Age dependent modulation of cell growth and functions in primary culture of rat hepatocytes

大鼠肝细胞原代培养物中细胞生长和功能的年龄依赖性调节

• 批准号: 07670593
• 负责人: MURA Tetsuo
• 金额: $ 1.28万
• 依托单位: Tottori University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07670593/
• 关键词: primary cultured of rat hepatocytes; EGF receptor assay; inhibitory effects on hepatocytes growth by TGF-beta and IL-1beta; EGF receotor from neonatal liver; cell density dependent of cell growth; effects of dibutyryl cAMP and TPA-related intracellul

Many metabolic functions besides proliferation are regulated by cell density and that there is a reciprocal relation between cell growth and expression of hepatocyte-specific functions. On the other hand, old rat hepatocytes in primary culture are well known not to respond normally to EGF.Therefore, we examined whether any reciprocal related between cell growth and expression of hepatpcytes-specific functions could be demonstrated in old rat hepatocytes by change in cell density or addition of plasma membrane protein from adult and old rat liver.The following results were obtained : (1) interleukin 1beta strongly inhibited DNA synthesis of adult and neonatal rat hepatocytes in primary culture induced by EGF plus insulin. Their inhibitory effects on hepatocyte growth were influenced reciprocally by cell density ; the inhibitory effects by TGF-beta was strong at low cell density, but weak at high cell density, whereas growth inhibition by IL-1beta was higher at high cell density. (2) Futhermore, effects of dibutyryl cyclic AMP and 12-O- tetradec anoylphorbol-13-acetate (TPA) -related intracellular signal transduction by TGF-beta and IL-1beta on growth of hepatocytes are also reciprocally modulated by cell density. Both TPA and db-cAMP alone had no effecton DNA synthesis of hepatocytes. But, TPA enhanced markedly DNA synthesis stimulated by EGF plus insulin at high cell density, and showed no effect at low cell density. ON the other hand, db-cAMP showed dual effect on growth of hepatocytes : at low concentration, at low cell density and exposure at erly stage of G1 phase enhanced DNA synthesis but at high cell density and at late stage of G1 phase, inhibited DNA synthesis. These results showed that signal transduction pathway involved in growth inhibition and stimulation in adult rat hepatocytes in primary culture was controled by cell densuty.

除增殖外，许多代谢功能受细胞密度调节，细胞生长和肝细胞特异性功能表达之间存在相互关系。另一方面，众所周知，原代培养的老年大鼠肝细胞对EGF没有正常反应。因此，我们通过改变细胞密度或添加来自成年和老年大鼠肝脏的质膜蛋白，研究了老年大鼠肝细胞中细胞生长和肝细胞特异性功能表达之间是否存在相互关系。结果如下：（1）IL 1 β对EGF+胰岛素诱导的原代培养大鼠肝细胞DNA合成有明显的抑制作用。它们对肝细胞生长的抑制作用受细胞密度的影响很大; TGF-β的抑制作用在低细胞密度下很强，但在高细胞密度下很弱，而IL-1 β的生长抑制作用在高细胞密度下更高。(2)此外，二丁酰环AMP和12-O-十四烷酰基佛波醇-13-乙酸酯（TPA）相关的TGF-β和IL-1 β对肝细胞生长的细胞内信号转导的影响也受到细胞密度的间接调节。TPA和db-cAMP单独作用对肝细胞DNA合成无影响。TPA在高细胞密度时对EGF+胰岛素刺激的DNA合成有明显的促进作用，而在低细胞密度时对DNA合成无影响。而db-cAMP对肝细胞的生长有双重作用：低浓度、低细胞密度和G_1期早期暴露促进DNA合成，而高细胞密度和G_1期晚期暴露则抑制DNA合成。这些结果表明，在原代培养的成年大鼠肝细胞中，参与生长抑制和刺激的信号转导途径受细胞密度的控制。

项目成果

K.Urakami: "Cu,Zn superoxide dismutase in patients with dementia of the Alzheimer type" Acta Neurol Scand. 91. 165-168 (1995)

K.Urakami：“阿尔茨海默型痴呆患者中的铜、锌超氧化物歧化酶”Acta Neurol Scand。