Project description:Culture medium of mesenchymal stromal cells (MSCs) is usually supplemented with either human platelet lysate (HPL) or fetal calf serum (FCS). Many studies have demonstrated that proliferation and cellular morphology is influenced by these additives – hence they may favor outgrowth of specific subpopulations, thereby affecting the heterogeneous composition of MSCs. We have isolated and expanded human bone marrow derived MSCs in parallel with HPL or FCS for two passages. In HPL the proliferation was significantly higher and cells reflected more spindle-shaped morphology. In contrast, global DNA-methylation profiles did not reveal any significant differences. None of the CpGs revealed significant differences between MSCs that were cultured in HPL versus FCS if the analysis was corrected for multiple testing (limma-adjusted P-value of <0.05). These results indicate that there is no systematic bias for specific subpopulations of MSCs by using either HPL or FCS.
Project description:Culture medium of mesenchymal stromal cells (MSCs) is usually supplemented with either human platelet lysate (HPL) or fetal calf serum (FCS). Many studies have demonstrated that proliferation and cellular morphology is influenced by these additives – hence they may favor outgrowth of specific subpopulations, thereby affecting the heterogeneous composition of MSCs. We have isolated and expanded human bone marrow derived MSCs in parallel with HPL or FCS for two passages. In HPL the proliferation was significantly higher and cells reflected more spindle-shaped morphology. Pairwise comparisons of gene expression profiles (Affymetrix HTA 2.0) revealed only moderate differences. When we apply a fold change >1.5 and limma-adjusted P-value of <0.05, only 69 transcripts were differentially expressed. These results indicate that there is no systematic bias for specific subpopulations of MSCs by using either HPL or FCS.
Project description:Gene expression was influenced most by the tissue source, followed by culture methodology, next by location where the cells were cultured and lastly the donor variability. On the normalized log2 expression values per gene a multifactorial Analyses of Variance (ANOVA) was conducted. Factors CELL CULTURES (cell source), MEDIUM (culture methodology), LOCATION (culture location), and SCAN DATE (hybridization batch) were included in the ANOVA model as independent factors. The following pairwise comparisons were made; Fetal calf serum vs. Human platelet lysate, Bone marrow vs. Adipose tissue, Utrecht vs. Leiden, Utrecht vs Nijmegen, and Leiden vs Nijmegen. Changes ≥2 and Benjamini Hochberg corrected p-values <0.05 were considered significant.
Project description:mRNA expression profiling of human mesenchymal stromal cell samples grown in vitro under different conditions (foetal calf serum (FCS) based medium versus human platelet lysate (PL) based medium)
Project description:Despite similarities in morphology, phenotype and in vitro behavior, Mesenchymal Stromal Cells (MSC) form various tissue sources show striking differences in their in vivo potential to form bone, cartilage and hematopoietic support tissue. Comparing four commonly use MSC sources (bone marrow (BM), white adipose tissue (WAT), umbilical cord (UC) and skin) we found only bone marrow (BM)-derived MSCs capable of endochondral ossification and marrow attraction. To gain mechanistic insights explaining this differences we analyzed gene expression characteristics of MSC from all four tissue sources using Affymetrix Genechip Human Gene 2.0 ST Array. MSCs from BM, WAT, UC and skin were isolated using plastic adherence. Cells were expanded in standard alpha-MEM supplemented with pooled human platelet lysate fully replacing fetal bovine serum. MSCs were subcutaneously implanted into immune-compromised mice to comparatively evaluate bone formation and subsequent bone marrow attraction. In parallel we have isolated RNA from all sources to analyze tissue source specific gene expression profile.
Project description: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.
Project description: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.
Project description:Most cell culture experiments utilize media containing fetal calf serum. Results are often interpreted regarding importance to human pathways. We studied gene expression in mouse macrophages grown in the absence of serum, and in fetal calf serum, mouse serum, and human serum using genome wide expression systems in resting conditions and after stimulation with lipopolysaccharide.