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1.
Nanotechnology ; 35(38)2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38861960

RESUMO

Magneto-controlling micro-nano materials' motion is a promising way that enable the noncontact, remote, and nondestructive controlling of their macrostructure as well as functionalities. Here, an optical microscope with an electromagnet was constructed toin-situmonitor the magneto-controlled motion process microscopically. Taking micro-nano graphite flake (MGF) as a model system, we experimentally demonstrate the key factors that influence the magneto-controlling of materials' motion. First, the product of intensity and gradient of the magnetic field (B∇B) has been confirmed as the dominant driving force and the flipping direction of the MGFs is accordingly determined by the vector direction ofB×∇B. Second, quantitatively comparative experiments further revealed that the threshold driving force has an exponential relationship with the structural aspect ratio (b/a) of MGFs. Third, the critical magneto-driving force is found as proportional to the viscosity of the solvent. Accordingly, a dynamic model is developed that describes the flip of the diamagnetic flake under external magnetic field excitation considering the shape factor. It is shown experimentally that the model accurately predicts the flip dynamics of the flake under different magnetic field conditions. In addition, we also discovered the delay effect, multiple cycle acceleration effect, and the fatigue effects due to gas adsorption in magneto-controlled MGFs flipping. These findings can be used to achieve magneto-controlling materials' macrostructure as well as their functionalities.

2.
Drug Metab Dispos ; 51(10): 1284-1294, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37349116

RESUMO

GDC-0810 is a small molecule therapeutic agent having potential to treat breast cancer. In plasma of the first-in-human study, metabolite M2, accounting for 20.7% of total drug-related materials, was identified as a discrete diglucuronide that was absent in rats. Acyl glucuronide M6 and N-glucuronide M4 were also identified as prominent metabolites in human plasma. Several in vitro studies were conducted in incubations of [14C]GDC-0810, synthetic M6 and M4 with liver microsomes, intestinal microsomes, and hepatocytes of different species as well as recombinant UDP-glucuronosyltransferase (UGT) enzymes to further understand the formation of M2. The results suggested that 1) M2 was more efficiently formed from M6 than from M4, and 2) acyl glucuronidation was mainly catalyzed by UGT1A8/7/1 that is highly expressed in the intestines whereas N-glucuronidation was mainly catalyzed by UGT1A4 that is expressed in the human liver. This complicated mechanism presented challenges in predicting M2 formation using human in vitro systems. The absence of M2 and M4 in rats can be explained by low to no expression of UGT1A4 in rodents. M2 could be the first discrete diglucuronide that was formed from both acyl- and N-glucuronidation on a molecule identified in human plasma. SIGNIFICANCE STATEMENT: A discrete diglucuronidation metabolite of GDC-0810, a breast cancer drug candidate, was characterized as a unique circulating metabolite in humans that was not observed in rats or little formed in human in vitro system.


Assuntos
Neoplasias da Mama , Glucuronídeos , Humanos , Ratos , Animais , Feminino , Glucuronídeos/metabolismo , Glucuronosiltransferase/metabolismo , Microssomos Hepáticos/metabolismo , UDP-Glucuronosiltransferase 1A , Administração Oral , Neoplasias da Mama/metabolismo
3.
J Nat Prod ; 86(2): 357-367, 2023 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-36753718

RESUMO

Bioinformatics analysis of a whole genome sequence coupled with HPLC-DAD analysis revealed that Streptomyces sp. Hu103 has the capacity to produce skyllamycin analogues. A subsequent chemical investigation of this strain yielded four new cinnamoyl-containing cyclopeptides, anulamycins A-D (1-4), two new cinnamoyl-containing linear peptides, anulamycins E and F (5 and 6), and two known cyclopeptides, skyllamycins A (7) and B (8). Their structures including absolute configurations were elucidated by detailed analysis of NMR and HRESIMS/MS spectroscopic data and the advanced Marfey's method. Compounds 1-4 exhibited antibacterial activity comparable to those of skyllamycins A and B.


Assuntos
Streptomyces , Streptomyces/química , Lagos , Peptídeos Cíclicos/química , Espectroscopia de Ressonância Magnética , Antibacterianos/química , Estrutura Molecular
4.
Lasers Med Sci ; 39(1): 18, 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38155274

RESUMO

Vascular diseases, such as venous insufficiency and coronary artery diseases, have been threatening the health of people. Efficient treatment with proper postoperative care is required to relieve the pain of the patients. Traditionally, venous insufficiency is treated with ligation and stripping, an open surgery whose complication rate cannot be ignored. Coronary artery disease is often treated with balloon angioplasty during which undilatable lesions may be encountered, limiting the efficacy of this approach. With advances in laser photonics and percutaneous coronary intervention procedure, laser ablation is emerging as an alternative and adjunctive therapy for these diseases. Endovenous laser ablation has the advantages of high success rate, low complication risk, and fast postoperative recovery. Laser ablation in arteries can handle uncrossable or undilatable lesions with a low incidence of serious complications. In this review, previously published research concerning vascular diseases and their therapies are analyzed in order to provide a clear explanation of the mechanisms and merits of laser ablation. For endovenous laser ablation, the main mechanisms are steam bubbles, heat conduction, and heat pipe, and three main influencing factors are wavelength, fiber types, and laser energy density. For excimer laser coronary atherectomy, the main mechanisms are photochemical, photothermal, and photomechanical effects, and three main influencing factors are catheter, medium, and laser parameters.


Assuntos
Angioplastia Coronária com Balão , Angioplastia com Balão , Ablação por Cateter , Doença da Artéria Coronariana , Terapia a Laser , Varizes , Insuficiência Venosa , Humanos , Terapia a Laser/métodos , Lasers , Insuficiência Venosa/cirurgia , Doença da Artéria Coronariana/cirurgia , Resultado do Tratamento , Varizes/cirurgia , Veia Safena/cirurgia
5.
Int J Mol Sci ; 24(5)2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36902234

RESUMO

BG45 is a class Ⅰ histone deacetylase inhibitor (HDACI) with selectivity for HDAC3. Our previous study demonstrated that BG45 can upregulate the expression of synaptic proteins and reduce the loss of neurons in the hippocampus of APPswe/PS1dE9 (APP/PS1) transgenic mice (Tg). The entorhinal cortex is a pivotal region that, along with the hippocampus, plays a critical role in memory in the Alzheimer's disease (AD) pathology process. In this study, we focused on the inflammatory changes in the entorhinal cortex of APP/PS1 mice and further explored the therapeutic effects of BG45 on the pathologies. The APP/PS1 mice were randomly divided into the transgenic group without BG45 (Tg group) and the BG45-treated groups. The BG45-treated groups were treated with BG45 at 2 months (2 m group), at 6 months (6 m group), or twice at 2 and 6 months (2 and 6 m group). The wild-type mice group (Wt group) served as the control. All mice were killed within 24 h after the last injection at 6 months. The results showed that amyloid-ß (Aß) deposition and IBA1-positive microglia and GFAP-positive astrocytes in the entorhinal cortex of the APP/PS1 mice progressively increased over time from 3 to 8 months of age. When the APP/PS1 mice were treated with BG45, the level of H3K9K14/H3 acetylation was improved and the expression of histonedeacetylase1, histonedeacetylase2, and histonedeacetylase3 was inhibited, especially in the 2 and 6 m group. BG45 alleviated Aß deposition and reduced the phosphorylation level of tau protein. The number of IBA1-positive microglia and GFAP-positive astrocytes decreased with BG45 treatment, and the effect was more significant in the 2 and 6 m group. Meanwhile, the expression of synaptic proteins synaptophysin, postsynaptic density protein 95, and spinophilin was upregulated and the degeneration of neurons was alleviated. Moreover, BG45 reduced the gene expression of inflammatory cytokines interleukin-1ß and tumor necrosis factor-α. Closely related to the CREB/BDNF/NF-kB pathway, the expression of p-CREB/CREB, BDNF, and TrkB was increased in all BG45 administered groups compared with the Tg group. However, the levels of p-NF-kB/NF-kB in the BG45 treatment groups were reduced. Therefore, we deduced that BG45 is a potential drug for AD by alleviating inflammation and regulating the CREB/BDNF/NF-kB pathway, and the early, repeated administration of BG45 can play a more effective role.


Assuntos
Doença de Alzheimer , Precursor de Proteína beta-Amiloide , Córtex Entorrinal , Inibidores de Histona Desacetilases , Inflamação , Microglia , Animais , Camundongos , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Modelos Animais de Doenças , Córtex Entorrinal/metabolismo , Hipocampo/metabolismo , Inflamação/metabolismo , Camundongos Transgênicos , Microglia/metabolismo , NF-kappa B/metabolismo , Presenilina-1/genética , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico
6.
Anal Chem ; 94(4): 2032-2041, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35041378

RESUMO

Macrocyclic peptides (MCPs) are an emerging class of promising drug modalities that can be used to interrogate hard-to-drug ("undruggable") targets. However, their poor intestinal stability is one of the major liabilities or obstacles for oral drug delivery. We therefore investigated the metabolic stability and biotransformation of MCPs via a systematic approach and established an integrated in vitro assay strategy to facilitate MCP drug discovery, with a focus on oral delivery liabilities. A group of diverse MCPs were incubated with representative matrices, including simulated intestinal fluid with pancreatin (SIFP), human enterocytes, liver S9 fractions, liver lysosomes, plasma, and recombinant enzymes. The results revealed that the stability and biotransformation of MCPs varied, with the major metabolic pathways identified in different matrices. Under the given conditions, the selected MCPs generally showed better stability in plasma compared to that in SIFP. Our data suggest that pancreatic enzymes act as the primary metabolic barrier for the oral delivery of MCPs, mainly through hydrolysis of their backbone amide bonds. Whereas in enterocytes, multiple metabolic pathways appeared to be involved and resulted in metabolic reactions such as oxidation and reduction in addition to hydrolysis. Further studies suggested that lysosomal peptidase cathepsin B could be a major enzyme responsible for the cleavage of side-chain amide bonds in lysosomes. Collectively, we developed and implemented an integrated assay for assessing the metabolic stability and biotransformation of MCPs for compound screening in the discovery stage toward oral delivery. The proposed question-driven assay cascade can provide biotransformation insights that help to guide and facilitate lead candidate selection and optimization.


Assuntos
Peptídeo Hidrolases , Peptídeos , Biotransformação , Descoberta de Drogas , Humanos , Preparações Farmacêuticas
7.
Xenobiotica ; 52(3): 219-228, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35379057

RESUMO

1. GDC-0575 is an ATP-competitive small-molecule inhibitor of ChK1 that is being developed by Genentech for the treatment of various human malignancies.2. In a radiolabeled mass balance study of GDC-0575 in rats, two novel metabolites, named M12 (-71 Da,) and M17 (+288 Da), were detected as abundant circulating metabolites.3. Subsequent mass spectrometry and nuclear magnetic resonance analysis showed that M12 was a cyclized metabolite of GDC-0575, whereas M17 was its heterodimer to the parent. We further determined that M12 was mainly generated by cytochrome P450 (Cyp) 2d2.4. We proposed the potential mechanism was initiated by the oxidation on the pyrrole ring and subsequent cyclisation of the free primary amine onto C-3 of the pyrrole ring. This was followed by expulsion of cyclopropylcarboxamide and a loss of water to form intermediate I, which can be further oxidised to form M12, or dimerise with another molecule of GDC-0575 as nucleophile to form M17.5. To verify this hypothesis, we attempted to trap the intermediate I with glutathione (GSH) trapping assay and the GSH conjugate on the pyrrole ring was identified. This suggests the oxidation on the pyrrole led to reactive metabolite formation and supported this proposed mechanism.


Assuntos
Sistema Enzimático do Citocromo P-450 , Microssomos Hepáticos , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Glutationa/metabolismo , Microssomos Hepáticos/metabolismo , Piperidinas , Piridinas/metabolismo , Pirróis/metabolismo , Ratos
8.
J Asian Nat Prod Res ; 24(11): 1058-1063, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35142242

RESUMO

Two previously undescribed cyclopentenone metabolites, (S)-2-(3-acetylamino-2-methyl)propyl-3-butyl-2-cyclopenten-1-one (1) and (S)-2-(3-acetylamino-2-ethyl)propyl-3-butyl-2-cyclopenten-1-one (2), were isolated from the fermentation broth of the strain Streptomyces sp. HU119. The structures of 1 and 2 were determined by the comprehensive spectroscopic analysis, including 1 D, 2 D NMR, MS spectral analysis and the comparison with data from the literature. The absolute configurations were elucidated by experimental and calculated optical rotations (OR). Compounds 1 and 2 displayed weak cytotoxic activity.


Assuntos
Streptomyces , Streptomyces/química , Estrutura Molecular , Ciclopentanos/farmacologia , Fermentação
9.
Molecules ; 27(13)2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35807406

RESUMO

As a neurodegenerative disease, Alzheimer's disease (AD) seriously affects the health of older people. Changes in synapses occur first over the course of the disease, perhaps even before the formation of Aß plaques. Histone deacetylase (HDAC) mediates the damage of Aß oligomers to dendritic spines. Therefore, we examined the relationship between HDAC activity and synaptic defects using an HDAC inhibitor (HDACI), BG45, in the human neuroblastoma SH-SY5Y cell line with stable overexpression of Swedish mutant APP (APPsw) and in APP/PS1 transgenic mice during this study. The cells were treated with 15 µM BG45 and the APP/PS1 mice were treated with 30 mg/kg BG45. We detected the levels of synapse-related proteins, HDACs, tau phosphorylation, and amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors using Western blotting and immunohistochemistry. We also measured the expression of cytoskeletal proteins in the cell model. The mRNA levels of the glutamate ion receptor alginate subunit 2 (GRIK2), sodium voltage-gated channel beta subunit (SCN3B), synaptophysin (SYP), Grm2 (the gene encoding glutamate receptor subunit 2 (GluR2)), Grid2IP, glutamate receptor interacting protein 1 (GRIP1), and GRIP2 were detected to explore the effects of the HDACI on regulating the expression of synaptic proteins and AMPA receptors. According to our studies, the expressions of HDAC1, HDAC2, and HDAC3 were increased, which were accompanied by the downregulation of the synapse-related proteins SYP, postsynaptic dendritic protein (PSD-95), and spinophilin as early as 24 h after transfection with the APPsw gene. BG45 upregulated the expression of synapse-related proteins and repaired cytoskeletal damage. In vivo, BG45 alleviated the apoptosis-mediated loss of hippocampal neurons, upregulated synapse-related proteins, reduced Aß deposition and phosphorylation of tau, and increased the levels of the synapse-related genes GRIK2, SCN3B, SYP, Grm2, and Grid2IP. BG45 increased the expression of the AMPA receptor subunits GluA1, GluA2, and GluA3 on APPsw-transfected cells and increased GRIP1 and GRIP2 expression and AMPA receptor phosphorylation in vivo. Based on these results, HDACs are involved in the early process of synaptic defects in AD models, and BG45 may rescue synaptic damage and the loss of hippocampal neurons by specifically inhibiting HDAC1, HDAC2, and HDAC3, thereby modulating AMPA receptor transduction, increasing synapse-related gene expression, and finally enhancing the function of excitatory synapses. BG45 may be considered a potential drug for the treatment of early AD in further studies.


Assuntos
Doença de Alzheimer , Neuroblastoma , Doenças Neurodegenerativas , Proteínas Adaptadoras de Transdução de Sinal , Idoso , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Proteínas de Transporte , Modelos Animais de Doenças , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Receptores de AMPA/genética , Receptores de AMPA/metabolismo , Receptores de AMPA/uso terapêutico , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/uso terapêutico
10.
Xenobiotica ; 51(1): 15-23, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32713280

RESUMO

Knowledge of inter-strain and inter-gender differences in drug metabolism studies is important for animal selection in pharmacokinetic and toxicological studies. The effects of rat strain and gender in in vitro metabolism were investigated in Sprague Dawley (SD) and Wister Han (WH) rats based on the hepatocyte metabolic profiles of 14 small molecule drugs. Similarities were found between the hepatocyte metabolic clearances of SD and WH strains, suggesting that only one strain can be confidently used for the evaluation of hepatic clearance. Neither strain of rat was preferable over the other to cover human metabolites. Higher similarities in metabolic pathways were found between the same gender than the same strain. Differences in metabolite identities, metabolite formation rates and potential biotransformation pathways were observed between SD and WH rat strains. Eleven metabolites from six drugs were "disproportionally" formed between SD and WH rats. The use of a specific rat strain model and gender for ADME and toxicity testing should, therefore, be carefully considered as metabolic profiles may differ, even though metabolic clearance was similar between SD and WH rats.


Assuntos
Hepatócitos/metabolismo , Taxa de Depuração Metabólica/fisiologia , Preparações Farmacêuticas/metabolismo , Animais , Metaboloma , Ratos , Ratos Sprague-Dawley
11.
J Cell Biochem ; 121(5-6): 3162-3172, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31907955

RESUMO

The abnormal expression of histone deacetylase 8 (HDAC8) has been reported to associate with various cancer entities (colon, breast cancer, pancreas, etc.) as well as parasitic diseases, making HDAC8 gradually develop into an attractive and potential therapeutic target. Among the various design strategies of selective HDAC8 inhibitors (modification of Cap, Linker, or zinc binding group regions), the optimization of Cap region has aroused great interest among the researchers. However, the detailed information underlying how the modification of Cap region influences the inhibitory activities is still unclear, and in this study, compounds 2c, 3g, and 3n were selected to explore the differences in binding mechanisms brought by Cap modifications via various computational approaches at the atomic level. Five residues (Y293, H167, D254, D165, and M261) have a large difference in energy contributions to the constructed systems, and the subpocket formed by Y293 and M261 could interact with Cap groups, triggering the differences in the energy contributions of the residues (H167, D254, and D165) located in metal-catalytic center. In summary, the compounds 2c, 3g, and 3n were selected as molecular probes to explore the binding mechanism, and the residues (Y293 and M261) forming the subpocket should be paid special attention in the design and synthesis of novel selective HDAC8 inhibitors.


Assuntos
Inibidores de Histona Desacetilases/farmacologia , Neoplasias/metabolismo , Proteínas Repressoras/antagonistas & inibidores , Algoritmos , Domínio Catalítico , Linhagem Celular Tumoral , Análise por Conglomerados , Biologia Computacional/métodos , Desenho de Fármacos , Histona Desacetilases/metabolismo , Humanos , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Neoplasias/genética , Ligação Proteica , Termodinâmica
12.
Drug Metab Dispos ; 48(9): 819-829, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32616543

RESUMO

After oral administration to monkeys of [14C]GDC-0810, an α,ß-unsaturated carboxylic acid, unchanged parent and its acyl glucuronide metabolite, M6, were the major circulating drug-related components. In addition, greater than 50% of circulating radioactivity in plasma was found to be nonextractable 12 hours post-dose, suggesting possible covalent binding to plasma proteins. In the same study, one of the minor metabolites was a cysteine conjugate of M6 (M11) that was detected in plasma and excreta (urine and bile). The potential mechanism for the covalent binding to proteins was further investigated using in vitro methods. In incubations with glutathione (GSH) or cysteine (5 mM), GSH and cysteine conjugates of M6 were identified, respectively. The cysteine reaction was efficient with a half-life of 58.6 minutes (k react = 0.04 1/M per second). Loss of 176 Da (glucuronic acid) followed by 129 Da (glutamate) in mass fragmentation analysis of the GSH adduct of M6 (M13) suggested the glucuronic acid moiety was not modified. The conjugation of N-glucuronide M4 with cysteine in buffer was >1000-fold slower than with M6. Incubations of GDC-0810, M4, or M6 with monkey or human liver microsomes in the presence of NADPH and GSH did not produce any oxidative GSH adducts, and the respective substrates were qualitatively recovered. In silico analysis quantified the inherent reactivity differences between the glucuronide and its acid precursor. Collectively, these results show that acyl glucuronidation of α,ß-unsaturated carboxylic acids can activate the compound toward reactivity with GSH, cysteine, or other biologically occurring thiols and should be considered during the course of drug discovery. SIGNIFICANCE STATEMENT: Acyl glucuronidation of the α,ß-unsaturated carboxylic acid in GDC-0810 activates the conjugated alkene toward nucleophilic addition by glutathione or other reactive thiols. This is the first example that a bioactivation mechanism could lead to protein covalent binding to α,ß-unsaturated carboxylic acid compounds.


Assuntos
Antineoplásicos Hormonais/farmacocinética , Ácidos Carboxílicos/farmacocinética , Cinamatos/farmacocinética , Glucuronídeos/metabolismo , Indazóis/farmacocinética , Administração Oral , Animais , Antineoplásicos Hormonais/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Ácidos Carboxílicos/administração & dosagem , Cinamatos/administração & dosagem , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Indazóis/administração & dosagem , Macaca fascicularis , Microssomos Hepáticos , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Estrogênio/metabolismo
13.
Chem Res Toxicol ; 33(7): 1950-1959, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32508087

RESUMO

The bioactivation of xenobiotics to yield reactive metabolites can lead to tolerability and toxicity concerns within a drug discovery program. Development of strategies for mitigating the metabolic liability of commonly encountered toxicophores, such as anilines, relies on an understanding of the relative tendency of these functionalities to undergo bioactivation. In this report, we present the first systematic study of the structure-activity relationships of the bioactivation of aryl amine fragments (molecular weight < 250 Da) using a glutathione (GSH) trapping assay in the presence of human liver microsomes and the reduced form of nicotinamide adenine dinucleotide phosphate. This study demonstrates that conversion of anilines to nitrogen-containing heteroarylamines results in a lower abundance of GSH conjugates in the order phenyl > pyrimidine ≈ pyridine > pyridazine. Introduction of electron-withdrawing functionality on the aromatic ring had a less pronounced effect on the extent of GSH conjugation. Examination of more drug-like compounds sourced from in-house drug discovery programs revealed similar trends in bioactivation between matched pairs containing (hetero)aryl amines. This study provides medicinal chemists with insights and qualitative guidance for the minimization of risks related to aryl amine metabolism.


Assuntos
Compostos de Anilina/metabolismo , Glutationa/metabolismo , Fenóis/metabolismo , Ativação Metabólica , Compostos de Anilina/química , Humanos , Microssomos Hepáticos/metabolismo , Fenóis/química , Relação Estrutura-Atividade
14.
Drug Metab Dispos ; 47(5): 547-555, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30858239

RESUMO

Duocarmycins [including cyclopropyl pyrroloindole (CPI) or cyclopropyl benzoindole (CBI)] are a class of DNA minor-groove alkylators and seco-CPI/CBIs are synthetic pro-forms that can spirocyclize to CPI/CBI. Bis-CPI/CBIs are potential drug candidates because of their enhanced cytotoxicity from DNA crosslinking, but it is difficult to analyze them for structure-activity correlation because of their DNA reactivity. To study their DNA alkylation, neutral thermal hydrolysis has been frequently applied to process depurination. However, unwanted side reactions under this condition have been reported, which could lead to poor correlation of DNA alkylation data with efficacy results, especially for bis-CPI/CBIs. In this study, an acidic depurination method was developed and applied for analysis of DNA alkylation and shown to be an easier and milder method than the traditional neutral thermal hydrolysis. DNA alkylation and stability of three bis-seco-CBIs were characterized in comparison with two mono-seco-CPIs. The results suggested that: 1) The acidic depurination method was capable of capturing a more representative population, sometimes a different population, of DNA adducts as they existed on DNA compared with the heat depurination method. 2) Di-adenine adducts were captured as expected for the CBI dimers, although the major type of adduct was still mono-adenine adducts. 3) The rate of DNA alkylation, DNA adduct profile, and relative amounts of di-adduct versus mono-adduct were significantly affected by the size, and possibly lipophilicity, of the nonalkylating part of the molecules. 4) Spirocyclization and amide hydrolysis represented two major pathways of degradation. Overall, by applying acidic depurination analyses, this study has illustrated DNA adduct characteristics of novel bis-seco-CBIs with dominating mono-alkylation and provides an alternative method for evaluating DNA minor-groove alkylators. These findings provide an effective analytical tool to evaluate DNA alkylators and to study the DNA alkylation that is a disposition mechanism of these compounds.


Assuntos
Alquilação/fisiologia , Antineoplásicos Alquilantes/metabolismo , DNA/metabolismo , Duocarmicinas/metabolismo , Adenina/metabolismo , Alquilantes/metabolismo , Adutos de DNA/metabolismo
15.
Cell Physiol Biochem ; 50(5): 1673-1686, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30384364

RESUMO

BACKGROUND/AIMS: Diabetic retinopathy (DR) is one of the most serious complications of diabetes and is the leading cause of adult blindness in developed countries. Advanced glycation end products (AGEs) accumulation in diabetes is associated with its complications. Thioredoxin (Trx) is a small molecule (12kDa) antioxidant protein widely distributed in mammalian tissues, which has important biological functions including anti-apoptosis and transcriptional regulation. In a previous study, we found that Trx plays a key role in retinal neurodegeneration prior to the occurrence of endothelial damage in diabetic mice. In this study, our aim is to determine the effect of Trx on neurodegeneration induced by AGEs in order to identify new therapeutic targets for the clinical treatment and prevention of DR. METHODS: In vivo, a high-fat diet and Streptozotocin (STZ) injection were used to generate a mouse model of diabetes. Histology was utilized to examine tissue morphology and measure the outer nuclear layer (ONL) thickness. Electroretinography (ERG) was used to assess retinal function and Western blot was used to examine protein expression. In vitro, three methods of Trx up-regulation were used, including a stable cell line that overexpresses Trx, treatment with Sulforaphane, and shRNA down-regulation Txnip. Cells were treated with AGEs, and level of apoptosis was performed to quantify this by flow cytometry and TUNEL. Quantitative Reverse Transcription PCR (qRT-PCR), Western blotting and immunofluorescence were used to measure gene and protein expression. Transmission electron microscopy (TEM) was used to observe autophagosomes. RESULTS: We found that diabetic mice display decreased retinal function and reduced ONL thickness with AGEs accumulation and a reduction of Trx expression. Up-regulation Trx can prevent the ONL thickness decrease in diabetic mice, as observed by H&E staining. In vitro, up-regulation Trx resulted in decreased intracellular ROS generation, reduced apoptosis by inhibited autophagy. CONCLUSION: Up-regulating Trx inhibited neurodegeneration induced by AGEs. The underlying mechanism may be related to inhibit Txnip/mTOR pathway-mediated autophagy.


Assuntos
Produtos Finais de Glicação Avançada/metabolismo , Tiorredoxinas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Retinopatia Diabética/etiologia , Retinopatia Diabética/metabolismo , Eletrorretinografia , Produtos Finais de Glicação Avançada/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Retina/metabolismo , Células Ganglionares da Retina/fisiologia , Epitélio Pigmentado da Retina/fisiologia , Tiorredoxinas/antagonistas & inibidores , Tiorredoxinas/genética , Regulação para Cima
16.
Bioconjug Chem ; 29(2): 267-274, 2018 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-29369629

RESUMO

The valine-citrulline (Val-Cit) dipeptide and p-aminobenzyl (PAB) spacer have been commonly used as a cleavable self-immolating linker in ADC design including in the clinically approved ADC, brentuximab vedotin (Adcetris). When the same linker was used to connect to the phenol of the cyclopropabenzindolone (CBI) (P1), the resulting ADC1 showed loss of potency in CD22 target-expressing cancer cell lines (e.g., BJAB, WSU-DLCL2). In comparison, the conjugate (ADC2) of a cyclopropapyrroloindolone (CPI) (P2) was potent despite the two corresponding free drugs having similar picomolar cell-killing activity. Although the corresponding spirocyclization products of P1 and P2, responsible for DNA alkylation, are a prominent component in buffer, the linker immolation was slow when the PAB was connected as an ether (PABE) to the phenol in P1 compared to that in P2. Additional immolation studies with two other PABE-linked substituted phenol compounds showed that electron-withdrawing groups accelerated the immolation to release an acidic phenol-containing payload (to delocalize the negative charge on the anticipated anionic phenol oxygen during immolation). In contrast, efficient immolation of LD4 did not result in an active ADC4 because the payload (P4) had a low potency to kill cells. In addition, nonimmolation of LD5 did not affect the cell-killing potency of its ADC5 since immolation is not required for DNA alkylation by the center-linked pyrrolobenzodiazepine. Therefore, careful evaluation needs to be conducted when the Val-Cit-PAB linker is used to connect antibodies to a phenol-containing drug as the linker immolation, as well as payload potency and stability, affects the cell-killing activity of an ADC.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Imunoconjugados/química , Imunoconjugados/farmacologia , Fenol/química , Fenol/farmacologia , Antineoplásicos Imunológicos/química , Antineoplásicos Imunológicos/farmacologia , Brentuximab Vedotin , Linhagem Celular Tumoral , Ciclopropanos/química , Ciclopropanos/farmacologia , Humanos , Neoplasias/tratamento farmacológico
17.
Biochem Biophys Res Commun ; 491(2): 374-381, 2017 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-28728844

RESUMO

While some long noncoding RNAs (lncRNAs) might promote nasopharyngeal carcinoma (NPC) initiation and progression, the involved molecular mechanisms remain largely unclear. Here, we discovered the novel LncRNA, prostate cancer associated transcript 7 (PCAT7), which was overexpressed and associated with worse prognosis in NPC. Decreased PCAT7 expression was found to significantly suppress tumor cell proliferation in vitro, and inhibited tumor growth and reduced the expression of proliferation antigen Ki-67 in vivo. Rescue assay was performed to further confirm that PCAT7 contributed to the progression of NPC through regulating miR-134-5p/ELF2 signal pathway. These results indicated that PCAT7 might contribute to the tumor progression in NPC by functioning as a ceRNA to sponge miR-134-5p.


Assuntos
Carcinoma/diagnóstico , Carcinoma/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/genética , RNA Longo não Codificante/genética , Fatores de Transcrição/genética , Sequência de Bases , Sítios de Ligação , Carcinogênese , Carcinoma/mortalidade , Carcinoma/patologia , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Genes Reporter , Humanos , Antígeno Ki-67/genética , Antígeno Ki-67/metabolismo , Luciferases/genética , Luciferases/metabolismo , MicroRNAs/metabolismo , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/patologia , Prognóstico , RNA Longo não Codificante/metabolismo , Transdução de Sinais , Análise de Sobrevida , Fatores de Transcrição/metabolismo
18.
Pharm Res ; 33(1): 217-36, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26334502

RESUMO

PURPOSE: Emodin (EMO) has multi-targets and multi-way antitumor effect, which was limited by the instability and poor solubility of EMO. The aim of this study was to formulate EMO-loaded poly (lactide-co-glycolide)-d-α-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) nanoparticles (EPTN) to increase the liver targeting of EMO for cancer therapy. METHODS: EMO/coumarin-6-loaded PLGA-TPGS nanoparticles (ECPTN) and EMO-loaded PLGA nanoparticles (EPN) were also prepared as comparison. The cellular uptake of ECPTN by HepG2 and HCa-F cells was investigated using Confocal laser scanning microscopy. The apoptosis of HepG2 cells handled with EPTN was assayed by flow cytometry. The liver targeting property of ECPTN in mice was evaluated using the drug concentration determined by RP-HPLC and the freezing slices were investigated via fluorescence inversion microscopy. The blood samples were obtained from vein intubation to illustrate the pharmacokinetics process of EPTN. The tumor-bearing mice model was established to elucidate the in vivo therapeutic effect of EPTN. RESULTS: The results demonstrated that ECPTN could be internalized by HepG2 and HCa-F cells respectively. The ratio of apoptosis cells was increased after dealing with EPTN. The detection indexes of drug concentration and fluorescence inversion microscopy images indicated ECPTN had an excellent effect on liver targeting property than EMO solutions (EMS). The pharmacokinetics process of EPTN showed obvious sustained-release effect than EMS. Compared with EPN, the in vivo antitumor activity of EPTN against tumor cells were better. CONCLUSIONS: In conclusion, EPTN could be used in the treatment of liver cancer acted as a kind of promising intravenous dosage forms.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Emodina/administração & dosagem , Emodina/uso terapêutico , Ácido Láctico/química , Neoplasias Hepáticas/tratamento farmacológico , Nanopartículas/química , Polietilenoglicóis/química , Ácido Poliglicólico/química , alfa-Tocoferol/química , Animais , Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Emodina/farmacocinética , Humanos , Camundongos , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos Sprague-Dawley
19.
Pharm Res ; 33(11): 2828-43, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27511028

RESUMO

PURPOSE: Heparin sodium (HS)-loaded polylactic-co-glycolic acid-D-α-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) nanoparticles (HPTNs) were prepared as a sustained and targeting delivery carrier and combined with emodin (EMO)-loaded PLGA-TPGS nanoparticles (EPTNs), which were investigated previously to form a combination therapy system for the treatment of liver cancer. METHODS: To assess cellular uptake and evaluate the liver-targeting capacity by analyzing the drug concentrations and frozen slices, HS/eosin-loaded PLGA-TPGS nanoparticles, HS/fluorescein- loaded PLGA-TPGS nanoparticles and EMO/C6-loaded PLGA-TPGS nanoparticles, which contained eosin, fluorescein and C6 as fluorescent probes, respectively, were also prepared. All of these nanoparticles were characterized in terms of their size, size distribution, surface charge, drug loading, encapsulation efficiency, in vitro release profile and cellular uptake. The apoptosis of HepG2 cells induced by EPTNs in combination with HPTNs was determined by Annexin V-FITC staining and PI labelling. RESULTS: Transmission electron microscopy indicated that these nanoparticles were stably dispersed spheres with sizes ranging from 100 to 200 nm. The results demonstrated that fluorescent nanoparticles were internalized into HepG2 and HCa-F cells efficiently and had improved liver-targeting properties. The combination of EPTNs and HPTNs effectively inhibited cell growth in vitro and had a remarkable synergistic anticancer effect in vivo. EPTNs combined with HPTNs induced HepG2 cell apoptosis with synergistic effects. The liver H&E slice images of a hepatocarcinogenic mouse model indicated that EPTNs in combination with HPTNs significantly suppressed tumour growth in vivo. CONCLUSIONS: The research suggests that the combination therapy system of EPTNs and HPTNs could be a new direction for liver cancer therapy.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Antineoplásicos/farmacologia , Emodina/farmacologia , Heparina/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Nanopartículas/química , Vitamina E/química , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos , Liberação Controlada de Fármacos , Emodina/administração & dosagem , Emodina/química , Corantes Fluorescentes/química , Heparina/administração & dosagem , Heparina/química , Humanos , Masculino , Camundongos , Tamanho da Partícula , Propriedades de Superfície
20.
Hemoglobin ; 40(3): 194-7, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26984456

RESUMO

The 2.4 kb (or -α(2.4)) deletion in the α-globin gene cluster (NG_000006.1) is an α(+)-thalassemia (α(+)-thal) allele. The molecular basis of -α(2.4) is a deletion from 36860 to 39251 of the α-globin gene cluster. It was reported by three research groups in 2005, 2012 and 2014, respectively. In routine thalassemia screening studies by this research group, we found an individual with the -α(2.4)/αα genotype and an Hb H (ß4) disease patient whose genotype was - -(SEA)/-α(2.4). Samples from the parents of the carrier of the -α(2.4)/αα genotype were collected to perform pedigree analysis, and the proband's mother's genotype was diagnosed to be - -(SEA)/-α(2.4). The research revealed that the -α(2.4) allele exists in the population of southern Guangxi, People's Republic of China.


Assuntos
Hemoglobina H/genética , Deleção de Sequência , alfa-Globinas/genética , Alelos , China/epidemiologia , Feminino , Genótipo , Hemoglobinas Anormais/genética , Humanos , Masculino , Epidemiologia Molecular , Linhagem
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