Ultrastructural Characterization of PBMCs and Extracellular Vesicles in Multiple Sclerosis: A Pilot Study

Area of Science:

• Neuroimmunology
• Cellular Biology
• Extracellular Vesicle Research

Background:

• Extracellular vesicles (EVs) are increasingly recognized as critical mediators of intercellular communication in autoimmune diseases like multiple sclerosis (MS).
• Peripheral blood mononuclear cells (PBMCs) are implicated in the pathogenesis of MS and associated neuroinflammation.
• EVs are proposed as key players in the neuroimmune crosstalk within the central nervous system (CNS) during MS.

Purpose of the Study:

• To investigate the role of plasma-derived EVs and the ultrastructure of PBMCs in multiple sclerosis (MS).
• To identify morphological and molecular differences in EVs and PBMCs between MS patients and healthy controls.

Main Methods:

• Electron microscopy (EM) was used to examine the morphology of plasma-derived EVs and the ultrastructure of PBMCs.
• Western blot analysis was employed to study the molecular content of EVs.
• Comparison was made between four MS patients and four healthy controls.

Main Results:

• PBMCs from MS patients exhibited increased pseudopods, large vesicles, endoplasmic vesicles, and multivesicular bodies, indicating an activated state.
• Significant differences were observed in the number and morphology of vesicles and cytoplasmic structures within PBMCs.
• Dysregulated molecules (GANAB, IFI35, Cortactin, Septin 2, Cofilin 1, ARHGDIA) were identified in EVs from MS patients, suggesting altered vesicular dynamics and inflammatory signaling.

Conclusions:

• Electron microscopy and Western blot analysis of PBMCs and EVs provide valuable insights into the physiopathology of MS.
• Altered EV morphology and cargo in MS patients highlight their potential role in disease mechanisms.
• These findings underscore the importance of studying vesicular dynamics in understanding MS pathogenesis.