OBJECTIVE: To construct Risk factor assessment table for hyperoxemia in patients after cardiopulmonary bypass heart surgery based on Delphi method, providing a basis for early prediction and assessment of the risk of hyperoxemia in patients after cardiac surgery.
METHODS: A research team was established. Based on the characteristics of extracorporeal circulation cardiac surgery, the Chinese and English literature published by each database until October 2022 was retrieved and the opinions of relevant professional clinicians were combined to screen the risk factors of hyperoxemia in patients after cardiopulmonary bypass heart surgery, and the preliminary draft of the Risk factor assessment table for hyperoxemia in patients after cardiopulmonary bypass heart surgery was drawn up. The Delphi method was used to conduct two rounds of expert letter consultation to supplement and improve the initial draft and finally established the final draft of the Risk factor assessment table for hyperoxemia in patients after cardiopulmonary bypass heart surgery.
RESULTS: The preliminary draft of the Risk factor assessment table for hyperoxemia in patients after cardiopulmonary bypass heart surgery was constructed according to the literature review and the opinions of relevant professional clinicians, which contained 4 dimensions and 21 items. A total of 14 experts were consulted by letter, including 5 senior titles and 9 associate senior titles. Six of them major in critical care and the other eight major in cardiovascular surgery. The effective response rates for the two rounds of questionnaire surveys were 100% and 85.71%, expert familiarity levels were 0.81 and 0.80, judgment coefficients were 0.94 and 0.92, respectively. Expert authority coefficients were both 0.86. Coefficients of variation for the importance and feasibility items in the two rounds ranged from 0.13 to 0.32 and 0.11 to 0.32, 0.06 to 0.26 and 0.06 to 0.35, respectively. The Kendall\'s W for importance and feasibility in the two rounds were 0.264 and 0.162, and 0.258 and 0.144 respectively, indicating statistically significant (all P < 0.05). After two rounds of expert consultations, a comprehensive evaluation and selection process resulted in the final establishment of the Risk factor assessment table for hyperoxemia in patients after cardiopulmonary bypass heart surgery, consisting of 4 dimensions and 23 items, which included general data, past history, operation-related data and postoperative data.
CONCLUSIONS: The Risk factor assessment table for hyperoxemia in patients after cardiopulmonary bypass heart surgery based on the Delphi method is highly scientific and feasible, which can provide reference for clinical assessments of the risk of hyperoxemia in such patients.

Bronchopulmonary dysplasia (BPD) is the most common sequela of prematurity and is characterized by alveolar simplification and lung angiogenesis failure. The aim of this study was to explore the immune signatures of BPD. Differentially expressed gene analysis and immune infiltration analysis were conducted to identify key immune cell types and related genes by using the mRNA-seq dataset GSE25286. The expression patterns of key genes were validated in the scRNA-seq dataset GSE209664 and in experiments. The cell-cell crosstalk of key immune cells was explored with CellChat. We found that differentially expressed genes between BPD mice and controls were mostly enriched in leukocyte migration and M1 macrophages were highly enriched in BPD lungs. Hub genes (Cybb, Papss2, F7 and Fpr2) were validated at the single-cell level, among which the downregulation of Cybb was most closely related to macrophage infiltration. The reduced mRNA and protein levels of Cybb were further validated in animal experiments. Colocalization analysis of Cybb and macrophage markers demonstrated a significant decrease of Cybb in M1 macrophages. Cell-cell crosstalk found that alveolar epithelial cells interacted actively with macrophages through MIF-(CD74 + CD44) signalling. In conclusion, M1 macrophages played important roles in promoting BPD-like lung injury, which was correlated with a specific reduction of Cybb in macrophages and the potential activation of MIF signalling.

Mesenchymal stem cells (MSC)-derived exosomes (Exo) are a possible option for hyperoxia-induced lung injury (HLI). We wanted to see if melatonin (MT)-pretreated MSC-derived exosomes (MT-Exo) were more effective against HLI, and we also tried to figure out the underlying mechanism. HLI models were established by hyperoxia exposure. HE staining was adopted to analyze lung pathological changes. MTT and flow cytometry were used to determine cell viability and apoptosis, respectively. The mitochondrial membrane potential (MMP) was analyzed using the JC-1 probe. LDH, ROS, SOD, and GSH-Px levels were examined by the corresponding kits. The interactions between miR-18a-5p, PUM2, and DUB3 were analyzed by molecular interaction experiments. MT-Exo could effectively inhibit hyperoxia-induced oxidative stress, inflammatory injury, and apoptosis in lung epithelial cells, while these effects of MT-Exo were weakened by miR-18a-5p knockdown in MSCs. miR-18a-5p reduced PUM2 expression in MLE-12 cells by directly targeting PUM2. In addition, PUM2 inactivated the Nrf2/HO-1 signaling pathway by promoting DUB3 mRNA decay post-transcriptionally. As expected, PUM2 overexpression or DUB3 knockdown abolished the protective effect of MT-Exo on hyperoxia-induced lung epithelial cell injury. MT-Exo carrying miR-18a-5p reduced hyperoxia-mediated lung injury in mice through activating Nrf2/HO-1 pathway. MT reduced PUM2 expression and subsequently activated the DUB3/Nrf2/HO-1 signal axis by increasing miR-18a-5p expression in MSC-derived exosomes to alleviate HLI.

OBJECTIVE: To investigate the effect of reactive oxygen species (ROS)/silent information regulator 1 (SIRT1) on hyperoxia-induced mitochondrial injury in BEAS-2B cells.
METHODS: The experiment was divided into three parts. In the first part, cells were divided into H0, H6, H12, H24, and H48 groups. In the second part, cells were divided into control group, H48 group, H48 hyperoxia+SIRT1 inhibitor group (H48+EX 527 group), and H48 hyperoxia+SIRT1 agonist group (H48+SRT1720 group). In the third part, cells were divided into control group, 48-hour hyperoxia+N-acetylcysteine group (H48+NAC group), and H48 group. The ROS kit was used to measure the level of ROS. Western blot and immunofluorescent staining were used to measure the expression levels of SIRT1 and mitochondria-related proteins. Transmission electron microscopy was used to observe the morphology of mitochondria.
RESULTS: Compared with the H0 group, the H6, H12, H24, and H48 groups had a significantly increased fluorescence intensity of ROS (P<0.05), the H48 group had significant reductions in the expression levels of SIRT1 protein and mitochondria-related proteins (P<0.05), and the H24 and H48 groups had a significant reduction in the fluorescence intensity of mitochondria-related proteins (P<0.05). Compared with the H48 group, the H48+SRT1720 group had significant increases in the expression levels of mitochondria-related proteins and the mitochondrial aspect ratio (P<0.05), and the H48+EX 527 group had a significant reduction in the mitochondrial area (P<0.05). Compared with the H48 group, the H48+NAC group had a significantly decreased fluorescence intensity of ROS (P<0.05) and significantly increased levels of SIRT1 protein, mitochondria-related proteins, mitochondrial area, and mitochondrial aspect ratio (P<0.05).
CONCLUSIONS: The ROS/SIRT1 axis is involved in hyperoxia-induced mitochondrial injury in BEAS-2B cells.
目的: 探讨活性氧簇（reactive oxygen species, ROS）/沉默信息调节因子1（silent information regulator 1, SIRT1）对高氧致BEAS-2B细胞线粒体损伤的影响。方法: 实验分为三部分：（1）细胞分为高氧0 h（H0）组、H6组、H12组、H24组、H48组。（2）细胞分为对照组、H48组、高氧48 h+SIRT1抑制剂（H48+EX 527）组和高氧48 h+SIRT1激动剂（H48+SRT1720）组。（3）细胞分为对照组、高氧48 h+乙酰半胱氨酸（H48+NAC）组和H48组。采用活性氧试剂盒检测ROS水平，Western blot法检测SIRT1和线粒体相关蛋白表达水平，免疫荧光染色法检测线粒体相关蛋白表达，透射电镜检测线粒体形态。结果: （1）与H0组相比，H6组、H12组、H24组和H48组ROS荧光强度增加（P<0.05），H48组SIRT1和线粒体相关蛋白表达水平降低（P<0.05），H24组和H48组线粒体相关蛋白荧光强度降低（P<0.05）。（2）与H48组相比，H48+SRT1720组线粒体相关蛋白表达水平升高，线粒体平均长宽比增加（P<0.05）；H48+EX 527组线粒体平均面积减少（P<0.05）。（3）与H48组相比，H48+NAC组ROS荧光强度降低，SIRT1和线粒体相关蛋白表达水平升高，线粒体平均面积和平均长宽比增加（P<0.05）。结论: ROS/SIRT1轴参与了高氧诱导的BEAS-2B细胞线粒体损伤。.

UNASSIGNED: Bronchopulmonary dysplasia (BPD) is one of the most important complications plaguing neonates and can lead to a variety of sequelae. the ability of the HIF-1α/VEGF signaling pathway to promote angiogenesis has an important role in neonatal lung development.
UNASSIGNED: Newborn rats were exposed to 85% oxygen. The effects of hyperoxia exposure on Pleomorphic Adenoma Gene like-2 (PLAGL2) and the HIF-1α/VEGF pathway in rats lung tissue were assessed through immunofluorescence and Western Blot analysis. In cell experiments, PLAGL2 was upregulated, and the effects of hyperoxia and PLAGL2 on cell viability were evaluated using scratch assays, CCK-8 assays, and EDU staining. The role of upregulated PLAGL2 in the HIF-1α/VEGF pathway was determined by Western Blot and RT-PCR. Apoptosis and ferroptosis effects were determined through flow cytometry and viability assays.
UNASSIGNED: Compared with the control group, the expression levels of PLAGL2, HIF-1α, VEGF, and SPC in lung tissues after 3, 7, and 14 days of hyperoxia exposure were all decreased. Furthermore, hyperoxia also inhibited the proliferation and motility of type II alveolar epithelial cells (AECII) and induced apoptosis in AECII. Upregulation of PLAGL2 restored the proliferation and motility of AECII and suppressed cell apoptosis and ferroptosis, while the HIF-1α/VEGF signaling pathway was also revived.
UNASSIGNED: We confirmed the positive role of PLAGL2 and HIF-1α/VEGF signaling pathway in promoting BPD in hyperoxia conditions, and provided a promising therapeutic targets.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a chronic lung disorder predominantly affecting preterm infants. Oxygen therapy, a common treatment for BPD, often leads to hyperoxia-induced pulmonary damage, particularly targeting alveolar epithelial cells (AECs). Crucially, disrupted lung epithelium-fibroblast interactions significantly contribute to BPD\'s pathogenesis. Previous studies on interleukin-11 (IL-11) in lung diseases have yielded conflicting results. Recent research, however, highlights IL-11 as a key regulator of fibrosis, stromal inflammation, and epithelial dysfunction. Despite this, the specific role of IL-11 in BPD remains underexplored. Our transcriptome analysis of normal and hyperoxia-exposed murine lung tissues revealed an increased expression of IL-11 RNA. This study aimed to investigate IL-11\'s role in modulating the disrupted interactions between AECs and fibroblasts in BPD.
METHODS: BPD was modeled in vivo by exposing C57BL/6J neonatal mice to hyperoxia. Histopathological changes in lung tissue were evaluated with hematoxylin-eosin staining, while lung fibrosis was assessed using Masson staining and immunohistochemistry (IHC). To investigate IL-11\'s role in pulmonary injury contributing to BPD, IL-11 levels were reduced through intraperitoneal administration of IL-11RαFc in hyperoxia-exposed mice. Additionally, MLE-12 cells subjected to 95% oxygen were collected and co-cultured with mouse pulmonary fibroblasts (MPFs) to measure α-SMA and Collagen I expression levels. IL-11 levels in the supernatants were quantified using an enzyme-linked immunosorbent assay (ELISA).
RESULTS: Both IHC and Masson staining revealed that inhibiting IL-11 expression alleviated pulmonary fibrosis in neonatal mice induced by hyperoxia, along with reducing the expression of fibrosis markers α-SMA and collagen I in lung tissue. In vitro analysis showed a significant increase in IL-11 levels in the supernatant of MLE-12 cells treated with hyperoxia. Silencing IL-11 expression in MLE-12 cells reduced α-SMA and collagen I concentrations in MPFs co-cultured with the supernatant of hyperoxia-treated MLE-12 cells. Additionally, ERK inhibitors decreased α-SMA and collagen I levels in MPFs co-cultured with the supernatant of hyperoxia-treated MLE-12 cells. Clinical studies found increased IL-11 levels in tracheal aspirates (TA) of infants with BPD.
CONCLUSIONS: This research reveals that hyperoxia induces IL-11 secretion in lung epithelium. Additionally, IL-11 derived from lung epithelium emerged as a crucial mediator in myofibroblast differentiation via the ERK signaling pathway, highlighting its potential therapeutic value in BPD treatment.

Bronchopulmonary dysplasia (BPD) is a common serious complication of premature babies. No effective means control it. Hyperoxia damage is one of the important mechanisms of BPD. The reaserach confirmed pyroptosis existed in BPD. Dexmedetomidine is a new, high-specific α2 receptor agonist. Previous research foundation found that dexmedetomidine has a protective effect on BPD. To investigate how dexmedetomidine improves hyperoxic lung injury in neonatal mice by regulating pyroptosis. Neonatal rats were randomly divided into four groups: normal control group, hyperoxic injury group, air plus dexmedetomidine group, and hyperoxia plus dexmedetomidine group. After seven days the lungs of rats in each group were extracted, and the wet-to-dry weight ratio of the lung was measured. The lung injury in rats was observed using hematoxylin-eosin staining. Additionally, the expression and localization of nucleotide-binding oligomerization domain-like receptor thermal protein domain associated protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), and gasdermin D (GSDMD) proteins were examined in the lungs of rats using immunofluorescence staining. The mRNA levels of NLRP3, ASC, caspase-1, and interleukin 18 (IL-18) in the lungs of rats were determined using real-time PCR. Moreover, the protein levels of NLRP3, ASC, caspase-1/cleaved caspase-1, interleukin 1beta (IL-1β), IL-18, and tunor necrosis factor alpha (TNF-α) were detected in lungs of rats using Western blot. The extent of mitochondrial damage in lung tissues of each group was observed by transmission electron microscopy. The lung tissue injury of the neonatal rats was significantly improved in the hyperoxia plus dexmedetomidine group compared to the hyperoxic injury group. Furthermore, the expressions of pyroptosis-related proteins such as NLRP3, ASC, cleaved-caspase-1, and GSDMD were significantly decreased, along with the expressions of inflammatory factors in lung tissues. By inhibiting the NLRP3/caspase-1/GSDMD pyroptosis pathway, dexmedetomidine reduces the activation and release of inflammatory factors and provides a protective effect against hyperoxic lung injury in neonatal mice.

暂无摘要。

OBJECTIVE: To investigate the role and mechanism of epithelial-mesenchymal transition (EMT) in a rat model of bronchopulmonary dysplasia (BPD).
METHODS: The experiment consisted of two parts. (1) Forty-eight preterm rats were randomly divided into a normoxia group and a hyperoxia group, with 24 rats in each group. The hyperoxia group was exposed to 85% oxygen to establish a BPD model, while the normoxia group was kept in room air at normal pressure. Lung tissue samples were collected on days 1, 4, 7, and 14 of the experiment. (2) Rat type II alveolar epithelial cells (RLE-6TN) were randomly divided into a normoxia group (cultured in air) and a hyperoxia group (cultured in 95% oxygen), and cell samples were collected 12, 24, and 48 hours after hyperoxia exposure. Hematoxylin-eosin staining was used to observe alveolarization in preterm rat lungs, and immunofluorescence was used to detect the co-localization of surfactant protein C (SPC) and α-smooth muscle actin (α-SMA) in preterm rat lung tissue and RLE-6TN cells. Quantitative real-time polymerase chain reaction and protein immunoblotting were used to detect the expression levels of EMT-related mRNA and proteins in preterm rat lung tissue and RLE-6TN cells.
RESULTS: (1) Compared with the normoxia group, the hyperoxia group showed blocked alveolarization and simplified alveolar structure after 7 days of hyperoxia exposure. Co-localization of SPC and α-SMA was observed in lung tissue, with decreased SPC expression and increased α-SMA expression in the hyperoxia group at 7 and 14 days of hyperoxia exposure compared to the normoxia group. In the hyperoxia group, the mRNA and protein levels of TGF-β1, α-SMA, and N-cadherin were increased, while the mRNA and protein levels of SPC and E-cadherin were decreased at 7 and 14 days of hyperoxia exposure compared to the normoxia group (P<0.05). (2) SPC and α-SMA was observed in RLE-6TN cells, with decreased SPC expression and increased α-SMA expression in the hyperoxia group at 24 and 48 hours of hyperoxia exposure compared to the normoxia group. Compared to the normoxia group, the mRNA and protein levels of SPC and E-cadherin in the hyperoxia group were decreased, while the mRNA and protein levels of TGF-β1, α-SMA, and E-cadherin in the hyperoxia group increased at 48 hours of hyperoxia exposure (P<0.05).
CONCLUSIONS: EMT disrupts the tight connections between alveolar epithelial cells in a preterm rat model of BPD, leading to simplified alveolar structure and abnormal development, and is involved in the development of BPD. Citation:Chinese Journal of Contemporary Pediatrics, 2024, 26(7): 765-773.
目的: 探讨上皮-间充质转化（epithelial-mesenchymal transition, EMT）在大鼠支气管肺发育不良（bronchopulmonary dysplasia, BPD）模型中的作用及机制。方法: 实验分为两部分。（1）将48只早产大鼠随机分为常氧组和高氧组，每组24只。高氧组暴露于85％氧气中建立早产大鼠BPD模型，常氧组置于同一室内常压空气中，于实验第1、4、7、14天收集早产大鼠肺组织标本。（2）将大鼠肺泡Ⅱ型上皮细胞系（RLE-6TN）随机分为常氧组（常规空气中培养）和高氧组（在95%氧气中培养），分别于高氧暴露后12 h、24 h、48 h收集细胞标本进行检测。使用苏木精-伊红染色法观察早产大鼠肺泡化情况，免疫荧光检测早产大鼠肺组织和RLE-6TN细胞肺表面活性蛋白C（surfactant protein C, SPC）和α-平滑肌肌动蛋白（α-smooth muscle actin, α-SMA）的共定位。实时荧光定量聚合酶链反应和蛋白免疫印迹法检测早产大鼠肺组织和RLE-6TN细胞EMT相关mRNA和蛋白表达水平。结果: （1）与常氧组相比，高氧暴露7 d开始高氧组早产鼠可见肺泡化阻滞和肺泡结构简单化改变；肺组织中SPC和α-SMA存在明显共定位现象，高氧暴露7 d、14 d时，与常氧组比较，高氧组SPC表达减少，α-SMA表达增加；高氧暴露7 d、14 d时，与常氧组比较，高氧组TGF-β1、α-SMA、N-钙黏蛋白mRNA和蛋白表达水平升高（P<0.05），SPC、E-钙黏蛋白mRNA和蛋白表达水平降低（P<0.05）。（2）高氧暴露24 h、48 h时，与常氧组比较，高氧组SPC表达减少，α-SMA表达增加；高氧暴露48 h时，与常氧组比较，高氧组SPC、E-钙黏蛋白mRNA和蛋白表达降低（P<0.05），TGF-β1、α-SMA、N-钙黏蛋白mRNA和蛋白表达升高（P<0.05）。结论: EMT破坏了BPD早产大鼠肺泡上皮细胞之间的紧密连接，造成肺泡结构简单化和发育异常，参与了BPD的发生发展。.

Bronchopulmonary dysplasia (BPD) is a serious disease that occurs in premature and low-birth-weight infants. In recent years, the incidence of BPD has not decreased, and there is no effective treatment for it. Oridonin (Ori) is a traditional Chinese medicine with a wide range of biological activities, especially pharmacological and anti-inflammatory. It is well known that inflammation plays a key role in BPD. However, the therapeutic effect of Ori on BPD has not been studied. Therefore, in the present study, we will observe the anti-inflammatory activity of Ori in an experimental animal model of BPD. Here, we showed that Ori could significantly decrease hyperoxia-induced alveolar injury, inhibit neutrophil recruitment, myeloperoxidase concentrations, and release inflammatory factors in BPD neonatal rats. Taken together, the experimental results suggested that Ori can significantly improve BPD in neonatal rats by inhibiting inflammatory response.