ABSTRACT
Objective To investigate the effect of epidermal growth factor (EGF) on the expression of Matrix metalloproteinase-9 (MMP-9) and the signalling pathways involved in the trophoblast cell line JEG-3. Methods The JEG-3 trophoblast cell line was used in this study. (1) JEG-3 cells were cultured with various concentrations of EGF (0, 1, 10,20 ng/ml) for 24 hours and the expression of MMP-9 was tested by western blotting and reverse transcription PCR (RT-PCR). (2) Western blotting and RT-PCR were also used to investigate the expression of MMP-9 expression after incubation for 0,4,12 and 24 hours with EGF treatment (10 ng/ml) in JEG-3 cells. (3) According to the different added ingredients, JEG-3 cells were divided into some groups: control group (without EGF), EGF group (exposure to l0ng/ml EGF),EGF + inhibitors group (exposure to 10 ng/ml EGF +20 ng/ml SB203580 or exposure to 10 ng/ml EGF + 10ng/ml U0126) inhibitors group (exposure to 20 ng/ml SB203580 or exposure to 10 ng/ml U0126). Western blotting were used to investigate the expression levels of MMP-9, nuclear factor kappa B (NF-kB) ,p38MAPK, phospho-p38MAPK (p-p38MAPK) , extracellular -signal regulated kinase (ERK) and phospho-ERK (p-ERK) protein in JEG-3 cells after incubation for 24 hours. Results (1) The profiles of MMP-9mRNA were increased by various concentrations of EGF (0, 1 , 10, 20 ng/ml) in JEG-3 cells after 24hculture. The expression of MMP-9 mRNA in JEG-3 cells exposure at 1 ng/ml of EGF (0. 567 ±0. 056) , 10ng/ml of EGF (1. 392 ±0. 133) , 20 ng/ml of EGF (1. 971 ±0. 067) were significantly higher respectively (P <0. 05) , compared with 0 ng/ml of EGF treatment (0. 166 ±0. 015). Similarly, MMP-9 mRNAs were also increased with the increasing incubation time. Compared to EGF (10 ng/ml) stimulation for 0 h (0.253 ±0.044), the MMP-9 mRNA profiles were 0. 470 ±0. 026, 1.061 ±0. 115, 1. 453 ±0. 180 for 4,12 and 24 hours, respectively (P < 0. 05). (2) In accordance to the mRNA profiles, the expression of MMP-9 protein was also increased by different concentrations of EGF (0,1, 10, 20 ng/ml) in JEG-3 cells after 24 h-culture. The abundance of MMP-9 protein in the three groups was 0. 043 ±0. 012, 0. 085 ±0. 008, 0. 142 ±0. 015, with a significantly higher expression, compared with 0 ng/ml of EGF treatment (0. 004 ±0.001, P < 0.05) respectively. Similarly, MMP-9 proteins were also increased with the increasing incubation time. Compared to EGF(10 ng/ml) stimulation for 0 h (0. 030 ±0. 009) , the profiles of MMP-9 protein were 0. 137 ± 0. 010, 0. 240 ± 0. 010, 1.240 ±0.061 for 4, 12 and 24 hours, respectively (P < 0.05). (3) Both p38MAPK and ERK signalling pathways were activated by EGF in JEG-3 cells. The expression of p-p38MAPK was significantly higher (without or with 10 ng/ml EGF, 234. 1 ± 4. 1 vs.260. 9 ± 2. 5 , P < 0. 05) , however, the p38 MAPK inhibitor SB203580 markedly suppressed the increase in p-p38MAPK content induced by EGF(227. 9 ±2. 4 vs. 260. 9 ±2. 5, P<0. 05). Similarly, the expression of p-ERK was significantly higher with EGF treatment (812. 2 ±3. 5) vs. without EGF group (453.4±5.8) (P <0. 05) , while the ERK inhibitor U0126 significantly inhibited the increased p-ERK content in response to EGF treatment (71. 0 ± 1. 2 vs. 812. 2 ± 3. 5, P < 0. 05) . (4) The p38MAPK inhibitor SB203580 significantly reduced the expression of EGF-induced MMP-9 (0. 645 ± 0. 270 vs. 1. 476 ± 0. 452, P < 0. 05)and NF-kB (0.530 ± 0.026 vs. 0.959 ± 0. 017, P < 0. 05) . (5) The ERK inhibitor U0126 also significantly reduced the expression of EGF-induced MMP-9 (0. 623 ±0. 030 vs. 2. 112 ±0. 056, P <0. 05)and NF-kB (0. 325 ± 0. 082 vs. 0. 939 ± 0. 153, P < 0. 05). Conclusion EGF induced the expression of MMP-9 in a time and dose-dependant manner in JEG-3 cells. EGF enhanced MMP-9 expression through the activation of p38MAPK and ERK signalling pathways in JEG-3 cells.
ABSTRACT
OBJECTIVE: The progesterone receptor (PR)-A/B ratio in the myometrium is reported to be closely related to labor onset. This might represent a potential target for therapeutic interventions for postterm and preterm deliveries, though the mechanisms currently remain unknown. The aim of this study was to investigate the regulation mechanism of PR-A and B expression in human preterm, term, and postterm placental villi. DESIGN: Experimental study. SETTING: People's Hospital of Jiangsu Province, China. POPULATION: Singleton women of preterm (PRNIL, not in labor, n = 10), term (TNIL, not in labor, n = 10; TIL, in labor, n = 10), and postterm (PONIL, not in labor, n = 10) cesarean deliveries. METHODS: The PR-A/PR-B mRNA and protein ratios were analyzed using real-time reverse transcription-polymerase chain reaction and western blots in villi from preterm, term, postterm groups. PONIL and PRNIL villi were incubated with prostaglandin F(2alpha) (PG) and indomethacin for 72 hours, respectively, and the PR-A/PR-B mRNA and protein ratios and p38 signaling pathway were explored. RESULTS: The PR-A/PR-B ratio was highest in TIL, followed by PRNIL, PONIL and TNIL. Indomethacin significantly up-regulated PR-B expression, thereby decreasing the PR-A/PR-B ratio (p < 0.05). Meanwhile, PG reduced the expression of PR-B and increased PR-A, leading to a significant increase in the PR-A/PR-B ratio (p < 0.05). We also determined that the PR-A/PR-B ratio was mediated through the activation of p38 mitogen-activated protein kinase. CONCLUSION: These results demonstrate that the PR-A/PR-B ratio plays a key role in the mechanisms regulating preterm, term, and postterm deliveries.
