Interleukin-6 mediates lipopolysaccharide-inhibited irisin secretion in Nile tilapia (Oreochromis niloticus). Issue 121 (February 2022)

• Record Type: Journal Article
• Authors: Yan, Yisha; Dong, Rui; Zhang, Chaoyi; Jiang, Quan
• Is Part Of: Fish & shellfish immunology. Issue 121(2022)
• Page Start: 99
• Page End: 107
• Publication Date: 2022-02
• Subjects: IL-6 -- Irisin -- Tilapia -- Head kidney leucocytes -- Signaling pathway; IL-6 Interleukin-6 -- LPS lipopolysaccharide -- JAK2 Janus kinase 2 -- STAT3 signal transducer and activator of transcription 3; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2021.12.039
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Irisin is a novel immunomodulatory adipomyokine released upon cleavage of the fibronectin type III domain-containing protein 5 (FNDC5). We aimed to examine interleukin-6 (IL-6) role in mediating irisin secretion in immunologically challenged animal and primary head kidney leukocytes cultured from tilapia. Intraperitoneal injection of lipopolysaccharide (LPS) increased plasma IL-6 levels and decreased irisin secretion, suggesting a causal relationship between the induction of IL-6 and irisin. To address this relationship, we further produced recombinant tilapia IL-6 and the anti-tilapia IL-6 polyclonal antiserum. Intraperitoneal injection of recombinant tilapia IL-6 inhibited plasma irisin levels. Consistent with this observation, LPS-induced inhibition of plasma irisin was significantly attenuated by neutralizing circulating IL-6 using an IL-6 antiserum. Besides, IL-6 treatment could inhibit irisin secretion and FNDC5 gene expression in primary cultures of tilapia head kidney leukocytes. In parallel experiments, both LPS and IL-6 blockade of irisin secretion could be reverted by IL-6 receptor antagonism. At the level of the leukocyte, IL-6 treatment also triggered rapid phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), whereas IL-6-reduced irisin secretion could be negated by inhibiting the JAK2 and STAT3 signaling pathways. These results, as a whole, provide the first evidence that IL-6 is the mediator of LPS-inhibited irisin secretion via activation of the JAK2/STAT3 signaling pathway. Highlights: LPS increased plasma IL-6 levels and decreased irisin secretion in vivo. Recombinant tilapia IL-6 inhibited plasma irisin concentrations. IL-6 mediated LPS-inhibited serum irisin levels in vivo. IL-6 inhibited irisin secretion via JAK2/STAT3 signaling pathway.