Mesenchyme cells degrade epithelial basal lamina glycosaminoglycan☆
[摘要] Weinvestigatedwhetherturnoverofbasallaminaglycosaminoglycan(GAG),anactiveprocessduringepithelialmorphogenesis,involvesthemesenchyme.Fixed,prelabeled,isolatedmouseembryosubmandibularepitheliawerepreparedretainingradioactivesurfacecomponents,asdeterminedbyautoradiographicandenzymaticstudies,andabasallamina,asassessedbyelectronmicroscopy.Recombinationofmouseembryosubmandibularmesenchymewiththeseepitheliastimulatesthereleaseofepithelialradioactivitywhenthelabeledprecursorisglucosamineorglucosebutnotwhenitisaminoacid.Thereleaseislinearwithtimeduring150minincubation.Augmentedreleaseofepitheliallabelrequireslivingmesenchymewhichmustbecloseproximitywiththeepithelia.Althoughheterologousmesenchymes,includinglung,trachea,andjaw,stimulatethereleaseofsubmandibularepitheliallabel,epithelialtissuesdonot.ThelabelreleasedbyintactsubmandibularmesenchymefromprelabeledepitheliaisinGAGandintwouniquefractions:heterogeneousmaterialsoftetrasaccharideorsmallersizeandN-acetylglucosamine.Enzymatictreatmentoftheheterogeneousmaterialsrevealedthepresenceofglycosaminoglycan-derivedoligosaccharides.Theseuniqueproductswerenotobtainedbyincubatingprelabeledepitheliawithamesenchymalcellextract,suggestingthatintactmesenchymalcellsarerequired.N-AcetylglucosaminewasalsoreleasedwhenmesenchymewasrecombinedwithlivingprelabeledepitheliawhichcontainedlabeledbasallaminarGAG.OurresultsestablishthatsubmandibularepithelialbasallaminaGAGsaredegradedbysubmandibularmesenchyme.Weproposethatonemechanismofepithelial-mesenchymalinteractionisthedegradationofepithelialbasallaminarGAGbymesenchyme.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
