Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier
Osteopontin (OPN) is a bioactive integrin-binding protein found in high concentrations in milk, where it is present both as a full-length protein and as several N-terminally derived fragments. OPN resists gastric digestion, and via interaction with receptors in the gut or by crossing the intestinal...
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MDPI AG
2023-03-01
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| Series: | Biomedicines |
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| Online Access: | https://www.mdpi.com/2227-9059/11/3/893 |
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| author | Brian Christensen Nanna R. Nielsen Marie R. Sørensen Lotte N. Jacobsen Marie S. Ostenfeld Esben S. Sørensen |
| author_facet | Brian Christensen Nanna R. Nielsen Marie R. Sørensen Lotte N. Jacobsen Marie S. Ostenfeld Esben S. Sørensen |
| author_sort | Brian Christensen |
| collection | DOAJ |
| description | Osteopontin (OPN) is a bioactive integrin-binding protein found in high concentrations in milk, where it is present both as a full-length protein and as several N-terminally derived fragments. OPN resists gastric digestion, and via interaction with receptors in the gut or by crossing the intestinal barrier into circulation, ingested milk OPN may influence physiological processes. The aim of this study was to investigate OPN interaction with intestinal cells and its transport across models of the intestinal barrier. Immunodetection of OPN incubated with Caco-2 cells at 4 °C and 37 °C showed that OPN binds to the intestinal cells, but it is not internalised. Transepithelial transport was studied using mono- and co-cultures of Caco-2 cells and mucus-producing HT29-MTX cells in transwell membranes. OPN was shown to cross the barrier models in a time-, temperature-, and energy-dependent process inhibited by wortmannin, indicating that the transport takes place via the transcytosis pathway. Analyses of the naturally occurring milk mixture of full-length and N-terminal fragments showed that the N-terminal fragments of OPN bound intestinal cells most effectively and that the fragments were transported across the intestinal membrane models. This suggests that proteolytic processing of OPN increases its biological activity after ingestion. |
| first_indexed | 2024-03-11T06:53:10Z |
| format | Article |
| id | doaj.art-07c66afda3c64c58a438d6a3d98022e7 |
| institution | Directory Open Access Journal |
| issn | 2227-9059 |
| language | English |
| last_indexed | 2024-03-11T06:53:10Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biomedicines |
| spelling | doaj.art-07c66afda3c64c58a438d6a3d98022e72023-11-17T09:47:10ZengMDPI AGBiomedicines2227-90592023-03-0111389310.3390/biomedicines11030893Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal BarrierBrian Christensen0Nanna R. Nielsen1Marie R. Sørensen2Lotte N. Jacobsen3Marie S. Ostenfeld4Esben S. Sørensen5Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, DenmarkDepartment of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, DenmarkDepartment of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, DenmarkArla Foods Ingredients Group P/S, DK-8260 Viby J, DenmarkArla Foods Ingredients Group P/S, DK-8260 Viby J, DenmarkDepartment of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, DenmarkOsteopontin (OPN) is a bioactive integrin-binding protein found in high concentrations in milk, where it is present both as a full-length protein and as several N-terminally derived fragments. OPN resists gastric digestion, and via interaction with receptors in the gut or by crossing the intestinal barrier into circulation, ingested milk OPN may influence physiological processes. The aim of this study was to investigate OPN interaction with intestinal cells and its transport across models of the intestinal barrier. Immunodetection of OPN incubated with Caco-2 cells at 4 °C and 37 °C showed that OPN binds to the intestinal cells, but it is not internalised. Transepithelial transport was studied using mono- and co-cultures of Caco-2 cells and mucus-producing HT29-MTX cells in transwell membranes. OPN was shown to cross the barrier models in a time-, temperature-, and energy-dependent process inhibited by wortmannin, indicating that the transport takes place via the transcytosis pathway. Analyses of the naturally occurring milk mixture of full-length and N-terminal fragments showed that the N-terminal fragments of OPN bound intestinal cells most effectively and that the fragments were transported across the intestinal membrane models. This suggests that proteolytic processing of OPN increases its biological activity after ingestion.https://www.mdpi.com/2227-9059/11/3/893osteopontinintestinal cellsCaco-2HT29-MTXprotein transportgastrointestinal digestion |
| spellingShingle | Brian Christensen Nanna R. Nielsen Marie R. Sørensen Lotte N. Jacobsen Marie S. Ostenfeld Esben S. Sørensen Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier Biomedicines osteopontin intestinal cells Caco-2 HT29-MTX protein transport gastrointestinal digestion |
| title | Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier |
| title_full | Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier |
| title_fullStr | Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier |
| title_full_unstemmed | Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier |
| title_short | Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier |
| title_sort | naturally occurring n terminal fragments of bovine milk osteopontin are transported across models of the intestinal barrier |
| topic | osteopontin intestinal cells Caco-2 HT29-MTX protein transport gastrointestinal digestion |
| url | https://www.mdpi.com/2227-9059/11/3/893 |
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