Frontiers in Ecology and Evolution (Oct 2022)

Concentrations of urinary neopterin, but not suPAR, positively correlate with age in rhesus macaques

  • Eve B. Cooper,
  • Eve B. Cooper,
  • Marina M. Watowich,
  • Marina M. Watowich,
  • Marina M. Watowich,
  • Nina Beeby,
  • Nina Beeby,
  • Connor Whalen,
  • Cayo Biobank Research Unit,
  • Michael J. Montague,
  • Lauren J. N. Brent,
  • Noah Snyder-Mackler,
  • Noah Snyder-Mackler,
  • Noah Snyder-Mackler,
  • James P. Higham,
  • James P. Higham

DOI
https://doi.org/10.3389/fevo.2022.1007052
Journal volume & issue
Vol. 10

Abstract

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Identifying biomarkers of age-related changes in immune system functioning that can be measured non-invasively is a significant step in progressing research on immunosenescence and inflammaging in free-ranging and wild animal populations. In the present study, we aimed to investigate the suitability of two urinary compounds, neopterin and suPAR, as biomarkers of age-related changes in immune activation and inflammation in a free-ranging rhesus macaque (Macaca mulatta) population. We also investigated age-associated variation in gene transcription from blood samples to understand the underlying proximate mechanisms that drive age-related changes in urinary neopterin or suPAR. Neopterin was significantly positively correlated with age, and had a moderate within-individual repeatability, indicating it is applicable as a biomarker of age-related changes. The age-related changes in urinary neopterin are not apparently driven by an age-related increase in the primary signaler of neopterin, IFN-y, but may be driven instead by an age-related increase in both CD14+ and CD14− monocytes. suPAR was not correlated with age, and had low repeatability within-individuals, indicating that it is likely better suited to measure acute inflammation rather than chronic age-related increases in inflammation (i.e., “inflammaging”). Neopterin and suPAR had a correlation of 25%, indicating that they likely often signal different processes, which if disentangled could provide a nuanced picture of immune-system function and inflammation when measured in tandem.

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