Enhanced proliferation and differentiation of human mesenchymal stem cells in the gravity‐controlled environment

Abstract

Background Human bone marrow mesenchymal stem cells (hMSCs) present a promising cell source with the potential to be used for curing various intractable diseases, and it is expected that the development of regenerative medicine employing cell‐based therapy would be significantly accelerated when such methods are established. For that, powerful methods for selective growth and differentiation of hMSCs should be developed. Methods We developed an efficient method for hMSC proliferation and differentiation into osteoblasts and adipocytes using gravity‐controlled environments. Results The results indicate that the average doubling time of hMSCs cultured in a regular maintenance medium under microgravity conditions (0.001 G) was 1.5 times shorter than that of cells cultured under natural gravity conditions (1.0 G). Furthermore, 99.2% of cells grown in the microgravity environment showed the expression of hMSC markers, as indicated by flow cytometry analysis. Osteogenic and adipogenic differentiation of hMSCs expanded in the microgravity environment was enhanced under microgravity and hypergravity conditions, respectively, as evidenced by the downregulation of hMSC markers and upregulation of osteoblast and adipocyte markers, respectively. Most cells differentiated into osteoblasts in the microgravity environment after 14 days (~80%) and adipocytes in the hypergravity environment after 12 days (~90%). Conclusions Our results indicate that hMSC proliferation and selective differentiation into specific cell lineages could be promoted under microgravity or hypergravity conditions, suggesting that cell culture in the gravity‐controlled environment is a useful method to obtain cell preparations for potential clinical applications.

Stimulating factors for regulation of osteogenic and chondrogenic differentiation of mesenchymal stem cells

“…Most of the research was thus for only conducted in a simulated MG (SMG) environment produced by a clinostat or rotating vessel, since examining the proliferation and differentiation patterns of MSCs in an actual MG environment led to some technical and budgetary challenges[ 44 ]. Quynh et al [ 45 ] found that SMG inhibited the proliferation of human umbilical cord MSCs by blocking the cell cycle; in contrast, a study by Nakaji-Hirabayashi et al [ 46 ] revealed a proliferative effect. The various SMG action times could be responsible for this circumstance.…”

“…Shorter SMG treatments appeared to inhibit osteogenesis[ 47 - 49 ] and promote endothelial cell differentiation[ 48 ], neuronal differentiation[ 44 , 48 ], and adipogenic differentiation[ 48 , 49 ]. However, extended SMG decreased the potential for chondrogenic differentiation in MSCs[ 50 ] and encouraged their differentiation toward osteogenesis[ 46 , 48 ]. Different SMG action times had different effects on the cytoskeleton and could even lead to the aforementioned changes through different signal transduction pathways.…”

Addressing Spaceflight Biology through the Lens of a Histologist–Embryologist

“…The cell differentiation process seems to be the key event affected in space expeditions, as suggested by analyzing specific cell cultures of cartilage, bone and muscle postexploration or induced gravitational variations [ 54 , 55 , 56 ]. Kacena and colleagues performed in vitro hypergravity experiments and presented altered actin and fibronectin elements, modifying the osteoblast–substrate adhesion [ 57 ].…”

The effect of source animal age, decellularization protocol, and sterilization method on bovine acellular dermal matrix as a scaffold for wound healing and skin regeneration

“…24 Exposure to ethylene oxide (EO) gas and gamma (γ) irradiation are two sterilization methods, which apply their sterilizing effects by changing the biomolecules of the residing microorganisms by chemical modifications or energy forces, respectively. 25 However, they may also alter the structural, mechanical, and biological features of the ECM by transforming proteins or other biological molecules. 26 Such effects have been studied in collagen-based reconstituted scaffolds, 27,28 human, [29][30][31] and porcine ADMs, 32 whereas the effects of the sterilization method on the properties of the bovine ADM have not been reported yet.…”

“…Scaffolds derived from ECMs need to be terminally sterilized as they pass through several decellularization and processing steps which are not conducted under sterile conditions 24 . Exposure to ethylene oxide (EO) gas and gamma (γ) irradiation are two sterilization methods, which apply their sterilizing effects by changing the biomolecules of the residing microorganisms by chemical modifications or energy forces, respectively 25 . However, they may also alter the structural, mechanical, and biological features of the ECM by transforming proteins or other biological molecules 26 .…”