Risk model for predicting mortality in patients with necrotizing soft tissue infections in the intensive care unit.

BACKGROUND: The goal of this study is to look into the factors that lead to death in patients with necrotizing soft tissue infections（NSTIs） in the intensive care unit and create a mortality risk model. METHODS: The clinical data of 106 patients with necrotizing soft tissue infections admitted to intensive care unit(ICU) of the First Affiliated Hospital of Wenzhou Medical University between January 2008 and December 2021 were retrospectively analyzed. Univariate analysis and multivariate analysis were performed to evaluate the risk factors impacting patient mortality. The regression coefficient in binary logistic regression analysis was converted into the item score in the model, and then the model score of each patient was calculated. Finally, an ROC curve was constructed to evaluate the efficiency of the model for predicting mortality. Thirteen patients with NSTIs admitted to ICU between January 2022 and November 2022 were used to validate the model. RESULTS: The death group had 44 patients, while the survival group had 62 patients. The overall mortality was 41.5%. Binary logistic regression analysis showed that risk factors for mortality were age≥ 60 years(OR:4.419; 95%CI:1.093-17.862; P = 0.037), creatinine ≥ 132µmol/L(OR:11.166; 95%CI:2.234-55.816; P = 0.003), creatine kinase ≥ 1104 U/L(OR:4.019; 95%CI:1.134-14.250; P = 0.031), prothrombin time ≥ 24.4 s(OR:11.589; 95%CI:2.510-53.506; P = 0.002), and invasive mechanical ventilation (OR:17.404; 95%CI:4.586-66.052; P＜0.000). The AUC of the model for predicting mortality was 0.940 (95% CI:0.894-0.986). When the cut-off value for the model was 4 points, the sensitivity was 95.5% and the specificity was 83.9%. CONCLUSION: The death risk model in this study for NSTIs patients in the intensive care unit shows high sensitivity and specificity. Patients with a score of ≥ 4 points have a higher risk of mortality.

A New Nomogram for Predicting 30-Day In-Hospital Mortality Rate of Acute Cholangitis Patients in the Intensive Care Unit.

Purpose: Acute cholangitis (AC) is a widespread acute inflammatory disease and the main cause of septic shock, which has a high death rate in hospitals. At present, the prediction models for short-term mortality of AC patients are still not ideal. We aimed at developing a new model that could forecast the short-term mortality rate of AC patients. Methods: Data were extracted from the Medical Information Mart for Intensive Care IV version 2.0 (MIMIC-IV v2.0). There were a total of 506 cases of AC patients that were included. Patients were given a 7 : 3 split between the training set and the validation set after being randomly assigned to one of the groups. Multivariate logistic regression was used to create an AC patient predictive nomogram for 30-day mortality. The overall efficacy of the model is evaluated using the area under the receiver operating characteristic curve (AUC), the calibration curve, the net reclassification improvement (NRI), the integrated discrimination improvement (IDI), and a decision curve analysis (DCA). Results: Out of 506 patients, 14.0% (71 patients) died. The training cohort had 354 patients, and the validation cohort had 152 patients. GCS, SPO2, albumin, AST/ALT, glucose, potassium, PTT, and peripheral vascular disease were the independent risk factors according to the multivariate analysis results. The newly established nomogram had better prediction performance than other common scoring systems (such as SOFA, OASIS, and SAPS II). For two cohorts, the calibration curve demonstrated coherence between the nomogram and the ideal observation (P > 0.05). The clinical utility of the nomogram in both sets was revealed by decision curve analysis. Conclusion: The novel prognostic model was effective in forecasting the 30-day mortality rate for acute cholangitis patients.

Development of a Novel Nomogram Incorporating Red Blood Cell Distribution Width-Albumin Ratio for the Prediction of 30-day Mortality in Acute Pancreatitis Patients.

Purpose: The available nomograms used to predict acute pancreatitis (AP) are not comprehensive. We sought to investigate the effect of red blood cell distribution width (RDW)-albumin ratio (RA) on prognosis of patients with AP and develop a new nomogram to identify AP patients at high risk for mortality. Methods: We used data from the Medical Information Mart for Intensive Care IV version 2.0 (MIMIC-IV v2.0). A total of 487 patients with acute pancreatitis were included. Patients enrolled in the study were randomly assigned to the training set and validation set at a 7 : 3 ratio. According to the 30-day mortality rate, the data were divided into a survival group and a death group. Multivariate logistic regression was used to establish a prognostic nomogram for predicting the 30-day mortality in AP patients. The area under the receiver operating characteristic curve (AUC), calibration curve, the net reclassification improvement (NRI), the integrated discrimination improvement (IDI), and a decision curve analysis (DCA) are used to verify the overall performance of the model. Results: Among 487 patients, 54 patients died (11.1%). 338 patients were assigned to the training cohort and 149 were assigned to the validation cohort. The multivariate analysis results showed that RA, age, heart rate, temperature, AST/ALT, BUN, hemoglobin, potassium, and bilirubin were independent risk factors. The prediction performance of the newly established nomogram was better than those of other common scoring systems (including SOFA, OASIS, and APSIII). The nomogram suggests that RA (OR = 1.706, 95% CI: 1.367-2.185) is the most significant laboratory test indicator influencing prognosis. Conclusion: The new nomogram incorporating RA performed well in predicting AP short-term mortality. A prospective study with a larger sample is needed to validate our findings.

Vesicle transport related protein Synaptotagmin-1 mediates paraquat transport to antagonize paraquat toxicity.

In this study, A549/PQ cells with moderate resistance to paraquat (PQ) were obtained by treating A549 cells with PQ, their growth rate was slowed down, the accumulation concentration of PQ and the levels of growth inhibition, injury and early apoptosis induced by PQ were significantly lower than those of parental A549 cells. Microarray screening and RT-qPCR detection found that Synaptotagmin-1 (SYT1) expression in drug-resistant cells was significantly increased, and PQ further enhanced its expression. After inhibiting SYT1 expression in A549/PQ cells, cell viability, intracellular PQ concentration and the expression of Bcl-2, SNAP25 and RAB26 were significantly reduced, while the mortality, early apoptosis rate and Bax expression were significantly increased. In vivo experiments also further showed that PQ promoted the expression of SYT1, SNAP25 and RAB26 in PQ-poisoned mice; when inhibiting SYT1 expression, PQ concentration in lung tissues was significantly increased, and the levels of lung injury and apoptosis were also significantly enhanced, while the expression of SNAP25 and RAB26 was significantly reduced. This indicates that PQ poisoning leads to compensatory up-regulation of vesicle transport related proteins such as SYT1 in vivo, thereby promoting PQ transmembrane transport, and then reducing the pulmonary accumulation of PQ and PQ-caused lung injury.

CD71+ Erythroid Cell Expansion in Adult Sepsis: Potential Causes and Role in Prognosis and Nosocomial Infection Prediction.

BACKGROUND: Immune suppression contributes to nosocomial infections (NIs) and poor prognosis in sepsis. Recent studies revealed that CD71+ erythroid cells had unappreciated immunosuppressive functions. This study aimed to investigate the values of CD71+ erythroid cells (CECs) in predicting NIs and prognosis among adult septic patients. The potential factors associated with the expansion of CECs were also explored. METHODS: In total, 112 septic patients and 32 critically ill controls were enrolled. The frequencies of CD71+ cells, CD71+CD235a+ cells, and CD45+ CECs were measured by flow cytometry. The associations between CECs and NIs and 30-day mortality were assessed by ROC curve analysis and Cox and competing-risk regression models. Factors associated with the frequency of CECs were identified by linear regression analysis. RESULTS: The percentage of CD71+ cells, CECs, and CD45+ CECs were higher in septic patients than critically ill controls. In septic patients, the percentages of CD71+ cells, CECs, and CD45+ CECs were associated with NI development, while CD71+ cells and CECs were independently associated with 30-day mortality. Linear regression analysis showed that the levels of interleukin (IL)-6 and interferon (IFN)-γ were positively associated with the frequencies of CD71+ cells, CECs, and CD45+ CECs, while IL-10 was negatively associated with them. Additionally, the levels of red blood cells (RBCs) were negatively associated with the percentage of CD45+ CECs. CONCLUSIONS: CECs were expanded in sepsis and can serve as independent predictors of the development of NI and 30-day mortality. Low levels of RBCs and high levels of IL-6 and IFN-γ may contribute to the expansion of CECs in sepsis. TRIAL REGISTRATION: ChiCTR, ChiCTR1900024887. Registered 2 August 2019, http://www.chictr.org.cn/showproj.aspx?proj=38645.

Arterial oxygen pressure targets in critically ill patients: Analysis of a large ICU database.

BACKGROUND: Providing supplemental oxygen is common in the management of critically ill patients, yet the optimal oxygen regimen remains unclear. OBJECTIVES: To explore the optimal range of PaO2 in critically ill patients. METHODS: This is a retrospective study conducted in the Medical Information Mart for Intensive Care III (MIMIC-III) database. The patients with a least 48 h of oxygen therapy were included. Nonlinear regression was used to analyze the association between PaO2 and mortality. We derived an optimal range of PaO2 and evaluated the association between the proportion of PaO2 measurements within this range and mortality. RESULTS: In total, 8401 patients were included in the study. A J-shaped relationship was observed between median PaO2 and hospital mortality. Compared with the reference group of 100-120 mmHg, patients with values of 80-100 mmHg and 120-140 mmHg had higher hospital mortality (adjusted odds ratio [aOR], 1.23; 95% CI, 1.05-1.43 and 1.29; 95%CI, 1.08-1.54, respectively). Similarly, mortality rates were significantly higher for PaO2 <80 mmHg and ≥140 mmHg (aOR, 1.97; 95%CI, 1.58-2.45 and 1.42; 95%CI, 1.19-1.69, respectively). Patients spent a greater proportion of time within 100-120 mmHg tended to have a lower mortality rate. CONCLUSION: Among critically ill patients, the relationship between median PaO2 and hospital mortality was J-shaped. The lowest rates of mortality was observed in those with PaO2 levels within 100 to 120 mmHg.

Association between furosemide administration and outcomes in critically ill patients with acute kidney injury.

BACKGROUND: Although current guidelines for AKI suggested against the use of furosemide in AKI management, the effect of furosemide on outcomes in real-world clinical settings remains uncertain. The aim of the present study was to investigate the association between furosemide administration and outcomes in critically ill patients with AKI using real-world data. METHODS: Critically ill patients with AKI were identified from the Medical Information Mart for Intensive Care (MIMIC)-III database. Propensity score (PS) matched analysis was used to match patients receiving furosemide to those without diuretics treatment. Linear regression, logistic regression model, and Cox proportional hazards model were used to assess the associations between furosemide and length of stay, recovery of renal function, and in-hospital and 90-day mortality, respectively. RESULTS: A total of 14,154 AKI patients were included in the data analysis. After PS matching, 4427 pairs of patients were matched between the patients who received furosemide and those without diuretics treatment. Furosemide was associated with reduced in-hospital mortality [hazard ratio (HR) 0.67; 95% CI 0.61-0.74; P < 0.001] and 90-day mortality [HR 0.69; 95% CI 0.64-0.75; P < 0.001], and it was also associated with the recovery of renal function [HR 1.44; 95% CI 1.31-1.57; P < 0.001] in over-all AKI patients. Nevertheless, results illustrated that furosemide was not associated with reduced in-hospital mortality in patients with AKI stage 0-1 defined by UO criteria, AKI stage 2-3 according to SCr criteria, and in those with acute-on-chronic (A-on-C) renal injury. CONCLUSIONS: Furosemide administration was associated with improved short-term survival and recovery of renal function in critically ill patients with AKI. Furosemide was especially effective in patients with AKI UO stage 2-3 degree. However, it was not effective in those with AKI SCr stage 2-3 and chronic kidney disease. The results need to be verified in randomized controlled trials.

Nrf2 overexpression protects against paraquat-induced A549 cell injury primarily by upregulating P-glycoprotein and reducing intracellular paraquat accumulation.

Paraquat (PQ) intoxication causes thousands of mortalities every year, worldwide. Its pulmonary-targeted accumulation and the acute lung injury it subsequently causes, remain a challenge for detoxification treatment. A previous study has demonstrated that the upregulation of nuclear factor erythroid-2 related factor 2 (Nrf2) prevents PQ toxicity in cell line and murine models. As Nrf2 target genes include a group of membrane transporters, the current study assessed the protective mechanism exerted by Nrf2 against PQ toxicity and intracellular PQ accumulation via its effects on P-glycoprotein (P-gp), a downstream transporter of Nrf2. Adenovirus vectors containing the Nrf2 gene were transfected into A549 cells. Cell proliferation was assessed by Cell Counting Kit-8. The levels of LDH, MDA, SOD, TNF-α, IL-6 levels were detected using their respective ELISA kits. In addition, the levels of Nrf2 and P-gp protein expression were detected by western blot analysis. The concentration of PQ was measured by HPLC. The results revealed that overexpressed Nrf2 significantly increased P-gp protein levels, decreased the intracellular accumulation of PQ and attenuated PQ-induced toxicity. However, the protective effects of Nrf2 overexpression on PQ-challenged A549 cells were abrogated following cyclosporine A treatment, a competitive inhibitor of P-gp, which also increased intracellular PQ levels. These data indicated that Nrf2 gene overexpression prevented PQ toxicity in A549 cells, potentially via the upregulation of P-gp activity and the inhibition of intracellular PQ accumulation. Thus, Nrf2 and P-gp may serve as potential therapeutic targets for the treatment of PQ-induced injury.

Partial Depletion of Regulatory T Cells Enhances Host Inflammatory Response Against Acute Pseudomonas aeruginosa Infection After Sepsis.

Immune dysfunction contributes to secondary infection and worse outcomes in sepsis. Regulatory T cells (Tregs) have been implicated in sepsis-induced immunosuppression. Nevertheless, the role of Tregs in secondary infection after sepsis remains to be determined. In the present study, a two-hit model which mimics clinical conditions was used and the potential role of Tregs in secondary Pseudomonas aeruginosa infection post-sepsis was investigated. Results showed that mice were susceptible to secondary P. aeruginosa infection 3 days, but not 7 days, post-cecal ligation and puncture (CLP). The levels of IL-17A, IL-1ß, and IL-6 remained low in CLP mice after P. aeruginosa infection, while the levels of IL-10 increased significantly. Additionally, increased number of Tregs in both lung and spleen was observed in "two-hit" mice. Injection with PC61 (anti-CD25) mAb reduced the number of Tregs by 50% in spleen and 60% in lung of septic mice. This partial depletion of Tregs elevated IL-17A, IL-1ß, and IL-6 production and decreased IL-10 levels in septic mice with P. aeruginosa infection, leading to lower bacterial load, attenuation of lung injury, and improvement of survival. The present findings demonstrate that Tregs play a crucial role in secondary P. aeruginosa infection after sepsis by modulating the inflammatory response.

Role of the Ca2+-Calcineurin-Nuclear Factor of Activated T cell Pathway in Mitofusin-2-Mediated Immune Function of Jurkat Cells.

BACKGROUND: Mitofusin-2 (MFN2), a well-known mitochondrial fusion protein, has been shown to participate in innate immunity, but its role in mediating adaptive immunity remains poorly characterized. In this study, we explored the potential role of MFN2 in mediating the immune function of T lymphocytes. METHODS: We manipulated MFN2 gene expression in Jurkat cells via lentiviral transduction of MFN2 small interfering RNA (siRNA) or full-length MFN2. After transduction, the immune response and its underlying mechanism were determined in Jurkat cells. One-way analysis of variance and Student's t-test were performed to determine the statistical significance between the groups. RESULTS: Overexpression of MFN2 enhanced the immune response of T lymphocytes by upregulating Ca2+ (359.280 ± 10.130 vs. 266.940 ± 10.170, P = 0.000), calcineurin (0.513 ± 0.014 vs. 0.403 ± 0.020 nmol/L, P = 0.024), and nuclear factor of activated T cells (NFATs) activation (1.040 ± 0.086 vs. 0.700 ± 0.115, P = 0.005), whereas depletion of MFN2 impaired the immune function of T lymphocytes by downregulating Ca2+ (141.140 ± 14.670 vs. 267.060 ± 9.230, P = 0.000), calcineurin (0.054 ± 0.030 nmol/L vs. 0.404 ± 0.063 nmol/L, P = 0.000), and NFAT activation (0.500 ± 0.025 vs. 0.720 ± 0.061, P = 0.012). Furthermore, upregulated calcineurin partially reversed the negative effects of MFN2 siRNA on T cell-mediated immunity evidenced by elevations in T cell proliferation (1.120 ± 0.048 vs. 0.580 ± 0.078, P = 0.040), interleukin-2 (IL-2) production (473.300 ± 24.100 vs. 175.330 ± 12.900 pg/ml, P = 0.000), and the interferon-γ/IL-4 ratio (3.080 ± 0.156 vs. 0.953 ± 0.093, P = 0.000). Meanwhile, calcineurin activity inhibitor depleted the positive effects of overexpressed MFN2 on T cells function. CONCLUSIONS: Our findings suggest that MFN2 may regulate T cell immune functions primarily through the Ca2+-calcineurin-NFAT pathway. MFN2 may represent a potential therapeutic target for T cell immune dysfunction-related diseases.

Ethyl pyruvate reverses development of Pseudomonas aeruginosa pneumonia during sepsis-induced immunosuppression.

Sepsis is characterized by an innate immune response and the following immune dysfunction which can increase the emergence of secondary infections. Ethyl pyruvate (EP) has multiple immunoregulation functions in several serious illnesses, such as burn injury, severe sepsis and acute respiratory syndrome. However, little data was shown the effect of EP administration on immunosuppression post-CLP and the following secondary infection. The cecal ligation and puncture (CLP) followed by the induction of Pseudomonas aeruginosa (PA) was used as a clinically relevant two-hit model of sepsis. We assessed the survival rate, lung damage and lung bacterial clearance in vehicle or EP treatment group to demonstrate the lung response to Pseudomonas aeruginosa of septic mice. Then cytokines including lung IL-6, IL-1ß, IL-10 and plasma HMGB1, apoptosis of splenic immune cells and Foxp3 level on regulatory T cells (Tregs) were studied to demonstrate the mechanisms of EP administration on two-hit mice. We found that the susceptibility of septic mice to Secondary Pseudomonas aeruginosa pneumonia could be down-regulated by ethyl pyruvate treatment and the protective effects of EP may via decreasing lung IL-10 and plasma HMGB1 expression, inhibiting the function of Tregs and relieving the apoptosis of splenic immune cells. The "immune paralysis" post-sepsis still remains a rigorous challenge for curing sepsis, our study may aid in the development of new therapeutic strategies to this problem.

Growth Arrest-Specific 6 Enhances the Suppressive Function of CD4+CD25+ Regulatory T Cells Mainly through Axl Receptor.

Background. Growth arrest-specific (Gas) 6 is one of the endogenous ligands of TAM receptors (Tyro3, Axl, and Mertk), and its role as an immune modulator has been recently emphasized. Naturally occurring CD4+CD25+ regulatory T cells (Tregs) are essential for the active suppression of autoimmunity. The present study was designed to investigate whether Tregs express TAM receptors and the potential role of Gas6-TAM signal in regulating the suppressive function of Tregs. Methods. The protein and mRNA levels of TAM receptors were determined by using Western blot, immunofluorescence, flow cytometry, and RT-PCR. Then, TAM receptors were silenced using targeted siRNA or blocked with specific antibody. The suppressive function of Tregs was assessed by using a CFSE-based T cell proliferation assay. Flow cytometry was used to determine the expression of Foxp3 and CTLA4 whereas cytokines secretion levels were measured by ELISA assay. Results. Tregs express both Axl and Mertk receptors. Gas6 increases the suppressive function of Tregs in vitro and in mice. Both Foxp3 and CTLA-4 expression on Tregs are enhanced after Gas6 stimulation. Gas6 enhances the suppressive activity of Tregs mainly through Axl receptor. Conclusion. Gas6 has a direct effect on the functions of CD4+CD25+Tregs mainly through its interaction with Axl receptor.

Mitofusin 2 Promotes Apoptosis of CD4+ T Cells by Inhibiting Autophagy in Sepsis.

Apoptosis of CD4+ T cells is a primary pathophysiological mechanism of immune dysfunction in the pathogenesis of sepsis. Mitofusin 2 (Mfn2), an integral mitochondrial outer membrane protein, has been confirmed to be associated with cellular metabolism, proliferation, and apoptosis. The function of Mfn2 in CD4+ T cell apoptosis in sepsis is poorly understood. Here, we discovered increased in vivo Mfn2 expression, autophagy deficiency, and elevated cell apoptosis in murine splenic CD4+ T cells after cecal ligation and puncture (CLP). We also observed almost identical results in splenic CD4+ T cells upon lipopolysaccharide (LPS) stimulation in vitro. Furthermore, overexpression of Mfn2 resulted in impaired autophagy and increased apoptosis in Jurkat cells. Pharmacological inhibition of autophagy with 3-methyladenine enhanced Mfn2 overexpression-induced cell apoptosis. In addition, overexpression of Mfn2 downregulated phorbol myristate acetate (PMA)/ionomycin-, rapamycin- and starvation-induced autophagy in Jurkat T cells. Taken together, these data indicate a critical role of Mfn2 in CD4+ T cell apoptosis in sepsis and the underlying mechanism of autophagy deficiency.

Incidence, risk factors and impact on outcomes of secondary infection in patients with septic shock: an 8-year retrospective study.

Secondary infection in septic patients has received widespread attention, although clinical data are still lacking. The present study was performed on 476 patients with septic shock. Time trends for mortality were analyzed using Spearman's rank correlation test. Risk factors for secondary infection were investigated by binary logistic regression. The extended Cox model with time-varying covariates and hazard ratios (HR) was performed to determine the impact of secondary infection on mortality. Differences in hospital length of stay (LOS) between patients with and without secondary infection were calculated using a multistate model. Thirty-nine percent of septic shock patients who survived the early phase of the disease developed secondary infection. There was a statistically significant increased odds ratio for secondary infection in older patients and patients with a longer LOS in the intensive care unit (ICU), a higher Sequential Organ Failure Assessment (SOFA) score, and endotracheal intubation. Secondary infection significantly reduced the rate of discharge (HR 5.607; CI95 3.612-8.704; P < 0.001) and was associated with an increased hospital LOS of 5.46 days. The present findings represent a direct description of secondary infection in septic shock patients and highlight the influence of this condition on septic shock outcomes.

SIRT1 exerts protective effects against paraquat-induced injury in mouse type II alveolar epithelial cells by deacetylating NRF2 in vitro.

Silent information regulator 2-related enzyme 1 (SIRT1), a protein deacetylase, is known to strongly protect cells against oxidative stress-induced injury. The nuclear factor E2-related factor 2 (NRF2)-antioxidant response element (ARE) antioxidant pathway plays important regulatory roles in the antioxidant therapy of paraquat (PQ) poisoning. In the present study, we investigated whether the SIRT1/NRF2/ARE signaling pathway plays an important role in lung injury induced by PQ. For this purpose, mouse type II alveolar epithelial cells (AECs­II) were exposed to various concentrations of PQ. The overexpression or silencing of SIRT1 was induced by transfecting the cells with a SIRT1 overexpression vector or shRNA targeting SIRT1, respectively. The protein expression levels of SIRT1 and NRF2 were measured by western blot analysis. The superoxide dismutase (SOD) and catalase (CAT) activities, as well as the glutathione (GSH) and malondialdehyde (MDA) levels were measured using respective kits. Heme oxygenase-1 (HO-1) activity was also determined by ELISA. In addition, cell apoptosis was determined by flow cytometry. The protein stability of NRF2 was analyzed using cycloheximide and its acetylation in the cells was also determined. The following findings were obtained: i) SIRT1 overexpression markedly increased NRF2 protein expression; ii) SIRT1 promoted the transcriptional activity of NRF2 and upregulated the expression of the NRF2 downstream genes, SOD, CAT, GSH and HO-1, thus inhibiting the apoptosis of AECs­II; iii) the inhibition of SIRT1 activity further induced the production of malondialdehyde (MDA), which resulted in increased oxidative damage; iv) SIRT1 promoted the stability of NRF2 by regulating the deacetylation and activation of the NRF2/ARE antioxidant pathway. The findings of this study demonstrate that the protective effects of SIRT1 are associated with the activation of the NRF2/ARE antioxidant pathway in lung injury induced by PQ poisoning.

PROGNOSTIC VALUE OF PLASMA TIGHT-JUNCTION PROTEINS FOR SEPSIS IN EMERGENCY DEPARTMENT: AN OBSERVATIONAL STUDY.

BACKGROUND: Studies have illustrated that the breakdown of tight junction (TJ) contributed to an increase in vascular permeability in response to stimulation of inflammatory cytokines. Additionally, the release of TJ-associated proteins into the circulation was observed in many diseases. The present study was designed to investigate whether plasma levels of TJ-associated proteins could serve as predictors of severity and clinical outcome of sepsis. METHODS: In total, 51 septic patients were enrolled. The peripheral blood samples were collected for each patient on emergency department arrival. Plasma levels of occludin (OCLN), claudins (CLDN)-5, and zonula occludens (ZO)-1 and serum levels of procalcitonin (PCT) and lactate were measured. In addition, APACHE II score as well as SOFA score was calculated. The prognostic values of OCLN, CLDN-5, and ZO-1 were compared with the first 24-h maximum APACHE II score and SOFA score. RESULTS: The median levels of OCLN and ZO-1 were elevated with sepsis severity. The levels of plasma OCLN and ZO-1 were positively correlated with APACHE II score, SOFA score as well as lactate levels of the patients. The levels of ZO-1 revealed valuable diagnostic capacity to diagnose MODS, and the areas under the receiver-operating characteristic (AUC) curves of ZO-1 were similar to those of lactate levels, but better than those of PCT levels. The prognostic value for in-hospital mortality of ZO-1 was comparable to that of lactate levels, APACHE II score, and SOFA score, and superior to OCLN or PCT. CONCULSIONS: OCLN and ZO1 levels appear to be early prognostic markers in patients suffering from sepsis.

Protective Effects of Growth Arrest-Specific Protein 6 (Gas6) on Sepsis-Induced Acute Kidney Injury.

Acute kidney injury (AKI) is a serious complication of sepsis, which has a high mortality rate. Growth arrest-specific protein 6 (Gas6), the protein product of the growth arrest specific gene 6, has been shown to have an anti-apoptotic effect as well as pro-survival capability. Here, we investigated the effects of Gas6 on sepsis-associated AKI in mice subjected to cecal ligation and puncture (CLP). We found that the administration of rmGas6 significantly reduced serum urea nitrogen and creatinine and improved the survival of septic mice. Furthermore, the renal pathological damage induced by CLP was attenuated by rmGas6 treatment. Finally, rmGas6 reduced the renal tissue apoptotic index and the expression of Bax, while it upregulated the expression of Bcl-2. The data suggest that rmGas6 might be used as a potential therapeutic agent for sepsis-induced AKI.

Cycloartenyl Ferulate Inhibits Paraquat-Induced Apoptosis in HK-2 Cells With the Involvement of ABCC1.

Nephrotoxicity induced by chemicals such as paraquat (PQ) is a common clinical phenomenon; therefore, searching for drugs with renal protective effect is of a great practical significance. Our previous investigation found that cycloartenyl ferulate (CF) can antagonize the cytotoxic effect of PQ, and recent studies also revealed a variety of bioactivities of CF. However, specific molecular mechanisms underlying the protective effect of CF have not been explored yet. HPLC detection of PQ content indicated that CF reduced PQ accumulation in HK-2 cells and thereby improved cell survival. Western blot results showed that both PQ and CF did not affect the expression of ABCB1; however, while PQ suppressed the expression of ABCC1, CF upregulated ABCC1 expression and thereby reversed the inhibitory effect of PQ on ABCC1 expression. Meanwhile, HK-2 cells did not express ABCG2. When the expression of ABCC1 was knocked down with siRNA, the inhibitory effect of CF on intracellular PQ accumulation was blocked. Further flow cytometric analysis showed that while PQ significantly induced the appearance of sub-G1 apoptotic peak in cells, CF evidently inhibited apoptosis. TUNEL-DAPI double-staining also detected that PQ significantly induced the occurrence of DNA fragmentation in cells, whereas CF effectively inhibited the effect of PQ. Further results showed that ABCC1 siRNA effectively abolished the protective effect of CF on PQ-induced apoptosis. Taken together, these data demonstrated that in HK-2 cells, CF could antagonize PQ-induced toxicity with the involvement of regulatiion of ABCC1 protein expression, which provides a new strategy for treatments of nephrotoxicity.

Septic shock due to community-acquired Pseudomonas aeruginosa necrotizing fasciitis: A case report and literature review.

Necrotizing fasciitis is a rare but fatal infection, characterized by the rapid progression of necrosis of the fascia, skin, soft tissue and muscle. The most common bacteria associated with necrotizing fasciitis is group A streptococcus, although other pathogens have also been implicated. In the present study, a case of community-acquired necrotizing fasciitis, complicated with septic shock and multiple organ dysfunction syndromes due to Pseudomonas aeruginosa, is presented. Despite intensive medical treatment, the condition of the patient deteriorated rapidly and the patient subsequently succumbed to multiple organ failure. In view of the rapid progression and high mortality rate of this disease, early surgery, as well as novel therapeutic approaches for septic shock are required to improve the outcome for patients.

Role of mitofusin-2 in high mobility group box-1 protein-mediated apoptosis of T cells in vitro.

BACKGROUND: High mobility group box-1 protein (HMGB1), a ubiquitous nuclear protein, which is recognized as a danger-associated molecular pattern (DAMP) triggering activation of the innate immune system. Previous studies have shown that HMGB1 also plays a role in T cell-mediated immunity, but the effect of HMGB1 on apoptosis of T cells and its precise mechanism remain to be determined. METHODS: Two kinds of apoptosis assay techniques were used, i.e., Annexin V-FITC conjunction with PI to identify early apoptotic cells, Hoechst 33342 staining for double-stranded DNA to observe nuclear fragmentation or apoptotic body. The activation status of caspase-3, caspase-8, as well as caspase-9 was examined by colorimetric assay. The dynamic changes in intracellular calcium concentration ([Ca(2+)]i) was monitored by flow cytometry. Overexpression of Mfn2 was preformed by lentiviral vector transfection. The mRNA and protein levels of Mfn2 were determined by RT-PCR and Western-blotting. RESULTS: Treatment of Jurkat T cells with recombinant human HMGB1 (rhHMGB1) causes a significant dose-dependent increase in percentage of apoptotic cells. When T cells are incubated with HMGB1 they express decreased mitochondria fusion-related protein mitofusin-2 (Mfn2) and activate mitochondrial apoptotic pathway via elevation of [Ca(2+)]i, Bax insertion, and activation of caspase. Furthermore, overexpression of Mfn2 ameliorates the apoptosis of T cells induced by HMGB1. This occurs at least partly through Mfn2 keeps Ca(2+) homeostasis in T cells evidenced by monitoring [Ca(2+)]i dynamics. CONCLUSION: HMGB1 can trigger apoptosis of T lymphocytes through mitochondrial death pathway associated with [Ca(2+)]i elevation. Mfn2 plays a pivotal role in this process, and it might be a novel therapeutic target in T cell apoptosis related disorders.