Comparison of two ASC-derived therapeutics in an in vitro OA model: secretome versus extracellular vesicles

Abstract

Background In the last years, several clinical trials have proved the safety and efficacy of adipose-derived stem/stromal cells (ASC) in contrasting osteoarthritis (OA). Since ASC act mainly through paracrine mechanisms, their secretome (conditioned medium, CM) represents a promising therapeutic alternative. ASC-CM is a complex cocktail of proteins, nucleic acids, and lipids released as soluble factors and/or conveyed into extracellular vesicles (EV). Here, we investigate its therapeutic potential in an in vitro model of OA. Methods Human articular chondrocytes (CH) were induced towards an OA phenotype by 10 ng/ml TNFα in the presence of either ASC-CM or EV, both deriving from 5 × 105 cells, to evaluate the effect on hypertrophic, catabolic, and inflammatory markers. Results Given the same number of donor cells, our data reveal a higher therapeutic potential of ASC-CM compared to EV alone that was confirmed by its enrichment in chondroprotective factors among which TIMP-1 and -2 stand out. In details, only ASC-CM significantly decreased MMP activity (22% and 29% after 3 and 6 days) and PGE2 expression (up to 40% at day 6) boosted by the inflammatory cytokine. Conversely, both treatments down-modulated of ~ 30% the hypertrophic marker COL10A1. Conclusions These biological and molecular evidences of ASC-CM beneficial action on CH with an induced OA phenotype may lay the basis for its future clinical translation as a cell-free therapeutic in the management of OA.

Towards Secretome Standardization: Identifying Key Ingredients of MSC-Derived Therapeutic Cocktail

“…Therefore, according to the aphorism “the process is the product,” any change in the manufacturing process will undoubtedly affect the final product. Moreover, it should be pointed out that ASC-CM thus produced retains a substantial number of EVs and indeed previous evidences demonstrated a vesicular yield even higher than the one obtained by ultracentrifugation [ 13 , 15 ].…”

“…The supernatants were then concentrated about 60 times by centrifuging at 4000 g for 90 min at 4°C in Amicon Ultra-15 Centrifugal Filter Devices with 3 kDa molecular weight cut-off (Merck Millipore, Burlington, MA, USA). This procedure allows the retention of the vesicular component of cell secretome, as previously demonstrated in [ 12 , 13 , 15 ]. The safety and efficacy of the final product obtained through this procedure have been already tested both in vitro [ 14 , 15 ] and in vivo [ 16 , 17 ].…”

“…This procedure allows the retention of the vesicular component of cell secretome, as previously demonstrated in [ 12 , 13 , 15 ]. The safety and efficacy of the final product obtained through this procedure have been already tested both in vitro [ 14 , 15 ] and in vivo [ 16 , 17 ].…”

“…In recent years, our research focused on the investigation of the conditioned medium (CM) from adipose tissue-derived MSCs (ASCs) in terms of biochemical composition [ 10 – 13 ] and therapeutic action, both in vitro [ 14 , 15 ] and in vivo [ 16 , 17 ]. Most of these studies provided the comparison between ASC-CM, consisting of both soluble factors and vesicle-conveyed ones, and ultracentrifuge-isolated EVs.…”

Extracellular Vesicles as Potential Theranostic Platforms for Skin Diseases and Aging

“…Phagocytosis index was increased in the ADSC-EV-treated group, while ADSC-CM-treated macrophages showed a suppressed immune response [106]. In an osteoarthritis (OA) model, ADSC-CM showed a higher reduction in MMP activity and pro-inflammatory cytokine expression, while miRNA-mediated immune suppression was expected in ADSC-EV-treated groups [107,108]. In many cases, EVs have been acknowledged for their reparative efficacy: ADSC-EV treatment protected renal tissue in a hypertension model and prevented muscle damage and inflammation in a hind limb ischemic model [109,110].…”