Renin-angiotensin system impairs macrophage lipid metabolism to promote age-related macular degeneration in mouse models

Commun Biol. 2020 Dec 9;3(1):767. doi: 10.1038/s42003-020-01483-2.

Abstract

Metabolic syndrome, a condition involving obesity and hypertension, increases the risk of aging-associated diseases such as age-related macular degeneration (AMD). Here, we demonstrated that high-fat diet (HFD)-fed mice accumulated oxidized low-density lipoprotein (ox-LDL) in macrophages through the renin-angiotensin system (RAS). The ox-LDL-loaded macrophages were responsible for visual impairment in HFD mice along with a disorder of the retinal pigment epithelium (RPE), which is required for photoreceptor outer segment renewal. RAS repressed ELAVL1, which reduced PPARγ, impeding ABCA1 induction to levels that are sufficient to excrete overloaded cholesterol within the macrophages. The ox-LDL-loaded macrophages expressed inflammatory cytokines and attacked the RPE. An antihypertensive drug, angiotensin II type 1 receptor (AT1R) blocker, resolved the decompensation of lipid metabolism in the macrophages and reversed the RPE condition and visual function in HFD mice. AT1R signaling could be a future therapeutic target for macrophage-associated aging diseases, such as AMD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter 1 / metabolism
  • Angiotensin II Type 1 Receptor Blockers / pharmacology
  • Animals
  • Biomarkers
  • Diet, High-Fat
  • Disease Models, Animal
  • Disease Susceptibility*
  • Lipid Metabolism*
  • Lipoproteins, LDL / metabolism
  • Macrophages / immunology*
  • Macrophages / metabolism*
  • Macrophages / ultrastructure
  • Macular Degeneration / etiology*
  • Macular Degeneration / metabolism*
  • Macular Degeneration / pathology
  • Mice
  • Models, Biological
  • PPAR gamma / metabolism
  • Receptor, Angiotensin, Type 1 / metabolism
  • Renin-Angiotensin System / physiology*
  • Retina / drug effects
  • Retina / metabolism
  • Retina / ultrastructure
  • Signal Transduction

Substances

  • ATP Binding Cassette Transporter 1
  • Angiotensin II Type 1 Receptor Blockers
  • Biomarkers
  • Lipoproteins, LDL
  • PPAR gamma
  • Receptor, Angiotensin, Type 1
  • oxidized low density lipoprotein