Ritsuro Ideta

Adenosine increases anagen hair growth and thick hairs in Japanese women with female pattern hair loss: A pilot, double-blind, randomized, placebo-controlled trial

Adenosine upregulates the expression of vascular endothelial growth factor and fibroblast growth factor‐7 in cultured dermal papilla cells. It has been shown that, in Japanese men, adenosine improves androgenetic alopecia due to the thickening of thin hair due to hair follicle miniaturization. To investigate the efficacy and safety of adenosine treatment to improve hair loss in women, 30 Japanese women with female pattern hair loss were recruited for this double‐blind, randomized, placebo‐controlled study. Volunteers used either 0.75% adenosine lotion or a placebo lotion topically twice daily for 12 months. Efficacy was evaluated by dermatologists and by investigators and in phototrichograms. As a result, adenosine was significantly superior to the placebo according to assessments by dermatologists and investigators and by self‐assessments. Adenosine significantly increased the anagen hair growth rate and the thick hair rate. No side‐effects were encountered during the trial. Adenosine improved hair loss in Japanese women by stimulating hair growth and by thickening hair shafts. Adenosine is useful for treating female pattern hair loss in women as well as androgenetic alopecia in men.

Cultured human dermal papilla cells secrete a chemotactic factor for melanocytes

Large numbers of pigmented melanocytes are located in human hair follicles, predominantly around the dermal papillae, and the number of melanocytes and the melanogenic activity of the hair follicles are closely related to the hair cycle. We found that cultured human dermal papilla cells secreted a melanocyte chemoattractant into the medium. Skin fibroblasts also showed weak chemoattraction of melanocytes, while skin keratinocytes and melanocytes did not. Since this chemotactic activity was heat-and protease-sensitive and was present in the relatively high molecular weight fraction (130-200 kDa), it may be due to extracellular matrix (ECM) that proteins secreted from the cultured dermal papilla cells. This chemotactic signal between dermal papillae and melanocytes may control the localization and migration of hair melanocytes in vivo.

Gene expression of the androgen repressed rat TR2 orphan receptor: a member of steroid receptor superfamily.

A full-length rat cDNA clone was obtained from the TR2 orphan receptor, a member of the steroid receptor superfamily, using cDNA library screening and 3′ RACE-PCR technology. Under these conditions, only the TR2-11 form of the TR2 orphan receptor, the major form found in prostate, was identified. The overall amino acid homology between human and rat TR2-11 orphan receptors was near 90% with one amino acid difference in the DNA-binding domain sequence. Northern blot analysis identified multiple forms of the TR2 orphan receptor mRNAs expressed in human and rat prostates. Androgens repressed TR2 orphan receptor mRNA levels in human prostate LNCaP cells and rat ventral prostate. Polyclonal anti-TR2 orphan receptor antibodies raised from a unique TR2 orphan receptor 20 amino acid peptide were used to localize the TR2 orphan receptor in the nuclei of prostate and epididymis epithelium cells. Together, these data demonstrate that the TR2 orphan receptor can be expressed at mRNA and protein levels in the human and rat prostrates and may have some potential function in mediating androgen action in these tissues.

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

A penta‐peptide, Gly‐Pro‐Ile‐Gly‐Ser (GPIGS), promotes proliferation of mouse hair keratinocytes and accelerates hair growth in mice.