Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCA345

Poster Communications

Short-term high salt diet induces changes in CD11a expression of peripheral blood granulocytes and monocytes in young healthy women

L. Baric1, M. Mihalj1, S. Novak1, A. Matic1, M. Stupin1,3, I. Drenjancevic1, A. Stupin1,2

1. Department of Physiology and Immunology, Faculty of Medicine Josip Juraj Strossmayer University of Osijek, Osijek, Croatia. 2. Department of Physiology and Immunology, Faculty of Dental Medicine and Health Josip Juraj Strossmayer University of Osijek, Osijek, Croatia. 3. Department for Cardiovascular Disease, Osijek University Hospital, Osijek, Croatia.

It has been proposed that inflammation has an important role in the mechanisms underlying endothelial dysfunction induced by high-salt (HS) intake, and that the leukocyte-endothelial cell interactions are important for this process. This study aimed to assess the effect of 7-days salt intake modulation (low salt - LS and HS diet) on leukocytes activation defined by CD11a expression (part of LFA-1/Leukocyte Function Antigen 1, which is ligand of ICAM-1-5/Intercellular Adhesion Molecules 1-5) using flow cytometry in young healthy women. 15 young healthy women participated in this study. After initial 7-days LS diet (<3.2 g salt/day) all participants took 7-days HS diet (~14 g salt/day). Blood pressure (BP) was measured, and 24h urine samples were analyzed for sodium, potassium, urea and creatinine levels before and after diet protocols. Also, before and after corresponding diet protocols, flow cytometry measurement of CD11a expression on peripheral blood leukocytes was performed. Cells were stained and incubated with a mixture of antibodies: CD45-PerCP, CD14 FITC, CD11a/LFA-1 PE-Cy7 and CD16 APC. Biotinylated antibody was labeled with streptavidin PE Cy7 (BD Bioscience) on room temperature for 30 min in the dark and washed. Following, erythrocytes were lysed by BD Lysing Solution for 10 min at 37°C. After last washing process, cells were fixated with 1 % formaldehyde. At least 10,000 live leukocytes were collected by a BD FACS Canto II cytometer and analyzed using the FlowLogic software (Inivai Technologies). Results of CD11a expression are presented as mean fluorescence intensity. This study was approved by the Ethical Committee of the Faculty of Medicine University of Osijek (Class: 602-04/17-08/12, No: 2158-61-07-17-42). Changes in 24h urinary sodium confirmed that subjects conformed to the diet protocol. BP was reduced after LS diet, but not changed after HS diet protocol. HS diet protocol significantly decreased CD11a expression on CD16high granulocyte (median expression of CD11a+ CD16high granulocytes LS diet 1834±214 vs. HS diet 1280±323, P<0.001), monocytes (median expression of CD11a+ monocytes LS diet 1191±232 vs. HS diet 1024±260, P=0.0242) and lymphocytes (median expression of CD11a+ lymphocytes LS diet 705±148 vs. HS diet 501±124, P=0.001) in peripheral blood, compared to LS diet measurement. The present study demonstrated that one week of HS diet significantly decreased expression of CD11a on CD16high granulocytes, monocytes and lymphocytes when compared to LS diet in young healthy women. It is possible that such decrease in activated leukocytes expressing high-level od CD11a provoked by short-term HS loading occurs due to activated leukocytes adhesion and migration through endothelial layer at the place of vascular injury.

Where applicable, experiments conform with Society ethical requirements