Bone marrow stromal cells (BMSCs CD45(‐)/CD44(+)/CD73(+)/CD90(+)) isolated from osteoporotic mice SAM/P6 as a novel model for osteoporosis investigation

Available therapies aimed at treating age‐related osteoporosis are still insufficient. Therefore, designing reliable in vitro model for the analysis of molecular mechanisms underlying senile osteoporosis is highly required. We have isolated and characterized progenitor cells isolated from bone marrow (BMSCs) of osteoporotic mice strain SAM/P6 (BMSC(SAM/P6)). The cytophysiology of BMSC(SAM/P6) was for the first time compared with BMSCs isolated from healthy BALB/c mice (BMSC(BALB/c)). Characterization of the cells included evaluation of their multipotency, morphology and determination of specific phenotype. Viability of BMSCs cultures was determined in reference to apoptosis profile, metabolic activity, oxidative stress, mitochondrial membrane potential and caspase activation. Additionally, expression of relevant biomarkers was determined with RT‐qPCR. Obtained results indicated that BMSC(SAM/P6) and BMSC(BALB/c) show the typical phenotype of mesenchymal stromal cells (CD44+, CD73+, CD90+) and do not express CD45. Further, BMSC(SAM/P6) were characterized by deteriorated multipotency, decreased metabolic activity and increased apoptosis occurrence, accompanied by elevated oxidative stress and mitochondria depolarisation. The transcriptome analyses showed that BMSC(SAM/P6) are distinguished by lowered expression of molecules crucial for proper osteogenesis, including Coll‐1, Opg and Opn. However, the expression of Trap, DANCR1 and miR‐124‐3p was significantly up‐regulated. Obtained results show that BMSC(SAM/P6) present features of progenitor cells with disturbed metabolism and could serve as appropriate model for in vitro investigation of age‐dependent osteoporosis.