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Abstract
Whereas physiological vascular permeability (VP) mediates selective transport of plasma, electrolytes, proteins, and cells across an intact endothelial barrier, pathological VP results in the loss of endothelial barrier integrity. Whereas physiological VP is a feature of regular host defense and tissue repair, compromised barrier function may lead to aberrant vascular leakage, concurrent tissue edema, and inflammation eventually causing life-threatening conditions such as acute lung injury or acute respiratory distress syndrome, cancer, kidney injury, etc. Measurement of VP helps to identify, design, and optimize anti-leak therapies. Further, it can define the effect of a stimulus or a gene modulation in endothelial-barrier regulation. The degree of VP can be of importance to determine the stage of cancer and disease prognosis. This chapter discusses Miles assay, which is a well-established, relatively simple, and a reliable in vivo technique to assess VP as a surrogate measurement. Although a reliable technique, Miles assay is time-consuming, and the technique does not consider the compounding factors that may increase VP independently of endothelial-barrier regulation, such as blood pressure or blood flow. As an alternative, we describe fluorescein isothiocyanate-dextran lung permeability assay, a method that can also be adapted to measure VP and edema in other organs such as the brain and kidney.
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Affiliation(s)
- Mir S Adil
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA
| | - Payaningal R Somanath
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA.
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Woting A, Blaut M. Small Intestinal Permeability and Gut-Transit Time Determined with Low and High Molecular Weight Fluorescein Isothiocyanate-Dextrans in C3H Mice. Nutrients 2018; 10:E685. [PMID: 29843428 DOI: 10.3390/nu10060685] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 05/18/2018] [Accepted: 05/23/2018] [Indexed: 02/07/2023] Open
Abstract
Protocols for intestinal permeability measurements in mice using 4-kDa fluorescein isothiocyanate-conjugated (FITC) dextran differ considerably among laboratories on the blood-sampling time. To find the optimal point in time for blood sampling, we administered 4-kDa FITC dextran to C3H mice and monitored the marker in plasma over 8 h. We also determined gut-transit time using 70-kDa FITC dextran, which does not cross the intestinal epithelium. The 4-kDa FITC dextran concentration in plasma reached its maximum 45 min after administration. The 70-kDa FITC dextran reached the jejunum after 15 min and passed the entire small intestine within 1 h after its administration, demonstrating that 4-kDa FITC dextran measured in plasma 1 h after its oral application is a marker of small intestinal permeability.
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Oertel S, Scholich K, Weigert A, Thomas D, Schmetzer J, Trautmann S, Wegner MS, Radeke HH, Filmann N, Brüne B, Geisslinger G, Tegeder I, Grösch S. Ceramide synthase 2 deficiency aggravates AOM-DSS-induced colitis in mice: role of colon barrier integrity. Cell Mol Life Sci 2017; 74:3039-3055. [PMID: 28405720 DOI: 10.1007/s00018-017-2518-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 02/07/2023]
Abstract
Loss of intestinal barrier functions is a hallmark of inflammatory bowel disease like ulcerative colitis. The molecular mechanisms are not well understood, but likely involve dysregulation of membrane composition, fluidity, and permeability, which are all essentially regulated by sphingolipids, including ceramides of different chain length and saturation. Here, we used a loss-of-function model (CerS2+/+ and CerS2-/- mice) to investigate the impact of ceramide synthase 2, a key enzyme in the generation of very long-chain ceramides, in the dextran sodium salt (DSS) evoked model of UC. CerS2-/- mice developed more severe disease than CerS2+/+ mice in acute DSS and chronic AOM/DSS colitis. Deletion of CerS2 strongly reduced very long-chain ceramides (Cer24:0, 24:1) but concomitantly increased long-chain ceramides and sphinganine in plasma and colon tissue. In naive CerS2-/- mice, the expression of tight junction proteins including ZO-1 was almost completely lost in the colon epithelium, leading to increased membrane permeability. This could also be observed in vitro in CerS2 depleted Caco-2 cells. The increase in membrane permeability in CerS2-/- mice did not manifest with apparent clinical symptoms in naive mice, but with slight inflammatory signs such as an increase in monocytes and IL-10. AOM/DSS and DSS treatment alone led to a further deterioration of membrane integrity and to severe clinical symptoms of the disease. This was associated with stronger upregulation of cytokines in CerS2-/- mice and increased infiltration of the colon wall by immune cells, particularly monocytes, CD4+ and Th17+ T-cells, and an increase in tumor burden. In conclusion, CerS2 is crucial for the maintenance of colon barrier function and epithelial integrity. CerS2 knockdown, and associated changes in several sphingolipids such as a drop in very long-chain ceramides/(dh)-ceramides, an increase in long-chain ceramides/(dh)-ceramides, and sphinganine in the colon, may weaken endogenous defense against the endogenous microbiome.
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Affiliation(s)
- Stephanie Oertel
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Klaus Scholich
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Andreas Weigert
- Institute of Biochemistry I-Pathobiochemistry, Faculty of Medicine, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Dominique Thomas
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Julia Schmetzer
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Sandra Trautmann
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Marthe-Susanna Wegner
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Heinfried H Radeke
- Institute of General Pharmacology and Toxicology, Faculty of Medicine, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Natalie Filmann
- Institute of Biostatistics and Mathematical Modeling Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Bernhard Brüne
- Institute of Biochemistry I-Pathobiochemistry, Faculty of Medicine, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Gerd Geisslinger
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.,Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Project Group Translational Medicine and Pharmacology (TMP), Frankfurt am Main, Germany
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Sabine Grösch
- Institute of Clinical Pharmacology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.
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