Garlic oil supplementation blocks inflammatory pyroptosis-related acute lung injury by suppressing the NF-κB/NLRP3 signaling pathway via H2S generation.

Acute lung injury (ALI) is a major cause of acute respiratory failure with a high morbidity and mortality rate, and effective therapeutic strategies for ALI remain limited. Inflammatory response is considered crucial for the pathogenesis of ALI. Garlic, a globally used cooking spice, reportedly exhibits excellent anti-inflammatory bioactivity. However, protective effects of garlic against ALI have never been reported. This study aimed to investigate the protective effects of garlic oil (GO) supplementation on lipopolysaccharide (LPS)-induced ALI models. Hematoxylin and eosin staining, pathology scores, lung myeloperoxidase (MPO) activity measurement, lung wet/dry (W/D) ratio detection, and bronchoalveolar lavage fluid (BALF) analysis were performed to investigate ALI histopathology. Real-time polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were conducted to evaluate the expression levels of inflammatory factors, nuclear factor-κB (NF-κB), NLRP3, pyroptosis-related proteins, and H2S-producing enzymes. GO attenuated LPS-induced pulmonary pathological changes, lung W/D ratio, MPO activity, and inflammatory cytokines in the lungs and BALF. Additionally, GO suppressed LPS-induced NF-κB activation, NLRP3 inflammasome expression, and inflammatory-related pyroptosis. Mechanistically, GO promoted increased H2S production in lung tissues by enhancing the conversion of GO-rich polysulfide compounds or by increasing the expression of H2S-producing enzymes in vivo. Inhibition of endogenous or exogenous H2S production reversed the protective effects of GO on ALI and eliminated the inhibitory effects of GO on NF-κB, NLRP3, and pyroptotic signaling pathways. Overall, these findings indicate that GO has a critical anti-inflammatory effect and protects against LPS-induced ALI by suppressing the NF-κB/NLRP3 signaling pathway via H2S generation.

Monochasma savatieri Franch. protects against acute lung injury via α7nAChR-TLR4/NF-κB p65 signaling pathway based on integrated pharmacology analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Acute lung injury (ALI) is a life-threatening condition with high morbidity and mortality, underscoring the urgent need for novel treatments. Monochasma savatieri Franch. (LRC) is commonly used clinically to treat wind-heat cold, bronchitis, acute pneumonia and acute gastroenteritis. However, its role in the treatment of ALI and its mechanism of action are still unclear. AIM OF THE STUDY: This study aimed to demonstrate the pharmacological effects and underlying mechanisms of LRC extract, and provide important therapeutic strategies and theoretical basis for ALI. MATERIALS AND METHODS: In this study, a research paradigm of integrated pharmacology combining histopathological analysis, network pharmacology, metabolomics, and biochemical assays was used to elucidate the mechanisms underlaying the effects of LRC extract on LPS-induced ALI in BALB/c mice. RESULTS: The research findings demonstrated that LRC extract significantly alleviated pathological damage in lung tissues and inhibited apoptosis in alveolar epithelial cells, and the main active components were luteolin, isoacteoside, and aucubin. Lung tissue metabolomic and immunohistochemical methods confirmed that LRC extract could restore metabolic disorders in ALI mice by correcting energy metabolism imbalance, activating cholinergic anti-inflammatory pathway (CAP), and inhibiting TLR4/NF-κB signaling pathway. CONCLUSIONS: This study showed that LRC extract inhibited the occurrence and development of ALI inflammation by promoting the synthesis of antioxidant metabolites, balancing energy metabolism, activating CAP and suppressing the α7nAChR-TLR4/NF-κB p65 signaling pathway. In addition, our study provided an innovative research model for exploring the effective ingredients and mechanisms of traditional Chinese medicine. To the best of our knowledge, this is the first report describing the protective effects of LRC extract in LPS-induced ALI mice.

Guben Qingfei decoction attenuates LPS-induced acute lung injury by modulating the TLR4/NF-κB and Keap1/Nrf2 signaling pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Acute lung injury (ALI) is a life-threatening and widespread disease, with exceptionally high morbidity and mortality rates. Unfortunately, effective drugs for ALI treatment are currently lacking. Guben Qingfei decoction (GBQF) is a Chinese herbal compound known for its efficacy in treating viral pneumonia, yet the precise underlying mechanisms remain unknown. AIM OF THE STUDY: This study aimed to validate the mitigating effect of GBQF on ALI and to further investigate its mechanism. MATERIALS AND METHODS: An ALI mice model was established by infusing LPS into the endotracheal tube. The effects of GBQF on ALI were investigated by measuring lung W/D; MPO; BALF total protein concentration; total number of cells; TNF-α, IL-1ß, and IL-6 levels; pathological changes in lung tissue, and oxidation products. Immunohistochemistry and Western Blotting were performed to verify the underlying mechanisms. MH-S and BEAS-2B cells were induced by LPS, and the effects of GBQF were confirmed by RT-PCR and immunofluorescence. RESULTS: GBQF significantly reduced LPS-induced ALI in mice, improved lung inflammation, reduced the production of oxidative products, increased the activity of antioxidant enzymes, and reduced the degree of lung tissue damage. GBQF prevents MH-S cells from releasing inflammatory factors and reduces oxidative damage to BEAS-2B cells. In vivo studies have delved deeper into the mechanism of action of GBQF, revealing its correlation with the TLR4/NF-κB and Keap1/Nrf2 pathways. CONCLUSIONS: Our study demonstrates that GBQF is an effective treatment for ALI, providing a new perspective on medication development for ALI treatment.

Ginsenosides: a potential natural medicine to protect the lungs from lung cancer and inflammatory lung disease.

Lung cancer is the malignancy with the highest morbidity and mortality. Additionally, pulmonary inflammatory diseases, such as pneumonia, acute lung injury, chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis (PF), also have high mortality rates and can promote the development and progression of lung cancer. Unfortunately, available treatments for them are limited, so it is critical to search for effective drugs and treatment strategies to protect the lungs. Ginsenosides, the main active components of ginseng, have been shown to have anti-cancer and anti-inflammatory activities. In this paper, we focus on the beneficial effects of ginsenosides on lung diseases and their molecular mechanisms. Firstly, the molecular mechanism of ginsenosides against lung cancer was summarized in detail, mainly from the points of view of proliferation, apoptosis, autophagy, angiogenesis, metastasis, drug resistance and immunity. In in vivo and in vitro lung cancer models, ginsenosides Rg3, Rh2 and CK were reported to have strong anti-lung cancer effects. Then, in the models of pneumonia and acute lung injury, the protective effect of Rb1 was particularly remarkable, followed by Rg3 and Rg1, and its molecular mechanism was mainly associated with targeting NF-κB, Nrf2, MAPK and PI3K/Akt pathways to alleviate inflammation, oxidative stress and apoptosis. Additionally, ginsenosides may also have a potential health-promoting effect in the improvement of COPD, asthma and PF. Furthermore, to overcome the low bioavailability of CK and Rh2, the development of nanoparticles, micelles, liposomes and other nanomedicine delivery systems can significantly improve the efficacy of targeted lung cancer treatment. To conclude, ginsenosides can be used as both anti-lung cancer and lung protective agents or adjuvants and have great potential for future clinical applications.

Hyperbaric oxygen combined with hydrogen-rich saline protects against acute lung injury.

Background: This study sought to investigate therapeutic effects of hydrogen-rich saline (HRS) combined with hyperbaric oxygen (HBO2) in an experimental rat model of acute lung injury (ALI). Method: Forty male Sprague-Dawley rats were randomly divided into sham, LPS, LPS + HBO2, LPS + HRS, and LPS + HBO2 + HRS groups. After an intratracheal injection of LPS-induced ALI, the rats were given a single-agent HBO2 or HRS or HBO2 + HRS treatment. The treatments were continued for three days in this experimental rat model of ALI. At the end of experiment, the lung pathological, inflammatory factors, and cell apoptosis in the pulmonary tissue were detected by Tunel method and cell apoptosis rate was calculated accordingly. Results: In the groups treated with HBO2 + HRS, pulmonary pathological data, wet-dry weight ratio, and inflammatory factors of pulmonary tissues and alveolar lavage fluid were significantly superior to those of the sham group (p≺0.05). Cell apoptosis detection revealed that no single agent treatment of HRS or HBO2, or combination treatment, could alleviate all cell apoptosis. HRS combined with HBO2 treatment was superior to single treatment (p≺0.05). Conclusion: HRS or HBO2 single treatment could decrease inflammatory cytokines release in lung tissue, reduce the accumulation of oxidative products and alleviate apoptosis of pulmonary cells, then lead to positive therapeutic effects on ALI induced by LPS. Furthermore, HBO2 combined with HRS treatment presented a synergy effect on cell apoptosis decrease and a decline in inflammatory cytokine release and related inflammatory product generation, compared with a single treatment.

Total tanshinones protect against acute lung injury through the PLCγ2/NLRP3 inflammasome signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Salvia miltiorrhiza Bunge is a widely used traditional Chinese medicine with anticholinesterase, antitumor, and anti-inflammatory. Total Tanshinones (TTN), the most significant active ingredient of Salvia miltiorrhiza Bunge, exerts anti-inflammatory activity. However, the protective mechanism of total Tanshinones on acute lung injury (ALI) still needs to be explored. AIM OF THIS STUDY: In this study, the underlying mechanisms of TTN to treat with ALI were investigated in vitro and in vivo. MATERIALS AND METHODS: Cell experiments established an in vitro model of LPS-induced J774A.1 and MH-S macrophages to verify the mechanism. The levels of inflammatory cytokines (TNF-α, IL-6 and IL-1ß) were estimated by ELISA. The changes of ROS, Ca2+ and NO were detected by flow cytometry. The expression levels of proteins related to the NLRP3 inflammasome were determined by Western blotting. The effect of TTN on NLRP3 inflammasome activation was examined by immunofluorescence analysis of caspase-1 p20. Male BALB/c mice were selected to establish the ALI model. The experiment was randomly divided into six groups: control, LPS, LPS + si-NC, LPA + si-Nek7, LPS + TTN, and DEX. Pathological alterations were explored by H&E staining. The expression levels of proteins related to the NLRP3 inflammasome were analyzed by Western blotting. RESULTS: TTN decreased pro-inflammatory cytokines levels like TNF-α, IL-6, IL-1ß, NO, and ROS in alveolar macrophages. TTN bound to NIMA-related kinase 7 (NEK7), a new therapeutic protein to modulate NLRP3 inflammasome and PLCγ2-PIP2 signaling pathway. In ALI mice, LPS enhanced IL-1ß levels in the serum, lung tissues, and bronchoalveolar lavage fluid (BALF),which were reversed by TTN. TTN decreased cleaved-caspase-1 and NLRP3 expressions in lung tissues. When Nek7 was knocked down in mice by siRNA, the syndrome of ALI in mice was significantly suppressed, of which the effect was similar to that of TTN. CONCLUSIONS: This research demonstrates that TTN alleviated ALI by binding to NEK7 in vitro and in vivo to modulate NLRP3 inflammasome activation and PLCγ2-PIP2 signaling pathways.

Isopropyl 3-(3, 4-dihydroxyphenyl)-2-hydroxypropanoate protects lipopolysaccharide-induced acute lung injury in mice by attenuating pyroptosis.

Isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoate (IDHP) is one of the main bioactive metabolites of the Chinese medicinal herb Danshen, which can be absorbed into blood compounds by oral administration of Compound Danshen dripping pills (CDDPs). Previous study showed that IDHP exerted anti-inflammatory effects by abolishing the secretion of proinflammatory factors stimulated by lipopolysaccharide (LPS). However, the effects of IDHP on LPS-induced acute lung injury (ALI) are not fully understood. In the present study, we observed the effects of IDHP on mortality and lung injury in LPS-treated mice and on LPS-induced THP-1 macrophages. Pretreatment with high dose of IDHP was found to reduce the mortality of ALI mice, significantly improve LPS-induced pathological changes, and reduce protein leakage and inhibited myeloperoxidase (MPO) activity in lung tissue. IDHP also inhibited the release of inflammatory factors in bronchoalveolar lavage fluid (BALF) and lung tissue. Meanwhile, IDHP treatment significantly reduced the expression of active-caspase1, Nlrp3, Asc speck formation, Gsdmd (part of the canonical pyroptosis pathway), caspase4 (part of the non-canonical pyroptosis pathway), therefore decreasing IL-1ß, IL-18, and ROS secretion in LPS-stimulated THP-1 macrophages. Moreover, after co-culturing endothelial/epithelial cells with conditioned medium (CM) from LPS-stimulated THP-1 macrophages, we found that the protein levels of occludin and Zonula occludens-1 (Zo-1) were increased in IDHP CM-treated endothelial cells compared to those that were LPS CM-treated. Lactic dehydrogenase (LDH) assay shows that IDHP also alleviated LPS-induced endothelial/epithelial cell injury. These findings indicate that the protective effect of IDHP on LPS-induced lung injury may be partly due to the inhibition of pyroptosis pathways.

Schisandrin B protects against LPS-induced inflammatory lung injury by targeting MyD88.

BACKGROUND: Acute lung injury (ALI) is a challenging clinical syndrome that manifests as an acute inflammatory response. Schisandrin B (Sch B), a bioactive lignan from Schisandra genus plants, has been shown to suppress inflammatory responses and oxidative stress. However, the underlying molecular mechanisms have remained elusive. HYPOTHESIS/PURPOSE: This study performed an in-depth investigation of the anti-inflammatory mechanism of Sch B in macrophages and in an animal model of ALI. METHODS: qPCR array was used to probe the differential effects and potential target of Sch B. ALI was induced by intratracheal administration of LPS in experimental mice with or without Sch B treatment. RESULTS: Our studies show that Sch B differentially modulates inflammatory factor induction by LPS in macrophages by directly binding myeloid differentiation response factor-88 (MyD88), an essential adaptor protein in the toll-like receptor-4 (TLR4) pathway. Sch B spares non-MyD88-pathways downstream of TLR4. Such inhibition suppressed key signaling mediators such as TAK1, MAPKs, and NF-κB, and pro-inflammatory factor induction. Pull down assay using biotinylated-Sch B validate the direct interaction between Sch B and MyD88 in macrophages. Treatment of mice with Sch B prior to LPS challenge reduced inflammatory cell infiltration in lungs, induction of MyD88-pathway signaling proteins, and prevented inflammatory cytokine induction. CONCLUSION: In summary, our studies have identified MyD88 as a direct target of Sch B for its anti-inflammatory activity, and suggest that Sch B may have therapeutic value for acute lung injury and other MyD88-dependent inflammatory diseases.

A High-Fiber Diet or Dietary Supplementation of Acetate Attenuate Hyperoxia-Induced Acute Lung Injury.

A high fiber diet (HFD) and dietary supplementation with acetate have been reported to have beneficial effects in a variety of diseases. We investigated the effects of a HFD and acetate supplementation on the gut microbiota and hyperoxia-induced acute lung injury (HALI) in mice. Mice were fed a control diet, HFD, or acetate supplementation for three weeks, and their gut microbiome composition, lung tissues, and bronchoalveolar lavage fluid (BALF) were examined after exposure to ambient air or hyperoxia. Both the HFD and acetate supplementation modified the gut microbiota community and increased the proportion of acetate-producing bacteria in mice exposed to hyperoxia. The HFD and acetate supplementation also increased the abundance of Bacteroides acidifaciens and reduced gut dysbiosis according to the ratio of Firmicutes to Bacteroidetes. Compared with hyperoxia-exposed mice fed a control diet, both the HFD and acetate supplementation significantly increased the survival time while reducing the severity of pulmonary edema and the concentrations of protein and inflammatory mediators in BALF. Moreover, the HFD and acetate supplementation reduced the production of free radicals, attenuated NF-κB signaling activation, and decreased apoptosis in the lung tissues. Overall, this study indicates that a HFD or acetate supplementation reduces the severity of HALI through alterations in the gut microbiota to exert anti-inflammatory effects.

Intestinal Microbiota-derived Propionic Acid Protects against Zinc Oxide Nanoparticle-induced Lung Injury.

With the rapid development of nanotechnology, the risks of accidental and/or occupational exposure to zinc oxide nanoparticles (ZnONPs) are increasing. Inhalation of ZnONPs induces metal fume fever in humans and acute lung injury (ALI) in animal models. Although the intestinal microbiota is considered an important modulator of various diseases, the role and mechanism of intestinal microbiota in the pathology of ZnONP-induced ALI are unclear. Herein, we established an intratracheal instillation of a ZnONP-induced ALI mouse model and found that the inhalation of ZnONPs caused ALI along with a perturbation of intestinal flora. Antibiotic cocktail treatment-mediated depletion of intestinal microbiota aggravated ZnONP-induced ALI, and in contrast, fecal microbiota transplantation-mediated restoration of intestinal microbiota exerted the opposite effects. A decrease in short-chain fatty acids, the intestinal microbiota-derived metabolites in the plasma-in particular, acetic acid and propionic acid-occurred after exposure to ZnONPs. It is important to note that supplementation with propionic acid, but not acetic acid, ameliorated ZnONP-induced ALI. We also showed that the source of inflammatory cytokines might partially be the infiltration of macrophages. Supplementation with propionic acid was found to act on macrophages through the receptor GPR43, because knockdown of GPR43 sharply reversed the protective effects of propionic acid during the ZnONP-induced inflammatory response and oxidative stress in both primary alveolar macrophages and RAW 264.7 macrophage cell lines. Altogether, a novel gut-lung axis mechanism is revealed in which intestinal microbiota and their derived metabolite propionic acid play protective roles against ZnONP-induced ALI and suggest that fecal microbiota transplantation and supplementation with propionic acid are potential remedy strategies.

Protective effects of lavender oil on sepsis-induced acute lung injury via regulation of the NF-κB pathway.

CONTEXT: Lavender oil (Lav) from Lavandula angustifolia L. (Lamiacease) exhibits antioxidative and anti-inflammatory properties against various diseases. OBJECTIVE: The study explores the effect of Lav pre-treatment on sepsis-induced acute lung injury (ALI). MATERIALS AND METHODS: Sprague-Dawley rats were assigned into Sham, caecal ligation and puncture (CLP), CLP + Lav (200, 400, and 800 mg/kg) groups. Lav was administered by gavage, once a day, for 7 days. Histological analysis was performed using haematoxylin and eosin staining. Cytokine and nitrite levels were detected by enzyme-linked immunosorbent assay kits and Griess reagent. Gene and protein expression were tested by quantitative real-time polymerase chain reaction and western blot. RESULTS: The levels of tumour necrosis factor-α (BALF: 64%, serum: 59%), interleukin (IL)-1ß (BALF: 63%, serum: 66%) and IL-6 (BALF: 54%, serum: 59%), and nitrite (40%) and inducible nitric oxide synthase (51%), and the level of myeloperoxidase (66%) and malondialdehyde (59%), and cleaved-caspase 3 (84%) and Bax expression (74%) induced by CLP were decreased when given Lav. Additionally, the level of superoxide dismutase (211%) and glutathione (139%), and the expression of Bcl-2 (980%) induced by CLP were increased when given Lav. The increased p-nuclear factor (NF)-κB/NF-κB (72%) and p-inhibitor of κBα (IκBα)/IκBα (77%) induced by CLP could be reversed by Lav. DISCUSSION AND CONCLUSIONS: Lav pre-treatment might protect rats from sepsis-induced ALI via deactivation of the NF-κB pathway. Our research demonstrated the regulatory mechanisms of Lav in sepsis-induced ALI and can provide a theoretical basis for the use of Lav in the treatment of sepsis-induced ALI.

Lianhuaqingwen alleviates p53-mediated apoptosis in alveolar epithelial cells to prevent LPS-induced ALI.

BACKGROUND: Our previous study found that Lianhuaqingwen reduces lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice by suppressing p53-mediated apoptosis. To identify the type of lung cells affected by Lianhuaqingwen, we conducted a cell experiment. METHODS: C57/B6 mice and A549 cells were administered Lianhuaqingwen and LPS. A549 cells were transfected with p53 siRNA to inhibit p53. The degree of ALI in mice was validated by haematoxylin and eosin staining as well as measurement of IL-1ß and MCP-1 levels. In A549 cells, Cell Counting Kit-8 (CCK-8), DHE and TUNEL assays were used to assess cell viability, reactive oxygen species (ROS) production and apoptosis, respectively. Western blot analysis was used to evaluate the protein expression of p53, Bcl-2, Bax, caspase-9 and caspase-3. Co-immunofluorescence was used to detect cytochrome C distribution. KEY FINDINGS: Lianhuaqingwen alleviated LPS-induced ALI in vivo. Lianhuaqingwen at 300 µg/ml increased cell viability, lowered ROS production and reduced apoptotic cells in vitro. Lianhuaqingwen enhanced Bcl-2 expression and reduced Bax, caspase-9 and caspase-3 expression as well as blocked cytochrome C release under LPS stimulation. Treatment with a combination of Lianhuaqingwen and p53 siRNA was more effective than treatment with Lianhuaqingwen alone. CONCLUSION: Lianhuaqingwen inhibits p53-mediated apoptosis in alveolar epithelial cells, thereby preventing LPS-induced ALI.

A strategy for attenuation of acute radiation-induced lung injury using crocetin from gardenia fruit.

PURPOSE: Radiation-induced lung injury limits the implementation of radiotherapy plans and severely impairs the quality of life. Crocetin has the capability to protect against radiation. This study is aimed at estimate the preventive effect and mechanism of crocetin on acute radiation induced lung injury. METHODS AND MATERIALS: In this study, we offer a strategy for radiation-induced lung injury by using crocetin, an extract of gardenia fruit. Histopathology, transcriptomics, flow cytometry, and other methods have served to examine the effect and mechanism of crocetin on acute radiation-induced lung injury. RESULTS: Crocetin effectively alleviates radiation-induced alveolar wall thickening and alveolar destruction. The number of normal alveoli and lung structure of mice is well protected by the prevention of crocetin. It is found that crocetin inhibits necroptosis to achieve effective radioprotection by down regulating the Tnfrsf10b gene in vitro. CONCLUSION: Crocetin inhibits necroptosis through transcriptional regulation of the Tnfrsf10b gene, thereby preventing radiation-induced lung injury. This work may provide a new strategy for the prevention of lung radiation injury by the extract from Chinese herbal medicine.

Metabolomics coupled with network pharmacology study on the protective effect of Keguan-1 granules in LPS-induced acute lung injury.

CONTEXT: Keguan-1 (KG-1) plays a vital role in enhancing the curative effects, improving quality of life, and reducing the development of acute lung injury (ALI). OBJECTIVE: To unravel the protective effect and underlying mechanism of KG-1 against ALI. MATERIALS AND METHODS: C57BL/6J mice were intratracheally instilled with lipopolysaccharide to establish the ALI model. Then, mice in the KG-1 group received a dose of 5.04 g/kg for 12 h. The levels of proinflammatory cytokines, chemokines, and pathological characteristics were determined to explore the effects of KG-1. Next, untargeted metabolomics was used to identify the differential metabolites and involved pathways for KG-1 anti-ALI. Network pharmacology was carried out to predict the putative active components and drug targets of KG-1 anti-ALI. RESULTS: KG-1 significantly improved the levels of TNF-α (from 2295.92 ± 529.87 pg/mL to 1167.64 ± 318.91 pg/mL), IL-6 (from 4688.80 ± 481.68 pg/mL to 3604.43 ± 382.00 pg/mL), CXCL1 (from 4361.76 ± 505.73 pg/mL to 2981.04 ± 526.18 pg/mL), CXCL2 (from 5034.09 ± 809.28 pg/mL to 2980.30 ± 747.63 pg/mL), and impaired lung histological damage. Untargeted metabolomics revealed that KG-1 significantly regulated 12 different metabolites, which mainly related to lipid, amino acid, and vitamin metabolism. Network pharmacology showed that KG-1 exhibited anti-ALI effects through 17 potentially active components acting on seven putative drug targets to regulate four metabolites. DISCUSSION AND CONCLUSIONS: This work elucidated the therapeutic effect and underlying mechanism by which KG-1 protects against ALI from the view of the metabolome, thus providing a scientific basis for the usage of KG-1.

Intense light-elicited alveolar type 2-specific circadian PER2 protects from bacterial lung injury via BPIFB1.

Circadian amplitude enhancement has the potential to be organ protective but has not been studied in acute lung injury (ALI). Consistent light and dark cycles are crucial for the amplitude regulation of the circadian rhythm protein Period2 (PER2). Housing mice under intense instead of ambient light for 1 wk (light: dark cycle:14h:10h), we demonstrated a robust increase of pulmonary PER2 trough and peak levels, which is consistent with circadian amplitude enhancement. A search for the affected lung cell type suggested alveolar type 2 (ATII) cells as strong candidates for light induction of PER2. A head-to-head comparison of mice with cell-type-specific deletion of Per2 in ATII, endothelial, or myeloid cells uncovered a dramatic phenotype in mice with an ATII-specific deletion of Per2. During Pseudomonas aeruginosa-induced ALI, mice with Per2 deletion in ATII cells showed 0% survival, whereas 85% of control mice survived. Subsequent studies demonstrated that intense light therapy dampened lung inflammation or improved the alveolar barrier function during P. aeruginosa-induced ALI, which was abolished in mice with an ATII-specific deletion of Per2. A genome-wide mRNA array uncovered bactericidal/permeability-increasing fold-containing family B member 1 (BPIFB1) as a downstream target of intense light-elicited ATII-PER2 mediated lung protection. Using the flavonoid and PER2 amplitude enhancer nobiletin, we recapitulated the lung-protective and anti-inflammatory effects of light and BPIFB1, respectively. Together, our studies demonstrate that light-elicited amplitude enhancement of ATII-specific PER2 is a critical control point of inflammatory pathways during bacterial ALI.

NF-κB and AMPK-Nrf2 pathways support the protective effect of polysaccharides from Polygonatum cyrtonema Hua in lipopolysaccharide-induced acute lung injury.

ETHNOPHARMACOLOGICAL RELEVANCE: The raw and honey-processed P. cyrtonema recorded in ancient classics of Chinese medicine as having the effect of moisturizing the lungs and relieving coughs, and it has also been proved to have therapeutic effects on lung diseases in modern research. Polysaccharides are the main components with biological activities in raw and honey-processed P. cyrtonema, but there is no research for their lung-protective effect. AIM OF STUDY: This study aimed to investigate the protective effect and the possible mechanism of polysaccharides from raw and honey-processed P. cyrtonema in LPS-induced acute lung injury in mice. MATERIALS AND METHODS: Polysaccharides, PCP and HPCP, were respectively separated and extracted from raw and honey-processed P. cyrtonema, and the molecular weight, monosaccharide composition and other basic chemical characteristics were analyzed by HPGCP, HPLC, FI-IR, and NMR. The model of ALI mice was established by intratracheal instillation of LPS. Moreover, the protective effects of PCP and HPCP for ALI mice were evaluated by detecting the wet-to-dry ratio and histopathology in the lungs, the content of inflammatory factors TNF-α, IL-6, IL-1ß in BLAF, and the content of MPO and SOD in lung tissue. In addition, the lung-protective mechanism of PCP and HPCP was explored by detecting the levels of some proteins and mRNA related to inflammation and oxidative stress pathways. RESULTS: PCP and HPCP with molecular weights of 8.842 × 103 and 5.521 × 103Da were mainly composed of three monosaccharides. Moreover, it is found that fructose and galactose were mainly ß-D, and glucose was α-D. Both PCP and HPCP could significantly improve lung injury, reduce the level of inflammatory factors in BALF and the level of MPO in lung tissue, and increase the level of SOD. In addition, PCR and WB indicated that PCP and HPCP at least inhibited pulmonary inflammation through the NF-κB pathway, and reduced the occurrence of pulmonary oxidative stress through the AMPK-Nrf2 pathway. CONCLUSIONS: Polysaccharides from raw and honey-processed P. cyrtonema had a protective effect in LPS-induced lung injury in mice. This effect may be related to the antioxidant and anti-inflammatory activities of PCP and HPCP in the lungs through the NF-κB pathway and AMPK-Nrf2 pathway. And HPCP seems to perform more than PCP.

Protective Effects of Carbon Dots Derived from Armeniacae Semen Amarum Carbonisata Against Acute Lung Injury Induced by Lipopolysaccharides in Rats.

INTRODUCTION: The charcoal processed product of Armeniacae Semen Amarum (ASA), ASA Carbonisata (ASAC), has long been used for its anti-inflammatory effects. However, the material basis and mechanism of action of ASAC remain unclear. AIM: To explore the anti-inflammatory effects of Armeniacae Semen Amarum Carbonisata-derived carbon dots (ASAC-CDs). METHODS: The physicochemical properties of ASAC-CDs including morphology, optical properties, functional groups were characterized by a series of methods, mainly including electron microscopy, optical technology and X-ray photoelectron spectroscopy. The anti-inflammatory effect of ASAC-CDs was evaluated and confirmed using acute lung injury (ALI) induced by lipopolysaccharides (LPS) in rats. RESULTS: The ASAC-CDs ranged from 1.5 to 5.5 nm in diameter, with a quantum yield of 3.17%. ASAC-CDs alleviated LPS-induced inflammation, as demonstrated by reducing the levels of IL-6, IL-1ß and TNF-α and increasing the contents of IL-10 in rat serum. More interestingly, ASAC-CDs reduce the content of MDA and MPO and increase the activity of SOD and the content of GSH, indicating the antioxidant activity of ASAC-CDs. CONCLUSION: These results demonstrate the remarkable anti-inflammatory effects of ASAC-CDs against ALI induced by LPS, which provide an important basis for the application of ASAC-CDs in clinical anti-pneumonia, and lay an experimental foundation for the research and development of novel nano-drugs.

Protective effect of pteryxin on LPS-induced acute lung injury via modulating MAPK/NF-κB pathway and NLRP3 inflammasome activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Peucedanum praeruptorum seed root is a common medicinal herb with antipyretic, expectorant, antitussive, and therapeutic effects against bronchitis and furuncle. The roots of this herb contain many coumarin compounds, including pteryxin. AIM OF THIS STUDY: To investigate whether pteryxin can alleviate the LPS-induced lung injury and the mechanism involved. MATERIAL AND METHODS: Male BALB/C mice were orally given sodium carboxymethylcellulose (CMC-Na) (0.5%, 1mL/100g) and pteryxin (suspended in CMC-Na; 0.5%) at 5, 10, 25 mg/kg once daily for 7 days. Subsequently, the mice received a single intratracheal instillation of 5 mg/kg LPS or saline as the control. After 8 hours, the mice were sacrificed to collect bronchoalveolar lavage fluid (BALF) and lung tissues. These samples were used to determine the lung W/D (wet/dry) weight ratio, total protein (TP) levels, inflammatory cytokines (IL-6, TNF-α, and IL-1ß) and expression of protein involved in MAPK/NF-κB pathway and NLRP3 inflammasome. H&E staining was carried out on tissue sections to explore the pathological alterations induced by LPS. The protein expression of F4/80 and NLRP3 in lung tissues was analyzed using immunohistochemical staining. The binding of pteryxin to target proteins (MAPK, NF-κB and NLRP3) was determined based on molecular docking tests. RESULTS: Treatment with pteryxin reduced the lung W/D weight ratio, total protein (TP) level and levels of inflammatory cytokines (TNFα, IL-6 and IL-1 ß) significantly. Therefore, it ameliorated LPS-induced inflammatory response in BALB/C mice. Moreover, pteryxin suppressed LPS-induced upregulation of proteins involved in MAPK/NF-κB signaling pathway and NLRP3 inflammasome activation. The expression level of F4/80 and NLRP3 was also downregulated by pteryxin pretreatment in lung tissues. Docking analysis revealed that pteryxin bound to target proteins (MAPK, NF- κB and NLRP3) with a fit-well pattern . CONCLUSION: Pteryxin may attenuate LPS-induced acute lung injury by dampening MAPK/NF-κB signaling and NLRP 3 inflammasome activation.

Targeting S100A9 Reduces Neutrophil Recruitment, Inflammation and Lung Damage in Abdominal Sepsis.

S100A9, a pro-inflammatory alarmin, is up-regulated in inflamed tissues. However, the role of S100A9 in regulating neutrophil activation, inflammation and lung damage in sepsis is not known. Herein, we hypothesized that blocking S100A9 function may attenuate neutrophil recruitment in septic lung injury. Male C57BL/6 mice were pretreated with the S100A9 inhibitor ABR-238901 (10 mg/kg), prior to cercal ligation and puncture (CLP). Bronchoalveolar lavage fluid (BALF) and lung tissue were harvested for analysis of neutrophil infiltration as well as edema and CXC chemokine production. Blood was collected for analysis of membrane-activated complex-1 (Mac-1) expression on neutrophils as well as CXC chemokines and IL-6 in plasma. Induction of CLP markedly increased plasma levels of S100A9. ABR-238901 decreased CLP-induced neutrophil infiltration and edema formation in the lung. In addition, inhibition of S100A9 decreased the CLP-induced up-regulation of Mac-1 on neutrophils. Administration of ABR-238901 also inhibited the CLP-induced increase of CXCL-1, CXCL-2 and IL-6 in plasma and lungs. Our results suggest that S100A9 promotes neutrophil activation and pulmonary accumulation in sepsis. Targeting S100A9 function decreased formation of CXC chemokines in circulation and lungs and attenuated sepsis-induced lung damage. These novel findings suggest that S100A9 plays an important pro-inflammatory role in sepsis and could be a useful target to protect against the excessive inflammation and lung damage associated with the disease.

Oxypaeoniflorin Prevents Acute Lung Injury Induced by Lipopolysaccharide through the PTEN/AKT Pathway in a Sirt1-Dependent Manner.

Acute lung injury (ALI) is featured by pulmonary edema, alveolar barrier injury, inflammatory response, and oxidative stress. The activation of Sirt1 could relieve lipopolysaccharide- (LPS-) induced murine ALI by maintaining pulmonary epithelial barrier function. Oxypaeoniflorin (Oxy) serves as a major component of Paeonia lactiflora Pall., exerting cardioprotection by activating Sirt1. However, the role of Oxy in ALI induced by LPS remains unclear. The aim of the present study is to illustrate the modulatory effects and molecular mechanisms by which Oxy operates in ALI induced by LPS. The intraperitoneal injection of LPS was performed to establish the murine ALI model while LPS-treated alveolar epithelial cells were used to mimic the in vitro ALI model. Levels of lung injury, oxidative stress, and inflammatory response were detected to observe the potential effects of Oxy on ALI. Oxy treatment mitigated lung edema, inflammatory response, and oxidative stress in mouse response to LPS, apart from improving 7-day survival. Meanwhile, Oxy also increased the expression and activity of Sirt1. Intriguingly, Sirt1 deficiency or inhibition counteracted the protective effects of Oxy treatment in LPS-treated mice or LPS-treated alveolar epithelial cells by regulating the PTEN/AKT signaling pathway. These results demonstrated that Oxy could combat ALI in vivo and in vitro through inhibiting inflammatory response and oxidative stress in a Sirt1-dependent manner. Oxy owns the potential to be a promising candidate against ALI.