Pulmonary Toxicity Research Articles

Ameliorative mechanism of dietary vitamin d and magnesium on newborn’s pulmonary toxicity induced by cadmium

Cadmium (Cd) exposure in mothers can cause respiratory issues in newborns, but the exact toxicity mechanisms are not fully understood. Vitamin D deficiency in Cd-exposed rats is associated with increased cadmium accumulation in tissues. Finding a cost-effective medication that is vital for the body while also reducing the effects of poisoning is crucial in treating poisonings. To investigate the mechanisms of Cd-induced lung toxicity, we examined the impact of prolonged Cd exposure in female rats before pregnancy on newborn lung health, focusing on sera TNF-α level, lung P53, Foxo1 mRNA, and lung VEGF, and BMP-4 protein level. A total of 50 rats were divided into control, Cd, Cd+Vitamin D, Cd+Mg, and Cd + Vitamin D+Mg groups. Cd exposure resulted in higher serum TNF-α levels and a significant rise in P53 mRNA levels. Additionally, the occurrence of hemorrhage, inflammatory cell infiltration, and thickening of alveolar walls decreased following treatment with vitamin D + Mg. Although Cd did not affect the newborns' body weight, it did impair their lung function. These findings suggest that the Cd-induced increase in the P53 gene expression could be alleviated by vitamin D and Mg, along with the elevation of VEGF and BMP-4 proteins and Foxo1 gene expression. The study revealed that environmental toxins can sometimes harm molecules and proteins, leading to damage in critical fetal tissues. However, these issues can be mitigated through essential supplements. Structured AbstractThe increasing role of Cd in the erratic behavior of numerous biological and molecular entities, notably the development of fetal lung tissue, has made it beneficial to investigate the possible adverse effects of Cd exposure in pregnant mothers and fetal organ development, where instinctive molecular events occur. Researchers are encouraged to create new aspects of medications to reduce clinical symptoms and improve the quality of life due to exposure to metal toxins, particularly in industrialized countries. The present study aimed to evaluate histopathological and molecular modifications of fetal lungs caused by maternal Cd toxicosis and evaluate the possible ameliorating effects of vitamin D and Mg alone and in combination with fetal lung developmental abnormalities, followed by maternal toxin induction, which can be generalized to humans.Fifty female Wistar rats were purchased from the Pasteur Institute of Iran. To induce the model, cadmium at a dose of 2 mg/kg body weight was injected intraperitoneally into the female rats over 28 days before mating (5 days after injection in a week). Afterward, the female rats were randomly divided into type IV polycarbonate cages and mated with healthy male rats. The pregnancy was confirmed by observation of the vaginal plaque, which was subsequently observed, and the number of days of embryo formation was calculated. Subsequently, the pregnant rats were assigned to the following groups and received PBS, vitamin D, Mg, or vitamin D + Mg. At the end of the nine-day treatment period (the 6th day of pregnancy to the 14th day), the neonates were born vaginally, and their body weight and mortality were recorded. The P53 and Foxo1 gene expression levels in the left and right lobes of the homogenized lungs of the newborns in each group were assessed. TNF-alpha was detected in the sera collected from the newborns by ELISA. The isolated left and right lung tissues were homogenized in radioimmunoprecipitation assay (RIPA) buffer and the superior phase was collected to determine the total protein content by Lowry's method and VEGF and BMP-4 protein levels. The obtained lung samples from newborn rats were fixed in a 10% formalin solution for tissue processing. The fixed samples were embedded in paraffin, and serial paraffin sections were prepared for hematoxylin and eosin staining. This study is the first to examine how maternal Cd exposure affects fetal lung development and to estimate the impact of prescribing Mg and vitamin D during pregnancy. The present study assessed the effects of a repeated dose of Cd for 4 weeks before pregnancy on the lung development of newborn rats born to mothers treated with vitamin D and Mg. The results showed that the P53 gene was overexpressed in the model group, while Foxo1 gene expression was downregulated, negatively impacting the lung structure and developmental indices of the fetuses. Therefore, the intake of vitamin D and Mg may contribute to improving the various stages of Cd-induced lung injury by modulating lung inflammation and mucosal secretion while also positively influencing the number of surviving offspring.

Human molybdenum exposure risk in industrial regions of China: New critical effect indicators and reference dose

Evidence increasingly suggests molybdenum exposure at environmental levels is still associated with adverse human health, emphasizing the necessity to establish a more protective reference dose (RfD). Herein, we conducted a study measuring 15 urinary metals and 30 clinical health indicators in 2267 participants residing near chemical enterprises across 11 Chinese provinces to investigate their relationships. The kidney and cystatin-C emerged as the most sensitive organ and critical effect indicator of molybdenum exposure, respectively. Odds of cystatin-C-defined chronic kidney disease (CKD) in the highest quantile of molybdenum exposure significantly increased by 133.5% (odds ratio [OR]: 2.34, 95% CI: 1.78, 3.11) and 75.8% (OR: 1.76, 95% CI: 1.24, 2.49) before and after adjusting for urinary 14 metals, respectively. Intriguingly, cystatin-C significantly mediated 15.9–89.5% of molybdenum's impacts on liver and lung function, suggesting nephrotoxicity from molybdenum exposure may trigger hepatotoxicity and pulmonary toxicity. We derived a new RfD for molybdenum exposure (0.87 μg/kg-day) based on cystatin-C-defined estimated glomerular filtration rate by employing Bayesian Benchmark Dose modeling analysis. This RfD is significantly lower than current exposure guidance values (5–30 μg/kg-day). Remarkably, >90% of participants exceeded the new RfD, underscoring the significant health impacts of environmental molybdenum exposure on populations in industrial regions of China.

Tert-butylhydroquinone prevents cyclophosphamide induce lung toxicity in rats via inhibiting oxidative stress and apoptosis: in vivo and in silico study

BackgroundCyclophosphamide (CP) is a chemotherapeutic and immunosuppressive agent that induces oxidative stress, causing lung tissue damage.AimThe study aims to explore the antioxidant role of tert-butylhydroquinone (TBHQ) in ameliorating CP-induced lung toxicity exhibited as oxidative stress and programmed cell death.MethodsThirty-two adult male rats were allocated randomly into four groups: group 1 (control), group 2 TBHQ 50 mg/kg orally for 14 days, and group 3 single dose of (200 mg/kg, CP, i.p.) on the 9th day. In group 4, TBHQ (50 mg/kg, orally) was provided for 14 days, and (200 mg/kg, CP, i.p.) was administrated on the 9th day. Rats’ body and lung weight were measured. Oxidative stress marker malondialdehyde (MDA) and pulmonary tissue enzymatic antioxidant levels were assessed: glutathione S transferase, catalase, superoxide dismutase, and glutathione peroxidase. Additionally, glutathione level was measured. Assessment of the levels of TNF-α, IL-1β, and IL-6 were done as well as histopathological and immunohistochemistry investigations. Molecular docking studies of the protein structures of p53-MDM2, IL-6, and IL-1β were performed.ResultsCP-intoxicated rats demonstrated a significant decline (CAT, GPx, SOD, GST, and GSH) levels and a significant increase in MDA levels. The proinflammatory parameters (TNF-α, IL-6, IL-1ß) were significantly elevated in group 3. The noted biochemical changes, accompanied by histopathological destruction, indicate CP-induced pulmonary tissue injury. TBHQ played a protective role by attenuating most of the aforementioned biochemical alterations and histopathological distortions in rats’ lungs.ConclusionsTBHQ might be utilized as a potential ameliorative agent to inhibit CP-induced pulmonary toxicity via TBHQ’s antioxidant and anti-inflammatory effects.

Toxicological Effects of Commonly Used Mosquito Coil Smoke on Liver and Lung Function in Rats

The utilization of mosquito coils as a household-level strategy for mosquito control is widely practiced in malaria-endemic regions spanning Africa, Asia, and South America. However, the continuous application of mosquito coils has prompted significant apprehensions concerning environmental and health implications. This research aims to evaluate the potential hepatic and pulmonary toxicities associated with the inhalation of mosquito coil smoke in rat subjects over both sub-chronic and chronic durations. A questionnaire was used to make inquiries regarding the prevalent types and brands of mosquito coils employed, the manner in which they are used, the durations for which they are utilized. A total of twenty-four albino rats were categorized into three distinct groups: the control group and two exposed groups. These groups were subjected to distinct brands of mosquito coil smoke across two distinct exposure regimens – a sub-chronic exposure lasting 4 weeks and a chronic exposure spanning 12 weeks. Following the exposure periods, blood samples were collected for the analysis of serum-based and biochemical markers, including serum aspartate aminotransferase (AST), alanine aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), bilirubin, serum bicarbonate, and Lactate dehydrogenase (LDH), oxygen saturation, C-reactive protein, total protein, and microscopic analysis of lung tissue and liver tissue. The histopathological analysis of lung tissue was appropriately included. However, the analysis of liver tissue was omitted. The results demonstrated a significant elevation in the levels of these biochemical markers among the exposed rats in comparison to the control group. Concurrently, a decrease in blood oxygen saturation was noted in the exposed rats when contrasted with the control group. Conversely, the serum concentrations of high-sensitivity C-reactive protein, total protein, and alanine aminotransferase (ALT) did not exhibit notable differences in relation to the control group. Additionally, microscopic analysis of lung tissue indicated the presence of histopathological lesions in the exposed rats, suggesting a detrimental impact of mosquito coil smoke exposure in a time-dependent progression.

A comparative study on the protective effects of cuminaldehyde, thymoquinone, and gallic acid against carbon tetrachloride-induced pulmonary and renal toxicity in rats by affecting ROS and NF-κB signaling

CCl4 toxicity is a fatal condition that can cause numerous organ dysfunctions. We evaluated and compared the protective effects of cuminaldehyde (CuA), thymoquinone (TQ), and gallic acid (GA) on CCl4-induced pulmonary and renal toxicity in rats. The impacts of these compounds on CCl4-induced oxidative stress, inflammation, and morphological alterations were examined. The results showed that the compounds under investigation prevented CCl4 from significantly increasing pulmonary and renal lipid peroxidation and NO levels, as well as massively depleting GSH levels and GPX and SOD activities. Moreover, they suppressed the CCl4-induced increase in mucus secretion in the lung and upregulated the gene expression of pulmonary and renal NF-ҡB, iNOS, TNF-α, and COX-2. The heatmap cluster plots showed that GA and TQ had better protective potencies than CuA. The external organ morphology, histopathological results, and chest X-ray analysis confirmed the toxicity of CCl4 and the protective influences of the tested compounds in both the lungs and kidneys of rats. These compounds displayed predicted competitive inhibitory effects on iNOS activity and may block the IL-13α2 receptor, as revealed by molecular docking analysis. Thus, CuA, TQ, and GA, particularly the latter two, are prospective protective compounds against the pulmonary and renal toxicity caused by CCl4.

Abstract PO1-03-05: Tolerance of adjuvant radiotherapy combined with pembrolizumab for triple negative breast cancer

Abstract BACKGROUND AND PURPOSE: The current standard-of-care management of locally advanced triple negative breast cancer (TNBC) is based on neoadjuvant chemo-immunotherapy with pembrolizumab, surgery, radiotherapy and adjuvant pembrolizumab. However, the safety of combining pembrolizumab with adjuvant breast radiotherapy has never been evaluated. This study evaluated the tolerance profile of concurrent pembrolizumab (P) with adjuvant radiotherapy (RT) in locally advanced TNBC patients. METHODS: This bicentric ambispective study included the first prospectively registered patients with non-metastatic TNBC treated with the KEYNOTE-522 regimen in our institution. They received P in combination with carboplatin and paclitaxel chemotherapy and a second chemotherapy with doxorubicin and cyclophosphamide, followed by surgery and locoregional RT with or without P as adjuvant treatment. RT was normo- or hypofractionated, for the breast or chest wall, with or without lymph node irradiation according to institutional guidelines. Adjuvant P was administered at a total dose of 1800 mg at 200 mg once every 3 weeks or 400 mg once every 6 weeks. The safety profile was evaluated during and after the end of RT (until the last contact) with CTCAE V.5 scale. RESULTS: A total of 55 patients (pts) were prospectively included between July 2021 and March 2023. The median age was 49 years (29-69). The median follow-up was 12 months ( range, 10-26). Of them, 27 (49%) did not receive P concomitantly with RT (RT-only group) because of neo-adjuvant treatment related toxicities, and 28 (51%) received P concomitantly with RT (P-RT group). There was no statistical difference in population and toxicity between the RT-only group and the P-RT group. Nine patients were diagnosed with cardiac toxicities before the beginning of the RT and did not receive P during the RT. No RT-induced grade ≥4 toxicities were observed. Early toxicities were mainly grade 1-2. Two grade 3 toxicities occurred (1 case of axillary pain in the P-RT group and 1 radiodermatitis in the RT-only group). No cardiac or pulmonary toxicities ≥grade 2 were observed with adjuvant therapy. The toxicity profile is given in table 1. DISCUSSION: In these series, the main cause of discontinuation of pembrolizumab was related to suspicion of cardiac adverse events occurring during the neoadjuvant treatment and related to the injection of pembrolizumab or of the chemotherapy. All myocarditis happened before radiotherapy and did not affect the administration of radiotherapy. In this context, the optimal radiotherapy technique and cardiac dose constraints after ICI-induced myocarditis is unknown and late cardiotoxicity studies will be needed to precise these points. Cardiac sparing techniques, such as deep-inspiration breath hold, proton therapy, or alternative positioning (such as isocentric lateral decubitus) could be considered. CONCLUSION: Adjuvant radiotherapy can be combined with pembrolizumab for TNBC patients without increasing the risk of radiation-induced adverse events, allowing maintaining a systemic treatment in these high-risk patients. Longer follow-up and prospective studies are needed to validate these results. Adjuvant treatment-related adverse events Citation Format: Youlia Kirova, Thaïs Tison, Pierre Loap, Emilie ARNAUD, Kim Cao, Solène Bringer, Manon Kissel, Safia Maaradji, Juliette Mainguene, Jean-Yves Pierga, Florence Lerebours, Anne Salomon, Mariana Mirabelle, Delphine Loirat, Francois-Clement Bidard. Tolerance of adjuvant radiotherapy combined with pembrolizumab for triple negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-03-05.

Polyhexamethylene guanidine phosphate induces pyroptosis via reactive oxygen species-regulated mitochondrial dysfunction in bronchial epithelial cells

Pyroptosis is a form of programmed cell death characterized by gasdermin (GSDM)-mediated pore formation in the cell membrane, resulting in the release of pro-inflammatory cytokines and cellular lysis. Increasing evidence has shown that pyroptosis is responsible for the progression of various pulmonary disorders. The inhalation of polyhexamethylene guanidine (PHMG) causes severe lung inflammation and pulmonary toxicity; however, the underlying mechanisms are unknown. Therefore, in this study, we investigate the role of pyroptosis in PHMG-induced pulmonary toxicity. We exposed bronchial epithelial cells, BEAS-2B, to PHMG phosphate (PHMG-p) and evaluated cell death type, reactive oxygen species (ROS) levels, and relative expression levels of pyroptosis-related proteins. Our data revealed that PHMG-p reduced viability and induced morphological alterations in BEAS-2B cells. Exposure to PHMG-p induced excessive accumulation of mitochondrial ROS (mtROS) in BEAS-2B cells. PHMG-p activated caspase-dependent apoptosis as well as NLRP3/caspase-1/GSDMD-mediated- and caspase-3/GSDME-mediated pyroptosis through mitochondrial oxidative stress in BEAS-2B cells. Notably, PHMG-p reduced mitochondrial respiratory function and induced the translocation of Bax and cleaved GSDM into the mitochondria, leading to mitochondrial dysfunction. Our results enhanced our understanding of PHMG-p-induced lung toxicity by demonstrating that PHMG-p induces pyroptosis via mtROS-induced mitochondrial dysfunction in bronchial epithelial cells.

Tetrahydrobiopterin metabolism attenuates ROS generation and radiosensitivity through LDHA S-nitrosylation: novel insight into radiogenic lung injury.

Genotoxic therapy triggers reactive oxygen species (ROS) production and oxidative tissue injury. S-nitrosylation is a selective and reversible posttranslational modification of protein thiols by nitric oxide (NO), and 5,6,7,8-tetrahydrobiopterin (BH4) is an essential cofactor for NO synthesis. However, the mechanism by which BH4 affects protein S-nitrosylation and ROS generation has not been determined. Here, we showed that ionizing radiation disrupted the structural integrity of BH4 and downregulated GTP cyclohydrolase I (GCH1), which is the rate-limiting enzyme in BH4 biosynthesis, resulting in deficiency in overall protein S-nitrosylation. GCH1-mediated BH4 synthesis significantly reduced radiation-induced ROS production and fueled the global protein S-nitrosylation that was disrupted by radiation. Likewise, GCH1 overexpression or the administration of exogenous BH4 protected against radiation-induced oxidative injury in vitro and in vivo. Conditional pulmonary Gch1 knockout in mice (Gch1fl/fl; Sftpa1-Cre+/- mice) aggravated lung injury following irradiation, whereas Gch1 knock-in mice (Gch1lsl/lsl; Sftpa1-Cre+/- mice) exhibited attenuated radiation-induced pulmonary toxicity. Mechanistically, lactate dehydrogenase (LDHA) mediated ROS generation downstream of the BH4/NO axis, as determined by iodoacetyl tandem mass tag (iodoTMT)-based protein quantification. Notably, S-nitrosylation of LDHA at Cys163 and Cys293 was regulated by BH4 availability and could restrict ROS generation. The loss of S-nitrosylation in LDHA after irradiation increased radiosensitivity. Overall, the results of the present study showed that GCH1-mediated BH4 biosynthesis played a key role in the ROS cascade and radiosensitivity through LDHA S-nitrosylation, identifying novel therapeutic strategies for the treatment of radiation-induced lung injury.

Pulmonary diseases in patients with classical Hodgkin lymphoma relative to a matched background population: A Danish national cohort study.

Late toxicities can impact survivorship in patients with classical Hodgkin lymphoma (cHL) with pulmonary toxicity after bleomycin-containing chemotherapy being a concern. The incidence of pulmonary diseases was examined in this Danish population-based study. A total of 1474 adult patients with cHL treated with ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine) or BEACOPP (bleomycin, vincristine, etoposide, doxorubicin, cyclophosphamide, procarbazine and prednisone) between 2000 and 2018 were included along with 7370 age- and sex-matched comparators from the background population. Median follow-up was 8.6 years for the patients. Patients with cHL had increased risk of incident pulmonary diseases (HR 2.91 [95% CI 2.30-3.68]), with a 10-year cumulative risk of 7.4% versus 2.9% for comparators. Excess risks were observed for interstitial lung diseases (HR 15.84 [95% CI 9.35-26.84]) and chronic obstructive pulmonary disease (HR 1.99 [95% CI 1.43-2.76]), with a 10-year cumulative risk of 4.1% and 3.5% respectively for patients. No excess risk was observed for asthma (HR 0.82 [95% CI 0.43-1.56]). Risk factors for interstitial lung diseases were age ≥60 years, the presence of B-symptoms and low albumin. These findings document a significant burden of pulmonary diseases among patients with cHL and emphasize the importance of diagnostic work-up of pulmonary symptoms.

The relative risk of immune checkpoint inhibitor pneumonitis in advanced non-small- cell lung cancer: Meta-analyses of controlled clinical trials.

Immune checkpoint inhibitor pneumonitis (CIP) is a prevalent form of immunotherapy-induced pulmonary toxicity, ranking among the leading causes of mortality associated with immune checkpoint inhibitors (ICIs). Despite its significance, the risk stratification of CIP in advanced non-small cell lung cancer (NSCLC) remains uncertain. In this study, we conducted a comprehensive analysis, comparing various factors such as histological types, treatment regimens, PD-L1 expression levels, and EGFR/ALK negativity in advanced NSCLC. Our investigation extends to evaluating the relative risk of developing CIP based on previous treatment history. This analysis aims to provide valuable insights for the identification of specific patient subgroups at higher risk, facilitating more effective risk management and precision therapy approaches. PubMed, Embase, and Cochrane databases were systematically searched up to February 16, 2023. We conducted a screening of randomized controlled trials (RCTs) that compared ICI monotherapy or its combination with chemotherapy in advanced NSCLC. The trials were categorized based on histological type, treatment regimen, PD-L1 expression level, EGFR/ALK-negative status, and prior treatment history. Subsequently, the data were stratified into five subgroups, and the occurrences of all-grades (1-5) and high-grades (3-5) pneumonia events were extracted. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were then calculated for further analysis. Twenty-two RCTs, encompassing 13,725 patients with advanced NSCLC, were included in this analysis. Regardless of histology (OR = 2.47, 95% CI 1.41-4.33, P = 0.002; OR = 1.84, 95% CI 1.10-3.09, P = 0.02), treatment regimen (OR = 3.27, 95% CI 2.00-5.35, P < 0.00001; OR = 2.91, 95% CI 1.98-4.27, P < 0.00001), PD-L1 expression level (OR = 5.11, 95% CI 2.58-10.12, P < 0.00001; OR = 5.15, 95% CI 2.48-10.70, P < 0.0001), negative EGFR/ALK expression (OR = 4.32, 95% CI 2.22-8.41, P < 0.0001; OR = 3.6, 95% CI 1.56-8.28, P = 0.003), whether there is a history of treatment (OR = 3.27, 95% CI 2.00-5.35, P < 0.00001; OR = 2.74, 95% CI 1.75-4.29, P < 0.0001), ICI use was associated with a higher risk of all-grade (1-5) and high-grade (3-5) pneumonia compared to chemotherapy. Subgroup analysis revealed that the squamous group, the ICI vs. combination chemotherapy (CT) group, the PD-L1 > 50% group, and the previously untreated group had a higher risk of developing all-grade and grade 3-5 CIP (P < 0.05). In advanced NSCLC, ICI treatment was linked to an elevated risk of pneumonitis across all grades (1-5) as well as high-grade occurrences (3-5) compared to chemotherapy. Notably, individuals with squamous histology and high PD-L1 expression, along with those lacking a history of prior treatment, demonstrated a heightened susceptibility to developing immune-related pneumonitis of all grades (1-5) and high grades (3-5). These observations provide valuable insights for clinicians seeking to enhance the management of pulmonary toxicity associated with immunotherapy.

Protective Role of Quercetin on Carmustine-induced Lung Toxicity in Adult Male Albino Rats

Background: Carmustine (BCNU) is an alkylating agent used as an antineoplastic agent. A major problem with the clinical use of BCNU is the occurrence of pulmonary toxicity. Quercetin (QUE) is an important polyphenolic flavonoid that exhibits antioxidant, anti-inflammatory and other health-promoting effects. This study aimed to investigate the protective effect of QUE on BCNU-induced lung injury in rats using histologic and biochemical methods. Methods: Forty adult male albino rats were divided into 4 groups: Group I served as the control group. Group ІІ received QUE orally in a dose of 100 mg/kg per day for 7 days. Group ІІI received a single dose (30 mg/kg) of BCNU intraperitoneally (i.p.) on the 7th day of the study. Group ІV received (BCNU + QUE). On the 8th day of the experiment, lung tissues were collected for histopathological examinations. The levels of malondialdehyde (MDA), hydroxyproline (HYP), myeloperoxidase (MPO), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were also determined in all dissected tissues. Results: Pretreatment with QUE ameliorated lung morphological changes noticed in the BCNU group and the levels of MDA, HYP, and MPO were significantly decreased whereas those of GSH, GSH-Px, and SOD were significantly increased. Conclusions: QUE provides a protective effect against BCNU-induced lung injury by reducing oxidative stress and pulmonary fibrosis.

Identification of early events in nitrogen mustard pulmonary toxicity that are independent of infiltrating inflammatory cells using precision cut lung slices

Nitrogen mustard (NM; mechlorethamine) is a cytotoxic vesicant known to cause acute lung injury which can progress to chronic disease. Due to the complex nature of NM injury, it has been difficult to analyze early responses of resident lung cells that initiate inflammation and disease progression. To investigate this, we developed a model of acute NM toxicity using murine precision cut lung slices (PCLS), which contain all resident lung cell populations. PCLS were exposed to NM (1–100 μM) for 0.5–3 h and analyzed 1 and 3 d later. NM caused a dose-dependent increase in cytotoxicity and a reduction in metabolic activity, as measured by LDH release and WST-1 activity, respectively. Optimal responses were observed with 50 μM NM after 1 h incubation and these conditions were used in further experiments. Analysis of PCLS bioenergetics using an Agilent Seahorse showed that NM impaired both glycolytic activity and mitochondrial respiration. This was associated with injury to the bronchial epithelium and a reduction in methacholine-induced airway contraction. NM was also found to cause DNA damage in bronchial epithelial cells in PCLS, as measured by expression of γ-H2AX, and to induce oxidative stress, which was evident by a reduction in glutathione levels and upregulation of the antioxidant enzyme catalase. Cleaved caspase-3 was also upregulated in airway smooth muscle cells indicating apoptotic cell death. Characterizing early events in NM toxicity is key in identifying therapeutic targets for the development of efficacious countermeasures.

Side effects and efficacy of low-dose amiodarone in rhythm disorders

Amiodarone is one of the most widely used antiarrhythmic drugs, which is the most effective drug for maintaining sinus rhythm.&amp;nbsp;&amp;nbsp; Taking this drug correlates with side effects such as pulmonary toxicity, thyroid dysfunction, neurotoxicity, hepatotoxicity, and skin manifestations. In addition, in some cases, amiodarone remains as a first-line therapy to maintain sinus rhythm. The side effects of amiodarone depend on the dose and duration of the drug. Systematic reviews and meta-analyses have shown the safety profile of a low dose of amiodarone, defined as 200 mg and a very low dose of amiodarone 100 mg. Due to the use of catheter ablation, the use of a low dose of amiodarone is sufficient. In this literature review, we have cited the side effects of a low dose of amiodarone. In addition, although there is evidence of a safer low-dose spectrum, it is not free from side effects and needs to develop an algorithm for early detection of adverse events, as well as studying the effectiveness according to modern research methods, such as an implantable heart monitor, which in turn is of undoubted interest.

Bleomycin induces senescence and repression of DNA repair via downregulation of Rad51

BackgroundBleomycin, a potent antitumor agent, is limited in clinical use due to the potential for fatal pulmonary toxicity. The accelerated DNA damage and senescence in alveolar epithelial cells (AECs) is considered a key factor in the development of lung pathology. Understanding the mechanisms for bleomycin-induced lung injury is crucial for mitigating its adverse effects.MethodsHuman lung epithelial (A549) cells were exposed to bleomycin and subsequently assessed for cellular senescence, DNA damage, and double-strand break (DSB) repair. The impact of Rad51 overexpression on DSB repair and senescence in AECs was evaluated in vitro. Additionally, bleomycin was intratracheally administered in C57BL/6 mice to establish a pulmonary fibrosis model.ResultsBleomycin exposure induced dose- and time-dependent accumulation of senescence hallmarks and DNA lesions in AECs. These effects are probably due to the inhibition of Rad51 expression, consequently suppressing homologous recombination (HR) repair. Mechanistic studies revealed that bleomycin-mediated transcriptional inhibition of Rad51 might primarily result from E2F1 depletion. Furthermore, the genetic supplement of Rad51 substantially mitigated bleomycin-mediated effects on DSB repair and senescence in AECs. Notably, decreased Rad51 expression was also observed in the bleomycin‐induced mouse pulmonary fibrosis model.ConclusionsOur works suggest that the inhibition of Rad51 plays a pivotal role in bleomycin-induced AECs senescence and lung injury, offering potential strategies to alleviate the pulmonary toxicity of bleomycin.

Durvalumab impacts progression-free survival while high-dose radiation >66 Gy improves local control without excess toxicity in unresectable NSCLC stage III: Real-world data from the Austrian radio-oncological lung cancer study association registry (ALLSTAR)

BackgroundChemo-radioimmunotherapy with total radiation doses of 60–66 Gy in 2 Gy fractions is the standard of care for non-small cell lung cancer (NSCLC) UICC stage III. The Austrian radio-oncological lung cancer study association registry (ALLSTAR) is a prospective multicentre registry intended to document clinical practice at the beginning of the Durvalumab era. Patients and methodsPatients were eligible if they had pathologically verified unresectable NSCLC stage III with a curative treatment option. Chemo-radiation combined with immunotherapy was performed according to local treatment practices. The endpoints were local control (LC), progression-free survival (PFS) and toxicity. ResultsBetween 2020/03 and 2023/04, 12/14 (86 %) Austrian radiation-oncology centres recruited 188 patients (median 17, range: 1–89). PD-L1 testing was performed in 173/188 (93 %) patients. The median interval between the end of chemoradiotherapy and start of Durvalumab was 14 days (range: 1–65). About 40 % (75/188) of the patients received a total radiation dose of > 66 Gy (range: 67.1–100), which improved 2-year LC (86 % versus 60 %, HR = 0.41; 95 %-CI: 0.17–0.98; log-rank p-value < 0.05). Median PFS for patients with Durvalumab was 25.8 months (95 %-CI: 21.9-not reached) compared to 15.7 months (95 %-CI: 13.2–27.8) for those without (HR = 1.88; 95 %-CI: 1.16–3.05; log-rank p-value < 0.01). The rates of esophageal and pulmonary toxicities were 34.6 % and 23.9 %, respectively, including one case of grade 4 pneumonitis. In the subcohort of 75 patients who received > 66 Gy, 19 (25 %) cases of pulmonary toxicity grades 1–3 were observed. ConclusionWhile Durvalumab impacts PFS, LC can be improved by total radiation doses > 66 Gy without excess toxicity.

Protective effects of microbial biosurfactants produced by Bacillus halotolerans and Candida parapsilosis on bleomycin-induced pulmonary fibrosis in mice: Impact of antioxidant, anti-inflammatory and anti-fibrotic properties via TGF-β1/Smad-3 pathway and miRNA-326

Idiopathic pulmonary fibrosis (IPF) is an irreversible disease which considered the most fatal pulmonary fibrosis. Pulmonary toxicity including IPF is the most severe adverse effect of bleomycin, the chemotherapeutic agent. Based on the fact that, exogenous surfactants could induce alveolar stabilization in many lung diseases, the aim of this study was to explore the effects of low cost biosurfactants, surfactin (SUR) and sophorolipids (SLs), against bleomycin-induced pulmonary fibrosis in mice due to their antioxidant, and anti-inflammatory properties. Surfactin and sophorolipids were produced by microbial conversion of frying oil and potato peel wastes using Bacillus halotolerans and Candida parapsilosis respectively. These biosurfactants were identified by FTIR, 1H NMR, and LC-MS/MS spectra. C57BL/6 mice were administered the produced biosurfactants daily at oral dose of 200 mg kg−1 one day after the first bleomycin dose (35 U/kg). We evaluated four study groups: Control, Bleomycin, Bleomycin+SUR, Bleomycin+SLs. After 30 days, lungs from each mouse were sampled for oxidative stress, ELISA, Western blot, histopathological, immunohistochemical analyses. Our results showed that the produced SUR and SLs reduced pulmonary oxidative stress and inflammatory response in the lungs of bleomycin induced mice as they suppressed SOD, CAT, and GST activities also reduced NF-κβ, TNF-α, and CD68 levels. Furthermore, biosurfactants suppressed the expression of TGF-β1, Smad-3, and p-JNK fibrotic signaling pathway in pulmonary tissues. Histologically, SUR and SLs protected against lung ECM deposition caused by bleomycin administration. Biosurfactants produced from microbial sources can inhibit the induced inflammatory and fibrotic responses in bleomycin-induced pulmonary fibrosis.

The pulmonary protective potential of vanillic acid-loaded TPGS-liposomes: modulation of miR-217/MAPK/NF-κb signalling pathway

The aim is to investigate the possible pulmonary protective effect of vanillic acid (VA) in liposome-TPGS nanoparticles, to overcome VA’s poor bioavailability. VA was successfully extracted. Liposomes were prepared using thin film hydration. Central composite design was adopted for optimisation of liposomes to get the maximum entrapment efficiency (EE%) and the minimum mean diameter, where the liposomes were further modified with TPGS, and tested for PDI, zeta-potential, and in-vitro drug release. In-vivo study on mice with LPS-acute pulmonary toxicity was tested. TPGS-modified VA-liposomes showed EE% of 69.35 ± 1.23%, PS of 201.7 ± 3.23 nm, PDI of 0.19 ± 0.02, and zeta-potential of −32.2 ± 0.32 mv. A sustained drug release of the TPGS-modified VA-liposomes was observed compared to standard VA, and a pulmonary-protective effect through decreasing miR-217 expression with subsequent anti-inflammatory effect through suppression of MAPK and PI3K/NF-κB pathways was also demonstrated in the current study. TPGS-modified VA-liposomes showed an enhanced bioavailability and a sustained drug release with promising pulmonary protective effects against acute pulmonary injury diseases.

Abstract LB344: A novel approach to limit off-tumor toxicity of CAR-T cells targeting solid cancers

Abstract T cells genetically engineered to express a chimeric antigen receptor (CAR) specific for the molecule CD19 have achieved significant gains in the treatment of chemotherapy-resistant leukemia and lymphoma. Despite evidence of long-lived cures in patients with metastatic solid cancer after receiving tumor-specific T cells, no CAR-T cell treatment is currently approved for use against any solid cancer. A large majority of solid cancers express one of many tumor-associated antigens (TAAs) that are vulnerable to CAR T cell recognition. However, in nearly all cases those same TAAs are present in healthy tissues. Since CAR T cells cannot differentiate between cancer and normal cells, CAR T cell recognition of TAAs on healthy tissues provokes dose-limiting ‘on-target off-tumor’ toxicities at sites of endogenous expression (lung, intestine). Thus, there remains a pressing need to develop strategies to mitigate off-tumor toxicity of CAR T cells. To this end, we develop two immunocompetent models of CAR T cell transfer targeting TAAs abundant in metastatic colorectal cancer and pancreatic cancer. TAA-specific CAR T cells affected tumor shrinkage along with infiltrating and damaging sites of endogenous expression (primarily lung, pancreas, &amp; colon). In both of our models, off-tumor toxicities were antigen-dependent and resulted in tissue damage, systemic inflammation, and host death that was titratable to CAR-T cell dose. TAA-specific CAR T cells infiltrated sites of endogenous expression such as the intestine, pancreas, and lungs. Notably, the respiratory system was the site of greatest pathology in both of our models, with massive CAR T cell accumulation and tissue destruction that resulted in systemic wasting and rapid weight loss. Remarkably, we found that the presence of an antigen-bearing tumor in the liver, but not other sites, greatly exacerbated CAR-T cell pulmonary infiltration, tissue destruction, and host mortality.The liver is the most common site of metastasis in patients with colorectal and pancreatic adenocarcinoma and the only site of metastasis in one-third of colorectal cancers. Our models indicated that TAA-specific CAR-T cells given for the treatment of liver metastasis result in dose-limiting pulmonary toxicity due to the presence of the TAA in the healthy lung. To address this translational barrier, we designed and validated a multiparameter genetic reprogramming targeting T cell trafficking and tissue residency introduced with the CAR to imbue CAR-T cells with liver tropism. In multiple models, CAR T cells programmed with liver-specific tropism augmented CAR T cell liver trafficking, decreased lung infiltration and toxicity, and effectively treated TAA+ liver metastasis. We aim to initiate a pilot clinical trial using tissue resident-programmed CAR T cells to treat colorectal liver metastasis. Citation Format: Alex Bartlett, Matthew Mcwhorter, Camille Collier, Chelsea Jenkins, Robert Eil. A novel approach to limit off-tumor toxicity of CAR-T cells targeting solid cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB344.

Acute Methotrexate Toxicity Managed with Leucovorin and Pegylated Granulocyte Colony-stimulating Factor: A Report of Two Cases and Review of Literature

Acute methotrexate (MTX) toxicity is most commonly due to overdose of the drug, which may be due to the patient's noncompliance to doctor's orders or physician's prescription error. Other causes include acute renal failure, concomitant use of other drugs, and genetic susceptibility. MTX toxicity presents with pancytopenia, mucositis, hepatotoxicity, pulmonary toxicity, and acute renal failure. Treatment involves a polypragmatic approach which includes vigorous hydration, urinary alkalinization, administration of leucovorin, and glucarpidase. Administration of granulocyte colony-stimulating factor should be considered in cases of severe neutropenia. Here, we present two cases of acute MTX toxicity in chronic plaque psoriasis presenting with ulceration of psoriatic lesions and mucosal ulceration successfully treated with leucovorin and pegylated granulocyte colony-stimulating factor (G-CSF). This case report demonstrates that G-CSF might be lifesaving by contributing to rapid reconstitution of leukopoiesis.

Toxic effect and mRNA mechanism of moon dust simulant induced pulmonary inflammation in rats

Moon dust presents a significant hazard to manned moon exploration missions, yet our understanding of its toxicity remains limited. The objective of this study is to investigate the pattern and mechanism of lung inflammation induced by subacute exposure to moon dust simulants (MDS) in rats. SD rats were exposed to MDS and silica dioxide through oral and nasal inhalation for 6hours per day continuously for 15 days. Pathological analysis indicated that the toxicity of MDS was lower than that of silica dioxide. MDS led to a notable recruitment and infiltration of macrophages in the rat lungs. Material characterization and biochemical analysis revealed that SiO2, Fe2O3, and TiO2 could be crucial sources of MDS toxicity. The study revealed that MDS-induced oxidative stress response can lead to pulmonary inflammation, which potentially may progress to lung fibrosis. Transcriptome sequencing revealed that MDS suppresses the PI3K-AKT signaling pathway, triggers the Tnfr2 non-classical NF-kB pathway and IL-17 signaling pathway, ultimately causing lung inflammation and activating predominantly antioxidant immune responses. Moreover, the study identified the involvement of upregulated genes IL1b, csf2, and Sod2 in regulating immune responses in rat lungs, making them potential key targets for preventing pulmonary toxicity related to moon dust exposure. These findings are expected to aid in safeguarding astronauts against the hazardous effects of moon dust and offer fresh insights into the implications and mechanisms of moon dust toxicity.