Department of Laboratory Medicine, Faculty of Medicine, University of Pécs, Ifjúság str. 13, 7624, Pecs, Hungary.
Eur Biophys J. 2010 Jul;39(8):1207-17. doi: 10.1007/s00249-009-0573-3. Epub 2009 Dec 31.
An increasing amount of recent research has demonstrated that the hexosamine biosynthesis pathway (HBP) plays a significant role in the modulation of intracellular signaling transduction pathways, and affects cellular processes via modification of protein by O-linked beta-N-acetylglucosamine (O-GlcNAc). Besides the many known and postulated effects of protein O-GlcNAc modifications, there is little available data on the role of O-GlcNAc in cellular volume regulation. Our objective was to test the effect of increased O-GlcNAc levels on hypotonia-induced volume changes in Jurkat cells. We pretreated Jurkat cells for 1 h with glucosamine (GlcN), PUGNAc (O-(2-acetamido-2-deoxy-D-glucopyranosylidene)-amino-N-phenylcarbamate) an inhibitor of O-GlcNAcase, or a high level of glucose to induce elevated levels of O-GlcNAc. We found that the response of Jurkat cells to hypotonic stress was significantly altered. The hypotonia induced cell-swelling was augmented in both GlcN and PUGNAc-treated cells and, to a lesser extent, in high glucose concentration-treated cells. Evaluated by NMR measurements, GlcN and PUGNAc treatment also significantly reduced intracellular water diffusion. Taken together, increased cell swelling and reduced water diffusion caused by elevated O-GlcNAc show notable analogy to the regulatory volume changes seen by magnetic resonance methods in nervous and other tissues in different pathological states. In conclusion, we demonstrate for the first time that protein O-GlcNAc could modulate cell volume regulation.
越来越多的最近研究表明，己糖胺生物合成途径（HBP）在细胞内信号转导途径的调节中起着重要作用，并通过 O-连接β-N-乙酰葡萄糖胺（O-GlcNAc）修饰蛋白质来影响细胞过程。除了蛋白质 O-GlcNAc 修饰的许多已知和推测的作用外，关于 O-GlcNAc 在细胞体积调节中的作用的数据很少。我们的目的是测试增加 O-GlcNAc 水平对 Jurkat 细胞低渗诱导体积变化的影响。我们用葡萄糖胺（GlcN）、PUGNAc（O-（2-乙酰氨基-2-脱氧-D-葡萄糖基）-氨基-N-苯甲酰胺）预处理 Jurkat 细胞 1 h，后者是 O-GlcNAcase 的抑制剂，或高浓度葡萄糖诱导 O-GlcNAc 水平升高。我们发现 Jurkat 细胞对低渗应激的反应明显改变。在 GlcN 和 PUGNAc 处理的细胞中，低渗诱导的细胞肿胀增强，而在高葡萄糖浓度处理的细胞中则较弱。通过 NMR 测量评估，GlcN 和 PUGNAc 处理也显著降低了细胞内水的扩散。总之，O-GlcNAc 升高引起的细胞肿胀增加和水扩散减少与磁共振方法在不同病理状态下观察到的神经和其他组织的调节体积变化具有显著的相似性。总之，我们首次证明蛋白质 O-GlcNAc 可以调节细胞体积调节。
