Activation of endothelial cells during insulin‐dependent diabetes mellitus: a biochemical and morphological study

Abstract

Plasma membrane lipid dynamics and cellular morphology were evaluated in endothelial cells obtained from umbilical cords of five women affected by insulin-dependent diabetes mellitus (IDDM) and six healthy pregnant women of similar age and gestational age. Endothelial cells were prepared by an adaptation of the method of Jaffe et al. Membrane fluidity was studied by means of the steady-state fluorescence anisotropy (r) of 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH), a fluorescent probe specifically anchoring at the membrane surface. Fluid phase endocytosis was evaluated by the measurement of the changes in fluorescence intensity of TMA-DPH at various times, owing to the internalization of the fluorescent marker in endocytic vesicles. The morphological and morphometric studies were performed by means of transmission electron microscopy (TEM). Endothelial cells obtained from IDDM women showed: (a) increased fluidity of the superficial region of the plasma membrane; (b) a more active fluid phase endocytosis compared with cells from healthy women; (c) increase in mitochondrial area, Weibel-Palade bodies and rough reticulum with wide cisternae. No statistically significant correlation was found between metabolic control and membrane fluidity and endocytosis. All the observed modifications suggest the presence of endothelial cell activation with membrane reshaping during IDDM. These alterations might play a central role in the pathophysiology of atherosclerosis and microangiopathy associated with diabetes mellitus.

Sinusoidal Constriction and Vascular Hypertrophy in the Diabetes-Induced Rabbit Penis

“…Hadcock et al (25) have also reported cytoplasmic vacuolization in endothelial cells in the aorta of alloxan-induced diabetic rabbits. In cells from the umbilical cord, this vacuolization has been shown to be correlated with an increase in mitochondrial area (28). Mitochondrial and nuclear changes are indicators of the reversible injury mechanism, vacuolar degeneration (29).…”

HUVECs from newborns with a strong family history of diabetes show diminished ROS synthesis in the presence of high glucose concentrations

“…Also, an increase in reactive oxygen species (ROS) synthesis has been shown in mononuclear cells isolated from type 2 diabetic patients stimulated with phorbol myristate acetate [8] and in young people with type 1 DM [9,10]. Sank et al [11], and Cester et al [12], have shown that human umbilical vein endothelial cells (HUVECs) isolated from newborns with type 1 diabetic mothers were 20-40% less resistant to shear stress, took up glucose more slowly, showed alterations in the plasma membrane, and had a more active fluid phase endocytosis and an increase in mitochondrial area, compared to control HUVECs. An increase in Larginine transport and nitric oxide synthesis as well as an impairment in the action of insulin due to hyperglycaemia has been shown in HUVECs isolated from newborns to women with gestational diabetes [13,14].…”

Purine Bases Oxidation and Repair Following Permethrin Insecticide Treatment in Rat Heart Cells

“…drugs, toxins, insecticides) that can change the physical properties of the plasma membrane [47]. Fluorescence polarization method has been extensively used in the assessment of membrane fluidity in a variety of biological membranes such as endothelial cells [48] and fibroblast [49] as well as those of the artificial membranes [50]. A wide range of probes, such as DPH and Laurdan, has been used to monitor plasma membrane fluidity in different regions of the bilayer [51].…”