The secreted protease Adamts18 links mammary epithelial hormone action to extracellular matrix changes and stem cell niche function
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ABSTRACT: Estrogens and progesterone control mammary gland development and breast carcinogenesis via their cognate receptors expressed in a subset of cells of the luminal layer of the mammary epithelium. The extracellular matrix (ECM) including the basement membrane (BM) is important in breast physiology and tumorigenesis but how epithelial hormone receptor signaling and ECM are linked mechanistically is unclear. We identify the secreted protease Adamts18 as critical intermediary. Luminal estrogen and progesterone receptor signaling via upregulation of Wnt4 expression and ensuing canonical Wnt signaling activation in basal cells control Adamts18 expression there. The protease has an epithelial-intrinsic role in stem cell activation. We identify multiple binding partners in the interstitial ECM and BM and show that ADAMTS18 cleaves fibronectin in vitro. Its deletion results in increased fibronectin, collagen I and IV, and laminin deposition in pubertal glands. Adamts18 interacts genetically with Col18a1, which encodes a proteoglycan that is BM-specific, in stem cell regulation. Adamts18 inactivation impairs Hippo signaling and reduces Fgfr2 expression and signaling, which are vital for stem cell function. Our findings link epithelial hormone signaling to BM remodeling by Adamts18, and define the BM as an essential stem cell niche component.
Project description:Estrogens and progesterone control mammary gland development and breast carcinogenesis via their cognate receptors expressed in a subset of cells of the luminal layer of the mammary epithelium. The extracellular matrix (ECM) including the basement membrane (BM) is important in breast physiology and tumorigenesis but how epithelial hormone receptor signaling and ECM are linked mechanistically is unclear. We identify the secreted protease Adamts18 as critical intermediary. Luminal estrogen and progesterone receptor signaling via upregulation of Wnt4 expression and ensuing canonical Wnt signaling activation in basal cells control Adamts18 expression there. The protease has an epithelial-intrinsic role in stem cell activation. We identify multiple binding partners in the interstitial ECM and BM and show that ADAMTS18 cleaves fibronectin in vitro. Its deletion results in increased fibronectin, collagen I and IV, and laminin deposition in pubertal glands. Adamts18 interacts genetically with Col18a1, which encodes a proteoglycan that is BM-specific, in stem cell regulation. Adamts18 inactivation impairs Hippo signaling and reduces Fgfr2 expression and signaling, which are vital for stem cell function. Our findings link epithelial hormone signaling to BM remodeling by Adamts18, and define the BM as an essential stem cell niche component.
Project description:Transforming growth factor beta (TGFβ) is a multifunctional cytokine with a well-established role in mammary gland development and both oncogenic and tumor-suppressive functions. The extracellular matrix (ECM) indirectly regulates TGFβ activity by acting as a storage compartment of latent TGFβ, but how TGFβ is released from the ECM via proteolytic mechanisms remains largely unknown. In this study, we demonstrate that hepsin, a type II transmembrane protease overexpressed in 70% of breast tumors, promotes canonical TGFβ signaling through the release of latent TGFβ from the ECM-storage compartment. Mammary glands in hepsin CRISPR knock-out mice showed reduced TGFβ signaling and increased epithelial branching, accompanied by increased levels of fibronectin and latent TGFβ1, while overexpression of hepsin in mammary tumors increased TGFβ signaling. Cell-free and cell-based experiments showed that hepsin is capable of direct proteolytic cleavage of fibronectin but not latent TGFβ and, importantly, that the ability of hepsin to activate TGFβ signaling is dependent on fibronectin. Altogether, this study demonstrates a role for hepsin as a regulator of the TGFβ pathway in the mammary gland via a novel mechanism involving proteolytic downmodulation of fibronectin.
Project description:ovariectomized mice treated with E2+Progesterone, E2+Progesterone+TPA, E2+Progesterone+RU486 and sham for 14 days, followed by isolation of luminal mature, luminal progenitor and mammary stem cells through FACS and RNASeq performed for each cell lineage population. TPA and RU486 treated mice show significant decline in mammary stem cell pool pulation comapared to EP treated mice
Project description:Transcriptional profiling of different mouse mammary cellular compartments (basal, luminal and stromal) under define hormone treatments: estrogen, progesterone, estrogen plus progesterone and the vehicle control. Goal was to determine the effect of ovarian hormones on mammary cellular compartment gene expression. Four-condition experiment within each cellular compartment. vehicle vs. estrogen, progesterone and estrogen plus progesterone. Biological replicates: 3 vehicle control, 4 estrogen treatment, 3 progesterone treatment, 4 estrogen plus progesterone treatment in each epithelial compartment (luminal, basal). 3 vehicle control, 3 estrogen, 3 progesterone, 3 estrogen plus progesterone in the stromal compartment.
Project description:The purpose of this microarray experiment was to obtain reference gene expression patterns of a number of epithelial cell populations [mammary stem cells (MASC), luminal progenitors (LP), alveolar luminal stem/progenitor cells (WC virgin-these are mammary epithelial cells genetically marked by Wap-Cre in virgin females), mature luminal cells (ML, mainly represent ductal luminal cells in virgin females), and alveolar luminal cells (WC preg M-bM-^@M-^S these are alveolar cells genetically marked by Wap-Cre during mid-gestation)] present in the mammary gland of wildtype adult mice on a C57BL6 genetic background. For the isolation of RNA from mammary stem cells (MASC, Lin-CD24+CD29hi), luminal progenitors (LP, Lin-CD24hiCD29+CD61+), and mature luminal cells (ML, lin-CD24hiCD29+CD61-), the thoracic and inguinal mammary glands from 3 adult virgin female mice were harvested, minced and digested into a single cell suspension. Form each of these 3 single cell suspensions, the above populations were sorted by FACS. For alveolar luminal stem/progenitor cells and alveolar luminal cells, Lin-YFP+ mammary epithelial cells were isolated from virgin or midgestation mice genetically marked by Wap-Cre;R26Y. R26Y is a conditional YFP reporter that would be turned on upon Cre-mediated recombination.
Project description:Mammary epithelium is composed by luminal and basal epithelial cells, which are adhere to the basement membrane (BM). To dissect how basal cell functions are regulated by BM laminin adhesion, we performed RNA sequencing of basal human mammary epithelial cells adhered on laminin-111, -421 or -521 coated cell culture plates for 48 hours.
Project description:The bovine mammary gland has a heterogeneous epithelial population which comprises terminally differentiated luminal and myoepithelial cells but also bipotent or lineage restricted progenitors and adult stem cells. The aim of our study was to use a novel surface marker (P-Cadherin) to characterize different mammary subpopulation, to sort adult stem cells with better enrichment and to perform whole RNA-seq among sorted population to identify biological processes or molecular functions associated gene enrichment. We found that only the CD49fhigh/PCadherinneg was enriched for adult mammary stem cells, while in other fractions we could detect luminal progenitors. Analysis of functional enrichments showed that in the stem cell compartment proliferation associated genes were downregulated, while genes relating to adhesion to ECM and to other neighboring cells were upregulated.
Project description:Mammary gland development and luminal differentiation occur largely postnatally during puberty and pregnancy. To explore the role of DNA methylation in luminal cell differentiation and pregnancy-induced changes, we determined the genome-wide DNA methylation and gene expression profiles of mammary epithelial stem, luminal progenitor, and mature luminal cells at different reproductive stages. We found that pregnancy had the most significant effects on stem cells, inducing a distinct epigenetic state that remained stable through life. Integrated analysis of gene expression, DNA methylation, and histone modification profiles revealed cell type and reproductive stage-specific changes in molecular signatures. We also identified p27 and TGFβ signaling as key regulators of luminal progenitor cell proliferation based on their expression patterns and by the use of explant cultures. Our results suggest relatively minor changes in DNA methylation during luminal cell differentiation as compared to the significant effects of pregnancy on mammary epithelial stem cells. Mammary glands were collected from mice treated with DNA methylation inhibitor 5-azacytidine (AzaC) and histone deacetylase inhibitor valproic acid (VPA) at non-pregnant and pregnant stages for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Mammary gland development and luminal differentiation occur largely postnatally during puberty and pregnancy. To explore the role of DNA methylation in luminal cell differentiation and pregnancy-induced changes, we determined the genome-wide DNA methylation and gene expression profiles of mammary epithelial stem, luminal progenitor, and mature luminal cells at different reproductive stages. We found that pregnancy had the most significant effects on stem cells, inducing a distinct epigenetic state that remained stable through life. Integrated analysis of gene expression, DNA methylation, and histone modification profiles revealed cell type and reproductive stage-specific changes in molecular signatures. We also identified p27 and TGFβ signaling as key regulators of luminal progenitor cell proliferation based on their expression patterns and by the use of explant cultures. Our results suggest relatively minor changes in DNA methylation during luminal cell differentiation as compared to the significant effects of pregnancy on mammary epithelial stem cells.
Project description:Skin-mammary specific knockout (SSKO) of Pygo2 (K14-cre; Pygo2 flox/-) , a WNT signaling co-activator, results in defective mouse mammary gland development. The FACS sorted mammary stem cell (MaSC)/basal population from Pygo2 SSKO mammary gland displays biased differentiation towards luminal/alveolar lineage in vitro, and reduced regeneration rate of new mammary gland in vivo To gain the insight into gene expression profiles in control and Pygo2 SSKO mammary epithelial cells (MECs), we sorted the freshly isolated mouse MECs into MaSC/basal (Lin-CD29hiCD24+) and mature luminal population (Lin-CD29lowCD24+CD61-), and extract total RNA for cDNA microarray analysis