Dynamics of circulating liver-derived and CD36+ extracellular vesicles in metabolic dysfunction-associated steatotic liver disease during weight loss intervention

INTRODUCTION<br/>Metabolic dysfunction-associated steatotic liver disease (MASLD) is an increasing health challenge, with early diagnosis hindered by the lack of reliable and non-invasive biomarkers. The fatty acid transporter, CD36, plays a significant role in ectopic liver fat accumulation during MASLD development. Extracellular vesicle (EV) secretion is modulated by lipotoxicity and likely represent the <br/>phenotype of the cell of origin. <br/><br/>MATERIALS AND METHODS<br/>Using high-resolution flow cytometry (hFCM) and our in-house-developed EV Array technology for high-throughput multiplexed phenotyping of EVs, our study is the first to characterize and report levels of circulating liver-derived and CD36+ EVs directly in plasma of obese individuals with MASLD (n=36) compared with obese (n=25) or lean (n=27) control individuals without MASLD. Moreover, <br/>these EV populations were assessed in the MASLD group before (baseline) and during weight-loss intervention (1 month and 5 months). <br/><br/>RESULTS<br/>Using a panel of antibodies and labels to CD9, lactadherin (EV markers), asialoglycoprotein receptor 1 (ASGR1, liver marker), and CD36, hFCM analysis revealed that at baseline, liver-EVs were significantly increased in the MASLD group compared with the lean control group, while CD36+-EVs were significantly increased in the MASLD group compared with either control group. During the weight loss intervention, levels of liver-derived EVs, CD36⁺ EVs, and liver-EVs expressing CD36 were significantly reduced in the MASLD group as early as 1 month, with further reductions observed after 5 months. Preliminary results from EV Array analysis confirm these findings and reveal a significant correlation between CD36⁺ EVs and ectopic liver fat accumulation.<br/><br/>CONCLUSION<br/>Our study advances the understanding of EVs in the development of MASLD and introduces a novel approach for characterizing organ-specific circulating EV phenotypes. Profiling the composition of these EV populations offers valuable insights into organ physiology and opens new avenues for biopsy-free diagnosis and monitoring of complex diseases such as MASLD.<br/>