RESUMO
Cardiovascular diseases (CVD) are the leading cause of death worldwide. Growth factor therapy has emerged as novel therapeutic strategy under investigation for CVD. In this sense, adrenomedullin-2 (ADM-2) has been recently identified as a new angiogenic factor able to regulate the regional blood flow and cardiovascular function. However, the therapeutic value of ADM-2 is limited by its short biological half-life and low plasma stability. Poly (lactic-co-glycolic acid) (PLGA) micro- and nanoparticles have been investigated as growth factor delivery systems for cardiac repair. In this study, we aimed to develop PLGA nanoparticles containing ADM-2 intended for therapeutic angiogenesis. PLGA nanoparticles containing ADM-2 were prepared by a double emulsion modified method, resulting in 300 nm-sized stable particles with zeta potential around - 30 mV. Electron microscopy analysis by SEM and TEM revealed spherical particles with a smooth surface. High encapsulation efficiency was reached (ca.70%), as quantified by ELISA. ADM-2 associated to polymer nanoparticles was also determined by EDS elemental composition analysis, SDS-PAGE and LC-MS/MS for peptide identification. In vitro release assays showed the sustained release of ADM-2 from polymer nanoparticles for 21 days. Cell viability experiments were performed in J774 macrophages and H9c2 cardiomyocyte cells, about which PLGA nanoparticles loaded with ADM-2 did not cause toxicity in the range 0.01-1 mg/ml. Of note, encapsulated ADM-2 significantly induced cell proliferation in EA.hy926 endothelial cells, indicating the ADM-2 bioactivity was preserved after the encapsulation process. Collectively, these results demonstrate the feasibility of using PLGA nanoparticles as delivery systems for the angiogenic peptide ADM-2, which could represent a novel approach for therapeutic angiogenesis in CVD using growth factor therapy.
Assuntos
Indutores da Angiogênese/administração & dosagem , Proliferação de Células/efeitos dos fármacos , Portadores de Fármacos , Células Endoteliais/efeitos dos fármacos , Hormônios Peptídicos/administração & dosagem , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Indutores da Angiogênese/química , Indutores da Angiogênese/toxicidade , Animais , Linhagem Celular , Preparações de Ação Retardada , Composição de Medicamentos , Liberação Controlada de Fármacos , Humanos , Cinética , Camundongos , Nanopartículas , Hormônios Peptídicos/química , Hormônios Peptídicos/toxicidade , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/toxicidade , Ratos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/química , SolubilidadeRESUMO
Growth hormone (GH) release is a process that is well regulated by several factors, including GH secretagogues. GH can mediate the regulation of the fatty acid level and composition. The aim of this study was to determine the effect of a synthetic GH secretagogue peptide (A233) on the growth and fatty acid composition in tilapia (Oreochromis niloticus). To address this objective, we administrated a diet supplemented with A233 to juvenile tilapia for 60 days. The group fed with a diet supplemented with 600 µg of A233 per kg of feed increased in weight (4.81 ± 0.09 g) and specific growth rate (2.49 ± 0.03%/day) compared to the control diet group (3.63 ± 0.08 g, 2.07 ± 0.04%/day; respectively) (p < 0.001). In the muscle, the total lipids for the control diet group were higher than that in the group fed with 600 µg of A233 per kg feed; however, no differences were detected in the liver. In both tissues, the patterns of fatty acid composition and content were generally similar, with some exceptions. Tilapia fed with 600 µg of A233 per kg of feed showed, in liver and muscle, a significantly higher composition and content of n-3 polyunsaturated fatty acids (such as 20:5n-3, 22:5n-3, 22:6n-3) and n-3/n-6 PUFA than animals fed with the control diet. To our knowledge, this is the first report on the the effects of natural or synthetic GH secretagogues (GHS) on fatty acid composition, implying an increase in the nutritional quality of the tilapia.
Assuntos
Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Fígado/efeitos dos fármacos , Músculos/efeitos dos fármacos , Hormônios Peptídicos/farmacologia , Secretagogos/farmacologia , Animais , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Fígado/metabolismo , Músculos/metabolismo , Hormônios Peptídicos/administração & dosagem , Hormônios Peptídicos/química , Secretagogos/administração & dosagem , Secretagogos/químicaRESUMO
Coordination of cell growth and cell division is very important for living organisms in order for these to develop harmonically. The present research is concerned with the purification and characterization of a new peptide hormone, namely ZmIGF (Zea mays insulin-like growth factor), which regulates growth and cell division in maize tissues. ZmIGF is a peptide of 5.7 kDa, as determined by mass spectroscopy. It was isolated either from maize embryonic axes of 48-h germinated seeds or from embryogenic callus and purified through several chromatographic procedures to obtain a single peak as shown by Reverse Phase High-Performance Liquid Chromatography (RP-HPLC). This peptide exhibits a well defined α-helix structure by circular dichroism analysis, similar to that reported for Insulin or for Insulin-like growth factor (IGF-1). Further, ZmIGF seems to perform, in maize, a similar function to that reported for insulin or peptides from the IGF family in animals. Indeed, maize tissues stimulated either by ZmIGF or insulin showed to induce selective synthesis of ribosomal proteins as well as of DNA. Taken together, the previously mentioned data strongly suggest that plants contain a peptide hormone of the IGF family, highly conserved through evolution that regulates growth and development.
Assuntos
Hormônios Peptídicos/química , Reguladores de Crescimento de Plantas/química , Somatomedinas/química , Zea mays/química , Hormônios Peptídicos/fisiologia , Reguladores de Crescimento de Plantas/fisiologia , Estrutura Secundária de Proteína , Plântula/fisiologia , Sementes/fisiologia , Somatomedinas/fisiologia , Zea mays/embriologia , Zea mays/fisiologiaRESUMO
The proteome originally described the entire set of proteins expressed by a genome, tissue or organism. Subsequently this term was limited to all the expressed proteins at a given time under defined conditions. Hence, specializations such as functional proteome, cancer proteome, liver proteome and so forth have arisen. One particular proteome that has been recently described is the cryptome, a unique subset of already known proteins that has the ability of generating bioactive peptides and proteins when submitted to proteolytic cleavage, rather than the classical processing pathways. This is an idea in agreement with the concept that evolution is not related to the amount of genes or putative proteins that could be secreted by an organism, but to the way these proteins are processed. These 'new' molecules may have related or increased properties when compared to the 'original' molecule or possess completely unrelated biological effects, thus increasing the array of biological roles that can be associated to one given protein (or gene). In this work, we review this recent concept and put it into the toxinology field as well, an area in which the diversity of functional molecules (and roles) is essential for the survival of a given organism.