RESUMO
The risk of internal and external exposure to ionizing radiation (IR) has increased alongside the development and implementation of nuclear technology. Therefore, serious security issues have emerged globally, and there has been an increase in the number of studies focusing on radiological prevention and medical countermeasures. Radioprotective drugs are particularly important components of emergency medical preparedness strategies for the clinical management of IR-induced injuries. However, a few drugs have been approved to date to treat such injuries, and the related mechanisms are not entirely understood. Thus, the aim of the present review was to provide a brief overview of the World Health Organization's updated list of essential medicines for 2023 for the proper management of national stockpiles and the treatment of radiological emergencies. This review also discusses the types of radiation-induced health injuries and the related mechanisms, as well as the development of various radioprotective agents, including Chinese herbal medicines, for which significant survival benefits have been demonstrated in animal models of acute radiation syndrome.
Assuntos
Síndrome Aguda da Radiação , Defesa Civil , Medicamentos Essenciais , Contramedidas Médicas , Protetores contra Radiação , Animais , Síndrome Aguda da Radiação/tratamento farmacológico , Síndrome Aguda da Radiação/prevenção & controle , Radiação Ionizante , Protetores contra Radiação/farmacologia , Protetores contra Radiação/uso terapêuticoRESUMO
BACKGROUND: Busulfan (BU) is an alkylating agent used as a conditioning agent prior to hematopoietic stem cell (HSC) transplantation as it is known to be cytotoxic to host hematopoietic stem and progenitor cells. The susceptibility of HSCs to BU injury plays an important role in the myeloablative efficacy of BU. Different susceptibilities were demonstrated in genetically diverse (GD) mice in our preliminary research. METHODS: Three strains of GD mice with different susceptibilities to BU-induced HSC injury were used for screening biological markers of HSC injury susceptibility in urine. The urine proteins were analyzed using liquid chromatography coupled with tandem mass spectrometry to screen for differentially expressed proteins. Screening for possible biomarkers based on differences in protein expression abundance was validated using enzyme-linked immunoassay (ELISA). RESULTS: Functional analysis showed that the differential proteins were all involved in a series of biological pathways related to cellular senescence, apoptosis, and angiogenesis; whereas the differential proteins of the high-susceptible strain were enriched for the regulation of bone marrow microenvironment pathways, those of low-susceptible strain were enriched for the proapoptotic effect of GTPase pathways. Based on protein abundance differences, several urinary proteins that may be indicative of susceptibility were screened, and ELISA validation results showed that angiotensin-converting enzyme may be a potential biomarker predicting HSC susceptibility for BU conditioning. CONCLUSIONS: This study indicates that urinary protein levels can reflect differences in susceptibility to BU-induced HSC injury. Using GD mice to construct genetic difference models will provide preclinical data for screening BU-related biological markers.
Assuntos
Bussulfano , Transplante de Células-Tronco Hematopoéticas , Camundongos , Animais , Bussulfano/farmacologia , Células-Tronco Hematopoéticas , Alquilantes/toxicidade , Espectrometria de Massas em Tandem/métodosRESUMO
OBJECTIVE: Spermidine, a natural polyamine, possesses anti-oxidant, autophagy-regulation, and anti-aging properties. Elevated levels of oxidative stress, which was mediated the senescence of hematopoietic stem cells (HSCs) induced by radiation exposure, may further contribute to long-term myelosuppression. Therefore, this study investigated the protective effect of spermidine on the long-term damage of the hematopoietic system caused by radiation exposure. METHODS: In vitro experiments, bone marrow mononuclear cells (BMMNCs) of C57BL/6 mice were isolated and incubated with 5 mM spermidine for 30 min, then irradiated by 2 Gy X ray. The survival rate, proliferation, and differentiation ability of BMMNCs were detected. In vivo experiment, mice received 4 Gy total body irradiation (TBI), 3 mM spermidine were administered in the drinking water every day for 14 days prior to irradiation and then continued for 30 days after irradiation. Peripheral blood, bone marrow cell typing, level of reactive oxygen species (ROS), colony-forming ability of HSC, and transplantation-reconstitution capability were detected. RESULTS: In vitro experiments, spermidine significantly improved the survival rate of BMMNCs as well as the proliferation and differentiation ability of HSCs exposure to ionizing radiation (IR). In vivo, spermidine reduced levels of ROS in HSCs; spermidine attenuated long-term myeloid differentiation deviation induced by TBI. Spermidine promoted the proliferation and differentiation ability of stem cells, but failed to ameliorate the decreased engraftment capacity of bone marrow cells in mice exposed to TBI. CONCLUSION: This study demonstrated that spermidine could promote the recovery of IR-induced inhibition of proliferation and differentiation ability of HSCs, partly through antioxidant effects. Whether combining spermidine with other radioprotectants could further increase protective efficacy and reduce the long-term bone marrow injury needs further investigation.
Assuntos
Lesões por Radiação , Espermidina , Animais , Camundongos , Espécies Reativas de Oxigênio , Espermidina/farmacologia , Camundongos Endogâmicos C57BL , Células-Tronco Hematopoéticas , Células da Medula Óssea , Antioxidantes/farmacologia , Irradiação Corporal TotalRESUMO
BACKGROUND: Gastrointestinal (GI) injury is one of the most common side effects of radiotherapy. However, there is no ideal therapy method except for symptomatic treatment in the clinic. Xuebijing (XBJ) is a traditional Chinese medicine, used to treat sepsis by injection. In this study, the protective effects of XBJ on radiation-induced intestinal injury (RIII) and its mechanism were explored. METHODS: The effect of XBJ on survival of irradiated C57BL/6 mice was monitored. Histological changes including the number of crypts and the length of villi were evaluated by H&E. The expression of Lgr5+ intestinal stem cells (ISCs), Ki67+ cells, villin and lysozymes were examined by immunohistochemistry. The expression of cytokines in the intestinal crypt was detected by RT-PCR. DNA damage and apoptosis rates in the small intestine were also evaluated by immunofluorescence. RESULTS: In the present study, XBJ improved the survival rate of the mice after 8.0 and 9.0 Gy total body irradiation (TBI). XBJ attenuated structural damage of the small intestine, maintained regenerative ability and promoted proliferation and differentiation of crypt cells, decreased apoptosis rate and reduced DNA damage in the intestine. Elevation of IL-6 and TNF-α was limited, but IL-1, TNF-ð½ and IL-10 levels were increased in XBJ-treated group after irradiation. The expression of Bax and p53 were decreased after XBJ treatment. CONCLUSIONS: Taken together, XBJ provides a protective effect on RIII by inhibiting inflammation and blocking p53-related apoptosis pathway.
Assuntos
Medicamentos de Ervas Chinesas , Proteína Supressora de Tumor p53 , Camundongos , Animais , Proteína Supressora de Tumor p53/metabolismo , Camundongos Endogâmicos C57BL , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Citocinas/metabolismoRESUMO
Objective To explore the effects of interleukin-6 (IL-6) gene knockout on the cognitive function and pathological changes in 5×FAD transgenic mice of Alzheimer's disease.Methods IL-6+/- mice were crossed with 5×FAD mice to establish the 5×FAD;IL-6-/- mouse model,and 3-month-old and 10-month-old mice were selected for experiments.The cognitive function of mice was detected by behavioral tests,and HE staining and ß-amyloid (Aß) immunohistochemical staining were performed to detect the pathological changes of mouse brain tissue.Results The number of 5×FAD;IL-6-/- model mice (3 months old,n=20;10 months old,n=5) and 5×FAD littermate control (3 months old,n=26;10 months old,n=24) conformed to the Mendel's law.Compared with that of the 5×FAD mice at the same age,the discrimination ratio of 3-month-old 5×FAD;IL-6-/- mice increased in the novel object recognition test (q=3.890,P=0.002).Morris water maze test results showed that the 3-month-old 5×FAD;IL-6-/- mice had longer time spent in target quadrant (q=3.797,P=0.012) and more times of crossing platform (q=2.505,P=0.017) than the 5×FAD mice at the same age.The results of immunohistochemical staining showed that IL-6 knockout reduced the Aß deposition in the hippocampus (q=13.490,P=0.002;q=45.680,P<0.001) and cortex (q=16.830,P=0.001;q=14.180,P=0.001) of 5×FAD mice.Conclusion IL-6 gene knockout can significantly improve the spatial memory and reduce the Aß deposition in the brain of 5×FAD mice.
Assuntos
Doença de Alzheimer , Doença de Alzheimer/genética , Animais , Cognição , Modelos Animais de Doenças , Flavina-Adenina Dinucleotídeo , Técnicas de Inativação de Genes , Interleucina-6 , Camundongos , Camundongos KnockoutRESUMO
Morphine is a widely used analgesic, but its use in clinical precision medicine is limited by the variance in response among individuals. Although previous studies have shown that individual differences in morphine can be explained in terms of pharmacodynamics and pharmacokinetics, genetic polymorphisms also play an important role. However, the genetic basis of different sensitivity and tolerance susceptibility to morphine remains ambiguous. Using 15 strains of inbred Genetic Diversity (GD) mice, a new resource with wide genetic and phenotypic variation, we demonstrated great variance in sensitivity to morphine analgesia and susceptibility to morphine tolerance between different GD strains. Among-individual variance in response to morphine analgesia in the population can be modeled in GD mice. Two loci respectively may be associated with the among-individual variance in morphine sensitivity and tolerance, confirming the role of genetic factors in among-individual different responses to morphine. These results indicate that GD mice may be a potential tool for the identification of new biomarkers to improve the clinical administration of morphine.
Assuntos
Analgesia , Morfina , Animais , Variação Genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Morfina/farmacologia , DorRESUMO
Radiation-induced pulmonary fibrosis (RIPF) is a late toxicity of therapeutic radiation in clinic with poor prognosis and limited therapeutic options. Previous results have shown that senescent cells, such as fibroblast and type II airway epithelial cell, are strongly implicated in pathology of RIPF. However, the role of senescent macrophages in the development RIPF is still unknown. In this study, we report that ionizing radiation (IR) increase cellular senescence with higher expression of senescence-associated ß-galactosidase (SA-ß-Gal) and senescence-specific genes (p16, p21, Bcl-2, and Bcl-xl) in irradiated bone marrow-derived monocytes/macrophages (BMMs). Besides, there's a significant increase in the expression of pro-fibrogenic factors (TGF-ß1 and Arg-1), senescence-associated secretory phenotype (SASP) proinflammatory factors (Il-1α, Il-6, and Tnf-α), SASP chemokines (Ccl2, Cxcl10, and Ccl17), and SASP matrix metalloproteinases (Mmp2, Mmp9 and Mmp12) in BMMs exposed to 10 Gy IR. In addition, the percentages of SA-ß-Gal+ senescent macrophages are significantly increased in the macrophages of murine irradiated lung tissue. Moreover, robustly elevated expression of p16, SASP chemokines (Ccl2, Cxcl10, and Ccl17) and SASP matrix metalloproteinases (Mmp2, Mmp9, and Mmp12) is observed in the macrophages of irradiated lung, which might stimulate a fibrotic phenotype in pulmonary fibroblasts. In summary, irradiation can induce macrophage senescence, and increase the secretion of SASP in senescent macrophages. Our findings provide important evidence that senescent macrophages might be the target for prevention and treatment of RIPF.
Assuntos
Senescência Celular/fisiologia , Macrófagos/fisiologia , Pneumonite por Radiação/patologia , Animais , Células Cultivadas , Senescência Celular/efeitos da radiação , Quimiocinas/metabolismo , Citocinas/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Pulmão/efeitos da radiação , Macrófagos/efeitos da radiação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Pneumonite por Radiação/metabolismo , Radiação IonizanteRESUMO
Sitagliptin, an inhibitor of the dipeptidyl peptidase IV (DPP4), has been implicated in the regulation of type 2 diabetes. However, the role and mechanism of sitagliptin administration in total body irradiation (TBI)- induced hematopoietic cells injury are unclear. In this study, we demonstrated that sitagliptin had therapeutic effects on hematopoietic damage, which protected mice from 7.5 Gy TBI-induced death, increased the numbers and colony formation ability of hematopoietic cells. These therapeutic effects might be attributed to the inhibition of NOX4-mediated oxidative stress in hematopoietic cells, and the alleviation of inflammation was also helpful. Therefore, sitagliptin has potential as an effective radiotherapeutic agent for ameliorating TBI-induced hematopoietic injury.
Assuntos
Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Neoplasias Hematológicas/tratamento farmacológico , Fosfato de Sitagliptina/uso terapêutico , Irradiação Corporal Total/métodos , Animais , Inibidores da Dipeptidil Peptidase IV/farmacologia , Neoplasias Hematológicas/mortalidade , Masculino , Camundongos , Fosfato de Sitagliptina/farmacologia , Análise de SobrevidaRESUMO
OBJECTIVE: Previous studies have shown that inhibition of inducible NO synthase (NOS2 or iNOS) with an inhibitor can selectively protect several normal tissues against radiation during radiotherapy. However, the role of NOS2 in ionizing radiation (IR)-induced bone marrow (BM) suppression is unknown and thus was investigated in the present study using NOS2-/- and wild-type mice 14 days after they were exposed to a sublethal dose of total body irradiation (TBI). METHODS: The effects of different doses of IR (1, 2 and 4 Gy) on the apoptosis and colony-forming ability of bone marrow cells from wild-type (WT) and NOS2-/- mice were investigated in vitro. In addition, we exposed NOS2-/- mice and WT mice to 6-Gy TBI or sham irradiation. They were euthanized 14 days after TBI for analysis of peripheral blood cell counts and bone marrow cellularity. Colony-forming unit-granulocyte and macrophage, burst-forming unit-erythroid and CFU-granulocyte, erythroid, macrophage in bone marrow cells from the mice were determined to evaluate the function of hematopoietic progenitor cells (HPCs), and the ability of hematopoietic stem cells (HSCs) to self-renew was analysed by the cobblestone area forming cell assay. The cell cycling of HPCs and HSCs were measured by flow cytometry. RESULTS: Exposure to 2 and 4 Gy IR induced bone marrow cell apoptosis and inhibited the proliferation of HPCs in vitro. However, there was no difference between the cells from WT mice and NOS2-/- mice in response to IR exposure in vitro. Exposure of WT mice and NOS2-/- mice to 6 Gy TBI decreased the white blood cell, red blood cell, and platelet counts in the peripheral blood and bone marrow mononuclear cells, and reduced the colony-forming ability of HPCs (P < 0.05), damaged the clonogenic function of HSCs. However, these changes were not significantly different in WT and NOS2-/- mice. CONCLUSION: These data suggest that IR induces BM suppression in a NOS2-independent manner.
RESUMO
Carcinoembryonic antigen (CEA) is a biomarker and therapy target for nonsmall cell lung cancer (NSCLC), which is the most common type of lung cancer. Nanobodies with high target specificity are promising candidates to function as antiCEA probes. In the present study, the targeting effects of an antiCEA nanobody obtained from phage display were investigated using technetium99 m (99mTc) and fluorescence labeling. In vitro binding and immunofluorescent staining assays, as well as in vivo blood clearance and biodistribution assays were performed. High specificity and affinity of the nanobody for CEApositive H460 cells was observed in vitro. The pharmacokinetics assay of the 99mTcnanobody in Wistar rats demonstrated that the nanobody had appropriate T1/2α and T1/2ß, which were 20.2 and 143.5 min, respectively. The biodistribution assay using H460 xenograftbearing nude mice demonstrated a high ratio of signal in tumor compared with background, which confirmed that the nanobody may be useful as a molecular probe for CEApositive cancer, particularly in NSCLC.
Assuntos
Antígeno Carcinoembrionário/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Imunofluorescência , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/diagnóstico , Anticorpos de Domínio Único , Animais , Antígeno Carcinoembrionário/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Xenoenxertos , Humanos , Marcação por Isótopo , Sondas Moleculares , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/isolamento & purificação , Compostos Radiofarmacêuticos/farmacocinética , Anticorpos de Domínio Único/administração & dosagem , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/isolamento & purificação , Tecnécio , Distribuição TecidualRESUMO
PURPOSE: Ionizing radiation (IR)-induced pulmonary fibrosis (PF) is an irreversible and severe late effect of thoracic radiation therapy. The goal of this study was to determine whether clearance of senescent cells with ABT-263, a senolytic drug that can selectively kill senescent cells, can reverse PF. METHODS AND MATERIALS: C57BL/6J mice were exposed to a single dose of 17 Gy on the right side of the thorax. Sixteen weeks after IR, they were treated with 2 cycles of vehicle or ABT-263 (50 mg/kg per day for 5 days per cycle) by gavage. The effects of ABT-263 on IR-induced increases in senescent cells; elevation in the expression of selective inflammatory cytokines, matrix metalloproteinases, and tissue inhibitors of matrix metalloproteinases; and the severity of the tissue injury and fibrosis in the irradiated lungs were evaluated 3 weeks after the last treatment, in comparison with the changes observed in the irradiated lungs before treatment or after vehicle treatment. RESULTS: At 16 weeks after exposure of C57BL/6 mice to a single dose of 17 Gy, thoracic irradiation resulted in persistent PF associated with a significant increase in senescent cells. Treatment of the irradiated mice with ABT-263 after persistent PF had developed reduced senescent cells and reversed the disease. CONCLUSIONS: To our knowledge, this is the first study to demonstrate that PF can be reversed by a senolytic drug such as ABT-263 after it becomes a progressive disease. Therefore, ABT-263 has the potential to be developed as a new treatment for PF.
Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Compostos de Anilina/uso terapêutico , Antineoplásicos/uso terapêutico , Senescência Celular , Pneumonite por Radiação/tratamento farmacológico , Sulfonamidas/uso terapêutico , Proteína X Associada a bcl-2/antagonistas & inibidores , Células Epiteliais Alveolares/patologia , Animais , Antineoplásicos/administração & dosagem , Inibidor p16 de Quinase Dependente de Ciclina/análise , Inibidor p16 de Quinase Dependente de Ciclina/genética , Citocinas/análise , Hidroxiprolina/análise , Mediadores da Inflamação/metabolismo , Pulmão/química , Pulmão/enzimologia , Pulmão/efeitos da radiação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-bcl-2/análise , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/análise , Pneumonite por Radiação/genética , Pneumonite por Radiação/patologia , Radiação Ionizante , Proteína X Associada a bcl-2/metabolismo , beta-Galactosidase/análiseRESUMO
Both resveratrol(Res) and diphenyleneiodonium(DPI) have been shown to have radioprotective effects on hematopoietic system injury. However, the cooperative effect of Res and DPI are unknown. In this study, we explored the radioprotective effect of the combination of Res and DPI both in vitro and in vivo. Our results showed that the combined treatment of Res and DPI was more effective in protecting irradiated BMMNCs in terms of cell viability, colony-forming ability, and reconstitution ability in vitro compared with Res or DPI treatment alone. However, in mice, the combination of Res and DPI had no enhanced protection on 4Gy total body irradiation (TBI)-induced hematopoietic system injury, including TBI-induced myelosuppression, induction of the splenic index, and increases in HSC/HPC numbers and the colony-forming ability of BMCs,compared to Res or DPI alone. An exception was the number of BMCs. These studies illustrated the inconsistency between experiments carried out in vitro and in vivo and suggest an interaction between Res or DPI in vivo.
Assuntos
Células da Medula Óssea/efeitos dos fármacos , Sistema Hematopoético/efeitos dos fármacos , Oniocompostos/uso terapêutico , Lesões Experimentais por Radiação/tratamento farmacológico , Estilbenos/uso terapêutico , Animais , Células da Medula Óssea/efeitos da radiação , Células Cultivadas , Interações Medicamentosas , Quimioterapia Combinada , Sistema Hematopoético/efeitos da radiação , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Resveratrol , Irradiação Corporal TotalRESUMO
Vam3, a resveratrol dimer, has been implicated in the regulation of chronic obstructive pulmonary disease. However, the effect of Vam3 on total body irradiation (TBI)-induced hematopoietic progenitor cells (HPCs), and hematopoietic stem cells (HSCs) injury is unknown. In this study, we examined whether Vam3could ameliorate hematopoietic system injury induced by TBI. Our results indicated that Vam3 alleviated TBI-induced injury by improving the self-renewal and differentiation of HPCs, and HSCs. Vam3 decreased the intracellular ROS levels in irradiated mice HPCs/HSCs or c-kit positive cells and inhibited apoptosis and DNA damage in LSKs and HPCs after TBI. Vam3 up-regulated the expression of Nrf2 and related genes and proteins in irradiated c-kit positive cells in vitro. However, Vam3 did not increase the cell viability or the number of CFU-GM c-kit positive cells in irradiated Nrf2-/- mice but decreased the cellular ROS level. The above data showed that Vam3 ameliorates total body irradiation-induced hematopoietic system injury and that Nrf2 is essential in mediating Vam3's protective effect on the proliferation of c-kit positive cells after irradiation but not its ability to scavenge for free radicals.
Assuntos
Antioxidantes/farmacologia , Benzofuranos/farmacologia , Células da Medula Óssea/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/genética , Protetores contra Radiação/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Estilbenos/farmacologia , Animais , Células da Medula Óssea/efeitos da radiação , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Raios gama , Expressão Gênica , Células-Tronco Hematopoéticas/efeitos da radiação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/deficiência , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Espécies Reativas de Oxigênio/agonistas , Espécies Reativas de Oxigênio/antagonistas & inibidores , Irradiação Corporal TotalRESUMO
Down syndrome (DS) is a genetic disorder caused by the presence of an extra partial or whole copy of chromosome 21. In addition to musculoskeletal and neurodevelopmental abnormalities, children with DS exhibit various hematologic disorders and have an increased risk of developing acute lymphoblastic leukemia and acute megakaryocytic leukemia. Using the Ts65Dn mouse model, we investigated bone marrow defects caused by trisomy for 132 orthologs of the genes on human chromosome 21. The results showed that, although the total bone marrow cellularity as well as the frequency of hematopoietic progenitor cells (HPCs) was comparable between Ts65Dn mice and their age-matched euploid wild-type (WT) control littermates, human chromosome 21 trisomy led to a significant reduction in hematopoietic stem cell (HSC) numbers and clonogenic function in Ts65Dn mice. We also found that spontaneous DNA double-strand breaks (DSBs) were significantly increased in HSCs from the Ts65Dn mice, which was correlated with the significant reduction in HSC clonogenic activity compared to those from WT controls. Moreover, analysis of the repair kinetics of radiation-induced DSBs revealed that HSCs from Ts65Dn mice were less proficient in DSB repair than the cells from WT controls. This deficiency was associated with a higher sensitivity of Ts65Dn HSCs to radiation-induced suppression of HSC clonogenic activity than that of euploid HSCs. These findings suggest that an additional copy of genes on human chromosome 21 may selectively impair the ability of HSCs to repair DSBs, which may contribute to DS-associated hematological abnormalities and malignancies.
Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , Síndrome de Down/genética , Síndrome de Down/patologia , Células-Tronco Hematopoéticas/patologia , Animais , Linhagem Celular , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Reparo do DNA/efeitos da radiação , CamundongosRESUMO
Senescent hematopoietic stem cells (HSCs) accumulate with age and exposure to stress, such as total-body irradiation (TBI), which may cause long-term myelosuppression in the clinic. However, the methods available for long-term myelosuppression remain limited. Previous studies have demonstrated that sustained p38 mitogen-activated protein kinases (p38 MAPK) activation in HSCs following exposure to TBI in mice and the administration of its inhibitor twenty-four hours after TBI may partially prevent long-term myelosuppression. However, long-term myelosuppression is latent and identified long after the administration of radiation. In this study, we investigated the effects of SB203580 (a small molecule inhibitor of p38 MAPK) on long-term myelosuppression induced by TBI. Mice with hematopoietic injury were injected intraperitoneally with SB203580 every other day five times beginning 70 days after 6 Gy of (137)Cs γ ray TBI. Our results at 80 days demonstrated that SB203580 did not significantly improve the TBI-induced long-term reduction of peripheral blood cell and bone marrow nucleated cell (BMNC) counts, or defects in hematopoietic progenitor cells (HPCs) and HSC clonogenic function. SB203580 reduced reactive oxygen species (ROS) production and p-p38 expression; however, SB203580 had no effect on p16 expression in the HSCs of mice. In conclusion, these findings suggest that treatment with SB203580 70 days after TBI in mice inhibits the ROS-p38 oxidative stress pathway; however, it has no therapeutic effect on long-term myelosuppression induced by TBI.
Assuntos
Senescência Celular/efeitos dos fármacos , Senescência Celular/efeitos da radiação , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Irradiação Corporal Total , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Células Sanguíneas/efeitos dos fármacos , Células Sanguíneas/metabolismo , Células Sanguíneas/efeitos da radiação , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Ensaio de Unidades Formadoras de Colônias , Imidazóis/farmacologia , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Piridinas/farmacologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Irradiation commonly causes pneumocyte senescence, which may lead to severe fatal lung injury characterized by pulmonary dysfunction and respiratory failure. However, the molecular mechanism underlying the induction of pneumocyte senescence by irradiation remains to be elucidated. In the present study, weighted gene coexpression network analysis (WGCNA) was used to screen for differentially expressed genes, and to identify the hub genes and gene modules, which may be critical for senescence. A total of 2,916 differentially expressed genes were identified between the senescence and nonsenescence groups following thoracic irradiation. In total, 10 gene modules associated with cell senescence were detected, and six hub genes were identified, including Bcell scaffold protein with ankyrin repeats 1, translocase of outer mitochondrial membrane 70 homolog A, actin filamentassociated protein 1, Cd84, Nuf2 and nuclear factor erythroid 2. These genes were markedly associated with cell proliferation, cell division and cell cycle arrest. The results of the present study demonstrated that WGCNA of microarray data may provide further insight into the molecular mechanism underlying pneumocyte senescence.
Assuntos
Células Epiteliais Alveolares/citologia , Células Epiteliais Alveolares/metabolismo , Senescência Celular/genética , Senescência Celular/efeitos da radiação , Regulação da Expressão Gênica/efeitos da radiação , Redes Reguladoras de Genes/efeitos da radiação , Tórax/efeitos da radiação , Animais , Perfilação da Expressão Gênica , Ontologia Genética , Estudos de Associação Genética , Camundongos , Anotação de Sequência Molecular , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiaçãoRESUMO
Senescent cells (SCs) accumulate with age and after genotoxic stress, such as total-body irradiation (TBI). Clearance of SCs in a progeroid mouse model using a transgenic approach delays several age-associated disorders, suggesting that SCs play a causative role in certain age-related pathologies. Thus, a 'senolytic' pharmacological agent that can selectively kill SCs holds promise for rejuvenating tissue stem cells and extending health span. To test this idea, we screened a collection of compounds and identified ABT263 (a specific inhibitor of the anti-apoptotic proteins BCL-2 and BCL-xL) as a potent senolytic drug. We show that ABT263 selectively kills SCs in culture in a cell type- and species-independent manner by inducing apoptosis. Oral administration of ABT263 to either sublethally irradiated or normally aged mice effectively depleted SCs, including senescent bone marrow hematopoietic stem cells (HSCs) and senescent muscle stem cells (MuSCs). Notably, this depletion mitigated TBI-induced premature aging of the hematopoietic system and rejuvenated the aged HSCs and MuSCs in normally aged mice. Our results demonstrate that selective clearance of SCs by a pharmacological agent is beneficial in part through its rejuvenation of aged tissue stem cells. Thus, senolytic drugs may represent a new class of radiation mitigators and anti-aging agents.
Assuntos
Compostos de Anilina/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Senescência Celular , Células-Tronco Hematopoéticas/efeitos dos fármacos , Mioblastos/efeitos dos fármacos , RNA Mensageiro/efeitos dos fármacos , Sulfonamidas/farmacologia , Animais , Antivirais/farmacologia , Linfócitos B/efeitos dos fármacos , Western Blotting , Ciclo Celular , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ensaio de Unidades Formadoras de Colônias , Inibidor p16 de Quinase Dependente de Ciclina/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Dano ao DNA , Ganciclovir/farmacologia , Técnicas de Silenciamento de Genes , Células-Tronco Hematopoéticas/patologia , Humanos , Camundongos , Microscopia , Músculo Esquelético/citologia , Mioblastos/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/metabolismo , Rejuvenescimento , Irradiação Corporal Total , Proteína bcl-X/genéticaRESUMO
BACKGROUND: Exposure to a moderate to high dose of ionizing radiation (IR) not only causes acute radiation syndrome but also induces long-term (LT) bone marrow (BM) injury. The latter effect of IR is primarily attributed to the induction of hematopoietic stem cell (HSC) senescence. Granulocyte colony-stimulating factor (G-CSF) is the only treatment recommended to be given to radiation victims soon after IR. However, clinical studies have shown that G-CSF used to treat the leukopenia induced by radiotherapy or chemotherapy in patients can cause sustained low white blood cell counts in peripheral blood. It has been suggested that this adverse effect is caused by HSC and hematopoietic progenitor cell (HPC) proliferation and differentiation stimulated by G-CSF, which impairs HSC self-renewal and may exhaust the BM capacity to exacerbate IR-induced LT-BM injury. METHODS: C57BL/6 mice were exposed to 4 Gy γ-rays of total body irradiation (TBI) at a dose-rate of 1.08 Gy per minute, and the mice were treated with G-CSF (1 µg/each by ip) or vehicle at 2 and 6 h after TBI on the first day and then twice every day for 6 days. All mice were killed one month after TBI for analysis of peripheral blood cell counts, bone marrow cellularity and long-term HSC (CD34-lineage-sca1+c-kit+) frequency. The colony-forming unit-granulocyte and macrophage (CFU-GM) ability of HPC was measured by colony-forming cell (CFC) assay, and the HSC self-renewal capacity was analyzed by BM transplantation. The levels of ROS production, the expression of phospho-p38 mitogen-activated protein kinase (p-p38) and p16(INK4a) (p16) mRNA in HSCs were measured by flow cytometry and RT-PCR, respectively. RESULTS: The results of our studies show that G-CSF administration mitigated TBI-induced decreases in WBC and the suppression of HPC function (CFU-GM) (p < 0.05), whereas G-CSF exacerbated the suppression of long-term HSC engraftment after transplantation one month after TBI (p < 0.05); The increase in HSC damage was associated with increased ROS production, activation of p38 mitogen-activated protein kinase (p38), induction of senescence in HSCs. CONCLUSION: Our findings suggest that although G-CSF administration can reduce ARS, it can also exacerbate TBI-induced LT-BM injury in part by promoting HSC senescence via the ROS-p38-p16 pathway.
RESUMO
OBJECTIVE: The aim of the present study was to develop potential candidates of integrin αvß3-targeted imaging agent, which can facilitate the diagnosis and treatment of malignant solid tumors. METHODS: Peptides derived from tumstatin, named T7 and T7-6H, were derivatized to contain histidine in the C-terminus of their sequence and were labeled with (99m)Tc via nitrido and carbonyl precursors. The radiochemical purity and stability of (99m)Tc-labeled T7 and T7-6H were characterized by thin-layer chromatography. The whole body biodistribution was studied in NCI-H157-bearing BALB/c nude mice. RESULTS: The (99m)Tc-labeled T7 and T7-6H showed adequate in vitro stability, with a high radiochemical purity of over 90%. The dissociation constant (Kd) value of the (99m)Tc-labeled T7 and T7-6H ranged from 68.5 nM to 140.8 nM in U251 and NCI-H157 cell lines. (99m)Tc-labeled T7 and T7-6H showed no significant difference of biodistribution in mice. Furthermore, both T7 and T7-6H exhibited a poor blood-brain barrier penetration and a transient accumulation in lung; the uptake in tumor tissues was significantly higher than in muscle tissue, with a ratio of 5.8. CONCLUSION: (99m)Tc-labeled T7 and T7-6H can be regarded as promising single-photon emission computed tomography probes for imaging integrin αvß3, and need to be further studied for noninvasive detection of tumors.