Acta Veterinaria et Zootechnica Sinica ›› 2024, Vol. 55 ›› Issue (11): 5267-5277.doi: 10.11843/j.issn.0366-6964.2024.11.042

• Basic Veterinary Medicine • Previous Articles     Next Articles

Effects of Irisin on Tissue Damage and Bacterial Clearance in Mice Infected with Escherichia coli

Yina AN(), Shuyu TAN, Landi FENG, Mingyue BAO, Menghan LIU, Qinhao YIN, Yanjun DONG*()   

  1. National Key Laboratory of Veterinary Public Health Security, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
  • Received:2024-01-03 Online:2024-11-23 Published:2024-11-30
  • Contact: Yanjun DONG E-mail:ann269462@cau.edu.cn;yanjund@cau.edu.cn

Abstract:

This study was conducted to investigate the effects of irisin on Escherichia coli (E. coli)-induced tissue damage in mice, and bacterial clearance and inflammation induced by macrophages. The mouse model was established by intraperitoneal infection with E. coli at a median lethal dose. The protective effect of irisin was evaluated by body temperature, clinical score, survival rate, degree of organ and tissue damage, bacterial load and inflammation level of tissue. E. coli was incubated with different concentrations of irisin in vitro, and the bacterial solution OD600 nm was detected by microplate reader to evaluate the antibacterial effect of irisin. After pretreatment of mouse mononuclear macrophages cells (RAW264.7) with irisin, macrophages were infected with E. coli, and cell lysates and mRNA were collected to evaluate the ability of macrophages to engulf and clear bacteria and the level of M1 polarization. Results showed that irisin could significantly improve the survival rate of bacterially infected mice, reduce the clinical score, promote body temperature recovery, and reduce the liver, lung and kidney damage (P < 0.000 1), decreased the bacterial load of heart (P < 0.05), liver (P < 0.01), spleen (P < 0.01), lung (P < 0.01), kidney (P>0.05), and reduced IL-1β(P < 0.000 1) and IL-6 (P < 0.001) mRNA levels in liver and interleukin (IL)-1β (P < 0.05) and IL-6 (P < 0.01) mRNA levels in kidney. Irisin did not inhibit the growth of E. coli in vitro, but promoted RAW264.7 phagocytosis (P < 0.001) and clearance of E. coli, and also reduced the inflammatory marker IL-1β(P < 0.000 1), IL-6 (P < 0.000 1) and iNOS (P < 0.001) mRNA levels. Irisin can promote the phagocytosis and clearance of bacteria by macrophages, reduce the pro-inflammatory response of macrophages induced by bacterial infection, and alleviate tissue damage in mice.

Key words: irisin, macrophage, inflammation, bacterial infection

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