Latent TGFbeta binding protein-1 and fibrillin-1 in human capsular opacification and in cultured lens epithelial cells.
OBJECTIVE
It was previously reported that collagenous extracellular matrix (ECM) in human capsular opacification contained isoforms of transforming growth factor beta (TGFbeta). In the present study, the authors performed immunohistochemistry to examine whether ECM in human capsular opacification and in cultures of bovine lens epithelial cells (LECs) contained latent TGFbeta binding protein-1 (LTBP-1), TGFbeta1 latency associated peptide (beta1-LAP), and fibrillin-1, a suspected ligand of LTBP-1 as well as a component of the extracellular microfibrillar apparatus. The aim of the study was to further clarify the mechanism of TGFbeta1 deposition in ECM of capsular opacification.


METHODS
Human capsular opacification specimens and uninjured lens capsules, as well as cultured bovine LECs, were processed for immunohistochemistry using antibodies against LTBP-1, beta1-LAP, fibrillin-1, and collagen type I.


RESULTS
LTBP-1, beta1-LAP, and fibrillin-1 all were localised to the ECM in human capsular opacification. Uninjured lens epithelium stained for beta1-LAP, but not for LTBP-1 and fibrillin-1. ECM deposited in confluent LEC cultures stained for LTBP-1, beta1-LAP, and fibrillin-1, while cultures with only sparse cellularity were unstained for LTBP-1 or fibrillin-1.


CONCLUSIONS
LECs upregulate LTBP-1 and fibrillin-1 during postoperative healing. LTBP-1, beta1-LAP, and fibrillin-1 colocalised to the ECM in capsular opacification and in confluent LEC cultures. TGFbeta1 is considered to deposit in ECM in the large latent form. ECM secreted by LEC may function as a scavenger or repository of TGFbeta.
Saika
S
S
Department of Ophthalmology, Wakayama Medical University School of Medicine, 811-1 Kimidera, Wakayama, 641-8509, Japan. shizuya@wakayama-med.ac.jp
Miyamoto
T
T
Tanaka
T
T
Ishida
I
I
Ohnishi
Y
Y
Ooshima
A
A
D030201:Activin Receptors, Type I / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002386:Cataract / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D000071838:Fibrillin-1; D000071837:Fibrillins; D006801:Humans; D007903:Lens Capsule, Crystalline / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism*; D008875:Middle Aged; D010446:Peptide Fragments / Q000378:metabolism; D011498:Protein Precursors / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1; D015854:Up-Regulation; D054392:Adipokines
D030201:Activin Receptors, Type I; D000071838:Fibrillin-1; D000071837:Fibrillins; D008840:Microfilament Proteins; D010446:Peptide Fragments; D011498:Protein Precursors; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C000605722:FBN1 protein, human; D054392:Adipokines