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Background A penta-peptide, Gly-Pro-Ile-Gly-Ser ( GPIGS), promotes proliferation of mouse hair keratinocytes and accelerates hair growth in mice. Aim of this study This study focused on the ability of the peptide to promote human hair growth. Methods We used a human hair keratinocyte proliferation assay and organ cultures of human hair follicle as in vitro systems. The lotions with and without the penta-peptide were administered to 22 Japanese men with androgenetic alopecia (AGA) for 4 months in a double-blind and randomized clinical study. Results The penta-peptide significantly stimulated the proliferation of human hair keratinocytes at a concentration of 2.3 μ m ( P < 0.01), and 5.0 μ m of this peptide had a marked effect on hair shaft elongation in the organ culture ( P < 0.05). The change in the proportion of thick hair (≥60 μm) compared to baseline in patients that received the peptide was significantly higher than in the placebo ( P = 0.006). The change in the proportion of vellus hair (<40 μm) was also significantly lower in the peptide group than in the placebo ( P = 0.029). The penta-peptide also significantly improved the appearance of baldness ( P = 0.020) when blinded reviewers graded photographs of the participants according to a standardized baldness scale. No adverse dermatological effects due to treatment were noted during this clinical study. Conclusions This penta-peptide promotes proliferation of human hair keratinocytes and hair shaft elongation of human hair follicles, in vitro. This peptide increases thick hair ratio in vivo, and this compound is useful for the improvement of AGA. [ABSTRACT FROM AUTHOR]

Adenosine is an effective treatment for androgenetic alopecia ( AGA) in Japanese men and women. Adenosine exerts its effects by significantly increasing the proportion of thick hair. In this study, we assessed the clinical outcome of adenosine treatment for 6 months in 38 Caucasian men. The change in proportion of thick hair (≥60 μm) compared with baseline in the adenosine group was significantly higher than that in the placebo group ( P < 0.0001). The change in vellus hair proportion (<40 μm) was significantly lower in the adenosine group than that in the placebo group ( P = 0.0154). The change in hair density compared with baseline of the adenosine group was also significantly higher compared with that of the placebo group ( P = 0.0470). No adverse effects due to treatment were noted during this study by dermatological evaluation. Adenosine is effective in increasing the proportion of thick hair in Caucasian men with AGA as well as in Japanese men and women. [ABSTRACT FROM AUTHOR]

To investigate the pathophysiological role of matrix metallo-proteinase (MMP)-9 in the skin, we analyzed MMP-9 expression from human keratinocytes in culture. MMP-9 and the terminal differentiation marker involucrin were co-localized in the same keratinocytes with a high concentration of Ca2+, a potent stimulator of differentiation. We identified the novel KRE-M9 element, further downstream to the previously reported TM responsive element in the MMP-9 promoter, and both of these two elements were shown to be important for MMP-9 transcription and Ca2+ induction. The concomitant upregulation of MMP-9 and involucrin transcripts was probably due to the very similar gene regulatory elements, KRE-M9 and KRE-4, in their respective promoters. These results indicate a novel mechanism of transcriptional regulation for MMP-9 in the process of keratinization, implying the probable association of apoptosis and differentiation of keratinocytes in epidermal skin tissue. [ABSTRACT FROM AUTHOR]