The Lautenberg center for Immunology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University Medical School, Jerusalem, Israel.
Department of Geochemistry, Geological Survey of Israel, Jerusalem, Israel.
J Biol Chem. 2022 Apr;298(4):101795. doi: 10.1016/j.jbc.2022.101795. Epub 2022 Mar 3.
Cell growth is driven by the acquisition and synthesis of both dry biomass and water mass. In this study, we examine the increase of water mass in T cell during cell growth. We found that T-cell growth is characterized by an initial phase of slow increase in cellular water, followed by a second phase of rapid increase in water content. To study the origin of the water gain, we developed a novel methodology we call cold aqua trap-isotope ratio mass spectrometry, which allows analysis of the isotope composition of intracellular water. Applying cold aqua trap-isotope ratio mass spectrometry, we discovered that glycolysis-coupled metabolism of water accounts on average for 11 fl out of the 20 fl of water gained per cell during the initial slow phase. In addition, we show that at the end of the rapid phase before initiation of cell division, a water influx occurs, increasing the cellular water mass by threefold. Thus, we conclude that activated T cells switch from metabolizing water to rapidly taking up water from the extracellular medium prior to cell division. Our work provides a method to analyze cell water content as well as insights into the ways cells regulate their water mass.
细胞生长是由干物质和水质量的获取和合成驱动的。在本研究中，我们研究了 T 细胞在细胞生长过程中细胞内水分的增加。我们发现，T 细胞的生长特点是细胞内水分缓慢增加的初始阶段，随后是水分含量快速增加的第二阶段。为了研究水分增加的来源，我们开发了一种新的方法，我们称之为冷 aqua 陷阱-同位素比质谱法，它允许分析细胞内水的同位素组成。应用冷 aqua 陷阱-同位素比质谱法，我们发现，糖酵解偶联的水分代谢平均占初始缓慢阶段每个细胞获得的 20fl 水分中的 11fl。此外，我们还表明，在细胞分裂开始前的快速阶段结束时，会发生水流入，使细胞内水质量增加两倍。因此，我们得出结论，激活的 T 细胞在细胞分裂前从代谢水转变为快速从细胞外介质中摄取水。我们的工作提供了一种分析细胞含水量的方法，并深入了解细胞调节其水质量的方式。
