Biomarkers Associated with Radiation-Induced Lung Injury in Cancer Patients

Radiotherapy (RT) is a common and effective non-surgical treatment for thoracic solid tumors, and radiation-induced lung injury (RILI) is the most common side effect of radiotherapy. Even if RT is effective in the treatment of cancer patients, severe radiation pneumonitis (RP) or pulmonary fibrosis (PF) can reduce the quality of life of patients and may even lead to serious consequences of death. Therefore, how to overcome the problem of accurate prediction and early diagnosis of RT for pulmonary toxicity is very important. This review summarizes the related factors of RILI and the related biomarkers for early prediction of RILI.

Correlation between miR-564, TGF-β1, and radiation-induced lung injury

Objective Our study aimed to analyze the expression of miR-564 and TGF-β1 in cancer tissues and the serum of patients with radiation-induced lung injury,and to investigate the relationship between them and radiation-induced lung injury.Methods In situ hybridization and real-time fluorescence quantitative method were used to detect the expression of miR-564.Additionally,immunohistochemistry and enzyme-linked immunosorbent assay(ELISA)were performed to detect the expression of TGF-β1.Results The overall incidence of acute radiation pneumonia was 55.9%(100/179).The incidence of≥grade 2 radioactive pneumonia was 24.0%(43/179)and that of grade 1 was 31.8%(57/179).The expression of miR-564 in grade≥2 was slightly higher than that in patients without or with grade 1,but there was no statistical difference(P=0.86).The serum level and ratio of miR-564 in patients with grade≥2 were significantly higher than those without or with grade 1(P=0.005,P=0.025,respectively).The expression of TGF-β1 in grade≥2 was significantly higher than that of patients without or with grade 1(P=0.017).The serum levels of TGF-β1 in grade≥2 were significantly higher than those in patients without or with grade 1(P=0.038).Although the ratio of TGF-β1 in radiation pneumonia of grade≥2 was significantly higher than that of without or with grade 1,there was no significant difference(P=0.24).Moreover,patients with higher expression of miR-564 and lower expression of TGF-β1 had better prognosis.Conclusion MiR-564 and TGF-β1 are predictors of radiation-induced lung injury.Monitoring its changing trend can improve the accuracy of predicting radiation-induced lung injury.The levels and ratio of serum miR-564 and TGF-β1 in patients with radiation-induced lung injury are related to the severity of radiationinduced lung injury.

Rabbit model of radiation-induced lung injury

Objective:To explore the feasibility of establishing an animal model of chronic radiationinduced lung injury.Methods:Twenty-eight New Zealand white rabbits were randomly divided into 3 groups(the right lung irradiation group,the whole lung irradiation group and the control group).Animal model of radiation-induced lung injury was established b) highdoes radiotherapy in the irradiation groups,then all rabbits underwent CT and pathological examinations at 1.2.4.8.12.16 weeks,respectively after radiation.Results:Within 4 weeks of irradiation,some rabbits in the right lung irradiation group and whole lung irradiation group died. CT and pathological examinations all showed acute radiation pneumonitis.At 8-12 weeks after irradiation,CT scanning showed ground glass samples signs,patchy shadows and fibrotic stripes. Pathological examination showed the fibrosis pulmonary alveolar wall thickened obviously. Conclusions:The clinical animal model of chronic radiation-induced lung injury which corresponds to practical conditions in clinic can be successfully established.

Expression of Angiotensin Ⅱ and Aldosterone in Radiation-induced Lung Injury

Objective Radiation-induced lung injury （RILl） is the most common, dose-limiting complication in thoracic malignancy radiotherapy. Considering its negative impact on patients and restrictions to efficacy, the mechanism of RILl was studied. Methods Wistar rats were locally irradiated with a single dose of 0, 16, and 20 Gy to the right half of the lung to establish a lung injury model. Two and six months after irradiation, the right half of the rat lung tissue was removed, and the concentrations of TGF-[31, angiotensin II, and aldosterone were determined via enzyme-linked immunosorbent assay. Results Statistical differences were observed in the expression levels of angiotensin II and aldosterone between the non-irradiation and irradiation groups. Moreover, the expression level of the angiotensin II-aldosterone system increased with increasing doses, and the difference was still observed as time progressed. Conclusions Angiotensin II-aldosterone system has an important pathophysiological function in the progression of RILI.

Prevention and treatment of radiation-induced lung injury by hydroxypiperquin phosphate: a clinical and experimental study

Objective: To evaluate the hydroxypiperquin phosphate (HPQP) as a modifier of radiation-induced injury in human and rat lungs. Methods: Sixty-five patients with lung cancer treated with conventional radiotherapy were divided into 2 groups randomly: Thirty cases were treated with HPQP and the others were in a control group. The changes of X - ray manifestation before, after and during taking drug were compared. An animal model of radiation-induced fibrosis of lungs was also established. Hydroxyproling (HP) content in lung tissue and the pathological changes in rat lungs were checked with microscope and electron microscope after 4 months and 6 months respectively. Results: The changes of lung X-ray manifestation in treatment group were much lighter than that in control group. The HP content and the change of pathology in the lungs of those rats with HPQP treatment were obviously less than that in control group. Conclusion: HPQP plays an important role in prevention and treatment of radiation-induced injury in lungs.

GSN antibody pretreatment aggravates radiation-induced lung injury in mice

Radiation-induced lung injury is one of the main dose limiting factors for thoracic radiation therapy.Gelsolin(GSN) is a widespread,multifunctional regulator of cellular structure and metabolism.In this work,the roles of GSN in radiation-induced lung injury in Balb/c mice were studied.The GSN levels in plasma reduced progressively in 72 hours after irradiation,and then increased gradually.GSN contents in the bronchoalveolar lavage(BAL) fluid increased after thoracic irradiation,whereas mRNA levels of GSN in the lung tissue decreased significantly within 24 hours after irradiation and then increased again.Mice were intravenously injected with 50 ug GSN antibody 0.5 hour before 20 Gy of thoracic irradiation.GSN antibody pretreatment increased lung inflammation,protein concentration in the BAL fluid and leukocytes infiltration in the irradiated mice.The activities of superoxidase dismutase(SOD) in the plasma and the BAL fluid in irradiated mice injected with GSN antibody were less than that of control groups,whereas the levels of malondialdehyde(MDA)increased.These results suggest that pretreatment of GSN antibody may aggravate radiation-induced pneumonitis.

An Appreciation for the Rabbit Ladderlike Modeling of Radiation-induced Lung Injury with High-energy X-Ray

Background：To evaluate the utility of rabbit ladderlike model of radiation-induced lung injury （RILI） for the future investigation of computed tomography perfusion.Methods：A total of 72 New Zealand rabbits were randomly divided into two groups：36 rabbits in the test group were administered 25 Gy of single fractionated radiation to the whole lung of unilateral lung;36 rabbits in the control group were sham-radiated.All rabbits were subsequently sacrificed at 1,6,12,24,48,72 h,and 1,2,4,8,1 6,24 weeks after radiation,and then six specimens were extracted from the upper,middle and lower fields of the bilateral lungs.The pathological changes in these specimens were observed with light and electron microscopy;the expression of tumor necrosis factor-α （TNF-a） and transforming growth factor-βl （TGF-β1） in local lung tissue was detected by immunohistochemistry.Results：（1） Radiation-induced lung injury occurred in all rabbits in the test group.（2） Expression of TNF-a and TGF-β1 at 1 h and 48 h after radiation,demonstrated a statistically significant difference between the test and control groups （each P 〈 0.05）.（3） Evaluation by light microscopy demonstrated statistically significant differences between the two groups in the following parameters （each P 〈 0.05）：thickness of alveolar wall,density of pulmonary interstitium area （1 h after radiation）,number offibroblasts and fibrocytes in interstitium （24 h after radiation）.The test group metrics also correlated well with the time ofpostradiation.（4） Evaluation by electron microscopy demonstrated statistically significant differences in the relative amounts of collagen fibers at various time points postradiation in the test group （P 〈 0.005）,with no significant differences in the control group （P 〉 0.05）.At greater than 48 h postradiation the relative amount of collagen fibers in the test groups significantly differ from the control groups （each P 〈 0.05）,correlating well with the time postradiation （r =0.99318）.Conclusions：A consistent and reliable rabbit model of RILI can be generated in gradient using 25 Gy of high-energy X-ray,which can simulate the development and evolution of RILI.

Treatment of radiation-induced brain injury with bisdemethoxycurcumin

Radiation therapy is considered the most effective non-surgical treatment for brain tumors.However,there are no available treatments for radiation-induced brain injury.Bisdemethoxycurcumin(BDMC)is a demethoxy derivative of curcumin that has anti-proliferative,anti-inflammatory,and anti-oxidant properties.To determine whether BDMC has the potential to treat radiation-induced brain injury,in this study,we established a rat model of radiation-induced brain injury by administe ring a single 30-Gy vertical dose of irradiation to the whole brain,followed by intraperitoneal injection of 500μL of a 100 mg/kg BDMC solution every day for 5 successive weeks.Our res ults showed that BDMC increased the body weight of rats with radiation-induced brain injury,improved lea rning and memory,attenuated brain edema,inhibited astrocyte activation,and reduced oxidative stress.These findings suggest that BDMC protects against radiationinduced brain injury.

TLD calibration and absorbed dose measurement in a radiation-induced liver injury model under a linear accelerator

The application of a thermoluminescent detector(TLD) for dose detection at the liver irradiation site in mice under linear accelerator precision radiotherapy and the use of a single high dose to irradiate the mouse liver to construct a biological model of a radiation-induced liver injury(RILD) in mice were to determine the feasibility of constructing a precision radiotherapy model in small animals under a linear accelerator. A 360° arc volumetric rotational intensity-modulated radiotherapy(VMAT) plan with a prescribed dose of 2 Gy was developed for the planned target volume(PTV) at the location of the TLD within solid water to compare the difference between the measured dose of TLD and the assessed parameters in the TPS system. The TLD was implanted in the livers of mice, and VMAT was planned based on TLD to compare the measured and prescribed doses. C57BL/6 J mice were randomly divided into control and 25-Gy radiation groups and were examined daily for changes in body weight. They were euthanized at 3 and 10 weeks after radiation, and the levels of liver serum enzymes such as alanine aminotransferase(ALT), aspartate aminotransferase(AST), and alkaline phosphatase(ALP) were measured to observe any pathological histological changes in the irradiated areas of the mouse liver. The measured values of solid underwater TLD were within ± 3% of the Dmean value of the evaluation parameter in the TPS system. The mice in the 25-Gy radiation group demonstrated pathological signs of radiation-induced liver injury at the site of liver irradiation. The deviation in the measured and prescribed doses of TLD in the mouse liver ranged from-1.5 to 6%;construction of an accurate model of RILD using the VMAT technique under a linear accelerator is feasible.

Impact of interleukin 6 levels on acute lung injury risk and disease severity in critically ill sepsis patients

BACKGROUND Sepsis is a life-threatening condition characterized by a dysregulation of the host response to infection that can lead to acute lung injury(ALI)and multiple organ dysfunction syndrome(MODS).Interleukin 6(IL-6)is a pro-inflammatory cytokine that plays a crucial role in the pathogenesis of sepsis and its complications.AIM To investigate the relationship among plasma IL-6 levels,risk of ALI,and disease severity in critically ill patients with sepsis.METHODS This prospective and observational study was conducted in the intensive care unit of a tertiary care hospital between January 2021 and December 2022.A total of 83 septic patients were enrolled.Plasma IL-6 levels were measured upon admission using an enzyme-linked immunosorbent assay.The development of ALI and MODS was monitored during hospitalization.Disease severity was evaluated by Acute Physiology and Chronic Health Evaluation II(APACHE II)and Sequential Organ Failure Assessment(SOFA)scores.RESULTS Among the 83 patients with sepsis,38(45.8%)developed ALI and 29(34.9%)developed MODS.Plasma IL-6 levels were significantly higher in patients who developed ALI than in those without ALI(median:125.6 pg/mL vs 48.3 pg/mL;P<0.001).Similarly,patients with MODS had higher IL-6 levels than those without MODS(median:142.9 pg/mL vs 58.7 pg/mL;P<0.001).Plasma IL-6 levels were strongly and positively correlated with APACHE II(r=0.72;P<0.001)and SOFA scores(r=0.68;P<0.001).CONCLUSIONElevated plasma IL-6 levels in critically ill patients with sepsis were associated with an increased risk of ALI andMODS.Higher IL-6 levels were correlated with greater disease severity,as reflected by higher APACHE II andSOFA scores.These findings suggest that IL-6 may serve as a biomarker for predicting the development of ALI anddisease severity in patients with sepsis.

MicroRNA-451 from Human Umbilical Cord-Derived Mesenchymal Stem Cell Exosomes Inhibits Alveolar Macrophage Autophagy via Tuberous Sclerosis Complex 1/Mammalian Target of Rapamycin Pathway to Attenuate Burn-Induced Acute Lung Injury in Rats

Objective Our previous studies established that microRNA(miR)-451 from human umbilical cord mesenchymal stem cell-derived exosomes(hUC-MSC-Exos)alleviates acute lung injury(ALI).This study aims to elucidate the mechanisms by which miR-451 in hUC-MSC-Exos reduces ALI by modulating macrophage autophagy.Methods Exosomes were isolated from hUC-MSCs.Severe burn-induced ALI rat models were treated with hUC-MSC-Exos carrying the miR-451 inhibitor.Hematoxylin-eosin staining evaluated inflammatory injury.Enzyme-linked immunosorbnent assay measured lipopolysaccharide(LPS),tumor necrosis factor-α,and interleukin-1βlevels.qRT-PCR detected miR-451 and tuberous sclerosis complex 1(TSC1)expressions.The regulatory role of miR-451 on TSC1 was determined using a dual-luciferase reporter system.Western blotting determined TSC1 and proteins related to the mammalian target of rapamycin(mTOR)pathway and autophagy.Immunofluorescence analysis was conducted to examine exosomes phagocytosis in alveolar macrophages and autophagy level.Results hUC-MSC-Exos with miR-451 inhibitor reduced burn-induced ALI and promoted macrophage autophagy.MiR-451 could be transferred from hUC-MSCs to alveolar macrophages via exosomes and directly targeted TSC1.Inhibiting miR-451 in hUC-MSC-Exos elevated TSC1 expression and inactivated the mTOR pathway in alveolar macrophages.Silencing TSC1 activated mTOR signaling and inhibited autophagy,while TSC1 knockdown reversed the autophagy from the miR-451 inhibitor-induced.Conclusion miR-451 from hUC-MSC exosomes improves ALI by suppressing alveolar macrophage autophagy through modulation of the TSC1/mTOR pathway,providing a potential therapeutic strategy for ALI.

Mogroside IIE,an in vivo metabolite of sweet agent,alleviates acute lung injury via Pla2g2a-EGFR inhibition

In the face of increasingly serious environmental pollution,the health of human lung tissues is also facing serious threats.Mogroside IIE(M2E)is the main metabolite of sweetening agents mogrosides from the anti-tussive Chinese herbal Siraitia grosvenori.The study elucidated the anti-inflammatory action and molecular mechanism of M2E against acute lung injury(ALI).A lipopolysaccharide(LPS)-induced ALI model was established in mice and MH-S cells were employed to explore the protective mechanism of M2E through the western blotting,co-immunoprecipitation,and quantitative real time-PCR analysis.The results indicated that M2E alleviated LPS-induced lung injury through restraining the activation of secreted phospholipase A2 type IIA(Pla2g2a)-epidermal growth factor receptor(EGFR).The interaction of Pla2g2a and EGFR was identified by co-immunoprecipitation.In addition,M2E protected ALI induced with LPS against inflammatory and damage which were significantly dependent upon the downregulation of AKT and m TOR via the inhibition of Pla2g2a-EGFR.Pla2g2a may represent a potential target for M2E in the improvement of LPS-induced lung injury,which may represent a promising strategy to treat ALI.

Mechanisms and Research Progress of Traditional Chinese Medicine Regulating NF-κB in the Treatment of Acute Lung Injury/Acute Respiratory Distress Syndrome

Acute lung injury(ALI)has multiple causes and can easily progress to acute respiratory distress syndrome(ARDS)if not properly treated.Nuclear factorκB(NF-κB)is a key pathway in the treatment of ALI/ARDS.By exploring the relevance of NF-κB and the pathogenesis of this disease,it was found that this disease was mainly associated with inflammation,dysfunction of the endothelial barrier,oxidative stress,impaired clearance of alveolar fluid,and coagulation disorders.Traditional Chinese medicine(TCM)has the characteristics of multitargeting,multipathway effects,and high safety,which can directly or indirectly affect the treatment of ALI/ARDS.This article summarizes the mechanism and treatment strategies of TCM in recent years through intervention in the NF-κB-related signaling pathways for treating ALI/ARDS.It provides an overview from the perspectives of Chinese herbal monomers,TCM couplet medicines,TCM injections,Chinese herbal compounds,and Chinese herbal preparations,offering insights into the prevention and treatment of ALI/ARDS with TCM.

Research Progress on the Pathogenesis of Acute Lung Injury(ALI)

In this review,the databases searched were PubMed and Web of Science.It is believed that the main causes of acute lung injury(ALI)and acute respiratory distress syndrome(ARDS)are inflammatory response disorders,excessive oxidative stress,cell death,endoplasmic reticulum stress,coagulation dysfunction,and weakened aquaporin function.

Research Progress on the Prevention of Premature Infant Lung Injury and Neonatal Respiratory Support

In the past 40 years,advances in neonatal intensive care unit(NICU)technology have enabled premature infants with lower birth weight and younger gestational age to survive.But with it comes an increase in the incidence of long-term respiratory dysfunction,mainly in the form of bronchopulmonary dysplasia(BPD).Preventing lung injury is crucial for preventing BPD and improving the long-term prognosis of premature infants.Therefore,how to avoid ventilator-associated lung injury has become a focus of clinical and scientific research in premature infants in recent years.This article will elaborate on the susceptibility and pathophysiology of premature infant lung injury,ventilation strategies for preventing lung injury,and new advances in neonatal respiratory support.

Modulating the crosstalk between macrophage and Th17: potential mechanism of natural products on acute lung injury

Sepsis is a life-threatening multiple organ dysfunction syndrome caused by the imbalance of the immune response to infection,featuring complex and variable conditions,and is one of the leading causes of mortality in ICU patients.Lung injury is a common organ damage observed in sepsis patients.Macrophages and Th17 cells,as crucial components of innate and adaptive immunity,play pivotal roles in the development of sepsis-induced acute lung injury(ALI).This review summarizes the alterations and mechanisms of macrophages and Th17 cells in sepsis-induced ALI.By focusing on the“cross-talk”between macrophages and Th17 cells,this review aims to provide a solid theoretical foundation for further exploring the therapeutic targets of traditional Chinese medicine formulas in the treatment of sepsis complicated with ALI,thereby offering insights and guidance for the clinical application of traditional Chinese medicine in managing sepsis-associated ALI.

Progress in the mechanism of radiation-induced lung injury

Radiation therapy is widely used to treat various thoracic tumors.However,X-rays inevitably cause damage to normal lung tissues while killing tumor cells,leading to the occurrence of radiation-induced lung injury(RILI).Recent data showed that lung cancer has the highest incidence of RILI(5-25%),followed by mediastinal lymphoma(5-10%),and breast cancer(1-5%).®With the progress in research,our understanding of the mechanism of RILI has changed from the traditional hypothesis of“target cell death”to“a continuous process involving multiple cells,”which is dynamic and evolving[Figure 1],In the present review,we summarize the current knowledge of RILI,and discuss the potential limitations of combined radio-immunotherapy.

Inhaled amifostine for the prevention of radiation-induced lung injury

Objective:To alleviate radiation-induced lung injury and prevent the related pneumonitis and pulmonary fibrosis by inhaled amifostine(AMI).Methods:15 Gy 60Coγ-ray irradiation was performed on the thoracic area of rats once to establish the radiation injury model.AMI was intraperitoneally(i.p.)injected or intratracheally(i.t.)administered to the rats 30 min preirradiation.The protective effects of the two AMI administration manners were compared in the aspects of hematopoietic system,lung edema,and histopathological examination,and the mechanisms were explored.Results:Compared to i.p.AMI,i.t.AMI remarkably alleviated radiation-induced lung injury and prevented consequent pneumonitis or pulmonary fibrosis.Specifically,i.t.AMI notably protected white blood cells and platelets,reduced the lung wet/dry weight ratio,and decreased collagen volume fractions compared to the model group(P<0.05),while i.p.AMI showed no significant difference with the model group(P>0.05).The high therapeutic efficiency of i.t.AMI was related to its high antioxidation and anti-inflammation effects with downregulation of pro-inflammatory cytokines,the enhanced superoxide dismutase activity,the low levels of malondialdehyde and total proteins.Conclusion:Inhaled AMI is a promising medicine for preventing radiation-induced lung injury,including pneumonitis and pulmonary fibrosis.

Periplaneta Americana Extract Ameliorates LPS-induced Acute Lung Injury Via Reducing Inflammation and Oxidative Stress

Objective Acute lung injury(ALI)is an acute clinical syndrome characterized by uncontrolled inflammation response,which causes high mortality and poor prognosis.The present study determined the protective effect and underlying mechanism of Periplaneta americana extract(PAE)against lipopolysaccharide(LPS)-induced ALI.Methods The viability of MH-S cells was measured by MTT.ALI was induced in BALB/c mice by intranasal administration of LPS(5 mg/kg),and the pathological changes,oxidative stress,myeloperoxidase activity,lactate dehydrogenase activity,inflammatory cytokine expression,edema formation,and signal pathway activation in lung tissues and bronchoalveolar lavage fluid(BALF)were examined by H&E staining,MDA,SOD and CAT assays,MPO assay,ELISA,wet/dry analysis,immunofluorescence staining and Western blotting,respectively.Results The results revealed that PAE obviously inhibited the release of proinflammatory TNF-α,IL-6 and IL-1βby suppressing the activation of MAPK/Akt/NF-κB signaling pathways in LPS-treated MH-S cells.Furthermore,PAE suppressed the neutrophil infiltration,permeability increase,pathological changes,cellular damage and death,pro-inflammatory cytokines expression,and oxidative stress upregulation,which was associated with its blockage of the MAPK/Akt/NF-κB pathway in lung tissues of ALI mice.Conclusion PAE may serve as a potential agent for ALI treatment due to its anti-inflammatory and anti-oxidative properties,which correlate to the blockage of the MAPK/NF-κB and AKT signaling pathways.

Mechanisms of the alternative activation of macrophages and non-coding RNAs in the development of radiation-induced lung fibrosis

Radiation-induced lung fibrosis(RILF) is a common side effect of thoracic irradiation therapy and leads to high mortality rates after cancer treatment. Radiation injury induces inflammatory M1 macrophage polarization leading to radiation pneumonitis, the first stage of RILF progression. Fibrosis occurs due to the transition of M1 macrophages to the anti-inflammatory pro-fibrotic M2 phenotype, and the resulting imbalance of macrophage regulated inflammatory signaling. Non-coding RNA signaling has been shown to play a large role in the regulation of the M2 mediated signaling pathways that are associated with the development and progression of fibrosis. While many studies show the link between M2 macrophages and fibrosis, there are only a few that explore their distinct role and the regulation of their signaling by non-coding RNA in RILF. In this review we summarize the current body of knowledge describing the roles of M2 macrophages in RILF, with an emphasis on the expression and functions of non-coding RNAs.