Moxifloxacin modifies corneal fibroblast-to-myofibroblast differentiation.
OBJECTIVE
Fibroblast-to-myofibroblast differentiation is associated with scarring, an important issue in corneal surgery. Moxifloxacin (MOX), commonly applied to prevent post-operative infection, would benefit more if it modifies fibroblast-to-myofibroblast differentiation other than antimicrobial activity. Our purpose was to explore whether MOX has anti-fibrotic effect in human corneal fibroblasts (HCFs).


METHODS
HCFs were incubated in MOX-containing medium concurrently with TGF-β1 (co-treatment), before (pretreatment) or after (post-treatment) adding TGF-β1. HCF contractility was evaluated with a type I collagen gel contraction assay. Expression of α-smooth muscle actin (α-SMA), Smad2, phospho-Smad2-Ser467, Smad4 and Smad7 was determined by immunoblotting. Formation of α-SMA-positive filaments and distribution of active Smad2 were observed under confocal microscopy. Expression of TGF-β receptor types I (TGFBR1) and II (TGFBR2) was assessed with flow cytometry.


RESULTS
MOX did not affect gel contractility or α-SMA filament formation in HCFs without TGF-β1 stimulation. MOX did, however, retard HCF-containing gel contractility and α-SMA filament formation following TGF-β1 stimulation in the pretreatment and co-treatment groups but not in the post-treatment group. MOX blocked the expression of Smad2, phospho-Smad2-Ser467 and TGFBR1 under TGF-β1 incubation. Additionally, MOX enhanced Smad7 expression in TGF-β1-incubated HCFs, but did not interfere with TGF-β-triggered Smad2 nuclear translocation or Smad4 expression.


CONCLUSIONS
MOX inhibited TGF-β-induced fibroblast-to-myofibroblast differentiation via blocking TGFBR1 and enhancing Smad7 expression. MOX should be used before or during surgery to achieve these effects. These results suggest a de novo mechanism by which MOX participates in corneal wound healing.
Department of Ophthalmology, Far Eastern Memorial Hospital, Banqiao District, New Taipei City, Taiwan.
T C
TC
Chen
S W
SW
Chang
T Y
TY
Wang
D008841:Actin Cytoskeleton / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology*; D054338:Cell Transdifferentiation / Q000187:drug effects*; D002478:Cells, Cultured; D004728:Endothelium, Corneal / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D019573:Epithelium, Corneal / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D005355:Fibrosis / Q000517:prevention & control; D024841:Fluoroquinolones; D006801:Humans; D000077266:Moxifloxacin; D058628:Myofibroblasts / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D009994:Osmolar Concentration; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011804:Quinolines / Q000494:pharmacology*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D051899:Smad2 Protein / Q000037:antagonists & inhibitors / Q000378:metabolism; D051906:Smad7 Protein / Q000096:biosynthesis / Q000378:metabolism; D059003:Topoisomerase Inhibitors / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects
D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D018125:Receptors, Transforming Growth Factor beta; D011994:Recombinant Proteins; C497782:SMAD2 protein, human; C497806:SMAD7 protein, human; D051899:Smad2 Protein; D051906:Smad7 Protein; C508960:TGFB1 protein, human; D059003:Topoisomerase Inhibitors; D053773:Transforming Growth Factor beta1; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human; D000077266:Moxifloxacin