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Isolation and Identification of Extravascular Immune Cells of the Heart
Published on: August 23, 2018
Expression of 20 KD homologous restriction factor of complement on myocardial cells: an immunohistochemical study
Insights
Homologous restriction factor (HRF20) (CD59) protects normal heart cells from complement damage. This study confirms HRF20 expression in various heart tissues and introduces a more accessible immunohistochemical method for its detection.
Area of Science:
- Cardiovascular Biology
- Immunology
- Cell Biology
Background:
- Complement system activation can lead to myocardial damage.
- Homologous restriction factor (HRF20) (CD59) is a known complement regulatory protein.
- Understanding HRF20 expression in the normal heart is crucial for interpreting its role in cardiac pathology.
Purpose of the Study:
- To investigate the expression and localization of HRF20 in normal human heart tissue.
- To evaluate the suitability of paraffin-embedded tissues for HRF20 immunohistochemistry.
Main Methods:
- Immunohistochemistry using a monoclonal antibody (MAb 1F5) against HRF20.
- Examination of both frozen and acetone-fixed, paraffin-embedded human heart tissues.
- Microscopic analysis of myocardial cells, endothelial cells, blood vessels, and peripheral nerve fibers.
Main Results:
- HRF20 was detected on the cell surface membrane and intercalated discs of myocardial cells in ventricular walls.
- Expression of HRF20 was also observed on endocardial endothelial cells, blood vessels (arteries, capillaries, veins), and Schwann cells.
- HRF20 epitopes were well-preserved in paraffin-embedded tissues, enabling easier and more accurate histological examination compared to conventional frozen sections.
Conclusions:
- HRF20 is expressed in normal human heart tissues, suggesting a protective role for cardiomyocytes against complement-mediated injury.
- The use of paraffin-embedded tissues for HRF20 immunohistochemistry offers a practical and reliable alternative for histological studies.
- This finding has implications for understanding complement regulation in cardiac health and disease.
Abstract:
Expression of 20 KD homologous restriction factor of complement (HRF20) (CD59) in normal human heart was immunohistochemically examined with monoclonal antibody (MAb) 1F5. HRF20 was clearly demonstrated on the cell surface membrane and intercalated discs of myocardial cells throughout the ventricular walls. Therefore, this factor may protect normal cardiomyocytes from complement deposition, which has been demonstrated on infarcted cardiomyocytes. Expression of HRF20 was also observed on endothelial cells of the endocardium and on blood vessels, including arteries, capillaries, and veins, and on the Schwann-cell sheath of peripheral nerve fibers. In the present study, we found that the epitopes of HRF20 were well preserved for immunohistochemistry even in acetone-fixed and paraffin-embedded tissues, as well as in frozen tissues that have been conventionally used for HRF20. This method using paraffin sections allows for easier staining and greater accuracy in histological examination.
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