Two classic OBPs modulate the responses of female Holotrichia oblita to three major ester host plant volatiles.

Insects possess a fairly sophisticated olfactory system in their antennae to detect odorants essential for their survival and reproduction. Among them, insect first perceives odour sources by odorant-binding proteins (OBPs) to locate host-plants. Methyl salicylate, (Z)-3-hexenyl acetate and dibutyl phthalate are major volatile components of Ulmus pumila and Ricinus communis and elicit strong responses of the scarab beetle Holotrichia oblita adults. However, olfactory perception of the scarab beetle to these odorant compounds is unclear. In the current study, we cloned the OBP6 and OBP7 of H. oblita. The expression pattern shows that the two genes were highly expressed in the antennae of female beetles. Binding assays verified that the HoblOBP6 had a better binding affinity to methyl salicylate, and so did HoblOBP7 to (Z)-3-hexenyl acetate and dibutyl phthalate. The effect on the responses of female beetles to the three compounds was decreased significantly after these two genes were silenced by RNA interference. These results indicate that HoblOBP6 and HoblOBP7 are essential for female H. oblita perception of methyl salicylate, (Z)-3-hexenyl acetate and dibutyl phthalate. Our study provides important insights into the olfactory mechanism of female H. oblita to ester plant volatiles and could facilitate the development of potential pest control strategies in the field.

[Preliminary study on the protective effect of glycosyltransferase Colgalt2 gene deletion on acetaminophen-induced liver injury].

Objective: To investigate the protective effect of Colgalt2 gene deletion on acute liver injury induced by acetaminophen (APAP) in mice. Methods: Colgalt2(+/+) wild-type control mice and Colgalt2(-/-) mice (all C57BL/6J strains) were selected as the research subject. APAP solution was injected intraperitoneally to establish a mouse model of acute liver injury. The mouse were divided into four groups: Colgalt2(+/+) wild-type control group, Colgalt2(+/+) wild-type drug group (APAP 500 mg/kg), Colgalt2(-/-) control group, and Colgalt2(-/-) drug group (APAP 500 mg/kg). The survival rate was measured to plot survival curve. Liver function was evaluated by detecting serum ALT and AST levels. Liver histopathological changes were observed by HE staining to evaluate the condition of liver injury. Western blot was used to detect protein c-Jun N-terminal kinase (JNK)-related liver injury. Results: Compared with Colgalt2(+/+) mice, the survival rate was significantly increased after giving APAP to Colgalt2(-/-) mice (86.7% vs. 40%), and liver cell necrosis and inflammatory cell infiltrates of Colgalt2(+/+) mice were milder. Serum ALT, and AST level was significantly decreased [ALT: (5 291.9 ± 1 016.34) U/L vs. (1 616.9 ± 330.65) U/L, P = 0.000; AST: (4 978.0 ± 1 028.43) U/L vs. (1 851.0 ± 437.55) U/L, P = 0.000]. The expression level of JNK was significantly decreased in liver tissue. Conclusion: Colgalt2 gene deletion has a protective effect on acute liver injury induced by acetaminophen (APAP) in mice. Therefore, Colgalt2 may be a potential therapeutic option for acetaminophen-induced hepatotoxicity.

Expression changes of activin A in the development of hepatic fibrosis.

AIM: To examine the expression of activin A, a member of the transforming growth factor (TGFbeta) superfamily, recently has been reported to be overexpressed in liver cirrhosis, in the course of carbon tetrachloride-induced rat hepatic fibrosis. METHODS: Hepatic fibrosis was induced in rats by subcutaneous injections of 40% carbon tetrachloride oily solution for a period of 1 to 7 weeks. At the end of 1, 2, 3, 4, 5, 6 and 7 weeks after carbon tetrachloride injections, the rats were killed in group (6-10 rats each time) for study. The activin A messenger RNA expression and its protein localization were assessed by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS: The normal rat liver expressed activin A mRNA and protein, and its expression was transiently decreased and became undetectable after carbon tetrachloride injections for 2 or 3 weeks and then increased gradually. After injection of carbon tetrachloride for 6 and 7 weeks, activin A mRNA and protein expressions were significantly enhanced in rat liver. Compared with that of the normal rat liver. Activin A mRNA expression levels in rats receiving carbon tetrachloride injections for 6 and 7 weeks were 1.6 and 2.2 times that of those in normal rat liver respectively (0.456 +/- 0.094 vs 0.2860.0670, P< 0.01; 0.620 +/- 0.134 vs 0.286 +/- 0670, P< 0.01). Immunohistochemistry showed that activin A expressed in hepatocytes of normal liver, and its expression was decreased in rats receiving carbon tetrachloride for 2 or 3 weeks. Compared with normal liver, activin A expression distribution mode changed in fibrotic liver, being increased significantly in hepatocytes around fibrotic areas. CONCLUSION: Activin A expression was increased in late stage of hepatic fibrosis, and this may be involved in hepatic fibrosis formation in this period.