Huang H M, Toral-Barza L, Thaler H, Tofel-Grehl B, Gibson G E
Burke Medical Research Institute, Department of Neurology and Neuroscience, Cornell University Medical College, White Plains, NY 10605.
Neurobiol Aging. 1991 Sep-Oct;12(5):469-73. doi: 10.1016/0197-4580(91)90075-u.
Several studies suggest that alterations in the receptor-mediated phosphoinositide cascade and cytosolic free calcium concentration ([Ca2+]i) are involved in the pathophysiology of aging and Alzheimer's disease. Therefore, the phosphoinositide cascade and [Ca2+]i were determined under resting conditions and after stimulation with bradykinin (100 nM) in cultured human skin fibroblasts from young (21 +/- 3 years), normal aged (59 +/- 6 years) and Alzheimer subjects (58 +/- 6 years). The inositol polyphosphates (IP3, IP2 and IP) were monitored after prelabeling the cells with [3H]inositol in serum free medium. [Ca2+]i was determined with the fluorescent probe, fura-2AM, under exactly analogous conditions. The bradykinin-induced formation of IP3 and IP2 increased significantly in fibroblasts from normal aged and Alzheimer donors compared to young subjects, but did not differ from each other. Bradykinin-induced IP3 formation was 63-117% above the young group at time points between 10-60 s in normal aged or Alzheimer donors. Bradykinin-induced IP2 formation was 49-59% above the young group at time points between 10-60 s in normal aged or Alzheimer subjects. Neither the basal [Ca2+]i, nor the bradykinin-stimulated [Ca2+]i, differed among fibroblasts from young, normal aged and Alzheimer donors. The precise molecular basis and pathophysiological significance of the enhanced bradykinin-induced phosphoinositide cascade in fibroblasts from aged donors remains to be determined.
多项研究表明，受体介导的磷酸肌醇级联反应和胞质游离钙浓度（[Ca2+]i）的改变与衰老及阿尔茨海默病的病理生理学有关。因此，在静息条件下以及用缓激肽（100 nM）刺激后，对来自年轻（21±3岁）、正常老年（59±6岁）和阿尔茨海默病患者（58±6岁）的培养人皮肤成纤维细胞中的磷酸肌醇级联反应和[Ca2+]i进行了测定。在用无血清培养基中的[3H]肌醇预标记细胞后，监测肌醇多磷酸（IP3、IP2和IP）。在完全类似的条件下，用荧光探针fura-2AM测定[Ca2+]i。与年轻受试者相比，正常老年和阿尔茨海默病供体的成纤维细胞中缓激肽诱导的IP3和IP2形成显著增加，但两者之间没有差异。在正常老年或阿尔茨海默病供体中，在10 - 60秒的时间点，缓激肽诱导的IP3形成比年轻组高63 - 117%。在正常老年或阿尔茨海默病受试者中，在10 - 60秒的时间点，缓激肽诱导的IP2形成比年轻组高49 - 59%。年轻、正常老年和阿尔茨海默病供体的成纤维细胞中，基础[Ca2+]i和缓激肽刺激后的[Ca2+]i均无差异。老年供体成纤维细胞中缓激肽诱导的磷酸肌醇级联反应增强的确切分子基础和病理生理学意义仍有待确定。
