Shatrova Alla N, Domnina Alisa P, Pugovkina Natalia A, Alekseenko Larisa L, Marakhova Irina I
Laboratory of Intracellular Membranes Dynamic, Institute of Cytology, Russian Academy of Sciences, Tikoretzky Ave, 4, 194064 Saint-Petersburg, Russia.
Laboratory of Intracellular Signaling, Institute of Cytology, Russian Academy of Sciences, Tikoretzky Ave, 4, 194064 Saint-Petersburg, Russia.
Biomedicines. 2023 Jan 21;11(2):301. doi: 10.3390/biomedicines11020301.
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. Further, eMSCs in spheroids were used to evaluate the role of K depletion and cellular signaling context in the induction of apoptosis. In both 2D and 3D eMSCs, treatment with ouabain (1 µM) results in inhibition of pump-mediated K uptake and severe K depletion as well as disruption of the mitochondrial membrane potential. In 3D eMSCs (but not in 2D eMSCs), ouabain initiates apoptosis via the mitochondrial pathway. It is concluded that, when blocking the Na/K pump, cardiac glycosides prime mitochondria to apoptosis, and whether a cell enters the apoptotic pathway depends on the cell-specific signaling context, which includes the type of apoptotic protein expressed.
本研究描述了人子宫内膜间充质干/基质细胞（eMSCs）在三维（3D）细胞结构（球体）形成过程中离子稳态的变化，并研究了3D eMSCs中诱导细胞凋亡的条件。从单层培养中分离出来的（二维）eMSCs积累了钠离子并消耗了跨膜离子梯度，而在紧密球体中，eMSCs恢复了功能活跃细胞所特有的较低钠离子含量和高钾/钠比。组织成球体的eMSCs是不增殖的细胞，具有活跃的钠钾泵，每克细胞蛋白的钾含量较低，这是静止细胞的典型特征，且3D eMSCs中的平均含水量较低（水合作用较低）。此外，球体中的eMSCs被用于评估钾离子耗竭和细胞信号环境在细胞凋亡诱导中的作用。在二维和三维eMSCs中，用哇巴因（1微摩尔）处理都会导致泵介导的钾离子摄取受到抑制、严重的钾离子耗竭以及线粒体膜电位的破坏。在3D eMSCs（但不在2D eMSCs）中，哇巴因通过线粒体途径引发细胞凋亡。得出的结论是，当阻断钠钾泵时，强心苷会使线粒体易于发生凋亡，并且细胞是否进入凋亡途径取决于细胞特异性信号环境，其中包括所表达的凋亡蛋白的类型。
