van den Bogert C, Spelbrink J N, Dekker H L
E.C. Slater Institute for Biochemical Research, University of Amsterdam, The Netherlands.
J Cell Physiol. 1992 Sep;152(3):632-8. doi: 10.1002/jcp.1041520323.
In cultured mammalian cells, the relationship was investigated between mitochondrial function and proliferation under various culture conditions. Continuous inhibition of the expression of the mitochondrial genome was used to reduce the activity of enzymes involved in oxidative phosphorylation by 50% at every cell division. Under these conditions, culturing in relatively poor media resulted in arrest of the proliferation of most cell lines after 1 cell division. This was preceded by decreasing levels of ATP and increasing levels of ADP, suggesting that the ATP-generating capacity of the cells was limiting. Culturing in richer media led to arrest of the proliferation after 5 to 6 divisions, but accumulation of ADP was not observed. Addition of pyruvate to rich culture media and, at least for 1 cell line, increasing the CO2 levels, completely prevented proliferation arrest. Inability to synthesise metabolic precursors via mitochondrial intermediary metabolism probably explains growth arrest of cells cultured in rich media. Pyruvate and CO2 were, however, without effect on the proliferation arrest of cells cultured in relatively poor media. Therefore, pyruvate dependency for growth of cells without functional mitochondria holds true only under culture conditions where the ATP-generating capacity of the cells is not limiting.
在培养的哺乳动物细胞中，研究了在各种培养条件下线粒体功能与细胞增殖之间的关系。通过持续抑制线粒体基因组的表达，使参与氧化磷酸化的酶的活性在每次细胞分裂时降低50%。在这些条件下，在相对贫瘠的培养基中培养导致大多数细胞系在1次细胞分裂后增殖停滞。在此之前，ATP水平降低，ADP水平升高，这表明细胞产生ATP的能力受到限制。在更丰富的培养基中培养导致在5至6次分裂后增殖停滞，但未观察到ADP的积累。向丰富的培养基中添加丙酮酸，并且至少对于1个细胞系而言，提高二氧化碳水平，可完全防止增殖停滞。无法通过线粒体中间代谢合成代谢前体可能解释了在丰富培养基中培养的细胞的生长停滞。然而，丙酮酸和二氧化碳对在相对贫瘠的培养基中培养的细胞的增殖停滞没有影响。因此，对于没有功能性线粒体的细胞生长的丙酮酸依赖性仅在细胞产生ATP的能力不受限制的培养条件下成立。
