PROGRESSIVE CHANGES IN THE PROTEIN-COMPOSITION OF THE NUCLEAR MATRIX DURING RAT OSTEOBLAST DIFFERENTIATION
PROGRESSIVE CHANGES IN THE PROTEIN-COMPOSITION OF THE NUCLEAR MATRIX DURING RAT OSTEOBLAST DIFFERENTIATION
复制标题
DOI：
10.1073/pnas.87.12.4605
复制
发表时间：
1990-06-01
影响因子：
11.1
通讯作者：
STEIN, GS
中科院分区：
文献类型：
--
作者：
DWORETZKY, SI;FEY, EG;STEIN, GS
胎鼠颅骨成骨细胞的原代培养经历了与编码成骨细胞表型标记的基因的时间表达有关的发育序列。基于先前关于基因-核基质关联参与调节细胞和组织特异性基因表达的建议，我们利用高分辨率二维凝胶电泳研究了核基质在这一发育序列中的蛋白质组成。在4周的培养期间，核基质被分离，这代表了三个主要的成骨细胞表型阶段：增殖、细胞外基质（ECM）成熟和矿化。核基质蛋白图谱变化最显著的时期是增殖期到ECM成熟期和ECM成熟期到矿化期，每个时期的变化都不大。这些阶段特异性变化与基因表达的主要转变点相对应，表明核基质蛋白反映了骨细胞表型的渐进式分化。原代细胞的继代培养延迟了矿化，并且观察到核基质蛋白模式的相应延迟。因此，在成骨细胞分化过程中发生的核基质蛋白质组成的顺序变化代表了骨样矿化ECM中成骨细胞向成骨细胞成熟的不同阶段特异性标记。这些变化与核基质在介导发育基因表达修饰中的功能参与是一致的。
Primary cultures of fetal rat calvarial osteoblasts undergo a developmental sequence with respect to the temporal expression of genes encoding osteoblast phenotypic markers. Based on previous suggestions that gene-nuclear matrix associations are involved in regulating cell- and tissue-specific gene expression, we investigated the protein composition of the nuclear matrix during this developmental sequence by using high-resolution two-dimensional gel electrophoresis. The nuclear matrix was isolated at times during a 4-week culture period that represent the three principal osteoblast phenotypic stages: proliferation, extracellular matrix (ECM) maturation, and mineralization. The most dramatic changes in the nuclear matrix protein patterns occurred during transitions from the proliferation to the ECM maturation stage and from ECM maturation to the mineralization period, with only minor variations in the profiles within each period. These stage-specific changes, corresponding to the major transition points in gene expression, indicate that the nuclear matrix proteins reflect the progressive differentiation of the bone cell phenotypes. Subcultivation of primary cells delays mineralization, and a corresponding delay was observed for the nuclear matrix protein patterns. Thus, the sequential changes in protein composition of the nuclear matrix that occur during osteoblast differentiation represent distinct stage-specific markers for maturation of the osteoblast to an osteocytic cell in a bone-like mineralized ECM. These changes are consistent with a functional involvement of the nuclear matrix in mediating modifications of developmental gene expression.