Mitochondrial transcription factor A (TFAM) was knocked down in HTR-8/SVneo cells

Compared with the blank control group, TFAM mRNA levels in the negative control group showed no statistical difference (P = 0.467), but were significantly decreased in siTFAM #1, #2 and #3 (P < 0.001). Furthermore, TFAM protein expression decreased after transfection of siTFAM #1 (B).

Moreover, ND-1/β2M and COX-3/β2M in the siTFAM group were significantly lower than those in the negative control group (P = 0.001; P < 0.001), indicating that the mtDNA copy number of trophoblast cells was significantly decreased (C, D). *P< 0.05; **P< 0.01; ***P< 0.001.