TRANSFORMING GROWTH FACTOR-BETA MESSENGER-RNA INCREASES DURING LIVER-REGENERATION - A POSSIBLE PARACRINE MECHANISM OF GROWTH-REGULATION
TRANSFORMING GROWTH FACTOR-BETA MESSENGER-RNA INCREASES DURING LIVER-REGENERATION - A POSSIBLE PARACRINE MECHANISM OF GROWTH-REGULATION
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DOI：
10.1073/pnas.85.5.1539
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发表时间：
1988-03-01
影响因子：
11.1
通讯作者：
FAUSTO, N
中科院分区：
文献类型：
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作者：
BRAUN, L;MEAD, JE;FAUSTO, N
转化生长因子β（TGF-β）是一种具有多种生物学特性的生长因子，包括刺激和抑制细胞增殖。为了确定TGF-β.参与体内肝细胞生长反应，我们测量了TGF-β的水平。大鼠正常肝脏和部分肝切除后肝再生过程中mRNA的表达。TGF-.beta. mRNA在再生肝脏中增加，并在ras原癌基因表达达到峰值后达到峰值（约为基础水平的8倍）。尽管来自正常和再生肝的肝细胞对TGF-β有应答，它们不合成TGF-β。mRNA。相反，该信息存在于肝脏非实质细胞中，并且在富含内皮细胞的细胞组分中特别丰富。TGF-.beta.抑制正常和再生肝的肝细胞中表皮生长因子诱导的体外DNA合成，尽管剂量-反应曲线根据所用培养基而变化。我们得出结论，TGF-β.可能作为抑制性旁分泌环的效应物，其在肝再生期间被激活，可能防止不受控制的肝细胞增殖。
Transforming growth factor .beta. (TGF-.beta.) is a growth factor with multiple biological properties including stimulation and inhibition of cell proliferation. To determine whether TGF-.beta. is involved in hepatocyte growth responses in vivo, we measured the levels of TGF-.beta. mRNA in normal liver and during liver regeneration after partial hepatectomy in rats. TGF-.beta. mRNA increases in the regenerating liver and reaches a peak (about 8 times higher than basal levels) after taken place and after the peak expression of the ras protooncogenes. Although hepatocytes from normal and regenerating liver respond to TGF-.beta., they do not synthesize TGF-.beta. mRNA. Instead, the message is present in liver nonparenchymal cells and is particularly abundant in cell fractions enriched for endothelial cells. TGF-.beta. inhibits epidermal growth factor-induced DNA synthesis in vitro in hepatocytes from normal and regenerating liver, although the dose-response curves vary according to the culture medium used. We conclude that TGF-.beta. may function as the effector of an inhibitory paracrine loop that is activated during liver regeneration, perhaps to prevent uncontrolled hepatocyte proliferation.