Erythropoietin promotes hair shaft growth in cultured human hair follicles and modulates hair growth in mice.
BACKGROUND
Recent studies have shown that erythropoietin (EPO)/erythropoietin receptor (EPOR) signaling exist in both human and mouse hair follicles (HFs).


OBJECTIVE
To investigate whether dermal papilla cells (DPCs) express functional EPOR and, if so, to investigate effects of EPO on hair shaft growth in cultured human scalp hair follicles and hair growth in mice.


METHODS
EPOR expression in DPCs and follicular keratinocytes was examined by RT-PCR and immunoblot. Phosphorylation of EPOR signaling pathway mediators by EPO treatment was examined by immunoblot. MTT assay was employed to check cell viability after EPO treatment. Hair shaft growth was measured in the absence or presence of EPO and matrix keratinocyte proliferation was examined by Ki-67 immunostaining in cultured hair follicles. Agarose beads containing EPO were implanted into dorsal skin of C57BL/6 mice to examine effects of EPO on hair growth in vivo.


RESULTS
EPOR mRNA and protein are expressed in cultured human DPCs. EPOR signaling pathway mediators such as EPOR and Akt are phosphorylated by EPO in DPCs. EPO significantly promoted the growth of DPCs and elongated hair shafts with increased proliferation of matrix keratinocytes in cultured human hair follicles. In addition, EPO not only promoted anagen induction from telogen but also prolonged anagen phase.


CONCLUSIONS
EPO may modulate hair growth by stimulating DPCs that express functional EPOR.
Kang
Bo Mi
BM
Department of Immunology, School of Medicine, Kyungpook National University, 101 Dong-In-Dong, Jung-Gu, Daegu 700-422, Republic of Korea.
Shin
Seung Hyun
SH
Kwack
Mi Hee
MH
Shin
Hyerim
H
Oh
Ji Won
JW
Kim
Jinoh
J
Moon
Chanil
C
Moon
Cheil
C
Kim
Jung Chul
JC
Kim
Moon Kyu
MK
Sung
Young Kwan
YK
D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004921:Erythropoietin / Q000494:pharmacology*; D005260:Female; D006197:Hair / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D018859:Hair Follicle / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017467:Receptors, Erythropoietin / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
D012333:RNA, Messenger; D017467:Receptors, Erythropoietin; D004921:Erythropoietin; D051057:Proto-Oncogene Proteins c-akt