Nährstoffe als Lehrmeister

Zusammenfassung

Nahrungsinhaltsstoffe können epigenetische Mechanismen in Zellen auf unterschiedliche Weise beeinflussen. Fettsäuren und deren Metabolite und andere Wirkstoffe wie Vitamin D bewirken über die Bindung an Kernrezeptoren eine vielschichtige Regulation der Genexpression, die auch an Tochterzellen bzw. nachfolgende Zellen weitergegeben werden kann. Dabei verhindern oder verbessern epigenetische Markierungen im Chromatin den Zugang zum Genregulationsschalter. Epigenetische Aktivitäten können durch den Energiezustand in der Zelle beeinflusst werden. Sirtuine mit Histondeacetylaseaktivität sind z. B. unter Energierestriktion bzw. unter dem Einfluss anderer Stoffe wie Resveratrol hochaktiv. Infolgedessen wird die Verpackung des Genoms (Chromatin) kompakter und die Genexpression möglicherweise so reduziert, um Vorgänge so auszurichten, die zur Langlebigkeit beitragen.

Von zentraler Bedeutung in der Epigenetik ist S-Adenosyl-Methionin (SAM), das als Methylgruppenträger für epigenetische DNA- und Histon-Methylierungen dient. Diese epigenetischen Markierungen verändern die Chromatinstruktur und infolgedessen die Genaktivität. Methylreiche Diäten mit Folat, Betain und Cholin während der Trächtigkeit führten im Agouti^vy-Mausmodell in der Folgegeneration F1 zu veränderten Methylierungsmustern in bestimmten DNA-Abschnitten, die den Phänotyp der Nachkommen veränderten und die Adipositasneigung reduzierten. Die epigenetische Forschung sucht künftig auch im Humangenom nach metastabilen Veränderungen an den Genen (Epiallele), die auf Umweltfaktoren wie Nahrung, Stress, Toxine oder Verhalten ansprechen.

Abstract

Food ingredients can affect epigenetic mechanisms in cells in different ways. Fatty acids and their metabolites, and other active substances such as vitamin D ensure by binding to nuclear receptors a complex regulation of gene expression, which can also be passed on to daughter cells or subsequent cells. In this process, epigenetic markings in the chromatin inhibit or improve access to the gene regulation switch. Epigenetic activities can be influenced by a cell’s energy status. Sirtuin proteins with histone deacetylase activity are highly active under conditions of restricted energy, for example, or under the influence of other substances such as resveratrol. As a result the packaging of the genome (chromatin) becomes more compact and the gene expression potentially reduced to such an extent that it directs processes in such a way that they contribute to longevity.

S-adenosyl-methionine (SAM), which is a methyl group carrier for epigenetic DNA and histone methylations, is of central importance in epigenetics. These epigenetic markings change the chromatin structure and thus the gene activity. Methyl-rich diets with folate, betaine, and choline during pregnancy in the Agouti^vy mouse model in the F1-generation led to changed methylation patterns in certain DNA segments, which changed the offspring’s phenotype and reduced the tendency to obesity. Future epigenetic research will look for metastable changes at genes (epialleles) in the human genome, which respond to environmental factors, such as nutrition, stress, toxins, or behaviors.

Schlüsselwörter

Fettsäuren - Peroxisom-Proliferator-aktivierter Rezeptor (PPAR) - Plazentafunktion - C1-Metabolismus - S-Adenosyl-Methionin (SAM) - Supplementierung - Folat - Agouti-Mäuse

Keywords

Fatty acids - peroxisome-proliferator-activated receptor (PPAR) - placental function - C1 metabolism - S-adenosyl methionine (SAM) - supplementation - folate - Agouti mice

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