Zheng Y, Ma C, Ding S
… +3 more, Zhang F, Liu H, Xu Y
Am J Respir Cell Mol Biol
· 2025 Oct · PMID 41086397
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As a 5-methylcytosine (m5C) methyltransferase, increased NOP2/Sun RNA methyltransferase 2 (NSUN2) has been revealed to promote the progression of non-small cell lung cancer (NSCLC) through m5C modification. Herein, this...As a 5-methylcytosine (m5C) methyltransferase, increased NOP2/Sun RNA methyltransferase 2 (NSUN2) has been revealed to promote the progression of non-small cell lung cancer (NSCLC) through m5C modification. Herein, this study aimed to investigate the potential molecular mechanisms underlying the high NSUN2 expression in NSCLC, and the potential downstream m5C mRNAs of NSUN2 in promoting NSCLC progression. Functional analyses were conducted using in vitro MTT, EdU, transwell, wound healing, sphere and tube formation assays, and in vivo murine model. m5C modification was determined by MeRIP assay. RIP assay determined the binding between NSUN2 and SLC7A5 mRNA. The upstream molecular mechanism of the upregulation of NSUN2 expression was explored using ChIP, Co-immunoprecipitation (Co-IP), and luciferase reporter assays. NSUN2 was highly expressed in NSCLC and predicted poor outcomes in NSCLC patients. Functionally, NSUN2 silencing suppressed cancer cell proliferation, migration, stemness properties, angiogenic ability and glutamine metabolism. Mechanistically, NSUN2 induced m5C methylation modification of SLC7A5, and stabilized SLC7A5 mRNA via a YBX1-dependent mechanism. Accordingly, SLC7A5 overexpression reversed the anticancer effects of NSUN2 on above oncogenic phenotypes. Further upstream molecular mechanism analysis showed that P300 could bind to and cooperate with transcription factor SP1 to increase NSUN2 expression by Histone H3 Lysine 27 acetylation (H3K27ac). Further in vivo analyses suggested that NSUN2 silencing suppressed ESCC growth and metastasis in vivo by regulating SLC7A5 expression. In conclusion, increased NSUN2 derived by P300/SP1 complex-mediated histone acetylation promoted the growth, metastasis and glutamine metabolism of NSCLC by stabilizing SLC7A5 mRNA via m5C modification.
RATIONALE: Lipid metabolism disorder is increasingly recognized as hallmarks of pulmonary hypertension (PH). Fatty acid-binding proteins (FABPs), particularly FABP4 and FABP5, which regulate lipid transport and metabolis...RATIONALE: Lipid metabolism disorder is increasingly recognized as hallmarks of pulmonary hypertension (PH). Fatty acid-binding proteins (FABPs), particularly FABP4 and FABP5, which regulate lipid transport and metabolism of fatty acid, are thought to contribute to the development of PH. However, it remains unclear whether FABP4 and FABP5 serve as therapeutic targets for the treatment of PH. Measurements and Main. RESULTS: The levels of FABP4/5 were elevated in the plasma and lung tissues of idiopathic pulmonary arterial hypertension (IPAH) patients, as well as in the lung tissues of the PH rat model compared with control. The circulating levels of FABP4 of IPAH patients were correlated with mean pulmonary arterial pressure (mPAP). To determine the preventive or therapeutic effect of FABP4 and FABP5 inhibition, FABP4 and FABP5 inhibitors alone or combination were administered at early (days 2 following monocrotaline [MCT] injection) and late (day 12 following MCT injection) stage of PH rat model, respectively. Combined treatment with FABP4/5 inhibitors in the early stage of the MCT-PH rat model effectively reduced right ventricular systolic pressure (RVSP) and improved right ventricular (RV) function, accompanied by reductions in pulmonary vascular and RV fibrosis, as well as blood lipid levels, lipid peroxidation, and inflammation. Combined treatment with FABP4/5 inhibitors at the late stage of MCT-PH improved RV function, suppressed pulmonary vascular and RV fibrosis, and lowered blood lipid levels, but did not affect RVSP. CONCLUSIONS: Combined inhibition of FABP4 and FABP5 can prevent the pathogenesis of PH, representing a potential therapeutic strategy for PH. p.
Pulmonary fibrosis is increasingly understood to involve dysfunction within and across multiple cellular compartments, with recent attention highlighting the involvement of pulmonary vascular dysfunction in failed repair...Pulmonary fibrosis is increasingly understood to involve dysfunction within and across multiple cellular compartments, with recent attention highlighting the involvement of pulmonary vascular dysfunction in failed repair and progression of fibrosis. Formulation and delivery of lung-targeting lipid nanoparticles (LNPs) may provide a means to selectively target the lung but not systemic vasculature. However, the feasibility and efficacy of such approaches in the fibrotic lung are unknown. We sought to test whether intravenously administered lung-targeting LNPs can safely deliver mRNA to the healthy and fibrotic lung vasculature in young and aged mice and whether delivery of mRNA encoding a matricellular protein could promote fibrosis resolution. We used a selective organ targeting LNP formulation and characterized cell-specificity of delivery after bleomycin-induced lung fibrosis. We then delivered Ccn3 mRNA (encoding cellular communication network factor 3) to aged mice in the setting of established lung fibrosis and evaluated fibrotic regression and vascular repair. The matricellular protein encoded by Ccn3 was previously identified by our group as an important regulator of lung endothelial function. We found that LNP delivery was lung specific and predominantly endothelial targeting in the setting of lung fibrosis. Delivery of Ccn3 mRNA to aged mice via LNPs modestly reduced fibrosis and improved microvascular density in the lungs. Our results support the concept that cell-specific and repair-promoting cargos delivered via lung-targeting LNPs may have utility for treatment of established fibrosis.
Upadhyay M, Nelson D, Phillips M
… +5 more, Gould S, Davis J, Dhar R, Murphy EA, Evans CE
Am J Respir Cell Mol Biol
· 2026 May · PMID 41072120
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Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are heterogeneous and potentially fatal consequences of serious conditions such as trauma and sepsis, an exacerbated inflammatory response to infecti...Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are heterogeneous and potentially fatal consequences of serious conditions such as trauma and sepsis, an exacerbated inflammatory response to infection. There are no effective treatments for ALI/ARDS, partly due to an incomplete understanding of its pathogenesis across different patient subpopulations, contributing to mortality rates of 25%-40%. ALI/ARDS is characterized by lung hypoxia, inflammatory cell infiltration, edema, and endothelial cell injury and death. Lung endothelial viability is essential for gas exchange, nutrient delivery, and immune cell migration, as well as the prevention of proteinaceous fluid accumulation. Given that lung endothelial death is a predominant feature of ALI/ARDS, its inhibition could represent a novel therapeutic strategy. In this article, we review studies examining pulmonary endothelium death during sepsis-induced ALI/ARDS, including studies of lung endothelium apoptosis, pyroptosis, necroptosis, and ferroptosis. We also highlight gaps in current knowledge that, if addressed, could facilitate the development of effective treatments for sepsis-induced ALI/ARDS. Future studies of the mechanisms regulating lung endothelial death may uncover novel therapeutic targets for ALI/ARDS. These targets could be leveraged in precision medicine approaches to treat patient subpopulations most likely to benefit from inhibiting specific forms of lung endothelial death.
Ghanbar MI, Villabona-Rueda A, Philip N
… +25 more, Rodriguez Ortega R, Fonti S, Wally A, Jiang H, Wang R, Berger W, Thiboutot J, Lee H, Forde P, Naidoo J, Brahmer J, Kim ST, Daver N, Altan M, Sheshadri A, Van Mol P, Wauters E, Danlos FX, Le Pavec J, Laparra A, Damico R, Yegnasubramanian S, Danoff SK, D'alessio F, Suresh K
BACKGROUND: Checkpoint inhibitor pneumonitis (CIP) is a highly morbid complication of immune checkpoint immunotherapy, characterized by acute lung injury leading, in severe cases, to hypoxic respiratory failure and death...BACKGROUND: Checkpoint inhibitor pneumonitis (CIP) is a highly morbid complication of immune checkpoint immunotherapy, characterized by acute lung injury leading, in severe cases, to hypoxic respiratory failure and death. CIP incidence in lung cancer is high (10%-15%). Yet, the pathophysiology of CIP is poorly understood. OBJECTIVE/METHODS: To investigate the mechanisms underlying alveolar inflammation in patients with CIP, human bronchoalveolar lavage fluid (BALF) samples from control patients and patients with CIP were analyzed using flow cytometry, single-cell RNA sequencing (scRNA-seq), and ELISA. Findings were validated using multiple external cohorts. In vitro experiments and in vivo rodent models were employed to investigate the mechanisms driving alveolar inflammation in CIP. RESULTS: Analysis of scRNA-seq and flow cytometry data demonstrated increased macrophages in patients with CIP compared to controls. Several distinct proinflammatory alveolar macrophage subsets were increased in CIP. CIP macrophages expressed increased CCL18 at the transcript (scRNA-seq), cellular (flow cytometry) and secreted protein (BALF ELISA) levels. BALF CCL18 levels were associated with clinical CIP severity. CCL18 overexpression in mice promoted lung inflammation that phenocopied human CIP, including upregulation of proinflammatory macrophage subsets. CONCLUSION: These findings suggest that BALF macrophages and CCL18 protein levels are increased in patients with CIP and associate with greater CIP severity. Additionally, CCL18 promotes lung inflammation in mice that mimics human CIP, suggesting a causal role for CCL18 in CIP.
Flerlage T, Boyd DF, Clark B
… +13 more, Marudai NG, Saini S, Guy C, Pobre-Piza K, Crawford JC, Poudel S, High AA, Zhou S, Wang X, Surman S, Jones B, Frevert CW, Thomas PG
RATIONALE: Lung injury caused by influenza is a leading cause of respiratory infection-related morbidity and mortality worldwide. In its severe form, influenza can cause acute respiratory distress syndrome (ARDS), which...RATIONALE: Lung injury caused by influenza is a leading cause of respiratory infection-related morbidity and mortality worldwide. In its severe form, influenza can cause acute respiratory distress syndrome (ARDS), which manifests as severe hypoxemic respiratory failure. Survivors of the acute stage of ARDS may develop lung fibrosis. The mechanisms underlying fibrotic responses in this context are unknown. OBJECTIVES: In this study, we investigate fibroblast responses to influenza challenge. METHODS: We used single cell gene expression (scGEX) and two-dimensional liquid chromatography coupled with tandem/mass spectrometry (TMT-LC/LC-MS/MS) on lung tissue collected longitudinally in a murine model of influenza A virus (IAV) infection. MEASUREMENTS AND MAIN RESULTS: By TMT-LC/LC-MS/MS, we identified profound changes in the composition of the lung matrisome, which were most evident 10 days after infection. In this context, we identified transcriptional heterogeneity amongst proximal/adventitial fibroblasts expressing Pi16 and Col15a1 as well as a myofibroblast activation state characterized by expression of Tnc, Spp1, Grem1, and Cthrc1. This activation state was transcriptionally similar to those previously described in other contexts. CONCLUSIONS: Together, these data suggest compartmentalization and conservation of pulmonary fibroblast responses to lung injury of different primary etiologies.
RATIONALE: A subset of severe asthma is characterized by neutrophilic airway inflammation in which epithelial activation of the NLRP3 inflammasome pathway is implicated. SERPINB10 is linked to neutrophil activation in in...RATIONALE: A subset of severe asthma is characterized by neutrophilic airway inflammation in which epithelial activation of the NLRP3 inflammasome pathway is implicated. SERPINB10 is linked to neutrophil activation in inflammatory diseases. OBJECTIVES: To investigate the role of SERPINB10 in airway neutrophilia in asthma. METHODS: We sensitized mice with house dust mite (HDM) and challenged them with HDM and poly(I: C), a viral double-stranded RNA analog. Airway inflammation and the expression of inflammatory cytokines in mouse lungs were analyzed. Mechanistic experiments were performed in HBE cells by RNA sequencing, western blotting, and immunofluorescence staining. The expression of SERPINB10, NLRP3, IL-1β, and IL-6 were determined in human bronchial brushings. MEASUREMENTS AND MAIN RESULTS: Serpinb10 -/- mice exhibited reduced neutrophil counts in bronchoalveolar lavage cells and alleviated inflammatory cell infiltration around airways. Il-1β and Il-6 expression was decreased in lung tissues from Serpinb10-/- mice. In cultured HBE cells, SERPINB10 knockdown decreased IκBα phosphorylation and suppressed poly(I: C)-induced IL-1β and IL-6 expression. Moreover, the expression of NLRP3 and pro-IL-1β in lung tissues of Serpinb10-/- mice was decreased. Conversely, SERPINB10 overexpression enhanced IL-1β and IL-6 expression in HBE cells, which was blocked by either an IκBα phosphorylation inhibitor or an NLRP3 inhibitor. Of note, SERPINB10 expression in bronchial brushings from non-eosinophilic asthma patients was enhanced and significantly correlated with the severity of airflow limitation, and the expression of NLRP3, IL-1β, and IL-6. CONCLUSIONS: SERPINB10 promotes IL-1β and IL-6 expression by upregulating NF-κB and NLRP3 signaling in airway epithelial cells, thereby driving neutrophilic airway inflammation in asthma.
BACKGROUND: Cisplatin resistance remains a major barrier to effective lung cancer treatment. This study explores the function of spliceosome associated factor 3 (SART3) in cisplatin resistance in non-small cell lung canc...BACKGROUND: Cisplatin resistance remains a major barrier to effective lung cancer treatment. This study explores the function of spliceosome associated factor 3 (SART3) in cisplatin resistance in non-small cell lung cancer (NSCLC). METHODS: H1299 and Calu-3 cells were exposed to incremental doses of cisplatin to generate resistant cell lines. SART3 deletion and re-expression was induced in these resistant cell lines, followed by analysis of cell viability, proliferation, and DNA damage and repair markers. Metabolic analysis was performed in cells upon SART3 loss or re-expression. Palmitic acid (PA) and Etomoxir, a CPT1A inhibitor, and gain- and loss-of-function assays of CD36 were applied to analyze the involvement of β-oxidation pathway in SART3-mediated cisplatin resistance. The interacting proteins of SART3 were explored using immunoprecipitation/liquid chromatography-mass spectrometry assays, and their effects on CD36 transcription were analyzed with immunoprecipitation and luciferase assays. RESULTS: SART3 was upregulated in cisplatin-resistant NSCLC cells. SART3 deletion sensitized cells to cisplatin, whereas re-expression restored resistance. Mechanistically, SART3 enhanced DNA repair mainly through the PARP pathway, and its deletion increased gH2AX levels and reduced BrdU incorporation. Metabolic analysis revealed that SART3-driven resistance relied on elevated fatty acid (FA) β-oxidation. Targeting FA metabolism with CPT1A inhibitors or CD36 antagonists, or blocking PARP activity, significantly reversed SART3-mediated resistance. Further, SART3 recruited FOXM1 to activate CD36 transcription by modulating H2b deubiquitination. In vivo, inhibition of the SART3-CD36-PARP axis suppressed tumor growth and restored cisplatin sensitivity in mice. CONCLUSION: This study suggests that SART3-driven metabolic reprogramming and DNA repair underpin cisplatin resistance.
RATIONALE: Chronic obstructive pulmonary disease (COPD) is a major contributor to global mortality rates, yet the cell-specific mechanisms underlying its pathobiology remain poorly understood, particularly in mild diseas...RATIONALE: Chronic obstructive pulmonary disease (COPD) is a major contributor to global mortality rates, yet the cell-specific mechanisms underlying its pathobiology remain poorly understood, particularly in mild disease stages. OBJECTIVES: To investigate the cooperative anti-inflammatory roles of macrophages and secretory cells in mild and moderate COPD. METHODS: Single-cell profiles of lung tissues from individuals with mild to moderate COPD or control lungs were analyzed using Microwell-seq. Transcriptomic findings were validated using microfluidic single-cell RNA sequencing of murine lungs, high-throughput single-nucleus total RNA sequencing (snHH-seq) of human lung tissues from severe COPD, spatial transcriptomics, functional in vitro models, and immunostaining of human lung samples. MEASUREMENTS AND MAIN RESULTS: An increased subpopulation, termed interstitial COPD-associated macrophages (ICMs), was identified, with transcriptional evidence of anti-inflammatory activity, and reduced the transcription of proteins associated with elastase secretion in mild to moderate COPD. Comprehensive analysis of single-cell datasets revealed enhanced expression of secretoglobin 3A2 (SCGB3A2) and macrophage receptor with collagenous structure (MARCO) across epithelial secretory cells and interstitial macrophages. Transcriptomic data demonstrated that MARCO activation was pivotal for phenotypic changes in interstitial macrophages transitioning to alveolar macrophages. Spi-1 proto-oncogene (SPI1) transcription factor levels aligned with the MARCO transcriptome in ICMs derived from COPD. CONCLUSIONS: In mild to moderate COPD, secretory cells play protective roles by regulating ICMs through the SCGB3A2-MARCO pathway. Targeting ICMs for COPD treatment may preserve the anti-inflammatory interstitial environment in patients.
RATIONALE: Ozone is associated with induction of airway hyperresponsiveness (AHR) and neutrophilic airway inflammation which is the characteristic of type 2 low inflammatory phenotype. Recently, epithelial cell-derived c...RATIONALE: Ozone is associated with induction of airway hyperresponsiveness (AHR) and neutrophilic airway inflammation which is the characteristic of type 2 low inflammatory phenotype. Recently, epithelial cell-derived cytokines such as thymic stromal lymphopoietin (TSLP) have been recognized as therapeutic targets for asthma with type 2 low inflammation, but the mechanisms remain unknown. METHODS: BALB/c mice and TSLP receptor-deficient mice were exposed to ozone at 2 ppm for 3 hours. AHR, cell counts, and cytokine analyses of bronchoalveolar lavage fluid (BALF) were examined. Single-cell RNA sequencing was performed to explore targeted cell clusters and genes. Batf3-deficient mice were analyzed to assess the effects of conventional type 1 dendritic cells (cDC1s), and treatment with NP-G2-044 was given to evaluate the impact of Fscn1 on ozone-induced airway responses. RESULTS: Ozone-exposed BALB/c mice showed greater AHR and neutrophils in BALF, with higher levels of TSLP in lungs than air-exposed BALB/c mice. Ozone-exposed TSLP receptor-deficient mice showed lower AHR and neutrophil counts in BALF than BALB/c mice. Single-cell RNA sequencing showed that DCs, especially cDC1s, were modified by ozone exposure and blockade of TSLP in terms of gene expressions including Fscn1. Ozone-exposed Batf3-deficient mice showed lower AHR and neutrophil counts in BALF, with depletion of cDC1s compared with C57BL/6J mice. Expression of Fscn1 was greater in bone marrow-derived cDC1s stimulated by TSLP, and ozone-exposed BALB/c mice treated with NP-G2-044 showed lower neutrophils in BALF than BALB/c mice treated with placebo. CONCLUSIONS: cDC1 derived Fscn1 was a potential target for ozone-induced neutrophilic airway inflammation via TSLP.
Gupta A, Dahlin A, Macario A
… +11 more, Gally F, Weaver MR, Guarino S, Kahn L, Sanford L, Gruca MA, Cho MH, Dowell RD, Weiss ST, Sasse SK, Gerber AN
Am J Respir Cell Mol Biol
· 2026 Mar · PMID 41021275
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As a consequence of climate change and land-use policies, there has been a historic rise in wildfire smoke across the United States and the world. Although the deleterious effects of wildfire smoke and associated air pol...As a consequence of climate change and land-use policies, there has been a historic rise in wildfire smoke across the United States and the world. Although the deleterious effects of wildfire smoke and associated air pollution on asthma outcomes are established epidemiologically, genetic risks and molecular mechanisms of how wildfire smoke affects asthma are unknown. This knowledge gap hinders the identification of high-risk individuals and the creation of targeted therapies or recommendations to protect these individuals. We identified 52 genetic risk variants that colocalized with genomic responses to woodsmoke particles (WSPs), a model of wildfire particulate matter, and associated with asthma in the GERA (Genetic Epidemiology Research on Adult Health and Aging) cohort. We used additional filters to prioritize variants for direct testing of allele-dependent transcriptional regulatory function in plasmid reporters. We found that the rs3861144 variant (odds ratioasthma, 1.036) changes SPRY2 responses to WSPs in airway epithelial cells, which are involved in IL-8 secretion, ERK (extracellular signal-related kinase) activation, and mechanical scratch repair in cell culture. These findings provide insights into the molecular pathways through which WSPs may influence asthma risk and propose genetic candidates that warrant further study for their potential as clinical tools for asthma.