Protective effects of P2X7R antagonist in sepsis-induced acute lung injury in mice via regulation of circ_0001679 and circ_0001212 and downstream Pln, Cdh2, and Nprl3 expression.

BACKGROUND: Sepsis induces pulmonary P2X7 receptor (P2X7 R) expression and P2X7 R-knockout reduced lung inflammation in mice. The present study investigated the expression of circular RNA (circRNA) and mRNA in sepsis-induced acute lung injury (ALI) treated with a P2X7 R antagonist. METHODS: Sepsis was induced by tracheal administration of lipopolysaccharide (LPS), and the mice were then divided into two groups: without [sepsis + dimethyl sulfoxide (DMSO)] or with P2X7 R antagonist treatment (sepsis + P2X7 A). Sham mice were administrated sterile normal saline. Serum levels of interleukin (IL)-1ß and tumor necrosis factor (TNF)-α, pathological changes, cell apoptosis and P2X7 R expression in lung were assessed, followed by RNA sequencing (RNA-seq) and bioinformatics analyses. A quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to validate circRNAs and mRNAs. RESULTS: Compared to the sham group, LPS-induced sepsis produced obvious pathological changes in lung tissue, as well as increased apoptotic lung cells, serum TNF-α and IL-1ß levels, and P2X7 R expression; P2X7 R antagonism significantly ameliorated these changes. RNA-seq identified many dysregulated circRNAs and mRNAs during sepsis, whereas this changed with P2X7 R antagonism. RT-qPCR confirmed that Mus musculus (mmu)_circ_0001679, mmu_circ_0001212, phospholamban (Pln), cadherin-2 (Cdh2) and nitrogen permease regulator 3-like (Nprl3) expression were significantly increased in the sepsis + DMSO group compared to that in the sham group but were decreased in the sepsis + P2X7 A group compared to that in the sepsis + DMSO group. The circRNA-microRNA-mRNA coexpression network indicated that mmu_circ_0001679 may regulate Nprl3 and that mmu_circ_0001212 may similarly regulate Pln, Cdh2 and Nprl3 as a competing endogenous RNA. CONCLUSIONS: P2X7 R antagonism attenuates sepsis-induced ALI by inhibiting dysregulated expression of circRNA (circ_0001679, circ_0001212) and mRNA (Pln, Cdh2 and Nprl3).

Chlamydia psittaci causing severe pneumonia with an initial complaint of massive watery sputum: a case report.

Background: With the widespread application of metagenomic next-generation sequencing (mNGS) in pathogen detection, the reports of severe Chlamydia psittaci (C. psittaci) pneumonia are increasing. It is essential to determine the best management of severe C. psittaci pneumonia. Case Description: This report describes a 51-year-old male patient who presented with symptoms of expectoration, relative bradycardia, and dyspnea. Lung computed tomography (CT) on day 1 (D1) showed consolidation of the left lower lobe. He was intubated and transferred to the intensive care unit (ICU). The symptoms of high fever and progressive dyspnea [the lowest level of arterial partial pressure of oxygen/fractional inspired oxygen (PaO2/FiO2): 52 mmHg] persisted on D3. Meanwhile, he produced a large volume of golden-yellow, watery sputum, due to which endotracheal suction was repeatedly performed to maintain patency of the airway. The repeat radiography showed extensive deterioration of diffuse exudation in bilateral lobes. An early treatment with methylprednisolone was initiated on D3, after which the watery sputum decreased and turned viscous. The mNGS of the bronchoalveolar lavage fluid (BALF) identified C. psittaci on D7, and combined targeted antimicrobial therapy (azithromycin and doxycycline) was subsequently initiated. After 1 week of treatment, the patient was extubated on D14. He was transferred to the respiratory department on D17 and discharged on D25 with oral medications (azithromycin and doxycycline for 2 weeks). The repeat chest CT on D68 showed that the bilateral exudation and left lower lobe consolidation had almost disappeared, without pleural effusion. Conclusions: In severe C. psittaci pneumonia, although the presentations differ, the rapid pathogen identification through BALF mNGS may facilitate the early use of effective antibiotics. Timely and comprehensive treatment is important for improving outcomes in severe C. psittaci pneumonia.

T cell activation profiles can distinguish gram negative/positive bacterial sepsis and are associated with ICU discharge.

Introduction: Sepsis is a life-threatening complication resulting from a dysregulated host response to a serious infection, of which bacteria are the most common cause. A rapid differentiation of the gram negative (G-)/gram positive (G+) pathogens facilitates antibiotic treatment, which in turn improves patients' survival. Methods: We performed a prospective, observational study of adult patients in intensive care unit (ICU) unit and underwent the analysis of peripheral blood lymphocyte subsets, cytokines and other clinical indexes. The enrolled 94 patients were divided into no infection group (n=28) and bacterial sepsis group (n=66), and the latter group was subdivided into G- (n=46) and G+ (n=20) sepsis subgroups. Results: The best immune biomarker which differentiated the diagnosis of G- sepsis from G+ sepsis, included activation markers of CD69, human leukocyte antigen DR (HLA-DR) on CD3+CD8+T subset. The ratio of CD3+CD4+CD69+T/CD3+CD8+CD69+T (odds ratio (OR): 0.078(0.012,0.506), P = 0.008), PCT>0.53 ng/ml (OR: 9.31(1.36,63.58), P = 0.023), and CO2CP<26.5 mmol/l (OR: 10.99(1.29, 93.36), P = 0.028) were predictive of G- sepsis (versus G+ sepsis), and the area under the curve (AUC) was 0.947. Additionally, the ratio of CD3+CD4+CD69+T/CD3+CD8+CD69+T ≤ 0.2697 was an independent risk factor for poor ICU discharge in G- sepsis patients (HR: 0.34 (0.13, 0.88), P=0.026). Conclusion: We conclude that enhanced activation of T cells may regulate the excessive inflammatory response of G- bacterial sepsis, and that T cell activation profiles can rapidly distinguish G- sepsis from G+ sepsis and are associated with ICU discharge.

[Impact of hypophosphatemia on weaning from mechanical ventilation].

OBJECTIVE: To explore the influence of hypophosphatemia on weaning from mechanical ventilation. METHODS: An observational study was conducted. The medical records of 30 mechanical ventilated patients with hypophosphatemia admitted to intensive care unit of Sun Yat-sen Memorial Hospital of Sun Yat-sen University from January 2018 to August 2020 were analyzed; another 60 mechanical ventilated patients with normophosphatemia around the same time were enrolled as controls by 1:2 case-control matching based on gender, age, acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score. And then the duration of invasive mechanical ventilation, times of spontaneous breathing trial (SBT), the diaphragmatic ultrasonography movement indexes, and outcome of weaning and prognosis during hospitalization were compared between the two groups. Receiver operator characteristic curve (ROC curve) was plotted to calculate the areas under ROC curve (AUC) and cut-off values of serum phosphorus for successful weaning and hospital survival. The correlations between the diaphragmatic ultrasonography movement indexes and serum phosphorus were analyzed by Pearson partial correlation analysis. RESULTS: Compared with normophosphatemic group, the duration of invasive mechanical ventilation in hypophosphatemia group was significantly longer [days: 13.0 (7.0, 22.0) vs. 10.0 (5.5, 14.0), P < 0.05], and SBT attempts were more often [times: 3 (0, 5) vs. 1 (1, 2), P < 0.01], while the rate of successful weaning was lower (53.3% vs. 91.7%, P < 0.01), and the hospital mortality was higher (20.0% vs. 1.7%, P < 0.01). ROC curve analysis showed that serum phosphorus could predict successful weaning of mechanical ventilated patients, the AUC was 0.795, and the optimum cut-off value of serum phosphorus was 0.85 mmol/L with sensitivity of 73.2% and specificity of 84.2%. Serum phosphorus could predict hospital survival of mechanical ventilated patients, the AUC was 0.782, and the optimum cut-off value of serum phosphorus was 0.48 mmol/L with sensitivity of 81.9% and specificity of 85.7%. Compared with normophosphatemic group, diaphragm thickness at the end of inspiration (DTei), diaphragm thickness at the end of expiration (DTee), diaphragm thickening fraction (DTF), diaphragm excursion (DE) in hypophosphatemia group were all significantly decreased [DTei (cm): 0.19±0.07 vs. 0.27±0.08, DTee (cm): 0.14±0.05 vs. 0.19±0.06, DTF: (33.55±16.17)% vs. (45.04±18.66)%, DE (cm): 1.17±0.49 vs. 2.28±0.69, all P < 0.01]. Pearson partial correlation analysis showed that linear correlations were found between serum phosphorus and DTei, DTee, DTF, DE (r values were 0.442, 0.351, 0.293, 0.628 respectively, all P < 0.01). CONCLUSIONS: Serum phosphorus may have correlation with the diaphragmatic ultrasonography movement indexes. Hypophosphatemia may impair the contractile properties of diaphragm, induce more SBT attempts and longer duration of invasive mechanical ventilation, and affect outcome of weaning and prognosis.

Caspofungin pharmacokinetics and probability of target attainment in ICU patients in China.

OBJECTIVES: Effective antifungal therapy is important to reduce mortality in patients with invasive fungal infections (IFIs). Numerous factors affect pharmacokinetic/pharmacodynamic (PK/PD) parameters in critically-ill patients. To guide individualised administration in critically-ill patients, it is of great significance to determine the population pharmacokinetics of caspofungin. METHODS: A prospective study in 42 ICU patients with IFIs was conducted in China. A population pharmacokinetic model of caspofungin was established using a non-linear mixed-effects model, which was utilised to investigate the effects of demographic indices, liver function and kidney function on pharmacokinetics. Additionally, appropriate dosages of caspofungin under various scenarios were determined based on MICs and probability of target attainment (PTA) at specific dosages. RESULTS: In critically-ill Chinese patients, clearance (CL), volume of distribution (V) and area under the curve at steady-state (AUCss) of caspofungin were 0.32 L/h, 6.77 L and 135.47 mg•h/L, respectively. Blood albumin and total bilirubin levels were factors affecting CL, while body weight was the only factor affecting V among Chinese people with relatively low weight compared with other populations. A maintenance dose of 50 mg caspofungin achieved a high PTA for treating IFIs caused by Candida albicans (MIC ≤ 0.06 mg/L) and Candida glabrata (MIC ≤ 0.125 mg/L). The maintenance dose of caspofungin should be adjusted to 70-200 mg for IFIs caused by C. albicans (MIC, 0.06-0.125 mg/L). For IFIs caused by Candida parapsilosis, an MIC > 0.03 mg/L is associated with a very low PTA, but higher doses of caspofungin or alternative antifungals need to be further studied. CONCLUSION: The population pharmacokinetic model established here described well the PK/PD characteristics of caspofungin in critically-ill Chinese patients. These results could guide the formulation of individualised caspofungin dosing regimens for critically-ill patients.

Silencing of LncRNA-PVT1 ameliorates lipopolysaccharide-induced inflammation in THP-1-derived macrophages via inhibition of the p38 MAPK signaling pathway.

BACKGROUND: Sepsis is common in intensive care units and has a high mortality rate; yet, its pathogenesis and treatment remain unclear. Recent studies have shown that long non-coding RNA plasmacytoma variant translocation 1 (lncRNA-PVT1) plays a pro-inflammatory role in immune-related inflammatory diseases. Therefore, we investigated whether lncRNA-PVT1 plays an important pro-inflammatory effect in the inflammatory response of sepsis. METHODS: Quantitative real-time PCR (RT-qPCR) was employed for the detection of lncRNA-PVT1, interleukin 1ß (IL-1ß), and tumor necrosis factor α (TNF-α) mRNA, and the correlations between their expressions were analyzed. After lncRNA-PVT1 knockdown by lncRNA Smart Silencer, abnormal expressions of lncRNA-PVT1, and IL-1ß and TNF-α mRNA were detected. The expressions of total and phosphorylated protein of p38 were detected by western blotting. The effect of silencing lncRNA-PVT1 on p38 mitogen-activated protein kinase (MAPK) signaling pathway during lipopolysaccharide (LPS)-induced inflammation was subsequently analyzed. The MAPK selective inhibitor, SB202190, was used to block this signaling pathway, and the expressions of lncRNA-PVT1 and TNF-α were detected by RT-qPCR. Furthermore, the effect of partial blockade of the p38 MAPK signaling pathway by SB202190 on the levels of lncRNA-PVT1 was explored. RESULTS: Following treatment of THP-1-derived macrophages with different concentrations of LPS, the levels of lncRNA-PVT1 and IL-1ß, TNF-α mRNA were increased in a dose-dependent manner. Silencing of lncRNA-PVT1 reduced the expressions of IL-1ß and TNF-α mRNA via inhibition of the p38 MAPK signaling pathway. Specifically, inhibiting the p38 MAPK pathway significantly decreased the LPS-induced lncRNA-PVT1 elevation. CONCLUSIONS: Our observations suggest that lncRNA-PVT1 can be silenced to ameliorate LPS-induced inflammation in macrophages via inhibition of the p38 MAPK pathway. Further, the p38 MAPK pathway can regulate the expression of lncRNA-PVT1 via a positive feedback loop.

Short-term dietary restriction ameliorates brain injury after cardiac arrest by modulation of mitochondrial biogenesis and energy metabolism in rats.

BACKGROUND: Dietary restriction (DR) is a well-known intervention that increases lifespan and resistance to multiple forms of acute stress, including ischemia reperfusion injury. However, the effect of DR on neurological injury after cardiac arrest (CA) remains unknown. METHODS: The effect of short-term DR (one week of 70% reduced daily diet) on neurological injury was investigated in rats using an asphyxial CA model. The survival curve was obtained using Kaplan-Meier survival analysis. Serum S-100ß levels were detected by enzyme linked immunosorbent assay. Cellular apoptosis and neuronal damage were assessed by terminal deoxyribonucleotide transferase dUTP nick end labeling assay and Nissl staining. The oxidative stress was evaluated by immunohistochemical staining of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Mitochondrial biogenesis was examined by electron microscopy and mitochondrial DNA copy number determination. The protein expression was detected by western blot. The reactive oxygen species (ROS) and metabolite levels were measured by corresponding test kits. RESULTS: Short-term DR significantly improved 3-day survival, neurologic deficit scores (NDS) and decreased serum S-100ß levels after CA. Short-term DR also significantly attenuated cellular apoptosis, neuronal damage and oxidative stress in the brain after CA. In addition, short-term DR increased mitochondrial biogenesis as well as brain PGC-1α and SIRT1 protein expression after CA. Moreover, short-term DR increased adenosine triphosphate, ß-hydroxybutyrate, acetyl-CoA levels and nicotinamide adenine dinucleotide (NAD+)/reduced form of NAD+ (NADH) ratios as well as decreased serum lactate levels. CONCLUSIONS: Reduction of oxidative stress, upregulation of mitochondrial biogenesis and increase of ketone body metabolism may play a crucial role in preserving neuronal function after CA under short-term DR.

A Risk Prediction Model for Invasive Fungal Disease in Critically Ill Patients in the Intensive Care Unit.

PURPOSE: Developing a risk prediction model for invasive fungal disease based on an analysis of the disease-related risk factors in critically ill patients in the intensive care unit (ICU) to diagnose the invasive fungal disease in the early stages and determine the time of initiating early antifungal treatment. METHODS: Data were collected retrospectively from 141 critically ill adult patients with at least 4 days of general ICU stay at Sun Yat-sen Memorial Hospital, Sun Yat-sen University during the period from February 2015 to February 2016. Logistic regression was used to develop the risk prediction model. Discriminative power was evaluated by the area under the receiver operating characteristics (ROC) curve (AUC). RESULTS: Sequential organ failure assessment (SOFA) score, antibiotic treatment period, and positive culture of Candida albicans other than normally sterile sites are the three predictors of invasive fungal disease in critically ill patients in the ICU. The model performs well with an ROC-AUC of .73. CONCLUSION: The risk prediction model performs well to discriminate between critically ill patients with or without invasive fungal disease. Physicians could use this prediction model for early diagnosis of invasive fungal disease and determination of the time to start early antifungal treatment of critically ill patients in the ICU.

Spontaneous hypothermia ameliorated inflammation and neurologic deficit in rat cardiac arrest models following resuscitation.

Cardiac arrest (CA) is a leading cause of mortality worldwide. The majority of the associated mortalities are caused by post­CA syndrome, which includes symptoms, such as neurologic damage, myocardial dysfunction and systemic inflammation. Following CA, return of spontaneous circulation (ROSC) leads to a brain reperfusion injury, which subsequently causes adverse neurologic outcomes or mortality. Therefore, investigating the underlying mechanisms of ROSC­induced neurologic deficits and establishing potential treatments is critical to prevent and treat post­CA syndrome. In the current study, CA rat models were established by asphyxia. Following ROSC, the temperature was controlled to achieve hypothermia. The general neurologic status was assessed using the neurologic deficit scale. Changes in the concentrations of interleukin (IL)­18 and IL­1ß were measured with ELISA and the dynamic change in NACHT, LRR and PYD domains­containing protein 3 inflammasome components was determined by western blot analysis and immunohistochemistry. Neuronal death and apoptosis were measured via TUNEL assays. In the CA rat models, increasing the duration of CA before cardiopulmonary resuscitation was found to aggravate the neural deficit and increase the incidence of inflammation. Following ROSC, the expression level of the inflammasome components was observed to increase in CA rat models, which was accompanied by increased secretion of IL­18 and IL­1ß, indicating the promotion of inflammation. In addition, the study identified the beneficial role of spontaneous hypothermia in ameliorating the ROSC­induced inflammation and neurologic deficit in CA rat models, including the downregulation of inflammasome components and attenuating neuronal apoptosis. The present study contributes to the understanding of underlying mechanisms in CA­evoked inflammation and the subsequent neurologic damage following ROSC. A novel potential therapeutic strategy that may increase survival times and the quality of life for patients suffering from post­CA syndrome is proposed in the present study.

Carbon Monoxide Improves Neurologic Outcomes by Mitochondrial Biogenesis after Global Cerebral Ischemia Induced by Cardiac Arrest in Rats.

Mitochondrial dysfunction contributes to brain injury following global cerebral ischemia after cardiac arrest. Carbon monoxide treatment has shown potent cytoprotective effects in ischemia/reperfusion injury. This study aimed to investigate the effects of carbon monoxide-releasing molecules on brain mitochondrial dysfunction and brain injury following resuscitation after cardiac arrest in rats. A rat model of cardiac arrest was established by asphyxia. The animals were randomly divided into the following 3 groups: cardiac arrest and resuscitation group, cardiac arrest and resuscitation plus carbon monoxide intervention group, and sham control group (no cardiac arrest). After the return of spontaneous circulation, neurologic deficit scores (NDS) and S-100B levels were significantly decreased at 24, 48, and 72 h, but carbon monoxide treatment improved the NDS and S-100B levels at 24 h and the 3-day survival rates of the rats. This treatment also decreased the number of damaged neurons in the hippocampus CA1 area and increased the brain mitochondrial activity. In addition, it increased mitochondrial biogenesis by increasing the expression of biogenesis factors including peroxisome proliferator-activated receptor-γ coactivator-1α, nuclear respiratory factor-1, nuclear respiratory factor-2 and mitochondrial transcription factor A. Thus, this study showed that carbon monoxide treatment alleviated brain injury after cardiac arrest in rats by increased brain mitochondrial biogenesis.

Effects of simvastatin on the expression of inducible NOS in acute lung injury in septic rats.

BACKGROUND: The available evidence suggests that simvastatin plays a beneficial role in lung injury. In addition, statins have been shown to inhibit the activity of inducible nitric oxide synthase (iNOS). The aim of the present study was to investigate the effects of simvastatin on iNOS expression based on a lipopolysaccharide (LPS)-induced septic rat model. METHODS: Thirty-six rats were randomly divided into 3 groups (control group, sepsis group and simvastatin group). A rat model of sepsis was established with LPS. The simvastatin group was pre-treated with simvastatin, whereas the control and sepsis groups were treated with saline before LPS treatment. LPS was injected into the rats in the simvastatin and sepsis groups, while as a negative control, the control group received saline alone. The oxygenation index, expression levels of iNOS and IL-6, and pathological integral of lung injury were analyzed to evaluate the effect of simvastatin on septic rats. RESULTS: Compared with the septic group, significant decreases in the oxygenation index and expression level of iNOS were observed in the simvastatin group. Furthermore, simvastatin treatment resulted in a significant decrease in iNOS levels and the pathological integral of lung injury score in septic rats. CONCLUSION: Simvastatin can relieve acute lung injury induced by sepsis in rats. Decreasing iNOS levels may contribute to the protective role of simvastatin in lung injury.