Epigenetic and genetic factors are suggested to be involved in the aging process. Indeed, aging research on various model organisms like Caenorhabditis elegans or Drosophila melanogaster improved our understanding of genomic, epigenetic and proteomic aspects regarding the lifespan of these organisms. Specific set of genes or genetic loci that are related to longevity and aging are being analyzed in these model systems. Genetic and epigenetic factors appear to have significant influence also on human longevity, since the heritability of human lifespan was estimated in a range of 20-30% in many studies. Unlike genetics, epigenetics refers to “functional changes of the genome without changing the DNA sequence”. This includes chromatin changes and remodeling, which in general is triggered by factors that promote or remove histone modifications and regulate exchange of histone variants. However, the underlying mechanisms linking epigenetics to aging are poorly understood. One reason is the fact that aging is associated with a variety of human disorders, which includes cancer.
Interestingly, the gene encoding the epigenetic regulator tumor suppressor, inhibitor of growth 1 (ING1) has been suggested to be one of the aging-related candidate genes among 47 healthy individuals at the age of 85 years or older. Within this cohort, no aging-related diseases such as cancer, cardiovascular disease, pulmonary disease, diabetes, or Alzheimer disease have been diagnosed.
The ING tumor suppressors are localized in the nucleus and directly associated with chromatin regulation and control of gene expression. ING factors control various cellular pathways which include cell cycle control, DNA repair and two tumor protective pathways: apoptosis and cellular senescence that both seems to be important pathways for tumor suppression.
No comments:
Post a Comment