RESUMO
Insulin-like growth factor 1 (IGF1) is involved in the proliferation of mouse and rat endometrial cells in a paracrine or autocrine manner. Insulin-like growth factor binding protein-3 (IGFBP3) modulates actions of IGFs directly or indirectly. The present study aimed to determine whether IGFBP3 is involved in the regulation of proliferation of mouse endometrial cells. Mouse endometrial epithelial cells and stromal cells were isolated, and cultured in a serum free medium. IGF1 stimulated DNA synthesis by endometrial epithelial and stromal cells, and IGFBP3 inhibited IGF1-induced DNA synthesis. Estradiol-17beta (E2) decreased the Igfbp3 mRNA level in endometrial stromal cells, whereas it increased the Igf1 mRNA level. Transforming growth factor alpha (TGFalpha) significantly decreased IGFBP3 expression at both the mRNA and secreted protein levels in endometrial stromal cells. Progesterone (P4) did not affect the E2-induced down-regulation of Igfbp3 mRNA expression in endometrial stromal cells, although P4 alone increased Igfbp3 mRNA levels. The present findings suggest that in mouse endometrial stromal cells E2 enhances IGF1 action through enhancement of IGF1 synthesis and reduction of IGFBP3 synthesis, and that TGFalpha affects IGF1 actions through modulation of IGFBP3 levels.
Assuntos
Endométrio/metabolismo , Estradiol/farmacologia , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/biossíntese , Progesterona/farmacologia , Fator de Crescimento Transformador alfa/farmacologia , Animais , Western Blotting , DNA/biossíntese , Endométrio/citologia , Endométrio/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/antagonistas & inibidores , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Fator de Crescimento Insulin-Like I/biossíntese , Fator de Crescimento Insulin-Like I/genética , Camundongos , Camundongos Endogâmicos ICR , Quinazolinas , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptor IGF Tipo 1/biossíntese , Receptor IGF Tipo 1/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Fator de Crescimento Transformador alfa/antagonistas & inibidores , Tirfostinas/farmacologiaRESUMO
Interleukin-18 (IL-18) is a proinflammatory cytokine involved in chronic inflammation, autoimmune diseases, and a variety of cancers, and is expressed in mouse uteri. Our previous study suggested that IL-18 acts as a paracrine factor, regulating endometrial function. To elucidate the physiological roles of IL-18 in the mouse endometrium, the expression of the IL-18 receptor (IL-18R) alpha subunit was analyzed. IL-18Ralpha mRNA was expressed in several mouse organs in addition to the endometrium. In situ hybridization analysis using a biotin-labeled mouse IL-18Ralpha riboprobe demonstrated that IL-18Ralpha mRNA expression was detected in glandular epithelial cells, stromal cells around uterine glands, and myometrial cells in the mouse uterus, suggesting that these cells are targets for IL-18. The uterine IL-18Ralpha mRNA expression level changed with the estrous cycle. The uterine IL-18Ralpha mRNA levels of estrous mice were higher than those of diestrous mice. In addition, the IL-18Ralpha mRNA levels in uteri at 3 and 14 days after ovariectomy were higher than those at diestrus and decreased following treatment with estradiol-17beta or progesterone. These findings suggest that IL-18Ralpha gene expression is regulated by estrogen and progesterone and that the uterine IL-18 system is involved in the regulation of uterine functions in a paracrine manner.
Assuntos
Endométrio/fisiologia , Subunidade alfa de Receptor de Interleucina-18/genética , Subunidade alfa de Receptor de Interleucina-18/metabolismo , Fatores Etários , Animais , Estradiol/farmacologia , Ciclo Estral/fisiologia , Feminino , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/fisiologia , Hibridização In Situ , Interleucina-18/genética , Interleucina-18/metabolismo , Subunidade beta de Receptor de Interleucina-18/genética , Subunidade beta de Receptor de Interleucina-18/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Ovariectomia , Comunicação Parácrina/fisiologia , Progesterona/farmacologia , RNA Mensageiro/metabolismo , RibonucleasesRESUMO
Interleukin-18 (IL-18) belongs to the interleukin-1 family and was identified as an interferon-gamma inducing factor. We investigated IL-18 mRNA-expressing cells in the mouse uterus. By RNase protection assay, IL-18 mRNA and alpha subunit of IL-18 receptor mRNA were detected in the uterus. In the uterus, IL-18 mRNA levels increased during sexual maturation. In situ hybridization analysis demonstrated IL-18 mRNA-expressing cells in the mouse uterus of different ages. At 21 days of age, IL-18 mRNA-expressing cells were detected in the luminal epithelial cells and stromal cells although the IL-18 mRNA signal was weak. At 42 days of age, IL-18 mRNA signal was mainly detected in the stromal cells located near the myometrium, and in some of the luminal and glandular epithelial cells. In the uterus of 63-day-old adult mice, a strong hybridization signal for IL-18 mRNA was detected at estrus, but was weak at diestrus. IL-18 mRNA was mainly detected in the glandular epithelial cells and stromal cells. The effect of estradiol-17beta (E(2)) on IL-18 mRNA-expressing cells in the uterus was examined in ovariectomized mice. In oil-treated mice IL-18 mRNA signal was localized in luminal epithelial cells and stromal cells, while in E(2)-treated mice IL-18 mRNA signal was localized in stromal cells alone. These results suggest that the mouse uterus has an IL-18 system, and IL-18 exerts a physiological role within the uterus in a paracrine manner, and that IL-18 gene expression is regulated by estrogen.