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1.
Molecules ; 29(5)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38474673

RESUMO

1,3,6-Trigalloylglucose is a natural compound that can be extracted from the aqueous extracts of ripe fruit of Terminalia chebula Retz, commonly known as "Haritaki". The potential anti-Helicobacter pylori (HP) activity of this compound has not been extensively studied or confirmed in scientific research. This compound was isolated using a semi-preparative liquid chromatography (LC) system and identified through Ultra-high-performance liquid chromatography-MS/MS (UPLC-MS/MS) and Nuclear Magnetic Resonance (NMR). Its role was evaluated using Minimum inhibitory concentration (MIC) assay and minimum bactericidal concentration (MBC) assay, scanning electron microscope (SEM), inhibiting kinetics curves, urea fast test, Cell Counting Kit-8 (CCK-8) assay, Western blot, and Griess Reagent System. Results showed that this compound effectively inhibits the growth of HP strain ATCC 700392, damages the HP structure, and suppresses the Cytotoxin-associated gene A (Cag A) protein, a crucial factor in HP infection. Importantly, it exhibits selective antimicrobial activity without impacting normal epithelial cells GES-1. In vitro studies have revealed that 1,3,6-Trigalloylglucose acts as an anti-adhesive agent, disrupting the adhesion of HP to host cells, a critical step in HP infection. These findings underscore the potential of 1,3,6-Trigalloylglucose as a targeted therapeutic agent against HP infections.


Assuntos
Helicobacter pylori , Terminalia , Extratos Vegetais/química , Terminalia/química , Cromatografia Líquida , Espectrometria de Massas em Tandem , Água
2.
J Clin Ultrasound ; 50(7): 953-954, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35900308

RESUMO

Cavernous hemangioma is a rare, benign tumor and usually uncommon in adults. It is often difficult to diagnose in time because conventional medical imaging examinations usually fail to provide valid information. Clinicians should attach importance to the value of contrast-enhanced ultrasound as an adjunct to rapidly diagnose cavernous hemangioma.


Assuntos
Hemangioma Cavernoso , Adulto , Hemangioma Cavernoso/diagnóstico por imagem , Hemangioma Cavernoso/patologia , Humanos , Tomografia Computadorizada por Raios X , Ultrassonografia
3.
J Bone Miner Metab ; 39(5): 748-756, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33829324

RESUMO

INTRODUCTION: The incidence of osteoporosis is positively correlated with age. Berberine has been reported to treat osteoporosis due to its beneficial actions on bone formation. However, the direct effects of berberine on senile osteoporosis remain unclear. The present study investigated the protective effects of berberine on senile osteoporosis in mice and preliminarily evaluated its potential mechanism. MATERIALS AND METHODS: 20-month-old male C57BL/6 J mice were used as senile osteoporosis mouse model and treated with strontium ranelate (SR) or berberine or solvent control by daily gavage for 2 months. Thereafter, bone mass and microstructure parameters were assessed. Histological staining was performed to identify the osteogenic, adipogenic and osteoclastic activity of bone tissue. Moreover, role of cAMP/PKA/CREB signaling pathway in berberine affecting bone marrow mesenchymal stem cells (BMSCs) differentiation was clarified by enzyme-linked immunosorbent assay and western blot analysis. RESULTS: The results showed that the SR-treated group displayed a high trabecular bone mass phenotype. For mice administrated with berberine, cancellous bone mass was upregulated in a dose-dependent manner, as indicated by gradually increased bone mass, trabecular bone volume fraction and trabecular number. Furthermore, berberine promotes osteogenic and inhibits adipogenic differentiation of BMSCs via cAMP/PKA/CREB signaling. Also, bone resorption effect becomes more obvious with increasing dose of berberine in vitro. CONCLUSION: The present results suggest that berberine exerts potent bone protective effects by promoting bone formation, inhibiting marrow fat accumulation and bone resorption. This effect may be achieved through cAMP/PKA/CREB signaling pathway.


Assuntos
Berberina , Células-Tronco Mesenquimais , Osteoporose , Animais , Berberina/farmacologia , Diferenciação Celular , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteogênese , Osteoporose/tratamento farmacológico
4.
Nanomedicine ; 11(7): 1773-84, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25959925

RESUMO

Herein, chiral selenium nanoparticles (L-SeNPs/D-SeNPs) modified with a dinuclear Ruthenium (II) complex were used to effectively deliver siRNA targeting the MDR1 gene. In this co-delivery system, the luminescent dinuclear Ruthenium (II) complex was developed to act as a gene carrier and anti-tumor drug, while offering luminescent imaging to follow the intracellular trafficking. Interestingly, Ru@L-SeNPs exhibited a stronger protein and pDNA affinity than Ru@D-SeNPs, indicating that chirality may have an effect on pDNA/siRNA binding and biocompatibility. Cisplatin-resistant A549R cells treated with Ru@L-SeNPs-siRNA demonstrated significant downregulation of P-glycoprotein (P-gp) expression, resulting in unprecedented enhanced cytotoxicity through the induction of apoptosis with the involvement of phosphorylation of p53, MAPK and PI3K/Akt signaling pathways. In vivo investigation confirmed that Ru@L-SeNPs-siRNA nanoparticles exhibited high tumor-targeted fluorescence, enhanced anti-tumor efficacy, and decreased systemic toxicity. These results suggest that Ru@L-SeNPs are promising vectors for the delivery of siRNA and for real-time tracking of treatment. FROM THE CLINICAL EDITOR: In this study, the authors designed bi-functional selenium nanoparticles with specific chirality to deliver siRNA, for targeting tumor MDR1 gene. The underlying ruthenium (II) complex could also offer fluorescence for real-time imaging. This new system has been shown to have enhanced efficacy against drug resistant tumor cells in both in-vitro and in-vivo experiments.


Assuntos
Técnicas de Transferência de Genes , Nanopartículas/administração & dosagem , Neoplasias/terapia , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Apoptose/genética , Linhagem Celular Tumoral , Cisplatino/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Nanopartículas/química , Neoplasias/genética , Neoplasias/patologia , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Rutênio/química , Selênio/administração & dosagem , Selênio/química
5.
Front Endocrinol (Lausanne) ; 14: 1308408, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38685911

RESUMO

Osteocyte, a cell type living within the mineralized bone matrix and connected to each other by means of numerous dendrites, appears to play a major role in body homeostasis. Benefiting from the maturation of osteocyte extraction and culture technique, many cross-sectional studies have been conducted as a subject of intense research in recent years, illustrating the osteocyte-organ/tissue communication not only mechanically but also biochemically. The present review comprehensively evaluates the new research work on the possible crosstalk between osteocyte and closely situated or remote vital organs/tissues. We aim to bring together recent key advances and discuss the mutual effect of osteocyte and brain, kidney, vascular calcification, muscle, liver, adipose tissue, and tumor metastasis and elucidate the therapeutic potential of osteocyte.


Assuntos
Osteócitos , Humanos , Osteócitos/fisiologia , Osteócitos/metabolismo , Osteócitos/citologia , Animais , Comunicação Celular/fisiologia , Encéfalo/patologia , Tecido Adiposo/metabolismo , Tecido Adiposo/fisiologia , Tecido Adiposo/patologia , Rim/patologia , Rim/fisiologia , Rim/citologia
6.
Nat Commun ; 14(1): 4278, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37460561

RESUMO

Current technologies to subtype glioblastoma (GBM), the most lethal brain tumor, require highly invasive brain biopsies. Here, we develop a dedicated analytical platform to achieve direct and multiplexed profiling of circulating RNAs in extracellular vesicles for blood-based GBM characterization. The technology, termed 'enzyme ZIF-8 complexes for regenerative and catalytic digital detection of RNA' (EZ-READ), leverages an RNA-responsive transducer to regeneratively convert and catalytically enhance signals from rare RNA targets. Each transducer comprises hybrid complexes - protein enzymes encapsulated within metal organic frameworks - to configure strong catalytic activity and robust protection. Upon target RNA hybridization, the transducer activates directly to liberate catalytic complexes, in a target-recyclable manner; when partitioned within a microfluidic device, these complexes can individually catalyze strong chemifluorescence reactions for digital RNA quantification. The EZ-READ platform thus enables programmable and reliable RNA detection, across different-sized RNA subtypes (miRNA and mRNA), directly in sample lysates. When clinically evaluated, the EZ-READ platform established composite signatures for accurate blood-based GBM diagnosis and subtyping.


Assuntos
Neoplasias Encefálicas , Glioblastoma , MicroRNAs , Humanos , MicroRNAs/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , RNA Mensageiro , Hibridização de Ácido Nucleico , Glioblastoma/genética , Glioblastoma/patologia
7.
Front Endocrinol (Lausanne) ; 13: 833485, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35273572

RESUMO

Bone diseases are the leading causes of disability and severely compromised quality of life. Neuropeptide Y (NPY) is a multifunctional neuropeptide that participates in various physiological and pathological processes and exists in both the nerve system and bone tissue. In bone tissue, it actively participates in bone metabolism and disease progression through its receptors. Previous studies have focused on the opposite effects of NPY on bone formation and resorption through paracrine modes. In this review, we present a brief overview of the progress made in this research field in recent times in order to provide reference for further understanding the regulatory mechanism of bone physiology and pathological metabolism.


Assuntos
Neuropeptídeo Y , Receptores de Neuropeptídeo Y , Osso e Ossos/metabolismo , Neuropeptídeo Y/metabolismo , Osteogênese , Qualidade de Vida , Receptores de Neuropeptídeo Y/metabolismo
8.
Mater Sci Eng C Mater Biol Appl ; 105: 110083, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546466

RESUMO

Cutaneous wounds, especially chronic wounds, remain clinical challenges, and this is partially due to the complex healing process composed of four overlapping but distinct stages including hemostasis, inflammation, proliferation and remodeling. Therefore, wound dressings with spatially designed structures which can temporally regulate certain bioactive components to function at specific healing stages might be able to accelerate the healing process. In this study, nanobioglass incorporated chitosan-PVA (polyvinyl alcohol) trilayer nanofibrous membrane (nBG-TFM) was fabricated via sequential electrospinning. This membrane exhibited excellent biocompatibility, antibacterial activity and regeneration promotion effect. Furthermore, spatially designed structure optimized functions of each component and provided more suitable microenvironment as compared with uniform membrane. Rat full-thickness skin defects model and mice diabetic chronic wound model showed that nBG-TFM could achieve significantly accelerated and enhanced healing, in terms of complete re-epithelialization, improved collagen alignment and formation of skin appendages. It was revealed that nBG-TFM functioned through upregulating growth factors including VEGF and TGF-ß. Meanwhile inflammatory cytokines such as TNF-α and IL-1ß were downregulated. The technology presented in this study shed new light on designing functional wound dressings which can promote healing of chronic wounds.


Assuntos
Bandagens , Cerâmica , Quitosana , Membranas Artificiais , Nanofibras , Álcool de Polivinil , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões , Animais , Linhagem Celular , Cerâmica/química , Cerâmica/farmacologia , Quitosana/química , Quitosana/farmacologia , Doença Crônica , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Complicações do Diabetes/terapia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/terapia , Masculino , Camundongos , Nanofibras/química , Nanofibras/uso terapêutico , Álcool de Polivinil/química , Álcool de Polivinil/farmacologia , Ratos , Ratos Sprague-Dawley , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/patologia , Ferimentos e Lesões/terapia
10.
ACS Appl Mater Interfaces ; 10(28): 23700-23710, 2018 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-29939711

RESUMO

Stem cells are well-known for their great capacity for tissue regeneration. This provides a promising source for cell-based therapies in treating various bone degenerative disorders. However, the major hurdles for their application in transplantation are the poor bone marrow homing and engraftment efficiencies. Stromal cell-derived factor 1 (SDF-1) has been identified as a major stem cell homing factor. With the aims of bone targeted SDF-1 delivery and regulating MSCs migration, alendronate modified liposomal nanoparticles (Aln-Lipo) carrying SDF-1 gene were developed in this study. Alendronate modification significantly increased the mineral binding affinity of liposomes, and facilitated the gene delivery to osteoblastic cells. Up-regulated SDF-1 expression in osteoblasts triggered MSCs migration. Systemic infusion of Aln-Lipo-SDF-1 with fluorescence labeling in mice showed the accumulation in osseous tissue by biophotonic imaging. Corresponding to the delivered SDF-1, the transplanted GFP+ MSCs were attracted to bone marrow and contributed to bone regeneration. This study may provide a useful technique in regulating stem cell migration.


Assuntos
Movimento Celular , Alendronato , Animais , Osso e Ossos , Quimiocina CXCL12 , Células-Tronco Mesenquimais , Camundongos , Nanopartículas , Células-Tronco
11.
ACS Appl Mater Interfaces ; 9(8): 6712-6724, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28191840

RESUMO

We report here a novel and personalized strategy of selenium/ruthenium nanoparticles modified metal organic frameworks MIL-101(Fe) for delivering pooled small interfering RNAs (siRNAs) to enhance therapy efficacy by silencing multidrug resistance (MDR) genes and interfere with microtubule (MT) dynamics in MCF-7/T (Taxol-resistance) cell. The existence of coordinatively unsaturated metal sites in MIL-101(Fe) can strongly interact with the electron-rich functional groups of cysteine, which can be regarded as the linkage between selenium/ruthenium nanoparticles and MIL-101(Fe). Se@MIL-101 and Ru@MIL-101 loaded with MDR gene-silencing siRNAs via surface coordination can significantly enhance protection of siRNAs against nuclease degradation, increase siRNA cellular uptake, and promote siRNA escape from endosomes/lysosome to silence MDR genes in MCF-7/T cell, resulting in enhanced cytotoxicity through the induction of apoptosis with the signaling pathways of phosphorylation of p53, MAPK, and PI3K/Akt and the dynamic instability of MTs and disrupting normal mitotic spindle formation. Furthermore, in vivo investigation of the nanoparticles on nude mice bearing MCF-7/T cancer xenografts confirmed that Se@MIL-101-(P+V)siRNA nanoparticles can significantly enhance cancer therapeutic efficacy and decrease systemic toxicity in vivo.


Assuntos
Nanopartículas , Animais , Neoplasias da Mama , Linhagem Celular Tumoral , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Humanos , Estruturas Metalorgânicas , Camundongos , Camundongos Nus , Paclitaxel , Fosfatidilinositol 3-Quinases , RNA Interferente Pequeno , Rutênio , Selênio
12.
J Mater Chem B ; 5(20): 3686-3696, 2017 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32264057

RESUMO

Uncontrolled hemorrhage is the main cause of death in many situations. Substantial efforts have been focused on developing more efficient hemostatic agents. Meanwhile, their safety is also critical for their application. Chitosan is an attractive natural polymer and has been widely investigated for hemostatic application. This study sought to incorporate poly(vinyl alcohol) (PVA) components and fabricate them into monodisperse millimeter-sized spheres to improve efficiency and safety. Chitosan-PVA spheres were fabricated by electrospraying and ionotropic gelation. The millimeter-sized spheres were obtained by adjusting the electrospraying parameters, including applied voltage, working distance, feed rate, polymer solution and component content. The morphology, chemical structure and thermostability of the spheres were characterized by variable pressure scanning electron microscopy (VP-SEM), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). These spheres showed narrow size distribution and good biocompatibility. The hemostatic effect was evaluated both in vitro and in vivo using a blood coagulation timing experiment and a rat liver hemorrhaging model, and chitosan50-PVA50 spheres showed the best effect. PVA contributed to the high swelling degree of the spheres and the enhanced hemostatic effect. These spheres also significantly reduced thromboembolus formation in controlling femoral artery bleeding compared with chitosan powder, providing an efficient and safe hemostasis agent.

13.
Acta Biomater ; 30: 397-407, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26518106

RESUMO

Developing highly effective antibacterial agents is important for a wide range of applications. However, the emergence of multiple antibiotic-resistant bacteria poses a public health threat. Many developed agents have limited practical application due to chemical instability, low biocompatibility, and poor long-term antibacterial efficiency. In the following study, we synthesize a synergistic nanocomposite by conjugating quercetin (Qu) and acetylcholine (Ach) to the surface of Se nanoparticles (Qu-Ach@SeNPs). Quercetin has been reported to exhibit a wide range of biological activities related to their antibacterial activity and acetylcholine as a neurotransmitter, which can combine with the receptor on the bacterial cell. Arrows indicate NPs and arrowheads indicate compromised cell walls. The study demonstrated how Qu-Ach@SeNPs exhibit a synergistically enhanced antibacterial performance against the multidrug-resistant superbugs (MDRs) compared to Qu@SeNPs and Ach@SeNPs alone. Qu-Ach@SeNPs are effective against MDRs, such as Methicillin-resistant Staphylococcus aureus (MRSA), at a low dose. The mechanistic studies showed that Qu-Ach@SeNPs attach to the bacterial cell wall, causing irreversible damage to the membrane, and thereby achieving a remarkable synergistic antibacterial effect to inhibit MRSA. The findings suggested that the synergistic properties of quercetin and acetylcholine enhance the antibacterial activity of SeNPs. In this way, Qu-Ach@SeNPs comprise a new class of inorganic nano-antibacterial agents that can be used as useful applications in biomedical devices. STATEMENT OF SIGNIFICANCE: The Qu-Ach@SeNPs have low cytotoxicity when tested on normal human cells in vitro. Qu-Ach@SeNPs are effective against MDRs, such as Methicillin-resistant S. aureus (MRSA), at a low dose. Importantly, Qu-Ach@SeNPs showed no emergence of resistance. These results suggest that Qu-Ach@SeNPs have excellent antibacterial activities. These agents can serve as good antibacterial agents against superbugs. Our data suggest that these antibacterial agents may have widespread application in the field of medicine for combating infectious diseases caused by MDRs, as well as other infectious diseases.


Assuntos
Anti-Infecciosos , Bactérias/crescimento & desenvolvimento , Nanopartículas Metálicas/química , Selênio , Acetilcolina/química , Acetilcolina/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Humanos , Nanocompostos/química , Quercetina/química , Quercetina/farmacologia , Selênio/química , Selênio/farmacologia
15.
Acta Biomater ; 31: 197-210, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26612416

RESUMO

Drug resistance mediated by P-glycoprotein (P-gp) and class III ß-tubulin (ß-tubulin III) is a major barrier in microtubule-targeting cancer chemotherapy. In this study, layered double hydroxide nanoparticles (LDHs) were employed to simultaneously deliver selenium (Se) and pooled small interfering RNAs (siRNAs) to achieve therapeutic efficacy. LDH-supported Se nanoparticles (Se@LDH) were compacted with siRNAs (anti-P-gp and anti-ß-tubulin III) via electrostatic interactions, which could protect siRNA from degradation. Se@LDH showed excellent abilities to deliver siRNA into cells, including enhancing siRNA internalization, and promoting siRNA escape from endosomes. siRNA transfection experiments further confirmed a higher gene silencing efficiency of Se@LDH than LDH. Interestingly, we found Se@LDH may be a microtubule (MT) stabilizing agent which could inhibit cell proliferation by blocking cell cycle at G2/M phase, disrupting normal mitotic spindle formation and inducing cell apoptosis. When complexed with different specific siRNAs, Se@LDH/siRNA nanoparticles, especially the Se@LDH-pooled siRNAs, exhibit an efficient gene-silencing effect that significantly downregulate the expression of P-gp and ß-tubulin III. Moreover, Se@LDH-pooled siRNAs could induce cell apoptosis, change cell morphology and increase cellular ROS levels through change the expression of Bcl-2/Bax, activation of caspase-3, PI3K/AKT/mTOR and MAPK/ERK pathways. These results suggested that co-delivery of Se and pooled siRNAs may be a promising strategy for overcoming the drug resistance mediated by P-gp and ß-tubulin III in drug-resistant breast cancers.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Nanopartículas Metálicas/química , RNA Interferente Pequeno/administração & dosagem , Selênio/administração & dosagem , Tubulina (Proteína)/química , Anexina A5/química , Apoptose , Ciclo Celular , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Feminino , Células HEK293 , Células Hep G2 , Humanos , L-Lactato Desidrogenase/química , Células MCF-7 , Microscopia de Fluorescência , Microtúbulos/química , Oxirredução , RNA Interferente Pequeno/química , Espécies Reativas de Oxigênio/química , Selênio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Fuso Acromático
16.
ACS Appl Mater Interfaces ; 8(24): 15000-12, 2016 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-26018505

RESUMO

Functionalization can promote the uptake of nanoparticles into cancer cells via receptor-mediated endocytosis, enabling them to exert their therapeutic effects. In this paper, epigallocatechin gallate (EGCG), which has a high binding affinity to 67 kDa laminin receptor (67LR) overexpressed in HCC cells, was employed in the present study to functionalized ruthenium nanoparticles (RuNPs) loaded with luminescent ruthenium complexes to achieve antiliver cancer efficacy. [Ru(bpy)2(4-B)] (ClO4)2·2H2O (RuBB)-loaded EGCG-RuNPs (bpy = 2,2'-bipyridine) showed small particle size with narrow distribution, better stability, and high selectivity between liver cancer and normal cells. The internalization of RuBB-loaded EGCG-RuNPs was inhibited by 67LR-blocking antibody or laminin, suggesting that 67LR-mediated endocytosis played an important role in the uptake into HCC cells. Moreover, transmission electron microscopy and confocal microscopic images showed that RuBB-loaded EGCG-RuNPs accumulated in the cytoplasm of SMMC-7721 cells. Furthermore, our results indicated that the EGCG-functionalized nanoparticles displayed enhanced anticancer effects in a target-specific manner. Concentrations of RuBB-loaded EGCG-RuNPs, nontoxic in normal L-02 cells, showed direct reactive oxygen species-dependent cytotoxic, pro-apoptotic, and anti-invasive effects in SMMC-7721 cells. Furthermore, in vivo animal study demonstrated that RuBB-loaded EGCG-RuNPs possessed high antitumor efficacy on tumor-bearing nude mice. It is encouraging to conclude that the multifunctional RuNPs may form the basis of new strategies on the treatment of liver cancer and other malignancies.


Assuntos
Apoptose , Animais , Catequina , Linhagem Celular , Humanos , Nanopartículas Metálicas , Camundongos , Camundongos Nus , Espécies Reativas de Oxigênio , Receptores de Laminina , Rutênio
17.
J Mater Chem B ; 3(35): 7055-7067, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32262708

RESUMO

Human islet amyloid polypeptide (hIAPP) was found as amyloid aggregate deposits in the pancreatic islets of patients with type-2 diabetes and studies showed that insulin and its derivatives were the potent inhibitors of hIAPP aggregation. However, several emerging therapies with this goal showed limited success due to the instability and inefficiency of insulin derivatives. Nanosized graphene oxide (nGO) possesses high stability and affinity toward aromatic rings. In this study, an insulin-derived peptide, EALYLV, was stabilized by loading on nGO@PEG to inhibit aggregation and hIAPP-induced cytotoxicity. The results showed that nGO@PEG@EALYLV (abbreviated as nGO@PEG@E) can effectively inhibit the aggregation of hIAPP via electrostatic adsorption and specific binding to the active sites of hIAPP. We further evaluated the protective effect of nGO@PEG@E on INS-1 cells in the presence of hIAPP. Treatment with nGO@PEG@E could significantly elevate the viability of INS-1 cells, decrease the level of intracellular reactive oxygen species, and stabilize mitochondrial membrane potential. All the results indicated that nGO@PEG@E could inhibit the aggregation of hIAPP, which reduces its cytotoxicity.

18.
J Mater Chem B ; 2(14): 1977-1987, 2014 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32261634

RESUMO

Amyloid ß (Aß) aggregates are considered as possible targets for therapy of Alzheimer's disease (AD). Metal ions play an important role in amyloid aggregation and neurotoxicity in the AD pathogenesis. Disruption of the interactions between these metal ions and peptides holds considerable promise as a therapeutic strategy for AD treatment. In this study, l-Cys-modified Se/Ru nanoparticles (NPs) have been designed as Aß-binding units to inhibit metal-induced Aß aggregation. l-Cys was used as both the reducing agent and surface modifier in the formation of SeNPs, RuNPs and Se/RuNPs. We found that RuNPs and Se/RuNPs have a strong affinity toward Aß species and efficiently suppress extracellular Aß40 self-assembly and Zn2+-induced fibrillization. Also, Se/RuNPs can suppress the Zn2+-Aß40 mediated generation of reactive oxygen species (ROS) and their corresponding neurotoxicity in PC12 cells. Intriguingly, SeNPs do not have the same ability as Se/RuNPs. In addition, Se/RuNPs also decrease intracellular Aß40 fibrillization, but this process does not involve the lysosomal pathway. These results suggest that ruthenium significantly enhances the activity of Se/RuNPs binding to Aß40. This interaction would block the Zn2+ binding to Aß40 peptides and lower the concentration of the free monomer, thus decreasing fibrillization. Owing to this, Se/RuNPs may represent a new strategy in AD treatment.

19.
Nanoscale ; 6(12): 6886-97, 2014 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-24834443

RESUMO

A neuropathological hallmark of Alzheimer's disease (AD) is aggregation of a forty-residue peptide known as amyloid beta forty (Aß40). While past work has indicated that blocking Aß40 aggregation could be an effective strategy for the treatment of AD, developing therapies with this goal has been met with limited success. Polyoxometalates (POMs) have been previously investigated for their anti-viral and anti-tumoral properties and we report here that three representative POM nanoclusters have been synthesized for use against Aß40 aggregation. Through the use of thioflavin T fluorescence, turbidity, circular dichroism spectroscopy, and transmission electron microscopy (TEM), we found that all three POM complexes can significantly inhibit both natural Aß40 self-aggregation and metal-ion induced Aß40 aggregation. We also evaluated the protective effect of POM complexes on Aß40-induced neurotoxicity in cultured PC12 cells and found that treatment with POM complexes can elevate cell viability, decrease levels of intracellular reactive oxygen species, and stabilize mitochondrial membrane potential. These findings indicate that all three representative POM complexes are capable of inhibiting Aß40 aggregation and subsequent neurotoxicity. While a complete mechanistic understanding remains to be elucidated, the synthesized POM complexes may work through a synergistic interaction with metal ions and Aß40. These data indicate that POM complexes have high therapeutic potential for use against one of the primary neuropathological features of AD.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/química , Nanopartículas Metálicas/química , Molibdênio/química , Nanocompostos/química , Fragmentos de Peptídeos/química , Compostos de Tungstênio/química , Peptídeos beta-Amiloides/ultraestrutura , Humanos , Teste de Materiais , Nanopartículas Metálicas/ultraestrutura , Complexos Multiproteicos/química , Complexos Multiproteicos/ultraestrutura , Nanocompostos/ultraestrutura , Fragmentos de Peptídeos/ultraestrutura
20.
J Inorg Biochem ; 130: 122-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24211604

RESUMO

Two ruthenium(II) complexes [Ru(IP)2(PIP)](ClO4)2·2H2O (1) and [Ru(PIP)2(IP)](ClO4)2·2H2O (2) (IP=imidazole [4, 5-f] [1,10] phenanthroline, PIP=2-phenylimidazo-[4, 5-f][1,10] phenanthroline) have been synthesized and characterized. The quadruplex binding of the compounds was evaluated by emission spectrum, CD spectroscopy, Visual detection assay and FRET (fluorescence resonance energy transfer)-melting assay. The results show that both complexes can induce the stabilization of quadruplex DNA, while complex 1 is a better G-quadruplex binder than complex 2. Furthermore, polymerase chain reaction-stop assay, electrophoretic mobility shift assay, telomerase repeat amplification protocol and MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay demonstrate that complex 1 not only can stabilize dimer forms of the G-quadruplex at low concentrations but also exhibit better inhibitory activity for telomerase and cancer cells.


Assuntos
Inibidores Enzimáticos/farmacologia , Quadruplex G , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , Rutênio/química , Telomerase/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Dicroísmo Circular , Relação Dose-Resposta a Droga , Ensaio de Desvio de Mobilidade Eletroforética , Inibidores Enzimáticos/química , Transferência Ressonante de Energia de Fluorescência , Células HeLa/efeitos dos fármacos , Humanos , Estrutura Molecular , Compostos Organometálicos/síntese química
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