title: Serum levels, tissue expression and cellular secretion of macrophage migration inhibitory factor in limited and diffuse systemic sclerosis.
abstract: OBJECTIVE
  To investigate serum levels, tissue/cellular expression of macrophage migration inhibitory factor (MIF) in patients with limited (lSSc) and diffuse (dSSc) systemic sclerosis.
  
  
  METHODS
  10 lSSc-patients, 10 dSSc-patients and 10 controls were enrolled. MIF serum levels were assayed by ELISA. MIF and its receptors CD74/CD44 were evaluated by immunohistochemistry on skin biopsies from patients with dSSc, lSSc (affected and not-affected skin) and controls. MIF levels were assessed (ELISA) in supernatants of healthy dermal microvascular endothelial cells (MVECs) and in control (CTR), non-affected SSc (NA) and affected (SSc) fibroblasts treated for 48 h with 10% control serum and 10% SSc-serum. MIF supernatant (ELISA) and mRNA (quantitative real-time PCR) levels were determined in SSc dermal fibroblasts and in control dermal fibroblasts untreated or stimulated at 6 h-24 h-48 h with bleomycin (50 mU/ml).
  
  
  RESULTS
  Serum MIF was significantly higher in dSSc (18.7±4.1 ng/ml, p<0.001) and in lSSc (10.4±4.4 ng/ml, p<0.001) patients respect to controls (2.6±1.4 ng/ml). Enhanced MIF immunoreactivity was found in keratinocytes, fibroblasts, endothelium, sebaceous/sweat glands from lSSc/dSSc affected skin. Faint MIF immunoreactivity was found in control skin and not-affected skin of lSSc patients. No differences were found in CD74/CD44 receptors' analysis among control and dSSc/lSSc affected and non-affected skin. MVECs and fibroblasts (CTR, NA and SSc) produced significantly more MIF, when stimulated with SSc serum respect to control-serum (p<0.001). Finally, MIF mRNA levels significantly increased at 6h (p<0.001) and decreased at 48 h (p<0.001) in control fibroblasts treated with bleomycin compared to control untreated. Simultaneously, MIF supernatant protein levels increased after 48 h (p<0.01) in bleomycin-treated fibroblasts respect to untreated ones.
  
  
  CONCLUSIONS
  These results suggest that MIF could be implicated in the pathogenesis of SSc, probably acting as protective factor against the SSc stressful conditions.
authors.affiliation: Department of Medicine, Surgery and Neurosciences, University of Siena, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Corallo
authors.affiliation: Department of Life Sciences, University of Siena, Italy.
authors.forename: Luana
authors.initials: L
authors.lastname: Paulesu
authors.affiliation: Research Laboratory and Academic Division of Clinical Rheumatology, Department of Internal Medicine, University of Genova, Genova, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cutolo
authors.affiliation: Department of Life Sciences, University of Siena, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Ietta
authors.affiliation: Department of Life Sciences, University of Siena, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Carotenuto
authors.affiliation: Department of Life Sciences, University of Siena, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Mannelli
authors.affiliation: Department of Life Sciences, University of Siena, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Romagnoli
authors.affiliation: Department of Medicine, Surgery and Neurosciences, University of Siena, Italy.
authors.forename: Ranuccio
authors.initials: R
authors.lastname: Nuti
authors.affiliation: Department of Medicine, Surgery and Neurosciences, University of Siena, Italy. nicola.giordano@unisi.it.
authors.forename: Nicola
authors.initials: N
authors.lastname: Giordano
mesh_terms: D000328:Adult; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D001761:Bleomycin / Q000494:pharmacology; D016022:Case-Control Studies; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000276:immunology / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D007150:Immunohistochemistry; D019746:Intramolecular Oxidoreductases / Q000097:blood* / Q000235:genetics; D008263:Macrophage Migration-Inhibitory Factors / Q000097:blood* / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D045743:Scleroderma, Diffuse / Q000097:blood* / Q000175:diagnosis / Q000235:genetics / Q000276:immunology; D045745:Scleroderma, Limited / Q000097:blood* / Q000175:diagnosis / Q000235:genetics / Q000276:immunology; D012867:Skin / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D015415:Biomarkers; C497483:CD44 protein, human; D000949:Histocompatibility Antigens Class II; D018960:Hyaluronan Receptors; D008263:Macrophage Migration-Inhibitory Factors; D012333:RNA, Messenger; C045084:invariant chain; D001761:Bleomycin; D019746:Intramolecular Oxidoreductases; C515598:MIF protein, human