The topical penta-peptide Gly-Pro-Ile-Gly-Ser increases the proportion of thick hair in Japanese men with androgenetic alopecia.

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.

A short peptide GPIGS promotes proliferation of hair bulb keratinocytes and accelerates hair regrowth in mice.

The aim of this study was to discover a novel agent that promotes hair growth. We carried out a screening test in 298 types of conditioned medium (CM) from cultures of bacteria by using a hair bulb keratinocyte (HBK) growth assay. As a result, we found a HBK growth factor in the CM of Bacillus sp.

Constitutively active Src facilitates NGF-induced phosphorylation of TrkA and causes enhancement of the MAPK signaling in SK-N-MC cells.

Here we investigated a biological association of constitutively active Src with TrkA in SK-N-MC human neuroblastoma cells. Activation of TrkA and extracellular signal-regulated kinase (ERK) by nerve growth factor (NGF) was inhibited by pretreatment with PP2, an inhibitor of Src family kinases. Moreover, NGF-induced phosphorylation of TrkA and ERK was also attenuated by the transfection with a dominant-negative src construct.