Instituto Cajal, CSIC, Madrid, Spain.
Exp Gerontol. 2010 Jun;45(6):457-63. doi: 10.1016/j.exger.2010.03.015. Epub 2010 Mar 27.
PTEN is a tumor suppressor gene known to play an important role in the regulation of cell size. In this study we compared PTEN expression in the spinal cord of young (5 months old) vs. aged (32 months old) female rats and correlated them with alterations in neuron size and morphology in the same animals. Total and phosphorylated PTEN (pPTEN) as well as its downstream target phosphorylated Akt (pAkt) were assessed by Western blotting. Spinal cord neurons were morphometrically characterized. Total PTEN, pPTEN and total Akt expression were significantly higher in young rats than in aged animals. Expression of pAkt was stronger in aged animals. A significant increase in neuronal size was observed in large motoneurons of aged as compared with young rats. Our data show that in the spinal cord of rats, neuronal PTEN expression diminishes with advanced age while neuronal size increases. These results suggest that in the spinal cord, an age-related reduction in PTEN and increase of pAkt expression may be involved in the progressive enlargement of neurons.
PTEN 是一种肿瘤抑制基因，已知在细胞大小调节中发挥重要作用。在这项研究中，我们比较了年轻（5 个月大）和年老（32 个月大）雌性大鼠脊髓中的 PTEN 表达，并将其与同一动物中神经元大小和形态的变化相关联。通过 Western blot 检测总 PTEN（pPTEN）及其下游靶标磷酸化 Akt（pAkt）的表达。对脊髓神经元进行形态计量学特征分析。年轻大鼠脊髓中的总 PTEN、pPTEN 和总 Akt 表达明显高于老年动物。老年动物的 pAkt 表达更强。与年轻大鼠相比，老年大鼠的大型运动神经元的大小显著增加。我们的数据表明，在大鼠脊髓中，神经元 PTEN 表达随着年龄的增长而减少，而神经元大小增加。这些结果表明，在脊髓中，PTEN 的年龄相关性减少和 pAkt 表达的增加可能与神经元的逐渐增大有关。
