[HTML][HTML] Exosome secreted by MSC reduces myocardial ischemia/reperfusion injury
Stem cell research, 2010•Elsevier
Human ESC-derived mesenchymal stem cell (MSC)-conditioned medium (CM) was
previously shown to mediate cardioprotection during myocardial ischemia/reperfusion injury
through large complexes of 50–100 nm. Here we show that these MSCs secreted 50-to 100-
nm particles. These particles could be visualized by electron microscopy and were shown to
be phospholipid vesicles consisting of cholesterol, sphingomyelin, and phosphatidylcholine.
They contained coimmunoprecipitating exosome-associated proteins, eg, CD81, CD9, and …
previously shown to mediate cardioprotection during myocardial ischemia/reperfusion injury
through large complexes of 50–100 nm. Here we show that these MSCs secreted 50-to 100-
nm particles. These particles could be visualized by electron microscopy and were shown to
be phospholipid vesicles consisting of cholesterol, sphingomyelin, and phosphatidylcholine.
They contained coimmunoprecipitating exosome-associated proteins, eg, CD81, CD9, and …
Human ESC-derived mesenchymal stem cell (MSC)-conditioned medium (CM) was previously shown to mediate cardioprotection during myocardial ischemia/reperfusion injury through large complexes of 50–100 nm. Here we show that these MSCs secreted 50- to 100-nm particles. These particles could be visualized by electron microscopy and were shown to be phospholipid vesicles consisting of cholesterol, sphingomyelin, and phosphatidylcholine. They contained coimmunoprecipitating exosome-associated proteins, e.g., CD81, CD9, and Alix. These particles were purified as a homogeneous population of particles with a hydrodynamic radius of 55–65 nm by size-exclusion fractionation on a HPLC. Together these observations indicated that these particles are exosomes. These purified exosomes reduced infarct size in a mouse model of myocardial ischemia/reperfusion injury. Therefore, MSC mediated its cardioprotective paracrine effect by secreting exosomes. This novel role of exosomes highlights a new perspective into intercellular mediation of tissue injury and repair, and engenders novel approaches to the development of biologics for tissue repair.
Elsevier