Gilchrest B A, Garmyn M, Yaar M
Department of Dermatology, Boston University School of Medicine, Mass.
Arch Dermatol. 1994 Jan;130(1):82-6.
Aging has two components: changes that occur in all individuals with the passage of time alone and changes that occur to varying degrees in different individuals as a result of repeated environmental injury. In the skin, the major environmental influence is sun exposure, and the combined effect of aging and sun damage has been termed photoaging. To determine whether aging and photoaging have characteristic effects on gene expression, we performed Northern blot analysis of several genes in early-passage cultured keratinocytes derived from donors of different ages (newborn, young adult, and old adult) and from paired sun-exposed (photoaged) and sun-protected sites of old-adult donors.
We examined genes involved in cell division, immunomodulation, or differentiation. Aging alone strikingly increased the baseline expression of the differentiation-associated SPR2 and interleukin 1 receptor antagonist (IL-1ra) genes but had relatively little effect on the UV inducibility of any genes studied. In contrast, photoaging markedly increased the inducibility of the c-fos proto-oncogene and decreased the baseline expression of SPR2 and IL-1ra relative to that in cells derived from sun-protected skin of the same donors.
Both aging and photoaging alter the expression of selected genes that are implicated in growth, differentiation, immunomodulation, and UV response in human epidermis. This may explain, in part, the predisposition to photocarcinogenesis in chronically sun-exposed skin of older individuals.
衰老有两个组成部分：仅随时间推移在所有个体中发生的变化，以及由于反复的环境损伤在不同个体中不同程度发生的变化。在皮肤中，主要的环境影响因素是阳光照射，衰老和阳光损伤的综合作用被称为光老化。为了确定衰老和光老化对基因表达是否有特征性影响，我们对来自不同年龄（新生儿、年轻成年人和老年人）供体以及老年供体配对的阳光暴露（光老化）和防晒部位的早期传代培养角质形成细胞中的几个基因进行了Northern印迹分析。
我们检测了参与细胞分裂、免疫调节或分化的基因。仅衰老就显著增加了与分化相关的SPR2和白细胞介素1受体拮抗剂（IL-1ra）基因的基线表达，但对所研究的任何基因的紫外线诱导性影响相对较小。相比之下，与来自同一供体防晒皮肤的细胞相比，光老化显著增加了原癌基因c-fos的诱导性，并降低了SPR2和IL-1ra的基线表达。
衰老和光老化均会改变人类表皮中与生长、分化、免疫调节和紫外线反应相关的特定基因的表达。这可能部分解释了老年个体长期阳光暴露皮肤中光致癌的易感性。
