Persistence and clearance of viral RNA in 2019 novel coronavirus disease rehabilitation patients

Background:

A patient's infectivity is determined by the presence of the virus in different body fluids, secretions, and excreta. The persistence and clearance of viral RNA from different specimens of patients with 2019 novel coronavirus disease (COVID-19) remain unclear. This study analyzed the clearance time and factors influencing 2019 novel coronavirus (2019-nCoV) RNA in different samples from patients with COVID-19, providing further evidence to improve the management of patients during convalescence.

Methods:

The clinical data and laboratory test results of convalescent patients with COVID-19 who were admitted to from January 20, 2020 to February 10, 2020 were collected retrospectively. The reverse transcription polymerase chain reaction (RT-PCR) results for patients’ oropharyngeal swab, stool, urine, and serum samples were collected and analyzed. Convalescent patients refer to recovered non-febrile patients without respiratory symptoms who had two successive (minimum 24 h sampling interval) negative RT-PCR results for viral RNA from oropharyngeal swabs. The effects of cluster of differentiation 4 (CD4)+ T lymphocytes, inflammatory indicators, and glucocorticoid treatment on viral nucleic acid clearance were analyzed.

Results:

In the 292 confirmed cases, 66 patients recovered after treatment and were included in our study. In total, 28 (42.4%) women and 38 men (57.6%) with a median age of 44.0 (34.0–62.0) years were analyzed. After in-hospital treatment, patients’ inflammatory indicators decreased with improved clinical condition. The median time from the onset of symptoms to first negative RT-PCR results for oropharyngeal swabs in convalescent patients was 9.5 (6.0–11.0) days. By February 10, 2020, 11 convalescent patients (16.7%) still tested positive for viral RNA from stool specimens and the other 55 patients’ stool specimens were negative for 2019-nCoV following a median duration of 11.0 (9.0–16.0) days after symptom onset. Among these 55 patients, 43 had a longer duration until stool specimens were negative for viral RNA than for throat swabs, with a median delay of 2.0 (1.0–4.0) days. Results for only four (6.9%) urine samples were positive for viral nucleic acid out of 58 cases; viral RNA was still present in three patients’ urine specimens after throat swabs were negative. Using a multiple linear regression model (F = 2.669, P = 0.044, and adjusted R² = 0.122), the analysis showed that the CD4+ T lymphocyte count may help predict the duration of viral RNA detection in patients’ stools (t = −2.699, P = 0.010). The duration of viral RNA detection from oropharyngeal swabs and fecal samples in the glucocorticoid treatment group was longer than that in the non-glucocorticoid treatment group (15 days vs. 8.0 days, respectively; t = 2.550, P = 0.013) and the duration of viral RNA detection in fecal samples in the glucocorticoid treatment group was longer than that in the non-glucocorticoid treatment group (20 days vs. 11 days, respectively; t = 4.631, P < 0.001). There was no statistically significant difference in inflammatory indicators between patients with positive fecal viral RNA test results and those with negative results (P > 0.05).

Conclusions:

In brief, as the clearance of viral RNA in patients’ stools was delayed compared to that in oropharyngeal swabs, it is important to identify viral RNA in feces during convalescence. Because of the delayed clearance of viral RNA in the glucocorticoid treatment group, glucocorticoids are not recommended in the treatment of COVID-19, especially for mild disease. The duration of RNA detection may relate to host cell immunity.

Epidemiology and outcome of severe sepsis and septic shock in intensive care units in mainland China

Introduction

Information about sepsis in mainland China remains scarce and incomplete. The purpose of this study was to describe the epidemiology and outcome of severe sepsis and septic shock in mixed ICU in mainland China, as well as the independent predictors of mortality.

Methods

We performed a 2-month prospective, observational cohort study in 22 closed multi-disciplinary intensive care units (ICUs). All admissions into those ICUs during the study period were screened and patients with severe sepsis or septic shock were included.

Results

A total of 484 patients, 37.3 per 100 ICU admissions were diagnosed with severe sepsis (n = 365) or septic shock (n = 119) according to clinical criteria and included into this study. The most frequent sites of infection were the lung and abdomen. The overall ICU and hospital mortality rates were 28.7% (n = 139) and 33.5% (n = 162), respectively. In multivariate analyses, APACHE II score (odds ratio[OR], 1.068; 95% confidential interval[CI], 1.027–1.109), presence of ARDS (OR, 2.676; 95%CI, 1.691–4.235), bloodstream infection (OR, 2.520; 95%CI, 1.142–5.564) and comorbidity of cancer (OR, 2.246; 95%CI, 1.141–4.420) were significantly associated with mortality.

Conclusions

Our results indicated that severe sepsis and septic shock were common complications in ICU patients and with high mortality in China, and can be of help to know more about severe sepsis and septic shock in China and to improve characterization and risk stratification in these patients.

Sepsis-related mortality in China: a descriptive analysis

PURPOSE

A population-level description and analysis of sepsis-related mortality in China is key to the planning and assessment of interventional strategies.

METHODS

Retrospective analysis of multiple cause of death (MCOD) recorded in the population-based national mortality surveillance system (NMSS) of China. All sepsis-related deaths occurring in 605 disease surveillance points (DSPs) covering 323.8 million population across China were included in our study. Age-standardized mortality and national estimate of sepsis-related deaths were estimated using the census population in 2010 and 2015, respectively.

RESULTS

In 2015, a total of 1,937,299 deaths occurring in any of the 605 DSPs and standardized sepsis-related mortality rate was 66.7 (95% confidence interval [CI] 66.4-67.0) deaths per 100,000 population. This produced a national estimate of 1,025,997 sepsis-related deaths. Sepsis-related mortality rates exhibited significant geographic variation. In multilevel analysis, male sex (rate ratio [RR] 1.582, 95% CI 1.570-1.595), increasing age (RR 1.914 for 5-year group, 95% CI 1.910-1.917), and presence of comorbidity (RR 2.316, 95% CI 2.298-2.335) were independently associated with increased sepsis-related mortality. Higher disposable income (RR 0.717 for the fourth interquartile range vs. the first interquartile range, 95% CI 0.515-0.978) and mean years of education (RR 0.808 for the fourth interquartile range vs. the first interquartile range, 95% CI 0.684-0.955) were negatively associated with sepsis-related mortality. However, population-based hospital doctors were not significantly associated with sepsis-related mortality.

CONCLUSIONS

The standardized sepsis-related mortality rate in China was high and varied according to socioeconomic indices, even though some uncertainty remained.

Paclitaxel alleviated sepsis-induced acute lung injury by activating MUC1 and suppressing TLR-4/NF-κB pathway

Purpose

It has been reported that approximately 40% of ALI (acute lung injury) incidence resulted from sepsis. Paclitaxel, as a classic anti-cancer drug, plays an important role in the regulation of inflammation. However, we do not know whether it has a protective effect against CLP (cecal ligation and puncture)-induced septic ALI. Our study aims to illuminate the mitigative effects of paclitaxel on sepsis-induced ALI and its relevant mechanisms.

Materials and methods

The survival rates and organ injuries were used to evaluate the effects of paclitaxel on CLP mice. The levels of inflammatory cytokines were tested by ELISA. MUC1 siRNA pre-treatment was used to knockdown MUC1 expression in vitro. GO203 was used to inhibit the homodimerization of MUC1-C in vivo. The expression levels of MUC1, TLR 4 and p-NF-κB/p65 were detected by Western blot.

Results

Our results showed that paclitaxel improved the survival rates and ameliorated organ injuries especially lung injury in CLP-induced septic mice. These were accompanied by reduced inflammatory cytokines in sera and BALF (bronchoalveolar lavage fluid). We also found paclitaxel could attenuate TLR 4-NF-κB/p65 activation both in lung tissues of septic mice and LPS-stimulated lung type II epithelial cell line A549. At the upstream level, paclitaxel-upregulated expression levels of MUC1 in both in vivo and in vitro experiments. The inhibitory effects of paclitaxel on TLR 4-NF-κB/p65 activation were reversed in lung tissues of septic mice pre-treated with MUC1 inhibitor and in MUC1-knockdown A549 cells. Protection of paclitaxel on sepsis-induced ALI and decrease of inflammatory cytokines were also abolished by inhibition of MUC1.

Conclusion

Collectively, these results indicated paclitaxel could significantly alleviate acute lung injury in CLP-induced septic mice and LPS-stimulated lung type II epithelial cell line A549 by activating MUC1 and suppressing TLR-4/NF-κB pathway.

Epidemiology, species distribution and outcome of nosocomial Candida spp. bloodstream infection in Shanghai

Background

Yeasts, mostly Candida, are important causes of bloodstream infections (BSI), responsible for significant mortality and morbidity among hospitalized patients. The epidemiology and species distribution vary from different regions. The goals of this study were to report the current epidemiology of Candida BSI in a Shanghai Teaching Hospital and estimate the impact of appropriate antifungal therapy on the outcome.

Methods

From January 2008 to December 2012, all consecutive patients who developed Candida BSI at Ruijin University Hospital were enrolled. Underlying diseases, clinical severity, species distribution, antifungal therapy and its impact on the outcome were analyzed.

Results

A total of 121 episodes of Candida BSI were identified, with an incidence of 0.32 episodes/1,000 admissions (0.21 in 2008 and 0.42 in 2012) The proportion of candidemia caused by non-albicans species (62.8%), including C. parapsilosis (19.8%), C. tropicalis (14.9%), C. glabrata (7.4%), C. guilliermondii (5.8%), C. sake (5.0%) was higher than that of candidemia caused by C. albicans (37.2%). The overall crude 28-day mortality was 28.1% and significantly reduced with appropriate empiric antifungal therapy administered within 5 days (P = 0.006). Advanced age (OR 1.04; P = 0.014), neutropenia < 500/mm³ (OR 17.44; P < 0.001) were independent risk factors for 28-day mortality, while appropriate empiric antifungal therapy (OR 0.369; P = 0.035) was protective against 28-day mortality.

Conclusion

The epidemiology of candidemia in Shanghai differed from that observed in Western countries. Appropriate empiric antifungal therapy influenced the short-term survival.

Regulation of fatty acid synthesis in immune cells

Metabolic reprogramming plays a critical role in the important cellular metabolic alterations that occur during the activation of immune cells to enable them to adapt to the extracellular environment. Here, we review recent studies on how substrate availability and metabolites mediate the signalling pathways that regulate fatty acid synthesis (FAS) in different immune cells and how FAS determines cellular fate and function. The major regulators sterol regulatory element-binding proteins and liver X receptors, the key enzyme ATP citrate lyase and the PI3K-Akt-mTOR signalling axis play important roles in de novo FAS during a variety of biological events, including cellular proliferation and differentiation and the development of organelles and intracellular membrane components in immune cells. In addition, the regulation of FAS substantially contributes to the inflammatory response of immune cells. Post-transcriptional modifications in FAS are also closely associated with the functional processes of immune cells. Understanding and investigating the intrinsic regulatory mechanism of FAS is of great significance for developing novel therapies for inflammation-induced diseases.

Beneficial aspects of high dose intravenous vitamin C on patients with COVID-19 pneumonia in severe condition: a retrospective case series study

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a global public health event without specific therapeutic agents till now. We aim to determine if high dose intravenous vitamin C (HDIVC) was effective for COVID-19 patients in severe condition.

METHODS

COVID-19 patients admitted in Shanghai Public Health Clinical Center from January 22, 2020 to April 11, 2020 were retrospectively scrolled. The enrolled patients were those with confirmed diagnosis of severe or critical COVID-19 pneumonia, who received HDIVC within 24 hours after disease aggravation. Main clinical outcomes obtained from 3-5 days (day 3) and 7-10 days (day 7) after HDIVC were compared to the ones just before (day 0) HDIVC.

RESULTS

Totally, twelve patients were enrolled including six severe [age of mean, 56; interquartile range (IQR), 32-65 years, 3 men] and six critical (age of mean, 63; IQR, 60-82 years, 4 men) patients. The dosage of vitamin C [median (IQR), mg/kg (body weight)/day] were [162.7 (71.1-328.6)] for severe and [178.6 (133.3-350.6)] for critical patients. By Generalized estimating equation (GEE) model, C-reactive protein (CRP) was found to decrease significantly from day 0 to 3 and 7 (severe: 59.01±37.9, 12.36±22.12, 8.95±20.4; critical: 92.5±41.21, 33.9±30.2, 59.56±41.4 mg/L). Lymphocyte and CD4+ T cell counts in severe patients reached to normal level since day 3. Similar improving trends were observed for PaO2/FiO2 (severe: 209.3±111.7, 313.4±146, 423.3±140.8; critical: 119.9±52.7, 201.8±86.64, 190.5±51.99) and sequential organ failure assessment score (severe: 2.83±1.72, 1.33±1.63, 0.67±1.03; critical: 6.67±2.34, 4.17±2.32, 3.83±2.56). Better improving effect was observed in severe than critical patients after HDIVC.

CONCLUSIONS

HDIVC might be beneficial in aspects of inflammatory response, immune and organ function for aggravation of COVID-19 patients. Further clinical trials are in warrant.

TRIAL REGISTRATION

This trial has been retrospectively registered in Chinese Clinical Trail Registry (ChiCTR2000032716) on May 8, 2020. http://www.chictr.org.cn/showproj.aspx?proj=53389.

Formalized therapeutic guideline for hyperlipidemic severe acute pancreatitis

AIM: To investigate a formalized therapeutic guideline for hyperlipidemic severe acute pancreatitis (HL-SAP).

METHODS: Thirty-two consecutive patients with severe acute pancreatitis were included in the clinical trial. All of them met the following five criteria for admission to the study, namely the Atlanta classification and stratification system for the clinical diagnosis of SAP, APACHEII score more than 8, time interval for therapeutic intervention less than 72 h after onset of the disease, serum triglyceride (TG) level 6.8 mmol/L or over, and exclusion of other etiologies. They were divided into severe acute pancreatitis group (SAP, 22 patients) and fulminant severe acute pancreatitis group (FSAP, 10 patients). Besides the conventional therapeutic measures, Penta-association therapy was also applied in the two groups, which consisted of blood purification (adsorption of triglyceride and hemofiltration), antihyperlipidemic agents (fluvastatin or lipanthyl), low molecular weight heparin (fragmin), insulin, topical application of Pixiao (a traditional Chinese medicine) over the whole abdomen. Serum triglyceride, pro-inflammatory cytokines and anti-inflammatory cytokines were determined before blood purification (PF), at the end of blood purification (AFE) and on the 7^th day after onset of the disease (AF7) respectively. Simultaneously, severity of the diseases was assessed by the APACHE II system. Prognosis was evaluated by non-operation cure rate, absorption rate of pseudocyst, time interval pseudocyst absorption, hospital stay and survival rate.

RESULTS: Serum triglyceride level (mmol/L), TNFα (U/mL) concentration and APACHE II score were significantly decreased (P < 0.05) at AFE and AF7, as compared with PF. However, serum IL-10 concentration (pg/mL) was increased significantly (P < 0.001) at AFE, and decreased significantly (P < 0.05) at AF7 when compared with PF. Operations: The First surgical intervention time was 55.8 ± 42.6 d in SAP group (5 patients) and 12.2 ± 6.6 d in FSAP group (7 patients), there was a significant difference between the two groups (P = 0.02). The number of operations in the two groups was 1.33 ± 0.5 vs 3.5 ± 1.2 (P = 0.0037), respectively. Prognosis: Non-operation cure rate, absorption rate of pseudocyst, hospital stay and survival rate in SAP group and FSAP group were 100% (22/22) vs 11.1% (1/9), 77.3% (17/22) vs 11.1% (1/9), 54.2 ± 35.9 vs 99.1 ± 49.5 d (P = 0.008) and 100% (22/22) vs 66.7% (6/9) (P = 0.0044). The time for absorption of pseudocyst was 135.1 ± 137.5 d in SAP group.

CONCLUSION: Penta-association therapy is an effective guideline in the treatment of hyperlipidemic severe acute pancreatitis at its early stage (within 72 h).

Increased levels of soluble vascular endothelial cadherin are associated with poor outcome in severe sepsis

Endothelial cells are thought to play a key role in sepsis pathogenesis: vascular endothelial damage occurs in severe sepsis and multiple organ dysfunction. Soluble vascular endothelial cadherin (VE-cadherin) levels were investigated in a prospective study involving 28 consecutive critically ill patients with or without severe sepsis who were admitted to surgical intensive care; 13 healthy age-matched volunteers were included as controls. Soluble VE-cadherin levels increased significantly in patients with severe sepsis compared with ill patients without severe sepsis and healthy controls. There was a significant linear correlation between soluble VE-cadherin levels and illness severity scores. Soluble VE-cadherin levels were significantly higher in patients who died compared with survivors. In vitro cell culture showed that serum from patients with severe sepsis greatly decreased VE-cadherin staining at intercellular junctions and total VE-cadherin expression in human umbilical cord vein endothelial cells. These findings suggest that endothelial cells play an important role in the poor outcome of patients with severe sepsis.

High-dose vitamin C alleviates pancreatic injury via the NRF2/NQO1/HO-1 pathway in a rat model of severe acute pancreatitis

Background

Oxidative stress plays a pivotal role in the progress of severe acute pancreatitis (SAP). Vitamin C (VC) is the most important antioxidant in plasma. However, the effects of an intravenous administration of high-dose VC and the mechanisms by which it exerts its antioxidant function in an experimental model of SAP have not been determined.

Methods

Sodium taurocholate was used to induce rat pancreatic injury and AR42J cells injury. After the establishment of SAP model, SAP rat and injured AR42J cells were treated with VC. For the injured AR42J cells, small interfering RNA-mediated knockdown of NRF2 was conducted after VC treatment. The histopathological characteristics, the apoptosis of pancreatic acinar cells, oxidative stress markers and levels of enzymes, biochemical indicators, and inflammatory cytokines were examined in vivo and in vitro. Furthermore, the mortality of rats was assessed.

Results

In vivo and in vitro results demonstrated that VC treatment ameliorated apoptosis of pancreatic acinar cells, as evidenced by the increase in Bcl-2, Bcl-XL, and MCL-1 expressions and decrease in Bax and cleaved caspase-3 expression along with decreased TUNEL-positive cells. Also, we found that the elevation of MDA and decrease of SOD, GPx, GSH/GSSG, and T-AOC induced by SAP were reversed by VC treatment in vivo and in vitro, and VC treatment increased expressions of Nrf2, NQO1, and HO-1 in SAP model at protein and gene level, indicating that VC attenuated oxidative stress via the NRF2/NQO1/HO-1 pathway. Meanwhile, it was found that sodium taurocholate significantly induced the release of amylase, lipase, IL-1β, and IL-6 in rat plasma and AR42J cells, which were declined by VC treatment. In vitro results also revealed that these alterations in sodium taurocholate-injured AR42J cells due to VC treatment was attenuated by NRF2 knockdown. In addition, VC at a dose of 500 mg/kg decreased the levels of lactic acid, Cre, NGAL, AST, and ALT in the plasma of SAP rats, suggesting the improvement of renal and pancreatic injury and liver function of SAP rats. Furthermore, the mortality of SAP rats was 50%, which declined to 30% after VC treatment.

Conclusions

The present study suggests that high-dose of VC ameliorate pancreatic injury of SAP via the NRF2/NQO1/HO-1 pathway to inhibit oxidative stress.

High Dose Intravenous Vitamin C for Preventing The Disease Aggravation of Moderate COVID-19 Pneumonia. A Retrospective Propensity Matched Before-After Study

Background: Coronavirus disease 2019 (COVID-19) pandemic is continuing to impact multiple countries worldwide and effective treatment options are still being developed. In this study, we investigate the potential of high-dose intravenous vitamin C (HDIVC) in the prevention of moderate COVID-19 disease aggravation.

Methods: In this retrospective before-after case-matched clinical study, we compare the outcome and clinical courses of patients with moderate COVID-19 patients who were treated with an HDIVC protocol (intravenous injection of vitamin C, 100 mg/kg/day, 1 g/h, for 7 days from admission) during a one-month period (between March 18 and april 18, 2020, HDIVC group) with a control group treated without the HDIVC protocol during the preceding two months (January 18 to March 18, 2020). Patients in the two groups were matched in a 1:1 ratio according to age and gender.

Results: The HDIVC and control groups each comprised 55 patients. For the primary outcomes, there was a significant difference in the number of patients that evolved from moderate to severe type between the two groups (HDIVC: 4/55 vs. control: 12/55, relative risk [RR] = 0.28 [0.08, 0.93], P = 0.03). Compared to the control group, there was a shorter duration of systemic inflammatory response syndrome (SIRS) (P = 0.0004) during the first week and lower SIRS occurrence (2/21 vs 10/22, P = 0.0086) on Day 7 (6–7 days after admission). In addition, HDIVC group had lower C-reactive protein levels (P = 0.005) and higher number of CD4⁺ T cells from Day 0 (on admission) to Day 7 (P = 0.04).” The levels of coagulation indicators, including activated partial thromboplastin time and D-dimer were also improved in the HDIVC compared to the control group on Day 7.

Conclusion: HDIVC may be beneficial in limiting disease aggravation in the early stage of COVID-19 pneumonia, which may be related to its improvements on the inflammatory response, immune function and coagulation function. Further randomized controlled trials are required to augment these findings.

Monocyte programmed death ligand-1 expression is an early marker for predicting infectious complications in acute pancreatitis

Background

Acute pancreatitis (AP) is a life-threatening disease that requires early identification of patients at risk of developing infectious complications. Immunosuppression is an initial event that is key to AP pathogenesis. The programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) system is reported to mediate evasion of host immune surveillance in many diseases; however, the relationship between PD-1/PD-L1 expression and these parameters or infectious complications in AP has not been elucidated. This study was conducted to determine whether PD-1 and PD-L1 are upregulated and to reveal the relationship between PD-1/PD-L1 expression and the development of infectious complications in AP.

Methods

Sixty-three patients with AP and 32 sex- and age-matched healthy control subjects were prospectively enrolled. On days 1 and 3 after the onset of AP, we measured PD-1 expression in peripheral CD4⁺ T cells and PD-L1 and human leukocyte antigen-DR (HLA-DR) expression in CD14⁺ monocytes using flow cytometry. Plasma interleukin (IL)-10 levels were measured by enzyme-linked immunosorbent assay.

Results

Compared with healthy volunteers, the percentages of PD-1-expressing CD4⁺ lymphocytes and PD-L1-expressing CD14⁺ monocytes were increased in patients with AP on days 1 and 3 after onset, especially those with infectious complications. Moreover, increased PD-1/PD-L1 expression was associated with increased occurrence of infectious complications, decreased circulating lymphocytes, and increased plasma IL-10 concentration. Multivariate regression analysis indicated that the increased percentage of PD-L1-expressing CD14⁺ monocytes was an independent risk factor for infectious complications in AP. Area under the ROC curve analysis showed the combination of Acute Physiology and Chronic Health Evaluation II score and PD-L1 and HLA-DR expression in CD14⁺ monocytes had high accuracy in predicting infectious complications in patients with AP.

Conclusions

The PD-1/PD-L1 system plays an essential role in the early immunosuppression of AP. PD-L1 expression in CD14⁺ monocytes may be a new marker for predicting risk of infectious complications in patients with AP.

The Warburg Effect Promotes Mitochondrial Injury Regulated by Uncoupling Protein-2 in Septic Acute Kidney Injury

BACKGROUND

Evidence implying that metabolism reprogramming plays an important role in the regulation of sepsis is increasing; however, whether it has a similar role in septic organ dysfunction remains unclear. Here, we provide evidence to support a new role of uncoupling protein-2 (UCP2)-regulated Warburg effect, i.e., aerobic glycolysis, in promoting mitochondrial injury in the kidney.

METHODS

To imitate sepsis condition, male C57BL/6 mice were operated by the cecal ligation puncture in vivo, whereas a normal human kidney cell line (HK-2) was treated with lipopolysaccharide in vitro. UCP2 small interfering RNA pretreatment was performed to knock down UCP2 expression in vitro. The glycolysis metabolite was detected by liquid chromatography/tandem mass spectrometry in vivo and detected by commercial kits in vitro. Oxidative phosphorylation level and glycolysis level were monitored by measuring the oxygen consumption rate (indicative of respiration) and extracellular acidification rate (indicative of glycolysis) in vitro. Exogenous lactate was supplied to stimulate HK-2 cells and indicators of mitochondrial dysfunction were also assessed.

RESULTS

Aerobic glycolysis is enhanced in septic tubular epithelial cells, and the glycolysis inhibitor 2-deoxyglucose can partially restore mitochondrial membrane potential and decrease the reactive oxygen species production. With the knockdown of UCP2, the aerobic glycolysis level upregulates, and mitochondrial injury increases.

CONCLUSIONS

These results provide insights on a new mechanism of metabolic regulation of mitochondrial injury and the importance of targeting aerobic glycolysis for the treatment of septic acute kidney injury.

CgPDR1 gain-of-function mutations lead to azole-resistance and increased adhesion in clinical Candida glabrata strains

Recently, Candida glabrata has emerged as a health-threatening pathogen and the rising resistance to antifungal agent in C. glabrata often leads to clinical treatment failure. To investigate the evolution of drug resistance and adherence ability in four paired clinical isolates collected before and after antifungal treatment. Sequence analysis, gene disruption, drug-susceptibility, adhesion tests and real-time quantitative PCR were performed. The azole-susceptible strains acquired azole resistance after antifungal therapy. Four gain-of-function (GOF) mutations in CgPDR1 were revealed by sequence analysis, namely G1099D, G346D, L344S and P927S, the last being reported for the first time. CDR1, CDR2 and SNQ2 efflux pump gene expression levels were elevated in strains harbouring GOF mutations in CgPDR1, resulting in decreased azole susceptibility. CgPDR1 alleles with distinct GOF mutations displayed different expression profiles for the drug-related genes. CgPDR1GOF mutations led to increased efflux pumps expression levels in a strain background independent way. Hyperactive Pdr1^G1099D and Pdr1^P927S displayed strain background-dependent increased adherence to host cells via upregulation of EPA1 transcription. Interestingly, the drug transporter gene expression levels did not always correspond with that of the adhesin EPA1 gene. GOF mutations in CgPDR1 conferred drug resistance and increased adherence in the clinical strains, possibly endowing C. glabrata with increased viability and pathogenicity.

OLFM4 Regulates Lung Epithelial Cell Function in Sepsis-Associated ARDS/ALI via LDHA-Mediated NF-κB Signaling

Background

Acute respiratory distress syndrome (ARDS) is one of the leading causes of death in patients with sepsis. As such, early and accurate identification of sepsis-related ARDS is critical.

Methods

Bioinformatic analysis was used to explore the GEO datasets. ELISA method was used to detect the plasma or cellular supernatant of relevant proteins. Quantitative real-time PCR was used for mRNA measurements and Western blot was applied for protein measurements. Immunohistochemistry staining and Immunofluorescence staining were used to identify the localization of OLFM4. Cecal ligation and puncture (CLP) model was used to establish sepsis model.

Results

The bioinformatic analysis results identified ten genes (CAMP, LTF, RETN, LCN2, ELANE, PGLYRP1, BPI, DEFA4, MPO, and OLFM4) as critical in sepsis and sepsis-related ARDS. OLFM4, LCN2, and BPI were further demonstrated to have diagnostic values in sepsis-related ARDS. Plasma expression of OLFM4 and LCN2 was also upregulated in sepsis-related ARDS patients compared to septic patients alone. OLFM4 expression was significantly increased in the lung tissues of septic mice and was co-localized with Ly6G+ neutrophils, F4/80+ macrophages and pro-surfactant C+ lung epithelial cells. In vitro data showed that OLFM4 expression in lung epithelial cells was downregulated upon LPS stimulation, whereas neutrophil media induced OLFM4 expression in lung epithelial cells. Overexpression of OLFM4 and treatment with recombinant OLFM4 effectively suppressed LPS-induced pro-inflammatory responses in lung epithelial cells. Furthermore, the increased levels of LDHA phosphorylation and the downstream NF-κB activation induced by LPS in epithelial cells were effectively diminished by OLFM4 overexpression and recombinant OLFM4 treatment via a reduction in ROS production and HIF1α expression.

Conclusion

OLFM4 may regulate the pro-inflammatory response of lung epithelial cells in sepsis-related ARDS by modulating metabolic disorders; this result could provide new insights into the treatment of sepsis-induced ARDS.

Altered intestinal microbiome and metabolome correspond to the clinical outcome of sepsis

BACKGROUND

The gut microbiome plays a pivotal role in the progression of sepsis. However, the specific mechanism of gut microbiota and its metabolites involved in the process of sepsis remains elusive, which limits its translational application.

METHOD

In this study, we used a combination of the microbiome and untargeted metabolomics to analyze stool samples from patients with sepsis enrolled at admission, then microbiota, metabolites, and potential signaling pathways that might play important roles in disease outcome were screened out. Finally, the above results were validated by the microbiome and transcriptomics analysis in an animal model of sepsis.

RESULTS

Patients with sepsis showed destruction of symbiotic flora and elevated abundance of Enterococcus, which were validated in animal experiments. Additionally, patients with a high burden of Bacteroides, especially B. vulgatus, had higher Acute Physiology and Chronic Health Evaluation II scores and longer stays in the intensive care unit. The intestinal transcriptome in CLP rats illustrated that Enterococcus and Bacteroides had divergent profiles of correlation with differentially expressed genes, indicating distinctly different roles for these bacteria in sepsis. Furthermore, patients with sepsis exhibited disturbances in gut amino acid metabolism compared with healthy controls; namely, tryptophan metabolism was tightly related to an altered microbiota and the severity of sepsis.

CONCLUSION

Alterations in microbial and metabolic features in the gut corresponded with the progression of sepsis. Our findings may help to predict the clinical outcome of patients in the early stage of sepsis and provide a translational basis for exploring new therapies.

mTOR-Myc axis drives acinar-to-dendritic cell transition and the CD4+ T cell immune response in acute pancreatitis

The inflammatory response in acute pancreatitis (AP) is associated with acinar-to-dendritic cell transition. The CD4⁺ T-cell-mediated adaptive immune response is necessary for pancreatic inflammatory damage. However, the effect of acinar-to-dendritic cell transition on the CD4⁺ T-cell response and the regulatory mechanism remain undefined. A mouse animal model of AP was established by repeated intraperitoneal injection of CAE. The mTOR inhibitor rapamycin was administered before AP induction. Primary acinar cells were isolated and co-incubated with subsets of differentiated CD4⁺ T cells. The expression of DC-SIGN was also assessed in pancreatic tissues from human AP patients. We found acinar cells expressed DC-SIGN and displayed the phenotype of dendritic cells (DCs), which promoted the differentiation of naive CD4⁺ T cells into CD4⁺/IFN-γ⁺ Th1 and CD4⁺/IL-17A⁺ Th17 cells in pancreatic tissues during AP. DC-SIGN was the target gene of Myc. The mTOR inhibitor rapamycin inhibited AP-induced DC-SIGN expression, CD4⁺ Th1/Th17 cell differentiation and the pro-inflammatory response via Myc. Acinar cells expressed DC-SIGN in pancreatic tissues of human patients with AP. In conclusion, acinar-to-dendritic cell transition is implicated in the CD4⁺ T-cell immune response via mTOR-Myc-DC-SIGN axis, which might be an effective target for the prevention of local pancreatic inflammation in AP.

Vitamin C treatment attenuates hemorrhagic shock related multi-organ injuries through the induction of heme oxygenase-1

BACKGROUND

Vitamin C (VitC) has recently been shown to exert beneficial effects, including protecting organ function and inhibiting inflammation, in various critical care conditions, but the specific mechanism remains unclear. Induction of heme oxygenase (HO)-1, a heat shock protein, has been shown to prevent organ injuries in hemorrhagic shock (HS) but the relationship between VitC and HO-1 are still ill-defined so far. Here we conducted a systemic in vivo study to investigate if VitC promoted HO-1 expression in multiple organs, and then tested if the HO-1 induction property of VitC was related to its organ protection and anti-inflammatory effect.

METHODS

Firstly, to determine the HO-1 induction property of VitC, the HO-1 level were measured in tissues including kidney, liver and lung of the normal and HS model of Sprague-Dawley (SD) rats after VitC treatment (100 mg/kg body weight). Secondly, to testify if VitC prevented HS related organ injuries via inducing HO-1, the HS model of rats were separately pre- and post-treated with VitC, and some of them also received Zinc protoporphyrin (Znpp), a specific HO-1 inhibitor. The HO-1 activity in tissues was tested; the organ injuries (as judged by histological changes in tissues and the biochemical indicators level in serum) and inflammatory response in tissues (as judged by the level of pro-inflammatory cytokines Tumor necrosis factor-α and Interleukin-6 ) were analyzed.

RESULTS

The HO-1 mRNA and protein level in kidney, liver, and lung were highly induced by VitC treatement under normal and HS conditions. The HO-1 activity in tissues was enhanced by both VitC pre- and post-treatment, which was shown to improve the organ injuries and inhibit the inflammatory response in the HS model of rats. Of note, the beneficial effects of VitC were abolished after HO-1 activity was blocked by Znpp.

CONCLUSIONS

VitC led to a profound induction of HO-1 in multiple organs including the kidney, liver and lung, and this property might be responsible for the organ protection and inflammation inhibitory effects of both pre- and post-treatment with VitC in HS.

Protective and predictive role of Mucin1 in sepsis-induced ALI/ARDS

OBJECTIVE

We aimed to investigate whether inhibition of MUC1 would aggravate sepsis-induced ALI, and explore the predictive value of plasma MUC1 for sepsis patients with or without ARDS.

MATERIALS AND METHODS

MUC1 siRNA pre-treatment was used to knockdown MUC1 expression in vitro. GO203 was used to inhibit the homodimerization of MUC1-C in vivo. Expression levels of MUC1, TLR 4 and HIF-1α were detected by Western blot. In addition, plasma MUC1 levels of enrolled patients were detected by ELISA on the day of admission and on the 3rd day. ROC curve was used to determine the predictive value of MUC1 in sepsis patients with ARDS.

RESULTS

Our results showed that inhibition of MUC1 could aggravate sepsis-induced acute lung injury and increase the expression of inflammatory cytokines in sera and BALF of sepsis mice. At the same time, we confirmed that inhibition of MUC1 could significantly decrease HIF-1α expression and thereby activate the expression level of TLR4. HIF-1α was a negative regulator of TLR-4. In addition, plasma MUC1 levels of sepsis patients with ARDS were significantly higher than those without ARDS and healthy adults. ROC curve showed that predictive value of plasma MUC1 on sepsis with ARDS on the 3rd day of enrollment was higher than the day of enrollment.

CONCLUSION

MUC1 could inhibit the expression of TLR-4 by stabilizing HIF-1α, thereby alleviate sepsis-induced lung injury and protect organ function. At the same time, elevated MUC1 levels in plasma had a good predictive valud on whether patients with sepsis would develop ARDS.

TUDCA Ameliorates Liver Injury Via Activation of SIRT1-FXR Signaling in a Rat Hemorrhagic Shock Model

OBJECTIVE

The aim of this study was to investigate the changes of bile acids in the liver during hemorrhagic shock (HS) and their potential to attenuate liver injury via activation of SIRT1 (sirtuin 1)-FXR (farnesoid X receptor) signaling.

METHODS

A Sprague-Dawley (SD) rat HS model was established, whereas HepG2 cells were hypoxically cultured to simulate HS in vitro. Liver bile acids (BA) were profiled with ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). FXR expression was detected by western blot and immunohistochemistry. The mRNA levels of SIRT1 and FXR were detected by polymerase chain reaction. Protein expression of SIRT1, FoxM1, NF-κB, acetyl-NF-κB, p53, and acetyl-p53 was analyzed by western blot. Hepatocyte apoptosis and proliferation were measured by TUNEL assay and Ki-67 staining, respectively. Serum and supernatant cytokines were analyzed using ELISA assays. Liver injury was also assessed. To investigate the possible mechanisms, SIRT1 agonist (SRT1720), SIRT1 inhibitor (EX527), and FXR inhibitor (Z-guggulsterone) were used.

RESULTS

Tauroursodeoxycholic acid (TUDCA) in the liver decreased significantly after HS. SIRT1 and FXR expression was time-dependently downregulated by HS or hypoxia condition. TUDCA upregulated SIRT1-FXR activity, which inhibited expression and acetylation of NF-κB and p53 and increased FoxM1 expression, leading to decreased inflammatory response and apoptosis and increased proliferative capacity in hepatocytes, and attenuation of liver injury. EX527 pretreatment reversed the protective effect of TUDCA. Moreover, Z-guggulsterone supplementation decreased the protective effect of TUDCA in vitro.

CONCLUSION

TUDCA in the liver decreased during HS. TUDCA supplementation might attenuate HS-induced liver injury by upregulating SIRT1-FXR signaling.

Effects of intestinal colonization by Clostridium difficile and Staphylococcus aureus on microbiota diversity in healthy individuals in China

Background

Intestinal colonization by pathogenic bacteria is a risk factor for infection, and contributes to environmental contamination and disease dissemination. Alteration of gut microbiota also plays a pivotal role in the development of disease. Although Clostridium difficile and Staphylococcus aureus are well-recognized pathogens causing nosocomial and community infections, the intestinal colonization was not fully investigated. Herein, we explored their overall carriage rates in healthy adults from the community, and characterized the gut microbiomes of C. difficile and S. aureus carriers.

Methods

Fecal samples were collected from 1709 healthy volunteers from communities in Shanghai, China, and tested for the presence of C. difficile, methicillin-sensitive S. aureus (MSSA), and methicillin-resistant S. aureus (MRSA) using culture-based techniques. To explore differences in the gut microbiome, 16S rRNA gene sequencing was conducted using samples from non-carriers (CH), C. difficile carriers (CCD), MRSA carriers (CM), and MSSA carriers (CS).

Results

Overall, we detected 12 C. difficile and 60 S. aureus isolates, accounting for 0.70% and 3.51% of total isolates, respectively. Eight isolates were determined to be MRSA, accounting for 13.3% of the S. aureus population. Sequencing data revealed that the microbial diversity and richness were similar among the four groups. However, at the phylum level, carriage of C. difficile or MRSA was associated with a paucity of Bacteroidetes and an overabundance of Proteobacteria compared with non-carriers. At the genus level, the prevalence of the genera Bacteroides, Prevotella, Faecalibacterium, and Roseburia was decreased in C. difficile-positive samples compared with the controls, while the proportion of Clostridium cluster XIVa species was increased. MRSA carriers exhibited a higher proportion of the genera Parasutterella and Klebsiella, but a decreased prevalence of Bacteroides. Compared with MSSA carriers, Klebsiella was the only genus found to be significantly enriched in MRSA carriers.

Conclusions

In healthy adults, colonization by C. difficile or S. aureus did not significantly affect gut microbiota diversity. However, the alteration of the gut microbiota composition in C. difficile carriers could indicate a predisposition to further infection. Our study provides essential data on the prevalence and effects of C. difficile and S. aureus colonization on gut microbiota composition in healthy adults.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3111-z) contains supplementary material, which is available to authorized users.