title: Expression of epidermal growth factor receptors and epidermal growth factor, amphiregulin and neuregulin in bovine uteroplacental tissues during gestation.
abstract: BACKGROUND
  Growth factors are proteins that bind to specific cell surface receptors that initiate signalling pathways and result in proliferation or differentiation of the affected cells. During gestation, epidermal growth factor receptors (ErbB1-4) and its ligands (epidermal growth factor-EGF, amphiregulin-AREG, neuregulin1-NRG1) play a significant role in differentiation, function and growth of the uterus.
  
  
  OBJECTIVE
  To determine the role of ErbB receptors and EGF, AREG and NRG1 in bovine uteroplacental tissues during gestation.
  
  
  METHODS
  Placentomes and interplacentomal areas from 30 cows from early gestation until near term were analysed by immunohistochemistry.
  
  
  RESULTS
  ErbB receptors and its ligands were observed in uteroplacental tissues and its expression was maintained throughout pregnancy, but ErbB1 receptor did not exist in the caruncular and cotyledonary stromal cells. Besides, caruncular stromal cells did not present with any immune reaction for EGF, AREG and NRG1. Generally, it was observed that total scores for ErbB receptors and its ligands (EGF, AREG and NRG1) had decreased from early to late gestation (p < 0.05).
  
  
  CONCLUSIONS
  Our study shows the presence of ErbB receptors and its ligands participate in the mid- and late-phases of pregnancy. To our knowledge, this is the first study on the expression of NRG1 during bovine pregnancy. These results indicates that these factors may play a crucial role not only to enable cellular proliferation and differentiation in the uterus throughout gestation, but also to have a potential role in the cellular communication maintained between the embryo/fetus and uterus by the placenta.
authors.affiliation: University of Dicle, Faculty of Veterinary Medicine, Department of Histology and Embryology, Diyarbakir 21280, Turkey. Electronic address: erdem_akbalik@hotmail.com.
authors.forename: M E
authors.initials: ME
authors.lastname: Akbalik
authors.forename: M A
authors.initials: MA
authors.lastname: Ketani
mesh_terms: D000003:Abattoirs; D066258:Amphiregulin; D000818:Animals; D017849:Animals, Inbred Strains; D002417:Cattle; D004815:Epidermal Growth Factor / Q000235:genetics / Q000378:metabolism*; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D020890:Neuregulin-1 / Q000235:genetics / Q000378:metabolism*; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D010929:Placentation; D011247:Pregnancy; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism; D014421:Turkey; D014599:Uterus / Q000166:cytology / Q000378:metabolism*
chemical_list: D066258:Amphiregulin; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D008024:Ligands; D020890:Neuregulin-1; D020033:Protein Isoforms; D004815:Epidermal Growth Factor; D066246:ErbB Receptors
keywords: AREG; Bovine; EGF; ErbB; NRG1; Uteroplacental