Peterson C, Vanderklish P, Seubert P, Cotman C, Lynch G
Department of Psychobiology, University of California, Irvine 92717.
Neurosci Lett. 1991 Jan 2;121(1-2):239-43. doi: 10.1016/0304-3940(91)90694-o.
Since calcium homeostasis is altered in cultured skin fibroblasts from aged and Alzheimer donors, the present study examined the degradation of spectrin, a substrate of the calcium dependent protease calpain. Spectrin proteolysis was estimated as the percentage of spectrin breakdown products (e.g., 150 + 155 kDa bands) per total spectrin immunoreactivity. In the baseline condition (e.g., unstimulated fibroblasts), spectrin breakdown was 53% greater in cells from aged donors when compared to cells from either young or Alzheimer donors. Compared to unstimulated cells, serum increased spectrin breakdown in cells from aged (22.4%) or Alzheimer (92.1%) donors but was ineffective in cells from young donors. Thus, when compared to young donors (100%), serum stimulation increased spectrin proteolysis by 183.9% (aged) or 231.7% (Alzheimer) after serum stimulation. Treatment of unstimulated cells with carbonyl cyanide 4-trifluoromethoxy-phenylhydrazone (FCCP), an uncoupler of mitochondrial function, increased spectrin degradation by 360.6% (young), 242.4% (aged) or 239.7% (Alzheimer) when compared to unstimulated cells of the same group. The combination of FCCP and serum stimulation enhanced spectrin breakdown in cells from aged (123.6%) and Alzheimer (154.0%) donors when compared to young cells (100%). Thus, changes in the regulation of calcium dependent proteases may contribute to decreased cell spreading and may play a role in the altered cytoskeletal dynamics characteristic of Alzheimer's disease.
由于老年和阿尔茨海默病患者供体的培养皮肤成纤维细胞中的钙稳态发生改变，本研究检测了血影蛋白（一种钙依赖性蛋白酶钙蛋白酶的底物）的降解情况。血影蛋白的蛋白水解以血影蛋白分解产物（如150 + 155 kDa条带）占总血影蛋白免疫反应性的百分比来估计。在基线条件下（如未刺激的成纤维细胞），与年轻或阿尔茨海默病患者供体的细胞相比，老年供体细胞中的血影蛋白分解增加了53%。与未刺激的细胞相比，血清增加了老年（22.4%）或阿尔茨海默病患者（92.1%）供体细胞中的血影蛋白分解，但对年轻供体细胞无效。因此，与年轻供体（100%）相比，血清刺激后，老年（183.9%）或阿尔茨海默病患者（231.7%）的血影蛋白水解增加。用羰基氰化物4 - 三氟甲氧基苯腙（FCCP，一种线粒体功能解偶联剂）处理未刺激的细胞，与同一组未刺激的细胞相比，血影蛋白降解增加了360.6%（年轻）、242.4%（老年）或239.7%（阿尔茨海默病患者）。与年轻细胞（100%）相比，FCCP和血清刺激的组合增强了老年（123.6%）和阿尔茨海默病患者（154.0%）供体细胞中的血影蛋白分解。因此，钙依赖性蛋白酶调节的变化可能导致细胞铺展减少，并可能在阿尔茨海默病特征性的细胞骨架动力学改变中起作用。
