A study on the radiosensitivity of radiation-induced lung injury at the acute phase based on single-cell transcriptomics
Ontology highlight
ABSTRACT: Radiation-induced lung injury (RILI) is the most common complication associated with chest tumors, such as lung and breast cancers, after radiotherapy; however, the pathogenic mechanisms are unclear.Here, a single-cell transcriptome map was established in a mouse model of acute RILI. In total, 18,500 single-cell transcripts were generated, and 10 major cell types were identified. The heterogeneity and radiosensitivity of each cell type or subtype in the lung tissues during the acute stage were revealed. It was found that immune cells had higher radiosensitivity than stromal cells. Immune cells were highly heterogeneous in terms of radiosensitivity, while some immune cells had the characteristics of radiation resistance. Two groups of radiation-induced Cd8+Mki67+ T cells and Cd4+Cxcr6+ helper T cells were identified. In summary, This study investigated the dynamic changes in the cellular microenvironment during acute lung injury.
Project description:Acute exposure to high-dose gamma radiation can result in radiation-induced lung injury (RILI), characterized by acute pneumonitis and subsequent lung fibrosis. A microfluidic organ-on-a-chip lined by human lung alveolar epithelium interfaced with pulmonary endothelium (Lung Alveolus Chip) is used to model acute, early stage RILI in vitro. Both lung epithelium and endothelium exhibit DNA damage, cellular hypertrophy, upregulation of inflammatory cytokines, and loss of barrier function within 6h of radiation exposure, and greater damage is observed in the endothelium. The alveolus chips are exposed to radiation injury at 16 Gy and shows effects that resemble the human lung greater than animal preclinical models. The Alveolus Chip is also used to evaluate the potential ability of two drugs to suppress the effects of acute RILI. These data demonstrate that the Lung Alveolus Chip provides a human relevant alternative approach for studying the molecular basis of acute RILI towards screening radiation countermeasure therapeutics.
Project description:Acute exposure to high-dose gamma radiation often results in radiation-induced lung injury (RILI), characterized by acute pneumonitis and subsequent lung fibrosis. A microfluidic organ-on-a-chip device consisting of human lung alveolar epithelium and pulmonary endothelium (Lung Alveolus Chip) is used to recapitulate acute, early stage RILI in vitro. This RNA-seq data captures that both the lung epithelium and endothelium in this model capture key hallmarks of this disease particularly, DNA damage, cellular hypertrophy, upregulation of inflammatory cytokines, and loss of barrier function within 6h of radiation exposure. The data also suggests that radiation affects the alveolar endothelium more significantly than the epithelium. The alveolus chips are exposed to radiation injury at 16 Gy and shows effects that resemble the human lung greater than animal preclinical models. These data demonstrate that the Lung Alveolus Chip provides a human relevant alternative approach for studying the molecular basis of acute RILI towards screening radiation countermeasure therapeutics.
Project description:Background: Microvascular injury and increased vascular leakage are prominent features of the radiation-induced lung injury (RILI) which follows cancerâ??associated thoracic irradiation. The mechanisms of RILI are incompletely understood and therapeutic strategies to limit RILI are currently unavailable. We established a murine model of radiation pneumonitis in order to assess mechanism-based therapies for RILI-induced inflammation and vascular barrier dysfunction. Based on prior studies, we investigated the therapeutic potential of simvastatin as a vascular barrier protective agent in RILI. Methods: C57BL6/J mice receiving single dose exposure to 18, 20, 22, or 25 Gy, (n=10/group) were temporally assessed (4-12 weeks) for cellular and biochemical indices of injury present in both bronchoalveolar lavage (BAL) and lung tissues (cytokines, tyrosine nitrosylated proteins, leukocytes, extravasation of Evans blue dye or EBD, BAL albumin, histology). In specific experiments, irradiated mice (25Gy) received simvastatin (10 mg/kg) via intraperitoneal injection three times a week (pre and post irradiation) for 2- 6 weeks post irradiation. Results. Acute RILI evolved in a dose- and time-dependent fashion. Mice irradiated with 25Gy exhibited modest increases in BAL leukocytes but significant increases in BAL IL-6 (p=0.03) and TNF-a (p=0.01) at 4 weeks compared to controls. Increases in BAL nitrotyrosine content peaked at 6 weeks (p=0.03) and was accompanied by marked nitrotyrosine immunostaining in lung tissues. Indices of increase lung vascular permeability such as EBD extravasation, BAL protein and BAL albumin significantly increased over time beginning at 6 weeks (p>0.002 all) with histological evidence of severe edema formation and airway inflammation. Simvastatin- treated irradiated mice were noted to exhibit marked attenuation of vascular leak with significantly decreased BAL protein (p=0.01) and inflammatory cell infiltration (50% reduction). Conclusion: Simvastatin is a potentially important therapeutic strategy to limit RILI and may influence radiation associated morbidity and mortality. We used microarrays to detail the global programme of gene expression induced by radiation in Wild type and the protection of SIMVA Experiment Overall Design: animals were treated by Vehical, Radiation (25Gy), SIMVA(10mg/kg), or both.
Project description:Clinically significant radiation-induced lung injury (RILI) is associated with significant morbidity and mortality and a common toxicity in patients administered thoracic radiotherapy. While the molecular etiology of RILI is poorly understood, we previously characterized a murine model of RILI in which alterations in lung endothelial barrier integrity surfaced as a potentially important pathobiologic event. In these studies, inhibition of HMG-CoA reductase activity (simvastatin) reduced murine RILI-associated lung inflammation and vascular leak and attenuated radiation-induced dysregulation of sphingolipid metabolic pathway genes identified by genome-wide lung gene expression profiling. In the present study, we test the hypothesis that sphingolipid signaling components serve as important modulators of RILI pathobiology and novel therapeutic targets. Sphingolipid involvement in murine RILI was confirmed by radiation-induced increases in lung expression of sphingosine kinase (SphK) isoforms 1 and 2 and increases in the ratio of ceramide to cumulative sphingosine-1-phosphate (S1P) and dihydro-S1P (DHS1P) levels in plasma, bronchoalveolar lavage (BAL) fluid and lung tissue following 25 Gy exposure (6 weeks). Moreover, genetically-engineered mice with either targeted deletion of SphK1 (SphK1-/-), or with reduced expression of selective members of the S1P receptor family (S1PR1+/-, S1PR2-/-, S1PR3-/-,), exhibited marked susceptibility to RILI-mediated lung inflammation. Finally, we assessed the efficacy of three potent vascular barrier-protective S1P analogues FTY720 (FTY), fTysiponate (fTyS) and SEW-2871 (SEW) in attenuating indices of RILI. The phosphonate analogue, fTyS, and to a lesser degree SEW, exhibited significant attenuation of RILI and RILI-induced gene dysregulation compared to control RILI-challenged mice (6 weeks). In contrast, FTY failed to significantly alter physiologic or genomic changes compared to RILI-challenged controls. Together, these results support the targeting of sphingolipid components as a novel and effective therapeutic strategy in RILI. Four mice were treated with PBS as a control. Three mice were treated with (S)-FTY-phosphonate (0.1mg/kg) as a drug control. Three mice were treated with SEW-2871 (0.1mg/kg) as a drug control. Three mice were treated with FTY720 (0.1mg/kg) as a drug control. Three mice were treated with administered radiation (25 Gy) alone. Three mice were treated with both administered radiation (25 Gy) and (S)-FTY-phosphonate (0.1mg/kg). Three mice were treated with both administered radiation (25 Gy) and SEW-2871 (0.1mg/kg). Three mice were treated with both administered radiation (25 Gy) and FTY720 (0.1mg/kg).
Project description:Purpose: Radiation-induced lung injury (RILI) is a progressive condition, with an early phase, radiation pneumonitis (RP), and a late phase, lung fibrosis (LF). RILI may occur after partial body ionizing radiation exposures or by internal radioisotope exposure, with wide individual variability in timing and extent of lung injury. This study aims to provide new insights into the pathogenesis and progression of RILI in the non-human primate (NHP) rhesus macaque model. Methods:We used an integrative approach to understand RILI and its evolution at clinical and molecular levels in seventeen NHPs exposed to10 Gy of whole thorax irradiation in comparison to three sham-irradiated control NHPs. Lung samples were collected at necropsy for molecular and histopathological analyses using RNA sequencing and immunohistochemistry Results: Our data enhances understanding of RILI in non-survivors and survivors in a NHP model. RNA sequencing highlighted the role of SERPINA3, ATP12A, GJB2, CLDN10, TOX3, LPA as possible biomarkers and potential therapeutic targets of RILI. Their differential expression in nonsurvivors and survivors correlated with the severity of the disease.
Project description:Twenty-five miRNAs were identified as having differential expression post-irradiation in CL1-0 or CL1-5 cells. Among these miRNAs, miR-449a, which was down-regulated in CL1-0 cells at 24 h after irradiation, was chosen for further investigation. Overexpression of miR-449a in CL1-0 cells effectively increased irradiation-induced DNA damage and apoptosis, altered the cell cycle distribution and eventually led to sensitization of CL1-0 to irradiation. MiR-449a might be a novel radiosensitizer for clinical applications. Two lung adenocarcinoma cell lines (CL1-0 and CL1-5) with different metastatic ability and radiosensitivity were used. In order to understand the regulatory mechanisms of differential radiosensitivity in these isogenic tumor cells, both CL1-0 and CL1-5 were treated with 10 Gy radiation, and were harvested respectively at 0, 1, 4, and 24 h after radiation exposure. The changes in expression of miRNA upon irradiation were examined using Illumina Human microRNA BeadChips.
Project description:Background: Microvascular injury and increased vascular leakage are prominent features of the radiation-induced lung injury (RILI) which follows cancer–associated thoracic irradiation. The mechanisms of RILI are incompletely understood and therapeutic strategies to limit RILI are currently unavailable. We established a murine model of radiation pneumonitis in order to assess mechanism-based therapies for RILI-induced inflammation and vascular barrier dysfunction. Based on prior studies, we investigated the therapeutic potential of simvastatin as a vascular barrier protective agent in RILI. Methods: C57BL6/J mice receiving single dose exposure to 18, 20, 22, or 25 Gy, (n=10/group) were temporally assessed (4-12 weeks) for cellular and biochemical indices of injury present in both bronchoalveolar lavage (BAL) and lung tissues (cytokines, tyrosine nitrosylated proteins, leukocytes, extravasation of Evans blue dye or EBD, BAL albumin, histology). In specific experiments, irradiated mice (25Gy) received simvastatin (10 mg/kg) via intraperitoneal injection three times a week (pre and post irradiation) for 2- 6 weeks post irradiation. Results. Acute RILI evolved in a dose- and time-dependent fashion. Mice irradiated with 25Gy exhibited modest increases in BAL leukocytes but significant increases in BAL IL-6 (p=0.03) and TNF-a (p=0.01) at 4 weeks compared to controls. Increases in BAL nitrotyrosine content peaked at 6 weeks (p=0.03) and was accompanied by marked nitrotyrosine immunostaining in lung tissues. Indices of increase lung vascular permeability such as EBD extravasation, BAL protein and BAL albumin significantly increased over time beginning at 6 weeks (p>0.002 all) with histological evidence of severe edema formation and airway inflammation. Simvastatin- treated irradiated mice were noted to exhibit marked attenuation of vascular leak with significantly decreased BAL protein (p=0.01) and inflammatory cell infiltration (50% reduction). Conclusion: Simvastatin is a potentially important therapeutic strategy to limit RILI and may influence radiation associated morbidity and mortality. We used microarrays to detail the global programme of gene expression induced by radiation in Wild type and the protection of SIMVA
Project description:Clinically significant radiation-induced lung injury (RILI) is associated with significant morbidity and mortality and a common toxicity in patients administered thoracic radiotherapy. While the molecular etiology of RILI is poorly understood, we previously characterized a murine model of RILI in which alterations in lung endothelial barrier integrity surfaced as a potentially important pathobiologic event. In these studies, inhibition of HMG-CoA reductase activity (simvastatin) reduced murine RILI-associated lung inflammation and vascular leak and attenuated radiation-induced dysregulation of sphingolipid metabolic pathway genes identified by genome-wide lung gene expression profiling. In the present study, we test the hypothesis that sphingolipid signaling components serve as important modulators of RILI pathobiology and novel therapeutic targets. Sphingolipid involvement in murine RILI was confirmed by radiation-induced increases in lung expression of sphingosine kinase (SphK) isoforms 1 and 2 and increases in the ratio of ceramide to cumulative sphingosine-1-phosphate (S1P) and dihydro-S1P (DHS1P) levels in plasma, bronchoalveolar lavage (BAL) fluid and lung tissue following 25 Gy exposure (6 weeks). Moreover, genetically-engineered mice with either targeted deletion of SphK1 (SphK1-/-), or with reduced expression of selective members of the S1P receptor family (S1PR1+/-, S1PR2-/-, S1PR3-/-,), exhibited marked susceptibility to RILI-mediated lung inflammation. Finally, we assessed the efficacy of three potent vascular barrier-protective S1P analogues FTY720 (FTY), fTysiponate (fTyS) and SEW-2871 (SEW) in attenuating indices of RILI. The phosphonate analogue, fTyS, and to a lesser degree SEW, exhibited significant attenuation of RILI and RILI-induced gene dysregulation compared to control RILI-challenged mice (6 weeks). In contrast, FTY failed to significantly alter physiologic or genomic changes compared to RILI-challenged controls. Together, these results support the targeting of sphingolipid components as a novel and effective therapeutic strategy in RILI.
Project description:Radiation-induced lung injury (RILI) initiates radiation pneumonitis and progresses to fibrosis as the main side effect of lung cancer patients treated with radiotherapy. There is no effective drug for RILI. Sustained vascular activation is a major contributor to the establishment of chronic disease. Here, using a whole thoracic irradiation (WTI) mouse model, we investigated the mechanisms and effectiveness of thrombopoietin mimetic (TPOm) for preventing RILI. We demonstrated that administering TPOm 24 hours before irradiation decreased histologic lung injury score, apoptosis, vascular permeability, expression of pro-inflammatory cytokines, and neutrophil infiltration in the lung of mice 2 weeks after WTI. We described the expression of c-MPL, a TPO receptor, in mouse primary pulmonary microvascular endothelial cells, showing TPOm reduced endothelial cell-neutrophil adhesion by inhibiting ICAM-1 expression. Seven months after WTI, TPOm-treated lung exhibited less collagen deposition, expression of MMP-9, TIMP-1, IL-6, TGF-b, and p21. Moreover, TPOm improved lung vascular structure, lung density, and respiration rate, leading to a prolonged survival time after WTI. Single-cell RNA sequencing analysis of lungs 2 weeks after WTI revealed that TPOm shifted populations of capillary endothelial cells towards a less activated and more homeostatic phenotype. Taken together, TPOm is protective for RILI by inhibiting endothelial cell activation.
Project description:Radiation Induced Lung Injury (RILI) is one of the main limiting factors of thorax irradiation, which can induce acute pneumonitis as well as pulmonary fibrosis, the latter being a life-threatening condition. The order of cellular and molecular events in the progression towards fibrosis is key to the physiopathogenesis of the disease, yet their coordination in space and time remains largely unexplored. Here, we present an interactive murine single cell atlas of the lung responses to irradiation. This analysis opens the door for exploration of the spatio-temporal dynamics of the mechanisms that lead to radiation-induced pulmonary fibrosis. It depicts with unprecedented detail cell type-specific radiation-induced responses associated with either lung regeneration or the failure thereof. A better understanding of the mechanisms leading to lung fibrosis will help finding new therapeutic options that could improve patients’ quality of life.