Guerriero C, De Santis D, Nocini P F, Gotte P, Armato U
Institute of Anatomy & Histology, University of Verona Medical School, Italy.
Ital J Anat Embryol. 1995;100 Suppl 1:83-93.
Shreds of biopsied adult human jaw bones were divided into four groups that were each incubated together with borosilicate glass chips in one of four variants of DMEM expansion medium (i.e., with a high or low calcium complement and with or without sodium ascorbate added). The outgrown bone cells were propagated in secondary cultures kept in the same DMEM expansion medium variants prior to being transferred to a beta-glycerophosphate-enriched high-Ca2+ and ascorbate-containing DMEM mineralisation medium. In this latter medium the proliferation rates and the simultaneous expression of alkaline phosphatase by the four distinct groups of osteoblasts were assessed during 7 days of staying in vitro via biochemical methods. Human osteoblasts previously expanded in high-Ca2+ ascorbate-added DMEM medium were found to initially express a quite high alkaline phosphatase activity that subsequently declined, while their proliferative activity remained rather low. Conversely, osteoblasts formerly expanded in low-Ca2+ ascorbate-devoid DMEM medium exhibited minimal levels of alkaline phosphatase activity while simultaneously maximally proliferating in the mineralisation medium. Moreover, a mixture (1:1 v/v) of the DMEM mineralisation medium with Ham's medium (in which the aminoacid proline abounds) was found to accelerate, in comparison to DMEM alone, the intracellular type I procollagen synthesis, the extracellular assembly of type I collagen fibrils, and the calcification of the extracellular matrix by the human osteoblasts. Hence, the presence or absence of calcium and/or ascorbate in the expansion medium and of proline in mineralisation medium can significantly modulate the progression of human jaw bone cells from an undifferentiated highly proliferating condition to the mature osteoblastic phenotype.
将活检得到的成人人类颌骨碎片分成四组，每组与硼硅酸盐玻璃芯片一起在四种变体的DMEM扩增培养基（即添加高钙或低钙补充剂以及添加或不添加抗坏血酸钠）中培养。生长出来的骨细胞在二级培养物中增殖，培养物保持在相同的DMEM扩增培养基变体中，然后转移到富含β-甘油磷酸的高钙2+和含抗坏血酸的DMEM矿化培养基中。在这种后一种培养基中，通过生化方法在体外培养7天期间评估了四组不同成骨细胞的增殖率和碱性磷酸酶的同时表达。先前在添加高钙2+抗坏血酸的DMEM培养基中扩增的人成骨细胞最初表现出相当高的碱性磷酸酶活性，随后下降，而其增殖活性仍然相当低。相反，先前在低钙2+无抗坏血酸的DMEM培养基中扩增的成骨细胞表现出最低水平的碱性磷酸酶活性，同时在矿化培养基中最大程度地增殖。此外，与单独的DMEM相比，发现DMEM矿化培养基与Ham培养基（其中富含氨基酸脯氨酸）的混合物（1:1 v/v）可加速人成骨细胞的细胞内I型前胶原合成、I型胶原纤维的细胞外组装以及细胞外基质的钙化。因此，扩增培养基中钙和/或抗坏血酸的存在与否以及矿化培养基中脯氨酸的存在与否可显著调节人类颌骨细胞从未分化的高度增殖状态向成熟成骨细胞表型的进展。
