PARP1 and hydrops fetalis: Western blot assay results showed that the expression of γH2AX and that of both 67 and 57 kDa AIF in HF-MSCs increased with cell passaging (p < 0.05; Figures 1F,I,O); 3), and the expression of DNA repair-related proteins Ku70, Ku80, Rad 51, PAR, and 116 kDa PARP1 in HF-MSCs decreased with cell passaging (p < 0.05; Figures 1F,O,P).