Pharmacological activation of the C5a receptor leads to stimulation of the β-adrenergic receptor and alleviates cognitive impairment in a murine model of familial Alzheimer's disease

Front Immunol. 2022 Aug 26:13:947071. doi: 10.3389/fimmu.2022.947071. eCollection 2022.

Abstract

Alzheimer's disease (AD) is a progressive neurodegenerative disease of the brain causing either familial or sporadic dementia. We have previously administered the modified C5a receptor agonist (EP67) for a short period to a transgenic mouse model of AD (5XFAD) and have observed not only reduction in β-amyloid deposition and gliosis but also improvement in cognitive impairment. Inquiring, however, on the effects of EP67 in an already heavily burdened animal, thus representing a more realistic scenario, we treated 6-month-old 5XFAD mice for a period of 14 weeks. We recorded a significant decrease in both fibrillar and pre-fibrillar β-amyloid as well as remarkable amelioration of cognitive impairment. Following proteomic analysis and pathway association, we postulate that these events are triggered through the upregulation of β-adrenergic and GABAergic signaling. In summary, our results reveal how inflammatory responses can be employed in inducing tangible phenotype improvements even in advanced stages of AD.

Keywords: Alzheimer’s disease; C5a receptor; EP67; GABA; β-adrenergic; β-amyloid.

MeSH terms

  • Alzheimer Disease* / drug therapy
  • Alzheimer Disease* / genetics
  • Alzheimer Disease* / metabolism
  • Animals
  • Cognitive Dysfunction* / drug therapy
  • Cognitive Dysfunction* / genetics
  • Cognitive Dysfunction* / metabolism
  • Disease Models, Animal
  • Mice
  • Mice, Transgenic
  • Oligopeptides* / pharmacology
  • Oligopeptides* / therapeutic use
  • Proteomics
  • Receptor, Anaphylatoxin C5a* / agonists
  • Receptor, Anaphylatoxin C5a* / genetics
  • Receptor, Anaphylatoxin C5a* / metabolism
  • Receptors, Adrenergic, beta* / genetics
  • Receptors, Adrenergic, beta* / metabolism

Substances

  • C5ar1 protein, mouse
  • Oligopeptides
  • Receptor, Anaphylatoxin C5a
  • Receptors, Adrenergic, beta
  • tyrosyl-seryl-phenylalanyl-lysyl-aspartyl-methionyl-prolyl-N-methyleucyl-alanyl-arginine