Mechanisms involved in dual vasopressin/apelin neuron dysfunction during aging

PLoS One. 2014 Feb 5;9(2):e87421. doi: 10.1371/journal.pone.0087421. eCollection 2014.

Abstract

Normal aging is associated with vasopressin neuron adaptation, but little is known about its effects on the release of apelin, an aquaretic peptide colocalized with vasopressin. We found that plasma vasopressin concentrations were higher and plasma apelin concentrations lower in aged rats than in younger adults. The response of AVP/apelin neurons to osmotic challenge was impaired in aged rats. The overactivity of vasopressin neurons was sustained partly by the increased expression of Transient receptor potential vanilloid2 (Trpv2), because central Trpv blocker injection reversed the age-induced increase in plasma vasopressin concentration without modifying plasma apelin concentration. The morphofunctional plasticity of the supraoptic nucleus neuron-astrocyte network normally observed during chronic dehydration in adults appeared to be impaired in aged rats as well. IL-6 overproduction by astrocytes and low-grade microglial neuroinflammation may contribute to the modification of neuronal functioning during aging. Indeed, central treatment with antibodies against IL-6 decreased plasma vasopressin levels and increased plasma apelin concentration toward the values observed in younger adults. Conversely, minocycline treatment (inhibiting microglial metabolism) did not affect plasma vasopressin concentration, but increased plasma apelin concentration toward control values for younger adults. This study is the first to demonstrate dual vasopressin/apelin adaptation mediated by inflammatory molecules and neuronal Trpv2, during aging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / blood*
  • Aging / pathology
  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Apelin
  • Astrocytes / metabolism*
  • Astrocytes / pathology
  • Gene Expression Regulation / drug effects
  • Intercellular Signaling Peptides and Proteins / blood*
  • Interleukin-6 / metabolism
  • Male
  • Minocycline / pharmacology
  • Neurons / metabolism*
  • Neurons / pathology
  • Osmotic Pressure
  • Rats
  • Rats, Wistar
  • TRPV Cation Channels / biosynthesis
  • Vasopressins / blood*

Substances

  • Anti-Bacterial Agents
  • Apelin
  • Apln protein, rat
  • Intercellular Signaling Peptides and Proteins
  • Interleukin-6
  • TRPV Cation Channels
  • Trpv2 protein, rat
  • Vasopressins
  • Minocycline

Grants and funding

This work was supported by the Fondation pour la Recherche Médicale (contract LLC20051005102) and by Groupement d'intérêt Scientifique Institut National de la Santé et de la Recherche Médicale “Longévité et vieillissement” (contract no. GISL0412). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.