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1.
Biomedicines ; 12(7)2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39062169

RESUMO

About one-fourth of patients with pancreatic ductal adenocarcinoma (PDAC) are categorized as borderline resectable (BR) or locally advanced (LA). Chemotherapy and radiation therapy have not yielded the anticipated outcomes in curing patients with BR/LA PDAC. The surgical resection of these tumors presents challenges owing to the unpredictability of the resection margin, involvement of vasculature with the tumor, the likelihood of occult metastasis, a higher ratio of positive lymph nodes, and the relatively larger size of tumor nodules. Oncolytic virotherapy has shown promising activity in preclinical PDAC models. Unfortunately, the desmoplastic stroma within the PDAC tumor microenvironment establishes a barrier, hindering the infiltration of oncolytic viruses and various therapeutic drugs-such as antibodies, adoptive cell therapy agents, and chemotherapeutic agents-in reaching the tumor site. Recently, a growing emphasis has been placed on targeting major acellular components of tumor stroma, such as hyaluronic acid and collagen, to enhance drug penetration. Oncolytic viruses can be engineered to express proteolytic enzymes that cleave hyaluronic acid and collagen into smaller polypeptides, thereby softening the desmoplastic stroma, ultimately leading to increased viral distribution along with increased oncolysis and subsequent tumor size regression. This approach may offer new possibilities to improve the resectability of patients diagnosed with BR and LA PDAC.

2.
Hepatology ; 77(6): 1943-1957, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36052732

RESUMO

BACKGROUND: Morreton virus (MORV) is an oncolytic Vesiculovirus , genetically distinct from vesicular stomatitis virus (VSV). AIM: To report that MORV induced potent cytopathic effects (CPEs) in cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC) in vitro models. APPROACH AND RESULTS: In preliminary safety analyses, high intranasal doses (up to 10 10 50% tissue culture infectious dose [TCID 50 ]) of MORV were not associated with significant adverse effects in immune competent, non-tumor-bearing mice. MORV was shown to be efficacious in a Hep3B hepatocellular cancer xenograft model but not in a CCA xenograft HuCCT1 model. In an immune competent, syngeneic murine CCA model, single intratumoral treatments with MORV (1 × 10 7 TCID 50 ) triggered a robust antitumor immune response leading to substantial tumor regression and disease control at a dose 10-fold lower than VSV (1 × 10 8 TCID 50 ). MORV led to increased CD8 + cytotoxic T cells without compensatory increases in tumor-associated macrophages and granulocytic or monocytic myeloid-derived suppressor cells. CONCLUSIONS: Our findings indicate that wild-type MORV is safe and can induce potent tumor regression via immune-mediated and immune-independent mechanisms in HCC and CCA animal models without dose limiting adverse events. These data warrant further development and clinical translation of MORV as an oncolytic virotherapy platform.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Terapia Viral Oncolítica , Camundongos , Humanos , Animais , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/patologia , Carcinoma Hepatocelular/patologia , Vesiculovirus , Modelos Animais de Doenças , Linhagem Celular Tumoral
3.
Front Oncol ; 12: 1042250, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36457491

RESUMO

It has long been known that oncolytic viruses wield their therapeutic capability by priming an inflammatory state within the tumor and activating the tumor immune microenvironment, resulting in a multifaceted antitumor immune response. Vaccine-derived viruses, such as measles and mumps, have demonstrated promising potential for treating human cancer in animal models and clinical trials. However, the extensive cost of manufacturing current oncolytic viral products makes them far out of reach for most patients. Here by analyzing the impact of intratumoral (IT) administrations of the trivalent live attenuated measles, mumps, and rubella viruses (MMR) vaccine, we unveil the cellular and molecular basis of MMR-induced anti-cancer activity. Strikingly, we found that IT delivery of low doses of MMR correlates with tumor control and improved survival in murine hepatocellular cancer and colorectal cancer models via increased tumor infiltration of CD8+ granzyme B+ T-cells and decreased macrophages. Moreover, our data indicate that MMR activates key cellular effectors of the host's innate and adaptive antitumor immunity, culminating in an immunologically coordinated cancer cell death. These findings warrant further work on the potential for MMR to be repurposed as safe and cost-effective cancer immunotherapy to impact cancer patients globally.

4.
Int J Mol Sci ; 23(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35563033

RESUMO

The gastrointestinal (GI) system is highly susceptible to irradiation. Currently, there is no Food and Drug Administration (FDA)-approved medical countermeasures for GI radiation injury. The vitamin E analog gamma-tocotrienol (GT3) is a promising radioprotector in mice and nonhuman primates (NHP). We evaluated GT3-mediated GI recovery in total-body irradiated (TBI) NHPs. Sixteen rhesus macaques were divided into two groups; eight received vehicle and eight GT3 24 h prior to 12 Gy TBI. Proximal jejunum was assessed for structural injuries and crypt survival on day 4 and 7. Apoptotic cell death and crypt cell proliferation were assessed with TUNEL and Ki-67 immunostaining. Irradiation induced significant shortening of the villi and reduced mucosal surface area. GT3 induced an increase in crypt depth at day 7, suggesting that more stem cells survived and proliferated after irradiation. GT3 did not influence crypt survival after irradiation. GT3 treatment caused a significant decline in TUNEL-positive cells at both day 4 (p < 0.03) and 7 (p < 0.0003). Importantly, GT3 induced a significant increase in Ki-67-positive cells at day 7 (p < 0.05). These data suggest that GT3 has radioprotective function in intestinal epithelial and crypt cells. GT3 should be further explored as a prophylactic medical countermeasure for radiation-induced GI injury.


Assuntos
Síndrome Aguda da Radiação , Cromanos , Protetores contra Radiação , Vitamina E , Síndrome Aguda da Radiação/tratamento farmacológico , Síndrome Aguda da Radiação/prevenção & controle , Animais , Cromanos/uso terapêutico , Modelos Animais de Doenças , Intestinos/patologia , Intestinos/efeitos da radiação , Antígeno Ki-67 , Macaca mulatta , Protetores contra Radiação/farmacologia , Protetores contra Radiação/uso terapêutico , Vitamina E/análogos & derivados , Vitamina E/uso terapêutico
5.
R Soc Open Sci ; 8(8): 210395, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34430045

RESUMO

The discovery of chimeric anti-melanoma agents is reported. These molecules are potent growth suppressors of melanoma cells in vitro with growth inhibition of 50% (GI50) values as low as 1.32 µM. Compounds were more toxic to melanoma cells in vitro than commonly used anti-melanoma agent dacarbazine as measured by TUNEL assay. They induced both caspase-independent apoptosis evident by colocalization of TUNEL with endonuclease G (EndoG) and caspase-mediated apoptosis measured by colocalization of TUNEL with caspase-activated DNase (CAD). In addition, compounds 3 and 5 strongly induced oxidative injury to melanoma cells as measured by TUNEL colocalization with heme oxygenase-1 (HO1). Dacarbazine induced only caspase-independent apoptosis, which may explain why it is less cytotoxic to melanoma cells than compounds 3, 4 and 5.

6.
Nat Commun ; 12(1): 476, 2021 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-33473107

RESUMO

Endonuclease G (ENDOG), a mitochondrial nuclease, is known to participate in many cellular processes, including apoptosis and paternal mitochondrial elimination, while its role in autophagy remains unclear. Here, we report that ENDOG released from mitochondria promotes autophagy during starvation, which we find to be evolutionally conserved across species by performing experiments in human cell lines, mice, Drosophila and C. elegans. Under starvation, Glycogen synthase kinase 3 beta-mediated phosphorylation of ENDOG at Thr-128 and Ser-288 enhances its interaction with 14-3-3γ, which leads to the release of Tuberin (TSC2) and Phosphatidylinositol 3-kinase catalytic subunit type 3 (Vps34) from 14-3-3γ, followed by mTOR pathway suppression and autophagy initiation. Alternatively, ENDOG activates DNA damage response and triggers autophagy through its endonuclease activity. Our results demonstrate that ENDOG is a crucial regulator of autophagy, manifested by phosphorylation-mediated interaction with 14-3-3γ, and its endonuclease activity-mediated DNA damage response.


Assuntos
Autofagia/fisiologia , Dano ao DNA/fisiologia , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Proteínas 14-3-3/metabolismo , Animais , Apoptose , Caenorhabditis elegans , Linhagem Celular , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Drosophila , Técnicas de Inativação de Genes , Células Hep G2 , Humanos , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Fosforilação , Transcriptoma , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo
7.
Int J Mol Sci ; 21(22)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33212932

RESUMO

Endonuclease-mediated DNA fragmentation is both an immediate cause and a result of apoptosis and of all other types of irreversible cell death after injury. It is produced by nine enzymes including DNase I, DNase 2, their homologs, caspase-activated DNase (CAD) and endonuclease G (EndoG). The endonucleases act simultaneously during cell death; however, regulatory links between these enzymes have not been established. We hypothesized that DNase I, the most abundant of endonucleases, may regulate other endonucleases. To test this hypothesis, rat kidney tubular epithelial NRK-52E cells were transfected with the DNase I gene or its inactive mutant in a pECFP expression vector, while control cells were transfected with the empty vector. mRNA expression of all nine endonucleases was studied using real-time RT-PCR; DNA strand breaks in endonuclease genes were determined by PCR and protein expression of the enzymes was measured by Western blotting and quantitative immunocytochemistry. Our data showed that DNase I, but not its inactive mutant, induces all other endonucleases at varying time periods after transfection, causes DNA breaks in endonuclease genes, and elevates protein expression of several endonucleases. This is the first evidence that endonucleases seem to be induced by the DNA-degrading activity of DNase I.


Assuntos
Quebras de DNA , Fragmentação do DNA , DNA/metabolismo , Desoxirribonuclease I/metabolismo , Células Epiteliais/enzimologia , Túbulos Renais/enzimologia , Animais , Linhagem Celular , DNA/genética , Desoxirribonuclease I/genética , Ratos
8.
Sci Rep ; 10(1): 7734, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32382091

RESUMO

Kruppel-like factor 2 (KLF2) is a positive transcriptional regulator of several endothelial protective molecules, including thrombomodulin (TM), a surface receptor, and endothelial nitric oxide synthase (eNOS), an enzyme that generates nitric oxide (NO). Loss of TM and eNOS causes endothelial dysfunction, which results in suppressed generation of activated protein C (APC) by TM-thrombin complex and in upregulation of intercellular adhesion molecule 1 (ICAM-1). Mechanistic studies revealed that activation of extracellular signal-regulated kinase 5 (ERK5) via upregulation of myocyte enhancer factor 2 (MEF2) induces KLF2 expression. Radiation causes endothelial dysfunction, but no study has investigated radiation's effects on the KLF2 pathway. Because fractionated radiation is routinely used during cancer radiotherapy, we decided to delineate the effects of radiation dose fractionation on the KLF2 signaling cascade at early time points (up to 24 h). We exposed human primary endothelial cells to radiation as a series of fractionated or as a single exposure, with the same total dose delivered to each group. We measured the expression and activity of critical members of the KLF2 pathway at subsequent time points, and determined whether pharmacological upregulation of KLF2 can reverse the radiation effects. Compared to single exposure, fractionated radiation profoundly suppressed KLF2, TM, and eNOS levels, subdued APC generation, declined KLF2 binding ability to TM and eNOS promoters, enhanced ICAM-1 expression, and decreased expression of upstream regulators of KLF2 (ERK5 and MEF2). Pharmacological inhibitors of the mevalonate pathway prevented fractionated-radiation-induced suppression of KLF2, TM, and eNOS expression. Finally, fractionated irradiation to thoracic region more profoundly suppressed KLF2 and enhanced ICAM-1 expression than single exposure in the lung at 24 h. These data clearly indicate that radiation dose fractionation plays a critical role in modulating levels of KLF2, its upstream regulators, and its downstream target molecules in endothelial cells. Our findings will provide important insights for selecting fractionated regimens during radiotherapy and for developing strategies to alleviate radiotherapy-induced toxicity to healthy tissues.


Assuntos
Células Endoteliais da Veia Umbilical Humana/efeitos da radiação , Fatores de Transcrição Kruppel-Like/genética , Óxido Nítrico Sintase Tipo III/genética , Trombomodulina/genética , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Regulação da Expressão Gênica/efeitos da radiação , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Molécula 1 de Adesão Intercelular/genética , Fatores de Transcrição MEF2/genética , Proteína Quinase 7 Ativada por Mitógeno/genética , Neoplasias/genética , Neoplasias/patologia , Neoplasias/radioterapia , Radiação , Transdução de Sinais/efeitos da radiação
9.
Antioxidants (Basel) ; 8(3)2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30845647

RESUMO

Natural antioxidant gamma-tocotrienol (GT3), a vitamin E family member, provides intestinal radiation protection. We seek to understand whether this protection is mediated via mucosal epithelial stem cells or sub-mucosal mesenchymal immune cells. Vehicle- or GT3-treated male CD2F1 mice were exposed to total body irradiation (TBI). Cell death was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Villus height and crypt depth were measured with computer-assisted software in tissue sections. Functional activity was determined with an intestinal permeability assay. Immune cell recovery was measured with immunohistochemistry and Western blot, and the regeneration of intestinal crypts was assessed with ex vivo organoid culture. A single dose of GT3 (200 mg/kg body weight (bwt)) administered 24 h before TBI suppressed cell death, prevented a decrease in villus height, increased crypt depth, attenuated intestinal permeability, and upregulated occludin level in the intestine compared to the vehicle treated group. GT3 accelerated mesenchymal immune cell recovery after irradiation, but it did not promote ex vivo organoid formation and failed to enhance the expression of stem cell markers. Finally, GT3 significantly upregulated protein kinase B or AKT phosphorylation after TBI. Pretreatment with GT3 attenuates TBI-induced structural and functional damage to the intestine, potentially by facilitating intestinal immune cell recovery. Thus, GT3 could be used as an intestinal radioprotector.

10.
J Appl Toxicol ; 37(11): 1325-1332, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28543094

RESUMO

Graphene, a crystalline allotrope or carbon, presents numerous useful properties; however, its toxicity is yet to be determined. One of the most dramatic and irreversible toxic abilities of carbon nanomaterials is the induction of DNA fragmentation produced by endogenous cellular endonucleases. This study demonstrated that pristine graphene exposed to cultured kidney tubular epithelial cells is capable of inducing DNA fragmentation measured by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, which is usually associated with cell death. TUNEL (cell death) and endonuclease activity measured using a near infrared fluorescence probe was significantly higher in cells containing graphene aggregates detected by Raman spectroscopy. The elevation of TUNEL coincided with the increased abundance of heme oxygenase 1 (HO-1), heat shock protein 90 (HSP90), active caspase-3 and endonucleases (deoxyribonuclease I [DNase I] and endonuclease G [EndoG]), as measured by quantitative immunocytochemistry. Specific inhibitors for HO-1, HSP90, caspase-3, DNase I and EndoG almost completely blocked the DNA fragmentation induced by graphene exposure. Therefore, graphene induces cell death through oxidative injury, caspase-mediated and caspase-independent pathways; and endonucleases DNase I and EndoG are important for graphene toxicity. Inhibition of these pathways may ameliorate cell injury produced by graphene. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Dano ao DNA , Desoxirribonuclease I/metabolismo , Endodesoxirribonucleases/metabolismo , Células Epiteliais/efeitos dos fármacos , Grafite/toxicidade , Túbulos Renais/efeitos dos fármacos , Nanopartículas/toxicidade , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular , Desoxirribonuclease I/antagonistas & inibidores , Relação Dose-Resposta a Droga , Endodesoxirribonucleases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Células Epiteliais/enzimologia , Células Epiteliais/patologia , Proteínas de Choque Térmico HSP90/metabolismo , Heme Oxigenase (Desciclizante)/antagonistas & inibidores , Heme Oxigenase (Desciclizante)/metabolismo , Túbulos Renais/enzimologia , Túbulos Renais/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Medição de Risco , Fatores de Tempo
11.
Nutr Metab (Lond) ; 13: 54, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27547236

RESUMO

BACKGROUND: 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), a heterocyclic aromatic amine (HCA) formed in meat that is cooked at high temperatures and then ingested, can potentially be retained in human adipose tissues. METHODS: To determine if PhIP is bioactive in the adipocyte, we exposed a human adipocyte cell line,HepG2 and Caco-2 cells to low dose PhIP. Uptake and retention of PhIP was determined and cytotoxicity was assessed by the TUNEL assay. Relative expression of PhIP-activating genes (CYP1A1, CYP1A2, SULT1A1 and UGT1A1) was determined by RT-PCR and global expression changes were also examined. RESULTS: The percent retention of 0.1 µCi [(14)C]-PhIP over a 24 h period was significantly higher in the adipocyte than the HepG2 (p = 0.0001) and Caco-2 (p = 0.0007) cell lines. Cytotoxicity rates were 14.4 and 2.6 % higher compared to controls in Caco-2 and HepG2 cells (p < 0.001 and 0.054, respectively); no significant differences were detected in adipocyte cells (p = 0.18). Caco-2 and HepG2 cells, respectively, had significantly higher basal expression of CYP1A1 (p = 0.001, p = 0.003), SULT1A1 (p = 0.04, p < 0.001) and UGT1A1 (p < 0.001, p = 0.01) compared to the adipocyte. Exposure to 5nM PhIP did not significantly induce expression of these genes in any of the cell lines. Global gene expression analysis of mature adipocytes exposed to 5nM PhIP for 72 h resulted in statistically significant changes in 8 genes (ANGPTL2, CD14, CIDEA, EGR1, FOS, IGFBP5, PALM and PSAT1). Gene-gene interaction and pathway analysis indicates that PhIP modulates genes controlled by the STAT3 transcriptional factor and initiates leptin signaling via the JAK/STAT and MAPK pathway cascades. Early growth response 1 (EGR1) and prostaglandin synthase 2 (COX-2) were down-regulated via c-Fos, while insulin binding protein 5 (IBP5) was up regulated. Expression of transcription factors (ANGPTL2, HP, LEP, SAA1, SAA2), genes related to inflammation (SAA1, LEP), diabetes (IGFBP5) and cancer risk (SAA2) were also elevated upon exposure to 5 nM PhIP.. CONCLUSIONS: PhIP mediates gene expression changes within the adipocyte, and the pathways most affected are related to cancer and other chronic diseases. Further studies are needed on the relationship between dietary carcinogens such as PhIP with cancer, obesity and diabetes.

12.
DNA Cell Biol ; 34(5): 316-26, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25849439

RESUMO

Cells contain several apoptotic endonucleases, which appear to act simultaneously before and after cell death by destroying the host cell DNA. It is largely unknown how the endonucleases are being induced and whether they can regulate each other. This study was performed to determine whether apoptotic mitochondrial endonuclease G (EndoG) can regulate expression of other apoptotic endonucleases. The study showed that overexpression of mature EndoG in kidney tubular epithelial NRK-52E cells can increase expression of caspase-activated DNase (CAD) and four endonucleases that belong to DNase I group including DNase I, DNase X, DNase IL2, and DNase γ, but not endonucleases of the DNase 2 group. The induction of DNase I-type endonucleases was associated with DNA degradation in promoter/exon 1 regions of the endonuclease genes. These results together with findings on colocalization of immunostained endonucleases and TUNEL suggest that DNA fragmentation after EndoG overexpression was caused by DNase I endonucleases and CAD in addition to EndoG itself. Overall, these data provide first evidence for the existence of the integral network of apoptotic endonucleases regulated by EndoG.


Assuntos
Apoptose , Fragmentação do DNA , Desoxirribonuclease I/metabolismo , Desoxirribonucleases/metabolismo , Endodesoxirribonucleases/metabolismo , Regulação Enzimológica da Expressão Gênica , Animais , Western Blotting , Encéfalo/citologia , Encéfalo/metabolismo , Células Cultivadas , Desoxirribonuclease I/genética , Desoxirribonucleases/genética , Endodesoxirribonucleases/genética , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Citometria de Fluxo , Processamento de Imagem Assistida por Computador , Técnicas Imunoenzimáticas , Marcação In Situ das Extremidades Cortadas , Túbulos Renais/citologia , Túbulos Renais/metabolismo , RNA Mensageiro/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
DNA Cell Biol ; 34(2): 92-100, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25401220

RESUMO

Apoptotic endonuclease G (EndoG) is responsible for DNA fragmentation both during and after cell death. Previous studies demonstrated that genetic inactivation of EndoG is cytoprotective against various pro-apoptotic stimuli; however, specific inhibitors for EndoG are not available. In this study, we have developed a high-throughput screening assay for EndoG and have used it to screen a chemical library. The screening resulted in the identification of two potent EndoG inhibitors, PNR-3-80 and PNR-3-82, which are thiobarbiturate analogs. As determined by their IC50s, the inhibitors are more potent than ZnCl2 or EDTA. They inhibit EndoG at one or two orders of magnitude greater than another apoptotic endonuclease, DNase I, and do not inhibit the other five tested cell death-related enzymes: DNase II, RNase A, proteinase, lactate dehydrogenase, and superoxide dismutase 1. Exposure of natural EndoG-expressing 22Rv1 or EndoG-overexpressing PC3 cells rendered them significantly resistant to Cisplatin and Docetaxel, respectively. These novel EndoG inhibitors have the potential to be utilized for amelioration of cell injuries in which participation of EndoG is essential.


Assuntos
Apoptose/efeitos dos fármacos , Endodesoxirribonucleases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Antineoplásicos/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Docetaxel , Relação Dose-Resposta a Droga , Resistência a Medicamentos , Endodesoxirribonucleases/metabolismo , Inibidores Enzimáticos/química , Humanos , Cinética , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/química , Taxoides/farmacologia , Tiobarbitúricos/química , Tiobarbitúricos/farmacologia
14.
Sci Rep ; 4: 4752, 2014 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-24810323

RESUMO

Nanotechnology has been extensively explored for cancer diagnostics. However, the specificity of current methods to identify simultaneously several cancer biomarkers is limited due to color overlapping of bio-conjugated nanoparticles. Here, we present a technique to increase both the molecular and spectral specificity of cancer diagnosis by using tunable silver-gold nanorods with narrow surface-enhanced Raman scattering (SERS) and high photothermal contrast. The silver-gold nanorods were functionalized with four Raman-active molecules and four antibodies specific to breast cancer markers and with leukocyte-specific CD45 marker. More than two orders of magnitude of SERS signal enhancement was observed from these hybrid nanosystems compared to conventional gold nanorods. Using an antibody rainbow cocktail, we demonstrated highly specific detection of single breast cancer cells in unprocessed human blood. By integrating multiplex targeting, multicolor coding, and multimodal detection, our approach has the potential to improve multispectral imaging of individual tumor cells in complex biological environments.


Assuntos
Neoplasias da Mama/diagnóstico , Ouro/química , Nanotubos/química , Células Neoplásicas Circulantes/química , Células Neoplásicas Circulantes/metabolismo , Prata/química , Anticorpos/química , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/sangue , Neoplasias da Mama/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Humanos , Antígenos Comuns de Leucócito/metabolismo , Células MCF-7 , Nanopartículas Metálicas , Sensibilidade e Especificidade , Análise Espectral Raman/métodos , Ressonância de Plasmônio de Superfície/métodos
15.
Environ Mol Mutagen ; 55(5): 428-35, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24535919

RESUMO

Respiratory mortality and morbidity has been associated with exposure to particulate matter (PM). Experimental evidence suggests involvement of cytotoxicity, oxidative stress, and inflammation in the development of PM-associated pathological states; however, the exact mechanisms remain unclear. In the current study, we analyzed short-term epigenetic response to PM10 (particles with aerodynamic diameter less than 10 µm) exposure in mouse ascitic RAW264.7 macrophages (BALB/C Abelson murine leukemia virus-induced tumor). Ambient PM10 was collected using a high volume sampler in Little Rock, AR. Analysis revealed that PM10 was composed mainly of Al and Fe, and the water soluble organic fraction was dominated by aliphatic and carbohydrate fragments and minor quantities of aromatic components. Exposure to PM10 compromised the cellular epigenome at concentrations 10-200 µg/ml. Specifically, epigenetic alterations were evident as changes in the methylation and expression of repetitive element-associated DNA and associated DNA methylation machinery. These results suggest that epigenetic alterations, in concert with cytotoxicity, oxidative stress, and inflammation, might contribute to the pathogenesis of PM-associated respiratory diseases.


Assuntos
Metilação de DNA/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Inflamação/induzido quimicamente , Macrófagos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/toxicidade , Sequências Repetitivas de Ácido Nucleico/efeitos dos fármacos , 5-Metilcitosina/análise , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Marcação In Situ das Extremidades Cortadas , L-Lactato Desidrogenase/metabolismo , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Fator de Necrose Tumoral alfa/metabolismo
16.
J Atheroscler Thromb ; 20(12): 878-92, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24067603

RESUMO

AIM: Both oxidized LDL and carbamylated LDL are considered important for initiating atherosclerosis in patients with end-stage kidney disease through vascular endothelial cell dysfunction or injury. However their effects on each other and their relationship related to pro-atherosclerotic effects on endothelial cells and macrophages have not been investigated. In this study, we analyzed the competition between LDL carbamylation and oxidation, tested biological effects of carbamylated-oxidized LDL (coxLDL) toward the endothelial cells, assessed its ability to cause foam cell development, and determined the roles of scavenger receptors in this process. METHODS: Cross-competition between carbamylation and oxidation of LDL particles was tested using cell-free fluorescent ligand-receptor assay. Pro-atherogenic properties (cell proliferation, cytotoxicity, and foam cell formation) of all LDL isoforms were tested in vitro and ex vivo using endothelial cells and peritoneal macrophages. In addition, coxLDL was assessed in human sera and in vivo atherosclerotic plaques which were developed in mouse model of uremia-induced atherosclerosis. RESULTS: Our data suggest that there is potential competition between carbamylation and oxidation of LDL, and that oxidation is a much stronger inhibitor of carbamylation than vice versa. coxLDL is highly cytotoxic to endothelial cells and strongly induce their proliferation measured by DNA synthesis. All three tested LDL isoforms demonstrated strong ability for transformation of primary mouse peritoneal macrophages to foam cells using predominantly CD36 scavenger receptor. coxLDL was the most potent inducer of foam cell development and macrophages/foam cell injury assessed by cell count and TUNEL, respectively. Finally, LDL particles modified by oxidation and carbamylation were detected in blood and shown to co-localize in atherosclerotic plaques in mice. CONCLUSION: Our study demonstrated that LDL particles can be simultaneously carbamylated and oxidized and modifications are likely coexisting in the same LDL particle. We also demonstrated proatherosclerotic properties of coxLDL and proposed its role in atherosclerosis.


Assuntos
Aterosclerose/metabolismo , Carbamatos/metabolismo , Endotélio Vascular/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Morte Celular , Células Cultivadas , Endotélio Vascular/citologia , Ensaio de Imunoadsorção Enzimática , Humanos , Marcação In Situ das Extremidades Cortadas , Oxirredução
17.
Am J Physiol Renal Physiol ; 305(7): F1022-30, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23825076

RESUMO

Cold storage of kidneys before transplantation is problematic because of the limited survival time of the allografts. In this study, zinc-N-acetylcysteine (ZnNAC) was shown to be a potent endonuclease inhibitor and antioxidant, and it was tested as a potential additive to a cold storage solution for kidney preservation. Exposure of normal rat kidney NRK-52E cells to ZnNAC resulted in zinc delivery to the cells as determined by TFL-Zn fluorophore and partial protection of the cells against injury by cold storage in University of Wisconsin solution (UWS) as measured by propidium iodide assay. Ex vivo, rat kidneys demonstrated time- and temperature-dependent DNA fragmentation as assessed by TUNEL assay, indicating irreversible cell death. DNA fragmentation was faster in the medulla than in the cortex, and tubules were affected more than glomeruli. Perfusion of rat kidneys with cold ZnNAC solution in UWS significantly inhibited cell death both in the cortex and medulla at concentrations of 0.3-30 mM compared with UWS alone, with a maximum effect at 1-10 mM ZnNAC. Cold storage of the kidney significantly increased quantities of cleaved caspase-3 and endonuclease G (EndoG) in the tissue, which were abolished by 10 mM ZnNAC, indicating its ability to suppress both caspase-dependent and -independent cell death. Therefore, supplementation of UWS with ZnNAC can decrease DNA fragmentation and protect kidney allografts from cell death due to cold storage.


Assuntos
Acetilcisteína/farmacologia , Rim/efeitos dos fármacos , Preservação de Órgãos , Acetilcisteína/química , Animais , Antioxidantes/análise , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Endonucleases/antagonistas & inibidores , Células Epiteliais/enzimologia , Marcação In Situ das Extremidades Cortadas , Rim/enzimologia , Masculino , Soluções para Preservação de Órgãos/química , Ratos , Ratos Sprague-Dawley , Refrigeração , Acetato de Zinco/química
18.
PLoS One ; 7(9): e45557, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23049814

RESUMO

Bacterial infections are a primary cause of morbidity and mortality worldwide. Bacteremia is a particular concern owing to the possibility of septic shock and the development of metastatic infections. Treatment of bacteremia is increasingly compromised by the emergence of antibiotic resistant strains, creating an urgent need for alternative therapy. Here, we introduce a method for in vivo photoacoustic (PA) detection and photothermal (PT) eradication of Staphylococcus aureus in tissue and blood. We show that this method could be applicable for label-free diagnosis and treatment of in the bloodstream using intrinsic near-infrared absorption of endogenous carotenoids with nonlinear PA and PT contrast enhancement. To improve sensitivity and specificity for detection of circulating bacteria cells (CBCs), two-color gold and multilayer magnetic nanoparticles with giant amplifications of PA and PT contrasts were functionalized with an antibody cocktail for molecular targeting of S. aureus surface-associated markers such as protein A and lipoprotein. With a murine model, the utility of this approach was demonstrated for ultrasensitive detection of CBCs with threshold sensitivity as low as 0.5 CBCs/mL, in vivo magnetic enrichment of CBCs, PT eradication of CBCs, and real-time monitoring of therapeutic efficacy by CBC counting. Our PA-PT nano-theranostic platform, which integrates in vivo multiplex targeting, magnetic enrichment, signal amplification, multicolor recognition, and feedback control, could be used as a biological tool to gain insights on dissemination pathways of CBCs, infection progression by bacteria re-seeding, and sepsis development and treatment, and could potentially be feasible in humans, especially using bypass schematic.


Assuntos
Bacteriemia/diagnóstico , Bacteriemia/terapia , Carotenoides/química , Nanopartículas de Magnetita/administração & dosagem , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/terapia , Animais , Anticorpos/química , Anticorpos/imunologia , Bacteriemia/microbiologia , Carotenoides/metabolismo , Cor , Terapias Complementares , Ouro/química , Temperatura Alta , Humanos , Lasers , Luz , Lipoproteínas/química , Lipoproteínas/imunologia , Camundongos , Camundongos Nus , Imagem Molecular , Técnicas Fotoacústicas , Processos Fotoquímicos , Ratos , Infecções Estafilocócicas/microbiologia , Proteína Estafilocócica A/química , Proteína Estafilocócica A/imunologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/efeitos da radiação
19.
Am J Physiol Gastrointest Liver Physiol ; 300(1): G109-19, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21051528

RESUMO

Male Sprague-Dawley rats were chronically fed a high-unsaturated-fat diet for 130 days by using total enteral nutrition (TEN), or the same diet in which ethanol (EtOH) isocalorically replaced carbohydrate calories. Additional groups were supplemented with the antioxidant N-acetylcysteine (NAC) at 1.7 g·kg(-1)·day(-1). Relative to an ad libitum chow-fed group, the high-fat-fed controls had three- to fourfold greater expression of fatty acid transporter CD36 mRNA and developed mild steatosis but little other hepatic pathology. NAC treatment resulted in increased somatic growth relative to controls (4.0 ± 0.1 vs. 3.1 ± 0.1 g/day) and increased hepatic steatosis score (3.5 ± 0.6 vs. 2.7 ± 1.2), associated with suppression of the triglyceride hydrolyzing protein adiponutrin, but produced no elevation in serum alanine aminotransferase (ALT). Chronic EtOH treatment increased expression of fatty acid transport protein FATP-2 mRNA twofold, resulting in marked hepatic steatosis, oxidative stress, and a twofold elevation in serum ALT. However, no changes in tumor necrosis factor-α or transforming growth factor-ß expression were observed. Fibrosis, as measured by Masson's trichrome and picrosirius red staining, and a twofold increase in expression of type I and type III collagen mRNA, was only observed after EtOH treatment. Long-term EtOH treatment increased hepatocyte proliferation but did not modify the hepatic mRNAs for hedgehog pathway ligands or target genes or genes regulating epithelial-to-mesenchymal transition. Although the effects of NAC on EtOH-induced fibrosis could not be fully evaluated, NAC had additive effects on hepatocyte proliferation and prevented EtOH-induced oxidative stress and necrosis, despite a failure to reverse hepatic steatosis.


Assuntos
Etanol/toxicidade , Fígado Gorduroso/etiologia , Hepatopatias Alcoólicas/metabolismo , Fígado/efeitos dos fármacos , Acetilcisteína/farmacologia , Acetilcisteína/uso terapêutico , Animais , Proliferação de Células/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Gorduras na Dieta/administração & dosagem , Nutrição Enteral , Etanol/farmacologia , Fígado Gorduroso/patologia , Proteínas Hedgehog/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/patologia , Hepatopatias Alcoólicas/patologia , Regeneração Hepática/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos
20.
Adv Clin Chem ; 51: 25-52, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20857617

RESUMO

Nonenzymatic modification of protein by cyanate, that is, carbamylation, has received new attention due to its apparent relevance in atherosclerosis. For example, carbamylation of low-density lipoprotein (LDL) is an important mechanism that potentially impacts high-risk atherosclerotic individuals with increased urea (renal insufficiency) or thiocyanate (tobacco smoking). Carbamylated LDL (cLDL) is increased in patients with end-stage kidney disease, especially those with atherosclerosis. In addition, cLDL exhibits distinct cytotoxic effects when tested in vitro on endothelial cells, induces the expression of adhesion molecules, and aggravates the monocyte adhesion to endothelial cells. It also facilitates the proliferation of vascular smooth-muscle cell (VSMC). Studies of potential pharmacological interruption of these processes in vivo may lead to discoveries of novel therapies for atherosclerosis.


Assuntos
Lipoproteínas LDL/fisiologia , Animais , Aterosclerose/etiologia , Autoanticorpos/sangue , Proteínas Sanguíneas/metabolismo , Adesão Celular , Proliferação de Células , Células Cultivadas , Células Endoteliais/fisiologia , Humanos , Lipoproteínas LDL/imunologia , Monócitos/fisiologia , Uremia/complicações
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