Department of Biomedical Sciences, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan.
Int J Mol Med. 2012 Sep;30(3):579-84. doi: 10.3892/ijmm.2012.1018. Epub 2012 Jun 11.
Alopecia is known as a symptom of acute radiation, yet little is known concerning the mechanism of this phenomenon and the alteration of hair protein profiles. To examine this, 6-week-old male C57/BL6 mice were exposed to 6 Gy of X-ray irradiation, which caused acute alopecia. Their hair and skin were collected, and hair proteins were analyzed with liquid chromatography/electrospray-ionization mass spectrometry and immunohistochemistry. No change was observed in the composition of major hair keratins, such as Krt81, Krt83 and Krt86. However, cytokeratin Krt15 and CD34, which are known as hair follicle stem cell markers, were decreased in alopecic mice. Cytokeratin Krt5, which is known as a marker for basal and undifferentiated keratinocytes, was increased in the epidermis of alopecic mice. These findings suggest that radiation damages hair stem cells and the differentiation of keratinocytes in the epidermis. For the evaluation of radiation exposure, chromosomal aberration is considered to be the gold standard, yet our results suggest that Krt5 may be a novel biological marker for acute radiation symptoms.
脱发是急性辐射的一种症状，但对于这种现象的机制以及毛发蛋白谱的改变知之甚少。为了研究这一点，将 6 周龄雄性 C57/BL6 小鼠暴露于 6 Gy 的 X 射线照射下，导致急性脱发。收集它们的毛发和皮肤，并通过液相色谱/电喷雾电离质谱和免疫组织化学分析毛发蛋白。主要毛发角蛋白如 Krt81、Krt83 和 Krt86 的组成没有变化。然而，已知作为毛囊干细胞标志物的细胞角蛋白 Krt15 和 CD34 在脱发小鼠中减少。已知作为基底和未分化角质形成细胞标志物的细胞角蛋白 Krt5 在脱发小鼠的表皮中增加。这些发现表明，辐射损伤了毛发干细胞和表皮角质形成细胞的分化。对于辐射暴露的评估，染色体畸变被认为是金标准，但我们的结果表明 Krt5 可能是急性辐射症状的一种新的生物标志物。
