Novel chimeric TLR2/NOD2 agonist CL429 exhibited significant radioprotective effects in mice.

Severe ionizing radiation causes the acute lethal damage of haematopoietic system and gastrointestinal tract. Here, we found CL429, the novel chimeric TLR2/NOD2 agonist, exhibited significant radioprotective effects in mice. CL429 increased mice survival, protected mice against the lethal damage of haematopoietic system and gastrointestinal tract. CL429 was more effective than equivalent amounts of monospecific (TLR2 or NOD2) and combination (TLR2 + NOD2) of molecules in preventing radiation-induced death. The radioprotection of CL429 was mainly mediated by activating TLR2 and partially activating NOD2. CL429-induced radioprotection was largely dependent on the activation of TLR2-MyD88-NF-κB signalling pathway. In conclusion, the data suggested that the co-activation of TLR2 and NOD2 could induce significant synergistic radioprotective effects and CL429 might be a potential high-efficiency selective agent.

Insufficient ablation promotes the metastasis of residual non-small cell lung cancer (NSCLC) cells via upregulating carboxypeptidase A4.

BACKGROUND: Thermal ablation is a potentially curative therapy for early-stage non-small cell lung cancer (NSCLC). Early recurrence after thermal ablation necessitates our attention. METHODS: The invasion and migration abilities of NSCLC after sublethal heat stimulus were observed in vitro and in vivo. Sublethal thermal stimulus molecular changes were identified by RNA sequencing. A xenograft model of NSCLC with insufficient ablation was established to explore the epithelial-to-mesenchymal transition (EMT) and metastasis-related phenotypes alteration of residual tumors. RESULTS: In vitro, the invasion and migration abilities of NSCLC cells were enhanced 72 h after 44 °C and 46 °C thermal stimulus. Epithelial-mesenchymal transition (EMT) phenotypes were also upregulated under these conditions. RNA sequencing revealed that the expression of carboxypeptidase A4 (CPA4) was significantly upregulated after thermal stimulus. Significant upregulation of CPA4 and EMT phenotypes was also found in the xenograft model of insufficient NSCLC ablation. The EMT process and invasion and migration abilities can be reversed by silencing CPA4. CONCLUSIONS: This study demonstrates that sublethal heat stimulus caused by insufficient ablation can promote EMT and enhance the metastatic capacity of NSCLC. CPA4 plays an important role in these biological processes. Inhibition of CPA4 might be of great significance for improving early-stage NSCLC survival after ablation.

Toll-like receptor 4 regulates spontaneous intestinal tumorigenesis by up-regulating IL-6 and GM-CSF.

Inflammation is as an important component of intestinal tumorigenesis. The activation of Toll-like receptor 4 (TLR4) signalling promotes inflammation in colitis of mice, but the role of TLR4 in intestinal tumorigenesis is not yet clear. About 80%-90% of colorectal tumours contain inactivating mutations in the adenomatous polyposis coli (Apc) tumour suppressor, and intestinal adenoma carcinogenesis in familial adenomatous polyposis (FAP) is also closely related to the germline mutations in Apc. The ApcMin/+ (multiple intestinal neoplasia) model mouse is a well-utilized model of FAP, an inherited form of intestinal cancer. In this study, ApcMin/+ intestinal adenoma mice were generated on TLR4-sufficient and TLR4-deficient backgrounds to investigate the carcinogenic effect of TLR4 in mouse gut by comparing mice survival, peripheral blood cells, bone marrow haematopoietic precursor cells and numbers of polyps in the guts of ApcMin/+ WT and ApcMin/+ TLR4-/- mice. The results revealed that TLR4 had a critical role in promoting spontaneous intestinal tumorigenesis. Significant differential genes were screened out by the high-throughput RNA-Seq method. After combining these results with KEGG enrichment data, it was determined that TLR4 might promote intestinal tumorigenesis by activating cytokine-cytokine receptor interaction and pathways in cancer signalling pathways. After a series of validation experiments for the concerned genes, it was found that IL6, GM-CSF (CSF2), IL11, CCL3, S100A8 and S100A9 were significantly decreased in gut tumours of ApcMin/+ TLR4-/- mice compared with ApcMin/+ WT mice. In the functional study of core down-regulation factors, it was found that IL6, GM-CSF, IL11, CCL3 and S100A8/9 increased the viability of colon cancer cell lines and decreased the apoptosis rate of colon cancer cells with irradiation and chemical treatment.

Radioprotective effects of roxadustat (FG-4592) in haematopoietic system.

BACKGROUND: Ionizing radiation often causes severe injuries to radiosensitive tissues, especially haematopoietic system. Novel radioprotective drugs with low toxicity and high effectiveness are required. Prolyl hydroxylases domain (PHD) inhibitors have been reported to protect against radiation-induced gastrointestinal toxicity. In this study, we demonstrated the protective effects of a PHD inhibitor, roxadustat (FG-4592), against radiation-induced haematopoietic injuries in vitro and in vivo. METHODS: Tissue injuries were evaluated by Haematoxilin-Eosin (HE) staining assay. HSCs were determined by flow cytometry with the Lin- Sca-1+ c-Kit+ (LSK) phenotype. Cell apoptosis was determined by Annexin V/PI staining assay. Immunofluorescence was performed to measure radiation-induced DNA damage. A western blot assay was used to detect the changes of proteins related to apoptosis. RESULTS: We found that FG-4592 pretreatment increased survival rate of irradiated mice and protected bone marrow and spleen from damages. Number of bone marrow cells (BMCs) and LSK cells were also increased both in irradiated mice and recipients after bone marrow transplantation (BMT). FG-4592 also protected cells against radiation-induced apoptosis and double strand break of DNA. CONCLUSIONS: Our data showed that FG-4592 exhibited radioprotective properties in haematopoietic system both in vivo and in vitro through up-regulating HIF-1α, indicating a potential role of FG-4592 as a novel radioprotector.

The mechanism for the radioprotective effects of zymosan-A in mice.

It proved that Zymosan-A protected the haematopoietic system from radiation-induced damage via Toll-Like Receptor2 in our previous study. In this study, we investigated the potential mechanism for the radioprotective effects of Zymosan-A. The mice were treated with Zymosan-A (50 mg/kg, dissolved in NS) via peritoneal injection 24 and 2 hours before ionizing radiation. Apoptosis of bone marrow cells and the levels of IL-6, IL-12, G-CSF and GM-CSF were evaluated by flow cytometry assay. DNA damage was determined by γ-H2AX foci assay. In addition, RNA sequencing was performed to identify differentially expressed genes (DEGs). Zymosan-A protected bone marrow cells from radiation-induced apoptosis, up-regulated IL-6, IL-12, G-CSF and GM-CSF in bone marrow cells. Zymosan-A also protected cells from radiation-induced DNA damage. Moreover, RNA sequencing analysis revealed that Zymosan-A induced 131 DEGs involved in the regulation of immune system process and inflammatory response. The DEGs were mainly clustered in 18 KEGG pathways which were also associated with immune system processes. Zymosan-A protected bone marrow cells from radiation-induced apoptosis and up-regulated IL-6, IL-12, G-CSF and GM-CSF. Moreover, Zymosan-A might also exhibit radioprotective effects through regulating immune system process and inflammatory response. These results provided new knowledge regarding the radioprotective effect of Zymosan-A.

Downregulation of SPINK13 Promotes Metastasis by Regulating uPA in Ovarian Cancer Cells.

BACKGROUND/AIMS: Ovarian cancer (OC) is the fifth leading cause of cancer-related death in women, and it is difficult to diagnose at an early stage. The purpose of this study was to explore the prognostic biological markers of OC. METHODS: Univariate Cox regression analysis was used to identify genes related to OC prognosis from the Cancer Genome Atlas(TCGA) database. Immunohistochemistry was used to analyse the level of SPINK13 in OC and normal tissues. Cell proliferation, apoptosis and invasion were performed using MTT assay, flow cytometric analysis and Transwell assay, respectively. RESULTS: We identified the Kazal-type serine protease inhibitor-13 (SPINK13) gene related to OC prognosis from the Cancer Genome Atlas (TCGA) database by univariate Cox regression analysis. Overexpression of SPINK13 was associated with higher overall survival rate in OC patients. Immunohistochemistry showed that the level of SPINK13 protein was significantly lower in OC tissues than in normal tissues (P < 0.05).In vitro experiments showed that the overexpression of SPINK13 inhibited cellular proliferation and promoted apoptosis. Moreover, SPINK13 inhibited cell migration and epithelial to mesenchymal transition (EMT). SPINK13 was found to inhibit the expression of urokinase-type plasminogen activator (uPA), while recombinant uPA protein could reverse the inhibitory effect of SPINK13 on OC metastasis. CONCLUSION: These results indicate that SPINK13 functions as a tumour suppressor. The role of SPINK13 in cellular proliferation, apoptosis and migration is uPA dependent, and SPINK13 may be used as a potential biomarker for diagnosis and targeted therapy in OC.

CpG-Oligodeoxynucleotides Improved Irradiation-Induced Injuries by G-CSF and IL-6 Up-Regulation.

BACKGROUND/AIMS: This study investigated the radioprotective properties of three classes of CpG-oligodeoxynucleotides (CpG-ODNs) and the underlying mechanisms. METHODS: Mice irradiated at different doses(7Gy or 9Gy) were treated with or without ODNs(50µg via intraperitoneal injection). Assays were performed to determine survival rate and the number of white blood cell in peripheral blood. The levels of granulocyte-colony stimulating factor(G-CSF), interleukin 6(IL-6) and interferon-α (IFN-α) were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: Survival rate of mice irradiated in 7Gy was increased from 50% to about 100% with ODNs pretreatment. ODNs administration increased the number of WBCs of irradiated mice. G-CSF, IL-6 and IFN-α levels were up-regulated with ODNs treatment. CONCLUSION: All three classes of ODNs protected mice from irradiation-induced injuries. B-class ODNs exhibited the most potent radioprotective property via the up-regulation of G-CSF and IL-6.

Zymosan-a Protects the Hematopoietic System from Radiation-Induced Damage by Targeting TLR2 Signaling Pathway.

BACKGROUND/AIMS: The hematopoietic system is vulnerable to ionizing radiation and is often severely damaged by radiation. Molecules affecting radioresistance include Toll-like receptor 2. We investigated whether Zymosan-A, a novel TLR2 agonist, can protect the hematopoietic system from radiation-induced damage after total body irradiation. METHODS: Mice were exposed to total body radiation after treatment with Zymosan-A or normal saline, and their survival was recorded. Tissue damage was evaluated by hematoxylin-eosin staining. The number of nucleated cells in bone marrow was determined by flow cytometry. Cell viability and apoptosis assay were determined by CCK-8 assay and flow cytometry assay. Enzyme-linked immunosorbent assay was used to detect the level of cytokines. RESULTS: Zymosan-A protected mice from radiation-induced death and prevented radiation-induced hematopoietic system damage. Zymosan-A also promoted cell viability and inhibited cell apoptosis caused by radiation, induced radioprotective effects via TLR2, upregulated IL-6, IL-11, IL-12, and TNF-α in vivo. CONCLUSION: Zymosan-A can provide protection against radiation-induced hematopoietic system damage by targeting the TLR2 signaling pathway. Thus, Zymosan-A can be potentially effective radioprotectant.

Polymyxin B Attenuates LPS-Induced Death but Aggravates Radiation-Induced Death via TLR4-Myd88-IL-6 Pathway.

BACKGROUND/AIMS: Polymyxin B (PMB) is a cyclic cationic polypeptide antibiotic widely used to counteract the effects of endotoxin contamination, both in vitro and in vivo. Lipopolysaccharide (LPS) is an endotoxin that acts as a radiation protection factor. In this study, we focus on the role of PMB in LPS-induced and radiation-induced mortality in mice. METHODS: Mice received total-body radiation or were pretreated by LPS or PMB, and the survival of mice was recorded. Elisa were used to detect the cytokines levels. RESULTS: PMB decreased LPS-induced, but increased radiation-induced mortality in mice. Moreover, PMB could block the LPS-induced radioprotective effect. The ELISA and gene knock-out experiments indicated that PMB reduces TNF-α level to block LPS-induced mortality in mice, and inhibits IL-6, G-CSF and IL-10 to increase radiation-induced mortality via the TLR4-Myd88-IL-6 pathway. CONCLUSIONS: Our study revealed a role of PMB in LPS-induced endotoxemia and radiation exposure. We infer that the TLR4-Myd88-IL-6 pathway may play a crucial role in the process.

Enriched environment ameliorates fear memory impairments induced by sleep deprivation via inhibiting PIEZO1/calpain/autophagy signaling pathway in the basal forebrain.

AIMS: To verify the hypothesis that an enriched environment (EE) alleviates sleep deprivation-induced fear memory impairment by modulating the basal forebrain (BF) PIEZO1/calpain/autophagy pathway. METHODS: Eight-week-old male mice were housed in a closed, isolated environment (CE) or an EE, before 6-h total sleep deprivation. Changes in fear memory after sleep deprivation were observed using an inhibitory avoidance test. Alterations in BF PIEZO1/calpain/autophagy signaling were detected. The PIEZO1 agonist Yoda1 or inhibitor GsMTx4, the calpain inhibitor PD151746, and the autophagy inducer rapamycin or inhibitor 3-MA were injected into the bilateral BF to investigate the pathways involved in the memory-maintaining role of EE in sleep-deprived mice. RESULTS: Mice housed in EE performed better than CE mice in short- and long-term fear memory tests after sleep deprivation. Sleep deprivation resulted in increased PIEZO1 expression, full-length tropomyosin receptor kinase B (TrkB-FL) degradation, and autophagy, as reflected by increased LC3 II/I ratio, enhanced p62 degradation, increased TFEB expression and nuclear translocation, and decreased TFEB phosphorylation. These molecular changes were partially reversed by EE treatment. Microinjection of Yoda1 or rapamycin into the bilateral basal forebrain induced excessive autophagy and eliminated the cognition-protective effects of EE. Bilateral basal forebrain microinjection of GsMTx4, PD151746, or 3-MA mimicked the cognitive protective and autophagy inhibitory effects of EE in sleep-deprived mice. CONCLUSIONS: EE combats sleep deprivation-induced fear memory impairments by inhibiting the BF PIEZO1/calpain/autophagy pathway.

Highly sensitive and accurate measurement of underivatized phosphoenolpyruvate in plasma and serum via EDTA-facilitated hydrophilic interaction liquid chromatography-tandem mass spectrometry.

Phosphoenolpyruvate (PEP) is an essential intermediate metabolite that is involved in various vital biochemical reactions. However, achieving the direct and accurate quantification of PEP in plasma or serum poses a significant challenge owing to its strong polarity and metal affinity. In this study, a sensitive method for the direct determination of PEP in plasma and serum based on ethylenediaminetetraacetic acid (EDTA)-facilitated hydrophilic interaction liquid chromatography-tandem mass spectrometry was developed. Superior chromatographic retention and peak shapes were achieved using a zwitterionic stationary-phase HILIC column with a metal-inert inner surface. Efficient dechelation of PEP-metal complexes in serum/plasma samples was achieved through the introduction of EDTA, resulting in a significant enhancement of the PEP signal. A PEP isotopically labelled standard was employed as a surrogate analyte for the determination of endogenous PEP, and validation assessments proved the sensitivity, selectivity, and reproducibility of this method. The method was applied to the comparative quantification of PEP in plasma and serum samples from mice and rats, as well as in HepG2 cells, HEK293T cells, and erythrocytes; the results confirmed its applicability in PEP-related biomedical research. The developed method can quantify PEP in diverse biological matrices, providing a feasible opportunity to investigate the role of PEP in relevant biomedical research.

A multifunctional biomimetic nanoplatform for image-guideded photothermal-ferroptotic synergistic osteosarcoma therapy.

Much effort has been devoted to improving treatment efficiency for osteosarcoma (OS). However, most current approaches result in poor therapeutic responses, thus indicating the need for the development of other therapeutic options. This study developed a multifunctional nanoparticle, PDA-MOF-E-M, an aggregation of OS targeting, programmed death targeting, and near-infrared (NIR)-aided targeting. At the same time, a multifunctional nanoparticle that utilises Fe-MOFs to create a cellular iron-rich environment and erastin as a ferroptosis inducer while ensuring targeted delivery to OS cells through cell membrane encapsulation is presented. The combination of PDA-MOF-E-M and PTT increased intracellular ROS and LPO levels and induced ferroptosis-related protein expression. A PDA-based PTT combined with erastin showed significant synergistic therapeutic improvement in the anti-tumour efficiency of the nanoparticle in vitro and vivo. The multifunctional nanoparticle efficiently prevents the osteoclasia progression of OS xenograft bone tumors in vivo. Finally, this study provides guidance and a point of reference for clinical approaches to treating OS.

Bacterial outer membrane vesicles-based therapeutic platform eradicates triple-negative breast tumor by combinational photodynamic/chemo-/immunotherapy.

Bacterial outer membrane vesicles (OMVs) are potent immuno-stimulating agents and have the potentials to be bioengineered as platforms for antitumor nanomedicine. In this study, OMVs are demonstrated as promising antitumor therapeutics. OMVs can lead to beneficial M2-to-M1 polarization of macrophages and induce pyroptosis to enhance antitumor immunity, but the therapeutic window of OMVs is narrow for its toxicity. We propose a bioengineering strategy to enhance the tumor-targeting ability of OMVs by macrophage-mediated delivery and improve the antitumor efficacy by co-loading of photosensitizer chlorin e6 (Ce6) and chemotherapeutic drug doxorubicin (DOX) into OMVs as a therapeutic platform. We demonstrate that systemic injection of the DOX/Ce6-OMVs@M therapeutic platform, providing combinational photodynamic/chemo-/immunotherapy, eradicates triple-negative breast tumors in mice without side effects. Importantly, this strategy also effectively prevents tumor metastasis to the lung. This OMVs-based strategy with bioengineering may serve as a powerful therapeutic platform for a synergic antitumor therapy.

Dopamine-derived nanoparticles for the protection of irradiation-induced intestinal injury by maintaining intestinal homeostasis.

Radiotherapy of abdominal and pelvic tumors almost inevitably injures the intestine by oxidative stress and causes inflammation. Regrettably, traditional radioprotective agents for irradiation (IR) induced intestinal injury suffer from challenges such as poor solubility, unsatisfactory bioactivity and undesired adverse reactions, which significantly limit their usefulness. Polydopamine nanoparticles (PDA-NPs) have shown promising potential in scavenging reactive oxygen species (ROS) and suppressing inflammation. In this study, PDA-NPs were prepared by a simple method and their physical properties were characterized. Mice received two doses of PDA-NPs by oral gavage 22 h apart, and were irradiated with X-rays 2 h after the last gavage. The protective effect of PDA-NPs and possible mechanisms of protection against IR-induced intestinal injury were explored. The results showed that PDA-NPs were spherical and well dispersed, with good shape uniformity, compact structure, good colloid dispersion stability, concentration-dependent light absorption, and accurate quantification. Importantly, PDA-NPs reduced mortality and prolonged the average survival time of mice after IR. Furthermore, PDA-NPs protected mice from IR-induced injury to crypt-villus units and maintained intestinal barrier function in the intestine. In particular, PDA-NPs significantly inhibited the depletion of Lgr5+ intestinal stem cells (ISCs) and promoted cell regeneration after IR, which indicated that the regeneration ability of ISCs was maintained and the repair of intestinal structure and function was promoted. Finally, PDA-NPs significantly suppressed the apoptosis, inflammatory pyroptosis and DNA damage of intestinal cells induced by ionizing radiation. Altogether, our study suggested that PDA-NPs may have great potential in protecting the intestines from ionizing radiation damage.

Dimethyl Sulfoxide Attenuates Radiation-Induced Testicular Injury through Facilitating DNA Double-Strand Break Repair.

The testis is susceptible to ionizing radiation, and male infertility and sexual dysfunction are prevalent problems after whole-body or local radiation exposure. Currently, there is no approved agent for the prevention or treatment of radiation-induced testicular injury. Herein, we investigated the radioprotective effect of dimethyl sulfoxide (DMSO), an organosulfur compound that acts as a free radical scavenger, on testicular injury. Treatment of mice with a single dose of DMSO prior to 5 Gy irradiation restored sex hormones and attenuated the reduction in testis weight. Histological analyses revealed that DMSO alleviated the distorted architecture of seminiferous tubules and promoted seminiferous epithelium regeneration following irradiation. Moreover, DMSO provided quantitative and qualitative protection for sperm and preserved spermatogenesis and fertility in male mice. Mechanistically, DMSO treatment enhanced GFRα-1+ spermatogonial stem cell and c-Kit+ spermatogonial survival and regeneration after radiation. DMSO also alleviated radiation-induced oxidative stress and suppressed radiation-induced germ cell apoptosis in vivo and in vitro. Additionally, DMSO efficiently reduced DNA damage accumulation and induced the expression of phosph-BRCA1, BRCA1, and RAD51 proteins, indicating that DMSO facilitates DNA damage repair with a bias toward homologous recombination. In summary, our findings demonstrate the radioprotective efficacy of DMSO on the male reproductive system, which warrants further studies for future application in the preservation of male fertility during conventional radiotherapy and nuclear accidents.

A simple, universal and multifunctional template agent for personalized treatment of bone tumors.

Bone tumors occur in bone or its accessory tissues. Benign bone tumors are easy to cure and have good prognosis, while malignant bone tumors develop rapidly and have poor and high mortality. So far, there is no satisfactory treatment method. Here, we designed a universal template vector for bone tumor therapy that simultaneously meets the needs of bone targeting, tumor killing, osteoclast suppression, and tumor imaging. The template is composed of a polydopamine (PDA) core and a multifunctional surface. PDA has excellent biosafety and photothermal performance. In this study, alendronate sodium (ALN) is grafted to enable its general bone targeting function. PDA core can carry a variety of chemotherapy drugs, and the rich ALN group can carry a variety of metal ions with an imaging function. Therefore, more personalized treatment plans can be designed for different bone tumor patients. In addition, the PDA core enables photothermal therapy and enhanced chemotherapy. Through template drug Doxorubicin (DOX) and template imaging ion Fe (Ⅱ), we systematically verified the therapeutic effect, imaging effect, and inhibition of bone dissolution of the agent on Osteosarcoma (OS), a primary malignant bone tumor, in vivo. In conclusion, our work provides a more general template carrier for the clinical treatment of bone tumors, through which personalized treatment of bone tumors can be achieved.

CRX-527 induced differentiation of HSCs protecting the intestinal epithelium from radiation damage.

Recently, Toll-like receptors (TLRs) have been extensively studied in radiation damage, but the inherent defects of high toxicity and low efficacy of most TLR ligands limit their further clinical transformation. CRX-527, as a TLR4 ligand, has rarely been reported to protect against radiation. We demonstrated that CRX-527 was safer than LPS at the same dose in vivo and had almost no toxic effect in vitro. Administration of CRX-527 improved the survival rate of total body irradiation (TBI) to 100% in wild-type mice but not in TLR4-/- mice. After TBI, hematopoietic system damage was significantly alleviated, and the recovery period was accelerated in CRX-527-treated mice. Moreover, CRX-527 induced differentiation of HSCs and the stimulation of CRX-527 significantly increased the proportion and number of LSK cells and promoted their differentiation into macrophages, activating immune defense. Furthermore, we proposed an immune defense role for hematopoietic differentiation in the protection against intestinal radiation damage, and confirmed that macrophages invaded the intestines through peripheral blood to protect them from radiation damage. Meanwhile, CRX-527 maintained intestinal function and homeostasis, promoted the regeneration of intestinal stem cells, and protected intestinal injury from lethal dose irradiation. Furthermore, After the use of mice, we found that CRX-527 had no significant protective effect on the hematopoietic and intestinal systems of irradiated TLR4-/- mice. in conclusion, CRX-527 induced differentiation of HSCs protecting the intestinal epithelium from radiation damage.

The Protective Effects of Apigenin Against Radiation-Induced Intestinal Injury.

Radiation-induced intestinal injury (RIII) restricts the therapeutic efficacy of radiotherapy in abdominal or pelvic malignancies. Also, intestinal injury is a major cause of death following exposure to high doses of radiation in nuclear accidents. No safe and effective prophylactics or therapeutics for RIII are currently available. Here, we reported that the apigenin, a natural dietary flavone, prolonged the survival in c57 mice after lethal irradiation. Apigenin pretreatment brought about accelerated restoration of crypt-villus structure, including enhanced regenerated crypts, more differentiated epithelium cells, and increased villus length. In addition, intestinal crypt cells in the apigenin-treated group exhibited more proliferation and less apoptosis. Furthermore, apigenin increased the expression of Nrf2 and its downstream target gene HO-1, and decreased oxidative stress after irradiation. In conclusion, our findings demonstrate the radioprotective efficacy of apigenin. Apigenin has the potential to be used as a radioprotectant in cancer therapy and nuclear accidents.

The hydrogen storage nanomaterial MgH2 improves irradiation-induced male fertility impairment by suppressing oxidative stress.

OBJECTIVE: This study aimed to reveal the protective effect of hydrogen storage nanomaterial MgH2 on radiation-induced male fertility impairment. METHODS: The characterization of MgH2 were analyzed by scanning electron microscopy (SEM) and particle size analyzer. The safety of MgH2 were evaluated in vivo and in vitro. The radioprotective effect of MgH2 on the reproductive system were analyzed in mice, including sperm quality, genetic effect, spermatogenesis, and hormone secretion. ESR, flow cytometry and western blotting assay were used to reveal the underlying mechanisms. RESULTS: MgH2 had an irregular spherical morphology and a particle size of approximately 463.2 nm, and the content of Mg reached 71.46%. MgH2 was safe and nontoxic in mice and cells. After irradiation, MgH2 treatment significantly protected testicular structure, increased sperm density, improved sperm motility, reduced deformity rates, and reduced the genetic toxicity. Particularly, the sperm motility were consistent with those in MH mice and human semen samples. Furthermore, MgH2 treatment could maintain hormone secretion and testicular spermatogenesis, especially the generation of Sertoli cells, spermatogonia and round sperm cells. In vitro, MgH2 eliminated the [·OH], suppressed the irradiation-induced increase in ROS production, and effectively alleviated the increase in MDA contents. Moreover, MgH2 significantly ameliorated apoptosis in testes and cells and reversed the G2/M phase cell cycle arrest induced by irradiation. In addition, MgH2 inhibited the activation of radiation-induced inflammation and pyroptosis. CONCLUSION: MgH2 improved irradiation-induced male fertility impairment by eliminating hydroxyl free radicals. Mice fertility and function were evaluated with or without MgH2 treatment after 5 Gy irradiation. MgH2 had the ability of hydroxyl radicals scavenging and MDA suppressing in testicular tissue induced by irradiation. Further, MgH2 could participate in spermatogenesis and protect sperm development in three stages: the generation of Sertoli cells (Sox-9+), spermatogonia (Stra8+) and round sperm cells (Crem+). Moreover, MgH2 alleviated the decrease of testosterone secreted by interstitial cells after irradiation. In addition, MgH2 suppressed apoptosis, pyroptosis and inflammatory response and alleviated cell cycle arrest by mediating IR-induced ROS.

Disulfiram Protects Against Radiation-Induced Intestinal Injury in Mice.

Radiation-induced intestinal injury (RIII) occurs after high doses of radiation exposure. RIII restricts the therapeutic efficacy of radiotherapy in cancer and increases morbidity and mortality in nuclear disasters. Currently, there is no approved agent for the prevention or treatment of RIII. Here, we reported that the disulfiram, an FDA-approved alcohol deterrent, prolonged the survival in mice after lethal irradiation. Pretreatment with disulfiram inhibited proliferation within 24 h after irradiation, but improved crypt regeneration at 3.5 days post-irradiation. Mechanistically, disulfiram promoted Lgr5+ intestinal stem cells (ISCs) survival and maintained their ability to regenerate intestinal epithelium after radiation. Moreover, disulfiram suppresses DNA damage accumulation, thus inhibits aberrant mitosis after radiation. Unexpectedly, disulfiram treatment did not inhibit crypt cell apoptosis 4 h after radiation and the regeneration of crypts from PUMA-deficient mice after irradiation was also promoted by disulfiram. In conclusion, our findings demonstrate that disulfiram regulates the DNA damage response and survival of ISCs through affecting the cell cycle. Given its radioprotective efficacy and decades of application in humans, disulfiram is a promising candidate to prevent RIII in cancer therapy and nuclear accident.