Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Environ Manage ; 70(6): 1078-1092, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36152066

RESUMO

High Island A-389-A (HI-A-389-A) is a gas platform situated in 125 m water within Flower Garden Banks National Marine Sanctuary in the northwestern Gulf of Mexico, and provides habitat to a diverse array of benthic organisms and fish species. Platform production ceased in 2012, beginning the decommissioning process for structural removal. Rather than complete removal of the structure, the lower portion was left intact as an artificial reef and the upper 21 m was removed. The biological communities (benthic and fish) were characterized during diver and remotely operated vehicle surveys, both before and after removal of the upper structure. The platform's benthic community, primarily categorized as fouling organisms, was mainly composed of sponges, hydroids, macroalgae, bivalves, zoanthids, and stony corals. The dominant stony coral was orange cup coral (Tubastraea sp.), an exotic species, while native coral species were rare. Fish species were predominantly demersal planktivores. Analyses of the benthic and fish communities documented four distinct biological zones strongly associated with depth. Significant differences in the benthic community were observed after partial removal and varied with depth, including the loss of hydroids, increase in macroalgae cover, and sponge and coral community changes. Both demersal and pelagic fish communities exhibited significant differences by depth after removal but no significant changes were observed in federally managed species. Results reflect changes in benthic and fish communities after partial removal of the platform that is likely, in part, influenced by structure removal and temporal variations.


Assuntos
Antozoários , Recifes de Corais , Animais , Golfo do México , Ecossistema , Peixes , Biota
2.
Am J Clin Nutr ; 116(5): 1219-1228, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36041172

RESUMO

BACKGROUND: Epidemiologic studies suggest that coffee consumption may be inversely associated with risk of endometrial cancer (EC), the most common gynecological malignancy in developed countries. Furthermore, coffee consumption may lower circulating concentrations of estrogen and insulin, hormones implicated in endometrial carcinogenesis. Antioxidants and other chemopreventive compounds in coffee may have anticarcinogenic effects. Based on available meta-analyses, the World Cancer Research Fund (WCRF) concluded that consumption of coffee probably protects against EC. OBJECTIVES: Our main aim was to examine the association between coffee consumption and EC risk by combining individual-level data in a pooled analysis. We also sought to evaluate potential effect modification by other risk factors for EC. METHODS: We combined individual-level data from 19 epidemiologic studies (6 cohort, 13 case-control) of 12,159 EC cases and 27,479 controls from the Epidemiology of Endometrial Cancer Consortium (E2C2). Logistic regression was used to calculate ORs and their corresponding 95% CIs. All models were adjusted for potential confounders including age, race, BMI, smoking status, diabetes status, study design, and study site. RESULTS: Coffee drinkers had a lower risk of EC than non-coffee drinkers (multiadjusted OR: 0.87; 95% CI: 0.79, 0.95). There was a dose-response relation between higher coffee consumption and lower risk of EC: compared with non-coffee drinkers, the adjusted pooled ORs for those who drank 1, 2-3, and >4 cups/d were 0.90 (95% CI: 0.82, 1.00), 0.86 (95% CI: 0.78, 0.95), and 0.76 (95% CI: 0.66, 0.87), respectively (P-trend < 0.001). The inverse association between coffee consumption and EC risk was stronger in participants with BMI > 25 kg/m2. CONCLUSIONS: The results of the largest analysis to date pooling individual-level data further support the potentially beneficial health effects of coffee consumption in relation to EC, especially among females with higher BMI.


Assuntos
Neoplasias do Endométrio , Feminino , Humanos , Fatores de Risco , Neoplasias do Endométrio/epidemiologia , Neoplasias do Endométrio/etiologia , Neoplasias do Endométrio/prevenção & controle , Modelos Logísticos , Estudos de Casos e Controles , Coleta de Dados
3.
Sci Rep ; 12(1): 1659, 2022 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-35102236

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) patients display distinct phenotypes of cachexia development, with either adipose tissue loss preceding skeletal muscle wasting or loss of only adipose tissue. Activin A levels were measured in serum and analyzed in tumor specimens of both a cohort of Stage IV PDAC patients and the genetically engineered KPC mouse model. Our data revealed that serum activin A levels were significantly elevated in Stage IV PDAC patients in comparison to age-matched non-cancer patients. Little is known about the role of activin A in adipose tissue wasting in the setting of PDAC cancer cachexia. We established a correlation between elevated activin A and remodeling of visceral adipose tissue. Atrophy and fibrosis of visceral adipose tissue was examined in omental adipose tissue of Stage IV PDAC patients and gonadal adipose tissue of an orthotopic mouse model of PDAC. Remarkably, white visceral adipose tissue from both PDAC patients and mice exhibited decreased adipocyte diameter and increased fibrotic deposition. Strikingly, expression of thermogenic marker UCP1 in visceral adipose tissues of PDAC patients and mice remained unchanged. Thus, we propose that activin A signaling could be relevant to the acceleration of visceral adipose tissue wasting in PDAC-associated cachexia.


Assuntos
Ativinas/metabolismo , Adipócitos Brancos/metabolismo , Adiposidade , Carcinoma Ductal Pancreático/metabolismo , Subunidades beta de Inibinas/metabolismo , Gordura Intra-Abdominal/metabolismo , Neoplasias Pancreáticas/metabolismo , Ativinas/genética , Adipócitos Brancos/patologia , Animais , Atrofia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Estudos de Casos e Controles , Linhagem Celular , Fibrose , Humanos , Subunidades beta de Inibinas/genética , Gordura Intra-Abdominal/patologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Estadiamento de Neoplasias , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Transdução de Sinais , Proteína Desacopladora 1/metabolismo
4.
Mol Cancer Ther ; 20(12): 2457-2468, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34625505

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) represents 3% of all cancer cases and 7% of all cancer deaths in the United States. Late diagnosis and inadequate response to standard chemotherapies contribute to an unfavorable prognosis and an overall 5-year survival rate of less than 10% in PDAC. Despite recent advances in tumor immunology, tumor-induced immunosuppression attenuates the immunotherapy response in PDAC. To date, studies have focused on IgG-based therapeutic strategies in PDAC. With the recent interest in IgE-based therapies in multiple solid tumors, we explored the MUC1-targeted IgE potential against pancreatic cancer. Our study demonstrates the notable expression of FceRI (receptor for IgE antibody) in tumors from PDAC patients. Our study showed that administration of MUC1 targeted-IgE (mouse/human chimeric anti-MUC1.IgE) antibody at intermittent levels in combination with checkpoint inhibitor (anti-PD-L1) and TLR3 agonist (PolyICLC) induces a robust antitumor response that is dependent on NK and CD8 T cells in pancreatic tumor-bearing mice. Subsequently, our study showed that the antigen specificity of the IgE antibody plays a vital role in executing the antitumor response as nonspecific IgE, induced by ovalbumin (OVA), failed to restrict tumor growth in pancreatic tumor-bearing mice. Utilizing the OVA-induced allergic asthma-PDAC model, we demonstrate that allergic phenotype induced by OVA cannot restrain pancreatic tumor growth in orthotopic tumor-bearing mice. Together, our data demonstrate the novel tumor protective benefits of tumor antigen-specific IgE-based therapeutics in a preclinical model of pancreatic cancer, which can open new avenues for future clinical interventions.


Assuntos
Adenocarcinoma/tratamento farmacológico , Carcinoma Ductal Pancreático/tratamento farmacológico , Imunoglobulina E/uso terapêutico , Animais , Humanos , Imunoglobulina E/farmacologia , Camundongos
5.
Cancers (Basel) ; 13(9)2021 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-34066839

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a poor prognosis. Tumor hypoxia plays an active role in promoting tumor progression, malignancy, and resistance to therapy in PDAC. We present evidence that nab-paclitaxel-gemcitabine (NPG) and/or a hypoxic tumor microenvironment (TME) up-regulate heme oxygenase-1 (HO-1), providing a survival advantage for tumors. Using PDAC cells in vitro and a PDAC mouse model, we found that NPG chemotherapy up-regulated expression of HO-1 in PDAC cells and increased its nuclear translocation. Inhibition of HO-1 with ZnPP and SnPP sensitized PDAC cells to NPG-induced cytotoxicity (p < 0.05) and increased apoptosis (p < 0.05). Additionally, HO-1 expression was increased in gemcitabine-resistant PDAC cells (p < 0.05), and HO-1 inhibition increased GEM-resistant PDAC sensitivity to NPG (p < 0.05). NPG combined with HO-1 inhibitor inhibited tumor size in an orthotopic model. In parallel, HO-1 inhibition abrogated the influx of macrophages and FoxP3+ cells, while increasing the proportion of CD8+ infiltration in the pancreatic tumors. These effects were mediated primarily by reducing expression of the immunosuppressive cytokine IL-10.

6.
Biomolecules ; 11(4)2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33915939

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) remains a very difficult cancer to treat. Recent in vitro and in vivo studies suggest that the activation of the receptor for advanced glycation end products (RAGE) by its ligands stimulates pancreatic cancer cell proliferation and tumor growth. Additional studies show that, in the RAGE ligand, the high mobility group box 1 (HMGB1) protein plays an important role in chemoresistance against the cytotoxic agent gemcitabine by promoting cell survival through increased autophagy. We hypothesized that blocking the RAGE/HMGB1 interaction would enhance the cytotoxic effect of gemcitabine by reducing cell survival and autophagy. Using a preclinical mouse model of PDAC and a monoclonal antibody (IgG 2A11) as a RAGE inhibitor, we demonstrate that RAGE inhibition concurrent with gemcitabine treatment enhanced the cytotoxic effect of gemcitabine. The combination of IgG 2A11 and gemcitabine resulted in decreased autophagy compared to treatment with gemcitabine combined with control antibodies. Notably, we also observed that RAGE inhibition protected against excessive weight loss during treatment with gemcitabine. Our data suggest that the combination of gemcitabine with a RAGE inhibitor could be a promising therapeutic approach for the treatment of pancreatic cancer and needs to be further investigated.


Assuntos
Autofagia/efeitos dos fármacos , Desoxicitidina/análogos & derivados , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Proteína HMGB1/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Poli(ADP-Ribose) Polimerases/metabolismo , Receptor para Produtos Finais de Glicação Avançada/antagonistas & inibidores , Receptor para Produtos Finais de Glicação Avançada/imunologia , Transplante Homólogo , Gencitabina
7.
Mol Ther ; 29(4): 1557-1571, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33359791

RESUMO

Aberrant expression of CA125/MUC16 is associated with pancreatic ductal adenocarcinoma (PDAC) progression and metastasis. However, knowledge of the contribution of MUC16 to pancreatic tumorigenesis is limited. Here, we show that MUC16 expression is associated with disease progression, basal-like and squamous tumor subtypes, increased tumor metastasis, and short-term survival of PDAC patients. MUC16 enhanced tumor malignancy through the activation of AKT and GSK3ß oncogenic signaling pathways. Activation of these oncogenic signaling pathways resulted in part from increased interactions between MUC16 and epidermal growth factor (EGF)-type receptors, which were enhanced for aberrant glycoforms of MUC16. Treatment of PDAC cells with monoclonal antibody (mAb) AR9.6 significantly reduced MUC16-induced oncogenic signaling. mAb AR9.6 binds to a unique conformational epitope on MUC16, which is influenced by O-glycosylation. Additionally, treatment of PDAC tumor-bearing mice with either mAb AR9.6 alone or in combination with gemcitabine significantly reduced tumor growth and metastasis. We conclude that the aberrant expression of MUC16 enhances PDAC progression to an aggressive phenotype by modulating oncogenic signaling through ErbB receptors. Anti-MUC16 mAb AR9.6 blocks oncogenic activities and tumor growth and could be a novel immunotherapeutic agent against MUC16-mediated PDAC tumor malignancy.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antígeno Ca-125/genética , Carcinogênese/genética , Carcinoma Ductal Pancreático/tratamento farmacológico , Receptores ErbB/genética , Proteínas de Membrana/genética , Adenocarcinoma/genética , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Animais , Anticorpos Monoclonais/farmacologia , Antígeno Ca-125/imunologia , Carcinogênese/imunologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Progressão da Doença , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/imunologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/imunologia , Camundongos , Metástase Neoplásica , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Transdução de Sinais
8.
World Neurosurg ; 139: 136-141, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32283320

RESUMO

BACKGROUND: Granular cell tumors (GCT) are rare soft tissue neoplasms with a nerve sheath origin, most often found in female adult populations. When these tumors arise in the central nervous system, they most commonly appear intradurally in the thoracic or lumbar spine. GCT malignancy rates vary and recurrence rates can be relatively high, thereby necessitating complete resection. CASE DESCRIPTION: We present an exceedingly rare case of an intradural, extramedullary GCT originating in the anterior cervical spine of a male pediatric patient who presented with progressive neck pain and gait instability. CONCLUSIONS: The patient underwent an anterior C7 corpectomy for resection of the tumor, followed by stabilization and fusion, and recovered without neurologic deficit. A literature review of spinal GCTs is provided.


Assuntos
Vértebras Cervicais/cirurgia , Tumor de Células Granulares/cirurgia , Procedimentos Neurocirúrgicos/métodos , Neoplasias da Medula Espinal/cirurgia , Adolescente , Tumor de Células Granulares/complicações , Tumor de Células Granulares/diagnóstico por imagem , Tumor de Células Granulares/patologia , Cefaleia/etiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Cervicalgia/etiologia , Neoplasias da Medula Espinal/complicações , Neoplasias da Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/patologia , Fusão Vertebral
9.
Sci Rep ; 9(1): 10656, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337812

RESUMO

The Muc-1 oncoprotein is a tumor-associated mucin often overexpressed in pancreatic cancer. We report that knockout of Muc-1 reduced the degree of pancreatic inflammation that resulted from infection with Coxsackievirus B3 (CVB3) in a mouse model. CVB3-infected Muc-1-deficient (Muc-1KO) mice had significantly reduced infiltration of macrophages into the murine pancreas. We found that Muc-1 signaling through NF-κB increased expression of ICAM-1, a pro-inflammatory mediator that recruits macrophages. Further investigation revealed that bone marrow derived macrophages (BMDM) from the Muc-1KO mice exhibited defective migration properties, in part due to low expression of the C-C motif chemokine receptor (CCR2) and the integrin Very Late Antigen 4 (VLA-4). The results presented here provide novel insight into the role of Muc-1 in regulating the inflammatory response and the cellular microenvironment in pancreatitis.


Assuntos
Infecções por Coxsackievirus/virologia , Mucina-1/metabolismo , Pancreatite/virologia , Animais , Infecções por Coxsackievirus/genética , Infecções por Coxsackievirus/metabolismo , Modelos Animais de Doenças , Enterovirus Humano B , Inflamação/genética , Inflamação/metabolismo , Inflamação/virologia , Camundongos , Camundongos Knockout , Mucina-1/genética , Pancreatite/genética , Pancreatite/metabolismo , Receptores CCR2/genética , Receptores CCR2/metabolismo
10.
J Pharmacol Exp Ther ; 370(3): 894-901, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30683666

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers. A combination of cisplatin (CDDP) and gemcitabine (Gem) treatment has shown favorable clinical results for metastatic disease; both are limited by toxicities and nontargeted delivery. More than 80% of PDAC aberrantly expresses the sialyl Tn (STn) antigen due to the loss of function of the core 1ß3-Gal-T-specific molecular chaperone, a specific chaperone for the activity of core 1 ß3-galactosyltransferase or C1GalT. Here, we report the development of polymeric nanogels (NGs) loaded with CDDP and coated with an anti-STn antigen-specific antibody (TKH2 monoclonal antibody) for the targeted treatment of PDAC. TKH2-functionalized, CDDP-loaded NGs delivered a significantly higher amount of platinum into the cells and tumors expressing STn antigens. We also confirmed that a synergistic cytotoxic effect of sequential exposure of pancreatic cancer cells to Gem followed by CDDP can be mimicked by the codelivery of CDDP-loaded NGs (NG/CDDP) and free Gem. In a murine orthotopic model of PDAC, combined simultaneous treatment with Gem and targeted NG/CDDP significantly attenuated tumor growth with no detectable acute toxicity. Altogether, these results suggest that combination therapy consisting of Gem followed by TKH2-conjugated CDDP NGs induces highly synergistic therapeutic efficacy against pancreatic cancer. Our results offer the basis for development of combination drug regimens using targeted nanomedicines to increase treatment effectiveness and improve outcomes of PDAC therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Ductal Pancreático/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Linhagem Celular Tumoral , Cisplatino/administração & dosagem , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Sinergismo Farmacológico , Géis , Humanos , Camundongos , Camundongos Nus , Nanoestruturas , Platina/metabolismo , Polímeros/química , Gencitabina
11.
Cancer Immunol Immunother ; 67(3): 445-457, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29204701

RESUMO

A substantial body of evidence suggests the existence of MUC1-specific antibodies and cytotoxic T cell activities in pancreatic cancer patients. However, tumor-induced immunosuppression renders these responses ineffective. The current study explores a novel therapeutic combination wherein tumor-bearing hosts can be immunologically primed with their own antigen, through opsonization with a tumor antigen-targeted antibody, mAb-AR20.5. We evaluated the efficacy of immunization with this antibody in combination with PolyICLC and anti-PD-L1. The therapeutic combination of mAb-AR20.5 + anti-PD-L1 + PolyICLC induced rejection of human MUC1 expressing tumors and provided a long-lasting, MUC1-specific cellular immune response, which could be adoptively transferred and shown to provide protection against tumor challenge in human MUC1 transgenic (MUC.Tg) mice. Furthermore, antibody depletion studies revealed that CD8 cells were effectors for the MUC1-specific immune response generated by the mAb-AR20.5 + anti-PD-L1 + PolyICLC combination. Multichromatic flow cytometry data analysis demonstrated a significant increase over time in circulating, activated CD8 T cells, CD3+CD4-CD8-(DN) T cells, and mature dendritic cells in mAb-AR20.5 + anti-PD-L1 + PolyICLC combination-treated, tumor-bearing mice, as compared to saline-treated control counterparts. Our study provides a proof of principle that an effective and long-lasting anti-tumor cellular immunity can be achieved in pancreatic tumor-bearing hosts against their own antigen (MUC1), which can be further potentiated using a vaccine adjuvant and an immune checkpoint inhibitor.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Antígeno B7-H1/antagonistas & inibidores , Carboximetilcelulose Sódica/análogos & derivados , Desoxicitidina/análogos & derivados , Mucina-1/genética , Neoplasias Pancreáticas/mortalidade , Poli I-C/administração & dosagem , Polilisina/análogos & derivados , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Carboximetilcelulose Sódica/administração & dosagem , Citotoxicidade Imunológica , Desoxicitidina/administração & dosagem , Humanos , Imunidade Celular , Camundongos , Camundongos Transgênicos , Mucina-1/química , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/prevenção & controle , Polilisina/administração & dosagem , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Gencitabina
12.
Sci Adv ; 3(6): e1603081, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28630914

RESUMO

Obscurins are cytoskeletal proteins with structural and regulatory roles encoded by OBSCN. Mutations in OBSCN are associated with the development of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Specifically, the R4344Q mutation present in immunoglobulin domain 58 (Ig58) was the first to be linked with the development of HCM. To assess the effects of R4344Q in vivo, we generated the respective knock-in mouse model. Mutant obscurins are expressed and incorporated normally into sarcomeres. The expression patterns of sarcomeric and Ca2+-cycling proteins are unaltered in sedentary 1-year-old knock-in myocardia, with the exception of sarco/endoplasmic reticulum Ca2+ adenosine triphosphatase 2 (SERCA2) and pentameric phospholamban whose levels are significantly increased and decreased, respectively. Isolated cardiomyocytes from 1-year-old knock-in hearts exhibit increased Ca2+-transients and Ca2+-load in the sarcoplasmic reticulum and faster contractility kinetics. Moreover, sedentary 1-year-old knock-in animals develop tachycardia accompanied by premature ventricular contractions, whereas 2-month-old knock-in animals subjected to pressure overload develop a DCM-like phenotype. Structural analysis revealed that the R4344Q mutation alters the distribution of electrostatic charges over the Ig58 surface, thus interfering with its binding capabilities. Consistent with this, wild-type Ig58 interacts with phospholamban modestly, and this interaction is markedly enhanced in the presence of R4344Q. Together, our studies demonstrate that under sedentary conditions, the R4344Q mutation results in Ca2+ deregulation and spontaneous arrhythmia, whereas in the presence of chronic, pathological stress, it leads to cardiac remodeling and dilation. We postulate that enhanced binding between mutant obscurins and phospholamban leads to SERCA2 disinhibition, which may underlie the observed pathological alterations.


Assuntos
Arritmias Cardíacas/genética , Arritmias Cardíacas/metabolismo , Sinalização do Cálcio , Cálcio/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Cardiopatias/genética , Cardiopatias/metabolismo , Proteínas Musculares/genética , Mutação , Animais , Arritmias Cardíacas/diagnóstico , Modelos Animais de Doenças , Ecocardiografia , Eletrocardiografia , Cardiopatias/diagnóstico , Espectroscopia de Ressonância Magnética , Camundongos , Camundongos Transgênicos , Proteínas Serina-Treonina Quinases , Fatores de Troca de Nucleotídeo Guanina Rho
13.
Am J Physiol Lung Cell Mol Physiol ; 312(5): L748-L759, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28258105

RESUMO

Right ventricular (RV) dysfunction is associated with numerous smoking-related illnesses, including chronic obstructive pulmonary disease (COPD), in which it is present even in the absence of pulmonary hypertension. It is unknown whether exposure to cigarette smoke (CS) has direct effects on RV function and cardiac fibroblast (CF) proliferation or collagen synthesis. In this study, we evaluated cardiac function and fibrosis in mice exposed to CS and determined mechanisms of smoke-induced changes in CF signaling and fibrosis. AKR mice were exposed to CS for 6 wk followed by echocardiography and evaluation of cardiac hypertrophy, collagen content, and pulmonary muscularization. Proliferation and collagen content were evaluated in primary isolated rat CFs exposed to CS extract (CSE) or nicotine. Markers of cell proliferation, fibrosis, and proliferative signaling were determined by immunoblot or Sircol collagen assay. Mice exposed to CS had significantly decreased RV function, as determined by tricuspid annular plane systolic excursion. There were no changes in left ventricular parameters. RV collagen content was significantly elevated, but there was no change in RV hypertrophy or pulmonary vascular muscularization. CSE directly increased CF proliferation and collagen content in CF. Nicotine alone reproduced these effects. CSE and nicotine-induced fibroblast proliferation and collagen content were mediated through α7 nicotinic acetylcholine receptors and were dependent on PKC-α, PKC-δ, and reduced p38-MAPK phosphorylation. CS and nicotine have direct effects on CFs to induce proliferation and fibrosis, which may negatively affect right heart function.


Assuntos
Fibroblastos/metabolismo , Fibroblastos/patologia , Ventrículos do Coração/patologia , Miocárdio/patologia , Fumar/efeitos adversos , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Hipertrofia Ventricular Direita/complicações , Hipertrofia Ventricular Direita/diagnóstico por imagem , Hipertrofia Ventricular Direita/patologia , Hipertrofia Ventricular Direita/fisiopatologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos Endogâmicos AKR , Nicotina/farmacologia , Fosforilação/efeitos dos fármacos , Proteína Quinase C-alfa/metabolismo , Proteína Quinase C-delta/metabolismo , Ratos Sprague-Dawley , Remodelação Vascular/efeitos dos fármacos , Disfunção Ventricular Direita/complicações , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/patologia , Disfunção Ventricular Direita/fisiopatologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
15.
Diabetes ; 60(4): 1286-94, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21346178

RESUMO

OBJECTIVE: Endothelial progenitor cells (EPCs) are decreased in number and function in type 2 diabetes. Mechanisms by which this dysfunction occurs are largely unknown. We tested the hypothesis that a chronic inflammatory environment leads to insulin signaling defects in EPCs and thereby reduces their survival. Modifying EPCs by a knockdown of nuclear factor-κB (NF-κB) can reverse the insulin signaling defects, improve EPC survival, and decrease neointimal hyperplasia in Zucker fatty rats postangioplasty. RESEARCH DESIGN AND METHODS: EPCs from Zucker fatty insulin-resistant rats were cultured and exposed to tumor necrosis factor-α (TNF-α). Insulin signaling defects and apoptosis were measured in the presence and absence of an NF-κB inhibitor, BAY11. Then, EPCs were modified by a knockdown of NF-κB (RelA) and exposed to TNF-α. For in vivo experiments, Zucker fatty rats were given modified EPCs post-carotid angioplasty. Tracking of EPCs was done at various time points, and neointimal hyperplasia was measured 3 weeks later. RESULTS: Insulin signaling as measured by the phosphorylated-to-total AKT ratio was reduced by 56% in EPCs exposed to TNF-α. Apoptosis was increased by 71%. These defects were reversed by pretreatment with an NF-κB inhibitor, BAY11. Modified EPCs exposed to TNF-α showed a lesser reduction (RelA 20%) in insulin-stimulated AKT phosphorylation versus a 55% reduction in unmodified EPCs. Apoptosis was 41% decreased for RelA knockdown EPCs. Noeintimal hyperplasia postangioplasty was significantly less in rats receiving modified EPCs than in controls (intima-to-media ratio 0.58 vs. 1.62). CONCLUSIONS: In conclusion, we have shown that insulin signaling and EPC survival is impaired in Zucker fatty insulin resistant rats. For the first time, we have shown that this defect can be significantly ameliorated by a knockdown of NF-κB and that these EPCs given to Zucker fatty rats decrease neointimal hyperplasia post-carotid angioplasty.


Assuntos
Células Endoteliais/citologia , Inflamação/fisiopatologia , Resistência à Insulina/fisiologia , Células-Tronco/metabolismo , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Diabetes Mellitus Tipo 2/imunologia , Diabetes Mellitus Tipo 2/metabolismo , Células Endoteliais/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Inflamação/metabolismo , Interleucina-8/metabolismo , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Nitrilas/farmacologia , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley , Ratos Zucker , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células-Tronco/efeitos dos fármacos , Sulfonas/farmacologia , Fator de Necrose Tumoral alfa/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA