Department of Biotechnology, Norwegian Institute of Technology, University of Trondheim, N-7034, Trondheim, Norway.
Cytotechnology. 1995 Oct;17(3):143-51. doi: 10.1007/BF00749652.
Addition of osmoprotective compounds has a positive effect on growth and monoclonal antibody production in hyperosmotic hybridoma cell cultures. In order to better understand the processes involved in the osmoprotective response, uptake of the osmoprotective compounds glycine betaine, proline, sarcosine and glycine in mouse hybridoma cell line 6H11 during exposure to hyperosmotic stress was studied. Hyperosmotic stress (510 mOsmol/kg) was introduced through the addition of NaCl (100 mM) to the growth medium, and amino acid transport activity was measured immediately after transfer of the cells to the hyperosmotic medium. The osmoprotective capability of the four osmoprotectants tested was negatively affected if methylaminosobutyric acid (MeAiB), a specific substrate for amino acid transport system A, was simultaneously included in the hyperosmotic medium in equimolar amounts with one of the osmoprotective compounds. This was due to accumulation of MeAiB in the stressed cells, giving a significant reduction in the concentration of the osmoprotective compound inside the cells. Furthermore, addition of excess meAiB gave approx. 905 reduction in the initial rate of uptake of glycine betaine, while 40-50% reduction in the initial rate of uptake of proline, glycine and sarcosine. Similarly, addition of proline, glycine or sarcosine also gave a significant reduction in the initial rate of glycine betaine uptake. These results suggest that the four osmoprotective compounds share, at least in part, a common, MeAiB inhibitable carrier for transport into osmotically stressed hybridoma cells. This carrier is probably equal to amino acid transport system A.
添加渗透保护化合物对高渗杂交瘤细胞培养中的生长和单克隆抗体生产有积极影响。为了更好地了解渗透保护反应过程，研究了在高渗应激条件下，小鼠杂交瘤细胞系 6H11 摄取渗透保护化合物甘氨酸甜菜碱、脯氨酸、肌氨酸和甘氨酸的情况。通过向生长培养基中添加 NaCl（100mM）来引入高渗应激（510mOsmol/kg），并在将细胞转移至高渗培养基后立即测量氨基酸转运活性。如果在等摩尔量下将高渗培养基中与一种渗透保护化合物同时包含的甲基氨基丁酸（MeAiB），一种氨基酸转运系统 A 的特定底物，渗透保护剂的四种渗透保护能力受到负面影响。这是由于 MeAiB 在应激细胞中的积累，导致细胞内渗透保护化合物的浓度显著降低。此外，添加过量的 MeAiB 会使甘氨酸甜菜碱的初始摄取速率降低约 905%，而脯氨酸、甘氨酸和肌氨酸的初始摄取速率降低 40-50%。同样，添加脯氨酸、甘氨酸或肌氨酸也会显著降低甘氨酸甜菜碱的初始摄取速率。这些结果表明，这四种渗透保护化合物至少部分共享一种共同的、可被 MeAiB 抑制的载体，用于将渗透保护化合物转运到渗透压应激的杂交瘤细胞中。该载体可能与氨基酸转运系统 A 相同。
