title: Erythropoietin promotes hair shaft growth in cultured human hair follicles and modulates hair growth in mice.
abstract: 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.
authors.affiliation: Department of Immunology, School of Medicine, Kyungpook National University, 101 Dong-In-Dong, Jung-Gu, Daegu 700-422, Republic of Korea.
authors.forename: Bo Mi
authors.initials: BM
authors.lastname: Kang
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Shin
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Kwack
authors.forename: Hyerim
authors.initials: H
authors.lastname: Shin
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Oh
authors.forename: Jinoh
authors.initials: J
authors.lastname: Kim
authors.forename: Chanil
authors.initials: C
authors.lastname: Moon
authors.forename: Cheil
authors.initials: C
authors.lastname: Moon
authors.forename: Jung Chul
authors.initials: JC
authors.lastname: Kim
authors.forename: Moon Kyu
authors.initials: MK
authors.lastname: Kim
authors.forename: Young Kwan
authors.initials: YK
authors.lastname: Sung
mesh_terms: 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
chemical_list: D012333:RNA, Messenger; D017467:Receptors, Erythropoietin; D004921:Erythropoietin; D051057:Proto-Oncogene Proteins c-akt