Morphogenetic restructuring and formation of basement membranes by Sertoli cells and testis peritubular cells in co-culture: Inhibition of the morphogenetic cascade by cyclic AMP derivatives and by blocking direct cell contact☆

摘要

AdditionofdibutyrylcyclicAMP(dbcAMP),methylisobutylxanthine(MIX),orcytochalasinDtoco-culturesofSertolicellsandtesticularperitubularmyoidcellsblocksaseriesofmorphogeneticchangeswhichotherwiseoccurduringculture.WhenSertolicellsareplateddirectlyontopreexistinglayersofperitubularcellsmaintainedunderbasalconditions,structuresformwhichdisplaymanyofthecharacteristicsofgermcell-depletedseminiferoustubules.ThepresenceofdbcAMP,MIX,orcytochalasinD,addedatvaryingtimesafterplatingSertolicells,resultsintheinhibitionofeachsuccessivestageofinvitroremodeling:theinhibitionofmigrationofSertolicells,theinhibitionofinitialridgeformation,theblockageofsubsequentformationofmoundsandnodulesofcompactedSertolicellaggregates,thepreventionoftheformationofbasallaminaandassociatedlayersofextracellularmatrixbetweenSertolicellaggregatesandsurroundingperitubularcells,andtheinhibitionoftubuleformation.ThepresenceofdbcAMPalsoinhibitsthemigrationofperitubularcells,contractionsbythesecells,andcompactionofSertolicellaggregates.Whenintimatecellappositionispreventedbyplatingthetwocelltypesoneithersideofamembranefilter,themorphogeneticcascadeisblocked,andnoformationofagermcell-depletedseminiferoustubule-likestructureoccurs.OthereffectsofdbcAMPoncellshape,cellmovement,andcellassociationpatternsduringco-culturearedescribed.PossiblemechanismsbywhichdbcAMP,MIX,orcytochalasinDblocksrestructuringarediscussed.Sinceeachelicitsperturbationsofthecytoskeleton,weoffertheinterpretationthatcytoskeletalchangesmaybecorrelatedwiththepreventionofcloselyapposingcellcompactandtheinhibitionofbasementmembraneformation.InteractionsobservedbetweenSertolicellsandperitubularcellsduringco-culturearepostulatedtobeanalogoustothoseoccurringinothertypesofmesenchymalcell-epithelialcellinteractionsduringorganogenesisandduringtubulogenesisinthefetaltestis.Speculatively,theblockagebydbcAMPofthemorphogeneticcascadeintheco-culturedsystemmayberelatedtotheinhibitionbydbcAMPoftestiscordformationinorganculturesoffetalgonadsreportedbyothers.