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Updated: Apr 20, 2026
Isolation and Culture of Resident Cardiac Macrophages from the Murine Sinoatrial and Atrioventricular Node
Published on: May 7, 2021
Activated macrophages as a feeder layer for growth of resident cardiac progenitor cells
Diana E Sepúlveda1, Patricia Cabeza Meckert1, Paola Locatelli2
1Department of Pathology, Universidad Favaloro, Solís 453, Buenos Aires, Argentina.
Insights
Activated macrophages support cardiac progenitor cell (CPC) growth. These CPCs, when transplanted into rats with myocardial infarction (MI), improved heart function and reduced scar size, offering a novel therapeutic approach.
Area of Science:
- Regenerative Medicine
- Cardiovascular Biology
- Cell Therapy
Background:
- The adult heart has cardiac progenitor cells (CPCs) crucial for repair.
- Current CPC expansion requires complex media with growth factors.
- Activated macrophages secrete growth factors, suggesting a potential role in CPC culture.
Purpose of the Study:
- To investigate if activated peritoneal macrophages (PM) can support CPC growth.
- To determine if these cultured CPCs can improve cardiac function in a rat myocardial infarction (MI) model.
Main Methods:
- Isolated rat heart cells were cultured on activated PM.
- Cells with CPC markers (c-Kit, Sca-1) formed clusters and monolayers.
- These cells were injected into the infarct border zone of MI rats.
- Cardiac function and histology were assessed after 3 weeks.
Main Results:
- Culturing heart cells on activated PM yielded CPCs with robust growth.
- Transplanted CPCs survived and differentiated into cardiocyte and smooth muscle lineages.
- CPC treatment significantly improved left ventricular ejection fraction.
- Histological analysis showed a reduced infarct scar size in treated rats.
Conclusions:
- Activated syngeneic PM provide an effective feeder layer for expanding CPCs.
- CPC-derived cells demonstrate therapeutic potential in a rat MI model.
- This method offers a promising strategy for cell-based cardiac repair.
Abstract:
The adult heart contains a population of cardiac progenitor cells (CPCs). Growing and collecting an adequate number of CPCs demands complex culture media containing growth factors. Since activated macrophages secrete many growth factors, we investigated if activated isolated heart cells seeded on a feeder layer of activated peritoneal macrophages (PM) could result in CPCs and if these, in turn, could exert cardioprotection in rats with myocardial infarction (MI). Heart cells of inbred Wistar rats were isolated by collagenase digestion and cultured on PM obtained 72 h after intraperitoneal injection of 12 ml thioglycollate. Cells (1 × 10(6)) exhibiting CPC phenotype (immunohistochemistry) were injected in the periphery of rat MI 10 min after coronary artery occlusion. Control rats received vehicle. Three weeks later, left ventricular (LV) function (echocardiogram) was assessed, animals were euthanized and the hearts removed for histological studies. Five to six days after seeding heart cells on PM, spherical clusters composed of small bright and spherical cells expressing mostly c-Kit and Sca-1 antigens were apparent. After explant, those clusters developed cobblestone-like monolayers that expressed smooth muscle actin and sarcomeric actin and were successfully transferred for more than ten passages. When injected in the MI periphery, many of them survived at 21 days after coronary ligature, improved LV ejection fraction and decreased scar size as compared with control rats. CPC-derived cells with cardiocyte and smooth muscle phenotypes can be successfully grown on a feeder layer of activated syngeneic PM. These cells decreased scar size and improved heart function in rats with MI.
