Genomic stability, anti-inflammatory phenotype, and up-regulation of the RNAseH2 in cells from centenarians

Cell Death Differ. 2019 Sep;26(9):1845-1858. doi: 10.1038/s41418-018-0255-8. Epub 2019 Jan 8.

Abstract

Current literature agrees on the notion that efficient DNA repair favors longevity across evolution. The DNA damage response machinery activates inflammation and type I interferon signaling. Both pathways play an acknowledged role in the pathogenesis of a variety of age-related diseases and are expected to be detrimental for human longevity. Here, we report on the anti-inflammatory molecular make-up of centenarian's fibroblasts (low levels of IL-6, type 1 interferon beta, and pro-inflammatory microRNAs), which is coupled with low level of DNA damage (measured by comet assay and histone-2AX activation) and preserved telomere length. In the same cells, high levels of the RNAseH2C enzyme subunit and low amounts of RNAseH2 substrates, i.e. cytoplasmic RNA:DNA hybrids are present. Moreover, RNAseH2C locus is hypo-methylated and RNAseH2C knock-down up-regulates IL-6 and type 1 interferon beta in centenarian's fibroblasts. Interestingly, RNAseH2C locus is hyper-methylated in vitro senescent cells and in tissues from atherosclerotic plaques and breast tumors. Finally, extracellular vesicles from centenarian's cells up-regulate RNAseH2C expression and dampen the pro-inflammatory phenotype of fibroblasts, myeloid, and cancer cells. These data suggest that centenarians are endowed with restrained DNA damage-induced inflammatory response, that may facilitate their escape from the deleterious effects of age-related chronic inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / chemistry
  • Breast Neoplasms / genetics
  • Cellular Senescence / genetics*
  • DNA Damage / drug effects
  • DNA Damage / genetics*
  • Extracellular Vesicles / immunology
  • Extracellular Vesicles / metabolism*
  • Female
  • Fibroblasts / enzymology
  • Fibroblasts / metabolism*
  • Genetic Loci
  • Humans
  • Inflammation / genetics
  • Inflammation / metabolism*
  • Interferon-beta / metabolism
  • Interleukin-6 / metabolism
  • Longevity / genetics*
  • Longevity / physiology
  • Male
  • Methylation
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Middle Aged
  • Plaque, Atherosclerotic / chemistry
  • Plaque, Atherosclerotic / genetics
  • Ribonuclease H / genetics
  • Ribonuclease H / metabolism*
  • Telomere Homeostasis / genetics
  • Young Adult

Substances

  • IL6 protein, human
  • Interleukin-6
  • MicroRNAs
  • Interferon-beta
  • ribonuclease HII
  • Ribonuclease H