RESUMO
Cells employ several adaptive mechanisms under conditions of accelerated cell division, such as the unfolded protein response (UPR). The UPR is composed of a tripartite signaling system that involves ATF6, PERK, and IRE1, which maintain protein homeostasis (proteostasis). However, deregulation of protein translation initiation could be associated with breast cancer (BC) chemoresistance. Specifically, eukaryotic initiation factor-4A (eIF4A) is involved in the unfolding of the secondary structures of several mRNAs at the 5' untranslated region (5'-UTR), as well as in the regulation of targets involved in chemoresistance. Importantly, the tumor suppressor gene PDCD4 could modulate this process. This regulation might be disrupted in chemoresistant triple negative-BC (TNBC) cells. Therefore, we characterized the effect of doxorubicin (Dox), a commonly used anthracycline medication, on human breast carcinoma MDA-MB-231 cells. Here, we generated and characterized models of Dox chemoresistance, and chemoresistant cells exhibited lower Dox internalization levels followed by alteration of the IRE1 and PERK arms of the UPR and triggering of the antioxidant Nrf2 axis. Critically, chemoresistant cells exhibited PDCD4 downregulation, which coincided with a reduction in eIF4A interaction, suggesting a sophisticated regulation of protein translation. Likewise, Dox-induced chemoresistance was associated with alterations in cellular migration and invasion, which are key cancer hallmarks, coupled with changes in focal adhesion kinase (FAK) activation and secretion of matrix metalloproteinase-9 (MMP-9). Moreover, eIF4A knockdown via siRNA and its overexpression in chemoresistant cells suggested that eIF4A regulates FAK. Pro-atherogenic low-density lipoproteins (LDL) promoted cellular invasion in parental and chemoresistant cells in an MMP-9-dependent manner. Moreover, Dox only inhibited parental cell invasion. Significantly, chemoresistance was modulated by cryptotanshinone (Cry), a natural terpene purified from the roots of Salvia brandegeei. Cry and Dox co-exposure induced chemosensitization, connected with the Cry effect on eIF4A interaction. We further demonstrated the Cry binding capability on eIF4A and in silico assays suggest Cry inhibition on the RNA-processing domain. Therefore, strategic disruption of protein translation initiation is a druggable pathway by natural compounds during chemoresistance in TNBC. However, plasmatic LDL levels should be closely monitored throughout treatment.
Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Fator de Iniciação 4A em Eucariotos/química , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Resistencia a Medicamentos Antineoplásicos , Proteínas de Ligação a RNA/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Doxorrubicina/farmacologia , Proteínas Serina-Treonina Quinases/metabolismoRESUMO
Infection caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is responsible for the Coronavirus disease (COVID-19) and the current pandemic. Its mortality rate increases, demonstrating the imperative need for acute and rapid diagnostic tools as an alternative to current serological tests and molecular techniques. Features of electrochemical genosensor devices make them amenable for fast and accurate testing closer to the patient. This work reports on a specific electrochemical genosensor for SARS-CoV-2 detection and discrimination against homologous respiratory viruses. The electrochemical biosensor was assembled by immobilizing thiolated capture probes on top of maleimide-coated magnetic particles, followed by specific target hybridization between the capture and biotinylated signaling probes in a sandwich-type manner. The probes were rigorously designed bioinformatically and tested in vitro. Enzymatic complexes based on streptavidin-horseradish peroxidase linked the biotinylated signaling probe to render the biosensor electrochemical response. The genosensor showed to reach a sensitivity of 174.4 µA fM-1 and a limit of detection of 807 fM when using streptavidin poly-HRP20 enzymatic complex, detected SARS-CoV-2 specifically and discriminated it against homologous viruses in spiked samples and samples from SARS-CoV-2 cell cultures, a step forward to detect SARS-CoV-2 closer to the patient as a promising way for diagnosis and surveillance of COVID-19.
Assuntos
Técnicas Biossensoriais , COVID-19 , Técnicas Biossensoriais/métodos , COVID-19/diagnóstico , Técnicas Eletroquímicas/métodos , Humanos , Pandemias , SARS-CoV-2/genética , EstreptavidinaRESUMO
The synthesis of light-responsive nanocarriers (LRNs) with a variety of surface functional groups and/or ligands has been intensively explored for space-temporal controlled cargo release. LRNs have been designed on demand for photodynamic-, photothermal-, chemo-, and radiotherapy, protected delivery of bioactive molecules, such as smart drug delivery systems and for theranostic duties. LRNs trigger the release of cargo by a light stimulus. The idea of modifying LRNs with different moieties and ligands search for site-specific cargo delivery imparting stealth effects and/or eliciting specific cellular interactions to improve the nanosystems' safety and efficacy. This work reviews photoresponsive polymeric nanocarriers and photo-stimulation mechanisms, surface chemistry to link ligands and characterization of the resultant nanosystems. It summarizes the interesting biomedical applications of functionalized photo-controlled nanocarriers, highlighting the current challenges and opportunities of such high-performance photo-triggered delivery systems.
RESUMO
PURPOSE: Anthocyanins (ACNs) are polyphenols that might reduce pathological processes associated with type 2 diabetes mellitus and other chronic diseases, but their bioavailability is still controversial. In this study, the metabolic activity of oral delivery of ACN-loaded niosomes was investigated and evaluated in a diet-induced obesity (DIO) mice model. METHODS: ACNs extracted from Vaccinium Meridionale by the supercritical fluid extraction method were loaded in niosomes. The niosomal formulation was physically characterized and further administrated in drinking water to obese, insulin resistant mouse. We evaluated the effect of ACN loaded niosomes on hyperglycemia, glucose and insulin intolerance and insulin blood levels in C57BL/6 J mice fed with a high-fat diet. RESULTS: The ACN-loaded particles were moderately monodisperse, showed a negative surface charge and 57% encapsulation efficiency. The ACN-loaded niosomes ameliorated the insulin resistance and glucose intolerance in the DIO mice model. Additionally, they reduced animal weight and plasma insulin, glucose, leptin and total cholesterol levels in obese mice. CONCLUSION: ACN-loaded niosomes administration, as a functional drink, had a beneficial effect on the reversal of metabolic abnormalities associated with obesity.
Assuntos
Antocianinas/química , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/química , Lipossomos/química , Nanocápsulas/química , Extratos Vegetais/química , Estreptófitas/química , Animais , Antocianinas/administração & dosagem , Glicemia/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Colesterol/sangue , Colesterol/metabolismo , Diabetes Mellitus Experimental , Dieta Hiperlipídica , Composição de Medicamentos , Liberação Controlada de Fármacos , Humanos , Hipoglicemiantes/administração & dosagem , Insulina/sangue , Insulina/metabolismo , Insulina/farmacologia , Resistência à Insulina , Leptina/sangue , Leptina/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/tratamento farmacológico , Extratos Vegetais/administração & dosagemRESUMO
The physicochemical properties of four N-halomethylated and one non-halomethylated ammonium salts, with proven in vitro antileishmanial activity, were determined according to pharmaceutical standard procedures. The effectiveness and toxicity of these compounds were assessed in hamsters infected with Leishmania (Viannia) braziliensis and compared to that showed by meglumine antimoniate. Animals were followed during 90 days after the completion of treatment. Therapeutic response was determined according to the reduction of size of skin lesions. Toxicity was determined by the effect of compounds on body weight changes and serum levels of renal and hepatic metabolites. The effectiveness of compound 4 was similar to that showed by intralesional administration of meglumine antimoniate and better than that of the other ammonium salts. Levels of creatinine, alanine amino transferase, and blood urea nitrogen in serum were not significantly different between treatment groups, including healthy or untreated hamsters. Results imply that compound 4 has potential as a pharmaceutical active ingredient in the development of new and better formulations for the treatment of cutaneous leishmaniasis.
Assuntos
Antiprotozoários/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Compostos de Amônio Quaternário/farmacologia , Administração Tópica , Animais , Antiprotozoários/química , Peso Corporal/efeitos dos fármacos , Cricetinae , Modelos Animais de Doenças , Feminino , Leishmaniose Cutânea/parasitologia , Masculino , Meglumina/farmacologia , Antimoniato de Meglumina , Compostos Organometálicos/farmacologia , Compostos de Amônio Quaternário/química , Sais , Pele/parasitologia , Testes de ToxicidadeRESUMO
Snakebite continues to be a significant health problem in many countries of Latin America. Even though, there has been an improvement in the antivenom therapy, the local effects caused by myotoxic phospholipases A2 (PLA2) present in the venoms, still persist. In search for alternatives to antagonize the PLA2 activity of Bothrops asper's venom, 36 extracts belonging to seventeen families of vascular plants and bryophytes were screened. A significant inhibition of the enzymatic activity of PLA2 present in B. asper's whole venom was seen in eleven of these extracts. In addition, the antioxidant activity of all the extracts was evaluated. The results evidenced a significant statistical correlation between extracts with an inhibitory effect against PLA2 and those with an antioxidant activity. Moreover, the amount of phenols was quantified finding a relationship between the bioactivity and the presence of these compounds. Nine extracts were screened against a fraction of the venom rich in basic PLA2 (Fx-V B. asper), exhibiting an inhibitory effect on PLA2 activity of this fraction in a range from 30-80 percent. This activity was supported by the inhibition that these extracts presented on the cytotoxicity caused by Fx-V B. asper on murine skeletal muscle C2C12 myoblasts. The results obtained, could point to minimize efforts in the search of PLA2 inhibitors by focusing in samples with known antioxidant properties.
Veneno de cobra continua a ser um problema importante de saúde em muitos países da América Latina. Apesar dos avanços na terapia antiveneno, os efeitos locais causados por fosfolipases A2 miotóxica (PLA2) presentes no veneno, ainda persistem. Em busca de alternativas para antagonizar a atividade da PLA2 do veneno de Bothrops asper, foram selecionados 36 extratos pertencentes a dezessete famílias de plantas vasculares e briófitas. Uma inibição significativa da atividade enzimática de PLA2 presente no veneno de B. asper foi observada em onze extratos. Além disso, a atividade antioxidante dos extratos foi avaliada. Os resultados evidenciaram uma correlação estatisticamente significativa entre os extratos com ação inibitória contra a PLA2 e aqueles com atividade antioxidante. Também, a quantidade de fenóis foi avaliada e foi encontrada uma relação entre a atividade biológica e a presença dessas substâncias. Nove extratos foram testados contra uma fração do veneno rico em PLA2 básica (Fx-V B. asper), resultando em um efeito inibitório na atividade desta fração da PLA2 na faixa de 30-80 por cento. Esta atividade foi apoiada pela inibição que esses extratos apresentaram na citotoxicidade causada pelo Fx-V B. asper sobre mioblastos C2C12 de músculo esquelético de murino. Os resultados podem indicar a minimização dos esforços na busca de inibidores da PLA2, com foco nas amostras com propriedades antioxidantes conhecidas.
RESUMO
A hemorrhagic metalloproteinase, named Batx-I, was isolated from the venom of Bothrops atrox specimens (from Southeastern Colombian region) by a combination of CM-Sephadex C25 ion-exchange and Affi-gel Blue affinity chromatographies. This enzyme accounts for about 45% of venom proteins, and it has an ESI-MS isotope-averaged molecular mass of 23296.2 Da and a blocked N-terminus. Two internal fragments sequenced by mass spectrometric analysis showed similarity to other SVMPs from Bothrops venoms. To investigate the possible participation of Batx-I in the envenomation pathophysiology, proteolytic, fibrinogenolytic, hemorrhagic, and other biological activities were evaluated. The minimal hemorrhagic dose obtained was 17 microg/20 g body weight. The enzyme showed proteolytic activity on azocasein, comparable with activity of BaP1. This activity was inhibited by EDTA and 1, 10 o-phenanthroline but not by aprotinin, pepstatin A or PMSF. Fibrinogenolytic activity was analyzed by SDS-PAGE, revealing a preference for degrading the A alpha- and B beta-chains, although partial degradation of the gamma-chain was also detected. The protein lacks coagulant and defibrinating activity. The CK levels obtained, clearly reflects a myotoxic activity induced by Batx-I. The hemorrhagic and fibrinogenolytic activities exhibited by the isolated PI-SVMP may play a role in the hemorrhagic and blood-clotting disorders observed in patients bitten by B. atrox in Colombia.
Assuntos
Bothrops/fisiologia , Venenos de Crotalídeos/química , Fibrinólise/efeitos dos fármacos , Hemorragia/induzido quimicamente , Metaloproteases/isolamento & purificação , Metaloproteases/toxicidade , Animais , Caseínas/metabolismo , Cromatografia de Afinidade , Cromatografia por Troca Iônica , Colômbia , Venenos de Crotalídeos/antagonistas & inibidores , Venenos de Crotalídeos/isolamento & purificação , Venenos de Crotalídeos/toxicidade , Eletroforese em Gel de Poliacrilamida , Metaloproteases/antagonistas & inibidores , Músculo Esquelético/enzimologia , Músculo Esquelético/metabolismo , Inibidores de Proteases/farmacologia , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
En el éxito de un tratamiento antimicrobiano influyen diversos factores objetivos y subjetivos que en los distintos informes del Comité de Farmacia y Terapéutica del Instituto Nacional de Oncología y Radiobiología, durante el 2006, se describieron problemas relacionados con el cumplimiento de la política de antibióticos, lo cual ha sido justificado, por parte del personal afectado, por la imposibilidad de utilización de las técnicas de la microbiología. De igual forma, estos profesionales plantean que la política antimicrobiana es incorrecta por no contar con el mapa microbiológico actualizado; sin embargo, se conoce la existencia de otros factores, como la información de cada profesional en la terapéutica a prescribir, que pueden influir en el resultado del uso de los antimicrobianos. Con el objetivo de determinar hasta donde se recuerdan los conocimientos adquiridos en la formación profesional del personal escogido, a partir de la literatura de pregrado, relacionada con la terapéutica y que pueden o no influir en la prescripción de antimicrobianos fue que se realizó el presente estudio. Se dise±ó una encuesta de 5 preguntas con opción múltiple y 4 opciones, a se±alar solo una, como correcta, y se validó por expertos, la cual se les aplicó a médicos y técnicos o tecnólogos de Farmacia. Los resultados obtenidos demostraron un cierto grado de olvido de algunos conceptos importantes que pueden influir negativamente en el éxito de una terapéutica antiinfecciosa en los pacientes oncológicos, fundamentalmente los que recibirßn como tratamiento oncoespecífico la cirugía, por lo que se recomienda a la dirección de docencia la realización de actualizaciones al personal de la institución.
Success of an antimicrobial treatment is influenced by several objective and subjective factors that in different reports from Pharmacy and Therapeutics Committee of National Institute of Oncology and Radiology during 2006, problems related to fulfillment of antibiotics policy were described which has been justified by affected persons due to impossibility to use microbiology techniques. In the same way, these professionals propose that antimicrobial policy is incorrect by lack of updated microbiologic map; however, it is unknown existence of other factors, like the information of each professional to prescribe a therapy that may influence in the result of antimicrobial use. To determine where does the knowledges acquired are reminded in professional training of staff selected, from pregraduate literature, related to therapeutics and that may or not to influence in antimicrobial prescription it was possible to perform present study. Authors designed a 5 questions survey with a multiple option and four options to mark only one as correct and it was validated by experts, which was applied to physicians and Pharmacy technicians. Results achieved showed a certain degree of forgetting of some significant concepts that may to influence in a negative way on success of anti-infectious therapy in oncologic patients, mainly those candidates for surgery as oncospecific treatment, thus, we recommend to Teaching Management the performing of updates for institution staff.
Assuntos
Aminofilina/uso terapêutico , Cefazolina/uso terapêutico , Combinação de Medicamentos , Interações Medicamentosas , Dose Máxima Tolerável , Penicilinas/uso terapêutico , Antibioticoprofilaxia/métodosRESUMO
En Colombia Bothrops asper (mapaná) es la especie causante del 70 al 90 por ciento de los cerca de 3.000 accidentes ofídicos informados cada año. Durante varios siglos, la medicina tradicional ha utilizado plantas para el tratamiento de la mordedura de serpiente. En nuestro país, el 60 por ciento de las mordeduras son atendidas inicialmente por curanderos o chamanes, que usan al menos 100 especies de plantas medicinales en diferentes formas, de acuerdo al estado clínico del paciente. En este estudio se evaluó la capacidad inhibitoria de tres especies de la familia Heliconiaceae, H. latispatha Benth, H. wagneriana Petersen y H. curtispatha Petersen, sobre los efectos proteolítico, coagulante y hemolítico indirecto inducido por el veneno de Botrhops asper. La primera indujo un mayor porcentaje de inhibición del efecto hemolítico indirecto del veneno de B. asper que la Heliconia wagneriana, así como una reducción en la intensidad en las proteínas del veneno con masa molecular de 14 KDa, mientras que el extracto de la segunda planta mostró una mayor inhibición del efecto proteolítico inducido por el veneno de B. asper, así como mayores cambios en las bandas de proteína del veneno con masas moleculares entre 95 y 110 KDa. El extracto de Heliconia curtispatha, mostró la mayor capacidad inhibitoria de los efectos hemolítico, proteolítico y coagulante; además indujo una degradación de todas las proteínas del veneno completo de B. asper, como había sido reportado previamente
Assuntos
Extratos Vegetais , Heliconiaceae , Venenos de SerpentesRESUMO
The purpose of this paper was to develop a statistical methodology to optimize tablet manufacturing considering drug chemical and physical properties applying a crossed experimental design. The assessed model drug was dried ferrous sulphate and the variables were the hardness and the relative proportions of three excipients, binder, filler and disintegrant. Granule properties were modeled as a function of excipient proportions and tablet parameters were defined by the excipient proportion and hardness. The desirability function was applied to achieve optimal values for excipient proportions and hardness. In conclusion, crossed experimental design using hardness as the only process variable is an efficient strategy to quickly determine the optimal design process for tablet manufacturing. This method can be applied for any tablet manufacturing method.