Benzo[a]pyrene modulation of acute immunologic responses in red Sea bream pretreated with lipopolysaccharide

Abstract

The effects of polycyclic aromatic hydrocarbons (PAHs) have been reported to modulate the immune response in aquatic animals, but the collected information of their effects on fish immunity is so far ambiguous. This study demonstrated that Benzo[a]pyrene (BaP) exposure altered the expression pattern of an antimicrobial peptide hepcidin (PM-hepc) gene and the activities of some immune-associated parameters in the lipopolysaccharide (LPS)-challenged red sea bream (Pagrus major). It was observed that LPS could increase respiratory burst, lysozyme and antibacterial activity in P. major. However when the P. major was exposed to different concentrations of BaP (1, 4, or 8 μg L(-1) ) for 14 days and then challenged with LPS there was no significant change in the lysozyme and antibacterial activity. It was further observed that LPS could induce the PM-hepc mRNA expression at 3, 6, and 12-h post-LPS challenge. However, when P. major was exposed first to BaP for 14 days and then challenged with LPS, the expression of PM-hepc mRNA was delayed in the liver until 24 h and not significantly induced until 48 and 96 h. The mRNA expression pattern was completely different from that only with LPS challenge, showing that BaP exposure changed the PM-hepc mRNA expression pattern of fish with LPS challenge. This study demonstrated that BaP exposure can weaken or inhibit the induction of lysozyme and antibacterial activity in the LPS-challenged P. major; conversely BaP exposure could enhance the mRNA expression of PM-hepc gene, indicating that the effect of BaP has different modulatory mechanism on hepcidin genes and immune-associated parameters.

Effects of dietary inactivatedPediococcus pentosaceuson growth performance, feed utilization and blood characteristics of red sea bream,Pagrus majorjuvenile

“…) and red sea bream (Bo et al . ). The immunomodulating activity of non‐viable bacteria may be due to the existence of certain microbial components, such as capsular polysaccharides, peptidoglycans and lipoteichoic acids, which are potent stimulators of the piscine immune system (Secombes et al .…”

Oral administration ofEscherichia colilipopolysaccharide enhances the immune system of striped catfish,Pangasianodon hypophthalmus(Sauvage)

“…LPS was considered as able to enhance antibacterial capacity by increasing lysozyme activity in red sea bream, Pagrus major (Temminck & Schlegel) (Bo et al . ). Nayak et al .…”

“…Similar stimulating effects of LPS on lysozyme activity and lysozyme mRNA were reported in Atlantic salmon (Salmo salar L.) (Paulsen et al 2003). LPS was considered as able to enhance antibacterial capacity by increasing lysozyme activity in red sea bream, Pagrus major (Temminck & Schlegel) (Bo et al 2012). Nayak et al (2008) also indicated the increase in serum lysozyme activity after injection of LPS (1 EU) in Indian carp, Labeo rohita (Hamilton) and its decrease at higher concentrations (10 and 20 EU).…”

“…Swain et al (2008) also reported that LPS can induce innumerable biological effects in all living system, including immunological responses. It enhances the total leucocytes, monocytes and neutrophils in carp (Selvaraj et al 2009), stimulates the peripheral leucocytes (Hirono, Nam, Kurobe & Aoki 2000;Park, Kurobe, Hirono & Aoki 2003) and macrophages as well as the phagocytic and respiratory burst activities (Sarmento, Marques, Anthony, Ellis & Afonso 2004;Bo, Singaram, Dan-Qing, Harikrishnan, Hai-Dong, Nai, Fang-Yi & Ke-Jian 2012). In addition, it can induce the production of lysozyme as well as activate the transcription of gene that encoded lysozyme (Paulsen, Lunde, Engstad & Robertsen 2003).…”

Variation of antioxidant/detoxification enzyme activities in response to benzo[a]pyrene in the gazami crab Portunus trituberculatus

“…Most of them are electrophilic compounds that have high activity, can interact with macromolecules in living bodies (e.g., proteins and nucleic acids), and have strong genotoxicity and immunotoxicity (Carlson et al 2002). BaP can cause oxidative stress by inducing a high level of reactive oxygen species (ROS), which could be related to cellular damage and apoptosis (Bo et al 2012), and it can also cause embryo toxicity and immunoa Corresponding author: jerrylee200224@126.com modulation in both invertebrates and vertebrates (Gopalakrishnan et al 2009). …”