Skin cell induction of calcitonin gene-related peptide in embryonic sensory neurons in vitro involves activin.
Target skin cells induce the neuropeptide calcitonin gene-related peptide (CGRP) in naïve embryonic dorsal root ganglion (DRG) neurons in vitro, but the molecular basis of that induction is not known. Recombinant activin or bone morphogenetic proteins (BMPs) dramatically increase the number of sensory neurons with CGRP and substance P in vitro (X. Ai et al., 1999, Mol. Cell. Neurosci. 14, 506-518). These experiments were designed to test if activin or BMPs accounted for the CGRP-inductive activity by skin cells. To identify factors from skin that induce CGRP, we developed a bioassay in which embryonic DRG neurons isolated before peripheral target contact in vivo are challenged in vitro with specific factors. Conditioned medium from an embryonic rat skin cell line induced neuronal CGRP expression, and induction was blocked by follistatin, implicating transforming growth factor family members. Immunoblot analysis revealed that the skin cell line medium contained several activin and bone morphogenetic protein moieties. Antibody specific to activin neutralized most of the CGRP-inductive activity in skin conditioned medium. These data indicate that the CGRP-inductive action of skin cells involves activin and establish activin as a candidate regulator of this sensory neuropeptide phenotype during development.
Hall
A K
AK
Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4975, USA.    
Dinsio
K J
KJ
Cappuzzello
J
J
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D055418:Bone Morphogenetic Protein 6; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology / Q000502:physiology*; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis / Q000235:genetics*; D002460:Cell Line; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D004622:Embryo, Mammalian; D038681:Follistatin; D005727:Ganglia, Spinal / Q000166:cytology / Q000196:embryology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006023:Glycoproteins / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology; D009475:Neurons, Afferent / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000166:cytology / Q000196:embryology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology
C525720:Bmp2 protein, rat; C525811:Bmp4 protein, rat; C525818:Bmp6 protein, rat; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D055418:Bone Morphogenetic Protein 6; D019485:Bone Morphogenetic Proteins; D017077:Culture Media, Conditioned; D038681:Follistatin; D006023:Glycoproteins; D006133:Growth Substances; D016212:Transforming Growth Factor beta; D015740:Calcitonin Gene-Related Peptide