Obesity remains one of the most pressing global health issues of the 21st century, with projections suggesting it may affect over half the world’s population in the coming decade. Morbid obesity, defined by a body mass index (BMI) ≥40 kg/m², is the most prevalent chronic metabolic condition in developed countries and is often associated with serious comorbidities. Initial treatments include dietary changes, physical activity, and behavioral therapy, but bariatric surgery is the most effective long-term solution when these fail. The development and persistence of obesity involve genetic, environmental, and behavioral factors. It also induces chronic low-grade inflammation, leading to molecular and cellular disruptions. In this context, the extracellular vesicles (EVs)—small membrane-bound particles released by cells—have emerged as key mediators of intercellular communication and metabolic regulation. These vesicles carry bioactive molecules, including proteins, reflecting the physiological state and origin of their parent cells. EVs also contribute to immune responses and inflammation.
This study analyzed EVs from the plasma of patients with morbid obesity, focusing on immune-cell-associated markers. The EV profiles were compared before and after bariatric surgery and with those from healthy controls. Plasma samples were obtained from morbidly obese patients (BMI > 40, aged 30–60) treated at Hospital Clínico de Valencia and from healthy individuals. The EVs were isolated using size-exclusion chromatography (qEV2 70 nm, IZON) and analyzed via electron microscopy, nanoparticle tracking, and Western blotting for general and immune-specific markers.
The EVs from the obese patients expressed both common and cell-type-specific markers. Post-surgery, the EV levels decreased, with significant changes in immune-cell-derived EVs. These results suggest that plasma EVs reflect immune and metabolic alterations in morbid obesity and following surgery, supporting their potential as biomarkers. Further studies are needed to clarify their diagnostic and therapeutic value.
Acknowledgements. This research was funded by Instituto de Salud Carlos III (ISCIII) through the project “PI23/00204” and co-funded by the European Union.
