Dietary Ribonucleic Acid Suppresses Inflammation of Adipose Tissue and Improves Glucose Intolerance That Is Mediated by Immune Cells in C57BL/6 Mice Fed a High-Fat Diet

• Published in: Journal of Nutritional Science and Vitaminology Vol. 61; no. 1; pp. 73 - 78
• Main Authors: SAKAI, Tohru, TAKI, Tomoyo, NAKAMOTO, Akiko, TAZAKI, Shiho, ARAKAWA, Mai, NAKAMOTO, Mariko, TSUTSUMI, Rie, SHUTO, Emi
• Format: Journal Article
• Language: English
• Published: Japan Center for Academic Publications Japan 2015
• Subjects: Adipose Tissue - drug effects; Adipose Tissue - metabolism; Adipose Tissue - pathology; Animals; Area Under Curve; B-Lymphocytes - metabolism; Blood Glucose - metabolism; Cytokines - blood; Cytokines - genetics; Cytokines - metabolism; Diet, High-Fat; Dietary Supplements; Glucose Intolerance - diet therapy; Glucose Intolerance - drug therapy; Glucose Intolerance - etiology; Glucose Intolerance - metabolism; Homeodomain Proteins - genetics; inflammation; Inflammation - diet therapy; Inflammation - etiology; Interleukin-6 - blood; Lymphocytes - metabolism; Macrophages - metabolism; Male; Mice, Inbred C57BL; Mice, Knockout; obesity; Obesity - etiology; Obesity - metabolism; Obesity - pathology; RAG-1 knockout mice; ribonucleic acid; RNA - pharmacology; RNA - therapeutic use; RNA, Messenger - metabolism; T and B cell; T-Lymphocytes - metabolism
• ISSN: 0301-4800; 1881-7742
• DOI: 10.3177/jnsv.61.73

Recent evidence suggests that immune cells play an important role in differentiation of inflammatory macrophages in adipose tissue, which contributes to systemic chronic inflammation. Dietary ribonucleic acid (RNA) has been shown to modulate immune function. We hypothesized that RNA affects immune cell function in adipose tissue and then improves inflammatory response in adipose tissue. C57/BL6 mice and recombination activating gene-1 (RAG-1) knockout mice on a C57BL/6 mice background were fed a high-fat diet containing 1% RNA for 12 wk. An oral glucose tolerance test was performed. Supplementation of dietary RNA in C57BL/6 mice fed a high-fat diet resulted in a smaller area under the curve (AUC) after oral glucose administration than that for control mice. The mRNA expression levels of inflammation-related cytokines in adipose tissue and serum interleukin-6 levels were reduced by dietary RNA supplementation. Interestingly, reduction of the AUC value by RNA supplementation was abolished in T and B cell-deficient RAG-1 knockout mice. These results indicate that RNA improves inflammation in adipose tissue and reduces the AUC value following oral glucose administration in a T and B cell-dependent manner.