Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia.
Research Clinical Center of JSC "Russian Railways", Moscow, Russia.
Sci Rep. 2017 Apr 26;7(1):1171. doi: 10.1038/s41598-017-01238-w.
The papillary dermis of human skin is responsible for its biomechanical properties and for supply of epidermis with chemicals. Dermis is mainly composed of structural protein molecules, including collagen and elastin, and contains blood capillaries. Connective tissue diseases, as well as cardiovascular complications have manifestations on the molecular level in the papillary dermis (e.g. alteration of collagen I and III content) and in the capillary structure. In this paper we assessed the molecular structure of internal and external regions of skin capillaries using two-photon fluorescence lifetime imaging (FLIM) of endogenous compounds. It was shown that the capillaries are characterized by a fast fluorescence decay, which is originated from red blood cells and blood plasma. Using the second harmonic generation signal, FLIM segmentation was performed, which provided for spatial localization and fluorescence decay parameters distribution of collagen I and elastin in the dermal papillae. It was demonstrated that the lifetime distribution was different for the inner area of dermal papillae around the capillary loop that was suggested to be due to collagen III. Hence, we propose a generalized approach to two-photon imaging of the papillary dermis components, which extends the capabilities of this technique in skin diagnosis.
人类皮肤的乳头真皮负责其生物力学特性，并为表皮提供化学物质。真皮主要由结构蛋白分子组成，包括胶原蛋白和弹性蛋白，并包含毛细血管。结缔组织疾病以及心血管并发症在乳头真皮（例如，I 型和 III 型胶原蛋白含量的改变）和毛细血管结构的分子水平上都有表现。在本文中，我们使用双光子荧光寿命成像（FLIM）对内源性化合物评估了皮肤毛细血管的分子结构。结果表明，毛细血管的荧光衰减很快，这是由红细胞和血液血浆产生的。利用二次谐波产生信号，进行了 FLIM 分段，该分段提供了真皮乳头中胶原蛋白 I 和弹性蛋白的空间定位和荧光衰减参数分布。结果表明，毛细血管环周围的真皮乳头内区的寿命分布不同，这可能是由于 III 型胶原蛋白所致。因此，我们提出了一种针对乳头真皮成分的双光子成像的通用方法，该方法扩展了该技术在皮肤诊断中的功能。
