Small Extracellular Vesicles from OSA Patients express Fetuin A

Introduction 

Obstructive sleep apnea (OSA) is a common disorder. Untreated it is believed to be a stressor for many disorders, especially for cardiovascular conditions. Continuous positive airway pressure (CPAP) is the standard treatment. The glycoprotein Fetuin-A (FA) is mainly synthesized in the liver and secreted in the bloodstream. Its functions are diverse: Studies have not only shown a correlation with insulin resistance and risk for diabetes but also still unclear involvement in cardiovascular diseases. In this study we analyzed how the content of small extracellular vesicles (sEV) differs between OSA patients in comparison to a healthy population (HD) and if it changes due to OSA treatment.

Materials & Methods 

Small extracellular vesicles were isolated from blood using mini size Exclusion chromatography (mini Sec) from 6 patients with OSA before and after treatment with CPAP and 2 HD respectively. All patients were diagnosed by polysomnography. The purified sEVs of OSA patients and HD were subjected to proteomics analysis (PA). Afterwards western blot (WB) was carried out with blood samples of OSA patients before and after CPAP and HD.

Results 

Compared to healthy donor controls we saw a significant upregulation of FA in the vesicles derived from OSA patients in the PA. These findings were also confirmed by WB analysis. Surprisingly after CPAP therapy FA expression was significantly reduced in OSA patients.

Conclusion 

The different content of sEV reflects the diagnosis OSA as concluded by polysomnography. Further studies are needed to examine the effects of the changed EV content. FA may serve as a correlate to the metabolic risk associated with OSAS and thus may additionally help in the future to assess the success of therapy by blood analysis.

Publikationsverlauf

Artikel online veröffentlicht:
24. Mai 2022