Effects of E. Coli Infection on the Expressions of TGF-/Smads Signaling Pathway in Broiler Intestine

ABSTRACT

This experiment aimed to investigate whether Escherichia coli (E. coli) infection could affect the TGF-/smads signaling pathway in the jejunal tissue of chickens. One-day-old Cobb 500 broilers were randomly divided into 2 groups and treated with intraperitoneal E. coli or broth injection. Clinical signs of the birds were assessed every day. Spleen and bursa of Fabricius of the birds, post-infection (pi), were collected to evaluate immune organ index. Jejunal tissues were collected to ascertain the expression of TGF-s, TRs, and Smads. The results showed that the infected birds had significantly higher index of the spleen (24hrs and 48hrs pi) compared with birds in the control group (p 0.05). The relative gene expression of TGF-4 increased (p 0.05), while the expression of Smad7 down-regulated in the E. coli group (p 0.01). There was no significant difference in TGF-2, TGF-3, TR I, TR II, Smad2, Smad3 expression (p>0.05). In conclusion, TGF-/Smad signaling pathway was associated with the immune response of broilers in E. coli infection and TGF-4 was the main subtype interacting with E. coli infection.(AU)