Related Experiment Video
Updated: Apr 15, 2026
Isolation, Characterization, and Purification of Macrophages from Tissues Affected by Obesity-related Inflammation
Published on: April 3, 2017
Microparticles release by adipocytes act as "find-me" signals to promote macrophage migration
Akiko Eguchi1, Anny Mulya2, Milos Lazic1
1Department of Pediatrics, University of California San Diego (UCSD), La Jolla, California, United States of America.
Abstract:
Macrophage infiltration of adipose tissue during weight gain is a central event leading to the metabolic complications of obesity. However, what are the mechanisms attracting professional phagocytes to obese adipose tissue remains poorly understood. Here, we demonstrate that adipocyte-derived microparticles (MPs) are critical "find-me" signals for recruitment of monocytes and macrophages. Supernatants from stressed adipocytes stimulated the attraction of monocyte cells and primary macrophages. The activation of caspase 3 was required for release of these signals. Adipocytes exposed to saturated fatty acids showed marked release of MPs into the supernatant while common genetic mouse models of obesity demonstrate high levels of circulating adipocyte-derived MPs. The release of MPs was highly regulated and dependent on caspase 3 and Rho-associated kinase. Further analysis identified these MPs as a central chemoattractant in vitro and in vivo. In addition, intravenously transplanting circulating MPs from the ob/ob mice lead to activation of monocytes in circulation and adipose tissue of the wild type mice. These data identify adipocyte-derived MPs as novel "find me" signals that contributes to macrophage infiltration associated with obesity.
Insights
Adipocyte-derived microparticles (MPs) act as critical signals attracting macrophages to adipose tissue during obesity. This discovery sheds light on obesity
Area of Science:
- Immunology
- Metabolic Disease Research
- Cell Biology
Background:
- Macrophage infiltration into adipose tissue is a key factor in obesity-related metabolic dysfunction.
- The precise mechanisms recruiting macrophages to obese adipose tissue are not fully understood.
Purpose of the Study:
- To investigate the role of adipocyte-derived microparticles (MPs) as signals attracting monocytes and macrophages to adipose tissue.
- To elucidate the regulatory pathways involved in the release and function of these MPs.
Main Methods:
- Stimulation of adipocytes with saturated fatty acids and observation of supernatant effects on immune cells.
- Analysis of caspase 3 activation and Rho-associated kinase involvement in MP release.
- In vitro and in vivo assessment of MP chemoattractant properties.
- Transplantation of circulating MPs from obese mice into wild-type mice.
Main Results:
- Stressed adipocytes release microparticles (MPs) that attract monocytes and macrophages.
- Caspase 3 activation is essential for the release of these chemoattractant MPs.
- Obesity models exhibit elevated levels of circulating adipocyte-derived MPs.
- Adipocyte-derived MPs function as potent chemoattractants both in vitro and in vivo.
- Transplanted MPs from obese mice induced monocyte activation in recipient mice.
Conclusions:
- Adipocyte-derived MPs serve as crucial "find-me" signals mediating macrophage recruitment in obesity.
- Targeting these MPs may offer a novel therapeutic strategy for obesity-associated metabolic complications.
Related Concept Videos
01:17Phagocytosis of Apoptotic Cells
Normal cells contain receptors that prevent them from being recognized...
01:38Inflammation
01:38Receptor-mediated Endocytosis