Mitochondria in Focus: From Function to Therapeutic Strategies in Chronic Lung Diseases

A novel mitochondrial quality regulation gene signature for anticipating prognosis, TME, and therapeutic response in LUAD by multi-omics analysis and experimental verification

BACKGROUND

Lung adenocarcinoma (LUAD) is the predominant form of non-small cell lung cancer (NSCLC). Mitochondrial quality-related genes (MQRGs) contribute to the genesis and advancement of tumors. Despite advances in LUAD treatment and detection, early diagnostic biomarkers are still lacking, and the roles of MQRGs in LUAD are not well understood.

METHODS

We extensively examined transcriptome and clinical data from TCGA and GEO databases to discover differentially expressed MQRGs. Utilizing the LASSO algorithm and multivariate COX regression, a predictive risk model was created. Kaplan-Meier study and ROC curves were implemented to predict patient prognosis, resulting in a new Mitochondrial Quality Regulation Gene Signature for accurate prognosis forecasting. R software and packages facilitated statistical, consensus cluster, survival, Cox regression, Lasso regression, and tumor microenvironment analyses. Model-related gene expression was measured using RT-qPCR, immunohistochemistry, single-cell sequencing, HPA data, and UNCAN data.

RESULTS

We created a concise risk model using four MQRGs (STRAP, SHCBP1, PKP2, and CRTAC1) to forecast overall survival in LUAD patients. High-risk patients experienced significantly lower survival rates. Functional analysis linked these MQRGs to alpha-linolenic acid metabolism pathways. Moreover, the tumor immune microenvironment supports previous findings that higher CD8 + T cell infiltration improves LUAD outcomes. Analysis of different risk scores showed increased activated memory T-cell CD4, suggesting its activation is crucial for LUAD prognosis. Nomograms were generated with clinical data and the MQRGscore model. mRNA and IHC analysis manifested significantly upregulated STRAP, SHCBP1, and PKP2 expression and mitigated CRTAC1 expression in the LUAD contrasted with normal lung tissue. qRT-PCR and immunohistochemistry confirmed these findings, aligning with TCGA data.

CONCLUSIONS

We created a succinct MQRGs risk model to ascertain the LUAD patient's prognosis, potentially offering a novel method for diagnosing and treating this condition.

Klotho improves Der p1-induced bronchial epithelial cell damage by inhibiting endoplasmic reticulum stress to regulate mitochondrial function

Asthma is a prevalent chronic pediatric lung disease which is commonly perceived as a syndrome of airway inflammation characterized by cough and wheeze in clinic. Klotho is implicated in diverse cellular activities, including inflammation, oxidative stress and apoptosis. This paper aims to explore the role of klotho in asthma and investigate the relevant molecular reaction mechanisms. To this end, we used Der p1 to induce an in vitro asthma model in BEAS-2B cells. Klotho expression was manipulated in Der p1-induced BEAS-2B cells with overexpression and its effects on Der p1-induced pathologies including apoptosis and inflammatory cytokine levels and the expressions of oxidative stress-related markers and major mediators in endoplasmic reticulum stress (ER stress) were investigated. Mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (mPTP) opening were also detected. Our data demonstrated that Der p1 stimulation decreased klotho expression and klotho overexpression inhibited the Der p1-induced inflammation, oxidative stress and apoptosis. Overexpressing klotho inhibited ER stress to modulate mitochondrial function. The inhibitory effects of klotho overexpression were reversed by ER stress agonist tunicamycin. This paper validated the role of klotho in asthma pathogenies and developed prospective therapeutic targets for asthma treatment.

Global research trends and hotspots in mitochondria and asthma: a bibliometric and visualized analysis

BACKGROUND

Asthma is a complex chronic respiratory disease marked by inflammation, bronchoconstriction, and hyperresponsiveness. Mitochondria, key regulators of energy production, ROS, and apoptosis, are increasingly recognized as crucial in asthma pathophysiology. However, a comprehensive analysis of global research trends in this area is lacking. This study aims to perform a bibliometric and visualized analysis of global research on mitochondria and asthma.

METHODS

A bibliometric analysis was conducted using Web of Science Core Collection data from 2004 to June 2024. CiteSpace and VOSviewer software were used to examine co-authorship, co-citation, keyword co-occurrence, and thematic clusters.

RESULTS

A total of 669 publications were identified. The number of studies grew significantly after 2015, with the United States, China, and the UK leading research. Co-citation and keyword analyses revealed mitochondrial dysfunction, oxidative stress, apoptosis, and airway inflammation as major themes. Emerging areas of interest include mitochondrial biogenesis, NLRP3 inflammasome, and innate immunity. Collaboration among institutions like Harvard University and the Council of Scientific & Industrial Research was significant, and journals, such as European Respiratory Journal and Nature Medicine were highly influential.

CONCLUSION

This study provides an overview of research on mitochondria and asthma, highlighting emerging trends, such as mitochondrial biogenesis and immune pathways. Future research should focus on these areas and the role of environmental triggers in mitochondrial dysfunction, offering valuable insights for therapeutic strategies targeting mitochondria in asthma.

CREB1 controls mitochondrial dysfunction in 1-nitropyrene-mediated apoptosis of human bronchial cells and lung injury

Airborne pollutants, particularly nitro-polycyclic aromatic hydrocarbons (nitro-PAHs), are significant contributors to respiratory diseases. Among these, 1-NP, a nitro-PAH prevalent in diesel exhaust particles (DEPs), is known to induce lung damage. While studies on the respiratory toxicity of 1-NP remain limited, the underlying molecular mechanisms, particularly the roles of mitochondrial dysfunction and toxicity-related gene expression in lung cell death, are even less understood. To address this gap, this study aims to elucidate the relationship between 1-NP-induced lung cell death, mitochondrial dysfunction, and gene expression. In vitro assays were used to assess mitochondrial dysfunction and apoptotic markers in human bronchial epithelial cells, while phosphoproteomic analysis and in vivo murine models were employed to investigate the role of CREB1 phosphorylation in 1-NP toxicity. This study demonstrated an increase in apoptotic cells using Annexin V/PI staining and the activation of apoptotic proteins, such as caspase-3 and PARP, following a 24-h exposure to 1-NP. Notably, the mitochondrial cristae disruption occurred, accompanied by elevated expression of cytochrome c and Bid. Additionally, exposure of human bronchial epithelial cells to 1-NP led to significant mitochondrial dysfunction, characterized by decreased oxygen consumption rate and membrane potential, increased mitochondrial reactive oxygen species (ROS), and upregulated voltage-dependent anion channel 1 (VDAC1) expression. Phosphoproteomic analysis revealed that CREB1 phosphorylation protects against 1-NP toxicity. In contrast, CREB1 knockdown exacerbated mitochondrial respiratory disruption and apoptotic cell death, rendering cells more susceptible to 1-NP exposure. Furthermore, intranasal exposure to 1-NP in a murine model significantly elevated chemokine CCL2 levels in bronchoalveolar lavage fluid along with IL-1β and CXCL1 expression in lung tissue compared to the controls. Additionally, 1-NP exposure induced lung collapse, fibrosis, and mucin hyperexpression, along with increased expression of CREB1, cleaved caspase-3, VDAC1, and 8-OHdG, indicating oxidative DNA damage. This study demonstrates that 1-NP exposure induces CREB1 phosphorylation, mitochondrial dysfunction, cell death, and lung pathologies, highlighting the potential of this model for developing pharmaceutical interventions targeting respiratory diseases.

Suppression of CDK1/Drp1-Mediated Mitochondrial Fission Attenuates Dexamethasone-Induced Extracellular Matrix Deposition in the Trabecular Meshwork

Aims: Deposition of extracellular matrix (ECM) in the trabecular meshwork (TM), as induced by dexamethasone (Dex), is believed to play an important role in the onset of glucocorticoid-induced glaucoma (GIG). Abnormal ECM deposition is a consequence of mitochondrial dysfunction. We aimed to clarify how mitochondrial dysfunction leads to ECM deposition within the TM and to support the development of novel therapeutic strategies. Results: In primary human TM cells (pHTMCs) and a Dex acetate-induced murine model of GIG, glucocorticoid administration stimulated both mitochondrial fission and ECM deposition. Excessive mitochondrial fission leads to dysfunction and the overexpression of ECM proteins in pHTMCs. Notably, when pHTMCs were treated with the dynamin-related protein 1 (Drp1) inhibitor Mdivi-1 or with Drp1 siRNA, we observed a marked reduction in Dex-induced mitochondrial damage and ECM proteins in vitro. Furthermore, in C57BL/6J mice, treatment with Mdivi-1 mitigated mitochondrial damage and blocked ECM deposition within the TM. We then used Ro3306 to inhibit the cyclin-dependent kinase (CDK)1-mediated phosphorylation of Drp1 at Ser 616, which restored mitochondrial function and diminished Dex-induced ECM protein expression in pHTMCs. Innovation: This study illuminates the pathogenic mechanism linking mitochondrial dysfunction to ECM deposition in GIG. Our innovative approach revealed that Dex stimulates mitochondrial fission via CDK1-mediated p-Drp1s616 overexpression, which drives ECM accumulation. It offered a novel therapeutic strategy for reducing ECM protein expression by inhibiting excessive mitochondrial fission and restoring mitochondrial function. Conclusion: By targeting the CDK1/Drp1-driven mitochondrial fission process, we can counteract Dex-induced ECM deposition in the TM both in vivo and in vitro. Antioxid. Redox Signal. 42, 249-264.

Myricetin Alleviates Silica-Mediated Lung Fibrosis via PPARγ-PGC-1α Loop and Suppressing Mitochondrial Senescence in Epithelial Cells

OBJECTIVE

Long-term inhalation of silica dust particles leads to lung tissue fibrosis, resulting in impaired gas exchange and increased mortality. Silica inhalation triggers the aging of epithelial cells (AECs), which is a key contributor to the development of pulmonary fibrosis. Myricetin, a flavonoid compound extracted from Myrica genus plants, possesses various biological activities, including antioxidant and immunomodulatory effects. However, the mechanisms underlying myricetin's ability to counter senescence and fibrosis need to be further studied.

EXPERIMENTAL APPROACH

In vivo, the antifibrotic and anti-senescence effects of myricetin were evaluated using a silica-induced pulmonary fibrosis mouse model. To further elucidate the mechanisms by which myricetin counteracts silica-induced senescence, in vitro experiments were conducted using AECs.

RESULTS

Our studies revealed that myricetin treatment alleviated silica-induced mortality, improved lung function, and reduced the severity of pulmonary fibrosis in mice. Immunofluorescence analysis suggests its potential in mitigating senescence of AECs. Under laboratory conditions, myricetin intervened in the cellular senescence pathway induced by silica dust by modulating mitochondrial function. It acted through the PPARγ-PGC1α axis, effectively reducing silica-induced mitochondrial oxidative stress in AECs, promoting mitophagy, and maintaining mitochondrial dynamics. However, the efficacy of myricetin was reversed under PPARγ siRNA intervention. Additionally, myricetin exhibited an enhancing effect on PPARγ and autophagy in animal models. Treatment with PPARγ and PGC-1α siRNA elucidated the role of myricetin in promoting the formation of a positive feedback loop between PPARγ and PGC-1α. Additionally, the PPARγ inhibitor GW9662 verified the in vivo effects of myricetin.

CONCLUSIONS

Myricetin activates PPARγ, forming a PPARγ-PGC-1α loop, which promotes mitophagy and maintains mitochondrial dynamics. This alleviates epithelial cell senescence induced by silica exposure, consequently mitigating silica-induced pulmonary fibrosis in mice.

Understanding the impact of ER stress on lung physiology

Human lungs consist of a distinctive array of cell types, which are subjected to persistent challenges from chemical, mechanical, biological, immunological, and xenobiotic stress throughout life. The disruption of endoplasmic reticulum (ER) homeostatic function, triggered by various factors, can induce ER stress. To overcome the elevated ER stress, an adaptive mechanism known as the unfolded protein response (UPR) is activated in cells. However, persistent ER stress and maladaptive UPR can lead to defects in proteostasis at the cellular level and are typical features of the lung aging. The aging lung and associated lung diseases exhibit signs of ER stress-related disruption in cellular homeostasis. Dysfunction resulting from ER stress and maladaptive UPR can compromise various cellular and molecular processes associated with aging. Hence, comprehending the mechanisms of ER stress and UPR components implicated in aging and associated lung diseases could enable to develop appropriate therapeutic strategies for the vulnerable population.

Mitochondrial dynamics in pulmonary disease: Implications for the potential therapeutics

Mitochondria are dynamic organelles that continuously undergo fusion/fission to maintain normal cell physiological activities and energy metabolism. When mitochondrial dynamics is unbalanced, mitochondrial homeostasis is broken, thus damaging mitochondrial function. Accumulating evidence demonstrates that impairment in mitochondrial dynamics leads to lung tissue injury and pulmonary disease progression in a variety of disease models, including inflammatory responses, apoptosis, and barrier breakdown, and that the role of mitochondrial dynamics varies among pulmonary diseases. These findings suggest that modulation of mitochondrial dynamics may be considered as a valid therapeutic strategy in pulmonary diseases. In this review, we discuss the current evidence on the role of mitochondrial dynamics in pulmonary diseases, with a particular focus on its underlying mechanisms in the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis (PF), pulmonary arterial hypertension (PAH), lung cancer and bronchopulmonary dysplasia (BPD), and outline effective drugs targeting mitochondrial dynamics-related proteins, highlighting the great potential of targeting mitochondrial dynamics in the treatment of pulmonary disease.

Insight into the role of mitochondrion-related gene anchor signature in mitochondrial dysfunction of neutrophilic asthma

OBJECTIVE

At present, targeting molecular-pharmacological therapy is still difficult in neutrophilic asthma. The investigation aims to identify and validate mitochondrion-related gene signatures for diagnosis and specific targeting therapeutics in neutrophilic asthma.

METHODS

Bronchial biopsy samples of neutrophilic asthma and healthy people were identified from the GSE143303 dataset and then matched with human mitochondrial gene data to obtain mitochondria-related differential genes (MitoDEGs). Signature mitochondria-related diagnostic markers were jointly screened by support vector machine (SVM) analysis, least absolute shrinkage, and selection operator (LASSO) regression. The expression of marker MitoDEGs was evaluated by validation datasets GSE147878 and GSE43696. The diagnostic value was evaluated by receiver operating characteristic (ROC) curve analysis. Meanwhile, the infiltrating immune cells were analyzed by the CIBERSORT. Finally, oxidative stress level and mitochondrial functional morphology for asthmatic mice and BEAS-2B cells were evaluated. The expression of signature MitoDEGs was verified by qPCR.

RESULTS

67 MitoDEGs were identified. Five signature MitoDEGs (SOD2, MTHFD2, PPTC7, NME6, and SLC25A18) were further screened out. The area under the curve (AUC) of signature MitoDEGs presented a good diagnostic performance (more than 0.9). There were significant differences in the expression of signature MitoDEGs between neutrophilic asthma and non-neutrophilic asthma. In addition, the basic features of mitochondrial dysfunction were demonstrated by in vitro and in vivo experiments. The expression of signature MitoDEGs in the neutrophilic asthma mice presented a significant difference from the control group.

CONCLUSIONS

These MitoDEGs signatures in neutrophilic asthma may hold potential as anchor diagnostic and therapeutic targets in neutrophilic asthma.

Role of mitochondria in inflammatory lung diseases

Mitochondria play a significant and varied role in inflammatory lung disorders. Mitochondria, known as the powerhouse of the cell because of their role in producing energy, are now recognized as crucial regulators of inflammation and immunological responses. Asthma, chronic obstructive pulmonary disease, and acute respiratory distress syndrome are characterized by complex interactions between immune cells, inflammatory substances, and tissue damage. Dysfunctional mitochondria can increase the generation of reactive oxygen species (ROS), triggering inflammatory pathways. Moreover, mitochondrial failure impacts cellular signaling, which in turn affects the expression of molecules that promote inflammation. In addition, mitochondria have a crucial role in controlling the behavior of immune cells, such as their activation and differentiation, which is essential in the development of inflammatory lung diseases. Their dynamic behavior, encompassing fusion, fission, and mitophagy, also impacts cellular responses to inflammation and oxidative stress. Gaining a comprehensive understanding of the intricate correlation between mitochondria and lung inflammation is essential in order to develop accurate treatment strategies. Targeting ROS generation, dynamics, and mitochondrial function may offer novel approaches to treating inflammatory lung diseases while minimizing tissue damage. Additional investigation into the precise contributions of mitochondria to lung inflammation will provide significant knowledge regarding disease mechanisms and potential therapeutic approaches. This review will focus on how mitochondria in the lung regulate these processes and their involvement in acute and chronic lung diseases.

Cellular and Molecular Biology of Mitochondria in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disorder characterized by enduring airflow limitation and chronic inflammation. Growing evidence highlights mitochondrial dysfunction as a critical factor in COPD development and progression. This review explores the cellular and molecular biology of mitochondria in COPD, focusing on structural and functional changes, including alterations in mitochondrial shape, behavior, and respiratory chain complexes. We discuss the impact on cellular signaling pathways, apoptosis, and cellular aging. Therapeutic strategies targeting mitochondrial dysfunction, such as antioxidants and mitochondrial biogenesis inducers, are examined for their potential to manage COPD. Additionally, we consider the role of mitochondrial biomarkers in diagnosis, evaluating disease progression, and monitoring treatment efficacy. Understanding the interplay between mitochondrial biology and COPD is crucial for developing targeted therapies to slow disease progression and improve patient outcomes. Despite advances, further research is needed to fully elucidate mitochondrial dysfunction mechanisms, discover new biomarkers, and develop targeted therapies, aiming for comprehensive disease management that preserves lung function and enhances the quality of life for COPD patients.

YiQi GuBen capsule alleviates OVA-induced asthma through improving mitochondrial dysfunction

Objective: This study aims to explore the effect of YiQi GuBen capsule on improving mitochondrial dysfunction in an animal model of asthma.Methods: The mice (n = 8) were divided into four groups including control (NC), ovalbumin (OVA), dexamethasone (OVA + DEX), and YiQi GuBen (OVA + YQGB) groups. Firstly, we established an OVA-induced mouse asthma model except for the NC group, which then were treated with dexamethasone and YiQi GuBen capsule. Subsequently, HE staining and Masson staining were used for pathological analysis of mice lung tissues. Next, we used transmission electron microscopy (TEM) to observe the effect of the Yiqi Guben capsule on the ultrastructure of mitochondria. Flow cytometry was used to analyze the ROS level, membrane potential, and the number of mitochondria in lung tissue. Moreover, we analyzed the copy number of mitochondrial DNA (mtDNA) and the expression levels of activator peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and mitochondrial transcription factor A (TFAM).Results: The results of the pathological analysis showed that after treatment with the YiQi GuBen capsule, the lung tissue damage was significantly reduced. In addition, we observed that the ultrastructural damage of mitochondria was improved. Flow cytometry proved that after treatment with the YiQi GuBen capsule, the level of ROS in the mitochondria was effectively reduced, while the mitochondrial membrane potential decreased and the number increased significantly. Moreover, we found that the copy number of mtDNA was significantly increased and the expression levels of PGC-1α and TFAM were significantly upgraded.Conclusion: This study suggests YiQi GuBen capsule can effectively improve mitochondrial dysfunction in the OVA-induced mouse model.

Revisiting airway epithelial dysfunction and mechanisms in chronic obstructive pulmonary disease: the role of mitochondrial damage

Chronic exposure to environmental hazards causes airway epithelial dysfunction, primarily impaired physical barriers, immune dysfunction, and repair or regeneration. Impairment of airway epithelial function subsequently leads to exaggerated airway inflammation and remodeling, the main features of chronic obstructive pulmonary disease (COPD). Mitochondrial damage has been identified as one of the mechanisms of airway abnormalities in COPD, which is closely related to airway inflammation and airflow limitation. In this review, we evaluate updated evidence for airway epithelial mitochondrial damage in COPD and focus on the role of mitochondrial damage in airway epithelial dysfunction. In addition, the possible mechanism of airway epithelial dysfunction mediated by mitochondrial damage is discussed in detail, and recent strategies related to airway epithelial-targeted mitochondrial therapy are summarized. Results have shown that dysregulation of mitochondrial quality and oxidative stress may lead to airway epithelial dysfunction in COPD. This may result from mitochondrial damage as a central organelle mediating abnormalities in cellular metabolism. Mitochondrial damage mediates procellular senescence effects due to mitochondrial reactive oxygen species, which effectively exacerbate different types of programmed cell death, participate in lipid metabolism abnormalities, and ultimately promote airway epithelial dysfunction and trigger COPD airway abnormalities. These can be prevented by targeting mitochondrial damage factors and mitochondrial transfer. Thus, because mitochondrial damage is involved in COPD progression as a central factor of homeostatic imbalance in airway epithelial cells, it may be a novel target for therapeutic intervention to restore airway epithelial integrity and function in COPD.

NADH Intraperitoneal Injection Prevents Lung Inflammation in a BALB/C Mice Model of Cigarette Smoke-Induced Chronic Obstructive Pulmonary Disease

Cigarette smoke is one of the main factors in Chronic Obstructive Pulmonary Disease (COPD), a respiratory syndrome marked by persistent respiratory symptoms and increasing airway obstruction. Perturbed NAD+/NADH levels may play a role in various diseases, including lung disorders like COPD. In our study, we investigated the preventive effect of NADH supplementation in an experimental model of COPD induced by cigarette smoke extract (CSE). N = 64 mice randomly distributed in eight groups were injected with NADH (two doses of 100 mg/kg or 200 mg/kg) or dexamethasone (2 mg/kg) before being exposed to CSE for up to 9 weeks. Additionally, NADH supplementation preserved lung antioxidant defenses by preventing the functional loss of key enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase, and the expression levels of glutathione (GSH) (n = 4, p < 0.001). It also reduced oxidative damage markers, such as malondialdehyde (MDA) and nitrites (n = 4, p < 0.001). A marked increase in tissue myeloperoxidase activity was assessed (MPO), confirming neutrophils implication in the inflammatory process. The latter was significantly ameliorated in the NADH-treated groups (p < 0.001). Finally, NADH prevented the CSE-induced secretion of cytokines such as Tumor Necrosis Factor alpha (TNF-α), IL-17, and IFN-y (n = 4, p < 0.001). Our study shows, for the first time, the clinical potential of NADH supplementation in preventing key features of COPD via its unique anti-inflammatory and antioxidant properties.

Unraveling the interplay between vital organelle stress and oxidative stress in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease characterized by excessive accumulation of extracellular matrix, leading to irreversible fibrosis. Emerging evidence suggests that endoplasmic reticulum (ER) stress, mitochondrial stress, and oxidative stress pathways play crucial roles in the pathogenesis of IPF. ER stress occurs when the protein folding capacity of the ER is overwhelmed, triggering the unfolded protein response (UPR) and contributing to protein misfolding and cellular stress in IPF. Concurrently, mitochondrial dysfunction involving dysregulation of key regulators, including PTEN-induced putative kinase 1 (PINK1), Parkin, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and sirtuin 3 (SIRT3), disrupts mitochondrial homeostasis and impairs cellular energy metabolism. This leads to increased reactive oxygen species (ROS) production, release of pro-fibrotic mediators, and activation of fibrotic pathways, exacerbating IPF progression. The UPR-induced ER stress further disrupts mitochondrial metabolism, resulting in altered mitochondrial mechanisms that increase the generation of ROS, resulting in further ER stress, creating a feedback loop that contributes to the progression of IPF. Oxidative stress also plays a pivotal role in IPF, as ROS-mediated activation of TGF-β, NF-κB, and MAPK pathways promotes inflammation and fibrotic responses. This review mainly focuses on the links between ER stress, mitochondrial dysfunctions, and oxidative stress with different signaling pathways involved in IPF. Understanding these mechanisms and targeting key molecules within these pathways may offer promising avenues for intervention.

Mapping the metabolic responses to oxaliplatin-based chemotherapy with in vivo spatiotemporal metabolomics

Adjuvant chemotherapy improves the survival outlook for patients undergoing operations for lung metastases caused by colorectal cancer (CRC). However, a multidisciplinary approach that evaluates several factors related to patient and tumor characteristics is necessary for managing chemotherapy treatment in metastatic CRC patients with lung disease, as such factors dictate the timing and drug regimen, which may affect treatment response and prognosis. In this study, we explore the potential of spatial metabolomics for evaluating metabolic phenotypes and therapy outcomes during the local delivery of the anticancer drug, oxaliplatin, to the lung. 12 male Yorkshire pigs underwent a 3 h left lung in vivo lung perfusion (IVLP) with various doses of oxaliplatin (7.5, 10, 20, 40, and 80 mg/L), which were administered to the perfusion circuit reservoir as a bolus. Biocompatible solid-phase microextraction (SPME) microprobes were combined with global metabolite profiling to obtain spatiotemporal information about the activity of the drug, determine toxic doses that exceed therapeutic efficacy, and conduct a mechanistic exploration of associated lung injury. Mild and subclinical lung injury was observed at 40 mg/L of oxaliplatin, and significant compromise of the hemodynamic lung function was found at 80 mg/L. This result was associated with massive alterations in metabolic patterns of lung tissue and perfusate, resulting in a total of 139 discriminant compounds. Uncontrolled inflammatory response, abnormalities in energy metabolism, and mitochondrial dysfunction next to accelerated kynurenine and aldosterone production were recognized as distinct features of dysregulated metabolipidome. Spatial pharmacometabolomics may be a promising tool for identifying pathological responses to chemotherapy.

Pathological Impact of Tau Proteolytical Process on Neuronal and Mitochondrial Function: a Crucial Role in Alzheimer's Disease

Tau protein plays a pivotal role in the central nervous system (CNS), participating in microtubule stability, axonal transport, and synaptic communication. Research interest has focused on studying the role of post-translational tau modifications in mitochondrial failure, oxidative damage, and synaptic impairment in Alzheimer's disease (AD). Soluble tau forms produced by its pathological cleaved induced by caspases could lead to neuronal injury contributing to oxidative damage and cognitive decline in AD. For example, the presence of tau cleaved by caspase-3 has been suggested as a relevant factor in AD and is considered a previous event before neurofibrillary tangles (NFTs) formation.Interestingly, we and others have shown that caspase-cleaved tau in N- or C- terminal sites induce mitochondrial bioenergetics defects, axonal transport impairment, neuronal injury, and cognitive decline in neuronal cells and murine models. All these abnormalities are considered relevant in the early neurodegenerative manifestations such as memory and cognitive failure reported in AD. Therefore, in this review, we will discuss for the first time the importance of truncated tau by caspases activation in the pathogenesis of AD and how its negative actions could impact neuronal function.

Prognostic signature based on mitochondria quality control proteins for the prediction of lung adenocarcinoma patients survival

Lung cancer is the leading cause of cancer mortality worldwide. In recent years, the incidence of lung cancer subtype lung adenocarcinoma (LUAD) has steadily increased. Mitochondria, as a pivotal site of cell bioenergetics, metabolism, cell signaling, and cell death, are often dysregulated in lung cancer cells. Mitochondria maintenance and integrity depend on mitochondrial quality control proteins (MQCPs). During lung cancer progression, the levels of MQCPs could change and promote cancer cell adaptation to the microenvironment and stresses. Here, univariate and multivariate proportional Cox regression analyses were applied to develop a signature based on the level of MQCPs (dimeric form of BNIP3, DRP1, and SIRT3) in tumorous and non-tumorous samples of 80 patients with LUAD. The MQCP signature could be used to separate the patients with LUAD into high- and low-risk groups. Survival analysis indicated that patients in the high-risk group had dramatically shorter overall survival compared with the low-risk patients. Moreover, a nomogram combining clinicopathologic features and the MQCP signature was constructed and validated to predict 1-, 3-, and 5-year overall survival of the patients. Thus, this study presents a novel signature based on MQCPs as a reliable prognostic tool to predict overall survival for patients with LUAD.

The Role of Mitochondrial Dysfunction in Idiopathic Pulmonary Fibrosis: New Perspectives for a Challenging Disease

Mitochondrial biology has always been a relevant field in chronic diseases such as fibrosis or cancer in different organs of the human body, not to mention the strong association between mitochondrial dysfunction and aging. With the development of new technologies and the emergence of new methodologies in the last few years, the role of mitochondria in pulmonary chronic diseases such as idiopathic pulmonary fibrosis (IPF) has taken an important position in the field. With this review, we will highlight the latest advances in mitochondrial research on pulmonary fibrosis, focusing on the role of the mitochondria in the aging lung, new proposals for mechanisms that support mitochondrial dysfunction as an important cause for IPF, mitochondrial dysfunction in different cell populations of the lung, and new proposals for treatment of the disease.

Novel treatments against airway inflammation in COPD based on drug repurposing

Chronic obstructive pulmonary disease (COPD) is a major cause of death and reduces quality of life that contributes to a health problem worldwide. Chronic airway inflammation is a hallmark of COPD, which occurs in response to exposure of inhaled irritants like cigarette smoke. Despite accessible to the most up-to-date medications, none of the treatments is currently available to decrease the disease progression. Therefore, it is believed that drugs which can reduce airway inflammation will provide effective disease modifying therapy for COPD. There are many broad-range anti-inflammatory drugs including those that inhibit cell signaling pathways like inhibitors of p38 mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), and phosphoinositide-3-kinase (PI3K), are now in phase III development for COPD. In this chapter, we review recent basic research data in the laboratory that may indicate novel therapeutic pathways arisen from currently used drugs such as selective monoamine oxidase (MAO)-B inhibitors and drugs targeting peripheral benzodiazepine receptors [also known as translocator protein (TSPO)] to reduce airway inflammation. Considering the impact of chronic airway inflammation on the lives of COPD patients, the potential pharmacological candidates for new anti-inflammatory targets should be further investigated. In addition, it is crucial to consider the phenotypes/molecular endotypes of COPD patients together with specific outcome measures to target novel therapies. This review will enhance our knowledge on how cigarette smoke affects MAO-B activity and TSPO activation/inactivation with specific ligands through regulation of mitochondrial function, and will help to identify new potential treatment for COPD in future.

Mitochondria-Targeted Antioxidants as a Therapeutic Strategy for Chronic Obstructive Pulmonary Disease

Oxidative stress is a major hallmark of COPD, contributing to inflammatory signaling, corticosteroid resistance, DNA damage, and accelerated lung aging and cellular senescence. Evidence suggests that oxidative damage is not solely due to exogenous exposure to inhaled irritants, but also endogenous sources of oxidants in the form of reactive oxygen species (ROS). Mitochondria, the major producers of ROS, exhibit impaired structure and function in COPD, resulting in reduced oxidative capacity and excessive ROS production. Antioxidants have been shown to protect against ROS-induced oxidative damage in COPD, by reducing ROS levels, reducing inflammation, and protecting against the development of emphysema. However, currently available antioxidants are not routinely used in the management of COPD, suggesting the need for more effective antioxidant agents. In recent years, a number of mitochondria-targeted antioxidant (MTA) compounds have been developed that are capable of crossing the mitochondria lipid bilayer, offering a more targeted approach to reducing ROS at its source. In particular, MTAs have been shown to illicit greater protective effects compared to non-targeted, cellular antioxidants by further reducing apoptosis and offering greater protection against mtDNA damage, suggesting they are promising therapeutic agents for the treatment of COPD. Here, we review evidence for the therapeutic potential of MTAs as a treatment for chronic lung disease and discuss current challenges and future directions.

Mitoquinone ameliorated airway inflammation by stabilizing β-catenin destruction complex in a steroid-insensitive asthma model

BACKGROUND AND PURPOSE

Mitochondrial dysfunction is an essential part of the pathophysiology of asthma, and potential treatments that target the malfunctioning mitochondria have attracted widespread attention. We have previously demonstrated that aberrant epithelial β-catenin signaling played a crucial role in a toluene diisocyanate (TDI)-induced steroid-insensitive asthma model. The objective of this study was to determine if the mitochondrially targeted antioxidant mitoquinone(MitoQ) regulated the activation of β-catenin in TDI-induced asthma.

METHOD

Mice were sensitized and challenged with TDI to generate a steroid-insensitive asthma model. Human bronchial epithelial cells (16HBE) were exposed to TDI-human serum albumin (HSA) and ethidium bromide(EB) to simulate the TDI-induced asthma model and mitochondrial dysfunction.

RESULTS

MitoQ dramatically attenuated TDI-induced AHR, airway inflammation, airway goblet cell metaplasia, and collagen deposition and markedly protected epithelial mitochondrial functions by preserving mass and diminishing the production of reactive oxygen species (ROS). MitoQ administration stabilized β-catenin destruction complex from disintegration and inhibited the activation of β-catenin. Similarly, YAP1, an important constituent of β-catenin destruction complex, was inhibited by Dasatinib, which alleviated airway inflammation and the activation of β-catenin, and restored mitochondrial mass. In vitro, treating 16HBE cells with EB led to the activation of YAP1 and β-catenin signaling, decreased the expression of glucocorticoid receptors and up-regulated interleukin (IL)-1β, IL6 and IL-8 expression.

CONCLUSION

Our results indicated that mitochondria mediates airway inflammation by regulating the stability of the β-catenin destruction complex and MitoQ might be a promising therapeutic approach to improve airway inflammation and severe asthma.

AVAILABILITY OF DATA AND MATERIALS

The data that support the findings of this study are available from the corresponding author upon reasonable request. Some data may not be made available because of privacy or ethical restrictions.

Disruption of the Molecular Regulation of Mitochondrial Metabolism in Airway and Lung Epithelial Cells by Cigarette Smoke: Are Aldehydes the Culprit?

Chronic obstructive pulmonary disease (COPD) is a devastating lung disease for which cigarette smoking is the main risk factor. Acetaldehyde, acrolein, and formaldehyde are short-chain aldehydes known to be formed during pyrolysis and combustion of tobacco and have been linked to respiratory toxicity. Mitochondrial dysfunction is suggested to be mechanistically and causally involved in the pathogenesis of smoking-associated lung diseases such as COPD. Cigarette smoke (CS) has been shown to impair the molecular regulation of mitochondrial metabolism and content in epithelial cells of the airways and lungs. Although it is unknown which specific chemicals present in CS are responsible for this, it has been suggested that aldehydes may be involved. Therefore, it has been proposed by the World Health Organization to regulate aldehydes in commercially-available cigarettes. In this review, we comprehensively describe and discuss the impact of acetaldehyde, acrolein, and formaldehyde on mitochondrial function and content and the molecular pathways controlling this (biogenesis versus mitophagy) in epithelial cells of the airways and lungs. In addition, potential therapeutic applications targeting (aldehyde-induced) mitochondrial dysfunction, as well as regulatory implications, and the necessary required future studies to provide scientific support for this regulation, have been covered in this review.

Associations between serum mitokine levels and outcomes in stable COPD: an observational prospective study

Mitokines (Humanin (HN), GDF15 and FGF21) are produced as a result of mitochondrial dysfunction and may have major roles in chronic inflammation, malnutrition and exercise capacity in people with COPD. Except for GDF15, studies on this subject are lacking. A total of 165 patients with stable COPD and 49 smokers without COPD were enrolled. We assessed their serum mitokine levels and clinical characteristics at baseline. We recorded moderate and severe exacerbation for the next 12 months. Baseline serum HN (p = 0.037) and GDF-15 (p = 0.013) levels were higher in the COPD group. High HN levels were independently associated with a high risk of exacerbation (HRE) (OR 2.798, 95% CI 1.266-6.187, p = 0.011), malnutrition (OR 6.645, 95% CI 1.859-23.749, p = 0.004), and 6MWD (OR 0.995, 95% CI 0.991-0.999, p = 0.008), and future moderate (HR 1.826, 95% CI 1.181-2.822, p = 0.007) and severe exacerbations (HR 3.445, 95% CI 1.357-8.740, p = 0.009). High GDF15 levels were associated with HRE (OR 3.028, 95% CI 1.134-8.083, p = 0.027), 6MWD (OR 0.995, 95% CI 0.990-0.999, p = 0.017) and predicted desaturation in 6MWT (OR 3.999, 95% CI 1.487-10.757, p = 0.006). High FGF21 levels were associated with HRE (OR 2.144, 95% CI 1.000-4.600, p = 0.05), and predicted future severe exacerbation (HR 4.217, 95% CI 1.459-12.193, p = 0.008). The mitokine levels were higher in patients with COPD than smokers without COPD, and were associated with important clinical outcomes such as exercise capacity and COPD exacerbation. Among the mitokines, HN showed the strongest association with COPD and may serve as a future risk biomarker in this disease.Trial registation NCT04449419.

Calycosin Ameliorates Bleomycin-Induced Pulmonary Fibrosis via Suppressing Oxidative Stress, Apoptosis, and Enhancing Autophagy

Calycosin (CA) is a flavonoid extracted from the root of Astragalus membranaceus and has antioxidant, anti-inflammation, and antiapoptosis properties. The objective of this study was to investigate the efficacy of CA in protecting against pulmonary fibrosis. CA (14 mg/kg) and SB216763 (20 mg/kg) were administrated to bleomycin-induced pulmonary fibrosis mice for 3 weeks. The results concluded that CA alleviated the inflammation and collagen deposition in pulmonary fibrosis. In addition, CA reduced MDA level, enhanced SOD and TAC activities, and increased the activity of the Nrf2/HO-1 pathway. CA also regulated the expressions of apoptosis-related proteins. Moreover, CA enhanced autophagy via upregulating LC3, beclin1, PINK1, and reducing p62. CA also increased expression of LAMP1 and TFEB, and inhibited the release of lysosome enzymes from ruptured lysosomes. These results provide new evidence that CA protects against pulmonary fibrosis through inhibiting oxidative stress and apoptosis. In addition, autophagy abnormality and lysosome dysfunction are restored by CA.

Impairment of Mitochondrial Respiration in Metabolic Diseases: An Overview

Mitochondrial dysfunction has emerged as a central pathomechanism in the setting of obesity and diabetes mellitus, linking these intertwined pathologies that share insulin resistance as a common denominator. High-resolution respirometry (HRR) is a state-of-the-art research method currently used to study mitochondrial respiration and its impairment in health and disease. Tissue samples, cells or isolated mitochondria are exposed to various substrate-uncoupler-inhibitor-titration protocols, which allows the measurement and calculation of several parameters of mitochondrial respiration. In this review, we discuss the alterations of mitochondrial bioenergetics in the main dysfunctional organs that contribute to the development of the obese and diabetic phenotypes in both animal models and human subjects. Herein we review data regarding the impairment of oxidative phosphorylation as integrated mitochondrial function assessed by means of HRR. We acknowledge the critical role of this method in determining the alterations in oxidative phosphorylation occurring in the early stages of metabolic pathologies. We conclude that there is a mutual two-way relationship between mitochondrial dysfunction and insulin insensitivity that characterizes these diseases.

Acquisition of cellular properties during alveolar formation requires differential activity and distribution of mitochondria

Alveolar formation requires coordinated movement and interaction between alveolar epithelial cells, mesenchymal myofibroblasts, and endothelial cells/pericytes to produce secondary septa. These processes rely on the acquisition of distinct cellular properties to enable ligand secretion for cell-cell signaling and initiate morphogenesis through cellular contraction, cell migration, and cell shape change. In this study, we showed that mitochondrial activity and distribution play a key role in bestowing cellular functions on both alveolar epithelial cells and mesenchymal myofibroblasts for generating secondary septa to form alveoli in mice. These results suggest that mitochondrial function is tightly regulated to empower cellular machineries in a spatially specific manner. Indeed, such regulation via mitochondria is required for secretion of ligands, such as platelet-derived growth factor, from alveolar epithelial cells to influence myofibroblast proliferation and contraction/migration. Moreover, mitochondrial function enables myofibroblast contraction/migration during alveolar formation. Together, these findings yield novel mechanistic insights into how mitochondria regulate pivotal steps of alveologenesis. They highlight selective utilization of energy in cells and diverse energy demands in different cellular processes during development. Our work serves as a paradigm for studying how mitochondria control tissue patterning.

The Role of Sphingolipid Signaling in Oxidative Lung Injury and Pathogenesis of Bronchopulmonary Dysplasia

Premature infants are born with developing lungs burdened by surfactant deficiency and a dearth of antioxidant defense systems. Survival rate of such infants has significantly improved due to advances in care involving mechanical ventilation and oxygen supplementation. However, a significant subset of such survivors develops the chronic lung disease, Bronchopulmonary dysplasia (BPD), characterized by enlarged, simplified alveoli and deformed airways. Among a host of factors contributing to the pathogenesis is oxidative damage induced by exposure of the developing lungs to hyperoxia. Recent data indicate that hyperoxia induces aberrant sphingolipid signaling, leading to mitochondrial dysfunction and abnormal reactive oxygen species (ROS) formation (ROS). The role of sphingolipids such as ceramides and sphingosine 1-phosphate (S1P), in the development of BPD emerged in the last decade. Both ceramide and S1P are elevated in tracheal aspirates of premature infants of <32 weeks gestational age developing BPD. This was faithfully reflected in the murine models of hyperoxia and BPD, where there is an increased expression of sphingolipid metabolites both in lung tissue and bronchoalveolar lavage. Treatment of neonatal pups with a sphingosine kinase1 specific inhibitor, PF543, resulted in protection against BPD as neonates, accompanied by improved lung function and reduced airway remodeling as adults. This was accompanied by reduced mitochondrial ROS formation. S1P receptor1 induced by hyperoxia also aggravates BPD, revealing another potential druggable target in this pathway for BPD. In this review we aim to provide a detailed description on the role played by sphingolipid signaling in hyperoxia induced lung injury and BPD.

Bisphenol-A/Radiation mediated inflammatory response activates EGFR/KRAS/ERK1/2 signaling pathway leads to lung carcinogenesis incidence

Background

Bisphenol (BPA) and ionizing radiation exposure (IR) are potent oxidants that cause free radical induction, leading to signaling pathway activation that alters cell growth. Due to the insufficient knowledge of the impact of BPA and IR on the lungs, the current study determined the impact of BPA and IR on the lung tissue of adult female Wistar rats.

Methods

Forty Wister female rats were used in this study and were randomly divided into four groups. The rats received BPA (150 mg/kg body weight/day for 6 weeks) and were exposed to IR at 2 Gy/week up to 12 Gy for 6 weeks.

Results

It was found that BPA and IR possess a harmful effect on the lungs via induction of oxidative stress, confirmed by increasing levels of malondialdehyde (MDA), nitric oxide, myeloperoxidase (MPO), and lactate dehydrogenase (LDH). Exposure to BPA and IR activates inflammatory cytokines TNF-α, IL-6, IL-1β, growth factors such as TGF-β, and gastrin-releasing peptides. BPA/IR exposures induced phosphorylated expression p-ERK1/2 and p-MEK1/2 associated with triggering of the GPER/EGFR/KRAS signaling factors, resulting in matrix metalloproteinase-2 and 9 overexpression and the development of lung tumors. Our findings support the causal role of two deleterious environmental pollutants BPA and IR, via the cytotoxicity in the respiratory system in the form of severe lung damage resulting in cancerous cells.