FGF Signaling in Chick Lens Development

Developmental Biology

Anh-Chi N. Le¹  Linda S. Musil¹ 

[1] Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland, Oregon, 97201

关键词: lens;    differentiation;    FGF;    vitreous humor;    chick;    ERK;    MAP kinase;    IGF;   

DOI  :  10.1006/dbio.2001.0194

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

TheprevailingconcepthasbeenthatanFGFinducesepithelial-to-fiberdifferentiationinthemammalianlens,whereaschicklenscellsareunresponsivetoFGFandareinsteadinducedtodifferentiatebyIGF/insulin-typefactors.Weshowherethatwhentreatedforperiodsinexcessofthoseusedinpreviousinvestigations(>5h),purifiedrecombinantFGFsstimulateproliferationofprimaryculturesofembryonicchicklensepithelialcellsand(athigherconcentrations)expressionofthefiberdifferentiationmarkersδ-crystallinandCP49.Surprisingly,upregulationofproliferationandδ-crystallinsynthesisbyFGFdoesnotrequireactivationofERKkinases.ERKfunctionis,however,essentialforstimulationofδ-crystallinexpressioninresponsetoinsulinorIGF-1.Vitreoushumor,thepresumptivesourceofdifferentiation-promotingactivityinvivo,containsafactorcapableofdiffusingoutofthevitreousbodyandinducingδ-crystallinandCP49expressioninchicklenscultures.Thisfactorbindsheparinwithhighaffinityandincreasesδ-crystallinexpressioninanERK-insensitivemanner,propertiesconsistentwithanFGFbutnotinsulinorIGF.OurfindingsindicatethatdifferentiationinthechicklensislikelytobemediatedbyanFGFandprovidethefirstinsightsintotheroleoftheERKpathwayingrowthfactor-inducedsignaltransductioninthelens.

【 授权许可】

Unknown