Circulating endothelial cells and angiogenic proteins in patients with systemic lupus erythematosus

Abstract

The aim of our study was to assess absolute counts of different subpopulations of circulating endothelial cells (CEC) in patients with active and inactive systemic lupus erythematosus (SLE). We have also investigated a potential correlation of CEC numbers with serum levels of angiogenic proteins as well as with clinical and laboratory symptoms of the disease. For the first time in SLE, CEC were enumerated directly, by the ‘single platform’ method. Resting (rCEC), activated (aCEC) and progenitor (pCEC) endothelial cells were identified in patients with SLE and healthy volunteers using four-colour flow cytometry. Serum concentrations of angiogenic proteins (vascular endothelial growth factor, placental growth factor (PIGF), soluble vascular cell adhesion molecule and endoglin) were evaluated by ELISA. The SLE activity was scored according to the Systemic Lupus Activity Measure system. We found that total CEC number in patients with SLE was significantly higher (median 14.2/μL) than in the control group (median 3.3/μL) (P < 0.0001). Absolute counts of aCEC, rCEC and pCEC (medians 4.9/μL, 6.8/μL and 2.3/μL, respectively) were also higher in patients with SLE than in healthy persons (medians 0.9/μL, 1.6/μL and 0.1/μL, respectively), with P < 0.0001 for all comparisons. There was no correlation between CEC or their subpopulations and SLE activity. Strong positive correlations were found between CEC, rCEC and pCEC numbers and serum levels of PIGF. Moreover, aCEC, rCEC and pCEC counts were significantly higher in SLE patients with leukopenia. In conclusion, our results show that absolute CEC counts and angiogenic proteins levels are elevated in patients with SLE as compared with healthy controls. These data may suggest that angiogenic process is involved in the pathogenesis of this disease.

Keywords

endoglin endothelial cell PIGF SLE sVCAM-1 VEGF

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References

1 Herrmann M Voll RE Kalden JR . Etiopathogenesis of systemic lupus erythematosus. Immunol Today 2000; 21: 424–426.

2 Clancy R Marder G Martin V Belmont HM Abramson SB Buyon J . Circulating activated endothelial cells in systemic lupus erythematosus: further evidence for diffuse vasculopathy. Arthritis Rheum 2001; 44: 1203–1208.

3 Lee PY Li Y Richards HB . Type I interferon as a novel risk factor for endothelial progenitor cell depletion and endothelial dysfunction in systemic lupus erythematosus. Arthritis Rheum 2007; 56: 3759–3769.

4 Lin Y Weisdorf DJ Solovey A Hebbel RP . Origins of circulating endothelial cells and endothelial outgrowth from blood. J Clin Invest 2000; 105: 71–77.

5 Kluz J Adamiec R Tubek S . The role of anti-endothelial cell antibodies in the pathogenesis of vascular complications in systemic lupus erythematosus. Pol Arch Med Wewn 2004; 111: 727–734.

6 Williams JM Colman R Brookes CJ Savage CO Harper L . Anti-endothelial cell antibodies from lupus patients bind to apoptotic endothelial cells promoting macrophage phagocytosis but do not induce apoptosis. Rheumatology 2005; 44: 879–884.

7 Navarro M Cervera R Font J . Anti-endothelial cell antibodies in systemic autoimmune diseases: prevalence and clinical significance. Lupus 1997; 6: 521–526.

8 D'Cruz DP Houssiau FA Ramirez G . Antibodies to endothelial cells in systemic lupus erythematosus: a potential marker for nephritis and vasculitis. Clin Exp Immunol 1991; 85: 254–261.

9 Song J Park YB Lee WK Lee KH Lee SK . Clinical associations of anti-endothelial cell antibodies in patients with systemic lupus erythematosus. Rheumatol Int 2000; 20: 1–7.

10.

10 Mancuso P Calleri A Cassi C . Circulating endothelial cells as a novel marker of angiogenesis. Adv Exp Med Biol 2003; 522: 83–97.

11.

11 Walsh DA . Pathophysiological mechanisms of angiogenesis. Adv Clin Chem 2007; 44: 187–221.

12.

12 Carmeliet P Moons L Luttun A . Synergism between vascular endothelial growth factor and placental growth factor contributes to angiogenesis and plasma extravasation in pathological conditions. Nat Med 2001; 7: 575–583.

13.

13 Clauss M Weich H Breier G . The vascular endothelial growth factor receptor Flt-1 mediates biological activities. Implication for a functional role of placenta growth factor in monocyte activation and chemotaxis. J Biol Chem 1996; 271: 17629–17634.

14.

14 Pipp F Heil M Issbrucker K . VEGFR-1-selective VEGF homologue PlGF is arteriogenic. Evidence for a monocyte-mediated mechanism. Circ Res 2003; 92: 378–385.

15.

15 Hattori K Heissig B Wu Y . Placental growth factor reconstitutes hematopoiesis by recruiting VEGFR1+ stem cells from bone marrow microenvironment. Nat Med 2002; 8: 841–849.

16.

16 Hochberg MC . Updating the American College of Rheumatology revised criteria for the classification of systemic lupus erythematosus. Arthritis Rheum 1997; 40: 1725.

17.

17 Liang MH Socher SA Larson MG Schur PH . Reliability and validity of six systems for the clinical assessment of disease activity in systemic lupus erythematosus. Arthritis Rheum 1989; 32: 1107–1118.

18.

18 Mancuso P Burlini A Pruneri G Goldhirsch A Martinelli G Bertolini F . Resting and activated endothelial cells are increased in the peripheral blood of cancer patients. Blood 2000; 9: 3658–3661.

19.

19 Fornas O Garcia J Petriz J . Flow cytometry counting of CD34+ cells in whole blood. Nat Med 2000; 6: 833–836.

20.

20 Wierzbowska A Robak T Krawczynska A . Kinetics and apoptotic profile of circulating endothelial cells as prognostic factors for induction treatment failure in newly diagnosed acute myeloid leukemia patients. Ann Hematol 2008; 87: 97–106.

21.

21 Robak E Kulczycka L Sysa-Jedrzejowska A Wierzbowska A Robak T . Circulating proangiogenic molecules PIGF, SDF-1 and sVCAM-1 in patients with systemic lupus erythematosus. Eur Cytokine Netw 2007; 18: 181–187.

22.

22 Robak E Woźniacka A Sysa-Jędrzejowska A Stiępień H Robak T . Serum levels of angiogenic cytokines in systemic lupus erythematosus and their correlation with disease activity. Eur Cytokine Netw 2001; 12: 445–452.

23.

23 Robak E Sysa-Jędrzejowska A Robak T . Vascular endothelial growth factor and its soluble receptors VEGFR-1 and VEGRF-2 in the serum of patients with systemic lupus erythematosus. Mediators Inflamm 2003; 12: 293–298.

24.

24 Shi Q Rafii S Wu MH . Evidence for circulating bone marrow-derived endothelial cells. Blood 1998; 92: 362–367.

25.

25 Heissig B Hattori K Dias S . Recruitment of stem and progenitor cells from the bone marrow niche requires MMP-9 mediated release of kit-ligand. Cell 2002; 109: 625–637.

26.

26 Woywodt A Streiber F de Groot K Regelsberger H Haller H Haubitz M . Circulating endothelial cells as markers for ANCA-associated small-vessel vasculitis. Lancet 2003; 361: 206–210.

27.

27 Westerweell PE Lnijten RK Hoefer IE Koomans HA Derksen RH Verhaar MC . Hematopoietic and endothelial progenitor cells are deficient in quiescent systemic lupus erythematosus. Ann Rheum Dis 2007; 66: 865–870.

28.

28 George J Shmilovich H Dentsch V Miller H Keren G Roth A . Comparative analysis of methods for assessment of circulating endothelial progenitor cells. Tissue Eng 2006; 12: 331–335.

29.

29 Allanore Y Batteux F Avonac J Assous N Weill B Kahan A . Levels of circulating endothelial progenitor cells in systemic sclerosis. Clin Exp Rheumatol 2007; 25: 60–66.

30.

30 Ho CY Wong CK Li EK Tam LS Lam CW . Elevated plasma concentrations of nitric oxide, soluble thrombomodulin and soluble vascular cell adhesion molecule-1 in patients with systemic lupus erythematosus. Rheumatology (Oxford) 2003; 42: 117–122.

31.

31 Janssen BA Luqmani RA Gordon C . Correlation or blood levels of soluble vascular adhesion molecule-1 with disease activity in systemic lupus erythematosus and vasculitis. Br J Rheumatol 1994; 33: 1112–1116.

32.

32 Autiero M Luttun A Tjwa M Carmeliet P . Placental growth factor and its receptor, vascular endothelial growth factor receptor-1: novel targets for stimulation of ischemic tissue revascularization and inhibition of angiogenic and inflammatory disorders. J Thromb Haemost 2003; 7: 1356–1370.

33.

33 Grisar J Aletaha D Steiner CW . Endothelial progenitor cells in active rheumatoid arthritis: effect of tumour necrosis factor and glicocorticoid therapy. Ann Rheum Dis 2007; 66: 1284–1288.