American Heart Association

  92
  0


Final ID: We074

Macrophages Endocytose the Extracellular Matrix Component Hyaluronan

Abstract Body: Background: Following myocardial infarction, macrophages clear cellular debris during remodeling of the extracellular matrix (ECM). The presence of macrophages coincides with a significant increase in the ECM component hyaluronan (HA). HA is produced in copious amounts following injury, such as myocardial infarction, and HA may interfere with myocardial wound healing. Because macrophages express hyaluronan receptors and are known to facilitate ECM remodeling, it is possible that macrophages remove HA early after MI. The extent to which macrophages clear HA is not known.

Goal: To determine the extent to which macrophages endocytose hyaluronan (HA).

Methods and Results: Bone marrow derived macrophages (BMDMs) were polarized into a pro-inflammatory (M1) phenotype using LPS and INF-g, or pro-reparative phenotype (M2) using IL-4 and IL-13. In addition to the polarization factors, cells were treated with 5,000 ng/ml of a fluorescein-labeled HA or a vehicle for 24 hours. At the time of collection, cells were stained with trypan blue to quench surface fluorescence and flow cytometry was used to measure the uptake of labeled HA. An increase in cellular fluorescence intensity after HA treatment indicates the extent of endocytosis of HA. Mean fluorescence intensity (MFI) values were recorded and used to calculate the change in fluorescence between the treated and control groups (DMFI). A significant increase in DMFI was observed when both M1 and M2 macrophages were compared to naïve (M0) controls.

Conclusion: Macrophages endocytose HA, and polarized macrophages endocytose HA at a greater level than naïve macrophages. Hence, polarized macrophages may play a role in clearing HA in the heart following injury. We speculate that enhancement of macrophage-mediated clearance of HA may improve acute scar formation following myocardial infarction.
  • Howard, Caitlin  ( UNIVERSITY OF LOUISVILLE , Louisville , Kentucky , United States )
  • Pendergraft, Emma  ( UNIVERSITY OF LOUISVILLE , Louisville , Kentucky , United States )
  • Belcher, Sarah  ( UNIVERSITY OF LOUISVILLE , Louisville , Kentucky , United States )
  • Jones, Steven  ( UNIVERSITY LOUISVILLE , Louisville , Kentucky , United States )
  • Author Disclosures:
    Caitlin Howard: DO NOT have relevant financial relationships | Emma Pendergraft: No Answer | Sarah Belcher: DO NOT have relevant financial relationships | Steven Jones: DO NOT have relevant financial relationships
Meeting Info:

Basic Cardiovascular Sciences

2024

Chicago, Illinois

Session Info:

Poster Session and Reception 3

Wednesday, 07/24/2024 , 04:30PM - 07:00PM

Poster Session and Reception

More abstracts on this topic:
Circulating Levels of the Pro-Fibrotic Collagen Hormone Endotrophin are Associated with the Risk of Experiencing Major Adverse Cardiovascular Events in Individuals with Type 2 Diabetes – The Thousand & 2 Study

Laursen Clara, Bahrami Hashmat, Martin Emily, Frederiksen Peder, Genovese Federica, Karsdal Morten, Jorgensen Peter, Rossing Peter, Jensen Magnus

A Loss of Function Polymorphism in the Propeptide of Lysyl Oxidase Exacerbates Atherosclerosis

Jung In-hyuk, Amrute Junedh, Luna Sophia, Wagoner Ryan, Lee Paul, Burks Kendall, Holloway Karyn, Alisio Arturo, Stitziel Nathan

More abstracts from these authors:
Sex Dependent Differences in Collagen Synthesis and Cell Cycling in Cardiac Fibroblasts

Howard Caitlin, Singhal Richa, Little Danielle, Jones Steven

Impact of Fibroblast-Derived Hyaluronan on Acute Ventricular Remodeling

Howard Caitlin, Little Danielle, Pendergraft Emma, Wysoczynski Marcin, Brittian Kenneth, Nong Yibing, Jones Steven

You have to be authorized to contact abstract author. Please, Login
Not Available