Substance P gene expression in sympathetic neurons is regulated by neuron/support cell interaction.
In agreement with previous findings, the presence of support cells was found to increase the level of preprotachykinin (i.e. substance P-encoding) mRNA in cultures of sympathetic neurons. Treatment of neuron-only cultures, which did not express detectable levels of preprotachykinin mRNA, with conditioned medium from support cell-only cultures, also increased the level of preprotachykinin mRNA. This elevation in substance P gene expression was reflected in a 2-fold increase in the number of substance P-like immunoreactive neurons. In contrast, treatment of neuron-only cultures with conditioned medium from co-cultures of sympathetic neurons and support cells did not increase the level of preprotachykinin mRNA or the number of neurons containing substance P-like immunoreactivity. These observations suggest that while support cells release a soluble factor(s) capable of inducing substance P expression in sympathetic neurons, the production or action of this factor(s) is inhibited by the interaction between support cells and sympathetic neurons. Thus, by interacting with non-neuronal cells in their environment, sympathetic neurons appear to play an active role in determining which neurotransmitter phenotype they express.
Lentz
S I
SI
Department of Psychiatry (Cellular and Clinical Neurobiology Program), Wayne State University School of Medicine, Detroit, MI 48201.
Poosch
M S
MS
Hirayama
K
K
Kapatos
G
G
Bannon
M J
MJ
D000818:Animals; D002450:Cell Communication; D017077:Culture Media, Conditioned; D003584:Cytological Techniques; D015870:Gene Expression; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D011498:Protein Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D013373:Substance P / Q000235:genetics* / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000166:cytology / Q000502:physiology*; D015320:Tachykinins / Q000235:genetics
D017077:Culture Media, Conditioned; D011498:Protein Precursors; D012333:RNA, Messenger; D015320:Tachykinins; C044206:preprotachykinin; D013373:Substance P