[
Biogerontology,
2019]
Aging is a natural and unavoidable part of life. However, aging is also the primary driver of the dominant human diseases, such as cardiovascular disease, cancer, and neurodegenerative diseases, including Alzheimer's disease. Unraveling the sophisticated molecular mechanisms of the human aging process may provide novel strategies to extend 'healthy aging' and the cure of human aging-related diseases. Werner syndrome (WS), is a heritable human premature aging disease caused by mutations in the gene encoding the Werner (WRN) DNA helicase. As a classical premature aging disease, etiological exploration of WS can shed light on the mechanisms of normal human aging and facilitate the development of interventional strategies to improve healthspan. Here, we summarize the latest progress of the molecular understandings of WRN protein, highlight the advantages of using different WS model systems, including Caenorhabditis elegans, Drosophila melanogaster and induced pluripotent stem cell (iPSC) systems. Further studies on WS will propel drug development for WS patients, and possibly also for normal age-related diseases.
[
Cells,
2021]
Werner syndrome (WS) is a rare recessive genetic disease characterized by premature aging. Individuals with this disorder develop normally during childhood, but their physiological conditions exacerbate the aging process in late adolescence. WS is caused by mutation of the human WS gene (<i>WRN</i>), which encodes two main domains, a 3'-5' exonuclease and a 3'-5' helicase. <i>Caenorhabditis elegans</i> expresses human WRN orthologs as two different proteins: MUT-7, which has a 3'-5' exonuclease domain, and <i>C</i><i>. elegans</i> WRN-1 (CeWRN-1), which has only helicase domains. These unique proteins dynamically regulate olfactory memory in <i>C. elegans</i>, providing insight into the molecular roles of WRN domains in humans. In this review, we specifically focus on characterizing the function of MUT-7 in small interfering RNA (siRNA) synthesis in the cytoplasm and the roles of siRNA in directing nuclear CeWRN-1 loading onto a heterochromatin complex to induce negative feedback regulation. Further studies on the different contributions of the 3'-5' exonuclease and helicase domains in the molecular mechanism will provide clues to the accelerated aging processes in WS.