Interleukin-8 and interleukin-10, brain volume and microstructure, and the influence of calorie restriction in old rhesus macaques

Age (Dordr). 2013 Dec;35(6):2215-27. doi: 10.1007/s11357-013-9518-y. Epub 2013 Mar 6.

Abstract

Higher systemic levels of the proinflammatory cytokine interleukin-6 (IL-6) were found to be associated with lower gray matter volume and tissue density in old rhesus macaques. This association between IL-6, and these brain indices were attenuated by long-term 30 % calorie restriction (CR). To extend these findings, the current analysis determined if a CR diet in 27 aged rhesus monkeys compared to 17 normally fed controls reduced circulating levels of another proinflammatory cytokine, interleukin-8 (IL-8), and raised levels of anti-inflammatory interleukin-10 (IL-10). Further, these cytokines were regressed onto imaged brain volume and microstructure using voxel-wise regression analyses. CR significantly lowered IL-8 and raised IL-10 levels. Across the two dietary conditions, higher IL-8 predicted smaller gray matter volumes in bilateral hippocampus. Higher IL-10 was associated with more white matter volume in visual areas and tracts. Consuming a CR diet reduced the association between systemic IL-8 and hippocampal volumes. Conversely, CR strengthened associations between IL-10 and microstructural tissue density in the prefrontal cortex and other areas, particularly in a region of dorsal prefrontal cortex, which concurred with our prior findings for IL-6. Consumption of a CR diet lowered proinflammatory and increased anti-inflammatory cytokine concentrations, which lessened the statistical association between systemic inflammation and the age-related alterations in important brain regions, including the hippocampus.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aging*
  • Animals
  • Brain / cytology*
  • Brain / growth & development
  • Brain / metabolism
  • Caloric Restriction*
  • Enzyme-Linked Immunosorbent Assay
  • Interleukin-10 / metabolism*
  • Interleukin-8 / metabolism*
  • Macaca mulatta / growth & development*
  • Magnetic Resonance Imaging
  • Organ Size

Substances

  • Interleukin-8
  • Interleukin-10