ABSTRACT
<p><b>OBJECTIVE</b>To explore the role of the interaction between glycogen synthase kinase-3β (GSK-3β) and endoplasmic reticulum stress (ERS) in the high glucose (HG)-induced injury in human umbilical vein endothelial cells (HUVECs).</p><p><b>METHODS</b>HUVECs treated with 40 mmol/L glucose for 24 h were examined for expression levels of GSK-3β, GRP78, CHOP and cleaved caspase-3 protein using Western blotting. The cell viability was examined using CCK-8 assay and cell apoptosis was detected with Hoechst 33258 nuclear staining and photofluorography. The intracellular level of reactive oxygen species (ROS) was measured with dichlorfluoresein staining and photofluorography. Mitochondrial membrane potential (MMP) was tested by rhodamine 123 (Rh123) staining and photofluorography.</p><p><b>RESULTS</b>Treatment of HUVECs with 40 µmol/L glucose for 3-24 h activated GSK-3β in a time-dependent manner, leading to significantly down-regulated expression of phosphorylated (p)-GSK-3β (P<0.05). HG exposure of the cells for 1-24 h induced ERS, evidenced by time-dependently up-regulated expression of GRP78 and CHOP (P<0.05). LiCl, an inhibitor of GSK-3β, attenuated HG-induced ERS and significantly lowered the expression levels of GRP78 and CHOP (P<0.01). 4-PBA, an inhibitor of ERS, obviously ameliorated the activation of GSK-3β by HG as shown by the increase in p-GSK-3β expression level (P<0.01). HG exposure for 24 h induced obvious injuries in HUVECs, which exhibited decreased cell viability, increased cell apoptosis, increased expression of cleaved caspase-3 and ROS generation, and loss of MMP. Pretreatment of the cells with LiCl or 4-PBA for 60 min before HG exposure significantly lessened the cell injuries (P<0.01).</p><p><b>CONCLUSION</b>Interactions between GSK-3β and ERS occur in HUVECs exposed to HG and participate in HG-induced cell injuries.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To explore whether angiotensin-(1-7) [Ang-(1-7)] protects cardiac myocytes against high glucose (HG)-induced injury by inhibiting ClC-3 chloride channels.</p><p><b>METHOD</b>H9c2 cardiac cells were exposed to 35 mmol/L glucose for 24 h to establish a cell injury model. The cells were treated with Ang-(1-7) or the inhibitor of chloride channel (NPPB) in the presence of HG for 24 h to observe the changes in HG-induced cell injury. Cell counter kit 8 (CCK-8) assay was used to test the cell viability, and the morphological changes of the apoptotic cells were detected using Hoechst 33258 staining and fluorescent microscopy. The intracellular level of reactive oxygen species (ROS) was examined by DCFH-DA staining, SOD activity in the culture medium was measured using commercial kits, and the mitochondrial membrane potential (MMP) of the cells was tested with rodamine 123 staining. The expression level of cardiac ClC-3 chloride channels was detected with Western blotting.</p><p><b>RESULTS</b>Exposure of H9c2 cardiac cells to 35 mmol/L glucose for 24 h markedly enhanced the expressions of cardiac ClC-3 channel protein (P<0.01). Co-treatment of the cells with 1 µmol/L Ang-(1-7) and HG for 24 h significantly attenuated HG- induced upregulation of ClC-3 channel protein expression (P<0.01). Co-treatment of the cells exposed to HG with 1 µmol/L Ang-(1-7) or 100 µmol/L NPPB for 24 h obviously ameliorated HG-induced injuries as shown by increased cell viability, enhanced SOD activity, decreased number of apoptotic cells, and reduced intracellular ROS generation and loss of MMP (P<0.01).</p><p><b>CONCLUSION</b>ClC-3 channels are involved in HG-induced injury in cardiac cells. Ang-(1-7) protects cardiac cells against HG-induced injury by inhibiting ClC-3 channels.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the risk factors of pulmonary fungal infections related to mechanical ventilation and the prognosis of patients.</p><p><b>METHODS</b>A retrospective case-controlled study was conducted to analyze the culture results of the pulmonary secretions in patients with pulmonary fungal and nonfungal infections in association with mechanical ventilations. The risk factors of pulmonary fungal infections related to mechanical ventilation were identified and their impact on the clinical outcome of the patients was evaluated.</p><p><b>RESULTS</b>Of the 127 patients included in this study, 81 (63.78%) were positive and 46 (36.22%) negative for pulmonary fungal infections according to the diagnostic criteria of ventilator-associated pneumonia (VAP). The mortality of the patients with fungal infection was 82.7%, significantly higher than that of patients with non-fungal infection (67.39%, chi2=3.910, P<0.05). Univariate analysis and multivariate logistic regression showed that such factors as old age, duration of mechanical ventilation, tracheal intubation or incision for over 7 days, diabetes, blood glucose over 6.1 mmol/L, multi-organ dysfunction, combined use of antibiotics, at least 3-time changes antibiotics, administration of glucocorticosteroid for over 7 days, and immunodepressant use were all the independence risk factors of pulmonary fungal infection related to mechanical ventilation. Old age, multi-organ dysfunction, blood glucose over 6.1 mmol/L, glucocorticosteroid use for over 7 days, anesthetic use for over 3 days and high APACHE III scores were the risk factors for mortality in patients with the infections.</p><p><b>CONCLUSIONS</b>Pulmonary fungal infection associated to mechanical ventilation is often the results of presence of multiple risk factors, and early identification of these factors for timely antifungal treatment may improve the prognostics of the patients and help reduce the mortality rate.</p>