Oxidative stress and pulmonary fibrosis

Aging in chronic lung disease: Will anti-aging therapy be the key to the cure?

Chronic lung disease is the third leading cause of death globally, imposing huge burden of death, disability and healthcare costs. However, traditional pharmacotherapy has relatively limited effects in improving the cure rate and reducing the mortality of chronic lung disease. Thus, new treatments are urgently needed for the prevention and treatment of chronic lung disease. It is particularly noteworthy that, multiple aging-related phenotypes were involved in the occurrence and development of chronic lung disease, such as blocked proliferation, telomere attrition, mitochondrial dysfunction, epigenetic alterations, altered nutrient perception, stem cell exhaustion, chronic inflammation, etc. Consequently, senescent cells induce a series of pathological changes in the lung, such as immune dysfunction, airway remodeling, oxidative stress and regenerative dysfunction, which is a critical issue that needs special attention in chronic lung diseases. Therefore, anti-aging interventions may bring new insights into the treatment of chronic lung diseases. In this review, we elaborate the involvement of aging in chronic lung disease and further discuss the application and prospects of anti-aging therapy.

Activation of SIRT3 by Tanshinone IIA ameliorates renal fibrosis by suppressing the TGF-β/TSP-1 pathway and attenuating oxidative stress

Although doxorubicin (DOX) is a common chemotherapeutic drug, the serious nephrotoxicity caused by DOX-induced renal fibrosis remains a considerable clinical problem. Tanshinone IIA (Tan IIA), a compound extracted from Salvia miltiorrhiza, has been reported to have an anti-fibrotic effect. Therefore, this study investigated the molecular pathway whereby Tan IIA protects the kidneys from DOX administration. DOX (3 mg/kg body weight) was intraperitoneally administered every 3 d for a total of 7 injections (cumulative dose of 21 mg/kg) to induce nephrotoxicity. Then, Tan IIA (5 or 10 mg/kg/d) was administered by intraperitoneal injection for 28 d. In an in vitro study, 293 T cells were cultured and treated with DOX and Tan IIA for 24 h. Tan IIA reduced the blood urea nitrogen levels elevated by DOX while increasing superoxide dismutase activity, down-regulating reactive oxygen species, ameliorating renal-tubule thickening, and rescuing mitochondrial morphology. Additionally, Tan IIA reduced the renal collagen deposition, increased ATP production and complex-I activity, down-regulated transforming growth factor-β1 (TGF-β1) and thrombospondin-1 (TSP-1), and up-regulated sirtuin 3 (SIRT3). Tan IIA significantly increased cell viability. Additionally, RNA interference was employed to silence the expression of SIRT3, which eliminated the effect of Tan IIA in suppressing the expression of TGF-β1 and TSP-1. In conclusion, Tan IIA ameliorated DOX-induced nephrotoxicity by attenuating oxidative injury and fibrosis. The Tan IIA-induced rescue of mitochondrial morphology and function while alleviating renal fibrosis may be associated with the activation of SIRT3 to suppress the TGF-β/TSP-1 pathway.

Therapeutic use of fisetin and pirfenidone combination in bleomycin-induced pulmonary fibrosis in adult male albino rats

Pulmonary fibrosis is an important health problem; one of the drugs used in its treatment is pirfenidone (PFD). Fisetin (FST) is a flavonoid with antioxidative, anti-inflammatory, and antifibrotic effects. The aim of this study was to induce PF in rats with bleomycin (BLM) and to investigate the combined effect of PFD and FST in the treatment of fibrosis. In the study, 40 male Wistar rats were divided into five groups (n = 8). Sham group was administered saline on day 0 and BLM (5 mg/kg, i.t.) was administered to the other groups; BLM + PFD group: PFD (50 mg/kg) was administered every day between the first and 15th days; BLM + FST group: FST (25 mg/kg) was administered between the first and 15th days; BLM + PFD + FST group: PFD (50 mg/kg) and FST (25 mg/kg) were administered by gavage every day between the first and 15th days. At the end of the 15th day, BAL was performed under anaesthesia and lung tissues were removed. Histopathological, biochemical, and RT-PCR analyses were performed in the lung tissue. In our study, the concomitant use of FST and PFD caused downregulation of NF-κB p65, TGF-β1, and α-SMA expressions; downregulation of TIMP-1, MMP-2, and MMP-9 genes; downregulation of HYP, MPO, and MDA activity; decrease in the number of differential cells in BAL; and upregulation of GSH. This shows that FST and PFD have antifibrotic, antioxidative, and anti-inflammatory effects. Our results show that the combined use of PFD and FST in BLM-induced pulmonary fibrosis reduces extracellular matrix accumulation, downregulates the level of gelatinases and their inhibitors, and provides significant improvements in antioxidative defence parameters.

Identification of oxidative stress-related diagnostic markers and immune infiltration features for idiopathic pulmonary fibrosis by bibliometrics and bioinformatics

Idiopathic pulmonary fibrosis (IPF) garners considerable attention due to its high fatality rate and profound impact on quality of life. Our study conducts a comprehensive literature review on IPF using bibliometric analysis to explore existing hot research topics, and identifies novel diagnostic and therapeutic targets for IPF using bioinformatics analysis. Publications related to IPF from 2013 to 2023 were searched on the Web of Science Core Collection (WoSCC) database. Data analysis and visualization were conducted using CiteSpace and VOSviewer software primarily. The gene expression profiles GSE24206 and GSE53845 were employed as the training dataset. The GSE110147 dataset was employed as the validation dataset. We identified differentially expressed genes (DEGs) and differentially expressed genes related to oxidative stress (DEOSGs) between IPF and normal samples. Then, we conducted Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The hub genes were screened by protein-protein interaction (PPI) networks and machine learning algorithms. The CIBERSORT was used to analyze the immune infiltration of 22 kinds of immune cells. Finally, we conducted the expression and validation of hub genes. The diagnostic efficacy of hub genes was evaluated by employing Receiver Operating Characteristic (ROC) curves and the associations between hub genes and immune cells were analyzed. A total of 6,500 articles were identified, and the annual number of articles exhibited an upward trend. The United States emerged as the leading contributor in terms of publication count, institutional affiliations, highly cited articles, and prolific authorship. According to co-occurrence analysis, oxidative stress and inflammation are hot topics in IPF research. A total of 1,140 DEGs were identified, and 72 genes were classified as DEOSGs. By employing PPI network analysis and machine learning algorithms, PON2 and TLR4 were identified as hub genes. A total of 10 immune cells exhibited significant differences between IPF and normal samples. PON2 and TLR4, as oxidative stress-related genes, not only exhibit high diagnostic efficacy but also show close associations with immune cells. In summary, our study highlights oxidative stress and inflammation are hot topics in IPF research. Oxidative stress and immune cells play a vital role in the pathogenesis of IPF. Our findings suggest the potential of PON2 and TLR4 as novel diagnostic and therapeutic targets for IPF.

Protective effects of E-CG-01 (3,4-lacto cycloastragenol) against bleomycin-induced lung fibrosis in C57BL/6 mice

Idiopathic pulmonary fibrosis is an aging-related, chronic lung disease, with unclear pathogenesis and no effective treatment. One of the triggering factors in cell aging is oxidative stress and it is known to have a role in idiopathic pulmonary fibrosis. In this paper, the protective effect of the E-CG-01 (3,4-lacto-cycloastragenol) molecule in terms of its antioxidant properties was evaluated in the bleomycin induced mice lung fibrosis model. Bleomycin sulfate was administered as a single dose (2.5 U/kg body weight) intratracheally to induce lung fibrosis. E-CG-01 was administered intraperitoneally in three different doses (2 mg/kg/day, 6 mg/kg/day, and 10 mg/kg/day) for 14 days, starting three days before the bleomycin administration. Fibrosis was examined by Hematoxylin-Eosin, Masson Trichrome, and immunohistochemical staining for TGF-beta1, Type I collagen Ki-67, and gama-H2AX markers. Activity analysis of catalase and Superoxide dismutase enzymes, measurement of total oxidant, total glutathione, and Malondialdehyde levels. In histological analysis, it was determined that all three different doses of the molecule provided a prophylactic effect against the progression of fibrosis compared to the bleomycin control group. However, it was observed that only the molecule applied in the high dose decreased the total oxidant stress level. Lung weight ratio increased in the BLM group but significantly reduced with high-dose E-CG-01. E-CG-01 at all doses reduced collagen deposition, TGF-β expression, and Ki-67 expression compared to the BLM group. Intermediate and high doses of E-CG-01 also significantly reduced alveolar wall thickness and edema formation. These findings suggest that E-CG-01 has potential therapeutic effects in mitigating lung fibrosis through its antioxidant properties.

Radiation Induced Skin Fibrosis (RISF): Opportunity for Angiotensin II-Dependent Intervention

Medical procedures, such as radiation therapy, are a vital element in treating many cancers, significantly contributing to improved survival rates. However, a common long-term complication of such exposure is radiation-induced skin fibrosis (RISF), a complex condition that poses substantial physical and psychological challenges. Notably, about 50% of patients undergoing radiation therapy may achieve long-term remission, resulting in a significant number of survivors managing the aftereffects of their treatment. This article delves into the intricate relationship between RISF, reactive oxygen species (ROS), and angiotensin II (Ang II) signaling. It proposes the underlying mechanisms and examines potential treatments for mitigating skin fibrosis. The primary goal is to offer essential insights in order to better care for and improve the quality of life of cancer survivors who face the risk of developing RISF.

Genome-wide RNA sequencing of ocular fibroblasts from glaucomatous and normal eyes: Implications for glaucoma management

Primary open angle glaucoma is a leading cause of visual impairment and blindness which is commonly treated with drugs or laser but may require surgery. Tenon's ocular fibroblasts are involved in wound-healing after glaucoma filtration surgery and may compromise a favourable outcome of glaucoma surgery by contributing to fibrosis. To investigate changes in gene expression and key pathways contributing to the glaucomatous state we performed genome-wide RNA sequencing. Human Tenon's ocular fibroblasts were cultured from normal and glaucomatous human donors undergoing eye surgery (n = 12). mRNA was extracted and RNA-Seq performed on the Illumina platform. Differentially expressed genes were identified using a bioinformatics pipeline consisting of FastQC, STAR, FeatureCounts and edgeR. Changes in biological functions and pathways were determined using Enrichr and clustered using Cytoscape. A total of 5817 genes were differentially expressed between Tenon's ocular fibroblasts from normal versus glaucomatous eyes. Enrichment analysis showed 787 significantly different biological functions and pathways which were clustered into 176 clusters. Tenon's ocular fibroblasts from glaucomatous eyes showed signs of fibrosis with fibroblast to myofibroblast transdifferentiation and associated changes in mitochondrial fission, remodeling of the extracellular matrix, proliferation, unfolded protein response, inflammation and apoptosis which may relate to the pathogenesis of glaucoma or the detrimental effects of topical glaucoma therapies. Altered gene expression in glaucomatous Tenon's ocular fibroblasts may contribute to an unfavourable outcome of glaucoma filtration surgery. This work presents a genome-wide transcriptome of glaucomatous versus normal Tenon's ocular fibroblasts which may identify genes or pathways of therapeutic value to improve surgical outcomes.

Tanshinone IIA positively regulates the Keap1-Nrf2 system to alleviate pulmonary fibrosis via the sestrin2-sqstm1 signaling axis-mediated autophagy

BACKGROUND

Activation of myofibroblasts, linked to oxidative stress, emerges as a pivotal role in the progression of pulmonary fibrosis (PF). Our prior research has underscored the therapeutic promise of tanshinone IIA (Tan-IIA) in mitigating PF by enhancing nuclear factor-erythroid 2-related factor 2 (Nrf2) activity. Nevertheless, the molecular basis through which Tan-IIA influences Nrf2 activity has yet to be fully elucidated.

METHODS

The influence of Tan-IIA on PF was assessed in vivo and in vitro models. Inhibitors, overexpression plasmids, and small interfering RNA (siRNA) were utilized to probe its underlying mechanism of action in vitro.

RESULTS

We demonstrate that Tan-IIA effectively activates the kelch-like ECH-associated protein 1 (Keap1)-Nrf2 antioxidant pathway, which in turn inhibits myofibroblast activation and ameliorates PF. Notably, the stability and nucleo-cytoplasmic shuttling of Nrf2 is shown to be dependent on augmented autophagic flux, which is in alignment with the observation that Tan-IIA induces autophagy. Inhibition of autophagy, conversely, fosters the activation of extracellular matrix (ECM)-producing myofibroblasts. Further, Tan-IIA initiates an autophagy program through the sestrin 2 (Sesn2)-sequestosome 1 (Sqstm1) signaling axis, crucial for protecting Nrf2 from Keap1-mediated degradation. Meanwhile, these findings were corroborated in a murine model of PF.

CONCLUSION

Collectively, we observed for the first time that the Sqstm1-Sesn2 axis-mediated autophagic degradation of Keap1 effectively prevents myofibroblast activation and reduces the synthesis of ECM. This autophagy-dependent degradation of Keap1 can be initiated by the Tan-IIA treatment, which solidifies its potential as an Nrf2-modulating agent for PF treatment.

Leptin in reproduction and hypertension in pregnancy

Leptin has important roles in numerous physiological functions, including those in the regulation of energy balance, and in immune and reproductive systems. However, in the recent years, evidence has implicated it in a number of obesity-related diseases, where its concentrations in serum are significantly elevated. Elevated serum leptin concentrations and increased placental leptin secretion have been reported in women with hypertensive disorders of pregnancy. Whether leptin is responsible for this disorder remains to be established. Leptin injections in healthy rats and mice during pregnancy result in endothelial activation, increased blood pressure and proteinuria. A potential role for leptin in the pathogenesis of pre-eclampsia is hypothesised, particularly in women who are overweight or obese where serum leptin concentrations are often elevated. This review summarises pertinent information in the literature on the role of leptin in puberty, pregnancy, and hypertensive disorders of pregnancy. In particular, the possible mechanism that may be involved in leptin-induced increase in blood pressure and proteinuria during pregnancy and the potential role of marinobufagenin in this disease entity. We hypothesise a significant role for oxidative stress in this, and propose a conceptual framework on the events that lead to endothelial activation, raised blood pressure and proteinuria following leptin administration.

Mitigation of Oxidative Stress in Idiopathic Pulmonary Fibrosis Through Exosome-Mediated Therapies

Idiopathic pulmonary fibrosis (IPF) poses a formidable clinical challenge, characterized by the thickening of alveolar septa and the onset of pulmonary fibrosis. The pronounced activation of oxidative stress emerges as a pivotal hallmark of inflammation. Traditional application of exogenous antioxidants proves inadequate in addressing oxidative stress, necessitating exploration into strategies to augment their antioxidant efficacy. Exosomes, nano-sized extracellular vesicles harboring a diverse array of bioactive factors, present as promising carriers with the potential to meet this challenge. Recent attention has been directed towards the clinical applications of exosomes in IPF, fueling the impetus for this comprehensive review. We have compiled fresh insights into the role of exosomes in modulating oxidative stress in IPF and delved into their potential as carriers for regulating endogenous reactive oxygen species generation. This review endeavors to bridge the divide between exosome research and IPF, traversing from bedside to bench. Through the synthesis of recent findings, we propose exosomes as a novel and promising strategy for improving the outcomes of IPF therapy.

Inhibition of reactive oxygen species generation by N-Acetyl Cysteine can mitigate male germ cell toxicity induced by bisphenol analogs

The estrogen-like effect of bisphenol A (BPA) disrupting the maintenance of functional male germ cells is associated with male sub-fertility. This study investigated toxicity of male germ cells induced by four bisphenol analogs: BPA, BPAF, BPF, and BPS. The investigation of bisphenol analogs' impact on male germ cells included assessing proliferation, apoptosis induction, and the capacity to generate reactive oxygen species (ROS) in GC-1 spermatogonia (spg) cells, specifically type B spermatogonia. Additionally, the therapeutic potential and protective effects of N-Acetyl Cysteine (NAC) and NF-κB inhibitor parthenolide was evaluated. In comparison to BPA, BPF and BPS, BPAF exhibited the most pronounced adverse effect in GC-1 spg cell proliferation. This effect was characterized by pronounced inhibition of phosphorylation of PI3K, AKT, and mTOR, along with increased release of cytochrome c and subsequent cleavages of caspase 3, caspase 7, and poly (ADP-ribose) polymerase. Both NAC and parthenolide were effective reducing cellular ROS induced by BPAF. However, only NAC demonstrated a substantial recovery in proliferation, accompanied by a significant reduction in cytochrome c release and cleaved PARP. These results suggest that NAC supplementation may play an effective therapeutic role in countering germ cell toxicity induced by environmental pollutants with robust oxidative stress-generating capacity.

Simvastatin attenuates silica-induced pulmonary inflammation and fibrosis in rats via the AMPK-NOX pathway

BACKGROUND

Simvastatin (Sim), a hydroxy-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, has been widely used in prevention and treatment of cardiovascular diseases. Studies have suggested that Sim exerts anti-fibrotic effects by interfering fibroblast proliferation and collagen synthesis. This study was to determine whether Sim could alleviate silica-induced pulmonary fibrosis and explore the underlying mechanisms.

METHODS

The rat model of silicosis was established by the tracheal perfusion method and treated with Sim (5 or 10 mg/kg), AICAR (an AMPK agonist), and apocynin (a NOX inhibitor) for 28 days. Lung tissues were collected for further analyses including pathological histology, inflammatory response, oxidative stress, epithelial mesenchymal transformation (EMT), and the AMPK-NOX pathway.

RESULTS

Sim significantly reduced silica-induced pulmonary inflammation and fibrosis at 28 days after administration. Sim could reduce the levels of interleukin (IL)-1β, IL-6, tumor necrosis factor-α and transforming growth factor-β1 in lung tissues. The expressions of hydroxyproline, α-SMA and vimentin were down-regulated, while E-cad was increased in Sim-treated rats. In addition, NOX4, p22pox, p40phox, p-p47phox/p47phox expressions and ROS levels were all increased, whereas p-AMPK/AMPK was decreased in silica-induced rats. Sim or AICAR treatment could notably reverse the decrease of AMPK activity and increase of NOX activity induced by silica. Apocynin treatment exhibited similar protective effects to Sim, including down-regulating of oxidative stress and inhibition of the EMT process and inflammatory reactions.

CONCLUSIONS

Sim attenuates silica-induced pulmonary inflammation and fibrosis by downregulating EMT and oxidative stress through the AMPK-NOX pathway.

Antrodia cinnamomea extract alleviates bleomycin-induced pulmonary fibrosis in mice by inhibiting the mTOR pathway

BACKGROUND

Pulmonary fibrosis is a progressive diffuse parenchymal lung disorder with a high mortality rate. Studies have indicated that injured lung tissues release various pro-inflammatory factors, and produce a large amount of nitric oxide. There is also accumulation of collagen and oxidative stress-induced injury, collectively leading to pulmonary fibrosis. Antrodia cinnamomea is an endemic fungal growth in Taiwan, and its fermented extracts exert anti-inflammatory effects to alleviate liver damages. Hence, we hypothesized and tested the feasibility of using A. cinnamomea extracts for treatment of pulmonary fibrosis.

METHODS

The TGF-β1-induced human lung fibroblast cells (MRC-5) in vitro cell assay were used to evaluate the effects of A. cinnamomea extracts on the collagen production in MRC-5. Eight-week-old ICR mice were intratracheally administered bleomycin and then fed with an A. cinnamomea extract on day 3 post-administration of bleomycin. At day 21 post-bleomycin administration, the pulmonary functional test, the expression level of inflammation- and fibrosis-related genes in the lung tissue, and the histopathological change were examined.

RESULTS

The A. cinnamomea extract significantly attenuated the expression level of collagen in the TGF-β1-induced MRC-5 cells. In the A. cinnamome-treated bleomycin-induced lung fibrotic mice, the bodyweight increased, pulmonary functions improved, the lung tissues expression level of inflammatory factor and the fibrotic indicator were decreased, and the histopathological results showed the reduction of thickening of the inter-alveolar septa.

CONCLUSIONS

The Antrodia cinnamomea extract significant protects mice against bleomycin-induced lung injuries through improvement of body weight gain and lung functions, and attenuation of expression of inflammatory and fibrotic indicators.

Co-Delivery of Astaxanthin and siTGF-β1 via Ionizable Liposome Nanoparticles for Improved Idiopathic Pulmonary Fibrosis Therapy

Alleviating the injury of type II alveolar epithelial cells (AEC 2s) and inhibiting the activation and differentiation of fibroblasts are significant for improving the therapeutic effect of idiopathic pulmonary fibrosis (IPF). To this aim, ionizable liposome nanoparticles (ASNPs) coloaded with antioxidant drug astaxanthin (AST) and small interfering RNA targeting transforming growth factor β1 (siTGF-β1) were developed for enhanced IPF therapy. ASNPs showed high loading and intracellular delivery efficiency for AST and siTGF-β1. After the injection of ASNPs in an IPF mice model, the loaded AST largely scavenged reactive oxygen species (ROS) in the diseased lung to reduce AEC2 apoptosis, thereby ensuring the integrity of the alveolar epithelium. Meanwhile, siTGF-β1, delivered by ASNPs, significantly silenced the expression of TGF-β1 in fibroblasts, inhibiting the differentiation of fibroblasts into myofibroblasts as well as reducing the excessive deposition of extracellular matrix (ECM). The combined use of the two drugs exhibited an excellent synergistic antifibrotic effect and was conducive to minimizing alveolar epithelial damage. This work provides a codelivery strategy of AST and siTGF-β1, which shows great promise for the treatment of IPF by simultaneously reducing alveolar epithelial damage and inhibiting fibroblast activation.

NBR1-p62-Nrf2 mediates the anti-pulmonary fibrosis effects of protodioscin

BACKGROUND

Idiopathic pulmonary fibrosis is a persistent disease of the lung interstitium for which there is no efficacious pharmacological therapy. Protodioscin, a steroidal saponin, possesses diverse pharmacological properties; however, its function in pulmonary fibrosis is yet to be established. Hence, in this investigation, it was attempted to figure out the anti-pulmonary fibrosis influences of protodioscin and its pharmacological properties related to oxidative stress.

METHODS

A mouse lung fibrosis model was generated using tracheal injections of bleomycin, followed by intraperitoneal injection of different concentrations of protodioscin, and the levels of oxidative stress and fibrosis were detected in the lungs. Multiple fibroblasts were treated with TGF-β to induce their transition to myofibroblasts. It was attempted to quantify myofibroblast markers' expression levels and reactive oxygen species levels as well as Nrf2 activation after co-incubation of TGF-β with fibroblasts and different concentrations of protodioscin. The influence of protodioscin on the expression and phosphorylation of p62, which is associated with Nrf2 activation, were detected, and p62 related genes were predicted by STRING database. The effects of Nrf2 inhibitor or silencing of the Nrf2, p62 and NBR1 genes, respectively, on the activation of Nrf2 by protodioscin were examined. The associations between p62, NBR1, and Keap1 in the activation of Nrf2 by protodioscin was demonstrated using a co-IP assay. Nrf2 inhibitor were used when protodioscin was treated in mice with pulmonary fibrosis and lung tissue fibrosis and oxidative stress levels were detected.

RESULTS

In vivo, protodioscin decreased the levels of fibrosis markers and oxidative stress markers and activated Nrf2 in mice with pulmonary fibrosis, and these effects were inhibited by Nrf2 inhibitor. In vitro, protodioscin decreased the levels of myofibroblast markers and oxidative stress markers during myofibroblast transition and promoted Nrf2 downstream gene expression, with reversal of these effects after Nrf2, p62 and NBR1 genes were silenced or Nrf2 inhibitors were used, respectively. Protodioscin promoted the binding of NBR1 to p62 and Keap1, thereby reducing Keap1-Nrf2 binding.

CONCLUSION

The NBR1-p62-Nrf2 axis is targeted by protodioscin to reduce oxidative stress and inhibit pulmonary fibrosis.

The role of epithelial cells in fibrosis: Mechanisms and treatment

Fibrosis is a pathological process that affects multiple organs and is considered one of the major causes of morbidity and mortality in multiple diseases, resulting in an enormous disease burden. Current studies have focused on fibroblasts and myofibroblasts, which directly lead to imbalance in generation and degradation of extracellular matrix (ECM). In recent years, an increasing number of studies have focused on the role of epithelial cells in fibrosis. In some cases, epithelial cells are first exposed to external physicochemical stimuli that may directly drive collagen accumulation in the mesenchyme. In other cases, the source of stimulation is mainly immune cells and some cytokines, and epithelial cells are similarly altered in the process. In this review, we will focus on the multiple dynamic alterations involved in epithelial cells after injury and during fibrogenesis, discuss the association among them, and summarize some therapies targeting changed epithelial cells. Especially, epithelial mesenchymal transition (EMT) is the key central step, which is closely linked to other biological behaviors. Meanwhile, we think studies on disruption of epithelial barrier, epithelial cell death and altered basal stem cell populations and stemness in fibrosis are not appreciated. We believe that therapies targeted epithelial cells can prevent the progress of fibrosis, but not reverse it. The epithelial cell targeting therapies will provide a wonderful preventive and delaying action.

Nanosensor detection of reactive oxygen and nitrogen species leakage in frustrated phagocytosis of nanofibres

Exposure to widely used inert fibrous nanomaterials (for example, glass fibres or carbon nanotubes) may result in asbestos-like lung pathologies, becoming an important environmental and health concern. However, the origin of the pathogenesis of such fibres has not yet been clearly established. Here we report an electrochemical nanosensor that is used to monitor and quantitatively characterize the flux and dynamics of reactive species release during the frustrated phagocytosis of glass nanofibres by single macrophages. We show the existence of an intense prolonged release of reactive oxygen and nitrogen species by single macrophages near their phagocytic cups. This continued massive leakage of reactive oxygen and nitrogen species damages peripheral cells and eventually translates into chronic inflammation and lung injury, as seen during in vitro co-culture and in vivo experiments.

Potential Rheumatoid Arthritis-Associated Interstitial Lung Disease Treatment and Computational Approach for Future Drug Development

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by swelling in at least one joint. Owing to an overactive immune response, extra-articular manifestations are observed in certain cases, with interstitial lung disease (ILD) being the most common. Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is characterized by chronic inflammation of the interstitial space, which causes fibrosis and the scarring of lung tissue. Controlling inflammation and pulmonary fibrosis in RA-ILD is important because they are associated with high morbidity and mortality. Pirfenidone and nintedanib are specific drugs against idiopathic pulmonary fibrosis and showed efficacy against RA-ILD in several clinical trials. Immunosuppressants and disease-modifying antirheumatic drugs (DMARDs) with anti-fibrotic effects have also been used to treat RA-ILD. Immunosuppressants moderate the overexpression of cytokines and immune cells to reduce pulmonary damage and slow the progression of fibrosis. DMARDs with mild anti-fibrotic effects target specific fibrotic pathways to regulate fibrogenic cellular activity, extracellular matrix homeostasis, and oxidative stress levels. Therefore, specific medications are required to effectively treat RA-ILD. In this review, the commonly used RA-ILD treatments are discussed based on their molecular mechanisms and clinical trial results. In addition, a computational approach is proposed to develop specific drugs for RA-ILD.

Role of lung ornithine aminotransferase in idiopathic pulmonary fibrosis: regulation of mitochondrial ROS generation and TGF-β1 activity

Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant lung remodeling and the excessive accumulation of extracellular matrix (ECM) proteins. In a previous study, we found that the levels of ornithine aminotransferase (OAT), a principal enzyme in the proline metabolism pathway, were increased in the lungs of patients with IPF. However, the precise role played by OAT in the pathogenesis of IPF is not yet clear. The mechanism by which OAT affects fibrogenesis was assessed in vitro using OAT-overexpressing and OAT-knockdown lung fibroblasts. The therapeutic effects of OAT inhibition were assessed in the lungs of bleomycin-treated mice. OAT expression was increased in fibrotic areas, principally in interstitial fibroblasts, of lungs affected by IPF. OAT levels in the bronchoalveolar lavage fluid of IPF patients were inversely correlated with lung function. The survival rate was significantly lower in the group with an OAT level >75.659 ng/mL than in the group with an OAT level ≤75.659 ng/mL (HR, 29.53; p = 0.0008). OAT overexpression and knockdown increased and decreased ECM component production by lung fibroblasts, respectively. OAT knockdown also inhibited transforming growth factor-β1 (TGF)-β1 activity and TGF-β1 pathway signaling. OAT overexpression increased the generation of mitochondrial reactive oxygen species (ROS) by activating proline dehydrogenase. The OAT inhibitor L-canaline significantly attenuated bleomycin-induced lung injury and fibrosis. In conclusion, increased OAT levels in lungs affected by IPF contribute to the progression of fibrosis by promoting excessive mitochondrial ROS production, which in turn activates TGF-β1 signaling. OAT may be a useful target for treating patients with fibrotic lung diseases, including IPF.

Sodium p-perfluorous nonenoxybenzene sulfonate induces ROS-mediated necroptosis by directly targeting catalase in HepG2 cells

Sodium p-perfluorous nonenoxybenzene sulfonate (OBS) has been widely used as a substitute for perfluorooctane sulfonic acid (PFOS) because of its high surface activity and low cost, but the knowledge of its biological effects is still limited. In this study, we compared the toxic effects of OBS and PFOS on human hepatoma cells (HepG2). OBS resulted in lower cell viability, higher ROS levels, and more severe necrosis than PFOS, indicating that OBS caused higher cytotoxicity than PFOS. In this process, OBS induced a burst of ROS and downregulation of catalase (CAT). OBS-induced oxidative stress was recovered after the CAT overexpression, but the CAT levels were not reversed after N-acetylcysteine (NAC) pretreatment. This indicates that the downregulated CAT is an upstream signal of the ROS burst. Moreover, drug affinity targeting assay, spectroscopic analysis and molecular docking were conducted, showing that OBS directly targeted CAT and therefore downregulated CAT. In addition, we found that OBS-induced necrosis is RIP1/RIP3-dependent programmed necroptosis. In summary, OBS directly targets CAT to reduce CAT levels and induces oxidative stress and necroptosis. Our findings are helpful to understand the toxicity of OBS and to evaluate the safety of OBS as a substitute for PFOS.

The Effect of Physalis angulata L. Administration on Gene Expressions Related to Lung Fibrosis Resolution in Mice-Induced Bleomycin

Purpose

To explore the potential therapeutic effects of Physalis angulata L. (Ciplukan) extract on lung fibrosis resolution in a Bleomycin-induced mouse model, researchers conducted a comprehensive study. The study focused on key genes associated with fibrosis progression, including Nox4, Mmp8, Klf4, and FAS, and assessed their mRNA expression levels following the administration of Ciplukan extract.

Methods

A Bleomycin-induced mice model was divided into seven groups to investigate the effects of ciplukan extract on fibrosis-related gene expressions. Mice were induced with subcutaneously injected Bleomycin to generate lung fibrosis and given different doses of the Ciplukan extract for four weeks. Lung fibrosis mRNA expression was analyzed by semi-quantitative PCR for Nox4, Klf4, Mmp8, and FAS.

Results

The administration of ciplukan extract resulted in a significant decrease in mRNA expression of Nox4 with p-value=0.000, Mmp8 with p-value =0.002, and Klf4 with p-value =0.007, indicating potential antifibrotic effects. However, FAS expression remained unchanged (p-value=0.127).

Conclusion

Ciplukan extract exhibited promising effects on fibrosis-related gene expressions, particularly Nox4, Mmp8, and Klf4. This study suggests that the extract has the potential to intervene in fibrosis progression, offering a potential avenue for therapeutic strategies.

Hypouricemia as a novel predictor of mortality in anti-MDA5 positive dermatomyositis patients with ILD: A retrospective cohort study

OBJECTIVE

Anti-melanoma differentiation-associated gene 5 antibody positive dermatomyositis (MDA5+ DM) is a unique subtype of idiopathic inflammatory myopathy (IIM) that is associated with rapidly progressive interstitial lung disease (RPILD) and high mortality. This retrospective study aimed to identify predictors of mortality and discover novel easily detectable indicators.

METHODS

We retrospectively reviewed 183 MDA5+ DM-ILD patients who were from West China Hospital of Sichuan University myositis cohort, the largest single-center cohort of southwest China, from January 2016 to October 2021. Clinical characteristics were reviewed, and risk factors for mortality were determined by univariate and multivariable Cox regression analyses.

RESULTS

Of the 183 MDA5+ DM-ILD patients, 59 were presented with RP-ILD, and 53 died during the follow-up period. Compared with the survived patients, deceased patients had higher rates of dyspnea, higher concentrations of CRP, and LDH, but lower rates of heliotrope sign, lower quantity of lymphocyte and lower levels of serum uric acid (SUA). Notably, patients with hypouricemia (SUA <154 μmol/L) had higher concentrations of CRP and LDH, higher neutrophil counts, lower lymphocyte counts and higher mortality rate when compared with the non-hypouricemia group. Multivariate Cox regression analyses confirmed that hypouricemia, smoking, RPILD, high HRCT score, elevated LDH, and lymphopenia were independent risk factors for mortality in MDA5+ DM-ILD patients. Moreover, patients with hypouricemia had significantly lower survival rates than non-hypouricemia patients.

CONCLUSION

Our study identified hypouricemia as a non-redundant promising prognostic factor for the mortality of MDA5+ DM-ILD patients, which may hopefully provide insight into the prevention and pathogenesis study.

Disease diagnosis and severity classification in pulmonary fibrosis using carbonyl volatile organic compounds in exhaled breath

BACKGROUND

Pathophysiological conditions underlying pulmonary fibrosis remain poorly understood. Exhaled breath volatile organic compounds (VOCs) have shown promise for lung disease diagnosis and classification. In particular, carbonyls are a byproduct of oxidative stress, associated with fibrosis in the lungs. To explore the potential of exhaled carbonyl VOCs to reflect underlying pathophysiological conditions in pulmonary fibrosis, this proof-of-concept study tested the hypothesis that volatile and low abundance carbonyl compounds could be linked to diagnosis and associated disease severity.

METHODS

Exhaled breath samples were collected from outpatients with a diagnosis of Idiopathic Pulmonary Fibrosis (IPF) or Connective Tissue related Interstitial Lung Disease (CTD-ILD) with stable lung function for 3 months before enrollment, as measured by pulmonary function testing (PFT) DLCO (%), FVC (%) and FEV1 (%). A novel microreactor was used to capture carbonyl compounds in the breath as direct output products. A machine learning workflow was implemented with the captured carbonyl compounds as input features for classification of diagnosis and disease severity based on PFT (DLCO and FVC normal/mild vs. moderate/severe; FEV1 normal/mild/moderate vs. moderately severe/severe).

RESULTS

The proposed approach classified diagnosis with AUROC=0.877 ± 0.047 in the validation subsets. The AUROC was 0.820 ± 0.064, 0.898 ± 0.040, and 0.873 ± 0.051 for disease severity based on DLCO, FEV1, and FVC measurements, respectively. Eleven key carbonyl VOCs were identified with the potential to differentiate diagnosis and to classify severity.

CONCLUSIONS

Exhaled breath carbonyl compounds can be linked to pulmonary function and fibrotic ILD diagnosis, moving towards improved pathophysiological understanding of pulmonary fibrosis.

Ang-(1-7)/Mas axis ameliorates bleomycin-induced pulmonary fibrosis in mice via restoration of Nox4-Nrf2 redox homeostasis

Pulmonary fibrosis (PF) is a chronic, progressive interstitial lung disease characterized by diffuse alveolar inflammation, fibroblast differentiation, and the excessive deposition of extracellular matrix. During the progression of PF, redox imbalance caused by excessive reactive oxygen species (ROS) production can result in further destruction of lung tissue. At present, data on the role of NADPH oxidase-4 (Nox4)-nuclear factor erythroid 2-related factor 2 (Nrf2) redox imbalance in PF are limited. The angiotensin (1-7) [Ang-(1-7)]/Mas axis is a protective axis in the renin-angiotensin system (RAS) that exerts antifibrotic effects. Therefore, this study aimed to investigate the role of the Ang-(1-7)/Mas axis in PF and to explore its mechanism in depth. The results revealed that the Ang-(1-7)/Mas axis inhibited TGF-β1-induced lung fibroblast differentiation, inflammation and fibrosis in bleomycin (BLM)-treated lung tissue. A mechanistic study suggested that the Ang-(1-7)/Mas axis may restore Nox4-Nrf2 redox homeostasis by upregulating the level of p62, reducing oxidative stress and the inflammatory response and thus delaying the progression of lung fibrosis. This study provides a theoretical basis for exploring the mechanisms of PF and therapeutic targets for PF.

Renal Fibrosis and Oxidative Stress Induced by Silica Nanoparticles in Male Rats and Its Molecular Mechanisms

Background

The utilization of amorphous silica nanoparticles (SiNPs) is gaining popularity in various applications, but it poses a potential risk to human and environmental health. However, the underlying causes and mechanisms of SiNPs-induced kidney damage are still largely unknown.

Objectives

This study aimed to investigate the SiNPs-induced damage in the kidney and further explore the possible mechanisms of SiNPs-induced nephrotoxicity.

Methods

Thirty adult male rats were divided into 3 different groups. Rats in groups 2 and 3 were administered SiNPs at 2 dosage levels (25 and 100 mg/kg of body weight), while the rats in the control group received no treatment for 28 days. Reactive oxygen species (ROS), antioxidant enzyme activities (glutathione peroxidase [GPx], superoxide dismutase [SOD], and catalase [CAT]), glutathione (GSH) levels, and oxidation markers (such as lipid peroxidation [malondialdehyde (MDA)] and protein oxidation [protein carbonyl (PCO)]) were analyzed in the kidney tissue. Additionally, renal fibrogenesis was studied through histopathological examination and the expression levels of fibrotic biomarkers.

Results

The findings revealed that in vivo treatment with SiNPs significantly triggered oxidative stress in kidney tissues in a dose-dependent manner. This was characterized by increased production of ROS, elevated levels of MDA, PCO, and nitric oxide (NO), along with a significant decline in the activities of SOD, CAT, GPx, and reduced GSH. These changes were consistent with the histopathological analysis, which indicated interstitial fibrosis with mononuclear inflammatory cell aggregation, tubular degeneration, glomerulonephritis, and glomerular atrophy. The fibrosis index was confirmed using Masson's trichrome staining. Additionally, there was a significant upregulation of fibrosis-related genes, including transforming growth factor-beta 1 (TGF-β1), matrix metalloproteinases 2 and 9 (MMP-2/9), whereas the expression of tissue inhibitor of metalloproteinase 2 (TIMP2) was downregulated.

Conclusions

This study provided a new research clue for the role of ROS and deregulated TGF-β signaling pathway in SiNPs nephrotoxicity.

Diabetic Pneumopathy- A Novel Diabetes-associated Complication: Pathophysiology, the Underlying Mechanism and Combination Medication

BACKGROUND

The "diabetic lung" has been identified as a possible target organ in diabetes, with abnormalities in ventilation control, bronchomotor tone, lung volume, pulmonary diffusing capacity, and neuroadrenergic bronchial innervation.

OBJECTIVE

This review summarizes studies related to diabetic pneumopathy, pathophysiology and a number of pulmonary disorders including type 1 and type 2 diabetes.

METHODS

Electronic searches were conducted on databases such as Pub Med, Wiley Online Library (WOL), Scopus, Elsevier, ScienceDirect, and Google Scholar using standard keywords "diabetes," "diabetes Pneumopathy," "Pathophysiology," "Lung diseases," "lung infection" for review articles published between 1978 to 2023 very few previous review articles based their focus on diabetic pneumopathy and its pathophysiology.

RESULTS

Globally, the incidence of diabetes mellitus has been rising. It is a chronic, progressive metabolic disease. The "diabetic lung" may serve as a model of accelerated ageing since diabetics' rate of respiratory function deterioration is two to three-times higher than that of normal, non-smoking people.

CONCLUSION

Diabetes-induced pulmonary dysfunction has not gained the attention it deserves due to a lack of proven causality and changes in cellular properties. The mechanism underlying a particular lung illness can still only be partially activated by diabetes but there is evidence that hyperglycemia is linked to pulmonary fibrosis in diabetic people.

Bezafibrate reduces the damage, activation and mechanical properties of lung fibroblast cells induced by hydrogen peroxide

In pulmonary fibrosis, the proliferation of fibroblasts and their differentiation into myofibroblasts is often caused by tissue damage, such as oxidative damage caused by reactive oxygen species, which leads to progressive rupture and thus destruction of the alveolar architecture, resulting in cell proliferation and tissue remodeling. Bezafibrate (BZF) is an important member of the peroxisome proliferator-activated receptor (PPARs) family agonists, used in clinical practice as antihyperlipidemic. However, the antifibrotic effects of BZF are still poorly studied. The objective of this study was to evaluate the effects of BZF on pulmonary oxidative damage in lung fibroblast cells. MRC-5 cells were treated with hydrogen peroxide (H2O2) to induce oxidative stress activation and BZF treatment was administered at the same moment as H2O2 induction. The outcomes evaluated were cell proliferation and cell viability; oxidative stress markers such as reactive oxygen species (ROS), catalase (CAT) levels and thiobarbituric acid reactive substances (TBARS); col-1 and α-SMA mRNA expression and cellular elasticity through Young's modulus analysis evaluated by atomic force microscopy (AFM). The H2O2-induced oxidative damage decreased the cell viability and increased ROS levels and decreased CAT activity in MRC-5 cells. The expression of α-SMA and the cell stiffness increased in response to H2O2 treatment. Treatment with BZF decreased the MRC-5 cell proliferation, ROS levels, reestablished CAT levels, decreased the mRNA expression of type I collagen protein (col-1) and α-smooth muscle actin (α-SMA), and cellular elasticity even with H2O2 induction. Our results suggest that BZF has a potential protective effect on H2O2-induced oxidative stress. These results are based on an in vitro experiment, derived from a fetal lung cell line and may emerge as a possible new therapy for the treatment of pulmonary fibrosis.

Melatonin alleviates particulate matter-induced liver fibrosis by inhibiting ROS-mediated mitophagy and inflammation via Nrf2 activation

OBJECTIVE

Fine particulate matter (PM2.5) is a source of pollution worldwide, that causes inflammation and liver fibrosis. Melatonin, as the predominant hormone secreted by the pineal gland, can inhibit PM2.5-induced lung injury by activating nuclear factor erythroid 2-related factor 2 (Nrf2) to inhibit ferroptosis. However, the possible role of melatonin in PM2.5-induced liver damage remains unclear.

EXPERIMENTAL APPROACH

In vitro, the effects of melatonin on PM2.5-induced oxidative stress and LX-2 cell activation were examined. In vivo, a PM2.5-induced inflammation and liver fibrosis mouse model was used to evaluate the hepatoprotective effect of melatonin.

RESULTS

In vitro, melatonin induced the expression of Nrf2 and its downstream genes and inhibited PM2.5-induced reactive oxygen species (ROS) production and mitochondrial damage. Melatonin also ameliorated the PM2.5-induced oxidative stress and fibrogenic marker upregulation. However, the antifibrotic effect of melatonin was abolished in siNrf2-treated LX-2 cells. In vivo, we observed mitochondrial abnormalities and mitochondrial fragmentation, which were accompanied by increased PTEN-induced kinase 1 (PINK1) and Parkin expression, in PM2.5-treated mouse hepatocytes. These changes were partially reversed by melatonin. In addition, melatonin activated the Nrf2 signaling pathway and protected against PM2.5-induced oxidative stress. Furthermore, melatonin alleviated inflammation and liver fibrosis. Moreover, Nrf2-KO mice exhibited more severe inflammation and liver fibrosis after PM2.5 exposure than wild-type mice, and the protective effect of melatonin on PM2.5- treated Nrf2-KO mice was greatly compromised.

CONCLUSION

These data suggest that melatonin effectively inhibits PM2.5-induced liver fibrosis by activating Nrf2 and inhibiting ROS-mediated mitophagy and inflammation.

Integrated mass spectrometry imaging reveals spatial-metabolic alteration in diabetic cardiomyopathy and the intervention effects of ferulic acid

Diabetic cardiomyopathy (DCM) is a metabolic disease and a leading cause of heart failure among people with diabetes. Mass spectrometry imaging (MSI) is a versatile technique capable of combining the molecular specificity of mass spectrometry (MS) with the spatial information of imaging. In this study, we used MSI to visualize metabolites in the rat heart with high spatial resolution and sensitivity. We optimized the air flow-assisted desorption electrospray ionization (AFADESI)-MSI platform to detect a wide range of metabolites, and then used matrix-assisted laser desorption ionization (MALDI)-MSI for increasing metabolic coverage and improving localization resolution. AFADESI-MSI detected 214 and 149 metabolites in positive and negative analyses of rat heart sections, respectively, while MALDI-MSI detected 61 metabolites in negative analysis. Our study revealed the heterogenous metabolic profile of the heart in a DCM model, with over 105 region-specific changes in the levels of a wide range of metabolite classes, including carbohydrates, amino acids, nucleotides, and their derivatives, fatty acids, glycerol phospholipids, carnitines, and metal ions. The repeated oral administration of ferulic acid during 20 weeks significantly improved most of the metabolic disorders in the DCM model. Our findings provide novel insights into the molecular mechanisms underlying DCM and the potential of ferulic acid as a therapeutic agent for treating this condition.

Silicon dioxide-induced endoplasmic reticulum stress of alveolar macrophages and its role on the formation of silicosis fibrosis: a review article

Silicosis is a chronic lung inflammatory disease induced by long-term inhalation of high concentrations of silicon dioxide (SiO2), characterized by pulmonary fibrosis. Inhalation of silica invades alveolar macrophages (AMs) and changes the micro-environment of the cell, resulting in abnormal morphology and dysfunction of the endoplasmic reticulum (ER). Once beyond the range of cell regulation, the endoplasmic reticulum stress (ERS) will occur, which will lead to cell damage, necrosis, and apoptosis, eventually causing silicosis fibrosis through various mechanisms. This is a complex and delicate process accompanied by various macrophage-derived cytokines. Unfortunately, the details have not been systematically summarized yet. In this review, we systematically introduce the basic two processes: the process of inducing ERS by inhaling SiO2 and the process of inducing pulmonary fibrosis by ERS. Moreover, the underlying mechanism of the above two sequential events is also be discussed. We conclude that the ERS of alveolar macrophages caused by silica dust are involved deeply in the pathogenesis of silicosis. Therefore, changing the states of SiO2-induced ERS of macrophage may be an attractive therapeutic target for silicosis fibrosis.

Vanadium Carbide Nanosheets with Broad-Spectrum Antioxidant Activity for Pulmonary Fibrosis Therapy

Idiopathic pulmonary fibrosis is a chronic and highly lethal lung disease that largely results from oxidative stress; however, effective antioxidant therapy by targeting oxidative stress pathogenesis is still lacking. The big challenge is to develop an ideal antioxidant material with superior antifibrotic effects. Herein, we report that V4C3 nanosheets (NSs) can serve as a potential antioxidant for treatment of pulmonary fibrosis by scavenging reactive oxygen and nitrogen species. Interestingly, subtle autoxidation can adjust the valence composition of V4C3 NSs and significantly improve their antioxidant behavior. Valence engineering triggers multiple antioxidant mechanisms including electron transfer, H atom transfer, and enzyme-like catalysis, thus endowing V4C3 NSs with broad-spectrum, high-efficiency, and persistent antioxidant capacity. Benefiting from antioxidant properties and good biocompatibility, V4C3 NSs can significantly prevent myofibroblast proliferation and extracellular matrix abnormality, thus alleviating the progression of bleomycin-induced pulmonary fibrosis in vivo by scavenging ROS, anti-inflammation, and rebuilding antioxidant defenses. This study not only provides an important strategy for designing excellent antioxidant nanomaterials, but also proposes a proof-of-concept demonstration for the treatment of pulmonary fibrosis and other oxidative stress-related diseases.

Ginkgo biloba Extract 50 (GBE50) Exerts Antifibrotic and Antioxidant Effects on Pulmonary Fibrosis in Mice by Regulating Nrf2 and TGF-β1/Smad Pathways

BACKGROUND

Pulmonary fibrosis (PF) is a progressive lung disorder with a poor prognosis. GBE50 is a new standardized Ginkgo biloba extract that has been widely used in cardiovascular diseases. However, the protective mechanism of GBE50 against PF remains to be elucidated.

METHODS

C57BL/6J mice were treated with bleomycin (Bleo) to induce PF in the presence or absence of GBE50. Protein content in bronchoalveolar lavage fluid (BALF) and wet weight/dry weight ratio were examined for analysis of pulmonary edema. Hematoxylin-eosin staining and Masson trichrome staining were used for histopathological observation of murine lung tissues. Ashcroft score was used for semi-quantitation of lung fibrosis degree. RT-qPCR was utilized for assessing mRNA levels of pro-fibrotic mediators in lung tissues. TUNEL staining was implemented for cell apoptosis assessment. The levels of oxidative stress- and inflammation-related markers were evaluated by corresponding commercial assay kits. Western blotting was used to evaluate levels of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling- and transforming growth factor (TGF)-β1/SMAD signaling-related proteins.

RESULTS

GBE50 alleviated lung injury and severity of fibrosis, reduced collagen deposition and cell apoptosis in lung tissues, and suppressed inflammatory response and oxidative stress injury in Bleo-stimulated PF mice. GBE50 activated Nrf2 signaling pathway and inactivated TGF-β1/SMAD signaling pathway in the lungs of Bleo-induced PF mice. Inhibition of Nrf2 signaling reversed GBE50-mediated inactivation of TGF-β1/SMAD signaling and attenuation of inflammation and oxidative stress in Bleo-induced PF mice.

CONCLUSION

GBE50 protects against Bleo-induced PF in mice by mitigating fibrosis, inflammation and oxidative stress via Nrf2 and TGF-β1/SMAD signaling pathways.

The molecular mechanisms of extracellular matrix-derived hydrogel therapy in idiopathic pulmonary fibrosis models

Idiopathic Pulmonary Fibrosis (IPF) is a progressively debilitating lung condition characterized by oxidative stress, cell phenotype shifts, and excessive extracellular matrix (ECM) deposition. Recent studies have shown promising results using decellularized ECM-derived hydrogels produced through pepsin digestion in various lung injury models and even a human clinical trial for myocardial infarction. This study aimed to characterize the composition of ECM-derived hydrogels, assess their potential to prevent fibrosis in bleomycin-induced IPF models, and unravel their underlying molecular mechanisms of action. Porcine lungs were decellularized and pepsin-digested for 48 h. The hydrogel production process, including visualization of protein molecular weight distribution and hydrogel gelation, was characterized. Peptidomics analysis of ECM-derived hydrogel contained peptides from 224 proteins. Probable bioactive and cell-penetrating peptides, including collagen IV, laminin beta 2, and actin alpha 1, were identified. ECM-derived hydrogel treatment was administered as an early intervention to prevent fibrosis advancement in rat models of bleomycin-induced pulmonary fibrosis. ECM-derived hydrogel concentrations of 1 mg/mL and 2 mg/mL showed subtle but noticeable effects on reducing lung inflammation, oxidative damage, and protein markers related to fibrosis (e.g., alpha-smooth muscle actin, collagen I). Moreover, distinct changes were observed in macroscopic appearance, alveolar structure, collagen deposition, and protein expression between lungs that received ECM-derived hydrogel and control fibrotic lungs. Proteomic analyses revealed significant protein and gene expression changes related to cellular processes, pathways, and components involved in tissue remodeling, inflammation, and cytoskeleton regulation. RNA sequencing highlighted differentially expressed genes associated with various cellular processes, such as tissue remodeling, hormone secretion, cell chemotaxis, and cytoskeleton engagement. This study suggests that ECM-derived hydrogel treatment influence pathways associated with tissue repair, inflammation regulation, cytoskeleton reorganization, and cellular response to injury, potentially offering therapeutic benefits in preventing or mitigating lung fibrosis.

Nε-Carboxymethyl-Lysine Modification of Extracellular Matrix Proteins Augments Fibroblast Activation

The extracellular matrix (ECM) is a dynamic complex protein network that provides structural integrity and plays an active role in shaping fibroblast behavior both in health and disease. Despite its essential functions, the impact of age-associated post-translational modifications on ECM-driven fibroblast activities such as proliferation, survival, fibroblast-to-myofibroblast transformation (FMT), and extracellular matrix production remains largely unknown. Nε-carboxymethyl-lysine (CML) is one of the well-characterized advanced glycation end-products (AGEs) that can occur on lysine residues within ECM proteins through non-enzymatic glycation. In this study, we determined the accumulation and the effects of the CML-modified ECM (CML-ECM) on fibroblast activation. Immunostainings and immunoblot analysis demonstrated significant increases in CML-AGE content in idiopathic pulmonary fibrosis (IPF) compared to age-matched healthy lungs. Gene expression analysis and fibroblast activation assays collectively implicate the ECM as a negative regulator of fibroblast activation. Notably, the CML modification of the ECM resulted in a significant decrease in its anti-fibrotic effects including proliferation, FMT, apoptosis, and ECM production. Together, the results of this study revealed an unexplored pathological role played by the CML-ECM on fibroblast activation, which has wide implications in IPF and other fibrotic diseases.

Role of the epithelial barrier in intestinal fibrosis associated with inflammatory bowel disease: relevance of the epithelial-to mesenchymal transition

In inflammatory bowel disease (IBD), chronic inflammation in the gastrointestinal tract can lead to tissue damage and remodelling, which can ultimately result in fibrosis. Prolonged injury and inflammation can trigger the activation of fibroblasts and extracellular matrix (ECM) components. As fibrosis progresses, the tissue becomes increasingly stiff and less functional, which can lead to complications such as intestinal strictures, obstructive symptoms, and eventually, organ dysfunction. Epithelial cells play a key role in fibrosis, as they secrete cytokines and growth factors that promote fibroblast activation and ECM deposition. Additionally, epithelial cells can undergo a process called epithelial-mesenchymal transition, in which they acquire a more mesenchymal-like phenotype and contribute directly to fibroblast activation and ECM deposition. Overall, the interactions between epithelial cells, immune cells, and fibroblasts play a critical role in the development and progression of fibrosis in IBD. Understanding these complex interactions may provide new targets for therapeutic interventions to prevent or treat fibrosis in IBD. In this review, we have collected and discussed the recent literature highlighting the contribution of epithelial cells to the pathogenesis of the fibrotic complications of IBD, including evidence of EMT, the epigenetic control of the EMT, the potential influence of the intestinal microbiome in EMT, and the possible therapeutic strategies to target EMT. Finally we discuss the pro-fibrotic interactions epithelial-immune cells and epithelial-fibroblasts cells.

Long-Term Radiological Pulmonary Changes in Mechanically Ventilated Patients with Respiratory Failure due to SARS-CoV-2 Infection

From the first reports of SARS-CoV-2, at the end of 2019 to the present, the global mortality associated with COVID-19 has reached 6,952,522 deaths as reported by the World Health Organization (WHO). Early intubation and mechanical ventilation can increase the survival rate of critically ill patients. This prospective study was carried out on 885 patients in the ICU of Mureș County Clinical Hospital, Romania. After applying inclusion and exclusion criteria, a total of 54 patients were included. Patients were monitored during hospitalization and at 6-month follow-up. We analyzed the relationship between invasive mechanical ventilation (IMV) and non-invasive mechanical ventilation (NIMV) and radiological changes on thoracic CT scans performed at 6-month follow-up and found no significant association. Regarding paraclinical analysis, there was a statistically significant association between patients grouped by IMV and ferritin level on day 1 of admission (p = 0.034), and between patients grouped by PaO2/FiO2 ratio with metabolic syndrome (p = 0.03) and the level of procalcitonin (p = 0.01). A significant proportion of patients with COVID-19 admitted to the ICU developed pulmonary fibrosis as observed at a 6-month evaluation. Patients with oxygen supplementation or mechanical ventilation require dynamic monitoring and radiological investigations, as there is a possibility of long-term pulmonary fibrosis that requires pharmacological interventions and finding new therapeutic alternatives.

Oxidative Stress and Lung Fibrosis: Towards an Adverse Outcome Pathway

Lung fibrosis is a progressive fatal disease in which deregulated wound healing of lung epithelial cells drives progressive fibrotic changes. Persistent lung injury due to oxidative stress and chronic inflammation are central features of lung fibrosis. Chronic cigarette smoking causes oxidative stress and is a major risk factor for lung fibrosis. The objective of this manuscript is to develop an adverse outcome pathway (AOP) that serves as a framework for investigation of the mechanisms of lung fibrosis due to lung injury caused by inhaled toxicants, including cigarette smoke. Based on the weight of evidence, oxidative stress is proposed as a molecular initiating event (MIE) which leads to increased secretion of proinflammatory and profibrotic mediators (key event 1 (KE1)). At the cellular level, these proinflammatory signals induce the recruitment of inflammatory cells (KE2), which in turn, increase fibroblast proliferation and myofibroblast differentiation (KE3). At the tissue level, an increase in extracellular matrix deposition (KE4) subsequently culminates in lung fibrosis, the adverse outcome. We have also defined a new KE relationship between the MIE and KE3. This AOP provides a mechanistic platform to understand and evaluate how persistent oxidative stress from lung injury may develop into lung fibrosis.

A systematic review of the research progress of traditional Chinese medicine against pulmonary fibrosis: from a pharmacological perspective

Pulmonary fibrosis is a chronic progressive interstitial lung disease caused by a variety of etiologies. The disease can eventually lead to irreversible damage to the lung tissue structure, severely affecting respiratory function and posing a serious threat to human health. Currently, glucocorticoids and immunosuppressants are the main drugs used in the clinical treatment of pulmonary fibrosis, but their efficacy is limited and they can cause serious adverse effects. Traditional Chinese medicines have important research value and potential for clinical application in anti-pulmonary fibrosis. In recent years, more and more scientific researches have been conducted on the use of traditional Chinese medicine to improve or reduce pulmonary fibrosis, and some important breakthroughs have been made. This review paper systematically summarized the research progress of pharmacological mechanism of traditional Chinese medicines and their active compounds in improving or reducing pulmonary fibrosis. We conducted a systematic search in several main scientific databases, including PubMed, Web of Science, and Google Scholar, using keywords such as idiopathic pulmonary fibrosis, pulmonary fibrosis, interstitial pneumonia, natural products, herbal medicine, and therapeutic methods. Ultimately, 252 articles were included and systematically evaluated in this analysis. The anti-fibrotic mechanisms of these traditional Chinese medicine studies can be roughly categorized into 5 main aspects, including inhibition of epithelial-mesenchymal transition, anti-inflammatory and antioxidant effects, improvement of extracellular matrix deposition, mediation of apoptosis and autophagy, and inhibition of endoplasmic reticulum stress. The purpose of this article is to provide pharmaceutical researchers with information on the progress of scientific research on improving or reducing Pulmonary fibrosis with traditional Chinese medicine, and to provide reference for further pharmacological research.

Low-dose vanadium pentoxide perturbed lung metabolism associated with inflammation and fibrosis signaling in male animal and in vitro models

Vanadium is available as a dietary supplement and also is known to be toxic if inhaled, yet little information is available concerning the effects of vanadium on mammalian metabolism when concentrations found in food and water. Vanadium pentoxide (V+5) is representative of the most common dietary and environmental exposures, and prior research shows that low-dose V+5 exposure causes oxidative stress measured by glutathione oxidation and protein S-glutathionylation. We examined the metabolic impact of V+5 at relevant dietary and environmental doses (0.01, 0.1, and 1 ppm for 24 h) in human lung fibroblasts (HLFs) and male C57BL/6J mice (0.02, 0.2, and 2 ppm in drinking water for 7 mo). Untargeted metabolomics using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) showed that V+5 induced significant metabolic perturbations in both HLF cells and mouse lungs. We noted 30% of the significantly altered pathways in HLF cells, including pyrimidines and aminosugars, fatty acids, mitochondrial and redox pathways, showed similar dose-dependent patterns in mouse lung tissues. Alterations in lipid metabolism included leukotrienes and prostaglandins involved in inflammatory signaling, which have been associated with the pathogenesis of idiopathic pulmonary fibrosis (IPF) and other disease processes. Elevated hydroxyproline levels and excessive collagen deposition were also present in lungs from V+5-treated mice. Taken together, these results show that oxidative stress from environmental V+5, ingested at low levels, could alter metabolism to contribute to common human lung diseases.NEW & NOTEWORTHY We used relevant dietary and environmental doses of Vanadium pentoxide (V+5) to examine its metabolic impact in vitro and in vivo. Using liquid chromatography-high-resolution mass spectrometry (LC-HRMS), we found significant metabolic perturbations, with similar dose-dependent patterns observed in human lung fibroblasts and male mouse lungs. Alterations in lipid metabolism included inflammatory signaling, elevated hydroxyproline levels, and excessive collagen deposition were present in V+5-treated lungs. Our findings suggest that low levels of V+5 could trigger pulmonary fibrotic signaling.

Supersulphides provide airway protection in viral and chronic lung diseases

Supersulphides are inorganic and organic sulphides with sulphur catenation with diverse physiological functions. Their synthesis is mainly mediated by mitochondrial cysteinyl-tRNA synthetase (CARS2) that functions as a principal cysteine persulphide synthase (CPERS). Here, we identify protective functions of supersulphides in viral airway infections (influenza and COVID-19), in aged lungs and in chronic lung diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF). We develop a method for breath supersulphur-omics and demonstrate that levels of exhaled supersulphides increase in people with COVID-19 infection and in a hamster model of SARS-CoV-2 infection. Lung damage and subsequent lethality that result from oxidative stress and inflammation in mouse models of COPD, IPF, and ageing were mitigated by endogenous supersulphides production by CARS2/CPERS or exogenous administration of the supersulphide donor glutathione trisulphide. We revealed a protective role of supersulphides in airways with various viral or chronic insults and demonstrated the potential of targeting supersulphides in lung disease.

Histological and biochemical evaluation of the effects of silver nanoparticles (AgNps) versus titanium dioxide nanoparticles (TiO2NPs) on rat parotid gland

The unlimited use of nanoparticles (NPs) results in toxic impacts on different tissues. The current study aimed to compare the adverse effects of AgNPs and TiO2NPs on the parotid gland of adult male albino rats as regards the histopathological, immunohistochemical, and biochemical changes, exploring the possible underlying mechanisms and the degree of improvement after cessation of administration. Fifty-four adult male albino rats were divided into control group (I), AgNPs-injected group (II), and TiO2NPs-injected group (III). We measured the levels of tumor necrosis factor-alpha (TNF-α) and interleukin (IL-6) in the serum, and levels of MDA and GSH in parotid tissue homogenate. Quantitative real-time polymerase-chain reaction (qRT-PCR) was used to measure the expression levels of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC1-α), nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4), mouse double minute 2 (MDM2), Caspase-3 Col1a1, and Occludin. Parotid tissue sections were examined by light microscope (Hematoxylin & Eosin and Mallory trichrome stains), electron microscope, and immunohistochemical examination of CD68 and anti-caspase-3 antibodies. Both NPs severely affected the acinar cells and damaged the tight junction between them by enhancing expression of the inflammatory cytokines, inducing oxidative stress, and disturbing the expression levels of the studied genes. They also stimulated fibrosis, acinar cell apoptosis, and inflammatory cells infiltration in parotid tissue. TiO2NPs effects were less severe than AgNPs. Cessation of exposure to both NPs, ameliorated the biochemical and structural findings with more improvement in TiO2NPs withdrawal. In conclusion: AgNPs and TiO2NPs adversely affected the parotid gland, but TiO2NPs were less toxic than AgNPs.

NecroX Improves Polyhexamethylene Guanidine-induced Lung Injury by Regulating Mitochondrial Oxidative Stress and Endoplasmic Reticulum Stress

Various environmental compounds are inducers of lung injury. Mitochondria are crucial organelles that can be affected by many lung diseases. NecroX is an indole-derived antioxidant that specifically targets mitochondria. We aimed to evaluate the therapeutic potential and related molecular mechanisms of NecroX in preclinical models of fatal lung injury. We investigated the therapeutic effects of NecroX on two different experimental models of lung injury induced by polyhexamethylene guanidine (PHMG) and bleomycin, respectively. We also performed transcriptome analysis of lung tissues from PHMG-exposed mice and compared the expression profiles with those from dozens of bleomycin-induced fibrosis public data sets. Respiratory exposure to PHMG and bleomycin led to fatal lung injury manifesting extensive inflammation followed by fibrosis. These specifically affected mitochondria regarding biogenesis, mitochondrial DNA integrity, and the generation of mitochondrial reactive oxygen species in various cell types. NecroX significantly improved the pathobiologic features of the PHMG- and bleomycin-induced lung injuries through regulation of mitochondrial oxidative stress. Endoplasmic reticulum stress was also implicated in PHMG-associated lung injuries of mice and humans, and NecroX alleviated PHMG-induced lung injury and the subsequent fibrosis, in part, via regulation of endoplasmic reticulum stress in mice. Gene expression profiles of PHMG-exposed mice were highly consistent with public data sets of bleomycin-induced lung injury models. Pathways related to mitochondrial activities, including oxidative stress, oxidative phosphorylation, and mitochondrial translation, were upregulated, and these patterns were significantly reversed by NecroX. These findings demonstrate that NecroX possesses therapeutic potential for fatal lung injury in humans.

Amifostine attenuates bleomycin-induced pulmonary fibrosis in mice through inhibition of the PI3K/Akt/mTOR signaling pathway

Amifostine is a normal cell protection agent, not only used in the adjuvant therapy of lung cancer, ovarian cancer, breast cancer, nasopharyngeal cancer, bone tumor, digestive tract tumor, blood system tumor and other cancers in order to reduce the toxicity of chemotherapy drugs, and recent studies have reported that the drug can also reduce lung tissue damage in patients with pulmonary fibrosis, but its mechanism of action is not yet fully understood. In this study, we explored the potential therapeutic effects and molecular mechanisms of AMI on bleomycin (BLM)-induced pulmonary fibrosis in mice. A mouse model of pulmonary fibrosis was established using BLM. We then assessed histopathological changes, inflammatory factors, oxidative indicators, apoptosis, epithelial-mesenchymal transition, extracellular matrix changes, and levels of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway-related proteins in the BLM-treated mice to determine the effect of AMI treatment on these factors. BLM-treated mice had substantial lung inflammation and abnormal extracellular matrix deposition. Overall, treatment with AMI significantly improved BLM-induced lung injury and pulmonary fibrosis. More specifically, AMI alleviated BLM-induced oxidative stress, inflammation, alveolar cell apoptosis, epithelial-mesenchymal transition, and extracellular matrix deposition by regulating the PI3K/Akt/mTOR signaling pathway. This finding that AMI can alleviate pulmonary fibrosis in a mouse model by inhibiting activation of the PI3K/Akt/mTOR signaling pathway lays a foundation for potential future clinical application of this agent in patients with pulmonary fibrosis.

Mitochondrial folate pathway regulates myofibroblast differentiation and silica-induced pulmonary fibrosis

BACKGROUND

Silica-induced pulmonary fibrosis (silicosis) is a diffuse interstitial fibrotic disease characterized by the massive deposition of extracellular matrix in lung tissue. Fibroblast to myofibroblast differentiation is crucial for the disease progression. Inhibiting myofibroblast differentiation may be an effective way for pulmonary fibrosis treatment.

METHODS

The experiments were conducted in TGF-β treated human lung fibroblasts to induce myofibroblast differentiation in vitro and silica treated mice to induce pulmonary fibrosis in vivo.

RESULTS

By quantitative mass spectrometry, we revealed that proteins involved in mitochondrial folate metabolism were specifically upregulated during myofibroblast differentiation following TGF-β stimulation. The expression level of proteins in mitochondrial folate pathway, MTHFD2 and SLC25A32, negatively regulated myofibroblast differentiation. Moreover, plasma folate concentration was significantly reduced in patients and mice with silicosis. Folate supplementation elevated the expression of MTHFD2 and SLC25A32, alleviated oxidative stress and effectively suppressed myofibroblast differentiation and silica-induced pulmonary fibrosis in mice.

CONCLUSION

Our study suggests that mitochondrial folate pathway regulates myofibroblast differentiation and could serve as a potential target for ameliorating silica-induced pulmonary fibrosis.

Overexpression of fatty acid synthase attenuates bleomycin induced lung fibrosis by restoring mitochondrial dysfunction in mice

Proper lipid metabolism is crucial to maintain alveolar epithelial cell (AEC) function, and excessive AEC death plays a role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). The mRNA expression of fatty acid synthase (FASN), a key enzyme in the production of palmitate and other fatty acids, is downregulated in the lungs of IPF patients. However, the precise role of FASN in IPF and its mechanism of action remain unclear. In this study, we showed that FASN expression is significantly reduced in the lungs of IPF patients and bleomycin (BLM)-treated mice. Overexpression of FASN significantly inhibited BLM-induced AEC death, which was significantly potentiated by FASN knockdown. Moreover, FASN overexpression reduced BLM-induced loss of mitochondrial membrane potential and the production of mitochondrial reactive oxygen species (ROS). Oleic acid, a fatty acid component increased by FASN overexpression, inhibited BLM-induced cell death in primary murine AECs and rescue BLM induced mouse lung injury/fibrosis. FASN transgenic mice exposed to BLM exhibited attenuated lung inflammation and collagen deposition compared to controls. Our findings suggest that defects in FASN production may be associated with the pathogenesis of IPF, especially mitochondrial dysfunction, and augmentation of FASN in the lung may have therapeutic potential in preventing lung fibrosis.

Activation of TRPA1 in Bladder Suburothelial Myofibroblasts Counteracts TGF-β1-Induced Fibrotic Changes

The activation of the transient receptor potential ankyrin 1 (TRPA1) channel has anti-fibrotic effects in the lung and intestine. Suburothelial myofibroblasts (subu-MyoFBs), a specialized subset of fibroblasts in the bladder, are known to express TRPA1. However, the role of the TRPA1 in the development of bladder fibrosis remains elusive. In this study, we use the transforming growth factor-β1 (TGF-β1) to induce fibrotic changes in subu-MyoFBs and assess the consequences of TRPA1 activation utilizing RT-qPCR, western blotting, and immunocytochemistry. TGF-β1 stimulation increased α-SMA, collagen type I alpha 1 chain(col1A1), collagen type III (col III), and fibronectin expression, while simultaneously suppressing TRPA1 in cultured human subu-MyoFBs. The activation of TRPA1, with its specific agonist allylisothiocyanate (AITC), inhibited TGF-β1-induced fibrotic changes, and part of these inhibition effects could be reversed by the TRPA1 antagonist, HC030031, or by reducing TRPA1 expression via RNA interference. Furthermore, AITC reduced spinal cord injury-induced fibrotic bladder changes in a rat model. The increased expression of TGF-β1, α-SMA, col1A1 and col III, and fibronectin, and the downregulation of TRPA1, were also detected in the mucosa of fibrotic human bladders. These findings suggest that TRPA1 plays a pivotal role in bladder fibrosis, and the negative cross talk between TRPA1 and TGF-β1 signaling may represent one of the mechanisms underlying fibrotic bladder lesions.

Landscape analysis and overview of the literature on oxidative stress and pulmonary diseases

Oxidative stress is caused by an imbalance in oxidant/antioxidant processes and is a critical process in pulmonary diseases. As no truly effective therapies exist for lung cancer, lung fibrosis and chronic obstructive pulmonary disease (COPD), at present, it is important to comprehensively study the relationship between oxidative stress and pulmonary diseases to identify truly effective therapeutics. Since there is no quantitative and qualitative bibliometric analysis of the literature in this area, this review provides an in-depth analysis of publications related to oxidative stress and pulmonary diseases over four periods, including from 1953 to 2007, 2008 to 2012, 2013 to 2017, and 2018 to 2022. Interest in many pulmonary diseases has increased, and the mechanisms and therapeutic drugs for pulmonary diseases have been well analyzed. Lung injury, lung cancer, asthma, COPD and pneumonia are the 5 most studied pulmonary diseases related to oxidative stress. Inflammation, apoptosis, nuclear factor erythroid 2 like 2 (NRF2), mitochondria, and nuclear factor-κB (NF-κB) are rapidly becoming the most commonly used top keywords. The top thirty medicines most studied for treating different pulmonary diseases were summarized. Antioxidants, especially those targeting reactive oxygen species (ROS) in specific organelles and certain diseases, may be a substantial and necessary choice in combined therapies rather than acting as a single "magic bullet" for the effective treatment of refractory pulmonary diseases.

Blood lead (Pb) is associated with lung fibrotic changes in non-smokers living in the vicinity of petrochemical complex: a population-based study

Lead (Pb) is a toxic metal that has been extensively used in various industrial processes, and it persists in the environment, posing a continuous risk of exposure to humans. This study investigated blood lead levels in participants aged 20 years and older, who resided in Dalinpu for more than two years between 2016 to 2018, at Kaohsiung Municipal Siaogang Hospital. Graphite furnace atomic absorption spectrometry was used to analyze the blood samples for lead levels, and the LDCT (Low-Dose computed tomography) scans were interpreted by experienced radiologists. The blood lead levels were divided into quartiles, with Q1 representing levels of ≤1.10 μg/dL, Q2 representing levels of >1.11 and ≤1.60 μg/dL, Q3 representing levels of >1.61 and ≤2.30 μg/dL, and Q4 representing levels of >2.31 μg/dL. Individuals with lung fibrotic changes had significantly higher (mean ± SD) blood lead levels (1.88±1.27vs. 1.72±1.53 μg/dl, p< 0.001) than those with non-lung fibrotic changes. In multivariate analysis, we found that the highest quartile (Q4: >2.31 μg/dL) lead levels (OR: 1.36, 95% CI: 1.01-1.82; p= 0.043) and the higher quartile (Q3: >1.61 and ≤2.30 μg/dL) (OR: 1.33, 95% CI: 1.01-1.75; p= 0.041) was significantly associated with lung fibrotic changes compared with the lowest quartile (Q1: ≤1.10 μg/dL) (Cox and Snell R², 6.1 %; Nagelkerke R², 8.5 %). The dose-response trend was significant (P_trend= 0.030). Blood lead exposure was significantly associated lung fibrotic change. To prevent lung toxicity, it is recommended to maintain blood lead levels lower than the current reference value.

Nanotherapeutic Approaches to Treat COVID-19-Induced Pulmonary Fibrosis

There have been significant collaborative efforts over the past three years to develop therapies against COVID-19. During this journey, there has also been a lot of focus on understanding at-risk groups of patients who either have pre-existing conditions or have developed concomitant health conditions due to the impact of COVID-19 on the immune system. There was a high incidence of COVID-19-induced pulmonary fibrosis (PF) observed in patients. PF can cause significant morbidity and long-term disability and lead to death in the long run. Additionally, being a progressive disease, PF can also impact the patient for a long time after COVID infection and affect the overall quality of life. Although current therapies are being used as the mainstay for treating PF, there is no therapy specifically for COVID-induced PF. As observed in the treatment of other diseases, nanomedicine can show significant promise in overcoming the limitations of current anti-PF therapies. In this review, we summarize the efforts reported by various groups to develop nanomedicine therapeutics to treat COVID-induced PF. These therapies can potentially offer benefits in terms of targeted drug delivery to lungs, reduced toxicity, and ease of administration. Some of the nanotherapeutic approaches may provide benefits in terms of reduced immunogenicity owing to the tailored biological composition of the carrier as per the patient needs. In this review, we discuss cellular membrane-based nanodecoys, extracellular vesicles such as exosomes, and other nanoparticle-based approaches for potential treatment of COVID-induced PF.

Epithelial Responses in Radiation-Induced Lung Injury (RILI) Allow Chronic Inflammation and Fibrogenesis

Radiation models, such as whole thorax lung irradiation (WTLI) or partial-body irradiation (PBI) with bone-marrow sparing, have shown that affected lung tissue displays a continual progression of injury, often for months after the initial insult. Undoubtably, a variety of resident and infiltrating cell types either contribute to or fail to resolve this type of progressive injury, which in lung tissue, often develops into lethal and irreversible radiation-induced pulmonary fibrosis (RIPF), indicating a failure of the lung to return to a homeostatic state. Resident pulmonary epithelium, which are present at the time of irradiation and persist long after the initial insult, play a key role in the maintenance of homeostatic conditions in the lung and have often been described as contributing to the progression of radiation-induced lung injury (RILI). In this study, we took an unbiased approach through RNA sequencing to determine the in vivo response of the lung epithelium in the progression of RIPF. In our methodology, we isolated CD326+ epithelium from the lungs of 12.5 Gy WTLI C57BL/6J female mice (aged 8-10 weeks and sacrificed at regular intervals) and compared irradiated and non-irradiated CD326+ cells and whole lung tissue. We subsequently verified our findings by qPCR and immunohistochemistry. Transcripts associated with epithelial regulation of immune responses and fibroblast activation were significantly reduced in irradiated animals at 4 weeks postirradiation. Additionally, alveolar type-2 epithelial cells (AEC2) appeared to be significantly reduced in number at 4 weeks and thereafter based on the diminished expression of pro-surfactant protein C (pro-SPC). This change is associated with a reduction of Cd200 and cyclooxygenase 2 (COX2), which are expressed within the CD326 populations of cells and function to suppress macrophage and fibroblast activation under steady-state conditions, respectively. These data indicate that either preventing epithelial cell loss that occurs after irradiation or replacing important mediators of immune and fibroblast activity produced by the epithelium are potentially important strategies for preventing or treating this unique injury.