Related Experiment Video
Updated: May 1, 2026
Digestion of Whole Mouse Eyes for Multi-Parameter Flow Cytometric Analysis of Mononuclear Phagocytes
Published on: June 17, 2020
Subretinal infiltration of monocyte derived cells and complement misregulation in mice with AMD-like pathology
Joseph Fogerty1, Joseph C Besharse
1Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, 53226, Milwaukee, WI, USA, jfogerty@mcw.edu.
Abstract:
We have characterized a naturally-occurring mutation in mice that causes slow, progressive photoreceptor degeneration, white fundus flecks, and late-onset RPE atrophy. These animals predictably lose visual function as photoreceptors degenerate. Genetic studies identified a deletion in the 5' coding sequence of Mfrp, designated Mfrp (174delG) , which essentially results in a complete knockout at the protein level. We have shown in Mfrp (174delG) mice that these white fundus flecks are due to the presence of F4/80+ inflammatory cells in the subretinal space. Here we expand on our initial description of the cells with additional markers and by determining their origin. We have also begun an analysis of complement factors in the RPE and found decreased levels of C3d, suggesting that the alternative complement pathway may be misregulated. Finally, we compare and contrast the characteristics of fundus images in Mfrp (174delG) mice with those of other mutations that cause similar irregularities, including Crb1 (rd8) and RDH5, and discuss the structural differences that may underlie them.
Insights
A mouse model with a Mfrp gene mutation exhibits progressive vision loss and fundus flecks caused by inflammatory cells. This study investigates the origin of these cells and potential complement pathway misregulation, offering insights into retinal degeneration.
Area of Science:
- Ophthalmology
- Genetics
- Immunology
Background:
- Naturally-occurring mutations can cause retinal degeneration and visual dysfunction.
- The Mfrp (174delG) mouse model displays progressive photoreceptor degeneration and fundus abnormalities.
- Previous studies linked fundus flecks to subretinal inflammatory cells.
Purpose of the Study:
- To further characterize the inflammatory cells in Mfrp (174delG) mice.
- To investigate the origin of these subretinal inflammatory cells.
- To analyze complement factor levels and explore potential alternative pathway dysregulation.
- To compare fundus phenotypes with other retinal degeneration models.
Main Methods:
- Genetic analysis to identify Mfrp mutation (174delG).
- Histological and immunohistochemical analysis using markers like F4/80.
- Complement factor analysis in the retinal pigment epithelium (RPE).
- Comparative fundus imaging analysis.
Main Results:
- The Mfrp (174delG) mutation leads to a complete knockout of Mfrp protein.
- White fundus flecks are associated with F4/80+ inflammatory cells in the subretinal space.
- Decreased levels of C3d suggest potential alternative complement pathway misregulation.
- Distinct fundus characteristics differentiate Mfrp (174delG) from Crb1 (rd8) and RDH5 models.
Conclusions:
- Mfrp (174delG) mice provide a valuable model for studying inflammatory retinal degeneration.
- Subretinal inflammation and potential complement dysregulation are key features of this model.
- Comparative analysis highlights unique pathological features and aids in understanding diverse retinal irregularities.
