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The pathophysiology of pseudoexfoliation syndrome is affected by interaction of TGF ‐ β 1 and LOXL 1
Author(s) -
Liravi P.,
Zenkel M.,
Kruse F.E.,
SchlötzerSchrehardt U.
Publication year - 2015
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2015.0554
Subject(s) - pseudoexfoliation syndrome , pathophysiology , pseudoexfoliation , medicine , transforming growth factor , ophthalmology , glaucoma
Purpose The cross‐linking enzyme lysyl oxidase‐like 1 ( LOXL 1) and profibrotic transforming growth factor ( TGF )‐ß1 play key roles in pathophysiology of pseudoexfoliation ( PEX ) syndrome/glaucoma. The purpose of this study was to investigate the interaction between LOXL 1 and TGF ‐ß1 with respect to the PEX ‐specific disordered matrix metabolism. Methods Primary human Tenon's capsule fibroblasts ( hTCF ) obtained from patients were treated with TGF ‐ß1 (0‐10 ng/ml) for 12‐72 hours without or with preincubation with inhibitors of TGF ‐ β signalling pathways. Expression of LOXL 1 and PEX ‐specific extracellular matrix components was examined by using quantitative RT ‐ PCR and Western immunoblot analysis. Direct binding of LOXL 1 to TGF ‐ß1 was analyzed by blot overlay assay and solid phase ELISA using purified LOXL 1, recombinant human TGF ‐ß1, TGF ß1‐ LAP . The effect of LOXL 1 on TGF ‐ß1 signaling was analyzed using TGF ‐ß receptor signaling real time PCR assays (BioRad) after transient transfection of hTCF with a full‐length pCMV 6‐ LOXL 1 vector construct/with empty vector . Results TGF ß1 significantly increased LOXL 1 expression, secretion and enzymatic activity and correlated with enhanced expression of BMP ‐1, elastin, fibrillin‐1, fibulin‐4 and fibulin‐5 with peak effects at 10 ng/ml for 48 hours. This induction was blocked by TGF ‐ β receptor inhibitors and inhibitors of the canonical Smad and non‐canonical signaling pathways. Direct binding between LOXL 1 and TGF ß1‐ LAP was demonstrated by Blot overlay assays and ELISA . LOXL 1 overexpression temporarily upregulates different transcriptional regulators and some protein kinases of p38‐ MAPK signalling pathway after 12 to 24 hours post‐transfection. Conclusions The results of this study indicate that the interaction of LOXL 1 and TGF ‐ß1 plays an important role in the PEX ‐associated abnormal matrix metabolism and fibrosis.