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Endothelin 3 expression by vagal neural crest cells
104
Abstracts from the 1l th International Symposium on Regulatory Peptides
ENDOTHELIN 3 EXPRESSION BY VAGAL NEURAL CREST CELLS MK Lancaster, C Blackmore, J Goldsmith, DE Edgar*, C Vaillant Departments of Veterinary Preclinical Sciences & *Human Anatomy, University of Liverpool, UK Factors regulating the migration of vagal neural crest cells which give rise to the enteric nervous system in the developing gut are poorly understood but an appropriate microenvironment (i.e. normal deposition of extracellular matrix molecules) in the gut wall is thought to be of major importance. Recently, a role for endothelin has been demonstrated: mutation of the gene coding for endothelin 3 in lethal spotted mice and gene knockout experiments result in impaired migration of neural crest cells in the hind gut and agauglionosis in the terminal bowel. How this peptide influences neural crest cell migration through the extracellular matrix of the gut is not known since the cells expressing endothelin 3 during development of the gut have not been identified. To address this question, we have examined the cellular sources of this peptide and deposition of extracellular matrix molecules in embryos of normal mice and those of lethal spotted (Is/Is) mice carrying a homozygous point mutation in the endothelin 3 gene which blocks cleavage of the precursor peptide, big endothelin 3. In control embryos, immunoreactivity for endothelin 3 was first detected 10.5 days post culture (El0.5) in cells associated with the fore gut. Staining for the neuronal antigen, PGP 9.5, identified these cells as vagal neural crest cells. Endothelin 3 immunoreactivity was also present in dorsal root and sympathetic ganglia. By day E14.5, immunoreactivity was detected in presumptive enteric neurons throughout the gut. No immunoreactivity was detected in gut mesenchyme. Up to day E l l . 5 , a similar pattern of staining was seen in Is/Is embryos, the endothelin 3 antiserum recognising epitopes in the uncleaved precursor. However, from day E14.5 onwards, a reduced number of endothelin 3/PGP 9.5immunoreactive cells was found in the hind gut, starting at the ileocaecal junction. No difference was seen between normal and Is/Is embryos in the deposition of laminin or tenascin in either distal ileum or caecum/proximal colon. These data indicate that neural crest cells are a major source of endothelin 3 during development, and that lesions in the enteric nervous system of Is/Is mice result from defects in the precursors of enteric neurons and not the extracellular matrix of the gut.
AUTOCRINE VIP REGULATION IN TIlE ENDOTHELIUM OF CEREBRAL VASCULATURE IN NEWBORN PIGLETS D. Lange I, K. Funa 2, U. Wollina 1. IDepartment Dermatology of the Friedrich-Schiller-Univcrsily t~l' Jean, Jena, Germany; 2Ludwig Institute of Cancer Research, Uppsala Branch, Uppsaht, Sweden. The neonatal period of the brain growth spurt is chnracterised by nq~id growlh as well as by dcvch~pment events like neuronal differentiation and nngiogenesis. The vasoactive intestinal peplide (VIP) is known not only as wlsodilntator but also as potent regulator of the CNS development [itill et ill. (1992), Ann N Y Acad Sci 739: 211-225]. The purpose of the study was to exmnine tile VIP regulation of cerebral vasculature in the postpartal period. The brainstem of 24-48 hours old piglets was used to examine the cxplession of nalive VIP, VIP-recept~r and VIP-mRNA by immunohistochemistry and in situ hybridisalion. We found, thai endothelial cells of cerebral arteries, veins al|d capilhmries are able to express native VIP, VIP-receplor and VIP-mRNA. The strongest signals were h~und in the peripheral zone of bnfin slem sections, especially in puns and mesenccphalon. Pinl vessels show positive signals t~o. The coincidence of VIP, VIP-mRNA and ViP-receptor in Ihe endothelium iadicatcs a aulocrine regulation ,nechanism, which has been found only in neuroblastomn [Pence el ill. (1993). Arch Surg 128: 591-5951. Comparing our results with the status of adult species, we found thai the lmtocrine mcchnnism is'strictly limited to the poslpnrtal period. This gives evidence tot the immaturity of the endolhelial cells at birlh and for a special event in the VIP regulnled system during Ihe change from intra- t~ extrauterine live. Wc asrume n role of VIP as a differentiating and growth t'~lctorof endolhelial cells.
Abstracts from the 1l th International Symposium on Regulatory Peptides
ENDOTHELIN 3 EXPRESSION BY VAGAL NEURAL CREST CELLS MK Lancaster, C Blackmore, J Goldsmith, DE Edgar*, C Vaillant Departments of Veterinary Preclinical Sciences & *Human Anatomy, University of Liverpool, UK Factors regulating the migration of vagal neural crest cells which give rise to the enteric nervous system in the developing gut are poorly understood but an appropriate microenvironment (i.e. normal deposition of extracellular matrix molecules) in the gut wall is thought to be of major importance. Recently, a role for endothelin has been demonstrated: mutation of the gene coding for endothelin 3 in lethal spotted mice and gene knockout experiments result in impaired migration of neural crest cells in the hind gut and agauglionosis in the terminal bowel. How this peptide influences neural crest cell migration through the extracellular matrix of the gut is not known since the cells expressing endothelin 3 during development of the gut have not been identified. To address this question, we have examined the cellular sources of this peptide and deposition of extracellular matrix molecules in embryos of normal mice and those of lethal spotted (Is/Is) mice carrying a homozygous point mutation in the endothelin 3 gene which blocks cleavage of the precursor peptide, big endothelin 3. In control embryos, immunoreactivity for endothelin 3 was first detected 10.5 days post culture (El0.5) in cells associated with the fore gut. Staining for the neuronal antigen, PGP 9.5, identified these cells as vagal neural crest cells. Endothelin 3 immunoreactivity was also present in dorsal root and sympathetic ganglia. By day E14.5, immunoreactivity was detected in presumptive enteric neurons throughout the gut. No immunoreactivity was detected in gut mesenchyme. Up to day E l l . 5 , a similar pattern of staining was seen in Is/Is embryos, the endothelin 3 antiserum recognising epitopes in the uncleaved precursor. However, from day E14.5 onwards, a reduced number of endothelin 3/PGP 9.5immunoreactive cells was found in the hind gut, starting at the ileocaecal junction. No difference was seen between normal and Is/Is embryos in the deposition of laminin or tenascin in either distal ileum or caecum/proximal colon. These data indicate that neural crest cells are a major source of endothelin 3 during development, and that lesions in the enteric nervous system of Is/Is mice result from defects in the precursors of enteric neurons and not the extracellular matrix of the gut.
AUTOCRINE VIP REGULATION IN TIlE ENDOTHELIUM OF CEREBRAL VASCULATURE IN NEWBORN PIGLETS D. Lange I, K. Funa 2, U. Wollina 1. IDepartment Dermatology of the Friedrich-Schiller-Univcrsily t~l' Jean, Jena, Germany; 2Ludwig Institute of Cancer Research, Uppsala Branch, Uppsaht, Sweden. The neonatal period of the brain growth spurt is chnracterised by nq~id growlh as well as by dcvch~pment events like neuronal differentiation and nngiogenesis. The vasoactive intestinal peplide (VIP) is known not only as wlsodilntator but also as potent regulator of the CNS development [itill et ill. (1992), Ann N Y Acad Sci 739: 211-225]. The purpose of the study was to exmnine tile VIP regulation of cerebral vasculature in the postpartal period. The brainstem of 24-48 hours old piglets was used to examine the cxplession of nalive VIP, VIP-recept~r and VIP-mRNA by immunohistochemistry and in situ hybridisalion. We found, thai endothelial cells of cerebral arteries, veins al|d capilhmries are able to express native VIP, VIP-receplor and VIP-mRNA. The strongest signals were h~und in the peripheral zone of bnfin slem sections, especially in puns and mesenccphalon. Pinl vessels show positive signals t~o. The coincidence of VIP, VIP-mRNA and ViP-receptor in Ihe endothelium iadicatcs a aulocrine regulation ,nechanism, which has been found only in neuroblastomn [Pence el ill. (1993). Arch Surg 128: 591-5951. Comparing our results with the status of adult species, we found thai the lmtocrine mcchnnism is'strictly limited to the poslpnrtal period. This gives evidence tot the immaturity of the endolhelial cells at birlh and for a special event in the VIP regulnled system during Ihe change from intra- t~ extrauterine live. Wc asrume n role of VIP as a differentiating and growth t'~lctorof endolhelial cells.