Radiation-Induced Normal Tissue Damage: Oxidative Stress and Epigenetic Mechanisms

Innovative insights: ITLN1 modulates renal injury in response to radiation

Radiation-induced kidney injury is a common side effect of radiotherapy, as the pelvic region is in close proximity to the kidneys, posing a risk of inducing radiation-induced kidney injury when treating any pelvic malignancies with radiotherapy. This type of injury typically manifests as chronic kidney disease a few months after radiotherapy, with the potential to progress to end-stage renal disease. Radiation-induced damage involves various components of the kidney, including glomeruli, tubules, interstitium, and extracellular matrix. Therefore, investigating its molecular mechanisms is crucial. In this study, we extensively searched literature databases, selecting recent transcriptomic studies related to acute kidney injury (AKI) published in the past decade. We downloaded the raw RNA sequencing datasets GSE30718 and GSE66494 related to AKI from the GEO database and identified that intestinal-type lectin ITLN1 plays a significant role in regulating radiation-induced kidney injury in rats. Differential gene analysis was performed using chip data from the GEO database, and further bioinformatics analysis identified 13 genes that may be involved in regulating kidney injury, with ITLN1 being the most relevant to kidney damage, thus selected as the target gene for this study. Subsequently, a rat model of radiation-induced kidney injury was established for experimental validation, assessing kidney tissue morphology and injury extent through staining observation and immunohistochemical staining. The protective effect of ITLN1 on kidney function was evaluated by measuring changes in rat body weight and blood pressure, serum kidney injury markers, and kidney structure. The experimental results indicate that overexpression of ITLN1 can improve kidney function in rats with radiation-induced kidney injury by activating the Akt/GSK-3β/Nrf2 signaling pathway, suppressing oxidative stress, cell apoptosis, inflammation, cellular senescence, and fibrosis. This study highlights the significant role of ITLN1 in regulating kidney injury, providing a novel target for future treatments of radiation-induced kidney injury.

Emerging role of mesenchymal stem cell-derived exosome microRNA in radiation injury

PURPOSE

Radiation injury (RI) is a common occurrence in malignant tumors patients receiving radiation therapy. While killing tumor cells, normal tissue surrounding the target area is inevitably irradiated at a certain dose, which can cause varying results of radiation injury. Currently, there are limited clinical treatments available for radiation injuries. In recent years, the negative effects of stem cell therapy have been reported more clearly and non-cellular therapies such as exosomes have become a focus of attention for researchers. As a type of vesicle-like substances secreted by mesenchymal stem cells (MSC), MSC derived exosomes (MSC-exo) carry DNA, mRNA, microRNA (miRNAs), specific proteins, lipids, and other active substances involved in intercellular information exchange. miRNAs released by MSC-exo are capable of alleviating and repairing damaged tissues through anti-apoptosis, modulating immune response, regulating inflammatory response and promoting angiogenesis, which indicates that MSC-exo miRNAs have great potential for application in the prevention and treatment of radiation injury. Therefore, it is necessary to explore the underlying therapeutic mechanisms of MSC-exo miRNAs in this process, which may shed new lights on the treatment of radiation injury.

CONCLUSIONS

Increasing evidence confirms that MSC-exo has shown encouraging applications in tissue repair due to the anti-apoptotic, immunoreactive, and pro-angiogenesis effects of the miRNAs it carries as intercellular communication carriers. However, miRNA-based therapeutics are still in their infancy and many practical issues remain to be addressed for clinical applications.

Analysis of the metabolic profile of humans naturally exposed to RF-EM radiation

INTRODUCTION

The world is experiencing exponential growth in communication, especially wireless communication. Wireless connectivity has recently become a part of everyone's daily life. Recent developments in low-cost, low-power, and miniature devices contribute to a significant rise in radiofrequency-electromagnetic field (RF-EM) radiation exposure in our environment, raising concern over its effect on biological systems. The inconsistent and conflicting research results make it difficult to draw definite conclusions about how RF-EM radiation affects living things.

OBJECTIVES

This study identified two micro-environments based on their level of exposure to cellular RF-EM radiation, one with significantly less exposure and another with very high exposure to RF-EM radiation. Emphasis is given to studying the metabolites in the urine samples of humans naturally exposed to these two different microenvironments to understand short-term metabolic dysregulations.

METHODS

Untargeted 1H NMR spectroscopy was employed for metabolomics analyses to identify dysregulated metabolites. A total of 60 subjects were recruited with 5 ml urine samples each. These subjects were divided into two groups: one highly exposed to RF-EM (n = 30) and the other consisting of low-exposure populations (n = 30).

RESULTS

The study found that the twenty-nine metabolites were dysregulated. Among them, 19 were downregulated, and 10 were upregulated. In particular, Glyoxylate and dicarboxylate and the TCA cycle metabolism pathway have been perturbed. The dysregulated metabolites were validated using the ROC curve analysis.

CONCLUSION

Untargeted urine metabolomics was conducted to identify dysregulated metabolites linked to RF-EM radiation exposure. Preliminary findings suggest a connection between oxidative stress and gut microbiota imbalance. However, further research is needed to validate these biomarkers and understand the effects of RF-EM radiation on human health. Further research is needed with a diverse population.

Oxidative Stress-Mediated RUNX3 Mislocalization Occurs Via Jun Activation Domain-Binding Protein 1 and Histone Modification

Runt domain transcription factor 3 (RUNX3) suppresses many different cancer types and is disabled by mutations, epigenetic repression, or cytoplasmic mislocalization. In this study, we investigated whether oxidative stress is associated with RUNX3 accumulation from the nucleus to the cytoplasm in terms of histone modification. Oxidative stress elevated histone deacetylase (HDAC) level and lowered that of histone acetyltransferase. In addition, oxidative stress decreased the expression of mixed lineage leukemia (MLL), a histone methyltransferase, but increased the expression of euchromatic histone-lysine N-methyltransferase 2 (EHMT2/G9a), which is also a histone methyltransferase. Moreover, oxidative stress-induced RUNX3 phosphorylation, Src activation, and Jun activation domain-binding protein 1 (JAB1) expression were inhibited by knockdown of HDAC and G9a, restoring the nuclear localization of RUNX3 under oxidative stress. Cytoplasmic RUNX3 localization was followed by oxidative stress-induced histone modification, activated Src along with RUNX3 phosphorylation, and induction of JAB1, resulting in RUNX3 inactivation.

Oxidative stress involvement in the molecular pathogenesis and progression of multiple sclerosis: a literature review

Multiple sclerosis (MS) is an autoimmune debilitating disease of the central nervous system caused by a mosaic of interactions between genetic predisposition and environmental factors. The pathological hallmarks of MS are chronic inflammation, demyelination, and neurodegeneration. Oxidative stress, a state of imbalance between the production of reactive species and antioxidant defense mechanisms, is considered one of the key contributors in the pathophysiology of MS. This review is a comprehensive overview of the cellular and molecular mechanisms by which oxidant species contribute to the initiation and progression of MS including mitochondrial dysfunction, disruption of various signaling pathways, and autoimmune response activation. The detrimental effects of oxidative stress on neurons, oligodendrocytes, and astrocytes, as well as the role of oxidants in promoting and perpetuating inflammation, demyelination, and axonal damage, are discussed. Finally, this review also points out the therapeutic potential of various synthetic antioxidants that must be evaluated in clinical trials in patients with MS.

Comparative study of the anti-inflammatory activity of etoricoxib and Matcha green tea against acute kidney injury induced by gamma radiation in rats

PURPOSE

The primary objective of this study was to conduct a comparative analysis of the anti-inflammatory activity between Etoricoxib (ETO) and Matcha green tea (MG) in the context of acute kidney injury (AKI) induced by ionizing gamma radiation (IR) in female rats. Furthermore, the potential impact of whole body IR exposure on the intestinal system and serum estradiol levels was investigated. Additionally, it was acknowledged that the ETO and MG treatments might have exerted favorable effects on the intestinal and hormonal responses.

MATERIALS AND METHODS

Six groups of rats were assigned to different treatments: control, ETO, MG, irradiation (IRR), ETO + IRR, and MG + IRR. The evaluation included measuring the total phenolic and flavonoid contents of ETO and MG, as well as assessing their antioxidant activity, radical scavenging capacity, reducing power, and total antioxidant capacity. Kidney function was assessed through serum creatinine and urea levels. Oxidative stress markers, including superoxide dismutase, glutathione, malondialdehyde, and catalase, were measured to evaluate the antioxidant effects of ETO and MG. The anti-inflammatory potential of the treatments was evaluated by measuring STAT-3 and interleukins (IL-6, IL-23, and IL-17) using an ELISA assay. Prostaglandin E2 receptor (PGE-2) mRNA expression, histopathological examination, and immunohistochemistry for NF-κB inhibitors were performed to investigate the underlying mechanisms in kidney tissue homogenates. Histopathological changes and DNA fragmentation in the intestinal tissues were determined, and the characterization of Matcha green tea was performed using liquid chromatography-mass spectrometry (LC-MS). This allowed for the identification and quantification of various compounds present in Matcha green tea. Furthermore, the study assessed the effect of IR and treatments on estrogen levels in female rats.

RESULTS

Data showed that both ETO and MG had the potential to mitigate the adverse effects of AKI induced by IR. Notably, MG exhibited greater efficacy in attenuating oxidative stress and inflammation associated with renal injury. These findings revealed and compared the effects of ETO and MG in alleviating AKI caused by IR. MG demonstrated greater anti-inflammatory and antioxidant properties, highlighting its potential as a natural therapeutic agent.

CONCLUSIONS

These results contribute to the growing evidence supporting the use of MG in managing IR-induced renal complications. Future studies should focus on elucidating the molecular mechanisms and optimizing the application of MG in clinical settings.

18β-glycyrrhetinic acid alleviates radiation-induced skin injury by activating the Nrf2/HO-1 signaling pathway

Radiation-induced skin injury is a common side effect of radiotherapy, but there are few therapeutic drugs available for prevention or treatment. In this study, we demonstrate that 18β-Glycyrrhetinic acid (18β-GA), a bioactive component derived from Glycyrrhiza glabra, substantially reduces the accumulation of reactive oxygen species (ROS) and inhibits apoptosis in HaCaT cells after ionizing radiation (IR), thereby mitigating radiation-induced skin injury. Mechanistically, 18β-GA promotes the nuclear import of Nrf2, leading to activation of the Nrf2/HO-1 signaling pathway in response to IR. Importantly, Nrf2 silencing increases cell apoptosis and reverse the protective effect of 18β-GA on radiation-induced skin injury. Furthermore, 18β-GA preserves skin tissue structure after irradiation, inhibits inflammatory cell infiltration, and alleviates radiation dermatitis. In conclusion, our results suggest that 18β-GA reduces intracellular ROS production and apoptosis by activating the Nrf2/HO-1 signaling pathway, leading to amelioration of radiation dermatitis.

Translating genetic findings to epigenetics: identifying the mechanisms associated with aging after high-radiation exposure on earth and in space

Purpose

Exposure to radiation is a health concern within and beyond the Earth's atmosphere for aircrew and astronauts in their respective austere environments. The biological effects of radiation exposure from a multiomics standpoint are relatively unexplored and stand to shed light on tailored monitoring and treatment for those in these career fields. To establish a reference variable for genetic damage, biological age seems to be closely associated with the effect of radiation. Following a genetic-based study, this study explores the epigenetic landscape of radiation exposure along with its associative effects on aging processes.

Methods

We imported the results of the genetics-based study that was a secondary analysis of five publicly available datasets (noted as Data1). The overlap of these genes with new data involving methylation data from two datasets (noted as Data2) following similar secondary analysis procedures is the basis of this study. We performed the standard statistical analysis on these datasets along with supervised and unsupervised learning to create preranked gene lists used for functional analysis in Ingenuity Pathway Analysis (IPA).

Results

There were 664 genes of interest from Data1 and 577 genes from Data2. There were 40 statistically significant methylation probes within 500 base pairs of the gene's transcription start site and 10 probes within 100 base pairs, which are discussed in depth. IPA yielded 21 significant pathways involving metabolism, cellular development, cell death, and diseases. Compared to gold standards for gestational age, we observed relatively low error and standard deviation using newly identified biomarkers.

Conclusion

We have identified 17 methylated genes that exhibited particular interest and potential in future studies. This study suggests that there are common trends in oxidative stress, cell development, and metabolism that indicate an association between aging processes and the effects of ionizing radiation exposure.

Orange peels and Chlorella vulgaris supplementation ameliorate gamma radiation-induced oxidative stress by regulating TGF-β and NOX2/NOX4 signaling pathways

Numerous studies revealed that Chlorella vulgaris and orange peels are potential sources for many valuable compounds such as flavonoids, which are natural polyphenols with antioxidant capacities that lessen oxidative stress via suppressing ROS levels. Thus, this study was designed to investigate their radioprotective efficiency either alone or in combination as natural food supplements. Sixty-four male Albino rats were divided into eight groups (n = 8) as follows: control, orange peel (10% in diet), C. vulgaris (1% in diet), orange peel + C. vulgaris, gamma irradiated (2Gy twice per week up to 8Gy), orange peel + gamma irradiation, C. vulgaris + gamma irradiation, and orange peel + C. vulgaris + gamma irradiation. After the experiment, blood serums were collected for biochemical analysis, whole bloods were collected for blood picture, bone marrows were collected for GSH, MDA, TGF-β, NOX2 and NOX4, and liver tissues were collected for histopathological evaluation. Current study revealed that exposure to gamma irradiation induced a significant disturbance in liver function markers (ALT and AST), kidney function markers (urea and creatinine), cholesterol and triglycerides levels in serum. In addition, a significant decrease in WBCs, RBCs, PLT, and Hb in blood of irradiated rats. Moreover, a significant elevation in TGF-β, NOX2, NOX4 activities, and MDA level, while showed a marked decrease in GSH concentration. Furthermore, hepatic inflammation appeared in the histopathological examination. Orange peels or C. vulgaris treatments showed acceptable amelioration in all measured parameters, combination between orange peels and C. vulgaris showed statistically significant additive amelioration in radiation induced disturbance.

Trimethyltin chloride induces apoptosis and DNA damage via ROS/NF-κB in grass carp liver cells causing immune dysfunction

Trimethyltin chloride (TMT), a common component in fungicides and plastic stabilizers, presents environmental risks, particularly to fish farming. The precise toxicological mechanisms of TMT in L8824 grass carp liver cells remain undefined. Our study investigates TMT's effects on these cells, focusing on its potential to induce hepatotoxicity via oxidative stress and NF-κB pathway activation. First, we selected 0, 3, 6, and 12 μM as the challenge doses, according to the inhibitory concentration of 50% (IC50) of TMT. Our results demonstrate that TMT decreases cell viability dose-dependently and triggers oxidative stress, as evidenced by increased ROS staining and MDA content. Concurrently, it inhibited the antioxidant activities of T-AOC, T-SOD, CAT, and GSH. The activation of the NF-κB pathway was confirmed by gene expression changes. Furthermore, we observed an increase in cell apoptosis rate by AO/EB staining and cell flow cytometry, and the downregulation of Bcl-2 and the upregulation of Bax, Cytc, Caspase-9, and casp3 verified that TMT passed through the BCL2/BAX/casp3 pathway induces apoptosis. DNA damage was validated by the comet assay and γH2AX gene overexpression. Lastly, our data showed increased expression of TNF-α, IL-1β, IL-6, and INF-γ and decreased antimicrobial peptides, validating immune dysfunction. In conclusion, our findings establish that TMT induces apoptosis and DNA damage via ROS/NF-κB in grass carp liver cells, causing immune dysfunction. This study provides novel insights into the toxicology research of TMT and sheds light on the immunological effects of TMT toxicity, enriching our understanding of the immunotoxicity of TMT on aquatic organisms and contributing to the protection of ecosystems.

Etoricoxib nanostructured lipid carriers attenuate inflammation by modulating Cyclooxygenase-2 signaling and activation of nuclear factor-κB-p65 pathways in radiation-induced acute cardiotoxicity in rats

The current investigation aimed to explore the potential of etoricoxib nanostructured lipid carriers (ET-NLCs) as an anti-inflammatory drug in radiation-exposed rats, with a focus on assessing its efficacy in reducing inflammation while minimizing cardiac toxicity compared to conventional etoricoxib (ET) treatment. The ET-NLCs were prepared by the low-temperature melt emulsification solidification technique. Various techniques were employed to characterize the NLCs. Rats were exposed to gamma-irradiation (6 Gy) to induce cardiac inflammation and injury, followed by oral administration of ET or ET-NLCs (10 mg/kg b.w.) for 14 consecutive days. Results demonstrated a significant increase in the levels of malondialdehyde (MDA), cyclooxygenase-2 (COX-2), nuclear factor kappa-B p65 (NF-κB-p65), and poly ADP-ribose polymerase (PARP-1) in the heart tissues of gamma-irradiated rats compared to the control group. This increase was accompanied by a reduction in the activity of antioxidant enzymes. However, treatment with ET and ET-NLCs exhibited a positive impact on these levels. Interestingly, the efficacy of ET-NLCs in mitigating radiation-induced inflammation in heart tissue was found to be superior to that of ET. In conclusion, the study suggests that the utilization of NLCs as a drug delivery system for ET may not only enhance its therapeutic efficacy but also help reduce the cardiovascular risks associated with ET, specifically focused on individuals who had been exposed to gamma radiation. These findings open new avenues for further research in the development of effective and safer therapeutic strategies for managing inflammatory diseases and their impact on cardiovascular health.

Identification of predictive biomarkers for endometrial cancer diagnosis and treatment response monitoring using plasma metabolome profiling

BACKGROUND

Endometrial cancer (EMC) is the most common female genital tract malignancy with an increasing prevalence in many countries including Japan, a fact that renders early detection and treatment necessary to protect health and fertility. Although early detection and treatment are necessary to further improve the prognosis of women with endometrial cancer, biomarkers that accurately reflect the pathophysiology of EMC patients are still unclear. Therefore, it is clinically critical to identify biomarkers to assess diagnosis and treatment efficacy to facilitate appropriate treatment and development of new therapies for EMC.

METHODS

In this study, wide-targeted plasma metabolome analysis was performed to identify biomarkers for EMC diagnosis and the prediction of treatment responses. The absolute quantification of 628 metabolites in plasma samples from 142 patients with EMC was performed using ultra-high-performance liquid chromatography with tandem mass spectrometry.

RESULTS

The concentrations of 111 metabolites increased significantly, while the concentrations of 148 metabolites decreased significantly in patients with EMC compared to healthy controls. Specifically, LysoPC and TGs, including unsaturated fatty acids, were reduced in patients with stage IA EMC compared to healthy controls, indicating that these metabolic profiles could be used as early diagnostic markers of EMC. In contrast, blood levels of amino acids such as histidine and tryptophan decreased as the risk of recurrence increased and the stages of EMC advanced. Furthermore, a marked increase in total TG and a decrease in specific TGs and free fatty acids including polyunsaturated fatty acids levels were observed in patients with EMC. These results suggest that the polyunsaturated fatty acids in patients with EMC are crucial for disease progression.

CONCLUSIONS

Our data identified specific metabolite profiles that reflect the pathogenesis of EMC and showed that these metabolites correlate with the risk of recurrence and disease stage. Analysis of changes in plasma metabolite profiles could be applied for the early diagnosis and monitoring of the course of treatment of EMC patients.

Tissue fibrosis induced by radiotherapy: current understanding of the molecular mechanisms, diagnosis and therapeutic advances

Cancer remains the leading cause of death around the world. In cancer treatment, over 50% of cancer patients receive radiotherapy alone or in multimodal combinations with other therapies. One of the adverse consequences after radiation exposure is the occurrence of radiation-induced tissue fibrosis (RIF), which is characterized by the abnormal activation of myofibroblasts and the excessive accumulation of extracellular matrix. This phenotype can manifest in multiple organs, such as lung, skin, liver and kidney. In-depth studies on the mechanisms of radiation-induced fibrosis have shown that a variety of extracellular signals such as immune cells and abnormal release of cytokines, and intracellular signals such as cGAS/STING, oxidative stress response, metabolic reprogramming and proteasome pathway activation are involved in the activation of myofibroblasts. Tissue fibrosis is extremely harmful to patients' health and requires early diagnosis. In addition to traditional serum markers, histologic and imaging tests, the diagnostic potential of nuclear medicine techniques is emerging. Anti-inflammatory and antioxidant therapies are the traditional treatments for radiation-induced fibrosis. Recently, some promising therapeutic strategies have emerged, such as stem cell therapy and targeted therapies. However, incomplete knowledge of the mechanisms hinders the treatment of this disease. Here, we also highlight the potential mechanistic, diagnostic and therapeutic directions of radiation-induced fibrosis.

Dual effects of radiotherapy on tumor microenvironment and its contribution towards the development of resistance to immunotherapy in gastrointestinal and thoracic cancers

Successful clinical methods for tumor elimination include a combination of surgical resection, radiotherapy, and chemotherapy. Radiotherapy is one of the crucial components of the cancer treatment regimens which allow to extend patient life expectancy. Current cutting-edge radiotherapy research is focused on the identification of methods that should increase cancer cell sensitivity to radiation and activate anti-cancer immunity mechanisms. Radiation treatment activates various cells of the tumor microenvironment (TME) and impacts tumor growth, angiogenesis, and anti-cancer immunity. Radiotherapy was shown to regulate signaling and anti-cancer functions of various TME immune and vasculature cell components, including tumor-associated macrophages, dendritic cells, endothelial cells, cancer-associated fibroblasts (CAFs), natural killers, and other T cell subsets. Dual effects of radiation, including metastasis-promoting effects and activation of oxidative stress, have been detected, suggesting that radiotherapy triggers heterogeneous targets. In this review, we critically discuss the activation of TME and angiogenesis during radiotherapy which is used to strengthen the effects of novel immunotherapy. Intracellular, genetic, and epigenetic mechanisms of signaling and clinical manipulations of immune responses and oxidative stress by radiotherapy are accented. Current findings indicate that radiotherapy should be considered as a supporting instrument for immunotherapy to limit the cancer-promoting effects of TME. To increase cancer-free survival rates, it is recommended to combine personalized radiation therapy methods with TME-targeting drugs, including immune checkpoint inhibitors.

The NIAID/RNCP Biodosimetry Program: An Overview

Established in 2004, the Radiation and Nuclear Countermeasures Program (RNCP), within the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health has the central mission to advance medical countermeasure mitigators/therapeutics, and biomarkers and technologies to assess, triage, and inform medical management of patients experiencing acute radiation syndrome and/or the delayed effects of acute radiation exposure. The RNCP biodosimetry mission space encompasses: (1) basic research to elucidate novel approaches for rapid and accurate assessment of radiation exposure, (2) studies to support advanced development for US Food and Drug Administration (FDA) clearance of promising triage or treatment devices/approaches, (3) characterization of biomarkers and/or assays to determine degree of tissue or organ dose that can predict outcome of radiation injuries (i.e., organ failure, morbidity, and/or mortality), and (4) outreach efforts to facilitate interactions with researchers developing cutting edge biodosimetry approaches. Thus far, no biodosimetry device has been FDA cleared for use during a radiological/nuclear incident. At NIAID, advancement of radiation biomarkers and biodosimetry approaches is facilitated by a variety of funding mechanisms (grants, contracts, cooperative and interagency agreements, and Small Business Innovation Research awards), with the objective of advancing devices and assays toward clearance, as outlined in the FDA's Radiation Biodosimetry Medical Countermeasure Devices Guidance. The ultimate goal of the RNCP biodosimetry program is to develop and establish accurate and reliable biodosimetry tools that will improve radiation preparedness and ultimately save lives during a radiological or nuclear incident.

Radioprotective Effects of Carvacrol and/or Thymol against Gamma Irradiation-Induced Acute Nephropathy: In Silico and In Vivo Evidence of the Involvement of Insulin-like Growth Factor-1 (IGF-1) and Calcitonin Gene-Related Peptide

Radiotherapy (RT) is an effective curative cancer treatment. However, RT can seriously damage kidney tissues resulting in radiotherapy nephropathy (RN) where oxidative stress, inflammation, and apoptosis are among the common pathomechanisms. Carvacrol and thymol are known for their antioxidative, anti-inflammatory, and radioprotective activities. Therefore, this study investigated the nephroprotective potentials of carvacrol and/or thymol against gamma (γ) irradiation-induced nephrotoxicity in rats along with the nephroprotection mechanisms, particularly the involvement of insulin-like growth factor-1 (IGF-1) and calcitonin gene-related peptide (CGRP). Methods: Male rats were injected with carvacrol and/or thymol (80 and 50 mg/kg BW in the vehicle, respectively) for five days and exposed to a single dose of irradiation (6 Gy). Then, nephrotoxicity indices, oxidative stress, inflammatory, apoptotic biomarkers, and the histopathological examination were assessed. Also, IGF-1 and CGRP renal expressions were measured. Results: Carvacrol and/or thymol protected kidneys against γ-irradiation-induced acute RN which might be attributed to their antioxidative, anti-inflammatory, and antiapoptotic activities. Moreover, both reserved the γ -irradiation-induced downregulation of CGRP- TNF-α loop in acute RN that might be involved in the pathomechanisms of acute RN. Additionally, in Silico molecular docking simulation of carvacrol and thymol demonstrated promising fitting and binding with CGRP, IGF-1, TNF-α and NF-κB through the formation of hydrogen, hydrophobic and alkyl bonds with binding sites of target proteins which supports the reno-protective properties of carvacrol and thymol. Collectively, our findings open a new avenue for using carvacrol and/or thymol to improve the therapeutic index of γ-irradiation.

Radiation Induces Bone Microenvironment Disruption by Activating the STING-TBK1 Pathway

Background and Objectives: Damage to normal bone tissue following therapeutic irradiation (IR) represents a significant concern, as IR-induced bone microenvironment disruption can cause bone loss and create a more favorable environment for tumor metastases. The aim of the present study was to explore the cellular regulatory mechanism of IR-induced bone microenvironment disruption to effectively prevent radiotherapy-associated adverse effects in the future. Materials and Methods: In this study, a mouse model of local IR was established via local irradiation of the left hind limb of BALB/c mice with 12 Gy X-rays, and an in vitro osteocyte (OCY) model was established by exposing osteocyte-like MLO-Y4 cells to 2, 4, and 8 Gy irradiation to analyze multicellular biological injuries and cellular senescence. Small interfering RNA (siRNA) transfection at the cellular level and a selective antagonist intervention C-176 at the animal level were used to explore the potential role of the stimulator of interferon genes (STING) on IR-induced bone microenvironment disruption. Results: The results showed that 12 Gy local IR induces multicellular dysfunction, manifested as ascension of OCYs exfoliation, activation of osteoclastogenesis, degeneration of osteogenesis and fate conversion of adipogenesis, as well as cellular senescence and altered senescence-associated secretory phenotype (SASP) secretion. Furthermore, the expression of STING was significantly elevated, both in the primary OCYs harvested from locally irradiated mice and in vitro irradiated MLO-Y4 cells, accompanied by the markedly upregulated levels of phosphorylated TANK-binding kinase 1 (P-TBK1), RANKL and sclerostin (SOST). STING-siRNA transfection in vitro restored IR-induced upregulated protein expression of P-TBK1 and RANKL, as well as the mRNA expression levels of inflammatory cytokines, such as IL-1α, IL-6 and NF-κB, accompanied by the alleviation of excessive osteoclastogenesis. Finally, administration of the STING inhibitor C-176 mitigated IR-induced activation of osteoclastogenesis and restraint of osteogenesis, ameliorating the IR-induced biological damage of OCYs, consistent with the inhibition of P-TBK1, RANKL and SOST. Conclusions: The STING-P-TBK1 signaling pathway plays a crucial role in the regulation of the secretion of inflammatory cytokines and osteoclastogenesis potential in IR-induced bone microenvironment disruption. The selective STING antagonist can be used to intervene to block the STING pathway and, thereby, repair IR-induced multicellular biological damage and mitigate the imbalance between osteoclastogenesis and osteoblastgenesis.

Investigating ionizing radiation-induced changes in breast cancer cells using stimulated Raman scattering microscopy

Significance

Altered lipid metabolism of cancer cells has been implicated in increased radiation resistance. A better understanding of this phenomenon may lead to improved radiation treatment planning. Stimulated Raman scattering (SRS) microscopy enables label-free and quantitative imaging of cellular lipids but has never been applied in this domain.

Aim

We sought to investigate the radiobiological response in human breast cancer MCF7 cells using SRS microscopy, focusing on how radiation affects lipid droplet (LD) distribution and cellular morphology.

Approach

MCF7 breast cancer cells were exposed to either 0 or 30 Gy (X-ray) ionizing radiation and imaged using a spectrally focused SRS microscope every 24 hrs over a 72-hr time period. Images were analyzed to quantify changes in LD area per cell, lipid and protein content per cell, and cellular morphology. Cell viability and confluency were measured using a live cell imaging system while radiation-induced lipid peroxidation was assessed using BODIPY C11 staining and flow cytometry.

Results

The LD area per cell and total lipid and protein intensities per cell were found to increase significantly for irradiated cells compared to control cells from 48 to 72 hrs post irradiation. Increased cell size, vacuole formation, and multinucleation were observed as well. No significant cell death was observed due to irradiation, but lipid peroxidation was found to be greater in the irradiated cells than control cells at 72 hrs.

Conclusions

This pilot study demonstrates the potential of SRS imaging for investigating ionizing radiation-induced changes in cancer cells without the use of fluorescent labels.

Autologous i-PRF promotes healing of radiation-induced skin injury

Skin, as an exposed tissue, often suffers damage after exposure to radiotherapy and accidental events, which may lead to the formation of chronic refractory wounds. However, effective treatment options are usually limited for severe radiation-induced skin injury (RSI). Platelet-rich plasma (PRP) has been identified to promote wound healing, but whether a new generation of blood-derived biomaterial, injectable platelet-rich fibrin (i-PRF), is effective in repairing RSI remains unclear. In this study, blood was drawn from humans and Sprague-Dawley rats to prepare PRP and i-PRF, and the regenerative functions of PRP and i-PRF were investigated by exposing the dorsal skin of SD rats to local radiation (45 Gy) and exposing HDF-α cells and human umbilical vein endothelial cells (HUVECs) cells to X-rays (10 Gy). The healing effect of i-PRF on RSI was analysed by tube formation assay, cell migration and apoptosis assays, ROS assay, wound healing assay, histological characterisation and immunostaining. The results showed that exposure to high doses of radiation reduced cell viability, increased ROS levels and induced cell apoptosis, thereby causing dorsal trauma of rats. However, both PRP and i-PRF could resisted RSI, and they were capable of reducing inflammation and promoting angiogenesis and vascular regeneration. i-PRF has a higher concentration of platelets and platelet-derived growth factors, which has a more convenient preparation method and better repair effect and possesses a good application prospect for the repair of RSI.

Revolutionizing Radiotoxicity Management with Mesenchymal Stem Cells and Their Derivatives: A Focus on Radiation-Induced Cystitis

Although radiation therapy plays a crucial role in cancer treatment, and techniques have improved continuously, irradiation induces side effects in healthy tissue. Radiation cystitis is a potential complication following the therapeutic irradiation of pelvic cancers and negatively impacts patients' quality of life (QoL). To date, no effective treatment is available, and this toxicity remains a therapeutic challenge. In recent times, stem cell-based therapy, particularly the use of mesenchymal stem cells (MSC), has gained attention in tissue repair and regeneration due to their easy accessibility and their ability to differentiate into several tissue types, modulate the immune system and secrete substances that help nearby cells grow and heal. In this review, we will summarize the pathophysiological mechanisms of radiation-induced injury to normal tissues, including radiation cystitis (RC). We will then discuss the therapeutic potential and limitations of MSCs and their derivatives, including packaged conditioned media and extracellular vesicles, in the management of radiotoxicity and RC.

Ferroptosis, necroptosis, and pyroptosis in cancer: Crucial cell death types in radiotherapy and post-radiotherapy immune activation

Tumor cell death and antitumor immune activation induced by radiotherapy are extensively well-studied. While radiotherapy is believed to mainly induce tumor cell necrosis and apoptosis, recent studies have shown that it can also induce ferroptosis, necroptosis, and pyroptosis in tumor cells. However, studies on the role of ferroptosis, necroptosis, and pyroptosis in radiotherapy and post-radiotherapy immune activation are limited. In this review, we summarize the comprehensive literature on the molecular mechanisms and more recent research progress related to radiotherapy-induced ferroptosis, necroptosis, and pyroptosis in tumor cells. Further, we discuss the role of tumor cells undergoing these types of cell death in immune activation after radiotherapy. In addition, we highlight some unresolved questions on the association of radiotherapy with ferroptosis, necroptosis, and pyroptosis. This review can improve our current understanding of the relationship between radiotherapy and different cell death pathways and provide a theoretical framework to improve the therapeutic effect of tumor radiotherapy in the future.

Radiosensitization of Nasopharyngeal Carcinoma by Graphene Oxide Nanosheets to Reduce Bcl-2 Level

There are many treatments for nasopharyngeal carcinoma (NPC), but none of them are very effective. Radiotherapy is used extensively in NPC treatment, but radioresistance is a major problem. Graphene oxide (GO) has been previously studied in cancer treatment, and this study is aimed to explore its role in radiosensitization of NPC. Therefore, graphene oxide nanosheets were prepared, and the relationship between GO and radioresistance was explored. The GO nanosheets were synthesized by a modified Hummers' method. The morphologies of the GO nanosheets were characterized by field-emission environmental scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphological changes and radiosensitivity of C666-1 and HK-1 cells with or without the GO nanosheets were observed by an inverted fluorescence microscopy and laser scanning confocal microscopy (LSCM). Colony formation assay and Western Blot were applied for analysis of NPC radiosensitivity. The as-synthesized GO nanosheets have lateral dimensions (sizes ∼1 μm) and exhibit a thin wrinkled two-dimensional lamellar structure with slight folds and crimped edges (thickness values ∼1 nm). C666-1 cells with the GO was significantly changed the morphology of cells postirradiation. The full field of view visualized by a microscope showed the shadow of dead cells or cell debris. The synthesized graphene oxide nanosheets inhibited cell proliferation, promoted cell apoptosis, and inhibited the expression of Bcl-2 in C666-1 and HK-1 cells but increased the level of Bax. The GO nanosheets could affect the cell apoptosis and reduce the pro-survival protein Bcl-2 related to the intrinsic mitochondrial pathway. The GO nanosheets could enhance radiosensitivity, which might be a radioactive material in NPC cells.

Reparative potential of mesenchymal stem cells and platelet-rich plasma on irradiated submandibular glands of male albino rats

OBJECTIVE

To appraise and compare the reparative role of bone marrow-mesenchymal stem cells (BM-MSCs) and platelet-rich plasma (PRP) against irradiation damage on albino rats' submandibular gland.

DESIGN

Seventy four male albino rats were used, one for BM-MSCs harvesting, 10 for PRP preparation, seven as control group (Group 1). The remaining 56 rats were subjected to single dose (6 Gy) gamma irradiation and were divided into equal four groups; (Group 2): received no treatment, (Group 3): each rat was injected with 1 × 10⁵ BM-MSCs, (Group 4): each rat was injected with 0.5 ml/kg PRP, and (Group 5): each rat was injected with 1 × 10⁵ BM-MSCs and 0.5 ml/kg PRP. Each group was further subdivided into two subgroups in which rats sacrificed after one and two weeks from irradiation. Any structural changes were examined histopathologically, immunohistochemically using proliferating cell nuclear antigen (PCNA) and CD31 primary antibodies and histochemically using picrosirius red (PSR) stain, then analyzed statistically.

RESULTS

Histopathological examination of Group 2 showed atrophied acini, with nuclear changes and signs of degeneration in duct systems. Treated groups revealed signs of regeneration in form of uniform acini and regenerated duct systems especially in Group 5 and in a time depended manner. Immunohistochemical examination revealed increased immunoexpression of PCNA and CD31, while histochemical examination showed decreased PSR in all treated groups in relation to the irradiated group and this was proved statistically.

CONCLUSIONS

BM-MSCs and PRP are effective as treatment for irradiation-induced submandibular gland damage. However, the combined therapy is recommended over each one separately.

Multiple low-dose radiation-induced neuronal cysteine transporter expression and oxidative stress are rescued by N-acetylcysteine in neuronal SH-SY5Y cells

Recently, several studies have demonstrated that low-dose radiation (LDR) therapy has positively impacts on the treatment of Alzheimer's disease (AD). LDR suppresses the production of pro-neuroinflammation molecules and improves cognitive function in AD. However, it is unclear whether direct exposure to LDR causes beneficial effects and what mechanism is involved in neuronal cells. In this study, we first determined the effect of high-dose radiation (HDR) alone on C6 cells and SH-SY5Y cells. We found that SH-SY5Y cells were more vulnerable than C6 cells to HDR. Moreover, in neuronal SH-SY5Y cells exposed to single or multiple LDR, N-type cells showed decreased cell viability with increasing radiation exposure time and frequency, but S-type cells were unaffected. Multiple LDR increased proapoptotic molecules such as p53, Bax and cleaved caspase-3, and decreased anti-apoptotic molecule (Bcl₂). Multiple LDR also generated free radicals in neuronal SH-SY5Y cells. We detected a change in the expression of the neuronal cysteine transporter EAAC1. Pretreatment with N-acetylcysteine (NAC) rescued the increased in EAAC1 expression and the generation of ROS in neuronal SH-SY5Y cells after multiple LDR. Furthermore, we verified whether the increased in EAAC1 expression induces cell defense or cell death promotion signaling. We showed that transient overexpression of EAAC1 reduced the multiple LDR-induced p53 overexpression in neuronal SH-SY5Y cells. Our results indicate that neuronal cells can be injured by increased production of ROS not only by HDR but also by multiple LDR, which suggests that combination treatment with anti-free radical agents such as NAC may be useful in multiple LDR therapy.

New Insights into the Understanding of Mechanisms of Radiation-Induced Heart Disease

OPINION STATEMENT

Cancer patients who receive high-dose thoracic radiotherapy may develop radiation-induced heart disease (RIHD). The clinical presentation of RIHD comprises coronary artery atherosclerosis, valvular disease, pericarditis, cardiomyopathy, and conduction defects. These complications have significantly reduced due to the improved radiotherapy techniques. However, such methods still could not avoid heart radiation exposure. Furthermore, people who received relatively low-dose radiation exposures have exhibited significantly elevated RIHD risks in cohort studies of atomic bomb survivors and occupational exposures. The increased potential in exposure to natural and artificial ionizing radiation sources has emphasized the necessity to understand the development of RIHD. The pathological processes of RIHD include endothelial dysfunction, inflammation, fibrosis, and hypertrophy. The underlying mechanisms may involve the changes in oxidative stress, DNA damage response, telomere erosion, mitochondrial dysfunction, epigenetic regulation, circulation factors, protein post-translational modification, and metabolites. This review will discuss the recent advances in the mechanisms of RIHD at cellular and molecular levels.

Depletion of Tip60/Kat5 affects the hepatic antioxidant system in mice

Tat-interactive protein 60 kDa (TIP60, also known as lysine acetyltransferase 5 [KAT5]) is a member of the MYST protein family with histone acetyltransferase activity. Recent studies have reported that TIP60 has multiple functions in many signal transduction mechanisms, especially p53-mediated apoptosis. Although the activation of apoptosis signaling pathways requires the presence of cellular reactive oxygen species (ROS) at a certain level, an imbalance between the production and consumption of ROS in cells results in oxidative stress (OS). In this study, we investigated for the first time how the absence of the Tip60 gene in the liver affects gene expression, enzyme activity, and protein expression of the hepatic antioxidant members localized in the cytoplasm, including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione S-transferase (GST). First, we successfully generated liver-specific Tip60 knockout mice (mutants) using Cre/LoxP recombination. The reduced glutathione level and nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) expression, a marker of OS, increased significantly in the Tip60 mutant liver. Gene expression, activity, and protein expression of the enzymatic antioxidant system, including SOD, CAT, GR, GPx, and GST were investigated in mutants and control groups. Despite a significant correlation between the gene, enzyme activity, and protein content for CAT and GR, this was not true for SOD and GPx. The overall results suggest that TIP60 acts on the hepatic antioxidant system both at the gene and protein levels, but the actual effect of the deletion of Tip60 is observed at the protein level, especially for SOD and GPx.

Capsular inflammation after immediate breast reconstruction - Gene expression patterns and inflammatory cell infiltration in irradiated and non-irradiated breasts

BACKGROUND

Capsular contracture following post-mastectomy radiotherapy (PMRT) is commonly seen in patients undergoing implant-based immediate breast reconstruction (IBR). Further understanding of the underlying biology is needed for the development of preventive or therapeutic strategies. Therefore, we conducted a comparative study of gene expression patterns in capsular tissue from breast cancer patients who had received versus those who had not received PMRT after implant-based IBR.

METHODS

Biopsies from irradiated and healthy non-irradiated capsular tissue were harvested during implant exchange following IBR. Biopsies from irradiated (n = 13) and non-irradiated (n = 12) capsules were compared using Affymetrix microarrays to identify the most differentially regulated genes. Further analysis using immunohistochemistry was performed in a subset of materials to compare the presence of T cells, B cells, and macrophages.

RESULTS

Enrichment testing using Gene Ontology (GO) analysis revealed that the 227 most differentially expressed genes were mainly involved in an inflammatory response. Twenty-one GO biological processes were identified [p < 0.05, false discovery rate (FDR) < 5%], several with B-cell-associated inflammation. Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) analysis identified macrophages as the most common inflammatory cell type in both groups, further supported by immunostaining of CD68. Radiation remarkably increased B-cell infiltration in the capsular region of biopsies, as quantified by immunostaining of CD20 (p = 0.016).

CONCLUSIONS

Transcript analysis and immunohistochemistry revealed inflammatory responses in capsular biopsies regardless of radiotherapy. However, the radiation response specifically involved B-cell-associated inflammatory responses.

Genetic and environmental reprogramming of the sarcoma epigenome

Sarcomas are rare and heterogenous mesenchymal tumors occurring in soft tissue and bone. The World Health Organization Classification of sarcomas comprises more than hundred different entities which are very diverse in their molecular, genetic and epigenetic signatures as they are in their clinical presentations and behaviors. While sarcomas can be associated with an underlying hereditary cancer predisposition, most sarcomas developed sporadically without identifiable cause. Sarcoma oncogenesis involves complex interactions between genetic, epigenetic and environmental factors which are intimately related and intensively studied. Several molecular discoveries have been made over the last decades leading to the development of new therapeutic avenues. Sarcoma research continues its effort toward a more specific and personalized approach to all sarcoma sub-types to improve patient outcomes and this through world-wide collaboration. This chapter on "Genetic and Environmental Reprogramming of the Sarcoma Epigenome" provides a comprehensive review of general concepts and epidemiology of sarcoma as well as a detailed description of the genetic, molecular and epigenetic alterations seen in sarcomas, their therapeutic implications and ongoing research. This review also presents evidenced-based data on the environmental and occupational factors possibly involved in the etiology of sarcomas and a brief discussion on the role of the microbiome in sarcoma.

Radiation-induced oral mucositis presenting as atypical vascular proliferation: a case report

Radiation-induced oral mucositis is an oral mucosal injury caused by radiation ionizing radiation, which often manifests as oral mucosal congestion, erosion, and ulcers. Radiation-induced oral mucositis manifesting as vascular proliferative changes in the oral mucosa has not been reported. We report a case of oral mucosal atypical vascular proliferation after radiotherapy for a malignant maxillofacial tumor. We discussed the mechanism and treatment of aty-pical vascular proliferation in the oral mucosa secondary to radiotherapy, including diagnosis, treatment, and previous literature.

Hunting down NLRP3 inflammasome: An executioner of radiation-induced injury

Radiotherapy is one of the mainstream treatment modalities for several malignancies. However, radiation-induced injury to surrounding normal tissues limits its efficacy. The NLRP3 inflammasome is an essential mechanism of innate immunity that reacts to challenges from endogenous danger signals and pathological microbes. A growing body of evidence has demonstrated a key role of NLRP3 inflammasome in the pathogenesis of radiation-induced tissue injury. Despite accumulating evidence, the potential value of the NLRP3 inflammasome in the management of radiation-induced tissue injury is not adequately recognized. We conducted a literature review to characterize the relationship between NLRP3 inflammasome and radiation injury. By analyzing recent evidence, we identify NLRP3 inflammasome as one of the executioners of radiation-induced injury, since it responds to the challenges of radiation, induces cell pyroptosis and tissue dysfunction, and initiates non-resolving inflammation and fibrosis. Based on these concepts, we propose early intervention/prevention strategies targeting NLRP3 inflammasome in a radiation context, which may help resolve imperative clinical problems.

NUPR1 contributes to radiation resistance by maintaining ROS homeostasis via AhR/CYP signal axis in hepatocellular carcinoma

BACKGROUND

Radiotherapy (RT) is one of the major therapeutic approaches to hepatocellular carcinoma (HCC). Ionizing radiation (IR) inducing the generation of reactive oxygen species (ROS) leads to a promising antitumor effect. However, the dysregulation of the redox system often causes radioresistance and impairs the efficacy of RT. Increasing evidence indicates that nuclear protein 1 (NUPR1) plays a critical role in redox reactions. In this study, we aim to explore the role of NUPR1 in maintaining ROS homeostasis and radioresistance in HCC.

METHODS

The radioresistant role of NUPR1 was determined by colony formation assay, comet assay in vitro, and xenograft tumor models in vivo. Probes for ROS, apoptosis assay, and lipid peroxidation assay were used to investigate the functional effect of NUPR1 on ROS homeostasis and oxidative stress. RNA sequencing and co-immunoprecipitation assay were performed to clarify the mechanism of NUPR1 inhibiting the AhR/CYP signal axis. Finally, we analyzed clinical specimens to assess the predictive value of NUPR1 and AhR in the radiotherapeutic efficacy of HCC.

RESULTS

We demonstrated that NUPR1 was upregulated in HCC tissues and verified that NUPR1 increased the radioresistance of HCC in vitro and in vivo. NUPR1 alleviated the generation of ROS and suppressed oxidative stress, including apoptosis and lipid peroxidation by downregulating cytochrome P450 (CYP) upon IR. ROS scavenger N-acetyl-L-cysteine (NAC) and CYP inhibitor alizarin restored the viability of NUPR1-knockdown cells during IR. Mechanistically, the interaction between NUPR1 and aryl hydrocarbon receptor (AhR) promoted the degradation and decreased nuclear translation of AhR via the autophagy-lysosome pathway, followed by being incapable of CYP's transcription. Furthermore, genetically and pharmacologically activating AhR abrogated the radioresistant role of NUPR1. Clinical data suggested that NUPR1 and AhR could serve as novel biomarkers for predicting the radiation response of HCC.

CONCLUSIONS

Our findings revealed the role of NUPR1 in regulating ROS homeostasis and oxidative stress via the AhR/CYP signal axis upon IR. Strategies targeting the NUPR1/AhR/CYP pathway may have important clinical applications for improving the radiotherapeutic efficacy of HCC.

Nattokinase attenuates bisphenol A or gamma irradiation-mediated hepatic and neural toxicity by activation of Nrf2 and suppression of inflammatory mediators in rats

Nattokinase (NK), a protease enzyme produced by Bacillus subtilis, has various biological effects such as lipid-lowering activity, antihypertensive, antiplatelet/anticoagulant, and neuroprotective effects. Exposure to environmental toxicants such as bisphenol A (BPA) or γ-radiation (IR) causes multi-organ toxicity through several mechanisms such as impairment of oxidative status, signaling pathways, and hepatic and neuronal functions as well as disruption of the inflammatory responses. Therefore, this study is designed to evaluate the ameliorative effect of NK against BPA- or IR-induced liver and brain damage in rats. Serum ammonia level and liver function tests were measured in addition to brain oxidative stress markers, amyloid-beta, tau protein, and neuroinflammatory mediators. Moreover, relative quantification of brain nuclear factor-erythroid 2-related factor-2 (Nrf2)/heme oxygenase-1 (HO-1) genes, as well as apoptotic markers in brain tissue, was carried out in addition to histopathological examination. The results showed that NK improved liver functions, impaired oxidative status, the cholinergic deficits, and minified the misfolded proteins aggregates. Furthermore, NK alleviated the neuroinflammation via modulating NF-κB/Nrf2/HO-1 pathway and glial cell activation in addition to their antiapoptotic effect. Collectively, the current results revealed the protective effect of NK against hepatic and neurotoxicity derived from BPA or IR.

Cooperation effects of radiation and ferroptosis on tumor suppression and radiation injury

Ferroptosis is a kind of oxidative stress-dependent cell death characterized by iron accumulation and lipid peroxidation. It can work in conjunction with radiation to increase reactive oxygen species (ROS) generation and disrupt the antioxidant system, suppressing tumor progression. Radiation can induce ferroptosis by creating ROS, depleting glutathione, activating genes linked to DNA damage and increasing the expression of acyl-CoA synthetase long-chain family member 4 (ACSL4) in tumor cells. Furthermore, ferroptosis can enhance radiosensitivity by causing an iron overload, destruction of the antioxidant system, and lipid peroxidation. Radiation can also cause ferroptosis in normal cells, resulting in radiation injury. The role of ferroptosis in radiation-induced lung, intestinal, skin, and hematological injuries have been studied. In this review, we summarize the potential mechanisms linking ferroptosis, oxidative stress and radiation; analyze the function of ferroptosis in tumor suppression and radiation injury; and discuss the potential of ferroptosis regulation to improve radiotherapy efficacy and reduce adverse effects.

Proton-induced DNA damage promotes integration of foreign plasmid DNA into human genome

High-risk human papillomaviruses (HPVs) cause virtually all cervical cancer cases and are also associated with other types of anogenital and oropharyngeal cancers. Normally, HPV exists as a circular episomal DNA in the infected cell. However, in some instances, it integrates into the human genome in such a way as to enable increased expression of viral oncogenes, thereby leading to carcinogenesis. Since viral integration requires breaks in both viral and human genomes, DNA damage likely plays a key role in this critical process. One potentially significant source of DNA damage is exposure to elevated doses of ionizing radiation. Natural background radiation is ubiquitous; however, some populations, including radiological workers, radiotherapy patients, and astronauts, are exposed to significantly higher radiation doses, as well as to different types of radiation such as particle radiation. We hypothesize that ionizing radiation-induced DNA damage facilitates the integration of HPV into the human genome, increasing the risk of developing HPV-related cancers in the exposed population. To test this, we first determined the kinetics of DNA damage in keratinocytes exposed to ionizing radiation (protons) by assessing γ-H2AX foci formation using immunofluorescence (direct damage), and also measured ROS and 8-oxoG levels via DCFDA and Avidin-FITC (indirect damage).As anticipated, direct DNA damage was observed promptly, within 30 min, whereas indirect DNA damage was delayed due to the time required for ROS to accumulate and cause oxidative damage. Although radiation was lethal at high doses, we were able to establish an experimental system where radiation exposure (protons and X-rays) induced DNA damage dose-dependently without causing major cytotoxic effects as assessed by several cytotoxicity assays. Most importantly, we explored the impact of radiation exposure on integration frequency using a clonogenic assay and demonstrated that as predicted, proton-induced DNA damage promotes the integration of HPV-like foreign DNA in oral keratinocytes. Overall, the insights gained from this work enable us to better understand the contribution of radiation exposure and DNA damage to HPV-mediated carcinogenesis and direct us toward strategies aimed at preventing malignancies in HPV-infected individuals.

Single-Cell Transcriptome Analysis of Radiation Pneumonitis Mice

Radiation-induced lung injury (RILI), especially radiation pneumonitis (RP), is a common clinical complication associated with thoracic radiotherapy for malignant tumors. However, the specific contributions of each cell subtype to this process are unknown. Here, we provide the single-cell pathology landscape of the RP in a mouse model by unbiased single-cell RNA-seq (scRNA-seq). We found a decline of type 2 alveolar cells in the RP lung tissue, with an expansion of macrophages, especially the Fabp4low and Spp1high subgroup, while Fabp4high macrophages were almost depleted. We observed an elevated expression of multiple mitochondrial genes in the RP group, indicating a type 2 alveolar cell (AT2) response to oxidative stress. We also calculated the enrichment of a cGAS-STING signaling pathway, which may be involved in regulating inflammatory responses and cancer progression in AT2 cells of PR mice. We delineate markers and transcriptional states, identify a type 2 alveolar cell, and uncover fundamental determinants of lung fibrosis and inflammatory response in RP lung tissue of mice.

Radiation-induced cardiac side-effects: The lung as target for interacting damage and intervention

Radiotherapy is part of the treatment for many thoracic cancers. During this treatment heart and lung tissue can often receive considerable doses of radiation. Doses to the heart can potentially lead to cardiac effects such as pericarditis and myocardial fibrosis. Common side effects after lung irradiation are pneumonitis and pulmonary fibrosis. It has also been shown that lung irradiation has effects on cardiac function. In a rat model lung irradiation caused remodeling of the pulmonary vasculature increasing resistance of the pulmonary vascular bed, leading to enhanced pulmonary artery pressure, right ventricle hypertrophy and reduced right ventricle performance. Even more pronounced effects are observed when both, lung and heart are irradiated.

The effects observed after lung irradiation show striking similarities with symptoms of pulmonary arterial hypertension. In particular, the vascular remodeling in lung tissue seems to have similar underlying features. Here, we discuss the similarities and differences of vascular remodeling observed after thoracic irradiation compared to those in pulmonary arterial hypertension patients and research models. We will also assess how this knowledge of similarities could potentially be translated into interventions which would be beneficial for patients treated for thoracic tumors, where dose to lung tissue is often unavoidable.

Additional Evidence for Commonalities between COVID-19 and Radiation Injury: Novel Insight into COVID-19 Candidate Drugs

COVID-19 is a challenge to biosecurity and public health. The speed of vaccine development lags behind that of virus evolution and mutation. To date, no agent has been demonstrated to be fully effective against COVID-19. Therefore, it remains of great urgency to rapidly develop promising therapeutic and diagnostic candidates. Intriguingly, mounting evidence hints at parallel etiologies between SARS-CoV-2 infection and radiation injury. Herein, from the perspectives of immunogenic pathway activation and metabolic alterations, we provide novel evidence of commonalities between these two pathological conditions based on the most recent findings. Since numerous agents have been developed to prevent or reverse radiation injury in the past 70 years to ensure nuclear safety, we also advocate investigating the promising function of radioprotectors and radiomitigators against COVID-19 in clinical settings.

Epigenetic Therapeutics Targeting NRF2/KEAP1 Signaling in Cancer Oxidative Stress

The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) and its negative regulator kelch-like ECH-associated protein 1 (KEAP1) regulate various genes involved in redox homeostasis, which protects cells from stress conditions such as reactive oxygen species and therefore exerts beneficial effects on suppression of carcinogenesis. In addition to their pivotal role in cellular physiology, accumulating innovative studies indicated that NRF2/KEAP1-governed pathways may conversely be oncogenic and cause therapy resistance, which was profoundly modulated by epigenetic mechanism. Therefore, targeting epigenetic regulation in NRF2/KEAP1 signaling is a potential strategy for cancer treatment. In this paper, the current knowledge on the role of NRF2/KEAP1 signaling in cancer oxidative stress is presented, with a focus on how epigenetic modifications might influence cancer initiation and progression. Furthermore, the prospect that epigenetic changes may be used as therapeutic targets for tumor treatment is also investigated.

[The role of molecular genetic factors in the development of cholangiocellular carcinoma]

The article lists the main inducers of cholangiocarcinogenesis. The main inflammatory mediators (IL-6, nitric oxide, COX2) have been considered. Data on the study of gene mutations in cholangiocarcinomas are presented. The spectrum of genetic mutations depends on the biliary cancer origin (FGFR2 with intrahepatic cholangiocarcinoma, PRKACA, PRKACB with extrahepatic cholangiocarcinoma). Mutations in the KRAS, TP53, ARIAD1A genes are common in extrahepatic bile duct cancer. The role of epigenetic changes such as DNA hypermethylation, histone modifications, chromatin remodeling, as well as disturbances in miRNA expression is presented. A number of epigenetic features, such as the presence of a TP53 mutations with hypermethylation of p14ARF, DAPK, and/or ASC, correlate with a more aggressive course of the disease. The role of the SOX17 gene in the development of drug resistance is highlighted. The study of the molecular genetic features of extrahepatic bile duct cancer can help to better understand the pathogenesis of this type of tumor, to establish new prognostic and diagnostic markers of the disease.

Effects of Concurrent Exposure to Chronic Restraint-Induced Stress and Total-Body Iron Ion Radiation on Induction of Kidney Injury in Mice

Concurrent exposure to ionizing radiation (IR) and psychological stress (PS) may affect the development of adverse health consequences in scenarios such as space missions, radiotherapy and nuclear accidents. IR can induce DNA damage and cell apoptosis in the kidneys, thus potentially leading to renal fibrosis, which is the ultimate outcome of various chronic progressive nephropathies and the morphological manifestation of a continuous coordinated response after renal injury. However, little is known regarding the effects of concurrent IR exposure and PS on renal damage, particularly renal fibrosis. In this study, using a chronic restraint-induced PS (CRIPS) model, we exposed Trp53-heterozygous mice to total body irradiation with 0.1 or 2 Gy ⁵⁶Fe ions on the eighth day of 28 consecutive days of a restraint regimen. At the end of the restraint period, the kidneys were collected. The histopathological changes and the degree of kidney fibrosis were assessed with H&E and Masson staining, respectively. Fibronectin (FN) and alpha smooth muscle actin (α-SMA), biomarkers of fibrosis, were detected by immunohistochemistry. Analysis of 8-hydroxy-2 deoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage, was performed with immunofluorescence, and terminal deoxynucleotidyl transferase-mediated nick end labeling assays were used to detect apoptotic cells. Histopathological observations did not indicate significant structural damage induced by IR or CRIPS + IR. Western blotting revealed that the expression of α-SMA was much higher in the CRIPS + IR groups than the CRIPS groups. However, no differences in the average optical density per area were observed for FN, α-SMA and 8-OHdG between the IR and CRIPS + IR groups. No difference in the induction of apoptosis was observed between the IR and CRIPS + IR groups. These results suggested that exposure to IR (0.1 and 2 Gy ⁵⁶Fe ions), 28 consecutive days of CRIPS or both did not cause renal fibrosis. Thus, CRIPS did not alter the IR-induced effects on renal damage in Trp53-heterozygous mice in our experimental setup.

Next-generation Tumor-homing Induced Neural Stem Cells as an Adjuvant to Radiation for the Treatment of Metastatic Lung Cancer

The spread of non-small cell lung cancer (NSCLC) to the leptomeninges is devastating with a median survival of only a few months. Radiation offers symptomatic relief, but new adjuvant therapies are desperately needed. Spheroidal, human induced neural stem cells (hiNeuroS) secreting the cytotoxic protein, TRAIL, have innate tumoritropic properties. Herein, we provide evidence that hiNeuroS-TRAIL cells can migrate to and suppress growth of NSCLC metastases in combination with radiation. In vitro cell tracking and post-mortem tissue analysis showed that hiNeuroS-TRAIL cells migrate to NSCLC tumors. Importantly, isobolographic analysis suggests that TRAIL with radiation has a synergistic cytotoxic effect on NSCLC tumors. In vivo, mice treated with radiation and hiNeuroS-TRAIL showed significant (36.6%) improvements in median survival compared to controls. Finally, bulk mRNA sequencing analysis showed both NSCLC and hiNeuroS-TRAIL cells showed changes in genes involved in migration following radiation. Overall, hiNeuroS-TRAIL cells +/- radiation have the capacity to treat NSCLC metastases.

Phytochemicals Targeting Oxidative Stress, Interconnected Neuroinflammatory, and Neuroapoptotic Pathways Following Radiation

The radiation for therapeutic purposes has shown positive effects in different contexts; however, it can increase the risk of many age-related and neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and Parkinson's disease (PD). These different outcomes highlight a dose-response phenomenon called hormesis. Prevailing studies indicate that high doses of radiation could play several destructive roles in triggering oxidative stress, neuroapoptosis, and neuroinflammation in neurodegeneration. However, there is a lack of effective treatments in combating radiation-induced neurodegeneration, and the present drugs suffer from some drawbacks, including side effects and drug resistance. Among natural entities, polyphenols are suggested as multi-target agents affecting the dysregulated pathogenic mechanisms in neurodegenerative disease. This review discusses the destructive effects of radiation on the induction of neurodegenerative diseases by dysregulating oxidative stress, apoptosis, and inflammation. We also describe the promising effects of polyphenols and other candidate phytochemicals in preventing and treating radiation-induced neurodegenerative disorders, aiming to find novel/potential therapeutic compounds against such disorders.

Multi-faced roles of reactive oxygen species in anti-tumor T cell immune responses and combination immunotherapy

T cells play a central role in anti-tumor immunity, and reactive oxygen species (ROS) lie at the crossroad on the anti-tumor T cell responses. To activate efficient T cell immunity, a moderate level of ROS is needed, however, excessive ROS would cause toxicity to the T cells, because the improper level leads to the formation and maintenance of an immunosuppressive tumor microenvironment. Up to date, strategies that modulate ROS, either increasing or decreasing, have been widely investigated. Some of them are utilized in anti-tumor therapies, showing inevitable impacts on the anti-tumor T cell immunity with both obverse and reverse sides. Herein, the impacts of ROS-increasing and ROS-decreasing treatments on the T cell responses in the tumor microenvironment are reviewed and discussed. At the same time, outcomes of combination immunotherapies are introduced to put forward inspirations to unleash the potential of immunotherapies.

Radioprotective Mechanisms of Arbutin: A Systematic Review

PURPOSE

Efforts to produce radioprotective agents of high potential are appropriate strategies for overcoming possible IR toxicity in organisms. The present research aims to evaluate the signaling pathways and mechanisms through which arbutin exerts radioprotective effects on organisms.

METHODS

The databases of PubMed, Web of Sciences, Google Scholar, and Scopus were searched to find studies that reported radioprotective effects for arbutin. Besides, the data were searched within the time period from 2010 to 2020.

RESULTS

Five research articles met our criteria, which were included in the analysis based on their relevance to the topic. The present systematic review provides conclusions about various mechanisms and pathways through which arbutin induces radioprotection.

CONCLUSIONS

Based on the relevant studies, various mechanisms can be proposed for inducing radioprotective effects by arbutin, including inhibition of oxidative stress, apoptosis, and inflammation.

Trans-resveratrol alleviates hepatic and renal injury in γ-irradiated rats

Background

Although ionizing radiation (IR) has been of immense value to human life due to its involvement in several fields, it doesn’t eliminate that exposure to IR results in an array of biological consequences, including oxidative stress, inflammation, and death. Thus, this study aimed to explore the curative effect of trans-Resveratrol (t-Res) on hepatic and renal injury in a rat model exposed to single and fractionated doses of γ-rays.

Methods

Rats exposed to a single dose of IR (6 Gy, as an acute effect) or a fractionated dose of IR (2 Gy/time/3 days, day after day; to imitate a chronic impact) were treated with t-Res. Then, the radio-protective effect of t-Res was investigated via biochemical and histological estimations in the liver and kidney of rats in the different groups.

Results

The data displayed a significant amelioration in biochemical and histological indices in the liver and kidney of rats exposed to IR doses and treated with t-Res. Particularly, t-Res reduced the oxidative stress milieu through decreasing HIF-1α, ROS, and MDA levels associated with increased CAT activity and Nrf-2 gene expression. Also, t-Res improved the inflammatory status via a decrease in TNF-α, NF-κB, SOCS-3, and HSP-70 genes expression linked with elevations in SIRT-1 and P53 genes expression.

Conclusion

It could be concluded that t-Res had hepatoprotective and renoprotective effects against the deleterious consequences of γ-rays exposure due to its antioxidant and anti-inflammatory properties.

Two-dimensional Speckle Tracking Echocardiography in Evaluating Radiation-induced Heart Damage

Objective

Radiation-induced heart damage (RIHD) in malignant tumor patients with thoracic radiotherapy has been well documented. However, there is no study on the cardiac toxicity of stereotactic body radiotherapy (SBRT) based on two-dimensional speckle tracking echocardiography (2D STE).

Methods

In a prospective cohort trial, 48 patients with malignant tumor (including patients with lung cancer, pulmonary metastases and other tumor) were assigned to receive thoracic SBRT. Circulating biomarkers, electrocardiogram (ECG), echocardiography, and 2D STE were performed prior to and within two months after thoracic radiotherapy. The primary outcome of the trial was a decrease in global longitudinal strain (GLS) ≥ 10%. The secondary outcomes were major adverse cardiovascular events (MACE). Analysis were conducted using paired sample t-test, Wilcoxon signed rank test and Chi square test.

Results

The morbidity of RIHD is 44% within 2 months after SBRT in malignant tumor patients. Compared with pre-RT, a significant decrease in GLS was observed post-RT (−17.98 ​± ​3.54% vs. −16.92 ​± ​3.41%; P ​= ​0.008), without any significant change in left ventricular ejection fraction (LVEF) (68.54 ​± ​6.06 vs. 69.63 ​± ​4.45; P ​= ​0.234), left ventricular mass (LVM) (P ​= ​0.342), ECG parameters, creatine kinase (P ​= ​0.074), cardiac troponin T (P ​= ​0.829) or N-terminal pro-B-type natriuretic peptide (P ​= ​0.453) at during the post-RT period. There was no evidence that RIHD was correlated with age (P ​= ​1.000), mean heart dose (P ​= ​0.602), BED (P ​= ​0.234), EQD2/2 (P ​= ​0.615), V5 (P ​= ​0.506), V10 (P ​= ​0.578), V20 (P ​= ​0.670) and V30 (P ​= ​0.741). Subgroup analysis showed, there is still a significant decline of GLS (−18.30 ​± ​3.79% vs. −17.11 ​± ​3.58%; P ​= ​0.018) in patients without anthracycline treatment. And the decrease of GLS (−19.14 ​± ​2.42% vs. −16.85 ​± ​2.46%; P ​= ​0.004) was more significantly post-RT in anthracycline treatment group. MACE were found in one patient over a period of two months after SBRT.

Conclusions

By using strain analysis subclinical cardiac dysfunction was found to be evident early after SBRT, despite unchanged conventional indices such as LVEF, ECG parameters or circulating biomarkers. And the decrease of GLS is still existed after the effect of anthracycline was removed.

Trial registration

ClinicalTrials.gov, registration number: NCT04443400.

Radiotherapy-Induced Digestive Injury: Diagnosis, Treatment and Mechanisms

Radiotherapy is one of the main therapeutic methods for treating cancer. The digestive system consists of the gastrointestinal tract and the accessory organs of digestion (the tongue, salivary glands, pancreas, liver and gallbladder). The digestive system is easily impaired during radiotherapy, especially in thoracic and abdominal radiotherapy. In this review, we introduce the physical classification, basic pathogenesis, clinical characteristics, predictive/diagnostic factors, and possible treatment targets of radiotherapy-induced digestive injury. Radiotherapy-induced digestive injury complies with the dose-volume effect and has a radiation-based organ correlation. Computed tomography (CT), MRI (magnetic resonance imaging), ultrasound (US) and endoscopy can help diagnose and evaluate the radiation-induced lesion level. The latest treatment approaches include improvement in radiotherapy (such as shielding, hydrogel spacers and dose distribution), stem cell transplantation and drug administration. Gut microbiota modulation may become a novel approach to relieving radiogenic gastrointestinal syndrome. Finally, we summarized the possible mechanisms involved in treatment, but they remain varied. Radionuclide-labeled targeting molecules (RLTMs) are promising for more precise radiotherapy. These advances contribute to our understanding of the assessment and treatment of radiation-induced digestive injury.

Sulforaphane-Mediated Nrf2 Activation Prevents Radiation-Induced Skin Injury through Inhibiting the Oxidative-Stress-Activated DNA Damage and NLRP3 Inflammasome

This article mainly observed the protective effect of sulforaphane (SFN) on radiation-induced skin injury (RISI). In addition, we will discuss the mechanism of SFN's protection on RISI. The RISI model was established by the irradiation of the left thigh under intravenous anesthesia. Thirty-two C57/BL6 mice were randomly divided into control group (CON), SFN group, irradiation (IR) group, and IR plus SFN (IR/SFN) group. At eight weeks after irradiation, the morphological changes of mouse skin tissues were detected by H&E staining. Then, the oxidative stress and inflammatory response indexes in mouse skin tissues, as well as the expression of Nrf2 and its downstream antioxidant genes, were evaluated by ELISA, real-time PCR, and Western blotting. The H&E staining showed the hyperplasia of fibrous tissue in the mouse dermis and hypodermis of the IR group. Western blotting and ELISA results showed that the inflammasome of NLRP3, caspase-1, and IL-1β, as well as oxidative stress damage indicators ROS, 4-HNE, and 3-NT, in the skin tissues of mice in the IR group were significantly higher than those in the control group (p < 0.05). However, the above pathological changes declined sharply after SFN treatment (p < 0.05). In addition, the expressions of Nrf2 and its regulated antioxidant enzymes, including CAT and HO-1, were higher in the skin tissues of SFN and IR/SFN groups, but lower in the control and IR groups (p < 0.05). SFN may be able to suppress the oxidative stress by upregulating the expression and function of Nrf2, and subsequently inhibiting the activation of NLRP3 inflammasome and DNA damage, so as to prevent and alleviate the RISI.

Recent Progress of Surface Modified Nanomaterials for Scavenging Reactive Oxygen Species in Organism

Reactive oxygen species (ROS) are essential for normal physiological processes and play important roles in signal transduction, immunity, and tissue homeostasis. However, excess ROS may have a negative effect on the normal cells leading to various diseases. Nanomaterials are an attractive therapeutic alternative of antioxidants and possess an intrinsic ability to scavenge ROS. Surface modification for nanomaterials is a critical strategy to improve their comprehensive performances. Herein, we review the different surface modified strategies for nanomaterials to scavenge ROS and their inherent antioxidant capability, mechanisms of action, and biological applications. At last, the primary challenges and future perspectives in this emerging research frontier have also been highlighted. It is believed that this review paper will offer a top understanding and guidance on engineering future high-performance surface modified ROS scavenging nanomaterials for wide biomedical applications.