Partial Reprogramming Exerts a Rejuvenating Effect on Human Mesenchymal Stem Cells That Underwent Replicative Senescence in Culture.

Mesenchymal stem/stromal cells (MSCs) are becoming increasingly important for biomedical applications, such as cell therapy, disease modeling, and drug screening. At the same time, long-term cultivation, which is necessary to prepare a sufficient amount of cellular material for therapeutic and research purposes, is accompanied by the development of replicative senescence. Partial reprogramming emerged as a novel method that shows promising results in the rejuvenation of cells in vitro and in vivo; however, it has not yet been applied for human MSCs that have undergone replicative senescence in culture.

The Role of Intracellular Potassium in Cell Quiescence, Proliferation, and Death.

This brief review explores the role of intracellular K during the transition of cells from quiescence to proliferation and the induction of apoptosis. We focus on the relationship between intracellular K and the growth and proliferation rates of different cells, including transformed cells in culture as well as human quiescent T cells and mesenchymal stem cells, and analyze the concomitant changes in K and water content in both proliferating and apoptotic cells. Evidence is discussed indicating that during the initiation of cell proliferation and apoptosis changes in the K content in cells occur in parallel with changes in water content and therefore do not lead to significant changes in the intracellular K concentration.

Mesenchymal stem cells lose the senescent phenotype under 3D cultivation.

Background: Three-dimensional (3D) cell culture is widely used in various fields of cell biology. In comparison to conventional two-dimensional (2D) cell culture, 3D cell culture facilitates a more accurate replication of the in vivo microenvironment, which is essential for obtaining more relevant results. The application of 3D cell culture techniques in regenerative medicine, particularly in mesenchymal stem cell (MSC)-based research, has been extensively studied.

Accumulation of Dystrophin-Positive Muscle Fibers and Improvement of Neuromuscular Junctions in mdx Mouse Muscles after Bone Marrow Transplantation under Different Conditions.

Duchenne muscular dystrophy (DMD) is a severe muscular disorder caused by mutations in the dystrophin gene. It leads to respiratory and cardiac failure and premature death at a young age. Although recent studies have greatly deepened the understanding of the primary and secondary pathogenetic mechanisms of DMD, an effective treatment remains elusive.

Mesenchymal Stem/Stromal Cells in Three-Dimensional Cell Culture: Ion Homeostasis and Ouabain-Induced Apoptosis.

This study describes the changes in ion homeostasis of human endometrial mesenchymal stem/stromal cells (eMSCs) during the formation of three-dimensional (3D) cell structures (spheroids) and investigates the conditions for apoptosis induction in 3D eMSCs. Detached from the monolayer culture, (2D) eMSCs accumulate Na and have dissipated transmembrane ion gradients, while in compact spheroids, eMSCs restore the lower Na content and the high K/Na ratio characteristic of functionally active cells. Organized as spheroids, eMSCs are non-proliferating cells with an active Na/K pump and a lower K content per g cell protein, which is typical for quiescent cells and a mean lower water content (lower hydration) in 3D eMSCs.