Autocrine regulation of norepinephrine transporter expression.
The norepinephrine transporter (NET) is a neurotransmitter scavenger and site of drug action in noradrenergic neurons. The aim of this study was to identify mechanisms that regulate NET expression during the development of quail (q) sympathetic neuroblasts, which develop from neural crest stem cells. Neurotrophin-3 (NT-3) and transforming growth factor beta1 (TGF-beta1) cause an increase of qNET mRNA levels in neural crest cells. When combined, the growth factors are additive in increasing qNET mRNA levels. Both NT-3 and TGF-beta1 are synthesized by neural crest cells. Onset of NET expression precedes the onset of neural crest stem cell emigration from the neural tube. In older embryos, qNET is expressed by several crest-derived and noncrest tissues. The data show that qNET expression in presumptive sympathetic neurons is initiated early in embryonic development by growth factors that are produced by neural crest cells themselves. Moreover, the results support our previous observations that norepinephrine transport contributes to the regulation of the differentiation of neural crest stem cells into sympathetic neurons.
Department of Cell Biology, Medical College of Wisconsin, Milwaukee 53226, USA.
Z G
ZG
Ren
P
P
Pörzgen
J M
JM
Zhang
X R
XR
Chen
S G
SG
Amara
R D
RD
Blakely
M
M
Sieber-Blum
D000818:Animals; D019898:Autocrine Communication / Q000187:drug effects / Q000502:physiology*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D002642:Chick Embryo; D003001:Cloning, Molecular; D018076:DNA, Complementary; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology; D020933:Neurotrophin 3 / Q000235:genetics / Q000494:pharmacology; D009638:Norepinephrine / Q000493:pharmacokinetics; D050484:Norepinephrine Plasma Membrane Transport Proteins; D011784:Quail; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013566:Sympathomimetics / Q000493:pharmacokinetics; D027981:Symporters; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000494:pharmacology; D053773:Transforming Growth Factor beta1
D002352:Carrier Proteins; D018076:DNA, Complementary; D020933:Neurotrophin 3; D050484:Norepinephrine Plasma Membrane Transport Proteins; D012333:RNA, Messenger; D013566:Sympathomimetics; D027981:Symporters; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D009638:Norepinephrine