Clathrin-Coated Pits and Coated Vesicles: Functional and Structural Studies

Steer, Clifford J.; Klausner, Richard D.

doi:10.1002/hep.1840030326

Cited by 36 publications

(3 citation statements)

References 149 publications

(112 reference statements)

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“…Void volume was collected and analyzed spectrophotometrically. The ratio of A465:A280 was 0.046 for these preparations, indicating complete saturation of the 2 iron binding sites of Tf (30).…”

Section: Methodsmentioning

confidence: 96%

Bioactive Dietary Polyphenols Decrease Heme Iron Absorption by Decreasing Basolateral Iron Release in Human Intestinal Caco-2 Cells

Kim

Han

2010

The Journal of Nutrition

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Because dietary polyphenolic compounds have a wide range of effects in vivo and vitro, including chelation of metals such as iron, it is prudent to test whether the regular consumption of dietary bioactive polyphenols impair the utilization of dietary iron. Because our previous study showed the inhibitory effect of (-) -epigallocatechin-3-gallate (EGCG) and grape seed extract (GSE) on nonheme iron absorption, we investigated whether EGCG and GSE also affect iron absorption from heme. The fully differentiated intestinal Caco-2 cells grown on microporous membrane inserts were incubated with heme (55)Fe in uptake buffer containing EGCG or GSE in the apical compartment for 7 h. Both EGCG and GSE decreased (P < 0.05) transepithelial transport of heme-derived iron. However, apical heme iron uptake was increased (P < 0.05) by GSE. Despite the increased cellular levels of heme (55)Fe, the transfer of iron across the intestinal basolateral membrane was extremely low, indicating that basolateral export was impaired by GSE. In contrast, EGCG moderately decreased the cellular assimilation of heme (55)Fe, but the basolateral iron transfer was extremely low, suggesting that the basolateral efflux of heme iron was also inhibited by EGCG. Expression of heme oxygenase, ferroportin, and hephaestin protein was not changed by EGCG and GSE. The apical uptake of heme iron was temperature dependent and saturable in fully differentiated Caco-2 cells. Our data show that bioactive dietary polyphenols inhibit heme iron absorption mainly by reducing basolateral iron exit rather than decreasing apical heme iron uptake in intestinal cells.

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Section: Methodsmentioning

confidence: 96%

Bioactive Dietary Polyphenols Decrease Heme Iron Absorption by Decreasing Basolateral Iron Release in Human Intestinal Caco-2 Cells

Kim

Han

2010

The Journal of Nutrition

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“…The GO overrepresentation of cluster 2 identified GO terms upregulated, which were related to endocytic vesicles and coated vesicles. The mechanism in which fibroblasts secrete proteins is through endocytosis of vesicles coated in the protein clathrin. , …”

Section: Resultsmentioning

confidence: 99%

“…The mechanism in which fibroblasts secrete proteins is through endocytosis of vesicles coated in the protein clathrin. 42,43 Coculture Spheroid Composition Identifies the Localization of Fibroblasts…”

Section: Gpf-dia Determined Global Profiles Of Spheroid Proteomesmentioning

confidence: 99%

Gas-Phase Fractionation Data-Independent Acquisition Analysis of 3D Cocultured Spheroid Tumor Model Reveals Altered Translational Processes and Signaling Using Proteomics

Shannon,

Boos,

Searle

et al. 2024

J. Proteome Res.

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Colorectal cancer (CRC) contains considerable heterogeneity; therefore, models of the disease must also reflect the multifarious components. Compared to traditional 2D models, 3D cellular models, such as tumor spheroids, have the utility to determine the drug efficacy of potential therapeutics. Monoculture spheroids are well-known to recapitulate gene expression, cell signaling, and pathophysiological gradients of avascularized tumors. However, they fail to mimic the stromal cell influence present in CRC, which is known to perturb drug efficacy and is associated with metastatic, late-stage colorectal cancer. This study seeks to develop a cocultured spheroid model using carcinoma and noncancerous fibroblast cells. We characterized the proteomic profile of cocultured spheroids in comparison to monocultured spheroids using data-independent acquisition with gas-phase fractionation. Specifically, we determined that proteomic differences related to translation and mTOR signaling are significantly increased in cocultured spheroids compared to monocultured spheroids. Proteins related to fibroblast function, such as exocytosis of coated vesicles and secretion of growth factors, were significantly differentially expressed in the cocultured spheroids. Finally, we compared the proteomic profiles of both the monocultured and cocultured spheroids against a publicly available data set derived from solid CRC tumors. We found that the proteome of the cocultured spheroids more closely resembles that of the patient samples, indicating their potential as tumor mimics.

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Sorting and transepithelial transport of adsorbed protein tracers: Effects of temperature

Wilson

King

1986

Anat. Rec.

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The epithelium of the guinea pig yolk sac is involved in the selective transport of macromolecules to the fetus. We studied the compartments involved in sorting and transepithelial transport of protein tracers and the effect of lowered temperature (18 degrees C) on these events. Explants of yolk sac were incubated with a mixture of cationized ferritin (CF) and horseradish peroxidase (HRP, Sigma type VI). At 4 degrees C, both tracers were bound to the cell surface and binding of an HRP-gold complex was shown to be inhibited by mannan. At 37 degrees C and 18 degrees C, both tracers were taken up into tubules and vesicles in the apical cytoplasm. Usually the tubules contained a mixture of tracers, but they often showed a polarized distribution with CF and HRP at opposite ends. The vesicles also contained mixtures of the tracers, but some contained only one. In addition, there were some irregularly shaped vacuoles composed of saccules that contained either a mixture, HRP alone, or CF alone. These results suggest that these adsorbed ligands are binding to unique microdomains of the endocytic complex. After 20 min at 37 degrees C coated vesicles 100 nm in diameter were located in the apical cytoplasm and coated vesicles of the same size were located at the lateral cell membrane. Usually they contained only HRP or CF, although occasional mixtures were seen. At 18 degrees C, HRP was transported across the cells in 100 nm vesicles. However, transport of CF was completely inhibited at the lower temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

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Clathrin-Coated Pits and Coated Vesicles: Functional and Structural Studies

Cited by 36 publications

References 149 publications

Bioactive Dietary Polyphenols Decrease Heme Iron Absorption by Decreasing Basolateral Iron Release in Human Intestinal Caco-2 Cells

Bioactive Dietary Polyphenols Decrease Heme Iron Absorption by Decreasing Basolateral Iron Release in Human Intestinal Caco-2 Cells

Gas-Phase Fractionation Data-Independent Acquisition Analysis of 3D Cocultured Spheroid Tumor Model Reveals Altered Translational Processes and Signaling Using Proteomics

Sorting and transepithelial transport of adsorbed protein tracers: Effects of temperature

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