Heterogeneity among cells that express osteoclast-associated genes in developing bone
Heterogeneity among cells that express osteoclast-associated genes in developing bone
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DOI：
10.1210/en.139.1.340
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发表时间：
1998-01-01
期刊：
影响因子：
4.8
通讯作者：
Segre, GV
中科院分区：
文献类型：
--
作者：
Jemtland, R;Lee, KC;Segre, GV
在本研究中，我们的特点是在破骨细胞系的细胞的表型通过原位杂交，使用反义互补RNA探针，编码三个基因通常表达的破骨细胞，抗酒石酸酸性磷酸酶（TRAP），IV型胶原酶（基质金属蛋白酶-9），和c-fms，巨噬细胞集落刺激因子的受体。通过使用互补的RNA探针标记的S-35，地高辛，或两种标记方法的组合（双标记原位杂交），我们发现，这些基因中的每一个表现出不同的表达模式在早期阶段的软骨内骨发育[胚胎第15天（ED 15）ED 17]在胎鼠后肢。IV型胶原酶信使RNA（mRNA）首先在限定软骨膜/骨膜的细胞层中或刚好在其外部表达，早于TRAP或c-fms的转录物出现在相同位点（ED 15）。尽管TRAP和c-fms的转录物在骨骼内共定位，但在周围软组织中也发现了c-fms，而TRAP mRNA从未在骨骼外检测到（ED 16）。IV型胶原酶mRNA唯一地分布在软骨-骨边缘，与TRAP或c-fms的分布不同（ED 17）。然而，在骨骼发育的后期阶段（ED 18至出生后15天的骨骼），TRAP、IV型胶原酶和c-fms mRNA在整个骨骼的细胞中有更多的重叠，除了在软骨-骨交界处，IV型胶原酶在所有发育阶段继续独特地定位于某些细胞。而IV型胶原酶mRNA的表达水平是最强烈的软骨-骨边缘，c-fms和TRAP mRNA的表达水平似乎是更均匀的整个发展中的骨。结果表明，有相当大的异质性细胞之间表达破骨细胞相关基因，特别是在早期阶段的endochonterial骨发育，但这种差异变得不太明显，后来在更成熟的骨骼。这些标志物的不同表达模式可能代表破骨细胞发生的不同阶段。或者，IV型胶原酶阳性和TRAP/c-fms阳性细胞可能代表破骨细胞谱系的不同细胞亚群。
In the present study, we characterized the phenotype of cells in the osteoclast lineage by in situ hybridization, using antisense complementary RNA probes that encode three genes typically expressed by osteoclasts, tartrate-resistant acid phosphatase (TRAP), type TV collagenase (matrix metalloproteinase-9), and c-fms, the receptor for macrophage colony-stimulating factor. By using complementary RNA probes labeled with S-35, digoxygenin, or a combination of the two labeling methods (dual labeling in situ hybridization), we found that each of these genes exhibited a distinct expression pattern during early stages of endochondral bone development [embryonic day 15 (ED15) to ED17] in fetal mouse hind limbs. Type IV collagenase messenger RNA (mRNA) was first expressed in or just outside of the cellular layers that define perichondrium/periosteum, earlier than transcripts for TRAP or c-fms appeared at the same sites (ED15). Although transcripts for TRAP and c-fms colocalized within the skeleton, c-fms was also found in surrounding soft tissue, whereas TRAP mRNA was never detected outside the skeleton (ED16). Type IV collagenase mRNA was uniquely distributed at the chondro-osseous border, being distinct from the distribution of TRAP or c-fms (ED17). At later stages of skeletal development (ED18 to 15-day-old postnatal bone), however, there was more overlap among TRAP, type IV collagenase, and c-fms mRNAs in cells throughout bone, except at the chondro-osseous junction, where type IV collagenase continued to be uniquely localized to some cells at all developmental stages. Whereas the levels of type IV collagenase mRNA expression was most intense at the chondro-osseous margin, the levels of c-fms and TRAP mRNA expression appeared to be more uniform throughout the developing bone. The results indicate that there is considerable heterogeneity among cells expressing osteoclast-associated genes, particularly during early stages of endochondral bone development, but that this difference becomes less pronounced later in the more mature skeleton. Distinct expression patterns of these markers may represent different stages of osteoclastogenesis. Alternatively, type IV collagenase-positive and TRAP/c-fms-positive cells may represent distinct subpopulations of cells of the osteoclast lineage.