Canine adipose-derived mesenchymal stem cells (cAD-MSCs) show therapeutic promise for their regenerative potential, particularly in their secretome. However, concerns arise regarding the impact of in vitro cultivation need for storing therapeutic doses, prompting this study to comprehensively explore the impact of in vitro aging on gene expression and secretome composition. The study involved collecting abdominal adipose tissue samples from nine healthy female dogs, from which cAD-MSCs were extracted and cultured. Stem cells were validated through trilineage differentiation assays and flow cytometry immunophenotyping. Gene expression profiling, using RT-qPCR array and cAD-MSCs secretome LC-MS/MS analysis, were conducted at passages 3 and 6 to reveal gene expression and protein composition alterations during in vitro culture. Gene expression profiling of in vitro aged cAD-MSCs revealed expression alterations, while significant downregulation was observed in two MSC-associated genes. Proteomic analysis revealed 10% distinctively expressed proteins, and several up- and downregulations. Grouping these proteins with biologically significant ones, Gene Ontology Panther Pathway analysis revealed that P3 proteins were significantly associated with cytoskeletal regulation, nicotinic acetylcholine receptor signaling, inflammation mediated by chemokine and cytokine signaling, Wnt signaling, and CCKR signaling map. In contrast, P6 proteins were linked to the xanthine and guanine salvage pathway, adenine and hypoxanthine salvage pathway, and blood coagulation pathway. To the best of our knowledge, this study presents the first original perspective on the changes in secretome composition that occur when cAD-MSCs age in vitro. Our findings highlight significant changes that, in conclusion, indicate the regenerative potential of cAD-MSCs and that their secretome may be compromised due to in vitro aging. Consequently, our study suggests a preference for earlier passages when considering these cells for therapeutic applications.
Overall design: Nine biological replicates are studied in two different cell conditions, passage 3 and passage 6.
Less...