Differentiation Capacity Of hMSCs Research Articles

Polymer-Coated Surface as an Enzyme-Free Culture Platform to Improve Human Mesenchymal Stem Cell (hMSC) Characteristics in Extended Passaging.

For efficient therapeutic use of human mesenchymal stem cells (hMSCs), maximizing their self-renewal performance and multipotency must be fully retained. However, conventional trypsin-based cell passaging methods are known to damage the attached cells to be detached because of the inherent corrosive nature of trypsin, and continuous passaging substantially degrades the self-renewal and differentiation capacity of hMSCs. Therefore, it is imperative to secure a damage-free passaging method that supports cell growth as well as their stem cell function. Here, an enzyme-free cell detachment method using a poly(ethylene glycol dimethacrylate) (pEGDMA)-coated surface is developed, which allows for reduced integrin-dependent cell adhesion. Cell detachment can be facilitated simply by treating the plated cells on the pEGDMA surface with Ca2+ and Mg2+-depleted DPBS. Spontaneous cell detachment occurs within 10 min with the full retention of the cell viability and proliferation ability of hMSCs. Especially, the detachment method can minimize the surface protein damage of hMSCs compared to the conventional trypsin treatment and preserve the self-renewal property and differentiation capacity even with an increased passage number over 10. The developed enzyme-free detachment method using the pEGDMA-coated surface is highly promising for a culture platform to broaden its application to the field of tissue engineering and regenerative medicine.

Cultivation of hMSCs in Human Plasma Prevents the Cytotoxic and Genotoxic Potential of ZnO-NP In Vitro

Zinc oxide nanoparticles (ZnO-NPs) are commonly used for industrial applications. Consequently, there is increasing exposure of humans to them. The in vitro analysis of cytotoxicity and genotoxicity is commonly performed under standard cell culture conditions. Thus, the question arises of how the results of genotoxicity and cytotoxicity experiments would alter if human plasma was used instead of cell culture medium containing of fetal calf serum (FCS). Human mesenchymal stem cells (hMSCs) were cultured in human plasma and exposed to ZnO-NPs. A cultivation in expansion medium made of DMEM consisting 10% FCS (DMEM-EM) served as control. Genotoxic and cytotoxic effects were evaluated with the comet and MTT assay, respectively. hMSC differentiation capacity and ZnO-NP disposition were evaluated by histology and transmission electron microscopy (TEM). The protein concentration and the amount of soluble Zn2+ were measured. The cultivation of hMSCs in plasma leads to an attenuation of genotoxic and cytotoxic effects of ZnO-NPs compared to control. The differentiation capacity of hMSCs was not altered. The TEM showed ZnO-NP persistence in cytoplasm in both groups. The concentrations of protein and Zn2+ were higher in plasma than in DMEM-EM. In conclusion, the cultivation of hMSCs in plasma compared to DMEM-EM leads to an attenuation of cytotoxicity and genotoxicity in vitro.

Differential analysis of genome-wide methylation and gene expression in mesenchymal stem cells of patients with fractures and osteoarthritis

ABSTRACTInsufficient activity of the bone-forming osteoblasts leads to low bone mass and predisposes to fragility fractures. The functional capacity of human mesenchymal stem cells (hMSCs), the precursors of osteoblasts, may be compromised in elderly individuals, in relation with the epigenetic changes associated with aging. However, the role of hMSCs in the pathogenesis of osteoporosis is still unclear. Therefore, we aimed to characterize the genome-wide methylation and gene expression signatures and the differentiation capacity of hMSCs from patients with hip fractures. We obtained hMSCs from the femoral heads of women undergoing hip replacement due to hip fractures and controls with hip osteoarthritis. DNA methylation was explored with the Infinium 450K bead array. Transcriptome analysis was done by RNA sequencing. The genomic analyses revealed that most differentially methylated loci were situated in genomic regions with enhancer activity, distant from gene bodies and promoters. These regions were associated with differentially expressed genes enriched in pathways related to hMSC growth and osteoblast differentiation. hMSCs from patients with fractures showed enhanced proliferation and upregulation of the osteogenic drivers RUNX2/OSX. Also, they showed some signs of accelerated methylation aging. When cultured in osteogenic medium, hMSCs from patients with fractures showed an impaired differentiation capacity, with reduced alkaline phosphatase activity and poor accumulation of a mineralized matrix. Our results point to 2 areas of potential interest for discovering new therapeutic targets for low bone mass disorders and bone regeneration: the mechanisms stimulating MSCs proliferation after fracture and those impairing their terminal differentiation.