Proinsulin stimulates growth of small intestinal crypt-like cells acting via specific receptors

1999 ◽  
Vol 276 (2) ◽  
pp. E262-E268 ◽  
Author(s):  
Peter M. Jehle ◽  
Rolf D. Fussgaenger ◽  
Niklas K. O. Angelus ◽  
Robert J. Jungwirth ◽  
Bernhard Saile ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Specific Binding ◽  
Physiological Role ◽  
Intestinal Epithelial ◽  
Binding Studies ◽  
C Peptide ◽  
Intestinal Crypt ◽  
Igf I ◽  
Confluent Cell ◽  
Small Intestinal

The mechanisms that regulate cell turnover in the intestinal epithelium are incompletely understood. Here we tested the hypothesis that proinsulin, present in serum and pancreatic juice in picomolar concentrations, stimulates growth of the rat small intestinal crypt-like cell line IEC-6 under serum-free conditions. Proinsulin binding was assessed by competitive ligand binding studies. Proinsulin and insulin-like growth factor I (IGF-I) stimulated cell proliferation up to threefold above controls, with half-maximal action already in the picomolar range and with additive effects. In early confluent cell monolayers, proinsulin bound with higher affinity (IC50 1.3 ± 0.05 nM) and capacity (87,200 ± 2,500 receptors/cell) than IGF-I (4.0 ± 0.6; 23,700 ± 2,200, P < 0.05). C-peptide competed with 10-fold lower affinity for binding of125I-proinsulin but not for125I-IGF-I or125I-insulin, suggesting a specific binding epitope of the proinsulin molecule within or close to the C-peptide region. In contrast, insulin showed ∼100-fold lower binding affinity and growth-promoting potency than proinsulin or IGF-I. We conclude that proinsulin stimulates growth of small intestinal crypt cells through specific binding and may play a physiological role in the regulation of intestinal epithelial cell proliferation.

scholarly journals Glucagon-Like Peptide-2 Activates β-Catenin Signaling in the Mouse Intestinal Crypt: Role of Insulin-Like Growth Factor-I

Endocrinology ◽  
2007 ◽  
Vol 149 (1) ◽  
pp. 291-301 ◽  
Author(s):  
Philip E. Dubé ◽  
Katherine J. Rowland ◽  
Patricia L. Brubaker
Keyword(s):  
Cell Proliferation ◽  
Nuclear Translocation ◽  
Glycogen Synthase ◽  
Crypt Cell ◽  
Acute Administration ◽  
Intestinal Crypt ◽  
Crypt Cell Proliferation ◽  
Igf I ◽  
Glucagon Like Peptide ◽  
Crypt Cells

Chronic administration of glucagon-like peptide-2 (GLP-2) induces intestinal growth and crypt cell proliferation through an indirect mechanism requiring IGF-I. However, the intracellular pathways through which IGF-I mediates GLP-2-induced epithelial tropic signaling remain undefined. Because β-catenin and Akt are important regulators of crypt cell proliferation, we hypothesized that GLP-2 activates these signaling pathways through an IGF-I-dependent mechanism. In this study, fasted mice were administered Gly2-GLP-2 or LR3-IGF-I (positive control) for 0.5–4 h. Nuclear translocation of β-catenin in non-Paneth crypt cells was assessed by immunohistochemistry and expression of its downstream proliferative markers, c-myc and Sox9, by quantitative RT-PCR. Akt phosphorylation and activation of its targets, glycogen synthase kinase-3β and caspase-3, were determined by Western blot. IGF-I receptor (IGF-IR) and IGF-I signaling were blocked by preadministration of NVP-AEW541 and through the use of IGF-I knockout mice, respectively. We found that GLP-2 increased β-catenin nuclear translocation in non-Paneth crypt cells by 72 ± 17% (P &lt; 0.05) and increased mucosal c-myc and Sox9 mRNA expression by 90 ± 20 and 376 ± 170%, respectively (P &lt; 0.05–0.01), with similar results observed with IGF-I. This effect of GLP-2 was prevented by blocking the IGF-IR as well as ablation of IGF-I signaling. GLP-2 also produced a time- and dose-dependent activation of Akt in the intestinal mucosa (P &lt; 0.01), most notably in the epithelium. This action was reduced by IGF-IR inhibition but not IGF-I knockout. We concluded that acute administration of GLP-2 activates β-catenin and proliferative signaling in non-Paneth murine intestinal crypt cells as well as Akt signaling in the mucosa. However, IGF-I is required only for the GLP-2-induced alterations in β-catenin.

Specific binding of the C-peptide of proinsulin to cultured B-cells from a transplantable rat islet cell tumor

1986 ◽  
Vol 6 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Peter R. Flatt ◽  
Sara K. Swanston-Flatt ◽  
Shelagh M. Hampton ◽  
Clifford J. Bailey ◽  
Vincent Marks
Keyword(s):  
B Cells ◽  
Islet Cell ◽  
Specific Binding ◽  
Islet Cell Tumor ◽  
Peptide Binding ◽  
Physiological Role ◽  
Scatchard Analysis ◽  
Trypan Blue Exclusion ◽  
C Peptide ◽  
Specificity Of Binding

Specific binding of the C-peptide of proinsulin was evaluated using a transplantable NEDH rat islet cell tumour predominantly composed of insulin-secreting B-cells. Cultured tumour B-cells exhibited greater than 90% viability assessed by trypan blue exclusion, and retained the ability to form tumours with accompanying hypoglycaemia and hyperinsulinaemia after reimplantation. During binding experiments with synthetic rat C-peptide I and iodinated tyrosylated rat C-peptide I, turnout B-cells exhibited 54±6% specific binding. Displacement of tracer increased with increasing concentrations of unlabelled rat C-peptide I (0.25–1,000 ng/ml), and the specificity of binding was substantiated by reduced displacement with human C-peptide. Scatchard analysis of specific C-peptide binding revealed a curvilinear plot with upward concavity. The demonstration of specific C-peptide binding to insulin-secreting B-cells provides evidence for a physiological role of proinsulin C-peptide.

scholarly journals Epithelioid cell cultures from rat small intestine. Characterization by morphologic and immunologic criteria.

1979 ◽  
Vol 80 (2) ◽  
pp. 248-265 ◽  
Author(s):  
A Quaroni ◽  
J Wands ◽  
R L Trelstad ◽  
K J Isselbacher
Keyword(s):  
Basement Membrane ◽  
Amorphous Material ◽  
Population Doubling ◽  
Antigenic Determinants ◽  
Intestinal Epithelial ◽  
Epithelioid Cells ◽  
Intestinal Crypt ◽  
Ultrastructural Studies ◽  
Small Intestinal

Rat small intestinal epithelial cell lines have been established in vitro and subcultured serially for periods up to 6 mo. These cells have an epithelioid morphology, grow as monolayers of closely opposed polygonal cells, and during the logarithmic phase of growth have a population doubling time of 19--22 h. Ultrastructural studies revealed the presence of microvilli, tight junctions, an extensive Golgi complex, and the presence of extracellular amorphous material similar in appearance to isolated basement membrane. These cells exhibit a number of features characteristic of normal cells in culture; namely, a normal rat diploid karyotype, strong density inhibition of growth, lack of growth in soft agar, and a low plating efficiency when seeded at low density. They did not produce tumors when injected in syngeneic animals. Immunochemical studies were performed to determine their origin using antisera prepared against rat small intestinal crypt cell plasma membrane, brush border membrane of villus cells and isolated sucrase-isomaltase complex. Antigenic determinants specific for small intestinal epithelial (crypt and villus) cells were demonstrated on the surface of the epithelioid cells, but they lacked immunological determinants specific for differentiated villus cells. An antiserum specifically staining extracellular material surrounding the cells cultured in vitro demonstrated cross-reactivity to basement membrane in rat intestinal frozen sections. It is concluded that the cultured epithelioid cells have features of undifferentiated small intestinal crypt cells.

scholarly journals The ubiquitin ligase ITCH coordinates small intestinal epithelial homeostasis by modulating cell proliferation, differentiation, and migration

2018 ◽  
Vol 99 ◽  
pp. 51-61 ◽  
Author(s):  
Heather L. Mentrup ◽  
Amanda Hartman ◽  
Elizabeth L. Thames ◽  
Wassim A. Basheer ◽  
Lydia E. Matesic
Keyword(s):  
Cell Proliferation ◽  
Ubiquitin Ligase ◽  
Intestinal Epithelial ◽  
Epithelial Homeostasis ◽  
Small Intestinal ◽  
And Migration

Interaction of vasoactive intestinal peptide with rat small intestinal epithelial cells after intestinal resection

1985 ◽  
Vol 5 (7) ◽  
pp. 559-566 ◽  
Author(s):  
José L. Diaz-Juarez ◽  
Guillermo Bodega ◽  
Eduardo Arilla ◽  
Juan C. Prieto
Keyword(s):  
Epithelial Cells ◽  
Cyclic Amp ◽  
Vasoactive Intestinal Peptide ◽  
Intestinal Epithelial Cells ◽  
Binding Capacity ◽  
Specific Binding ◽  
Intestinal Resection ◽  
Intestinal Epithelial ◽  
Cyclic Amp Accumulation ◽  
Small Intestinal

Specific binding of vasoactive intestinal peptide (VIP) and VIP-stimulated cyclic AMP accumulation were studied in small intestinal epithelial cells (both of crypt and villous levels) 3, 7 and 14 d after a 60% resection of the small intestine. The affinity, but not the binding capacity, of VIP receptors decreased during the adaptive hyperplastic response. Basal cyclic AMP levels were similar in cells of both control and resected rats. Resection induced a decrease of potency, but not of efficiency, of VIP on the stimulation of cyclic AMP accumulation.

scholarly journals α-Chaconine Affects the Apoptosis, Mechanical Barrier Function, and Antioxidant Ability of Mouse Small Intestinal Epithelial Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuhua He ◽  
Jiaqi Chen ◽  
Qiyue Zhang ◽  
Jialong Zhang ◽  
Lulai Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cells ◽  
Barrier Function ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Antioxidant Ability ◽  
Glutamylcysteine Synthetase ◽  
A Cell ◽  
Small Intestinal ◽  
Mechanical Barrier

α-Chaconine is the most abundant glycoalkaloid in potato and toxic to the animal digestive system, but the mechanisms underlying the toxicity are unclear. In this study, mouse small intestinal epithelial cells were incubated with α-chaconine at 0, 0.4, and 0.8 μg/mL for 24, 48, and 72 h to examine apoptosis, mechanical barrier function, and antioxidant ability of the cells using a cell metabolic activity assay, flow cytometry, Western blot, immunofluorescence, and fluorescence quantitative PCR. The results showed that α-chaconine significantly decreased cell proliferation rate, increased apoptosis rate, decreased transepithelial electrical resistance (TEER) value, and increased alkaline phosphatase (AKP) and lactate dehydrogenase (LDH) activities, and there were interactions between α-chaconine concentration and incubation time. α-Chaconine significantly reduced the relative and mRNA expressions of genes coding tight junction proteins zonula occludens-1 (ZO-1) and occludin, increased malondialdehyde (MDA) content, decreased total glutathione (T-GSH) content, reduced the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and γ-glutamylcysteine synthetase (γ-GCS) and the mRNA expressions of SOD, CAT, GSH-Px, and γ-GCS genes. In conclusion, α-chaconine disrupts the cell cycle, destroys the mechanical barrier and permeability of mucosal epithelium, inhibits cell proliferation, and accelerates cell apoptosis.

Targeted Intestinal Deletion of Rho Guanine Nucleotide Exchange Factor 7, βPIX, Impairs Enterocyte Proliferation, Villus Maturation and Mucosal Defenses in Mice

2021 ◽  
Author(s):  
Kunrong Cheng ◽  
Shannon M Larabee ◽  
Mazen Tolaymat ◽  
Marie Hanscom ◽  
Aaron C Shang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Sodium Sulfate ◽  
Mucosal Injury ◽  
Dextran Sodium Sulfate ◽  
Intestinal Epithelial ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Wnt Proteins ◽  
Small Intestinal

Rho guanine nucleotide exchange factors (RhoGEFs) regulate Rho GTPase activity and cytoskeletal and cell adhesion dynamics. βPix, a CDC42/RAC family RhoGEF encoded by ARHGEF7, is reported to modulate human colon cancer cell proliferation and post-wounding restitution of rat intestinal epithelial monolayers. We hypothesized βPix plays a role in maintaining intestinal epithelial homeostasis. To test this hypothesis, we examined βPix distribution in the human and murine intestine and created mice with intestinal epithelial-selective βPix deletion [βPixflox/flox/Tg(Villin-Cre); Arhgef7 CKO mice]. Using Arhgef7 CKO and control mice, we investigated the consequences of βPix deficiency in vivo on intestinal epithelial and enteroid development, dextran sodium sulfate-induced mucosal injury, and gut permeability. In normal human and murine intestines, we observed diffuse cytoplasmic and moderate nuclear βPix immunostaining in enterocytes. Arhgef7 CKO mice were viable and fertile with normal gross intestinal architecture but reduced small intestinal villus height, villus/crypt ratio, and goblet cells; small intestinal crypt cells had reduced Ki67 staining, compatible with impaired cell proliferation. Enteroids derived from control mouse small intestine were viable for more than 20 passages, but those from Arhgef7 CKO mice did not survive beyond 24 h despite adding Wnt proteins or conditioned media from normal enteroids. Adding a Rho kinase (ROCK) inhibitor partially rescued CKO enteroid development. Compared to littermate control mice, dextran sodium sulfate-treated βPix-deficient mice lost more weight, had greater impairment of intestinal barrier function, and more severe colonic mucosal injury. These findings reveal βPix expression is important for enterocyte development, intestinal homeostasis and resistance to toxic injury.

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