Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nanotechnology ; 30(37): 372001, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-30840941

RESUMO

The field of nanotechnology is rapidly growing. The promise of pharmacotherapeutics emerging from this vast field has drawn the attention of many researchers. However, with the increase in the prevalence of antibiotic resistant microorganisms, the manifestations of these promises are needed now more than ever. Many have postulated the antimicrobial potential of nanoparticle constructs derived from precious metals/noble metals nanoparticles (NMNPs), such as silver nanoparticles that show activity against multidrug resistant bacteria. In this review we will evaluate the current studies and explore the data to obtain a clear picture of the potential of these particles and the validity of the claims of drug resistant treatments with NMNPs.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Nanopartículas Metálicas/uso terapêutico , Metais/farmacologia , Animais , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Química Verde , Humanos , Nanopartículas Metálicas/química , Metais/química
2.
Cell Physiol Biochem ; 42(5): 1837-1846, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28750366

RESUMO

BACKGROUND: Hepatic ischemia reperfusion is one the main causes for graft failure following transplantation. Although, the molecular events that lead to hepatic failure following ischemia reperfusion (IR) are diverse and complex, previous studies have shown that excessive formation of reactive oxygen species (ROS) are responsible for hepatic IR injury. Cerium oxide (CeO2) nanoparticles have been previously shown to act as an anti-oxidant and anti-inflammatory agent. Here, we evaluated the protective effects of CeO2 nanoparticles on hepatic ischemia reperfusion injury. METHODS: Male Sprague Dawley rats were randomly assigned to one of the four groups: Control, CeO2 nanoparticle only, hepatic ischemia reperfusion (IR) group and hepatic ischemia reperfusion (IR) plus CeO2 nanoparticle group (IR+ CeO2). Partial warm hepatic ischemia was induced in left lateral and median lobes for 1h, followed by 6h of reperfusion. Animals were sacrificed after 6h of reperfusion and blood and tissue samples were collected and processed for various biochemical experiments. RESULTS: Prophylactic treatment with CeO2 nanoparticles (0.5mg/kg i.v (IR+CeO2 group)) 1 hour prior to hepatic ischemia and subsequent reperfusion injury lead to a decrease in serum levels of alanine aminotransaminase and lactate dehydrogenase at 6 hours after reperfusion. These changes were accompanied by significant decrease in hepatocyte necrosis along with reduction in several serum inflammatory markers such as macrophage derived chemokine, macrophage inflammatory protein-2, KC/GRO, myoglobin and plasminogen activator inhibitor-1. However, immunoblotting demonstrated no significant changes in the levels of apoptosis related protein markers such as bax, bcl2 and caspase 3 in IR and IR+ CeO2 groups at 6 hours suggesting necrosis as the main pathway for hepatocyte death. CONCLUSION: Taken together, these data suggest that CeO2 nanoparticles attenuate IR induced cell death and can be used as a prophylactic agent to prevent hepatic injury associated with graft failure.


Assuntos
Cério/química , Nanopartículas Metálicas/uso terapêutico , Substâncias Protetoras/química , Traumatismo por Reperfusão/prevenção & controle , Alanina Transaminase/sangue , Animais , Caspase 3/metabolismo , Quimiocina CXCL2/metabolismo , Quimiocinas/metabolismo , Imunoensaio , L-Lactato Desidrogenase/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Nanopartículas Metálicas/química , Mioglobina/metabolismo , Substâncias Protetoras/farmacologia , Substâncias Protetoras/uso terapêutico , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/etiologia , Proteína X Associada a bcl-2/metabolismo
3.
Crit Care Med ; 43(11): e477-89, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26327202

RESUMO

OBJECTIVES: Peritonitis is a life-threatening disease that is associated with high mortality. The purpose of this study was to determine if cerium oxide nanoparticles can be used to diminish intra-abdominal infection-induced mortality and systemic inflammatory response syndrome in the laboratory rat. DESIGN: Randomized, controlled animal study and cell culture study. SETTING: University research laboratory. SUBJECTS: Male Sprague-Dawley rats aged 12 weeks, RAW 246.7 macrophage cell line. INTERVENTIONS: Intra-abdominal infection or peritonitis was induced by intraperitoneal injection of cecal material (600 mg/kg in 5% sterile dextrose water at a dosage of 5 mL/kg) obtained from healthy donors. Rats in control and peritonitis groups received 200 µL of sterile deionized water IV via the tail vein, whereas rats in cerium oxide-only group and peritonitis+cerium oxide group received cerium oxide nanoparticles (0.5 mg/kg) IV at the time of polymicrobial injection. Survival rate was monitored for 14 days, while in other experiments, animals were killed at 3 and 18 hours after induction of peritonitis for biochemical analysis. MEASUREMENTS AND MAIN RESULTS: Administration of a single dose (0.5 mg/kg) of cerium oxide nanoparticles IV to rats in the peritonitis group significantly improved survival rates and functioned to restore core body temperature toward baseline. Treatment-induced increases in animal survivability were associated with reduced systemic and hepatic oxidative stress, diminished serum cytokines, and chemokine levels. Changes in serum inflammatory markers with treatment were accompanied by decreased monocyte and lymphocyte extravasation into the peritoneal cavity along with decreased infiltration of macrophages into liver. In the heart, treatment diminished extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase-Stat-3 signaling and attenuated endothelial expression of P-selectin and vascular cell adhesion molecule-1. CONCLUSIONS: Cerium oxide nanoparticles attenuate the systemic inflammatory response associated with peritonitis, suggesting potential use as a novel therapeutic agent for the treatment of severe intra-abdominal infection.


Assuntos
Cério/uso terapêutico , Nanopartículas/uso terapêutico , Peritonite/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Análise de Variância , Animais , Biópsia por Agulha , Modelos Animais de Doenças , Immunoblotting , Imuno-Histoquímica , Injeções Intraperitoneais , Masculino , Estresse Oxidativo/fisiologia , Peritonite/microbiologia , Peritonite/mortalidade , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Valores de Referência , Taxa de Sobrevida , Resultado do Tratamento
4.
J Nanobiotechnology ; 13: 75, 2015 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-26498824

RESUMO

BACKGROUND: Intra-abdominal infection or peritonitis is a cause for great concern due to high mortality rates. The prognosis of severe intra-abdominal infection is significantly diminished in the presence of acute kidney injury (AKI) which is often characterized by renal tubular cell death that can lead to renal failure. The purpose of the current study is to examine the therapeutic efficacy of cerium oxide (CeO2) nanoparticles for the treatment of peritonitis-induced AKI by polymicrobial insult. RESULTS: A one-time administration of CeO2 nanoparticles (0.5 mg/kg) in the absence of antibiotics or other supportive care, attenuated peritonitis-induced tubular dilatation and the loss of brush border in male Sprague-Dawley rats. These improvements in renal structure were accompanied by decreases in serum cystatin-C levels, reduced renal oxidative stress, diminished Stat-3 phosphorylation and an attenuation of caspase-3 cleavage suggesting that the nanoparticle treatment improved renal glomerular filtration rate, diminished renal inflammation and reduced renal apoptosis. Consistent with these data, further analysis demonstrated that the CeO2 nanoparticle treatment diminished peritonitis-induced increases in serum kidney injury molecule-1 (KIM-1), osteopontin, ß-2 microglobulin and vascular endothelial growth factor-A (VEGF-A) levels. In addition, the nanoparticle attenuated peritonitis-induced hyperglycemia along with increases in blood urea nitrogen (BUN), serum potassium and sodium. CONCLUSION: CeO2 nanoparticles scavenge reactive oxygen species and attenuate polymicrobial insult induced increase in inflammatory mediators and subsequent AKI. Taken together, the data indicate that CeO2 nanoparticles may be useful as an alternative therapeutic agent or in conjunction with standard medical care for the treatment of peritonitis induced acute kidney injury.


Assuntos
Injúria Renal Aguda/etiologia , Cério/uso terapêutico , Infecções Intra-Abdominais/complicações , Nanopartículas/química , Actinas/metabolismo , Injúria Renal Aguda/sangue , Injúria Renal Aguda/patologia , Animais , Apoptose , Biomarcadores/sangue , Caspase 3/metabolismo , Inflamação/sangue , Inflamação/complicações , Inflamação/patologia , Infecções Intra-Abdominais/sangue , Infecções Intra-Abdominais/patologia , Túbulos Renais/patologia , Masculino , Nanopartículas/ultraestrutura , Estresse Oxidativo , Peritonite/sangue , Peritonite/complicações , Ratos Sprague-Dawley , Insuficiência Renal/sangue , Fator de Transcrição STAT3/metabolismo , Superóxidos/metabolismo
5.
Cell Physiol Biochem ; 31(2-3): 219-29, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23486111

RESUMO

BACKGROUND: Insulin resistance (IR) may decrease muscle adaptability. Heat shock proteins (HSPs), mitogen-activated protein kinases (MAPKs), and miRNA are thought to play a role in muscle hypertrophy but it is unclear if IR may affect their regulation. METHODS: Soleus muscles of lean Zucker (LZ) and insulin resistant obese Zucker (OZ) rats were overloaded for 7 or 21 days and subjected to immunoblotting and RT-PCR. RESULTS: IR was associated with decreased muscle hypertrophy. Overload increased HSP27 phosphorylation in both the LZ and OZ rats at day 7 but only in the LZ at day 21. IR was associated with diminished overload induced MAPK phosphorylation and decreased expression of miR-1 and miR133. Overload decreased mir-1 levels in both the LZ and OZ but to a greater extent in the LZ animals. CONCLUSION: These results suggest that alterations in the regulation of HSPs, MAPKs and miRNA may be associated with the diminished hypertrophy of IR muscle.


Assuntos
Resistência à Insulina , Músculo Esquelético/metabolismo , Animais , Extremidades/fisiologia , Proteínas de Choque Térmico HSP27/metabolismo , Hipertrofia/patologia , MicroRNAs/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/cirurgia , Fosforilação , Ratos , Ratos Zucker
6.
Cell Physiol Biochem ; 30(5): 1202-14, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23075566

RESUMO

BACKGROUND/AIMS: Muscle disuse can lead to muscle atrophy and impaired skeletal muscle function. How skeletal muscle modulates protein translational signaling in response to prolonged muscle disuse is not well understood. Using the hindlimb unloading (HU) model of muscle atrophy we examined how hindlimb unweighting affects protein translational signaling, including the activation of Akt/mTOR/p70S6K/S6 signaling and the inhibitory association of 4EBP1 with translation initiation factor eIF4E. METHODS: Male F344BN rats were randomized into baseline control, or subjected to HU for 3, 7 or 14 days. Body weight, gastrocnemius muscle, and individual myofiber cross-sectional area were measured to evaluate the degree of muscle atrophy. The amounts of myosin and related muscle contractile proteins were assessed using SDS-PAGE and immunoblotting. Microarray analysis was used to evaluate changes in the mRNA expression of muscle contractile proteins. Total and phosphorylated proteins of Akt/mTOR/p70S6K/S6 pathway were determined via immunoblotting, while the association of 4EBP1 with eIF4E was detected via co-immunoprecipitation. RESULTS: Unloading for 3 days significantly reduced cytosolic myosin content and was associated with increased binding of 4EBP1 to eIF4E, while prolonged unloading (14 days) was associated with the activation of Akt/mTOR/p70S6K/S6 signaling, decreased binding of 4EBP1 to eIF4E, increased cytosolic myosin and elevations in myofibrillar mRNA levels. CONCLUSION: Taken together, these data suggest that prolonged muscle disuse induces a biphasic translational signaling response that is associated with diminished and then increased muscle contractile protein expression.


Assuntos
Proteínas Musculares/biossíntese , Músculo Esquelético/metabolismo , Transtornos Musculares Atróficos/metabolismo , Biossíntese de Proteínas , Transdução de Sinais , Animais , Regulação da Expressão Gênica , Masculino , Proteínas Musculares/metabolismo , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344
7.
Eur J Drug Metab Pharmacokinet ; 47(3): 319-330, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35137360

RESUMO

BACKGROUND AND OBJECTIVES: Whole-body radiation exposure has been shown to alter the pharmacokinetics of certain drugs in both animal models and humans, but little is known about the effect of radiation on psychoactive medications. These drugs may have altered pharmacokinetics when administered during or after space travel or therapeutic or accidental radiation exposure, resulting in reduced efficacy or increased toxicity. METHODS: Methamphetamine was used to determine the effects of acutely administered 1, 3, and 6 Gy radiation on drug pharmacokinetics and pharmacodynamics. Male Wistar rats were exposed to 0, 1, 3, or 6 Gy X-ray radiation on day 0. The serum pharmacokinetics of subcutaneously administered 1 mg/kg methamphetamine was determined on day 3. Methamphetamine-induced (1 mg/kg) locomotor activity was measured on day 5. Brain methamphetamine concentrations were determined 2 h after methamphetamine administration (1 mg/kg) on day 6. Renal and hepatic serum biomarkers were assessed on days 3 and 6, with liver histology performed on day 6. RESULTS: While serum half-life and unchanged methamphetamine urine clearance were unaffected by any radiation dose, maximum methamphetamine concentrations and methamphetamine and amphetamine metabolite area under the serum concentration-time curve values from 0 to 300 min were significantly reduced after 6 Gy radiation exposure. Additionally, methamphetamine-induced locomotor activity and the brain to serum methamphetamine concentration ratio were significantly elevated after 6 Gy radiation. CONCLUSIONS: While 1-6 Gy radiation exposure did not affect methamphetamine elimination, 6 Gy exposure had effects on both subcutaneous absorption and brain distribution. These effects should be considered when administering drugs during or after radiation exposure.


Assuntos
Metanfetamina , Anfetamina/farmacocinética , Animais , Meia-Vida , Fígado , Masculino , Metanfetamina/farmacocinética , Ratos , Ratos Wistar
8.
J Cell Physiol ; 226(1): 29-36, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20672327

RESUMO

The Akt/protein kinase B is critical regulator of cellular homeostasis with diminished Akt activity being associated with dysregulation of cellular metabolism and cell death while Akt over-activation has been linked to inappropriate cell growth and proliferation. Although the regulation of Akt function has been well characterized in vitro, much less is known regarding the function of Akt in vivo. Here we examine how skeletal muscle Akt expression and enzymatic activity are controlled, the role of Akt in the regulation of skeletal muscle contraction, stress response glucose utilization, and protein metabolism, and the potential participation of this important molecule in skeletal muscle atrophy, aging, and cancer.


Assuntos
Músculo Esquelético/fisiologia , Doenças Musculares/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Regulação da Expressão Gênica/fisiologia , Humanos , Doenças Musculares/patologia , Proteínas Proto-Oncogênicas c-akt/genética
9.
J Pharmacol Exp Ther ; 336(1): 56-63, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20947636

RESUMO

Excess cardiac iron levels are associated with cardiac damage and can result in increased morbidity and mortality. Here, we hypothesize that elevations in tissue iron can activate caspase-dependent signaling, which leads to increased cardiac apoptosis and fibrosis, and that these alterations can be attenuated by iron chelation. Using an iron-overloaded gerbil model, we show that increased cardiac iron is associated with reduced activation of Akt (Ser473 and Thr308), diminished phosphorylation of the proapoptotic regulator Bad (Ser136), and an increased Bax/Bcl-2 ratio. These iron-overload-induced alterations in Akt/Bad phosphorylation and Bax/Bcl-2 ratio were coupled with increased activation of the downstream caspase-9 (40/38- and 17-kDa fragments) and apoptosis executioner caspase-3 (19- and 17-kDa fragments), which were accompanied by evidence of elevated cytoskeletal α-fodrin cleavage (150- and 120-kDa fragments), discontinuity of myocardial membrane dystrophin immunoreactivity, increases in the number of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells (nucleic DNA fragmentation), and cardiac fibrosis. We demonstrate that the administration of deferasirox, a tridentate iron chelator, is associated with diminished tissue iron deposition, attenuated activation of caspases, reduced α-fodrin cleavage, improved membrane integrity, decreased TUNEL reactivity, and attenuated cardiac fibrosis. These results suggest that the activation of caspase-dependent signaling may play a role in the development of iron-induced cardiac apoptosis and fibrosis, and deferasirox, via a reduction in cardiac tissue iron levels, may be useful for decreasing the extent of iron-induced cardiac damage.


Assuntos
Apoptose/efeitos dos fármacos , Benzoatos/uso terapêutico , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/patologia , Sobrecarga de Ferro/prevenção & controle , Ferro/toxicidade , Miocárdio/patologia , Triazóis/uso terapêutico , Animais , Apoptose/fisiologia , Benzoatos/farmacologia , Deferasirox , Gerbillinae , Quelantes de Ferro/farmacologia , Sobrecarga de Ferro/metabolismo , Masculino , Miocárdio/metabolismo , Triazóis/farmacologia
10.
Nanotechnology ; 22(24): 245101, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-21508464

RESUMO

The potential of using actin bundles for the transport of liposomes and single cells across myosin-coated surfaces is investigated. Compared to that observed with filamentous actin, the liposome transport using actin bundles was more linear in nature and able to occur over longer distances. Bundles, but not filamentous actin, were capable of moving single cells. Cargo unloading from bundles was achieved by incubation with Triton X-100. These data suggest that actin bundling may improve the ability of the myosin motor system for nanotransport applications.


Assuntos
Actinas/metabolismo , Escherichia coli/citologia , Escherichia coli/metabolismo , Miosina Tipo II/metabolismo , Nanoestruturas/química , Nanotecnologia/métodos , Actinas/ultraestrutura , Animais , Transporte Biológico , Biotinilação , Galinhas , Humanos , Lipossomos/ultraestrutura , Microscopia de Fluorescência , Nanoestruturas/ultraestrutura , Coelhos
11.
Am J Pharm Educ ; 85(2): 8422, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-34283743

RESUMO

The COVID-19 pandemic has impacted almost every facet of modern life, causing almost a million deaths worldwide as well as widespread economic and social strife. While contemplating how we might emerge from this pandemic, we were reminded of the Stockdale paradox. We suggest that the Academy must not only confront the brutal facts of the current situation, but we must also maintain faith in the endgame and a commitment to prevail despite the enormous challenges we face. The Academy can play a key role in helping the world recover from this pandemic if we build on the diversity and strengths of our programs nationally and globally. We suggest that there are three key actions that pharmacists and pharmacy educators must take to show leadership in this time of need. First, we must be the voice that reassures the public about the value of science and the scientific method. Second, we must work locally and nationally to ensure an optimal public health response. Finally, members of the Academy must serve as role models with respect to the essential public health tools to prevent the spread of COVID-19. By remaining positive, keeping the endgame in mind, and confronting the most brutal facts of the COVID-19 pandemic, we are confident that pharmacy education and pharmacy will weather this storm and arise even stronger for it.


Assuntos
COVID-19/epidemiologia , Educação em Farmácia/ética , Educação em Farmácia/organização & administração , Humanos , Pandemias
12.
Front Med Technol ; 3: 661421, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35047918

RESUMO

The United States spends billions of dollars to treat chronic wounds each year. Wound healing is complex in nature which involves several intricate multiphase processes that can be delayed for a number of reasons leading to the development of chronic wounds. Wound healing therapies range from topical preparations to surgical repair with treatment options that vary based on other underlying factors like co-infection, age, or co-morbidities such as diabetes. Historically, micelles and liposomes are some of the nanoparticle drug delivery systems explored to treat chronic wounds; however, recent data suggests that dendrimers have shown potential to rival these systems in treating chronic wounds as well as other diseases. This mini review examines advances in dendrimer nanoparticle drug delivery systems to treat chronic wounds.

13.
Small ; 6(3): 452-7, 2010 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-20082357

RESUMO

The utilization of motor proteins for the movement and assembly of synthetic components is currently a goal of nanoengineering research. Application of the myosin actin motor system for nanotechnological uses has been hampered due to the low flexural rigidity of individual F-actin filaments. Here it is demonstrated how actin bundling can be used to affect the translational behavior of myosin-propelled filaments, transport molecules across a motor-patterned surface, and that the movement of bundled actin can be regulated photonically. These data suggest that actin bundling may significantly improve the applicability of the myosin motor for future nanotechnological applications.


Assuntos
Actinas/metabolismo , Miosinas/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/efeitos da radiação , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/efeitos da radiação , Galinhas , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Luz , Nanopartículas/química , Coelhos
14.
Basic Res Cardiol ; 105(4): 535-44, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20407780

RESUMO

There is a growing need for pharmacological agents to manage cardiovascular disease in the rapidly growing elderly population. Here, we determine if acetaminophen is efficacious in decreasing age-related increases in cardiac reactive oxygen species (ROS) and apoptosis in aging Fischer 344 X Brown Norway rats. Compared to 6-month control animals, indices of oxidative (superoxide anion [O2( *-)] and 4-hydroxy-2-nonenal [4-HNE]) and nitrosative (protein nitrotyrosylation) stress were markedly increased in 33-month-old rat hearts. 33-month animals that had been treated with acetaminophen (30 mg/kg/day p.o. for 6 months) exhibited diminished age-related increases in cardiac ROS levels and TUNEL positive nuclei and these changes were accompanied by improvements in the Bax/Bcl2 ratio, diminished evidence of caspase-3 activation and increased phosphorylation of protein kinase B, ERK1/2, p70S6K and GSK-3beta. Taken together these results suggests that acetaminophen may attenuate the age-associated increases in the cardiomyocyte apoptosis, possibly via diminishing age associated elevation in ROS production.


Assuntos
Acetaminofen/farmacologia , Envelhecimento/efeitos dos fármacos , Analgésicos não Narcóticos/farmacologia , Apoptose/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Envelhecimento/metabolismo , Animais , Sobrevivência Celular , Miócitos Cardíacos/metabolismo , Ratos , Ratos Endogâmicos F344 , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
15.
Am J Physiol Regul Integr Comp Physiol ; 299(6): R1666-75, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20926758

RESUMO

Recent data have suggested that insulin resistance may be associated with a diminished ability of skeletal muscle to undergo hypertrophy (Paturi S, Gutta AK, Kakarla SK, Katta A, Arnold EC, Wu M, Rice KM, Blough ER. J Appl Physiol 108: 7-13, 2010). Here we examine the effects of insulin resistance using the obese Zucker (OZ) rat with increased muscle loading on the regulation of the mammalian target of rapamycin (mTOR) and its downstream signaling intermediates 70-kDa ribosomal protein S6 kinase (p70S6k), ribosomal protein S6 (rpS6), eukaryotic elongation factor 2 (eEF2), and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1). Compared with that observed in lean Zucker (LZ) rats, the degree of soleus muscle hypertrophy as assessed by changes in muscle wet weight (LZ: 35% vs. OZ: 16%) was significantly less in the OZ rats after 3 wk of muscle overload (P < 0.05). This diminished growth in the OZ rats was accompanied by significant impairments in the ability of the soleus to undergo phosphorylation of mTOR (Ser(2448)), p70S6k (Thr(389)), rpS6 (Ser(235/236)), and protein kinase B (Akt) (Ser(473) and Thr(308)) (P < 0.05). Taken together, these data suggest that impaired overload-induced hypertrophy in insulin-resistant skeletal muscle may be related to decreases in the ability of the muscle to undergo mTOR-related signaling.


Assuntos
Resistência à Insulina/fisiologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Obesidade/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Análise de Variância , Animais , Glicemia/metabolismo , Western Blotting , Ensaio de Imunoadsorção Enzimática , Hipertrofia/metabolismo , Insulina/sangue , Ratos , Ratos Zucker
16.
Langmuir ; 26(9): 6079-82, 2010 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-20355744

RESUMO

The study and utilization of bionanomotors represents a rapid and progressing field of nanobiotechnology. Here, we demonstrate that poly(amidoamine) (PAMAM) dendrimers are capable of supporting heavy meromyosin dependent actin motility of similar quality to that observed using nitrocellulose, and that microcontact printing of PAMAM dendrimers can be exploited to produce tracks of active myosin motors leading to the restricted motion of actin filaments across a patterned surface. These data suggest that the use of dendrimer surfaces will increase the applicability of using protein biomolecular motors for nanotechnological applications.


Assuntos
Dendrímeros/química , Nanotecnologia/métodos , Animais , Bovinos , Colódio/química , Eletricidade , Movimento , Miosinas/metabolismo , Propriedades de Superfície , Compostos de Estanho/química
17.
Biotechnol Appl Biochem ; 55(2): 85-90, 2010 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-20055757

RESUMO

Vascular intervention procedures can lead to endothelial damage and expose the underlying VSMCs (vascular smooth muscle cells) to shear stress. Although shear stress has been implicated in the proliferation and migration of VSMCs, the molecular mechanism(s) underlying these events are not well understood. In the present study, we examined the effect of shear stress on VSMC reorientation and the activation of Akt (also called protein kinase B) pathway signalling. Cells were subjected to a shear of 9.8 dynes/cm2 (1 dyne=10-5 N) for 0 min, 5 min, 15 min, 30 min, 1 h, 4 h and 24 h. Shear stress caused the VSMCs to realign at an angle that was approximately 45 degrees relative to the shear force vector after 24 h. Immunoblotting demonstrated that the phosphorylations of Akt and Akt-related signalling proteins [mTOR (mammalian target of rapamycin), PTEN (phosphatase and tensin homologue deleted on chromosome 10) and p70S6k (p70 S6-kinase)] were increased after shear stimulation. These results indicate that the activation of the Akt pathway signalling is closely correlated with shear-induced VSMC reorientation.


Assuntos
Movimento Celular , Proliferação de Células , Células Endoteliais/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Estresse Fisiológico , Células Endoteliais/citologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Serina-Treonina Quinases TOR
18.
Exp Clin Endocrinol Diabetes ; 128(8): 512-519, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30616241

RESUMO

INTRODUCTION: Empagliflozin, a known inhibitor of sodium-glucose cotransporter type 2 (SGLT2) decreases glucose reabsorption by the renal tubules and promotes glucose excretion into the urine. While the effectiveness of Empagliflozin in the management of hyperglycemia along with associated cardiovascular and all-cause mortality has been demonstrated previously, the therapeutic benefits associated with the long-term use of this drug in obese animals have yet to be investigated. METHODS: Male 5-week-old lean and obese Zucker rats were randomly assigned to one of the 4 groups- lean control, lean treated, obese control, obese treated and treated with either Empagliflozin (10 mg/kg BW / day) or placebo for 25 weeks to investigate the therapeutic effect of Empagliflozin. RESULTS: Empagliflozin treatment in the obese animals was associated with decreased body weight, attenuated the loss of F-actin from the renal tubules and improved renal structure and function. These changes in renal function were associated with significant improvements in the glucose tolerance, and decreased non-fasting circulatory levels of glucose, amylase, and other inflammatory markers including NGAL, cystatin C, and clusterin. CONCLUSION: Long-term use of Empagliflozin in diabetic obese Zucker rats is associated with improvements in glucose tolerance and decreased loss of renal structure and function.


Assuntos
Compostos Benzidrílicos/administração & dosagem , Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Glucosídeos/administração & dosagem , Obesidade/tratamento farmacológico , Animais , Compostos Benzidrílicos/farmacologia , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Esquema de Medicação , Glucosídeos/farmacologia , Rim/efeitos dos fármacos , Rim/fisiopatologia , Quimioterapia de Manutenção , Masculino , Obesidade/complicações , Obesidade/metabolismo , Ratos , Ratos Zucker , Fatores de Tempo
19.
Diabetes Metab Res Rev ; 25(3): 279-86, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19177471

RESUMO

BACKGROUND: Aging-related hyperglycemia is associated with increased oxidative stress and diminished muscle glucose transporter-4 (Glut4) that may be regulated, at least in part, by the mitogen-activated protein kinases (MAPK). METHODS: To test the possibility that aging-related hyperglycemia can be prevented by pharmacological manipulation of MAPK hyperactivation, aged (27-month old) Fischer 344/NNiaHSD x Brown Norway/BiNia F1 (F344BN) rats were administered acetaminophen (30 mg/kg body weight/day) for 6 months in drinking water. RESULTS: Hepatic histopathology, serum aspartate aminotransferase and alanine aminotransferase analyses suggested that chronic acetaminophen did not cause hepatotoxicity. Compared with adult (6-month) and aged (27-month) rats, very aged rats (33-month) had higher levels of blood glucose, phosphorylation of soleus p38-MAPK and extracellular-regulated kinase 1/2 (ERK1/2), superoxide and oxidatively modified proteins (p<0.05), and these changes were associated with decreased soleus Glut4 protein abundance (p<0.05). Chronic acetaminophen treatment attenuated age-associated increase in blood glucose by 61.3% (p<0.05) and increased soleus Glut4 protein by 157.2% (p<0.05). These changes were accompanied by diminished superoxide levels, decrease in oxidatively modified proteins (-60.8%; p<0.05) and reduced p38-MAPK and ERK1/2 hyperactivation (-50.4% and -35.4%, respectively; p<0.05). CONCLUSIONS: These results suggest that acetaminophen may be useful for the treatment of age-associated hyperglycemia.


Assuntos
Acetaminofen/farmacologia , Envelhecimento/efeitos dos fármacos , Hiperglicemia/prevenção & controle , Envelhecimento/fisiologia , Animais , Glicemia/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Transportador de Glucose Tipo 4/metabolismo , Fígado/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344 , Superóxidos/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
20.
Am J Hematol ; 84(9): 565-70, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19650117

RESUMO

Iron-induced cardiovascular disease is the leading cause of death in iron-overloaded patients. Deferasirox is a novel, once daily oral iron chelator that was recently approved for the treatment of transfusional iron overload. Here, we investigate whether deferasirox is capable of removing cardiac iron and improving iron-induced pathogenesis of the heart using the iron overload gerbil model. Animals were randomly divided into three groups: control, iron overload, and iron overload + deferasirox treatment. Iron-dextran was given 100 mg/kg per 5 days i.p for 10 weeks. Deferasirox treatment was taken post iron loading and was given at 100 mg/kg/day p.o for 1 or 3 months. Cardiac iron concentration was determined by inductively coupled plasma atomic emission spectroscopy. Compared with the untreated group, deferasirox treatment for 1 and 3 months decreased cardiac iron concentration 17.1% (P = 0.159) and 23.5% (P < 0.05), respectively. These treatment-associated reductions in cardiac iron were paralleled by decreases in tissue ferritin expression of 20% and 38% at 1 and 3 months, respectively (P < 0.05). Using oxyblot analysis and hydroethidine fluorescence, we showed that deferasirox significantly reduces cardiac protein oxidation and superoxide abundance by 36 and 47.1%, respectively (P < 0.05). Iron-induced increase in oxidative stress was also associated with increased phosphorylation of ERK-, p38-, and JNK-mitogen-activated protein kinase (MAPK). Interestingly, deferasirox treatment significantly diminished the phosphorylation of all three MAPK subfamilies. These results suggest that deferasirox may confer a cardioprotective effect against iron induced injury.


Assuntos
Benzoatos/farmacologia , Sobrecarga de Ferro/tratamento farmacológico , Ferro/análise , Miocárdio/química , Estresse Oxidativo/efeitos dos fármacos , Triazóis/farmacologia , Animais , Benzoatos/administração & dosagem , Cardiotônicos , Deferasirox , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Gerbillinae , Coração/efeitos dos fármacos , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/farmacologia , MAP Quinase Quinase 4/metabolismo , Masculino , Miocárdio/metabolismo , Fosforilação , Triazóis/administração & dosagem , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA