Related Experiment Video
Updated: May 27, 2026
Isolation and Culture of Primary Retinal Müller Cells from Sprague-Dawley (SD) Rats
Published on: June 17, 2025
Vitreous IGFBP-3 effects on Müller cell proliferation and tractional force generation
1Department of Ophthalmology, University of Alabama School of Medicine, Birmingham, Alabama 35294, USA.
Purpose:
Previous studies from this laboratory revealed that vitreous insulin-like growth factor binding protein-3 (IGFBP-3) is a biologically active fragment of the intact protein. The goal of this study was to characterize its effects on Müller cell proliferation and tractional force generation, activities relevant to proliferative diabetic retinopathy (PDR).
Methods:
Müller cells were isolated from normal porcine retina. The vitreous-type IGFBP-3 fragment was isolated from normal human plasma and compared with intact recombinant protein for the ability to modulate Müller cell proliferation and tractional force generation in tissue culture models.
Results:
Müller cells were stimulated to proliferate by serum and platelet-derived growth factor (PDGF), but not insulin-like growth factor (IGF)-I or IGF-II. The cells were similarly unresponsive to IGFBP-3 or the IGFBP-3 fragment alone or in combination with IGF-I or IGF-II. In contrast, Müller cells demonstrated robust extracellular matrix contraction in response to IGF-I, IGF-II, and PDGF. Intact IGFBP-3 attenuated extracellular matrix contraction in response to IGF-I and IGF-II while the IGFBP-3 fragment modulated cell responses to IGF-II only. Neither binding protein altered cell responses to PDGF.
Conclusions:
Intact IGFBP-3 modulates Müller cell tractional force generation stimulated by IGF-I and IGF-II while the effects of the vitreous-type fragment are limited to IGF-II. Porcine Müller cells proliferate in response to PDGF, but not IGF-I or IGF-II. Both forms of IGFBP-3 are also without mitogenic effects alone or in combination with IGFs. It appears that Müller cell tractional force generation in PDR is driven by vitreous IGF activity and proliferation is stimulated by growth factors outside of the IGF system.
Insights
Vitreous insulin-like growth factor binding protein-3 (IGFBP-3) affects Müller cell traction but not proliferation in models relevant to proliferative diabetic retinopathy (PDR). IGFBP-3 modulates cell responses to growth factors, impacting PDR pathogenesis.
Area of Science:
- Ophthalmology
- Cell Biology
- Endocrinology
Background:
- Vitreous insulin-like growth factor binding protein-3 (IGFBP-3) is a biologically active fragment.
- Understanding IGFBP-3's role in Müller cells is crucial for proliferative diabetic retinopathy (PDR).
- Müller cells are key retinal cells involved in PDR pathogenesis.
Purpose of the Study:
- To characterize the effects of vitreous IGFBP-3 on Müller cell proliferation.
- To investigate IGFBP-3's impact on Müller cell tractional force generation.
- To assess the relevance of these activities in the context of PDR.
Main Methods:
- Müller cells were isolated from normal porcine retina.
- Vitreous-type IGFBP-3 fragment and intact IGFBP-3 were used in tissue culture.
- Effects on Müller cell proliferation and extracellular matrix contraction were measured.
Main Results:
- Müller cells proliferated in response to PDGF, not IGF-I or IGF-II.
- Intact IGFBP-3 attenuated extracellular matrix contraction stimulated by IGF-I and IGF-II.
- The IGFBP-3 fragment modulated responses to IGF-II only; neither form affected PDGF response.
Conclusions:
- Intact IGFBP-3 influences Müller cell tractional force generation via IGF-I and IGF-II.
- The vitreous IGFBP-3 fragment's effect is limited to IGF-II.
- Müller cell proliferation in PDR is likely driven by non-IGF growth factors.
