Role of the ACTH/MC2R System in the Hair Cycle in Mice

Keiichi Hiramoto,Emiko Kasahara,Kumi Orita,Yurika Yamate

doi:10.4236/jbm.2016.47001

Abstract

Adrenocorticotropin hormone (ACTH), which is secreted in response to psychological stress, plays an important role in the hair cycle. This study examined the mechanism by which ACTH affects the hair cycle using mice deficient in melanocortin receptor-2(MC2R-/-), which is a main receptor for ACTH. We observed the hair cycle using female MC2R-/- mice at 15 weeks old and five days old to determine whether there were any age-dependent differences. The 15-week-old MC2R-/- mice showed the anagen phase for all mice. On the other hand, all of the MC2R+/+ mice showed the telogen phase at the same age. Moreover, in the five-day-old mice, the hair growth of the MC2R-/- mice occurred earlier than in the MC2R+/+ mice. Both the 15-week-old and five-day-old MC2R-/- mice had higher levels of ACTH and alpha-melanocyte stimulating hormone in the blood than did the MC2R+/+ mice. In addition, in the 15-week-old MC2R-/- mice, the hair cycle shifted to the telogen phase following the administration of a cyclic guanosine monophosphate (cGMP) inhibitor and MC1R/MC5R inhibitor. In the five-day-old MC2R-/- mice, the hair growth was slowed by the administration of corticosterone. These results suggest that the ACTH/MC2R system has an important role in the hair cycle.

Highlights

In response to psychological stress, corticotropin-releasing hormone (CRH) is secreted from the hypothalamus, and CRH leads to the secretion of adrenocorticotropin hormone (ACTH) from the pituitary gland and local tissuesHow to cite this paper: Hiramoto, K., Orita, K., Yamate, Y. and Kasahara, E. (2016) Role of the ACTH/melanocortine 2 receptor (MC2R) System in the Hair Cycle in Mice
The hair cycle of the control mice when they were 10, 15 and 20 weeks old had stopped at the telogen phase, but the cycle in the MC2R−/− mice was maintained in the anagen phase (Figure 1(a))
To analyze the factors associated with the hair growth of MC2R−/− mice, we investigated the expression of phosphodiesterase 9A (PDE9A), MC1R, MC5R, Per1, the corticosterone receptor, TGF-β2 receptor and Cry1 in the skin

Summary

Introduction

In response to psychological stress, corticotropin-releasing hormone (CRH) is secreted from the hypothalamus, and CRH leads to the secretion of adrenocorticotropin hormone (ACTH) from the pituitary gland and local tissuesHow to cite this paper: Hiramoto, K., Orita, K., Yamate, Y. and Kasahara, E. (2016) Role of the ACTH/MC2R System in the Hair Cycle in Mice. In response to psychological stress, corticotropin-releasing hormone (CRH) is secreted from the hypothalamus, and CRH leads to the secretion of adrenocorticotropin hormone (ACTH) from the pituitary gland and local tissues. (2016) Role of the ACTH/MC2R System in the Hair Cycle in Mice. ACTH stimulates adrenal glucocorticoid biosynthesis and serection via the membrane-bound specific receptor, the melanocortine 2 receptor (MC2R) [3]. This action is a psychological stress management response which induces immunosuppression [4]. It is known that stress exposure can affect the hair cycle [5]-[7]

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