Skin Research Center, Johnson & Johnson Consumer & Personal Products Worldwide Division of Johnson & Johnson Consumer Companies, Inc., Skillman, NJ, USA.
J Dermatol Sci. 2013 Jun;70(3):159-65. doi: 10.1016/j.jdermsci.2013.03.004. Epub 2013 Mar 21.
While skin color is the most notable difference among ethnic skins the current knowledge on skin physiological and aging properties are based mainly on Caucasian skin studies.
To evaluate histological differences in elastin fiber network and differential responsiveness to TGF-β in skin of Caucasians and African Americans.
These studies were undertaken using human skin biopsies, primary dermal fibroblasts, Western blot analyses, immunofluorescence microscopy, cDNA array and quantitative real-time PCR.
In Caucasian subjects, tropoelastin expression and elastin fibers in photoprotected skin was substantially less than in age-matched African American skin. Expression of tropoelastin in photoexposed skin of African American was similar to their photoprotected skin, suggesting that photoexposure did not affect elastin fibers in African American skin to the same extent as Caucasian skin. An elevated level of TGF-β1 present in media from dermal fibroblasts derived from African American skins correlated well with the higher levels of TGF-β mRNA in African American skins analyzed by cDNA array. Treatment with TGF-β1 resulted in a considerably higher induction of elastin mRNA in dermal fibroblasts from African Americans than from Caucasian fibroblasts, indicative of enhanced TGF-β signaling in African American skins. Furthermore, UVA exposure decreased levels of elastin mRNA in Caucasian fibroblasts compared to African Americans fibroblasts.
These results suggest that there are ethnic differences in the elastin fiber network and in TGF-β signaling in African American and Caucasian skin, and that African American have less UV dependent loss of elastin than Caucasian which may contribute to the different perceived aging phenotypes.
虽然肤色是种族皮肤之间最显著的差异，但目前关于皮肤生理和衰老特性的知识主要基于白种人皮肤研究。
评估白种人和非裔美国人皮肤中弹性纤维网络的组织学差异以及对 TGF-β的不同反应性。
这些研究使用人皮肤活检、原代真皮成纤维细胞、Western blot 分析、免疫荧光显微镜、cDNA 阵列和定量实时 PCR 进行。
在白种人受试者中，光保护皮肤中的原肌球蛋白表达和弹性纤维明显少于年龄匹配的非裔美国人皮肤。非裔美国人皮肤中暴露于光下的皮肤中的原肌球蛋白表达与光保护皮肤中的相似，表明光暴露对非裔美国人皮肤中的弹性纤维没有像白种人皮肤那样产生相同程度的影响。来自非裔美国人皮肤的真皮成纤维细胞培养基中存在高水平的 TGF-β1，与通过 cDNA 阵列分析的非裔美国人皮肤中 TGF-β mRNA 的更高水平密切相关。用 TGF-β1 处理导致来自非裔美国人真皮成纤维细胞的弹性蛋白 mRNA 的诱导显著高于来自白种人真皮成纤维细胞的诱导，表明非裔美国人皮肤中的 TGF-β 信号增强。此外，与非裔美国人真皮成纤维细胞相比，UVA 暴露使白种人真皮成纤维细胞中的弹性蛋白 mRNA 水平降低。
这些结果表明，非裔美国人和白种人皮肤中的弹性纤维网络和 TGF-β 信号存在种族差异，并且非裔美国人皮肤中由于紫外线导致的弹性蛋白丢失比白种人少，这可能导致不同的衰老表型感知。
