RESUMEN
Arterial hypertension (HTN) is a global public health concern and an important risk factor for cardiovascular diseases and renal failure. We previously reported overexpression of ENaC on the plasma membrane of human platelets is a hallmark of HTN. In this double-blinded study of an open population (n = 167), we evaluated the sensitivity and specificity of a diagnostic assay based on gold nanoparticles (AuNPs) conjugated to an antibody against epithelial sodium channel (ENaC) expressed on platelets, which is detected using a fluorescent anti-ENaC secondary antibody and spectrofluorometry. Using the cutoff value for the AuNP-anti-ENaC assay, we confirmed the diagnosis for 62.1% of patients with clinical HTN and detected 59.7% of patients had previously undiagnosed HTN. Although some shortcomings in terms of accurately discriminating healthy individuals and patients with HTN still need to be resolved, we propose this AuNP-anti-ENaC assay could be used for initial screening and early diagnosis to critically improve opportune clinical management of HTN.
Asunto(s)
Hipertensión , Nanopartículas del Metal , Humanos , Canales Epiteliales de Sodio/metabolismo , Oro , Hipertensión/diagnóstico , Hipertensión/metabolismo , BiomarcadoresRESUMEN
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.
Asunto(s)
Plaquetas/metabolismo , Membrana Celular/ultraestructura , Hipertensión/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilserinas/metabolismo , Anciano , Plaquetas/ultraestructura , Membrana Celular/química , Membrana Celular/metabolismo , Células Cultivadas , Femenino , Humanos , Masculino , Fluidez de la Membrana , Persona de Mediana EdadRESUMEN
Genetic and environmental factors may contribute to high blood pressure, which is termed essential hypertension. Hypertension is a major independent risk factor for cardiovascular disease, stroke and renal failure; thus, elucidation of the etiopathology of hypertension merits further research. We recently reported that the platelets and neutrophils of patients with hypertension exhibit altered biophysical characteristics. In the present study, we assessed whether the major structural elements of erythrocyte plasma membranes are altered in individuals with hypertension. We compared the phospholipid (phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingosine) and cholesterol contents of erythrocytes from individuals with hypertension (HTN) and healthy individuals (HI) using LC/MS-MS. HTN erythrocytes contained higher phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine contents and a lower cholesterol content than HI erythrocytes. Furthermore, atomic force microscopy revealed important morphological changes in HTN erythrocytes, which reflected the increased membrane fragility and fluidity and higher levels of oxidative stress observed in HTN erythrocytes using spectrophotofluorometry, flow cytometry and spectrometry. This study reveals that alterations to the lipid contents of erythrocyte plasma membranes occur in hypertension, and these alterations in lipid composition result in morphological and physiological abnormalities that modify the dynamic properties of erythrocytes and contribute to the pathophysiology of hypertension.