Specific Modulation of Intestinal Epithelial Brush Border Enzyme Expression by a Phorbol Ester

Although the intestinal epithelium undergoes complex deformations during normal function, nutrient absorption, fasting, lactation, and disease, the effects of deformation on intestinal mucosal biology are poorly understood. We previously demonstrated that 24 h of cyclic deformation at an average 10% deformation every 6 s stimulates proliferation and modulates brush-border enzyme activity in human intestinal Caco-2 cell monolayers. In the present study we sought potential mechanisms for these effects. Protein kinase C (PKC) activity increased within 1 min after initiation of cyclic deformation, and the PKC-α and -ζ isoforms translocated from the soluble to the particulate fraction. Cyclic deformation also rapidly increased tyrosine kinase activity. Tyrosine phosphorylation of several proteins was increased in the soluble fraction but decreased in the particulate fraction by cyclic deformation for 30 min. Inhibition of PKC and tyrosine kinase signals by calphostin C, G-06967, and erbstatin attenuated or blocked cyclic deformation-mediated modulation of Caco-2 DNA synthesis and differentiation. These results suggest that cyclic deformation may modulate intestinal epithelial proliferation and brush-border enzyme activity by regulating PKC and tyrosine kinase signals.

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Changes in brush-border enzyme activities of intestinal epithelial cells isolated from the villus-crypt axis during the early phase of alloxan diabetes in rats

Cellular and Molecular Life Sciences ◽

10.1007/bf01966159 ◽

1985 ◽

Vol 41 (4) ◽

pp. 482-484 ◽

Cited By ~ 6

Author(s):

Y. Nakabou ◽

K. Ikeuchi ◽

H. Minami ◽

H. Hagihira

Keyword(s):

Epithelial Cells ◽

Brush Border ◽

Enzyme Activities ◽

Early Phase ◽

Alloxan Diabetes ◽

Intestinal Epithelial Cells ◽

Intestinal Epithelial ◽

Brush Border Enzyme

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Vaginal birth stimulates brush border enzyme expression and activity in the neonatal period

Gastroenterology ◽

10.1016/s0016-5085(03)81396-3 ◽

2003 ◽

Vol 124 (4) ◽

pp. A278

Author(s):

Per T. Sangild ◽

Yvette M. Petersen ◽

Mette Schmidt

Keyword(s):

Brush Border ◽

Neonatal Period ◽

Vaginal Birth ◽

Enzyme Expression ◽

Brush Border Enzyme ◽

Expression And Activity

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Different diuresis-dependent excretions of urinary enzymes: N-acetyl-beta-D-glucosaminidase, alanine aminopeptidase, alkaline phosphatase, and gamma-glutamyltransferase.

Clinical Chemistry ◽

10.1093/clinchem/32.3.529 ◽

1986 ◽

Vol 32 (3) ◽

pp. 529-532 ◽

Cited By ~ 27

Author(s):

K Jung ◽

G Schulze ◽

C Reinholdt

Keyword(s):

Alkaline Phosphatase ◽

Brush Border ◽

Excretion Rate ◽

Urine Flow ◽

High Intake ◽

Brush Border Enzymes ◽

Urinary Creatinine ◽

Gamma Glutamyltransferase ◽

Alanine Aminopeptidase ◽

Brush Border Enzyme

Abstract We studied how much of the lysosomal enzyme N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) and of the brush-border enzymes alanine aminopeptidase (EC 3.4.11.2), alkaline phosphatase (EC 3.1.3.1), and gamma-glutamyltransferase (EC 2.3.2.2) was excreted in urine over 8 h after a high intake of fluid (22 mL per kilogram of body weight). The hourly excretion of all four enzymes increased with the increasing urine flow rate. The excretion rate of the brush-border enzymes was more markedly influenced than that of N-acetyl-beta-D-glucosaminidase. By relating the enzyme excretion to urinary creatinine we could reduce the variability of brush-border enzyme output and could completely compensate for the effect of diuresis on the excretion of N-acetyl-beta-D-glucosaminidase.

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A combined microphysiological-computational omics approach in dietary protein evaluation

npj Science of Food ◽

10.1038/s41538-020-00082-z ◽

2020 ◽

Vol 4 (1) ◽

Author(s):

Paulus G. M. Jochems ◽

Willem R. Keusters ◽

Antoine H. P. America ◽

Pascale C. S. Rietveld ◽

Shanna Bastiaan-Net ◽

...

Keyword(s):

Enzyme Activity ◽

Brush Border ◽

Biological Effects ◽

Whey Protein Concentrate ◽

World Population ◽

Biological Efficacy ◽

Protein Sources ◽

Immune Parameters ◽

Peptide Composition ◽

Brush Border Enzyme

AbstractFood security is under increased pressure due to the ever-growing world population. To tackle this, alternative protein sources need to be evaluated for nutritional value, which requires information on digesta peptide composition in comparison to established protein sources and coupling to biological parameters. Here, a combined experimental and computational approach is presented, which compared seventeen protein sources with cow’s whey protein concentrate (WPC) as the benchmark. In vitro digestion of proteins was followed by proteomics analysis and statistical model-based clustering. Information on digesta peptide composition resulted in 3 cluster groups, primarily driven by the peptide overlap with the benchmark protein WPC. Functional protein data was then incorporated in the computational model after evaluating the effects of eighteen protein digests on intestinal barrier integrity, viability, brush border enzyme activity, and immune parameters using a bioengineered intestine as microphysiological gut system. This resulted in 6 cluster groups. Biological clustering was driven by viability, brush border enzyme activity, and significant differences in immune parameters. Finally, a combination of proteomic and biological efficacy data resulted in 5 clusters groups, driven by a combination of digesta peptide composition and biological effects. The key finding of our holistic approach is that protein source (animal, plant or alternative derived) is not a driving force behind the delivery of bioactive peptides and their biological efficacy.

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Functional coupling of the downregulated in adenoma Cl−/base exchanger DRA and the apical Na+/H+ exchangers NHE2 and NHE3

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.90350.2008 ◽

2009 ◽

Vol 296 (2) ◽

pp. G202-G210 ◽

Cited By ~ 44

Author(s):

Mark W. Musch ◽

Donna L. Arvans ◽

Gary D. Wu ◽

Eugene B. Chang

Keyword(s):

Carbonic Anhydrase ◽

Brush Border ◽

Brush Border Membrane ◽

Intestinal Epithelial Cells ◽

Functional Coupling ◽

Intestinal Epithelial ◽

Colon Cells ◽

Base Exchange ◽

Synaptotagmin I

Non-nutrient-dependent salt absorption across the brush-border membrane of intestinal epithelial cells is primarily mediated by coupled apical Na+/H+ (aNHE) and anion exchange transport, with the latter suspected of being mediated by DRA (downregulated in adenoma; SLC26A3) that is defective in congenital chloridorrhea. To investigate DRA in greater detail and determine whether DRA and NHE activities can be coupled, we measured 22Na+ and 36Cl− uptake in Caco2BBE colon cells infected with the tet-off-inducible DRA transgene. Under basal conditions, DRA activity was low in normal and infected Caco2BBE cells in the presence of tetracycline, whereas NHE activities could be easily detected. When apical NHE activity was increased by transfection or serum-induced expression of the aNHE isoforms NHE2 and NHE3, increased 36Cl− uptake was observed. Inhibition of DRA activity by niflumic acid was greater than that by DIDS as well as by the NHE inhibitor dimethylamiloride and the carbonic anhydrase inhibitor methazolamide. DRA activity was largely aNHE-dependent, whereas a component of DRA-independent aNHE uptake continued to be observed. Coupled aNHE and DRA activities were inhibited by increased cellular cAMP and calcium and were associated with synaptotagmin I-dependent, clathrin-mediated endocytosis. In summary, these data support the role of DRA in electroneutral NaCl absorption involving functional coupling of Cl−/base exchange and apical NHE.

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Non-muscle myosin-2 contractility-dependent actin turnover limits the length of epithelial microvilli

10.1101/2020.05.01.072389 ◽

2020 ◽

Cited By ~ 2

Author(s):

Colbie R. Chinowsky ◽

Julia A. Pinette ◽

Leslie M. Meenderink ◽

Matthew J. Tyska

Keyword(s):

Brush Border ◽

Isotropic Layer ◽

Intestinal Epithelial ◽

Actin Bundles ◽

Terminal Web ◽

Actin Turnover ◽

Genetic Perturbations ◽

And Function ◽

Pointed End ◽

Muscle Myosin

ABSTRACTEpithelial brush borders are large arrays of microvilli that enable efficient solute uptake from luminal spaces. In the context of the intestinal tract, brush border microvilli drive functions that are critical for physiological homeostasis, including nutrient uptake and host defense. However, cytoskeletal mechanisms that regulate the assembly and morphology of these protrusions are poorly understood. The parallel actin bundles that support microvilli have their pointed-end rootlets anchored in a highly crosslinked filamentous meshwork referred to as the “terminal web”. Although classic EM studies revealed complex ultrastructure, the composition, organization, and function of the terminal web remains unclear. Here, we identify non-muscle myosin-2C (NM2C) as a major component of the brush border terminal web. NM2C is found in a dense, isotropic layer of puncta across the sub-apical domain, which transects the rootlets of microvillar actin bundles. Puncta in this network are separated by ∼210 nm, dimensions that are comparable to the expected size of filaments formed by NM2C. In primary intestinal organoid cultures, the terminal web NM2C network is highly dynamic and exhibits continuous remodeling. Using pharmacological and genetic perturbations to disrupt NM2C activity in cultured intestinal epithelial cells, we found that this motor controls the length of growing microvilli by regulating actin turnover in a manner that requires a fully active motor domain. Our findings answer a decades old question on the function of terminal web myosin and hold broad implications for understanding apical morphogenesis in diverse epithelial systems.

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