High level of hepcidin mRNA expression is associated with high production of immune factors in Tibetan pigs

• The transcripts of hepcidin were higher in Tibetan pigs than those of Landrace pigs.
• Serum iron concentration was higher in Tibetan pigs than that of Landrace pigs.
• The immune response-associated factors mRNA levels were higher in Tibetan pigs.

Hepcidin, an antimicrobial peptide, is considered to be a key homeostatic regulator of iron metabolism. Tibetan pigs are a Chinese indigenous plateau breed with strong disease resistance. It is therefore of interest to look for porcine hepcidin (pHepc) gene expression in Tibetan pigs in order to clarify the involvement of pHepc in interaction of host defenses and iron homeostasis. In this study, the mRNA expressions of pHepc and the immune response-associated factors were determined by real-time PCR in 30-day-old Tibetan pigs and Landrace pigs were chosen as control. The results showed that the expression of pHepc mRNA in most tissues were higher in Tibetan pigs than those of Landrace pigs, which corresponded to the higher serum iron concentration in Tibetan pigs. In addition, compared to Landrace pigs, higher levels of pro-inflammatory cytokines (TNF-α, IL-1α, IL-1β and IFN-γ), pattern recognition receptors (TLR-2, TLR-4, NOD-1 and NOD-2) and chemokines (MCP-1 and IL-8) were detected in Tibetan pigs, which suggested that Tibetan pigs have a strong immunity. The high expression of pHepc may affect the production of immune factors by regulating iron homeostasis, which may partly explain the strong disease resistance of Tibetan pigs.