Embryonic lung morphogenesis in organ culture:  experimental evidence for a proteoglycan function in the extracellular matrix.
The lung rudiment, isolated from mid-gestation (11 day) mouse embryos, can undergo morphogenesis in organ culture.  Observation of living rudiments, in culture, reveals both growth and ongoing bronchiolar branching activity.  To detect proteoglycan (PG) biosynthesis, and deposition in the extracellular matrix, rudiments were metabolically labeled with radioactive sulfate, then fixed, embedded, sectioned and processed for autoradiography.  The sulfated glycosaminoglycan (GAG) types, composing the carbohydrate component of the proteoglycans, were evaluated by selective GAG degradative approaches that showed chondroitin sulfate PG principally associated with the interstitial matrix, and heparan sulfate PG principally associated with the basement membrane.  Experiments using the proteoglycan biosynthesis disrupter, beta-xyloside, suggest that when chondroitin sulfate PG deposition into the ECM is perturbed, branching morphogenesis is compromised.
Spooner
B S
BS
NSCORT in Gravitational Biology, Kansas State University, Manhattan 66506, USA.
Bassett
K E
KE
Spooner
B S
BS
D000818:Animals; D001345:Autoradiography; D001485:Basement Membrane / Q000737:chemistry / Q000196:embryology* / Q000378:metabolism; D002809:Chondroitin Sulfates / Q000032:analysis / Q000378:metabolism / Q000502:physiology; D004848:Epithelium / Q000737:chemistry / Q000196:embryology / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D005260:Female; D006025:Glycosaminoglycans / Q000032:analysis / Q000378:metabolism / Q000502:physiology; D006027:Glycosides / Q000494:pharmacology; D006497:Heparan Sulfate / Q000032:analysis / Q000378:metabolism / Q000502:physiology; D008168:Lung / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D008297:Male; D051379:Mice; D009024:Morphogenesis / Q000187:drug effects / Q000502:physiology; D009924:Organ Culture Techniques; D011509:Proteoglycans / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D013462:Sulfur Radioisotopes
D002809:Chondroitin Sulfates; D006025:Glycosaminoglycans; D006027:Glycosides; D006497:Heparan Sulfate; D011509:Proteoglycans; D013462:Sulfur Radioisotopes; C010807:xylosides