Hai-Dong Qu

Xiamen University, Xiamen, Fujian, China

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Publications (5)12.4 Total impact

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    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. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
    Environmental Toxicology 05/2012; · 2.71 Impact Factor
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    ABSTRACT: The importance of endocrine disrupting chemicals and their effects on fish has been documented in recent years. However, little is known about whether the estrogenic compound 17β estradiol (E2) causes oxidative stress in the hepatic tissue of fish. Therefore, this work tested the hypothesis that E2 might cause oxidative stress in the Japanese sea bass Lateolabrax japonicus liver. To test this hypothesis, its effects on reactive oxygen species (ROS) production, DNA damage, antioxidants and biotransformation enzyme were investigated in two different size groups (fingerling and juvenile groups) following 30 days exposure. Results showed that there was a good relationship between the E2 exposure concentration, plasma E2 level and ROS generation. In addition ROS production correlated negatively with 7-ethoxyresorufin-O-deethylase activity and positively with DNA damage and lipid peroxidation (LPO). Antioxidant enzymes such as superoxide dismutase and catalase did not show any significant relation with ROS, LPO and DNA damage. In contrast, glutathione mediated enzymes showed a good relationship with the above parameters suggesting that the glutathione system in fish might be responsible for protection against the impact of E2 and also indicating a possible adaptive response during exposure periods. In addition, it was observed that fingerling was more susceptible to E2 exposure than juvenile fish. The present study provided strong evidence that the ROS level increased significantly in the liver of E2 exposed fish, and that ROS might serve as a biomarker to indicate estrogen contamination.
    Ecotoxicology 10/2010; 19(7):1258-67. · 2.77 Impact Factor
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    ABSTRACT: Scygonadin is an anionic antimicrobial peptide recently identified from the seminal plasma of Scylla serrata. To gain more detailed information on its antimicrobial activity, scygonadin mature peptide was expressed in Escherichia coli in order to obtain a large quantity of biologically active product. An approximately 43 kDa fusion protein CKS-scygonadin was obtained in a highly stable and soluble form. The soluble component of the fusion CKS-scygonadin was purified by immobilized metal affinity chromatography (IMAC). A single 11 kDa recombinant scygonadin was cleaved from CKS-scygonadin and purified from the cleavage mixture using an affinity chromatography column with a yield of 10.6 mg/L. Alternatively, a recombinant scygonadin was purified from pET28-scygonadin by one-step Ni(2+) affinity chromatography and 65.9 mg/L pure recombinant scygonadin was obtained which was higher than that purified from pTrc-CKS/scygonadin in bacteria culture. The recombinant scygonadin was confirmed using SDS-PAGE analysis and MS-fingerprinting. Both recombinant products of scygonadin from different expressed plasmids showed the activity against both Gram-positive and Gram-negative bacteria, but no activity against yeast and fungi tested. The kinetic studies showed that the recombinant scygonadin was strong active against Staphylococcus aureus and the killing of S. aureus appeared time and dose dependent. Considering the quantity of recombinant product and the applicability of purification, the pET28-scygonadin expression system is a better choice to produce large quantities of recombinant scygonadin for commercial use in future. This is the first report on the heterologous expression of antimicrobial peptide scygonadin in E. coli.
    Protein Expression and Purification 09/2009; 70(1):109-15. · 1.43 Impact Factor
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    ABSTRACT: Hepcidin gene is widely expressed in various fish, suggesting that this antimicrobial peptide is a very important component in the innate immune system. Large yellow croaker (Pseudosciaena crocea) is one of the important economic species of marine-cultured fish but knowledge of its innate immune mechanism is lacking. In this study, we characterize a P. crocea hepcidin gene named as PC-hepc. It consists of an open reading frame of 258 bases encoding 85 amino acids and has a conserved sequence in common with other known hepcidins. The genomic DNA of PC-hepc contains three exons and two introns, the same organization as other reported hepcidins, indicating that PC-hepc is one member of the hepcidin family in fish. The tissue-specific expression of PC-hepc gene in normal fish and the expression pattern in LPS-challenged fish at the time course of stimulation were investigated. The expression of PC-hepc mRNA was significantly increased in the spleen, heart and stomach but not significantly induced in the liver after LPS challenge. An interesting finding is the demonstration of high amounts of PC-hepc transcripts in the kidney in normal fish and their maintenance through 48h exposure to LPS challenge. The synthetic PC-hepc demonstrated a rather wide spectrum of antimicrobial activity in vitro against bacteria and fungi tested, and particularly showed strong activity against the principal fish pathogens, Aeromonas hydrophila, Vibrio parahaemloyticus, Vibrio alginolyticus and Vibrio harvryi. The study indicates that PC-hepc may play a role with a tissue-specific mode in the innate immunity of P. crocea.
    Peptides 01/2009; 30(4):638-46. · 2.52 Impact Factor
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    ABSTRACT: Hepcidin is an antimicrobial peptide and putative iron regulatory hormone previously described in mice and humans. Dozens of fish hepcidins have been isolated and characterized so far. Here we present seven hepcidin-like cDNA sequences named AS-hepc1-7, amplified from the normal commercially cultured fish (black porgy) by RACE-PCR. Sequence analysis reveals that these seven potential hepcidin peptides have highly conserved sequences with other known hepcidins, but they are different from each other in constitution and characteristics of predicted mature amino acids. Based on the study, it is deduced that AS-hepc1-7 represent different variants of a family of hepcidin genes in black porgy. To understand the organization of these hepcidin-like genes, we sequenced AS-hepc2 DNA, AS-hepc3 DNA, AS-hepc4 DNA, AS-hepc7 DNA and AS-hepc2 upstream region; and all of the four genomic DNAs consisted of two introns and three exons, the same organization as other reported hepcidins. The tissue-specific gene expression of hepcidins in normal black porgy was evaluated using RT-PCR and dot blot approaches. RT-PCR showed that transcripts of hepcidin-like mRNAs were present in each tested tissue of normal juvenile black porgy, including liver, spleen, kidney, heart, brain, stomach, intestine, gill, skin and blood, but abundant hepcidin-like mRNA transcripts were only detected in the liver, kidney, spleen, intestine and stomach by dot blot assay. In addition, using dot blot and Northern blot approach, a significant increase of hepcidin mRNA transcription was observed in the liver within 48 h after immersion in a suspension of live bacteria, which suggested that the expression pattern of hepcidin-like genes in black porgy might be different in the liver from the other tissues as previously reported in several hepcidin studies.
    Fish &amp Shellfish Immunology 12/2007; 23(5):1060-71. · 2.96 Impact Factor

Publication Stats

96 Citations
12.40 Total Impact Points

Institutions

  • 2010–2012
    • Xiamen University
      • State Key Laboratory of Marine Environmental Science
      Xiamen, Fujian, China