Changes in the function of angiotensin II type 1 receptor due to cholesterol depletion from cell membrane

Authors:
Matsuo Y, Suematsu Y, Idemoto Y, Kuwano T, Kitajima K, Miura SI
In:
Source: Biochem Biophys Res Commun
Publication Date: (2019)
Issue: 514: 3
Research Area:
Cardiovascular
Cells used in publication:
Cardiomyocyte (R-CM), rat
Species: rat
Tissue Origin: heart
SMC, vascular, rat
Species: rat
Tissue Origin:
Experiment


Abstract

Blockers of G-protein coupled receptors (GPCRs), angiotensin II (Ang II) type 1 (AT1) receptor and ß1-adrenergic (Ad) receptor, have been shown to improve the prognosis of cardiovascular disease. Cholesterol molecules in the cell membrane are needed to stabilize GPCRs as well as the cell membrane itself. We determined whether the functions of AT1 and ß1-Ad receptors were changed by cholesterol depletion from cardiovascular cell membranes. Ang II-induced inositol phosphate production through AT1 receptor was suppressed by cholesterol depletion from cell membranes using rosuvastatin or methyl-ß-cyclodextrin (MßCD), whereas isoproterenol-induced cyclic AMP production through ß1-Ad receptor did not change after cholesterol depletion. In addition, the binding affinities of Ang II and AT1 receptor blocker after cholesterol depletion were significantly lower than those before depletion. Although AT1 receptor expression levels did not change after cholesterol depletion, the expression levels of AT1 receptor that could bind to Ang II significantly decreased after depletion. The changes in the structure of AT1 receptor due to depletion were confirmed by substituted-cysteine accessibility mapping. In conclusion, Ang II-induced activation of AT1 receptor is reduced without affecting the function of ß1-Ad receptor after cholesterol depletion from cardiovascular cell membranes.