title: Decreased expression of the endothelial cell-derived factor EGFL7 in systemic sclerosis: potential contribution to impaired angiogenesis and vasculogenesis.
abstract: BACKGROUND
  Microvascular damage and defective angiogenesis and vasculogenesis have a major role in the pathogenesis of systemic sclerosis (SSc). Epidermal growth factor-like domain 7 (EGFL7) is a proangiogenic molecule which is predominantly expressed and secreted by endothelial cells and their progenitors and controls vascular development and integrity. In this study, we investigated the possible involvement of EGFL7 in SSc.
  
  
  METHODS
  Serum EGFL7 levels from 60 patients with SSc and 35 age- and sex-matched healthy controls were examined by colorimetric sandwich enzyme-linked immunosorbent assay. The expression of EGFL7 in forearm skin biopsies (n = 16 SSc, n = 10 controls), cultured dermal microvascular endothelial cells (MVECs) (n = 3 SSc, n = 3 controls) and late-outgrowth peripheral blood endothelial progenitor cell (EPC)-derived endothelial cells (n = 15 SSc, n = 8 controls) was investigated by immunofluorescence and Western blotting.
  
  
  RESULTS
  Serum EGFL7 levels were detectable in 68.6% of healthy controls and 45% of SSc cases (P < 0.05). Circulating levels of EGFL7 were significantly decreased in SSc patients compared with healthy controls (P = 0.01). Serum levels of EGFL7 were significantly lower in both limited cutaneous SSc and diffuse cutaneous SSc patients than in controls (P = 0.02 and P = 0.04, respectively). In SSc, decreased serum EGFL7 levels were significantly correlated with the severity of nailfold capillary abnormalities. Patients with the most severe capillary changes and digital ulcers had serum EGFL7 levels significantly lower than healthy controls, while the EGFL7 levels did not differ significantly between controls and SSc patients with less capillary damage and lack of digital ulcers. Endothelial EGFL7 expression was strongly downregulated or even almost completely undetectable in SSc-affected dermis compared with controls (P < 0.001). In cultured SSc dermal MVECs and late-outgrowth peripheral blood EPC-derived endothelial cells, EGFL7 was significantly downregulated compared with cells obtained from healthy subjects (P < 0.01 and P < 0.001, respectively).
  
  
  CONCLUSIONS
  Our findings suggest that the loss of EGFL7 expression in endothelial cells and their progenitors might play a role in the development and progression of peripheral microvascular damage and the defective vascular repair process characteristic of SSc.
authors.forename: Mirko
authors.initials: M
authors.lastname: Manetti
authors.forename: Serena
authors.initials: S
authors.lastname: Guiducci
authors.forename: Eloisa
authors.initials: E
authors.lastname: Romano
authors.forename: Jérôme
authors.initials: J
authors.lastname: Avouac
authors.forename: Irene
authors.initials: I
authors.lastname: Rosa
authors.forename: Barbara
authors.initials: B
authors.lastname: Ruiz
authors.forename: Gemma
authors.initials: G
authors.lastname: Lepri
authors.forename: Silvia
authors.initials: S
authors.lastname: Bellando-Randone
authors.forename: Lidia
authors.initials: L
authors.lastname: Ibba-Manneschi
authors.forename: Yannick
authors.initials: Y
authors.lastname: Allanore
authors.forename: Marco
authors.initials: M
authors.lastname: Matucci-Cerinic
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001808:Blood Vessels / Q000378:metabolism / Q000503:physiopathology; D015153:Blotting, Western; D002135:Calcium-Binding Proteins; D016022:Case-Control Studies; D015536:Down-Regulation; D066255:EGF Family of Proteins; D016228:Endothelial Growth Factors / Q000235:genetics* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000235:genetics*; D012016:Reference Values; D012595:Scleroderma, Systemic / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D002135:Calcium-Binding Proteins; D066255:EGF Family of Proteins; C527877:EGFL7 protein, human; D016228:Endothelial Growth Factors