紫外线（UV）会减少人体皮肤表皮中游离脂肪酸和甘油三酯的合成，从而导致皮肤光老化的发生。

UV decreases the synthesis of free fatty acids and triglycerides in the epidermis of human skin in vivo, contributing to development of skin photoaging.

机构信息

Department of Dermatology, Seoul National University College of Medicine, Seoul, Republic of Korea.

出版信息

J Dermatol Sci. 2010 Jan;57(1):19-26. doi: 10.1016/j.jdermsci.2009.10.008. Epub 2009 Nov 20.

DOI:10.1016/j.jdermsci.2009.10.008

PMID:19932008

Abstract

BACKGROUND

Although fatty acids are known to be important in various skin functions, their roles on photoaging in human skin are poorly understood.

OBJECTIVE

We investigated the alteration of lipid metabolism in the epidermis by photoaging and acute UV irradiation in human skin.

METHODS

UV irradiated young volunteers (21-33 years, n=6) and elderly volunteers (70-75 years, n=7) skin samples were obtained by punch biopsy. Then the epidermis was separated from dermis and lipid metabolism was investigated.

RESULTS

We observed that the amounts of free fatty acids (FFA) and triglycerides (TG) in the epidermis of photoaged or acutely UV irradiated human skin were significantly decreased. The expressions of genes related to lipid synthesis, including acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD), sterol regulatory element binding proteins (SREBPs), and peroxisome proliferator-activated receptors (PPARgamma) were also markedly decreased. To elucidate the significance of these changes of epidermal lipids in human skin, we investigated the effects of TG or various inhibitors for the enzymes involved in TG synthesis on the expression of matrix metalloproteinase-1 (MMP-1) in cultured human epidermal keratinocytes. We demonstrated that triolein (TG) reduced basal and UV-induced MMP-1 mRNA expression. In addition, each inhibitor for various lipid synthesis enzymes, such as TOFA (ACC inhibitor), cerulenin (FAS inhibitor) and trans-10, cis-12-CLA (SCD inhibitor), increased the MMP-1 expression significantly in a dose-dependent manner. We also demonstrated that triolein could inhibit cerulenin-induced MMP-1 expression. Furthermore, topical application of triolein (10%) significantly prevented UV-induced MMP-13, COX-2, and IL-1beta expression in hairless mice.

CONCLUSION

Our results suggest that TG and FFA may play important roles in photoaging of human skin.

摘要

背景

尽管脂肪酸在各种皮肤功能中起着重要作用，但它们在人类皮肤光老化中的作用尚不清楚。

目的

我们研究了光老化和急性 UV 照射对人皮肤表皮脂质代谢的改变。

方法

通过打孔活检获得年轻志愿者（21-33 岁，n=6）和老年志愿者（70-75 岁，n=7）的皮肤样本。然后将表皮从真皮中分离出来，并研究其脂质代谢。

结果

我们观察到光老化或急性 UV 照射后人皮肤表皮中的游离脂肪酸（FFA）和甘油三酯（TG）含量明显减少。与脂质合成相关的基因表达，包括乙酰辅酶 A 羧化酶（ACC）、脂肪酸合成酶（FAS）、硬脂酰辅酶 A 去饱和酶（SCD）、固醇调节元件结合蛋白（SREBPs）和过氧化物酶体增殖物激活受体（PPARγ），也明显降低。为了阐明人皮肤表皮脂质变化的意义，我们研究了 TG 或各种参与 TG 合成的酶抑制剂对培养的人表皮角质形成细胞中基质金属蛋白酶-1（MMP-1）表达的影响。我们证明三油酸甘油酯（TG）降低了基础和 UV 诱导的 MMP-1 mRNA 表达。此外，各种脂质合成酶的抑制剂，如 TOFA（ACC 抑制剂）、cerulenin（FAS 抑制剂）和 trans-10，cis-12-CLA（SCD 抑制剂），以剂量依赖的方式显著增加 MMP-1 的表达。我们还证明三油酸甘油酯可以抑制 cerulenin 诱导的 MMP-1 表达。此外，三油酸甘油酯（10%）的局部应用显著预防了无毛小鼠中 UV 诱导的 MMP-13、COX-2 和 IL-1β表达。