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Front Neurosci ; 14: 581915, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33177984


Cerebral ischemia induces neuronal cell death and causes various kinds of brain dysfunction. Therefore, prevention of neuronal cell death is most essential for protection of the brain. On the other hand, it has been reported that epigenetics including DNA methylation plays a pivotal role in pathogenesis of some diseases such as cancer. Accumulating evidences indicate that aberrant DNA methylation is related to cell death. However, DNA methylation after cerebral ischemia has not been fully understood yet. The aim of this present study was to investigate the relationships between DNA methylation and neuronal cell death after cerebral ischemia. We examined DNA methylation under the ischemic condition by using transient middle cerebral artery occlusion and reperfusion (MCAO/R) model rats and N-methyl-D-aspartate (NMDA)-treated cortical neurons in primary culture. In this study, we demonstrated that DNA methylation increased in these neurons 24 h after MCAO/R and that DNA methylation, possibly through activation of DNA methyltransferases (DNMT) 3a, increased in such neurons immediately after NMDA treatment. Furthermore, NMDA-treated neurons were protected by treatment with a DNMT inhibitor that were accompanied by inhibition of DNA methylation. Our results showed that DNA methylation would be an initiation factor of neuronal cell death and that inhibition of such methylation could become an effective therapeutic strategy for stroke.

J Chromatogr B Analyt Technol Biomed Life Sci ; 878(29): 2997-3002, 2010 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-20870466


An oral sorbent AST-120 composed of spherical porous carbon particles has superior adsorption ability for certain small-molecular-weight organic compounds known to accumulate in patients with chronic renal failure (CRF). A metabolomic approach was applied to search for uremic toxins as possible indicators of the effect of AST-120. Serum metabolites in normal and CRF rats before and after administration of AST-120 for 3 days were analyzed by liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) and principal component analysis. Further, serum and urine levels of the indicators were quantified by selected reaction monitoring of LC/ESI-MS/MS. Indoxyl sulfate was the first principal serum metabolite, which could differentiate CRF from both normal and AST-120-administered CRF rats, followed by hippuric acid, phenyl sulfate and 4-ethylphenyl sulfate. CRF rats showed increased serum levels of indoxyl sulfate, hippuric acid, phenyl sulfate, 4-ethylphenyl sulfate and p-cresyl sulfate. Administration of AST-120 for 3 days to the CRF rats reduced the serum and urine levels of these metabolites. In conclusion, indoxyl sulfate is the best indicator of the effect of AST-120 in CRF rats. Hippuric acid, phenyl sulfate and 4-ethylphenyl sulfate are suggested as the additional indicators. 4-Ethylphenyl sulfate is a newly identified uremic substance.

Carbono/administração & dosagem , Cromatografia Líquida/métodos , Falência Renal Crônica/terapia , Óxidos/administração & dosagem , Espectrometria de Massas em Tandem/métodos , Toxinas Biológicas/sangue , Toxinas Biológicas/urina , Uremia/terapia , Adsorção , Animais , Carbono/química , Hipuratos/sangue , Hipuratos/metabolismo , Hipuratos/urina , Indicã/sangue , Indicã/metabolismo , Indicã/urina , Falência Renal Crônica/sangue , Falência Renal Crônica/metabolismo , Falência Renal Crônica/urina , Masculino , Metabolômica , Óxidos/química , Ratos , Ratos Sprague-Dawley , Toxinas Biológicas/metabolismo , Uremia/sangue , Uremia/metabolismo , Uremia/urina
J Chromatogr B Analyt Technol Biomed Life Sci ; 878(20): 1662-8, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20036201


We applied the metabolomic analysis of comprehensive small-molecular metabolites using liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) and principal component analysis to identify uremic toxins accumulated in the serum of chronic renal failure (CRF) rats. CRF rats were produced by 5/6-nephrectomy. Indoxyl sulfate was demonstrated to be the first principal serum metabolite which differentiates CRF from normal, followed by phenyl sulfate, hippuric acid and p-cresyl sulfate. Then, we measured the serum levels of indoxyl sulfate, phenyl sulfate, hippuric acid and p-cresyl sulfate by the selected reaction monitoring (SRM) of LC/ESI-MS/MS, and demonstrated that these serum levels were markedly increased in CRF rats as compared with normal rats. As creatinine clearance decreased, the serum levels of the metabolites increased.

Cromatografia Líquida/métodos , Falência Renal Crônica/sangue , Metabolômica/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Toxinas Biológicas/sangue , Animais , Cresóis/sangue , Modelos Animais de Doenças , Hipuratos/sangue , Humanos , Indicã/sangue , Rim/química , Falência Renal Crônica/urina , Masculino , Ratos , Ratos Sprague-Dawley , Ésteres do Ácido Sulfúrico/sangue , Toxinas Biológicas/urina
Biosci Biotechnol Biochem ; 73(6): 1333-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19502734


DIMBOA [2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one] is a benzoxazinoid (Bx), part of the chemical defense system of graminaceous plants such as maize, wheat, and rye. When Bombyx mori larvae were fed artificial diets containing DIMBOA, they died in three days. In contrast, Mythimna separata larvae, a serious pest of rice, maize, sorghum, wheat etc., grew well on the same diets. Three kinds of glucosides [1-(2-hydroxy-4-methoxyphenylamino)-1-deoxy-beta-glucopyranoside-1,2-carbamate (methoxy glucoside carbamate), 2-O-beta-glucopyranosyl-4-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA-2-O-Glc), and 2-O-beta-glucopyranosyl-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (HMBOA-2-O-Glc)] were identified by LC-MS and NMR analyses from the frass of M. separata that had been fed on a DIMBOA-containing diet. Furthermore, the incubation of DIMBOA with a midgut tissue suspension of M. separata in the presence of UDP-D-glucose generated DIMBOA-2-O-Glc. These findings strongly suggest that glucosylation by UDP-glucosyltransferase(s) was important for detoxification to circumvent the defenses of host plants against M. separata larvae.

Benzoxazinas/metabolismo , Bombyx/metabolismo , Glucose/metabolismo , Larva/metabolismo , Animais , Bombyx/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão , Especificidade da Espécie , Espectrofotometria Ultravioleta
Insect Biochem Mol Biol ; 37(5): 506-11, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17456445


A 24-alkylsterol, crinosterol [(24S)-24-methylcholesta-5,22(E)-dien-3beta-ol] has been isolated from sea-dwelling animals, protists and plants. Here, we identified crinosterol from nine species of mites (Acari). The compound was identified by using (1)H-NMR analysis and GCMS spectral data along with the HPLC retention time by comparing with those of the synthesized compound. As far as we know, this is the first report on the identification of crinosterol from arthropods. Furthermore, after Rhizoglyphus robini were fed on artificial diets with d(3)-methionine, d(2)-crinosterol was detected from the mite's extracts. The incorporation of two deuterium atoms into the sterol indicated that a d(3)-methyl group was introduced into the C24 of the side chain to form crinosterol. Although the details of the biosynthesis of crinosterol remain unknown, the discovery of crinosterol in the mites implies the existence of interesting sterol metabolisms in the animals.

Acaridae/química , Esteróis/isolamento & purificação , Animais , Cromatografia Líquida de Alta Pressão , Deutério , Cromatografia Gasosa-Espectrometria de Massas , Ressonância Magnética Nuclear Biomolecular , Esteróis/química
Exp Appl Acarol ; 36(1-2): 107-17, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16082928


The female sex pheromone of Rhizoglyphus setosus Manson (Astigmata: Acaridae) was identified as S-isorobinal (4S-4-isopropenyl-3-oxo-1-cyclohexene-1-carboxyaldehyde), which stimulated males sexually and enhanced the frequency of the male's tapping and mounting behavior. Although the female hexane extract indicated no sign of sex pheromone activity against tested males, possibly due to the presence of the alarm pheromone neryl formate, an SiO2 column fraction containing isorobinal elicited sex pheromone activity at a dose of one female equivalent. The stereochemistry of natural isorobinal was identified as S by an HPLC using a chiral column. Both S- and R-isorobinals exhibited maximum activity at the same dose of 1 and 10 ng with a convex dose-response relationship. Amounts of S-isorobinal were determined to be 11.7 +/- 1.0 ng per female and 6.4 +/- 1.3 ng per male by GLC. This is the second example of two pheromones (the alarm pheromone neryl formate, and the sex pheromone S-isorobinal) demonstrated to be components of the same opisthonotal gland secretion.

Acaridae/química , Monoterpenos/isolamento & purificação , Atrativos Sexuais/isolamento & purificação , Acaridae/fisiologia , Animais , Cromatografia Líquida de Alta Pressão , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Monoterpenos/química , Atrativos Sexuais/fisiologia