Visualizing Changes in Cdkn1c Expression Links Early-Life Adversity to Imprint Mis-regulation in Adults
CELL REPORTS
Authors: Van de Pette, Mathew; Abbas, Allifia; Feytout, Amelie; McNamara, Grainne; Bruno, Ludovica; To, Wilson K.; Dimond, Andrew; Sardini, Alessandro; Webster, Zoe; McGinty, James; Paul, Eleanor J.; Ungless, Mark A.; French, Paul M. W.; Withers, Dominic J.; Uren, Anthony; Ferguson-Smith, Anne C.; Merkenschlager, Matthias; John, Rosalind M.; Fisher, Amanda G.
Abstract
Imprinted genes are regulated according to parental origin and can influence embryonic growth and metabolism and confer disease susceptibility. Here, we designed sensitive allele-specific reporters to non-invasively monitor imprinted Cdkn1c expression in mice and showed that expression was modulated by environmental factors encountered in utero. Acute exposure to chromatin-modifying drugs resulted in de-repression of paternally inherited (silent) Cdkn1c alleles in embryos that was temporary and resolved after birth. In contrast, deprivation of maternal dietary protein in utero provoked permanent de-repression of imprinted Cdkn1c expression that was sustained into adulthood and occurred through a folate-dependent mechanism of DNA methylation loss. Given the function of imprinted genes in regulating behavior and metabolic processes in adults, these results establish imprinting deregulation as a credible mechanism linking early-life adversity to later-life outcomes. Furthermore, Cdkn1c-luciferase mice offer non-invasive tools to identify factors that disrupt epigenetic processes and strategies to limit their long-term impact.
Effects of flavonoids on expression of genes involved in cell cycle regulation and DNA replication in human fibroblasts
MOLECULAR AND CELLULAR BIOCHEMISTRY
Authors: Moskot, Marta; Jakobkiewicz-Banecka, Joanna; Smolinska, Elwira; Piotrowska, Ewa; Wegrzyn, Grzegorz; Gabig-Ciminska, Magdalena
Abstract
Flavonoids have been studied as potential agents in medicine for many years. Among them, genistein was found to be active in various biological systems, mainly in prevention of cancer. Our recent work supported the idea that genistein also impacts multiple cellular processes in healthy fibroblasts; however, its effects on cell cycle-related pathways remained to be elucidated. Thus, in this work, high throughput screening with microarrays coupled to real-time quantitative Reverse Transcription PCR analyses was employed to study the changes in expression of key genes associated with cell cycle regulation and/or DNA replication in response to genistein, kaempferol, daidzein, and mixtures of genistein and either kaempferol or daidzein. Among them, genistein was found as the most significantly modulating, in a time- and dose-dependent manner, compound of activity of studied genes, whose products are involved in different phases of the cell cycle and/or in regulatory processes important for DNA replication and cell growth. It considerably reduced the efficiency of expression of genes coding for MCM2-7 and MCM10 helicases, as well as some other proteins involved in the S phase control. In addition, genistein caused cell cycle arrest in the G2/M phase, which was accompanied by activation of CDKN1A, CDKN1C, CDKN2A, CDKN2B, CDKN2C, and GADD45A genes, as well as down-regulation of several mRNAs specific for this stage, demonstrated by transcriptomic assessments. We believe that studies described in this paper will be helpful in elucidating molecular mechanisms of action of genistein as modulator of cell cycle and inhibitor of DNA replication in humans.