Induction of somatostatin immunoreactivity in cultured ciliary ganglion neurons by activin in choroid cell-conditioned medium.
We have previously shown that the expression of somatostatin-like immunoreactivity in cultured ciliary ganglion neurons is stimulated by a macromolecule found in choroid cell-conditioned medium (ChCM). Here, we present the following evidence that this somatostatin-stimulating activity (SSA) is activin: human recombinant activin induces somatostatin-like immunoreactivity in CG neurons; ChCM induces hemoglobin synthesis in K562 cells, a biological activity characteristic of activin; activin A-specific antibodies recognize a protein in ChCM; cultured choroid cells contain activin RNA; and SSA is inhibited by follistatin, a specific activin-binding protein. Thus, activin is likely to be a neurodifferentiation factor for CG neurons in vivo.
Coulombe
J N
JN
Department of Cell Biology and Anatomy Oregon Health Sciences University Portland 97201.
Schwall
R
R
Parent
A S
AS
Eckenstein
F P
FP
Nishi
R
R
D028341:Activins; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002478:Cells, Cultured; D002642:Chick Embryo; D002831:Choroid Plexus / Q000737:chemistry / Q000378:metabolism*; D017077:Culture Media, Conditioned; D038681:Follistatin; D005726:Ganglia, Parasympathetic / Q000187:drug effects / Q000378:metabolism*; D006023:Glycoproteins / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology; D006454:Hemoglobins / Q000096:biosynthesis; D006801:Humans; D007265:Inhibins / Q000235:genetics / Q000494:pharmacology*; D012313:RNA / Q000032:analysis; D011994:Recombinant Proteins / Q000494:pharmacology; D013004:Somatostatin / Q000096:biosynthesis*
D017077:Culture Media, Conditioned; D038681:Follistatin; D006023:Glycoproteins; D006133:Growth Substances; D006454:Hemoglobins; D011994:Recombinant Proteins; D028341:Activins; D013004:Somatostatin; D007265:Inhibins; D012313:RNA