Expression array of early postnatal Mt2-mmp-targeted mammary glands. Mus musculus

Mammary gland branching morphogenesis is thought to depend on the mobilization of the membrane-anchored matrix metalloproteinases, MT1-MMP and MT2-MMP, that drive epithelial cell invasion by remodeling the extracellular matrix and triggering associated signaling cascades. However, the roles that these proteinases play during mammary gland development in vivo remains undefined. A mammary gland branching program that occurs during the first 10 days of early postnatal development was used to characterize the impact of global Mt1-mmp or Mt2-mmp targeting on mammary gland morphogenesis. Transcriptome profiling of ductal networks and associated stroma was used to investigate the functional roles of MT2-MMP in the early postnatal mammary gland in an unbiased fashion. Overall design: Intact mammary gland tissue was harvested from global knockout [Mt2-mmp(-/-)] mice and wild-type [Mt2-mmp(+/+)] littermates on a congenic C57Bl/6J background at postnatal day 10 for RNA extraction and hybridization on Affymetrix microarrays.

乳腺分支形态发生被认为依赖于膜锚定基质金属蛋白酶（membrane-anchored matrix metalloproteinases，MT1-MMP和MT2-MMP）的动员——这类蛋白酶可通过重塑细胞外基质、触发相关信号级联反应，驱动上皮细胞侵袭。然而，这些蛋白酶在体内乳腺发育过程中所发挥的作用仍未明确。本研究以出生后早期前10天内发生的乳腺分支发育程序为模型，解析全身靶向Mt1-mmp或Mt2-mmp对乳腺形态发生的影响。通过对导管网络及其相关基质进行转录组分析（transcriptome profiling），本研究以无偏倚的方式探究了MT2-MMP在出生后早期乳腺中的功能角色。实验设计：于出生后第10天，从同基因C57Bl/6J背景的全身敲除[Mt2-mmp(-/-)]小鼠及其野生型[Mt2-mmp(+/+)]同窝幼鼠体内获取完整乳腺组织，用于RNA提取及Affymetrix基因芯片杂交。