title: Expression and function of the Transforming Growth Factor-b system in the human and rat enteric nervous system.
abstract: BACKGROUND
  Transforming growth factor-betas (TGF-bs) are pleiotropic growth factors exerting neurotrophic functions upon various neuronal populations of the central nervous system. In contrast, the role of TGF-b isoforms in the enteric nervous system (ENS) is largely unknown. We therefore analyzed the gene expression pattern of the TGF-b system in the human colon and in rat myenteric plexus, and smooth muscle cell cultures and determined the effect of TGF-b isoforms on neuronal differentiation.
  
  
  METHODS
  Human colonic samples as well as cultured rat myenteric plexus, and smooth muscle cells were assessed for mRNA expression levels of the TGF-b system (TGF-b1-3, TbR-1-3) by qPCR. The colonic wall was separated into mucosa and tunica muscularis and enteric ganglia were isolated by laser microdissection (LMD) to allow site-specific gene expression analysis. Effects of TGF-b isoforms on neurite outgrowth and branching pattern of cultured myenteric neurons were monitored.
  
  
  RESULTS
  mRNA expression of the TGF-b system was detected in all compartments of the human colonic wall as well as in LMD-isolated myenteric ganglia. Cultured myenteric neurons and smooth muscle cells of rat intestine also showed mRNA expression of all ligands and receptors. Transforming growth factor-b2 treatment increased neurite length and branching pattern in cultured myenteric neurons.
  
  
  CONCLUSIONS
  The TGF-b system is abundantly expressed in the human and rat ENS arguing for an auto-/paracrine function of this system on enteric neurons. Transforming growth factor-b2 promotes neuronal differentiation and plasticity characterizing this molecule as a relevant neurotrophic factor for the ENS.
authors.affiliation: Department of Informatics and Microsystems Technology, University of Applied Sciences, Kaiserslautern/Zweibrücken, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Hagl
authors.forename: K-H
authors.initials: KH
authors.lastname: Schäfer
authors.forename: I
authors.initials: I
authors.lastname: Hellwig
authors.forename: M
authors.initials: M
authors.lastname: Barrenschee
authors.forename: J
authors.initials: J
authors.lastname: Harde
authors.forename: M
authors.initials: M
authors.lastname: Holtmann
authors.forename: S
authors.initials: S
authors.lastname: Porschek
authors.forename: J-H
authors.initials: JH
authors.lastname: Egberts
authors.forename: T
authors.initials: T
authors.lastname: Becker
authors.forename: T
authors.initials: T
authors.lastname: Wedel
authors.forename: M
authors.initials: M
authors.lastname: Böttner
mesh_terms: D000368:Aged; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D017615:Enteric Nervous System / Q000166:cytology* / Q000378:metabolism*; D005260:Female; D006801:Humans; D061346:Laser Capture Microdissection; D008297:Male; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D059467:Transcriptome; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000096:biosynthesis*
chemical_list: D016212:Transforming Growth Factor beta