Gene expression profile of human follicle dermal papilla cells in response to Camellia japonica phytoplacenta extract.

Camellia japonica L. is a flowering tree with several medicinal and cosmetic applications. Here, we investigated the efficacy of C. japonica placenta extract (CJPE) as a potential therapeutic agent for promotion of hair growth and scalp health by using various in vitro and in vivo assays. Moreover, we performed transcriptome analysis to examine the relative expression of human follicle dermal papilla cells (HFDPC) in response to CJPE by RNA-sequencing (RNA-seq). In vitro assays revealed upregulation of the expression of hair growth marker genes in HFDPC after CJPE treatment. Moreover, in vivo clinical tests with 42 adult female participants showed that a solution containing 0.5% CJPE increased the moisture content of the scalp and decreased the scalp's sebum content, dead scalp keratin, and erythema. Furthermore, RNA-seq analysis revealed key genes in HFDPC which are associated with CJPE. Interestingly, genes associated with lipid metabolism and cholesterol efflux were upregulated. Genes upregulated by CJPE are associated with several hormones, including parathyroid, adrenocorticotropic hormone, α-melanocyte-stimulating hormone (alpha-MSH), and norepinephrine, which are involved in hair follicle biology. Furthermore, some upregulated genes are associated with the regulation of axon guidance. In contrast, many genes downregulated by CJPE are associated with structural components of the cytoskeleton. In addition, CJPE suppressed genes associated with muscle structure and development. Taken together, this study provides extensive evidence that CJPE may have potential as a therapeutic agent for scalp treatment and hair growth promotion.

A novel gene homologous to teashirt is differentially expressed in neonatal mouse skin during development of hair follicles.

Neonatal mouse skin is useful for studying changes in gene expression during development of hair follicles, as the mitotic activity of skin cells changes shortly after birth. Using ribonucleic acid (RNA) differential display, a 261-nt message has been identified in the skin, specifically on d 3-5 but not on d 2 after birth. Confirmation of its expression by ribonuclease protection assay showed that stronger expression is seen on d 3-5 compared with d 1-2. Using RNA ligase-mediated rapid amplification of 5' complementary deoxyribonucleic acid ends, we have successfully isolated a 3046-bp gene, which has 93% sequence homology to a mouse teashirt1 gene. Amino acid analysis showed that it has 74% identity to the mouse teashirt1 protein and possesses zinc-finger motifs 1, 2, and 3. In situ hybridization data revealed that it is mainly expressed in the follicle bulb, including dermal papilla and matrix cells. As the proliferation of bulb cells is important to follicle development during this period, the finding of its strong expression on d 3-5 suggests that the identified gene is a potential candidate for follicle growth.

Indications for a 'brain-hair follicle axis (BHA)': inhibition of keratinocyte proliferation and up-regulation of keratinocyte apoptosis in telogen hair follicles by stress and substance P.

It has long been suspected that stress can cause hair loss, although convincing evidence of this has been unavailable. Here, we show that in mice sonic stress significantly increased the number of hair follicles containing apoptotic cells and inhibited intrafollicular keratinocyte proliferation in situ. Sonic stress also significantly increased the number of activated perifollicular macrophage clusters and the number of degranulated mast cells, whereas it down-regulated the number of intraepithelial gd T lymphocytes. These stress-induced immune changes could be mimicked by injection of the neuropeptide substance P in nonstressed mice and were abrogated by a selective substance P receptor antagonist in stressed mice. We conclude that stress can indeed inhibit hair growth in vivo, probably via a substance P-dependent activation of macrophages and/or mast cells in the context of a brain-hair follicle axis.