CELL CELL AND CELL MATRIX INTERACTIONS DIFFERENTIALLY REGULATE THE EXPRESSION OF HEPATIC AND CYTOSKELETAL GENES IN PRIMARY CULTURES OF RAT HEPATOCYTES
CELL CELL AND CELL MATRIX INTERACTIONS DIFFERENTIALLY REGULATE THE EXPRESSION OF HEPATIC AND CYTOSKELETAL GENES IN PRIMARY CULTURES OF RAT HEPATOCYTES
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DOI：
10.1073/pnas.85.7.2161
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发表时间：
1988-04-01
影响因子：
11.1
通讯作者：
FARMER, SR
中科院分区：
文献类型：
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作者：
BENZEEV, A;ROBINSON, GS;FARMER, SR
新鲜分离的成年大鼠肝细胞在生长因子存在下在干鼠尾胶原蛋白上培养时表现出扁平、延伸的形态；它们积极合成DNA并表达高水平的细胞骨架mRNA和蛋白质（肌动蛋白、微管蛋白、细胞角蛋白、纽蛋白、α-肌动蛋白和桥粒斑蛋白），同时表现出低水平的肝脏特异性mRNA（白蛋白、α1-抑制剂III和α1-抗胰蛋白酶）以及白蛋白的有限合成和分泌。在来自 Engelbreth-Holm-Swarm (EHS) 小鼠肿瘤的水合凝胶基质上培养的肝细胞形成小球形聚集体，并表现出低 DNA、细胞骨架 mRNA 和蛋白质合成，同时表现出肝脏特异性 mRNA 和白蛋白产量升高；因此，这些细胞更符合正常动物体内的基因表达程序。在低密度培养时，水合鼠尾胶原蛋白上的肝细胞类似于干胶原蛋白上的肝细胞，但在高密度下，它们会形成致密的小梁聚集体，合成可忽略不计的 DNA 量，并维持类似于接种在 EHS 基质上的肝细胞的基因表达模式。如果细胞形态紧凑，如 EHS 或水合鼠尾胶原细胞密集时，DNA 合成和细胞骨架基因表达较低，而肝脏特异性 mRNA 丰富。当细胞延伸时，情况相反。如果没有生长补充剂，DNA 合成始终较低，但基因表达几乎不受影响。这些研究指出了细胞-细胞和细胞-基质相互作用在确定肝细胞分化表型中的重要性，并且揭示了细胞骨架和肝脏特异性蛋白表达之间的反比关系。
Freshly isolated adult rat hepatocytes exhibit a flat, extended morphology when cultured on dried rat tail collagen in the presence of growth factors; they actively synthesize DNA and express high levels of cytoskeletal mRNAs and proteins (actin, tubulin, cytokeratins, vinculin, .alpha.-actinin, and desmoplakin), while exhibiting low levels of liver-specific mRNAs (albumin, .alpha.1-inhibitor III, and .alpha.1-antitrypsin) and limited synthesis and secretion of albumin. Hepatocytes cultured on hydrated gel matrix from the Engelbreth-Holm-Swarm (EHS) mouse tumor form small spherical aggregates and exhibit low DNA, cytoskeletal mRNA, and protein synthesis, while at the same time exhibiting elevated liver-specific mRNAs and albumin production; these cells, therefore, more nearly conform to the program of gene expression seen within the normal animal. Hepatocytes on hydrated rat tail collagen resemble those on dry collagen when cultured at low density, but at high density they form compact trabecular aggregates, synthesize negligible amounts of DNA, and maintain a pattern of gene expression resembling that of hepatocytes seeded on the EHS matrix. If cell morphology is compact, as on EHS or on hydrated rat tail collagen when densely populated, DNA synthesis and expression of cytoskeletal genes are low, while liver-specific mRNAs are abundant. When cells are extended the opposite is the case. Without the growth supplement DNA synthesis is low throughout but gene expression is little affected. These studies point to the importance of cell-cell and cell-matrix interactions in determining the differentiated phenotype of hepatocytes, and they reveal an inverse relationship between cytoskeletal and liver-specific protein expression.