Distinctive characteristics of extracellular vesicles from feline adipose and placenta stromal cells unveil potential for regenerative medicine in cats

OBJECTIVE Extracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) are promising avenues in regenerative medicine, offering unique immunomodulatory and regenerative properties with lower immunogenicity. This study delves into the distinctive features of EVs extracted from feline adipose -derived MSCs (ASCs) and placenta -derived MSCs (PMSCs). The tissues were collected from 11 female cats aged between 4 and 7 years old. SAMPLE EVs extracted from MSCs from discarded fetal membranes from 7 female cats and SC adipose tissue from 11 cats. METHODS We comprehensively explored morphological characteristics, mitochondrial density, surface markers, and pro- and anti-inflammatory mediators, uncovering notable differences between ASCs and PMSCs. RESULTS Morphologically, ASCs exhibit a spindle -shaped form in contrast to the spherical morphology of PMSCs. Proliferation and clonogenic potential assessments reveal the faster proliferation and robust clonogenic nature of ASCs, suggesting their potential vital role in regenerative processes. Surface marker expression analysis indicates a significantly higher expression of multipotency-associated markers in ASCs, suggesting their superior proregenerative potential. Phenotyping of EVs demonstrates distinctive features, with CD9 expression suggesting varied EV secretion patterns. Notably, PMSCs exhibit superior CD81 expression, indicating their potential as preferred donors of mitochondria. Pro- and anti-inflammatory mediators analyzed at mRNA and microRNA levels reveal higher RNA content in EVs compared to source cells, emphasizing the potential of EVs in directing regenerative processes. Differential microRNA expression in EVs derived from ASCs hints at their regulatory roles in anti-inflammatory and immuno - metabolic processes. CLINICAL RELEVANCE This study lays a foundation for understanding the nuances between ASCs and PMSCs, which is crucial for harnessing the full therapeutic potential of MSCs and their EVs in tissue repair and regeneration.