Alterations to the contents of plasma membrane structural lipids are associated with structural changes and compartmentalization in platelets in hypertension

Highlights: • We assessed the lipid composition of platelets in hypertension (HTN). • Phosphatidylethanolamine and phosphatidylserine increased in HTN platelets. • HTN platelet plasma membranes have low phosphatidylcholine and cholesterol content. • HTN platelets had increased membrane fluidity. • HTN platelets exhibit a reduced open canalicular system. -- Abstract: Arterial hypertension (HTN) can lead to serious organ damage. Several mechanisms have been implicated in the pathogenesis of HTN including constitutive activation of platelets, which increases the risk of aggregation and clot formation. We recently demonstrated the plasma membranes of platelets from patients with HTN exhibit modified structural and physicochemical properties; Raman and Fourier transform infrared by attenuated total reflectance (FTIR‐ATR) spectroscopy also indicated lipid content and protein structure alterations. This study aimed to precisely quantify the constituents of the main structural phospholipids and cholesterol in the plasma membranes of platelets from patients with HTN and normotensive individuals. We also assessed the consequence of these alterations on platelet structure and function. Liquid chromatography coupled to triple quadrupole mass spectrometry revealed the plasma membranes of HTN platelets contained less cholesterol and phosphatidylcholine, more phosphatidylserine and phosphatidylethanolamine and had similar sphingosine contents. Atomic force microscopy revealed HTN platelets exhibited increased surface roughness and more pleats. Transmission electron microscopy revealed diminution of the internal membranous structures in HTN platelets. Our findings strongly suggest plasma membrane lipid content alterations—including cholesterol depletion—occur in HTN, and these alterations may induce morphological and physiological abnormalities that participate in the functional changes associated with hypertension.