scholarly journals Inhibition of Rac1 Attenuates Radiation-Induced Lung Injury while Sensitizes Lung Tumor to Radiotherapy

2020 ◽  
Author(s):  
Ni An ◽  
Zhenjie Li ◽  
Xiaodi Yan ◽  
Hainan Zhao ◽  
Yajie Yang ◽  
...  
Keyword(s):  
Mouse Model ◽  
Lung Tumor ◽  
Cellular Level ◽  
Normal Lung ◽  
Mouse Lung ◽  
Differential Effects ◽  
Tumor Bearing ◽  
Lung Epithelial ◽  
Radiation Induced

Abstract Backgrounds: There is still little progress in the effective treatment of radiation-induced lung injury (RILI), a key dose-limiting factor for thoracic radiotherapy. Ras-related C3 botulinum toxin substrate1, Rac1, is a small guanosine triphosphatase involved in various mechanisms of radiation-induced damage and is over-expressed/mutated in various tumors. The gain-of-function mutation of Rac1 mediates tumor cells’ resistance to radiotherapy. Therefore, inhibiting Rac1 has the potential of protecting normal tissues from radiation-induced injury, and at the same time, sensitizing tumor to radiation therapy, which makes it a promising ideal target for radiation protection. To investigate the protective effects and mechanisms of Rac1 inhibition on RILI, and explore the possible mechanisms that mediate the differential effects of Rac1 inhibition on normal lung tissue and tumor cells.Methods: 60Co radioactive source was used for ionizing radiation (IR). RILI mouse model was constructed. Influence of Rac1 inhibition which was achieved by Rac1-specific inhibitor, NSC23766, on RILI were studied by H & E and Masson staining, and immunohistochemical staining of vimentin, TGF-βand γ-H2AX. Normal mouse lung epithelial cell line, MLE-12, and mouse lung cancer cell line, LLC, were used to study the effects of Rac1 inhibition on the cellular level. RNA-seq analysis was used for screening differential gene expression caused by Rac1 knockdown. The molecular mechanisms of Rac1 inhibition were studied at the cellular level. Subcutaneous tumor-bearing nude mouse model and orthotopic lung tumor-bearing mouse model were constructed to verify the bidirectional effects of Rac1 inhibition in vivo. Results: RILI of mouse was alleviated by intraperitoneal injection of NSC23766. Rac1 inhibition/knockdown reduced the radiation-induced damage of MLE-12 while aggravated that of LLC. Rac1 translocated from cytoplasm to nucleus after radiation. Tumor protein p53-inducible nuclear protein 1, Trp53inp1, was down-regulated by Rac1 knockdown. In vivo study further proved the differential effects of Rac1 inhibition. Rac1 was over-expressed and mutated in LLC cells, and the expression level of Trp53inp1 significantly lower, compared with that of MLE-12.Conclusion: Rac1 inhibition reduced the radiation-induced damage of normal lung epithelial cells, thereby alleviating RILI of mouse. These effects were partially mediated by down-regulating the expression of Trp53inp1. However, Rac1 inhibition significantly increased the sensitivity of LLC to radiation damage and inhibited its growth. The over-expression and mutation of Rac1, and the significant low expression of Trp53inp1 in LLC, may be the fundamental reasons mediating the differential effects of Rac1 inhibition.

scholarly journals Inhibition of Rac1 attenuates radiation-induced lung injury while suppresses lung tumor in mice

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Ni An ◽  
Zhenjie Li ◽  
Xiaodi Yan ◽  
Hainan Zhao ◽  
Yajie Yang ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Lung Injury ◽  
Mouse Model ◽  
Tumor Cells ◽  
Nuclear Translocation ◽  
Lung Tumor ◽  
Lung Epithelial Cells ◽  
Normal Lung ◽  
Limiting Factor ◽  
Radiation Induced

AbstractThe lung is one of the most sensitive tissues to ionizing radiation, thus, radiation-induced lung injury (RILI) stays a key dose-limiting factor of thoracic radiotherapy. However, there is still little progress in the effective treatment of RILI. Ras-related C3 botulinum toxin substrate1, Rac1, is a small guanosine triphosphatases involved in oxidative stress and apoptosis. Thus, Rac1 may be an important molecule that mediates radiation damage, inhibition of which may produce a protective effect on RILI. By establishing a mouse model of radiation-induced lung injury and orthotopic lung tumor-bearing mouse model, we detected the role of Rac1 inhibition in the protection of RILI and suppression of lung tumor. The results showed that ionizing radiation induces the nuclear translocation of Rac1, the latter then promotes nuclear translocation of P53 and prolongs the residence time of p53 in the nucleus, thereby promoting the transcription of Trp53inp1 which mediates p53-dependent apoptosis. Inhibition of Rac1 significantly reduce the apoptosis of normal lung epithelial cells, thereby effectively alleviating RILI. On the other hand, inhibition of Rac1 could also significantly inhibit the growth of lung tumor, increase the radiation sensitivity of tumor cells. These differential effects of Rac1 inhibition were related to the mutation and overexpression of Rac1 in tumor cells.

scholarly journals Radiation-induced lung fibrosis in a tumor-bearing mouse model is associated with enhanced Type-2 immunity

2015 ◽  
Vol 57 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Jing Chen ◽  
Yacheng Wang ◽  
Zijie Mei ◽  
Shimin Zhang ◽  
Jie Yang ◽  
...  
Keyword(s):  
Mouse Model ◽  
Lung Fibrosis ◽  
Tumor Bearing Mouse ◽  
Tumor Bearing ◽  
Type 2 Immunity ◽  
Radiation Induced

scholarly journals Metformin Protects against Radiation-Induced Acute Effects by Limiting Senescence of Bronchial-Epithelial Cells

2021 ◽  
Vol 22 (13) ◽  
pp. 7064
Author(s):  
Christine Hansel ◽  
Samantha Barr ◽  
Alina V. Schemann ◽  
Kirsten Lauber ◽  
Julia Hess ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lung Tissue ◽  
Cellular Stress ◽  
Lung Epithelial Cells ◽  
Normal Lung Tissue ◽  
Normal Lung ◽  
Metformin Treatment ◽  
Acute Effects ◽  
Lung Epithelial ◽  
Radiation Induced

Radiation-induced damage to normal lung parenchyma remains a dose-limiting factor in thorax-associated radiotherapy (RT). Severe early and late complications with lungs can increase the risk of morbidity in cancer patients after RT. Herein, senescence of lung epithelial cells following RT-induced cellular stress, or more precisely the respective altered secretory profile, the senescence-associated secretory phenotype (SASP), was suggested as a central process for the initiation and progression of pneumonitis and pulmonary fibrosis. We previously reported that abrogation of certain aspects of the secretome of senescent lung cells, in particular, signaling inhibition of the SASP-factor Ccl2/Mcp1 mediated radioprotection especially by limiting endothelial dysfunction. Here, we investigated the therapeutic potential of a combined metformin treatment to protect normal lung tissue from RT-induced senescence and associated lung injury using a preclinical mouse model of radiation-induced pneumopathy. Metformin treatment efficiently limited RT-induced senescence and SASP expression levels, thereby limiting vascular dysfunctions, namely increased vascular permeability associated with increased extravasation of circulating immune and tumor cells early after irradiation (acute effects). Complementary in vitro studies using normal lung epithelial cell lines confirmed the senescence-limiting effect of metformin following RT finally resulting in radioprotection, while fostering RT-induced cellular stress of cultured malignant epithelial cells accounting for radiosensitization. The radioprotective action of metformin for normal lung tissue without simultaneous protection or preferable radiosensitization of tumor tissue might increase tumor control probabilities and survival because higher radiation doses could be used.

scholarly journals Effect of Slit/Robo signaling on regeneration in lung emphysema

2021 ◽  
Author(s):  
Jin-Soo Park ◽  
RyeonJin Cho ◽  
Eun-Young Kang ◽  
Yeon-Mok Oh
Keyword(s):  
Epithelial Cells ◽  
Mouse Model ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Chronic Obstructive ◽  
Irreversible Damage ◽  
Lung Epithelial ◽  
And Migration ◽  
Proliferation And Migration

AbstractEmphysema, a pathological component of chronic obstructive pulmonary disease, causes irreversible damage to the lung. Previous studies have shown that Slit plays essential roles in cell proliferation, angiogenesis, and organ development. In this study, we evaluated the effect of Slit2 on the proliferation and migration of mouse lung epithelial cells and its role in regeneration in an emphysema lung mouse model. Here, we have shown that Slit2/Robo signaling contributes to the regeneration of lungs damaged by emphysema. Mouse epithelial lung cells treated with Slit2 exhibited increased proliferation and migration in vitro. Our results also showed that Slit2 administration improved alveolar regeneration in the emphysema mouse model in vivo. Furthermore, Slit2/Robo signaling increased the phosphorylation of ERK and Akt, which was mediated by Ras activity. These Slit2-mediated cellular signaling processes may be involved in the proliferation and migration of mouse lung epithelial cells and are also associated with the potential mechanism of lung regeneration. Our findings suggest that Slit2 administration may be beneficial for alveolar regeneration in lungs damaged by emphysema.

scholarly journals P062 Dose-dependent differential effects of vedolizumab therapy on adhesion of regulatory and effector T cells

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S165-S166
Author(s):  
E Becker ◽  
M Wiendl ◽  
A Schulz-Kuhnt ◽  
I Atreya ◽  
R Atreya ◽  
...  
Keyword(s):  
T Cell ◽  
Mouse Model ◽  
T Cell Subsets ◽  
Dependent Manner ◽  
Differential Effects ◽  
Preferential Binding ◽  
Exposure Levels ◽  
Differential Binding ◽  
Dose Dependent

Abstract Background Vedolizumab has emerged as an important pillar of treatment in inflammatory bowel disease (IBD). However, for unknown reasons, not all patients respond to therapy. Earlier clinical studies suggested decreased response rates in the highest compared with medium dosage groups. Interestingly, vedolizumab has been shown to inhibit the homing of both regulatory (Treg) and effector T (Teff) cells and previous data from our group suggested different effect sizes in both populations. Thus, we hypothesised that the non-linear exposure–efficacy correlation might be explained by dose-dependent differential effects of vedolizumab on Treg and Teff homing. Therefore, we studied functional effects of different vedolizumab exposure levels on Treg and Teff cell trafficking. Methods The α4β7 expression on different human T-cell subsets as well as the binding characteristics of vedolizumab to these cells at different exposure levels was analysed via flow cytometry. Functional effects of different vedolizumab concentrations on the adhesion of Tregs and Teffs to mucosal addressin cell adhesion molecule 1 (MAdCAM-1) were analysed using dynamic in vitro adhesion assays, transmigration assays and in vivo homing assays in a humanised mouse model. The in vivo binding of vedolizumab to Tregs and Teffs in patients receiving therapy was quantified and correlated with the corresponding serum levels. Results We found a preferential binding of vedolizumab to Tregs at an exposure with 0.4 µg/ml vedolizumab that shifted to a preferential binding to Teffs at an exposure with 10 µg/ml. Further increase of vedolizumab to 50 µg/ml led to equal binding to Tregs and Teffs (Figure 1). Consistently, at 10 µg/ml, dynamic adhesion of Tregs to MAdCAM-1 was increased compared with Teffs, but no difference was noted at 50 µg/ml. Additionally, a higher number of Treg compared with Teff cells were able to transmigrate in a MAdCAM-1-dependent manner at a concentration of 10 µg/ml vedolizumab. Preliminary data from homing experiments in a humanised mouse model and from IBD patients treated with vedolizumab support the notion that differential binding preferences depending on the exposure level can also be observed in vivo. Conclusion Our findings support a dose-dependent differential binding of vedolizumab to different T-cell subpopulations and suggest that an optimal ‘window’ of exposure exists, in which effects on Teffs predominate over Tregs. While offering a potential explanation for earlier findings in dose-ranging studies, our data might lay the basis for the establishment of individualised dose optimisation in IBD patients.

Elevated proteinase activities in mouse lung tumors quantitated by synthetic fluorogenic substrates.

1979 ◽  
Vol 27 (11) ◽  
pp. 1505-1508 ◽  
Author(s):  
R Grabske ◽  
A Azevedo ◽  
R E Smith
Keyword(s):  
Lung Tumor ◽  
Lung Tumors ◽  
Normal Lung ◽  
Mouse Lung ◽  
Lewis Lung ◽  
Fluorogenic Substrates ◽  
Ph Optimum ◽  
Peptide Moiety ◽  
Hydrolytic Activities ◽  
Hydrolysis Of

Proteinase activities in malignant and normal lung tissues were measured using two synthetic substrates that consist of a fluorophor coupled to a peptide moiety. The hydrolysis of CBZ-Val-Lys-Lys-Arg-4-methoxy-2-naphthylamide and BZ-Gly-Gly-Arg-4-methoxy-2-naphthylamide were studied in homogenates of two types of mouse lung tumors, the Lewis lung tumor of the C57 black mouse and the KHT tumor of the C3H mouse. The activity of CBZ-Val-Lys-Lys-Arg-4-methoxy-2-naphthylamide hydrolysis had a pH optimum of 6.3 and a Km of 2.1 x 10(-4) M, required a thiol activator, and was inhibited by leupeptin suggesting the activity of a cathepsin B-like enzyme. The activity of BZ-Gly-Gly-Arg-4-methoxy-2-naphthylamide hydrolysis had a pH optimum of 6.7 and a Km of 3 x 10(-5) M. Lung tumor homogenates contained higher hydrolytic activities for both substrates than normal lung homogenates.

scholarly journals A magnetic resonance nanoprobe with STING activation character collaborates with platinum-based drug for enhanced tumor immunochemotherapy

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jiali Li ◽  
Shichao Li ◽  
Yang Li ◽  
Guanjie Yuan ◽  
Yaqi Shen ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Therapeutic Strategy ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Therapeutic Drugs ◽  
Lung Epithelial ◽  
M1 Phenotype ◽  
Sting Pathway

Abstract Background Immunochemotherapy is a potent anti-tumor strategy, however, how to select therapeutic drugs to enhance the combined therapeutic effect still needs to be explored. Methods and results Herein, a magnetic resonance nanoprobe (MnP@Lip) with STING (Stimulator of INterferon Genes) activation character was synthesized and co-administered with platinum-based chemotherapeutics for enhanced immunochemotherapy. MnP@Lip nanoparticles was prepared by simple fabrication process with good reproducibility, pH-sensitive drug release behavior and biocompatibility. In vitro experiments elucidated that Mn2+ can promote the polarization of M0 and/or M2 macrophages to M1 phenotype, and promote the maturation of BMDC cells. Upon Mn2+ treatment, the STING pathway was activated in tumor cells, mouse lung epithelial cells, and immune cells. More importantly, anti-tumor experiments in vivo proved that MnP@Lip combined with platinum-based chemotherapeutics increased T cells infiltration in the tumor microenvironment, and inhibited tumor growth in the orthotopic therapeutic and postoperative tumor models. Conclusions This kind of therapeutic strategy that combined MnP@Lip nanoparticles with platinum-based chemotherapeutics may provide a novel insight for immunochemotherapy. Graphical Abstract

Effect of glycolysis inhibition by miR-448 on glioma radiosensitivity

2020 ◽  
Vol 132 (5) ◽  
pp. 1456-1464 ◽  
Author(s):  
Fengming Lan ◽  
Qing Qin ◽  
Huiming Yu ◽  
Xiao Yue
Keyword(s):  
Mouse Model ◽  
Cell Lines ◽  
Radiation Treatment ◽  
Glioma Cells ◽  
Luciferase Reporter ◽  
Bioinformatics Analyses ◽  
Subcutaneous Tumor ◽  
Tumor Bearing ◽  
U87 Cells

OBJECTIVEAlthough glucose metabolism reengineering is a typical feature of various tumors, including glioma, key regulators of glycolytic reprogramming are still poorly understood. The authors sought to investigate whether glycolysis inhibition by microRNA (miR)–448 increases radiosensitivity in glioma cells.METHODSThe authors used glioma tissue samples from glioma patients, cells from glioblastoma (GBM) cell lines and normal human astrocyte cells, and subcutaneous tumor–bearing U87 cells in mice to examine the effects of signaling regulation by miR-448 in the response of glioma tissues and cells to radiation treatment. Techniques used for investigation included bioinformatics analyses, biochemical assays, luciferase reporter assays, and establishment of subcutaneous tumors in a mouse model. Glucose consumption, LDH activity, and cellular ATP were measured to determine the ability of glioma cells to perform glycolysis. Expression of HIF-1α was measured as a potential target gene of miR-448 in glycolysis.RESULTSmiR-448 was detected and determined to be significantly downregulated in both glioma tissues from glioma patients and GBM cell lines. Furthermore, miR-448 acted as a tumor-inhibiting factor and suppressed glycolysis in glioma by negatively regulating the activity of HIF-1α signaling and then interfering with its downstream regulators relative to glycolysis, HK1, HK2, and LDHA. Interestingly, overexpression of miR-448 increased the x-radiation sensitivity of glioma cells. Finally, in in vivo experiments, subcutaneous tumor–bearing U87 cells in a mouse model verified that high expression of miR-448 also enhanced glioma radiosensitivity via inhibiting glycolytic factors.CONCLUSIONSmiR-448 can promote radiosensitivity by inhibiting HIF-1α signaling and then negatively controlling the glycolysis process in glioma. A newly identified miR-448–HIF-1α axis acts as a potentially valuable therapeutic target that may be useful in overcoming radioresistance in glioma treatment.

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