title: Effect of TGF-β on ocular surface epithelial cells.
abstract: A role for transforming growth factor (TGF)-β in the pathogenesis of some ocular surface diseases has been proposed. We determined if secretion of TGF-β and expression of TGF-β receptors RI, RII, and RIII by human ocular surface epithelial cells were modified under inflammatory conditions. We also determined how these cells responded to TGF-β. A human corneal epithelial (HCE) cell line and a conjunctival epithelial cell line (IOBA-NHC) were exposed to TGF-β1 and -β2 and to proinflammatory cytokines. TGF-β receptor mRNAs were analyzed by real time reverse transcription polymerase chain reaction (RT-PCR) in both cell lines, and in conjunctival, limbal, and corneal epithelial cells from post-mortem human specimens. Expression of TGF-β receptors and pSMAD2/SMAD2 were determined by Western blot and immunofluorescence assays. Secretion of TGF-β isoforms, cytokine/chemokine, and metalloproteinases (MMPs) were analyzed in cell supernatants by immunobead-based assays. Secretory leukocyte proteinase inhibitor (SLPI) secretion was analyzed by enzyme-linked immunosorbent assay. TGF-β isoform and receptor gene expression was determined by RT-PCR in conjunctival epithelium of dry eye (DE) patients and healthy subjects. Our results showed that TGF-β RI expression was down-regulated with IL-4 exposure, whereas TGF-β RII and TGF-β2 were upregulated by TNF-α in HCE cells. TGF-β RIII receptor expression was upregulated in IOBA-NHC cells by TNF-α and IFN-γ. SMAD2 phosphorylation occurred in HCE and IOBA-NHC cells after TGF-β treatment. TGF-β significantly up- and down-regulated secretion of several cytokines/chemokines by both cell lines and MMP by HCE cells. TGF-β2 and TGF-β3 were upregulated and TGF-β RIII mRNA was down-regulated in DE conjunctival epithelium. These results show that TGF-β plays an important role in directing local inflammatory responses in ocular surface epithelial cells.
authors.affiliation: IOBA-University of Valladolid, Campus Miguel Delibes, Paseo de Belén 17, Valladolid E-47011, Spain.
authors.forename: Maria Jesús
authors.initials: MJ
authors.lastname: Benito
authors.forename: Virginia
authors.initials: V
authors.lastname: Calder
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Corrales
authors.forename: Carmen
authors.initials: C
authors.lastname: García-Vázquez
authors.forename: Srihari
authors.initials: S
authors.lastname: Narayanan
authors.forename: José M
authors.initials: JM
authors.lastname: Herreras
authors.forename: Michael E
authors.initials: ME
authors.lastname: Stern
authors.forename: Margarita
authors.initials: M
authors.lastname: Calonge
authors.forename: Amalia
authors.initials: A
authors.lastname: Enríquez-de-Salamanca
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D003228:Conjunctiva / Q000166:cytology*; D016207:Cytokines / Q000378:metabolism; D015352:Dry Eye Syndromes / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011509:Proteoglycans / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D000077293:Receptor, Transforming Growth Factor-beta Type I; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000378:metabolism; D051899:Smad2 Protein / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000378:metabolism / Q000494:pharmacology*; D053781:Transforming Growth Factor beta2 / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D016207:Cytokines; D011509:Proteoglycans; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; C506814:SLPI protein, human; C497782:SMAD2 protein, human; D053481:Secretory Leukocyte Peptidase Inhibitor; D051899:Smad2 Protein; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; C071736:betaglycan; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; D000077294:Receptor, Transforming Growth Factor-beta Type II