Effect of Diet and Nutrients on Molecular Mechanism of Gene ExpressionMediated by Nuclear Receptor and Epigenetic Modulation

摘要

Major research progress in the last few decades has elucidated the complex nexus between nutrition and health.Diet and lifestyle influence epigenetic changes that are heritable. However, a statement of reservation is needed here, viz.that it is often difficult to distinguish between epigenetic changes that are inherited from one generation to the next andtrue mutations, for instance in mitochondrial DNA. The last topic is a big one in its own right and will not be further discussedin this article. Epigenetic changes induced by dietary nutrients ultimately culminate in changes of the expression ofgenes through transcription and translation. The interaction between dietary nutrients and nuclear receptors triggers thesignaling pathway, leading to modulation of epigenetic change and gene expression. Knowledge about nuclear receptors isimportant for explaining dietary modulation of transcription via recruitment of large protein complexes. These proteinsare capable of causing modification of chromosomal components, can influence chromatin proteins, and affect the bindingof proteins to particular parts of the DNA molecules controlling the expression of individual genes. Chromatin complexesbetween DNA and proteins can be destabilized by recruitment of transcriptional coactivators by histone acetylation. However,in the presence of hormone antagonists or in the absence of relevant ligands, recruitment of other cellular core proteinsmay stabilize chromatin by their influence on histone deacetylases, thus antagonizing the effect of enzymes causinghistone acetylation. This article reviews the current knowledge on nutritional modulation of bioactive molecules by epigeneticchanges, if they can regulate genetic expressions. The molecular mechanism of action of various dietary nutrients ongene expression mediated by nuclear receptors is also discussed.