Journal article

Publication year: 2021

Journal: Cytokine

Volume number: 148

ISSN: 1043-4666

eISSN: 1096-0023

DOI Link: https://doi.org/10.1016/j.cyto.2021.155663

Publisher: Elsevier

Abstract: 
Background and aim: CAMP (Cathelicidin antimicrobial peptide) expression in adipocytes is regulated by Toll-like receptor (TLR) agonists. Secreted adipokines such as CTRP-3 have been suggested to participate in innate im-mune signaling in adipose tissue (AT). This study investigates whether TLR-induced CAMP expression in adi-pocytes is antagonized by CTRP-3. Methods: 3T3-L1 adipocytes were co-stimulated with TLR agonists (LPS, MALP-2, Pam3CSK4, pI:C) and re-combinant CTRP-3. In a SIRS model, C57BL/6 wild-type mice were intraperitoneally (ip) injected with recom-binant CTRP-3 prior to LPS. CAMP expression was analyzed by real-time PCR in AT of wild-type mice and in AT and primary adipocytes from transgenic mice lacking adipocyte CTRP-3 expression. Comparative transcriptome analysis by RNA seq. was applied in CTRP-3 KO adipocytes. Results: In vitro, CTRP-3 antagonized TLR4-and TLR1/2-induced CAMP expression in adipocytes whereas TLR3-and TLR2/6-mediated induction of CAMP was not affected. in vivo, application of exogenous CTRP-3 dose-dependently antagonized LPS-induced CAMP expression in intra-abdominal AT. CAMP expression in total AT and in primary adipocytes of subcutaneous and intra-abdominal AT did not differ between wild-type mice and transgenic mice lacking adipocyte CTRP-3 expression. Conclusions: The study suggests a hypothetical role of CAMP in host defense not only against Gram-positive bacteria sensed by TLR1/2 and TLR2/6 but also against Gram-negative bacteria sensed by TLR4 and poten-tially against viruses sensed by TLR3. The machinery of TLR-mediated pro-inflammatory activation of the CAMP gene in adipocytes seems to be partly modulated by secreted adipokines belonging to the growing family of C1q/ TNF-related proteins such as CTRP-3.

Harvard Citation style: Karrasch, T., Hoepfinger, A., Schaeffler, A. and Schmid, A. (2021) The adipokine C1q/TNF-related protein-3 (CTRP-3) inhibits Toll-like receptor (TLR)-induced expression of Cathelicidin antimicrobial peptide (CAMP) in adipocytes, Cytokine, 148, Article 155663. https://doi.org/10.1016/j.cyto.2021.155663

APA Citation style: Karrasch, T., Hoepfinger, A., Schaeffler, A., & Schmid, A. (2021). The adipokine C1q/TNF-related protein-3 (CTRP-3) inhibits Toll-like receptor (TLR)-induced expression of Cathelicidin antimicrobial peptide (CAMP) in adipocytes. Cytokine. 148, Article 155663. https://doi.org/10.1016/j.cyto.2021.155663