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Localization of TGF-beta type II receptor and ED-A fibronectin in normal conjunctiva and failed filtering blebs.

Meyer-Ter-Vehn T, Grehn F, Schlunck G - Mol. Vis. (2008)

Bottom Line: TGF-beta receptor type II (TGF-beta-RII), alpha-smooth muscle actin, O-linked sialoglycoprotein, fibronectin and the ED-A fibronectin splice-variant were also detected using specific antibodies.Labeled sections were viewed with a confocal laser scanning microscope.Vascular endothelial cells expressed TGF-beta-RII in both normal and scarred tissue.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, University of Würzburg, Würzburg, Germany. meyer_T3@augenklinik.uni-wuerzburg.de

ABSTRACT

Purpose: The cytokine transforming growth factor-beta (TGF-beta), and the ED-A splice variant of the extracellular matrix protein fibronectin modulate wound healing and scar formation. To further elucidate their possible role in filtering bleb scarring after glaucoma surgery in human eyes in vivo, we studied the cell type specific localization of TGF-beta receptors and the presence of ED-A fibronectin in sections of normal conjunctiva and scarred filtering blebs.

Methods: Cryosections of normal conjunctiva (four patients) and scarred filtering blebs (seven patients) were studied by double-label immunofluorescence. Antibodies against PECAM-1 and prolyl-4-hydroxylase allowed for specification of vascular endothelial cells and activated fibroblasts, respectively. TGF-beta receptor type II (TGF-beta-RII), alpha-smooth muscle actin, O-linked sialoglycoprotein, fibronectin and the ED-A fibronectin splice-variant were also detected using specific antibodies. Labeled sections were viewed with a confocal laser scanning microscope.

Results: Vascular endothelial cells expressed TGF-beta-RII in both normal and scarred tissue. TGF-beta-RII was sparsely detected in the fibroblasts of normal conjunctiva while it was strongly expressed in most fibroblasts of the scarred filtering blebs. Similarly, ED-A fibronectin was not detected in the extracellular matrix of normal conjunctiva but abundantly present in scarred filtering blebs.

Conclusions: Filtering bleb scarring is associated with an abundant expression of TGF-beta receptors in activated fibroblasts and the deposition of the fibrogenic ED-A fibronectin splice-variant. These data support the concept of targeting TGF-beta signaling to prevent scar formation after filtering glaucoma surgery.

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Related in: MedlinePlus

Colocalization of TGF-β-RII and the fibroblast marker prolyl-4-hydroxylase. Native conjunctiva (A) and scarred filtering bleb specimens (B, C) were double-stained for TGF-β-RII (green) and prolyl-4-hydroxylase (red). C is a close-up of a portion of B as indicated by the frame. Arrows point to a TGF-β-RII positive fibroblast, which are positive for both TGF-β-RII and prolyl-4-hydroxylase. Scale bar represents 50 µm (A,B) and 10 µm (C).
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f3: Colocalization of TGF-β-RII and the fibroblast marker prolyl-4-hydroxylase. Native conjunctiva (A) and scarred filtering bleb specimens (B, C) were double-stained for TGF-β-RII (green) and prolyl-4-hydroxylase (red). C is a close-up of a portion of B as indicated by the frame. Arrows point to a TGF-β-RII positive fibroblast, which are positive for both TGF-β-RII and prolyl-4-hydroxylase. Scale bar represents 50 µm (A,B) and 10 µm (C).

Mentions: To assess TGF-β receptor expression and identify TGF-β-responsive cell types, immunofluorescent double stains were performed. Vascular endothelial cells were stained with an antibody recognizing PECAM-1, and activated fibroblasts were detected using an antibody against the enzyme prolyl-4-hydroxylase. TGF-β-RII expression was strong in epithelial cells (Figure 2A) and in vascular endothelial cells (Figure 2A,B,C). Activated, prolyl-4-hydroxylase-positive fibroblasts were absent in normal conjunctiva, and a faint staining for TGF-β-RII was rarely seen in non-vascular areas of the normal conjunctival stroma (Figure 2A and Figure 3A).


Localization of TGF-beta type II receptor and ED-A fibronectin in normal conjunctiva and failed filtering blebs.

Meyer-Ter-Vehn T, Grehn F, Schlunck G - Mol. Vis. (2008)

Colocalization of TGF-β-RII and the fibroblast marker prolyl-4-hydroxylase. Native conjunctiva (A) and scarred filtering bleb specimens (B, C) were double-stained for TGF-β-RII (green) and prolyl-4-hydroxylase (red). C is a close-up of a portion of B as indicated by the frame. Arrows point to a TGF-β-RII positive fibroblast, which are positive for both TGF-β-RII and prolyl-4-hydroxylase. Scale bar represents 50 µm (A,B) and 10 µm (C).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2255025&req=5

f3: Colocalization of TGF-β-RII and the fibroblast marker prolyl-4-hydroxylase. Native conjunctiva (A) and scarred filtering bleb specimens (B, C) were double-stained for TGF-β-RII (green) and prolyl-4-hydroxylase (red). C is a close-up of a portion of B as indicated by the frame. Arrows point to a TGF-β-RII positive fibroblast, which are positive for both TGF-β-RII and prolyl-4-hydroxylase. Scale bar represents 50 µm (A,B) and 10 µm (C).
Mentions: To assess TGF-β receptor expression and identify TGF-β-responsive cell types, immunofluorescent double stains were performed. Vascular endothelial cells were stained with an antibody recognizing PECAM-1, and activated fibroblasts were detected using an antibody against the enzyme prolyl-4-hydroxylase. TGF-β-RII expression was strong in epithelial cells (Figure 2A) and in vascular endothelial cells (Figure 2A,B,C). Activated, prolyl-4-hydroxylase-positive fibroblasts were absent in normal conjunctiva, and a faint staining for TGF-β-RII was rarely seen in non-vascular areas of the normal conjunctival stroma (Figure 2A and Figure 3A).

Bottom Line: TGF-beta receptor type II (TGF-beta-RII), alpha-smooth muscle actin, O-linked sialoglycoprotein, fibronectin and the ED-A fibronectin splice-variant were also detected using specific antibodies.Labeled sections were viewed with a confocal laser scanning microscope.Vascular endothelial cells expressed TGF-beta-RII in both normal and scarred tissue.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, University of Würzburg, Würzburg, Germany. meyer_T3@augenklinik.uni-wuerzburg.de

ABSTRACT

Purpose: The cytokine transforming growth factor-beta (TGF-beta), and the ED-A splice variant of the extracellular matrix protein fibronectin modulate wound healing and scar formation. To further elucidate their possible role in filtering bleb scarring after glaucoma surgery in human eyes in vivo, we studied the cell type specific localization of TGF-beta receptors and the presence of ED-A fibronectin in sections of normal conjunctiva and scarred filtering blebs.

Methods: Cryosections of normal conjunctiva (four patients) and scarred filtering blebs (seven patients) were studied by double-label immunofluorescence. Antibodies against PECAM-1 and prolyl-4-hydroxylase allowed for specification of vascular endothelial cells and activated fibroblasts, respectively. TGF-beta receptor type II (TGF-beta-RII), alpha-smooth muscle actin, O-linked sialoglycoprotein, fibronectin and the ED-A fibronectin splice-variant were also detected using specific antibodies. Labeled sections were viewed with a confocal laser scanning microscope.

Results: Vascular endothelial cells expressed TGF-beta-RII in both normal and scarred tissue. TGF-beta-RII was sparsely detected in the fibroblasts of normal conjunctiva while it was strongly expressed in most fibroblasts of the scarred filtering blebs. Similarly, ED-A fibronectin was not detected in the extracellular matrix of normal conjunctiva but abundantly present in scarred filtering blebs.

Conclusions: Filtering bleb scarring is associated with an abundant expression of TGF-beta receptors in activated fibroblasts and the deposition of the fibrogenic ED-A fibronectin splice-variant. These data support the concept of targeting TGF-beta signaling to prevent scar formation after filtering glaucoma surgery.

Show MeSH
Related in: MedlinePlus