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1.
Micromachines (Basel) ; 15(5)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38793219

RESUMO

In recent years, diseases such as age-related macular degeneration and retinal pigment degeneration caused by excessive exposure to short-wavelength visible light have become significant concerns. With the aim of quantitatively evaluating the toxicity of short-wavelength light, proliferating cell nuclear antigen (PCNA) accumulation at the irradiation site was investigated using live cell imaging techniques to irradiate individual living cells with short-wavelength laser light. By examining the dependency of PCNA accumulation on the irradiation site within the cells and their cell cycle, it was observed that PCNA accumulation occurred only when the cell nucleus of cells in the S phase of the cell cycle was irradiated. We investigated the accumulation of PCNA at the laser irradiation site using laser light at wavelengths of 405 nm and 375 nm, with intensities ranging from 0.5 µW to 9.0 µW. The results confirmed an increase in PCNA accumulation with increasing intensity, and a higher accumulation was observed with laser light irradiation at a wavelength of 375 nm compared to 405 nm. By comparing the PCNA accumulation and 24 h cell viability, we demonstrated the feasibility of quantitatively assessing laser light toxicity through the measurement of PCNA accumulation.

2.
FEBS Lett ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38604984

RESUMO

Endogenous retroviruses (ERVs) are remnants of ancestral viruses in the host genome. The present study identified the expression of a defective retroviral env gene belonging to the ERV group V member Env (EnvV) in Felis catus (EnvV-Fca). EnV-Fca was specifically detected in the placental trophoblast syncytiotrophobic layer and expressed as a secreted protein in cultured cells. Genetic analyses indicated that EnvV2 genes are widely present in vertebrates and are under purifying selection among carnivores, suggesting a potential benefit for the host. This study suggests that birds, bats, and rodents carrying EnvV2 may play significant roles as intermediate vectors in spreading or cross-transmitting viruses among species. Our findings provide valuable insights into the evolution of ERV in vertebrate hosts.

3.
Free Radic Res ; 57(6-12): 430-443, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37897411

RESUMO

Age-related macular degeneration (AMD) is one of an increasing number of diseases that causes irreversible impairment and loss of vision in the elderly. AMD occurs by oxidative stress-mediated apoptosis of retinal pigment epithelium cells. The onset of AMD may be positively correlated with the exposure to blue light. We screened food-derived carotenoids for cytoprotective action against blue light irradiation using human ARPE-19 retinal pigment epithelium cells. This study revealed that blue light irradiation triggered apoptosis and oxidative stress in all-trans-retinal (atRAL)-exposed ARPE-19 cells by generating singlet oxygen (1O2), leading to significant cell death. We found that astaxanthin, a potent anti-oxidative xanthophyll abundant in several marine organisms including microalgae, salmon, and shrimp, significantly suppresses blue light-induced apoptotic cell death of atRAL-exposed ARPE-19 cells by scavenging 1O2. Mechanistic studies using the blue-light irradiated cells also demonstrated that the cytoprotective effects of astaxanthin can be attributed to scavenging of 1O2 directly. Our results suggest the potential value of astaxanthin as a dietary strategy to prevent blue light-induced retinal degeneration including AMD.


KEY POLICY HIGHLIGHTSBlue light irradiation triggered apoptosis and oxidative stress in all-trans-retinal (atRAL)-exposed human ARPE-19 retinal pigment epithelium cells by generating singlet oxygen (1O2), leading to significant cell death.Astaxanthin, a potent anti-oxidative xanthophyll abundant in several marine organisms including microalgae, salmon, and shrimp, significantly suppresses blue light-induced cell death of atRAL-exposed ARPE-19 cells.Astaxanthin inhibited apoptosis and oxidative stress induced by blue light by directly scavenging 1O2.


Assuntos
Degeneração Macular , Oxigênio Singlete , Humanos , Idoso , Oxigênio Singlete/metabolismo , Oxigênio Singlete/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Luz Azul , Epitélio Pigmentado da Retina/metabolismo , Estresse Oxidativo , Apoptose , Xantofilas/farmacologia , Degeneração Macular/tratamento farmacológico , Degeneração Macular/metabolismo
4.
Org Biomol Chem ; 21(22): 4656-4660, 2023 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-37212260

RESUMO

Tuning the electrophilicities of Michael acceptors is important for the development of targeted covalent drugs. To this end, the electronic effects of electrophilic structures have been well investigated, but not the steric effects. In this work, we synthesized ten α-methylene cyclopentanones (MCPs), screened them for NF-κB inhibitory activity, and analyzed their conformations. We found that MCP-4b, MCP-5b, and MCP-6b are novel NF-κB inhibitors, whereas the corresponding diastereomers MCP-4a, MCP-5a, and MCP-6a are inactive. Conformational analysis suggested that the stereochemistry of the side chain (R) on MCPs dictates the stable conformation of the core bicyclic 5/6 ring system. The conformational preference seemed to influence their reactivity toward nucleophiles. Consequently, a thiol reactivity assay showed that MCP-5b has higher reactivity than MCP-5a. The results indicate that the conformational switching of MCPs may control reactivity and bioactivity in the presence of steric effects.


Assuntos
Ciclopentanos , NF-kappa B , Conformação Molecular , Ciclopentanos/farmacologia , Compostos de Sulfidrila/química , Quimiocina CCL2
5.
J Org Chem ; 88(11): 6973-6986, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37191633

RESUMO

The one-pot de novo synthesis of pentasubstituted pyridines was realized following the process of Au(I)-autotandem catalysis and subsequent aromatization. The process involves aza-enyne metathesis with aryl propiolates to yield 1-azabutadienes and their addition/6π-electrocyclization sequence with the other propiolate units. The resultant 1,4-dihydropyridines were aromatized to furnish the pyridines in the presence of atmospheric oxygen. The aryl propiolates were regioselectively incorporated into the ring system to afford 2-arylpyridines as the sole product.

6.
Bioresour Bioprocess ; 10(1): 22, 2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38647826

RESUMO

Chloroethenes are widely used as solvent in the metal industry and the dry cleaning industry, but their spillage into soil and groundwater due to improper handling has negatively impacted human health. Bioremediation using microorganisms is one of the technologies to clean up soil and groundwater contaminated with chloroethenes. In this study, we examined the bioremediation of chloroethene-contaminated soil using wine pomace extract (WPE). WPE is a liquid containing seven major carboxylic acids and other substances extracted from grape pomace produced in winemaking. WPE clearly promoted the anaerobic bioremediation of chloroethenes. In the tetrachloroethene (PCE) degradation test that used fractions derived from WPE, the water-eluted fraction containing L-lactic acid, L-tartaric acid, and others promoted the dechlorination of PCE, whereas the methanol-eluted fraction containing mainly syringic acid did not. In another PCE degradation test that used L-lactic acid, L-tartaric acid, and syringic acid test solutions, L-lactic acid and L-tartaric acid enhanced the dechlorination of PCE, but syringic acid did not. The results suggest that L-lactic acid and L-tartaric acid in WPE function as hydrogen donors in the anaerobic microbial degradation of chloroethene. This technology realizes environmental remediation through the effective use of food by-products.

7.
IEEE Trans Neural Netw Learn Syst ; 33(3): 1324-1337, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33326388

RESUMO

Remarkable achievements by deep neural networks stand on the development of excellent stochastic gradient descent methods. Deep-learning-based machine learning algorithms, however, have to find patterns between observations and supervised signals, even though they may include some noise that hides the true relationship between them, more or less especially in the robotics domain. To perform well even with such noise, we expect them to be able to detect outliers and discard them when needed. We, therefore, propose a new stochastic gradient optimization method, whose robustness is directly built in the algorithm, using the robust student-t distribution as its core idea. We integrate our method to some of the latest stochastic gradient algorithms, and in particular, Adam, the popular optimizer, is modified through our method. The resultant algorithm, called t-Adam, along with the other stochastic gradient methods integrated with our core idea is shown to effectively outperform Adam and their original versions in terms of robustness against noise on diverse tasks, ranging from regression and classification to reinforcement learning problems.

8.
Biochem Biophys Res Commun ; 567: 177-182, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34166915

RESUMO

The gastric proton pump (H+,K+-ATPase) responsible for the H+ secretion of gastric acid is an essential therapeutic target for acid-related diseases. H+,K+-ATPase belongs to a P2-type ATPase family. Here, we examined the effects of a newly synthesized dihydropyrazole derivative KYY-008 on the H+,K+-ATPase. KYY-008 concentration-dependently inhibited the enzyme activity of the ATPase in the membrane fractions prepared from isolated hog gastric mucosa and from human kidney HEK293 cells in which gastric H+,K+-ATPase is exogenously expressed. The IC50 values in these samples were 3.4 µM and 3.7 µM, respectively. In addition, KYY-008 significantly inhibited the H+,K+-ATPase-derived H+ uptake into the tightly sealed vesicles prepared from the hog gastric mucosa. In contrast, KYY-008 has no effect on the activities of other P2-type ATPases such as Na+,K+-ATPase and Ca2+-ATPase. KYY-008 did not change the ionic currents of voltage-dependent Ca2+ channels, that were potential targets for some dihydropyrazole derivatives. Together, we discovered a new dihydropyrazole derivative which acts as a selective inhibitor of gastric H+,K+-ATPase.


Assuntos
ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Inibidores da Bomba de Prótons/química , Inibidores da Bomba de Prótons/farmacologia , Pirazóis/química , Pirazóis/farmacologia , Animais , Células HEK293 , Humanos , Suínos
9.
Org Lett ; 23(10): 3981-3985, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-33979152

RESUMO

A gold(I) autotandem catalysis protocol is reported for the de novo synthesis of densely substituted pyrazolines and dihydropyridines from the corresponding imine derivatives in a highly regioselective fashion via a one-pot aza-enyne metathesis/6π-electrocyclization sequence. The substituents on the nitrogen atom of the imine perfectly control the reaction pathways from the pivotal 1-azabutadiene intermediate; thus, carbazates were converted into pyrazolines via 6π-electrocyclization of α,ß-unsaturated hydrazones, while aryl imines provided dihydropyridines via 6π-electrocyclization of 3-azahexatrienes.

10.
J Org Chem ; 86(5): 3970-3980, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33567822

RESUMO

By the aid of the catalytic desymmetrization of divinylcarbinol as one-pot asymmetric induction and protection of olefin, asymmetric total syntheses of two chiral hydroxylated fatty acid derivatives were successfully achieved. The desired stereoisomers could be concisely prepared in mild conditions in a highly convergent manner. Thus, this novel strategy can help stereochemical elucidations of natural products, which have difficulties in spectroscopic stereochemical analyses due to their local symmetries in the vicinities of the stereogenic secondary hydroxyl units.


Assuntos
Alcenos , Produtos Biológicos , Catálise , Ácidos Graxos , Estereoisomerismo
11.
J Biosci Bioeng ; 131(2): 213-218, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33077361

RESUMO

Deep learning has emerged as a breakthrough tool for the segmentation of images without supporting human experts. Here, we propose an automated approach that uses deep learning to generate pseudo-nuclear staining of cells from phase contrast images. Our proposed approach, which has the feature to generate pseudo-nuclear stained images by simple DNN, showed remarkable advantages over existing approaches in the cell-detection and the detection of the relative position of cells for various cell densities, as well as in counting the exact cell numbers. Pseudo-nuclear staining of cells by deep learning will improve the accuracy of automated cell counting in a label-free cellular population on phase contrast images.


Assuntos
Contagem de Células/métodos , Aprendizado Profundo , Automação , Humanos , Microscopia , Coloração e Rotulagem
12.
Chem Pharm Bull (Tokyo) ; 67(9): 1019-1022, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474725

RESUMO

A novel catalyst system-a combination of the readily available 2,2'-biphenol with the inexpensive, nontoxic, and eco-friendly B(OH)3-promoted the Nazarov cyclization of activated and inactivated divinyl ketones to afford the corresponding cyclopentenones up to 96% yield under, in a cis-selective manner. Compared with the conventional harsh conditions with hazardous reagents, user-friendly method was established with bench-stable and easy-to-handle reagents.


Assuntos
Fenóis/química , Ácidos Borônicos/química , Catálise , Ciclização , Ciclopentanos/química
13.
Biosci Biotechnol Biochem ; 83(7): 1255-1262, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30907250

RESUMO

Terminal deoxynucleotidyltransferase interacting factor 2/estrogen receptor α-binding protein (TdIF2/ERBP) is a multifunctional nucleolar protein. The nucleolar localization of TdIF2/ERBP is important for its functions because it promotes ribosomal RNA transcription. However, signal sequences that direct TdIF2/ERBP to the nucleolus are not well characterized. We examined the TdIF2/ERBP sequence using truncation and mutation analyses to determine whether the nucleosome binding and C-terminal domains of TdIF2/ERBP possess nucleolar localization signals (NoLSs). In these domains, four NoLSs that could direct the mCherry protein to the nucleolus were detected. In addition, a short stretch of hydrophobic residues (VLLVL) in the center of TdIF2/ERBP acted as a nucleolar exclusion signal, which reduced the nucleolar accumulation of mCherry-NoLS fusion proteins. These results would contribute to improving the prediction of NoLSs from protein sequences. The short, transferrable localization signals would be valuable tools for understanding the association between localization and functions of nucleolar proteins. Abbreviations TdIF2: terminal deoxynucleotidyltransferase interacting factor 2; ERBP: estrogen receptor α-binding protein; EGFP: enhanced green fluorescent protein; NLS: nuclear localization signal; NoLS: nucleolar localization signal; NoES: nucleolar exclusion signal; DAPI: 4',6-diamidino-2-phenylindole.


Assuntos
Nucléolo Celular/metabolismo , Sinais de Localização Nuclear , Proteínas Nucleares/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Proteínas de Ligação a RNA
14.
J Pestic Sci ; 43(2): 79-87, 2018 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-30363091

RESUMO

To clarify species differences in the developmental toxicity of procymidone (Sumilex®, a fungicide for agricultural use), placental transfer studies were conducted using 14C-labeled procymidone in pregnant rats, rabbits, and monkeys. These studies demonstrated that maternal-to-fetal transfer of the parent compound and its hydroxylated metabolite, which are both weak anti-androgenic agents, occurred more easily than that of other metabolites, with much higher absolute concentrations achieved in the fetal circulation of rats than of rabbits or monkeys. Notably, in rats, the fetal plasma concentration of the hydroxylated metabolite was higher than that of procymidone, especially after repeated oral administration of procymidone. These results suggest that the hydroxylated metabolite is the most relevant metabolite involved in teratogenic activity in rats.

15.
Yakugaku Zasshi ; 138(9): 1151-1161, 2018.
Artigo em Japonês | MEDLINE | ID: mdl-30175759

RESUMO

 Nitrogen heterocycles are important skeletons in biologically active compounds such as medicines and natural alkaloids. However, in terms of the efficiency of the synthetic process, the many synthetic steps required to achieve the target compounds with complex architectures pose a significant problem. To overcome this challenge, novel approaches were developed to afford biologically active heterocycles, 1,2-diazepines, pyrroloisoquinolines, and pyrrolizidines utilizing cascade reactions that enable multiple bond formation in a one-pot process. This review discusses three one-pot reactions: 1) 1,2-diazepine synthesis from cyclobutenones and lithiodiazoesters via cascade 4π-8π electrocyclization; 2) synthesis of pyrroloisoquinolines from alkynylimino esters triggered by gold-catalyzed azomethine ylide formation; and 3) pyrrolizidine synthesis via three-component coupling reactions of iminoesters, acetylenes, and maleimides through the gold-catalyzed azomethine ylide generation/[3+2]-cycloaddition/enamine cyclization reaction.


Assuntos
Compostos Heterocíclicos/química , Compostos Heterocíclicos/síntese química , Compostos de Nitrogênio/química , Compostos de Nitrogênio/síntese química , Fenômenos de Química Orgânica , Compostos Azo/síntese química , Catálise , Ciclização , Ouro/química , Pirróis/química , Alcaloides de Pirrolizidina/síntese química , Alcaloides de Pirrolizidina/química , Quinolinas/química , Tiossemicarbazonas/síntese química
16.
Xenobiotica ; 48(11): 1113-1127, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29157071

RESUMO

1. 14 C-Labelled E/Z isomers of a synthetic pyrethroid metofluthrin ((E/Z)-(1 R,3 R)-2,3,5,6-tetrafluoro-4-(methoxymethyl)benzyl 2,2-dimethyl-3-(1-propenyl)-cyclopropanecarboxylate, abbreviated as RTE/RTZ, respectively) were used for rat metabolism studies. 14 C-RTE or RTZ labelled at the carbonyl-carbon [acid-14C] or the methoxymethylbenzyl-α-carbon [alcohol-14 C] was administered orally to rats at 1 and 20 mg/kg. 2. Dosed compounds were mostly absorbed, metabolised, and rapidly excreted. Dose-related increase in blood AUC suggested no saturation of absorption at the high dose. Blood 14 C was maximal at 3-8 h and decreased with a half-life of 52-163 h. Radioactivity in tissues, blood and plasma decreased basically at the same rate and the sum fell below 0.2% of the dose at 168 h. 3. Although the major metabolic pathways of the isomers, that is, ester cleavage, O-demethylation and ω-oxidation, were similar, there was a notable difference. The RTZ double bond commonly undergoes epoxidation while RTE double bond mainly undergoes glutathione conjugation, which causes faster elimination from plasma and greater excretion into faeces on RTE. Faster urinary excretion and elimination from blood were observed for the alcohol moiety than the acid moiety. 4. In conclusion, this study described the overall metabolic profiles of metofluthrin and identified the differences in metabolic breakdown between the isomers. No marked sex-/dose-related differences were observed.


Assuntos
Ciclopropanos/farmacocinética , Fluorbenzenos/farmacocinética , Inseticidas/farmacocinética , Animais , Bile/química , Bile/efeitos dos fármacos , Radioisótopos de Carbono/análise , Ciclopropanos/química , Ciclopropanos/metabolismo , Fezes/química , Feminino , Fluorbenzenos/química , Fluorbenzenos/metabolismo , Inseticidas/química , Inseticidas/metabolismo , Isomerismo , Masculino , Ratos Sprague-Dawley , Distribuição Tecidual
17.
Biochem Biophys Rep ; 9: 257-265, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28956013

RESUMO

Fluid shear stress (FSS) induces a series of biochemical responses in osteoblasts, and this "mechanoresponse" regulates their survival, proliferation and differentiation. However, the events in cells immediately after FSS application are unclear, and how biochemical signals from soluble factors modify the mechanoresponses is largely unknown. We used the orbital shaking method, instead of the frequently used parallel plate method, to examine activation of ERK and AKT by FSS for detailed tracking of its temporal transition. We found that ERK activation by orbital shaking was biphasic. The early phase was independent of Ca2+, PI3-kinase, and Rho kinase but required RAF activity. The late phase was dependent on Ca2+ but not RAF. These results suggest that the superior time-resolving capability of the orbital shaking method to separate the previously unrecognized Ca2+-independent early phase of ERK activation from the late phase. We also found that a certain combination of serum starvation and medium renewal affected ERK activation by FSS, suggesting that a soluble factor(s) may be secreted during serum starvation, which modified the phosphorylation level of ERK. These findings revealed novel aspects of the osteoblastic mechanoresponses and indicated that the orbital shaking method would be a useful, complementary alternative to the parallel plate method for certain types of study on cellular mechanoresponses.

18.
Neural Netw ; 94: 13-23, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28732231

RESUMO

We propose a new value function approach for model-free reinforcement learning in Markov decision processes involving high dimensional states that addresses the issues of brittleness and intractable computational complexity, therefore rendering the value function approach based reinforcement learning algorithms applicable to high dimensional systems. Our new algorithm, Kernel Dynamic Policy Programming (KDPP) smoothly updates the value function in accordance to the Kullback-Leibler divergence between current and updated policies. Stabilizing the learning in this manner enables the application of the kernel trick to value function approximation, which greatly reduces computational requirements for learning in high dimensional state spaces. The performance of KDPP against other kernel trick based value function approaches is first investigated in a simulated n DOF manipulator reaching task, where only KDPP efficiently learned a viable policy at n=40. As an application to a real world high dimensional robot system, KDPP successfully learned the task of unscrewing a bottle cap via a Pneumatic Artificial Muscle (PAM) driven robotic hand with tactile sensors; a system with a state space of 32 dimensions, while given limited samples and with ordinary computing resources.


Assuntos
Aprendizado de Máquina , Redes Neurais de Computação , Robótica/métodos , Membros Artificiais , Cadeias de Markov
19.
Angew Chem Int Ed Engl ; 55(34): 10079-82, 2016 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-27403766

RESUMO

Novel sequential 1,2-Brook/Wittig reactions were developed for the preparation of silyl enol ethers. This method enables highly selective preparation of both geometric isomers of glyoxylate silyl enol ethers, using aldehydes (E-selective) and tosylimines (Z-selective) as a Wittig electrophile. The salt-free conditions of this reaction system are likely to be advantageous for switching the selectivity. The optimal reaction conditions and generality of the reaction were investigated, and plausible explanations for the observed selectivity were also discussed.

20.
Molecules ; 21(7)2016 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-27376255

RESUMO

The aim of the study was to obtain new compounds during biotransformation of two halocompounds, the δ-bromo and δ-iodo-γ-bicyclolactones 1 and 2. Unexpectedly Pleurotus ostreatus produced together with the hydroxylactone, 2-hydroxy-4,4-dimethyl-9-oxabicyclo[4.3.0]nonane-8-one (3), its own metabolite (3S,9S,15S)-(6E,12E)-3,9,15-trimethyl-4,10,16-trioxacyclohexa-deca-6,12-diene-1,5,8,11,14-pentaone (4). The method presented here, in which this macrosphelide 4 was obtained by biotransformation, has not been previously described in the literature. To the best of our knowledge, this compound has been prepared only by chemical synthesis to date. This is the first report on the possibility of the biosynthesis of this compound by the Pleurotus ostreatus strain. The conditions and factors, like temperature, salts, organic solvents, affecting the production of this macrosphelide by Pleurotus ostreatus strain were examined. The highest yield of macroshphelide production was noticed for halolactones, as well with iodide, bromide, iron and copper (2+) ions as inductors.


Assuntos
Biotransformação , Compostos Heterocíclicos/química , Compostos Heterocíclicos/metabolismo , Lactonas/metabolismo , Pleurotus/metabolismo , Hidrólise , Espectroscopia de Ressonância Magnética , Estrutura Molecular
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