Meier T J, Ho D Y, Sapolsky R M
Department of Biological Sciences, Stanford University, California 94305-5020, U.S.A.
J Neurochem. 1997 Sep;69(3):1039-47. doi: 10.1046/j.1471-4159.1997.69031039.x.
Disruption of Ca2+ homeostasis often leads to neuron death. Recently, the function of calcium-binding proteins as neuronal Ca2+ buffers has been debated. We tested whether calbindin D28k functions as an intracellular Ca2+ buffer by constructing bicistronic herpes simplex virus vectors to deliver rat calbindin cDNA to hippocampal neurons in vitro. Neurons were infected with vectors delivering calbindin or a negative control or were mock-infected. After 12 or 24 h of hypoglycemia, infected cells were made aglycemic during fura-2 calcium ratiometric imaging. In response to this challenge, neuronal overexpressing calbindin had less Ca2+ mobilized as compared with negative controls or mock-infected cells. Cells were assayed for survival after 12- or 24-h hypoglycemia or aglycemia. The calbindin vector decreased neuronal death due to hypoglycemia but not aglycemia. Here we demonstrate, in response to hypoglycemic challenge, both decreased Ca2+ mobilization and increased survival of cells infected with the calbindin vector.
钙离子稳态的破坏常常导致神经元死亡。最近，钙结合蛋白作为神经元钙离子缓冲剂的功能一直存在争议。我们通过构建双顺反子单纯疱疹病毒载体，将大鼠钙结合蛋白cDNA体外递送至海马神经元，来测试钙结合蛋白D28k是否作为细胞内钙离子缓冲剂发挥作用。用递送钙结合蛋白的载体、阴性对照载体感染神经元，或进行模拟感染。低血糖12或24小时后，在使用fura-2进行钙比率成像期间，使感染细胞无糖。应对这一挑战时，与阴性对照或模拟感染细胞相比，过表达钙结合蛋白的神经元动员的钙离子较少。在低血糖或无糖12或24小时后，对细胞进行存活检测。钙结合蛋白载体减少了因低血糖而非无糖导致的神经元死亡。在此我们证明，应对低血糖挑战时，感染钙结合蛋白载体的细胞钙离子动员减少且存活率增加。
