A novel model for predicting prognosis and response to immunotherapy in nasopharyngeal carcinoma patients.

Blood-based biomarkers of immune checkpoint inhibitors (ICIs) response in patients with nasopharyngeal carcinoma (NPC) are lacking, so it is necessary to identify biomarkers to select NPC patients who will benefit most or least from ICIs. The absolute values of lymphocyte subpopulations, biochemical indexes, and blood routine tests were determined before ICIs-based treatments in the training cohort (n = 130). Then, the least absolute shrinkage and selection operator (Lasso) Cox regression analysis was developed to construct a prediction model. The performances of the prediction model were compared to TNM stage, treatment, and Epstein-Barr virus (EBV) DNA using the concordance index (C-index). Progression-free survival (PFS) was estimated by Kaplan-Meier (K-M) survival curve. Other 63 patients were used for validation cohort. The novel model composed of histologic subtypes, CD19+ B cells, natural killer (NK) cells, regulatory T cells, red blood cells (RBC), AST/ALT ratio (SLR), apolipoprotein B (Apo B), and lactic dehydrogenase (LDH). The C-index of this model was 0.784 in the training cohort and 0.735 in the validation cohort. K-M survival curve showed patients with high-risk scores had shorter PFS compared to the low-risk groups. For predicting immune therapy responses, the receiver operating characteristic (ROC), decision curve analysis (DCA), net reclassifcation improvement index (NRI) and integrated discrimination improvement index (IDI) of this model showed better predictive ability compared to EBV DNA. In this study, we constructed a novel model for prognostic prediction and immunotherapeutic response prediction in NPC patients, which may provide clinical assistance in selecting those patients who are likely to gain long-lasting clinical benefits to anti-PD-1 therapy.

BCL6 attenuates hyperoxia-induced lung injury by inhibiting NLRP3-mediated inflammation in fetal mouse.

BACKGROUND: The transcriptional repressor B-cell lymphoma 6 (BCL6) has been reported to inhibit inflammation. So far, experimental evidence for the role of BCL6 in bronchopulmonary dysplasia (BPD) is lacking. Our study investigated the roles of BCL6 in the progression of BPD and its downstream mechanisms. METHODS: Hyperoxia or lipopolysaccharide (LPS) was used to mimic the BPD mouse model. To investigate the effects of BCL6 on BPD, recombination adeno-associated virus serotype 9 expressing BCL6 (rAAV9-BCL6) and BCL6 inhibitor FX1 were administered in mice. The pulmonary pathological changes, inflammatory chemokines and NLRP3-related protein were observed. Meanwhile, BCL6 overexpression plasmid was used in human pulmonary microvascular endothelial cells (HPMECs). Cell proliferation, apoptosis, and NLRP3-related protein were detected. RESULTS: Either hyperoxia or LPS suppressed pulmonary BCL6 mRNA expression. rAAV9-BCL6 administration significantly inhibited hyperoxia-induced NLRP3 upregulation and inflammation, attenuated alveolar simplification and dysregulated angiogenesis in BPD mice, which were characterized by decreased mean linear intercept, increased radical alveolar count and alveoli numbers, and the upregulated CD31 expression. Meanwhile, BCL6 overexpression promoted proliferation and angiogenesis, inhibited apoptosis and inflammation in hyperoxia-stimulated HPMECs. Moreover, administration of BCL6 inhibitor FX1 arrested growth and development. FX1-treated BPD mice exhibited exacerbation of alveolar pathological changes and pulmonary vessel permeability, with upregulated mRNA levels of pro-inflammatory cytokines and pro-fibrogenic factors. Furthermore, both rAAV9-BCL6 and FX1 administration exerted a long-lasting effect on hyperoxia-induced lung injury (≥4 wk). CONCLUSIONS: BCL6 inhibits NLRP3-mediated inflammation, attenuates alveolar simplification and dysregulated pulmonary vessel development in hyperoxia-induced BPD mice. Hence, BCL6 may be a target in treating BPD and neonatal diseases.

4-OI ameliorates bleomycin-induced pulmonary fibrosis by activating Nrf2 and suppressing macrophage-mediated epithelial-mesenchymal transition.

OBJECTIVES: Pulmonary fibrosis (PF) is a chronic and refractory interstitial lung disease with limited therapeutic options. 4-octyl itaconate (4-OI), a cell-permeable derivative of itaconate, has been shown to have anti-oxidative and anti-inflammatory properties. However, the effect and the underlying mechanism of 4-OI on PF are still unknown. METHODS: WT or Nrf2 knockout (Nrf2-/-) mice were intratracheally injected with bleomycin (BLM) to establish PF model and then treated with 4-OI. The mechanism study was performed by using RAW264.7 cells, primary macrophages, and conditional medium-cultured MLE-12 cells. RESULTS: 4-OI significantly alleviated BLM-induced PF and EMT process. Mechanism studies have found that 4-OI can not only directly inhibit EMT process, but also can reduce the production of TGF-ß1 by restraining macrophage M2 polarization, which in turn inhibits EMT process. Moreover, the effect of 4-OI on PF and EMT depends on Nrf2. CONCLUSION: 4-OI ameliorates BLM-induced PF in an Nrf2-dependent manner, and its role in alleviating PF is partly due to the direct inhibition on EMT, and partly through indirect inhibition of M2-mediated EMT. These findings suggested that 4-OI has great clinical potential to develop as a new anti-fibrotic agent for PF therapy.

Ethyl ferulate protects against lipopolysaccharide-induced acute lung injury by activating AMPK/Nrf2 signaling pathway.

Ethyl ferulate (EF) is abundant in Rhizoma Chuanxiong and grains (e.g., rice and maize) and possesses antioxidative, antiapoptotic, antirheumatic, and anti-inflammatory properties. However, its effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) is still unknown. In the present study, we found that EF significantly alleviated LPS-induced pathological damage and neutrophil infiltration and inhibited the gene expression of proinflammatory cytokines (TNF-α, IL-1ß, and IL-6) in murine lung tissues. Moreover, EF reduced the gene expression of TNF-α, IL-1ß, IL-6, and iNOS and decreased the production of NO in LPS-stimulated RAW264.7 cells and BMDMs. Mechanistic experiments revealed that EF prominently activated the AMPK/Nrf2 pathway and promoted Nrf2 nuclear translocation. AMPK inhibition (Compound C) and Nrf2 inhibition (ML385) abolished the beneficial effect of EF on the inflammatory response. Furthermore, the protective effect of EF on LPS-induced ALI was not observed in Nrf2 knockout mice. Taken together, the results of our study suggest that EF ameliorates LPS-induced ALI in an AMPK/Nrf2-dependent manner. These findings provide a foundation for developing EF as a new anti-inflammatory agent for LPS-induced ALI/ARDS therapy.

Dehydrocostus Lactone Attenuates Methicillin-Resistant Staphylococcus aureus-Induced Inflammation and Acute Lung Injury via Modulating Macrophage Polarization.

Dehydrocostus lactone (DHL), a natural sesquiterpene lactone isolated from the traditional Chinese herbs Saussurea lappa and Inula helenium L., has important anti-inflammatory properties used for treating colitis, fibrosis, and Gram-negative bacteria-induced acute lung injury (ALI). However, the effects of DHL on Gram-positive bacteria-induced macrophage activation and ALI remains unclear. In this study, we found that DHL inhibited the phosphorylation of p38 MAPK, the degradation of IκBα, and the activation and nuclear translocation of NF-κB p65, but enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and the expression of Nrf2 and HO-1 in lipoteichoic acid (LTA)-stimulated RAW264.7 cells and primary bone-marrow-derived macrophages (BMDMs). Given the critical role of the p38 MAPK/NF-κB and AMPK/Nrf2 signaling pathways in the balance of M1/M2 macrophage polarization and inflammation, we speculated that DHL would also have an effect on macrophage polarization. Further studies verified that DHL promoted M2 macrophage polarization and reduced M1 polarization, then resulted in a decreased inflammatory response. An in vivo study also revealed that DHL exhibited anti-inflammatory effects and ameliorated methicillin-resistant Staphylococcus aureus (MRSA)-induced ALI. In addition, DHL treatment significantly inhibited the p38 MAPK/NF-κB pathway and activated AMPK/Nrf2 signaling, leading to accelerated switching of macrophages from M1 to M2 in the MRSA-induced murine ALI model. Collectively, these data demonstrated that DHL can promote macrophage polarization to an anti-inflammatory M2 phenotype via interfering in p38 MAPK/NF-κB signaling, as well as activating the AMPK/Nrf2 pathway in vitro and in vivo. Our results suggested that DHL might be a novel candidate for treating inflammatory diseases caused by Gram-positive bacteria.

Nrf2 protects against seawater drowning-induced acute lung injury via inhibiting ferroptosis.

BACKGROUND: Ferroptosis is a new type of nonapoptotic cell death model that was closely related to reactive oxygen species (ROS) accumulation. Seawater drowning-induced acute lung injury (ALI) which is caused by severe oxidative stress injury, has been a major cause of accidental death worldwide. The latest evidences indicate nuclear factor (erythroid-derived 2)-like 2 (Nrf2) suppress ferroptosis and maintain cellular redox balance. Here, we test the hypothesis that activation of Nrf2 pathway attenuates seawater drowning-induced ALI via inhibiting ferroptosis. METHODS: we performed studies using Nrf2-specific agonist (dimethyl fumarate), Nrf2 inhibitor (ML385), Nrf2-knockout mice and ferroptosis inhibitor (Ferrostatin-1) to investigate the potential roles of Nrf2 on seawater drowning-induced ALI and the underlying mechanisms. RESULTS: Our data shows that Nrf2 activator dimethyl fumarate could increase cell viability, reduced the levels of intracellular ROS and lipid ROS, prevented glutathione depletion and lipid peroxide accumulation, increased FTH1 and GPX4 mRNA expression, and maintained mitochondrial membrane potential in MLE-12 cells. However, ML385 promoted cell death and lipid ROS production in MLE-12 cells. Furthermore, the lung injury became more aggravated in the Nrf2-knockout mice than that in WT mice after seawater drowning. CONCLUSIONS: These results suggested that Nrf2 can inhibit ferroptosis and therefore alleviate ALI induced by seawater drowning. The effectiveness of ferroptosis inhibition by Nrf2 provides a novel therapeutic target for seawater drowning-induced ALI.

Isoalantolactone suppresses LPS-induced inflammation by inhibiting TRAF6 ubiquitination and alleviates acute lung injury.

Isoalantolactone (IAL) is a sesquiterpene lactone extracted from roots of Inula helenium L and has shown anti-inflammatory effects. In this study we investigated the therapeutic effects of IAL on acute lung injury (ALI) and elucidated the mechanisms underlying its anti-inflammation potential in vitro and in vivo. Treatment with lipopolysaccharide (LPS, 100 ng/mL) drastically stimulated production of inflammatory mediators such as NO, TNF-α, IL-1ß, and IL-6 in mouse bone marrow-derived macrophages (BMDMs), which was dose-dependently suppressed by pretreatment with IAL (2.5, 5, 10, 20 µM). We further revealed that IAL suppressed LPS-induced NF-κB, ERK, and Akt activation. Moreover, the downregulation of non-degradable K63-linked polyubiquitination of TRAF6, an upstream transcription factor of NF-κB, contributed to the anti-inflammatory effects of IAL. ALI was induced in mice by intratracheal injection of LPS (5 mg/kg). Administration of IAL (20 mg/kg, i.p.) significantly suppressed pulmonary pathological changes, neutrophil infiltration, pulmonary permeability, and pro-inflammatory cytokine expression. Our results demonstrate that IAL is a potential therapeutic reagent against inflammation and ALI.

Protostemonine effectively attenuates lipopolysaccharide-induced acute lung injury in mice.

Protostemonine (PSN) is the main anti-inflammatory alkaloid extracted from the roots of Stemona sessilifolia (known as "Baibu" in traditional Chinese medicine). Here, we reported the inhibitory effects of PSN on lipopolysaccharide (LPS)-induced macrophage activation in vitro and LPS-induced acute lung injury in mice. Macrophage cell line RAW264.7 cells and mouse bone marrow-derived macrophages (BMDMs) were treated with PSN (1, 3, 10, 30 and 100 µmol/L) for 0.5 h and then challenged with LPS (0.1 µg/mL) for 24 h. Pretreatment with PSN significantly inhibited LPS-induced phosphorylation of MAPKs and AKT, iNOS expression and NO production in the macrophages. C57BL/6 mice were intratracheally injected with LPS (5 mg/kg) to induce acute lung injury (ALI). The mice were subsequently treated with PSN (10 mg/kg, ip) at 4 and 24 h after LPS challenge. PSN administration significantly attenuated LPS-induced inflammatory cell infiltration, reduced pro-inflammatory cytokine (TNF-α, IL-1ß and IL-6) production and eliminated LPS-mediated lung edema. Furthermore, PSN administration significantly inhibited LPS-induced pulmonary MPO activity. Meanwhile, LPS-induced phosphorylation of p38 MAPK, iNOS expression and NO production in the lungs were also suppressed. The results demonstrate that PSN effectively attenuates LPS-induced inflammatory responses in vitro and in vivo; the beneficial effects are associated with the decreased phosphorylation of MAPK and AKT and the reduced expression of pro-inflammatory mediators, such as iNOS, NO and cytokines. These data suggest that PSN may be a potential therapeutic agent in the treatment of ALI.

Emodin alleviates alternatively activated macrophage and asthmatic airway inflammation in a murine asthma model.

Alternatively activated macrophages (AAMs) are not only associated with asthma but also lead to asthmatic airway inflammation and remodeling. Inhibition of AAMs is an alternative therapeutic strategy for treating asthma. In this study we investigated whether emodin (1,3,8-trihydroxy-6-methylanthraquinone), isolated from the rhizome of Rheum palmatum, alleviated asthmatic airway inflammation and reduced AAM polarization in a murine asthma model. Mice were sensitized with a triple allergen mix containing dust mite, ragweed and aspergillus (DRA). In mice with DRA-induced asthma, asthmatic inflammation was significantly enhanced. Intraperitoneal injection of emodin (20 mg·kg-1·d-1, ip) 1 h prior to DRA challenge on days 12-14 significantly decreased pulmonary eosinophil and lymphocyte infiltration, mucus secretion and serum IgE production, as well as IL-4 and IL-5 production in bronchoalveolar lavage fluid. In response to emodin treatment, activated markers of AAM Ym-1, Fizz-1 and arginase-1 in the lung tissues were remarkably decreased. In mouse bone marrow-derived macrophages (BMDMs) in vitro, emodin (2-50 µmol/L) dose-dependently inhibited IL-4-induced AAM polarization and STAT6 phosphorylation. Collectively, our results suggest that emodin effectively ameliorates asthmatic airway inflammation and AAM polarization, and it may therefore become a potential agent for the treatment of asthma.

LYRM03, an ubenimex derivative, attenuates LPS-induced acute lung injury in mice by suppressing the TLR4 signaling pathway.

Toll-like receptor 4 (TLR4)-mediated signaling plays a critical role in sepsis-induced acute lung injury (ALI). LYRM03 (3-amino-2-hydroxy-4-phenyl-valyl-isoleucine) is a novel derivative of ubenimex, a widely used antineoplastic medicine. We previously found that LYRM03 has anti-inflammatory effects in cecal ligation puncture mouse model. In this study we determined whether LYRM03 attenuated LPS-induced ALI in mice. LPS-induced ALI mouse model was established by challenging the mice with intratracheal injection of LPS (5 mg/kg), which was subsequently treated with LYRM03 (10 mg/kg, ip). LYRM03 administration significantly alleviated LPS-induced lung edema, inflammatory cell (neutrophils and macrophages) infiltration and myeloperoxidase (MPO) activity, decreased pro-inflammatory and chemotactic cytokine (TNF-α, IL-6, IL-1ß, MIP-2) generation and reduced iNOS and COX-2 expression in the lung tissues. In cultured mouse alveolar macrophages in vitro, pretreatment with LYRM03 (100 µmol/L) suppressed LPS-induced macrophage activation by reducing Myd88 expression, increasing IκB stability and inhibiting p38 phosphorylation. These results suggest that LYRM03 effectively attenuates LPS-induced ALI by inhibiting the expression of pro-inflammatory mediators and Myd88-dependent TLR4 signaling pathways in alveolar macrophages. LYRM03 may serve as a potential treatment for sepsis-mediated lung injuries.

[Novel hybrids of (phenylsulfonyl)furoxan and N-benzyl matrinol as anti-hepatocellular carcinoma agents].

N-Benzyl matrinol was obtained by hydrolysis, benzylation and reduction reaction from matrine. A series of hybrids (8a-8n) from (phenylsulfonyl)furoxan and N-benzyl matrinol were synthesized and biologically evaluated as anti-hepatocellular carcinoma agents. All target compounds were evaluated for anti-proliferative activity against human hepatocellular Bel-7402, SMMC-7721, Bel-7404, and HepG2 cells in vitro by MTT method. The results indicated that all of these compounds had potent anti-proliferative activity which were more potent than their parent compound and 5-FU, especially 8a-8h and 8j showed the strongest anti-HCC HepG2 cell activity with IC50 values of 0.12-0.93 µmol x L(-1).

MiR-196a-5p hinders vascular smooth muscle cell proliferation and vascular remodeling via repressing BACH1 expression.

Hyperproliferation of vascular smooth muscle cells (VSMCs) is a driver of hypertensive vascular remodeling. This study aimed to uncover the mechanism of BTB and CNC homology 1 (BACH1) and microRNAs (miRNAs) in VSMC growth and hypertensive vascular remodeling. With the help of TargetScan, miRWalk, miRDB, and miRTarBase online database, we identified that BACH1 might be targeted by miR-196a-5p, and overexpressed in VSMCs and aortic tissues from spontaneously hypertensive rats (SHRs). Gain- and loss-of-function experiments demonstrated that miR-196a-5p suppressed VSMC proliferation, oxidative stress and hypertensive vascular remodeling. Double luciferase reporter gene assay and functional verification showed that miR-196a-5p cracked down the transcription and translation of BACH1 in both Wistar Kyoto rats (WKYs) and SHRs. Silencing BACH1 mimicked the actions of miR-196a-5p overexpression on attenuating the proliferation and oxidative damage of VSMCs derived from SHRs. Importantly, miR-196a-5p overexpression and BACH1 knockdown cooperatively inhibited VSMC proliferation and oxidative stress in SHRs. Furthermore, miR-196a-5p, if knocked down in SHRs, aggravated hypertension, upregulated BACH1 and promoted VSMC proliferation, all contributing to vascular remodeling. Taken together, targeting miR-196a-5p to downregulate BACH1 may be a promising strategy for retarding VSMC proliferation and hypertensive vascular remodeling.

Nrf2 deficiency exacerbated pulmonary pyroptosis in maternal hypoxia-induced intrauterine growth restriction offspring mice.

Maternal prenatal hypoxia is an important contributor to intrauterine growth restriction (IUGR), which impedes fetal lung maturation and leads to the development of chronic lung diseases. Although evidence suggests the involvement of pyroptosis in IUGR, the molecular mechanism of pyroptosis is still unclear. Nuclear factor erythroid 2-related factor 2 (Nrf2) has been found to potentially interact with gasdermin D (GSDMD), the key protein responsible for pyroptosis, indicating its crucial role in inhibiting pyroptosis. Therefore, we hypothesized that Nrf2 deficiency is a key molecular responsible for lung pyroptosis in maternal hypoxia-induced IUGR offspring mice. Pregnant WT and Nrf2-/- mice were exposed to hypoxia (10.5 % O2) to mimic IUGR model. We assessed body weight, lung histopathology, pulmonary angiogenesis, oxidative stress levels, as well as mRNA and protein expressions related to inflammation in the 2-week-old offspring. Additionally, we conducted a dual-luciferase reporter assay to confirm the targeting relationship between Nrf2 and GSDMD. Our findings revealed that offspring with maternal hypoxia-induced IUGR exhibited reduced birth weight, catch-up growth delay, and pulmonary dysplasia. Furthermore, we observed impaired nuclear translocation of Nrf2 and increased GSDMD-mediated pyroptosis in these offspring with IUGR. Moreover, the dual-luciferase reporter assay demonstrated that Nrf2 could directly inhibit GSDMD transcription; deficiency of Nrf2 exacerbated pyroptosis and pulmonary dysplasia in offspring with maternal hypoxia-induced IUGR. Collectively, our findings suggest that Nrf2 deficiency induces GSDMD-mediated pyroptosis and pulmonary dysplasia in offspring with maternal hypoxia-induced IUGR; thus highlighting the potential therapeutic approach of targeting Nrf2 for treating prenatal hypoxia-induced pulmonary dysplasia in offspring.

MiR-155-5p Attenuates Vascular Smooth Muscle Cell Oxidative Stress and Migration via Inhibiting BACH1 Expression.

The malfunction of vascular smooth muscle cells (VSMCs) is an initiating factor in the pathogenesis of pathological vascular remodeling, including hypertension-related vascular lesions. MicroRNAs (miRNAs) have been implicated in the pathogenesis of VSMC proliferation and migration in numerous cases of cardiovascular remodeling. The evidence for the regulatory role of miR-155-5p in the development of the cardiovascular system has been emerging. However, it was previously unclear whether miR-155-5p participated in the migration of VSMCs under hypertensive conditions. Thus, we aimed to define the exact role and action of miR-155-5p in VSMC migration by hypertension. Here, we detected that the level of miR-155-5p was lower in primary VSMCs from spontaneously hypertensive rats (SHRs). Its overexpression attenuated, while its depletion accelerated, the migration and oxidative damage of VSMCs from SHRs. Our dual-luciferase reporter assay showed that miRNA-155-5p directly targeted the 3'-untranslated region (3'-UTR) of BTB and CNC homology 1 (BACH1). The miR-155-5p mimic inhibited BACH1 upregulation in SHR VSMCs. By contrast, the deletion of miR-155-5p further elevated the upregulation of BACH1 in SHR-derived VSMCs. Importantly, the overexpression of miR-155-5p and knockdown of BACH1 had synergistic effects on the inhibition of VSMCs in hypertension. Collectively, miR-155-5p attenuates VSMC migration and ameliorates vascular remodeling in SHRs, via suppressing BACH1 expression.

Multiple TMA-aided CRISPR/Cas13a platform for highly sensitive detection of IL-15 to predict immunotherapeutic response in nasopharyngeal carcinoma.

BACKGROUND: Immune checkpoint inhibitors (ICIs)-based treatments have been recommended as the first line for refractory recurrent and/or metastatic nasopharyngeal carcinoma (NPC) patients, yet responses vary, and predictive biomarkers are urgently needed. We selected serum interleukin-15 (sIL-15) out of four interleukins as a candidate biomarker, while most patients' sIL-15 levels were too low to be detected by conventional methods, so it was necessary to construct a highly sensitive method to detect sIL-15 in order to select NPC patients who would benefit most or least from ICIs. METHODS: Combining a primer exchange reaction (PER), transcription-mediated amplification (TMA), and a immuno-PER-TMA-CRISPR/Cas13a system, we developed a novel multiple signal amplification platform with a detection limit of 32 fg/mL, making it 153-fold more sensitive than ELISA. RESULTS: This platform demonstrated high specificity, repeatability, and versatility. When applied to two independent cohorts of 130 NPC sera, the predictive value of sIL-15 was accurate in both cohorts (area under the curve: training, 0.882; validation, 0.898). Additionally, lower sIL-15 levels were correlated with poorer progression-free survival (training, HR: 0.080, p<0.0001; validation, HR: 0.053, p<0.0001). CONCLUSION: This work proposes a simple and sensitive approach for sIL-15 detection to provide insights for personalized immunotherapy of NPC patients.

Nrf2/PHB2 alleviates mitochondrial damage and protects against Staphylococcus aureus-induced acute lung injury.

Staphylococcus aureus (SA) is a major cause of sepsis, leading to acute lung injury (ALI) characterized by inflammation and oxidative stress. However, the role of the Nrf2/PHB2 pathway in SA-induced ALI (SA-ALI) remains unclear. In this study, serum samples were collected from SA-sepsis patients, and a SA-ALI mouse model was established by grouping WT and Nrf2-/- mice after 6 h of intraperitoneal injection. A cell model simulating SA-ALI was developed using lipoteichoic acid (LTA) treatment. The results showed reduced serum Nrf2 levels in SA-sepsis patients, negatively correlated with the severity of ALI. In SA-ALI mice, downregulation of Nrf2 impaired mitochondrial function and exacerbated inflammation-induced ALI. Moreover, PHB2 translocation from mitochondria to the cytoplasm was observed in SA-ALI. The p-Nrf2/total-Nrf2 ratio increased in A549 cells with LTA concentration and treatment duration. Nrf2 overexpression in LTA-treated A549 cells elevated PHB2 content on the inner mitochondrial membrane, preserving genomic integrity, reducing oxidative stress, and inhibiting excessive mitochondrial division. Bioinformatic analysis and dual-luciferase reporter assay confirmed direct binding of Nrf2 to the PHB2 promoter, resulting in increased PHB2 expression. In conclusion, Nrf2 plays a role in alleviating SA-ALI by directly regulating PHB2 transcription and maintaining mitochondrial function in lung cells.

Maternal propionate supplementation ameliorates glucose and lipid metabolic disturbance in hypoxia-induced fetal growth restriction.

Intrauterine growth restriction (IUGR), one of the major complications of pregnancy, is characterized by low birth weight and results in higher risks for long-term problems including developing metabolic and cardiovascular diseases. Short-chain fatty acids (SCFAs), especially propionate, have been reported to correct glucose and lipid disorders in metabolic diseases. We hypothesized that maternal propionate supplementation could prevent glucose and lipid metabolic disturbance in hypoxia-induced IUGR. Here, in our study, maternal hypoxia was induced from gestational day (GD) 11 to GD 17.5 to establish an IUGR mouse model. Maternal propionate treatment reversed reduced birth weight in male IUGR offspring. Hepatic transcriptomics demonstrated that SP treatment significantly lowered glucose and lipid metabolism-related genes (Scd1, G6pc, Pck1 and Fasl) in IUGR offspring. KOG enrichment analysis showed that propionate-induced down-regulated differential expressed genes (DEGs) mainly belonged to lipid transport and metabolism. KEGG enrichment results showed that the down-regulated DEGs were mostly enriched in PPAR and FoxO signaling pathways. We also found that maternal oral administration of SP decreased serum lipid content, attenuated hepatic insulin resistance and liver lipid accumulation, reduced hepatic key gene expressions of gluconeogenesis and lipogenesis, increased energy expenditure and improved liver function in 11-week-old male IUGR offspring. These results indicate that maternal propionate supplementation increases birth weight and corrects hepatic glucose and lipid metabolic disturbance and energy expenditure in male mice born with IUGR, which may provide a basis for using propionate to treat IUGR disease.

Sodium Propionate Enhances Nrf2-Mediated Protective Defense Against Oxidative Stress and Inflammation in Lipopolysaccharide-Induced Neonatal Mice.

BACKGROUND: Alveolar arrest and the impaired angiogenesis caused by chronic inflammation and oxidative stress are two main factors in bronchopulmonary dysplasia (BPD). Short-chain fatty acids (SCFAs), especially propionate, possess anti-oxidant and anti-inflammatory effects. The present study was designed to examine the roles of sodium propionate (SP) on lipopolysaccharide (LPS)-challenged BPD and its potential mechanisms. METHODS: WT, Nrf2-/- mice and pulmonary microvascular endothelial cells (HPMECs) were used in this study. LPS was performed to mimic BPD model both in vivo and vitro. Lung histopathology, inflammation and oxidative stress-related mRNA expressions in lungs involved in BPD pathogenesis were investigated. In addition, cell viability and angiogenesis were also tested. RESULTS: The increased nuclear factor erythroid 2-related factor (Nrf2) and decreased Kelch-like ECH-associated protein-1 (Keap-1) expressions were observed after SP treatment in the LPS-induced neonatal mouse model of BPD. In LPS-induced wild-type but not Nrf2-/- neonatal mice, SP reduced pulmonary inflammation and oxidative stress and exhibited obvious pathological alterations of the alveoli. Moreover, in LPS-evoked HPMECs, SP accelerated Nrf2 nuclear translocation presented and exhibited cytoprotective and pro-angiogenesis effects. In addition, SP diminished the LPS-induced inflammatory response by blocking the activation of nuclear factor-kappa B pathway. Moreover, pretreatment with ML385, an Nrf2 specific inhibitor, offsets the beneficial effects of SP on inflammation, oxidative stress and angiogenesis in LPS-evoked HPMECs. CONCLUSION: SP protects against LPS-induced lung alveolar simplification and abnormal angiogenesis in neonatal mice and HPMECs in an Nrf2-dependent manner.

Sophoricoside attenuates lipopolysaccharide-induced acute lung injury by activating the AMPK/Nrf2 signaling axis.

Sophoricoside (SOP), an isoflavone glycoside isolated from seed of Sophora japonica L., has been reported to have various pharmacological activities, including anti-cancer, anti-allergy and anti-inflammation. However, the effect of SOP on lipopolysaccharides (LPS)-acute lung injury (ALI) is completely unclear. Here, we found that SOP pretreatment significantly ameliorated LPS-induced pathological damage, tissue permeability, neutrophil infiltration and the production of pro-inflammatory cytokines (TNF-α, IL-1ß and IL-6) in a murine model of ALI. Besides, SOP reduced the production of pro-inflammatory mediators such as iNOS, NO and inflammatory cytokines including TNF-α, IL-1ß and IL-6 in LPS-stimulated RAW264.7 cells and bone marrow derived macrophages. Interestingly, treatment with SOP exhibited no effect on the activation of NF-κB and MAPKs in macrophages but prominently accelerated the expression and nuclear translocation of Nrf2. By using ML385, a specific Nrf2 inhibitor, we found that inhibition of Nrf2 abolished the inhibitory effect of SOP on LPS-induced iNOS expression, NO production as well as pro-inflammatory cytokine generation. SOP also activated AMPK, an upstream protein of Nrf2, under LPS stimuli. Furthermore, we demonstrated that the accelerated expression of Nrf2 induced by SOP was reversed by interference with the AMPK inhibitor Compound C. Taken together, our results suggested that SOP attenuated LPS-induced ALI in AMPK/Nrf2 dependent manner and indicated that SOP might be a potential therapeutic candidate for treating ALI/ARDS.

Salvinorin A protects against methicillin resistant staphylococcus aureus-induced acute lung injury via Nrf2 pathway.

Salvinorin A (SA), a neoclerodane diterpene, is isolated from the dried leaves ofSalvia divinorum. SA has traditionally been used treatments for chronic pain diseases. Recent research has demonstrated that SA possesses the anti-inflammatory property. The present study aim to explore the effects and potentialmechanisms ofSA in protection against Methicillin Resistant Staphylococcus aureus (MRSA)-induced acute lung injury (ALI). Here, we firstly found that verylowdosesof SA (50 µg/kg) could markedly decrease the infiltration of pulmonary neutrophils, mRNA expression of pro-inflammatory cytokines (TNF-α, IL-1ß and IL-6) and then attenuated ALI cause by MRSA infection in mice. In vitro findings revealed that SA attenuated lipoteichoicacid-induced apoptosis, inflammation and oxidative stress in RAW264.7 cells. Mechanism research revealed that SA increased both mRNA levels and protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and up-regulated mRNA expression of its downstream genes (HO-1, Gclm, Trx-1, SOD1 and SOD2). Additionally, Nrf2 knockout mice abolished the inhibitory effect of SA on neutrophil accumulation and oxidative stress in MRSA-induced ALI. In conclusion, SA attenuates MRSA-induced ALI via Nrf2 signaling pathways.