title: Expression of endothelin receptors in frog, chicken, mouse and human pigment cells.
abstract: Several reports have shown the participation of vasoactive endothelins (ETs) in the regulation of vertebrate pigment cells. In the present study, we identified ET receptors in pigment cells of vertebrate species by RT-PCR assays, and compared the differential expression of the various subtypes in each species by quantitative PCR. RT-PCR was performed with specific primers for ETC, ETA(X) or ETA in Xenopus laevis melanophores, ETA or ETB(2) in chicken melanocytes, ETA or ETB in murine (B-16, S-91 or Melan-A) or human (SK-Mel 23 or SK-Mel 28) melanoma cells, and the products obtained were confirmed by cloning and sequencing. The results showed the presence of ETA(X), but not ETA mRNA, and confirmed the expression of ETC in X. laevis melanophores. ETA and ETB(2) mRNAs were also demonstrated in chicken melanocytes. ETA and ETB receptor were identified in S-91, B16 and Melan-A murine cells. In human melanoma cells, SK-Mel 23 and SK-Mel 28, we confirmed the presence of ETB mRNA, and also found ETA mRNA. The comparison between the two subtypes present in the pigment cell of each species and among species demonstrated that the expression of ETAs in chicken, mouse, and human melanocytes is negligible, as is the expression of ETA(X) in Xenopus melanophores. The relative expression, as determined by quantitative PCR, was as follows: chicken ETB>SK-Mel 23 ETB>S91 ETB>>>Xenopus ETC, suggesting that the endothelin system plays a major role in avian and mammalian pigment cell regulation, as compared to lower vertebrates. The phylogenetic analysis revealed that subtype A receptors were probably the most primitive ET receptors, directly deriving from the ancestral type; all the other receptors, B subtypes and C, originated from diverse derivative molecules.
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Scarparo
authors.affiliation: Department of Biology, University of Virginia, Charlottesville, VA, USA.
authors.forename: Mauro César
authors.initials: MC
authors.lastname: Isoldi
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Leonardo Henrique Ribeiro Graciani
authors.initials: LHRG
authors.lastname: de Lima
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Maria Aparecida
authors.initials: MA
authors.lastname: Visconti
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil; Department of Biology, University of Virginia, Charlottesville, VA, USA. Electronic address: amdlcast@usp.br.
authors.forename: Ana Maria de Lauro
authors.initials: AML
authors.lastname: Castrucci
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D002645:Chickens / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D008544:Melanocytes / Q000378:metabolism*; D051379:Mice; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017466:Receptors, Endothelin / Q000235:genetics* / Q000378:metabolism; D014982:Xenopus laevis / Q000235:genetics*
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D017466:Receptors, Endothelin