Identification of HK3 as a promising immunomodulatory and prognostic target in sepsis-induced acute lung injury.

BACKGROUND: Sepsis is a life-threatening global disease with a significant impact on human health. Acute lung injury (ALI) has been identified as one of the primary causes of mortality in septic patients. This study aimed to identify candidate genes involved in sepsis-induced ALI through a comprehensive approach combining bioinformatics analysis and experimental validation. METHODS: The datasets GSE65682 and GSE32707 obtained from the Gene Expression Omnibus database were merged to screen for sepsis-induced ALI related differentially expressed genes (DEGs). Functional enrichment and immune infiltration analyses were conducted on DGEs, with the construction of protein-protein interaction (PPI) networks to identify hub genes. In vitro and in vivo models of sepsis-induced ALI were used to study the expression and function of hexokinase 3 (HK3) using various techniques including Western blot, real-time PCR, immunohistochemistry, immunofluorescence, Cell Counting Kit-8, Enzyme-linked immunosorbent assay, and flow cytometry. RESULTS: The results of bioinformatics analysis have identified HK3, MMP9, and S100A8 as hub genes with diagnostic and prognostic significance for sepsis-induced ALI. The HK3 has profound effects on sepsis-induced ALI and exhibits a correlation with immune regulation. Experimental results showed increased HK3 expression in lung tissue of septic mice, particularly in bronchial and alveolar epithelial cells. In vitro studies demonstrated upregulation of HK3 in lipopolysaccharide (LPS)-stimulated lung epithelial cells, with cytoplasmic localization around the nucleus. Interestingly, following the knockdown of HK3 expression, lung epithelial cells exhibited a significant decrease in proliferation activity and glycolytic flux, accompanied by an increase in cellular inflammatory response, oxidative stress, and cell apoptosis. CONCLUSIONS: It was observed for the first time that HK3 plays a crucial role in the progression of sepsis-induced ALI and may be a valuable target for immunomodulation and therapy.Bioinformatics analysis identified HK3, MMP9, and S100A8 as hub genes with diagnostic and prognostic relevance in sepsis-induced ALI. Experimental findings showed increased HK3 expression in the lung tissue of septic mice, particularly in bronchial and alveolar epithelial cells. In vitro experiments demonstrated increased HK3 levels in lung epithelial cells stimulated with LPS, with cytoplasmic localization near the nucleus. Knockdown of HK3 expression resulted in decreased proliferation activity and glycolytic flux, increased inflammatory response, oxidative stress, and cell apoptosis in lung epithelial cells.

MIF signaling blocking alleviates airway inflammation and airway epithelial barrier disruption in a HDM-induced asthma model.

Recent studies have indicated that Macrophage migration inhibitory factor (MIF) plays an important role in the prevention and treatment of asthma. However the role of MIF in airway inflammation and airway epithelial barrier disruption in house dust mite (HDM)-induced asthma has not been addressed. We hypothesized that MIF contributed to HDM-induced the production of Th2-associated cytokines and E-cadherin dysfunction in asthmatic mice and 16HBE cells. In vivo, a HDM-induced asthma mouse model was set up and mice treated with MIF antagonist ISO-1 after HDM. The mice treated with the ISO-1 ameliorated airway hyper-reactivity, airway inflammation, increased serum IgE levels, the aberrant arrangement of E-cadherin as well as the release of Th2 cytokines induced by HDM. In vitro, the exposure of 16HBE cells to HDM and rhMIF resulted in airway epithelial barrier disruption, inflammatory cytokine production and enhanced glycolytic flux. While these changes were attenuated by MIF siRNA treatment. Sequentially, treatment of 16HBE cells with PFKFB3 antagonist PFK15 significantly lowered rhMIF-induced these changes in 16HBE cells. Therefore, these results indicate that MIF may be an important contributor in airway inflammation and airway epithelial barrier disruption of HDM-induced asthma. Moreover, HDM specifically induces airway inflammation and airway epithelial barrier disruption of 16HBE cells through MIF-mediated enhancement of aerobic glycolysis.

FABP4 inhibitors suppress inflammation and oxidative stress in murine and cell models of acute lung injury.

Acute lung injury (ALI) is a severe disease with high morbidity and mortality, and is characterized by devastating inflammation of the lung and increased production of reactive oxygen species (ROS). Recent studies have indicated that fatty acid binding protein (FABP4) is important in the regulation of inflammation. However, the role of FABP4 in sepsis-related ALI, and the specific mechanism of action have not been examined. In vitro, the exposure of human alveolar epithelial A549 cells to lipopolysaccharide (LPS) and recombinant FABP4 (hrFABP4) resulted in the production of pro-inflammatory cytokines, inflammatory cytokines, and ROS, while these changes were ameliorated by pretreatment with the FABP4 inhibitor BMS309403 and FABP4 siRNA. Sequentially, treatment of A549 cells with N-acetylcysteine (NAC) significantly attenuated LPS and hrFABP4-induced the generation of ROS and the release of inflammatory cytokines. In vivo, a cecal ligation and puncture (CLP)-induced ALI murine model was successfully established. Then, the mice were treated with FABP4 inhibitor BMS309403. The results showed treatment with BMS309403 improved the survival rate of CLP-induced ALI mice, and prevented lung inflammation, histopathological changes, and increase of FABP4 induced by CLP. These data indicate that FABP4 plays an important role in lung inflammation of sepsis-induced ALI. Blockade of FABP4 signaling exhibits a protective effect in a CLP-induced ALI mouse model, and in A549 cell LPS specifically induces enhanced expression of FABP4, which then causes inflammatory cytokine production by elevating the ROS level.

Macrophage migration inhibitory factor (MIF) promotes rat airway muscle cell proliferation and migration mediated by ERK1/2 and FAK signaling.

Macrophage migration inhibitory factor (MIF) is an inflammatory mediator that contributes to asthmatic airway remodeling; however, little is known regarding the effects of MIF on airway smooth muscle cells (ASMCs). In the present study, we found that an enhanced expression of MIF promoted ASMC proliferation, increased the population of cells in the S/G2 phase, downregulated P21 expression, and upregulated cyclin D1, cyclin D3, and Cdk6 expression. In addition, the apoptosis of ASMCs was significantly decreased in response to MIF overexpression, compared with the negative control. Moreover, MIF facilitated the migration of ASMCs by upregulating the expression of matrix metalloproteinase (MMP)-2. Finally, we showed that MIF increased the phosphorylation of extracellular regulated protein kinases (ERK) 1/2 and focal adhesion kinase (FAK), which are associated with proliferation and migration. In conclusion, this study demonstrated that MIF overexpression promotes the proliferation and migration of ASMCs by upregulating the activity of the ERK1/2 and FAK signaling pathways in these cells, further indicating that inhibition of MIF may prove to be an effective strategy for treating asthma patients with airway remodeling.

A COL1A1 Promoter-Controlled Expression of TGF-ß Soluble Receptor Inhibits Hepatic Fibrosis Without Triggering Autoimmune Responses.

BACKGROUND: Soluble TGF-ß1 type II receptor (sTßRII) via TGF-ß1 inhibition could inhibit hepatic fibrosis, but over-dosage triggers autoimmune responses. AIM: To test whether the use of a TGF-ß1-responsive collagen I promoter COL1A1, via generating a feedback loop to TGF-ß1 level, could offer accurate control on sTßRII expression. METHODS: Recombinant adenoviruses with COL1A1 (Ad-COL-sTßRII/Luc) or CMV promoter (Ad-CMV-sTßRII/Luc) were constructed and characterized. Inhibition of TGF-ß activity was determined both in vitro and in vivo. Total and bioactive TGF-ß, hepatic fibrosis scale, α-SMA, collagen levels, and liver function were determined. RESULTS: COL1A1, but not CMV, responded to TGF-ß1 in vitro. Both in vitro and in vivo, Ad-COL-sTßRII could significantly, but not completely inhibit TGF-ß1 activity while Ad-CMV-sTßRII almost completely inhibited TGF-ß1 activity. As evidenced by fibrosis scale, α-SMA, and collagen levels in liver tissue, Ad-COL-sTßRII and Ad-CMV-sTßRII had comparable efficacies in treating hepatic fibrosis. Ad-COL-sTßRII was better than Ad-CMV-sTßRII in liver function restore. Ad-CMV-sTßRII, but not Ad-COL-sTßRII, induced high level of anti-dsDNA and anti-Sm antibodies in rats. CONCLUSIONS: COL1A1 can precisely control sTßRII expression to inhibit excessive bioactive TGF-ß level and thus inhibit hepatic fibrosis but without inducing autoimmune responses.

Blockage of glycolysis by targeting PFKFB3 alleviates sepsis-related acute lung injury via suppressing inflammation and apoptosis of alveolar epithelial cells.

Sepsis-related acute lung injury (ALI) is characterized by excessive lung inflammation and apoptosis of alveolar epithelial cells resulting in acute hypoxemic respiratory failure. Recent studies indicated that anaerobic glycolysis play an important role in sepsis. However, whether inhibition of aerobic glycolysis exhibits beneficial effect on sepsis-induced ALI is not known. In vivo, a cecal ligation and puncture (CLP)-induced ALI mouse model was set up and mice treated with glycolytic inhibitor 3PO after CLP. The mice treated with the 3PO ameliorated the survival rate, histopathological changes, lung inflammation, lactate increased and lung apoptosis of mice with CLP-induced sepsis. In vitro, the exposure of human alveolar epithelial A549 cells to lipopolysaccharide (LPS) resulted in cell apoptosis, inflammatory cytokine production, enhanced glycolytic flux and reactive oxygen species (ROS) increased. While these changes were attenuated by 3PO treatment. Sequentially, treatment of A549 cells with lactate caused cell apoptosis and enhancement of ROS. Pretreatment with N-acetylcysteine (NAC) significantly lowered LPS and lactate-induced the generation of ROS and cell apoptosis in A549 cells. Therefore, these results indicate that anaerobic glycolysis may be an important contributor in cell apoptosis of sepsis-related ALI. Moreover, LPS specifically induces apoptotic insults to A549 cell through lactate-mediated enhancement of ROS.

Cuproptosis-related Gene Signatures and Immunological Characterization in Sepsis-associated Acute Lung Injury.

BACKGROUND: Sepsis is a frequent cause of acute lung injury (ALI), characterized by immune dysregulation and a high mortality rate. The role of cuproptosis, a recently discovered cell death mechanism, in sepsis-associated ALI is still unclear. The study aimed to investigate the regulatory mechanisms and immune characteristics associated with cuproptosis in sepsisassociated ALI, with implications for novel diagnostic and therapeutic approaches. METHODS: Data from the GEO database was utilized to conduct a comprehensive analysis of the cuproptosis-related genes (CRGs) in sepsis-associated ALI. Gene enrichment analysis, WGCNA, CIBERSORT algorithm, and consensus clustering were employed to investigate the associations between CRGs and immune cells. A predictive model for sepsis-associated ALI was developed based on key CRGs, and its diagnostic accuracy was assessed. Finally, qPCR was employed to validate alterations in the expression of CRGs in the sepsis-associated ALI cellular model. RESULTS: A total of 14 CRGs were identified in sepsis-associated ALI. Strong correlations between the CRGs and immune cells were observed, and two different CRG subtypes were identified. The expression of immune-related factors in both the CRG and gene clusters exhibited similarities, suggesting a connection between the subgroups and immune cells. The prediction model effectively forecasted the incidence of sepsis-associated ALI based on the expression of CRGs. Finally, qPCR analysis confirmed that the expressions of CRGs in the sepsis-associated ALI cell model closely matched those identified through bioinformatic analyses. CONCLUSION: The study comprehensively evaluated the complex relationship between cuproptosis and sepsis-associated ALI. CRGs were found to be significantly associated with the occurrence, immune characteristics, and biological processes of sepsis-associated ALI. These findings provide valuable new insights into the mechanisms underlying sepsis-associated ALI.

[Signal transducer and activator of transcription 6 mediates skeletal muscle cell injury in septic mice by regulating ferroptosis].

OBJECTIVE: To explore the effect of signal transducer and activator of transcription 6 (STAT6) on ferroptosis in skeletal muscle cells in sepsis model and its potential mechanism. METHODS: Twenty-four 8-week-old male specific pathogen free Kunming mice were divided into normal control group, sham group, sepsis model group and STAT6 inhibitor pretreatment group according to random number table method with 6 mice in each group. A mouse sepsis model was reproduced by cecal ligation and perforation (CLP). In the sham group, the skin of mice was sutured after exposing the cecum tissue. In the STAT6 inhibitor pretreatment group, 10 mg/kg AS1517499 was injected intraperitoneally 1 hour before model reproduction. The sham group and the model group were intraperitoneally injected with the same volume of normal saline. Mice in the normal control group did not receive any operation or drug intervention. The mice were sacrificed 24 hours after model reproduction, and the muscle tissue of hind limb was obtained under sterile condition. Hematoxylin-eosin (HE) staining was used to observe the histopathology with optical microscope, and mitochondrial morphological changes were observed by transmission electron microscopy after double staining with uranium acetate lead citrate. The ferroptosis marker proteins expressions of chitinase-3-like protein 1 (CHI3L1), cyclooxygenase-2 (COX-2), acyl-CoA synthetase long-chain family member 4 (ACSL4), ferritin heavy chain 1 (FTH1), and glutathione peroxidase 4 (GPx4) were detected by Western blotting. RESULTS: Under the optical microscope, the morphology and structure of skeletal muscle tissues in the normal control and sham groups were normal. In the model group, the structure of skeletal muscle tissues was loose, the muscle fiber became smaller and atrophic, inflammatory cell infiltration and even muscle fiber loss were found. Compared with the model group, the structure of skeletal muscle tissues was tight and skeletal muscle atrophy was improved in the STAT6 inhibitor pretreatment group. The ultrastructure of skeletal muscle cell in the normal control and sham groups was normal under transmission electron microscope. The ultrastructure characteristics of skeletal muscle in the model group showed that cell membrane was broken and blister, mitochondria became smaller and membrane density increased, the mitochondrial crista decreased or disappeared, the mitochondrial outer membrane was broken, and the nucleus was normal in size but lacked chromatin condensation. Compared with the model group, the STAT6 inhibitor pretreatment group had a significant improvement in the ultrastructure of muscle cells. Compared with the normal control and sham groups, the protein expressions of CHI3L1, COX-2, ACSL4 and FTH1 in the muscle of the model group were significantly increased, while the protein expression of GPx4 was decreased significantly, indicating that the skeletal muscle cells in the mouse sepsis model showed characteristic mitochondrial injury and abnormal expression of ferroptosis markers. Compared with the model group, the protein expressions of CHI3LI, COX-2, ACSL4 and FTH1 in the STAT6 inhibitor pretreatment group were significantly decreased [CHI3L1 protein (CHI3L1/GAPDH): 0.70±0.08 vs. 0.97±0.09, COX-2 protein (COX-2/GAPDH): 0.61±0.03 vs. 0.83±0.03, ACSL4 protein (ACSL4/GAPDH): 0.75±0.04 vs. 1.02±0.16, FTH1 protein (FTH1/GAPDH): 0.49±0.06 vs. 0.76±0.13, all P < 0.05], while the protein expression of GPx4 was significantly increased (GPx4/GAPDH: 1.14±0.29 vs. 0.53±0.03, P < 0.05). CONCLUSIONS: Sepsis can induce ferroptosis in skeletal muscle cells of mice. STAT6 may mediate ferroptosis in mouse skeletal muscle cells by regulating the expressions of COX-2, ACSL4, FTH1 and GPx4, thereby inducing skeletal muscle cell injury in sepsis.

Impact of heart failure on outcomes in patients with sepsis: A systematic review and meta-analysis.

BACKGROUND: Heart failure (HF) often affects the progress of sepsis patients, although its impact on outcomes is inconsistent and inconclusive. AIM: To conduct a systematic review and meta-analysis of the impact of HF on mortality in patients with sepsis. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library databases were searched to compare the outcomes of sepsis patients with HF. A random effect model was used to summarize the mortality data, and the odds ratio (OR) and 95% confidence interval (CI) were calculated as effect indicators. RESULTS: Among 18001 records retrieved in the literature search, 35712 patients from 10 separate studies were included. The results showed that sepsis patients with HF were associated with increased total mortality (OR = 1.80, 95%CI: 1.34-2.43; I2 = 92.1%), with high heterogeneity between studies. Significant subgroup differences according to age, geographical location, and HF patient sample were observed. HF did not increase the 1-year mortality of patients (OR = 1.11, 95%CI: 0.75-1.62; I2 = 93.2%), and the mortality of patients with isolated right ventricular dysfunction (OR=2.32, 95%CI: 1.29-4.14; I2 = 91.5%) increased significantly. CONCLUSION: In patients with sepsis, HF is often associated with adverse outcomes and mortality. Our results call for more high-quality research and strategies to improve outcomes for sepsis patients with HF.

Effect of the Lipoxin Receptor Agonist BML-111 on Cigarette Smoke Extract-Induced Macrophage Polarization and Inflammation in RAW264.7 Cells.

Background: Macrophages are known to play a crucial role in the chronic inflammation associated with Chronic Obstructive Pulmonary Disease (COPD). BML-111, acting as a lipoxin A4 (LXA4) receptor agonist, has shown to be effective in protecting against COPD. However, the precise mechanism by which BML-111 exerts its protective effect remains unclear. Methods: In order to establish a cell model of inflammation, cigarette smoke extract (CSE) was used on the RAW264.7 cell line. Afterwards, an Enzyme-linked immunosorbent assay (ELISA) kit was employed to measure concentrations of tumor necrosis factor-α (TNF-α), interleukin-1beta (IL-1ß), interleukin-18 (IL-18), and interleukin-10 (IL-10) in the cell supernatants of the RAW264.7 cells.In this study, we examined the markers of macrophage polarization using two methods: quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Additionally, we detected the expression of Notch-1 and Hes-1 through Western blotting. Results: BML-111 effectively suppressed the expression of pro-inflammatory cytokines TNF-α, IL-1ß, and IL-18, as well as inflammasome factors NLRP3 and Caspase-1, while simultaneously up-regulating the expression of the anti-inflammatory cytokine IL-10 induced by CSE. Moreover, BML-111 reduced the expression of iNOS, which is associated with M1 macrophage polarization, and increased the expression of Arg-1, which is associated with M2 phenotype. Additionally, BML-111 downregulated the expression of Hes-1 and the ratio of activated Notch-1 to Notch-1 induced by CSE. The effect of BML-111 on inflammation and macrophage polarization was reversed upon administration of the Notch-1 signaling pathway agonist Jagged1. Conclusion: BML-111 has the potential to suppress inflammation and modulate M1/M2 macrophage polarization in RAW264.7 cells. The underlying mechanism may involve the Notch-1 signaling pathway.

Dynamic Changes in Coagulation Function in Patients With Pneumonia Under Admission and Non-admission Treatment.

Objective: We aimed to explore the dynamic changes in coagulation function and the effect of age on coagulation function in patients with pneumonia under admission and non-admission treatment. Methods: We included 178 confirmed adult inpatients with COVID-19 from Wuhan Union Hospital Affiliated to Huazhong University of Science and Technology (Wuhan, China). Patients were classified into common types, and all were cured and discharged after hospitalization. We recorded the time of the first clinical symptoms of the patients and performed blood coagulation tests at the time of admission and after admission. In total, eight factors (TT, FIB, INR, APTT, PT, DD, ATIII, and FDP) were analyzed. Patients were classified into four groups according to the time from the first symptom onset to hospital admission for comparative analysis. The patients who were admitted within 2 weeks of disease onset were analyzed for the dynamic changes in their blood coagulation tests. Further division into two groups, one group comprising patients admitted to the hospital within 2 weeks after the onset of disease and the other comprising patients admitted to the hospital 2 weeks after disease onset, was performed to form two groups based on whether the patient ages were over or under 55 years. Chi-square tests and T tests were used to explore the dynamic changes in coagulation function and the influence of age on the results of coagulation function tests. Results: A total of 178 inpatients, 34 of whom underwent dynamic detection, were included in this analysis. We divided these patients into four groups according to the interval between the onset of COVID-19 pneumonia and the time to admission in the hospital: the 1-7 days (group 1), 8-14 days (group 2), 15-21 days (group 3), and >21-days (group 4). Eight factors all increased within 2 weeks after onset and gradually decreased to normal 2 weeks before the patient was admitted. The changes in coagulation function of patients admitted to the hospital were similar. After being admitted to the hospital, the most significant decreases among the eight factors were between week 2 and 3. There were distinct differences among the eight factors between people older than 55 years and those younger than 55 years. In the first 2 weeks after being admitted, the levels of the eight factors in patients >55 years were significantly higher than those in patients <55 years, and after another 2 weeks of treatment, the factor levels in both age groups returned to normal. Conclusion: The eight factors all increased within 2 weeks after onset and gradually decreased to normal after 2 weeks regardless of treatment. Compared with patients younger than 55 years, patients older than 55 years have greater changes in their blood coagulation test values.

[miR-181c inhibits glycolysis by targeting hexokinase 2 in cancer-associated fibroblasts].

OBJECTIVE: To investigate the role of miR-181c in glycolysis of cancer-associated fibroblasts (CAFs) and explore the mechanism. METHODS: Human lung CAFs and normal fibroblasts (NFs), isolated from fresh human lung adenocarcinoma tissue specimens by primary culture of tissue explants, were transfected with a miR -181c mimics, a miR-181c inhibitor, a siRNA siRNA-HK2 or the vector HK2-vector via Lipofectamine(TM) 2000. Quantitative real-time PCR was used to analyze the changes in miR-125b expression in the transfected cells; hexokinase-2 (HK2) protein expression in the cells was detected using Western blotting, and the cellular glucose uptake was assessed with 2-NBDG. Lactate production in the cells was examined and expression of HK2 mRNA was detected with dual luciferase reporter gene assay. RESULTS: No obvious difference was found in the cell morphology between CAFs and NFs. Compared with the NFs, the CAFs showed obviously increased glucose uptake, lactate production and HK2 protein expression with decreased expressions of the miR-181 family (P<0.05). Transfection with the miR-181 inhibito- rsignificantly increased glucose uptake, lactate production and HK2 protein expression in the NFs. In CAFs, transfection with the miR-181 mimics caused significantly lowered glucose uptake, lactate production and HK2 protein expression of. Knockdown of endogenous HK2 by siRNA abolished miR-181 mimics-mediated decrease of glucose uptake and lactate production in CAFs, while transfection with miR-181 mimics suppressed HK2 overexpression-induced enhancement of glucose uptake and lactate production in NFs. CONCLUSION: Transfection with miR-181 mimics can suppress glycolysis in CAFs by inhibiting HK2 expression.