Cyclic Hypoxia Conditioning Alters the Content of Myoblast-Derived Extracellular Vesicles and Enhances Their Cell-Protective Functions.

Yan Yan,Thomas Ravn Lassen,Ping Song,Iju Lo,Hans Erik Bøtker,Kim Ryun Drasbek,Junyi Su,Blagoy Blagoev,Jørgen Kjems,Morten Schallburg Nielsen,Susanne Trillingsgaard Venø,Stine Duelund Kaas Christensen,Marie Vognstoft Hjortbak,Andrea Erzsebet Tóth,Tingting Gu

doi:10.3390/biomedicines9091211

Abstract

Remote ischemic conditioning (RIC) is a procedure that can attenuate ischemic-reperfusion injury by conducting brief cycles of ischemia and reperfusion in the arm or leg. Extracellular vesicles (EVs) circulating in the bloodstream can release their content into recipient cells to confer protective function on ischemia-reperfusion injured (IRI) organs. Skeletal muscle cells are potential candidates to release EVs as a protective signal during RIC. In this study, we used C2C12 cells as a model system and performed cyclic hypoxia-reoxygenation (HR) to mimic RIC. EVs were collected and subjected to small RNA profiling and proteomics. HR induced a distinct shift in the miRNA profile and protein content in EVs. HR EV treatment restored cell viability, dampened inflammation, and enhanced tube formation in in vitro assays. In vivo, HR EVs showed increased accumulation in the ischemic brain compared to EVs secreted from normoxic culture (N EVs) in a mouse undergoing transient middle cerebral artery occlusion (tMCAO). We conclude that HR conditioning changes the miRNA and protein profile in EVs released by C2C12 cells and enhances the protective signal in the EVs to recipient cells in vitro.

Highlights

We found that blood flow restricted exercise (BFRE) on humans, which creates ischemic conditions, altered the miRNA profile in Extracellular vesicles (EVs) purified from human plasma and that BFRE-EVs induced muscle stem cell (MuSC, satellite cell) activation and proliferation [28]
The average size of HR EVs and N EVs was 123 ± 5 nm and 123 ± 3 nm measured by nanoparticle tracking analysis (NTA) (Figure 1a,b)
Our secreted from myoblasts undergoing cyclic hypoxia-reoxygenation treatment may contain hypothesis is that EVs secreted from myoblasts undergoing cyclic hypoxia-reoxygenation protective signals

Summary

Introduction

Remote ischemic conditioning (RIC) is a therapeutic procedure that attenuates ischemia-reperfusion injury (IRI) by repeated temporary occlusion and release of blood flow to an effector organ distant to the target organ exposed to ischemia and reperfusion. The effector organ is typically the upper limb since repetitive occlusion of blood flow and reperfusion is achieved with an ordinary blood pressure cuff [1]. The nature of the protective signals and their transmission from the remote conditioned organ to the damaged tissue remain unclear. (1) a humoral pathway [2,3,4,5,6], (2) a neuronal pathway [4,6,7], and (3) an immunological path- 4.0/).

Methods

Results

Conclusion