LPS-induced monocarboxylate transporter-1 inhibition facilitates lactate accumulation triggering epithelial-mesenchymal transformation and pulmonary fibrosis.

The epithelial-mesenchymal transformation (EMT) process of alveolar epithelial cells is recognized as involved in the development of pulmonary fibrosis. Recent evidence has shown that lipopolysaccharide (LPS)-induced aerobic glycolysis of lung tissue and elevated lactate concentration are associated with the pathogenesis of sepsis-associated pulmonary fibrosis. However, it is uncertain whether LPS promotes the development of sepsis-associated pulmonary fibrosis by promoting lactate accumulation in lung tissue, thereby initiating EMT process. We hypothesized that monocarboxylate transporter-1 (MCT1), as the main protein for lactate transport, may be crucial in the pathogenic process of sepsis-associated pulmonary fibrosis. We found that high concentrations of lactate induced EMT while moderate concentrations did not. Besides, we demonstrated that MCT1 inhibition enhanced EMT process in MLE-12 cells, while MCT1 upregulation could reverse lactate-induced EMT. LPS could promote EMT in MLE-12 cells through MCT1 inhibition and lactate accumulation, while this could be alleviated by upregulating the expression of MCT1. In addition, the overexpression of MCT1 prevented LPS-induced EMT and pulmonary fibrosis in vivo. Altogether, this study revealed that LPS could inhibit the expression of MCT1 in mouse alveolar epithelial cells and cause lactate transport disorder, which leads to lactate accumulation, and ultimately promotes the process of EMT and lung fibrosis.

Borrelia burgdorferi sensu lato prevalence in Ixodes scapularis from Canada: a thirty-year summary and meta-analysis (1990-2020).

Borrelia burgdorferi sensu lato (Bb) are a complex of bacteria genospecies that can cause Lyme disease (LD) in humans after the bite of an infected Ixodes spp. vector tick. In Canada, incidence of LD is increasing in part due to the rapid geographic expansion of Ixodes scapularis across the southcentral and eastern provinces. To better understand temporal and spatial (provincial) prevalence of Bb infection of I. scapularis and how tick surveillance is utilized in Canada to assess LD risk, a literature review was conducted. Tick surveillance studies published between January 1975 to November 2023, that measured the prevalence of Bb in I. scapularis via "passive surveillance" from the public citizenry or "active surveillance" by drag or flag sampling of host-seeking ticks in Canada were included for review. Meta-analyses were conducted via random effects modeling. Forty-seven articles, yielding 26 passive and 28 active surveillance studies, met inclusion criteria. Mean durations of collection for I. scapularis were 2.1 years in active surveillance studies (1999-2020) and 5.5 years by passive surveillance studies (1990-2020). Collectively, data were extracted on 99,528 I. scapularis nymphs and adults collected between 1990-2020 across nine provinces, including Newfoundland & Labrador (33 ticks) and Alberta (208 ticks). More studies were conducted in Ontario (36) than any other province. Across nine provinces, the prevalence of Bb infection in I. scapularis collected by passive surveillance was 14.6% with the highest prevalence in Nova Scotia at 20.5% (minimum studies >1). Among host-seeking I. scapularis collected via active surveillance, Bb infection prevalence was 10.5% in nymphs, 31.9% in adults, and 23.8% across both life stages. Host-seeking I. scapularis nymphs and adults from Ontario had the highest Bb prevalence at 13.6% and 34.8%, respectively. Between 2007-2019, Bb infection prevalence in host-seeking I. scapularis was positively associated over time (p<0.001) which is concurrent with a ∼25-fold increase in the number of annually reported LD cases in Canada over the same period. The prevalence of Bb-infection in I. scapularis has rapidly increased over three decades as reported by tick surveillance studies in Canada which coincides with increasing human incidence for LD. The wide-ranging distribution and variable prevalence of Bb-infected I. scapularis ticks across provinces demonstrates the growing need for long-term standardized tick surveillance to monitor the changing trends in I. scapularis populations and best define LD risk areas in Canada.

Pharmacological inhibition of the ACE/Ang-2/AT1 axis alleviates mechanical ventilation-induced pulmonary fibrosis.

Mechanical ventilation (MV) is an essential therapy for acute respiratory distress syndrome (ARDS) and pulmonary fibrosis. However, it can also induce mechanical ventilation-induced pulmonary fibrosis (MVPF) and the underlying mechanism remains unknown. Based on a mouse model of MVPF, the present study aimed to explore the role of the angiotensin-converting enzyme/angiotensin II/angiotensin type 1 receptor (ACE/Ang-2/AT1R) axis in the process of MVPF. In addition, recombinant angiotensin-converting enzyme 2(rACE2), AT1R inhibitor valsartan, AGTR1-directed shRNA and ACE inhibitor perindopril were applied to verify the effect of inhibiting ACE/Ang-2/AT1R axis in the treatment of MVPF. Our study found MV induced an inflammatory reaction and collagen deposition in mouse lung tissue accompanied by the activation of ACE in lung tissue, increased concentration of Ang-2 in bronchoalveolar lavage fluid (BALF), and upregulation of AT1R in alveolar epithelial cells. The process of pulmonary fibrosis could be alleviated by the application of the ACE inhibitor perindopril, ATIR inhibitor valsartan and AGTR1-directed shRNA. Meanwhile, rACE2 could also alleviate MVPF through the degradation of Ang-2. Our finding indicated the ACE/Ang-2/AT1R axis played an essential role in the pathogenesis of MVPF. Pharmacological inhibition of the ACE/Ang-2/AT1R axis might be a promising strategy for the treatment of MVPF.

Worldwide productivity and research trend of publications concerning extracellular vesicles role in fibrosis: A bibliometric study from 2013 to 2022.

Background: Fibrosis is a heavy burden on the global healthcare system. Recently, an increasing number of studies have demonstrated that Extracellular vesicles play an important role in intercellular communication under both physiological and pathological conditions. This study aimed to explore the role of extracellular vesicles' in fibrosis using bibliometric methods. Methods: Original articles and reviews related to extracellular vesicles and fibrosis were obtained from the Web of Science Core Collection database on November 9, 2022. VOSviewer was used to obtain general information, including co-institution, co-authorship, and co-occurrence visualization maps. The CiteSpace software was used to analyze citation bursts of keywords and references, a timeline view of the top clusters of keywords and cited articles, and the dual map. R package "bibliometrix" was used to analyze annual production, citation per year, collaboration network between countries/regions, thematic evolution map, and historiography network. Results: In total, 3376 articles related to extracellular vesicles and fibrosis published from 2013 to 2022 were included in this study, with China and the United States being the top contributors. Shanghai Jiao Tong University has the highest number of publications. The main collaborators were Giovanni Camussi, Stefania Bruno, Marta Tepparo, and Cristina Grange. Journals related to molecular, biology, genetics, health, immunology, and medicine tended to publish literature on extracellular vesicles and fibrosis. "Recovery," "heterogeneity," "degradation," "inflammation," and "mesenchymal stem cells" are the keywords in this research field. Literature on extracellular vesicles and fibrosis associated with several diseases, including "kidney disease," "rheumatoid arthritis," and "skin regeneration" may be the latest hot research field. Conclusions: This study provides a comprehensive perspective on extracellular vesicles and fibrosis through a bibliometric analysis of articles published between 2013 and 2022. We identified the most influential countries, institutions, authors, and journals. We provide information on recent research frontiers and trends for scholars interested in the field of extracellular vesicles and fibrosis. Their role in biological processes has great potential to initiate a new upsurge in future research.

METFORMIN MITIGATES SEPSIS-ASSOCIATED PULMONARY FIBROSIS BY PROMOTING AMPK ACTIVATION AND INHIBITING HIF-1α-INDUCED AEROBIC GLYCOLYSIS.

ABSTRACT: Recent research has revealed that aerobic glycolysis has a strong correlation with sepsis-associated pulmonary fibrosis (PF). However, at present, the mechanism and pathogenesis remain unclear. We aimed to test the hypothesis that the adenosine monophosphate-activated protein kinase (AMPK) activation and suppression of hypoxia-inducible factor 1α (HIF-1α)-induced aerobic glycolysis play a central role in septic pulmonary fibrogenesis. Cellular experiments demonstrated that lipopolysaccharide increased fibroblast activation through AMPK inactivation, HIF-1α induction, alongside an augmentation of aerobic glycolysis. By contrast, the effects were reversed by AMPK activation or HIF-1α inhibition. In addition, pretreatment with metformin, which is an AMPK activator, suppresses HIF-1α expression and alleviates PF associated with sepsis, which is caused by aerobic glycolysis, in mice. Hypoxia-inducible factor 1α knockdown demonstrated similar protective effects in vivo . Our research implies that targeting AMPK activation and HIF-1α-induced aerobic glycolysis with metformin might be a practical and useful therapeutic alternative for sepsis-associated PF.

[Research on the mechanism of mechanical ventilation induced endoplasmic reticulum stress promoting mechanical ventilation-induced pulmonary fibrosis].

OBJECTIVE: To demonstrate the mechanism of mechanical ventilation (MV) induced endoplasmic reticulum stress (ERS) promoting mechanical ventilation-induced pulmonary fibrosis (MVPF), and to clarify the role of angiotensin receptor 1 (AT1R) during the process. METHODS: The C57BL/6 mice were randomly divided into four groups: Sham group, MV group, AT1R-shRNA group and MV+AT1R-shRNA group, with 6 mice in each group. The MV group and MV+AT1R-shRNA group mechanically ventilated for 2 hours after endotracheal intubation to establish MVPF animal model (parameter settings: respiratory rate 70 times/minutes, tidal volume 20 mL/kg, inhated oxygen concentration 0.21). The Sham group and AT1R-shRNA group only underwent intubation after anesthesia and maintained spontaneous breathing. AT1R-shRNA group and MV+AT1R-shRNA group were airway injected with the adeno-associated virus one month before modeling to inhibit AT1R gene expression in lung tissue. The expressions of AT1R, ERS signature proteins [immunoglobulin heavy chain-binding protein (BIP), protein disulfide isomerase (PDI)], fibrosis signature proteins [collagen I (COL1A1), α-smooth muscle actin (α-SMA)] in lung tissues were detected by immunofluorescence and Western blotting. Hematoxylin-eosin (HE) staining was used to evaluate lung injury and Masson staining was used to evaluate pulmonary fibrosis. RESULTS: Compared with the Sham group, the degree of pulmonary fibrosis and lung injury were more significant in the MV group. In the MV group, the protein expressions of AT1R, BIP, PDI, COL1A1 and α-SMA were increased (AT1R/ß-actin: 1.40±0.02 vs. 1, BIP/ß-actin: 2.79±0.07 vs. 1, PDI/ß-actin: 2.07±0.02 vs. 1, COL1A1/α-Tubulin: 2.60±0.15 vs. 1, α-SMA/α-Tubulin: 2.80±0.25 vs. 1, all P < 0.01). The number of E-cad+/AT1R+ and E-cad+/BIP+ cells in lung tissue increased, and the fluorescence intensity of COL1A1 and α-SMA increased. Compared with the MV group, the degree of pulmonary fibrosis and lung injury were significantly relieved in the MV+AT1R-shRNA group. In the MV+AT1R-shRNA group, the protein expressions of AT1R, BIP, PDI, COL1A1 and α-SMA were decreased (AT1R/ß-actin: 0.53±0.03 vs. 1.40±0.02, BIP/ß-actin: 1.73±0.15 vs. 2.79±0.07, PDI/ß-actin: 1.04±0.07 vs. 2.07±0.02, COL1A1/α-Tubulin: 1.29±0.11 vs. 2.60±0.15, α-SMA/α-Tubulin: 1.27±0.10 vs. 2.80±0.25, all P < 0.01). The number of E-cad+/AT1R+ and E-cad+/BIP+ cells in lung tissue decreased, and the fluorescence intensity of COL1A1 and α-SMA decreased. There was no statistically significant difference in the indicators between AT1R-shRNA group and Sham group. CONCLUSIONS: MV up-regulate the expression of AT1R in alveolar epithelial cells, activate the AT1R pathway, induce ERS and promote the progression of MVPF.

A deep learning model for predicting COVID-19 ARDS in critically ill patients.

Background: The coronavirus disease 2019 (COVID-19) is an acute infectious pneumonia caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection previously unknown to humans. However, predictive studies of acute respiratory distress syndrome (ARDS) in patients with COVID-19 are limited. In this study, we attempted to establish predictive models to predict ARDS caused by COVID-19 via a thorough analysis of patients' clinical data and CT images. Method: The data of included patients were retrospectively collected from the intensive care unit in our hospital from April 2022 to June 2022. The primary outcome was the development of ARDS after ICU admission. We first established two individual predictive models based on extreme gradient boosting (XGBoost) and convolutional neural network (CNN), respectively; then, an integrated model was developed by combining the two individual models. The performance of all the predictive models was evaluated using the area under receiver operating characteristic curve (AUC), confusion matrix, and calibration plot. Results: A total of 103 critically ill COVID-19 patients were included in this research, of which 23 patients (22.3%) developed ARDS after admission; five predictive variables were selected and further used to establish the machine learning models, and the XGBoost model yielded the most accurate predictions with the highest AUC (0.94, 95% CI: 0.91-0.96). The AUC of the CT-based convolutional neural network predictive model and the integrated model was 0.96 (95% CI: 0.93-0.98) and 0.97 (95% CI: 0.95-0.99), respectively. Conclusion: An integrated deep learning model could be used to predict COVID-19 ARDS in critically ill patients.

Fibrotic extracellular vesicles contribute to mechanical ventilation-induced pulmonary fibrosis development by activating lung fibroblasts via JNK signalling pathway: an experimental study.

Recent research has revealed that mechanical ventilation (MV) could initiate ventilator-induced lung injury along with the initiation of the process of pulmonary fibrosis (PF), leading to MV-induced PF (MVPF). However, the underlying mechanism remains unclear. This study aimed to explore the role of MV-induced extracellular vesicles (MV-EVs) and the c-Jun N-terminal kinase (JNK) signalling pathway in the pathogenesis of MVPF in vivo and in vitro. The process of MV is accompanied by the secretion of MV-EVs, which could induce lung fibroblast activation. Furthermore, single-cell RNA-sequencing analysis revealed that the JNK pathway in lung fibroblasts was activated after MV initiation. Inhibiting the JNK pathway could both restrain MV-EV-induced lung fibroblast activation in vitro or reduce the severity of MVPF in vivo. In conclusion, this study demonstrated that MV-EVs contribute to MVPF progression by activating lung fibroblasts via the JNK signalling pathway and that inhibiting the secretion of EV and the activation of the JNK signalling pathway is a promising strategy for treating MVPF.

Non-coding RNA alterations in extracellular vesicles from bronchoalveolar lavage fluid contribute to mechanical ventilation-induced pulmonary fibrosis.

Objective: For respiratory failure patients, mechanical ventilation (MV) is a life-saving therapy to maintain respiratory function. However, MV could also cause damage to pulmonary structures, result in ventilator-induced lung injury (VILI) and eventually progress to mechanical ventilation-induced pulmonary fibrosis (MVPF). Mechanically ventilated patients with MVPF are closely related to increased mortality and poor quality of life in long-term survival. Thus, a thorough understanding of the involved mechanism is necessary. Methods: We used next-generation sequencing to identify differentially expressed non-coding RNAs (ncRNAs) in BALF EVs which were isolated from Sham and MV mice. Bioinformatics analysis was conducted to identify the engaged ncRNAs and related signaling pathways in the process of MVPF. Results: We found 1801 messenger RNAs (mRNA), 53 micro RNAs (miRNA), 273 circular RNAs (circRNA) and 552 long non-coding RNAs (lncRNA) in mice BALF EVs of two groups, which showed significant differential expression. TargetScan predicted that 53 differentially expressed miRNAs targeted 3105 mRNAs. MiRanda revealed that 273 differentially expressed circRNAs were associated with 241 mRNAs while 552 differentially expressed lncRNAs were predicated to target 20528 mRNAs. GO, KEGG pathway analysis and KOG classification showed that these differentially expressed ncRNA-targeted mRNAs were enriched in fibrosis related signaling pathways and biological processes. By taking the intersection of miRNAs target genes, circRNAs target genes and lncRNAs target genes, we found 24 common key genes and 6 downregulated genes were confirmed by qRT-PCR. Conclusions: Changes in BALF-EV ncRNAs may contribute to MVPF. Identification of key target genes involved in the pathogenesis of MVPF could lead to interventions that slow or reverse fibrosis progression.

Integrin ß3 Mediates Sepsis and Mechanical Ventilation-Associated Pulmonary Fibrosis Through Glycometabolic Reprogramming.

Mechanical ventilation (MV) has become a clinical first-line treatment option for patients with respiratory failure. However, it was unclear whether MV further aggravates the process of sepsis-associated pulmonary fibrosis and eventually leads to sepsis and mechanical ventilation-associated pulmonary fibrosis (S-MVPF). This study aimed to explore the mechanism of S-MVPF concerning integrin ß3 activation in glycometabolic reprogramming of lung fibroblasts. We found that MV exacerbated sepsis-associated pulmonary fibrosis induced by lipopolysaccharide, which was accompanied by proliferation of lung fibroblasts, increased deposition of collagen in lung tissue, and increased procollagen type I carboxy-terminal propeptide in the bronchoalveolar lavage fluid. A large number of integrin ß3- and pyruvate kinase M2-positive fibroblasts were detected in lung tissue after stimulation with lipopolysaccharide and MV, with an increase in lactate dehydrogenase A expression and lactate levels. S-MVPF was primarily attenuated in integrin ß3-knockout mice, which also resulted in a decrease in the levels of pyruvate kinase M2, lactate dehydrogenase A, and lactate. In conclusion, MV aggravated sepsis-associated pulmonary fibrosis, with glycometabolic reprogramming mediated by integrin ß3 activation. Thus, integrin ß3-mediated glycometabolic reprogramming might be a potential therapeutic target for S-MVPF.

MACHINE LEARNING MODELS FOR PREDICTING ACUTE KIDNEY INJURY IN PATIENTS WITH SEPSIS-ASSOCIATED ACUTE RESPIRATORY DISTRESS SYNDROME.

ABSTRACT: Background: Acute kidney injury (AKI) is a prevalent and serious complication among patients with sepsis-associated acute respiratory distress syndrome (ARDS). Prompt and accurate prediction of AKI has an important role in timely intervention, ultimately improving the patients' survival rate. This study aimed to establish machine learning models to predict AKI via thorough analysis of data derived from electronic medical records. Method: The data of eligible patients were retrospectively collected from the Medical Information Mart for Intensive Care III database from 2001 to 2012. The primary outcome was the development of AKI within 48 hours after intensive care unit admission. Four different machine learning models were established based on logistic regression, support vector machine, random forest, and extreme gradient boosting (XGBoost). The performance of all predictive models was evaluated using the area under receiver operating characteristic curve, precision-recall curve, confusion matrix, and calibration plot. Moreover, the discrimination ability of the machine learning models was compared with that of the Sequential Organ Failure Assessment (SOFA) model. Results; Among 1,085 sepsis-associated ARDS patients included in this research, 375 patients (34.6%) developed AKI within 48 hours after intensive care unit admission. Twelve predictive variables were selected and further used to establish the machine learning models. The XGBoost model yielded the most accurate predictions with the highest area under receiver operating characteristic curve (0.86) and accuracy (0.81). In addition, a novel shiny application based on the XGBoost model was established to predict the probability of developing AKI among patients with sepsis-associated ARDS. Conclusions: Machine learning models could be used for predicting AKI in patients with sepsis-associated ARDS. Accordingly, a user-friendly shiny application based on the XGBoost model with reliable predictive performance was released online to predict the probability of developing AKI among patients with sepsis-associated ARDS.

ASK1-ER stress pathway-mediated fibrotic-EV release contributes to the interaction of alveolar epithelial cells and lung fibroblasts to promote mechanical ventilation-induced pulmonary fibrosis.

Recent clinical research has revealed that mechanical ventilation (MV) can initiate pulmonary fibrosis and induce mechanical ventilation-induced pulmonary fibrosis (MVPF). However, the underlying mechanism remains largely uncharacterized. Based on a mouse model of MVPF and an alveolar epithelial cell cyclic strain model, the present study explores the possible mechanism of MVPF. Single-cell RNA-sequencing and EV RNA-sequencing analysis revealed that MV promoted apoptosis signal-regulating kinase 1 (ASK1)-mediated endoplasmic reticulum (ER) stress pathway activation and extracellular vesicle (EV) release from alveolar epithelial cells. Furthermore, the ASK1-ER stress pathway was shown to mediate mechanical stretch (MS)- or MV-induced EV release and lung fibroblast activation in vivo and in vitro. These processes were suppressed by ER stress inhibitors or by silencing ASK1 with ASK1- short hairpin RNA (shRNA). In addition, MVPF was suppressed by inhibiting ASK1 and ER stress in vivo. Therefore, the present study demonstrates that ASK1-ER stress pathway-mediated fibrotic-EV release from alveolar epithelial cells contributes to fibroblast activation and the initiation of pulmonary fibrosis during MV. The inhibited release of EVs targeting the ASK1-ER stress pathway might be a promising treatment strategy for MVPF.

Scars of COVID-19: A bibliometric analysis of post-COVID-19 fibrosis.

Background: The coronavirus disease 2019 (COVID-19) becomes a worldwide public health threat. Increasing evidence proves that COVID-19-induced acute injuries could be reversed by a couple of therapies. After that, post-COVID-19 fibrosis (PCF), a sequela of "Long COVID," earns rapidly emerging concerns. PCF is associated with deteriorative lung function and worse quality of life. But the process of PCF remains speculative. Therefore, we aim to conduct a bibliometric analysis to explore the overall structure, hotspots, and trend topics of PCF. Materials and methods: A comprehensive search was performed in the Web of Science core database to collect literature on PCF. Search syntax included COVID-19 relevant terms: "COVID 19," "COVID-19 Virus Disease," "COVID-19 Virus Infection," "Coronavirus Disease-19," "2019 Novel Coronavirus Disease," "2019 Novel Coronavirus Infection," "SARS Coronavirus 2 Infection," "COVID-19 Pandemic," "Coronavirus," "2019-nCoV," and "SARS-CoV-2"; and fibrosis relevant terms: "Fibrosis," "Fibroses," and "Cirrhosis." Articles in English were included. Totally 1,088 publications were enrolled. Searching results were subsequentially exported and collected for the bibliometric analysis. National, organizational, and individual level data were analyzed and visualized through biblioshiny package in the R, VOSviewer software, the CiteSpace software, and the Graphical Clustering Toolkit (gCLUTO) software, respectively. Results: The intrinsic structure and development in the field of PCF were investigated in the present bibliometric analysis. The topmost keywords were "COVID-19" (occurrences, 636) surrounded by "SARS-CoV-2" (occurrences, 242), "coronavirus" (occurrences, 123), "fibrosis" (occurrences, 120), and "pneumonia" (occurrences, 94). The epidemiology, physiopathology, diagnosis, and therapy of PCF were extensively studied. After this, based on dynamic analysis of keywords, hot topics sharply changed from "Wuhan," "inflammation," and "cytokine storm" to "quality of life" and "infection" through burst detection; from "acute respiratory syndrome," "cystic-fibrosis" and "fibrosis" to "infection," "COVID-19," "quality-of-life" through thematic evolution; from "enzyme" to "post COVID." Similarly, co-cited references analysis showed that topics of references with most citations shift from "pulmonary pathology" (cluster 0) to "COVID-19 vaccination" (cluster 6). Additionally, the overview of contributors, impact, and collaboration was revealed. Summarily, the USA stood out as the most prolific, influential, and collaborative country. The Udice French Research University, Imperial College London, Harvard University, and the University of Washington represented the largest volume of publications, citations, H-index, and co-authorships, respectively. Dana Albon was the most productive and cited author with the strongest co-authorship link strength. Journal of Cystic Fibrosis topped the list of prolific and influential journals. Conclusion: Outcomes gained from this study assisted professionals in better realizing PCF and would guide future practices. Epidemiology, pathogenesis, and therapeutics were study hotspots in the early phase of PCF research. As the spread of the COVID-19 pandemic and progress in this field, recent attention shifted to the quality of life of patients and post-COVID comorbidities. Nevertheless, COVID-19 relevant infection and vaccination were speculated to be research trends with current and future interest. International cooperation as well as in-depth laboratory experiments were encouraged to promote further explorations in the field of PCF.

Integrin ß3-PKM2 pathway-mediated aerobic glycolysis contributes to mechanical ventilation-induced pulmonary fibrosis.

Background: Mechanical ventilation (MV) can induce pulmonary fibrosis. This study aims to investigate whether MV-induced pulmonary fibrosis is associated with aerobic glycolysis and seeks to uncover the underlying mechanisms mediated by integrin ß3-pyruvate kinase M2 (PKM2) pathway. Methods: PKM2 knockdown or inhibition, integrin ß3 knockout or inhibition and wild-type mice were exposed to MV (20 mL/kg) for 2 h. Results: Mice exposed to MV exhibited increased expression of collagen deposition, and upregulation of α-smooth muscle actin and collagen I in lung tissues. Single cells analysis showed that MV-induced pulmonary fibrosis was associated with increased gene expression of integrin and glycolysis in pulmonary fibroblasts, as well as upregulation of glycolytic products tested by metabolomics. Meanwhile, increased protein level of integrin ß3 and PKM2 was confirmed by western blot and immunohistochemistry. Double immunofluorescence staining and flow cytometric analysis showed increased number of fibronectin+/integrin ß3+ and fibronectin+/PKM2+ fibroblasts in lung tissues. Furthermore, MV-induced aerobic glycolysis and pulmonary fibrosis were ameliorated after treatment with PKM2 knockdown-AAV and inhibition, or in integrin ß3 knockout and inhibition mice. Conclusions: Integrin ß3-PKM2 pathway-mediated aerobic glycolysis contributes to MV-induced pulmonary fibrosis. The inhibition of aerobic glycolysis targeting integrin ß3-PKM2 pathway may be a promising treatment for MV-induced pulmonary fibrosis.

The role of macrophage-fibroblast interaction in lipopolysaccharide-induced pulmonary fibrosis: an acceleration in lung fibroblast aerobic glycolysis.

Recent evidence has shown that lipopolysaccharide (LPS)-induced aerobic glycolysis of lung fibroblasts is closely associated with the pathogenesis of septic pulmonary fibrosis. Nevertheless, the underlying mechanism remains poorly defined. In this study, we demonstrate that LPS promotes c-Jun N-terminal kinase (JNK) signaling pathway activation and endogenous tumor necrosis factor-α (TNF-α) secretion in pulmonary macrophages. This, in turn, could significantly promote aerobic glycolysis and increase lactate production in lung fibroblasts through 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3) activation. Culturing human lung fibroblast MRC-5 cell line with TNF-α or endogenous TNF-α (cell supernatants of macrophages after LPS stimulation) both enhanced the aerobic glycolysis and increased lactate production. These effects could be prevented by treating macrophages with JNK pathway inhibitor, by administering TNF-α receptor 1 (TNFR1) siRNA, PFKFB3 inhibitor, or by silencing PFKFB3 with fibroblasts-specific shRNA. In addition, the inhibition of TNF-α secretion and PFKFB3 expression prevented LPS-induced pulmonary fibrosis in vivo. In conclusion, this study revealed that LPS-induced macrophage secretion of TNF-α could initiate fibroblast aerobic glycolysis and lactate production, implying that inflammation-metabolism interactions between lung macrophages and fibroblasts might play an essential role in LPS-induced pulmonary fibrosis.

Poor Uncorrected Visual Acuity and Association With Sleep Duration and Screen Time: A Dose-Response Relationship Study.

BACKGROUND: We aimed to investigate the prevalence of poor uncorrected visual acuity and the difference among students with different ages and residential areas in the Northeast of China. The relationships between screen time, nighttime sleep duration, and poor uncorrected visual acuity would be explored. METHODS: It was a cross-sectional study using multi-stage stratified random sampling method to recruit participants. 2149 students have completed questionnaires and underwent visual acuity examinations. The dose-response curve method was applied to examine the non-linear associations between sleep duration and poor uncorrected visual acuity under different screen time subgroups. RESULTS: The overall prevalence of poor uncorrected visual acuity and severe poor uncorrected visual acuity was 84.7% and 63.3%, respectively. The dose-response curve showed the odds ratios (ORs) of sleep duration for the poor uncorrected visual increased relatively slowly when screen time <1 hour, then increased dramatically in screen time ≥1 hours. The ORs of sleep time and poor uncorrected visual acuity showed a U-shaped change trend among students with 2 or more hours of screen time every day. CONCLUSION: We found associations between nighttime sleep duration and poor uncorrected visual acuity in adolescents. However, these associations were not consistent across all screen time categories.

Favorable Outcomes of Anticoagulation With Unfractioned Heparin in Sepsis-Induced Coagulopathy: A Retrospective Analysis of MIMIC-III Database.

Backgrounds: Anticoagulation in sepsis-associated disseminated intravascular coagulation (DIC) remains uncertain. The aim of this study was to investigate whether unfractioned heparin (UFH) could improve clinical outcomes in patients with sepsis-induced coagulopathy (SIC). Methods: Septic patients with SIC were identified from the Medical Information Mart for Intensive Care (MIMIC)-III database. Cox-proportional hazards model, logistic regression model and linear regression were used to assess the associations between UFH administration and 28-day mortality, hospital mortality, occurrence of bleeding complications and length of stay, respectively. Propensity score matching (PSM) analysis was used to match the imbalance between patients in the UFH group and the control group. Patients were further stratified according to SIC score and Simplified Acute Physiology Score II (SAPS II). Results: A total of 1,820 septic patients with SIC were included in the data analysis. After PSM, 652 pairs of patients were matched between the patients in the UFH group and the control group. UFH was significantly associated with reduced 28-day mortality (HR, 0.323, 95% CI, 0.258-0.406; p < 0.001) and hospital mortality (HR, 0.380, 95% CI, 0.307-0.472; p < 0.001) without increasing the risks of intracranial hemorrhage (OR, 1.480, 95% CI, 0.955-2.294; p = 0.080) or gastrointestinal bleeding (OR, 1.094, 95% CI, 0.503-2.382; p = 0.820). For subgroup analysis, it didn't change the favorable results of UFH on mortality and UFH didn't increase the risk of hemorrhage in patients with severe disease. Conclusions: The analysis of MIMIC-III database indicated that anticoagulant therapy with UFH may be associated with a survival benefit in patients with SIC.

Cardiopulmonary Bypass Induces Acute Lung Injury via the High-Mobility Group Box 1/Toll-Like Receptor 4 Pathway.

During cardiopulmonary bypass (CPB), pulmonary ischemia/reperfusion (I/R) injury can cause acute lung injury (ALI). Our previous research confirmed that abnormal high-mobility group box 1 (HMGB1) release after CPB was closely related to ALI. However, the mechanism underlying the HMGB1-mediated induction of ALI after CPB is unclear. Our previous study found that HMGB1 binds Toll-like receptor 4 (TLR4), leading to lung injury, but direct evidence of a role for these proteins in the mechanism of CPB-induced lung injury has not been shown. We examined the effects of inhibiting HMGB1 or reducing TLR4 expression on CPB-induced lung injury in rats administered anti-HMBG1 antibody or TLR4 short-hairpin RNA (shTLR4), respectively. In these rat lungs, we studied the histologic changes and levels of interleukin- (IL-) 1ß, tumour necrosis factor- (TNF-) α, HMGB1, and TLR4 after CPB. After CPB, the lung tissues from untreated rats showed histologic features of injury and significantly elevated levels of IL-1ß, TNF-α, HMGB1, and TLR4. Treatment with anti-HMGB1 attenuated the CPB-induced morphological inflammatory response and protein levels of IL-1ß, TNF-α, HMGB1, and TLR4 in the lung tissues and eventually alleviated the ALI after CPB. Treatment with shTLR4 attenuated the CPB-induced morphological inflammatory response and protein levels of IL-1ß, TNF-α, and TLR4 in the lung tissues and eventually alleviated the ALI after CPB, but could not alleviate the HMGB1 protein levels induced by CPB. In summary, the present study demonstrated that the HMGB1/TLR4 pathway mediated the development of ALI induced by CPB.

PI3K-Akt-mTOR/PFKFB3 pathway mediated lung fibroblast aerobic glycolysis and collagen synthesis in lipopolysaccharide-induced pulmonary fibrosis.

Metabolic reprogramming plays a critical role in many diseases. A recent study revealed that aerobic glycolysis in lung tissue is closely related to pulmonary fibrosis, and also occurs during lipopolysaccharide (LPS)-induced sepsis. However, whether LPS induces aerobic glycolysis in lung fibroblasts remains unknown. The present study demonstrated that LPS promotes collagen synthesis in the lung fibroblasts through aerobic glycolysis via the activation of the PI3K-Akt-mTOR/PFKFB3 pathway. Challenging the human lung fibroblast MRC-5 cell line with LPS activated the PI3K-Akt-mTOR pathway, significantly upregulated the expression of 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3), enhanced the aerobic glycolysis, and promoted collagen synthesis. These phenomena could be reversed by the PI3K-Akt inhibitor LY294002, mTOR inhibitor rapamycin, PFKFB3 inhibitor 3PO, or PFKFB3 silencing by specific shRNA, or aerobic glycolysis inhibitor 2-DG. In addition, PFKFB3 expression and aerobic glycolysis were also detected in the mouse model of LPS-induced pulmonary fibrosis, which could be reversed by the intraperitoneal injection of PFKFB3 inhibitor 3PO. Taken together, this study revealed that in LPS-induced pulmonary fibrosis, LPS might mediate lung fibroblast aerobic glycolysis through the activation of the PI3K-Akt-mTOR/PFKFB3 pathway.

Thy-1 depletion and integrin ß3 upregulation-mediated PI3K-Akt-mTOR pathway activation inhibits lung fibroblast autophagy in lipopolysaccharide-induced pulmonary fibrosis.

Lipopolysaccharide (LPS)-induced autophagy inhibition in lung fibroblasts is closely associated with the activation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K-Akt-mTOR) pathway. However, the underlying mechanism remains unknown. In this study, we demonstrated that LPS activated the PI3K-Akt-mTOR pathway and inhibited lung fibroblast autophagy by depleting thymocyte differentiation antigen-1 (Thy-1) and upregulating integrin ß3 (Itgb3). Challenge of the human lung fibroblast MRC-5 cell line with LPS resulted in significant upregulation of integrin ß3, activation of the PI3K-Akt-mTOR pathway and inhibition of autophagy, which could be abolished by integrin ß3 silencing by specific shRNA or treatment with the integrin ß3 inhibitor cilengitide. Meanwhile, LPS could inhibit Thy-1 expression accompanied with PI3K-Akt-mTOR pathway activation and lung fibroblast autophagy inhibition; these effects could be prevented by Thy-1 overexpression. Meanwhile, Thy-1 downregulation with Thy-1 shRNA could mimic the effects of LPS, inducing the activation of PI3K-Akt-mTOR pathway and inhibiting lung fibroblast autophagy. Furthermore, protein immunoprecipitation analysis demonstrated that LPS reduced the binding of Thy-1 to integrin ß3. Thy-1 downregulation, integrin ß3 upregulation and autophagy inhibition were also detected in a mouse model of LPS-induced pulmonary fibrosis, which could be prohibited by intratracheal injection of Thy-1 overexpressing adeno-associated virus (AAV) or intraperitoneal injection of the integrin ß3 inhibitor cilengitide. In conclusion, this study demonstrated that Thy-1 depletion and integrin ß3 upregulation are involved in LPS-induced pulmonary fibrosis, and may serve as potential therapeutic targets for pulmonary fibrosis.