Propofol promotes migration, alleviates inflammation, and apoptosis of lipopolysaccharide-induced human pulmonary microvascular endothelial cells by activating PI3K/AKT signaling pathway via upregulating APOM expression

Anthrahydroquinone‑2,6‑disulfonate attenuates PQ‑induced acute lung injury through decreasing pulmonary microvascular permeability via inhibition of the PI3K/AKT/eNOS pathway

In paraquat (PQ)‑induced acute lung injury (ALI)/ acute respiratory distress syndrome, PQ disrupts endothelial cell function and vascular integrity, which leads to increased pulmonary leakage. Anthrahydroquinone‑2,6‑disulfonate (AH2QDS) is a reducing agent that attenuates the extent of renal injury and improves survival in PQ‑intoxicated Sprague‑Dawley (SD) rats. The present study aimed to explore the beneficial role of AH2QDS in PQ‑induced ALI and its related mechanisms. A PQ‑intoxicated ALI model was established using PQ gavage in SD rats. Human pulmonary microvascular endothelial cells (HPMECs) were challenged with PQ. Superoxide dismutase, malondialdehyde, reactive oxygen species and nitric oxide (NO) fluorescence were examined to detect the level of oxidative stress in HPMECs. The levels of TNF‑α, IL‑1β and IL‑6 were assessed using an ELISA. Transwell and Cell Counting Kit‑8 assays were performed to detect the migration and proliferation of the cells. The pathological changes in lung tissues and blood vessels were examined by haematoxylin and eosin staining. Evans blue staining was used to detect pulmonary microvascular permeability. Western blotting was performed to detect target protein levels. Immunofluorescence and immunohistochemical staining were used to detect the expression levels of target proteins in HPMECs and lung tissues. AH2QDS inhibited inflammatory responses in lung tissues and HPMECs, and promoted the proliferation and migration of HPMECs. In addition, AH2QDS reduced pulmonary microvascular permeability by upregulating the levels of vascular endothelial‑cadherin, zonula occludens‑1 and CD31, thereby attenuating pathological changes in the lungs in rats. Finally, these effects may be related to the suppression of the phosphatidylinositol‑3‑kinase (PI3K)/protein kinase B (AKT)/endothelial‑type NO synthase (eNOS) signalling pathway in endothelial cells. In conclusion, AH2QDS ameliorated PQ‑induced ALI by improving alveolar endothelial barrier disruption via modulation of the PI3K/AKT/eNOS signalling pathway, which may be an effective candidate for the treatment of PQ‑induced ALI.

Endothelial RSPO3 mediates pulmonary endothelial regeneration by LGR4-dependent activation of β-catenin and ILK signaling pathways after inflammatory vascular injury

Endothelial repair is essential for restoring tissue fluid homeostasis following lung injury. R-spondin3 (RSPO3), a secreted protein mainly produced by endothelial cells (ECs), has shown its protective effect on endothelium. However, the specific mechanisms remain unknown. To explore whether and how RSPO3 regulates endothelial regeneration after inflammatory vascular injury, the role of RSPO3 in sepsis-induced pulmonary endothelial injury was investigated in EC-specific RSPO3 knockdown, inducible EC-specific RSPO3 deletion mice, EC-specific RSPO3 overexpression mice, systemic RSPO3-administration mice, in isolated mouse lung vascular endothelial cells (MLVECs), and in plasma from septic patients. Here we show that plasma RSPO3 levels are decreased in septic patients and correlated with endothelial injury markers and PaO2/FiO2 index. Both pulmonary EC-specific knockdown of RSPO3 and inducible EC-specific RSPO3 deletion inhibit pulmonary ECs proliferation and exacerbate ECs injury, whereas intra-pulmonary EC-specific RSPO3 overexpression promotes endothelial recovery and attenuates ECs injury during endotoxemia. We show that RSPO3 mediates pulmonary endothelial regeneration by a LGR4-dependent manner. Except for β-catenin, integrin-linked kinase (ILK)/Akt is also identified as a novel downstream effector of RSPO3/LGR4 signaling. These results conclude that EC-derived RSPO3 mediates pulmonary endothelial regeneration by LGR4-dependent activation of β-catenin and ILK signaling pathways after inflammatory vascular injury.

Analysis of abnormal expression of signaling pathways in PQ-induced acute lung injury in SD rats based on RNA-seq technology

Background: Paraquat (PQ) plays an important role in agricultural production due to its highly effective herbicidal effect. However, it has led to multiple organ failure in those who have been poisoned, with damage most notable in the lungs and ultimately leading to death. Because of little research has been performed at the genetic level, and therefore, the specific genetic changes caused by PQ exposure are unclear.Methods: Paraquat poisoning model was constructed in Sprague Dawley (SD) rats, and SD rats were randomly divided into Control group, paraquat (PQ) poisoning group and Anthrahydroquinone-2,6-disulfonate (AH2QDS) treatment group. Then, the data was screened and quality controlled, compared with reference genes, optimized gene structure, enriched at the gene expression level, and finally, signal pathways with significantly different gene enrichment were screened.Results: This review reports on lung tissues from paraquat-intoxicated Sprague Dawley (SD) rats that were subjected to RNA-seq, the differentially expressed genes were mainly enriched in PI3K-AKT, cGMP-PKG, MAPK, Focal adhesion and other signaling pathways.Conclusion: The signaling pathways enriched with these differentially expressed genes are summarized, and the important mechanisms mediated through these pathways in acute lung injury during paraquat poisoning are outlined to identify important targets for AH2QDS treatment of acute lung injury due to paraquat exposure, information that will be used to support a subsequent in-depth study on the mechanism of PQ action.

HSF1 enhances the attenuation of exosomes from mesenchymal stem cells to hemorrhagic shock induced lung injury by altering the protein profile of exosomes

Severe hemorrhagic shock (HS) leads to lung injury, resulting in respiratory insufficiency. Mesenchymal stem cell (MSC)-derived exosomes have therapeutic effects on the organ injury. HSF1 has been reported to protect the lung against injury. In this study, the role of exosomes from HSF1-overexpressed MSCs (HSF1-EVs) in HS-induced lung injury was investigated. We constructed a mouse model of lung injury by induction with HS and pre-treated it with HSF1-EVs. It was clarified that HSF1-EVs manifested better protective effects on HS-induced lung injury compared with the exosomes derived from control MSCs. Inhalation of HSF1-EVs declined the ratio of wet to dry and total protein concentration in bronchoalveolar lavage fluids. Besides, HSF1-EVs greatly inhibited the production of inflammatory cytokines (IL-1β, IL-6, MCP-1 and HMGB1), and constrained the pulmonary neutrophilic infiltration induced by HS. A reduction of oxidative stress was observed in HSF1-EV-treated mice. HSF1-EVs suppressed the HS-induced apoptosis of lung cell and downregulated Bcl-2 expression, while promoting Bax expression. The key proteins of pulmonary epithelial barrier, E-cadherin, ZO-1 and Occludin, were all upregulated in HS-treated mice after HSF1-EV inhalation, suggesting that HSF1-EVs played a protective role in the epithelial barrier of lung. Additionally, the results of proteomics showed that HSF1 overexpression altered the protein profile of MSC-derived exosomes, which might explain the more significant relief effect of HSF1-EVs on lung injury compared with that of Plasmid-EVs. These new findings demonstrated that the exosomes secreted by HSF1-overexpressed MSCs can be an effective precautionary measure for lung injury induced by HS.

Hydrogen Sulfide Downregulates Oncostatin M Expression via PI3K/Akt/NF-κB Signaling Processes in Neutrophil-like Differentiated HL-60 Cells

The cytokine oncostatin M (OSM) is regarded as a critical mediator in various inflammatory responses. While the gaseous signaling molecule hydrogen sulfide (H₂S) plays a role in a variety of pathophysiological conditions, such as hypertension, inflammatory pain, osteoarthritis, ischemic stroke, oxidative stress, retinal degeneration, and inflammatory responses, the underlying mechanism of H₂S action on OSM expression in neutrophils needs to be clarified. In this work, we studied how H₂S reduces OSM expression in neutrophil-like differentiated (d)HL-60 cells. To evaluate the effects of H₂S, sodium hydrosulfide (NaHS, a donor that produces H₂S), ELISA, real-time PCR (qPCR), immunoblotting, and immunofluorescence staining were utilized. Although exposure to granulocyte-macrophage colony-stimulating factor (GM-CSF) resulted in upregulated levels of production and mRNA expression of OSM, these upregulated levels were reduced by pretreatment with NaHS in dHL-60 cells. Similarly, the same pretreatment lowered phosphorylated levels of phosphatidylinositol 3-kinase, Akt, and nuclear factor-kB that had been elevated by stimulation with GM-CSF. Overall, our results indicated that H₂S could be a therapeutic agent for inflammatory disorders via suppression of OSM.

Penehyclidine hydrochloride protects against lipopolysaccharide-induced acute lung injury by promoting the PI3K/Akt pathway

INTRODUCTION

Acute lung injury (ALI) attracted attention among physicians because of its high mortality. We aimed to determine whether the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt) pathway is involved in the protective effects of penehyclidine hydrochloride (PHC) against lipopolysaccharide (LPS)-induced ALI.

METHODS

H&E staining was used to observed pathological changes in the lung tissues. ELISA was used to evaluate the concentration of inflammatory mediators in the bronchoalveolar lavage fluid (BALF). White-light microscopy was performed to observe the TUNEL-positive nuclei. The viability of NR8383 alveolar macrophages was determined by using CCK-8. The levels of MPO, MDA, SOD, and GSH-Px were analyzed using ELISA kits. Western blotting was used to evaluate the ERS-associated protein levels and the phosphorylation of PI3K and Akt.

RESULTS

PHC administration defended against LPS-induced histopathological deterioration and increased pulmonary edema and lung injury scores, while all of these beneficial effects were inhibited by LY. In addition, PHC administration mitigated oxidative stress as indicated by decreases in lung myeloperoxidase (MPO) and malondialdehyde (MDA) concentrations, and increases in glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) concentrations. It also alleviated LPS-induced inflammation. PHC administration attenuated apoptosis-associated protein levels, improved cell viability, and decreased the number of TdT-mediated dUTP Nick-End Labeling (TUNEL)-positive cells. Furthermore, PHC inhibited ERS-associated protein levels. Meanwhile, the protection of PHC against inflammation, oxidative stress, apoptosis, and ERS was inhibited by LY. Moreover, PHC administration increased PI3K and Akt phosphorylation, indicating that the upregulation of the PI3K/Akt pathway, while this pathway was inhibited by LY.

CONCLUSION

PHC significantly activates the PI3K/Akt pathway to ameliorate the extent of damage to pulmonary tissue, inflammation, oxidative stress, apoptosis, and ERS in LPS-induced ALI.

HDL-Associated Lipoproteins: Potential Prognostic Biomarkers for Gram-Negative Sepsis

Purpose

To determine the levels of serum HDL-associated apolipoproteins (apoM and apoC) and HDL-binding receptor (scavenger receptor BI, SR-BI) in patients with gram-negative bacteria sepsis (G-sepsis) and to evaluate the value of lipoproteins in the diagnosis, severity and prognosis of G-sepsis.

Patients and Methods

A total of 128 patients with sepsis, 40 patients with system inflammatory reaction syndrome (SIRS) and 40 healthy subjects were enrolled in the Second People’s Hospital of Hunan Province from September 2019 to September 2020. The levels and the correlation of lipoproteins were detected and dynamically monitored by enzyme-linked adsorption method, ROC curve for the diagnostic, severity and prognostic value of lipoproteins in G-sepsis.

Results

The levels of serum HDL-associated lipoproteins in patients with G-sepsis were significantly decreased (P < 0.05), and the ROC curve showed that HDL-C, SR-BI, apoM and apoC had cut-off values of 0.915 mmol/L, 122.100 pg/mL, 102.400 ug/mL and 17.55 mg/mL, respectively, for the diagnosis of G-sepsis, with the sensitivity was 85.56%, 97.78%, 93.33% and 73.03%, and the specificity was 95.0%, 82.50%, 61.54% and 82.50%, respectively. There was a correlation between HDL-associated apolipoproteins. Changes in serum HDL-associated lipoproteins were more obvious in shock group than classic inflammation indicators, such as PCT, IL-6 and CRP. They showed a trend change on day 3, with the levels of SR-BI and apoC changing 2–3 times, and the sensitivity of HDL-C, SR-BI, apoM and apoC for the diagnosis of G-septic shock were 32.43%, 72.97%, 65.75%, and 43.24%, and specificity of 94.34%, 81.13%, 83.07%, and 86.79%, respectively. The AUC, sensitivity and specificity of apoM combined with SR-BI were improved.

Conclusion

HDL-associated lipoproteins were correlated with bacterial-infected types, and serum levels of HDL-associated lipoproteins can be used as potential biomarkers for early diagnosis and progress of G-sepsis. ApoM combined with SR-BI could improve the sensitivity and specificity of prognosis assessment.

Ursolic Acid Suppresses Oncostatin M Expression through Blockade of PI3K/Akt/NF-κB Signaling Processes in Neutrophil-like Differentiated HL-60 Cells

Cytokine oncostatin M (OSM) plays an important role in a variety of inflammatory reactions and is mainly produced in neutrophils in inflammatory diseases. While natural pentacyclic triterpenoid ursolic acid (UA) possesses a wide range of beneficial effects, such as anti-oxidant, anti-tumor, and anti-inflammatory, the regulatory processes of OSM suppression by UA in neutrophils are still poorly understood. This study was aimed at examining how UA regulates OSM expression in neutrophil-like differentiated (d)HL-60 cells. Enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, and immunoblotting were employed to analyze the effects of UA. Whereas stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF) led to elevations of OSM production and mRNA expression, these elevations were lowered by treatment with UA in neutrophil-like dHL-60 cells. When the cells were exposed to GM-CSF, phosphorylated levels of phosphatidylinositol 3-kinase, Akt, and nuclear factor-kB were upregulated. However, the upregulations were diminished by treatment with UA in neutrophil-like dHL-60 cells. The results of this study proposed that UA might relieve inflammatory diseases via inhibition of OSM.

Resveratrol Downregulates Granulocyte-Macrophage Colony-Stimulating Factor-Induced Oncostatin M Production through Blocking of PI3K/Akt/NF-κB Signal Cascade in Neutrophil-like Differentiated HL-60 Cells

Oncostatin M (OSM) is essential in a wide range of inflammatory responses, and most OSM is produced by neutrophils in respiratory diseases. While resveratrol (RES) is regarded as an anti-inflammatory agent in a variety of conditions, the mechanism of OSM inhibition by RES in neutrophils remains to be elucidated. In this study, we investigated whether RES could inhibit OSM production in neutrophil-like differentiated (d)HL-60 cells. The effects of RES were measured by means of an enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blotting. Increases in production and mRNA expression of OSM resulted from the addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) in neutrophil-like dHL-60 cells; however, these increases were downregulated by RES treatment. Exposure to GM-CSF led to elevations of phosphorylation of phosphatidylinositol 3-kinase (PI3K), Akt, and nuclear factor (NF)-kB. Treatment with RES induced downregulation of the phosphorylated levels of PI3K, Akt, and NF-κB in neutrophil-like dHL-60 cells. These results suggest that RES could be applicable to prevent and/or treat inflammatory disorders through blockade of OSM.

Octreotide activates autophagy to alleviate lipopolysaccharide-induced human pulmonary epithelial cell injury by inhibiting the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway

Octreotide is a synthetic octapeptide of natural somatostatin. We aimed to investigate the influence of Octreotide on lipopolysaccharide (LPS)-stimulated human pulmonary epithelial cell damage. After stimulated by LPS, BEAS-2B cells were treated with various concentrations of Octreotide. CCK-8 assay and LDH kits were to evaluate cell cytotoxicity. ELISA kits were to analyze the levels of inflammatory factors. TUNEL staining was to measure cell apoptosis. Western blot assay was used to assess the expression of apoptosis-related proteins, autophagy-related proteins and AKT/mTOR signaling-related proteins. Then, 3-methyladenine (3-MA) was adopted for treating BEAS-2B cells to determine its effects on inflammation and apoptosis. Afterward, adding AKT agonist (SC79) or mTOR antagonist (rapamycin) to explore the impact of Octreotide on autophagy. Results revealed that Octreotide notably enhanced cell viability and reduced LDH activity. The levels of inflammatory factors were significantly decreased following Octreotide treatment. Additionally, Octreotide attenuated the apoptotic capacity of LPS-induced BEAS-2B cells, led to the up-regulation of Bcl-2 protein level while cut down the protein levels of Bax and cleaved caspase3. Remarkably, the expression of autophagy-related protein LC3II/I and Beclin1 was elevated after Octreotide administration. Importantly, the suppressive effects of Octreotide on the inflammation and apoptosis of LPS-induced BEAS-2B cells was abrogated by 3-MA. Further experiments suggested that Octreotide downregulated p-AKT and mTOR expression in LPS-stimulated BEAS-2B cells. SC79 addition inhibited autophagy, evidenced by downregulated LC3II/I and Beclin1 expression while rapamycin presented the opposite effects. To conclude, Octreotide activates autophagy to alleviate LPS-induced pulmonary epithelial cell injury by inhibiting the AKT/mTOR signaling.