Integration of transcriptomics reveals ferroptosis-related signatures and immune cell infiltration in bronchopulmonary dysplasia

The tryptophan metabolite 3-hydroxyanthranilic acid alleviates hyperoxia-induced bronchopulmonary dysplasia via inhibiting ferroptosis

Bronchopulmonary dysplasia (BPD) is a prevalent chronic respiratory condition in preterm infants with an increasing incidence, severely affecting their survival rate and quality of life. Exploring the underlying mechanisms of BPD helps to develop novel effective therapeutic strategies. In this study, integrated metabolomic analyses of tracheal aspirates (TAs) from BPD infants and non-BPD infants, along with lung tissues from hyperoxia-induced experimental BPD neonatal rats and control rats, demonstrated that BPD was associated with a significant reduction in 3-hydroxyanthranilic acid (3-HAA), which was confirmed to be partly caused by tryptophan-metabolizing enzyme disorders. In vivo and in vitro models were subsequently established to assess the efficacy and underlying mechanisms of 3-HAA in relation to BPD. Compared with the BPD group, 3-HAA nebulization improved lung development and suppressed inflammation in rats. Limited proteolysis-small molecule mapping (LiP-SMap) proteomic analysis revealed the involvement of the ferroptosis pathway in the underlying mechanism by which 3-HAA alleviated hyperoxia-induced BPD injury. Ferroptosis was identified by detecting Fe2+ levels, malondialdehyde (MDA), 4-HNE, total aldehydes, mitochondrial morphology, ferroptosis-associated protein and mRNA expression, and this dysregulation was indeed ameliorated by 3-HAA nebulization in vivo. Furthermore, a combination of LiP-SMap, molecular docking, SPR and Co-IP analyses confirmed that 3-HAA can bind directly to FTH1 and disrupt the nuclear receptor coactivator 4 (NCOA4)-FTH1 interaction. In conclusion, our study is the first to reveal that BPD is linked to the reduction of 3-HAA, and 3-HAA could inhibit the ferroptosis pathway by targeting FTH1, thereby alleviating hyperoxia-induced injury in rats and alveolar type II epithelial cells, highlighting the potential of targeting 3-HAA and ferroptosis for clinical applications in BPD.

Upregulation of ferroptosis in glucocorticoids-induced posterior subcapsular cataracts

The Glucocorticoid-induced posterior subcapsular cataracts (GIC) is a common complication of patients received glucocorticoid treatment in clinic. We find that dexamethasone (DEX) induces lens epithelial cells' ferroptosis. DEX treatment increases intracellular ferroptosis signatures in lens epithelial cell line in vitro as well as in rat lens in vivo. The inhibition of ferroptosis by liproxstatin-1 reduces the incidence of DEX-induced rat GIC. Experimental evidence and expression profiling showed that DEX induces ferroptosis through upregulating tetraspanin CD82- controlled P53 expression. DEX-activated glucocorticoid receptors directly bind to the CD82 promoter, driving its transcriptional upregulation. CD82 expression is upregulated in the anterior capsular epithelium of GIC patients as well as in the DEX-treated rat lens and caused the cell death of anterior capsule. DEX treatment and Overexpression of CD82 in cells recapitulated ferroptotic signatures through P53 activation and GPX4/SLC7A11 suppression. Taken together, GIC is closely associated with the upregulation of CD82-P53-GPX4/SLC7A11 axis-mediated ferroptosis.

[Prognosis of bronchopulmonary dysplasia]

Children with bronchopulmonary dysplasia (BPD) often exhibit severe respiratory problems and significant pulmonary dysfunction during school age and adulthood. Exercise tests show a decline in cardiopulmonary function and physical performance in children with BPD, who also have a higher incidence of pulmonary hypertension. These children generally perform poorly in terms of intelligence, language, and motor development. As they age, the risk of neurodevelopmental disorders increases, and health-related quality of life is also affected. This article reviews the prognosis of the respiratory system, physical capacity, cardiovascular system, nervous system, and health-related quality of life in children with BPD, aiming to improve the management of these patients and enhance their subsequent quality of life.

Predictive analytics in bronchopulmonary dysplasia: past, present, and future

Bronchopulmonary dysplasia (BPD) remains a significant complication of prematurity, impacting approximately 18,000 infants annually in the United States. Advances in neonatal care have not reduced BPD, and its management is challenged by the rising survival of extremely premature infants and the variability in clinical practices. Leveraging statistical and machine learning techniques, predictive analytics can enhance BPD management by utilizing large clinical datasets to predict individual patient outcomes. This review explores the foundations and applications of predictive analytics in the context of BPD, examining commonly used data sources, modeling techniques, and metrics for model evaluation. We also highlight bioinformatics' potential role in understanding BPD's molecular basis and discuss case studies demonstrating the use of machine learning models for risk prediction and prognosis in neonates. Challenges such as data bias, model complexity, and ethical considerations are outlined, along with strategies to address these issues. Future directions for advancing the integration of predictive analytics into clinical practice include improving model interpretability, expanding data sharing and interoperability, and aligning predictive models with precision medicine goals. By overcoming current challenges, predictive analytics holds promise for transforming neonatal care and providing personalized interventions for infants at risk of BPD.

Investigation of the miRNA-mRNA Regulatory Circuits and Immune Signatures Associated with Bronchopulmonary Dysplasia

Background

Bronchopulmonary dysplasia (BPD) has become a major cause of morbidity and mortality in preterm infants worldwide, yet its pathogenesis and underlying mechanisms remain poorly understood. The present study sought to explore microRNA-mRNA regulatory networks and immune cells involvement in BPD through a combination of bioinformatic analysis and experimental validation.

Methods

MicroRNA and mRNA microarray datasets were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed microRNAs (DEMs) were identified in BPD patients compared to control subjects, and their target genes were predicted using miRWalk, miRNet, miRDB, and TargetScan databases. Subsequently, protein-protein interaction (PPI) and functional enrichment analyses were conducted on the target genes. 30 hub genes were screened using the Cytohubba plugin of the Cytoscape software. Additionally, mRNA microarray data was utilized to validate the expression of hub genes and to perform immune infiltration analysis. Finally, real-time PCR (RT-PCR), immunohistochemistry (IHC), and flow cytometry were conducted using a mouse model of BPD to confirm the bioinformatics findings.

Results

Two DEMs (miR-15b-5p and miR-20a-5p) targeting genes primarily involved in the regulation of cell cycle phase transition, ubiquitin ligase complex, protein serine/threonine kinase activity, and MAPK signaling pathway were identified. APP and four autophagy-related genes (DLC1, PARP1, NLRC4, and NRG1) were differentially expressed in the mRNA microarray dataset. Analysis of immune infiltration revealed significant differences in levels of neutrophils and naive B cells between BPD patients and control subjects. RT-PCR and IHC confirmed reduced expression of APP in a mouse model of BPD. Although the proportion of total neutrophils did not change appreciably, the activation of neutrophils, marked by loss of CD62L, was significantly increased in BPD mice.

Conclusion

Downregulation of APP mediated by miR-15b-5p and miR-20a-5p may be associated with the development of BPD. Additionally, increased CD62L- neutrophil subset might be important for the immune-mediated injury in BPD.

Cellular preconditioning and mesenchymal stem cell ferroptosis

In this editorial, we comment on the article published in the recent issue of the World Journal of Stem Cells. They focus on stem cell preconditioning to prevent ferroptosis by modulating the cystathionine γ-lyase/hydrogen sulfide (H2S) pathway as a novel approach to treat vascular disorders, particularly pulmonary hypertension. Preconditioned stem cells are gaining popularity in regenerative medicine due to their unique ability to survive by resisting the harsh, unfavorable microenvironment of the injured tissue. They also secrete various paracrine factors against apoptosis, necrosis, and ferroptosis to enhance cell survival. Ferroptosis, a regulated form of cell death characterized by iron accumulation and oxidative stress, has been implicated in various pathologies encompassing degenerative disorders to cancer. The lipid peroxidation cascade initiates and sustains ferroptosis, generating many reactive oxygen species that attack and damage multiple cellular structures. Understanding these intertwined mechanisms provides significant insights into developing therapeutic modalities for ferroptosis-related diseases. This editorial primarily discusses stem cell preconditioning in modulating ferroptosis, focusing on the cystathionase gamma/H2S ferroptosis pathway. Ferroptosis presents a significant challenge in mesenchymal stem cell (MSC)-based therapies; hence, the emerging role of H2S/cystathionase gamma/H2S signaling in abrogating ferroptosis provides a novel option for therapeutic intervention. Further research into understanding the precise mechanisms of H2S-mediated cytoprotection against ferroptosis is warranted to enhance the therapeutic potential of MSCs in clinical settings, particularly vascular disorders.

[Overexpression of LncRNA MEG3 promotes ferroptosis and enhances chemotherapy sensitivity of hepatocellular carcinoma cells to cisplatin]

OBJECTIVE

To investigate the effect of overexpression of LncRNA MEG3 on proliferation, migration and cisplatin sensitivity of hepatoma cells HepG2 and LM3 and explore the underlying and mechanism.

METHODS

The expression of MEG3 in healthy individuals and patients with hepatocellular carcinoma (HCC) was analyzed by online bioinformatics analysis, and Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect MEG3 expression in different HCC cell lines. A MEG3-overexpresing plasmid was transfected in HepG2 and LM3 cells, and the changes in cell proliferation and migration were examined using CCK8 assay and scratch assay. CCK8 assay was used to determine the inhibitory rate of cisplatin on the transfected cells. A reactive oxygen species (ROS) fluorescence probe (DCFH-DA) and malondialdehyde (MDA) kit were used to assess the changes in ROS production and MDA level in the cells. Western blotting was performed to detect the expression levels of ferroptosis-related proteins glutathione peroxidase 4 (GPX4) and ferritin heavy chain 1 (FTH1).

RESULTS

The expression of MEG3 was significantly lower in HCC cells than in LO2 cells, which was consistent with the results of bioinformatic analysis (P < 0.05). Overexpression of MEG3 in the HCC cell lines significantly suppressed cell proliferation and migration (P < 0.05), increased the cell inhibition rate of cisplatin (P < 0.05), enhanced cellular ROS production and increased MDA levels in the cells (P < 0.05). MEG3 overexpression significantly decreased the expressions of GPX4 and FTH1 in the HCC cell lines.

CONCLUSION

The expression of MEG3 is decreased in HCC cells, and its overexpression inhibits proliferation and migration and enhances cisplatin sensitivity of HCC cells by promoting ferroptosis of the cells.