ABSTRACT
Imidazole derivative KK-42 is a well-known regulator of insect growth. KK-42 pretreatment has been shown to promote the survival of Macrobrachium nipponense infected with Aeromonas hydrophila, possibly via activation of superoxide dismutase (SOD). In this study, the cytMnSOD gene was cloned from the hepatopancreas of M. nipponense using the rapid amplification of cDNA ends technique. The full-length cDNA of cytMnSOD was 1233 bp long, and the open reading frame was 858 bp long, encoding a 286-aa protein with a 60-aa leader sequence. The calculated molecular mass of the translated cytMnSOD protein was 31.33 kDa, with an estimated isoelectric point of 5.62. cytMnSOD contained two N-glycosylation sites, four conserved amino acids responsible for binding manganese, and a manganese SOD domain (DVWEHAYY). Real-time RT-PCR analysis showed that cytMnSOD was expressed in all tissues examined with the highest expression observed in the hepatopancreas. Levels of the cytMnSOD transcript in the hepatopancreas were highest in stage C of the molting cycle. Real-time PCR analysis revealed that cytMnSOD expression increased significantly 3, 6, and 12 h after KK-42 treatment, with simultaneous increases in SOD activity from 6 to 12 h. Our results demonstrate that cytMnSOD expression and SOD activity may be induced by KK-42, which may represent one of the molecular mechanisms through which KK-42 promotes increased survival of prawns infected with A. hydrophila.
Subject(s)
Hepatopancreas/drug effects , Imidazoles/pharmacology , Juvenile Hormones/pharmacology , Palaemonidae/drug effects , RNA, Messenger/genetics , Superoxide Dismutase/genetics , Aeromonas hydrophila/growth & development , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , Cytosol/drug effects , Cytosol/enzymology , Cytosol/immunology , Cytosol/microbiology , Gene Expression Regulation, Developmental , Hepatopancreas/enzymology , Hepatopancreas/immunology , Hepatopancreas/microbiology , Host-Pathogen Interactions , Molecular Weight , Open Reading Frames , Palaemonidae/genetics , Palaemonidae/immunology , Palaemonidae/microbiology , Protein Domains , Protein Sorting Signals , RNA, Messenger/immunology , Superoxide Dismutase/immunology , Up-Regulation/drug effectsABSTRACT
BACKGROUND AND STUDY AIMS: Antizyme 1, a specific inhibitor of Ornithine decarboxylase (ODC), plays a critical role in cell proliferation. Little is known about the impact of glucocorticoid on antizyme expression in the regenerating liver. In this paper, the effect of corticosterone on the gene expression of antizyme 1 in early regenerating rat liver induced by partial hepatectomy (PH) was investigated. MATERIALS AND METHODS: Bilateral adrenalectomies (ADX) were performed 3 days before PH. Corticosterone in sesame oil or sesame oil was injected sub-cutaneously to ADX rats. Antizyme 1 mRNA and protein levels as well as polyamine contents in the regenerating liver were determined by RT-PCR, Western blotting and HPLC, respectively. RESULTS: Antizyme 1 protein content in the oil-treated ADX group decreased significantly at 5, 7 and 9 h after PH compared to control. Following corticosterone administration the content rose dose-dependently during the whole experiment. At 5 h post-PH, the protein levels in 10 and 40 mg/kg corticosterone-treated ADX rats increased by 66% and 148%, respectively, when compared with the control group. However, no significant changes in antizyme 1 mRNA levels were observed in oil-treated ADX rats or corticosterone-treated groups compared to control. Polyamine contents in oil-treated ADX rats were the highest among all groups at 5 and 9 h. Corticosterone treatment resulted in a dramatic decrease of polyamine contents at most of the time points investigated when compared with those in control rats. CONCLUSIONS: Corticosterone treatment induces antizyme 1 protein synthesis in early regenerating rat liver. However, it has little effect on antizyme 1 gene transcription. (Acta gastroenterol. belg., 2011, 74, 289-294).
