[Electron-immunostaining characteristics of platelet-derived growth factor, transforming growth factor beta1 and
1Department of Ophthalmology, Shanghai First People's Hospital, Shanghai 200080, China.
Objective:
To investigate the ultrastructural distribution of platelet-derived growth factor (PDGF), transforming growth factor beta(1) (TGF-beta(1)) and their receptors in epiretinal membranes (ERM) and discuss the clinical significance of the distribution.
Methods:
25 membrane specimens were surgically removed by vitrectomy from 9 patients with rhegmatogenous retinal detachment. Double-staining techniques of immunoelectromicroscopy for eight antibodies (PDGF, TGF-beta(1), PDGF receptor subunits alpha and beta, TGF-beta subunits I and II, type I and III collagen) were used in these specimens as previously designed.
Results:
PDGF and TGF-beta(1) staining appeared to be stronger on early (< 2 months) and late (> 6 months) stage membranes than that of middle (2 - 6 months) stage of membranes, and the immunostaining intensity inverted with the degree of proliferative vitreoretinopathy (PVR). We found that the gold particles of PDGF and TGF-beta(1) tended to get together with that of type I and III collagen. In addition, the stainings of four growth factor receptors were frequently positive in a type of epithelial-like cells with rich cytoplasm components, and also the gold particles of PDGF and TGF-beta(1) were found around these cells.
Conclusions:
A concentration change of PDGF and TGF-beta(1) exists in development of ERM throughout. The epithelial-like cells are of a type of active cells, and autocrine and paracrine activity may be involved in ERM pathogenesis. PDGF and TGF-beta(1) influence the contractile activity of ERM.
Insights
Platelet-derived growth factor (PDGF) and transforming growth factor beta(1) (TGF-beta(1)) are concentrated in epiretinal membranes (ERM), particularly in early and late stages. These growth factors influence ERM contractile activity and may involve autocrine/paracrine signaling.
Area of Science:
- Ophthalmology
- Cell Biology
- Biochemistry
Context:
- Epiretinal membranes (ERM) are fibrocellular proliferations on the retinal surface.
- ERM formation is associated with conditions like proliferative vitreoretinopathy (PVR).
- Understanding the molecular mechanisms of ERM pathogenesis is crucial for developing targeted therapies.
Purpose:
- To investigate the ultrastructural localization of platelet-derived growth factor (PDGF), transforming growth factor beta(1) (TGF-beta(1)), and their receptors within ERM.
- To correlate the distribution of these factors with ERM staging and PVR severity.
- To elucidate the potential role of PDGF and TGF-beta(1) in ERM pathogenesis and contractile activity.
Summary:
- Immunoelectron microscopy revealed the presence of PDGF and TGF-beta(1) in ERM specimens.
- Staining intensity for PDGF and TGF-beta(1) varied with ERM stage and PVR, with higher concentrations in early (<2 months) and late (>6 months) stages.
- PDGF and TGF-beta(1) colocalized with type I and III collagen and were associated with epithelial-like cells, suggesting autocrine/paracrine signaling and influence on ERM contractility.
Impact:
- This study provides ultrastructural evidence for the involvement of PDGF and TGF-beta(1) in ERM development.
- The findings suggest that epithelial-like cells in ERM are active participants in the disease process.
- Understanding the role of these growth factors may lead to novel therapeutic strategies for ERM and PVR.
