RESUMO
The antioxidant activity and protective effect in the toxicity model of H2O2 were studied for arachidonic (AA-CHOL), docosahexaenoic (DHA-CHOL), linoleic (Ln-CHOL), and oleic (Ol-CHOL) fatty acids, as well as arachidonoyl dicholine (AA-diCHOL) and O-arachidonoyl bistetramethylaminoisopropanol (ABTAP). AA-CHOL, DHA-CHOL and Ln-CHOL provided a 20% increase in cell survival. AA-CHOL, AA-diCHOL, Ol-CHOL, and ABTAP had a radical-scavenging effect in the ABTS test, approximately equal to the activity of a standard radical scavenger Trolox.
Assuntos
Antioxidantes/química , Ácidos Araquidônicos/química , Colina/química , 2-Propanol/química , Ácido Araquidônico/química , Linhagem Celular Tumoral , Cromanos/química , Ácidos Docosa-Hexaenoicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Ácidos Graxos , Radicais Livres/química , Humanos , Peróxido de Hidrogênio/química , Ácido Linoleico/química , Ácido Oleico/químicaRESUMO
Experiments on resting hepatocytes with inactive c-fos gene and active albumin gene. We revealed that DNA of the transcribed gene is less susceptible to the influence of endogenous Ca2+/Mg(2+)-dependent DNases in matrix-associated and highly soluble chromatin fractions. In the fraction of low soluble chromatin active gene was more accessible for DNases. Our results indicate that activity of endogenous DNases can change in the transcribed gene locus.
Assuntos
Cromatina/metabolismo , Desoxirribonucleases/metabolismo , Hepatócitos/metabolismo , Transcrição Gênica , Albuminas/genética , Animais , Regulação da Expressão Gênica , Genes fos , Masculino , Ratos , Ratos WistarRESUMO
Accumulation of c-fos gene locus DNA in the nuclear matrix of hepatocyte nuclei was observed during induction of c-fos with cycloheximide. No enhanced association with the nuclear matrix was detected for inactive immunoglobulin gene locus. The use of endogenous DNAses allows isolation of nuclear matrix preparations enriched with transcribing chromatin.
Assuntos
Cromatina/metabolismo , Genes fos , Matriz Nuclear/metabolismo , Animais , Cromatina/genética , Cicloeximida/metabolismo , Regulação da Expressão Gênica , Hepatócitos/citologia , Hepatócitos/fisiologia , Imunoglobulina G/genética , Masculino , Inibidores da Síntese de Proteínas/metabolismo , Ratos , Ratos WistarRESUMO
Degree of nucleolysis has critical significance for isolation of nuclear matrix (NM) specifically enriched in transcribed DNA sequences as demonstrated at the example of inactive (c-fos, c-myc, and Ck) and active (p53, albumin, and 28S rRNA) genes in resting hepatocytes. Optimal degree of nucleolysis features degradation of loop domains of chromatin with preserved relatively uniform molecular weight distribution of DNA. Deviation from these parameters leads to nonspecific fragmentation of chromatin in various gene loci and isolation of NM samples nonspecifically enriched or depleted of transcribed DNA sequences. Under optimal hydrolytic conditions, the transcribed chromatin is more resistant to endogenous DNase attack, which allows selective conservation of its association with the nuclear matrix.