235. Activin C antagonises activin A in vitro and over-expression leads to prostate pathologies in vivo

2008 ◽  
Vol 20 (9) ◽  
pp. 35
Author(s):  
E. Gold ◽  
N. Jetly ◽  
S. Behuria ◽  
T. Woodruff ◽  
S. Hedwards ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Receptor Activation ◽  
Activin A ◽  
Ventral Prostate ◽  
Cell Hyperplasia ◽  
Signalling Molecules ◽  
Significant Difference

Activin A is a well characterised inhibitor of proliferation in most epithelial cells. The actions of activin A on cell growth are mediated through Smad-dependent pathways. Activin A is potent at low levels, therefore its synthesis and bioactivity must be tightly regulated. Follistatin binding or inhibin subunit heterodimerisation block access to the activin receptor and/or receptor activation. We postulate that another mechanism of regulating activin A bioactivity is through the activin-βC subunit. In order to test our hypothesis produced recombinant activin C and mice overexpressing activin-βC. Recombinant activin C abrogated activin A-induced growth inhibition in vitro and the mechanism of action was downregulation of activin A-induced Smad signalling molecules. In the prostate overexpression of activin-βC increased epithelial cell proliferation while there was no significant difference in apoptotic epithelial cells. This imbalance between proliferation and apoptosis led to a significant increase in ventral prostate weight, prostatic hypertrophy and epithelial cell hyperplasia. A significant decrease in nuclear localisation of Smad-2 was associated with activin-βC overexpression in the prostate which implies antagonism of activin signalling also occurs in vivo. This is the first study to provide evidence that activin-βC is an antagonist of activin A in vitro and in vivo and implicates a role for the activin-βC subunit in maintenance of tissue homeostasis in the prostate.

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.

Progastrin1–80stimulates growth of intestinal epithelial cells in vitro via high-affinity binding sites

2003 ◽  
Vol 284 (2) ◽  
pp. G328-G339 ◽  
Author(s):  
P. Singh ◽  
X. Lu ◽  
S. Cobb ◽  
B. T. Miller ◽  
N. Tarasova ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Binding Sites ◽  
Intestinal Epithelial Cells ◽  
Full Length ◽  
Intestinal Epithelial ◽  
Growth Effects ◽  
High Affinity ◽  
Significant Difference

Proliferation and carcinogenesis of the large intestinal epithelial cells (IEC) cells is significantly increased in transgenic mice that overexpress the precursor progastrin (PG) peptide. It is not known if the in vivo growth effects of PG on IEC cells are mediated directly or indirectly. Full-length recombinant human PG (rhPG1–80) was generated to examine possible direct effects of PG on IEC cells. Surprisingly, rhPG (0.1–1.0 nM) was more effective than the completely processed gastrin 17 (G17) peptide as a growth factor. Even though IEC cells did not express CCK1and CCK2receptors (-R), fluorescently labeled G17 and Gly-extended G17 (G-Gly) were specifically bound to the cells, suggesting the presence of binding proteins other than CCK1-R and CCK2-R on IEC cells. High-affinity ( Kd= 0.5–1.0 nM) binding sites for125I-rhPG were discovered on IEC cells that demonstrated relative binding affinity for gastrin-like peptides in the order PG ≥ COOH-terminally extended G17 ≥ G-Gly > G17 > *CCK-8 (* significant difference; P< 0.05). In conclusion, our studies demonstrate for the first time direct growth effects of the full-length precursor peptide on IEC cells in vitro that are apparently mediated by the high-affinity PG binding sites that were discovered on these cells.

scholarly journals Identifying human and murine M cells in vitro

2019 ◽  
Vol 244 (7) ◽  
pp. 554-564 ◽  
Author(s):  
Ana Klisuric ◽  
Benjamin Thierry ◽  
Ludivine Delon ◽  
Clive A Prestidge ◽  
Rachel J Gibson
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
In Vitro Models ◽  
Oral Drug ◽  
M Cells ◽  
Cell Marker ◽  
M Cell ◽  
Follicle Associated Epithelium

M cells are an epithelial cell population found in the follicle-associated epithelium overlying gut-associated lymphoid tissues. They are specialized in the transcytosis of luminal antigens. Their transcytotic capacity and location in an immunocompetent environment has prompted the study of these cells as possible targets for oral drug delivery systems. Currently, the models most commonly used to study M cells are restricted to in vivo experiments conducted in mice, and in vitro studies conducted in models comprised either of primary epithelial cells or established cell lines of murine or human origin. In vitro models of the follicle-associated epithelium can be constructed in several ways. Small intestinal Lgr5+ stem cells can be cultured into a 3D organoid structure where M cells are induced with RANKL administration. Additionally, in vitro models containing an “M cell-like” population can be obtained through co-culturing intestinal epithelial cells with cells of lymphocytic origin to induce the M cell phenotype. The evaluation of the efficiency of the variations of these models and their relevance to the in vivo human system is hampered by the lack of a universal M cell marker. This issue has also hindered the advancement of M cell-specific targeting approaches aimed at improving the bioavailability of orally administered compounds. This critical review discusses the different approaches utilized in the literature to identify M cells, their efficiency, reliability and relevance, in the context of commonly used models of the follicle-associated epithelium. The outcome of this review is a clearly defined and universally recognized criteria for the assessment of the relevance of models of the follicle-associated models currently used. Impact statement The study of M cells, a specialized epithelial cell type found in the follicle-associated epithelium, is hampered by the lack of a universal M cell marker. As such, many studies lack reliable and universally recognized methods to identify M cells in their proposed models. As a result of this it is difficult to ascertain whether the effects observed are due to the presence of M cells or an unaccounted variable. The outcome of this review is the thorough evaluation of the many M cell markers that have been used in the literature thus far and a proposed criterion for the identification of M cells for future publications. This will hopefully lead to an improvement in the quality of future publications in this field.

scholarly journals Microfluidic approaches for epithelial cell layer culture and characterisation

The Analyst ◽  
2014 ◽  
Vol 139 (13) ◽  
pp. 3206-3218 ◽  
Author(s):  
Roland Thuenauer ◽  
Enrique Rodriguez-Boulan ◽  
Winfried Römer
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Layer ◽  
Microfluidic Biochips ◽  
Epithelial Cell Layer

Novelin vitromodels of epithelia in which thein vivomicroenvironment of epithelial cells is precisely reconstituted can be realised with microfluidic biochips.

179. CHARACTERISATION OF THE IN VITRO FUNCTION OF ACTIVIN AC

2009 ◽  
Vol 21 (9) ◽  
pp. 97
Author(s):  
E. Gold ◽  
C. Harrison ◽  
Y. Makanji ◽  
G. Risbridger
Keyword(s):  
Physiological Role ◽  
Activin A ◽  
Type I ◽  
Lncap Cells ◽  
Inhibitory Effects ◽  
Signalling Molecules ◽  
Growth Inhibitory ◽  
Potent Growth

Activins are members of the TGF-β superfamily that signal via type II and type I receptor subunits and intracellular Smads1. Activin A stimulates FSH release from the pituitary and is also a potent growth and differentiation factor in many physiological systems2. Over-expression of the activin-βC subunit in vitro leads to a reduction in activin A and an increase in activin AC3. Transgenic mice over-expressing activin-βC show decreased circulating activin A, implying that activin AC may also be formed in vivo4. Recently recombinant activin AC has become available, therefore this study examines the in vitro function and mechanism of action of activin AC. Activin AC stimulates FSH release in LβT2 cells and is a negative growth regulator in LNCaP cells, however the potency of activin AC is 8-10 fold less than activin A. Incubation of LNCaP cells with activin receptor antibodies (ALK4, ActRIIA, ActRIIB) abolishes the growth inhibitory effects of activin AC. Activin AC binds to ActRIIB, however a 20-30 fold decrease in both the potency and affinity of activin AC is evident compared to activin A. In addition, activin AC increases Smad-2 phosphorylation. These results indicate activin AC utilises the same receptors and intracellular signalling molecules as activin A. The activin A antagonists, follistatin and activin C4, also antagonise the growth inhibitory effects of activin AC and reduce Smad-2 phosphorylation and Smad-4 expression. This study shows for the first time that the in vitro function of activin AC is similar to activin A, albeit at a lower potency and provides the impetus to determine the physiological role of activin AC in vivo.

scholarly journals Acidified Pepsin Promotes Laryngeal Precancerosis by Upregulating H+/K+-ATPase and Activating Mitophagy in Laryngeal Epithelial Cells

2020 ◽  
Author(s):  
Ke-Jia Cheng ◽  
Qiong Xu ◽  
Zhi-Mei Li ◽  
Shui-Hong Zhou ◽  
Yang-Yang Bao ◽  
...  
Keyword(s):  
Cell Growth ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Laryngopharyngeal Reflux ◽  
Upper Aerodigestive Tract ◽  
Promoting Effect ◽  
Growth And Survival ◽  
Laryngeal Mucosa

Abstract Background: Although laryngopharyngeal reflux (LPR) has been implicated in various upper aerodigestive tract and laryngeal diseases, the underlying mechanisms remain elusive. In this study, we investigated the role of gastric acidified pepsin in laryngeal precancerosis. Results: Acidified pepsin (pH=3) enhanced the growth and survival of mouse laryngeal epithelial cells in vitro and promoted laryngeal mucosal thickening and laryngeal epithelial cell growth in vivo. Furthermore, acidified pepsin promoted autophagy/mitophagy induction, accompanied by a significant decrease in mitochondrial membrane potential (MMP). Inhibition of autophagy by chloroquine abolished the ability of acidified pepsin to promote mitophagy and cell growth in laryngeal epithelial cells. Additionally, chloroquine promoted cell apoptosis and further reduced MMP in laryngeal epithelial cells treated with acidified pepsin. The expression levels of pepsin and H+/K+-ATPase α and β subunits in 31 human laryngeal mucosa specimens were 51.6%, 48.4%, and 48.4%, respectively. Importantly, the pepsin level was correlated with the H+/K+-ATPase β subunit level. H+/K+-ATPase upregulation in laryngeal epithelial cells in response to acidified pepsin was essential for the mitophagy-promoting effect of acidified pepsin. H+/K+-ATPase knockout or inhibition further reduced MMP in the presence of acidified pepsin. Conclusions: Our findings suggest that in an acidic environment, pepsin promotes laryngeal epithelial cell growth and survival by upregulating H+/K+-ATPase and activating mitophagy, potentially leading to laryngeal precancerosis.

scholarly journals Rapid protein kinase D1 signaling promotes migration of intestinal epithelial cells

2012 ◽  
Vol 303 (3) ◽  
pp. G356-G366 ◽  
Author(s):  
Steven H. Young ◽  
Nora Rozengurt ◽  
James Sinnett-Smith ◽  
Enrique Rozengurt
Keyword(s):  
Protein Kinase ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Transgenic Mice ◽  
Intestinal Epithelial Cell ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Protein Kinase D1

We have examined the role of protein kinase D1 (PKD1) signaling in intestinal epithelial cell migration. Wounding monolayer cultures of intestinal epithelial cell line IEC-18 or IEC-6 induced rapid PKD1 activation in the cells immediately adjacent to the wound edge, as judged by immunofluorescence microscopy with an antibody that detects the phosphorylated state of PKD1 at Ser916, an autophosphorylation site. An increase in PKD1 phosphorylation at Ser916 was evident as early as 45 s after wounding, reached a maximum after 3 min, and persisted for ≥15 min. PKD1 autophosphorylation at Ser916 was prevented by the PKD family inhibitors kb NB 142-70 and CRT0066101. A kb NB 142-70-sensitive increase in PKD autophosphorylation was also elicited by wounding IEC-6 cells. Using in vitro kinase assays after PKD1 immunoprecipitation, we corroborated that wounding IEC-18 cells induced rapid PKD1 catalytic activation. Further results indicate that PKD1 signaling is required to promote migration of intestinal epithelial cells into the denuded area of the wound. Specifically, treatment with kb NB 142-70 or small interfering RNAs targeting PKD1 markedly reduced wound-induced migration in IEC-18 cells. To test whether PKD1 promotes migration of intestinal epithelial cells in vivo, we used transgenic mice that express elevated PKD1 protein in the small intestinal epithelium. Enterocyte migration was markedly increased in the PKD1 transgenic mice. These results demonstrate that PKD1 activation is one of the early events initiated by wounding a monolayer of intestinal epithelial cells and indicate that PKD1 signaling promotes the migration of these cells in vitro and in vivo.

scholarly journals Induction of Persistent Colitis by a Human Commensal, Enterotoxigenic Bacteroides fragilis, in Wild-Type C57BL/6 Mice

2009 ◽  
Vol 77 (4) ◽  
pp. 1708-1718 ◽  
Author(s):  
Ki-Jong Rhee ◽  
Shaoguang Wu ◽  
XinQun Wu ◽  
David L. Huso ◽  
Baktiar Karim ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Bacteroides Fragilis ◽  
Receptor Activation ◽  
Intestinal Epithelial ◽  
Wild Type ◽  
Bowel Diseases ◽  
Specific Pathogen ◽  
E Cadherin

ABSTRACT Enterotoxigenic Bacteroides fragilis (ETBF) causes diarrhea and is implicated in inflammatory bowel diseases and colorectal cancer. The only known ETBF virulence factor is the Bacteroides fragilis toxin (BFT), which induces E-cadherin cleavage, interleukin-8 secretion, and epithelial cell proliferation. A murine model for ETBF has not been characterized. Specific pathogen-free (SPF) C57BL/6J or germfree 129S6/SvEv mice were orally inoculated with wild-type ETBF (WT-ETBF) strains, a nontoxigenic WT strain of B. fragilis (WT-NTBF), WT-NTBF overexpressing bft (rETBF), or WT-NTBF overexpressing a biologically inactive mutated bft (rNTBF). In SPF and germfree mice, ETBF caused colitis but was lethal only in germfree mice. Colonic histopathology demonstrated mucosal thickening with inflammatory cell infiltration, crypt abscesses, and epithelial cell exfoliation, erosion, and ulceration. SPF mice colonized with rETBF mimicked WT-ETBF, whereas rNTBF caused no histopathology. Intestinal epithelial E-cadherin was rapidly cleaved in vivo in WT-ETBF-colonized mice and in vitro in intestinal tissues cultured with purified BFT. ETBF mice colonized for 16 months exhibited persistent colitis. BFT did not directly induce lymphocyte proliferation, dendritic cell stimulation, or Toll-like receptor activation. In conclusion, WT-ETBF induced acute then persistent colitis in SPF mice and rapidly lethal colitis in WT germfree mice. Our data support the hypothesis that chronic colonization with the human commensal ETBF can induce persistent, subclinical colitis in humans.

Growth and differentiation of mouse tracheal epithelial cells: selection of a proliferative population

2002 ◽  
Vol 283 (6) ◽  
pp. L1315-L1321 ◽  
Author(s):  
Yingjian You ◽  
Edward J. Richer ◽  
Tao Huang ◽  
Steven L. Brody
Keyword(s):  
Gene Expression ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Airway Epithelial Cell ◽  
Airway Epithelial ◽  
Tracheal Epithelial Cells ◽  
Proliferation And Differentiation ◽  
Tracheal Epithelial

Highly regulated programs for airway epithelial cell proliferation and differentiation during development and repair are often disrupted in disease. These processes have been studied in mouse models; however, it is difficult to isolate and identify epithelial cell-specific responses in vivo. To investigate these processes in vitro, we characterized a model for primary culture of mouse tracheal epithelial cells. Small numbers of cells seeded at low density (7.5 × 104 cells/cm2) rapidly proliferated and became polarized. Subsequently, supplemented media and air-liquid interface conditions resulted in development of highly differentiated epithelia composed of ciliated and nonciliated cells with gene expression characteristic of native airways. Genetically altered or injured mouse tracheal epithelial cells also reflected in vivo patterns of airway epithelial cell gene expression. Passage of cells resulted in continued proliferation but limited differentiation after the first passage, suggesting that transit-amplifying cell populations were present but with independent programs for proliferation and differentiation. This approach provides a high-fidelity in vitro model for evaluation of gene regulation and expression in mouse airway epithelial cells.

scholarly journals Plasmolipin regulates basolateral-to-apical transcytosis of ICAM-1 and leukocyte adhesion in polarized hepatic epithelial cells

2022 ◽  
Vol 79 (1) ◽  
Author(s):  
Cristina Cacho-Navas ◽  
Natalia Reglero-Real ◽  
Natalia Colás-Algora ◽  
Susana Barroso ◽  
Gema de Rivas ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Intracellular Transport ◽  
Molecular Mechanisms ◽  
Apical Membrane ◽  
Membrane Domains ◽  
Adhesion Receptor ◽  
Epithelial Barriers

AbstractApical localization of Intercellular Adhesion Receptor (ICAM)-1 regulates the adhesion and guidance of leukocytes across polarized epithelial barriers. Here, we investigate the molecular mechanisms that determine ICAM-1 localization into apical membrane domains of polarized hepatic epithelial cells, and their effect on lymphocyte-hepatic epithelial cell interaction. We had previously shown that segregation of ICAM-1 into apical membrane domains, which form bile canaliculi and bile ducts in hepatic epithelial cells, requires basolateral-to-apical transcytosis. Searching for protein machinery potentially involved in ICAM-1 polarization we found that the SNARE-associated protein plasmolipin (PLLP) is expressed in the subapical compartment of hepatic epithelial cells in vitro and in vivo. BioID analysis of ICAM-1 revealed proximal interaction between this adhesion receptor and PLLP. ICAM-1 colocalized and interacted with PLLP during the transcytosis of the receptor. PLLP gene editing and silencing increased the basolateral localization and reduced the apical confinement of ICAM-1 without affecting apicobasal polarity of hepatic epithelial cells, indicating that ICAM-1 transcytosis is specifically impaired in the absence of PLLP. Importantly, PLLP depletion was sufficient to increase T-cell adhesion to hepatic epithelial cells. Such an increase depended on the epithelial cell polarity and ICAM-1 expression, showing that the epithelial transcytotic machinery regulates the adhesion of lymphocytes to polarized epithelial cells. Our findings strongly suggest that the polarized intracellular transport of adhesion receptors constitutes a new regulatory layer of the epithelial inflammatory response.

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