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Luiskari L, Lindén J, Lehto M, Salmenkari H, Korpela R. Ketogenic Diet Protects from Experimental Colitis in a Mouse Model Regardless of Dietary Fat Source. Nutrients 2024; 16:1348. [PMID: 38732595 PMCID: PMC11085069 DOI: 10.3390/nu16091348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/16/2024] [Accepted: 04/19/2024] [Indexed: 05/13/2024] Open
Abstract
While ketogenic diets (KDs) may have potential as adjunct treatments for gastrointestinal diseases, there is little knowledge on how the fat source of these diets impacts intestinal health. The objective of this study was to investigate how the source of dietary fat of KD influences experimental colitis. We fed nine-week-old male C57BL/6J mice (n = 36) with a low-fat control diet or KD high either in saturated fatty acids (SFA-KD) or polyunsaturated linoleic acid (LA-KD) for four weeks and then induced colitis with dextran sodium sulfate (DSS). To compare the diets, we analyzed macroscopic and histological changes in the colon, intestinal permeability to fluorescein isothiocyanate-dextran (FITC-dextran), and the colonic expression of tight junction proteins and inflammatory markers. While the effects were more pronounced with LA-KD, both KDs markedly alleviated DSS-induced histological lesions. LA-KD prevented inflammation-related weight loss and the shortening of the colon, as well as preserved Il1b and Tnf expression at a healthy level. Despite no significant between-group differences in permeability to FITC-dextran, LA-KD mitigated changes in tight junction protein expression. Thus, KDs may have preventive potential against intestinal inflammation, with the level of the effect being dependent on the dietary fat source.
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Affiliation(s)
- Lotta Luiskari
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Jere Lindén
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland;
- Finnish Centre for Laboratory Animal Pathology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Markku Lehto
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, 00290 Helsinki, Finland; (M.L.); (H.S.)
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Hanne Salmenkari
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, 00290 Helsinki, Finland; (M.L.); (H.S.)
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Riitta Korpela
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
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Luiskari L, Launonen H, Lindén J, Lehto M, Vapaatalo H, Salmenkari H, Korpela R. Ketogenic Diet High in Saturated Fat Promotes Colonic Claudin Expression without Changes in Intestinal Permeability to Iohexol in Healthy Mice. Nutrients 2023; 16:18. [PMID: 38201850 PMCID: PMC10780785 DOI: 10.3390/nu16010018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/11/2023] [Accepted: 12/16/2023] [Indexed: 01/12/2024] Open
Abstract
Ketogenic diets (KDs) have been studied in preclinical models of intestinal diseases. However, little is known of how the fat source of these diets influences the intestinal barrier. Herein, we studied the impact of four-week feeding with KD high either in saturated fatty acids (SFA-KD) or polyunsaturated linoleic acid (LA-KD) on paracellular permeability of the intestine to iohexol in healthy male C57BL/6J mice. We investigated jejunal and colonic tight junction protein expression, histological changes, and inflammatory markers (Il1b, Il6, Tnf, and Lcn2), as well as the activity and expression of intestinal alkaline phosphatase (IAP) in feces and jejunal tissue, respectively, and plasma lipopolysaccharide. KDs did not change intestinal permeability to iohexol after two or twenty-six days of feeding regardless of fat quality. SFA-KD, but not LA-KD, upregulated the colonic expression of tight junction proteins claudin-1 and -4, as well as the activity of IAP. Both KDs resulted in increased epithelial vacuolation in jejunum, and this was pronounced in SFA-KD. Jejunal Il1β expression was lower and colonic Il6 expression higher in LA-KD compared to SFA-KD. In colon, Tnf mRNA was increased in LA-KD when compared to controls. Overall, the results suggest that KDs do not influence intestinal permeability to iohexol but elicit changes in colonic tight junction proteins and inflammatory markers in both jejunum and colon. Future research will show whether these changes become of importance upon proinflammatory insults.
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Affiliation(s)
- Lotta Luiskari
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland; (H.L.); (H.V.)
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Hanna Launonen
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland; (H.L.); (H.V.)
| | - Jere Lindén
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland;
- Finnish Centre for Laboratory Animal Pathology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Markku Lehto
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, 00290 Helsinki, Finland; (M.L.); (H.S.)
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Heikki Vapaatalo
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland; (H.L.); (H.V.)
| | - Hanne Salmenkari
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, 00290 Helsinki, Finland; (M.L.); (H.S.)
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Riitta Korpela
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland; (H.L.); (H.V.)
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
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Launonen H, Luiskari L, Linden J, Siltari A, Salmenkari H, Korpela R, Vapaatalo H. Adverse effects of an aldosterone synthase (CYP11B2) inhibitor, fadrozole (FAD286), on inflamed rat colon. Basic Clin Pharmacol Toxicol 2023; 133:211-225. [PMID: 37345281 DOI: 10.1111/bcpt.13918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/01/2023] [Accepted: 05/08/2023] [Indexed: 06/23/2023]
Abstract
Recently, we described local aldosterone production in the murine large intestine. Upregulated local aldosterone synthesis in different tissues has been linked with inflammatory conditions, which have been attenuated by the aldosterone synthase (CYP11B2) inhibitor, fadrozole (FAD286). Therefore, we investigated the effect of inhibition of intestinal aldosterone synthesis on the development of intestinal inflammation. Sprague-Dawley rats were administered 5% (v/w) dextran sodium sulphate (DSS) for 7 days with or without daily FAD286 (30 mg/kg/d) subcutaneous injections on 3 days before, during and one day after DSS. Tissue aldosterone concentrations were evaluated by ELISA, CYP11B2 by Western blot and RT-qPCR. FAD286 halved adrenal aldosterone production but, intriguingly, increased the colonic aldosterone concentration. The lack of inhibitory effect of FAD286 in the colon might have been affected by the smaller size of colonic vs. adrenal CYP11B2, as seen in Western blot. When combined with DSS, FAD286 aggravated the macroscopic and histological signs of intestinal inflammation, lowered the animals' body weight gain and increased the incidence of gastrointestinal bleeding and the permeability to iohexol in comparison to DSS-animals. To conclude, FAD286 exerted harmful effects during intestinal inflammation. Local intestinal aldosterone did not seem to play any role in the inflammatory pathogenesis occurring in the intestine.
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Affiliation(s)
- Hanna Launonen
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
| | - Lotta Luiskari
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
| | - Jere Linden
- Faculty of Veterinary Medicine, Department of Veterinary Biosciences and Finnish Centre for Laboratory Animal Pathology (FCLAP), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Aino Siltari
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Hanne Salmenkari
- Folkhälsan Research Center, Folkhälsan Institute of Genetics, Helsinki, Finland
- Abdominal Center, Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Riitta Korpela
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
- Faculty of Medicine, Human Microbiome Research Program, University of Helsinki, Helsinki, Finland
| | - Heikki Vapaatalo
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
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