Evidence for autocrine or paracrine roles of alpha2-macroglobulin in regulation of estradiol production by granulosa cells and development of dominant follicles
| Autor: | James J. Ireland, David S. Burns, M. E. Winn, Fermin Jimenez-Krassel, J.L.H. Ireland |
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| Rok vydání: | 2004 |
| Předmět: |
Ovulation
endocrine system medicine.medical_specialty medicine.drug_class Granulosa cell Alpha (ethology) Biology Paracrine signalling Endocrinology Ovarian Follicle Internal medicine Follicular phase Paracrine Communication medicine Animals alpha-Macroglobulins Ovarian follicle Autocrine signalling Cells Cultured Granulosa Cells Estradiol Autocrine Communication medicine.anatomical_structure Estrogen Cattle Female Folliculogenesis Low Density Lipoprotein Receptor-Related Protein-1 |
| Zdroj: | Endocrinology. 145(6) |
| ISSN: | 0013-7227 |
| Popis: | alpha(2)-Macroglobulin (alpha(2)-M) inhibits proteinases and modulates the actions of growth factors and cytokines. Despite the key roles proteinases, growth factors, and cytokines have in folliculogenesis, the role of alpha(2)-M in follicular development is unknown. Our objectives were to: 1) determine whether granulosa cells produce alpha(2)-M and have alpha(2)-M receptors, 2) examine the effect of alpha(2)-M on estradiol production by granulosa cells, 3) establish whether amounts of alpha(2)-M and alpha(2)-M receptors were altered during dominant nonovulatory follicle development, and 4) examine alpha(2)-M's mechanism of action. The results demonstrated that bovine granulosa cells contain 5.2- and 15-kb mRNAs and 720- and 500-kDa proteins that correspond, respectively, to sizes of mRNAs and proteins for alpha(2)-M and the alpha(2)-M receptor. Treatment of granulosa cells with alpha(2)-M resulted in a specific dose-responsive increase in estradiol production. Cell viability, cell number, and the amount of aromatase in granulosa cells were not altered by alpha(2)-M. Treatment of granulosa cells with factors that bind alpha(2)-M or its receptor did not mimic alpha(2)-M action. Although intrafollicular amounts of alpha(2)-M remained unchanged, amounts of alpha(2)-M receptor in granulosa cells were strongly inversely associated with concentrations of estradiol in dominant and subordinate follicles. Based on these results, we concluded that alpha(2)-M may have autocrine or paracrine roles in granulosa cells potentially important for regulation of estradiol production and development of dominant follicles. |
| Databáze: | OpenAIRE |
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