Comparison between MLO-Y4 osteocyte and osteoblast to support osteoclast formation in vitro

Abstract

OBJECTIVE: To compare between MLO-Y4 osteocyte and osteoblast to support osteoclast formation in co-culture system. METHODS: MLO-Y4 cells and murine osteoblast cells were co-cultured with bone marrow cells with or without vitamin D(3) presence.Bone marrow cells were as control group. Tartrat resistant acid phosphatase (TRAP)+ giant cells with three or more nuclei were counted and compared under a microscope at day 9. RESULTS: In the absence of vitamin D(3), (1963.3 +/- 93.1)/plate osteoclasts were observed when MLO-Y4 cells co-cultured with bone marrow cells in 24-well plate.While only (12.7 +/- 5.5)/plate osteoclasts were found in the osteoblast group, and (6.0 +/- 1.0)/plate in control group. The statistical difference occurs for any two groups (P < 0.05). Vitamin D(3) could significantly increase osteoclast formation in the three groups. CONCLUSIONS: Osteocytes could induce osteoclastogenesis without the presence of vitamin D(3) and vitamin D(3) could enhance the induction effects of MLO-Y4 and osteoblast cells.

目的比較骨細胞和成骨細胞對破骨細胞分化形成的支持作用,初步探討骨細胞在骨改建過程中的作用.方法以小鼠骨髓基質細胞單獨培養為空白對照組,以小鼠顱頂骨來源的成骨細胞與小鼠骨髓基質細胞共培養為成骨細胞組,以MLO-Y4骨細胞與小鼠骨髓基質細胞共培養為骨細胞組.使用骨吸收促進因子維生素D3處理3組細胞,抗酒石酸磷酸酶(tartrat resistant acid phosphatase,TRAP)染色後比較維生素D3處理前後3組破骨細胞數量的差異.結果維生素D3處理前空白對照組破骨細胞計數為(6.0±1.O)個/孔板;成骨細胞組破骨細胞計數為(12.7±5.5)個/孔板,兩組差異有統計學意義(P<0.05);骨細胞組破骨細胞計數為(1963.3±93.1)個/孔板,與其他兩組間差異均有統計學意義(P<0.001).維生素D3對3組破骨細胞的分化形成均有促進作用.結論在沒有骨吸收促進因子存在的情況下,成骨細胞無法單獨誘導破骨細胞分化,而MLO-Y4骨細胞可單獨促進破骨細胞分化.骨吸收促進因子維生素D3可加強成骨細胞和骨細胞誘導破骨細胞分化的能力.