Abstract： Objective　To elucidate the antigenic antibody reaction of recombinant expression of non-structural protein 1 (NS1) of Japanese encephalitis (JE) virus with various mosquito-borne flaviviruses, including JE virus, and the antigenic antibody reaction of serum samples of patients infected with JE virus in acute stage. Methods　In this study, Escherichia coli prokaryotic expression vector (pET) system was used to recombinant express Japanese encephalitis virus NS1 gene. Western Blot assay was performed to detect the antibody responses of the recombinantly expressed protein against a variety of mosquito-transmitted flaviviruses, including JE virus, as well as antigen-antibody reactions of serum from patients with acute JE virus infection. Results　The NS1 gene expression product of JE virus (P3 strain) was in the form of an inclusion body, and the denatured and renatured expression product was displayed as a single band in the denatured gel (polyacrylamide gel electrophoresis, PAGE), with a molecular weight of about 45 000. The results of further antigen-antibody analysis showed that the antigen/antibody hybridization reaction of the expression product with polyclonal or monoclonal antibody of JE virus (mosquito isolates, encephalitis isolates) and serum samples of patients with acute JE virus infection could be completely consistent. The recombinant product showed negative antigen/antibody hybridization reactions with mosquito-transmitted flaviviruses, such as dengue virus and yellow fever virus polyclonal antibodies, but positive reactions with polyclonal antibodies to West Nile virus and Murray Valley encephalitis virus. Conclusions　In this study, the recombinant expression of the NS1 protein of JE virus was successfully obtained, and the antigen/antibody reaction between the recombinant protein and samples of patients infected with mosquito-borne flavivirus and JE virus was analyzed. The study results provide important basic data for elucidating the antigen-antibody reaction between the NS1 protein of JE virus and mosquito-borne flavivirus. The recombinant expression protein obtained in this study provides an important material basis for further research on the function of JE virus NS1 protein.

Background Di(2-ethylhexyl) phthalate (DEHP) is the highest consumed and the most widely used phthalic acid ester, their effects on lipid metabolism have attracted the attention of many scholars. However, the associated mechanism is still unclear. Objective To observe the effect of DEHP on lipid metabolism in rats, probe its possible mechanism, and provide a research basis for the effect of DEHP on human lipid metabolism. Methods Forty healthy male SD rats were randomly divided into 4 groups: solvent control (0 mg·kg⁻¹ DEHP), low DEHP (187 mg·kg⁻¹), medium DEHP (375 mg·kg⁻¹), and high DEHP (750 mg·kg⁻¹) groups. DEHP was administered by oral gavage for 6 d per week, consecutively 8 weeks. The rats were weighed once a week during the exposure period. At 24 h after the last exposure, the rats were anesthetized with 20% urethane and sacrificed by apical puncture. Rat livers were harvested and weighed before hematoxylin-eosin (HE) histopathological observation. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA levels of lipid metabolism-related genes Janus kinase 3 (JAK3), signal transducer and activator of transcription 5b (STAT5b), and peroxisome proliferator-activated receptor γ (PPARγ) in liver, and Western blot was used to detect the expression levels of lipid metabolism-related proteins JAK3, STAT5b, and PPARγ in liver. Results Compared with the control group, there was no significant difference in the body weight gain of the rats in each group (P>0.05). The liver organ coefficients of the DEHP exposure groups were higher than that of the control group (P<0.001), and increased with higher DEHP dosages. The level of high-density lipoprotein cholesterol (HDL-C) in serum decreased in all DEHP exposure groups (P<0.05), and the level of low-density lipoprotein cholesterol (LDL-C) in serum increased in the high DEHP group (P<0.05). The results of liver histopathological morphology showed that the hepatocytes of each DEHP group were enlarged and edematous in varying degrees, with loose stroma and irregular arrangement of cells, which were manifested as inflammatory cell infiltration and fatty degeneration of liver cells. Compared to the control group, the mRNA levels of JAK3, STAT5b, and PPARγ in liver tissues of rats in each DEHP group decreased (P<0.001). Compared to the control group, the relative expression levels of JAK3 in each DEHP group decreased (P<0.05), and the relative expression levels of STAT5b and PPARγ in the medium and high DEHP groups decreased (P<0.05). Conclusion DEHP exposure can induce abnormal lipid metabolism in rats, and the mechanism may be related to DEHP inhibiting the activation of JAK3/STAT5b/PPARγ signaling pathway.