Pregnancy exposure to carbon black nanoparticles exacerbates bleomycin-induced lung fibrosis in offspring via disrupting LKB1-AMPK-ULK1 axis-mediated autophagy

Environmental low-dose nanosized carbon black exposure aggravates lung fibrosis-induced by radiation in vivo and in vitro

The question of whether the emerging nano-material, nanosized carbon black (CB) could influence the lung damage-induced by radiation exposure in cancer patients or in acute nuclear accident population remains incompletely uncovered. Therefore, our study investigated potential health risk from environmental low-dose CB exposure level (0.1 mg/kg/d, once per three days, for 12 weeks) via nasal instillation using a lung fibrosis mouse model induced by radiation. Compared to either CB or radiation single exposure, low-dose CB plus radiation exposure showed an aggravated risk of lung damage in mice, which was embodied in more increased collagen, reactive oxygen species (ROS) concentrations, and inflammation cytokines levels including IL-1β and TNF-α, as well as promoted epithelial-mesenchymal transition (EMT) progress through increasing relative biomarkers such as N-cadherin and α-SMA. Mechanistically, CB triggered the cGAS-STING signaling pathway to aggravation of radiation-induced lung injury. Furthermore, knocking down the GAS or STING expression would suppress the EMT process and inflammation reaction, resulting in significantly attenuating the combination effects of low-dose CB plus radiation on lung damage. Overall, our study indicates that environmental CB exposure may increase the lung damage in certain special population cannot be ignored. It sheds light on possible molecular mechanisms from cGAS-STING inflammation perspective and providing valuable basic understanding for future study on radiation-induced lung damage. Synopsis State of exposure of environmentally relevant nanosized carbon black may exacerbate the lung injury among cancer patients undergoing radiotherapy.

Reticulophagy promotes EMT-induced fibrosis in offspring's lung tissue after maternal exposure to carbon black nanoparticles during gestation by a m5C-dependent manner

Accumulating evidence indicates that maternal exposure to carbon black nanoparticles (CBNPs) during gestation can induce multiple system abnormalities in offspring, whereas its potential mechanism in respiratory disease is still largely unknown. In order to explore the effect of maternal exposure to CBNPs on offspring's lung and latent pathogenesis, we respectively established in vivo model of pregnant rats exposed to CBNPs and ex vivo model of lung epithelial cells treated with pups' serum of pregnant rats exposed to CBNPs. After maternal exposure to CBNPs, epithelial-mesenchymal transition (EMT) and fibrosis levels increased as a result of DDRGK1-mediated reticulophagy upregulated in offspring's lung. DDRGK1 as FAM134B's cargo bound with FAM134B to mediate reticulophagy. Transcription factor "SP1" positively regulated DDRGK1 gene expression by binding to its promoter. Furthermore, the upregulation of NSUN2 elevated m5C methylation of SP1 mRNA and the protein level of SP1 subsequently increased through Ybx1 recognizing and stabilizing m5C-methylated SP1 mRNA, followed by the increased levels of reticulophagy and fibrosis in lung epithelial cells treated with offspring's serum of matrix exposed to CBNPs during gestation. In conclusion, NSUN2/Ybx1/m5C-SP1 axis promoted DDRGK1-mediated reticulophagy, which played an important role in EMT-induced fibrosis in offspring's lung tissue after maternal exposure to CBNPs during gestation.

Review on the role of autophagy in the toxicity of nanoparticles and the signaling pathways involved

As the development of nanotechnology, the application of nanoproducts and the advancement of nanomedicine, the contact of nanoparticles (NPs) with human body is becoming increasingly prevalent. This escalation elevates the risk of NPs exposure for workers, consumers, researchers, and both aquatic and terrestrial organisms throughout the production, usage, and disposal stages. Consequently, evaluating nanotoxicity remains critically important, though standardized assessment criteria are still lacking. The diverse and complex properties of NPs further complicate the understanding of their toxicological mechanisms. Autophagy, a fundamental cellular process, exhibits dual functions-both pro-survival and pro-death. This review offers an updated perspective on the dual roles of autophagy in nanotoxicity and examines the factors influencing autophagic responses. However, no definitive framework exists for predicting NPs-induced autophagy. Beyond the conventional autophagy pathways, the review highlights specific transcription factors activated by NPs and explores metabolic reprogramming. Particular attention is given to NPs-induced selective autophagy, including mitophagy, ER-phagy, ferritinophagy, lysophagy, and lipophagy. Additionally, the review investigates autophagy's involvement in NPs-mediated biological processes such as ferroptosis, inflammation, macrophage polarization, epithelial-mesenchymal transition, tumor cell proliferation and drug resistance, as well as liver and kidney injury, neurotoxicity, and other diseases. In summary, this review presents a novel update on selective autophagy-mediated nanotoxicity and elucidates the broader interactions of autophagy in NPs-induced biological processes. Collectively, these insights offer valuable strategies for mitigating nanotoxicity through autophagy modulation and advancing the development of NPs in biomedical applications.

All Roads Lead to Rome: Comparing Nanoparticle- and Small Molecule-Driven Cell Autophagy

Autophagy, vital for removing cellular waste, is triggered differently by small molecules and nanoparticles. Small molecules, like rapamycin, non-selectively activate autophagy by inhibiting the mTOR pathway, which is essential for cell regulation. This can clear damaged components but may cause cytotoxicity with prolonged use. Nanoparticles, however, induce autophagy, often causing oxidative stress, through broader cellular interactions and can lead to a targeted form known as "xenophagy." Their impact varies with their properties but can be harnessed therapeutically. In this review, the autophagy induced by nanoparticles is explored and small molecules across four dimensions: the mechanisms behind autophagy induction, the outcomes of such induction, the toxicological effects on cellular autophagy, and the therapeutic potential of employing autophagy triggered by nanoparticles or small molecules. Although small molecules and nanoparticles each induce autophagy through different pathways and lead to diverse effects, both represent invaluable tools in cell biology, nanomedicine, and drug discovery, offering unique insights and therapeutic opportunities.

Societal Co-benefits of Zero-Emission Vehicles in the Freight Industry

This study was set in the Greater Toronto and Hamilton Area (GTHA), where commercial vehicle movements were assigned across the road network. Implications for greenhouse gas (GHG) emissions, air quality, and health were examined through an environmental justice lens. Electrification of light-, medium-, and heavy-duty trucks was assessed to identify scenarios associated with the highest benefits for the most disadvantaged communities. Using spatially and temporally resolved commercial vehicle movements and a chemical transport model, changes in air pollutant concentrations under electric truck scenarios were estimated at 1-km2 resolution. Heavy-duty truck electrification reduces ambient black carbon and nitrogen dioxide on average by 10 and 14%, respectively, and GHG emissions by 10.5%. It achieves the highest reduction in premature mortality attributable to fine particulate matter chronic exposure (around 200 cases per year) compared with light- and medium-duty electrification (less than 150 cases each). The burden of all traffic in the GTHA was estimated to be around 600 cases per year. The benefits of electrification accrue primarily in neighborhoods with a high social disadvantage, measured by the Ontario Marginalization Indices, narrowing the disparity of exposure to traffic-related air pollution. Benefits related to heavy-duty truck electrification reflect the adverse impacts of diesel-fueled freight and highlight the co-benefits achieved by electrifying this sector.

Preclinical evidence using synthetic compounds and natural products indicates that AMPK represents a potential pharmacological target for the therapy of pulmonary diseases

Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is a highly conserved eukaryotic enzyme discovered as a key regulator of cellular energy homeostasis, with anti-inflammation, antioxidative stress, anticancer, and antifibrosis beneficial effects. AMPK is dysregulated in human pulmonary diseases such as acute lung injury, nonsmall cell lung cancer, pulmonary fibrosis, chronic obstructive pulmonary disease, and asthma. This review provides an overview of the beneficial role of natural, synthetic, and Chinese traditional medicines AMPK modulators in pulmonary diseases, and highlights the role of the AMPK signaling pathway in the lung, emphasizing the importance of finding lead compounds and drugs that can target and modulate AMPK to treat the lung diseases.

Unveiling Vaginal Fibrosis: A Novel Murine Model Using Bleomycin and Epithelial Disruption

Objective

Develop, validate, and characterize a fibrotic murine vaginal wound healing model using bleomycin instillations and epithelial disruption.

Approach

We tested the effect of repeated bleomycin instillations with mucosal layer disruption on induction of vaginal fibrosis. Tissue samples collected at various time points were analyzed for fibrosis-related gene expression changes and collagen content.

Results

Low (1.5U/kg) and high-dose (2.5U/kg) bleomycin instillations alone did not induce fibrosis, but when high-dose bleomycin was combined with epithelial disruption, increased pro-fibrotic gene expression and trichrome staining were observed. To evaluate spatial and temporal changes in the ECM structure and gene expression, tissue samples were collected at 1 day, 3 weeks, and 6 weeks after bleomycin and epithelial disruption. Data analyses revealed a significant decrease in matrix metabolizing genes and an increase in pro-fibrotic genes and inhibitors of matrix metabolizing genes in the bleomycin plus epithelial disruption group at 3 weeks. Elevated levels of the profibrotic genes Acta2 , Col1a1 , and Col3a were exclusively detected in this group at 3 weeks, and trichrome staining confirmed increased collagen content after 3 weeks. Hydroxyproline levels showed a tendency towards elevation at 3 weeks (p=0.12) and 6 weeks (p=0.14), indicating fibrosis manifestation at 3 weeks and resolution by 6 weeks post-instillation and epithelial disruption.

Innovation

We combined bleomycin instillations with epithelial disruption to induce fibrosis and understand the mechanisms of the vaginal repair process.

Conclusions

Epithelial disruption combined with bleomycin induces murine vaginal fibrosis within three weeks, characterized by increased collagen synthesis. Remarkably, the vaginal tissue fully recovers within six weeks, elucidating the regenerative capacity of the vagina.

Autophagy regulation by inorganic, organic, and organic/inorganic hybrid nanoparticles: Organelle damage, regulation factors, and potential pathways

The rapid development of nanotechnology requires a more thorough understanding of the potential health effects caused by nanoparticles (NPs). As a programmed cell death, autophagy is one of the biological effects induced by NPs, which maintain intracellular homeostasis by degrading damaged organelles and removing aggregates of defective proteins through lysosomes. Currently, autophagy has been shown to be associated with the development of several diseases. A significant number of research have demonstrated that most NPs can regulate autophagy, and their regulation of autophagy is divided into induction and blockade. Studying the autophagy regulation by NPs will facilitate a more comprehensive understanding of the toxicity of NPs. In this review, we will illustrate the effects of different types of NPs on autophagy, including inorganic NPs, organic NPs, and organic/inorganic hybrid NPs. The potential mechanisms by which NPs regulate autophagy are highlighted, including organelle damage, oxidative stress, inducible factors, and multiple signaling pathways. In addition, we list the factors influencing NPs-regulated autophagy. This review may provide basic information for the safety assessment of NPs.

Autophagy in the pharmacological activities of celastrol (Review)

Celastrol, a natural compound extracted from the traditional Chinese medicinal herb Tripterygium wilfordii Hook F, possesses broad-spectrum pharmacological properties. Autophagy is an evolutionarily conserved catabolic process through which cytoplasmic cargo is delivered to the lysosomes for degradation. Autophagy dysregulation contributes to multiple pathological processes. Therefore, targeting autophagic activity is a promising therapy for various diseases, as well as a drug-development strategy. According to previous studies, autophagy is specifically targeted and may be altered in response to celastrol treatment, highlighting that autophagy modulation is an important mechanism underlying the therapeutic efficacy of celastrol for the treatment of various diseases. The present study summarizes the currently available information regarding the role of autophagy in the effect of celastrol to exert anti-tumor, anti-inflammatory, immunomodulatory, neuroprotective, anti-atherosclerosis, anti-pulmonary fibrosis and anti-macular degeneration activities. The diverse signaling pathways involved are also analyzed to provide insight into the mechanisms of action of celastrol and thereby pave the way for establishing celastrol as an efficacious autophagy modulator in clinical practice.

Diesel exhaust PM2.5 greatly deteriorates fibrosis process in pre-existing pulmonary fibrosis via ferroptosis

Fine particulate matter (PM2.5) has been widely reported to contribute to the pathogenesis of pulmonary diseases. The direct hazardous effect of PM2.5 on the respiratory system at high concentrations in vitro and in vivo have been well identified. However, its effect on the pre-existing respiratory diseases of patients at environment-related concentrations remains unclear. Diesel exhaust PM2.5 as a primary representative of ambient PM2.5 fine particles were used to investigated the effect of PM2.5 on the fibrosis progression of existing pulmonary fibrosis disease models. This study reported that PM2.5 could result in the enhanced sensitivity to fibrotic response, which may be ascribed to ferroptosis induced by PM2.5 in damaged lung areas. Proteomic analysis revealed that the upregulation of HO-1 as a key mechanism in the ferroptosis and exacerbation of pulmonary fibrosis induced by PM2.5. As a result, HO-1 degraded heme-containing protein and released iron in fibrotic cells, leading to generation of mitochondrial ROS and impaired mitochondrial function. Transmission electron microscopic assay verified that PM2.5 entered the mitochondria of fibrotic cells and was accompanied by significant mitochondrial morphological changes characterized by increased mitochondrial membrane density and reduced mitochondrial size. The HO-1 inhibitor zinc protoporphyrin and mitochondrion-targeted antioxidant Mito-TEMPO significantly attenuated PM2.5-induced ferroptosis and exacerbation of fibrosis. In addition, AMPK-ULK1 axis-triggered autophagy activation and NCOA4-mediated degradation of ferritin by autophagy were found to be related to the PM2.5-induced ferroptosis of fibrotic cells. As evidenced by the inhibition of autophagy with 3-methyladenine or AMPK inhibitor, NCOA4 knockdown decreased intracellular iron accumulation and lipid peroxidation, thereby relieving PM2.5-induced epithelial-mesenchymal transition and cell death in fibrotic cells. Overall, this study provided experimental support for the idea that PM2.5 greatly deteriorates fibrosis process in pre-existing pulmonary fibrosis, and HO-1-mediated mitochondrial dysfunction and NCOA4-mediated ferritinophagy are jointly required for the PM2.5-induced ferroptosis and enhanced fibrosis effects.

The Effects and Pathogenesis of PM2.5 and Its Components on Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD), a heterogeneous disease, is the leading cause of death worldwide. In recent years, air pollution, especially particulate matter (PM), has been widely studied as a contributing factor to COPD. As an essential component of PM, PM2.5 is associated with COPD prevalence, morbidity, and acute exacerbations. However, the specific pathogenic mechanisms were still unclear and deserve further research. The diversity and complexity of PM2.5 components make it challenging to get its accurate effects and mechanisms for COPD. It has been determined that the most toxic PM2.5 components are metals, polycyclic aromatic hydrocarbons (PAHs), carbonaceous particles (CPs), and other organic compounds. PM2.5-induced cytokine release and oxidative stress are the main mechanisms reported leading to COPD. Nonnegligibly, the microorganism in PM 2.5 may directly cause mononuclear inflammation or break the microorganism balance contributing to the development and exacerbation of COPD. This review focuses on the pathophysiology and consequences of PM2.5 and its components on COPD.

Maternal NO2 exposure disturbs the long noncoding RNA expression profile in the lungs of offspring in time-series patterns

Gestation is a sensitive window to nitrogen dioxide (NO₂) exposure, which may disturb fetal lung development and lung function later in life. Animal and epidemiological studies indicated that long noncoding RNAs (lncRNAs) participate in abnormal lung development induced by environmental pollutant exposure. In the present study, pregnant C57BL/6J mice were exposed to 2.5 ppm NO₂ (mimicking indoor occupational exposure) or clean air, and lncRNAs expression profiles in the lungs of offspring mice were determined by lncRNA-seq on embryonic day 13.5 (E13.5), E18.5, postnatal day 1 (P1), and P14. The lung histopathology examination of offspring was performed, followed by weighted gene coexpression network analysis (WGCNA), prediction of lncRNAs-target genes, and the biological processes enrichment analysis of lncRNAs. Our results indicated that maternal NO₂ exposure induced hypoalveolarization on P14 and differentially expressed lncRNAs showed a time-series pattern. Following WGCNA and enrichment analysis, 2 modules participated in development-related pathways. Importantly, the expressions of related genes were altered, some of which were confirmed to be related to abnormal vascular development and even lung diseases. The research points out that the maternal NO₂ exposure leads to abnormal lung development in offspring that might be related to altered lncRNAs expression profiles with time-series-pattern.

Function and regulation of ULK1: From physiology to pathology

The expression of ULK1, a core protein of autophagy, is closely related to autophagic activity. Numerous studies have shown that pathological abnormal expression of ULK1 is associated with various human diseases such as neurological disorders, infections, cardiovascular diseases, liver diseases and cancers. In addition, new advances in the regulation of ULK1 have been identified. Furthermore, targeting ULK1 as a therapeutic strategy for diseases is gaining attention as new corresponding activators or inhibitors are being developed. In this review, we describe the structure and regulation of ULK1 as well as the current targeted activators and inhibitors. Moreover, we highlight the pathological disorders of ULK1 expression and its critical role in human diseases.

ROCK inhibitor attenuates carbon blacks-induced pulmonary fibrosis in mice via Rho/ROCK/NF-kappa B pathway

Exposure to carbon blacks (CBs) has been associated with the progression of pulmonary fibrosis, whereas the mechanism is still not clear. We therefore aimed to investigate the effect of RhoA/ROCK pathway on pulmonary fibrosis caused by CBs exposure. Western blot analysis indicated that CBs could promote the activation of RhoA/ROCK pathway and phosphorylation of p65 and IκBα in mice lung. However, ROCK inhibitor Y-27632 could attenuate phosphorylation levels of p65 and IκBα and restore histopathological changes of the lung tissue. Then, we evaluated the effect of RhoA/ROCK pathway on pulmonary fibrosis by detecting the expression levels of α-SMA, vimentin, and Collagen type-I (Col-I), which could be partly inhibited by Y-27632. It was assumed that inhibition of ROCK could be a promising therapeutic candidate for CBs-induced pulmonary fibrosis, which possibly through the blockage of RhoA/ROCK/NF-κB pathway.

Nanomaterial-mediated autophagy: coexisting hazard and health benefits in biomedicine

BACKGROUND

Widespread biomedical applications of nanomaterials (NMs) bring about increased human exposure risk due to their unique physicochemical properties. Autophagy, which is of great importance for regulating the physiological or pathological activities of the body, has been reported to play a key role in NM-driven biological effects both in vivo and in vitro. The coexisting hazard and health benefits of NM-mediated autophagy in biomedicine are nonnegligible and require our particular concerns.

MAIN BODY

We collected research on the toxic effects related to NM-mediated autophagy both in vivo and in vitro. Generally, NMs can be delivered into animal models through different administration routes, or internalized by cells through different uptake pathways, exerting varying degrees of damage in tissues, organs, cells, and organelles, eventually being deposited in or excreted from the body. In addition, other biological effects of NMs, such as oxidative stress, inflammation, necroptosis, pyroptosis, and ferroptosis, have been associated with autophagy and cooperate to regulate body activities. We therefore highlight that NM-mediated autophagy serves as a double-edged sword, which could be utilized in the treatment of certain diseases related to autophagy dysfunction, such as cancer, neurodegenerative disease, and cardiovascular disease. Challenges and suggestions for further investigations of NM-mediated autophagy are proposed with the purpose to improve their biosafety evaluation and facilitate their wide application. Databases such as PubMed and Web of Science were utilized to search for relevant literature, which included all published, Epub ahead of print, in-process, and non-indexed citations.

CONCLUSION

In this review, we focus on the dual effect of NM-mediated autophagy in the biomedical field. It has become a trend to use the benefits of NM-mediated autophagy to treat clinical diseases such as cancer and neurodegenerative diseases. Understanding the regulatory mechanism of NM-mediated autophagy in biomedicine is also helpful for reducing the toxic effects of NMs as much as possible.

Self-eating: friend or foe? The emerging role of autophagy in fibrotic diseases

Fibrosis occurs in most human organs including the liver, lung, heart and kidney, and is crucial for the progression of most chronic diseases. As an indispensable catabolic process for intracellular quality control and homeostasis, autophagy occurs in most mammalian cells and is implicated in many biological processes including fibrogenesis. Although advances have been made in understanding autophagy process, the potential role of autophagy in fibrotic diseases remains controversial and has recently attracted a great deal of attention. In the current review, we summarize the commonalities of autophagy affecting different types of fibrosis in different organs, including the liver, lung, heart, and kidney as well as in cystic fibrosis, systematically outline the contradictory results and highlight the distinct role of autophagy during the various stages of fibrosis. In summary, the exact role autophagy plays in fibrogenesis depends on specific cell types and different stimuli, and identifying and evaluating the pathogenic contribution of autophagy in fibrogenesis will promote the discovery of novel therapeutic strategies for the clinical management of these fibrotic diseases.

Lysosomal dysfunction is associated with persistent lung injury in dams caused by pregnancy exposure to carbon black nanoparticles

AIMS

Carbon black nanoparticles (CBNPs) are widely used in industrial field. Sensitive stages such as pregnancy are assumed to be more susceptible to stimulus, however whether pregnancy exposure to CBNPs (PrE-to-CBNPs) would cause long-term toxic effects in dams and the underlying mechanisms remain poorly addressed. The present study is aimed to determine the long-term toxic effects of PrE-to-CBNPs in dams.

MATERIALS AND METHODS

The pregnant mice were randomly divided into control group, low (21 μg/animal), medium (103 μg/animal) and high (515 μg/animal) CBNPs-treated groups. From gestational day (GD) 9 to GD18, the pregnant mice were intranasal exposed. At 49 days after parturition, lung tissues and bronchoalveolar lavage fluid (BALF) were obtained. Weight change, lung histopathology, lung ultrastructural pathology, cell count in BALF, oxidative stress/inflammatory maker and autophagy/lysosome-related protein expression were determined.

KEY FINDINGS

PrE-to-CBNPs caused a dose-dependent persistent lung injury in mice even 49 days after parturition, including the deteriorative lung histopathological changes, elevation of oxidative stress marker Nrf-2, HO-1 and CHOP, infiltration of macrophage and increased mRNA expression of inflammatory cytokines in the lung tissues and elevation of cells in BALF. However, PrE-to-CBNPs did not induce significant neutrophil infiltration and fibrosis. Moreover, we found that CBNPs could deposit in the lysosomes and decrease cathepsin D (an important hydrolase in lysosome), which might be associated with the dysfunction of lysosome and autophagy.

SIGNIFICANCE

Our study demonstrated that PrE-to-CBNPs could result in long-term lung injury in dams, and lysosomal dysfunction was probably linked to this process.