Comparison of Differences in Mouse Mammary gland gene expression data at POSTNATAL DAY 70 in Akt1wildtype versus Akt1-deficient mice
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ABSTRACT: Akt1, a serine-threonine protein kinase member of the PKB/Akt gene family, plays a critical role in the regulation of several cellular processes including cell proliferation and apoptosis. In this study, we utilized Akt1+/+ and Akt1¬-/- C57/Bl6 female mice to demonstrate that Akt1 is required for normal mammary gland postnatal development and homeostasis. Akt1 deficiency resulted in severely delayed postnatal mammary gland growth as well as a significant decrease in the number of terminal end buds during puberty. Adult Akt1-/- mammary glands exhibited significantly fewer alveolar buds coupled with a significant increase in epithelial cell apoptosis compared to their wild-type counterparts. Microarray analysis revealed that Akt1 deficiency resulted in several altered gene expression changes and biological processes in adult mammary glands, including organismal development, cell death, and tissue morphology. Of particular importance, a significant decrease in expression of Btn1a1, a gene involved in milk lipid secretion, was observed in Akt1-/- mammary glands by both microarray and RT-PCR validation. Transcriptome analysis of Akt1 wild type and akt1-homozygous mouse mammary glands
Project description:Akt1, a serine-threonine protein kinase member of the PKB/Akt gene family, plays a critical role in the regulation of several cellular processes including cell proliferation and apoptosis. In this study, we utilized Akt1+/+ and Akt1¬-/- C57/Bl6 female mice to demonstrate that Akt1 is required for normal mammary gland postnatal development and homeostasis. Akt1 deficiency resulted in severely delayed postnatal mammary gland growth as well as a significant decrease in the number of terminal end buds during puberty. Adult Akt1-/- mammary glands exhibited significantly fewer alveolar buds coupled with a significant increase in epithelial cell apoptosis compared to their wild-type counterparts. Microarray analysis revealed that Akt1 deficiency resulted in several altered gene expression changes and biological processes in adult mammary glands, including organismal development, cell death, and tissue morphology. Of particular importance, a significant decrease in expression of Btn1a1, a gene involved in milk lipid secretion, was observed in Akt1-/- mammary glands by both microarray and RT-PCR validation. Transcriptome analysis of Akt1 wild type and akt1-homozygous mouse mammary glands wild type mammary glands from 3 mice and Akt1-deficient mammary glands from 3 mice were analyzed for differences in gene expression at postnatal day 70
Project description:Macrophages have important roles in mammary gland development and tissue homeostasis, but the specific mechanisms that regulate macrophage function need further elucidation. We have identified C/EBPβ as an important macrophage factor that is present in multiple populations of the normal mammary gland. Mammary glands from mice with C/EBPβ-deficient macrophages showed a significant decrease in alveolar budding during the estrus cycle. Deletion of C/EBPβ from macrophages resulted in changes in cytokine production, and an inability of both epithelial cells and macrophages to respond progesterone. RNA sequencing showed significant changes in PR-responsive genes and alterations in the Wnt landscape of epithelial cells in mammary glands that lacked C/EBPbeta in macrophages, which have been shown to mediate stem cell expansion during diestrus. These studies suggest that C/EBPbeta is a critical macrophage factor that facilitates macrophage-epithelial crosstalk during a key stage of mammary gland tissue homeostasis, and have critical implications for how disruption of tissue homeostasis can lead to tumorigenesis.
Project description:Mammary gland branching morphogenesis is thought to depend on the mobilization of proteolytic machinery from the matrix metalloproteinase (MMP) family, namely MT1-MMP/MMP14, to drive coordinated epithelial cell invasion through the interstitial extracellular matrix, but the dominant effector has remained undefined. Unexpectedly, we find MMP14 controls postnatal mammary gland branching from the periductal stroma. Transcriptome profiling of stromal cell-targeted mammary glands was used to characterize the impact of stromal Mmp14-targeting on the growth factor and signaling cascades implicated in mammary gland morphogenesis. Transcriptome profiling of ductal networks and associated stroma was used to investigate the functional roles of MMP14 in the postnatal mammary gland stroma in an unbiased fashion.
Project description:Mammary gland development is fueled by stem cell self-renewal and differentiation. External cues from the microenvironment coupled with internal cues such as post-transcriptional regulation exerted by miRNAs regulate stem cell behavior and stem cell fate. We have identified a miR205 regulatory network required for mammary gland morphogenesis and stem cell maintenance. In the postnatal mammary gland, miR205 is predominantly expressed in the basal/stem cell enriched population. Conditional deletion of miR205 in mammary epithelial cells severely impaired stem cell self-renewal and mammary repopulating potential both in vitro and in vivo. miR205 null glands displayed significant changes in the basal population, basement membrane and stroma. NKD1 and PP2A-B56, which inhibit the Wnt signaling pathway, and AMOT, which causes YAP cytoplasmic retention and inactivation were identified as miR205 downstream effectors. Collectively these findings reveal an essential role of miR205 in mammary gland development.
Project description:Stat1-null mice (129S6/SvEvTac-Stat1tm1Rds homozygous) uniquely develop estrogen-receptor-positive mammary tumors with incomplete penetrance and long latency. We studied the growth and development of the mammary glands in Stat1-null mice. Stat1-null MGs have faulty branching morphogenesis with abnormal terminal end buds. The Stat1-null MG also fails to sustain growth of 129S6/SvEv wild-type and null epithelium. These abnormalities are partially reversed by added progesterone and prolactin. Transplantation of wild-type bone-marrow into Stat1-null mice does not reverse the mammary gland developmental defects. Media conditioned by Stat1-null epithelium-cleared mammary fat pads does not stimulate epithelial proliferation whereas it is stimulated by conditioned media derived from either wild-type or progesterone and prolactin-treated Stat1-null epithelium-cleared mammary fat pads. Microarrays and multiplex cytokine protein assays showed that the mammary gland of Stat1-null mice had lower levels of growth factors that have been implicated in normal mammary gland growth and development. Transplanted Stat1-null tumors and their isolated cells also grow slower in Stat1-null mammary gland compared to wild-type recipient mammary gland. Stat1-null hosts responded to tumor transplants with granulocytic infiltrates while wild-type hosts show a mononuclear response. These studies demonstrate that growth of normal and neoplastic Stat1-null epithelium primarily depends on the hormonal milieu and factors, such as cytokines, from the mammary stroma. Stat1-null mammary glands were compared to 129SvEv WT mammary glands with respect to development, gene expression profiles, growth factors and histology.
Project description:Purpose: To assess global changes to the levels of mRNA and protein in butyrophilin-null mice (Btn1a1-/-), which were previously shown to be defective in regulated milk-lipid secretion in the lactating mammary gland. Methods: mRNA profiles of wild-type (WT) and Btn1a1-/-mice were generated by mRNA/cDNA library preparation (Illumina), qPCR quantitation, cluster generation and pair-end deep sequencing (Illumina HiSeq 4000 sequencer) using an Illumina HiSeq SBS kit. Changes in mRNA levels (null/WT ≥ ± 2-fold; adjusted p ≤ 0.05) were assesed by GSEA and IPA analysis and compared with a proteomic analysis of the same sample set.. Results: Samples had 95-167 million pass filter reads (92% above Q30). Mapping of all samples was > 97% (mm10 reference genome). Significant changes in mRNA amounts accounted for 1.4% of 11,834 transcipts (113 up and 53 down regulated). Only 10 mRNA/protein pairs were significantly upregulated and one (Btn1a1) downregulated. Pathways and networks associated with inflammation, apoptosis and the cell cycle were upregulated and lipid synthesis and metabolism were downregulated. Biochemical and histochemical analysis confirmed that lactation is maintained in null animals, in the face of significant apoptosis, by the continual regeneration of secretory epithelial cells. Cell death proceeded through several pathways including activation of caspases 8 and 3 and not by the lysosomal lysis pathway predominant in WT cells Conclusions: Ablation of Btn1a1 has multiple effects on milk-secreting mammary cells, including disruption of lipid secretion, increased cell damage and death. Lactation is maintained by continuous regeneration of the epithelium. Expression of functional Btn1a1 is essential for the maintainance of terminally differentiated mammary cells and optimal milk production throughout lactation.
Project description:Organoid culture has been extensively exploited for normal tissue reconstruction and disease modeling, however, it is still challenging to establish physiologically relevant architecture, size and functions in homeostasis. Here, we describe the development of a long-term adult stem cell derived mammary mini-gland culture system that supports robust 3D outgrowths recapitulating the morphology, cellular context, transcriptional heterogeneity of the normal mammary gland. The self-organization ability of stem cells and the stability of the outgrowths were determined by a coordinated combination of extracellular matrix, environmental signalings and dynamic physiological cycles. These mini glands are hormone responsive and reproduce the entire postnatal mammary development including puberty, estrous cycle, lactation and involution. Most intriguingly, these mini glands maintained the mammary stem cells and represented the fate transition from embryonic bipotency to postnatal unipotency in lineage tracing assays. In addition, induced oncogene expression in the mini glands drove the clinically relevant cancer initiation that can be monitored chronologically. Together, this study provides an experimental system fostering a dynamic organ miniature that can be studied chronologically and spatially for physiologically relevant biological processes with complexity.
Project description:The present experiments were performed to determine the roles of estrogen receptors α and β (ERα and ERβ) in normal and neoplastic development in the mouse mammary gland. In wild-type mice, in vivo administration of estradiol (E) + progesterone (P) stimulated mammary ductal growth and alveolar differentiation. Mammary glands from mice in which the ERβ gene has been deleted (βERKO mice) demonstrated normal ductal growth and differentiation in response to E + P. By contrast, mammary glands from mice in which the ERα gene has been deleted (αERKO mice) demonstrated only rudimentary ductal structures that did not differentiate in response to E + P. EGF demonstrates estrogen-like activity in the mammary glands of αERKO mice: treatment of αERKO mice with EGF + P (without E) supported normal mammary gland development, induced expression of progesterone receptor (PR), and increased levels of G- protein-coupled receptor (GPR30) protein. Mammary gland development in βERKO mice treated with EGF + P was comparable to that of wild-type mice receiving EGF + P; EGF had no statistically significant effects on the induction of PR or expression of GPR30 in mammary glands harvested from either wild-type mice or βERKO mice. In vitro exposure of mammary glands to 7,12-dimethylbenz[a]anthracene (DMBA) induced preneoplastic mammary alveolar lesions (MAL) in glands from wild-type mice and βERKO mice, but failed to induce MAL in mammary glands from αERKO mice. Microarray analysis of DMBA-treated mammary glands identified 28 functional pathways whose expression was significantly different in αERKO mice versus both βERKO and wild-type mice; key functions that were differentially expressed in αERKO mice included cell division, cell proliferation, and apoptosis. The data demonstrate distinct roles for ERα and ERβ in normal and neoplastic development in the mouse mammary gland, and suggest that EGF can mimic the ERα-mediated effects of E in this organ.
Project description:The present experiments were performed to determine the roles of estrogen receptors M-NM-1 and M-NM-2 (ERM-NM-1 and ERM-NM-2) in normal and neoplastic development in the mouse mammary gland. In wild-type mice, in vivo administration of estradiol (E) + progesterone (P) stimulated mammary ductal growth and alveolar differentiation. Mammary glands from mice in which the ERM-NM-2 gene has been deleted (M-NM-2ERKO mice) demonstrated normal ductal growth and differentiation in response to E + P. By contrast, mammary glands from mice in which the ERM-NM-1 gene has been deleted (M-NM-1ERKO mice) demonstrated only rudimentary ductal structures that did not differentiate in response to E + P. EGF demonstrates estrogen-like activity in the mammary glands of M-NM-1ERKO mice: treatment of M-NM-1ERKO mice with EGF + P (without E) supported normal mammary gland development, induced expression of progesterone receptor (PR), and increased levels of G- protein-coupled receptor (GPR30) protein. Mammary gland development in M-NM-2ERKO mice treated with EGF + P was comparable to that of wild-type mice receiving EGF + P; EGF had no statistically significant effects on the induction of PR or expression of GPR30 in mammary glands harvested from either wild-type mice or M-NM-2ERKO mice. In vitro exposure of mammary glands to 7,12-dimethylbenz[a]anthracene (DMBA) induced preneoplastic mammary alveolar lesions (MAL) in glands from wild-type mice and M-NM-2ERKO mice, but failed to induce MAL in mammary glands from M-NM-1ERKO mice. Microarray analysis of DMBA-treated mammary glands identified 28 functional pathways whose expression was significantly different in M-NM-1ERKO mice versus both M-NM-2ERKO and wild-type mice; key functions that were differentially expressed in M-NM-1ERKO mice included cell division, cell proliferation, and apoptosis. The data demonstrate distinct roles for ERM-NM-1 and ERM-NM-2 in normal and neoplastic development in the mouse mammary gland, and suggest that EGF can mimic the ERM-NM-1-mediated effects of E in this organ. Gene expression of mammary gland organ culture and DMBA-induced lesions from 4 mouse strains.
Project description:The aim was to carry out global analysis of gene expression changes occurring in the normal pubertal mouse mammary gland from the appearance to the regression of terminal end buds. Experiment Overall Design: 5 time points were chosen for analysis: 3wk, 4wk, 5wk, 6wk and 7wk. Each time point was analysed in triplicate with the exception of the 5wk time point which was analysed in duplicate. Total: 14 samples. Each sample was prepared from a pool of RNA from mammary glands of a minimum of three mice.