Análise dos mecanismos pró-inflamatórios do ácido úrico solúvel: efeito sobre proteínas sensíveis à modulação redox e sobre a polarização de células THP-1 / Analysis of the pro-inflammatory mechanisms of soluble uric acid: effect on redox sensitive proteins and THP-1 cell polarization

Vários estudos epidemiológicos estabelecem correlação positiva entre os níveis de ácido úrico sérico e o aumento do risco para doenças cardiovasculares. Fatores dietéticos e socioeconômicos, além da presença de comorbidades estão diretamente associados aos níveis séricos de ácido úrico. Países desenvolvidos apresentam maior incidência e prevalência da gota e alguns grupos étnicos são particularmente susceptíveis à hiperuricemia. Cristais de ácido úrico são descritos por iniciar e perpetuar resposta inflamatória, e sinalizar um padrão de resposta molecular associado ao dano (DAMP), permitindo a diferenciação de macrófagos para perfis pró-inflamatórios. Por outro lado, os efeitos do ácido úrico em sua forma solúvel ainda carecem de estudos. Macrófagos derivados de precursores monocíticos apresentam diferenciação específica e respondem a um conjunto de fatores extrínsecos, resultando em perfis distintos, um fenômeno conhecido como polarização. Assim, os macrófagos podem ser classicamente ativados para uma resposta Th1 (T helper 1) e polarizados a um perfil pró- inflamatório (M1, resposta Th1) ou a um perfil alternativo e oposto, um perfil de resolução da inflamação (M2, resposta Th2, T helper 2). Nesse sentindo, buscamos analisar os efeitos do ácido úrico solúvel sobre vias de modulação da polarização fenotípica de macrófagos e modificação redox. Utilizamos a linhagem monocítica humana THP-1, a qual foi diferenciada em macrófagossímile por acetato miristato de forbol (PMA; 5 ng.mL-1) por 48 h, seguidas da incubação com ácido úrico em meio ausente de tióis e soro fetal bovino por 8h ou 24h (0-1000 µM). A expressão de fatores de transcrição e marcadores de polarização foi realizada através de citometria de fluxo, western-blotting e por microscopia de fluorescência com alto conteúdo de imagens (HCI). Em concentrações fisiológicas, verificamos que o ácido úrico solúvel regulou positivamente a frequência de células para receptor manose CD206, um marcador clássico de perfil alternativo/M2 e regulou negativamente a expressão óxido nítrico sintase induzível (iNOS), um marcador M1, sugerindo inicialmente uma modulação para o perfil de polarização M2. Além disso, as proteínas redoxsensíveis, heme oxigenase-1 (HO-1) e tiorredoxina (Trx) tiveram sua expressão reduzida e aumentada, respectivamente, pelo tratamento com ácido úrico. Os fatores de transcrição Nrf2 e STAT3 tiveram regulação negativa após a exposição ao ácido úrico solúvel. Os resultados apresentados nesta tese sugerem uma função do urato no priming de macrófagos através da alteração da polarização destas células

Several epidemiological studies have established a positive correlation between high serum uric acid levels and increased risk for cardiovascular diseases. Developed countries have a higher incidence and prevalence of gout and some ethnic groups are particularly susceptible to hyperuricemia. Although hyperuricemia is a prevalent condition, it has still controversy biological consequences. Uric acid crystals are described as capable of initiating and perpetuating inflammatory responses, by activating the damage-associated molecular response pattern (DAMP) cascade, allowing macrophage differentiation to inflammatory profiles. In spite of that, biological response to soluble uric acid are not completely understood. Monocyte-derived macrophages respond to a set of extrinsic factors that result in different profiles and can be polarized to a proinflammatory (M1) or anti-inflammatory (M2) profile. In this thesis, we analyzed the effects of soluble uric acid on redox-modulated pathways and the phenotypic polarization of macrophages. We used human monocytic THP-1 cell line, differentiated into macrophage by phorbol myristate acetate (PMA; 5 ng.mL-1) for 48 h. After differentiation, cells were incubated with soluble uric acid in medium without thiols and fetal bovine serum for 8 h and 24 h (0-1000 µM). The expression of transcription factors and polarization markers were assessed by flow cytometry, western-blotting and fluorescence microscopy with high content imaging (HCI). At physiological concentrations, soluble uric acid positively regulated the frequency of cells for mannose receptor CD206, a classic marker of the anti-inflammatory M2 profile and negatively regulated the inducible nitric oxide synthase (iNOS) expression, a proinflammatory M1 marker, suggesting that the soluble uric acid changes the polarization profile to M2 profile. In addition, the redox-sensitive proteins heme oxygenase-1 (HO-1) and thioredoxin (Trx) had their expression decreased and increased, respectively, after exposure to urate. STAT3 and Nrf2 transcription factors were downregulated upon soluble uric acid exposure. The results presented in this thesis suggest a role of uric acid in macrophage priming through the alteration of cell polarization

Pure redox-sensitive paclitaxel-maleimide prodrug nanoparticles: Endogenous albumin-induced size switching and improved antitumor efficiency

A commercial albumin-bound paclitaxel nano-formulation has been considered a gold standard against breast cancer. However, its application still restricted unfavorable pharmacokinetics and the immunogenicity of exogenous albumin carrier. Herein, we report an albumin-bound tumor redox-responsive paclitaxel prodrugs nano-delivery strategy. Using diverse linkages (thioether bond and disulfide bond), paclitaxel (PTX) was conjugated with an albumin-binding maleimide (MAL) functional group. These pure PTX prodrugs could self-assemble to form uniform and spherical nanoparticles (NPs) in aqueous solution without any excipients. By immediately binding to blood circulating albumin after intravenous administration, NPs are rapidly disintegrated into small prodrug/albumin nanoaggregates

Self-assembled ternary hybrid nanodrugs for overcoming tumor resistance and metastasis

Traditional chemotherapy exhibits a certain therapeutic effect toward malignant cancer, but easily induce tumor multidrug resistance (MDR), thereby resulting in the progress of tumor recurrence or metastasis. In this work, we deigned ternary hybrid nanodrugs (PEI/DOX@CXB-NPs) to simultaneously combat against tumor MDR and metastasis.

Research progress in pH/redox dual sensitive nano-carrier system / 国际生物医学工程杂志

Malignant tumors are the second most important cause of death after cardiovascular and cerebrovascular diseases. Chemotherapeutic drugs for tumor treatment have strong toxic side effects. The common solution is to use nanoparticle as a carrier that can deliver drugs to tumor issues so as to kill the tumor cells. However, most of the current drug-carriers have a serious drug loss before reaching the tumor area, which makes the difficult control of drug release. Multi-stimulus responsive nano-carrier systems can overcome these drawbacks and make drug release controllable. pH/redox dual sensitive nano-carrier systems are currently hot research direction. In this paper, the research progress of pH/redox dual sensitive nano-carrier systems in recent years was reviewed in order to provide reference for relative researches.

Preparation of doxorubicin-loaded nanoparticles based on modified popaccharide and its targeting effect on hepatocellular carcinoma cells / 国际生物医学工程杂志

Objective To prepare a redox-responsive doxorubicin-loaded nanoparticle,and to study its in vitro realease behavior and targeting effect on heptoma cells.Methods Cystamine was grafted on the side chains of hyaluronic acid with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide catalyst,and then β-cyclodextrin (β-CD) was conjugated on the amine groups of the cystamine by Schiff's base reaction to prepare β-CD modified hyaluronic acid (HACD).The HACD/DOX nanoparticles were prepared by encapsulating DOX into HACD using dialysis method.The drug loading,encapsulation efficiency,particle size and distribution,zeta potential and other physical and chemical properties,as well as in vitro drug release behavior of the HACD/DOX nanoparticles were characterized.The cytotoxicity of HACD/DOX nanoparticles to HepG2 cells was studied by cell counting kit-8 (CCK-8) method.The targeting effect of HACD/DOX nanoparticles on HepG2 cells was studied using flow cytometry and confocal laser scanning microscopy (CLSM).Results HACD were successfully synthesized,which could carry DOX to form uniform homogeneous nanoparticles.The drug loading of DOX in the nanoparticles was (16.1±0.2)％ and the encapsulation efficiency was (64.2±0.9)％.The transmission electron microscope images indicated that the shape of the HACD/DOX nanoparticles was homogeneous sphere.The results of granularity analysis showed that the average size of the HACD/DOX nanoparticles was (203.1 ±2.5) nm with a narrow size distribution (PDI =0.202).The zeta potential of the HACD/DOX nanoparticles was (-29.1±0.8) mV.The in vitro release behavior of the nanoparticles exhibited obvious redox-sensitivity.The results of in vitro cytotoxicity showed that the blank carrier material HACD had no obvious toxicity to hepatoma cells,and the HACD/DOX nanoparticles could effectively kill hepatoma cells with the 0.38 μg/ml half maximal inhibitory concentration (IC50) value at 48 h.Flow cytometry and CLSM results demonstrated that the HACD/DOX nanoparticles could target hepatoma cells through the mediating effect of hyaluronic acid.Conclusions The prepared HACD/DOX nanoparticles have suitable particle size,high drug loading and encapsulation efficiency,and can release DOX under the stimulation of reducing agent.These nanoparticles have obvious targeting effect on hepatoma cells,which is expected to be applied as the drug delivery system of hepatocellular carcinoma (HCC) therapy.

Co-delivery of siRNA and docetaxel by hyaluronic acid modified redox-sensitive disulfide-crosslinked nanoparticles / 中国药科大学学报

@#The aims of this research were to constitute and evaluate one targeting anticancer co-delivery system for both micro-molecularchemotherapeutic drugs(docetaxel, DTX)and small interfering RNA(siRNA)expressed by COX-2. The nanoparticles composed of poly(D, L-lactide-co-glycolide)(PLGA)bearing disulfide-linkaged reducible polyethyleneimine(PEIss)covered by hyaluronic acid(HA). Meanwhile, HA-PEI-PLGA nanoparticles were prepared as control. Firstly, the solvent evaporation was used to the particles which exhibited a core-shell structure with a uniform size of 150-200 nm. The cumulative drug release in two kinds of PBS media(pH 7. 4 and pH 5. 0)during 72 hours indicated that DTX-loaded nanoparticles had sustained-release effect within 24 hours. The cumulative release of DTX of HRPSP NPs in PBS pH 5. 0 was 10%-25% more than that in PBS pH 7. 4, which demonstrated that favored release of DTX from nanoparticles could be achieved in acidic tumor microenvironment. Then, the highest transfection efficiency was observed after 14-16 h incubation at N/P ratio of 40/1. Following the saturation of CD44 receptor, the mean fluorescence intensity of HRPSP NPs from the cells decreased drastically in the case of saturation with free HA before. However, there existed no significance in the fluorescence of RPSP NPs between the cells with and without saturation with free HA, which indicated the nanoparticles′ targeting potential toward tumor cells. In the Western blot, the relative silencing efficiency of Bcl-2, bax, capase-3 and COX-2 mRNAprotein was calculated. In comparison to the control group, the silence efficiencies of bax and capase-3 were both significantly increased while that of Bcl-2 was evidently reduced, particularly in siCOX-2/HRPSP NPs group(P< 0. 01). The similar results were obtained in the silence efficiency of COX-2 protein in which the COX-2 quantity on mRNA and protein decreased. The results suggest that the nanoparticles could achieve the synergistic effect on the combinatorial delivery of siRNA and lipophilic anti-tumor drugs.

Especies reactivas de oxígeno y su efecto sobre la actividad de las células óseas / Reactive oxygen species on bone cells activity / Espécies reativas de oxigênio e seu efeito na atividade das células ósseas

Las mitocondrias generan especies reactivas de oxígeno (ERO) que cumplen con una multiplicidad de procesos celulares; cuando se producen en exceso son responsables del estrés oxidativo y de múltiples procesos patológicos, incluyendo osteoporosis. Los factores de transcripción FoxO 1, 3 y 4 actúan como moléculas sensoras de ERO convirtiendo la señal de estrés oxidativo en la inducción de mecanismos de protección o señales apoptóticas. La insulina y los factores de crecimiento insulínicos (IGFs) regulan negativamente a FoxOs en mamíferos. Las ERO están involucradas en el remodelamiento óseo a través del efecto que ejercen sobre osteoblastos y osteoclastos. Los FoxOs controlan la acción de ERO sobre la osteoblastogénesis y la osteoclastogénesis. Con la edad, el aumento del estrés oxidativo acelera la adipogénesis a expensas de la osteoblastogénesis, al mismo tiempo que aumenta la oxidación de ácidos grasos generando compuestos pro-oxidantes que incrementan el estrés oxidativo. Asimismo, la caída estrogénica acelera la osteoclastogénesis por vía genómica o no genómica. Dada la importancia de FoxOs y ERO en la fisiología ósea y durante el envejecimiento, clarificar los eventos celulares y pasos moleculares involucrados en el control del estrés oxidativo sería vital para entender la regulación de la osteoporosis relacionada a la edad.

Reactive oxygen species (ROS) are key players in oxidative stress, and they are generated as by-products of cellular metabolism, primarily in the mitochondria. ROS are well recognised for playing a dual role as both deleterious and beneficial species. FoxOs transcription factors are activated in oxidative stress responses and participate in the regulation of cellular functions, including cell cycle arrest, cell death, and protection from stress stimuli. FoxO activity is inhibited by growth factors and the insulin signaling pathways. They play a fundamental role in skeletal homeostasis by exerting both ROS céludependent and independent effects on bone cells. FoxOs modulate osteoblastogenesis and attenuate osteoclastogenesis through both cell autonomous and indirect mechanisms. With aging there is an inevitable increment in oxidative stress that accelerates adipogenesis at the expense of osteoblastogenesis. There is also an increment in lipid oxidation to form pro-oxidant products that enhance oxidative stress generation. In addition, the estrogen withdrawal accelerates osteoclastogenesis. Given the importance of both FoxOs and ROS in aging and bone biology, understanding the cellular events and molecular pathways that are controlled by FoxOs during aging may be vital to our understanding of the regulation of age-related osteoporosis.

Mitocôndrias geram espécies reativas de oxigênio (ERO) que cumprem uma grande variedade de processos celulares; se produzidas em excesso são responsáveis pelo estresse oxidativo e por múltiplos processos patológicos, incluindo a osteoporose. Os fatores de transcrição FoxO 1.3 e 4 funcionam como moléculas sensoras de ERO transformando o sinal de estresse oxidativo na indução de mecanismos de proteção ou sinais apoptóticos. A insulina e os fatores de crescimento insulínicos (IGFs) regulam em forma negativa Foxos em mamíferos. As ERO estão envolvidos na remodelação óssea através do seu efeito nos osteoblastos e osteoclastos. Os Foxos controlam a ação de ERO na osteoblastogênese e na osteoclastogênese. Com a idade, o aumento do estresse oxidativo acelera a adipogênese à custa de osteoblastogênese; ao mesmo tempo que aumentam a oxidação de ácidos graxos gerando compostos pró-oxidantes que incrementam o estresse oxidativo. Além disso, a queda estrogênica acelera a osteoclastogênese por via genômica ou não genômica. Devido à importância de FoxOs e ERO na fisiologia óssea e durante o envelhecimento, esclarecer os eventos celulares e passos moleculares envolvidos no controle do estresse oxidativo seria vital para a compreensão da regulação da osteoporose relacionada com a idade.

Research development in the effect of reactive oxygen species on protein kinase and gene expression / 中国药理学通报

Reactive oxygen species (ROS) play a very important role in vascular homeostasis both physiologically and pathophysiologically. The imbalance between production and metabolism of ROS contributes to various vascular diseases. Recent studies have demonstrated that ROS regulated the redox-sensitive protein kinases in the signal transduction pathways,affected the activities of these kinases, and thus modulated the gene expression.