Lachgar S, Charveron M, Gall Y, Bonafe J L
Laboratoire de Biologie Cellulaire Cutanée, Institut de Recherche Pierre Fabre, Faculté de Médecine Rangueil, Toulouse, France.
Br J Dermatol. 1998 Mar;138(3):407-11. doi: 10.1046/j.1365-2133.1998.02115.x.
The hair follicle dermal papilla which controls hair growth, is characterized in the anagen phase by a highly developed vascular network. We have demonstrated in a previous study that the expression of an angiogenic growth factor called vascular endothelial growth factor (VEGF) mRNA varied during the hair cycle. VEGF mRNA is strongly expressed in dermal papilla cells (DPC) in the anagen phase, but during the catagen and telogen phases. VEGF mRNA is less strongly expressed. This involvement of VEGF during the hair cycle allowed us to determine whether VEGF mRNA expression by DPC was regulated by minoxidil. In addition, the effect of minoxidil on VEGF protein synthesis in both cell extracts and DPC-conditioned medium, was investigated immunoenzymatically. Both VEGF mRNA and protein were significantly elevated in treated DPC compared with controls. DPC incubated with increasing minoxidil concentrations (0.2, 2, 6, 12 and 24 mumol/L) induced a dose-dependent expression of VEGF mRNA. Quantification of transcripts showed that DPC stimulated with 24 mumol/L minoxidil express six times more VEGF mRNA than controls. Similarly, VEGF protein production increases in cell extracts and conditioned media following minoxidil stimulation. These studies strongly support the likely involvement of minoxidil in the development of dermal papilla vascularization via a stimulation of VEGF expression, and support the hypothesis that minoxidil has a physiological role in maintaining a good vascularization of hair follicles in androgenetic alopecia.
控制头发生长的毛囊真皮乳头，在生长期的特征是具有高度发达的血管网络。我们在之前的一项研究中证明，一种名为血管内皮生长因子（VEGF）的血管生成生长因子的mRNA表达在毛发周期中有所变化。VEGF mRNA在生长期的真皮乳头细胞（DPC）中强烈表达，但在退行期和休止期表达较弱。VEGF在毛发周期中的这种作用使我们能够确定DPC中VEGF mRNA的表达是否受米诺地尔调节。此外，通过免疫酶法研究了米诺地尔对细胞提取物和DPC条件培养基中VEGF蛋白合成的影响。与对照组相比，经处理的DPC中VEGF mRNA和蛋白均显著升高。用递增浓度（0.2、2、6、12和24μmol/L）的米诺地尔孵育DPC可诱导VEGF mRNA的剂量依赖性表达。转录本定量显示，用24μmol/L米诺地尔刺激的DPC表达的VEGF mRNA比对照组多6倍。同样，米诺地尔刺激后，细胞提取物和条件培养基中的VEGF蛋白产量增加。这些研究有力地支持了米诺地尔可能通过刺激VEGF表达参与真皮乳头血管化的发展，并支持了米诺地尔在雄激素性秃发中维持毛囊良好血管化方面具有生理作用的假说。
