1α,25-Dihydroxyvitamin D3 Ameliorates Seawater Aspiration-Induced Lung Injury By Inhibiting The Translocation Of NF-κB and RhoA

Serum 25-hydroxyvitamin D levels and peripheral blood eosinophil percentages as predictive indicators for eosinophilic chronic sinusitis with nasal polyps

PURPOSE

Chronic rhinosinusitis (CRS) has a high incidence rate and different endotypes. Serum 25-hydroxyvitamin D (25(OH)D) deficiency is common in patients with eosinophilic and non-eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP and nECRSwNP, respectively). This study explored the relationship between serum 25(OH)D levels and CRS risk and determined the value of combining serum 25(OH)D with peripheral blood markers in distinguishing between ECRSwNP and nECRSwNP.

METHODS

This study enrolled 275 CRS patients and 298 healthy controls. The relationship between serum 25(OH)D levels and CRS risk was determined using logistic regression after propensity score matching (PSM). The efficiency of various peripheral blood markers in distinguishing between ECRSwNP and nECRSwNP was assessed using a decision-tree model.

RESULTS

The final analysis included 189 CRS patients and 189 controls after 1:1 PSM. Serum 25(OH)D levels were significantly lower in CRS patients than in controls. Patients with mild CRS showed higher serum 25(OH)D levels than those with moderate or severe CRS, and ECRSwNP patients had lower serum 25(OH)D levels than nECRSwNP patients (all Ps < 0.05). Eosinophil percentages and IgE levels were independent risk factors for ECRSwNP, whereas serum 25(OH)D was an independent protective factor. 25(OH)D deficiency increased the ECRSwNP risk (OR = 3.074, P = 0.04). An eosinophil percentage ≥ 5% and a 25(OH)D level < 61.8 nmol/L could be used to predict ECRSwNP, with training and test set accuracies of 89.7% and 85.7%, respectively.

CONCLUSION

Our findings suggest that serum 25(OH)D deficiency is an independent risk factor for CRS, especially ECRSwNP. Combining serum 25(OH)D levels with peripheral eosinophil percentages could be a promising biomarker for ECRSwNP.

Vaporization of perfluorocarbon attenuates sea-water-drowning-induced acute lung injury by deactivating the NLRP3 inflammasomes in canines

Seawater-drowning-induced acute lung injury (SD-ALI) is a life-threatening disorder characterized by increased alveolar-capillary permeability, an excessive inflammatory response, and refractory hypoxemia. Perfluorocarbons (PFCs) are biocompatible compounds that are chemically and biologically inert and lack toxicity as oxygen carriers, which could reduce lung injury in vitro and in vivo. The aim of our study was to explore whether the vaporization of PFCs could reduce the severity of SD-ALI in canines and investigate the underlying mechanisms. Eighteen beagle dogs were randomly divided into three groups: the seawater drowning (SW), perfluorocarbon (PFC), and control groups. The dogs in the SW group were intratracheally administered seawater to establish the animal model. The dogs in the PFC group were treated with vaporized PFCs. Probe-based confocal laser endomicroscopy (pCLE) was performed at 3 h. The blood gas, volume air index (VAI), pathological changes, and wet-to-dry (W/D) lung tissue ratios were assessed. The expression of heme oxygenase-1 (HO-1), nuclear respiratory factor-1 (NRF1), and NOD-like receptor family pyrin domain containing-3 (NLRP3) inflammasomes was determined by means of quantitative real-time polymerase chain reaction (qRT-PCR) and immunological histological chemistry. The SW group showed higher lung injury scores and W/D ratios, and lower VAI compared to the control group, and treatment with PFCs could reverse the change of lung injury score, W/D ratio and VAI. PFCs deactivated NLRP3 inflammasomes and reduced the release of caspase-1, interleukin-1β (IL-1β), and interleukin-18 (IL-18) by enhancing the expression of HO-1 and NRF1. Our results suggest that the vaporization of PFCs could attenuate SD-ALI by deactivating NLRP3 inflammasomes via the HO-1/NRF1 pathway.

Vitamin D3 improved hypoxia-induced lung injury by inhibiting the complement and coagulation cascade and autophagy pathway

BACKGROUND

Pulmonary metabolic dysfunction can cause lung tissue injury. There is still no ideal drug to protect against hypoxia-induced lung injury, therefore, the development of new drugs to prevent and treat hypoxia-induced lung injury is urgently needed. We aimed to explore the ameliorative effects and molecular mechanisms of vitamin D3 (VD3) on hypoxia-induced lung tissue injury.

METHODS

Sprague-Dawley (SD) rats were randomly divided into three groups: normoxia, hypoxia, and hypoxia + VD3. The rat model of hypoxia was established by placing the rats in a hypobaric chamber. The degree of lung injury was determined using hematoxylin and eosin (H&E) staining, lung water content, and lung permeability index. Transcriptome data were subjected to differential gene expression and pathway analyses. In vitro, type II alveolar epithelial cells were co-cultured with hepatocytes and then exposed to hypoxic conditions for 24 h. For VD3 treatment, the cells were treated with low and high concentrations of VD3.

RESULTS

Transcriptome and KEGG analyses revealed that VD3 affects the complement and coagulation cascade pathways in hypoxia-induced rats, and the genes enriched in this pathway were Fgb/Fga/LOC100910418. Hypoxia can cause increases in lung edema, inflammation, and lung permeability disruption, which are attenuated by VD3 treatment. VD3 weakened the complement and coagulation cascade in the lung and liver of hypoxia-induced rats, characterized by lower expression of fibrinogen alpha chain (Fga), fibrinogen beta chain (Fgb), protease-activated receptor 1 (PAR1), protease-activated receptor 3 (PAR3), protease-activated receptor 4 (PAR4), complement (C) 3, C3a, and C5. In addition, VD3 improved hypoxic-induced type II alveolar epithelial cell damage and inflammation by inhibiting the complement and coagulation cascades. Furthermore, VD3 inhibited hypoxia-induced autophagy in vivo and in vitro, which was abolished by the mitophagy inducer, carbonyl cyanide-m-chlorophenylhydrazone (CCCP).

CONCLUSION

VD3 alleviated hypoxia-induced pulmonary edema by inhibiting the complement and coagulation cascades and autophagy pathways.

N-phenethyl-5-phenylpicolinamide alleviates inflammation in acute lung injury by inhibiting HIF-1α/glycolysis/ASIC1a pathway

AIMS

Acute lung injury (ALI) is triggered by an acute inflammatory response. Lipopolysaccharide (LPS) is recognized as an important participant in the pathogenesis of sepsis, which may induce ALI. N-phenethyl-5-phenylpicolinamide (N5P) is a newly synthesized HIF-1α inhibitor. The purpose of the present study was to investigate the potential protective effects of N5P on LPS-induced ALI and the underlying mechanisms.

MAIN METHODS

In vivo experiment, the ALI rat model was induced by intratracheal injection of LPS, and various concentrations of N5P were injected intraperitoneally before LPS administration. In vitro experiment, RAW264.7 macrophages were administrated LPS and N5P to detect inflammatory cytokine changes. HIF-1α overexpression plasmid (HIF1α-OE) and granulocyte-macrophage colony-stimulating factor (GM-CSF), a glycolysis agonist, were used to examine the relationship between the HIF-1α/glycolysis/ASIC1a pathway.

KEY FINDINGS

Pretreatment with N5P inhibited not only the histopathological changes that occurred in the lungs but also lung dysfunction in LPS-induced ALI. N5P also decreased the levels of lactic acid in lung tissue and arterial blood, and inflammatory factors IL-1β and IL-6 levels in serum. LPS increased HIF-1α, glycolysis proteins GLUT1, HK2, ASIC1a, IL-1β, IL-6, and these changes were reversed by N5P in primary alveolar macrophages and RAW264.7 macrophages. Overexpression of HIF-1α significantly increased glycolysis genes and ASIC1a as well as inflammatory cytokines. Excessive glycolysis levels weaken the ability of N5P to inhibit inflammation.

SIGNIFICANCE

N5P may alleviate inflammation in ALI through the HIF-1α/glycolysis/ASIC1a signaling pathway. The present findings have provided pertinent information in the assessment of N5P as a potential, future therapeutic drug for ALI.

Andrographolide sulfonate attenuates alveolar hypercoagulation and fibrinolytic inhibition partly via NF-κB pathway in LPS-induced acute respiratory distress syndrome in mice

BACKGROUND

Alveolar hypercoagulation and fibrinolytic inhibition are important characteristics during acute respiratory distress syndrome (ARDS), and NF-κB p65 signaling pathway is involved to regulate these pathophysiologies. We hypothesize that targeting NF-κB signal pathway could ameliorate alveolar hypercoagulation and fibrinolyitc inhibition, thus attenuating lung injury in ARDS.

PURPOSE

We explore the efficacy and the potential mechanism of andrographolide sulfonate (Andro-S) on alveolar hypercoagulation and fibrinolytic inhibition in LPS-induced ARDS in mice.

METHODS

ARDS was made by lipopolysaccharide (LPS) inhalation in C57BLmice. Andrographolide sulfonate (2.5, 5 and 10 mg/kg) was intraperitoneally given to the mice (once a day for three consecutive days) before LPS administration. NEMO binding domain peptide (NBD), an inhibitor of NF-κB, was used as the positive control and it replaced Andro-S in mice of NBD group. Mice in normal control received saline instead of LPS. Lung tissues and bronchoalveolar lavage fluid (BALF) were collected for analysis of alveolar coagulation, fibrinolytic inhibition as well as of pulmonary inflammatory response after 8 h of LPS inhalation. NF-κB signal pathway in lung tissue was simultaneously determined.

RESULTS

Andro-S dose-dependently inhibited tissue factor (TF) and plasminogen activator inhibitor (PAI)-1 expressions either in mRNA or in protein in lung tissue of ARDS mice, and it also decreased the concentrations of TF, PAI-1, thrombin-antithrombin complex (TAT), procollagen peptide type Ⅲ (PⅢP) while promoting the production of activated protein C (APC) in BALF. Meanwhile, Andro-S effectively inhibited inflammatory response (interleukin 1β and myeloperoxidase) induced by LPS. LPS stimulation dramatically activated NF-κB signal pathway, indicated by increased expressions of phosphorylation of p65 (p-p65), p-IKKα/β and p-IκBα and the higher p65-DNA binding activity, which were all dose-dependently reversed by Andro-S. Andro-S and NBD presented similar efficacies.

CONCLUSIONS

Andro-S treatment improves alveolar hypercoagulation and fibrinolytic inhibition and attenuates pulmonary inflammation in LPS-induced ARDS in mice partly through NF-κB pathway inactivation. The drug is expected to be an effective choice for ARDS.

Dioscin alleviates lung ischemia/reperfusion injury by regulating FXR-mediated oxidative stress, apoptosis, and inflammation

Dioscin showed various pharmacological effects in our previous studies; however, the effects and mechanisms against lung ischemia/reperfusion injury (LI/RI) have not been reported. Hypoxia/reoxygenation (H/R) models were established using A549 and primary AEC-II cells, while LI/RI models were established in rats and mice. The effects of dioscin on oxidative stress, inflammation and apoptosis in vivo and in vitro were investigated. The mechanisms were investigated focus on dioscin regulating FXR/LKB1 signaling pathway. Dioscin improved cell viability and mitochondrial membrane potential, reduced reactive oxygen species level, and inhibited H/R-mediated cell apoptosis. It also significantly decreased the lung wet/dry weight ratio, ameliorated levels of oxidative stress indicators, and enhanced the mitochondrial membrane potential and inhibited cell apoptosis in vivo. The results of mechanism research showed that dioscin activated FXR/LKB1 signals by increasing the expression of p-LKB1 and p-AMPKα, promoting the nuclear translocation of Nrf2, up-regulating the levels of HO-1, NQO1 and GCLC, expressed against oxidative stress. Furthermore, dioscin reduced Cyt C released, decreased the expression levels of Caspase-9 and Caspase-3 during apoptosis. Dioscin suppressed inflammation by inhibiting NF-κB translocation, reducing the expression levels of NF-κB, HMGB1, COX-2, IL-1β, IL-6 and TNF-α. The transfection of FXR or LKB1 siRNA further confirmed that the protective effect of dioscin against LI/RI was attributable to the regulation of FXR/LKB1 signaling pathway. Our research showed that dioscin exhibited potent activity against LI/RI, by adjusting the levels of FXR/LKB1-mediated oxidative stress, apoptosis, and inflammation, and should be considered as a new candidate for treating LI/RI.

PLCε1 mediates one-lung ventilation injury by regulating the p38/RhoA/NFκB activation loop

BACKGROUND

Phospholipase C epsilon-1 (PLCε1) might be a novel and potential target in treating inflammatory conditions. In the present study, we aimed to clarify whether PLCε1 is involved in lung injury caused by one-lung ventilation (OLV) and to elucidate the potential molecular mechanism of PLCε1-mediated signaling pathway on OLV induced inflammatory response and injury.

METHODS

Male Sprague-Dawley (SD) rats were divided into wide-type (PLCε1-WT) group and PLCε1-KO group, and were treated with OLV for 0.5 h, 1 h, and 2 h respectively. Observation of lung tissue injury in rats was performed by Hematoxylin and eosin (HE) staining and Wet/dry (W/D) radios. In addition, pulmonary microvascular endothelial cells (PMVECs) transfected with PLCε1-si RNA, were stimulated by lipopolysaccharide (LPS). To explore the possible roles of PLCε1 in the OLV induced inflammatory injury and the involved pathway underlying, the lung tissue and bronchoalveolar lavage fluids (BALF) of OLV rats, as well as the PMVECs were prepared for further analysis. Enzyme-linked immunoassay (ELISA) was used to detect the expression of pro-inflammatory factors. The activities of related pathway proteins (NF-κB, phospho-p38, p38, phospho-ERK1/2, ERK1/2, RhoA and ROCK) were also detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis.

RESULTS

Compared to the PLCε1-WT rats, PLCε1-KOrats exhibited marked alleviation of lung inflammation as shown by great reduction in lung wet/dry weight ratios, decreases in the expressions of pro-inflammatory mediators, and declines in the number of neutrophils and the protein concentration in bronchoalveolar lavage fluid (BALF). Moreover, the increased expressions of RhoA and NF-κB p65 mRNA induced by OLV were significantly inhibited in PLCε1-KO rats. In LPS treated PMVECs, PLCε1-si RNA transfection ones also showed the decrease expression of proinflammatory mediators, reduction in p38 phosphorylation levels and downregulation of RhoA/ROCK signaling activation. Co-cultured with PLCε1-si RNA and BTRB796 (p38 inhibitors) in LPS-stimulated PMVECs resulted in a significant reduction in RhoA and NF-κB activity. In addition, treatment with either ROCK inhibitor (Y-27632) or dominant negative mutant of RhoA (RhoT19 N) significantly reduced the expression of NF-κB in PLCε1-si RNA treated PMVECs.

CONCLUSION

The results indicated that PLCε1 played an important role in the inflammatory response induced by OLV. Moreover, through promoting p38/RhoA/ROCK activation loop, PLCε1 promoted NF-κB activation and thereby increased the expressions of inflammatory mediators, which induced the PMVECs inflammation and subsequent injury. The results of this study provide a potential therapeutic target for the reduction of inflammatory response in patients with OLV.

Influence of Pseudomonas autoinducer N-3-oxododecanoyl homoserine lactone on human corneal epithelial cells

The quorum-sensing (QS) signaling-dependent extracellular virulence factors of Pseudomonas aeruginosa can cause infections such as P. aeruginosa keratitis. P. aeruginosa communicates by secreting and sensing small chemical molecules called autoinducers in QS system. The key QS signal molecule, N-3-oxododecanoyl-homoserine lactone (3OC12HSL), can affect the behavior of host cells and initiate immune response. In this report we investigated the influence of 3OC12HSL on human corneal epithelial cells (HCECs) and the mechanisms of 3OC12HSL on activated toll-like receptor 2 (TLR2)-dependent interleukin-8 (IL-8) secretion in HCECs. Cells were cultured under different concentrations of 3OC12HSL. Cell viability was assessed using Crystal violet staining and the cell counting kit-8 assay. We demonstrated the administration of 3OC12HSL decreased HCEC viability and survival in a concentration- and time-dependent manner. At high concentrations, 3OC12HSL rapidly promoted a time-dependent increase in the expressions of TLR2 and TLR4. It was found that the nuclear translocation and expression of nuclear factor-κB (NF-κB) were also increased in response to 3OC12HSL treatment. The significantly elevated expressions of TLR2, TLR4, and NF-κB, encouraged us to further test their mechanisms that cause inflammatory response. Among the inflammatory factors examined (IL-6, IL-8, IL-10, and TNF-α), we found that IL-8 was significantly increased after treatment with 3OC12HSL and its expression was inhibited when TLR2 was specifically blocked or silenced. These results indicated that the QS signaling molecule 3OC12HSL could be recognized by the host innate immune system in HCECs. This recognition then triggered an immune inflammatory response involving the activation of TLR2 and an increase in expression of IL-8. This crosstalk between 3OC12HSL and host immunity in HCECs contributes to the development and progression of P. aeruginosa keratitis.

Emodin improves alveolar hypercoagulation and inhibits pulmonary inflammation in LPS-provoked ARDS in mice via NF-κB inactivation

BACKGROUND

Alveolar hypercoagulation and pulmonary inflammation are important characteristics and they regulate each other in acute respiratory distress syndrome (ARDS). NF-κB pathway has been confirmed to be involved in regulation of this crosstalk. Emodin, a traditional Chinese herb, shows potent inhibitory effect on NF-κB pathway, but whether it is effective in alveolar hypercoagulation and pulmonary inflammation in ARDS remains to be elucidated.

PURPOSE

The aim of this experiment was to evaluate the efficacy of emodin on LPS-provoked alveolar hypercoagulation and excessive pulmonary inflammation in ARDS, and its potential mechanism.

METHODS

Mice ARDS was set up through LPS (40 μl, 4 mg/ml) inhalation. Male mice were randomly received with BPS, LPS only, LPS+ emodin (5 mg/kg, 10 mg/kg, 20 mg/kg, respectively) and BAY65-1942, an inhibitor of IKKβ. After 48 h of LPS stimulation, pulmonary pathological injury, expressions of Tissue factor (TF), plasminogen activator inhibitor (PAI)-1, activated protein C (APC), collagen Ⅰ, collagen III, interleukin (IL) 8, IL-1β and tumor necrosis factor (TNF)-α in lung tissues, as well as concentrations of antithrombin III (AT III), procollagen peptide type III (PIIIP), soluble thrombomodulin (sTM), thrombin antithrombin complex (TAT), myeloperoxidase (MPO) and the percentage of inflammatory cells in bronchoalveolar lavage fluid (BALF) were all determined. NF-κB pathway activation as well as NF-κB DNA binding activity in pulmonary tissue were simultaneously checked.

RESULTS

LPS stimulation resulted in obvious lung injury, excessive inflammatory cells infiltration, which all were dose-dependently ameliorated by emodin. Expressions of TF, PAI-1, collagen Ⅰ and collagen III as well as IL-8, IL-1β and TNF-α in pulmonary tissue were all elevated while APC decreased under LPS provocation, which were all reversed by emodin treatment in dose-dependent manner. LPS promoted the secretions of PIIIP, sTM, TAT and inhibited AT III production in BALF, and resulted in high levels of MPO and the percentage of inflammatory cells in BALF, all of which were significantly and dose-dependently attenuated while AT III production was increased by emodin. Meanwhile, emodin effectively inhibited NF-κB pathway activation and attenuated p65 DNA binding activity induced by LPS inhalation. Emodin and BAY-65-1942 had similar impacts in this experiment.

CONCLUSIONS

Emodin improves alveolar hypercoagulation and fibrinolytic inhibition and depresses excessive pulmonary inflammation in ARDS mice in dose-dependent manner via NF-κB inactivation. Our data demonstrate that emodin is expected to be an effective drug in alveolar hypercoagulation and pulmonary inflammation in ARDS.

Aryl Hydrocarbon Receptor Role in Co-Ordinating SARS-CoV-2 Entry and Symptomatology: Linking Cytotoxicity Changes in COVID-19 and Cancers; Modulation by Racial Discrimination Stress

There is an under-recognized role of the aryl hydrocarbon receptor (AhR) in co-ordinating the entry and pathophysiology of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) that underpins the COVID-19 pandemic. The rise in pro-inflammatory cytokines during the 'cytokine storm' induce indoleamine 2,3-dioxygenase (IDO), leading to an increase in kynurenine that activates the AhR, thereby heightening the initial pro-inflammatory cytokine phase and suppressing the endogenous anti-viral response. Such AhR-driven changes underpin the heightened severity and fatality associated with pre-existent high-risk medical conditions, such as type II diabetes, as well as to how racial discrimination stress contributes to the raised severity/fatality in people from the Black Asian and Minority Ethnic (BAME) communities. The AhR is pivotal in modulating mitochondrial metabolism and co-ordinating specialized, pro-resolving mediators (SPMs), the melatonergic pathways, acetyl-coenzyme A, and the cyclooxygenase (COX) 2-prostaglandin (PG) E2 pathway that underpin 'exhaustion' in the endogenous anti-viral cells, paralleling similar metabolic suppression in cytolytic immune cells that is evident across all cancers. The pro-inflammatory cytokine induced gut permeability/dysbiosis and suppression of pineal melatonin are aspects of the wider pathophysiological underpinnings regulated by the AhR. This has a number of prophylactic and treatment implications for SARS-CoV-2 infection and cancers and future research directions that better investigate the biological underpinnings of social processes and how these may drive health disparities.

Heme oxygenase-1 attenuates seawater drowning-induced acute lung injury through a reduction in inflammation and oxidative stress

OBJECTIVE

Heme oxygenase-1 (HO-1) plays a critical protective role in various insults-induced acute lung injury (ALI) through its strong anti-inflammatory, anti-oxidant, and anti-apoptotic properties, but its protective role and mechanism on seawater aspiration-induced acute lung injury remains unclear. This study aimed to explore the therapeutic potential and mechanism of HO-1 to attenuate seawater aspiration-induced ALI in vivo and in vitro.

METHODS

The viability and invasion of A549 cell were analyzed through cell counting kit-8 and lactate dehydrogenase release assay; the transcriptional level of inflammatory cytokines (TNF-α, IL-6, IL-8 and MCP-1) and cell proliferation-related cytokines (FoxM1, Ccnb1 and Cdc25C) in seawater-treated A549 cell were tested by qPCR; apoptotic cells were analyzed by flow cytometryd; HO-1mRNA and protein were determined by qPCR and western blotting; the fluorescent indicators (DCFH-DA, dihydroethidium, MitoSox Red and Fluo-4) were used to monitor generation of ROS and mitochondrial function. The lung wet/dry weight radio and lactate dehydrogenase activity, Sirius red staining, TUNEL assay and immunohistochemical staining with anti-pan Cytokeratin antibody were analyzed in seawater-drowning mice. The role of HO-1 on seawater-drowning pulmonary injury was explored via HO-1 activity inhibitors (Zinc protoporphyrin) in vitro and in vivo.

RESULTS

Seawater exposure decreased the cellular viability, increased the production of pro-inflammatory cytokines (IL-6, IL-8 and TNF-α), induced cellular apoptosis and inhibited the expression of cell proliferation-related cytokines (FoxM1, Ccnb1 and Cdc25C). Moreover, seawater exposure led to mitochondrial dysfunction in A549 cells. Supplement of HO-1 sepcific inducer (heme) or its catalytic product (biliverdin) significantly attenuated seawater-induced A549 damage and promoted cell proliferation. However, Zinc protoporphyrin abolished the beneficial effects of HO-1 on seawater drowning-induced pulmonary tissue injury.

CONCLUSION

HO-1 attenuates seawater drowning-induced lung injury by its anti-inflammatory, anti-oxidative, and anti-apoptosis function.

Grape Seed Proanthocyanidin Extract Inhibits Human Esophageal Squamous Cancerous Cell Line ECA109 via the NF-κB Signaling Pathway

Esophageal squamous cell carcinoma is the most common type of squamous cell carcinoma. Grape seed proanthocyanidin extract (GSPE) is considered to exhibit anticancer activity against several different types of cancer. We aimed to determine whether GSPE inhibited esophageal squamous cancerous cells and the possible involvement of NF-κB in this process. The human esophageal squamous cancer cell line ECA109 was treated with GSPE (0-80 μg/mL) and BAY11-7082 (10 μmol/L) for 12, 24, and 48 h. The MTT assay was used to determine cell proliferation; alterations in cell apoptosis were detected by flow cytometry; levels of inflammatory factors interleukin-6 and cyclooxygenase-2 and apoptotic proteins Bax/Bcl-2 were measured by ELISA; qRT-PCR and western blots were used to examine the activation of caspase-3 and NF-κB signaling. GSPE inhibited the proliferation of ECA109 cells and induced cellular apoptosis in a time- and dose-dependent manner. ELISA results showed that GSPE and BAY11-7082 reduced the secretion of inflammatory cytokines interleukin-6 and cyclooxygenase-2. The results of PCR and western blotting indicated that GSPE and BAY11-7082 activated caspase-3 and attenuated the activation of the NF-κB signaling pathway. GSPE induced apoptosis in ECA109 cells and inhibited ECA109 cell proliferation via a reduction in the secretion of inflammatory cytokines. This mechanism may be related to the attenuation of NF-κB activity and the sensitization of caspase-3.

ACE-2/ANG1-7 ameliorates ER stress-induced apoptosis in seawater aspiration-induced acute lung injury

Previous studies have shown that apoptosis of alveolar cells can be regulated by autocrine of angiotensin (ANG)II and its counter regulatory ACE-2/ANG1-7 axis. Our earlier study has shown that endoplasmic reticulum (ER) stress in response to seawater aspiration eventually led to apoptosis in lung tissue. In this study, we examined the hypothesis that ER stress-induced apoptosis in seawater aspiration-induced acute lung injury (ALI) might also be regulated by the ANGII/ANG1-7 system. ER stress was induced by seawater stimulation and proteasome inhibitor MG132 (an ER stress inductor). Moreover, ER stress in seawater-stimulated lung tissues and rat pulmonary microvascular endothelial cells (RPMVECs) promoted ANGII expression and decreased ACE-2/ANG1-7 expression. ER stress induced by seawater stimulation also led to apoptosis. Apoptosis induced by seawater stimulation and MG132 were inhibited by ANGII receptor blocker and abrogated by the addition of ANG1-7. These results suggest that apoptosis induced by ER stress in seawater aspiration-induced ALI is regulated by ANG II/ANG1-7 in lung tissues and RPMVECs. In addition, the active form of X-box binding protein 1 (XBP1), spliced XBP1 (XBP1s), a transcription factor that regulates ER-associated degradation genes during ER stress was significantly activated in seawater stimulated cells. Based on this phenomenon we designed a tandem gene, Wfs1 promoter (a target gene promoter of XBP1s)- ACE2 and ANG1-7 and transfected this tandem gene into seawater-stimulated cells. ACE-2/ANG1-7 expression were significantly promoted and apoptosis was inhibited in cells transfected with the tandem gene. These results suggest that stimulation of ACE-2/ANG1-7 may be a therapeutic target of ER stress-induced apoptosis in seawater aspiration-induced ALI.

Inhibition of neurite outgrowth using commercial myelin associated glycoprotein-Fc in neuro-2a cells

Myelin-associated glycoprotein (MAG) inhibits the growth of neurites from nerve cells. Extraction and purification of MAG require complex operations; therefore, we attempted to determine whether commercially available MAG-Fc can replace endogenous MAG for research purposes. Immunofluorescence using specific antibodies against MAG, Nogo receptor (NgR) and paired immunoglobulin-like receptor B (PirB) was used to determine whether MAG-Fc can be endocytosed by neuro-2a cells. In addition, neurite outgrowth of neuro-2a cells treated with different doses of MAG-Fc was evaluated. Enzyme linked immunosorbent assays were used to measure RhoA activity. Western blot assays were conducted to assess Rho-associated protein kinase (ROCK) phosphorylation. Neuro-2a cells expressed NgR and PirB, and MAG-Fc could be endocytosed by binding to NgR and PirB. This activated intracellular signaling pathways to increase RhoA activity and ROCK phosphorylation, ultimately inhibiting neurite outgrowth. These findings not only verify that MAG-Fc can inhibit the growth of neural neurites by activating RhoA signaling pathways, similarly to endogenous MAG, but also clearly demonstrate that commercial MAG-Fc is suitable for experimental studies of neurite outgrowth.