GSE194295
Batch effect during human bone marrow stromal cell propagation prevails donor variation and culture duration impact on phenotype, transcriptome and function [MethylCap-seq]
Donor variation is a prominent critical issue limiting applicability of cell-based therapies. We asked whether reference protocols for pre-clinical bone marrow stromal cell (BMSC) propagation using human platelet lysate (hPL) to replace xenogeneic fetal bovine serum (FBS) might also reduce donor variability for osteo-chondral regeneration. We therefore investigated the impact of donor variability, hPL- vs FBS driven propagation and exhaustive proliferation, on BMSC epigenome, transcriptome, phenotype, coagulation risk and osteochondral regenerative function. Polychromatic flow cytometry revealed maintained canonical fibroblastic phenotype in all cells tested. We confirmed significantly declining proliferative potential in FBS-expanded BMSC after proliferative challenge. Notably, BMSC propagation under the aegis of hPL, compared to FBS, significantly increased BMSC proliferation, created significantly different gene expression trajectories and diverging surface marker signatures, already after just one culture passage. We observed limited but measurable effects on DNA methylation irrespective of culture duration. Moreover, expansion under xenogenic serum conditions resulted in significant loss of function during 3D cartilage organoid-like disk formation and significantly increased clotting risk. Superior chondrogenic function under hPL conditions was maintained over culture duration. As an additional observation, platelet blood group and isoagglutinin levels showed phenotypic changes but only minor impact on BMSC chondrogenesis and clotting behaviour. Overall design: MethylCap-seq analysis of Bone marrow derived Mesenchymal stromal cells from four different donors cultivated in either FBS medium or hPL at two different passages (p1 and p4/5)