleated cells increased in number significantly (p < 0.05) when cultured in the presence of 1,25(OH)2D3, and at a higher density of mononuclear marrow cells per dish, and 3) the multinucleated cells were very difficult to observe in the culture of marrow cells from old-aged donors. In conclusion, the osteoclasts were successfully cultured from the mononuclear cells of human bone marrow. The factors which correlated with increased development and differentiation of the multinucleated osteoclasts included a higher initial density of mononuclear cells, and a young age of bone marrow donor, in addition to the presence of the 1,25(OH)2D3 in the culture medium.