RESUMO
Small heat shock proteins (sHSPs) are ATP-independent molecular chaperones with the α-crystalline domain that is critical to their chaperone activity. Within the sHSP family, three (HSPB1, HSPB3, and HSPB8) proteins are linked with inherited peripheral neuropathies, including distal hereditary motor neuropathy (dHMN) and Charco-Marie-Tooth disease (CMT). In this study, we introduced the HSPB3 Y118H (HSPB3Y118H) mutant gene identified from the CMT2 family in Drosophila. With a missense mutation on its α-crystalline domain, this human HSPB3 mutant gene induced a loss of motor activity accompanied by reduced mitochondrial membrane potential in fly neuronal tissues. Moreover, mitophagy, a critical mechanism of mitochondrial quality control, is downregulated in fly motor neurons expressing HSPB3Y118H. Surprisingly, PINK1 and Parkin, the core regulators of mitophagy, successfully rescued these motor and mitochondrial abnormalities in HSPB3 mutant flies. Results from the first animal model of HSPB3 mutations suggest that mitochondrial dysfunction plays a critical role in HSPB3-associated human pathology.
Assuntos
Doença de Charcot-Marie-Tooth , Proteínas de Drosophila , Proteínas de Choque Térmico Pequenas , Animais , Humanos , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/metabolismo , Drosophila , Proteínas de Drosophila/genética , Proteínas de Choque Térmico/genética , Mitocôndrias/metabolismo , Mutação , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Charcot-Marie-Tooth disease (CMT) is a group of inherited peripheral nerve disorders characterized by progressive muscle weakness and atrophy, sensory loss, foot deformities and steppage gait. Missense mutations in the gene encoding the small heat shock protein HSPB8 (HSP22) have been associated with hereditary neuropathies, including CMT. HSPB8 is a member of the small heat shock protein family sharing a highly conserved α-crystallin domain that is critical to its chaperone activity. In this study, we modeled HSPB8 mutant-induced neuropathies in Drosophila. The overexpression of human HSPB8 mutants in Drosophila neurons produced no significant defect in fly development but led to a partial reduction in fly lifespan. Although these HSPB8 mutant genes failed to induce sensory abnormalities, they reduced the motor activity of flies and the mitochondrial functions in fly neuronal tissue. The motor defects and mitochondrial dysfunction were successfully restored by PINK1 and parkin, which are Parkinson's disease-associated genes that have critical roles in maintaining mitochondrial function and integrity. Consistently, kinetin riboside, a small molecule amplifying PINK1 activity, also rescued the loss of motor activity in our HSPB8 mutant model.
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DJ-1 is one of the causative genes of early-onset familial Parkinson's disease (PD). As a result, DJ-1 influences the pathogenesis of sporadic PD. DJ-1 has various physiological functions that converge to control the levels of intracellular reactive oxygen species (ROS). Based on genetic analyses that sought to investigate novel antioxidant DJ-1 downstream genes, pyruvate dehydrogenase (PDH) kinase (PDK) was demonstrated to increase survival rates and decrease dopaminergic (DA) neuron loss in DJ-1 mutant flies under oxidative stress. PDK phosphorylates and inhibits the PDH complex (PDC), subsequently downregulating glucose metabolism in the mitochondria, which is a major source of intracellular ROS. A loss-of-function mutation in PDK was not found to have a significant effect on fly development and reproduction, but severely ameliorated oxidative stress resistance. Thus, PDK plays a critical role in the protection against oxidative stress. Loss of PDH phosphatase (PDP), which dephosphorylates and activates PDH, was also shown to protect DJ-1 mutants from oxidative stress, ultimately supporting our findings. Further genetic analyses suggested that DJ-1 controls PDK expression through hypoxia-inducible factor 1 (HIF-1), a transcriptional regulator of the adaptive response to hypoxia and oxidative stress. Furthermore, CPI-613, an inhibitor of PDH, protected DJ-1 null flies from oxidative stress, suggesting that the genetic and pharmacological inhibition of PDH may be a novel treatment strategy for PD associated with DJ-1 dysfunction.
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Drosophila , Doença de Parkinson , Animais , Neurônios Dopaminérgicos/metabolismo , Drosophila/genética , Estresse Oxidativo/genética , Doença de Parkinson/patologia , Piruvato Desidrogenase Quinase de Transferência de Acetil , Espécies Reativas de Oxigênio/metabolismoRESUMO
In previous reports, bisphenol A (BPA) exposure affects reproductive function in Drosophila melanogaster females. To test the maternal effect of BPA exposure on fly reproductive function, F0 mothers were exposed to 0, 0.1, 1, and 10 mg/L of BPA and the fecundity in F1 and F2 generations were checked. In this experiment, 1 and 10 mg/L BPA significantly decreased the fecundity of F1 females. Moreover, 0.1 and 1 mg/L BPA substantially reduced egg production in the F2 generation. These results suggested that maternal exposure to BPA at enviromentally relavant concnetrations reduces reproductive function in Drosophila melanogaster females and that this effect is transgenerational.
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Distal hereditary motor neuropathies (dHMN) are a group of inherited peripheral nerve disorders characterized by length-dependent motor neuron weakness and subsequent muscle atrophy. Missense mutations in the gene encoding small heat shock protein HSPB1 (HSP27) have been associated with hereditary neuropathies including dHMN. HSPB1 is a member of the small heat shock protein (sHSP) family characterized by a highly conserved α-crystallin domain that is critical to their chaperone activity. In this study, we modeled HSPB1 mutant-induced neuropathies in Drosophila using a human HSPB1S135F mutant that has a missense mutation in its α-crystallin domain. Overexpression of the HSPB1 mutant produced no significant defect in the Drosophila development, however, a partial reduction in the life span was observed. Further, the HSPB1 mutant gene induced an obvious loss of motor activity when expressed in Drosophila neurons. Moreover, suppression of histone deacetylase 6 (HDAC6) expression, which has critical roles in HSPB1 mutant-induced axonal defects, successfully rescued the motor defects in the HSPB1 mutant Drosophila model.
Assuntos
Drosophila melanogaster/genética , Proteínas de Choque Térmico/genética , Neuropatia Hereditária Motora e Sensorial/genética , Chaperonas Moleculares/genética , Animais , Modelos Animais de Doenças , Proteínas de Choque Térmico/metabolismo , Neuropatia Hereditária Motora e Sensorial/metabolismo , Humanos , Chaperonas Moleculares/metabolismo , Atividade Motora/genética , Mutação , alfa-Cristalinas/genética , alfa-Cristalinas/metabolismoRESUMO
Drosophila cyclophilin 1 (Cyp1) is a structural and functional homolog of mammalian cyclophilin D (CypD), a unique mitochondrial cyclophilin (Cyp) that regulates the inner mitochondrial membrane permeability transition and cell survival under cellular stresses such as oxidative damage. In this study, we generated and characterized a Drosophila Cyp1 mutant. Cyp1 mutant flies successfully developed into adults and showed no significant defects in mitochondrial morphology, function, and content. However, oxidative damage significantly decreased in Cyp1 mutant flies, and inhibition of Cyp1 expression substantially increased the survival under various oxidative stress paradigms. Moreover, Cyp1 mutation successfully ameliorated survival rates, locomotor activity, and dopaminergic neuron quantity in a Drosophila DJ-1 mutant under oxidative stress, further confirming the protective role of Cyp1 mutation against oxidative stress. In conclusion, these results suggest Cyp1 and its human homolog CypD as putative molecular targets for the treatment of DJ-1 deficiency-associated diseases, including Parkinson's disease.
Assuntos
Ciclofilinas/genética , Drosophila melanogaster/genética , Estresse Oxidativo/efeitos dos fármacos , Animais , Peptidil-Prolil Isomerase F , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/genética , Humanos , Mutação , Doença de Parkinson , Taxa de SobrevidaRESUMO
Fermented microalgae Pavlova lutheri (P. lutheri), the product of Hansenula polymorpha fermentation, exhibited an increase in alkaline phosphatase (ALP) activity in MG63 osteoblastic cells when compared to that of nonfermented P. lutheri. Fractionation of the fermented P. lutheri resulted in identification of the active peptide [peptide of P. lutheri fermentation (PPLF)] with the sequence of EPQWFL. PPLF significantly increased ALP release from MG63 cells and mineralization in a dosedependent manner. In addition, the intracellular levels of ALP and osteocalcin (OCN) proteins were augmented by PPLF treatment. To identify the molecular mechanism underlying the effect of PPLF on osteoblastic differentiation, the phosphorylation levels of the mitogenactivated protein kinases, p38, extracellular signalregulated kinases 1/2 and Jun, and nuclear factor (NF)κB were determined following PPLF treatment and the differences in expression were analyzed using p38 and NFκB selective inhibitors. These results concluded that PPLF from fermented P. lutheri induced osteoblastic differentiation by increasing ALP and OCN release in MG63 cells via the p38/p65 signaling pathway, indicating that PPLF supplement may be effective for therapeutic application in the field of bone health.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Haptófitas/química , Microalgas/química , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Peptídeos/farmacologia , Fosfatase Alcalina/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Linhagem Celular , Fermentação , Humanos , Osteoblastos/citologia , Osteocalcina/metabolismo , Peptídeos/químicaRESUMO
Tracking the effectiveness of CE over time beyond simply confirming its efficacy in continuing education (CE) in nursing is crucial. However, research evidence on the analysis of change of the effectiveness of CE over time is limited, particularly in the context of case management. This methodological study aimed to introduce both a growth curve modeling and an intra-individual variability index and demonstrate step-by-step procedures and interpretations of those analyses to assess case manager competency over time, using secondary data analysis. Data were collected from 22 case managers affiliated with the Korean National Health Insurance Corporation who attended three series of CE to improve their competency between May 2008 and August 2009. Unexpected results revealed a negative fixed effect of education level in the overall estimation of case managers' competency trajectory and a negative correlation between education level and case managers' intra-individual competency inconsistency over time. J Contin Nurs Educ. 2017;48(5):230-238.
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Administração de Caso/normas , Gerentes de Casos/educação , Educação Continuada/estatística & dados numéricos , Educação Continuada/normas , Avaliação Educacional/métodos , Competência Profissional/estatística & dados numéricos , Competência Profissional/normas , Adulto , Administração de Caso/estatística & dados numéricos , Gerentes de Casos/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
INTRODUCTION: We investigate the effect of active peptide from Urechis unicinctus (UU) by high temperature/pressure and ultra-wave assisted lysis on erectile dysfunction in streptozotocin-induced diabetic rats. MATERIALS AND METHODS: Forty 12-week-old Sprague-Dawley rats were used in this study. Diabetes was induced by a one-time intraperitoneal injection of streptozotocin (50mg/kg). One week later, the diabetic rats were randomly divided into four groups: normal control, untreated diabetes control, and groups treated with 100 or 500mg/kg/d UU peptide. Rats were fed with UU peptide by intragastric administration for 8 weeks. After 8 weeks, penile hemodynamic function was evaluated in all groups by measuring the intracavernosal pressure after electrostimulating the cavernous nerve. Nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) activities were measured and endothelial nitric oxide synthase (eNOS) and neuronal NOS (nNOS) protein expression. was determined by Western blot. RESULTS: Maximum intracavernosal pressure in diabetic control rats decreased significantly compared to normal control rats, and was increased significantly compared to untreated diabetic rats after UU peptide supplementation. Treatment with the higher dose of UU peptide significantly increased the NO and cGMP levels compared with the diabetic control group. Decreased activity and expression eNOS and nNOS were found in the diabetic rats compared with the normal control group. Decreased eNOS and nNOS in diabetic rats were improved by UU peptide administration. CONCLUSIONS: Active peptide from UU ameliorates erectile function in a streptozotocin induced diabetic rat model of erectile dysfunction.
Assuntos
Anelídeos/química , Diabetes Mellitus Experimental/complicações , Disfunção Erétil/tratamento farmacológico , Peptídeos/farmacologia , Animais , Células Cultivadas , Diabetes Mellitus Experimental/induzido quimicamente , Disfunção Erétil/etiologia , Disfunção Erétil/fisiopatologia , Masculino , Pênis/efeitos dos fármacos , Peptídeos/análise , Peptídeos/uso terapêutico , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Estreptozocina , TemperaturaRESUMO
ABSTRACT Introduction: We investigate the effect of active peptide from Urechis unicinctus (UU) by high temperature/pressure and ultra-wave assisted lysis on erectile dysfunction in streptozotocin-induced diabetic rats. Materials and Methods: Forty 12-week-old Sprague-Dawley rats were used in this study. Diabetes was induced by a one-time intraperitoneal injection of streptozotocin (50mg/kg). One week later, the diabetic rats were randomly divided into four groups: normal control, untreated diabetes control, and groups treated with 100 or 500mg/kg/d UU peptide. Rats were fed with UU peptide by intragastric administration for 8 weeks. After 8 weeks, penile hemodynamic function was evaluated in all groups by measuring the intracavernosal pressure after electrostimulating the cavernous nerve. Nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) activities were measured and endothelial nitric oxide synthase (eNOS) and neuronal NOS (nNOS) protein expression was determined by Western blot. Results: Maximum intracavernosal pressure in diabetic control rats decreased significantly compared to normal control rats, and was increased significantly compared to untreated diabetic rats after UU peptide supplementation. Treatment with the higher dose of UU peptide significantly increased the NO and cGMP levels compared with the diabetic control group. Decreased activity and expression eNOS and nNOS were found in the diabetic rats compared with the normal control group. Decreased eNOS and nNOS in diabetic rats were improved by UU peptide administration. Conclusions: Active peptide from UU ameliorates erectile function in a streptozotocin induced diabetic rat model of erectile dysfunction.
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Animais , Masculino , Ratos , Peptídeos/farmacologia , Diabetes Mellitus Experimental/complicações , Disfunção Erétil/tratamento farmacológico , Anelídeos/química , Pênis/efeitos dos fármacos , Peptídeos/análise , Peptídeos/uso terapêutico , Temperatura , Distribuição Aleatória , Células Cultivadas , Ratos Sprague-Dawley , Estreptozocina , Diabetes Mellitus Experimental/induzido quimicamente , Disfunção Erétil/etiologia , Disfunção Erétil/fisiopatologiaRESUMO
Although ultraviolet B (UVB) has a low level of skin penetration, it readily results in epidermal sunburn of keratinocytes that are destined to apoptosis after sun expose, and leads to DNA damage. Dioxinodehydroeckol (DHE), a phlorotannin from Ecklonia cava has been explored for its preventive activity against UVB-induced apoptosis in human keratinocyte (HaCaT) cells; however, the protective effects of treatment with low doses of DHE on UVB-damaged cells post-UVB exposure and their underlying mechanisms still remain unclear. The HaCaT cells were exposed to 20 mJcm(-2) of UVB irradiation which is the minimal erythema dose (MED) for individuals to be able to tan, and the expression levels of Bax/Bcl-2 and caspase-3,-8, -9 which are associated genes with apoptosis were investigated when we either treated cells with DHE doses after UVB irradiation or exposed them to UVB only. Our results suggest insight into proposed mechanistic pathway of protective activity of DHE on the HaCaT cells from UVB-induced apoptosis, indicating the benefit of DHE as a repair agent for skin damage against UVB.
Assuntos
Apoptose/efeitos dos fármacos , Dioxinas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Raios Ultravioleta , Proteína X Associada a bcl-2/metabolismo , Apoptose/efeitos da radiação , Caspase 3/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Phaeophyceae/química , Phaeophyceae/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteína X Associada a bcl-2/genéticaRESUMO
Polysaccharide-based bioflocculants have attracted considerable attention in recent years due to their biodegradable, harmless and negligible secondary pollution. Bioflocculants are organic macromolecular substances secreted by microorganisms. A simple, cost-effective and green method was developed for the biosynthesis of silver nanoparticles using polysaccharides as reducing and stabilizing agents. In this paper, we report on the production and optimization of polysaccharide-based bioflocculant for the green synthesis of silver nanoparticles by Streptomyces sp. MBRC-91. Medium composition and culture conditions for polysaccharide-based bioflocculants were statistically optimized by response surface methodology (RSM). The bioflocculant production was statistically optimized with most significant factors, namely palm jaggery (18.73g/L), yeast extract (2.07g/L), K2HPO4 (3.74g/L) and NaCl (0.38g/L), respectively. The biosynthesized silver nanoparticles were characterized by UV-vis spectroscopy, XRD, FTIR, FESEM, EDXA and HRTEM. The biosynthesized silver nanoparticles revealed strong antibacterial activity in sewage water and this result could make a new avenue in the wastewater treatment. Therefore, the biosynthesized silver nanoparticles can be extended as an alternative for the development of new bactericidal bionanomaterials for wastewater treatment and biotechnological applications.
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Nanopartículas Metálicas , Nanotecnologia/métodos , Polissacarídeos/metabolismo , Prata/química , Prata/metabolismo , Streptomyces/metabolismo , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Floculação , Concentração de Íons de Hidrogênio , Polissacarídeos/química , Esgotos/microbiologia , Prata/farmacologia , Streptomyces/crescimento & desenvolvimento , Streptomyces/isolamento & purificação , Temperatura , Fatores de TempoRESUMO
Advancement of biological process for the synthesis of bionanoparticles is evolving into a key area of research in nanotechnology. The present study deals with the biosynthesis, characterization of gold bionanoparticles by Nocardiopsis sp. MBRC-48 and evaluation of their antimicrobial, antioxidant and cytotoxic activities. The gold bionanoparticles obtained were characterized by UV-visible spectroscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis and transmission electron microscopy (TEM). The synthesized gold bionanoparticles were spherical in shape with an average of 11.57 ± 1.24 nm as determined by TEM and dynamic light scattering (DLS) particle size analyzer, respectively. The biosynthesized gold nanoparticles exhibited good antimicrobial activity against pathogenic microorganisms. It showed strong antioxidant activity as well as cytotoxicity against HeLa cervical cancer cell line. The present study demonstrated the potential use of the marine actinobacterial strain of Nocardiopsis sp. MBRC-48 as an important source for gold nanoparticles with improved biomedical applications including antimicrobial, antioxidant as well as cytotoxic agent.
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Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Ouro/química , Nanopartículas Metálicas , Actinobacteria , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Testes de Sensibilidade Microbiana , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
Nano-Hydroxyapatite (nHA) was isolated from salmon bone by alkaline hydrolysis. The resulting nHA was characterized using several analytical tools, including thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), to determine the purity of the nHA sample. The removal of organic matter from the raw fish was confirmed by TGA. FT-IR confirmed the presence of a carbonated group and the similarities to synthetic Sigma HA. XRD revealed that the isolated nHA was amorphous. Microscopy demonstrated that the isolated nHA possessed a nanostructure with a size range of 6-37 nm. The obtained nHA interacted with mesenchymal stem cells (MSCs) and was non-toxic. Increased mineralization was observed for nHA treated MSCs compared to the control group. These results suggest that nHA derived from salmon is a promising biomaterial in the field of bone tissue engineering.
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The aim of this study was to investigate antihypertensive effect of bioactive peptides from skate (Okamejei kenojei) skin gelatin. The Alcalase/protease gelatin hydrolysate below 1 kDa (SAP) exhibited the highest angiotensin-I converting enzyme (ACE) inhibition compared to other hydrolysates. SAP can decrease systolic blood pressure significantly in spontaneously hypertensive rats. SAP inhibited vasoconstriction via PPAR-γ expression, activation and phosphorylation of eNOS in lungs. Moreover, the expression levels of endothelin-1, RhoA, α-smooth muscle actin, cleaved caspase 3 and MAPK were decreased by SAP in lungs. Vascularity, muscularization and cellular proliferation in lungs were detected by immunohistochemical staining. Finally, two purified peptides (LGPLGHQ, 720Da and MVGSAPGVL, 829Da) showed potent ACE inhibition with IC50 values of 4.22 and 3.09 µM, respectively. These results indicate that bioactive peptides isolated from skate skin gelatin may serve as candidates against hypertension and could be used as functional food ingredients.
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Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Proteínas de Peixes/química , Gelatina/química , Hipertensão/tratamento farmacológico , Peptídeos/administração & dosagem , Rajidae , Pele/química , Inibidores da Enzima Conversora de Angiotensina/química , Animais , Anti-Hipertensivos/química , Pressão Sanguínea/efeitos dos fármacos , Feminino , Humanos , Hidrólise , Hipertensão/enzimologia , Masculino , Peptídeos/química , Peptidil Dipeptidase A/metabolismo , Ratos , Ratos Endogâmicos SHR , Subtilisinas/química , Vasoconstrição/efeitos dos fármacosRESUMO
Marine polysaccharides have been found as the principle component in cell wall structures of seaweeds or exoskeletons of crustaceans. Due to numerous pharmaceutical properties of marine polysaccharides such as antioxidant, anti-inflammatory, antiallergic, antitumor, antiobesity, antidiabetes, anticoagulant, antiviral, immunomodulatory, cardioprotective, and antihepatopathy activities, they have been applied in many fields of biomaterials, food, cosmetic, and pharmacology. Recently, several marine polysaccharides such alginate, porphyran, fucoidan, and chitin and its derivatives have been evidenced as downregulators of allergic responses due to enhancement of innate immune system, alteration of Th1/Th2 balance forward to Th1 cells, inhibition of IgE production, and suppression of mast cell degranulation. This contribution, therefore, focuses on antiallergic properties of marine polysaccharides and emphasizes their potential application as bioactive food ingredients as well as nutraceuticals for prevention of allergic disorders.
Assuntos
Alginatos/farmacologia , Quitina/farmacologia , Hipersensibilidade/tratamento farmacológico , Polissacarídeos/farmacologia , Alga Marinha/química , Sefarose/análogos & derivados , Alginatos/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Antivirais/química , Antivirais/farmacologia , Quitina/análogos & derivados , Quitina/química , Quitosana/química , Quitosana/farmacologia , Suplementos Nutricionais , Ácido Glucurônico/química , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/química , Ácidos Hexurônicos/farmacologia , Hipersensibilidade/imunologia , Imunoglobulina E/imunologia , Mastócitos/imunologia , Oligossacarídeos , Polissacarídeos/química , Sefarose/química , Sefarose/farmacologia , Equilíbrio Th1-Th2RESUMO
Bone is a complex and hierarchical tissue consisting of nano hydroxyapatite and collagen as major portion. Several attempts have been made to prepare the artificial bone so as to replace the autograft and allograft treatment. Tissue engineering is a promising approach to solve the several issues and is also useful in the construction of artificial bone with materials including polymer, ceramics, metals, cells and growth factors. Composites consisting of polymer-ceramics, best mimic the natural functions of bone. Alginate, an anionic polymer owing enormous biomedical applications, is gaining importance particularly in bone tissue engineering due to its biocompatibility and gel forming properties. Several composites such as alginate-polymer (PLGA, PEG and chitosan), alginate-protein (collagen and gelatin), alginate-ceramic, alginate-bioglass, alginate-biosilica, alginate-bone morphogenetic protein-2 and RGD peptides composite have been investigated till date. These alginate composites show enhanced biochemical significance in terms of porosity, mechanical strength, cell adhesion, biocompatibility, cell proliferation, alkaline phosphatase increase, excellent mineralization and osteogenic differentiation. Hence, alginate based composite biomaterials will be promising for bone tissue regeneration. This review will provide a broad overview of alginate preparation and its applications towards bone tissue engineering.
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Alginatos/química , Regeneração Óssea , Osteogênese , Engenharia Tecidual , Alginatos/uso terapêutico , Materiais Biocompatíveis/uso terapêutico , Osso e Ossos/metabolismo , Osso e Ossos/fisiopatologia , Quitosana/química , Durapatita , Ácido Glucurônico/química , Ácido Glucurônico/uso terapêutico , Ácidos Hexurônicos/química , Ácidos Hexurônicos/uso terapêutico , Humanos , Polímeros/química , Polímeros/uso terapêutico , Alicerces TeciduaisRESUMO
Marine actinobacterial synthesis of gold nanoparticles has good potential to develop simple, cost-effective and eco-friendly methods for production of important biomaterials. In this context, gold nanoparticles have attracted considerable attention in recent years, owing to their various applications. In this paper, we report on the production of α-amylase for the extracellular synthesis of gold nanoparticles using Streptomyces sp. MBRC-82. Medium composition and culture conditions for α-amylase production were statistically optimized. Plackett-Burman design was employed to find out the optimal medium constituents and culture conditions to enhance α-amylase production. Box-Behnken design revealed that three independent variables namely soluble starch (5.8484 g), peptone (3.5191 g), and NaCl (0.3829) significantly influenced α-amylase production. The gold nanoparticles were characterized by ultraviolet-visible (UV-vis) spectrometer, X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA), and transmission electron microscopy (TEM). The particles synthesized using the optimized enzyme activity ranged from 20 to 80 nm with an average particle size of 40 nm and therefore can be extended to various medicinal applications.
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Ouro/química , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Streptomyces/enzimologia , alfa-Amilases/biossíntese , Análise de Variância , Nanopartículas Metálicas/ultraestrutura , Filogenia , Análise de Regressão , Espectrometria por Raios X , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Streptomyces/isolamento & purificação , Difração de Raios XRESUMO
8,4â´-dieckol is a natural product which has been isolated from brown alga, Ecklonia cava. This polyphenolic compound is a phlorotannin derivative with a broad range of bioactivities. Its inhibitory activity on human immunodeficiency virus type-1 (HIV-1) was tested and the results indicated that 8,4â´-dieckol inhibited HIV-1 induced syncytia formation, lytic effects, and viral p24 antigen production at noncytotoxic concentrations. Furthermore, it was found that 8,4â´-dieckol selectively inhibited the activity of HIV-1 reverse trancriptase (RT) enzyme with 91% inhibition ratio at the concentration of 50 µM. HIV-1 entry was also inhibited by 8,4â´-dieckol. According to data from this study, 8,4â´-dieckol is an effective compound against HIV-1 with high potential for further studies. These results suggest that it might be used as a drug candidate for the development of new generation therapeutic agents, although further studies on the mechanism of inhibition should be addressed.
Assuntos
Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Benzofuranos/química , Benzofuranos/farmacologia , HIV-1/efeitos dos fármacos , Phaeophyceae/química , Taninos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Efeito Citopatogênico Viral/efeitos dos fármacos , Células Gigantes/efeitos dos fármacos , Proteína do Núcleo p24 do HIV/biossíntese , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/enzimologia , HIV-1/metabolismo , HIV-1/fisiologia , Humanos , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacosRESUMO
SCOPE: Spirulina has been found suitable for use as a bioactive additive. It is an excellent source of protein that can be hydrolyzed into bioactive peptides. Two peptides LDAVNR (P1) and MMLDF (P2) purified from enzymatic hydrolysate of Spirulina maxima have been reported to be effective against early atherosclerotic responses. In this study, the intracellular mechanism involved in the downregulation of these peptides on high-affinity IgE receptor-mediated allergic reaction was further investigated. METHODS AND RESULTS: RBL-2H3 mast cells were pretreated with P1 or P2 and sensitized with dinitrophenyl-specific IgE antibody before stimulation of antigen dinitrophenyl-BSA. It was revealed that P1 and P2 exhibited significant inhibition on mast-cell degranulation via decreasing histamine release and intracellular Ca(2+) elevation. The inhibitory activity of P1 was found due to blockade of calcium- and microtubule-dependent signaling pathways. Meanwhile, the inhibition of P2 was involved in suppression of phospholipase Cγ activation and reactive oxygen species production. Moreover, the suppressive effects of P1 and P2 on generation of IL-4 were evidenced via depression of nuclear factor-κB translocation. CONCLUSION: These findings indicate that peptides P1 and P2 from S. maxima may be promising candidates of antiallergic therapeutics, contributing to development of bioactive food ingredients for amelioration of allergic diseases.