SU5416 attenuated lipopolysaccharide-induced acute lung injury in mice by modulating properties of vascular endothelial cells

MiR-144/451 attenuates lipopolysaccharide-induced lung inflammation by downregulating Rac1 and STAT-3 in macrophages

MicroRNAs have been shown to play a critical role in lung inflammatory diseases. Here, we report that knocking out miR-144/451 in mice exacerbates lipopolysaccharide (LPS)-induced lung inflammation. The lung inflammation in mice was induced by intratracheal instillation of LPS. Loss-of-function experiments demonstrated that miR-144/451 gene knockout (KO) increased LPS-induced lung inflammation and oxidant stress compared with wild-type (WT) mice, as manifested by increased total bronchoalveolar lavage fluid cells and neutrophil counts, elevated TNF-α and IL-6 levels in bronchoalveolar lavage fluid, enhanced myeloperoxidase activity, and reduced catalase and glutathione peroxidase activity in lung tissues. We also found that LPS significantly decreased miR-451 expression in lung tissues and macrophages; while miR-451 overexpression in LPS-induced RAW264.7 cells remarkably reduced TNF-α and IL-6 levels as well as reactive oxygen species (ROS) production, suggesting a feedback loop might exist in inflammatory cells. Rac1 mRNA and protein levels were downregulated in miR-451-overexpressed RAW264.7 cells. Ex vivo stimulation experiments, performed using alveolar macrophages isolated from miR-144/451 KO mice, confirmed that Rac1 inhibitor alleviated levels of TNF-α and ROS in response to LPS stimulation compared with WT controls. Luciferase reporter assay demonstrated that STAT-3 is a direct target of miR-451. STAT-3 protein levels were elevated in miR-144/451 KO macrophages. LPS treatment also resulted in higher phosphorylation levels of STAT-3 in macrophages from KO mice than in WT cells. Our study identified miR-144/451 as an anti-inflammatory factor in LPS-induced lung inflammation that acts by downregulating Rac1 and STAT-3.

Interplay between pulmonary epithelial stem cells and innate immune cells contribute to the repair and regeneration of ALI/ARDS

Mammalian lung is the important organ for ventilation and exchange of air and blood. Fresh air and venous blood are constantly delivered through the airway and vascular tree to the alveolus. Based on this, the airways and alveolis are persistently exposed to the external environment and are easily suffered from toxins, irritants and pathogens. For example, acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a common cause of respiratory failure in critical patients, whose typical pathological characters are diffuse epithelial and endothelial damage resulting in excessive accumulation of inflammatory fluid in the alveolar cavity. The supportive treatment is the main current treatment for ALI/ARDS with the lack of targeted effective treatment strategies. However, ALI/ARDS needs more targeted treatment measures. Therefore, it is extremely urgent to understand the cellular and molecular mechanisms that maintain alveolar epithelial barrier and airway integrity. Previous researches have shown that the lung epithelial cells with tissue stem cell function have the ability to repair and regenerate after injury. Also, it is able to regulate the phenotype and function of innate immune cells involving in regeneration of tissue repair. Meanwhile, we emphasize that interaction between the lung epithelial cells and innate immune cells is more supportive to repair and regenerate in the lung epithelium following acute lung injury. We reviewed the recent advances in injury and repair of lung epithelial stem cells and innate immune cells in ALI/ARDS, concentrating on alveolar type 2 cells and alveolar macrophages and their contribution to post-injury repair behavior of ALI/ARDS through the latest potential molecular communication mechanisms. This will help to develop new research strategies and therapeutic targets for ALI/ARDS.

Huaiyu pill alleviates inflammatory bowel disease in mice blocking toll like receptor 4/ myeloid differentiation primary response gene 88/ nuclear factor kappa B subunit 1 pathway

OBJECTIVE

To investigate the therapeutic effects of Huaiyu pill (, HYP) on inflammatory bowel disease (IBD) and the underlying mechanisms have not been elucidated.

METHODS

To establish the IBD model, mice were administered with dextran sulfate sodium (DSS). Mice were intragastrically pre-treated with sulfasalazine (SASP) and HYP. Disease activity index (DAI) and colon length were monitored, and the colonic tissues were subjected to hematoxylin-eosin staining. Pro-inflammatory factors and vascular inflammation-related proteins were determined using enzyme-linked immunosorbent assay (ELISA). The potential mechanisms of HYP were examined using network pharmacology analysis.The expressions of zona occludens 1 (ZO-1), occludin, toll like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MYD88), and nuclear factor kappa B p65 subunit (NF-κB p65) in colon tissues were examined using Western blotting or immunohistochemical analyses.

RESULTS

Pre-treatment with HYP enhanced the colon length, decreased DAI scores, and mitigated histopathological alterations in DSS-treated mice. HYP alleviated intestinal inflammation by downregulating the levels of interleukin 1 beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) and interleukin 17 (IL-17). Additionally, HYP suppressed the disruption of the gut barrier by upregulating the ZO-1, occludin, and mucin 2 (MUC2) levels and downregulating the endothelin 1 (ET-1) and erythropoietin (EPO) levels. Network pharmacological analysis and experimental results revealed that HYP downregulated the colonic tissue levels of TLR4, MYD88, and NF-κB p65 in DSS-treated mice.

CONCLUSION

This study investigated the in vivotherapeutic effects of HYP on IBD and the underlying molecular mechanisms. These findings provide an experimental foundation for the clinical application of HYP.

Indole‑3‑propionic acid alleviates intestinal epithelial cell injury via regulation of the TLR4/NF‑κB pathway to improve intestinal barrier function

Indole‑3‑propionic acid (IPA), a product of Clostridium sporogenes metabolism, has been shown to improve intestinal barrier function. In the present study, in vitro experiments using NCM460 human colonic epithelial cells were performed to investigate how IPA alleviates lipopolysaccharide (LPS)‑induced intestinal epithelial cell injury, with the aim of improving intestinal barrier function. In addition, the underlying mechanism was explored. NCM460 cell viability and apoptosis were measured using the Cell Counting Kit‑8 assay and flow cytometry, respectively. The integrity of the intestinal epithelial barrier was evaluated by measuring transepithelial electrical resistance (TEER). The underlying molecular mechanism was explored using western blotting, immunofluorescence staining, a dual luciferase reporter gene assay and quantitative PCR. The results showed that 10 µg/ml LPS induced the most prominent decrease in cell viability after 24 h of treatment. By contrast, IPA effectively inhibited LPS‑induced apoptosis in the intestinal epithelial cells. Additionally, >0.5 mM IPA improved intestinal barrier function by increasing TEER and upregulating the expression of tight junction proteins (zonula occludens‑1, claudin‑1 and occludin). Furthermore, IPA inhibited the release of pro‑inflammatory cytokines (IL‑1β, IL‑6 and TNF‑α) in a dose‑dependent manner and this was achieved via regulation of the Toll‑like receptor 4 (TLR4)/myeloid differentiation factor 88/NF‑κB and TLR4/TRIF/NF‑κB pathways. In conclusion, IPA may alleviate LPS‑induced inflammatory injury in human colonic epithelial cells. Taken together, these results suggest that IPA may be a potential therapeutic approach for the management of diseases characterized by LPS‑induced intestinal epithelial cell injury and intestinal barrier dysfunction.

Global research progress of endothelial cells and ALI/ARDS: a bibliometric analysis

Background

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe respiratory conditions with complex pathogenesis, in which endothelial cells (ECs) play a key role. Despite numerous studies on ALI/ARDS and ECs, a bibliometric analysis focusing on the field is lacking. This study aims to fill this gap by employing bibliometric techniques, offering an overarching perspective on the current research landscape, major contributors, and emerging trends within the field of ALI/ARDS and ECs.

Methods

Leveraging the Web of Science Core Collection (WoSCC) database, we conducted a comprehensive search for literature relevant to ALI/ARDS and ECs. Utilizing Python, VOSviewer, and CiteSpace, we performed a bibliometric analysis on the corpus of publications within this field.

Results

This study analyzed 972 articles from 978 research institutions across 40 countries or regions, with a total of 5,277 authors contributing. These papers have been published in 323 different journals, spanning 62 distinct research areas. The first articles in this field were published in 2011, and there has been a general upward trend in annual publications since. The United States, Germany, and China are the principal contributors, with Joe G. N. Garcia from the University of Arizona identified as the leading authority in this field. American Journal of Physiology-Lung Cellular and Molecular Physiology has the highest publication count, while Frontiers in Immunology has been increasingly focusing on this field in recent years. "Cell Biology" stands as the most prolific research area within the field. Finally, this study identifies endothelial glycocalyx, oxidative stress, pyroptosis, TLRs, NF-κB, and NLRP3 as key terms representing research hotspots and emerging frontiers in this field.

Conclusion

This bibliometric analysis provides a comprehensive overview of the research landscape surrounding ALI/ARDS and ECs. It reveals an increasing academic focus on ALI/ARDS and ECs, particularly in the United States, Germany, and China. Our analysis also identifies several emerging trends and research hotspots, such as endothelial glycocalyx, oxidative stress, and pyroptosis, indicating directions for future research. The findings can guide scholars, clinicians, and policymakers in targeting research gaps and setting priorities to advance the field.

Antineoplastic indole-containing compounds with potential VEGFR inhibitory properties

Cancer is one of the most significant health challenges worldwide. Various techniques, tools and therapeutics/materials have been developed in the last few decades for the treatment of cancer, together with great interest, funding and efforts from the scientific society. However, all the reported studies and efforts seem insufficient to combat the various types of cancer, especially the advanced ones. The overexpression of tyrosine kinases is associated with cancer proliferation and/or metastasis. VEGF, an important category of tyrosine kinases, and its receptors (VEGFR) are hyper-activated in different cancers. Accordingly, they are known as important factors in the angiogenesis of different tumors and are considered in the development of effective therapeutic approaches for controlling many types of cancer. In this case, targeted therapeutic approaches are preferable to the traditional non-selective approaches to minimize the side effects and drawbacks associated with treatment. Several indole-containing compounds have been identified as effective agents against VEGFR. Herein, we present a summary of the recent indolyl analogs reported within the last decade (2012-2023) with potential antineoplastic and VEGFR inhibitory properties. The most important drugs, natural products, synthesized potent compounds and promising hits/leads are highlighted. Indoles functionalized and conjugated with various heterocycles beside spiroindoles are also considered.

Glycogen Synthase Kinase-3 Inhibition by CHIR99021 Promotes Alveolar Epithelial Cell Proliferation and Lung Regeneration in the Lipopolysaccharide-Induced Acute Lung Injury Mouse Model

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury that currently lacks effective clinical treatments. Evidence highlights the potential role of glycogen synthase kinase-3 (GSK-3) inhibition in mitigating severe inflammation. The inhibition of GSK-3α/β by CHIR99021 promoted fetal lung progenitor proliferation and maturation of alveolar epithelial cells (AECs). The precise impact of CHIR99021 in lung repair and regeneration during acute lung injury (ALI) remains unexplored. This study intends to elucidate the influence of CHIR99021 on AEC behaviour during the peak of the inflammatory phase of ALI and, after its attenuation, during the repair and regeneration stage. Furthermore, a long-term evaluation was conducted post CHIR99021 treatment at a late phase of the disease. Our results disclosed the role of GSK-3α/β inhibition in promoting AECI and AECII proliferation. Later administration of CHIR99021 during ALI progression contributed to the transdifferentiation of AECII into AECI and an AECI/AECII increase, suggesting its contribution to the renewal of the alveolar epithelial population and lung regeneration. This effect was confirmed to be maintained histologically in the long term. These findings underscore the potential of targeted therapies that modulate GSK-3α/β inhibition, offering innovative approaches for managing acute lung diseases, mostly in later stages where no treatment is available.

Bacteria-mediated cancer therapy: A versatile bio-sapper with translational potential

Bacteria are important symbionts for humans, which sustain substantial influences on our health. Interestingly, some bastrains have been identified to have therapeutic applications, notably for antitumor activity. Thereby, oncologists have developed various therapeutic models and investigated the potential antitumor mechanisms for bacteria-mediated cancer therapy (BCT). Even though BCT has a long history and exhibits remarkable therapeutic efficacy in pre-clinical animal models, its clinical translation still lags and requires further breakthroughs. This review aims to focus on the established strains of therapeutic bacteria and their antitumor mechanisms, including the stimulation of host immune responses, direct cytotoxicity, the interference on cellular signal transduction, extracellular matrix remodeling, neoangiogenesis, and metabolism, as well as vehicles for drug delivery and gene therapy. Moreover, a brief discussion is proposed regarding the important future directions for this fantastic research field of BCT at the end of this review.

Salvianolactone acid A isolated from Salvia miltiorrhiza ameliorates lipopolysaccharide-induced acute lung injury in mice by regulating PPAR-γ

BACKGROUND

Severe inflammation of the lungs results from acute lung injury (ALI), a common life-threatening lung disease with a high mortality rate. The ligand-activated transcription factor peroxisome proliferator-activated receptor (PPAR) γ plays essential roles in diverse biological processes including inflammation, metabolism, development, and immune response. Salvianolactone acid A (SA) is a terpenoid derived from the herb Salvia miltiorrhiza. However, there is a scarcity of experimental evidence indicating whether the effect of SA on ALI occurs via PPAR-γ.

METHODS

SA (20 or 40 mg/kg, i.g., 1 time/day) was administered to mice for 3 d, followed by the induction of ALI by intranasal lipopolysaccharide (LPS, 10 mg/kg). The lung function and levels of inflammation, reactive oxygen species (ROS), immune cells, apoptosis, and PPAR-γ were examined. The antagonistic activity of GW9662 (GW, 1 µM, specific PPAR-γ blocker) and PPAR-γ transfection silencing against SA (10 μM) in BEAS-2B cells induced by LPS (10 μg/ml, 24 h) was also investigated to assess whether the observed effects caused by SA were mediated by PPAR-γ.

RESULTS

The results showed that lung histopathological injury, the B-line, the fluorescence intensity of live small animal, and the biomarkers in BALF or lung in the treatment of SA could regulate significantly. In addition, SA obviously decreased the levels of ROS and apoptosis in the primary lung cells, and MDA, increased the levels of GSH-Px and SOD. SA reduced levels of macrophages and neutrophils. Furthermore, SA reduced the protein levels of Keap-1, Cleaved-caspase-3, Cleaved-caspase-9, p-p65/p65, NLRP3, IL-1β, and upregulated the levels of p-Nrf2/Nrf2, HO-1, Bcl-2/Bax, PPAR-γ, p-AMPK/AMPK in lung tissue. In addition, silencing and inhibition of PPAR-γ effectively decreased the protective effects of SA in BEAS-2B cells induced by LPS, which might indicate that the active molecules of SA regulate ALI via mediation by PPAR-γ, which exhibited that the effect of SA related to PPAR-γ.

CONCLUSIONS

The anti-ALI effects of SA were partially mediated through PPAR-γ signaling. These data provide the molecular justification for the usage of SA in treating ALI and can assist in increasing the comprehensive utilization rate of Salvia miltiorrhiza.

Huangkui Capsule Attenuates Lipopolysaccharide-Induced Acute Lung Injury and Macrophage Activation by Suppressing Inflammation and Oxidative Stress in Mice

Background

Huangkui capsule (HKC) comprises the total flavonoid extract of flowers of Abelmoschus manihot (L.) Medicus. This study aimed to explore the effects of HKC on lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice and LPS-stimulated RAW 264.7 cells.

Methods

Enzyme-linked immunosorbent assay, histopathology, spectrophotometry, and quantitative real-time polymerase chain reaction were used for the assessments. Statistical analysis was performed using a one-way analysis of variance.

Results

LPS significantly increased lung inflammation, neutrophil infiltration, and oxidative stress and downregulated lung miR-451 expression. Treatment with HKC dramatically, reduced the total cell count in the bronchoalveolar lavage fluid (BALF), and inhibited myeloperoxidase activity in the lung tissues 24 h after LPS challenge. Histopathological analysis demonstrated that HKC attenuated LPS-induced tissue oedema and neutrophil infiltration in the lung tissues. Additionally, the concentrations of tumour necrosis factor- (TNF-) α and interleukin- (IL-) 6 in BALF and IL-6 in the plasma reduced after HKC administration. Moreover, HKC could enhance glutathione peroxidase and catalase activities and upregulate the expression of miR-451 in the lung tissues. In vitro experiments revealed that HKC inhibited the production of nitric oxide, TNF-α, and IL-6 in LPS-induced RAW 264.7 cells and mouse primary peritoneal macrophages. Additionally, HKC downregulated LPS-induced transcription of TNF-α and IL-6 in RAW 264.7 cells.

Conclusions

These findings suggest that HKC has anti-inflammatory and antioxidative effects that may protect mice against LPS-induced ALI and macrophage activation.

The Biological Functions and Regulatory Mechanisms of Fatty Acid Binding Protein 5 in Various Diseases

In recent years, fatty acid binding protein 5 (FABP5), also known as fatty acid transporter, has been widely researched with the help of modern genetic technology. Emerging evidence suggests its critical role in regulating lipid transport, homeostasis, and metabolism. Its involvement in the pathogenesis of various diseases such as metabolic syndrome, skin diseases, cancer, and neurological diseases is the key to understanding the true nature of the protein. This makes FABP5 be a promising component for numerous clinical applications. This review has summarized the most recent advances in the research of FABP5 in modulating cellular processes, providing an in-depth analysis of the protein's biological properties, biological functions, and mechanisms involved in various diseases. In addition, we have discussed the possibility of using FABP5 as a new diagnostic biomarker and therapeutic target for human diseases, shedding light on challenges facing future research.

Targeting the lung endothelial niche to promote angiogenesis and regeneration: A review of applications

Lung endothelial cells comprise the pulmonary vascular bed and account for the majority of cells in the lungs. Beyond their role in gas exchange, lung ECs form a specialized microenvironment, or niche, with important roles in health and disease. In early development, progenitor ECs direct alveolar development through angiogenesis. Following birth, lung ECs are thought to maintain their regenerative capacity despite the aging process. As such, harnessing the power of the EC niche, specifically to promote angiogenesis and alveolar regeneration has potential clinical applications. Here, we focus on translational research with applications related to developmental lung diseases including pulmonary hypoplasia and bronchopulmonary dysplasia. An overview of studies examining the role of ECs in lung regeneration following acute lung injury is also provided. These diseases are all characterized by significant morbidity and mortality with limited existing therapeutics, affecting both young children and adults.

Dimethyl fumarate prevents acute lung injury related cognitive impairment potentially via reducing inflammation

OBJECTIVE

Dimethyl fumarate (DMF) has been reported to exert a protective role against diverse lung diseases and cognitive impairment-related diseases. Thus this study aimed to investigate its role on acute lung injury (ALI) and related cognitive impairment in animal model.

METHODS

C57BL/6 mice were divided into four groups: control group, DMF group, ALI group, and ALI + DMF group. For ALI group, the ALI mice model was created by airway injection of LPS (50 μL, 1 μg/μL); for ALI + DMF group, DMF (dissolved in 0.08% methylcellulose) was treated twice a day for 2 days, and on the third day, mice were injected with LPS for ALI modeling. Mice pre-administered with methylcellulose or DMF without LPS injection (PBS instead) were used as the control group and DMF group, respectively. Morris water maze test was performed before any treatment (0 h) and 6 h after LPS-induction (54 h) to evaluate the cognitive impairment of mice. Next, the brain edema and blood brain barrier (BBB) permeability of ALI mice were assessed by brain water content, Evans blue extravasation and FITC-Dextran uptake assays. In addition, the effect of DMF on the numbers of total cells and neutrophils, protein content in BALF were quantified; the inflammatory factors in BALF, serum, and brain tissues were examined by ELISA, qRT-PCR, and Western blot assays. The effect of DMF on the cognitive impairment-related factor HIF-1α level in lung and brain tissues was also examined by Western blot.

RESULTS

DMF reduced the numbers of total cells, neutrophils and protein content in BALF of ALI mice, inhibited the levels of IL-6, TNF-α and IL-1β in BALF, serum and brain tissues of ALI mice. The protein expressions of p-NF-κB/NF-κB and p-IKBα/IKBα was also suppressed by DMF in ALI mice. Morris water maze test showed that DMF alleviated the cognitive impairment in ALI mice by reducing the escape latency and path length. Moreover, DMF lessened the BBB permeability by decreasing cerebral water content, Evans blue extravasation and FITC-Dextran uptake in ALI mice. The HIF-1α levels in lung and brain tissues of ALI mice were also lessened by DMF.

CONCLUSION

In conclusion, DME had the ability to alleviate the lung injury and cerebral cognitive impairment in ALI model mice. This protective effect partly associated with the suppression of inflammation by DMF.

Effect of Food Endotoxin on Infant Health

Endotoxin is a complex molecule derived from the outer membrane of Gram-negative bacteria, and it has strong thermal stability. The processing of infant food can kill pathogenic bacteria but cannot remove endotoxin. Because the intestinal structure of infants is not fully developed, residual endotoxin poses a threat to their health by damaging the intestinal flora and inducing intestinal inflammation, obesity, and sepsis, among others. This paper discusses the sources and contents of endotoxin in infant food and methods for preventing endotoxin from harming infants. However, there is no clear evidence that endotoxin levels in infant food cause significant immune symptoms or even diseases in infants. However, in order to improve the safety level of infant food and reduce the endotoxin content, this issue should not be ignored. The purpose of this review is to provide a theoretical basis for manufacturers and consumers to understand the possible harm of endotoxin content in infant formula milk powder and to explore how to reduce its level in infant formula milk powder. Generally, producers should focus on cleaning the milk source, securing the cold chain, avoiding long-distance transportation, and shortening the storage time of raw milk to reduce the level of bacteria and endotoxin. After production and processing, the endotoxin content should be measured as an important index to test the quality of infant formula milk powder so as to provide high-quality infant products for the healthy growth of newborns.

Echinacea polysaccharide alleviates LPS-induced lung injury via inhibiting inflammation, apoptosis and activation of the TLR4/NF-κB signal pathway

Lung injury is a common critical life-threatening syndrome. Inflammation is a key factor in the pathogenesis of lung injury. It is reported that Echinacea Polysaccharides (EP) has anti-inflammatory activity. However, the effect of EP on lung injury remains unclear. In our study, murine model of lung injury was induced with 2.5 mg/kg LPS before administration of 5 mg/kg or 10 mg/kg EP. EP ameliorated LPS-induced lung pathological damage, along with reduction in lung wet/dry weight ratio and myeloperoxidase activity. EP decreased the number of leukocytes, eosinophils, neutrophils, lymphocytes and macrophages in bronchoalveolar lavage fluid, and the release of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in LPS-treated lung. EP suppressed LPS-induced apoptosis along with down-regulation of Bcl2-associated X (Bax) and cleaved caspase-3 (CC3), and elevated B-cell lymphoma-2 (Bcl-2). Besides, RAW 264.7 cells were treated with EP 100 μg/ml for 1 h and then incubated with 1 μg/ml LPS for 24 h. TNF-α, IL-6 and IL-1β levels were lowered by treatment of EP in LPS-treated RAW 264.7 cells. Moreover, EP down-regulated the expression of toll-like receptor 4 (TLR4), myeloid differentiating factor 88 (MyD88), p-IκBα, nuclear factor kappa-B (NF-κB), p-NF-κB, and up-regulated the inhibitor of NF-κB (IκBα) in vivo and in vitro following LPS induction, which is consistent with the effect of TAK-242. In conclusion, EP may alleviate LPS-induced lung injury via inhibiting inflammation, apoptosis and activation of TLR4/NF-κB signal pathway.

miR-138-5p targets sirtuin1 to regulate acute lung injury by regulation of the NF-κB signaling pathway

Acute lung injury (ALI), a disease with a high mortality rate, is a noncardiogenic pulmonary inflammatory response and characterized by damage to the pulmonary system. In this study, we explored the mechanism of the occurrence and development of ALI. It was firstly found that miR-138-5p could inhibit the expression of sirtuin1 (SIRT1), and we further demonstrated that miR-138-5p targets directly SIRT1 through the luciferase assay, while the latter negatively regulated the expression of NF-κB. A549 cells were treated with lipopolysaccharide in vitro to simulate ALI cells and induce ALI in the model mice. The results showed that inhibiting the expression of miR-138-5p could effectively increase the viability of damaged cells, promote cell proliferation, reduce apoptosis, inhibit the inflammatory response, reduce oxidative stress, and then relieve ALI symptoms. Collectively, our results suggested that miR-138-5p can inhibit SIRT1 expression and indirectly activate the NF-κB signaling pathway, thus regulating the development of ALI.

Endothelial-Derived Interleukin-1α Activates Innate Immunity by Promoting the Bactericidal Activity of Transendothelial Neutrophils

Migration of neutrophils across endothelial barriers to capture and eliminate bacteria is served as the first line of innate immunity. Bacterial virulence factors damage endothelium to produce inflammatory cytokines interacts with neutrophils. However, the mechanisms that behind endothelial-neutrophil interaction impact on the bactericidal activity remain unclear. Therefore, we aimed to find the target proteins on endothelial cells that triggered the bactericidal activity of transendothelial neutrophils. Herein, we built the infected models on rats and endothelial-neutrophil co-cultural system (Transwell) and discovered that endothelial-derived IL-1α promoted the survival of rats under Escherichia coli infection and enhanced the bactericidal activity of transendothelial neutrophils in vivo and in vitro. Results further showed that IL-1α was inhibited by lipopolysaccharide (LPS) in the endothelial-neutrophil interaction. We found that LPS mainly damaged cell membrane and induced cell necrosis to interrupt neutrophil migration from endothelial barrier. Thus, we used the isobaric tags for relative and absolute quantification (iTRAQ) method to identify different proteins of endothelial cells. Results showed that IL-1α targeted cellular plasma membrane, endoplasmic reticulum and mitochondrial envelope and triggered eleven common proteins to persistently regulate. During the early phase, IL-1α triggered the upregulation of cell adhesion molecules (CAMs) to promote neutrophil adhesion, while oxidative phosphorylation was involved in long time regulation to induce transmigration of neutrophils against bacteria. Our results highlight the critical mechanism of endothelial-derived IL-1α on promoting bactericidal activity of transendothelial neutrophils and the findings of IL-1α triggered proteins provide the potentially important targets on the regulation of innate immunity.

Isochlorogenic acid A attenuates acute lung injury induced by LPS via Nf-κB/NLRP3 signaling pathway

Nowadays, there is still no effective drug with small side effects for acute lung injury. Monomer of herb is promising for anti-inflammation therapy. In this study, we first investigated the possible effects of isochlorogenic acid A in acute lung injury induced by LPS. The effects of oxidant stress, pulmonary edema and inflammation factors induced by LPS were inhibited by isochlorogenic acid A. Levels of lung active markers and inflammation factors induced by LPS were reversed by isochlorogenic acid A. Isochlorogenic acid A inhibited the cell apoptosis induced by LPS. The protein expressions of Nf-κB/NLRP3 signaling pathway induced by LPS were inhibited by isochlorogenic acid A. In summary, isochlorogenic acid A reversed the effects induced by LPS in acute lung injury and is a promising monomer for therapy of acute lung injury, providing references for future research on therapy of acute lung injury.

Anti-Inflammatory Activity of Adenosine 5'-Trisphosphate in Lipopolysaccharide-Stimulated Human Umbilical Vein Endothelial Cells Through Negative Regulation of Toll-Like Receptor MyD88 Signaling

Activation of TLR4-MyD88-NF-κB signaling by lipopolysaccharide (LPS) evokes a proinflammatory immune response, and plays a pivotal role in initiation and progression of atherosclerosis (AS). ATP (adenosine 5'-trisphosphate), a powerful extracellular signal transduction molecule, functions to regulate immune inflammatory responses depending on the type of P2 receptors and cell lines. In this study, we first performed RT-PCR to detect the mRNA expression of monocyte chemoattractant protein-1 (MCP-1), IL-8, and IL-1β induced by different concentrations of LPS in human umbilical vein endothelial cells (HUVECs). Protein level of TLR4 signaling including TLR4, myeloid differentiation factor (MyD88), and CD14 induced by LPS (1 μg/mL) at different times (0, 10, 30, 60, 120 min) was analyzed by Western blot. Then, RT-PCR was performed to detect the effect of different concentrations of ATP on mRNA expression of IL-1β and MCP-1 induced by LPS (1 μg/mL) and the TLR4 signaling pathway. Western blot was performed to detect the effect of low concentrations of ATP on phosphorylation of p65 induced by 1 μg/mL LPS. Finally, we used P2Y receptor blocker Suramin to verify whether the role of ATP on LPS-induced inflammatory cytokine expression was through P2Y receptors. The results showed that LPS upregulated the expression of MCP-1, IL-8, and IL-1β in a dose-dependent manner accompanied by the activation of TLR4-MyD88 signaling in HUVECs. Only low concentration ATP (1, 10 μM) inhibited LPS-induced mRNA expression of IL-1β and MCP-1. ATP at low concentrations also downregulated the mRNA expression of TLR4, CD14, and MyD88 and inhibited LPS-induced phosphorylation of p65. Furthermore, Suramin, a nonspecific P2Y receptor antagonist, did not attenuate the inhibition of ATP on LPS-induced IL-1β and MCP-1 expression. Taking this together, low concentration ATP inhibited LPS-induced inflammation in HUVECs by negatively regulating TLR4-MyD88 signaling, and P2Y receptors were not involved in this process, which might provide new ideas for prevention and treatment of inflammatory diseases such as AS.