RESUMEN
CONTEXT: Endometrial breakdown during menstruation and dysfunctional bleeding is triggered by the abrupt expression of matrix metalloproteinases (MMPs), including interstitial collagenase (MMP-1). The paracrine induction of MMP-1 in stromal cells via epithelium-derived IL-1alpha is repressed by ovarian steroids. However, the control by estradiol (E) and progesterone (P) of endometrial IL-1alpha expression and bioactivity remains unknown. OBJECTIVE AND DESIGN: Variations of endometrial IL-1alpha mRNA and protein along the menstrual cycle and during dysfunctional bleeding were determined using RT-PCR, in situ hybridization, and immunolabeling. The mechanism of EP control was analyzed using culture of explants, laser capture microdissection, and purified cells. Data were compared with expression changes of IL-1beta and IL-1 receptor antagonist. RESULTS: IL-1alpha is synthesized by epithelial cells throughout the cycle but E and/or P prevents its release. In contrast, endometrial stromal cells produce IL-1alpha only at menses and during irregular bleeding in areas of tissue breakdown. Stromal expression of IL-1alpha, like that of MMP-1, is repressed by P (alone or with E) but triggered by epithelium-derived IL-1alpha released upon EP withdrawal. CONCLUSIONS: Our experiments in cultured endometrium suggest that IL-1alpha released by epithelial cells triggers the production of IL-1alpha by stromal cells in a paracrine amplification loop to induce MMP-1 expression during menstruation and dysfunctional bleeding. All three steps of this amplification cascade are repressed by EP.
Asunto(s)
Endometrio/metabolismo , Epitelio/efectos de los fármacos , Hormonas Esteroides Gonadales/farmacología , Interleucina-1alfa/metabolismo , Menstruación/metabolismo , Metrorragia/metabolismo , Células del Estroma/metabolismo , Células Cultivadas , Endometrio/efectos de los fármacos , Epitelio/metabolismo , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Proteína Antagonista del Receptor de Interleucina 1/análisis , Proteína Antagonista del Receptor de Interleucina 1/genética , Proteína Antagonista del Receptor de Interleucina 1/metabolismo , Interleucina-1alfa/análisis , Interleucina-1alfa/genética , Interleucina-1beta/análisis , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Menstruación/genética , Metrorragia/genética , Modelos Biológicos , Técnicas de Cultivo de Órganos , Ovario/metabolismo , Comunicación Paracrina/genética , Comunicación Paracrina/fisiología , ARN Mensajero/metabolismo , Células del Estroma/efectos de los fármacosRESUMEN
TGF-betas have been reported to mediate the repression by progesterone of several matrix metalloproteinases in the human endometrium, thereby preventing menstrual breakdown. Because of conflicting reports on the expression profiles, source, and regulation of the TGF-beta system in this tissue, we investigated by real-time RT-PCR and ELISA the expression of the three TGF-betas (total and mature forms) and their two receptors throughout the menstrual cycle, and their regulation by ovarian steroids in cultured explants including their microdissected epithelial and stromal compartments. Regulation by cAMP and MAPK was further investigated. This comprehensive study on a large collection of endometrial samples evidenced a differential regulation of TGF-beta isoforms expression, both in vivo and in explant culture. In vivo, TGF-beta2 increased by about 5-fold at the mid-late secretory phase then declined after menstruation; TGF-beta3 increased at menstruation and remained high during the proliferative phase; TGF-beta1 was maximal at menstruation. In explants cultured without ovarian steroids both TGF-beta2 and -beta3 were preferentially expressed in the stroma. Ovarian steroids strongly repressed both TGF-beta2 and -beta3 in stroma but only TGF-beta2 in glands. cAMP prevented inhibition by ovarian steroids of TGF-beta2 but not -beta3. In presence of ovarian steroids, MAPK inhibitors (p38 and ERK pathways) stimulated TGF-beta3 but inhibited TGF-beta2 expression. In conclusion, TGF-beta2 and -beta3 are differentially expressed during the menstrual cycle and regulated by progesterone in epithelial vs stromal cells. The opposite regulation of TGF-beta2 and -beta3 by cAMP and MAPK could account for their distinct expression in vivo.
Asunto(s)
Endometrio/metabolismo , Ciclo Menstrual/metabolismo , Factor de Crecimiento Transformador beta2/metabolismo , Factor de Crecimiento Transformador beta3/metabolismo , Adulto , Células Cultivadas , AMP Cíclico/metabolismo , AMP Cíclico/farmacología , Endometrio/efectos de los fármacos , Endometrio/patología , Células Epiteliales/metabolismo , Células Epiteliales/patología , Estradiol/fisiología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Humanos , Persona de Mediana Edad , Progesterona/fisiología , ARN Mensajero/metabolismo , Transducción de Señal/fisiología , Células del Estroma/metabolismo , Células del Estroma/patología , Tretinoina/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
CONTEXT: Cyclic remodeling and breakdown of the extracellular matrix, a unique feature of the human endometrium, depends on matrix metalloproteinases (MMPs). These enzymes are globally controlled by estradiol and progesterone or their withdrawal, but various MMPs and their tissue inhibitors (TIMPs) show distinct responses. OBJECTIVE AND DESIGN: To clarify the role of ovarian steroids in the differential regulation of MMP-1, MMP-3, MMP-7, MMP-8, MMP-10, TIMP-1, TIMP-2, and TIMP-3 mRNAs, we compared their variations in the cycling endometrium in vivo with their response to hormone addition or withdrawal in corresponding explants. RESULTS: Different patterns were identified in vivo according to the time frame (secretory vs. perimenstrual increase), sharpness (peak vs. progressive increase or decrease), and magnitude of the changes. In vivo ratios between early/midsecretory and perimenstrual phases ranged from more than 1000 (MMP-1, MMP-3, and MMP-10) to less than 10 (TIMPs). Differential response to ovarian steroids of the various MMPs and TIMPs mRNAs tested in cultured explants matched the same ranking and varied according to the phase at sampling. Remarkably, ovarian steroids repressed MMPs and TIMP-1 and TIMP-2 but, in secretory explants, increased TIMP-3 mRNA. Finally, in situ hybridization evidenced the major contribution of fibroblasts to the increase in MMP-8 mRNA at menstruation or in explants cultured without hormones. CONCLUSIONS: Both phase- and gene-specific modulators finely tune in space, time, and amplitude the global control of MMPs and TIMPs mRNAs by estradiol and progesterone in the cycling human endometrium.