title: Expression patterns of the glial cell line-derived neurotrophic factor, neurturin, their cognate receptors GFRalpha-1, GFRalpha-2, and a common signal transduction element c-Ret in the human skin hair follicles.
abstract: BACKGROUND
  Glial cell line-derived neurotrophic factor (GDNF) and a related family member, neurturin (NTN), and their cognate receptors (GFRalpha-1 and GFRalpha-2, for GDNF and NTN, respectively) are distal members of the transforming growth factor-beta superfamily. They are involved in the control of murine hair follicle (HF) cycling. This study tests the hypothesis that GDNF and NTN, and their cognate receptors, are expressed in the human HF and their expression varies in the different stages of the HF cycle.
  
  
  METHODS
  The expression pattern of these proteins was examined in human HF by immunofluorescence, immunoalkalinephosphatase staining methods, and reverse transcription-polymerase chain reaction (GDNF). The functional effects (GDNF and NTN) were examined in organ culture of the microdissected HFs.
  
  
  RESULTS
  GDNF, NTN, GFRalpha-1, GFRalpha-2, and c-Ret proteins were weakly expressed in catagen and telogen HFs. In contrast, they were strongly expressed in the epithelial and mesenchymal compartments of the anagen HF. GDNF gene was transcribed, both in the human scalp skin and in the isolated anagen HFs (reverse transcription-polymerase chain reaction). In HF organ culture, GDNF (but not NTN) increased the number of the proliferating HF keratinocytes (Ki 67 + cells). GDNF partially protected HFs from transforming growth factor-beta2-induced premature catagen transition.
  
  
  CONCLUSIONS
  None.
  
  
  CONCLUSIONS
  GDNF, NTN, GFRalpha-1, GFRalpha-2, and c-Ret proteins are differentially expressed in the different stages of HF cycle. GFRalpha-mediated signaling involves c-Ret and may play a role in human HF biology.
authors.affiliation: Department of Zoology, Faculty of Science, Sohag University, Sohag, Egypt.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Adly
authors.forename: Hanan A
authors.initials: HA
authors.lastname: Assaf
authors.forename: Paolo
authors.initials: P
authors.lastname: Pertile
authors.forename: Mahmoud R
authors.initials: MR
authors.lastname: Hussein
authors.forename: Ralf
authors.initials: R
authors.lastname: Paus
mesh_terms: D000818:Animals; D005260:Female; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000096:biosynthesis* / Q000502:physiology; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors / Q000096:biosynthesis*; D018859:Hair Follicle / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008875:Middle Aged; D051101:Neurturin / Q000096:biosynthesis*; D009924:Organ Culture Techniques; D051096:Proto-Oncogene Proteins c-ret / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C494987:GFRA1 protein, human; C494990:GFRA2 protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D051101:Neurturin; D051096:Proto-Oncogene Proteins c-ret