Integrin Signaling Regulates Blastocyst Adhesion to Fibronectin at Implantation: Intracellular Calcium Transients and Vesicle Trafficking in Primary Trophoblast Cells

Developmental Biology

Jun Wang¹  Linda Mayernik¹  D.Randall Armant¹ 

[1] C. S. Mott Center for Human Growth and Development, Departments of Anatomy and Cell Biology, Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, 48201

关键词: ovum implantation;    blastocyst;    trophoblast;    fibronectin;    integrins;    extracellular matrix;    trafficking;    cell adhesion;    Ca2+ signaling;    signal transduction;   

DOI  :  10.1006/dbio.2002.0644

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Accumulatingevidenceindicatesthattheendometrialextracellularmatrix(ECM)modulatestrophoblastadhesionduringmouseblastocystimplantation.Inpreviousstudiesofadhesion-competentmouseblastocysts,wehavedemonstratedthatintegrin-mediatedfibronectin(FN)-bindingactivityontheapicalsurfaceoftrophoblastcellsisinitiallylow,butbecomesstrengthenedafterembryosareexposedtoFN.Inthepresentstudy,wehaveexaminedwhethertheligand-inducedupregulationoftrophoblastadhesiontoFNismediatedbyintegrinsignaling.ThestrengtheningofadhesiontoFNrequiredintegrinligation,whichrapidlyelevatedcytoplasmic-freeCa2+.ChelationofintracellularCa2+usingBAPTA-AM,orinhibitionoftheCa2+-dependentproteins,proteinkinaseCorcalmodulin,significantlyattenuatedtheeffectofFNonbindingactivity.Furthermore,directelevationofcytoplasmicCa2+levelswithionomycinupregulatedFN-bindingactivity,demonstratingthatCa2+signalingisrequiredandsufficientforstrongadhesiontoFN.Ca2+signalingmayinduceproteintrafficking,aknownrequirementforligand-inducedupregulationofFN-bindingactivity.Indeed,intracellularvesiclesaccumulatedinadhesion-competentblastocysts,butwereabsentafterexposuretoeitherFNorionomycin.Thesefindingssuggestthat,duringimplantation,contactbetweenperi-implantationblastocystsandFNelevatesintracellularCa2+,whichstrengthenstrophoblastadhesiontoECMthroughproteinredistribution.

【 授权许可】

Unknown