ABSTRACT
Fatores produzidos no ovário como os membros da família dos fatores de crescimento transformantes beta (TGFβ) e seus receptores, são essenciais durante o desenvolvimento folicular. Membros desta superfamília desempenham papel chave na fertilidade e diferenças espécie-específicas na regulação desses fatores têm sido descritas, envolvendo as funções ovarianas em condições fisiológicas ou patológicas. A proteína morfogenética óssea 15 (BMP15) e o fator de crescimento e diferenciação 9 (GDF9) destacam-se, pois desempenham papéis importantes na regulação do crescimento e da diferenciação folicular. Ainda, há evidências de que outras BMPs, ativinas, inibinas e seus receptores também possam estar envolvidos no controle da foliculogênese, ovulação/luteinização e luteólise. A maioria dos dados demostram que os TGFs atuam regulando negativamente a síntese de progesterona, o que sugere envolvimento na inibição da luteinização e promoção da luteólise. O avanço no entendimento das funções destes fatores locais poderá possibilitar o desenvolvimento tanto de novas estratégias contraceptivas, como também para controle do ciclo estral ou menstrual.
Factors produced in the ovary, such as transforming growth factors beta members (TGFβ) and their receptors, play a key role during follicular development. Members from this family have an important role in female fertility and species-specific differences in their regulation have been described, being involved in ovarian function regulation under both physiological and pathological conditions. Bone morphogenetic protein 15 (BMP15) and growth and differentiation factor 9 (GDF9) are the most studied factors due to their involvement in the regulation of follicular development and differentiation. Besides BMP15 and GDF9, other BMPs, activins, inhibins and their receptors may be involved in the control of folliculogenesis, ovulation/luteinization and luteolysis. Most studies demonstrate that TGFβ members negatively regulate progesterone synthesis, suggesting an involvement in luteolysis. The advance in the knowledge of the function of these local factors may allow the development of new contraceptive strategies as well as new approaches to control the estrous or menstrual cycle.
Subject(s)
Female , Animals , Transforming Growth Factors/analysis , Transforming Growth Factors/biosynthesis , Luteinization , LuteolysisABSTRACT
Fatores produzidos no ovário como os membros da família dos fatores de crescimento transformantes beta (TGFβ) e seus receptores, são essenciais durante o desenvolvimento folicular. Membros desta superfamília desempenham papel chave na fertilidade e diferenças espécie-específicas na regulação desses fatores têm sido descritas, envolvendo as funções ovarianas em condições fisiológicas ou patológicas. A proteína morfogenética óssea 15 (BMP15) e o fator de crescimento e diferenciação 9 (GDF9) destacam-se, pois desempenham papéis importantes na regulação do crescimento e da diferenciação folicular. Ainda, há evidências de que outras BMPs, ativinas, inibinas e seus receptores também possam estar envolvidos no controle da foliculogênese, ovulação/luteinização e luteólise. A maioria dos dados demostram que os TGFs atuam regulando negativamente a síntese de progesterona, o que sugere envolvimento na inibição da luteinização e promoção da luteólise. O avanço no entendimento das funções destes fatores locais poderá possibilitar o desenvolvimento tanto de novas estratégias contraceptivas, como também para controle do ciclo estral ou menstrual.(AU)
Factors produced in the ovary, such as transforming growth factors beta members (TGFβ) and their receptors, play a key role during follicular development. Members from this family have an important role in female fertility and species-specific differences in their regulation have been described, being involved in ovarian function regulation under both physiological and pathological conditions. Bone morphogenetic protein 15 (BMP15) and growth and differentiation factor 9 (GDF9) are the most studied factors due to their involvement in the regulation of follicular development and differentiation. Besides BMP15 and GDF9, other BMPs, activins, inhibins and their receptors may be involved in the control of folliculogenesis, ovulation/luteinization and luteolysis. Most studies demonstrate that TGFβ members negatively regulate progesterone synthesis, suggesting an involvement in luteolysis. The advance in the knowledge of the function of these local factors may allow the development of new contraceptive strategies as well as new approaches to control the estrous or menstrual cycle.(AU)
Subject(s)
Animals , Female , Luteinization , Luteolysis , Transforming Growth Factors/analysis , Transforming Growth Factors/biosynthesisABSTRACT
Mutations in growth and differentiation factor9 (GDF9) gene are associated to sterility or,paradoxically, increased ovulation rate in ewes. Despiteits importance, the exact function of GDF9 in ovarianphysiology is still poorly understood. This study aimedto investigate GDF9 function during dominant folliclegrowth and its regulation in follicular fluid. Theregulation of GDF9 receptors in GnRH/LH-stimulatedgranulosa cells was also investigated. In a firstexperiment, a new follicular wave was induced and theintrafollicular GDF9 treatment into the largest growingfollicle (8.5-9.5 mm) at both 100 (n = 3) and 1000ng/ml(n = 4) had no effect on follicular growth, estrusmanifestation and ovulation compared to control (PBSinjected)follicles (n = 3). In a second experiment,follicles were obtained just after follicular deviation(day 4 after follicular emergence) and the abundance ofGDF9 in follicular fluid did not differ between healthydominant (n = 4) and atretic subordinate follicles (n =4), as assessed by western blot analysis. Finally, mRNAexpression of BMPR2 and TGFBR1 receptors wasevaluated in granulosa cells obtained from preovulatoryfollicles (>12 mm diameter) obtained 0, 3, 6, 12 or 24 hafter i.m. GnRH administration (n = 4-5follicles/moment). Both receptors were significantly upregulated 12 h after GnRH treatment. Present results donot confirm the hypothesis that GDF9 inhibits dominantfollicle growth and suggests a minor role in determiningfollicle fate. In the other hand, GDF9 receptorsregulation in GnRH/LH-stimulated granulosa cellsprovides the first in vivo evidence of its involvement inthe complex cascade of events that culminates inovulation and luteinization in cattle.(AU)
Subject(s)
Animals , Female , Cattle , Cattle/growth & development , Cattle/physiology , Follicular Phase , Ovulation , Oocytes , InfertilityABSTRACT
Mutations in growth and differentiation factor9 (GDF9) gene are associated to sterility or,paradoxically, increased ovulation rate in ewes. Despiteits importance, the exact function of GDF9 in ovarianphysiology is still poorly understood. This study aimedto investigate GDF9 function during dominant folliclegrowth and its regulation in follicular fluid. Theregulation of GDF9 receptors in GnRH/LH-stimulatedgranulosa cells was also investigated. In a firstexperiment, a new follicular wave was induced and theintrafollicular GDF9 treatment into the largest growingfollicle (8.5-9.5 mm) at both 100 (n = 3) and 1000ng/ml(n = 4) had no effect on follicular growth, estrusmanifestation and ovulation compared to control (PBSinjected)follicles (n = 3). In a second experiment,follicles were obtained just after follicular deviation(day 4 after follicular emergence) and the abundance ofGDF9 in follicular fluid did not differ between healthydominant (n = 4) and atretic subordinate follicles (n =4), as assessed by western blot analysis. Finally, mRNAexpression of BMPR2 and TGFBR1 receptors wasevaluated in granulosa cells obtained from preovulatoryfollicles (>12 mm diameter) obtained 0, 3, 6, 12 or 24 hafter i.m. GnRH administration (n = 4-5follicles/moment). Both receptors were significantly upregulated 12 h after GnRH treatment. Present results donot confirm the hypothesis that GDF9 inhibits dominantfollicle growth and suggests a minor role in determiningfollicle fate. In the other hand, GDF9 receptorsregulation in GnRH/LH-stimulated granulosa cellsprovides the first in vivo evidence of its involvement inthe complex cascade of events that culminates inovulation and luteinization in cattle.