Ferritin and hemosiderin in pathological tissues

Area of Science:

• Cell Biology
• Biochemistry
• Pathology

Background:

• Iron is essential for cellular function, but both deficiency and overload have serious health implications.
• Iron overload is a recognized metabolic abnormality with potentially damaging consequences.
• Ferritin and hemosiderin are key iron-storing compounds, ultrastructurally identifiable by their electron density.

Purpose of the Study:

• To review the electron microscopic features of iron overload in various subcellular compartments, cell types, and tissues.
• To discuss the cellular defense mechanisms against iron overload.

Main Methods:

• Review of electron microscopic findings related to iron overload.
• Analysis of cellular structures involved in iron storage and detoxification.

Main Results:

• Iron overload manifests ultrastructurally in diverse cellular locations and tissue types.
• Cells employ defense mechanisms including apoferritin synthesis, iron binding, and ferritin degradation to hemosiderin within siderosomes.
• Examples of cytosiderosis and iron-related ultrastructural pathology are presented.

Conclusions:

• Cells possess sophisticated mechanisms to manage iron levels and mitigate toxicity.
• Electron microscopy is crucial for visualizing iron storage and overload pathology at the ultrastructural level.