Inhibitory effect of angiogenin on the expression of type Ⅰ collagen and fibronectin in dermal papilla cells from androgenetic alopecia areas / 中华皮肤科杂志

ABSTRACT

Objective To evaluate effects of angiogenin on the expression of type Ⅰ collagen and fibronectin in dermal papilla cells from androgenetic alopecia areas,and to explore its possible mechanisms.Methods Dermal papilla cells were isolated from androgenetic alopecia areas and cultured.Real-time fluorescence-based quantitative PCR was performed to determine the mRNA expression of androgen receptor in dermal papilla cells of different passages,and cell counting kit-8 (CCK-8) assay to evaluate the effect of angiogenin at different concentrations of 0,10,20,40,80,160 μg/L on the proliferative activity of the dermal papilla cells cultured in a medium with or without 0.1 nmol/L dihydrotestosterone.The confluent first-passage dermal papilla cells were divided into 3 groupscontrol group receiving no treatment,dihydrotestosterone group treated with 0.1 nmol/L dihydrotestosterone,and dihydrotestosterone + angiogenin group treated with 0.1 nmol/L dihydrotestosterone and 80 μg/L angiogenin.After 48-hour treatment,realtime fluorescence-based quantitative PCR was conducted to measure the mRNA expression of type Ⅰ collagen gene,fibronectin and transforming growth factor-β1 (TGF-β1),and Western blot analysis to determine the protein expression of type Ⅰ collagen,fibronectin,TGF-β1,phosphorylated Smad2 (p-Smad2) and p-Smad3.Statistical analysis was done by one-way analysis of variance (ANOVA),least significant difference (LSD)-t test and t test for two independent samples.Results The mRNA expression of androgen receptor significantly decreased during the subcultivation of in vitro cultured dermal papilla cells from androgenetic alopecia areas (P ＜ 0.05).Cell proliferation assay showed that 20-160 μg/L angiogenin could evidently antagonize the inhibitory effect of 0.1 nmol/L dihydrotestosterone on the proliferation of dermal papilla cells (all P ＜ 0.05).Compared with the control group,the dihydrotestosterone group showed significantly higher mRNA expression of type Ⅰ collagen gene,fibronectin and TGF-β1.However,the mRNA expression of type Ⅰ collagen gene,fibronectin and TGF-β1 was significantly lower in the dihydrotestosterone + angiogenin group than in the dihydrotestosterone group (type Ⅰ collagen gene1.563 ± 0.143 vs.4.329 ± 0.165;fibronectin1.290 ± 0.063 vs.2.156 ± 0.115;TGF-β11.136 ± 0.098 vs.1.707 ± 0.100;all P ＜ 0.05).Moreover,angiogenin could obviously suppress the expression of type Ⅰ collagen,fibronectin,TGF-β1,p-Smad2 and p-Smad3 protein by dihydrotestosterone-induced dermal papilla cells (all P ＜ 0.05).Conclusion Angiogenin can inhibit the expression of type Ⅰ collagen and fibronectin in dermal papilla cells from androgenetic alopecia areas in vitro,which may be associated with the downregulated expression of TGF-β1 and inhibition of TGF-β1/Smad signaling pathway.