Dependence of energy metabolism on the density of cells in culture
Dependence of energy metabolism on the density of cells in culture
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DOI：
10.1247/csf.23.85
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发表时间：
1998-04-01
影响因子：
1.5
通讯作者：
Woiteneck, P
中科院分区：
文献类型：
--
作者：
Bereiter-Hahn, J;Münnich, A;Woiteneck, P
培养细胞中的代谢强烈依赖于细胞密度，因此细胞密度可能是细胞培养物的生物技术维持中的重要因素，因此具有不同增殖活性的三种相关细胞类型的能量代谢已被表征：密度控制的原代或次级成纤维细胞[pmf]，永生化但仍然密度控制的3 T3细胞，以及缺乏生长控制的SV 40转化的3 T3。随着培养密度的增加，pmfs细胞的耗氧量、净乳酸产生量、ATP含量、NAD含量、NAD氧化还原电位和F-actin含量均下降，但3 T3细胞和SV 40 - 3 T3细胞的变化不明显。这些因子的主要减少与细胞-细胞接触有关，而不是与增殖有关，增殖在大多数细胞接触邻近细胞后至少停止两个分裂周期。如上述因素所揭示的，在汇合前密度下的SV 40 - 3 T3细胞也表现出相对低的代谢活性。还原型NADH/总NAD比值的降低表明，细胞内代谢产物的供应可能是细胞能量代谢的限速因素，而细胞内缺乏接触介导的能量代谢的降低，这与细胞运动和增殖的接触抑制机制的缺失是雅阁的。由于糖酵解酶可能与肌动蛋白结合，因此测定了F-肌动蛋白的含量。然而，F-肌动蛋白/乳酸盐比率显示无相关性。这可能是由于释放到培养基中的乳酸盐的约50%来源于β-内酰胺分解而不是糖酵解。只有在SV 40 - 3 T3细胞的呼吸和乳酸生产不敏感谷氨酰胺剥夺，在这些细胞中，这两个参数并没有显着变化，因此，他们不允许测试是否f-肌动蛋白含量和糖酵解活性是related.Fractionated释放的腺嘌呤核苷酸显示，在胞质馏分中的能量电荷是唯一的因素，严格与停止增殖。因此，能量电荷的胞质溶胶似乎是唯一的因素，这些研究在这里，它可以被用来作为一个指标的文化的承诺，进一步增殖。为了比较不同细胞类型之间的能量代谢参数，气道必须考虑这些因素的密度依赖性。
Metabolism in cultured cells strongly depends on cell density, thus cell density may be an important factor in biotechnological maintenance of cell cultures, Therefore the energy metabolism of three related cell types with different proliferation activity has been characterised: density controlled primary or secondary fibroblasts [pmf], immortalized, but still density controlled 3T3 cells, and SV40-transformed 3T3 lacking growth control. The investigations revealed the decrease of oxygen consumption, net lactate production, ATP-content, NAD-content and NAD-redox potential, and F-actin content with increasing culture density in pmfs, less distinct in 3T3 cells and in SV40-3T3 cells. The main decrease of these factors is related to cell-cell contacts rather than to proliferation which ceases at least two division cycles after most cells contacted a neighbouring cell. SV40-3T3 cells also at preconfluent densities exhibit relatively low metabolic activity as revealed by the above mentioned factors. Supply with metabolites for catalytic processes seems to be the rate limiting factor as deduced from a decreasing NADH/total NAD ratio.SV40-3T3 cells lack a contact mediated reduction of energy metabolism which is in accord with the missing contact inhibition of motility and proliferation in SV40-3T3 cells. Because of a possible association of glycolytic enzymes with actin, F-actin content has been determined. No correlation, however, was revealed by the F-actin/lactate ratio. This may be due to the fact that about 50% of the lactate released into the culture medium originated to from glutaminolysis rather than glycolysis. Only in SV40-3T3 cells were respiration and lactate production insensitive to glutamine deprivation and in these cells both these parameters did not change significantly, therefore they did not allow testing as to whether f-actin content and glycolytic activity are correlated.Fractionated release of adeninnucleotides revealed that energy charge in the cytosolic fraction is the only factor which strictly correlates with the cessation of proliferation. Thus energy charge of the cytosol seems to be the only factor of these studied here, which can be used as an indicator of a culture's commitment for further proliferation. To compare energy metabolic parameters among different cell types one airways has to take into account the density dependence of these factors.