title: Inflammatory Cytokine-Mediated Regulation of Thrombospondin-1 and CD36 in Conjunctival Cells.
abstract: OBJECTIVE
  Increased expression of transforming growth factor-β2 (TGF-β2) is reported in the conjunctiva of dry eye patients with no increase of anti-inflammatory activity of TGF-β2. Our aim was to compare the expression of molecules involved in TGF-β2 activation, thrombospondin-1 (TSP-1) and CD36, during murine and human conjunctival inflammation.
  
  
  METHODS
  Human conjunctival tissue from cadaveric donors, human conjunctival epithelial primary cells and fibroblasts, and murine conjunctivas were immunostained for TSP-1, CD36, or TGF-β2. Inflamed conjunctival tissues were obtained from C57BL/6 wild-type (WT) mice induced to develop experimental dry eye (EDE) with 10 days of desiccating conditions and scopolamine injections and TSP-1-deficient (TSP1(-/-)) mice, which spontaneously develop Sjögren's syndrome-associated conjunctival inflammation with age. Immunostaining intensities were compared using ImageJ software. Cultures of human conjunctival fibroblasts were stimulated with IL-1β and both secreted protein and message levels of TSP-1, CD36, and TGF-β2 were analyzed.
  
  
  RESULTS
  TSP-1 and CD36 were detectable in human and murine conjunctival tissues as well as primary conjunctival epithelial cells and fibroblasts. Increased conjunctival immunostaining of TGF-β2 and reduced CD36 were detected in EDE mice compared with WT mice. Interestingly, increased TGF-β2 and CD36 conjunctival immunostaining was detected in TSP1(-/-) mice. The expression of TSP-1 and CD36 was downregulated in IL-1β-stimulated conjunctival fibroblasts at both the protein and message level, while active TGF-β2 was undetected.
  
  
  CONCLUSIONS
  The absence or reduced expression of either of the molecules involved in TGF-β2 activation supports proinflammatory conditions in the conjunctiva. Changes in TSP-1 and CD36 may serve as potential biomarkers of conjunctival inflammation.
authors.affiliation: 1 Ocular Surface Group-IOBA, University of Valladolid , Valladolid, Spain .|2 Biomedical Research Networking Center on Bioengineering , Biomaterials and Nanomedicine (CIBER-BBN), Spain .
authors.forename: Laura
authors.initials: L
authors.lastname: Soriano-Romaní
authors.affiliation: 3 Department of Ophthalmology, Boston University School of Medicine , Boston, Massachusetts.
authors.forename: Laura
authors.initials: L
authors.lastname: Contreras-Ruiz
authors.affiliation: 1 Ocular Surface Group-IOBA, University of Valladolid , Valladolid, Spain .|2 Biomedical Research Networking Center on Bioengineering , Biomaterials and Nanomedicine (CIBER-BBN), Spain .
authors.forename: Laura
authors.initials: L
authors.lastname: García-Posadas
authors.affiliation: 1 Ocular Surface Group-IOBA, University of Valladolid , Valladolid, Spain .|2 Biomedical Research Networking Center on Bioengineering , Biomaterials and Nanomedicine (CIBER-BBN), Spain .
authors.forename: Antonio
authors.initials: A
authors.lastname: López-García
authors.affiliation: 3 Department of Ophthalmology, Boston University School of Medicine , Boston, Massachusetts.
authors.forename: Sharmila
authors.initials: S
authors.lastname: Masli
authors.affiliation: 1 Ocular Surface Group-IOBA, University of Valladolid , Valladolid, Spain .|2 Biomedical Research Networking Center on Bioengineering , Biomaterials and Nanomedicine (CIBER-BBN), Spain .
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Diebold
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism*; D003228:Conjunctiva / Q000378:metabolism*; D003231:Conjunctivitis / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D007638:Keratoconjunctivitis Sicca / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D019700:Thrombospondin 1 / Q000378:metabolism*; D053781:Transforming Growth Factor beta2 / Q000378:metabolism
chemical_list: D018955:CD36 Antigens; D016207:Cytokines; D019700:Thrombospondin 1; D053781:Transforming Growth Factor beta2