Related Experiment Video
Updated: May 27, 2026
Assessing Iron Deposition in the Brains of 5xFAD Mice by Perls'/DAB Staining
Published on: May 23, 2025
Aceruloplasminemia: retinal histopathologic manifestations and iron-mediated melanosome degradation
Natalie Wolkow1, Ying Song, Ting-Di Wu
1F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104, USA.
Objective:
To examine the retinal histopathologic manifestation of aceruloplasminemia, an autosomal recessive disease caused by mutation of the ferroxidase ceruloplasmin, resulting in tissue iron overload.
Methods:
The morphologic features of the human aceruloplasminemic retina were studied with light and electron microscopy. Retinal iron accumulation was assessed with Perls Prussian blue staining, immunohistochemistry, and secondary ion mass spectrometry.
Results:
Light and electron microscopic analysis revealed several ocular pathologic findings that resembled age-related macular degeneration, including retinal pigment epithelium (RPE) depigmentation, atrophy and hypertrophy, nodular and diffuse drusen, and lipofuscin and melanolipofuscin granules. Complement deposition was detected in drusen. The RPE cells and neural retina had increased levels of iron. Two major types of RPE cells were observed: melanosome rich and melanosome poor. Melanosome-rich cells had increased levels of iron and melanolipofuscin. The melanolipofuscin granules were observed in large aggregates, where some of the melanosomes were degrading. Melanosome-poor cells lacked melanosomes, melanolipofuscin, and lipofuscin but contained electron-dense aggregates high in iron, phosphorus, and sulfur.
Conclusions:
The findings in the aceruloplasminemic retina resemble some of those found in age-related macular degeneration. Also, they suggest that melanosomes in the RPE can be degraded via iron-mediated reactive oxygen species production.
Clinical Relevance:
Mechanisms underlying the pathologic mechanisms found in aceruloplasminemia also may be important in age-related macular degeneration.
Insights
Aceruloplasminemia, a genetic iron overload disorder, causes retinal changes similar to age-related macular degeneration. These findings suggest iron
Area of Science:
- Ophthalmology
- Genetics
- Cell Biology
Background:
- Aceruloplasminemia is an autosomal recessive disorder characterized by iron accumulation in tissues due to ceruloplasmin gene mutations.
- Iron overload in the retina can lead to cellular damage and dysfunction.
Purpose of the Study:
- To investigate the histopathologic retinal manifestations of aceruloplasminemia.
- To understand the role of iron accumulation in retinal pathology.
Main Methods:
- Light and electron microscopy were used to examine human aceruloplasminemic retinal tissue.
- Perls Prussian blue staining, immunohistochemistry, and secondary ion mass spectrometry assessed retinal iron levels.
Main Results:
- Retinal findings included RPE depigmentation, atrophy, hypertrophy, drusen, and lipofuscin accumulation, mimicking age-related macular degeneration.
- Increased iron levels were observed in RPE cells and neural retina.
- Two RPE cell types were identified: melanosome-rich with iron and melanolipofuscin, and melanosome-poor with iron-rich aggregates.
Conclusions:
- Retinal pathology in aceruloplasminemia shares similarities with age-related macular degeneration.
- Iron-mediated reactive oxygen species may contribute to melanosome degradation in RPE cells.
- Understanding aceruloplasminemia's mechanisms may offer insights into age-related macular degeneration pathogenesis.
