RESUMO
The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and onset of the coronavirus disease-19 (COVID-19) pandemic led to an immediate need for therapeutic treatment options. Therapeutic antibodies were developed to fill a gap when traditional antivirals were not available. In late 2020, the United States Government undertook an effort to compare candidate therapeutic antibodies in virus neutralization assays and in the hamster model of SARS-CoV-2 infection. With the emergence of SARS-CoV-2 variants, the effort expanded to evaluate the efficacy of nearly 50 products against major variants. A subset of products was further evaluated for therapeutic efficacy in hamsters. Here we report results of the hamster studies, including pathogenicity with multiple variants, neutralization capacity of products, and efficacy testing of products against Delta and Omicron variants. These studies demonstrate the loss of efficacy of early products with variant emergence and support the use of the hamster model for evaluating therapeutics.
RESUMO
The pathophysiology of long-recognized hematologic abnormalities in Ebolavirus (EBOV) disease (EVD) is unknown. From limited human sampling (of peripheral blood), it has been postulated that emergency hematopoiesis plays a role in severe EVD, but the systematic characterization of the bone marrow (BM) has not occurred in human disease or in nonhuman primate models. In a lethal rhesus macaque model of EVD, 18 sternal BM samples exposed to the Kikwit strain of EBOV were compared to those from uninfected controls (n = 3). Immunohistochemistry, RNAscope in situ hybridization, transmission electron microscopy, and confocal microscopy showed that EBOV infects BM monocytes/macrophages and megakaryocytes. EBOV exposure was associated with severe BM hypocellularity, including depletion of myeloid, erythroid, and megakaryocyte hematopoietic cells. These depletions were negatively correlated with cell proliferation (Ki67 expression) and were not associated with BM apoptosis during disease progression. In EBOV-infected rhesus macaques with terminal disease, BM showed marked hemophagocytosis, megakaryocyte emperipolesis, and the release of immature hematopoietic cells into the sinusoids. Collectively, these data demonstrate not only direct EBOV infection of BM monocytes/macrophages and megakaryocytes but also that disease progression is associated with hematopoietic failure, notably in peripheral cytopenia. These findings inform current pathophysiologic unknowns and suggest a crucial role for BM dysfunction and/or failure, including emergency hematopoiesis, as part of the natural history of severe human disease.
Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Animais , Humanos , Ebolavirus/fisiologia , Macaca mulatta , Medula Óssea , Progressão da DoençaRESUMO
BACKGROUND: Ebola virus (EBOV) disease (EVD) is one of the most severe and fatal viral hemorrhagic fevers and appears to mimic many clinical and laboratory manifestations of hemophagocytic lymphohistiocytosis syndrome (HLS), also known as macrophage activation syndrome. However, a clear association is yet to be firmly established for effective host-targeted, immunomodulatory therapeutic approaches to improve outcomes in patients with severe EVD. METHODS: Twenty-four rhesus monkeys were exposed intramuscularly to the EBOV Kikwit isolate and euthanized at prescheduled time points or when they reached the end-stage disease criteria. Three additional monkeys were mock-exposed and used as uninfected controls. RESULTS: EBOV-exposed monkeys presented with clinicopathologic features of HLS, including fever, multiple organomegaly, pancytopenia, hemophagocytosis, hyperfibrinogenemia with disseminated intravascular coagulation, hypertriglyceridemia, hypercytokinemia, increased concentrations of soluble CD163 and CD25 in serum, and the loss of activated natural killer cells. CONCLUSIONS: Our data suggest that EVD in the rhesus macaque model mimics pathophysiologic features of HLS/macrophage activation syndrome. Hence, regulating inflammation and immune function might provide an effective treatment for controlling the pathogenesis of acute EVD.
Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Linfo-Histiocitose Hemofagocítica , Síndrome de Ativação Macrofágica , Animais , Síndrome de Ativação Macrofágica/terapia , Macaca mulattaRESUMO
The COVID-19 pandemic spurred the rapid development of a range of therapeutic antibody treatments. As part of the US government's COVID-19 therapeutic response, a research team was assembled to support assay and animal model development to assess activity for therapeutics candidates against SARS-CoV-2. Candidate treatments included monoclonal antibodies, antibody cocktails, and products derived from blood donated by convalescent patients. Sixteen candidate antibody products were obtained directly from manufacturers and evaluated for neutralization activity against the WA-01 isolate of SARS-CoV-2. Products were further tested in the Syrian hamster model using prophylactic (-24 h) or therapeutic (+8 h) treatment approaches relative to intranasal SARS-CoV-2 exposure. In vivo assessments included daily clinical scores and body weights. Viral RNA and viable virus titers were quantified in serum and lung tissue with histopathology performed at 3d and 7d post-virus-exposure. Sham-treated, virus-exposed hamsters showed consistent clinical signs with concomitant weight loss and had detectable viral RNA and viable virus in lung tissue. Histopathologically, interstitial pneumonia with consolidation was present. Therapeutic efficacy was identified in treated hamsters by the absence or diminution of clinical scores, body weight loss, viral loads, and improved semiquantitative lung histopathology scores. This work serves as a model for the rapid, systematic in vitro and in vivo assessment of the efficacy of candidate therapeutics at various stages of clinical development. These efforts provided preclinical efficacy data for therapeutic candidates. Furthermore, these studies were invaluable for the phenotypic characterization of SARS CoV-2 disease in hamsters and of utility to the broader scientific community.
Assuntos
COVID-19 , SARS-CoV-2 , Cricetinae , Animais , Humanos , Mesocricetus , Pandemias , Anticorpos Monoclonais/uso terapêutico , Modelos Animais de Doenças , RNA ViralRESUMO
This study compared disease progression of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in three different models of golden hamsters: aged (≈60 weeks old) wild-type (WT), young (6 weeks old) WT, and adult (14-22 weeks old) hamsters expressing the human-angiotensin-converting enzyme 2 (hACE2) receptor. After intranasal (IN) exposure to the SARS-CoV-2 Washington isolate (WA01/2020), 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography with computed tomography (18F-FDG PET/CT) was used to monitor disease progression in near real time and animals were euthanized at pre-determined time points to directly compare imaging findings with other disease parameters associated with coronavirus disease 2019 (COVID-19). Consistent with histopathology, 18F-FDG-PET/CT demonstrated that aged WT hamsters exposed to 105 plaque forming units (PFU) developed more severe and protracted pneumonia than young WT hamsters exposed to the same (or lower) dose or hACE2 hamsters exposed to a uniformly lethal dose of virus. Specifically, aged WT hamsters presented with a severe interstitial pneumonia through 8 d post-exposure (PE), while pulmonary regeneration was observed in young WT hamsters at that time. hACE2 hamsters exposed to 100 or 10 PFU virus presented with a minimal to mild hemorrhagic pneumonia but succumbed to SARS-CoV-2-related meningoencephalitis by 6 d PE, suggesting that this model might allow assessment of SARS-CoV-2 infection on the central nervous system (CNS). Our group is the first to use (18F-FDG) PET/CT to differentiate respiratory disease severity ranging from mild to severe in three COVID-19 hamster models. The non-invasive, serial measure of disease progression provided by PET/CT makes it a valuable tool for animal model characterization.
Assuntos
COVID-19 , Pneumonia , Humanos , Animais , Cricetinae , COVID-19/diagnóstico por imagem , SARS-CoV-2 , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Enzima de Conversão de Angiotensina 2 , Tomografia por Emissão de Pósitrons , Mesocricetus , Progressão da DoençaRESUMO
The pathogenesis of Ebola virus disease (EVD) is still incomplete, in spite of the availability of a nonhuman primate modelfor more than 4 decades. To further investigate EVD pathogenesis, a natural history study was conducted using 27 Chinese-origin rhesus macaques. Of these, 24 macaques were exposed intramuscularly to Kikwit Ebola virus and euthanized at predetermined time points or when end-stage clinical disease criteria were met, and 3 sham-exposed macaques were euthanized on study day 0. This study showed for the first time that Ebola virus causes uterine cervicitis, vaginitis, posthitis, and medullary adrenalitis. Not only was Ebola virus detected in the interstitial stromal cells of the genital tract, but it was also present in the epididymal and seminal vesicular tubular epithelial cells, ectocervical and vaginal squamous epithelial cells, and seminal fluid. Furthermore, as early as day 3 after exposure, Ebola virus replicative intermediate RNA was detected in Kupffer cells and hepatocytes. These findings in the nonhuman model provide additional insight into potential sexual transmission, possible disruption of sympathetic hormone production, and early virus replication sites in human EVD patients.
Assuntos
Ebolavirus/fisiologia , Hormônios/metabolismo , Fígado/virologia , Tropismo/fisiologia , Replicação Viral/fisiologia , Animais , Células Cromafins/patologia , Células Cromafins/virologia , Modelos Animais de Doenças , Epididimo/patologia , Epididimo/virologia , Células Epiteliais/patologia , Células Epiteliais/virologia , Feminino , Hepatócitos/patologia , Hepatócitos/virologia , Células de Kupffer/patologia , Células de Kupffer/virologia , Macaca mulatta , Masculino , Cervicite Uterina/patologia , Cervicite Uterina/virologia , Vaginite/patologia , Vaginite/virologiaRESUMO
Ongoing Ebola virus disease outbreaks in the Democratic Republic of the Congo follow the largest recorded outbreak in Western Africa (2013-2016). To combat outbreaks, testing of medical countermeasures (therapeutics or vaccines) requires a well-defined, reproducible, animal model. Here we present Ebola virus disease kinetics in 24 Chinese-origin rhesus monkeys exposed intramuscularly to a highly characterized, commercially available Kikwit Ebola virus Filovirus Animal Non-Clinical Group (FANG) stock. Until reaching predetermined clinical disease endpoint criteria, six animals underwent anesthesia for repeated clinical sampling and were compared to six that did not. Groups of three animals were euthanized and necropsied on days 3, 4, 5, and 6 post-exposure, respectively. In addition, three uninfected animals served as controls. Here, we present detailed characterization of clinical and laboratory disease kinetics and complete blood counts, serum chemistries, Ebola virus titers, and disease kinetics for future medical countermeasure (MCM) study design and control data. We measured no statistical difference in hematology, chemistry values, or time to clinical endpoint in animals that were anesthetized for clinical sampling during the acute disease compared to those that were not.
Assuntos
Modelos Animais de Doenças , Ebolavirus/patogenicidade , Doença pelo Vírus Ebola/fisiopatologia , Macaca mulatta , Animais , Progressão da Doença , Ebolavirus/classificação , Feminino , Masculino , Carga Viral , ViremiaRESUMO
Neurological signs and symptoms are the most common complications of Ebola virus disease. However, the mechanisms underlying the neurologic manifestations in Ebola patients are not known. In this study, peripheral ganglia were collected from 12 rhesus macaques that succumbed to Ebola virus (EBOV) disease from 5 to 8 days post exposure. Ganglionitis, characterized by neuronal degeneration, necrosis, and mononuclear leukocyte infiltrates, was observed in the dorsal root, autonomic, and enteric ganglia. By immunohistochemistry, RNAscope in situ hybridization, transmission electron microscopy, and confocal microscopy, we confirmed that CD68+ macrophages are the target cells for EBOV in affected ganglia. Further, we demonstrated that EBOV can induce satellite cell and neuronal apoptosis and microglial activation in infected ganglia. Our results demonstrate that EBOV can infect peripheral ganglia and results in ganglionopathy in rhesus macaques, which may contribute to the neurological signs and symptoms observed in acute and convalescent Ebola virus disease in human patients.
Assuntos
Doença pelo Vírus Ebola/complicações , Doença pelo Vírus Ebola/patologia , Degeneração Neural/complicações , Degeneração Neural/patologia , Doenças do Sistema Nervoso Periférico/complicações , Doenças do Sistema Nervoso Periférico/patologia , Animais , Antígenos CD , Antígenos de Diferenciação Mielomonocítica , Modelos Animais de Doenças , Ebolavirus , Feminino , Gânglios , Gânglios Espinais/patologia , Gânglios Espinais/virologia , Cistos Glanglionares/patologia , Doença pelo Vírus Ebola/virologia , Humanos , Imuno-Histoquímica , Leucócitos Mononucleares , Macaca mulatta , Macrófagos/patologia , Masculino , Microglia/patologia , Microglia/virologia , Necrose , Sistema Nervoso Parassimpático/patologia , Doenças do Sistema Nervoso Periférico/virologia , Células Receptoras Sensoriais/patologia , Células Receptoras Sensoriais/virologia , Sistema Nervoso Simpático/patologiaRESUMO
The most commonly reported symptom of post-Ebola virus disease syndrome in survivors is arthralgia, yet involvement of the joints in acute or convalescent Ebola virus infection is not well characterized in human patients or animal models. Through immunohistochemistry, we found that the lining synovial intima of the stifle (knee) is a target for acute infection by Ebola virus/Kikwit, Ebola virus/Makona-C05, and Marburg virus/Angola in the rhesus macaque model. Furthermore, histologic analysis, immunohistochemistry, RNAscope in situ hybridization, and transmission electron microscopy showed that synoviocytes of the stifle, shoulder, and hip are a target for mouse-adapted Ebola virus/Yambuku-Mayinga infection during acute disease in rhesus macaques. A time course of infection study with Ebola virus/Kikwit found that the large joint synovium became immunopositive beginning on postinfection day 6. In total, the synovium of 28 of 30 rhesus macaques with terminal filovirus disease had evidence of infection (64 of 96 joints examined). On the basis of immunofluorescence, infected cell types included CD68+ type A (macrophage-like) synoviocytes and CD44+ type B (fibroblast-like) synoviocytes. Cultured primary human fibroblast-like synoviocytes were permissive to infection with Ebola and Marburg viruses in vitro. Because synovial joints include immune privileged sites, these findings are significant for future investigations of filovirus pathogenesis and persistence as well as arthralgias in acute and convalescent filovirus disease.
Assuntos
Infecções por Filoviridae/virologia , Sinoviócitos/virologia , Animais , Células Cultivadas , Filoviridae , Humanos , Macaca mulattaRESUMO
Simian hemorrhagic fever virus (SHFV) causes a fulminant and typically lethal viral hemorrhagic fever (VHF) in macaques (Cercopithecinae: Macaca spp.) but causes subclinical infections in patas monkeys (Cercopithecinae: Erythrocebus patas). This difference in disease course offers a unique opportunity to compare host responses to infection by a VHF-causing virus in biologically similar susceptible and refractory animals. Patas and rhesus monkeys were inoculated side-by-side with SHFV. Unlike the severe disease observed in rhesus monkeys, patas monkeys developed a limited clinical disease characterized by changes in complete blood counts, serum chemistries, and development of lymphadenopathy. Viral RNA was measurable in circulating blood 2 days after exposure, and its duration varied by species. Infectious virus was detected in terminal tissues of both patas and rhesus monkeys. Varying degrees of overlap in changes in serum concentrations of interferon (IFN)-γ, monocyte chemoattractant protein (MCP)-1, and interleukin (IL)-6 were observed between patas and rhesus monkeys, suggesting the presence of common and species-specific cytokine responses to infection. Similarly, quantitative immunohistochemistry of livers from terminal monkeys and whole blood flow cytometry revealed varying degrees of overlap in changes in macrophages, natural killer cells, and T-cells. The unexpected degree of overlap in host response suggests that relatively small subsets of a host's response to infection may be responsible for driving hemorrhagic fever pathogenesis. Furthermore, comparative SHFV infection in patas and rhesus monkeys offers an experimental model to characterize hostâ»response mechanisms associated with viral hemorrhagic fever and evaluate pan-viral hemorrhagic fever countermeasures.
Assuntos
Infecções por Arterivirus/veterinária , Arterivirus/patogenicidade , Febres Hemorrágicas Virais/veterinária , Interações Hospedeiro-Patógeno , Doenças dos Macacos/imunologia , Animais , Anticorpos Antivirais/sangue , Arterivirus/imunologia , Infecções por Arterivirus/imunologia , Citocinas/sangue , Erythrocebus , Feminino , Febres Hemorrágicas Virais/imunologia , Macaca , Macrófagos/virologia , Masculino , Doenças dos Macacos/virologia , RNA Viral , Replicação ViralRESUMO
Lassa fever (LF) survivors develop various clinical manifestations including polyserositis, myalgia, epididymitis, and hearing loss weeks to months after recovery from acute infection. We demonstrate a systemic lymphoplasmacytic and histiocytic arteritis and periarteritis in guinea pigs more than 2 months after recovery from acute Lassa virus (LASV) infection. LASV was detected in the arterial tunica media smooth muscle cells by immunohistochemistry, in situ hybridization, and transmission electron microscopy. Our results suggest that the sequelae of LASV infection may be due to virus persistence resulting in systemic vascular damage. These findings shed light on the pathogenesis of LASV sequelae in convalescent human survivors.
Assuntos
Febre Lassa/virologia , Vírus Lassa/imunologia , Animais , Convalescença , Modelos Animais de Doenças , Progressão da Doença , Feminino , Cobaias , Humanos , Imuno-Histoquímica , Inflamação , Febre Lassa/patologia , MasculinoRESUMO
Radiation injury to the lung is the result of acute and chronic free radical formation, and there are currently few effective means of mitigating such injury. Studies in rodents indicate that superoxide dismutase mimetics may be effective in this regard; however, studies in humans or large animals are lacking. We hypothesized that post-exposure treatment with the lipophilic mitochondrial superoxide dismutase mimetic, MnTnHex-2-PyP5+ (hexyl), would reduce radiation-induced pneumonitis and fibrosis in the lungs of nonhuman primates. Rhesus monkeys (Macaca mulatta) received 10 Gy whole thorax irradiation, 10 Gy + hexyl treatment, sham irradiation, or sham irradiation + hexyl. Hexyl was given twice daily, subcutaneously, at 0.05 mg/kg, for 2 months. Animals were monitored daily, and respiratory rates, pulse oximetry, hematology and serum chemistry panels were performed weekly. Computed tomography scans were performed at 0, 2, and 4 months after irradiation. Supportive fluid therapy, corticosteroids, analgesics, and antibiotics were given as needed. All animals were humanely euthanized 4.5 months after irradiation, and pathologic assessments were made. Multifocal, progressive lung lesions were seen at 2 and 4 months in both irradiated groups. Hexyl treatment delayed the onset of radiation-induced lung lesions, reduced elevations of respiratory rate, and reduced pathologic increases in lung weight. No adverse effects of hexyl treatment were found. These results demonstrate (1) development of a nonhuman primate model of radiation-induced lung injury, (2) a significant mitigating effect of hexyl treatment on lung pathology in this model, and (3) no evidence for toxicity of hexyl at the dose studied.
RESUMO
Sexual transmission of Ebola virus (EBOV) has been demonstrated more than a year after recovery from the acute phase of Ebola virus disease (EVD). The mechanisms underlying EBOV persistence and sexual transmission are not currently understood. Using the acute macaque model of EVD, we hypothesized EBOV would infect the reproductive tissues and sought to localize the infection in these tissues using immunohistochemistry and transmission electron microscopy. In four female and eight male macaques that succumbed to EVD between 6 and 9 days after EBOV challenge, we demonstrate widespread EBOV infection of the interstitial tissues and endothelium in the ovary, uterus, testis, seminal vesicle, epididymis, and prostate gland, with minimal associated tissue immune response or organ pathology. Given the widespread involvement of EBOV in the reproductive tracts of both male and female macaques, it is reasonable to surmise that our understanding of the mechanisms underlying sexual transmission of EVD and persistence of EBOV in immune-privileged sites would be facilitated by the development of a nonhuman primate model in which the macaques survived past the acute stage into convalescence.
Assuntos
Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/virologia , Ovário/virologia , Próstata/virologia , Testículo/virologia , Útero/virologia , Animais , Feminino , Doença pelo Vírus Ebola/patologia , Macaca , Masculino , Ovário/patologia , Próstata/patologia , Testículo/patologia , Útero/patologiaRESUMO
The 2013-2016 West African Ebola virus (EBOV) disease outbreak was the largest filovirus outbreak to date. Over 28 000 suspected, probable, or confirmed cases have been reported, with a 53% case-fatality rate. The magnitude and international impact of this EBOV outbreak has highlighted the urgent need for a safe and efficient EBOV vaccine. To this end, we demonstrate the immunogenicity and protective efficacy of FILORAB1, a recombinant, bivalent, inactivated rabies virus-based EBOV vaccine, in rhesus and cynomolgus monkeys. Our results demonstrate that the use of the synthetic Toll-like receptor 4 agonist glucopyranosyl lipid A in stable emulsion (GLA-SE) as an adjuvant increased the efficacy of FILORAB1 to 100% protection against lethal EBOV challenge, with no to mild clinical signs of disease. Furthermore, all vaccinated subjects developed protective anti-rabies virus antibody titers. Taken together, these results support further development of FILORAB1/GLA-SE as an effective preexposure EBOV vaccine.
Assuntos
Vacinas contra Ebola/imunologia , Ebolavirus/imunologia , Glucosídeos/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Lipídeo A/imunologia , Vírus da Raiva/imunologia , Raiva/prevenção & controle , Adjuvantes Imunológicos , Animais , Anticorpos Antivirais/imunologia , Emulsões , Feminino , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Macaca fascicularis , Macaca mulatta , Masculino , Raiva/imunologia , Raiva/virologia , Vacina Antirrábica/imunologia , Receptor 4 Toll-Like/imunologia , Vacinas de Produtos Inativados/imunologia , Vacinas Sintéticas/imunologiaRESUMO
We previously demonstrated that small-particle (0.5-3.0 µm) aerosol infection of rhesus monkeys (Macaca mulatta) with cowpox virus (CPXV)-Brighton Red (BR) results in fulminant respiratory tract disease characterized by severe lung parenchymal pathology but only limited systemic virus dissemination and limited classic epidermal pox-like lesion development (Johnson et al., 2015). Based on these results, and to further develop CPXV as an improved model of human smallpox, we evaluated a novel large-particle aerosol (7.0-9.0 µm) exposure of rhesus monkeys to CPXV-BR and monitored for respiratory tract disease by serial computed tomography (CT). As expected, the upper respiratory tract and large airways were the major sites of virus-induced pathology following large-particle aerosol exposure. Large-particle aerosol CPXV exposure of rhesus macaques resulted in severe upper airway and large airway pathology with limited systemic dissemination.
Assuntos
Aerossóis , Vírus da Varíola Bovina/patogenicidade , Varíola Bovina/patologia , Varíola Bovina/virologia , Modelos Animais de Doenças , Infecções Respiratórias/patologia , Infecções Respiratórias/virologia , Animais , Macaca mulatta , Infecções Respiratórias/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
Baboons are susceptible to natural Ebola virus (EBOV) infection and share 96% genetic homology with humans. Despite these characteristics, baboons have rarely been utilized as experimental models of human EBOV infection to evaluate the efficacy of prophylactics and therapeutics in the United States. This review will summarize what is known about the pathogenesis of EBOV infection in baboons compared to EBOV infection in humans and other Old World nonhuman primates. In addition, we will discuss how closely the baboon model recapitulates human EBOV infection. We will also review some of the housing requirements and behavioral attributes of baboons compared to other Old World nonhuman primates. Due to the lack of data available on the pathogenesis of Marburg virus (MARV) infection in baboons, discussion of the pathogenesis of MARV infection in baboons will be limited.
Assuntos
Modelos Animais de Doenças , Ebolavirus/patogenicidade , Doença pelo Vírus Ebola/patologia , Doença do Vírus de Marburg/patologia , Papio/virologia , Animais , Sequência de Bases , Fatores de Coagulação Sanguínea/metabolismo , Fibrina/metabolismo , Doença pelo Vírus Ebola/metabolismo , Doença pelo Vírus Ebola/virologia , Humanos , Doenças Linfáticas/patologia , Doenças Linfáticas/virologia , Doença do Vírus de Marburg/metabolismo , Doença do Vírus de Marburg/virologia , Marburgvirus/patogenicidade , Necrose/patologia , Necrose/virologia , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Trombocitopenia/patologia , Trombocitopenia/virologiaRESUMO
A common treatment of advanced prostate cancer involves the deprivation of androgens. Despite the initial response to hormonal therapy, eventually all the patients relapse. In the present study, we sought to determine whether dietary polyunsaturated fatty acid (PUFA) affects the development of castration-resistant prostate cancer. Cell culture, patient tissue microarray, allograft, xenograft, prostate-specific Pten knockout and omega-3 desaturase transgenic mouse models in conjunction with dietary manipulation, gene knockdown and knockout approaches were used to determine the effect of dietary PUFA on castration-resistant Pten-null prostate cancer. We found that deletion of Pten increased androgen receptor (AR) expression and Pten-null prostate cells were castration resistant. Omega-3 PUFA slowed down the growth of castration-resistant tumors as compared with omega-6 PUFA. Omega-3 PUFA decreased AR protein to a similar extent in tumor cell cytosolic and nuclear fractions but had no effect on AR messenger RNA level. Omega-3 PUFA treatment appeared to accelerate AR protein degradation, which could be blocked by proteasome inhibitor MG132. Knockdown of AR significantly slowed down prostate cancer cell proliferation in the absence of androgens. Our data suggest that omega-3 PUFA inhibits castration-resistant prostate cancer in part by accelerating proteasome-dependent degradation of the AR protein. Dietary omega-3 PUFA supplementation in conjunction with androgen ablation may significantly delay the development of castration-resistant prostate cancer in patients compared with androgen ablation alone.
Assuntos
Gorduras Insaturadas na Dieta/farmacologia , Ácidos Graxos Ômega-3/farmacologia , Ácidos Graxos Insaturados/farmacologia , PTEN Fosfo-Hidrolase/deficiência , Neoplasias da Próstata/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Gorduras Insaturadas na Dieta/metabolismo , Resistencia a Medicamentos Antineoplásicos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Ômega-6/metabolismo , Ácidos Graxos Insaturados/metabolismo , Técnicas de Silenciamento de Genes/métodos , Técnicas de Inativação de Genes , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Knockout , Camundongos Nus , Camundongos Transgênicos , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Orquiectomia , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/cirurgia , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismoRESUMO
Short-term dietary studies of soy-protein-derived isoflavonoids, using rodent and nonhuman primate models, have documented variable effects on the reproductive tract. Long-term effects of dietary soy and/or isoflavonoids on the reproductive tract of nonhuman primates have not been determined. The objective of this study was to assess the effects of long-term consumption of dietary soy isoflavonoids on histomorphology of the mammary glands and prostate gland, testis, and sperm counts in adult male cynomolgus macaques. Ninety-one adult male cynomolgus macaques (Macaca fascicularis) were fed diets for 3 y differing only in protein source: 1) a soy-free, casein-lactalbumin-based diet or 2) a low-soy isoflavonoid diet ( approximately 6 mg . kg(-1) . d(-1)) or 3) a high-soy isoflavonoid diet ( approximately 12 mg . kg(-1) . d(-1)). Serum isoflavonoids were measured by liquid chromatographic-photodiode array electrospray MS. Mammary gland, prostate gland, and testes were obtained at postmortem and evaluated histopathologically and histomorphometrically. Epididymal and testicular sperm counts were performed. Serum isoflavonoid concentrations at 4 h postfeeding differed among all groups (P < 0.001) and were (means +/- SEM) 67 +/- 23 (soy-free diet), 799 +/- 44 (low-soy isoflavonoid diet), and 1458 +/- 80 nmol . L(-1) (high-soy isoflavonoid diet). Diet did not alter serum estradiol and testosterone concentrations or epididymal and testicular sperm counts. Organ weights and histologic indices did not differ among treatment groups. Mammary gland histopathologic and histomorphometric analysis revealed no abnormalities and no indication of gynecomastia. We found no evidence of an adverse effect of soy isoflavonoids at physiologically relevant doses within the reproductive organs of adult male macaques.