Chronic hepatitis B virus(HBV)infection is a major global public health threat.In areas with moderate to high prevalence of HBV,mother-to-child transmission(MTCT)remains the main source of chronic HBV infection.With the application of combined immunization of hepatitis B vaccine and hepatitis B immunoglobulin in neonates,there has been a significant reduction in the incidence rate of HBV MTCT,but there is still a high risk of HBV MTCT in infants born to mothers with positive HBeAg and high viral loads.Although antiviral therapy for pregnant women with high HBV viral loads in late pregnancy can further reduce the risk of HBV MTCT,it is still difficult to completely block HBV MTCT.A deep understanding of the molecular virological mechanisms of HBV MTCT can provide clear ideas for blocking HBV MTCT,which is of great significance for the prevention and management of HBV MTCT.

Objective:To investigate the changes in adaptive phenotypes of Yersinia pestis ( Yp) during successive passages in macrophages. Methods:A Yp strain of 201-MI was induced by 50 successive passages of Yp 201 strain in Raw264.7 cells. Phenotypic characteristics of 201 and 201-MI strains were compared by analyzing their survival rates in macrophages, growth curves, biofilm formation abilities, acid and hydrogen peroxide-stress tolerance, and virulence to mammal cells (Raw264.7 and HeLa cells) and mice. Results:Comparing with 201 strain, 201-MI strain showed various phenotypic changes, including higher survival rate in Raw264.7 cells, faster growth in iron-deficient medium, higher tolerance to acid and hydrogen peroxide, decreased biofilm formation ability, and less damages to Raw264.7 and HeLa cells. More-over, 201-MI strain showed decreased virulence to mice in both subcutaneous and intraperitoneal challenges. Preliminary comparative genomics analysis revealed some indel and nonsense mutations in 201-MI strain, which might account for its phenotype changes.Conclusions:After successive passages in macrophages, Yp showed some phenotypic changes, which might reflect its adaptive evolution under the pressure of macrophages. Detailed multi-omics analysis would be of great help to understand the underlying genetic mechanisms of these changes, and the related Yp-macrophage interaction processes as well.

Objective:To investigate the regulatory effect of miR-26a in radiation-induced heart disease (RIHD) mice.Methods:C57/BL6 mice were used to establish RIHD models. The cardiac function, fibrosis, the expression levels of collagen 1 (COL1) and connective tissue growth factor (CTGF), and miR-26a were detected in RIHD mice. Whether CTGF was the target gene of miR-26a was verified by dual luciferase kit. Moreover, cardiac fibroblasts were transfected with miR-26a up and miR-26a down lentivirus vectors to construct the miR-26a overexpression and underexpression cell models. The expression of CTGF, proliferation, and apoptosis of cardiac fibroblasts were detected.Results:In the RIHD mice, heart function was decreased, myocardial fibrosis was remodeled, the expression levels of COL1 and CTGF were up-regulated, and the expression level of miR-26a was down-regulated. Dual luciferase reporter assay confirmed that CTGF was the target gene regulated by miR-26a. Overexpression of miR-26a could inhibit the expression of CTGF, suppress the proliferation of cardiac fibroblasts, promote cell apoptosis and secrete collagen. Underexpression of miR-26a yielded the opposite results.Conclusion:MiR-26a affects the function of cardiac fibroblasts by targeting CTGF and probably mediates the process of radiation-induced myocardial fibrosis, which may become a new regulatory target of RIHD.

Objective:To investigate the effects of centromere protein-A (CENP-A) on the invasion and migration of ovarian cancer (OC) cells and explore the related mechanism.Methods:OC cell line A2780 was cultured in vitro, and they were divided into Ng Group (Blank Control Group) , pcDNA group (negative transfection group:PCDNA vector plasmid) , pcDNA-CENP-A group (over-expression Group: pcDNA-CENP-A Vector Plasmid) and pathway inhibitor group (TRANSFECTION-CENP-A+ PI3K pathway inhibitor LY294002) . The cell proliferation was detected by CCK-8 method; the cell migration and invasion was detected by Scratch test and Transwell test; the expression of CENP-A, E-cadherin, N-cadherin and phosphatidylinositol 3-kinase/protein kinase B/nuclear factor-kappa B (PI3K/AKT/NF-κB) pathway related proteins was detected by Western blot.Results:A2780 cells were successfully transfected. After 24 hours, with the extension of culture time, compared with that in NG group [ (0.50±0.07) , (0.72±0.11) , (0.99±0.14) ] and pcDNA group [ (0.55±0.08) , (0.78±0.12) , (1.02±0.15) ], the viability of A2780 cells in pcDNA-CENP-A group [ (0.78±0.12) , (1.03±0.15) , (1.67±0.25) ] and pathway inhibitor group [ (0.63±0.09) , (0.87±0.13) , (1.39±0.20) ] increased significantly ( P<0.05) , compared with that in the pcDNA-CENP-A group, the viability of A2780 cells in the pathway inhibitor group was significantly decreased ( P<0.05) , in a time-dependent manner. Compared with those in NG group [ (15.83±1.46) %, (105.32±15.78) individual] and pcDNA group [ (16.79±1.46) %, (108.98±16.35) individual], the migration rate [ (37.96±5.80) %, (25.15± 2.19) %] and invasion number [ (327.87±49.18) individual, 206.53±30.97) individual] of A2780 cells, protein expression of CENP-A, N-cadherin, Vimentin, p-PI3K/PI3K, p-AKT/AKT, NF-κB, interleukin (IL-1β) , tumor necrosis factor-α (TNF-α) in pcDNA-CENP-A group and pathway inhibitor group were significantly higher ( P<0.05) , the expression of E-cadherin was significantly lower ( P<0.05) ; compared with those in the pcDNA-CENP-A group, the migration rate and invasion number of A2780 cells, protein expression of CENP-A, N-cadherin, Vimentin, p-PI3K/PI3K, p-AKT/AKT, NF-κB, interleukin (IL-1β) , tumor necrosis factor-α (TNF-α) in pathway inhibitor group were significantly lower ( P<0.05) , and the expression of E-cadherin was significantly higher ( P<0.05) . Conclusion:Overexpression of CENP-A can promote the proliferation, invasion and migration of ovarian cancer cells, which may be achieved by activating PI3K/AKT/NF-κB signaling pathway.

Objective:To investigate the regulatory role of microRNA in radiation-induced heart disease (RIHD) in mice and provide a new strategy for its treatment.Methods:Based on the Gene Expression Omnibus database (GSE147241), which includes normal heart tissue and irradiation heart tissue, we conducted bioinformatics research and analysis to determine the differentially-expressed genes. Then, thirty male C57/BL6 mice were randomly divided into the control group, irradiation group and miR-133a overexpression intervention group. The heart received single dose of X-ray 20 Gy in the irradiation group and miR-133a overexpression intervention group, but not in the control group, and then fed for 16 weeks. Cardiac function was assessed by echocardiography. Myocardial fibrosis was detected by Masson staining. The expression levels of miR-133a, CTGF, COL-1 and COL-3 mRNA were detected by qRT-PCR. The expression levels of CTGF, COL-1 and COL-3 proteins were detected by western blot.Results:miR-133a was the differentially-expressed gene between the irradiation and control groups. Overexpression of miR-133a could mitigate the decrease in cardiac function and increase in myocardial collagen content ( P<0.01). Meantime, overexpression of miR-133a could down-regulate the expression levels of CTGF, COL-1, COL-3 mRNA and protein ( P<0.01). Conclusions:Radiation increases the synthesis of collagen and leads to myocardial fibrosis remodeling. Overexpression of miR-133a can alleviate the radiation-induced myocardial fibrosis.

Objective:To establish the C57BL/6 mouse models of radiation-induced cardiopulmonary dysfunction.Methods:Twenty-four male C57BL/6 mice were randomly divided into the control and irradiation groups. Mice in the irradiation group were irradiated with 20 Gy electron beam and bred for 6 months after irradiation. Cardiac function was assessed using ultrasonography. The partial pressure of oxygen was detected by blood gas analysis. Cell apoptosis was observed by Tunel assay. Myocardial and pulmonary fibrosis was assessed by Masson staining.Results:The LVEF in the irradiation group was (68.60±10.92)%, significantly less compared with (81.75±8.79)% in the control group ( P< 0.01). The apoptotic index of heart in the irraiation group was (23.90±6.60)%, considerably higher than (3.25±3.38)% in the control group ( P< 0.01). The CVF of heart in the irradiation group was (15.42±5.72)%, significantly higher than (1.45±0.64)% in the control group ( P< 0.01). The PaO 2 level in the irradiation group was (86.10±7.60) mmHg, significantly lower compared with (107.16±9.01) mmHg in the control group ( P< 0.01). The apoptotic index of lung in the irradiation group was (27.90±8.94)%, significantly higher than (2.50±3.55)% in the control group ( P<0.01). The CVF of lung in the irradiation group was (17.76±5.77)%, remarkably higher than (2.50±3.55)% in the control group ( P< 0.01). Conclusion:Radiation can induce cardiopulmonary apotosis and fibrosis remodeling, which leads to cardiopulmonary dysfunction, suggesting the successful establishment of C57BL/6 mouse model of radiation-induced cardiopulmonary dysfunction.

Purpose: Gastric cancer (GC) is a malignant tumor with a high mortality rate. Drug resistance is a major obstacle to GC therapy. This study aimed to investigate the role and mechanism of exosomal circPRRX1 in doxorubicin resistance in GC. Materials and Methods: HGC-27 and AGS cells were exposed to different doses of doxorubicin to construct doxorubicin-resistant cell lines. Levels of circPRRX1, miR-3064-5p, and nonreceptor tyrosine phosphatase 14 (PTPN14) were detected by quantitative real-time PCR or Western blot assay. Then, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, transwell,and Western blot assays were used to explore the function of circPRRX1 in GC cells. Interactions among circPRRX1, miR-3064-5p,and PTPN14 were confirmed by dual-luciferase reporter assay. The in vivo function of circPRRX1 was analyzed in a xenograft tumor model. Results: CircPRRX1 was highly expressed in doxorubicin-resistant GC cell lines. Knockdown of circPRRX1 reversed doxorubicin resistance in doxorubicin-resistant GC cells. Additionally, extracellular circPRRX1 was carried by exosomes to spread doxorubicin resistance. CircPRRX1 silencing reduced doxorubicin resistance by targeting miR-3064-5p or regulating PTPN14. In GC patients,high levels of circPRRX1 in serum exosomes were associated with poor responses to doxorubicin treatment. Moreover, depletion of circPRRX1 reduced doxorubicin resistance in vivo. Conclusion CircPRRX1 strengthened doxorubicin resistance by modulating miR-3064-5p/PTPN14 signaling and might be a therapeutic target for GC patients.