scholarly journals Induction of Autophagy during Extracellular Matrix Detachment Promotes Cell Survival

2008 ◽  
Vol 19 (3) ◽  
pp. 797-806 ◽  
Author(s):  
Christopher Fung ◽  
Rebecca Lock ◽  
Sizhen Gao ◽  
Eduardo Salas ◽  
Jayanta Debnath
Keyword(s):  
Extracellular Matrix ◽  
Cell Death ◽  
Cell Survival ◽  
Three Dimensional ◽  
Clonogenic Survival ◽  
Mammary Epithelial ◽  
Lumen Formation ◽  
Stable Reduction ◽  
Promote Cell Death

Autophagy has been proposed to promote cell death during lumen formation in three-dimensional mammary epithelial acini because numerous autophagic vacuoles are observed in the dying central cells during morphogenesis. Because these central cells die due to extracellular matrix (ECM) deprivation (anoikis), we have directly interrogated how matrix detachment regulates autophagy. Detachment induces autophagy in both nontumorigenic epithelial lines and in primary epithelial cells. RNA interference-mediated depletion of autophagy regulators (ATGs) inhibits detachment-induced autophagy, enhances apoptosis, and reduces clonogenic recovery after anoikis. Remarkably, matrix-detached cells still exhibit autophagy when apoptosis is blocked by Bcl-2 overexpression, and ATG depletion reduces the clonogenic survival of Bcl-2–expressing cells after detachment. Finally, stable reduction of ATG5 or ATG7 in MCF-10A acini enhances luminal apoptosis during morphogenesis and fails to elicit long-term luminal filling, even when combined with apoptotic inhibition mediated by Bcl-2 overexpression. Thus, autophagy promotes epithelial cell survival during anoikis, including detached cells harboring antiapoptotic lesions.

scholarly journals Regulation of the Extrinsic Apoptotic Pathway by the Extracellular Matrix Glycoprotein EMILIN2

2007 ◽  
Vol 27 (20) ◽  
pp. 7176-7187 ◽  
Author(s):  
Maurizio Mongiat ◽  
Giovanni Ligresti ◽  
Stefano Marastoni ◽  
Erica Lorenzon ◽  
Roberto Doliana ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Survival ◽  
Three Dimensional ◽  
Death Receptor ◽  
Death Receptors ◽  
Soft Agar ◽  
Apoptotic Pathway ◽  
Signaling Complex ◽  
Extrinsic Apoptotic Pathway ◽  
Trail Receptors

ABSTRACT Elastin microfibril interface-located proteins (EMILINs) constitute a family of extracellular matrix (ECM) glycoproteins characterized by the presence of an EMI domain at the N terminus and a gC1q domain at the C terminus. EMILIN1, the archetype molecule of the family, is involved in elastogenesis and hypertension etiology, whereas the function of EMILIN2 has not been resolved. Here, we provide evidence that the expression of EMILIN2 triggers the apoptosis of different cell lines. Cell death depends on the activation of the extrinsic apoptotic pathway following EMILIN2 binding to the TRAIL receptors DR4 and, to a lesser extent, DR5. Binding is followed by receptor clustering, colocalization with lipid rafts, death-inducing signaling complex assembly, and caspase activation. The direct activation of death receptors by an ECM molecule that mimics the activity of the known death receptor ligands is novel. The knockdown of EMILIN2 increases transformed cell survival, and overexpression impairs clonogenicity in soft agar and three-dimensional growth in natural matrices due to massive apoptosis. These data demonstrate an unexpected direct and functional interaction of an ECM constituent with death receptors and discloses an additional mechanism by which ECM cues can negatively affect cell survival.

scholarly journals Hypoxia Suppression of Bim and Bmf Blocks Anoikis and Luminal Clearing during Mammary Morphogenesis

2010 ◽  
Vol 21 (22) ◽  
pp. 3829-3837 ◽  
Author(s):  
Kelly A. Whelan ◽  
Sarah A. Caldwell ◽  
Kristina S. Shahriari ◽  
S. RaElle Jackson ◽  
Lisa D. Franchetti ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Survival ◽  
Cancer Progression ◽  
Three Dimensional ◽  
Mammary Epithelial ◽  
Mitogen Activated Protein Kinase ◽  
Specific Cell ◽  
Anoikis Resistance ◽  
Hypoxic Conditions ◽  
Mammary Morphogenesis

Proper adhesion to extracellular matrix is critical for epithelial cell survival. Detachment from matrix signals results in apoptosis, referred to as anoikis. Selective apoptosis of cells that become detached from matrix is associated with the formation of a lumen in three-dimensional mammary epithelial acinar structures in vitro. Because early breast cancer lesions such as carcinoma in situ, characterized by ducts exhibiting lumens filled with cells, are often associated with hypoxic markers, we sought to examine the role of hypoxia in anoikis and lumen formation in mammary epithelial cells. Here, we show that hypoxic conditions inhibit anoikis and block expression of proapoptotic BH3-only family members Bim and Bmf in epithelial cells. Hypoxia-mediated anoikis protection is associated with increased activation of the epidermal growth factor receptor–mitogen-activated protein kinase kinase–extracellular signal-regulated kinase (Erk) kinase pathway and requires the hypoxia-activated transcription factor. Consistent with these data, hypoxic conditions inhibit luminal clearing during morphogenesis in human mammary epithelial acini when grown in three-dimensional cultures and are associated with decreased expression of Bim and Bmf as well as Erk activation. We show that hypoxia regulates specific cell survival pathways that disrupt tissue architecture related to clearing of luminal space during mammary morphogenesis and suggest that hypoxia-mediated anoikis resistance may contribute to cancer progression.

scholarly journals Polyploidy and Mitotic Cell Death Are Two Distinct HIV-1 Vpr-Driven Outcomes in Renal Tubule Epithelial Cells

2017 ◽  
Vol 92 (2) ◽  
Author(s):  
Emily H. Payne ◽  
Dhivya Ramalingam ◽  
Donald T. Fox ◽  
Mary E. Klotman
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Epithelial Cells ◽  
Cell Survival ◽  
Renal Cell ◽  
Cell Biology ◽  
Renal Tubule ◽  
Mitotic Cell ◽  
Hiv Positive

ABSTRACTPrior studies have found that HIV, through the Vpr protein, promotes genome reduplication (polyploidy) in infection-surviving epithelial cells within renal tissue. However, the temporal progression and molecular regulation through which Vpr promotes polyploidy have remained unclear. Here we define a sequential progression to Vpr-mediated polyploidy in human renal tubule epithelial cells (RTECs). We found that as in many cell types, Vpr first initiates G2cell cycle arrest in RTECs. We then identified a previously unreported cascade of Vpr-dependent events that lead to renal cell survival and polyploidy. Specifically, we found that a fraction of G2-arrested RTECs reenter the cell cycle. Following this cell cycle reentry, two distinct outcomes occur. Cells that enter complete mitosis undergo mitotic cell death due to extra centrosomes and aberrant division. Conversely, cells that abort mitosis undergo endoreplication to become polyploid. We further show that multiple small-molecule inhibitors of the phosphatidylinositol 3-kinase-related kinase (PIKK) family, including those that target ATR, ATM, and mTOR, indirectly prevent Vpr-mediated polyploidy by preventing G2arrest. In contrast, an inhibitor that targets DNA-dependent protein kinase (DNA-PK) specifically blocks the Vpr-mediated transition from G2arrest to polyploidy. These findings outline a temporal, molecularly regulated path to polyploidy in HIV-positive renal cells.IMPORTANCECurrent cure-focused efforts in HIV research aim to elucidate the mechanisms of long-term persistence of HIV in compartments. The kidney is recognized as one such compartment, since viral DNA and mRNA persist in the renal tissues of HIV-positive patients. Further, renal disease is a long-term comorbidity in the setting of HIV. Thus, understanding the regulation and impact of HIV infection on renal cell biology will provide important insights into this unique HIV compartment. Our work identifies mechanisms that distinguish between HIV-positive cell survival and death in a known HIV compartment, as well as pharmacological agents that alter these outcomes.

scholarly journals Three-Dimensional Extracellular Matrix Scaffolds by Microfluidic Fabrication for Long-Term Spontaneously Contracted Cardiomyocyte Culture

2014 ◽  
Vol 20 (21-22) ◽  
pp. 2931-2941 ◽  
Author(s):  
Jeng-Chun Mei ◽  
Aden Yuan Kun Wu ◽  
Po-Chen Wu ◽  
Nai-Chen Cheng ◽  
Wei-Bor Tsai ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Three Dimensional ◽  
Cardiomyocyte Culture ◽  
Extracellular Matrix Scaffolds

scholarly journals ErbB4 Splice Variants Cyt1 and Cyt2 Differ by 16 Amino Acids and Exert Opposing Effects on the Mammary Epithelium In Vivo

2009 ◽  
Vol 29 (18) ◽  
pp. 4935-4948 ◽  
Author(s):  
Rebecca S. Muraoka-Cook ◽  
Melissa A. Sandahl ◽  
Karen E. Strunk ◽  
Leah C. Miraglia ◽  
Carty Husted ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mammary Epithelial Cells ◽  
Splice Variants ◽  
Three Dimensional ◽  
Mammary Epithelium ◽  
Mammary Epithelial ◽  
Lumen Formation ◽  
Transgenic Expression ◽  
Opposing Effects

ABSTRACT Data concerning the prognostic value of ErbB4 in breast cancer and effects on cell growth have varied in published reports, perhaps due to the unknown signaling consequences of expression of the intracellular proteolytic ErbB4 s80HER4 fragment or due to differing signaling capabilities of alternatively spliced ErbB4 isoforms. One isoform (Cyt1) contains a 16-residue intracellular sequence that is absent from the other (Cyt2). We expressed s80Cyt1 and s80Cyt2 in HC11 mammary epithelial cells, finding diametrically opposed effects on the growth and organization of colonies in three-dimensional matrices. Whereas expression of s80Cyt1 decreased growth and increased the rate of three-dimensional lumen formation, that of s80Cyt2 increased proliferation without promoting lumen formation. These results were recapitulated in vivo, using doxycycline-inducible, mouse breast-transgenic expression of s80Cyt1 amd s80Cyt2. Expression of s80Cyt1 decreased growth of the mammary ductal epithelium, caused precocious STAT5a activation and lactogenic differentiation, and increased cell surface E-cadherin levels. Remarkably, ductal growth inhibition by s80Cyt1 occurred simultaneously with lobuloalveolar growth that was unimpeded by s80Cyt1, suggesting that the response to ErbB4 may be influenced by the epithelial subtype. In contrast, expression of s80Cyt2 caused epithelial hyperplasia, increased Wnt and nuclear β-catenin expression, and elevated expression of c-myc and cyclin D1 in the mammary epithelium. These results demonstrate that the Cyt1 and Cyt2 ErbB4 isoforms, differing by only 16 amino acids, exhibit markedly opposing effects on mammary epithelium growth and differentiation.

scholarly journals Three-Dimensional Modeling of Mechanical Forces in the Extracellular Matrix during Epithelial Lumen Formation

2006 ◽  
Vol 90 (12) ◽  
pp. 4380-4391 ◽  
Author(s):  
Dehong Zeng ◽  
Aldo Ferrari ◽  
Jens Ulmer ◽  
Alexey Veligodskiy ◽  
Peter Fischer ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Three Dimensional ◽  
Mechanical Forces ◽  
Lumen Formation ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling

scholarly journals Interleukin-1 β regulation of fibroblast proteoglycan synthesis involves a decrease in versican steady-state mRNA levels

1993 ◽  
Vol 294 (2) ◽  
pp. 613-620 ◽  
Author(s):  
E E Qwarnström ◽  
H T Järveläinen ◽  
M G Kinsella ◽  
C O Ostberg ◽  
L J Sandell ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Steady State ◽  
Chondroitin Sulphate ◽  
Interleukin 1 ◽  
Mrna Level ◽  
Three Dimensional ◽  
Proteoglycan Synthesis ◽  
Mrna Levels ◽  
Pronounced Decrease

This study investigates the effects of interleukin (IL)-1 beta on proteoglycan metabolism by fibroblasts surrounded by endogenous extracellular matrix. In both three-dimensional matrix cultures and long-term monolayer cultures IL-1 beta caused a significant decrease in synthesis and deposition of sulphated proteoglycans, but had no effect on release of deposited material. The decrease in synthesis became successively more pronounced, and corresponded to 40-60% of the control after 72 h incubation. The reduction was almost totally accounted for by an effect on the chondroitin ABC-lyase-sensitive proteoglycans. Gel electrophoresis showed a significant decrease in a high-molecular-mass chondroitin ABC-lyase-sensitive proteoglycan after incubation with IL-1 beta. Northern-blot analyses of total RNA revealed a pronounced decrease in the steady-state mRNA levels of versican, the large chondroitin sulphate, with levels corresponding to 10-30% of controls. In comparison, the steady-state mRNA level for decorin, the major sulphated proteoglycan synthesized by the cells, was only slightly affected. The prominent decrease in synthesis of sulphated proteoglycans induced in long-term fibroblast cultures, including the pronounced decrease in versican steady-state mRNA levels, is likely to have a significant effect on the structure of the extracellular matrix. Induction of this type of change may constitute a significant mechanism whereby IL-1 beta can affect the properties of connective tissue during inflammation and wound healing.

scholarly journals The Intracellular Domain of ErbB4 Induces Differentiation of Mammary Epithelial Cells

2006 ◽  
Vol 17 (9) ◽  
pp. 4118-4129 ◽  
Author(s):  
Rebecca S. Muraoka-Cook ◽  
Melissa Sandahl ◽  
Carty Husted ◽  
Debra Hunter ◽  
Leah Miraglia ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Nuclear Localization ◽  
Transmembrane Domain ◽  
Mammary Epithelial Cells ◽  
Three Dimensional ◽  
Mammary Epithelial ◽  
Differentiation Markers ◽  
Intracellular Domain ◽  
Lumen Formation ◽  
Hc11 Cells

Differentiation of mammary epithelium in vivo requires signaling through prolactin- and ErbB4/HER4-dependent mechanisms; how these pathways intersect is unknown. We show herein that HC11 mouse mammary cells undergo ErbB4-dependent lactational differentiation. Prolactin and the ErbB4 ligand HB-EGF each induced STAT5A activation, expression of lactogenic differentiation markers, and lumen formation in three-dimensional Matrigel cultures in HC11 cells. ErbB4 undergoes ligand-dependent transmembrane domain cleavage at Val-675, releasing a soluble 80-kDa intracellular domain (s80HER4) that localizes to nuclei; the physiological relevance of s80HER4 is unknown. A HER4V675A mutant abolishing transmembrane cleavage impaired STAT5A activity, lactogenic gene expression, and lumen formation. Kinase-dead HER4KD was neither cleaved nor able to induce differentiation of HC11 cells. Without treating HC11 cells with prolactin or HB-EGF, s80HER4 (expressed from a cDNA construct) localized to the nucleus, activated STAT5A, and induced three-dimensional lumen formation. Nuclear localization of exogenous s80HER4 required intact kinase activity of s80HER4, as did activation of STAT5A. In contrast, nuclear localization of s80HER4 and STAT5A activation did not require the 16-amino acid region of the ErbB4 intracellular domain specific to the Cyt-1 isoform of ErbB4, and absent in the Cyt-2 isoform. These results suggest that s80HER4 formation contributes to ErbB4-dependent differentiation of mammary epithelial cells.

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