pp60c-Src Kinase Mediates Growth Effects of the Full-Length Precursor Progastrin1–80 Peptide on Rat Intestinal Epithelial Cells, in Vitro

Abstract Growth factor effects of precursor forms of gastrins have become evident in recent years. However, intracellular pathways that mediate growth effects of the precursor molecules are not known. In previous studies, we reported an increase in Tyr phosphorylation of pp60c-Src in intestinal epithelial cells (IEC) in response to the fully processed form of gastrin [gastrin1–17 (G17)]. We have now examined whether c-Src kinase is similarly phosphorylated and activated in response to the full-length precursor molecule, progastrin (PG)1–80, (recombinant human PG) in IEC cells. We found a significant increase in pp60c-Src kinase activity in response to both G17 and PG (0.1–1.0 nm), suggesting that growth effects of both the precursor and fully processed gastrin molecules may be mediated via similar pathways. On the other hand, pp62c-Yes was not phosphorylated or activated in response to either G17 or PG. To examine whether c-Src kinase mediates proliferative effects of PG, IEC cells were microinjected with anti-Src-IgG and 3H-thymidine (3H-Tdr) uptake of the cells measured. Control cells received nonimmune IgG. The 3H-Tdr uptake of cells stimulated with 1.0 nm PG was significantly reduced in cells microinjected with anti-c-Src-IgG; control IgG had no effect. In cells stimulated with 1.0% fetal calf serum, microinjection with c-Src-IgG had no effect on 3H-Tdr uptake. The specificity of the effect was further confirmed by blocking the inhibitory effect of anti-c-Src-IgG with antigenic Src peptide. These results suggest that activation of c-Src kinase likely represents a critical step in mediating proliferative effects of both the precursor and fully processed forms of gastrins on IEC.

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

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00351.2002 ◽

2003 ◽

Vol 284 (2) ◽

pp. G328-G339 ◽

Cited By ~ 41

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.

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Mechanism of riboflavine uptake by Caco-2 human intestinal epithelial cells

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1994.266.1.g15 ◽

1994 ◽

Vol 266 (1) ◽

pp. G15-G21 ◽

Cited By ~ 20

Author(s):

H. M. Said ◽

T. Y. Ma

Keyword(s):

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Sulfhydryl Group ◽

Inhibitory Effect ◽

Significant Inhibition ◽

Water Soluble ◽

Disulfonic Acid ◽

Maximal Velocity ◽

Intestinal Epithelial

The cellular and molecular regulation of intestinal absorption of the water-soluble vitamin riboflavine (RF) is poorly understood. The availability of a suitable in vitro cultured system that possesses the transport characteristics of the native intestinal absorptive cells would provide a powerful means to address this issue. In this study, we examined RF uptake by the human-derived cultured Caco-2 intestinal epithelial cells. RF uptake was Na+ and pH independent and occurred without metabolic alterations of the transported RF. Initial rate of RF uptake was temperature dependent and saturable as a function of concentration at 37 degrees C but not at 4 degrees C (apparent Michaelis constant = 0.30 +/- 0.03 microM, maximal velocity = 209.90 +/- 24.40 pmol.mg protein-1.3 min-1). Unlabeled RF, lumiflavine, 8-amino-riboflavine, isoriboflavine, and lumichrome in the incubation solution caused significant inhibition of RF uptake. RF uptake was also energy dependent and was sensitive to the inhibitory effect of sulfhydryl group reagents. The membrane transport inhibitor amiloride, but not 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, 4-acetamide-4'-isothiocyanostilbene-2,2'-disulfonic acid, furosemide, or probenecid, inhibited RF uptake in a competitive (inhibitory constant = 0.48 mM) and reversible manner. Growing Caco-2 monolayers in a RF-deficient and oversupplemented media caused significant up- and downregulation of RF uptake, respectively. These results demonstrate the existence of a carrier-mediated system for RF uptake by Caco-2 cells and provide new information regarding amiloride sensitivity, involvement of sulfhydryl groups, and up- and downregulation by the substrate level and clarify the controversy regarding the role of Na+ in the uptake process.(ABSTRACT TRUNCATED AT 250 WORDS).

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Protective Effects of Lactoferrin against SARS-CoV-2 Infection In Vitro

Nutrients ◽

10.3390/nu13020328 ◽

2021 ◽

Vol 13 (2) ◽

pp. 328 ◽

Cited By ~ 1

Author(s):

Claudio Salaris ◽

Melania Scarpa ◽

Marina Elli ◽

Alice Bertolini ◽

Simone Guglielmetti ◽

...

Keyword(s):

Immune Response ◽

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Plaque Assay ◽

Immune Response Gene ◽

Intestinal Epithelial ◽

Antiviral Immune Response ◽

Qrt Pcr ◽

Anti Inflammatory

SARS-CoV-2 is a newly emerging virus that currently lacks curative treatments. Lactoferrin (LF) is a naturally occurring non-toxic glycoprotein with broad-spectrum antiviral, immunomodulatory and anti-inflammatory effects. In this study, we assessed the potential of LF in the prevention of SARS-CoV-2 infection in vitro. Antiviral immune response gene expression was analyzed by qRT-PCR in uninfected Caco-2 intestinal epithelial cells treated with LF. An infection assay for SARS-CoV-2 was performed in Caco-2 cells treated or not with LF. SARS-CoV-2 titer was determined by qRT-PCR, plaque assay and immunostaining. Inflammatory and anti-inflammatory cytokine production was determined by qRT-PCR. LF significantly induced the expression of IFNA1, IFNB1, TLR3, TLR7, IRF3, IRF7 and MAVS genes. Furthermore, LF partially inhibited SARS-CoV-2 infection and replication in Caco-2 intestinal epithelial cells. Our in vitro data support LF as an immune modulator of the antiviral immune response with moderate effects against SARS-CoV-2 infection.

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Berberine Ameliorates Pro-inflammatory Cytokine-Induced Endoplasmic Reticulum Stress in Human Intestinal Epithelial Cells In Vitro

Inflammation ◽

10.1007/s10753-011-9385-6 ◽

2011 ◽

Vol 35 (3) ◽

pp. 841-849 ◽

Cited By ~ 28

Author(s):

Xianhua Hao ◽

Anlong Yao ◽

Jianfeng Gong ◽

Weiming Zhu ◽

Ning Li ◽

...

Keyword(s):

Endoplasmic Reticulum ◽

Epithelial Cells ◽

Endoplasmic Reticulum Stress ◽

Inflammatory Cytokine ◽

Intestinal Epithelial Cells ◽

Intestinal Epithelial ◽

Human Intestinal Epithelial Cells

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The effect of berberine in vitro on tight junctions in human Caco-2 intestinal epithelial cells

Fitoterapia ◽

10.1016/j.fitote.2009.02.005 ◽

2009 ◽

Vol 80 (4) ◽

pp. 241-248 ◽

Cited By ~ 36

Author(s):

Lili Gu ◽

Ning Li ◽

Qiurong Li ◽

Qiang Zhang ◽

Chengyang Wang ◽

...

Keyword(s):

Epithelial Cells ◽

Tight Junctions ◽

Intestinal Epithelial Cells ◽

Intestinal Epithelial

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TFF3 and EGF Induce Different Migration Patterns of Intestinal Epithelial Cells In Vitro and Trigger Increased Internalization of E-cadherin

Cellular Physiology and Biochemistry ◽

10.1159/000107519 ◽

2007 ◽

Vol 20 (5) ◽

pp. 329-346 ◽

Cited By ~ 32

Author(s):

Uwe Dürer ◽

Roland Hartig ◽

Susanne Bang ◽

Lars Thim ◽

Werner Hoffmann

Keyword(s):

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Intestinal Epithelial ◽

Migration Patterns ◽

E Cadherin

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A σ28-Regulated Nonflagella Gene Contributes to Virulence of Campylobacter jejuni 81-176

Infection and Immunity ◽

10.1128/iai.74.1.769-772.2006 ◽

2006 ◽

Vol 74 (1) ◽

pp. 769-772 ◽

Cited By ~ 35

Author(s):

Scarlett Goon ◽

Cheryl P. Ewing ◽

Maria Lorenzo ◽

Dawn Pattarini ◽

Gary Majam ◽

...

Keyword(s):

Epithelial Cells ◽

Campylobacter Jejuni ◽

Diarrheal Disease ◽

Intestinal Epithelial Cells ◽

Disease Model ◽

Intestinal Epithelial ◽

Model Expression

ABSTRACT A Campylobacter jejuni 81-176 mutant in Cj0977 was fully motile but reduced >3 logs compared to the parent in invasion of intestinal epithelial cells in vitro. The mutant was also attenuated in a ferret diarrheal disease model. Expression of Cj0977 protein was dependent on a minimal flagella structure.

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