Kozlowska U, Blume-Peytavi U, Kodelja V, Sommer C, Goerdt S, Majewski S, Jablonska S, Orfanos C E
Department of Dermatology, University Medical Center Benjamin Franklin, The Free University of Berlin, Germany.
Arch Dermatol Res. 1998 Dec;290(12):661-8. doi: 10.1007/s004030050370.
Hair follicle vascularization appears to be closely related to the processes involved in hair cycle regulation, in which growth factors, cytokines and other bioactive molecules are involved. In particular, vascular endothelial growth factor (VEGF), essential for angiogenesis and vascular permeability, may be responsible for maintaining proper vasculature around the hair follicle during the anagen growth phase. The aim of our study was to compare the in vitro angiogenic capacity, i.e. the steady-state expression of the VEGF gene, of different cultured cell types derived from normal human hair follicles, corresponding to different follicular compartments. Human dermal papilla cells (DPC), fibrous sheath fibroblasts, dermal fibroblasts, and follicular and interfollicular keratinocytes were cultured and studied in vitro for VEGF expression at the mRNA level using RT-PCR, and for VEGF protein synthesis by radioimmunoprecipitation and immunocytochemistry. In vivo examination for VEGF expression in human terminal hair follicles was performed using immunohistochemical methods. In the present report the expression of four different VEGF molecular isoforms, differing in their angiogenic capacity, are described in different cultured follicular cell types for the first time. Cultured follicular cells strongly expressed mRNA of four VEGF molecular species identified as the 121-, 145-, 165- and 189-amino acid splice variants, the most prominent being the 121-amino acid molecule. DPC, and also other mesenchymal cells such as fibrous sheath fibroblasts and dermal fibroblasts, in vivo and in vitro strongly expressed VEGF mRNA and synthesized a 46-kDa VEGF protein, whereas follicular and interfollicular keratinocytes in vitro expressed lower levels of VEGF mRNA and proteins than mesenchymal cells. As the highest expression of VEGF was found in DPC, we suggest that DPC are mainly responsible for angiogenic processes possibly related to the human hair cycle.
毛囊血管形成似乎与毛囊周期调控过程密切相关，生长因子、细胞因子及其他生物活性分子都参与其中。特别地，血管内皮生长因子（VEGF）对血管生成和血管通透性至关重要，可能在生长期负责维持毛囊周围正常的脉管系统。我们研究的目的是比较源自正常人毛囊、对应不同毛囊区域的不同培养细胞类型的体外血管生成能力，即VEGF基因的稳态表达。培养人真皮乳头细胞（DPC）、纤维鞘成纤维细胞、真皮成纤维细胞以及毛囊和毛囊间角质形成细胞，并通过逆转录聚合酶链反应（RT-PCR）在mRNA水平体外研究VEGF表达，通过放射免疫沉淀和免疫细胞化学研究VEGF蛋白合成。使用免疫组织化学方法对人终毛毛囊中的VEGF表达进行体内检测。在本报告中，首次描述了具有不同血管生成能力的四种不同VEGF分子异构体在不同培养毛囊细胞类型中的表达。培养的毛囊细胞强烈表达四种VEGF分子种类的mRNA，分别鉴定为121、145、165和189个氨基酸的剪接变体，最突出的是121个氨基酸的分子。DPC以及其他间充质细胞如纤维鞘成纤维细胞和真皮成纤维细胞在体内和体外均强烈表达VEGF mRNA并合成46 kDa的VEGF蛋白，而毛囊和毛囊间角质形成细胞在体外表达的VEGF mRNA和蛋白水平低于间充质细胞。由于在DPC中发现VEGF表达最高，我们认为DPC主要负责可能与人类毛囊周期相关的血管生成过程。
