Identification of molecular signatures involved in radiation-induced lung fibrosis

FGL1: a novel biomarker and target for non-small cell lung cancer, promoting tumor progression and metastasis through KDM4A/STAT3 transcription mechanism

Non-small cell lung cancer (NSCLC) is characterized by a high incidence rate and poor prognosis worldwide. A deeper insight into the pathogenesis of NSCLC and identification of novel therapeutic targets are essential to improve the prognosis of NSCLC. In this study, we revealed that fibrinogen-like protein 1 (FGL1) promotes proliferation, migration, and invasion of NSCLC cells. Mechanistically, we found that Stat3 acts as a transcription factor and can be recruited to the FGL1 promoter, enhancing FGL1 promoter activity. Lysine-specific demethylase 4A (KDM4A) interacts with Stat3 and facilitates the removal of methyl groups from H3K9me3, thereby enhancing Stat3-mediated transcription of FGL1. Furthermore, we observed that Stat3 and KDM4A promote NSCLC cell proliferation, migration, and invasion partly by upregulating FGL1 expression. Additionally, the expression of FGL1 was significantly higher in cancer tissues (n = 90) than in adjacent non-cancerous tissues (n = 90). Furthermore, patients with high FGL1 expression had a shorter overall survival (OS) compared to those with low FGL1 expression. We measured the expression levels of FGL1 on circulating tumor cells (CTCs) in 65 patients and found that patients with a dynamic decrease in FGL1 expression on CTCs exhibited a better therapeutic response. These findings suggest that the dynamic changes in FGL1 expression can serve as a potential biomarker for predicting treatment efficacy in NSCLC. Overall, this study revealed the significant role and regulatory mechanisms of FGL1 in the development of NSCLC, suggesting its potential as a therapeutic target for patients with NSCLC. Future studies should provide more personalized and effective treatment options for patients with NSCLC to improve clinical outcomes.

Fibrinogen-like 1: A hepatokine linking liver physiology to hematology

A recent study identified the critical contribution of the hepatokine FGL1 to the regulation of iron metabolism during the recovery from anemia. FGL1 is secreted by hepatocytes in response to hypoxia to sequester BMP ligands and repress the transcription of the iron-regulatory hormone hepcidin. This process ensures the proper supply of iron to the bone marrow for new red blood cell synthesis and the restoration of physiological oxygen levels. FGL1 may therefore contribute to the recovery from common anemias and cause iron overload in chronic anemias with ineffective erythropoiesis, such as ß-thalassemia, dyserythropoietic anemia, and myelodysplastic syndromes. However, FGL1 has also been described as a regulator of hepatocyte proliferation, glucose homeostasis, and insulin signaling, as well as a mediator of liver steatosis and immune evasion. Chronic exposure to elevated levels of FGL1 during anemia may therefore have systemic metabolic effects besides iron regulation and erythropoiesis. Here, we are providing an overview of the proposed functions of FGL1 in physiology and pathophysiology.

Potential clinical value of fibrinogen-like protein 1 as a serum biomarker for the identification of diabetic cardiomyopathy

Diabetic individuals with diabetic cardiomyopathy (DbCM) present with abnormal myocardial structure and function. DbCM cannot be accurately diagnosed due to the lack of suitable diagnostic biomarkers. In this study, 171 eligible participants were divided into a healthy control (HC), type 2 diabetes mellitus (T2DM) patients without DbCM (T2DM), or DbCM group. Serum fibrinogen-like protein 1 (FGL-1) and other biochemical parameters were determined for all participants. Serum FGL-1 levels were significantly higher in patients with DbCM compared with those in the T2DM group and HCs. Serum FGL-1 levels were negatively correlated with left ventricular fractional shortening and left ventricular ejection fraction (LVEF) and positively correlated with left ventricular mass index in patients with DbCM after adjusting for age, sex and body mass index. Interaction of serum FGL-1 and triglyceride levels on LVEF was noted in patients with DbCM. A composite marker including serum FGL-1 and triglycerides could differentiate patients with DbCM from those with T2DM and HCs with an area under the curve of 0.773 and 0.789, respectively. Composite marker levels were negatively correlated with N-terminal B-type natriuretic peptide levels in patients with DbCM. Circulating FGL-1 may therefore be a valuable index reflecting cardiac functions in DbCM and to diagnose DbCM.

Radiation-induced upregulation of FGL1 promotes esophageal squamous cell carcinoma metastasis via IMPDH1

BACKGROUND

While radiation therapy remains pivotal in esophageal squamous cell carcinoma (ESCC) treatment, the perplexing phenomenon of post-radiation metastasis presents a formidable clinical challenge. This study investigates the role of fibrinogen-like protein 1 (FGL1) in driving ESCC metastasis following radiation exposure.

METHODS

FGL1 expression in post-radiation ESCC cells was meticulously examined using qRT-PCR, western blotting, and immunofluorescence. The impact of FGL1 on ESCC cell invasion and migration was assessed through Transwell and wound healing assays. In vivo, the metastatic potential of ESCC in response to FGL1 was scrutinized using nude mice models. Comprehensive RNA sequencing and functional experiments elucidated the intricate mechanism associated with FGL1.

RESULTS

Radiation induced upregulation of FGL1 in ESCC cells through FOXO4, intensifying ESCC cell invasion and migration. Targeted knockdown of FGL1 effectively alleviated these characteristics both in vitro and in vivo. FGL1 depletion concurrently suppressed IMPDH1 expression. Rescue experiments underscored that IMPDH1 knockdown robustly reversed the pro-invasive effects induced by FGL1 in ESCC cells. ESCC tissues exhibited heightened IMPDH1 mRNA levels, demonstrating a correlation with patient survival.

CONCLUSIONS

Radiation-induced upregulation of FGL1 propels ESCC metastasis through IMPDH1, proposing a potential therapeutic target to mitigate post-radiotherapy metastasis in ESCC patients.

Transcriptional Changes in Radiation-Induced Lung Injury: A Comparative Analysis of Two Radiation Doses for Preclinical Research

In a recent stereotactic body radiation therapy animal model, radiation pneumonitis and radiation pulmonary fibrosis were observed at around 2 and 6 weeks, respectively. However, the molecular signature of this model remains unclear. This study aimed to examine the molecular characteristics at these two stages using RNA-seq analysis. Transcriptomic profiling revealed distinct transcriptional patterns for each stage. Inflammatory response and immune cell activation were involved in both stages. Cell cycle processes and response to type II interferons were observed during the inflammation stage. Extracellular matrix organization and immunoglobulin production were noted during the fibrosis stage. To investigate the impact of a 10 Gy difference on fibrosis progression, doses of 45, 55, and 65 Gy were tested. A dose of 65 Gy was selected and compared with 75 Gy. The 65 Gy dose induced inflammation and fibrosis as well as the 75 Gy dose, but with reduced lung damage, fewer inflammatory cells, and decreased collagen deposition, particularly during the inflammation stage. Transcriptomic analysis revealed significant overlap, but differences were observed and clarified in Gene Ontology and KEGG pathway analysis, potentially influenced by changes in interferon-gamma-mediated lipid metabolism. This suggests the suitability of 65 Gy for future preclinical basic and pharmaceutical research connected with radiation-induced lung injury.

Development of LAG-3/FGL1 blocking peptide and combination with radiotherapy for cancer immunotherapy

Aside from antibodies, peptides show great potential as immune checkpoint inhibitors (ICIs) due to several advantages, such as better tumor penetration and lower cost. Lymphocyte-activation gene 3 (LAG-3) is an immune checkpoint which can induce T cell dysfunction through interaction with its soluble ligand fibrinogen like protein-1 (FGL1). Here, we found that LAG-3 expression was higher than programmed cell death protein 1 (PD-1) in multiple human cancers by TCGA databases, and successfully identified a LAG-3 binding peptide LFP-6 by phage display bio-panning, which specifically blocks the interaction of LAG-3/FGL1 but not LAG-3/MHC-II. Subsequently, d-amino acids were introduced to substitute the N- and C-terminus of LFP-6 to obtain the proteolysis-resistant peptide LFP-D1, which restores T cell function in vitro and inhibits tumor growth in vivo. Further, a bispecific peptide LFOP targeting both PD-1/PD-L1 and LAG-3/FGL1 was designed by conjugating LFP-D1 with PD-1/PD-L1 blocking peptide OPBP-1(8-12), which activates T cell with enhanced proliferation and IFN-γ production. More importantly, LFOP combined with radiotherapy significantly improve the T cell infiltration in tumor and elevate systemic antitumor immune response. In conclusion, we developed a novel peptide blocking LAG-3/FGL1 which can restore T cell function, and the bispecific peptide synergizes with radiotherapy to further enhance the antitumor immune response.

Influence of the irradiated pulmonary microenvironment on macrophage and T cell dynamics

BACKGROUND

The lung is sensitive to radiation, increasing normal tissue toxicity risks following radiation therapy. Adverse outcomes include pneumonitis and pulmonary fibrosis, which result from dysregulated intercellular communication within the pulmonary microenvironment. Although macrophages are implicated in these pathogenic outcomes, the impact of their microenvironment is not well understood.

MATERIALS AND METHODS

C57BL/6J mice received 6Gyx5 irradiation to the right lung. Macrophage and T cell dynamics were investigated in ipsilateral right lungs, contralateral left lungs and non-irradiated control lungs 4-26wk post exposure. Lungs were evaluated by flow cytometry, histology and proteomics.

RESULTS

Following uni-lung irradiation, focal regions of macrophage accumulation were noted in both lungs by 8wk, however by 26wk fibrotic lesions were observed only in ipsilateral lungs. Infiltrating and alveolar macrophages populations expanded in both lungs, however transitional CD11b + alveolar macrophages persisted only in ipsilateral lungs and expressed lower CD206. Concurrently, arginase-1 + macrophages accumulated in ipsilateral but not contralateral lungs at 8 and 26wk post exposure, while CD206 + macrophages were absent from these accumulations. While radiation expanded CD8 + T cells in both lungs, T regulatory cells only increased in ipsilateral lungs. Unbiased proteomics analysis of immune cells revealed a substantial number of differentially expressed proteins in ipsilateral lungs when compared to contralateral lungs and both differed from non-irradiated controls.

CONCLUSIONS

Pulmonary macrophage and T cell dynamics are impacted by the microenvironmental conditions that develop following radiation exposure, both locally and systemically. While macrophages and T cells infiltrate and expand in both lungs, they diverge phenotypically depending on their environment.

Xue-Jie-San restricts ferroptosis in Crohn's disease via inhibiting FGL1/NF-κB/STAT3 positive feedback loop

Crohn's disease (CD) is an incurable inflammatory bowel disease due to unclear etiology and pathogenesis. Accumulating evidences have shown the harmful role of ferroptosis in CD onset and development. Additionally, fibrinogen-like protein 1 (FGL1) has been verified to be a potential therapeutic target of CD. Xue-Jie-San (XJS) is an effective prescription for treating CD. However, its therapeutic mechanism has not been fully elucidated. This study aimed to determine whether XJS alleviating CD via regulating ferroptosis and FGL1 expression. A colitis rat model was induced by 2,4,6-trinitrobenzene sulfonic acid and treated with XJS. The disease activity indices of the colitis rats were scored. Histopathological damage was assessed using HE staining. ELISA was performed to examine inflammatory cytokines. Transmission electron microscopy was utilized to observe ultrastructure changes in intestinal epithelial cells (IECs). Iron load was evaluated by examining iron concentrations, the expressions of FPN, FTH and FTL. Lipid peroxidation was investigated through detecting the levels of ROS, 4-HNE, MDA and PTGS2. Furthermore, the SLC7A11/GSH/GPX4 antioxidant system and FGL1/NF-κB/STAT3 signaling pathway were examined. The results showed that colitis was dramatically ameliorated in the XJS-treated rats as evidenced by relief of clinical symptoms and histopathological damages, downregulation of pro-inflammatory cytokines IL-6, IL-17 and TNF-α, and upregulation of anti-inflammatory cytokine IL-10. Furthermore, XJS administration led to ferroptosis inhibition in IECs by reducing iron overload and lipid peroxidation. Mechanistically, XJS enhanced the SLC7A11/GSH/GPX4 antioxidant system negatively regulated by the FGL1/NF-κB/STAT3 positive feedback loop. In conclusion, XJS might restrain ferroptosis in IECs to ameliorate experimental colitis by inhibition of FGL1/NF-κB/STAT3 positive feedback loop.

The mapping of mRNA alterations elucidates the etiology of radiation-induced pulmonary fibrosis

The etiology of radiation-induced pulmonary fibrosis is not clearly understood yet, and effective interventions are still lacking. This study aimed to identify genes responsive to irradiation and compare the genome expression between the normal lung tissues and irradiated ones, using a radiation-induced pulmonary fibrosis mouse model. We also aimed to map the mRNA alterations as a predictive model and a potential mode of intervention for radiation-induced pulmonary fibrosis. Thirty C57BL/6 mice were exposed to a single dose of 16 Gy or 20 Gy thoracic irradiation, to establish a mouse model of radiation-induced pulmonary fibrosis. Lung tissues were harvested at 3 and 6 months after irradiation, for histological identification. Global gene expression in lung tissues was assessed by RNA sequencing. Differentially expressed genes were identified and subjected to functional and pathway enrichment analysis. Immune cell infiltration was evaluated using the CIBERSORT software. Three months after irradiation, 317 mRNAs were upregulated and 254 mRNAs were downregulated significantly in the low-dose irradiation (16 Gy) group. In total, 203 mRNAs were upregulated and 149 were downregulated significantly in the high-dose irradiation (20 Gy) group. Six months after radiation, 651 mRNAs were upregulated and 131 were downregulated significantly in the low-dose irradiation group. A total of 106 mRNAs were upregulated and 4 downregulated significantly in the high-dose irradiation group. Several functions and pathways, including angiogenesis, epithelial cell proliferation, extracellular matrix, complement and coagulation cascades, cellular senescence, myeloid leukocyte activation, regulation of lymphocyte activation, mononuclear cell proliferation, immunoglobulin binding, and the TNF, NOD-like receptor, and HIF-1 signaling pathways were significantly enriched in the irradiation groups, based on the differentially expressed genes. Irradiation-responsive genes were identified. The differentially expressed genes were mainly associated with cellular metabolism, epithelial cell proliferation, cell injury, and immune cell activation and regulation.

Study on Proteomics-Based Aortic Dissection Molecular Markers Using iTRAQ Combined With Label Free Techniques

Background: Aortic dissection refers to the separation of aortic media and extension along the long axis to form the true and false chambers of the aortic wall. 65–70% of the patients died of cardiac tamponade, arrhythmia, dissection rupture, etc. At present, echocardiography, computed tomography angiography (CTA), etc. are the main diagnosis tools for aortic dissection. To date, there is no rapid serum molecular marker that can be used for differential diagnosis and risk assessment.

Objectives: To screen serum molecular markers systematically amid aortic dissection and acute coronary syndrome and to preliminarily identify the pathogenesis of acute aortic dissection.

Methods: Related disputes cases of all hospitals were statistically analyzed for the AAD medical disputes ratio, early death ratio and misdiagnosis ratio from the database of Guangdong Province Medical Disputes Coordination Committee from 2013 to 2017. Serum and Aortic tissues samples were respectively quantified by iTRAQ and label-free analysis, further validated by ELISA and protein verified by immunofluorescence and Western blot from AAD and control patients enrolled from the Zhujiang Hospital of Southern Medical University and Guangdong Province people's Hospital from 2016 to 2018.

Results: AAD cases ratio accounted for 15.29% in all 150 cardiovascular disputes, 59.26% in all cardiovascular death less than 24 h, and 88.89% in the patients who remained undiagnosed at the time of death, 84 proteins (66 and 18 upregulated and downregulated, respectively) were identified by iTRAQ and 16 proteins (9 and 7 upregulated and downregulated, respectively) by Label-free. Nine proteins (Lumican, FGL1, PI16, MMP9, FBN1, MMP2, VWF, MMRN1, and PF4) related to the pathogenesis of aortic dissection were identified by David /Ease and String techniques as candidate biomarkers for verification test. Four proteins (Lumican, FGL1, PI16, and MMP9) were found to be statistically different after ELISA verification. The expression of FGL1, PI16, and MMP9 proteins was pathologically significantly increased except for Lumican. Histologically, TGF-β1, α-SMA, and Collagen1 were also significantly higher in the aortic group.

Conclusion: Lumican, FGL1, PI16, and MMP9 may be potential biomarkers in AAD patients, and the Lumican-mediated TGF-β1 pathway is likely to be involved in the pathogenesis of aortic dissection.

Diagnostic Value of 18F-NOTA-FAPI PET/CT in a Rat Model of Radiation-Induced Lung Damage

In this study, we explore the diagnostic value of a novel PET/CT imaging tracer that specifically targets fibroblast activation protein (FAP), ¹⁸F-NOTA-FAPI, in a radiation induced lung damage (RILD) rat model. High focal radiation (40, 60, or 90 Gy) was administered to a 5-mm diameter area of the right lung in Wistar rats for evaluation of RILD induction. Lung tissues exposed to 90 Gy radiation were scanned with ¹⁸F-NOTA-FAPI PET/CT and with ¹⁸F-FDG. Dynamic ¹⁸F-NOTA-FAPI PET/CT scanning was performed on day 42 post-irradiation. After in vivo scanning, lung cryosections were prepared for autoradiography, hematoxylin and eosin (HE) and immunohistochemical (IHC) staining. An animal model of RILD was established and validated by histopathological analysis. On ¹⁸F-NOTA-FAPI PET/CT, RILD was first observed on days 42, 35 and 7 in the 40, 60 and 90 Gy groups, respectively. After treatment with 90 Gy, ¹⁸F-NOTA-FAPI uptake in an area of RILD emerged on day 7 (0.65 ± 0.05%ID/ml) and reappeared on day 28 (0.81 ± 0.09%ID/ml), remaining stable for 4–6 weeks. Autoradiography and HE staining IHC staining revealed that ¹⁸F-NOTA-FAPI accumulated mainly in the center of the irradiated area. IHC staining confirmed the presence of FAP+ macrophages in the RILD area, while FAP+ fibroblasts were observed in the peripheral area of irradiated lung tissue. ¹⁸F-NOTA-FAPI represents a promising radiotracer for in vivo imaging of RILD in a dose- and time-dependent manner. Noninvasive imaging of FAP may potentially aiding in the clinical management of radiotherapy patients.

Selective inhibitors of bromodomain BD1 and BD2 of BET proteins modulate radiation-induced pro-fibrotic fibroblast responses

Radiotherapy can induce various adverse effects including fibrosis in cancer patients. Radiation-induced aberrant expression of pro-fibrotic genes has been associated with dysregulated epigenetic mechanisms. Pan-BET (bromodomain and extra-terminal domain) inhibitors, such as JQ1 and I-BET151, have been reported to attenuate the pro-fibrotic response after irradiation. Despite their profound pre-clinical efficacy, the clinical utility of pan-inhibitors is limited due to observed cyto-toxicicities. Recently, inhibitors were developed that selectively target the first (BD1) and second (BD2) bromodomain of the BET proteins (iBET-BD1 (GSK778) and iBET-BD2 (GSK046)). Here, their potential to attenuate radiation-induced fibroblast activation with low-toxicity was investigated. Our results indicated that cell proliferation and cell cycle progression in fibroblasts from BJ cells and six donors were reduced when treated with I-BET151 and iBET-BD1, but not with iBET-BD2. After irradiation, induction of DGKA and pro-fibrotic markers, especially COL1A1 and ACTA2, was attenuated with all BET inhibitors. H3K27ac enrichment was similar at the DGKA enhancer region after I-BET151 treatment and irradiation, but was reduced at the COL1A1 transcription start site and the ACTA2 enhancer site. iBET-BD2 did not change H3K27ac levels in these regions. BRD4 occupancy at these regions was not altered by any of the compounds. Cell migration activity was measured as a characteristic independent of extracellular matrix production and was un-changed in fibroblasts after irradiation and BET inhibitor-treatment. In conclusion, iBET-BD2 efficiently suppressed radiation-induced expression of DGKA and pro-fibrotic markers without showing cyto-toxicity. Thus BD2-selective targeting is a promising new therapeutic avenue for further investigations to prevent or attenuate radiotherapy-induced fibrosis. This article is protected by copyright. All rights reserved.

Fibrinogen-like protein 1 (FGL1): the next immune checkpoint target

Immune checkpoint therapy has achieved significant efficacy by blocking inhibitory pathways to release the function of T lymphocytes. In the clinic, anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) monoclonal antibodies (mAbs) have progressed to first-line monotherapies in certain tumor types. However, the efficacy of anti-PD-1/PD-L1 mAbs is still limited due to toxic side effects and de novo or adaptive resistance. Moreover, other immune checkpoint target and biomarkers for therapeutic response prediction are still lacking; as a biomarker, the PD-L1 (CD274, B7-H1) expression level is not as accurate as required. Hence, it is necessary to seek more representative predictive molecules and potential target molecules for immune checkpoint therapy. Fibrinogen-like protein 1 (FGL1) is a proliferation- and metabolism-related protein secreted by the liver. Multiple studies have confirmed that FGL1 is a newly emerging checkpoint ligand of lymphocyte activation gene 3 (LAG3), emphasizing the potential of targeting FGL1/LAG3 as the next generation of immune checkpoint therapy. In this review, we summarize the substantial regulation mechanisms of FGL1 in physiological and pathological conditions, especially tumor epithelial to mesenchymal transition, immune escape and immune checkpoint blockade resistance, to provide insights for targeting FGL1 in cancer treatment.

Promising Biomarkers of Radiation-Induced Lung Injury: A Review

Radiation-induced lung injury (RILI) is one of the main dose-limiting side effects in patients with thoracic cancer during radiotherapy. No reliable predictors or accurate risk models are currently available in clinical practice. Severe radiation pneumonitis (RP) or pulmonary fibrosis (PF) will reduce the quality of life, even when the anti-tumor treatment is effective for patients. Thus, precise prediction and early diagnosis of lung toxicity are critical to overcome this longstanding problem. This review summarizes the primary mechanisms and preclinical animal models of RILI reported in recent decades, and analyzes the most promising biomarkers for the early detection of lung complications. In general, ideal integrated models considering individual genetic susceptibility, clinical background parameters, and biological variations are encouraged to be built up, and more prospective investigations are still required to disclose the molecular mechanisms of RILI as well as to discover valuable intervention strategies.

GTSE1 Facilitates the Malignant Phenotype of Lung Cancer Cells via Activating AKT/mTOR Signaling

The expression of G2 and S phase-expressed-1 (GTSE1) was upregulated in human cancer. However, its expression and roles in lung cancer have not been identified yet. In our study, we reported that GTSE1 expression was statistically higher in lung tissues than in the adjacent noncancerous tissues which might be a consequence of hypomethylation of the GTSE1 promoter. The upregulated expression of GTSE1 mRNA predicted the poorer survival of the lung patients. Ectopic expression of GTSE1 in lung cancer cells significantly increased while knockdown of GTSE1 decreased cell proliferation, cell migration, and cell invasion in H460 and A549 cells. Furthermore, knockdown of GTSE1 regulated the cell cycle and promoted cell apoptosis in H460 and A549 cells. Finally, we presented that GTSE1 was able to activate AKT/mTOR signaling in H460 and A549 cells. In conclusion, these results indicated that the overexpressed GTSE1 was involved in the progress of lung cancer by promoting proliferation migration and invasion and inhibiting apoptosis of lung cancer cells via activating AKT/mTOR signaling.

Pulmonary toxicants and fibrosis: innate and adaptive immune mechanisms

Pulmonary fibrosis is characterized by destruction and remodeling of the lung due to an accumulation of collagen and other extracellular matrix components in the tissue. This results in progressive irreversible decreases in lung capacity, impaired gas exchange and eventually, hypoxemia. A number of inhaled and systemic toxicants including bleomycin, silica, asbestos, nanoparticles, mustard vesicants, nitrofurantoin, amiodarone, and ionizing radiation have been identified. In this article, we review the role of innate and adaptive immune cells and mediators they release in the pathogenesis of fibrotic pathologies induced by pulmonary toxicants. A better understanding of the pathogenic mechanisms underlying fibrogenesis may lead to the development of new therapeutic approaches for patients with these debilitating and largely irreversible chronic diseases.

The Differential Effect of Carbon Dots on Gene Expression and DNA Methylation of Human Embryonic Lung Fibroblasts as a Function of Surface Charge and Dose

This study presents a toxicological evaluation of two types of carbon dots (CD), similar in size (<10 nm) but differing in surface charge. Whole-genome mRNA and miRNA expression (RNAseq), as well as gene-specific DNA methylation changes, were analyzed in human embryonic lung fibroblasts (HEL 12469) after 4 h and 24 h exposure to concentrations of 10 and 50 µg/mL (for positive charged CD; pCD) or 10 and 100 µg/mL (for negative charged CD, nCD). The results showed a distinct response for the tested nanomaterials (NMs). The exposure to pCD induced the expression of a substantially lower number of mRNAs than those to nCD, with few commonly differentially expressed genes between the two CDs. For both CDs, the number of deregulated mRNAs increased with the dose and exposure time. The pathway analysis revealed a deregulation of processes associated with immune response, tumorigenesis and cell cycle regulation, after exposure to pCD. For nCD treatment, pathways relating to cell proliferation, apoptosis, oxidative stress, gene expression, and cycle regulation were detected. The expression of miRNAs followed a similar pattern: more pronounced changes after nCD exposure and few commonly differentially expressed miRNAs between the two CDs. For both CDs the pathway analysis based on miRNA-mRNA interactions, showed a deregulation of cancer-related pathways, immune processes and processes involved in extracellular matrix interactions. DNA methylation was not affected by exposure to any of the two CDs. In summary, although the tested CDs induced distinct responses on the level of mRNA and miRNA expression, pathway analyses revealed a potential common biological impact of both NMs independent of their surface charge.

Radiation-Induced Lung Fibrosis: Preclinical Animal Models and Therapeutic Strategies

Radiation-induced lung injury (RILI), including acute radiation pneumonitis and chronic radiation-induced lung fibrosis, is the most common side effect of radiation therapy. RILI is a complicated process that causes the accumulation, proliferation, and differentiation of fibroblasts and, finally, results in excessive extracellular matrix deposition. Currently, there are no approved treatment options for patients with radiation-induced pulmonary fibrosis (RIPF) partly due to the absence of effective targets. Current research advances include the development of small animal models reflecting modern radiotherapy, an understanding of the molecular basis of RIPF, and the identification of candidate drugs for prevention and treatment. Insights provided by this research have resulted in increased interest in disease progression and prognosis, the development of novel anti-fibrotic agents, and a more targeted approach to the treatment of RIPF.

Plasma Fibrinogen-Like 1 as a Potential Biomarker for Radiation-Induced Liver Injury

Liver damage upon exposure to ionizing radiation, whether accidental or because of therapy can contribute to liver dysfunction. Currently, radiation therapy is used for various cancers including hepatocellular carcinoma; however, the treatment dose is limited by poor liver tolerance to radiation. Furthermore, reliable biomarkers to predict liver damage and associated side-effects are unavailable. Here, we investigated fibrinogen-like 1 (FGL1)-expression in the liver and plasma after radiation exposure. We found that 30 Gy of liver irradiation (IR) induced cell death including apoptosis, necrosis, and autophagy, with fibrotic changes in the liver occurring during the acute and subacute phase in mice. Moreover, FGL1 expression pattern in the liver following IR was associated with liver damage represented by injury-related proteins and oxidative stress markers. We confirmed the association between FGL1 expression and hepatocellular injury by exposing human hepatocytes to radiation. To determine its suitability, as a potential biomarker for radiation-induced liver injury, we measured FGL1 in the liver tissue and the plasma of mice following total body irradiation (TBI) or liver IR. In TBI, FGL1 showed the highest elevation in the liver compared to other major internal organs including the heart, lung, kidney, and intestine. Notably, plasma FGL1 showed good correlation with radiation dose by liver IR. Our data revealed that FGL1 upregulation indicates hepatocellular injury in response to IR. These results suggest that plasma FGL1 may represent a potential biomarker for acute and subacute radiation exposure to the liver.