SN50, a Cell-Permeable Inhibitor of Nuclear Factor-κB, Attenuates Ventilator-Induced Lung Injury in an Isolated and Perfused Rat Lung Model

Mechanisms of mechanical stimulation in the development of respiratory system diseases

During respiration, mechanical stress can initiate biological responses that impact the respiratory system. Mechanical stress plays a crucial role in the development of the respiratory system. However, pathological mechanical stress can impact the onset and progression of respiratory diseases by influencing the extracellular matrix and cell transduction processes. In this article, we explore the mechanisms by which mechanical forces communicate with and influence cells. We outline the basic knowledge of respiratory mechanics, elucidating the important role of mechanical stimulation in influencing respiratory system development and differentiation from a microscopic perspective. We also explore the potential mechanisms of mechanical transduction in the pathogenesis and development of respiratory diseases such as asthma, lung injury, pulmonary fibrosis, and lung cancer. Finally, we look forward to new research directions in cellular mechanotransduction, aiming to provide fresh insights for future therapeutic research on respiratory diseases.

rFGF4 alleviates lipopolysaccharide-induced acute lung injury by inhibiting the TLR4/NF-κB signaling pathway

Acute lung injury (ALI) is a serious and common clinical disease. Despite significant progress in ALI treatment, the morbidity and mortality rates remain high. However, no effective drug has been discovered for ALI. FGF4, a member of the FGF family, plays an important role in the regulation of various physiological and pathological processes. Therefore, in the present study, we aimed to study the protective effects of FGF4 against LPS-induced lung injury in vivo and in vitro. We found that rFGF4 treatment improved the lung W/D weight ratio, the survival rate, immune cell infiltration and protein concentrations in mice with LPS-induced ALI. Histological analysis revealed that rFGF4 significantly attenuated lung tissue injury and cell apoptosis. Furthermore, rFGF4 inhibited the activation of the TLR4/NF-κB signaling pathway and the production of pro-inflammatory mediators in LPS-injured lung tissues, murine alveolar macrophages (MH-S) and murine pulmonary epithelial (MLE-12) cells. The results of cell experiments further verified that rFGF4 inhibited the production of inflammatory mediators in MH-S cells and MLE-12 cells by regulating the TLR4/NF-κB signaling pathway. These results revealed that rFGF4 protected lung tissues and inhibited inflammatory mediators in mice with LPS-induced ALI by inhibiting the TLR4/NF-κB signaling pathway in MH-S and MLE-12 cells.

Qianliexin capsule exerts anti-inflammatory activity in chronic non-bacterial prostatitis and benign prostatic hyperplasia via NF-κB and inflammasome

Qianliexin capsule (QLX) is a standardized traditional Chinese herbal preparation that has long been used to treat chronic non‐bacterial prostatitis (CNP) and benign prostatic hyperplasia (BPH). This study investigated the anti‐inflammatory activity of QLX in improving lower urinary tract symptoms (LUTS) associated with CNP and BPH. Rat models of CNP and BPH were induced by oestradiol or testosterone (hormonal imbalance) or chemical inflammation (carrageenan). QLX significantly relieved LUTS in CNP and BPH rat model by reducing prostate enlargement, epithelial thickness, pain response time, urine volume and bleeding time, and by improving prostatic blood flow. The expression of the pro‐inflammatory cytokines interleukin (IL)‐1β and tumour necrosis factor (TNF)‐α, the pro‐inflammatory transcription factor nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB), and inflammasome components (NLRP3, caspase‐1 and ASC) in CNP and BPH tissues was reduced by QLX addition. QLX treatment was followed by reduced cellular malondialdehyde and increased superoxide dismutase, catalase and glutathione peroxidase activity, consistent with antioxidant activity. Increases in Beclin‐1 expression and the LC3II/I ratio following QLX treatment indicated that autophagy had been induced. QLX relieved LUTS in CNP and BPH rat models by inhibiting inflammation. The underlying mechanisms included inhibition of inflammasome activation, NF‐κB activation, oxidant stress and autophagy.

Attenuation of ventilator-induced lung injury through suppressing the pro-inflammatory signaling pathways: A review on preclinical studies

Mechanical ventilation (MV) is a relatively common medical intervention in ICU patients. The main side effect of MV is the so-called "ventilator-induced lung injury" (VILI). The pathogenesis of VILI is not completely understood; however, it has been reported that MV might be associated with up-regulation of various inflammatory mediators within the lung tissue and that these mediators might act as pathogenic factors in lung tissue injury. One potential mechanism for the generation of inflammatory mediators is through the release of endogenous molecules known as damage associated molecular patterns (DAMPs). These molecules are released from injured tissues and can bind to pattern recognition receptors (PRRs). PRR activation generally leads to the production and release of inflammation-related molecules including innate immune cytokines and chemokines. It has been suggested that blocking DAMP/PRR signaling pathways might diminish the progression of VILI. Herein, we review the latest findings with regard to the effects of DAMP/PRRs and their blockade, as well as the potential therapeutic targets and future research directions in VILI. Results of studies performed on human samples, animal models of disease, as well as relevant in vitro systems will be discussed.

Potential mechanism and key genes involved in mechanical ventilation and lipopolysaccharide‑induced acute lung injury

Mechanical ventilation (MV) and lipopolysaccharide (LPS) infection are common causes of acute lung injury. The aim of the present study was to identify the key genes and potential mechanisms involved in mechanical ventilation (MV) and lipopolysaccharide (LPS)-induced acute lung injury (ALI). Gene expression data of adult C57BL/6 mice with ALI induced by inhaling LPS, MV and LPS + MV were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) associated with MV, LPS and LPS + MV were screened, followed by functional enrichment analysis, protein-protein interaction network construction, and prediction of transcription factors and small molecule drugs. Finally, the expression of key genes was verified in vivo using reverse transcription-quantitative PCR. A total of 63, 538 and 1,635 DEGs were associated with MV, LPS and LPS + MV, respectively. MV-associated genes were significantly enriched in the ‘purine ribonucleotide metabolic process’. LPS and LPS + MV-associated genes were significantly enriched in ‘cellular response to cytokine stimulus’ and ‘cell chemotaxis’. All three conditions were enriched in ‘TNF signaling pathway’ and ‘IL-17 signaling pathway’. Expression levels of C-X-C motif chemokine ligand (CXCL)2, CXCL3 and CXCL10 were upregulated in the LPS and LPS + MV groups. Adenosine A2b receptor, zinc finger and BTB domain-containing 16 and hydroxycarboxylic acid receptor 2 were identified as DEGs in the MV group. Compared with the control group, Early growth response 1 and activating TF 3 was upregulated in all three groups. Similarities and differences were observed among the MV- and LPS-induced ALI, and MV may enhance the effects of LPS on gene expression. MV may affect urine ribonucleotide metabolic-related processes, whereas LPS may cause cell chemotaxis and cytokine stimulus responses in ALI progression. The inflammatory response was shared by MV and LPS. The results of the present study may provide insight into a theoretical basis for the study and treatment of ALI.

Treatment of Lung Cancer by Peptide-Modified Liposomal Irinotecan Endowed with Tumor Penetration and NF-κB Inhibitory Activities

Current chemotherapy for lung cancer achieved limited efficacy due to poor tumor targeting and tissue penetration. Another obstacle in the therapy is activated nuclear factor-κB (NF-κB) in tumor cells, which plays a crucial role in promotion of antiapoptosis and drug resistance. In this study, we utilized a multifunctional liposome loaded with irinotecan and surface modified with a cell-permeable NF-κB inhibitor (CB5005), for treatment of non-small-cell lung carcinoma. CB5005 downregulated the level of NF-κB-related protein in the nuclei of A549 cells, and increased cellular uptake of the modified liposomes. In vivo antitumor activity in mice bearing A549 xenografts revealed that modification with CB5005 significantly improved the tumor inhibition rate of irinotecan. Immunohistochemical assays showed that the tumors treated with CB5005-modified liposomes possessed the most apoptotic cells and the lowest level of p50 in the cell nuclei. These results strongly suggest that antitumor efficacy of the irinotecan liposomes can be enhanced by tumor-penetrating and NF-κB-inhibiting functions of CB5005. Consequently, CB5005-modified liposomes provide a possible synergistic therapy for lung cancer, and would also be appropriate for other types of tumors associated with elevated NF-κB activity.

Dexmedetomidine alleviates non-ventilation associated lung injury via modulating immunology phenotypes of macrophages

AIMS

We aimed to evaluate the effect of Dexmedetomidine (Dex) on immunology function of macrophages and inflammatory reactions in non-ventilated lung tissues from both humans and rats.

MAIN METHODS

Patients scheduled for lung lobectomy were randomly assigned to traditional anesthesia group or Dex anesthesia group, 15 subjects in each group. CD68, CD86 and CD206 were used to mark activate and polarized macrophages using immunofluorescence staining in human lung tissues. Sprague-Dawley rats were used to set lung injury model and randomly divided into Control group, one-lung ventilation group (CLI group) and CLI + Dex group. Lung tissues and bronchoalveolar lavage fluid (BALF) from non-ventilated lungs were collected. The acquired lung tissues were subjected to hematoxylin-eosin (H&E) staining and the inflammatory cells in BALF were calculated. Levels of cytokines and chemokines were detected by enzyme-linked immunosorbent assays (ELISA).

KEY FINDINGS

Results from humans showed that anesthesia with Dex decreased the number of both CD68 positive cells and CD86 positive cells and down-regulated level of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and monocyte chemotactic protein 1 (MCP-1) in human lung. Results from rats demonstrated that treatment with Dex reversed the increased inflammatory cells in lung and the increased levels of TNF-α, interleukin-1β (IL-β), MCP-1 and chemokine (C-X-C motif) ligand 1 (CXCL1) resulted from non-ventilation; Dex increased the anti-inflammatory cytokine interleukin-10 (IL-10) in BALF from non-ventilated lung.

SIGNIFICANCE

This study showed that Dex modulated the activation and immunological function of macrophages in non-ventilated lung and revealed a protective role in collapsed lung injury.

[Effect of directive differentiation of microglia by SN50 on hypoxia-caused neurons injury in mice]

OBJECTIVE

To explore the effect and mechanism of directive differentiation of microglia by SN50 on hypoxia-caused neurons injury in mice.

METHODS

The microglia were isolated and purified from brain tissue of new-born BALB/c mice through differential velocity adherent and vibration technique. The quantity of the microglia was identified by immunofluorescence staining of inducible nitric oxide synthetase (iNOS) and ionized calcium binding adapter molecule 1 (Iba1) and real-time fluorescence quantitative PCR (qRT-PCR) for special expression genes [iNOS, CD32, and interlenkin 10 (IL-10)]. Then the microglia were cultured with SN50, and the expressions of nuclear factor κB (NF-κB), differentiation-related genes (iNOS, CD11b, IL-10, and CD206), and apoptosis were detected by Western blot, qRT-PCR, and flow cytometry, respectively. The hypoxia model of neuron was established, and the cell apoptosis was evaluated by MTT after 0, 2, 6, 12, 24, and 48 hours of anoxic treatment. The apoptosis related markers (Bcl-2 and Caspase-3) were measured by Western blot and flow cytometry. In addition, the neurons after anoxic treatment were co-cultured with SN50 treated microglia (experimental group) and normal microglia (control group) for 24 hours. And the cell viability and apoptosis related markers (Bcl-2 and Caspase-3) were also measured.

RESULTS

Immunofluorescence staining and qRT-PCR analysis showed that the cells expressed the specific proteins and genes of microglia. Compared with the normal microglia, the relative expressions of NF-κB protein and iNOS and CD11b mRNAs in the microglia treated with SN50 significantly decreased ( P<0.05), the relative expressions of IL-10 and CD206 mRNAs significantly increased ( P<0.05), and the cell apoptosis rate had no significant change ( P>0.05). Compared with the normal neurons, the cell viability, the relative expressions of Bcl-2 and Caspase-3 proteins after anoxic treatment significantly decreased ( P<0.05), while the relative expressions of cleaved-Caspase-3 protein and cell apoptosis rate of neurons significantly increased ( P<0.05). In the co-culture system, the cell viability, the relative expressions of Bcl-2 and Caspase-3 proteins were significantly higher in experimental group than those in control group ( P<0.05), while the relative expressions of cleaved-Caspase-3 protein and cell apoptosis rate were significantly lower in experimental group than those in control group ( P<0.05).

CONCLUSION

SN50 can induce the microglia differentiation into M2 type through NF-κB pathway. The SN50-induced microglia can protect neurons from hypoxic injury.

Non‑canonical Wnt signaling contributes to ventilator‑induced lung injury through upregulation of WISP1 expression

Mechanical ventilation may cause ventilator-induced lung injury (VILI). Canonical Wnt signaling has been reported to serve an important role in the pathogenesis of VILI. Bioinformatics analysis revealed that canonical and non-canonical Wnt signaling pathways were activated in VILI. However, the role of non-canonical Wnt signaling in the pathogenesis of VILI remains unclear. The present study aimed to analyze the potential role of non-canonical Wnt signaling in VILI pathogenesis. Lung injury was assessed via Evans blue albumin permeability and histological scoring, as well as by inflammatory cytokine expression and total protein concentration in bronchoalveolar lavage fluid. The relative protein expression of canonical and non-canonical Wnt signaling pathway components were examined via western blotting and immunohistochemistry. The results demonstrated that 6 h of mechanical ventilation at low tidal volume (LTV; 6 ml/kg) or moderate tidal volume (MTV; 12 ml/kg) induced lung injury in sensitive A/J mice. Ventilation with MTV increased the protein levels of Wnt-induced secreted protein 1 (WISP1), Rho-associated protein kinase 1 (ROCK1), phosphorylated (p)-Ras homolog gene family, member A and p-C-Jun N-terminal kinase (JNK). Inhibition of ROCK1 by Y27632 and JNK by SP600125 attenuated MTV-induced lung injury and decreased the expression of proteins involved in non-canonical Wnt signaling, including WISP1. In conclusion, non-canonical Wnt signaling participates in VILI by modulating WISP1 expression, which has been previously noted as critical for VILI development. Therefore, the non-canonical Wnt signaling pathway may provide a preventive and therapeutic target in VILI.

3-Methyladenine ameliorates liver fibrosis through autophagy regulated by the NF-κB signaling pathways on hepatic stellate cell

3-Methyladenine (3-MA) is a selective type III phosphatidylinositol 3-kinase (PI3K) inhibitor and also blocks autophagosome formation. However, the effect of 3-MA in liver fibrosis has yet to be determined. Recent studies have demonstrated that autophagy is closely related to activation of hepatic stellate cells (HSC), a process critical in the pathogenesis of liver fibrosis. And the transcription factor nuclear factor-kappaB (NF-κB) is proved to play an important role in autophagy-induced signaling pathways. Thus, inhibition of autophagy regulated by NF-κB signaling pathway in HSCs is a potential therapeutic approach for attenuating liver fibrosis. Our studies proposed that 3-MA attenuates liver fibrosis induced by carbon tetrachloride (CCl4), and inhibit the expression of autophagy markers and transcriptional regulator NF-κB of hepatic stellate cell in vivo. The function of inhibition of autophagy in activation of human hepatic stellate cell line LX-2 was blocked by the inhibitor of NF-κB in vitro. Conclusively, 3-MA ameliorates liver fibrosis through inhibition of autophagy regulated by the NF-κB signaling pathways on hepatic stellate cell.

Synergism of ursolic acid and cisplatin promotes apoptosis and enhances growth inhibition of cervical cancer cells via suppressing NF-κB p65

Objective

This study was designed to investigate the effect of combination of ursolic acid (UA) with cisplatin (DDP) on cervical cancer cell proliferation and apoptosis.

Methods

The mRNA and protein expressions of nuclear factor-kappa B (NF-κB) p65 in cervical cancer cells were examined using RT-PCR and western blot. MTT and colony formation assays were performed to examine the DDP toxicity and the proliferation ability of cervical cancer cells. Cell morphology was observed by means of Hoechst33258 and transmission electron microscopy (TEM). The apoptosis rate and cell cycle were assessed through flow cytometry assay. Western blot was used to detect the expression of apoptosis-related molecules.

Results

The mRNA and protein expressions of NF-κB p65 in cervical cancer cells were significantly higher than that in cervical epithelial cells. The combined treatment of UA and DDP inhibited cervical cancer cell growth and promoted apoptosis more effectively than DDP treatment or UA treatment alone (P < 0.05). Compared with the DDP group and UA group, the expressions of Bcl-2 and NF-κB p65 in DDP +UA group were decreased, while the expressions of Bax, Caspase-3 and PARP cleavage were observably increased. The expression of nuclear NF-κB p65 significantly reduced in UA group and DDP +UA group. si-p65 group displayed a decrease of cell proliferation ability and led to a significant reduction in the number of SiHa cell colony formation.

Conclusion

The combination of UA with DDP could more effectively inhibit SiHa cells proliferation and facilitate cell apoptosis through suppressing NF-κB p65.

LincRNA-Gm4419 knockdown ameliorates NF-κB/NLRP3 inflammasome-mediated inflammation in diabetic nephropathy

Diabetic nephropathy (DN) as the primary cause of end-stage kidney disease is a common complication of diabetes. Recent researches have shown the activation of nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) and NACHT, LRR and PYD domain-containing protein 3 (NLRP3) inflammasome are associated with inflammation in the progression of DN, but the exact mechanism is unclear. Long noncoding RNAs (lncRNAs) have roles in the development of many diseases including DN. However, the relationship between lncRNAs and inflammation in DN remains largely unknown. Our previous study has revealed that 14 lncRNAs are abnormally expressed in DN by RNA sequencing and real-time quantitative PCR (qRT-PCR) in the renal tissues of db/db DN mice. In this study, these lncRNAs were verified their expressions by qRT-PCR in mesangial cells (MCs) cultured under high- and low-glucose conditions. Twelve lncRNAs displayed the same expressional tendencies in both renal tissues and MCs. In particular, long intergenic noncoding RNA (lincRNA)-Gm4419 was the only one associating with NF-κB among these 12 lncRNAs by bioinformatics methods. Moreover, Gm4419 knockdown could obviously inhibit the expressions of pro-inflammatory cytokines and renal fibrosis biomarkers, and reduce cell proliferation in MCs under high-glucose condition, whereas overexpression of Gm4419 could increase the inflammation, fibrosis and cell proliferation in MCs under low-glucose condition. Interestingly, our results showed that Gm4419 could activate the NF-κB pathway by directly interacting with p50, the subunit of NF-κB. In addition, we found that p50 could interact with NLRP3 inflammasome in MCs. In conclusion, our findings suggest lincRNA-Gm4419 may participate in the inflammation, fibrosis and proliferation in MCs under high-glucose condition through NF-κB/NLRP3 inflammasome signaling pathway, and may provide new insights into the regulation of Gm4419 during the progression of DN.

Endothelial cell signaling and ventilator-induced lung injury: molecular mechanisms, genomic analyses, and therapeutic targets

Mechanical ventilation is a life-saving intervention in critically ill patients with respiratory failure due to acute respiratory distress syndrome (ARDS). Paradoxically, mechanical ventilation also creates excessive mechanical stress that directly augments lung injury, a syndrome known as ventilator-induced lung injury (VILI). The pathobiology of VILI and ARDS shares many inflammatory features including increases in lung vascular permeability due to loss of endothelial cell barrier integrity resulting in alveolar flooding. While there have been advances in the understanding of certain elements of VILI and ARDS pathobiology, such as defining the importance of lung inflammatory leukocyte infiltration and highly induced cytokine expression, a deep understanding of the initiating and regulatory pathways involved in these inflammatory responses remains poorly understood. Prevailing evidence indicates that loss of endothelial barrier function plays a primary role in the development of VILI and ARDS. Thus this review will focus on the latest knowledge related to 1) the key role of the endothelium in the pathogenesis of VILI; 2) the transcription factors that relay the effects of excessive mechanical stress in the endothelium; 3) the mechanical stress-induced posttranslational modifications that influence key signaling pathways involved in VILI responses in the endothelium; 4) the genetic and epigenetic regulation of key target genes in the endothelium that are involved in VILI responses; and 5) the need for novel therapeutic strategies for VILI that can preserve endothelial barrier function.