Journal article

Publication year: 2015

Pages: 80-87

Journal: Experimental and Clinical Endocrinology & Diabetes

Volume number: 123

Issue number: 2

ISSN: 0947-7349

eISSN: 1439-3646

DOI Link: https://doi.org/10.1055/s-0034-1398502

Publisher: Thieme Publishing

Abstract: 
Background: Studies postulate an involvement of adipokines in inflammatory gastrointestinal diseases. Leptin-deficient ob/ ob mice as well as TLR9-deficient mice have a more moderate course of chronic DSS-induced colitis ( DSS-CC) and adipocytes do express functional TLR9 molecules. Material and Methods: Adipokine mRNA expression in visceral adipose tissue of mice before and after the induction of DSS-CC was investigated. Experiments were performed in both TLR9(wt/wt) and TLR9(-/)-mice. In vitro, the effect of TLR9 blocking peptide on leptin and visfatin protein secretion was studied in 3T3-L1 adipocytes. Results: Induction of DSS-CC led to an upregulation of leptin mRNA expression in TLR9(wt/wt) mice, while TLR9-/-animals showed a significant reduction of leptin expression even below baseline. While visfatin expression remained unchanged in TLR9(wt/wt) animals, TLR9(-/)-mice exhibited a significant induction during DSS-CC. CTRP-3 expression was reduced after colitis induction only in TLR9-/-animals. Of note, IL-6 expression levels remained unchanged, while CXCL1/ KC and cyclophilin A expression was reduced in DSS-CC. Inhibition of TLR9 signaling by using TLR9 blocking peptide led to reduced leptin protein secretion into cell culture supernatants in 3T3-L1 adipocytes, while visfatin protein secretion was enhanced. Conclusions: DSS-CC leads to differential adipokine expression profiles in the visceral fat pad in TLR9wt/ wt vs. TLR9-/-mice. In vitro, inhibition of TLR9 signaling induces visfatin secretion while inhibiting leptin secretion in adipocytes. Thus, visceral adipokines are regulated by intact TLR9 signaling pathway and a specific interplay between the leptin-and the TLR9-pathways might be of pathophysiological importance in chronic intestinal inflammation.

Harvard Citation style: Karrasch, T., Schmid, A., Kopp, A., Obermeier, F., Hofmann, C. and Schaeffler, A. (2015) Impact of Toll-like-receptor-9 (TLR9) Deficiency on Visceral Adipose Tissue Adipokine Expression during Chronic DSS-induced Colitis in Mice, Experimental and Clinical Endocrinology & Diabetes, 123(2), pp. 80-87. https://doi.org/10.1055/s-0034-1398502

APA Citation style: Karrasch, T., Schmid, A., Kopp, A., Obermeier, F., Hofmann, C., & Schaeffler, A. (2015). Impact of Toll-like-receptor-9 (TLR9) Deficiency on Visceral Adipose Tissue Adipokine Expression during Chronic DSS-induced Colitis in Mice. Experimental and Clinical Endocrinology & Diabetes. 123(2), 80-87. https://doi.org/10.1055/s-0034-1398502