Improved prediction of sepsis-associated encephalopathy in intensive care unit sepsis patients with an innovative nomogram tool.

Background: Sepsis-associated encephalopathy (SAE) occurs as a result of systemic inflammation caused by sepsis. It has been observed that the majority of sepsis patients experience SAE while being treated in the intensive care unit (ICU), and a significant number of survivors continue suffering from cognitive impairment even after recovering from the illness. The objective of this study was to create a predictive nomogram that could be used to identify SAE risk factors in patients with ICU sepsis. Methods: We conducted a retrospective cohort study using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. We defined SAE as a Glasgow Coma Scale (GCS) score of 15 or less, or delirium. The patients were randomly divided into training and validation cohorts. We used least absolute shrinkage and selection operator (LASSO) regression modeling to optimize feature selection. Independent risk factors were determined through a multivariable logistic regression analysis, and a prediction model was built. The performance of the nomogram was evaluated using various metrics including the area under the receiver operating characteristic curve (AUC), calibration plots, Hosmer-Lemeshow test, decision curve analysis (DCA), net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Results: Among the 4,476 sepsis patients screened, 2,781 (62.1%) developed SAE. In-hospital mortality was higher in the SAE group compared to the non-SAE group (9.5% vs. 3.7%, p < 0.001). Several variables were analyzed, including the patient's age, gender, BMI on admission, mean arterial pressure, body temperature, platelet count, sodium level, and use of midazolam. These variables were used to create and validate a nomogram. The nomogram's performance, assessed by AUC, NRI, IDI, and DCA, was found to be superior to the conventional SOFA score combined with delirium. Calibration plots and the Hosmer-Lemeshow test confirmed the accuracy of the nomogram. The enhanced NRI and IDI values demonstrated that our scoring system outperformed traditional diagnostic approaches. Additionally, the DCA curve indicated the practicality of the nomogram in clinical settings. Conclusion: This study successfully identified autonomous risk factors associated with the emergence of SAE in sepsis patients and utilized them to formulate a predictive model. The outcomes of this investigation have the potential to serve as a valuable clinical resource for the timely detection of SAE in patients.

ERRα protects against sepsis-induced acute lung injury in rats.

BACKGROUND: Sepsis-induced acute lung injury (ALI) is associated with poor survival rates. The identification of potential therapeutic targets for preventing sepsis-induced ALI has clinical importance. This study aims to investigate the role of estrogen-related receptor alpha (ERRα) in sepsis-induced ALI. METHODS: Lipopolysaccharide (LPS) was used to simulate sepsis-induced ALI model in rat pulmonary microvascular endothelial cells (PMVECs). The effects of ERRα overexpression and knockdown on LPS-induced endothelial permeability, apoptosis and autophagy were determined by horseradish peroxidase permeability assay, TdT-mediated dUTP Nick End Labeling (TUNEL) assay, flow cytometry, immunofluorescence staining, RT-PCR and Western Blotting. The rat model with sepsis-induced ALI was established by cecal ligation and puncture in anesthetized rats to verify the results of in vitro experiments. Animals were randomly assigned to receive intraperitoneal injection of vehicle or ERRα agonist. Lung vascular permeability, pathological injury, apoptosis and autophagy were examined. RESULTS: Overexpression of ERRα ameliorated LPS-induced endothelial hyperpermeability, degradation of adherens junctional molecules, upregulation of bax, cleaved caspase 3 and cleaved caspase 9 levels, downregulation of anti-apoptotic protein Bcl-2 level, and promoted the formation of autophagic flux, while the knockdown of ERRα exacerbated LPS-induced apoptosis and inhibited the activation of autophagy. Administration of ERRα agonist alleviated the pathological damage of lung tissue, increased the levels of tight junction proteins and adherens junction proteins, and decreased the expression of apoptosis-related proteins. Promoting the expression of ERRα significantly enhanced the process of autophagy and reduced CLP-induced ALI. Mechanistically, ERRα is essential to regulate the balance between autophagy and apoptosis to maintain the adherens junctional integrity. CONCLUSION: ERRα protects against sepsis-induced ALI through ERRα-mediated apoptosis and autophagy. Activation of ERRα provides a new therapeutic opportunity to prevent sepsis-induced ALI.

Hierarchical Sampling for the Visualization of Large Scale-Free Graphs.

Graph sampling frequently compresses a large graph into a limited screen space. This paper proposes a hierarchical structure model that partitions scale-free graphs into three blocks: the core, which captures the underlying community structure, the vertical graph, which represents minority structures that are important in visual analysis, and the periphery, which describes the connection structure between low-degree nodes. A new algorithm named hierarchical structure sampling (HSS) was then designed to preserve the characteristics of the three blocks, including complete replication of the connection relationship between high-degree nodes in the core, joint node/degree distribution between high- and low-degree nodes in the vertical graph, and proportional replication of the connection relationship between low-degree nodes in the periphery. Finally, the importance of some global statistical properties in visualization was analyzed. Both the global statistical properties and local visual features were used to evaluate the proposed algorithm, which verify that the algorithm can be applied to sample scale-free graphs with hundreds to one million nodes from a visualization perspective.

Early Warning Factors of Death in COVID-19 Patients.

The infectious coronavirus disease 2019 (COVID-19) has spread all over the world and been persistently evolving so far. The number of deaths in the whole world has been rising rapidly. However, the early warning factors for mortality have not been well ascertained. In this retrospective, single-centre cohort study, we included some adult inpatients (≥18 years old) with laboratory-confirmed COVID-19 from Renmin Hospital of Wuhan University who had been discharged or had died by Apr. 8, 2020. Demographic, clinical and laboratory data at admission were extracted from electronic medical records and compared between survivors and non-survivors. We used univariable analysis, Cox proportional hazard model analysis and receiver operating characteristic (ROC) curve to explore the early warning factors associated with in-hospital death. A total of 159 patients were included in this study, of whom 86 were discharged and 73 died in hospital. Hypertension (52.1% vs. 29.1%, P=0.003) and coronary heart disease (28.8% vs. 12.8%, P=0.012) were more frequent among non-survived patients than among survived patients. The proportions of patients with dyspnoea (67.1% vs. 25.6%, P<0.001), chest distress (58.9% vs. 26.7%, P<0.001) and fatigue (64.4% vs. 25.6%, P<0.001) were significantly higher in the non-survived group than in the survived group. Regression analysis with the Cox proportional hazards mode revealed that increasing odds of in-hospital death were associated with higher IL-6 (odds ratio 10.87, 95% CI 1.41-83.59; P=0.022), lactate (3.59, 1.71-7.54; P=0.001), older age (1.86, 1.03-3.38; P=0.041) and lower lymphopenia (5.44, 2.71-10.93; P<0.001) at admission. The areas under the ROC curve (AUCs) of IL-6, lymphocyte, age and lactate were 0.933, 0.928, 0.786 and 0.753 respectively. The AUC of IL-6 was significantly higher than that of age (z=3.332, P=0.0009) and lactate (z=4.441, P<0.0001) for outcome prediction. There was no significant difference between the AUCs of IL-6 and lymphocyte for outcome prediction (z=0.372, P=0.7101). It was concluded that the potential risk factors of higher IL-6, lactate, older age and lower lymphopenia at admission could help clinicians to identify patients with poor prognosis at an early stage.

[A case report on treatment of compartment syndrome with novel coronavirus pneumonia].

A 49-year-old male patient with compartment syndrome of the right leg caused by acute carbon monoxide poisoning was admitted on December 30, 2019. The patient had a 10-year history of chronic nephritis and began dialysis treatment due to renal failure 1 month ago. Emergency surgical decompression for compartment syndrome was performed after admission. Two weeks later, the patient was diagnosed as the novel coronavirus pneumonia caused by 2019 novel coronavirus (2019-nCoV) infection. Then, the patient was transferred to the isolation ward, where he was given anti-infection, anti-virus, expectorant, heat-clearing and detoxifying drugs, bedside dialysis, and nutrition support symptomatic treatment. After 2 weeks of treatment, the patient is getting better, with no fever, cough, wheezing, and other discomfort. Meanwhile, the sensory and motor functions of right lower limb recovered gradually. This case is rare, severe, and difficult to diagnose and treat. It is the first reported case of novel coronavirus pneumonia after orthopedic surgery.

Inhibition of ERRα Aggravates Sepsis-Induced Acute Lung Injury in Rats via Provoking Inflammation and Oxidative Stress.

Inflammation and oxidative stress are critical pathologies that contribute to sepsis-induced acute lung injury (ALI). This study investigated the regulatory role of estrogen-related receptor alpha (ERRα) in an experimental model of sepsis-induced ALI. In vivo, a cecal ligation and puncture- (CLP-) induced ALI model was established in anesthetized rats. Animals were then randomly assigned to receive an intraperitoneal injection of vehicle or ERRα inverse agonist (XCT-790, 2.5 mg/kg). Administration of XCT-790 significantly aggravated a sepsis-induced increase in pathological damage of lung tissues, lung endothelial permeability, myeloperoxidase (MPO) activity in lung tissues, production of serum inflammatory factors, and inflammatory cell accumulation in bronchoalveolar lavage fluid. In addition, XCT-790 treatment exacerbated a CLP-induced decrease in lung superoxide dismutase and an increase in lung malondialdehyde levels. In vitro, the exposure of rat pulmonary microvascular endothelial cells (PMVECs) to lipopolysaccharide (LPS) resulted in increased endothelial permeability and reduced expression of tight junction protein ZO-1, Occludin, JAM-A, and adherens junction protein VE-cadherin, which were further deteriorated by knockdown of ERRα. In addition, LPS-triggered inflammatory factor production and increase in the expression of phosphorylated IκBα and NF-κB p65 were also exacerbated by silencing ERRα gene. Meanwhile, knockdown of ERRα dramatically promoted LPS-activated mitochondrial reactive oxygen species production and LPS-induced downregulation of Sirt3 protein levels in rat PMVECs. Taken together, our present study provides evidences that ERRα functions as a novel negative modulator of sepsis-induced ALI in rats. The underlying mechanisms responsible for ERRα-elicited effects are largely dependent on the regulation of inflammatory response and oxidative stress.

Hypercapnia attenuates ventilator-induced lung injury through vagus nerve activation.

PURPOSE: To investigate the role of vagus nerve activation in the protective effects of hypercapnia in ventilator-induced lung injury (VILI) rats. METHODS: Male Sprague-Dawley rats were randomized to either high-tidal volume or low-tidal volume ventilation (control) and monitored for 4h. The high-tidal volume group was further divided into either a vagotomy or sham-operated group and each surgery group was further divided into two subgroups: normocapnia and hypercapnia. Injuries were assessed hourly through hemodynamics, respiratory mechanics and gas exchange. Protein concentration, cell count and cytokines (TNF-α and IL-8) in bronchoalveolar lavage fluid (BALF), lung wet-to-dry weight and pathological changes were examined. Vagus nerve activity was recorded for 1h. RESULTS: Compared to the control group, injurious ventilation resulted in a decrease in PaO2/FiO2 and greater lung static compliance, MPO activity, enhanced BALF cytokines, protein concentration, cell count, and histology injury score. Conversely, hypercapnia significantly improved VILI by decreasing the above injury parameters. However, vagotomy abolished the protective effect of hypercapnia on VILI. In addition, hypercapnia enhanced efferent vagus nerve activity compared to normocapnia. CONCLUSION: These results indicate that the vagus nerve plays an important role in mediating the anti-inflammatory effect of hypercapnia on VILI.

Mechanism of Cxc Chemokine Ligand 5 (CXCL5)/Cxc Chemokine Receptor 2 (CXCR2) Bio-Axis in Mice with Acute Respiratory Distress Syndrome.

BACKGROUND Acute respiratory distress syndrome (ARDS) is a common acute and severe disease in clinic. Recent studies indicated that Cxc chemokine ligand 5 (CXCL5), an inflammatory chemokine, was associated with tumorigenesis. The present study investigated the role of the CXCL5/Cxc chemokine receptor 2 (CXCR2) bio-axis in ARDS, and explored the underlying molecular mechanism. MATERIAL AND METHODS The pathological morphology of lung tissue and degree of pulmonary edema were assessed by hematoxylin-eosin staining and pulmonary edema score, respectively. Real-time PCR and Western blot analysis were performed to detect the expression levels of CXCL5, CXCR2, Matrix metalloproteinases 2 (MMP2), and Matrix metalloproteinases 9 (MMP9) in lung tissues. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the expression levels of CXCL5 and inflammatory factors (IL-1ß, IL-6, TNF-alpha, and IL-10) in serum. RESULTS The results demonstrated that diffuse alveolar damage and pulmonary edema appeared in lipopolysaccharide (LPS)-induced ARDS and were positively correlated with the severity of ARDS. In addition, CXCL5 and its receptor CXCR2 were overexpressed by upregulation of MMP2 and MMP9 in lung tissues of ARDS. In addition, CXCL5 neutralizing antibody effectively alleviated inflammatory response, diffuse alveolar damage, and pulmonary edema, and decreased the expression levels of MMP2 and MMP9 compared to LPS-induced ARDS. CONCLUSIONS We found that CXCL5/CXCR2 accelerated the progression of ARDS, partly by upregulation of MMP2 and MMP9 in lung tissues with the release of inflammatory factors.

XueBiJing Injection Versus Placebo for Critically Ill Patients With Severe Community-Acquired Pneumonia: A Randomized Controlled Trial.

OBJECTIVES: To investigate whether XueBiJing injection improves clinical outcomes in critically ill patients with severe community-acquired pneumonia. DESIGN: Prospective, randomized, controlled study. SETTING: Thirty-three hospitals in China. PATIENTS: A total of 710 adults 18-75 years old with severe community-acquired pneumonia. INTERVENTIONS: Participants in the XueBiJing group received XueBiJing, 100 mL, q12 hours, and the control group received a visually indistinguishable placebo. MEASUREMENTS AND MAIN RESULTS: The primary outcome was 8-day improvement in the pneumonia severity index risk rating. Secondary outcomes were 28-day mortality rate, duration of mechanical ventilation and total duration of ICU stay. Improvement in the pneumonia severity index risk rating, from a previously defined endpoint, occurred in 203 (60.78%) participants receiving XueBiJing and in 158 (46.33%) participants receiving placebo (between-group difference [95% CI], 14.4% [6.9-21.8%]; p < 0.001). Fifty-three (15.87%) XueBiJing recipients and 84 (24.63%) placebo recipients (8.8% [2.4-15.2%]; p = 0.006) died within 28 days. XueBiJing administration also decreased the mechanical ventilation time and the total ICU stay duration. The median mechanical ventilation time was 11.0 versus 16.5 days for the XueBiJing and placebo groups, respectively (p = 0.012). The total duration of ICU stay was 12 days for XueBiJing recipients versus 16 days for placebo recipients (p = 0.004). A total of 256 patients experienced adverse events (119 [35.63%] vs 137 [40.18%] in the XueBiJing and placebo groups, respectively [p = 0.235]). CONCLUSIONS: In critically ill patients with severe community-acquired pneumonia, XueBiJing injection led to a statistically significant improvement in the primary endpoint of the pneumonia severity index as well a significant improvement in the secondary clinical outcomes of mortality, duration of mechanical ventilation and duration of ICU stay.

Inhibition of MRP4 alleviates sepsis-induced acute lung injury in rats.

This study was undertaken to examine the regulatory role of multidrug resistance-associated protein 4 (MRP4) in an experimental model of sepsis-induced acute lung injury in rats. Sepsis was induced by cecal ligation and puncture in anesthetized rats. Animals were then randomly assigned to receive intravenous injection of vehicle or MRP4 inhibitor (MK571, 20 mg/kg). The pathological changes were observed by hematoxylin and eosin staining. Lung water content, lung vascular permeability and inflammatory cell count in bronchoalveolar lavage fluid (BALF) were quantified. Serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels were measured. In addition, lung tissue cyclic adenosine monophosphate (cAMP) levels were examined by enzyme-linked immunosorbent assay. Furthermore, the effects of MRP4 knockdown on lipopolysaccharide (LPS)-induced endothelial permeability and the cytoskeleton of rat pulmonary microvascular endothelial cells (PMVECs) were detected. The protein expression levels of MRP4, Rac1, VE-cadherin, ß-catenin and ZO-1 were measured by Western blot analysis. MK571 significantly reduced lung tissue damage, lung water content and lung vascular permeability. Lung tissue cAMP levels were attenuated in MK571-treated animals compared with vehicle controls. MK571 also decreased sepsis-induced inflammatory cell accumulation in BALF. In addition, the MK571 group had significantly lower serum TNF-α and IL-6 levels compared with vehicle controls. Consistently, knockdown of MRP4 protected against LPS-induced increase in the endothelial permeability and the destruction of cytoskeleton in vitro. Furthermore, silencing MRP4 gene significantly reduced MRP4 protein expression and restored the protein expression of Rac1, VE-cadherin, ß-catenin and ZO-1 in rat PMVECs in response to LPS stimulation. These data suggest that inhibition of MRP4 significantly alleviates sepsis-induced acute lung injury in rats.

Hypercapnia attenuates ventilator-induced lung injury through vagus nerve activation

Abstract Purpose: To investigate the role of vagus nerve activation in the protective effects of hypercapnia in ventilator-induced lung injury (VILI) rats. Methods: Male Sprague-Dawley rats were randomized to either high-tidal volume or low-tidal volume ventilation (control) and monitored for 4h. The high-tidal volume group was further divided into either a vagotomy or sham-operated group and each surgery group was further divided into two subgroups: normocapnia and hypercapnia. Injuries were assessed hourly through hemodynamics, respiratory mechanics and gas exchange. Protein concentration, cell count and cytokines (TNF-α and IL-8) in bronchoalveolar lavage fluid (BALF), lung wet-to-dry weight and pathological changes were examined. Vagus nerve activity was recorded for 1h. Results: Compared to the control group, injurious ventilation resulted in a decrease in PaO2/FiO2 and greater lung static compliance, MPO activity, enhanced BALF cytokines, protein concentration, cell count, and histology injury score. Conversely, hypercapnia significantly improved VILI by decreasing the above injury parameters. However, vagotomy abolished the protective effect of hypercapnia on VILI. In addition, hypercapnia enhanced efferent vagus nerve activity compared to normocapnia. Conclusion: These results indicate that the vagus nerve plays an important role in mediating the anti-inflammatory effect of hypercapnia on VILI.

Enteral nutrition feeding in Chinese intensive care units: a cross-sectional study involving 116 hospitals.

BACKGROUND: There is a lack of large-scale epidemiological data on the clinical practice of enteral nutrition (EN) feeding in China. This study aimed to provide such data on Chinese hospitals and to investigate factors associated with EN delivery. METHODS: This cross-sectional study was launched in 118 intensive care units (ICUs) of 116 mainland hospitals and conducted on April 26, 2017. At 00:00 on April 26, all patients in these ICUs were included. Demographic and clinical variables of patients on April 25 were obtained. The dates of hospitalization, ICU admission and nutrition initiation were reviewed. The outcome status 28 days after the day of investigation was obtained. RESULTS: A total of 1953 patients were included for analysis, including 1483 survivors and 312 nonsurvivors. The median study day was day 7 (IQR 2-19 days) after ICU entry. The proportions of subjects starting EN within 24, 48 and 72 h after ICU entry was 24.8% (84/352), 32.7% (150/459) and 40.0% (200/541), respectively. The proportion of subjects receiving > 80% estimated energy target within 24, 48, 72 h and 7 days after ICU entry was 10.5% (37/352), 10.9% (50/459), 11.8% (64/541) and 17.8% (162/910), respectively. Using acute gastrointestinal injury (AGI) 1 as the reference in a Cox model, patients with AGI 2-3 were associated with reduced likelihood of EN initiation (HR 0.46, 95% CI 0.353-0.599; p < 0.001). AGI 4 was significantly associated with lower hazard of EN administration (HR 0.056; 95% CI 0.008-0.398; p = 0.004). In a linear regression model, greater Sequential Organ Failure Assessment scores (coefficient - 0.002, 95% CI - 0.008 to - 0.001; p = 0.024) and male gender (coefficient - 0.144, 95% CI - 0.203 to - 0.085; p < 0.001) were found to be associated with lower EN proportion. As compared with AGI 1, AGI 2-3 was associated with lower EN proportion (coefficient - 0.206, 95% CI - 0.273 to - 0.139; p < 0.001). CONCLUSIONS: The study showed that EN delivery was suboptimal in Chinese ICUs. More attention should be paid to EN use in the early days after ICU admission.

MiR-6835 promoted LPS-induced inflammation of HUVECs associated with the interaction between TLR-4 and AdipoR1 in lipid rafts.

BACKGROUND: High mortality rate of critically-ill patients could be induced by sepsis and septic shock, which is the extremely life threatening. The purpose of this work is to identify and evaluate the potential regulatory mechanism of LPS-induced inflammation associated with miR-6835 and lipid rafts in HUVECs. METHODS: The 3' UTR luciferase activity of AdipoR1 was detected, which was predicted the potential target gene of miR-6835. Moreover, the treated HUVECs with or without inhibitors or mimics of miR-6835 were used. Furthermore, the bio-functions of HUVECs were explored. The protein expression levels of SIRT-1, AMPK, and AdipoR1 were assessed, which were involved in the AdipoR1 signaling pathway. Then, the interaction between TLR-4 and AdipoR1 in lipid rafts and its mediation role on LPS-induced inflammation was investigated in HUVECs. RESULTS: MiR-6835 targeted directly on AdipoR1, and suppressed its expression in mRNA (mimics of miR-6835: 0.731±0.016 vs control: 1.527±0.015, P<0.001) and proteins levels, then regulated protein expression of SIRT-1 and AMPK, which were the downstream target genes of AdipoR1 signaling pathway. MiR-6835 enhanced LPS-induced inflammation process in HUVECs (TNF-α: LPS+mimics of miR-6835: 1638.51±78.43 vs LPS: 918.73±39.73, P<0.001; IL-6: LPS+mimics of miR-6835: 1249.35±69.51 vs LPS: 687.52±43.64, P<0.001), which was associated with the interaction between TLR-4 and AdipoR1 in lipid rafts. CONCLUSIONS: MiR-6835 is the key regulator of LPS-induced inflammation process in HUVECs. The interaction between TLR-4 and AdipoR1 mediated by lipid rafts at membrane of HUVECs with inflammation process induced by miR-6835. Our results demonstrated a hopeful strategy for treatment on sepsis by aiming at lipid rafts and miR-6835.

[Effect of multidrug resistant associated protein 4 overexpression on lipopolysaccharide-induced vascular endothelial hyperpermeability and its mechanism].

OBJECTIVE: To investigate the effect of multidrug resistance protein 4 (MRP4) overexpression on lipopolysaccharide (LPS)-induced vascular endothelial hyperpermeability of rat pulmonary micro-vascular endothelial cells (PMVECs) and its molecule mechanism. METHODS: Three to six passages of PMVECs were cultured in vitro, and they were divided into three groups: the cells in LPS group were only challenged by LPS 10 µg/mL after being cultured in serum-free medium for 24 hours; the cells in Ad-shRNA and Ad-MRP4 groups were infected with the empty virus control or recombinant adenovirus expressing MRP4 for 2 hours, and then were cultured in serum-free medium for 24 hours followed by stimulation of LPS 10 µg/mL. Endothelial permeability was assayed by the Transwell chamber models at 2, 6, 12, and 24 hours after LPS stimulation. Intracellular cyclic adenosine monophosphate (cAMP) levels were detected by enzyme-linked immunosorbent assay (ELISA). The morphological characteristics and distribution of F-actin was determined by laser confocal fluorescence microscope. The protein expressions of MRP4, ß-catenin, vascular endothelium-cadherin (VE-cad) and ZO-1 were measured by Western Blot. RESULTS: (1) After LPS stimulation, endothelium permeability and intracellular cAMP levels in PMVECs were significantly increased, peaked at 12 hours, and then decreased after 24 hours. Compared with LPS group and Ad-shRNA group, PMVECs of Ad-MRP4 group were exhibited a significant increase in endothelial permeability [12-hour permeability (A value): 1.88±0.06 vs. 1.12±0.17, 1.10±0.18] and a significant decrease in intracellular cAMP level [12-hour cAMP (µg/L): 2.39±0.02 vs. 2.97±0.01, 3.00±0.02, all P < 0.05]. There was no significant difference in endothelium permeability and intracellular cAMP levels at all time points between the LPS group and the Ad-shRNA group (all P > 0.05). (2) Under laser confocal fluorescence microscope, after LPS stimulation, the stress fiber formation was induced in three groups. But there were pronounced irregular aggregation of fiber in PMVECs of Ad-MRP4 group. (3) Furthermore, compared with LPS group and Ad-shRNA group, protein expression of MRP4 in Ad-MRP4 group was dramatically increased (gray value: 0.76±0.03 vs. 0.44±0.02, 0.43±0.02, both P < 0.05), and the protein expressions of ß-catenin, VE-cad, and ZO-1 were significantly decreased [ß-catenin (gray value): 0.14±0.03 vs. 0.23±0.04, 0.23±0.03); VE-cad (gray value): 0.21±0.01 vs. 0.34±0.02, 0.35±0.04; ZO-1 (gray value): 0.14±0.02 vs. 0.37±0.06, 0.33±0.07, all P < 0.05]. There was no significant difference in all protein expressions between the LPS group and Ad-shRNA group (all P > 0.05). CONCLUSIONS: MRP4 overexpression can decrease intracellular cAMP levels, reduce intercellular junction protein expression, and then exaggerate LPS-induced vascular endothelial hyperpermeability.

Lipopolysaccharide Stimulates Surfactant Protein-A in Human Renal Epithelial HK-2 Cells through Upregulating Toll-like Receptor 4 Dependent MEK1/2-ERK1/2-NF-κB Pathway.

BACKGROUND: Surfactant protein-A (SP-A) contributes to the regulation of sepsis-induced acute kidney injury. In a previous study, we demonstrated that the expression of SP-A in the human renal tubular epithelial (HK-2) cells can be stimulated by lipopolysaccharide (LPS). The present study evaluated the possible signal-transducing mechanisms of LPS-induced SP-A biosynthesis in the HK-2 cells. METHODS: Tetrazolium salt colorimetry (MTT) assay was used to detect cell viability of HK-2 cells after LPS stimulation on different time points. HK-2 cells were stimulated with 100 ng/ml of LPS for different durations to determine the effects of LPS on SP-A and toll-like receptor 4 (TLR4) messenger RNA (mRNA) expression, as well as phosphorylation of mitogen-activated/extracellular signal-regulated kinase (MEK) 1, extracellular signal-regulated kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase (p38MAPK), and nuclear factor-kappa B (NF-κB) inhibitor-alpha (IkB-α). Then, HK-2 cells were pretreated with CLI-095, a TLR4 inhibitor, to analyze mRNA and protein levels of SP-A and TLR4 and expression of NF-κB in the cytoplasm and nucleus of HK-2 before LPS exposure. RESULTS: HK-2 cells exposed to 100 ng/ml of LPS for 1, 6, and 24 h did not affect cell viability which showed no toxic effect of 100 ng/ml LPS on cells (P = 0.16); however, the biosynthesis of SP-A mRNA and protein in HK-2 cells was significantly increased (P = 0.02). As to the mechanism, LPS enhanced transmembrane receptor TLR4 protein expression. Sequentially, LPS time dependently augmented phosphorylation of MEK1, ERK1/2, and p38MAPK. In addition, levels of phosphorylated IκB-α and nuclear NF-κB were augmented with LPS exposure for 2 h. LPS-induced SP-A and TLR4 mRNA as well as NF-κB expression were significantly inhibited by pretreatment with CLI-095. CONCLUSIONS: The present study exhibited that LPS can increase SP-A synthesis in human renal epithelial cells through sequentially activating the TLR4-related MEK1-ERK1/2-NF-κB-dependent pathway.

Upregulation of TSPAN12 is associated with the colorectal cancer growth and metastasis.

Tetraspanin 12 (TSPAN12), as an earliest member of tetraspanin family, has been recently shown to be highly expressed in several malignant tumors, such as lung cancer and breast cancer, which plays an important role in regulating cell proliferation, migration and invasion. However, the functional roles of TSPAN12 in colorectal cancer (CRC) remain largely unclear. In this study, the expression of TSPAN12 was up-regulated compared to that in paracarcinoma tissues. Higher TSPAN12 expression was significantly correlated with TNM stage, tumor size and lymph node metastasis. The vitro functional analysis, including MTT, colony formation, flow cytometry and transwell assays indicated that lentivirus-mediated TSPAN12 knockdown significantly suppressed cell proliferation, migration and invasion, induced cell apoptosis of CRC cells. In addition, knockdown of TSPAN12 remarkably decreased the growth of subcutaneously inoculated tumors in nude mice. Our findings for the first time supported that TSPAN12 might play a positive role in the regulation of CRC cell proliferation, migration and invasion. The inhibition of TSPAN12 may serve as a novel promising therapeutic strategy against human CRC.

Surfactant protein-D (SP-D) gene polymorphisms and serum level as predictors of susceptibility and prognosis of acute kidney injury in the Chinese population.

BACKGROUND: Injury to the kidney epithelial barrier is a characteristic feature of acute kidney injury (AKI). Serum surfactant protein-D (SP-D), a known biomarker of damaged alveolar epithelium, is also secreted by renal tubular epithelial cells. Therefore, the aim of this study was to examine the possible association of SP-D with AKI susceptibility and prognosis. METHODS: In this study, 159 AKI patients and 120 healthy individuals were included. SP-D polymorphisms Thr11Met and Thr160Ala, AKI patient serum SP-D levels at days 1, 3 and 7 and urine KIM-1 levels in both AKI patients and controls were examined. The obtained results were correlated with the AKI stage, duration of renal replacement therapy (RRT) and prognosis. RESULTS: Serum SP-D level in AKI patients was higher than controls (p < 0.01). SP-D 11Thr/Thr genotype was more frequent in AKI patients than in controls (p < 0.01). Furthermore, AKI patients with SP-D 11Thr/Thr genotype had significantly higher serum SP-D levels (p < 0.05) compared to other genotypes. Serum SP-D levels corrected to the progression of AKI with a peak at day 3. Furthermore, the SP-D 11Thr/Thr genotype frequency and baseline serum SP-D level were higher in patients who subsequently died. Baseline serum SP-D levels positively correlated with the urine KIM-1 levels, AKI stage and RRT duration. CONCLUSION: In our study, elevated serum SP-D was associated with worse AKI clinical outcomes and patients with SP-D 11Thr/Thr genotype were more susceptible to AKI. Collectively, these findings suggest that SP-D may be useful as a biomarker of AKI susceptibility and prognosis.