Expression of myofibroblast activation molecules in proliferative vitreoretinopathy epiretinal membranes.
OBJECTIVE
Fibrotic disorders are associated with activation of fibroblasts into extracellular matrix-secreting myofibroblasts expressing α-smooth muscle actin (α-SMA). Myofibroblasts are the predominant cellular component of proliferative vitreoretinopathy (PVR) epiretinal membranes. We investigated the expression of molecules involved in myofibroblast activation, migration and proliferation in PVR epiretinal membranes.


METHODS
Fifteen membranes were studied by immunohistochemical techniques using monoclonal and polyclonal antibodies directed against snail, fibroblast activation protein (FAP), CD44, hydrogen peroxide-inducible clone-5 (Hic-5), galectin-3, interleukin-13 receptor α2 (IL-13Rα2) and receptor for advanced glycation end products (RAGE).


RESULTS
Myofibroblasts expressing α-SMA were present in all membranes. Myofibroblasts expressed nuclear immunoreactivity for Snail and Hic-5, cytoplasmic immunoreactivity for FAP, IL-13Rα2 and RAGE and membranous immunoreactivity for CD44. There was no immunoreactivity for galectin-3. The number of cells expressing α-SMA correlated significantly with the number of cells expressing Snail (r = 0.56; p = 0.03), Hic-5 (r = 0.526; p = 0.044), IL-13Rα2 (r = 0.773; p = 0.001) and RAGE (r = 0.734; p = 0.002).


CONCLUSIONS
Snail, FAP, CD44, Hic-5, IL13Rα2 and RAGE may be involved in proliferative events occurring in PVR.
Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia. abuasrar@KSU.edu.sa
Ahmed M
AM
Abu El-Asrar
Luc
L
Missotten
Karel
K
Geboes
D000199:Actins / Q000378:metabolism; D002452:Cell Count; D002465:Cell Movement; D049109:Cell Proliferation; D010450:Endopeptidases; D019773:Epiretinal Membrane / Q000378:metabolism*; D037502:Galectin 3 / Q000378:metabolism; D018093:Gelatinases / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D007124:Immunoenzyme Techniques; D053663:Interleukin-13 Receptor alpha2 Subunit / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D060588:LIM Domain Proteins; D008565:Membrane Proteins / Q000378:metabolism; D058628:Myofibroblasts / Q000378:metabolism*; D000067759:Receptor for Advanced Glycation End Products / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D018630:Vitreoretinopathy, Proliferative / Q000378:metabolism*; D000099167:Fibroblast Activation Protein Alpha
D000199:Actins; D010450:Endopeptidases; D037502:Galectin 3; D018093:Gelatinases; D018960:Hyaluronan Receptors; D053663:Interleukin-13 Receptor alpha2 Subunit; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; D008565:Membrane Proteins; D000067759:Receptor for Advanced Glycation End Products; D012697:Serine Endopeptidases; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D000099167:Fibroblast Activation Protein Alpha; C541116:ACTA2 protein, human; C497483:CD44 protein, human; C490351:TGFB1I1 protein, human