scholarly journals Ablation of β1 integrin in mammary epithelium reveals a key role for integrin in glandular morphogenesis and differentiation

2005 ◽  
Vol 171 (4) ◽  
pp. 717-728 ◽  
Author(s):  
Matthew J. Naylor ◽  
Na Li ◽  
Julia Cheung ◽  
Emma T. Lowe ◽  
Elise Lambert ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Milk Fat ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelium ◽  
Mouse Mammary Gland ◽  
Mammary Epithelial ◽  
Glandular Epithelium ◽  
Cytokine Signaling ◽  
Β1 Integrin

Integrin-mediated adhesion regulates the development and function of a range of tissues; however, little is known about its role in glandular epithelium. To assess the contribution of β1 integrin, we conditionally deleted its gene in luminal epithelia during different stages of mouse mammary gland development and in cultured primary mammary epithelia. Loss of β1 integrin in vivo resulted in impaired alveologenesis and lactation. Cultured β1 integrin–null cells displayed abnormal focal adhesion function and signal transduction and could not form or maintain polarized acini. In vivo, epithelial cells became detached from the extracellular matrix but remained associated with each other and did not undergo overt apoptosis. β1 integrin–null mammary epithelial cells did not differentiate in response to prolactin stimulation because of defective Stat5 activation. In mice where β1 integrin was deleted after the initiation of differentiation, fewer defects in alveolar morphology occurred, yet major deficiencies were also observed in milk protein and milk fat production and Stat5 activation, indicating a permissive role for β1 integrins in prolactin signaling. This study demonstrates that β1 integrin is critical for the alveolar morphogenesis of a glandular epithelium and for maintenance of its differentiated function. Moreover, it provides genetic evidence for the cooperation between integrin and cytokine signaling pathways.

Cytodifferentiation of mouse mammary epithelial cells cultured on a reconstituted basement membrane reveals striking similarities to development in vivo

1991 ◽  
Vol 99 (2) ◽  
pp. 407-417 ◽  
Author(s):  
J. Aggeler ◽  
J. Ward ◽  
L.M. Blackie ◽  
M.H. Barcellos-Hoff ◽  
C.H. Streuli ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Basement Membrane ◽  
Milk Fat ◽  
Milk Protein ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Milk Protein Gene ◽  
Primary Mouse ◽  
Beta Casein

In the present study we provide evidence that the cytodifferentiation of primary mouse mammary epithelial cells within the alveolar-like structures formed after culture on a reconstituted basement membrane resembles development in vivo during late pregnancy and early lactation. During the first two days in culture on a basement membrane gel in the presence of lactogenic hormones, epithelial cells isolated from mid-pregnant mice are disorganized and central lumina are largely absent. Levels of mRNA for the milk proteins, beta-casein and transferrin, are dramatically reduced. By the second or third day in culture, cytoplasmic polarization becomes evident and prominent apical junctional complexes are formed. Synthesis of both mRNA and milk protein is reinitiated at this time. By day 4, well-defined lumina appear, and abundant synthesis and secretion of casein and lipid is observed. A striking feature of this differentiation in culture is the specific localization of milk protein gene expression (beta-casein mRNA) to luminal epithelial cells in the alveolar-like structures. At the ultrastructural level, increased milk protein synthesis and secretion are paralleled by a fourfold increase in rough ER that resembles the dramatic increase in the ER observed in vivo following parturition. One indication of tissue-specific differentiation observed in later cultures (days 4–11) is the synthesis and secretion of abundant casein micelles. A second characteristic of lactating mammary epithelial cells in vivo that has not previously been observed in culture is the secretion of milk fat globules. Taken together, these observations indicate that mammary epithelial cells plated onto a reconstituted basement membrane differentiate to the lactating phenotype in culture.

scholarly journals UFM1-Specific Ligase 1 Ligating Enzyme 1 Mediates Milk Protein and Fat Synthesis-Related Gene Expression via the JNK Signaling Pathway in Mouse Mammary Epithelial Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Meiqian Kuang ◽  
Min Yang ◽  
Lian Li ◽  
Chengmin Li ◽  
Genlin Wang
Keyword(s):  
Protein Synthesis ◽  
Epithelial Cells ◽  
Milk Fat ◽  
Milk Protein ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Fat Synthesis ◽  
Jnk Activation

Ubiquitin-like modifier 1 ligating enzyme 1 (UFL1) has been characterized as a ubiquitin-like (Ubl) protein that affects a range of cellular processes across various pathways. In this study, mouse mammary epithelial cells (HC11 cell line) and UFL1 knockout (KO) mice were used to establish UFL1 knockdown models to explore the influence of UFL1 on milk protein and fat synthesis in the mouse mammary gland and the underlying mechanisms. This is the first study to show UFL1 localization in mouse mammary epithelial cells. UFL1 depletion by transfected UFL1 siRNA (siUFL1) caused aggravated apoptosis. In addition, UFL1 depletion suppressed milk protein synthesis-related protein level in vivo and in vitro. Conversely, ACACA and FASN expressions increased in UFL1-deficient mice. Moreover, UFL1 depletion increased triglyceride synthesis levels and inhibited the p-JNK expression. Importantly, the expression of proteins related to milk protein synthesis was decreased in JNK- and UFL1-deficient cells, whereas proteins related to milk fat synthesis showed the opposite trend, indicating that UFL1 affects milk protein and fat synthesis via the suppression of JNK activation. Overall, our findings indicate that UFL1 plays a key role in mammary milk and fat synthesis via JNK activation.

scholarly journals Mouse mammary gland reconstitution with extrinsic gene-transferred mammary epithelial cells in vitro and in vivo

2008 ◽  
Vol 28 (3) ◽  
pp. 181-188
Author(s):  
Kazuharu Kai ◽  
Takatsune Shimizu ◽  
Eiji Sugihara ◽  
Yutaka Yamamoto ◽  
Hirotaka Iwase ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Mouse Mammary Gland ◽  
Mammary Epithelial

scholarly journals Transduction of the Mammary Epithelium with Adenovirus Vectors In Vivo

2003 ◽  
Vol 77 (10) ◽  
pp. 5801-5809 ◽  
Author(s):  
Tanya D. Russell ◽  
Andreas Fischer ◽  
Neal E. Beeman ◽  
Emily F. Freed ◽  
Margaret C. Neville ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Fluorescent Protein ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelium ◽  
Normal Function ◽  
Mammary Epithelial ◽  
Intraductal Injection ◽  
Adenovirus Vectors

ABSTRACT Because the mammary parenchyma is accessible from the exterior of an animal through the mammary duct, adenovirus transduction holds promise for the short-term delivery of genes to the mammary epithelium for both research and therapeutic purposes. To optimize the procedure and evaluate its efficacy, an adenovirus vector (human adenovirus type 5) encoding a green fluorescent protein (GFP) reporter and deleted of E1 and E3 was injected intraductally into the mouse mammary gland. We evaluated induction of inflammation (by intraductal injection of [14C]sucrose and histological examination), efficiency of transduction, and maintenance of normal function in transduced cells. We found that transduction of the total epithelium in the proximal portion of the third mammary gland varied from 7% to 25% at a dose of 2 × 106 PFU of adenovirus injected into day 17 pregnant mice. Transduction was maintained for at least 7 days with minimal inflammatory response; however, significant mastitis was observed 12 days after transduction. Adenovirus transduction could also be used in the virgin animal with little mastitis 3 days after transduction. Transduced mammary epithelial cells maintained normal morphology and function. Our results demonstrate that intraductal injection of adenovirus vectors provides a versatile and noninvasive method of investigating genes of interest in mouse mammary epithelial cells.

ADIPOR1 regulates genes involved in milk fat metabolism in goat mammary epithelial cells

2021 ◽  
Author(s):  
Wangsheng Zhao ◽  
Michael Adjei ◽  
Hongmei Wang ◽  
Yueling Yangliu ◽  
Jiangjiang Zhu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Milk Fat ◽  
Mammary Epithelial Cells ◽  
Fat Metabolism ◽  
Mammary Epithelial ◽  
Goat Mammary Epithelial Cells

Liver X receptor α participates in LPS-induced reduction of triglyceride synthesis in bovine mammary epithelial cells

2020 ◽  
pp. 1-7
Author(s):  
Jianfa Wang ◽  
Shuai Lian ◽  
Jun Song ◽  
Hai Wang ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Epithelial Cells ◽  
Dairy Cow ◽  
Milk Fat ◽  
Mammary Epithelial Cells ◽  
Liver X Receptor ◽  
Mammary Epithelial ◽  
Triglyceride Synthesis ◽  
Milk Fat Depression ◽  
Liver X Receptor Α

Abstract Lipopolysaccharides (LPS) could induce milk fat depression via regulating the body and blood fat metabolism. However, it is not completely clear how LPS might regulate triglyceride synthesis in dairy cow mammary epithelial cells (DCMECs). DCMECs were isolated and purified from dairy cow mammary tissue and treated with LPS. The level of triglyceride synthesis, the expression and activity of the liver X receptor α (LXRα), enzymes related to de novo fatty acid synthesis, and the expression of the fatty acid transporters were investigated. We found that LPS decreased the level of triglyceride synthesis via a down-regulation of the transcription, translation, and nuclear translocation level of the LXRα. The results also indicated that the transcription level of the LXRα target genes, sterol regulatory element binding protein 1 (SREBP1), fatty acid synthetase (FAS), acetyl-CoA carboxylase-1 (ACC1), were significantly down-regulated in DCMECs after LPS treatment. Our data may provide new insight into the mechanisms of milk fat depression caused by LPS.

scholarly journals A Dual Role for Oncostatin M Signaling in the Differentiation and Death of Mammary Epithelial Cells in Vivo

2008 ◽  
Vol 22 (12) ◽  
pp. 2677-2688 ◽  
Author(s):  
Paul G. Tiffen ◽  
Nader Omidvar ◽  
Nuria Marquez-Almuina ◽  
Dawn Croston ◽  
Christine J. Watson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Oncostatin M ◽  
Specific Gene ◽  
Mammary Involution

Abstract Recent studies in breast cancer cell lines have shown that oncostatin M (OSM) not only inhibits proliferation but also promotes cell detachment and enhances cell motility. In this study, we have looked at the role of OSM signaling in nontransformed mouse mammary epithelial cells in vitro using the KIM-2 mammary epithelial cell line and in vivo using OSM receptor (OSMR)-deficient mice. OSM and its receptor were up-regulated approximately 2 d after the onset of postlactational mammary regression, in response to leukemia inhibitory factor (LIF)-induced signal transducer and activator of transcription-3 (STAT3). This resulted in sustained STAT3 activity, increased epithelial apoptosis, and enhanced clearance of epithelial structures during the remodeling phase of mammary involution. Concurrently, OSM signaling precipitated the dephosphorylation of STAT5 and repressed expression of the milk protein genes β-casein and whey acidic protein (WAP). Similarly, during pregnancy, OSM signaling suppressed β-casein and WAP gene expression. In vitro, OSM but not LIF persistently down-regulated phosphorylated (p)-STAT5, even in the continued presence of prolactin. OSM also promoted the expression of metalloproteinases MMP3, MMP12, and MMP14, which, in vitro, were responsible for OSM-specific apoptosis. Thus, the sequential activation of IL-6-related cytokines during mammary involution culminates in an OSM-dependent repression of epithelial-specific gene expression and the potentiation of epithelial cell extinction mediated, at least in part, by the reciprocal regulation of p-STAT5 and p-STAT3.

MicroRNA-432 inhibits milk fat synthesis by targeting SCD and LPL in ovine mammary epithelial cells

2021 ◽  
Author(s):  
Zhiyun Hao ◽  
Yuzhu Luo ◽  
Jiqing Wang ◽  
Jon Hickford ◽  
Huitong Zhou ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Milk Production ◽  
Milk Fat ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Differentially Expressed ◽  
Differentially Expressed Mirnas ◽  
Fat Synthesis ◽  
Milk Fat Synthesis

In our previous studies, microRNA-432 (miR-432) was found to be one of differentially expressed miRNAs in ovine mammary gland between the two breeds of lactating sheep with different milk production...

scholarly journals Fine-tuning of Epithelial EGFR signals Supports Coordinated Mammary Gland Development

2020 ◽  
Author(s):  
Alexandr Samocha ◽  
Hanna M. Doh ◽  
Vaishnavi Sitarama ◽  
Quy H. Nguyen ◽  
Oghenekevwe Gbenedio ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelium ◽  
Gene Signature ◽  
Mammary Epithelial ◽  
Fine Tuning ◽  
Basal Cells ◽  
Stem And Progenitor Cells

SummaryDuring puberty, robust morphogenesis occurs in the mammary gland; stem- and progenitor-cells develop into mature basal- and luminal-cells to form the ductal tree. The receptor signals that govern this process in mammary epithelial cells (MECs) are incompletely understood. The EGFR has been implicated and here we focused on EGFR’s downstream pathway component Rasgrp1. We find that Rasgrp1 dampens EGF-triggered signals in MECs. Biochemically and in vitro, Rasgrp1 perturbation results in increased EGFR-Ras-PI3K-AKT and mTORC1-S6 kinase signals, increased EGF-induced proliferation, and aberrant branching-capacity in 3D cultures. However, in vivo, Rasgrp1 perturbation results in delayed ductal tree maturation with shortened branches and reduced cellularity. Rasgrp1-deficient MEC organoids revealed lower frequencies of basal cells, the compartment that incorporates stem cells. Molecularly, EGF effectively counteracts Wnt signal-driven stem cell gene signature in organoids. Collectively, these studies demonstrate the need for fine-tuning of EGFR signals to properly instruct mammary epithelium during puberty.

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