1.Amentoflavone alleviates acute lung injury in mice by inhibiting cell pyroptosis.
Yalei SUN ; Meng LUO ; Changsheng GUO ; Jing GAO ; Kaiqi SU ; Lidian CHEN ; Xiaodong FENG
Journal of Southern Medical University 2025;45(4):692-701
OBJECTIVES:
To investigate the effect of amentoflavone (AF) for alleviating lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and inhibiting NLRP3/ASC/Caspase-1 axis-mediated pyroptosis.
METHODS:
Female BALB/c mice were randomly divided into control group, LPS group, and AF treatment groups at low, moderate and high doses (n=12). ALI models were established by tracheal LPS instillation, and in AF treatment groups, AF was administered by gavage 30 min before LPS instillation. Six hours after LPS instillation, the mice were euthanized for examining lung tissue histopathological changes, protein levels in BALF, and MPO levels in the lung tissue. In the in vitro experiment, RAW264.7 cells were pretreated with AF, AC (a pyroptosis inhibitor), or their combination for 2 h before stimulation with LPS and ATP. The changes in cell proliferation and viability were detected using CCK-8 assay, and IL-1β, IL-6, IL-18, and TNF-α levels were determined with ELISA. Immunohistochemistry, immunofluorescence assay, and immunoblotting were used to detect the protein levels of NLRP3, ASC, cleaved caspase-1, and GSDMD N in rat lung tissues and the treated cells.
RESULTS:
In mice with LPS exposure, AF treatment significantly improved lung pathologies and edema, reduced protein levels in BALF and pulmonary MPO level, inhibited the high expression of NLRP3/ASC/Aspase-1 axis, reduced the expression of GSDMD N, and lowered the release of IL-1β, IL-6, IL-18, and TNF‑α. In RAW264.7 cells with LPS and ATP stimulation, AF pretreatment effectively reduced cell death, inhibited activation of the NLRP3/ASC/Aspase-1 axis, and reduced GSDMD N expression and the inflammatory factors. The pyroptosis inhibitor showed a similar effect to AF, and their combination produced more pronounced effects in RAW264.7 cells.
CONCLUSIONS
Amentoflavone can alleviate ALI in mice possibly by inhibiting NLRP3/ASC/Caspase-1 axis-mediated cell pyroptosis.
Animals
;
Pyroptosis/drug effects*
;
Acute Lung Injury/pathology*
;
Mice
;
Mice, Inbred BALB C
;
Female
;
Lipopolysaccharides
;
Biflavonoids/pharmacology*
;
RAW 264.7 Cells
;
NLR Family, Pyrin Domain-Containing 3 Protein
;
Caspase 1/metabolism*
;
Lung
2.Comparison of anti-inflammatory, antibacterial and analgesic activities of formulated granules versus traditional decoction of Yinqiao Powder.
Zhuolin GUO ; Zhiheng ZHANG ; Xindeng GUO ; Weiwei YANG ; Zhiqing LIANG ; Jinying OU ; Huihui CAO ; Zibin LU ; Linzhong YU ; Junshan LIU
Journal of Southern Medical University 2025;45(5):1003-1012
OBJECTIVES:
To compare the anti-inflammatory, antibacterial and analgesic effects of Yinqiao Powder (YQS) formulated granules and decoction.
METHODS:
We first evaluated the anti-inflammatory effects of the two dosage forms of YQS in a LPS-induced RAW 264.7 cell model using RT-qPCR and Western blotting. We further constructed zebrafish models of inflammation by copper sulfate exposure, caudal fin transection, or LPS and Poly (I:C) microinjection, and evaluated anti-inflammatory effects of YQS granules and decoction by examining neutrophil aggregation and HE staining findings. In a mouse model of acute lung injury (ALI) induced by intratracheal LPS instillation, the effects of YQS gavage at 10, 15, and 20 g/kg on lung pathologies were evaluated by calculating lung wet-dry weight ratio and using HE staining, ELISA and Western blotting. The microbroth dilution method was used to evaluate the antibacterial effect of YQS. Mouse pain models established by hot plate and intraperitoneal injection of glacial acetic acid were used to evaluate the analgesic effects of YQS at 10, 15, and 20 g/kg.
RESULTS:
Both YQS granules and decoction significantly reduced TNF-α, IL-6, and IL-1β expressions and p-STAT3 (Tyr 705) phosphorylation level in LPS-induced RAW 264.7 cells, and obviously inhibited neutrophil aggregation in the zebrafish models. In ALI mice, YQS granules and decoction effectively ameliorated lung injury, lowered lung wet-dry weight ratio, and reduced p-STAT3 (Tyr 705) expression and TNF-α and IL-6 levels. YQS produced obvious antibacterial effect at the doses of 15.63 and 31.25 mg/mL, and significantly reduced body torsion and increased pain threshold in the mouse pain models.
CONCLUSIONS
The two dosage forms of TQS have similar anti-inflammatory, antibacterial and analgesic effects with only differences in their inhibitory effect on TNF-α, IL-6 and IL-1β mRNA expressions in LPS-induced RAW 264.7 cells.
Animals
;
Mice
;
Drugs, Chinese Herbal/pharmacology*
;
Anti-Inflammatory Agents/pharmacology*
;
Analgesics/pharmacology*
;
RAW 264.7 Cells
;
Zebrafish
;
Anti-Bacterial Agents/pharmacology*
;
Powders
;
Tumor Necrosis Factor-alpha/metabolism*
;
Acute Lung Injury/drug therapy*
;
Interleukin-6/metabolism*
;
Lipopolysaccharides
3.Curcumin inhibits lipid metabolism in non-small cell lung cancer by downregulating the HIF-1α pathway.
Dandan LI ; Jiaxin CHU ; Yan YAN ; Wenjun XU ; Xingchun ZHU ; Yun SUN ; Haofeng DING ; Li REN ; Bo ZHU
Journal of Southern Medical University 2025;45(5):1039-1046
OBJECTIVES:
To investigate the effect of curcumin on lipid metabolism in non-small cell lung cancer (NSCLC) and its molecular mechanism.
METHODS:
The inhibitory effect of curcumin (0-70 μmol/L) on proliferation of A549 and H1299 cells was assessed using MTT assay, and 20 and 40 μmol/L curcumin was used in the subsequent experiments. The effect of curcumin on lipid metabolism was evaluated using cellular uptake assay, wound healing assay, triglyceride (TG)/free fatty acid (NEFA) measurements, and Oil Red O staining. Western blotting was performed to detect the expressions of PGC-1α, PPAR-α, and HIF-1α in curcumin-treated cells. Network pharmacology was used to predict the metabolic pathways, and the results were validated by Western blotting. In a nude mouse model bearing A549 cell xenograft, the effects of curcumin (20 mg/kg) on tumor growth and lipid metabolism were assessed by measuring tumor weight and observing the changes in intracellular lipid droplets.
RESULTS:
Curcumin concentration-dependently inhibited the proliferation of A549 and H1299 cells and significantly reduced TG and NEFA levels and intracellular lipid droplets. Western blotting revealed that curcumin significantly upregulated PGC-1α and PPAR‑α expressions in the cells. KEGG pathway enrichment analysis predicted significant involvement of the HIF-1 signaling pathway in curcumin-treated NSCLC, suggesting a potential interaction between HIF-1α and PPAR‑α. Western blotting confirmed that curcumin downregulated the expression of HIF-1α. In the tumor-bearing mice, curcumin treatment caused significant reduction of the tumor weight and the number of lipid droplets in the tumor cells.
CONCLUSIONS
Curcumin inhibits NSCLC cell proliferation and lipid metabolism by downregulating the HIF-1α pathway.
Curcumin/pharmacology*
;
Humans
;
Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*
;
Animals
;
Lipid Metabolism/drug effects*
;
Carcinoma, Non-Small-Cell Lung/pathology*
;
Lung Neoplasms/pathology*
;
Mice, Nude
;
Down-Regulation
;
Mice
;
Cell Proliferation/drug effects*
;
Cell Line, Tumor
;
Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
;
PPAR alpha/metabolism*
;
Signal Transduction/drug effects*
;
A549 Cells
4.Inhibitory effect of Fuzheng Huaji Decoction against non-small cell lung cancer cells in vitro and the possible molecular mechanism.
Lijun HE ; Xiaofei CHEN ; Chenxin YAN ; Lin SHI
Journal of Southern Medical University 2025;45(6):1143-1152
OBJECTIVES:
To investigate the inhibitory effect of Fuzheng Huaji Decoction against non-small cell lung cancer (NSCLC) cells in vitro and explore the underlying mechanism.
METHODS:
The active ingredients and targets of Fuzheng Huaji Decoction were identified using TCMSP and SwissTargetPrediction databases. NSCLC-related targets from GeneCards and PharmGKB were intersected with the targets of the Decoction, and a protein-protein interaction (PPI) network was constructed to identify the core targets, which were analyzed with GO and KEGG pathway enrichment analysis. Cultured A549 cells were treated with different concentrations of Fuzheng Huaji Decoction-medicated serum, and the changes in cell proliferation, apoptosis, and protein expressions were examined using CCK-8 assay, annexin V-FITC/PI staining and Western blotting.
RESULTS:
Fuzheng Huaji Decoction contained 140 active ingredients, and 707 drug-disease intersecting targets were identified. Among these targets, TP53, AKT1, HIF1A, GAPDH, ALB, EGFR, CTNNB1, and TNF were identified as the core targets which were involved in the biological processes related to kinases and receptors and the PI3K-AKT, Ras, calcium, and MAPK pathways. Molecular docking studies indicated strong binding affinity of the active ingredients with TP53, AKT1, and HIF1A. In cultured A549 cells, treatment with 2.5%, 5%, and 10% Fuzheng Huaji Decoction-medicated serum significantly inhibited cell proliferation, promoted cell apoptosis, and downregulated the expression levels of HIF1A, p-AKT (Thr308), and TP53 proteins.
CONCLUSIONS
Fuzheng Huaji Decoction inhibits proliferation of NSCLC cells possibly by downregulating the expressions of HIF1A, p-AKT (Thr308), and TP53.
Humans
;
Carcinoma, Non-Small-Cell Lung/metabolism*
;
Drugs, Chinese Herbal/pharmacology*
;
Cell Proliferation/drug effects*
;
Apoptosis/drug effects*
;
Lung Neoplasms/metabolism*
;
A549 Cells
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Protein Interaction Maps
;
Signal Transduction/drug effects*
;
Cell Line, Tumor
5.Pingchuanning Formula suppresses airway inflammation in a rat model of asthmatic cold syndrome by regulating the HMGB1/Beclin-1 axis-mediated autophagy.
Xinheng WANG ; Xiaohan SHAO ; Tongtong LI ; Lu ZHANG ; Qinjun YANG ; Weidong YE ; Jiabing TONG ; Zegeng LI ; Xiangming FANG
Journal of Southern Medical University 2025;45(6):1153-1162
OBJECTIVES:
To explore the mechanism of Pingchuanning Formula (PCN) for inhibiting airway inflammation in rats with asthmatic cold syndrome.
METHODS:
A total of 105 SD rats were randomized equally into 7 groups, including a control group, an asthmatic cold syndrome model group, 3 PCN treatment groups at high, medium and low doses, a Guilong Kechuanning (GLCKN) treatment group, and a dexamethasone (DEX) treatment group. In all but the control rats, asthma cold syndrome models were established and daily gavage of saline, PCN, GLCKN or DEX was administered 29 days after the start of modeling. The changes in general condition, lung function and lung histopathology of the rats were observed, and inflammatory factors in the alveolar lavage fluid (BALF), oxidative stress, lung tissue ultrastructure, cytokine levels, and expressions of the genes related to the HMGB1/Beclin-1 axis and autophagy were analyzed.
RESULTS:
The rat models had obvious manifestations of asthmatic cold syndrome with significantly decreased body mass, food intake, and water intake, reduced FEV0.3, FVC, and FEV0.3/FVC, obvious inflammatory cell infiltration in the lung tissue, and increased alveolar inflammation score and counts of neutrophils, eosinophils, lymphocytes, macrophages, and leukocytes in the BALF. The rat models also had significantly increased MDA level and decreased SOD level and exhibited obvious ultrastructural changes in the lung tissues, where the expressions of HMGB1, Beclin-1, ATG5, TNF-α, IL-6,IL-1β, and IL-13 and the LC3II/I ratio were increased, while the levels of Bcl-2 and IFN-γ were decreased. PCN treatment significantly improved these pathological changes in the rat models, and its therapeutic effect was better than that of GLKCN and similar to that of DEX.
CONCLUSIONS
PCN can effectively alleviate airway inflammation in rat models of asthmatic cold syndrome possibly by modulating the HMGB1/Beclin-1 signaling axis to suppress cell autophagy, thereby attenuating airway inflammatory damages.
Animals
;
Rats
;
Autophagy/drug effects*
;
Rats, Sprague-Dawley
;
Asthma/pathology*
;
Beclin-1
;
HMGB1 Protein/metabolism*
;
Drugs, Chinese Herbal/therapeutic use*
;
Disease Models, Animal
;
Male
;
Lung/pathology*
;
Inflammation
6.LncRNA SNHG15 promotes proliferation, migration and invasion of lung adenocarcinoma cells by regulating COX6B1 through sponge adsorption of miR-30b-3p.
Xiuying GONG ; Shunfu HOU ; Miaomiao ZHAO ; Xiaona WANG ; Zhihan ZHANG ; Qinghua LIU ; Chonggao YIN ; Hongli LI
Journal of Southern Medical University 2025;45(7):1498-1505
OBJECTIVES:
To explore the molecular mechanism by which lncRNA SNHG15 regulates proliferation, invasion and migration of lung adenocarcinoma cells.
METHODS:
The lncRNA microarray chip dataset GSE196584 and LncBase were used to predict the lncRNAs that interact with miR-30b-3p, and their association with patient prognosis were investigated using online databases, after which lncRNA nucleolar RNA host gene 15 (SNHG15) was selected for further analysis. The subcellular localization of lncRNA SNHG15 and its expression levels in normal human lung epithelial cells and lung adenocarcinoma cell lines were detected using fluorescence in situ hybridization and qRT-PCR. In cultured A549 cells, the changes in cell proliferation, migration, and invasion following transfection with a SNHG15 knockdown plasmid (sh-SNHG15), a miR-30b-3p inhibitor, or their co-transfection were assessed with EdU, wound healing, and Transwell assays. Bioinformatics analyses were used to predict the regulatory relationship between lncRNA SNHG15 and COX6B1, and the results were verified using Western blotting and rescue experiments in A549 cells transfected with sh-SNHG15, a COX6B1-overexpressing plasmid, or both.
RESULTS:
LncRNA SNHG15 was shown to target miR-30b-3p, and the former was highly expressed in lung adenocarcinoma, and associated with a poor patient prognosis. LncRNA SNHG15 was localized in the cytoplasm and expressed at higher levels in A549 and NCI-H1299 cells than in BEAS-2B cells. In A549 cells, lncRNA SNHG15 knockdown significantly inhibited cell migration, invasion and proliferation, and these changes were reversed by miR-30b-3p inhibitor. A regulatory relationship was found between lncRNA SNHG15 and COX6B1, and their expression levels were positively correlated (r=0.128, P=0.003). MiR-30b-3p knockdown obviously decreased COX6B1 expression in A549 cells, and COX6B1 overexpression rescued the cells from the inhibitory effects of lncRNA-SNHG15 knockdown.
CONCLUSIONS
LncRNA SNHG15 may compete with COX6B1 to bind miR-30b-3p through a ceRNA mechanism to affect proliferation, migration, and invasion of lung adenocarcinoma cells.
Humans
;
MicroRNAs/metabolism*
;
RNA, Long Noncoding/genetics*
;
Cell Proliferation
;
Cell Movement
;
Lung Neoplasms/genetics*
;
Adenocarcinoma of Lung
;
Neoplasm Invasiveness
;
A549 Cells
;
Adenocarcinoma/genetics*
;
Gene Expression Regulation, Neoplastic
;
Cell Line, Tumor
7.Mitochondrial-associated programmed-cell-death patterns for predicting the prognosis of non-small-cell lung cancer.
Xueyan SHI ; Sichong HAN ; Guizhen WANG ; Guangbiao ZHOU
Frontiers of Medicine 2025;19(1):101-120
Mitochondria are the convergence point of multiple pathways that trigger programmed cell death (PCD). Mitochondrial-associated PCD (mtPCD) is involved in the pathogenesis of several diseases. However, the role of mtPCD in the prognostic prediction of cancers including non-small-cell lung cancer (NSCLC) remains to be investigated. Here, 12 mtPCD patterns were analyzed in transcriptomics, genomics, and clinical data collected from 4 datasets containing 977 patients. A risk-score assessment system containing 18 genes was established. We found that NSCLC patients with a high-risk score had a poorer prognosis. A nomogram was constructed by incorporating the risk score with clinical features. The risk score was further associated with clinicopathological information, tumor-mutation frequency, and immunotherapy responses. NSCLC patients with a high risk score had more Treg cells infiltration. However, these patients had higher tumor-mutation burden scores and may be more sensitive to immunotherapy. Moreover, receptor-interacting serine/threonine protein kinase 2 (RIPK2) was selected from mtPCD gene model for validation. We found that RIPK2 exhibited oncogenic function, and its expression level was inversely associated with the overall survival of NSCLC. Taken together, our results indicated the accuracy and practicability of the mtPCD gene model and RIPK2 in predicting the prognosis of NSCLC.
Humans
;
Carcinoma, Non-Small-Cell Lung/pathology*
;
Lung Neoplasms/pathology*
;
Prognosis
;
Male
;
Female
;
Nomograms
;
Middle Aged
;
Mitochondria/metabolism*
;
Apoptosis/genetics*
;
Mutation
;
Biomarkers, Tumor/genetics*
;
Aged
8.CHAF1B promotes the progression of lung squamous-cell carcinoma by inhibiting SETD7 expression.
Zhuo ZHENG ; Yongfang LIN ; Hua GUO ; Zheng LIU ; Xiaoliang JIE ; Guizhen WANG ; Guangbiao ZHOU
Frontiers of Medicine 2025;19(2):318-328
The p60 subunit of the chromatin assembly factor-1 complex, that is, chromatin assembly factor-1 subunit B (CHAF1B), is a histone H3/H4 chaperone crucial for the transcriptional regulation of cell differentiation and self-renewal. CHAF1B is overexpressed in several cancers and may represent a potential target for cancer therapy. However, its expression and clinical significance in lung squamous-cell carcinoma (LUSC) remain unclear. In this study, we performed weighted gene correlation network analysis to analyze the Gene Expression Omnibus GSE68793 LUSC dataset and identified CHAF1B as one of the most important driver gene candidates. Immunohistochemical analysis of 126 LUSC tumor samples and 80 adjacent normal lung tissues showed the marked upregulation of CHAF1B in tumor tissues and the negative association of its expression level with patient survival outcomes. Silencing of CHAF1B suppressed LUSC proliferation in vitro and LUSC tumor growth in vivo. Furthermore, bulk RNA sequencing of CHAF1B knockdown cells indicated SET domain containing 7 (SETD7) as a significant CHAF1B target gene. In addition, CHAF1B competitively binds to the SETD7 promoter region and represses its transcription. Altogether, these results imply that CHAF1B plays a vital role in LUSC tumorigenesis and may represent a potential molecular target for this deadly disease.
Humans
;
Lung Neoplasms/metabolism*
;
Histone-Lysine N-Methyltransferase/metabolism*
;
Carcinoma, Squamous Cell/metabolism*
;
Gene Expression Regulation, Neoplastic
;
Disease Progression
;
Cell Proliferation/genetics*
;
Cell Line, Tumor
;
Chromatin Assembly Factor-1/metabolism*
;
Animals
;
Mice
;
Male
;
Female
9.G protein-coupled estrogen receptor alleviates lung injury in mice with exertional heat stroke by inhibiting ferroptosis.
Ziwei HAN ; Jiansong GUO ; Xiaochen WANG ; Zhi DAI ; Chao LIU ; Feihu ZHOU
Chinese Critical Care Medicine 2025;37(3):268-274
OBJECTIVE:
To investigate whether the G protein-coupled estrogen receptor (GPER) can attenuates acute lung injury in mice with exertional heat stroke (EHS) by inhibiting ferroptosis.
METHODS:
Sixty SPF-grade male C57BL/6 mice were randomly divided into four groups: normal control group (control group), EHS model group (EHS group), dimethyl sulfoxide (DMSO) solvent group (EHS+DMSO group), and GPER-specific agonist G1 group (EHS+G1 group), with 15 mice in each group. All mice underwent 14 days of adaptive training at 24-26 centigrade before modeling, and the EHS model was established using a high-temperature treadmill device. After successful modeling, the mice were allowed to cool naturally at room temperature. In the EHS+G1 group, 40 μg/kg of the GPER-specific agonist G1 was slowly injected intraperitoneally immediately after modeling. In the EHS+DMSO group, 40 μg/kg of DMSO was slowly injected intraperitoneally immediately after modeling. The control group received no treatment. Five hours after modeling, abdominal aortic blood was collected, and lung tissues were harvested after euthanasia. The lung coefficient was calculated to evaluate lung injury. Lung histopathological changes were observed under a light microscope after hematoxylin-eosin (HE) staining, and a lung histopathological score was assigned. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), malondialdehyde (MDA), and Fe2+ in lung tissue. Immunofluorescence was used to detect the expression of glutathione peroxidase 4 (GPX4). Real-time polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of GPX4, ferroportin 1 (FPN1), and ferritin heavy chain 1 (FTH1). Western blotting was performed to detect the protein expression of GPX4, FPN1, and FTH1.
RESULTS:
Compared with the control group, the lung coefficient and lung histopathological score were significantly increased in the EHS group. HE staining showed significant thickening and unevenness of the alveolar septa and alveolar walls, partial alveolar collapse, and extensive erythrocyte, inflammatory cell, and plasma-like material extravasation in the alveolar spaces. Serum levels of TNF-α, IL-1β, MDA, and Fe2+ were significantly elevated. Immunofluorescence staining showed a significant decrease in GPX4-positive expression in lung tissue. Western blotting and RT-PCR showed significantly reduced protein and mRNA expression of GPX4, FPN1, and FTH1 in lung tissue. Compared with the EHS group, the EHS+G1 group showed a significant reduction in lung coefficient and lung histopathological score [lung coefficient (mg/g): 3.9±0.1 vs. 4.6±0.3, lung histopathological score: 4.2±0.2 vs. 6.9±0.2, both P < 0.05]. HE staining revealed reduced severity of lung tissue fluid extravasation, inflammatory infiltration, decreased hemorrhage, and less severe alveolar structural damage. Serum levels of TNF-α, IL-1β, MDA, and Fe2+ were significantly reduced [TNF-α (ng/L): 44.3±0.2 vs. 64.6±0.3, IL-1β (ng/L): 69.3±0.4 vs. 97.8±0.2, MDA (nmol/L): 2.8±0.3 vs. 3.6±0.5, Fe2+ (nmol/L): 0.021±0.004 vs. 0.028±0.004, all P < 0.05]. Immunofluorescence staining showed a significant decrease in GPX4-positive expression in lung tissue (fluorescence intensity: 35.53±2.41 vs. 16.45±0.31, P < 0.05). RT-PCR and Western blotting showed significantly increased mRNA and protein expression of GPX4, FPN1, and FTH1 in lung tissue [mRNA expression: GPX4 mRNA (2-ΔΔCt): 0.44±0.05 vs. 0.09±0.01, FPN1 mRNA (2-ΔΔCt): 0.77±0.17 vs. 0.42±0.14, FTH1 mRNA (2-ΔΔCt): 0.75±0.04 vs. 0.58±0.01; protein expression: GPX4/β-actin: 0.96±0.11 vs. 0.24±0.04, FPN1/β-actin: 1.26±0.21 vs. 0.44±0.14, FTH1/β-actin: 0.27±0.12 vs. 0.15±0.07; all P < 0.05]. However, there were no statistically significant differences in any of the above indicators between the EHS+DMSO group and the EHS group.
CONCLUSION
Activation of GPER can attenuate EHS-related lung injury in mice, and its mechanism may be related to the activation of the GPX4 signaling pathway and inhibition of ferroptosis.
Animals
;
Mice, Inbred C57BL
;
Male
;
Mice
;
Heat Stroke/metabolism*
;
Receptors, G-Protein-Coupled
;
Ferroptosis
;
Receptors, Estrogen
;
Acute Lung Injury/metabolism*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Interleukin-1beta/metabolism*
;
Lung Injury
;
Lung/metabolism*
10.Distribution characteristics of polymorphonuclear neutrophil pulmonary infiltration and the mechanism of neutrophil elastase in promoting lung injury in the early stages of severe burns.
Xin ZHANG ; Chunfang ZHENG ; Jiahui CHEN ; Zaiwen GUO ; Linbin LI ; Jiamin HUANG ; Bingwei SUN
Chinese Critical Care Medicine 2025;37(5):431-437
OBJECTIVE:
To investigate the distribution characteristics of polymorphonuclear neutrophil (PMN) in the lungs during the early stage of severe burns and the mechanism of neutrophil elastase (NE) promoting lung injury.
METHODS:
6-8-week-old male C57BL/6J mice were selected for the experiments. A 30% total body surface area (TBSA) III degree burn mouse model was established (severe burn group); the Sham-injury group was treated with 37 centigrade water. In the sodium sivelestat intervention group (SV intervention group), NE competitive inhibitor, sivelestat, 100 mg/kg, was injected via tail vein immediately after injury, while other groups received an equal volume of saline. Ten mice were harvested from each group to observe survival for 72 hours. Respiratory function tests were tested at 0 (immediate), 3, 6, 12, and 24 hours after molding. hematoxylin-eosin (HE) and immunohistochemical staining were used to observe lung tissue structure, inflammatory changes and PMN infiltration. The PMN absolute count in mice lung tissue was detected buy flow cytometry. At 6, 12, and 24 hours after molding, PMN counts and the concentration of NE [enzyme linked immunosorbent assay (ELISA)] in peripheral blood plasma, lung tissue, and bronchoalveolar lavage fluid (BALF) were detected.
RESULTS:
(1) HE staining results showed that compared with the Sham-injury group, the lungs of mice in the severe burn group showed inflammatory changes and PMN infiltration, with more significant changes at 6 hours. Immunohistochemistry results also confirmed that the expression of NE protein released from PMN significantly increased after 6 hours of severe burn injury [(3.79±0.62)% vs. (0.18±0.05)%, t = 11.56, P < 0.01]. (2) Compared with the Sham-injury group, the number of PMN and the concentration of NE in the peripheral blood and lung tissues in the severe burn group were significantly increased (F values were 13.709, 55.350 and 29.890, 13.286, respectively, all P < 0.01), peaking at 6 hours [plasma PMN count (×109/L): 2.92±1.01 vs. 0.92±0.29, lung tissue PMN absolute count (cells): 48 788.03±11 833.91 vs. 1 516.72±415.35, plasma NE (ng/L): 24 522.71±3 842.92 vs. 7 009.34±4 067.86, lung tissue NE (ng/L): 262 189.04±9 695.13 vs. 65 026.03± 16 016.31, all P < 0.01]. The number of PMN in the lung of severely burned mice was highly correlated with NE concentration (r = 0.892, P < 0.001). There was no significantly difference in the PMN absolute count in the BALF of mice between the Sham-injury group and severe burn group (F = 1.403, P > 0.05). The Sham-injury group and severe burn group contained a small amount of NE in the BALF, and the concentration of NE in the BALF of the severely burned 6 hours and 12 hours groups were significantly higher than those of the Sham-injury group (ng/L: 328.58±158.10, 415.30±240.89 vs. 61.95±15.80, both P < 0.05). (3) Kaplan-Meier survival curve showed that the 72-hour survival rate of mice in the SV intervention group was significantly higher than that in the severe burn group (100% vs. 10%, Log-Rank test: χ2 = 19.12, P < 0.001). (4) Compared with the Sham-injury group, all lung function indices of the severe burn group decreased significantly. All lung function indices of SV intervention group improved gradually over time, which were significantly better than those of the severe burn group. (5) Compared with the Sham-injury group, the PMN absolute count in lung tissue and the concentration of NE in plasma and lung tissue were significantly higher in the SV intervention group (F values were 46.709, 3.535, 32.701, respectively, all P < 0.05), with a peak at 6 hours. Compared with the severe burn group, the SV intervention group had a higher PMN absolute count in lung tissue (cells: 8 870.80±7 013.89 vs. 25 974.92±22 240.8, P < 0.05), and higher plasma and lung tissue NE concentrations (ng/L: 14 955.94±3 944.41 vs. 21 972.75±4 573.05, 81 956.87±38 658.35 vs. 168 182.30±83 513.91, both P < 0.01) were significantly decreased.
CONCLUSIONS
In the early stage of severe burns, there is a significant infiltration of PMN into the lungs. The NE promotes lung injury in the early stage of severe burn, and improve lung injury by inhibiting the action of NE.
Animals
;
Burns/metabolism*
;
Leukocyte Elastase/metabolism*
;
Male
;
Mice, Inbred C57BL
;
Mice
;
Neutrophils/metabolism*
;
Lung/metabolism*
;
Disease Models, Animal
;
Neutrophil Infiltration
;
Lung Injury/metabolism*
;
Glycine/analogs & derivatives*
;
Sulfonamides

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