CD28 Deficiency Ameliorates Blast Exposure-Induced Lung Inflammation, Oxidative Stress, Apoptosis, and T Cell Accumulation in the Lungs via the PI3K/Akt/FoxO1 Signaling Pathway

Proteomic and metabolomic profiling of plasma predicts immune-related adverse events in older patients with advanced non-small cell lung cancer

The clinical success of immune checkpoint inhibitors is compromised by the fact of immune-related adverse events (irAEs), especially for older patients. To identify predictive biomarkers for older patients with irAEs, we used multiplex immunoassay and flow cytometry and liquid chromatography-tandem mass spectrometry to test immune factors and plasma protein and metabolites levels in non-small cell lung cancer (NSCLC) patients. The results showed that older patients with irAEs displayed lower CD28, CD4+ T cell, and B cell and higher interleukin (IL)-10 and CCL2 levels at baseline. Besides, lower aldolase, fructose-bisphosphate B (ALDOB), higher ST6GAL1, and lower lactate/pyruvate ratio at baseline were found in older patients with irAEs. Based on metabolomic markers, predictive models were developed to distinguish patients with grade 2-4 irAEs from grade 0-1 (Area under curve, AUC = 0.831) and to distinguish patients with grade 3-4 irAEs from grade 2 (AUC = 1). Our results confirmed the predictive value of plasma metabolites for irAEs in older patients with NSCLC.

SIRT3 improves alveolar epithelial cell damage caused by bronchopulmonary dysplasia through deacetylation of FOXO1

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a serious and long-term lung condition commonly observed in premature babies. Sirtuin 3 (SIRT3) has been reported to reduce pulmonary injury and pulmonary fibrosis.

OBJECTIVE

The present study investigated the specific role of SIRT3 in BPD by establishing hyperoxia-induced BPD rat and cell models. Hematoxylin and eosin staining was used to observe pathological changes in lung tissues.

MATERIALS AND METHODS

The expression levels of SIRT3 and forkhead box protein O1 (FOXO1), as well as its acetylation levels, were detected in hyperoxia-induced lung tissues and cells by Western blot analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Levels of reactive oxygen species, superoxide dismutase, and malondialdehyde were assessed by using biochemical kits. Following SIRT3 overexpression, the levels of inflammatory cytokines were assessed by RT-qPCR. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nickend labeling (TUNEL) and Western blot analysis. Upon FOXO1 knockout, cell inflammation, oxidative stress and apoptosis were evaluated again.

RESULTS

Compared to the control group, the SIRT3 and FOXO1 expression levels were decreased and the FOXO1 acetylation levels were increased in hyperoxia-induced lung tissues and cells. In addition, SIRT3 reduced hyperoxia-induced inflammation, oxidative stress, and apoptosis in A549 cells, and inhibited FOXO1 acetylation to activate FOXO1. However, FOXO1 knockdown reversed the effects of SIRT3 overexpression in hyperoxia-induced A549 cells.

CONCLUSION

SIRT3 relieved alveolar epithelial cell damage caused by BPD via deacetylation of FOXO1, suggesting that SIRT3 could be a therapeutic target in BPD.

Establishment and evaluation of an in vitro blast lung injury model using alveolar epithelial cells

Background

Gas explosion is a fatal disaster commonly occurred in coal mining and often causes systematic physical injuries, of which blast lung injury is the primary one and has not yet been fully investigated due to the absence of disease models. To facilitate studies of this field, we constructed an in vitro blast lung injury model using alveolar epithelial cells.

Methods

We randomly divided the alveolar epithelial cells into the control group and blast wave group, cells in the blast wave group were stimulated with different strengths of blast wave, and cells in the control group received sham intervention. Based on the standards we set up for a successful blast injury model, the optimal modeling conditions were studied on different frequencies of blast wave, modeling volume, cell incubation duration, and cell density. The changes of cell viability, apoptosis, intracellular oxidative stress, and inflammation were measured.

Results

We found that cell viability decreased by approximately 50% at 6 h after exposing to 8 bar energy of blast wave, then increased with the extension of culture time and reached to (74.33 ± 9.44) % at 12 h. By applying 1000 ~ 2500 times of shock wave to 1 ~ 5 × 105 cells /ml, the changes of cell viability could well meet the modeling criteria. In parallel, the content of reactive oxide species (ROS), malonaldehyde (MDA), interleukin 18 (IL-18), tumor necrosis factor alpha (TNF-α), and transforming growth factor beta (TGF-β) increased in the blast wave group, while superoxide dismutase (SOD) and Glutathione -S- transferase (GST) decreased, which were highly consistent with that of human beings with gas explosion-induced pulmonary injury.

Conclusion

An in vitro blast lung injury model is set up using a blast wave physiotherapy under 8 bar, 10 Hz blast wave on (1 ~ 5) ×105 alveolar epithelial cells for 1 000 times. This model is flexible, safe, and stable, and can be used for studies of lung injury caused by gas explosion and blast-associated other external forces.

Potential Functions of the tRNA-Derived Fragment tRF-Gly-GCC Associated With Oxidative Stress in Radiation-Induced Lung Injury

Objective

Transfer RNA-derived small RNAs (tsRNAs) are a novel type of non-coding RNA with various regulatory functions. They are associated with oxidative stress in various diseases, but their potential functions in radiation-induced lung injury (RILI) remain uncertain.

Methods

To explore the role of tsRNAs in RILI, we used X-rays to irradiate human bronchial epithelial cells and examined the expression profile of altered tsRNAs by RNA sequencing and bioinformatics analysis. Sequencing results were verified by qRT-PCR. tsRNA functions were explored using several methods, including CCK-8, reactive oxygen species (ROS) assays, cell transfection, and western blotting.

Results

Eighty-six differentially expressed tRNA-derived fragments (tRFs) were identified: 64 were upregulated, and 22 were downregulated. Among them, the regulation of tRF-Gly-GCC, associated with oxidative stress, may be mediated by the inhibition of cell proliferation, promotion of ROS production, and apoptosis in the occurrence and development of RILI. A Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that the underlying molecular mechanism may involve the PI3K/AKT and the FOXO1 signaling pathways.

Conclusion

Our findings provide new insights into the molecular mechanisms underpinning RILI, advancing the clinical prevention and treatment of this disease.

IL-5 enhances the resistance of Actinobacillus pleuropneumoniae infection in mice through maintaining appropriate levels of lung M2, PMN-II and highly effective neutrophil extracellular traps

Interleukin 5 (IL-5) regulates the maturation, activation, proliferation and function of immune cells, and plays an important role in the inflammatory response induced by an allergy. However, its anti-pathogen effect is poorly understood currently, especially on pneumonia. Here, this study was designed to elucidate the immunological role of IL-5 in the infection of mice with Actinobacillus pleuropneumoniae (APP). We established an acute lung infection model of APP in IL-5 knockout mice (IL-5-/-) and wild-type mice (WT) through nasal infusion or intraperitoneal injection, compared the survival rate, clinical symptoms, lung bacterial load, proportion of various immune cells, immune molecular expression, and neutrophil germicidal ability through flow cytometry, RT-qPCR, ELISA and immunofluorescence. Compared to WT mice, the IL-5-/- mice had a lower survival rate, more severe clinical symptoms, significantly increased bacterial load, and inflammatory cell infiltration in the lung after APP infection. In an uninfected state, IL-5 deficiency decreased the number of M1 interstitial macrophages and CD14- monocytes, while after infection, IL-5 deficiency significantly reduced the M2 alveolar macrophages, and increased PMN-II cells in the lung. Furthermore, the expression of IL-10, IL-4, IL-33, TNF-α, iNOS in the lung was lower in IL-5-/- mice under an uninfected condition, and the secretion of IL-18 was significantly increased after infection. In addition, IL-5 deficiency decreased bactericidal ability by inhibiting the formation of neutrophil extracellular traps (NETs). Collectively, these results provide evidence that IL-5 can enhance the resistance of APP infection, and its anti-infection mechanism, implying new targets and ideas for APP or similar respiratory agents' prevention and treatment.

Exosomes: Potential Player in Endothelial Dysfunction in Cardiovascular Disease

Exosomes are spherical bilayer membrane vesicles with an average diameter of 40-100 nm. These particles perform a wide range of biological activities due to their contents, including proteins, nucleic acids, lipids, lncRNA, and miRNA. Exosomes are involved in inflammation induction, oxidative stress and apoptosis, which can be effective in endothelial dysfunction. Due to the induction of mentioned processes in the endothelial cells, the intercellular connections are destroyed, cell permeability increases and finally cell efficiency decreases and functional defects occur. Cardiovascular disease (CVDs) are of consequences of endothelial dysfunction. Thus by identifying the exosome signaling pathways, which induce inflammation, oxidative stress, and apoptosis, endothelial dysfunction and subsequently CVDs can be reduced; exosomes can be used for appropriate target therapy.

FOXO1 Is a Critical Switch Molecule for Autophagy and Apoptosis of Sow Endometrial Epithelial Cells Caused by Oxidative Stress

Oxidative stress (OS) is involved in various reproductive diseases and can induce autophagy and apoptosis, which determine the different fates of cells. However, the sequence and the switch mechanism between autophagy and apoptosis are unclear. Here, we reported that chronic restraint stress (CRS) induced OS (decreased T-AOC, T-SOD, CAT and GSH-Px and increased MDA) and then disturbed the endocrine environment of sows during early pregnancy, including the hypothalamic-pituitary-ovarian (HPO) and the hypothalamic-pituitary-adrenal (HPA) axes. Meanwhile, after CRS, the KEAP1/NRF2 pathway was inhibited and attenuated the antioxidative ability to cause OS of the endometrium. The norepinephrine (NE) triggered β₂-AR to activate the FOXO1/NF-κB pathway, which induced endometrial inflammation. CRS induced the caspase-dependent apoptosis pathway and caused MAP1LC3-II accumulation, SQSTM1/p62 degradation, and autophagosome formation to initiate autophagy. Furthermore, in vitro, a cellular OS model was established by adding hydrogen peroxide into cells. Low OS maintained the viability of endometrial epithelial cells by triggering autophagy, while high OS induced cell death by initiating caspase-dependent apoptosis. Autophagy preceded the occurrence of apoptosis, which depended on the subcellular localization of FOXO1. In the low OS group, FOXO1 was exported from the nucleus to be modified into Ac-FOXO1 and bound to ATG7 in the cytoplasm, which promoted autophagy to protect cells. In the high OS group, FOXO1 located in the nucleus to promote transcription of proapoptotic proteins and then induce apoptosis. Here, FOXO1, as a redox sensor switch, regulated the transformation of cell autophagy and apoptosis. In summary, the posttranslational modification of FOXO1 may become the target of OS treatment.

Resveratrol ameliorates thoracic blast exposure-induced inflammation, endoplasmic reticulum stress and apoptosis in the brain through the Nrf2/Keap1 and NF-κB signaling pathway

Blast injuries include the various types of internal and external trauma caused by the impact force of high-speed blast waves with multiple mechanisms involved. Thoracic blast exposure could induce neurotrauma as well, but effective therapies are lacking. Resveratrol is a polyphenol flavonoid secreted by plants and has been shown to provide cardiovascular protection and play anti-inflammatory, anti-oxidation and anti-cancer roles. However, the effects of resveratrol on thoracic blast exposure-induced brain injury have not been investigated. To explore this, a mouse model of thoracic blast exposure-induced brain injury was established. Sixty C57BL/6 wild type mice were randomly divided equally into four groups (one control group, one model group, and model groups with 25 or 50 mg/kg resveratrol injected intraperitoneally). As traumatic brain injury often accompanied by mental symptoms, cognitive dysfunction and anxious behavior were evaluated by Y maze, elevated plus maze and open field test. We also examined the mice for histopathological changes by hematoxylin-eosin staining; the expressions of inflammatory-related factors by ELISA; endoplasmic reticulum stress in brain tissue via the generation of reactive oxygen species (ROS) and the expressions of inositol-requiring enzyme-α (IRE-α) and C/EBP homologous protein (CHOP); apoptosis by measuring levels of Bax, p53 and Bcl-2. In addition, proteins of related pathways were also studied by western blotting. We found that resveratrol significantly reduced the levels of inflammatory-related factors, including interleukin (IL)-1β, IL-4, and high mobility group box protein 1(HMGB1), and increased the level of anti-inflammatory-related factor, IL-10, under thoracic blast exposure (P < 0.05). Cognitive dysfunction and anxious behavior were also ameliorated by resveratrol. In brain tissue, resveratrol significantly attenuated thoracic blast exposure-induced generation of ROS and expressions of IRE-α and CHOP, lowered the expressions of Bax and p53, and maintained Bcl-2 expression (P < 0.05). Additionally, resveratrol significantly ameliorated thoracic blast exposure-induced increases of Kelch-like ECH-associated protein 1 (Keap1) and nuclear factor (NF)-κB and the decrease in nuclear factor erythroid 2-related factor 2(Nrf2) expression in the brain (P < 0.05). Our results indicate that resveratrol has a protective effect on thoracic blast exposure-induced brain injury that is likely mediated through the Nrf2/Keap1 and NF-κB signaling pathways.

Downregulation of HDAC8 expression decreases CD163 levels and promotes the apoptosis of macrophages by activating the ERK signaling pathway in recurrent spontaneous miscarriage

Recurrent spontaneous miscarriage (RSM) is a systemic disorder that has been defined as two or more pregnancies lost before the 20th week of gestation. Although the impaired function of macrophages at the maternal-fetal interface has been reported to be associated with RSM, the underlying mechanisms have not been fully elucidated. Here, we revealed that HDAC8 plays a critical role in RSM. Our results show that the mRNA and protein expression of HDAC8 was decreased in decidual macrophages from RSM patients. Moreover, the knockdown of HDAC8 resulted in a significant decrease in CD163 expression and an increase in apoptosis in dTHP-1 macrophages. Mechanistically, the ERK signaling pathway was activated in HDAC8-knockdown macrophages. When HDAC8-knockdown cells were pretreated with the ERK inhibitor U0126, expression levels of CD163, activated caspases 3, 7 and 9, and the apoptosis rate, were rescued. Taken together, our current results suggest that HDAC8 plays an important role in macrophage activation and apoptosis and may contribute to maintaining normal pregnancy by increasing the expression of M2 marker genes and inhibiting the apoptosis of macrophages at the maternal-fetal interface.

rhKGF-2 Attenuates Smoke Inhalation Lung Injury of Rats via Activating PI3K/Akt/Nrf2 and Repressing FoxO1-NLRP3 Inflammasome

Smoke inhalation injury is an acute pathological change caused by thermal stimulation or toxic substance absorption through respiratory epithelial cells. This study aims to probe the protective effect and mechanism of recombinant human keratinocyte growth factor 2 (rhKGF-2) against smoke inhalation-induced lung injury (SILI) in rats. The SILI was induced in rats using a smoke exposure model, which were then treated with rhKGF-2. The rat blood was collected for blood-gas analysis, and the levels of inflammatory factors and oxidative stress markers in the plasma were measured. The rat lung tissues were collected. The pathological changes and cell apoptosis were determined by hematoxylin-eosin (HE) staining and TdT-mediated dUTP nick end labeling (TUNEL) assay, and the PI3K/Akt/Nrf2/HO-1/NQO1, and FoxO1-NLRP3 inflammasome expression were verified by western blot (WB). Both of the human alveolar epithelial cell (HPAEpiC) and primary rat alveolar epithelial cell were exposed to lipopolysaccharide (LPS) for making in-vitro alveolar epithelial cell injury model. After treatment with rhKGF-2, GSK2126458 (PI3K inhibitor) and AS1842856 (FoxO1 inhibitor), the cell viability, apoptosis, inflammation, oxidative stress, reactive oxygen species (ROS), PI3K/Akt/Nrf2, HO-1/NQO1, and FoxO1-NLRP3 in HPAEpiC and primary rat alveolar epithelial cell were examined. The data suggested that rhKGF-2 reduced LPS-induced HPAEpiC cell and primary rat alveolar epithelial cell apoptosis and the expression of inflammatory factors and oxidative stress factors. Moreover, rhKGF-2 improved the blood gas and alleviated SILI-induced lung histopathological injury in vivo via repressing inflammation, NLRP3 inflammasome activation and oxidative stress. Mechanistically, rhKGF-2 activated PI3K/Akt pathway, enhanced Nrf2/HO-1/NQO1 expression, and attenuated FoxO1-NLRP3 inflammasome both in vitro and in vivo. However, pharmaceutical inhibition of PI3K/Akt pathway attenuated rhKGF-2-mediated protective effects against SILI, while suppressing FoxO1 promoted rhKGF-2-mediated protective effects. Taken together, this study demonstrated that rhKGF-2 mitigated SILI by regulating the PI3K/Akt/Nrf2 pathway and the FoxO1-NLRP3 axis, which provides new reference in treating SILI.