ABSTRACT
Objective:To investigate the protective effects of Ghrelin on LPS-induced apoptosis of human alveolar epithelial A549 cells,along with the possible molecular mechanisms.Methods: CCK-8 assay was used to examine the cell viability of A549 treated by LPS.Apoptosis of A549 cells was measured by TUNEL.NO(Nitric oxide)production was detected by NO-specific fluorescent probe 3-Amino,4-aminomethyl-2′,7′-difluoresceindiacetate(DAF-FM DA).Western blot was also performed to examine the expressions of iNOS(inducible nitric oxide synthase),AKT,ERK,p-AKT,p-ERK and apoptotic proteins,such as Bcl-2,Bax,and cleaved caspase-3.Results: LPS exposure impaired cell viability and increased apoptosis of A549 cells significantly in concentration-and time-dependent manners accompanied with increased Bax and cleaved caspase-3 production,coupled with decreased Bcl-2 levels.Meanwhile,LPS promoted iNOS expression and the production of NO.Ghrelin pretreatment ameliorated LPS-caused alterations in the ratio of Bax/Bcl-2 and cleaved caspase-3 expression.TUNEL analysis showed that Ghrelin could decrease the apoptosis induced by LPS in A549(P<0.05).Simultaneously,LPS remarkably decreased the expression of p-AKT and p-ERK in A549 cells,which was abrogated by Ghrelin pretreatment.However,Ghrelin had no significant effect on NO production induced by LPS.Conclusion: Ghrelin reduces LPS-induced apoptosis of human alveolar epithelial cells partly through activating the AKT and ERK pathway,but the level of iNOS derived NO could not be reduced.
ABSTRACT
Objective To determine the diagnostic and assessment value of soluble urokinase plasminogen activator receptor (suPAR) level in septic patients.Methods Totally 82 septic patients in the Department of Intensive Care Unit of The First Affiliated Hospital,Sun Yat-Sen University were prospectively analyzed from June 2013 to March 2014.Another 29 patients with systemic inflammatory response syndrome (SIRS) and 15 healthy subjects served as controls.Septic patients were divided into sepsis group (n =27),severe sepsis group (n =27) and septic shock group (n =28) according to the severity,and there was no significant difference in age and sex among these groups.Measurement of plasma suPAR,serum procalcitonin (PCT) and C-reactive protein (CRP) levels,and calculation of acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) and sequential organ failure assessment (SOFA) score were performed.Comparison of group differences for continuous variables was done by oneway ANOVA or nonparametric Kruskal-Wallis test.Spearman rank correlation analysis was applied to establish the relation between variables.Receiver operating characteristics (ROC) curve was created and area under curve (AUC) was calculated to determine the diagnostic value of these variables in sepsis.Results The levels of plasma suPAR in SIRS group,sepsis group,severe sepsis group,septic shock group,and healthy control group were (8.22±0.61),(11.45±1.12),(12.99±1.28),(15.75± 1.23) and (4.65 ±0.30) ng/mL,respectively.Plasma suPAR levels in SIRS group and sepsis group were higher than that in healthy control group (P ＜ 0.01),and elevated plasma suPAR was accompanied by increased severity of sepsis (P ＜ 0.05).PCT levels of sepsis group (17.66 ± 8.42) ng/mL,severe sepsis group (9.67 ±3.56) ng/mL and septic shock group (29.19 ± 10.78) ng/mL were greater than that in SIRS group (1.10 ± 0.78) ng/mL,P ＜ 0.01.CRP levels elevated in all groups,but there were no significant differences among them.When suPAR and CRP were applied to distinguishing sepsis from SIRS,the AUC values from suPAR and combination of suPAR and PCT were 0.817 (P ＜ 0.01,95 ％ CI:0.714-0.921) and 0.927 (P＜0.01,95％ CI:0.870-0.985),respectively.Using9.52 ng/mL suPAR as the best cut-off to distinguish sepsis from SIRS,there were 71.93％ sensitivity and 95.46％ specificity.The levels of plasma suPAR positively correlated with PCT levels (r =0.326),APACHE Ⅱ score (r =0.492) and SOFA score (r =0.386),P ＜ 0.01.Conclusions Plasma suPAR levels significantly elevated in septic patients and correlated with the severity of sepsis.Sepsis and SIRS may be discerned by plasma suPAR levels.Joint use of suPAR and PCT could greatly increase the specificity of diagnosis of sepsis.