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1.
BMC Nephrol ; 24(1): 298, 2023 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-37821807

RESUMO

BACKGROUND: Low levels of Free Triiodothyronine (FT3) are associated with poor survival in chronic kidney disease, and the aim of this study was to further assess the relationship between changes in FT3 levels and renal damage in patients with type 2 diabetes based on glomerular and tubular markers. METHODS: We retrospectively studied 452 type 2 diabetic patients, measured glomerular damage markers (UACR, eGFR) and tubular damage markers (NAG/Cr,ß2-MG), analyzed the relationship between FT3 and renal damage by logistic regression models, and plotted restrictive cubic splines. RESULTS: 41.6% of subjects had diabetic kidney disease (DKD), and the prevalence of DKD decreased progressively with increasing FT3 levels in the third quartile. Spearman correlation analysis showed that FT3 was negatively associated with UACR, NAG/Cr and ß2-MG, while eGFR was positively associated with FT3. Multifactorial analysis, after adjusting for relevant confounders, revealed that compared with the lowest quartile of FT3, the highest quartile reduced the risk of developing urinary albumin (OR = 0.499,95% CI:0.289-0.856), moderate to severe impairment of glomerular filtration rate (OR = 0.106,95% CI:0.032-0.354), renal tubular marker ß2 -MG positive (OR = 0.516,95% CI:0.299 to 0.883) and the risk of DKD occurrence (OR = 0.450,95% CI:0.260 to 0.774). In the sample model, FT3 levels below 4.39 pmol/L were associated with an increased risk of glomerular tubule injury and DKD occurrence. CONCLUSIONS: FT3 is closely associated with glomerular tubular injury and is a protective factor. As FT3 levels (< 4.39 pmol/L) decrease, the risk of developing DKD becomes higher, and FT3 can be used as an independent predictor of developing DKD.


Assuntos
Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Humanos , Nefropatias Diabéticas/diagnóstico , Nefropatias Diabéticas/epidemiologia , Nefropatias Diabéticas/etiologia , Tri-Iodotironina , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Estudos Retrospectivos , Biomarcadores , Taxa de Filtração Glomerular
2.
J Colloid Interface Sci ; 607(Pt 2): 1762-1775, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34600340

RESUMO

Excess fluoride in water poses a threat to ecology and human health, which has attracted global attention. In this study, a series of lanthanum-based metal-organic frameworks (La-MOFs) were synthesized by varying the organic ligands (i.e., terephthalic acid (BDC), trimesic acid (BTC), biphenyl-4,4-dicarboxylic acid (BPDC), 2,5-dihydroxyterephthalic acid (BHTA), and 1,2,4,5-benzenetetracarboxylic acid (PMA)) to control the microscopic structure of the MOFs and subsequently apply them for the removal of fluoride in water. The maximum capture capacities of La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC at 298 K are 105.2, 125.9, 145.5, 158.9, and 171.7 mg g-1, respectively. The adsorption capacity is greater than most reported adsorbents. The adsorption isotherms of La-MOFs for fluoride are well fit to the Langmuir isotherm model. In addition, the adsorption kinetics of La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC follows the pseudo-second-order kinetic model, and the kinetic rate-limiting step of adsorption is chemical adsorption. Thermodynamics revealed that temperature is favorable for the adsorption of fluoride. Meanwhile, La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC are suitable for the removal of fluoride in a relatively wide pH range (4.0-9.0). Simultaneously, from X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis, electrostatic attraction and ligand exchange are identified as the main action mechanisms for the adsorption of fluoride of La-MOFs. The prepared La-MOFs are used as efficient adsorbents for removal of fluoride in actual water, indicating that they have great potential in removing fluoride in real and complex environmental water. This work provides a new strategy for designing adsorbents with adjustable microstructure and expected function to effectively recover fluorosis in water.


Assuntos
Estruturas Metalorgânicas , Poluentes Químicos da Água , Adsorção , Fluoretos , Humanos , Concentração de Íons de Hidrogênio , Cinética , Lantânio , Ligantes , Espectroscopia de Infravermelho com Transformada de Fourier , Água , Poluentes Químicos da Água/análise
3.
Xenobiotica ; 51(12): 1360-1365, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34806927

RESUMO

The effect of agrimoniin on the activity of cytochrome P450 (CYP450) enzymes would induce drug-drug interaction, which leads to adverse effects or even failure of therapy.Agrimoniin was incubated with the specific substrates of eight human liver CYP isoforms in pooled human liver microsomes. The enzyme kinetics and time-dependent study were performed to obtain kinetic parameters and characteristics in vitro.Agrimoniin significantly inhibited the activity of CYP1A2, 2D6, and 3A4 in a dose-dependent manner with IC50 values of 6.26, 9.35, and 8.30 µM, respectively. Agrimoniin served as a non-competitive inhibitor of CYP3A4 and a competitive inhibitor of CYP1A2 and 2D6. Moreover, the incubation time also significantly affected the inhibition of CYP3A4.In vitro inhibitory effect of agrimoniin on the activity of CYP1A2, 2A6, and 3A4 was reported in this study. The potential drug-drug interactions between agrimoniin and drugs metabolised by CYP1A2, 2D6, and 3A4 should be paid special attention.


Assuntos
Citocromo P-450 CYP1A2 , Microssomos Hepáticos , Inibidores das Enzimas do Citocromo P-450/farmacologia , Humanos , Taninos Hidrolisáveis
4.
BMC Complement Med Ther ; 21(1): 138, 2021 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-33966625

RESUMO

BACKGROUND: Cornin is a commonly used herb in cardiology for its cardioprotective effect. The effect of herbs on the activity of cytochrome P450 enzymes (CYP450s) can induce adverse drug-drug interaction even treatment failure. Therefore, it is necessary to investigate the effect of cornin on the activity of CYP450s, which can provide more guidance for the clinical application of cornin. METHODS: Cornin (100 µM) was incubated with eight isoforms of CYP450s, including CYP1A2, 2A6, 3A4, 2C8, 2C9, 2C19, 2D6, and 2E1, in pooled human liver microsomes. The inhibition model and corresponding parameters were also investigated. RESULTS: Cornin exerted significant inhibitory effect on the activity of CYP3A4, 2C9, and 2E1 in a dose-dependent manner with the IC50 values of 9.20, 22.91, and 14.28 µM, respectively (p < 0.05). Cornin inhibited the activity of CYP3A4 non-competitively with the Ki value of 4.69 µM, while the inhibition of CYP2C9 and 2E1 by cornin was competitive with the Ki value of 11.31 and 6.54 µM, respectively. Additionally, the inhibition of CYP3A4 by cornin was found to be time-dependent with the KI/Kinact value of 6.40/0.055 min- 1·µM- 1. CONCLUSIONS: The inhibitory effect of cornin on the activity of CYP3A4, 2C9, and 2E1 indicated the potential drug-drug interaction between cornin and drugs metabolized by these CYP450s, which needs further investigation and validation.


Assuntos
Inibidores das Enzimas do Citocromo P-450/farmacologia , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Glicosídeos Iridoides/farmacologia , Microssomos Hepáticos/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Humanos , Cinética , Verbena
5.
Ecotoxicol Environ Saf ; 197: 110637, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32315789

RESUMO

Immobilization of phosphorus in lake sediments and control of internal-loading phosphorus release have become crucial aspects of eutrophication lake management. In this study, the immobilization efficiency of phosphorus by ferric chloride in Dianchi Lake sediments was investigated. In addition, effects of the dosage of ferric chloride and contact time on the release of phosphorus from sediments were investigated. Laboratory experiments revealed that ferric chloride can effectively inhibit the release of phosphorus from sediments. At a ferric chloride dosage of 10 mg/g, the total phosphorus concentration of the overlying water was reduced by ~87%. With the increase in the contact time, the amount of phosphorus immobilized by ferric chloride increased. To further evaluate the feasibility of ferric chloride for immobilising phosphorus in sediments, an amplification experiment with a water volume of 50 L was carried out. By the addition of 6 mg/g of ferric chloride, the total phosphorus concentration of the overlying water was still less than 0.01 mg/L after 100 days. At the same time, the phosphorus species in the sediment after treatment with ferric chloride were analyzed. Results revealed that ferric chloride mainly converts unstable exchangeable phosphorus (Ex-P), ferric phosphate (Fe-P) and organic phosphorus (Or-P) into more stable occluded phosphate (O-P), reducing the possible release of phosphorus from sediments. Practical applications of ferric chloride to control the release of phosphorus from Dianchi Lake sediments were discussed.


Assuntos
Cloretos/química , Compostos Férricos/química , Sedimentos Geológicos/química , Lagos/química , Fósforo/análise , Poluentes Químicos da Água/análise , China , Eutrofização , Compostos Férricos/análise , Organofosfatos/análise
6.
J Colloid Interface Sci ; 560: 321-329, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31671353

RESUMO

In this work, water-stable Al-MIL-101 analogues were successfully synthesized by adjusting the Fe/Al ratio to obtain excellent phosphorus removal efficiencies. The introduction of Fe3+ into the precursor solution allowed the final structure of aluminum metal-organic frameworks (Al-MOFs) to be tuned without introducing Fe into the final structure. The formation of Al-MIL-101 analogues with different morphologies and surface areas was accomplished by adjusting the Fe/Al molar ratio in the precursor solution. Compared with pure Fe-MIL-101 or Al-MIL-101, Al-MIL-101 analogues exhibited ultra-fast phosphorous adsorption kinetics and high phosphorous adsorption capacities. Al-MIL-101, produced with an Fe/Al feed molar ratio of 0.5, achieved a maximum phosphorus uptake capacity of 90 mg P/g, which is much higher than the phosphorus absorption reported in most literatures. More importantly, the Al-MIL-101 analogue obtained using an Fe/Al molar ratio of 0.5 exhibited an excellent phosphorus removal efficiency, even after multiple adsorption/desorption cycles. These results indicate that Al-MOFs produced by adjusting the Fe amount in the precursor solution are promising candidates for the removal of phosphate from water.

7.
Nanoscale Res Lett ; 14(1): 352, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31781982

RESUMO

Magnetic nanomaterials were functionalized with dopamine hydrochloride as the functional reagent to afford a core-shell-type Fe3O4 modified with polydopamine (Fe3O4@PDA) composite, which was used for the adsorption of cadmium ions from an aqueous solution. In addition, the effects of environmental factors on the adsorption capacity were investigated. Furthermore, the adsorption kinetics, isotherm, and thermodynamics of the adsorbents were discussed. Results revealed that the adsorption of cadmium by Fe3O4@PDA reaches equilibrium within 120 min, and kinetic fitting data are consistent with the pseudo-second-order kinetics (R2 > 0.999). The adsorption isotherm of Cd2+ on Fe3O4@PDA was in agreement with the Freundlich model, with the maximum adsorption capacity of 21.58 mg/g. The thermodynamic parameters revealed that adsorption is inherently endothermic and spontaneous. Results obtained from the adsorption-desorption cycles revealed that Fe3O4@PDA exhibits ultra-high adsorption stability and reusability. Furthermore, the adsorbents were easily separated from water under an enhanced external magnetic field after adsorption due to the introduction of an iron-based core. Hence, this study demonstrates a promising magnetic nano-adsorbent for the effective removal of cadmium from cadmium-containing wastewater.

8.
Water Sci Technol ; 79(11): 2046-2055, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31318342

RESUMO

The purpose of this study was to optimize the coagulation-flocculation effect of a wastewater treatment system using the response surface methodology (RSM) and three-step method to minimize phosphorus concentration in the distillate wastewater. In order to minimize the concentration of total phosphorus (TP), experiments were carried out using 33-factorial designs with three levels and three factors. A Box-Behnken design, which is the standard design of RSM, was used to evaluate the effects and interactions of three major factors (Fe:P (w/w) ratio, coagulation pH and fast mixing speed (FMS)) on the treatment efficiency. A multivariable quadratic model developed for studying the response indicated that the values for optimum conditions for Fe:P (w/w) ratio, coagulation pH and FMS were 2.40, 6.48 and 100 rev min-1, respectively. Under optimal process conditions, the TP concentration in the distillery effluent was reduced from 10 mg L-1 to 0.215 mg L-1, representing a removal efficiency of 97.85%. Based upon the statistical evaluation of results, it is inferred that RSM can be used as an appropriate approach to optimize the coag-flocculation process. Meanwhile, the study has shown that, for the equivalent dose of ferric chloride, the average three-step effect is better than that of the one-time addition.


Assuntos
Fósforo/análise , Eliminação de Resíduos Líquidos/métodos , Cloretos/química , Compostos Férricos/química , Floculação , Fósforo/química
9.
Mol Cell ; 66(2): 169-179.e8, 2017 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-28392175

RESUMO

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, which kills 1.8 million annually. Mtb RNA polymerase (RNAP) is the target of the first-line antituberculosis drug rifampin (Rif). We report crystal structures of Mtb RNAP, alone and in complex with Rif, at 3.8-4.4 Å resolution. The results identify an Mtb-specific structural module of Mtb RNAP and establish that Rif functions by a steric-occlusion mechanism that prevents extension of RNA. We also report non-Rif-related compounds-Nα-aroyl-N-aryl-phenylalaninamides (AAPs)-that potently and selectively inhibit Mtb RNAP and Mtb growth, and we report crystal structures of Mtb RNAP in complex with AAPs. AAPs bind to a different site on Mtb RNAP than Rif, exhibit no cross-resistance with Rif, function additively when co-administered with Rif, and suppress resistance emergence when co-administered with Rif.


Assuntos
Proteínas de Bactérias/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Regulação Bacteriana da Expressão Gênica , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/genética , Transcrição Gênica , Antituberculosos/metabolismo , Antituberculosos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Sítios de Ligação , RNA Polimerases Dirigidas por DNA/antagonistas & inibidores , RNA Polimerases Dirigidas por DNA/química , Farmacorresistência Bacteriana , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Modelos Moleculares , Mycobacterium tuberculosis/efeitos dos fármacos , Ligação Proteica , Conformação Proteica , Rifampina/metabolismo , Rifampina/farmacologia , Relação Estrutura-Atividade , Transcrição Gênica/efeitos dos fármacos
10.
Artigo em Inglês | MEDLINE | ID: mdl-26925256

RESUMO

Human intravenous immune globulin (IVIg), a purified IgG fraction composed of ~ 60% IgG1 and obtained from the pooled plasma of thousands of donors, is clinically used for a wide range of diseases. The biological actions of IVIg are incompletely understood and have been attributed both to the polyclonal antibodies therein and also to their IgG (IgG) Fc regions. Recently, we demonstrated that multiple therapeutic human IgG1 antibodies suppress angiogenesis in a target-independent manner via FcγRI, a high-affinity receptor for IgG1. Here we show that IVIg possesses similar anti-angiogenic activity and inhibited blood vessel growth in five different mouse models of prevalent human diseases, namely, neovascular age-related macular degeneration, corneal neovascularization, colorectal cancer, fibrosarcoma and peripheral arterial ischemic disease. Angioinhibition was mediated by the Fc region of IVIg, required FcγRI and had similar potency in transgenic mice expressing human FcγRs. Finally, IVIg therapy administered to humans for the treatment of inflammatory or autoimmune diseases reduced kidney and muscle blood vessel densities. These data place IVIg, an agent approved by the US Food and Drug Administration, as a novel angioinhibitory drug in doses that are currently administered in the clinical setting. In addition, they raise the possibility of an unintended effect of IVIg on blood vessels.

11.
Artigo em Inglês | MEDLINE | ID: mdl-26918197

RESUMO

Aberrant angiogenesis is implicated in diseases affecting nearly 10% of the world's population. The most widely used anti-angiogenic drug is bevacizumab, a humanized IgG1 monoclonal antibody that targets human VEGFA. Although bevacizumab does not recognize mouse Vegfa, it inhibits angiogenesis in mice. Here we show bevacizumab suppressed angiogenesis in three mouse models not via Vegfa blockade but rather Fc-mediated signaling through FcγRI (CD64) and c-Cbl, impairing macrophage migration. Other approved humanized or human IgG1 antibodies without mouse targets (adalimumab, alemtuzumab, ofatumumab, omalizumab, palivizumab and tocilizumab), mouse IgG2a, and overexpression of human IgG1-Fc or mouse IgG2a-Fc, also inhibited angiogenesis in wild-type and FcγR humanized mice. This anti-angiogenic effect was abolished by Fcgr1 ablation or knockdown, Fc cleavage, IgG-Fc inhibition, disruption of Fc-FcγR interaction, or elimination of FcRγ-initated signaling. Furthermore, bevacizumab's Fc region potentiated its anti-angiogenic activity in humanized VEGFA mice. Finally, mice deficient in FcγRI exhibited increased developmental and pathological angiogenesis. These findings reveal an unexpected anti-angiogenic function for FcγRI and a potentially concerning off-target effect of hIgG1 therapies.

12.
J Org Chem ; 81(4): 1391-400, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26756271

RESUMO

(Z) Enol triflates 6, 11b-d, (E) enol triflate 11e, and phenol triflate 11a, derived from ß-keto esters or 2-carboalkoxy phenols, respectively, react with N-Boc 2-lithiopyrrolidine (5a), N-Boc N-methylaminomethyllithium (5b), or 2-lithio-1,3-dithiane (14) to afford 3(2H)-furanones in modest to good yields (38-81%). Product and carbanion reagent studies suggest that the 3(2H)-furanone is formed in a cascade of reactions involving nucleophilic acyl substitution, enolate formation, trifluoromethyl transfer, iminium or sulfenium ion formation, and subsequent ring closure to form the 3(2H)-furanone. The use of 2-lithio-1,3-dithiane affords a cyclic α-keto-S,S,O-orthoester in which the functionality can be selectively manipulated for synthetic applications.

13.
J Biol Chem ; 290(51): 30225-39, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26475854

RESUMO

RING proteins constitute the largest class of E3 ubiquitin ligases. Unlike most RINGs, AO7 (RNF25) binds the E2 ubiquitin-conjugating enzyme, UbcH5B (UBE2D2), with strikingly high affinity. We have defined, by co-crystallization, the distinctive means by which AO7 binds UbcH5B. AO7 contains a structurally unique UbcH5B binding region (U5BR) that is connected by an 11-amino acid linker to its RING domain, forming a clamp surrounding the E2. The U5BR interacts extensively with a region of UbcH5B that is distinct from both the active site and the RING-interacting region, referred to as the backside of the E2. An apparent paradox is that the high-affinity binding of the AO7 clamp to UbcH5B, which is dependent on the U5BR, decreases the rate of ubiquitination. We establish that this is a consequence of blocking the stimulatory, non-covalent, binding of ubiquitin to the backside of UbcH5B. Interestingly, when non-covalent backside ubiquitin binding cannot occur, the AO7 clamp now enhances the rate of ubiquitination. The high-affinity binding of the AO7 clamp to UbcH5B has also allowed for the co-crystallization of previously described and functionally important RING mutants at the RING-E2 interface. We show that mutations having marked effects on function only minimally affect the intermolecular interactions between the AO7 RING and UbcH5B, establishing a high degree of complexity in activation through the RING-E2 interface.


Assuntos
Enzimas de Conjugação de Ubiquitina/química , Ubiquitina-Proteína Ligases/química , Ubiquitinação , Humanos , Mutação , Ligação Proteica , Estrutura Terciária de Proteína , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
14.
Mol Cancer Ther ; 14(10): 2187-97, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26208524

RESUMO

Oncogenic BRAF, which drives cell transformation and proliferation, has been detected in approximately 50% of human malignant melanomas and 5% to 15% of colorectal cancers. Despite the remarkable clinical activities achieved by vemurafenib and dabrafenib in treating BRAF(V600E) metastatic melanoma, their clinical efficacy in BRAF(V600E) colorectal cancer is far less impressive. Prior studies suggested that feedback activation of EGFR and MAPK signaling upon BRAF inhibition might contribute to the relative unresponsiveness of colorectal cancer to the first-generation BRAF inhibitors. Here, we report characterization of a dual RAF kinase/EGFR inhibitor, BGB-283, which is currently under clinical investigation. In vitro, BGB-283 potently inhibits BRAF(V600E)-activated ERK phosphorylation and cell proliferation. It demonstrates selective cytotoxicity and preferentially inhibits proliferation of cancer cells harboring BRAF(V600E) and EGFR mutation/amplification. In BRAF(V600E) colorectal cancer cell lines, BGB-283 effectively inhibits the reactivation of EGFR and EGFR-mediated cell proliferation. In vivo, BGB-283 treatment leads to dose-dependent tumor growth inhibition accompanied by partial and complete tumor regressions in both cell line-derived and primary human colorectal tumor xenografts bearing BRAF(V600E) mutation. These findings support BGB-283 as a potent antitumor drug candidate with clinical potential for treating colorectal cancer harboring BRAF(V600E) mutation.


Assuntos
Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Receptores ErbB/antagonistas & inibidores , Naftiridinas/farmacologia , Proteínas Proto-Oncogênicas B-raf/genética , Quinases raf/antagonistas & inibidores , Animais , Domínio Catalítico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Receptores ErbB/genética , Receptores ErbB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Modelos Moleculares , Fosforilação , Ligação Proteica , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Carga Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Quinases raf/metabolismo
15.
Cell Rep ; 11(11): 1686-93, 2015 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-26074074

RESUMO

Excess iron induces tissue damage and is implicated in age-related macular degeneration (AMD). Iron toxicity is widely attributed to hydroxyl radical formation through Fenton's reaction. We report that excess iron, but not other Fenton catalytic metals, induces activation of the NLRP3 inflammasome, a pathway also implicated in AMD. Additionally, iron-induced degeneration of the retinal pigmented epithelium (RPE) is suppressed in mice lacking inflammasome components caspase-1/11 or Nlrp3 or by inhibition of caspase-1. Iron overload increases abundance of RNAs transcribed from short interspersed nuclear elements (SINEs): Alu RNAs and the rodent equivalent B1 and B2 RNAs, which are inflammasome agonists. Targeting Alu or B2 RNA prevents iron-induced inflammasome activation and RPE degeneration. Iron-induced SINE RNA accumulation is due to suppression of DICER1 via sequestration of the co-factor poly(C)-binding protein 2 (PCBP2). These findings reveal an unexpected mechanism of iron toxicity, with implications for AMD and neurodegenerative diseases associated with excess iron.


Assuntos
Elementos Alu , Proteínas de Transporte/metabolismo , Ferro/toxicidade , Epitélio Pigmentado da Retina/metabolismo , Animais , Proteínas de Transporte/genética , Caspase 1/genética , Caspase 1/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Inflamassomos/metabolismo , Ferro/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Epitélio Pigmentado da Retina/efeitos dos fármacos , Ribonuclease III/genética , Ribonuclease III/metabolismo
16.
Science ; 346(6212): 1000-3, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25414314

RESUMO

Nucleoside reverse transcriptase inhibitors (NRTIs) are mainstay therapeutics for HIV that block retrovirus replication. Alu (an endogenous retroelement that also requires reverse transcriptase for its life cycle)-derived RNAs activate P2X7 and the NLRP3 inflammasome to cause cell death of the retinal pigment epithelium in geographic atrophy, a type of age-related macular degeneration. We found that NRTIs inhibit P2X7-mediated NLRP3 inflammasome activation independent of reverse transcriptase inhibition. Multiple approved and clinically relevant NRTIs prevented caspase-1 activation, the effector of the NLRP3 inflammasome, induced by Alu RNA. NRTIs were efficacious in mouse models of geographic atrophy, choroidal neovascularization, graft-versus-host disease, and sterile liver inflammation. Our findings suggest that NRTIs are ripe for drug repurposing in P2X7-driven diseases.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Inflamassomos/efeitos dos fármacos , Inibidores da Transcriptase Reversa/farmacologia , Elementos Alu , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Apoptose/efeitos dos fármacos , Proteínas de Transporte/metabolismo , Caspase 1/metabolismo , Neovascularização de Coroide/tratamento farmacológico , Modelos Animais de Doenças , Atrofia Geográfica/tratamento farmacológico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Hepatite/tratamento farmacológico , Fígado/efeitos dos fármacos , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Receptores Purinérgicos P2X7/metabolismo , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/fisiologia , Inibidores da Transcriptase Reversa/uso terapêutico
17.
Proc Natl Acad Sci U S A ; 111(45): 16082-7, 2014 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-25349431

RESUMO

Geographic atrophy, an advanced form of age-related macular degeneration (AMD) characterized by death of the retinal pigmented epithelium (RPE), causes untreatable blindness in millions worldwide. The RPE of human eyes with geographic atrophy accumulates toxic Alu RNA in response to a deficit in the enzyme DICER1, which in turn leads to activation of the NLRP3 inflammasome and elaboration of IL-18. Despite these recent insights, it is still unclear how RPE cells die during the course of the disease. In this study, we implicate the involvement of Caspase-8 as a critical mediator of RPE degeneration. Here we show that DICER1 deficiency, Alu RNA accumulation, and IL-18 up-regulation lead to RPE cell death via activation of Caspase-8 through a Fas ligand-dependent mechanism. Coupled with our observation of increased Caspase-8 expression in the RPE of human eyes with geographic atrophy, our findings provide a rationale for targeting this apoptotic pathway in this disease.


Assuntos
Elementos Alu , Apoptose , Caspase 8/metabolismo , RNA Helicases DEAD-box/metabolismo , Proteínas do Olho/metabolismo , Degeneração Macular/metabolismo , RNA/metabolismo , Ribonuclease III/metabolismo , Animais , Caspase 8/genética , RNA Helicases DEAD-box/genética , Proteínas do Olho/genética , Humanos , Interleucina-18/genética , Interleucina-18/metabolismo , Degeneração Macular/patologia , Camundongos , Camundongos Knockout , RNA/genética , Ribonuclease III/genética , Regulação para Cima/genética
18.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 43(3): 346-52, 2014 05.
Artigo em Chinês | MEDLINE | ID: mdl-24998660

RESUMO

OBJECTIVE: To investigate the efficacy of novel object recognition (NOR) test in assessment of learning and memory ability in ICR mice in different experimental conditions. METHODS: One hundred and thirty male ICR mice were randomly divided into 10 groups: 4 groups for different inter-trial intervals (ITI: 10 min, 90 min, 4 h, 24 h), 4 groups for different object materials (wood-wood, plastic-plastic, plastic-wood, wood-plastic) and 2 groups for repeated test (measured once a day or every 3 days, totally three times in each group). The locomotor tracks in the open field were recorded. The amount of time spent exploring the novel and familiar objects, the discrimination ratio (DR) and the discrimination index (DI) were analyzed. RESULTS: Compared with familiar object, DR and DI of novel object were both increased at ITI of 10 min and 90 min (P<0.01). Exploring time, DR and DI were greatly influenced by different object materials. DR and DI remained stable by using identical object material. NOR test could be done repeatedly in the same batch of mice. CONCLUSION: NOR test can be used to assess the learning and memory ability in mice at shorter ITI and with identical material. It can be done repeatedly.


Assuntos
Aprendizagem , Memória , Animais , Masculino , Camundongos , Camundongos Endogâmicos ICR , Fatores de Tempo
19.
Mol Cell ; 50(4): 516-27, 2013 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-23665230

RESUMO

Cue1p is an integral component of yeast endoplasmic reticulum (ER)-associated degradation (ERAD) ubiquitin ligase (E3) complexes. It tethers the ERAD ubiquitin-conjugating enzyme (E2), Ubc7p, to the ER and prevents its degradation, and also activates Ubc7p via unknown mechanisms. We have now determined the crystal structure of the Ubc7p-binding region (U7BR) of Cue1p with Ubc7p. The U7BR is a unique E2-binding domain that includes three α-helices that interact extensively with the "backside" of Ubc7p. Residues essential for E2 binding are also required for activation of Ubc7p and for ERAD. We establish that the U7BR stimulates both RING-independent and RING-dependent ubiquitin transfer from Ubc7p. Moreover, the U7BR enhances ubiquitin-activating enzyme (E1)-mediated charging of Ubc7p with ubiquitin. This demonstrates that an essential component of E3 complexes can simultaneously bind to E2 and enhance its loading with ubiquitin. These findings provide mechanistic insights into how ubiquitination can be stimulated.


Assuntos
Proteínas de Transporte/química , Proteínas de Membrana/química , Estrutura Terciária de Proteína , Proteínas de Saccharomyces cerevisiae/química , Enzimas de Conjugação de Ubiquitina/química , Sequência de Aminoácidos , Sítios de Ligação/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Cristalografia por Raios X , Eletroforese em Gel de Poliacrilamida , Interações Hidrofóbicas e Hidrofílicas , Cinética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Ligação Proteica , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de Aminoácidos , Eletricidade Estática , Especificidade por Substrato , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitinação
20.
Nan Fang Yi Ke Da Xue Xue Bao ; 30(10): 2307-9, 2010 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-20965833

RESUMO

OBJECTIVE: To study of the role of nuclear transcription factor-κB (NF-κB) in high glucose-induced apoptosis in INS-1 cells. METHODS: Rat insulinoma (INS-1) cells cultured in RPMI 1640 medium were treated with 11.1 mmol/L glucose, 33.3 mmol/L glucose, or 33.3 mmol/L glucose plus 5 µmol/L NF-κB inhibitors for 48 h. The expression of NF-κB subunit P65 protein in the cell nuclei was detected by Western blotting, IKK belta mRNA level by quantitative RT-PCR, and cell apoptosis by Annexin V-PI double staining. RESULTS: Compared with the control levels, IKK belta mRNA levels of the cells significantly increased in response to 33.3 mmol/L glucose exposure (P<0.01), which also resulted in significantly increased P65 protein expression in the cell nuclei (P<0.01) and cell apoptosis rate (P<0.05). Compared with those in the high glucose group, the expression of IKK belta mRNA and P65 protein and cell apoptosis rate decreased significantly after treatment with 33.3 mmol/L glucose plus 5 µmol/L NF-κB inhibitors (P<0.05). CONCLUSION: High glucose induces NF-κB activation in INS-1 cells, and inhibition of NF-κB activation may protect INS-1 cells from high glucose-induced cell apoptosis.


Assuntos
Glucose/efeitos adversos , Insulinoma/patologia , Neoplasias Pancreáticas/patologia , Fator de Transcrição RelA/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Glucose/metabolismo , Ratos
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