Fig. 7

Role of CCL20 in the onset of labor. A, B Increased CCL20 mRNA (A) and protein (B) in the human amnion in TL_P group. *P < 0.05; **P < 0.01. Unpaired Student’s t-test was used to assess the difference between TNL_P and TL_P, and paired Student’s t-test was used to assess the difference between TL_P and TL_D. TNL_P, term non-labor-proximal; TL_P, term labor-proximal (ZAM zone); TL_D, term labor-distal (non-ZAM zone). C Intraperitoneal injection of CCL20 (10 μg/kg BW) into pregnant mice on dpc 17 induced preterm birth. **P < 0.01. Data was analyzed with unpaired Student’s t-test. D–I Immunohistochemical staining of CD45 positive cells in uterus (D and E), placenta (F and G), decidua (F and G) and fetal membranes (H and I) obtained from the mice with CCL20 or vehicle administration. Negative control was shown in Additional file 1: Fig. S6