Reactive Oxygen Species Are Required for Human Mesenchymal Stem Cells to Initiate Proliferation after the Quiescence Exit

Figure 5

Tempol treatment blocks endometrial mesenchymal stem cells in the G₁ phase of the cell cycle. (a) Expression of Ki-67 protein in the serum-starved cells; (b) expression of Ki-67 protein in the cells treated with Tempol (1 mM) immediately after activation of the cell proliferation; cells were fixed and treated with Ki-67 antibodies 16 h after activation; (c) expression of Ki-67 protein in the control cells.  h: the moment of the activation of the cell proliferation.