Matrix Metallopeptidase 9 Promotes Contraction in Human Uterine Myometrium

Figures

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  Fig. 1. MMP9 enhances oxytocin-induced contractions in ex vivo human uterine smooth muscle. A Human term non-laboring myometrial strips were stimulated with oxytocin (OT) and baseline contractions (g force) were recorded. MMP9 was added to 1 µg/mL (~ 10 nM). Control strips were treated with vehicle. B Addition of MMP9 increased the area under the curve by 18% compared to an average decrease of 12% in vehicle-treated tissue (***p = 0.0003). C Contraction amplitude not significantly different after MMP9 treatment compared to vehicle treatment; however, (D) the median interval was shorter after addition of MMP9 (73% of baseline). In comparison, the median interval increased in vehicle-treated tissues (138% of baseline, **** p < 0.0001). Data points represent average measurements from tissue samples (n = 3 strips per participant × 6 participants = 18 samples per group)

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  Fig. 2. Specific inhibition of MMP9 reduces oxytocin-induced contractions in human uterine smooth muscle. A Term non-laboring human myometrial strips were stimulated with oxytocin (OT) and baseline contractions recorded. The MMP9-specific inhibitor AG-L-66085 was added to 1 µM, followed by washout to remove drug effects. Control strips were treated with vehicle only. B AG-L-66085 reduced the area under the curve (AUC) by 47% over 15 min compared to 27% in vehicle-treated tissue (****p < 0.0001). C Contraction amplitude was reduced by 14% after AG-L-66085 treatment compared to 3.4% after vehicle treatment (**p < 0.0068). D MMP9 inhibition did not impact contraction interval. Data points represent average measurements from tissue samples (n = 2–4 tissue strips per participant × 9 participants = 23 samples per group)

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  Fig. 3. Specific inhibition of MMP9 reduces spontaneous contractions in human uterine smooth muscle. Term non-laboring human myometrial strips were primed with 60 mM KCl for 3 min, followed by washout (W). Baseline spontaneous contractions were recorded for at least 30 min before addition of 1 μM AG-L-66085, control strips were treated with vehicle only. Contractions were recorded for an additional 60 min before washout. A Two tissue samples responded to AG-L-66085 with an almost complete loss of contractions. B Six tissue samples showed less response to the inhibitor. C MMP9 inhibition reduced the area under the curve (AUC) by 24% over 60 min compared to 9% in vehicle-treated tissue (*p = 0.0415). E Amplitude was reduced after AG-L-66085 addition (*p = 0.0354), while the interval was unchanged (D) in the six tissue samples for which these measurements could be determined. Data points represent average measurements from tissue samples (n = 2–4 tissue strips per participant × 8 participants = 24 samples per treatment group)

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  Fig. 4. AG-L-66085 reduces spontaneous contractions in a dose-dependent manner. Term non-laboring human myometrial strips were primed with 60 mM potassium chloride (KCl) for 3 min, followed by washout. Baseline spontaneous contractions were recorded for at least 30 min. AG-L-66085 was added to 333 nM, 1 µM, and 3.3 µM for 30 min at each concentration. Control tissue strips were treated with the corresponding vehicle dilution at each dose time point. Contractions were recorded for an additional 30 min before washout. Percent inhibition was calculated by determining the change in response to AG-L-66085 minus any change in response to vehicle. AG-L-66085 inhibited contractions as measured by area under the curve, amplitude, and interval in a dose dependent manner. n = 3 tissue strips per participant × 4 participants = 12 samples per treatment group