Estrogen induces distinct patterns of microRNA expression within the mouse uterus

Abstract

Control of estrogenic activity within the uterus is evident as unopposed estrogen action is associated with endometrial pathologies such as endometriosis and endometrial carcinoma. MicroRNAs (miRNAs) have emerged as important posttranscriptional regulators, which are postulated to fine-tune the actions of steroids in many systems including the uterus. The objective of the current study was to examine uterine expression of miRNAs in response to estrogen treatment within the mouse uterus using an ovariectomized, steroid-reconstituted mouse model. MicroRNA microarray analysis and subsequent quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) verification revealed that expression of mirn155, mirn429, and mirn451 was significantly increased by estrogen administration whereas mirn181b and mirn204 expression was significantly reduced. Pretreatment with the estrogen receptor (ER) antagonist ICI 182,780 confirmed that estrogen regulation was mediated via the classical ER pathway. This study demonstrates that estrogen regulates specific miRNAs within the murine uterus, which may participate in posttranscriptional regulation of estrogen-regulated genes.

Figure 1. Estrogen regulation of uterine mirn429

(A) Uterine mirn429 expression was quantitated by qRT-PCR as described in “Materials and Methods” after estrogen administration to ovariectomized mice. (B). Specificity of estrogen modulation was confirmed using the estrogen receptor antagonist, 182,780 ICI (ICI). Data were normalized to the level of U6 expression and are expressed as the fold change from 0h (A) or vehicle (Veh; B) ± SD. Data are representative of 4 to 5 data points/time point or treatment group (N≥4). Different letters indicate statistical significance among the means as determined by one-way ANOVA. Significance was set at P<0.05 for all analysis.

Figure 2. Estrogen regulation of uterine mirn155

A) Uterine mirn155 expression was quantitated by qRT-PCR as described in “Materials and Methods” after estrogen administration to ovariectomized mice. (B). Specificity of estrogen modulation was confirmed using the estrogen receptor antagonist, 182,780 ICI (ICI). Data were normalized to the level of U6 expression and are expressed as the fold change from 0h (A) or vehicle (Veh; B) ± SD. Data are representative of 4 to 5 data points/time point or treatment group (N≥4). Different letters indicate statistical significance among the means as determined by one-way ANOVA. Significance was set at P<0.05 for all analysis.

Figure 3. Estrogen regulation of uterine mirn451

A) Uterine mirn451 expression was quantitated by qRT-PCR as described in “Materials and Methods” after estrogen administration to ovariectomized mice. (B). Specificity of estrogen modulation was confirmed using the estrogen receptor antagonist, 182,780 ICI (ICI). Data were normalized to the level of U6 expression and are expressed as the fold change from 0h (A) or vehicle (Veh; B) ± SD. Data are representative of 4 to 5 data points/time point or treatment group (N≥4). Different letters indicate statistical significance among the means as determined by one-way ANOVA. Significance was set at P<0.05 for all analysis.

Figure 4. Estrogen regulation of uterine mirn181b

A) Uterine mirn181b expression was quantitated by qRT-PCR as described in “Materials and Methods” after estrogen administration to ovariectomized mice. (B). Specificity of estrogen modulation was confirmed using the estrogen receptor antagonist, 182,780 ICI (ICI). Data were normalized to the level of U6 expression and are expressed as the fold change from 0h (A) or vehicle (Veh; B) ± SD. Data are representative of 4 to 5 data points/time point or treatment group (N≥4). Different letters indicate statistical significance among the means as determined by one-way ANOVA. Significance was set at P<0.05 for all analysis.

Figure 5. Estrogen regulation of uterine mirn204

A) Uterine mirn204 expression was quantitated by qRT-PCR as described in “Materials and Methods” after estrogen administration to ovariectomized mice. (B). Specificity of estrogen modulation was confirmed using the estrogen receptor antagonist, 182,780 ICI (ICI). Data were normalized to the level of U6 expression and are expressed as the fold change from 0h (A) or vehicle (Veh; B) ± SD. Data are representative of 4 to 5 data points/time point or treatment group (N≥4). Different letters indicate statistical significance among the means as determined by one-way ANOVA. Significance was set at P<0.05 for all analysis.