Project description:Planar cell polarity PCP proteins coordinate tissue morphogenesis by governing cell patterning and polarity. Asymmetrically localized on the plasma membrane of cells, transmembrane PCP proteins aretrafficked by endocytosis, suggesting they may have intracellular functions that are dependent or independent of their extracellular role, but whether these functions extend to transcriptional control remains unknown. Here, we show the nuclear localization of transmembrane, PCP protein, VANGL2, in undifferentiated, but not differentiated, HC11 cells, which serve as a model for mammary lactogenic differentiation. Loss ofVangl2function results in upregulation of pathways related to STAT5 signaling.We identify DNA binding sites and a nuclear localization signal in VANGL2, and use CUT&RUN to demonstrate recruitment of VANGL2 to specific DNA binding motifs, including one in theStat5apromoter. Knockdown KD ofVangl2in HC11 cells and primary mammary organoids results in upregulation ofStat5a,Ccnd1andCsn2, larger acini and organoids, and precocious differentiation; phenotypes rescued by overexpression ofVangl2, but notVangl2ΔNLS. Together, these results advance a paradigm whereby PCP proteins coordinate tissue morphogenesis by keeping transcriptional programs governing differentiation in check.
Project description:Planar cell polarity PCP proteins coordinate tissue morphogenesis by governing cell patterning and polarity. Asymmetrically localized on the plasma membrane of cells, transmembrane PCP proteins aretrafficked by endocytosis, suggesting they may have intracellular functions that are dependent or independent of their extracellular role, but whether these functions extend to transcriptional control remains unknown. Here, we show the nuclear localization of transmembrane, PCP protein, VANGL2, in undifferentiated, but not differentiated, HC11 cells, which serve as a model for mammary lactogenic differentiation. Loss ofVangl2function results in upregulation of pathways related to STAT5 signaling.We identify DNA binding sites and a nuclear localization signal in VANGL2, and use CUT&RUN to demonstrate recruitment of VANGL2 to specific DNA binding motifs, including one in theStat5apromoter. Knockdown KD ofVangl2in HC11 cells and primary mammary organoids results in upregulation ofStat5a,Ccnd1andCsn2, larger acini and organoids, and precocious differentiation; phenotypes rescued by overexpression ofVangl2, but notVangl2ΔNLS. Together, these results advance a paradigm whereby PCP proteins coordinate tissue morphogenesis by keeping transcriptional programs governing differentiation in check.
Project description:Differentiation of stem cells embedded within the mammary epithelium is orchestrated by lineage-specifying transcription factors. Unlike the well-defined luminal hierarchy, dissection of the basal lineage has been hindered by a lack of specific markers. Inhibitor of Differentiation 4 (ID4) is a basally-restricted helix-loop-helix (HLH) transcription factor essential for mammary development. Here we show that ID4 is highly expressed in basal stem cells and decreases during myoepithelial differentiation. By integrating transcriptomic, proteomic and chromatin-association data we reveal that ID4 is required to suppress myoepithelial gene expression and cell fate.
Project description:Development of mammary secretory epithelium and its functional differentiation occur during pregnancy under combined actions of ovarian steroids, pituitary hormones and growth factors. If the effect of these molecules is relatively well known, effect of differentiation factors expressed locally is not enough characterized. To understand local regulation of mammary tissue development and differentiation we realized transcriptional analysis on 5 physiological stages (4 during pregnancy and 1 during lactation). An appropriate experimental design was drawn to follow gene expression profiles during differentiation of mammary tissue. Results showed that at mid-pregnancy, mammary tissue was enough defferentiated into secretory epithelium to express milk protein genes and genes of the immune response system actors. But the secretoty activation of mammary epithelium was done only after parturition and wwas characterized by the expression of lipidogenesis genes. Keywords: time course, mammary gland differentiation, goat, pregnancy