title: Extracellular vesicles participate in the transport of cytokines and angiogenic factors in diabetic patients with ocular complications.
abstract: BACKGROUND
  Extracellular vesicles (EVs), including circulating microvesicles (MVs) or mi- croparticles (MPs) and exosomes, derived from cells or platelets are present in the peripheral blood and are important elements involved in the activation of the coagulation system, transport of macromolecules and intercellular communication. In patients with vascular complications (including diabetes), the number of EVs is significantly increased during the acute phase of the disease. However, less is known about EVs release in the chronic state of diabetes.
  
  
  OBJECTIVE
  To analyse the profile of inflammatory cytokines and angiogenic factors in EVs in diabetic patients with ocular and vascular complications.
  
  
  METHODS
  The study included patients with diabetes and varying degrees of ocular complications including retinopathy (n = 48) and the control group (n = 13). EV-enriched and EV-depleted fractions were obtained from platelet-poor plasma by means of the centrifugation method (16 000 g, for 90 min). In screening, the profile of cytokines with pro-angiogenic effects was preliminary assessed using the protein microarray technology for controlled diabetic patients - CD, uncontrolled diabetic patients - UD and for the control group. In all patients, concentrations of cytokines: RANTES (Regulated on Activation, Normal T-cell Expressed and secreted) and Ang-2 (angiopoietin-2) were assayed using the ELISA method. Common blood and biochemical tests were performed.
  
  
  RESULTS
  In patients with diabetes, analysis of supernatant revealed significantly increased concentrations of basic fibroblast growth factor (bFGF) and soluble receptor for vascular endothelial growth factor 2 (V-EGFR2) when compared to the control group: 49 (10.5-122) vs. 24 (2-72.5) SD (p = 0.03) and 260 (195.5-351) vs. 360 (256-461.5) SD (p = 0.01). In UD patients, concentrations of RANTES, angiostatin, tumor necrosis factor-α (TNF), and tissue inhibitors of metalloproteinase 1 and 2 (TIMP1 and TIMP2) were relatively higher in the EV-enriched fraction when compared to the EV-depleted fraction. Post hoc analysis revealed significant differences between UC patients and the control group in RANTES (16.73 (14.41-18.93) vs. 14.62 (12.37-15.28) mg/ml; p = 0.0235) and Ang-2 (2.76 (2.23-4.64) ng/ml vs. 1.74 (1.54-1.93); p = 0.0316) concentrations. These analyses did not reveal any significant differences in RANTES and Ang-2 concentrations between CD patients and the control group.
  
  
  CONCLUSIONS
  The profiles of cytokines and angiogenic factors in EVs are significantly increased in patients with diabetes. Also, the formation of specific cytokines related to EVs is strongly influenced by disease duration and successful treatment. EVs seem to be the conveyors of upregulated cytokines and angiogenic agents in diabetic patients.
authors: Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland.
authors: Aleksandra
authors: A
authors: Tokarz
authors: Iwona
authors: I
authors: Szuścik
authors: Beata
authors: B
authors: Kuśnierz-Cabala
authors: Maria
authors: M
authors: Kapusta
authors: Magdalena
authors: M
authors: Konkolewska
authors: Aleksander
authors: A
authors: Żurakowski
authors: Adriana
authors: A
authors: Georgescu
authors: Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland.|Department of Medical Physics, M. Smoluchowski Institute of Physics, Jagiellonian University, Krakow, Poland. e.stepien@uj.edu.pl.
authors: Ewa
authors: E
authors: Stępień
mesh_terms: D000328:Adult; D042702:Angiopoietin-2 / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D018946:Chemokine CCL5 / Q000097:blood*; D003930:Diabetic Retinopathy / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D033921:Vesicular Transport Proteins / Q000097:blood*
chemical_list: D042702:Angiopoietin-2; D015415:Biomarkers; C483024:CCL5 protein, human; D018946:Chemokine CCL5; D033921:Vesicular Transport Proteins
keywords: Angiopoietin-2; Extracellular vesicles (EVs); RANTES; cytokines; diabetes; retinopathy