A quantitative immunoelectronmicroscopic study on soluble, membrane-associated and membrane-bound lysosomal enzymes in human intestinal epithelial cells

Willemsen, Rob; Brünken, R.; Sorber, C. W. J.; Hoogeveen, André T.; Wisselaar, H. A.; Dongen, Jacques J. M. van; Reuser, Arnold

doi:10.1007/bf01041377

Cited by 11 publications

(6 citation statements)

References 29 publications

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“…There is evidence in literature that some flavonoid glucosides can be hydrolyzed in the small intestine . They may be hydrolyzed by LPH, located in the brush border of the small intestine , and/or by a BSβG and/or glucocerebrosidase upon entering the intestinal epithelial cells via specific transporters . In subsequent experiments of the present study, incubations with intestinal S9 fractions from human and rat were used to study the deconjugation of the isoflavone glucosides in the absence or presence of specific inhibitors of LPH, glucocerebrosidase, and BSβG (Table ).…”

Section: Discussionmentioning

confidence: 98%

Conversion of major soy isoflavone glucosides and aglycones in in vitro intestinal models

Islam

Punt

Spenkelink

et al. 2013

Molecular Nutrition Food Res

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Scope: This study compares conversion of three major soy isoflavone glucosides and their aglycones in a series of in vitro intestinal models. Methods and results:In an in vitro human digestion model isoflavone glucosides were not deconjugated, whereas studies in a Caco-2 transwell model confirmed that deconjugation is essential to facilitate transport across the intestinal barrier. Deconjugation was shown upon incubation of the isoflavone glucosides with rat as well as human intestinal S9. In incubations with rat intestinal S9 lactase phlorizin hydrolase, glucocerebrosidase, and cytosolic broadspecific ␤-glucosidase all contribute significantly to deconjugation, whereas in incubations with human intestinal S9 deconjugation appeared to occur mainly through the activity of broad-specific ␤-glucosidase. Species differences in glucuronidation and sulfation were limited and generally within an order of magnitude with 7-O-glucuronides being the major metabolites for all three isoflavone aglycones and the glucuronidation during first pass metabolism being more efficient in rats than in humans. Comparison of the catalytic efficiencies reveals that deconjugation is less efficient than conjugation confirming that aglycones are unlikely to enter the systemic circulation. Conclusion: Altogether, the data point at possible differences in the characteristics for intestinal conversion of the major soy isoflavones between rat and human, especially with respect to their deconjugation.

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Section: Discussionmentioning

confidence: 98%

Conversion of major soy isoflavone glucosides and aglycones in in vitro intestinal models

Islam

Punt

Spenkelink

et al. 2013

Molecular Nutrition Food Res

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“…Especially in the case of PTP-SL, however, some α-SL-reactive vesicles were negative for the TGN mark- D, G, J). Lysosomes were stained with an antiserum against β-glucocerebrosidase (Willemsen et al 1991). The MVBs were detected immunohistochemically using an antibody directed against lysobisphosphatidic acid (LBPA; Kobayashi et al 1998).…”

Section: Resultsmentioning

confidence: 99%

“…The generation of the antisera α-SL (van den Maagdenberg et al 1999), anti-EGFP (Cuppen et al 1999), anti-β glucocerebrosidase (Willemsen et al 1991), anti-cMyc hybridoma 9E10 (Kari et al 1986) and the antilysobisphosphatidic acid (LBPA) antibody (Kobayashi et al 1998) have been described elsewhere. The generation of the antisera α-SL (van den Maagdenberg et al 1999), anti-EGFP (Cuppen et al 1999), anti-β glucocerebrosidase (Willemsen et al 1991), anti-cMyc hybridoma 9E10 (Kari et al 1986) and the antilysobisphosphatidic acid (LBPA) antibody (Kobayashi et al 1998) have been described elsewhere.…”

Section: Expression Plasmid Constructionsmentioning

confidence: 99%

Colocalisation of the protein tyrosine phosphatases PTP-SL and PTPBR7 with β4-adaptin in neuronal cells

Dilaver

Schepens

Maagdenberg

et al. 2002

Histochem Cell Biol

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The mouse gene Ptprr encodes the neuronal protein tyrosine phosphatases PTP-SL and PTPBR7. These proteins differ in their N-terminal domains, with PTP-SL being a cytosolic, membrane-associated phosphatase and PTPBR7 a type I transmembrane protein. In this study, we further explored the nature of the PTP-SL-associated vesicles in neuronal cells using a panel of organelle markers and noted a comparable subcellular distribution for PTP-SL and the β4-adaptin subunit of the AP4 complex. PTP-SL, PTPBR7 and β4-adaptin are localised at the Golgi apparatus and at vesicles throughout the cytoplasm. Immunohistochemical analysis demonstrated that PTP-SL, PTPBR7 and β4-adaptin are all endogenously expressed in brain. Interestingly, coexpression of PTP-SL and β4-adaptin leads to an altered subcellular localisation for PTP-SL. Instead of the Golgi and vesicle-type staining pattern, still observable for β4adaptin, PTP-SL is now distributed throughout the cytoplasm. Although β4-adaptin was found to interact with the phosphatase domain of PTP-SL and PTPBR7 in the yeast two-hybrid system, it failed to do so in transfected neuronal cells. Our data suggest that the tyrosine phosphatases PTP-SL and PTPBR7 may be involved in the formation and transport of AP4-coated vesicles or in the dephosphorylation of their transmembrane cargo molecules at or near the Golgi apparatus.

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“…They are ubiquitously distributed, mainly located in lysosomes, and have been found in other intracellular vesicles with acidic matrix, in plasma membranes, cytosol, and blood plasma [7, 8]. Plasma membrane and cytosol glycohydrolases, namely, Hexosaminidase (HEX), β -D-Glucuronidase (GCR), α -D-Glucosidase ( α -GLU), and O- β -N-Acetyl-glucosaminidase (O-GlcNAcase,), were also found in human erythrocytes where [9, 10] they have a role in signalling early membrane alterations [6], in pathologies related to strong oxidative stress, such as type 2 diabetes mellitus [11] or Down's syndrome [12, 13].…”

Section: Introductionmentioning

confidence: 99%

Levels of Human Erythrocyte Membrane-Bound and Cytosolic Glycohydrolases Are Associated with Oxidative Stress in Erectile Dysfunction Patients

et al. 2014

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Oxidative stress (OS) and production of NO, by endothelium nitric oxide synthetase (eNOS), are involved in the pathophysiology of erectile dysfunction (ED). Moreover, OS induces modifications of the physicochemical properties of erythrocyte (RBC) plasma membranes and of the enzyme content of the same membranes. Due to their role in signalling early membrane alterations in OS-related pathologies, several plasma membrane and cytosolic glycohydrolases of human RBC have been proposed as new markers of cellular OS. In RBC, NOS can be activated and deactivated by phosphorylation/glycosylation. In this regulatory mechanism O-β-N-AcetylGlucosaminidase is a key enzyme. Cellular levels of O-GlcNAcylated proteins are related to OS; consequently dysfunctional eNOS O-GlcNAcylation seems to have a crucial role in ED. To elucidate the possible association between RBC glycohydrolases and OS, plasma hydroperoxides and antioxidant total defenses (Lag-time), cytosolic O-β-N-AcetylGlucosaminidase, cytosolic and membrane Hexosaminidase, membrane β-D-Glucuronidase, and α-D-Glucosidase have been studied in 39 ED patients and 30 controls. In ED subjects hydroperoxides and plasma membrane glycohydrolases activities are significantly increased whereas Lag-time values and cytosolic glycohydrolases activities are significantly decreased. These data confirm the strong OS status in ED patients, the role of the studied glycohydrolases as early OS biomarker and suggest their possible use as specific marker of ED patients, particularly in those undergoing nutritional/pharmacological antioxidant therapy.

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A quantitative immunoelectronmicroscopic study on soluble, membrane-associated and membrane-bound lysosomal enzymes in human intestinal epithelial cells

Cited by 11 publications

References 29 publications

Conversion of major soy isoflavone glucosides and aglycones in in vitro intestinal models

Conversion of major soy isoflavone glucosides and aglycones in in vitro intestinal models

Colocalisation of the protein tyrosine phosphatases PTP-SL and PTPBR7 with β4-adaptin in neuronal cells

Levels of Human Erythrocyte Membrane-Bound and Cytosolic Glycohydrolases Are Associated with Oxidative Stress in Erectile Dysfunction Patients

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