Objective To investigate the effects of dengue type 2 virus(DENV-2)on the apopto-sis and autophagy of primary human hepatic sinusoidal endothelial cells(HHSECs)and the expression of ICAM-1 and Beclin-1 at mRNA level and to analyze the possible pathogenic mechanism of DENV-2. Meth-ods Immunohistochemistry(IHC)and flow cytometry analysis(FCM)were performed to identify HHSECs by detecting factor Ⅷ and CD31. The DENV-2 strain was identified by using PCR and HindⅢ. The 50%tissue culture infective dose(TCID50 )of DENV-2 was calculated after infecting C6 / 36 cells with DENV-2. Dynamic changes of DENV-2 NS1 were measured by real-time PCR after infecting HHSECs with DENV-2. CCK-8 was used to dynamically detect the cytotoxicity of DENV-2 to HHSECs. The transcriptional levers of Beclin-1 and ICAM-1 in DENV-2-infected HHSECs were detected by real-time PCR. FCM was performed to analyze the apoptosis of HHSECs and the expression of LC3B and ICAM-1. Results The cells in the exper-imental group were stained brown by DAB and the positive expression rate of CD31 reached 87. 1% . The TICD50 of DENV-2 to C6 / 36 cells was 10-6. 845 / 0. 1 ml. Compared with the uninfected cells,partial se-quences of NS1 gene were expressed in DENV-2-infected HHSECs. DENV-2 suppressed the cell activities of HHSECs. The suppression rates of DENV-2 to HHSECs at 12 h,24 h,36 h and 48 h were respectively (10. 90±1. 24)% ,(16. 40±0. 42)% ,(17. 00±0. 46)% and(29. 60±0. 26)%(P﹤0. 05). The tran-scriptional levels of Beclin-1 and ICAM-1 in HHSECs were significantly increased at the time point of 24 h after DENV-2 infection,the 2-△△Ct values of which were 46. 77±2. 55 and 40. 97±4. 91,respectively. The expression of LC3B and ICAM-1 in DENV-2-infected HHSECs were increased,the peaks of which were reached at 24 h(14. 7% )and 36 h(35. 5% ),respectively. The apoptosis of DENV-2-infected HHSECs was remarkably enhanced at 12 h with an apoptosis rate of 13. 17% . Conclusion HHSECs was susceptible to DENV-2. DENV-2 induced the upregulation of ICAM-1 and the activation of HHSECs. Moreover,autoph-agy and apoptosis of HHSECs could also be induced by DENV-2.

Objective:To reveal the primary mechanism of changing permeability in DENV-2 infected pHDMECs. Methods:pHDMECs was incubated by DENV-2 on the concentration of 103 TCID50 ,and the penetrability of the cell was detected by Transwell at 4,8,12,24,48 h,respectively. Then,the partial sequence of DENV-2 NS1 was analyzed by Real time-PCR,and NS1 protein was detected by immunofluorescence and flow cytometer (FCM). The apoptosis rate of pHDMECs was assayed by FCM. Finally,IL-6 and IL-8 secreted by pHDMECs were analyzed by Real time-PCR and double antibody sandwich ELISA. Results:The relative expression of NS1 gene was elevated but NS1 protein was not detected;the permeability of DENV-2 infected pHDMECs had dramatically increased both at 24,48 h,but the apoptosis rate has little changed even been influenced by DENV-2 at 72 h. However,the relative expression of IL-6/IL-8 mRNA was boosted at 8,24 h[(2. 49±0. 50) and (6. 82±1. 69) fold,respectively,P<0. 05]. In protein level,compared with control(869. 6±50. 70)pg/ml,IL-6 secreted by DENV-2 infected pHDMECs could reach by(1 248. 8±86. 9)pg/ml(P<0. 05),and IL-8 was(1 331. 0±86. 3)pg/ml(P<0. 05) while the control was (967. 6±156. 6)pg/ml. Conclusion:Indeed,pHDMECs can be infected by DENV-2;the increasing permeability of DENV-2 infected pHDMECs may not be caused by the pHDMECs′ apoptosis but the enhancing of pro-inflammatory cytokine IL-6 /IL-8.

Objective:To evaluate the effect of panaxydol on ventilator-induced lung injury(VILI) in mice, and the relationship with Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor E2-related factor 2 (Nrf2) signaling pathway.Methods:Fifty healthy clean-grade male C57BL/6 mice, aged 6-8 weeks, weighing 20-25 g, were divided into 5 groups ( n=10 each) using a random number table method: control group (group C), VILI group, low-dose panaxydol group (L-PX group, 5 mg/kg), medium-dose panaxydol group (M-PX group, 10 mg/kg) and high-dose panaxydol group (H-PX group, 20 mg/kg). The corresponding doses of panaxydol were intraperitoneally injected for 7 consecutive days once a day in L-PX group, M-PX group and H-PX group. The equal volume of normal saline was given instead in C group and VILI group. Only tracheotomy was performed and animals kept spontaneous breathing for 4 h in group C, and the animals were mechanically ventilated (tidal volume 30 ml/kg, respiratory rate 70 breaths/min, inspiratory/expiratory ratio 1∶2, fraction of inspired oxygen 21%) for 4 h in VILI, L-PX, M-PX and H-PX groups. Blood samples from the femoral artery were collected for arterial blood gas analysis at 4 h of ventilation, and PaO 2 was recorded. The mice were then sacrificed under deep anesthesia, and bronchoalveolar lavage fluid (BALF), lung tissues and serum samples were collected. The concentrations of TNF-α and IL-1β in BALF and serum were measured by enzyme-linked immunosorbent assay. The wet/dry lung weight (W/D) ratio was measured, the protein concentrations in BALF were measured by bicinchoninic acid assay, the pathological changes of lung tissues were examined by HE staining, lung injury was scored, and the level of ROS in lung tissues was detected by DCFH-DA fluorescence probe.The expression of Keap1 and Nrf2 in lung tissues was detected by Western blot. Results:Compared with group C, the PaO 2 was significantly decreased, the lung injury score, W/D ratio, protein concentrations in BALF and concentrations of TNF-α and IL-1β in BALF and serum were increased, the expression of Keap1 and Nrf2 was up-regulated, and the fluorescence of ROS was enhanced in the other four groups ( P<0.05). Compared with group VILI, PaO 2 was significantly increased, the lung injury score was decreased, lung W/D ratio, protein concentrations in BALF, and concentrations of TNF-α and IL-1 β in BALF and serum were decreased, and the fluorescence of ROS was weakened in L-PX, M-PX, and H-PX groups, and the expression of Keap1 was down-regulated, the fluorescence of ROS was weakened, and the expression of Nrf2 was up-regulated in M-PX and H-PX groups ( P<0.05). Compared with group L-PX, PaO 2 was significantly increased, the lung injury score, W/D ratio, protein concentrations in BALF and concentrations of TNF-α and IL-1β in BALF were decreased, the expression of Keap1 was down-regulated, and the expression of Nrf2 was up-regulated and the fluorescence of ROS was weakened in M-PX and H-PX groups ( P<0.05). Compared with group M-PX, PaO 2 was significantly increased, the lung injury score, W/D ratio, protein concentrations in BALF and concentrations of TNF-α and IL-1β in BALF were decreased, the expression of Keap1 was down-regulated, the expression of Nrf2 was up-regulated, and the fluorescence of ROS was weakened in H-PX group( P<0.05). Conclusions:Panaxydol can reduce VILI in mice, and the mechanism may be related to activation of the Keap1/Nrf2 signaling pathway and inhibition of oxidative stress.