title: Interleukin-8 and interleukin-10, brain volume and microstructure, and the influence of calorie restriction in old rhesus macaques.
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.
authors: Geriatric Research Education and Clinical Center, Wm. S. Middleton Memorial Veterans Hospital, D-4225 Veterans Administration Hospital, 2500 Overlook Terrace, Madison, WI, 53705, USA.
authors: A A
authors: AA
authors: Willette
authors: C L
authors: CL
authors: Coe
authors: A C
authors: AC
authors: Birdsill
authors: B B
authors: BB
authors: Bendlin
authors: R J
authors: RJ
authors: Colman
authors: A L
authors: AL
authors: Alexander
authors: D B
authors: DB
authors: Allison
authors: R H
authors: RH
authors: Weindruch
authors: S C
authors: SC
authors: Johnson
mesh_terms: D000375:Aging; D000818:Animals; D001921:Brain / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D031204:Caloric Restriction; D004797:Enzyme-Linked Immunosorbent Assay; D016753:Interleukin-10 / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism*; D008253:Macaca mulatta / Q000254:growth & development*; D008279:Magnetic Resonance Imaging; D009929:Organ Size
chemical_list: D016209:Interleukin-8; D016753:Interleukin-10