Expression of Toll-like receptors and effects of lipopolysaccharide on the expression of proinflammatory cytokines and chemokine in the testis and epididymis of roosters.

The aim of this study was to determine the expression profiles of Toll-like receptors (TLR) in the testis and epididymis of rooster and whether the expression of IL-1β, IL-6, CXCLi2, and TLR-4 was affected by lipopolysaccharide (LPS), a TLR-4 ligand. Roosters were intravenously injected with LPS or phosphate-buffered saline. Testes and epididymis were collected before and after 3 or 6 h postinjection. Total RNA was isolated from those tissues and expression of TLR and proinflammatory cytokines was analyzed by reverse-transcription PCR and quantitative real-time PCR. Reverse-transcription PCR analysis revealed that 7 of the known 10 chicken TLR in the testis and 9 of 10 in the epididymis were expressed. Expression of TLR-4 was found in both tissues. Expression of TLR-4 was significantly upregulated by LPS in the testis but not in the epididymis. Injection with LPS upregulated the expression of IL-1β, IL-6, and CXCLi2 in the testis and epididymis by 3 to 6 h postinjection. However, injection with phosphate-buffered saline (control) did not affect their expression. These results suggest that proinflammatory cytokines and chemokine expression was upregulated by LPS probably through TLR-4 activation, and thus the reproductive tissues are comprehensively equipped to deal with a pathogenic insult.