Objective : To investigate the effect of polystyrene microplastics(PS-MPs) on myocardial injury in mice and its molecular mechanism. Methods: A total of 60 male C57BL/6 mice were randomly divided into normal saline group, 0.1, 1, 10 mg/kg PS-MPs exposed group, and doxorubicin [5 mg/(kg·w)] group treated for 8 weeks. After treatment, we measured blood pressure, cardiac organ coefficient, cardiac histopathological changes, oxidative stress markers reactive oxygen species(ROS), malondialdehyde(MDA), glutathione(GSH), 4-hydroxynonenal(4-HNE) and nuclear factor E2-related factor 2(Nrf2), serum centroid injury markers creatine kinase MB(CK-MB) and troponin(cTnT), ferroptosis marker recombinant glutathione peroxidase 4(GPX4), Recombinant solute carrier family 7(SLC7A11) as well as ferrous ions(Fe2+). Results : Compared with the negative control group, vacuolation, inflammatory infiltration and collagen fiber deposition were evident in the hearts of mice after PS exposure. The levels of myocardial injury markers CK-MB and cTnT significantly increased. Cardiac organ coefficient decreased, blood pressure increased, oxidative stress markers and ferroptosis markers increased. Conclusion PS-MPs exposure can induce oxidative stress and activate ferroptosis pathway, resulting in myocardial injury in mice.

Objective To construct a recombinant Bifidobacterium bifidum (Bb)vaccine[Bb (pGEX-Sj26GST-Sj14-3-3)] of Schistosomajaponicum (Sj) and analyze the expression of the fusion gene Sj26GST-Sj14-3-3 of Sj in Bb.Methods The recombinant plasmid pGEX-Sj26GST-Sj14-3-3 was electroporated into Bb to construct a recombinant Bb (pGEX-Sj26GST-Sj14-3-3) vaccine.Mter induction with isopropyl-β-D-thiogalactoside (IPTG),double restriction enzymes digestion and polymerase chain reaction (PCR) were used to identify the recombinant Bb (pGEX-Sj26GST-Sj14-3-3),expression of the recombinant protein was analyzed and identified by sodium dodecyl sulfonate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting.Results The recombinant plasmid pGEX-Sj26GST-Sj14-3-3 was successfully transformed into Bb identified by double restriction enzymes digestion and PCR.SDS-PAGE analysis showed that the relative molecular mass of the expressed recombinant protein was approximately 67 × 103.The expressed protein could be recognized by the immune sera from rabbits infected with Sj by Western blotting.Conclusions The recombinant Bb (pGEX-Sj26GST-Sj14-3-3) vaccine of Sj is successfully constructed.The fusion gene Sj26GST-Sj14-3-3 can be expressed in recombinant Bb and the expressed target protein shows specific antigenicity.

Objective To construct and express a recombinant plasmid pGEX-Sj 14-3-3-Sj32 of Schistosoma japonicum in Escherichia coli (E.Coli) BL21 (DE3).Methods Sj14-3-3 and Sj32 antigen genes were amplified by PCR from template of plasmids pGEX-Sj14-3-3 and pET28α-Sj32 which were extracted from recombinant bacteria BL21 (pET28α-Sj32) and BL21 (pGEX-Sj14-3-3) stored in Institute of Infectious and Parasitic Disease of the First Affiliated Hospital of Chongqing Medical University.Sj14-3-3-Sj32 fusion gene obtained with gene SOEing was cloned into the vector pGEX-1λT to construct pGEX-Sj14-3-3-Sj32 which was identified by double digestion.The recombinant plasmid pGEX-Sj 14-3-3-Sj32 was transformed into E.Coli BL21 (DE3).The recombinant strains were induced by isopropyl-β-d-thiogalactoside (IPTG),and the expressed products were analyzed and identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting.Results The 1 750 bp Sj14-3-3-Sj32 fusion gene was successfully amplified by gene SOEing and cloned into the vector pGEX-1 λT verified by restriction analysis,the recombinant plasmid pGEX-Sj 14-3-3-Sj32 was successfully constructed.The molecular mass of the expressed recombinant protein was proximately 73 × 103 as detected by SDS-PAGE.Western blotting confirmed that the expressed protein could be recognized by the immune sera from rabbit infected with Schistosomajaponicum.Conclusion The recombinant plasmid pGEX-Sj14-3-3-Sj32 is successfully constructed and could be highly expressed in E.coli and the expressed recombinant protein has specific antigenicity.

OBJECTIVETo observe the dynamic changes of immune responses of splenocytes in mice immunized with recombinant vaccine Bifidobacterium bifidum (pGEX-Sj32) of Schistosoma japonicum and investigate the immunological mechanism of the vaccine.

METHODSEighty-eight BALB/c mice were randomized for immunization with 10⁶ CFU recombinant vaccine orally or with 10⁵ CFU recombinant vaccine intranasally. Four mice were selected from each group every two weeks to test the responses of the splenocytes to stimulations with SjAWA or ConA. MTT assay and flow cytometry were used to assess splenocyte proliferation and the distribution of CD4⁺ and CD8⁺ T cells, respectively; the levels of interleukin-10 (IL-10), IL-12 and tumor necrosis factor-α (TNF-α) in the cell culture supernatant were detected by ELISA.

RESULTSRegardless of the stimulations, the splencytes showed significantly enhanced proliferation in weeks 2-16 in oral administration group and in weeks 2-18 in intranasal group (P<0.01). CD4⁺ subsets in both two groups increased obviously in weeks 2-12 (P<0.01) but CD8⁺ subsets remained stable. In oral administration group, the levels of TNF-α, IL-10 and IL-12 increased in weeks 2-14, 2-18 and 2-14, and peaked at week 8, 10 and 6, respectively; in intranasal group, the cytokines increased in weeks 2-14, 2-18 and 2-18, and peaked at week 8, 10 and 8, respectively.

CONCLUSIONThe recombinant vaccine rBb (pGEX-Sj32) can induce effective immune responses in mice.

Animals ; Antigens, Helminth ; immunology ; Bifidobacterium ; CD4-Positive T-Lymphocytes ; immunology ; CD8-Positive T-Lymphocytes ; immunology ; Interleukin-10 ; immunology ; Interleukin-12 ; immunology ; Mice ; Mice, Inbred BALB C ; Schistosoma japonicum ; Schistosomiasis japonica ; prevention & control ; Spleen ; cytology ; immunology ; Tumor Necrosis Factor-alpha ; immunology ; Vaccination ; Vaccines, Synthetic ; immunology

Objective To observe the dynamic changes of immune responses of splenocytes in mice immunized with recombinant vaccine Bifidobacterium bifidum (pGEX- Sj32) of Schistosoma japonicum and investigate the immunological mechanism of the vaccine. Methods Eighty-eight BALB/c mice were randomized for immunization with 106 CFU recombinant vaccine orally or with 105 CFU recombinant vaccine intranasally. Four mice were selected from each group every two weeks to test the responses of the splenocytes to stimulations with SjAWA or ConA. MTT assay and flow cytometry were used to assess splenocyte proliferation and the distribution of CD4+and CD8+T cells, respectively;the levels of interleukin-10 (IL-10), IL-12 and tumor necrosis factor-α (TNF-α) in the cell culture supernatant were detected by ELISA. Results Regardless of the stimulations, the splencytes showed significantly enhanced proliferation in weeks 2-16 in oral administration group and in weeks 2-18 in intranasal group (P<0.01). CD4+subsets in both two groups increased obviously in weeks 2-12 (P<0.01) but CD8+subsets remained stable. In oral administration group, the levels of TNF-α, IL-10 and IL-12 increased in weeks 2-14, 2-18 and 2-14, and peaked at week 8, 10 and 6, respectively;in intranasal group, the cytokines increased in weeks 2-14, 2-18 and 2-18, and peaked at week 8, 10 and 8, respectively. Conclusion The recombinant vaccine rBb (pGEX-Sj32) can induce effective immune responses in mice.

Objective To observe the dynamic changes of immune responses of splenocytes in mice immunized with recombinant vaccine Bifidobacterium bifidum (pGEX- Sj32) of Schistosoma japonicum and investigate the immunological mechanism of the vaccine. Methods Eighty-eight BALB/c mice were randomized for immunization with 106 CFU recombinant vaccine orally or with 105 CFU recombinant vaccine intranasally. Four mice were selected from each group every two weeks to test the responses of the splenocytes to stimulations with SjAWA or ConA. MTT assay and flow cytometry were used to assess splenocyte proliferation and the distribution of CD4+and CD8+T cells, respectively;the levels of interleukin-10 (IL-10), IL-12 and tumor necrosis factor-α (TNF-α) in the cell culture supernatant were detected by ELISA. Results Regardless of the stimulations, the splencytes showed significantly enhanced proliferation in weeks 2-16 in oral administration group and in weeks 2-18 in intranasal group (P<0.01). CD4+subsets in both two groups increased obviously in weeks 2-12 (P<0.01) but CD8+subsets remained stable. In oral administration group, the levels of TNF-α, IL-10 and IL-12 increased in weeks 2-14, 2-18 and 2-14, and peaked at week 8, 10 and 6, respectively;in intranasal group, the cytokines increased in weeks 2-14, 2-18 and 2-18, and peaked at week 8, 10 and 8, respectively. Conclusion The recombinant vaccine rBb (pGEX-Sj32) can induce effective immune responses in mice.