Effects of Peripheral Blood Mononuclear Cells Morphology on Vascular Calcification in Uremic Patients on Maintenance Hemodialysis

Abstract

We used high-resolution atomic force microscopy (AFM) to examine possible changes in the morphology of peripheral blood mononuclear cells (PBMCs), and to investigate their influence on vascular calcification in uremic patients on maintenance hemodialysis (MHD). 36 uremic patients had cardiovascular diseases after MHD (MHD group1) and 30 uremic patients did not (MHD group 2), and 20 healthy volunteers were the control group. The extent of coronary artery calcification was assessed with coronary artery calcification score (CACS). AFM was used to analyze PBMCs nuances. Concentrations of bone morphogenetic protein-2 (BMP-2) in PBMC supernatants were detected by ELISA. Protein expressions of BMP-2 were measured by Western blot. No significant differences in PBMC morphology were observed among groups by light microscopy. AFM images revealed that uremic patients exhibited significant differences of PBMC morphology and vascular calcification when compared with healthy volunteers. The PBMCs in uremic patients were larger in volume, mean height, half-maximum amplitude, average roughness and higher concentrations and expression of BMP-2 and CACS (P < 0.05), with granular processes or caveolae of uneven size distributed over cell surfaces. These differences were also significant between MHD group 1 and group 2 (P < 0.05). PBMC volume, mean height, half-maximum amplitude, and average roughness were positively correlated with BMP-2 and CACS. Moreover, the correlation PBMC with BMP-2 was higher than with CACS. PBMC morphology in MHD patients was related to the degree of vascular calcification. The larger mean height, half-maximum amplitude, average roughness and cell volume were, the higher degree of vascular calcification was.