Laboratory of Cell and Molecular Physiology, Université Libre de Bruxelles, Brussels B-1070, Belgium.
Mol Med Rep. 2013 Aug;8(2):473-9. doi: 10.3892/mmr.2013.1559. Epub 2013 Jun 27.
The non-invasive imaging of GLUT2-expressing cells remains a challenge. As streptozotocin, and similarly alloxan, may be transported into cells by GLUT2, the major aim of the present study was to assess the possible use of fluorescent desnitroso-streptozotocin analogs for in vitro labeling of GLUT2-expressing cells. INS-1E cells, human embryonic kidney (HEK) cells, rat isolated pancreatic islets, rat hepatic cells, rat exocrine pancreatic cells and tumoral insulin-producing BRIN-BD11 cells were incubated in the presence of two distinct fluorescent desnitroso-streptozotocin analogs, probes A and B. The immunocytochemistry of GLUT2 in INS-1E cells and the phosphorylation of D-glucose by INS-1E cell homogenates were also examined. The uptake of probes A and B (12.0 µM) by INS-1E cells yielded apparent intracellular concentrations approximately one order of magnitude higher than the extracellular concentration. The two probes differed from one another by the absolute values for their respective uptake and time course, but not so by the pattern of their concentration dependency. Comparable results were recorded in HEK cells, rat isolated pancreatic islets and hepatocytes. Vastly different findings were recorded, however, in rat exocrine pancreatic cells, which do not express GLUT2. Moreover, an unusual concentration dependency for the uptake of each probe was observed in tumoral BRIN-BD11 cells. It is proposed that suitable fluorescent desnitroso-streptozotocin analogs may be used to label GLUT2-expressing cells.
GLUT2 表达细胞的非侵入性成像仍然是一个挑战。由于链脲佐菌素和类似的所有氧嗪都可以通过 GLUT2 被转运到细胞内,因此本研究的主要目的是评估荧光去亚硝基链脲佐菌素类似物用于体外标记 GLUT2 表达细胞的可能性。INS-1E 细胞、人胚肾 (HEK) 细胞、大鼠分离的胰岛、大鼠肝实质细胞、大鼠外分泌胰腺细胞和肿瘤胰岛素分泌 BRIN-BD11 细胞在两种不同的荧光去亚硝基链脲佐菌素类似物探针 A 和 B 的存在下孵育。还检查了 INS-1E 细胞中 GLUT2 的免疫细胞化学和 INS-1E 细胞匀浆中 D-葡萄糖的磷酸化。探针 A 和 B(12.0 µM)在 INS-1E 细胞中的摄取导致细胞内浓度比细胞外浓度高约一个数量级。两个探针在各自的摄取和时间过程中的绝对值上彼此不同,但在浓度依赖性的模式上却不同。在 HEK 细胞、大鼠分离的胰岛和肝细胞中记录到了类似的结果。然而,在不表达 GLUT2 的大鼠外分泌胰腺细胞中记录到了截然不同的结果。此外,在肿瘤 BRIN-BD11 细胞中观察到每个探针摄取的异常浓度依赖性。因此,建议使用合适的荧光去亚硝基链脲佐菌素类似物来标记 GLUT2 表达细胞。