Local regulation of antral follicle development and ovulation in monovulatory species

The identification of mutations in the genes encoding bone morphogenetic protein 15 (BMP15) and growth and differentiation factor 9 (GDF9) associated with phenotypes of sterility or increased ovulation rate in sheep aroused interest in the study of the role of local factors in preantral and antral folliculogenesis in different species. An additive mutation in the BMP15 receptor, BMPR1b, which determines an increase in the ovulatory rate, has been introduced in several sheep breeds to increase the number of lambs born. Although these mutations indicate extremely relevant functions of these factors, the literature data on the regulation of the expression and function of these proteins and their receptors are very controversial, possibly due to differences in experimental models. The present review discusses the published data and preliminary results obtained by our group on the participation of local factors in the selection of the dominant follicle, ovulation, and follicular atresia in cattle, focusing on transforming growth factors beta and their receptors. The study of the expression pattern and the functionality of proteins produced by follicular cells and their receptors will allow increasing the knowledge about this local system, known to be involved in ovarian physiopathology and with the potential to promote contraception or increase the ovulation rate in mammals.(AU)

Polysaccharides from aloe vera target the Wnt/ß-catenin pathway to impact the tooth density of pulpitis rats

Purpose: To investigate the mechanism of polysaccharides from aloe vera (PAV), a main active ingredient of Aloe vera, treatment in pulpitis rats. Methods: Pulpitis were modeled by drilling the occlusal central fossa with Sprague Dawley rats. Next, the rats were treated with 20, 40, and 80 mg/kg PAV for three weeks, respectively. Computed tomography scanning assay, hematoxylin and eosin staining, and tartrate-resistant acid phosphatase staining were used to detect the pathology change. Then, levels of tumor necrosis factor-α, interleukin-1ß, prostaglandin E2, and ciclooxigenase 2 were detected by enzyme-linked immunosorbent assay. The expressions of bone morphogenetic protein 2 human (BMP-2), osteocalcin, osterix, and runt-related transcription factor 2 (Runx2) were quantified by quantitative real-time polymerase chain reaction and Western blotting (WB). Finally, Wnt3a expression, p-GSK3ß/GSK3ß and p-ß-catenin/ß-catenin ratio were analyzed by WB. Results: PAV up regulated the bone mineral density, and reduced the breakage of the crown and cervical structures, and the necrosis of the crown and root pulp of pulpitis rats. In addition, results indicated that PAV could inhibit osteoblast formation. While osteoblasts' number was decreased, proteins of BMP-2, osteocalcin, osterix, and Runx2 were up-regulated by PAV. Furthermore, PAV increased the Wnt3a expression and the p-ß-catenin/ß-catenin ratio, and decreased p-GSK3ß/GSK3ß ratio. Interestingly, these effects were all in dose dependence. Conclusions: PAV could inhibit pulp inflammation and promote osteoblasts differentiation via suppressing the activation of the Wnt/ß-catenin signaling, enhancing the dental bone density.

Detection of SNPs in the BMP6 Gene and Their Association with Carcass and Bone Traits in Chicken

BMP6, a member of the subfamilies of the morphogenetic proteins (BMPs), plays a crucial role in osteogenic and chondrocyte differentiation in vitro and stimulates chondrogenesis, making chondrocytes differen-tiate on their terminal stage. The objective of this study is to explore the relationship between polymorphism of BMP6 gene and slaughter traits in chicken respectively. We screened the exonic and intronic regions of BMP6 gene by DNA pool construction and amplified DNA fragment by PCR, and finally, we got nine SNPs. Association analysis revealed that BMP6 had no significant association among all slaughter traits in Yellow bantam chicken. However, BMP6 had a significant difference with femur weight, tibia weight, femur length (p 0.05), and was extremely significant with tibia length (p 0.01) in Avian chicken. Moreover, femur perimeter also had significant correlation with BMP6 in Avian chicken. These results provide useful information for further investigation on the function of chicken BMP6 gene.(AU)

Detection of SNPs in the BMP6 Gene and Their Association with Carcass and Bone Traits in Chicken

BMP6, a member of the subfamilies of the morphogenetic proteins (BMPs), plays a crucial role in osteogenic and chondrocyte differentiation in vitro and stimulates chondrogenesis, making chondrocytes differen-tiate on their terminal stage. The objective of this study is to explore the relationship between polymorphism of BMP6 gene and slaughter traits in chicken respectively. We screened the exonic and intronic regions of BMP6 gene by DNA pool construction and amplified DNA fragment by PCR, and finally, we got nine SNPs. Association analysis revealed that BMP6 had no significant association among all slaughter traits in Yellow bantam chicken. However, BMP6 had a significant difference with femur weight, tibia weight, femur length (p 0.05), and was extremely significant with tibia length (p 0.01) in Avian chicken. Moreover, femur perimeter also had significant correlation with BMP6 in Avian chicken. These results provide useful information for further investigation on the function of chicken BMP6 gene.

O desenvolvimento embrionário da Piapara, Leporinus elongatus (Pisces, Anostomidae), utilizando técnicas de histologia, microscopia eletrônica de varredura e imunológicas empregando marcadores ósseos / The embryonic development of Piapara, Leporinus elongatus (Pisces, Anostomidae), using histological techniques, electron microscopy and immunological techniques using bone markers

O desenvolvimento embrionário dos peixes é de grande importância para a piscicultura e na reintrodução de espécies ameaçadas de extinção em seus ambientes, e seu conhecimento constitui uma importante maneira para minimizar doenças e mortalidades dessas espécies. Com o auxílio de técnicas como a Microscopia Eletrônica de Varredura (MEV) e a imuno-histoquimica para identificar proteínas ósseas, foi possível avaliar as fases de desenvolvimento com mais riqueza de detalhes, facilitando a compreensão de hábitos e da biologia da espécie. Neste trabalho pudemos observar a ontogenia e osteogênese da Piapara (Leporinus elongatus), desde a fecundação até a fase juvenil, sendo evidenciadas estruturas importantes como o tamanho do vitelo, essencial para a nutrição do embrião; o fechamento do blastóporo, evento principal da embriogênese, que indica as taxas de fertilização; a metamorfose, que indica a formação dos primeiros e principais órgãos do animal e a formação de sua estrutura óssea. As Proteínas Ósseas Morfogenéticas (BMP-2 e BMP-4), moléculas essenciais reguladoras no desenvolvimento embrionário e na formação óssea, foram observadas apenas no estádio larval até o período juvenil, não sendo evidenciadas nos estágios anteriores. Os resultados desse trabalho trouxeram novas informações quanto à biologia do desenvolvimento dessa espécie, que certamente poderão auxiliar no aprimoramento de técnicas reprodutivas visando uma melhora na sua produção seja para fins comerciais ou de repovoamento.(AU)

The embryonic development of fishes has great importance in fish culture and on reintroduction of species at risk of extinction into their environment; its knowledge constitutes an important way to minimize diseases and mortality of these species. By using techniques like electron microscopy and immunohistochemistry for bone markers identification, it was possible to evaluate the developmental stages of Leporinus elongatus in more details, helping to clarify the habits and biology of this species. Results showed the ontogeny and ostheogenesis of of Leporinus elongatus this species from fecundation to juvenile, evidencing important structures as size of the yolk, essential to embryo nutrition, the blastopores closure, important event in embryogenesis because it indicates fertilization indexes, and the metamorphosis, which shows the main organs' development including bones. Bone morphogenetic markers 1 and 4, essential regulatory molecules for bone development, had their expression restricted from larva to fry stages, and were not observed in their previous stages. In sum, these results provided new data that may improve reproductive techniques for L. elongatus, and will support commercial and repopulation purposes.(AU)

The effect of simvastatin on the regeneration of surgical cavities in the femurs of rabbits

To evaluate the effect of a local application of simvastatin gel in repairing bone defects in the femurs of rabbits. METHODS: Two standard surgical cavities were created in the femoral epiphysis of 18 rabbits. In the simvastatin group (SG), the cavities were filled with a collagen sponge soaked in 0.5 ml of a simvastatin (1 mg) gel, and the cavities were covered with a biological membrane. The bone cavities in the second group (control group) were filled with a blood clot and covered with a biological membrane. On the 7th, 21st and 42nd days, six animals in each group were euthanized, and the femurs were subject to histological evaluation (vascularity, fibrosis, reactive bone formation, osteoblasts, and osteoclasts) and immunohistochemical (anti-VEGF and anti-osteocalcin) analysis. The results were analyzed using a Wilcoxon test (p<0.05). RESULTS: There were significant differences between the two groups: the SG had greater scores in comparison with the CG in terms of the degree of vascularity on the 7th and the 21st days, fibrosis on the 21st day, bone formation reaction on the 21st and the 42nd days and the number of osteoblasts and osteoclasts on the 42nd day. The immunohistochemical expression was also greater for osteocalcin and VEGF on the 7th, 21st and 42nd days. CONCLUSION: Surgical defects created in rabbit femurs were treated locally with simvastatin gel to stimulate bone repair, which promoted an ameliorative effect in the morphological and immunohistochemical markers of bone regeneration.(AU)

Hydrogel of polysaccharide of sugarcane molasses as carrier of bone morphogenetic protein in the reconstruction of critical bone defects in rats

PURPOSE: To evaluate the benefit of using carriers such as the biopolymer gel (hidrogel of polysaccharide of sugarcane molasses) associated with the bone morphogenetic proteins (BMP's) in the repair of critical bone defects in calvaria of Wistar rats. METHODS: Forty-two rats were submitted to a surgical calvaria bone defects. These animals were divided into two experimental groups, positive control group and negative control group. The Group I the calvaria defect was filled up with biopolymer gel, biological membrane, BMP and lyophilized graft. The Group II was treated with biopolymer gel, BMP and lyophilized graft. And the group III (positive control group) was treated with BMP, lyophilized graft and biological membrane. In the negative control group (Group IV) a defect was made in the rat calvaria and the animals were sacrificed immediately after the surgery. The animals of experimental groups and positive control group were slaughtered after subsequent periods of 90 and 180 days. In these periods, the histological analysis and image assessment by cone bean tomographic imaging were obtained. RESULTS: There was highest bone tissue formation with statistically significant results in the groups that associated biopolymer gel and membrane (Group I), followed by the group III (BMP, lyophilized graft and biological membrane). The lower bone formation occurred in the group not using the sugarcane biopolymer gel (Group II). The radiolucent areas of the analyzes of 180 days among the groups studied were respectively, 14.98 mm², 26.65 mm² and 35.81 mm². CONCLUSION: The biopolymer gel showed to be an excellent bone morphogenetic protein carrier, probably by facilitating the controlled release of these proteins in the process of bone repair.(AU)

Regulação da função ovariana: caracterização estrutural e papel do hormônio anti-mülleriano (AMH) / Regulation of Ovarian Function: Structural Characterization and Role of Anti-Müllerian Hormone (AMH)

Background: The anti-müllerian hormone (AMH) is a member of the transforming growth factor ß (TGF-ß) superfamily, which exerts important functions on local regulation of folliculogenesis. Although in vivo and in vitro studies suggest that AMH affects the primordial follicle assembly and activation, as well as the responsiveness of growing follicles to folliclestimulating hormone (FSH), the physiological mechanisms involved in these actions remain to be fully elucidated. Given the relevance of AMH in the folliculogenesis, this review aimed to describe the structural features, expression and the main biological effects of AMH on the follicular development. Review: Originally identified as a testicular product, AMH is responsible for regression of the Müllerian ducts during sexual differentiation of male embryos. In females, AMH is produced almost exclusively by granulosa cells of ovarian growing follicles, whose serum levels are positively related to the number of ovarian follicles, making AMH an excellent clinic marker of ovarian reserve. Along this work, it was shown aspects related to the structural characterization of AMH and its specific type II receptor (AMHRII). AMH is a glycoprotein dimer linked by disulfide bonds. The mature protein comprises two unequal domains: a long N-terminal domain (110-kDa) and a short C-terminal domain (25-kDa), responsible for the biological activity of the molecule. The AMHRII is an 82-kDa protein. Like others members of TGF-ß family, AMH signals through two types of serine/threonine kinase receptors called type I and type II, and two types of Smad proteins, receptor-regulated Smad (R-Smad) and common Smad, Smad4. However, the identity of the AMH type I receptor is not clear; three type I receptors of Bone Morphogenetic Proteins (BMPs), Alk2, Alk3 and Alk6 may transduce AMH signals. AMH expression was detected in granulosa cells of growing follicles and it decreases once FSH-dependent follicular growth has been initiated. Follicles showing signs of atresia also have decreased or no AMH expression, and expression is completely lost in corpora lutea. AMH is not found in primordial follicles, theca cells, oocytes or the interstitium. This specific expression pattern of AMH suggests a role in the two regulatory steps of folliculogenesis: the recruitment of primordial follicles and the sensitivity of large preantral and small antral follicles to FSH. Evidences obtained from studies with AMH-knockout mice suggest that AMH inhibits activation of primordial follicles into the growing pool, while at cyclic recruitment AMH lowers the FSH-sensitivity of follicles. In addition, AMH was recently implicated in the primordial follicle assembly. AMH was found to inhibit primordial follicle assembly and decrease the initial primordial follicle pool size in a rat ovarian organ culture. Conclusion: From this review, we can conclude that AMH plays a key role on the modulation of ovarian function in mammals. This substance is an important player in two checkpoints that regulate the efficiency of primordial follicle pool usage and the choice of the dominant follicle: activation and selection, respectively. However, it is necessary to perform additional studies that may provide a better understanding about the importance of AMH during folicullogenesis.

Proteínas morfogenéticas ósseas (BMPs) e seu papel na regulação da oogênese e da foliculogênese ovariana em mamíferos / The bone morphogenetic proteins (BMPs) and its role in the regulation of ovarian folliculogenesis and oogenesis in mammalian

O processo de foliculogênese é controlado por uma variedade de gonadotrofinas e de fatores de crescimento locais, que agem em conjunto para regular a formação e o desenvolvimento dos folículos ovarianos. Dentre esses fatores, destacam-se as proteínas morfogenéticas ósseas (BMPs), que representam uma família de fatores de crescimento amplamente estudados e que se caracterizam por controlar as funções ovarianas em diferentes estágios do desenvolvimento folicular. Dessa forma, a presente revisão tem como foco principal descrever os locais de expressão das BMPs dos tipos 2, 4, 6, 7 e 15 e discutir o papel delas, bem como das gonadotrofinas FSH e LH durante a foliculogênese em mamíferos.(AU)

The process of folliculogenesis is controlled by a variety of gonadotropins and local growth factors that act together to regulate formation and development of ovarian follicles. Among these factors, the bone morphogenetic proteins (BMPs) represent a family of growth factors widely studied that have important functions at different stages of ovarian follicular development. Thus, this review aims to describe the local of expression and to discuss the role of BMPs 2, 4, 6, 7 and 15 as well as the gonadotropins FSH and LH during folliculogenesis in mammals. (AU)

Proteínas morfogenéticas ósseas (BMPs) e seu papel na regulação da oogênese e da foliculogênese ovariana em mamíferos / The bone morphogenetic proteins (BMPs) and its role in the regulation of ovarian folliculogenesis and oogenesis in mammalian

O processo de foliculogênese é controlado por uma variedade de gonadotrofinas e de fatores de crescimento locais, que agem em conjunto para regular a formação e o desenvolvimento dos folículos ovarianos. Dentre esses fatores, destacam-se as proteínas morfogenéticas ósseas (BMPs), que representam uma família de fatores de crescimento amplamente estudados e que se caracterizam por controlar as funções ovarianas em diferentes estágios do desenvolvimento folicular. Dessa forma, a presente revisão tem como foco principal descrever os locais de expressão das BMPs dos tipos 2, 4, 6, 7 e 15 e discutir o papel delas, bem como das gonadotrofinas FSH e LH durante a foliculogênese em mamíferos.

The process of folliculogenesis is controlled by a variety of gonadotropins and local growth factors that act together to regulate formation and development of ovarian follicles. Among these factors, the bone morphogenetic proteins (BMPs) represent a family of growth factors widely studied that have important functions at different stages of ovarian follicular development. Thus, this review aims to describe the local of expression and to discuss the role of BMPs 2, 4, 6, 7 and 15 as well as the gonadotropins FSH and LH during folliculogenesis in mammals.

Papel da Proteína Morfogenética Óssea 15 (BMP-15) e Kit Ligand (KL) na regulação da foliculogênese em mamíferos / Role of Bone Morphogenetic Protein 15 (BMP-15) and Kit Ligand (KL) in the regulation of folliculogenesis in mammalian

A foliculogênese é coordenada por diversos fatores de crescimento e hormônios responsáveis por garantir o sucesso do desenvolvimento folicular e oocitário. Para a obtenção de oócitos competentes, é necessária uma perfeita interação entre as células somáticas foliculares e o oócito, sendo esta potencialmente regulada por fatores parácrinos produzidos no ovário. Dentre estes fatores, destacam-se a BMP-15 e o KL, sintetizados pelo oócito e pelas células da granulosa, respectivamente. Este artigo revisa o importante papel da BMP-15 e do KL na foliculogênese, enfocando suas características, sítios de expressão, receptores e vias de sinalização, bem como a interação entre estas duas substâncias(AU)

Folliculogenesis is coordinated by many growth factors and hormones responsible for ensuring the success of follicular and oocyte development. To obtain competent oocytes is necessary to have a perfect interaction between follicular somatic cells and the oocyte, which is potentially regulated by paracrine factors produced in the ovary. Among these factors, we highlight BMP-15 and KL, synthesized by the oocyte and granulosa cells, respectively. This article reviews the important role of BMP-15 and KL in folliculogenesis, focusing on their characteristics, sites of expression, receptors and signaling pathways, as well as the interaction between these two substances(AU)

Papel da Proteína Morfogenética Óssea 15 (BMP-15) e Kit Ligand (KL) na regulação da foliculogênese em mamíferos / Role of Bone Morphogenetic Protein 15 (BMP-15) and Kit Ligand (KL) in the regulation of folliculogenesis in mammalian

A foliculogênese é coordenada por diversos fatores de crescimento e hormônios responsáveis por garantir o sucesso do desenvolvimento folicular e oocitário. Para a obtenção de oócitos competentes, é necessária uma perfeita interação entre as células somáticas foliculares e o oócito, sendo esta potencialmente regulada por fatores parácrinos produzidos no ovário. Dentre estes fatores, destacam-se a BMP-15 e o KL, sintetizados pelo oócito e pelas células da granulosa, respectivamente. Este artigo revisa o importante papel da BMP-15 e do KL na foliculogênese, enfocando suas características, sítios de expressão, receptores e vias de sinalização, bem como a interação entre estas duas substâncias

Folliculogenesis is coordinated by many growth factors and hormones responsible for ensuring the success of follicular and oocyte development. To obtain competent oocytes is necessary to have a perfect interaction between follicular somatic cells and the oocyte, which is potentially regulated by paracrine factors produced in the ovary. Among these factors, we highlight BMP-15 and KL, synthesized by the oocyte and granulosa cells, respectively. This article reviews the important role of BMP-15 and KL in folliculogenesis, focusing on their characteristics, sites of expression, receptors and signaling pathways, as well as the interaction between these two substances

Effect of bone morphogenetic protein-7 (BMP-7) on in vitro survival of caprine preantral follicles / Efeito da proteína morfogenética óssea 7 (BMP-7) para a sobrevivência in vitro de folículos pré-antrais caprinos

This study was conducted in order to verify the effect of different concentrations of BMP-7 in the in vitro survival and development of caprine preantral follicles. Fragments of caprine ovarian cortical tissue were cultured for 1 or 7 days in Minimum Essential Medium (MEM+) supplemented with different concentrations of BMP-7 (1, 10, 50 or 100ng/ml). Non-cultured fragments or those cultured for 1 or 7 days were processed for classical histology and transmission electron microscopy (TEM). Parameters such as follicular survival, activation and growth were evaluated. The results showed that, after 1 or 7 days of culture, the percentage of morphologically normal follicles was significantly reduced in all treatments when compared with fresh control, except at 1ng/ml of BMP-7 for 1 day. In addition, the concentration of 10ng/ml of BMP-7 significantly increases follicular diameter from day 1 to 7 of culture. There was no influence of the other concentrations of BMP-7 regarding to the follicular and oocyte diameter. Ultrastructure studies confirmed follicular integrity after 7 days of culture in 1ng/ml BMP-7. In conclusion, small concentrations of BMP-7 can improve the survival and growth of caprine preantral follicles during in vitro culture.(AU)

O presente trabalho foi conduzido de modo a se verificar o efeito de diferentes concentrações da BMP-7 no desenvolvimento in vitro de folículos pré-antrais caprinos. Fragmentos de tecido cortical ovariano caprino foram cultivados por 1 ou 7 dias em Minimum Essential Medium (MEM+) suplementado com diferentes concentrações de BMP-7 (1, 10, 50 ou 100ng/ml). Os fragmentos não cultivados ou aqueles cultivados por 1 ou 7 dias foram processados para histologia clássica e microscopia eletrônica de transmissão (TEM), sendo avaliados parâmetros morfológicos indicativos de viabilidade, ativação e crescimento. Os resultados mostraram que o percentual de folículos morfologicamente normais diminuiu significativamente em todos os tratamentos quando comparados ao controle, exceto na concentração de 1ng/ml por 1 dia de cultivo. Já no D7 todos os tratamentos reduziram significativamente os percentuais de folículos morfologicamente normais. Utilizando 10ng/ml de BMP-7 foi observado um aumento significativo no diâmetro folicular quando comparados os diferentes períodos de cultivo. Não houve influência das demais concentrações de BMP-7 quando avaliados além do diâmetro folicular o diâmetro oocitário. A análise por TEM confirmou a integridade ultra-estrutural nos folículos após 7 dias de cultivo com 1ng/ml de BMP-7 . Em conclusão, o BMP-7 em baixas concentrações pode melhorar a sobrevivência e o crescimento durante o cultivo in vitro de folículos pré-antrais caprinos.(AU)

Bone Morphogenetic Protein-6 (BMP-6) induces atresia in goat primordial follicles cultured in vitro / / A Proteína Morfogenética Óssea-6 (BMP-6) induz a atresia em folículos primordiais caprinos cultivados in vitro

This study investigated the effects of bone morphogenetic protein 6 (BMP-6) on in vitro primordial follicle development in goats. Samples of goat ovarian cortex were cultured in vitro for 1 or 7 days in Minimum Essential Medium (control medium) supplemented with different concentrations of BMP-6. Follicle survival, activation and growth were evaluated through histology and transmission electron microscopy (TEM). After 7 days of culture, histological analysis demonstrated that BMP-6 enhanced the percentages of atretic primordial follicles when compared to fresh control (day 0). Nevertheless, BMP-6 increased follicular and oocyte diameter during both culture periods. As the culture period progressed from day 1 to day 7, a significant increase in follicle diameter was observed with 1 or 50ng/ml BMP-6. However, on the contrary to that observed with the control medium TEM revealed that follicles cultured for up to 7 days with 1 or 50ng/ml BMP-6 had evident signs of atresia. In conclusion, this study demonstrated that BMP-6 negatively affects the survival and ultrastructure of goat primordial follicles.(AU)

O presente estudo investigou os efeitos da proteína morfogenética óssea-6 (BMP-6) no desenvolvimento in vitro de folículos primordiais caprinos. Amostras de córtex ovariano de cabras foram cultivados por 1 ou 7 dias em Meio Essencial Mínimo (meio controle) suplementado com diferentes concentrações de BMP-6. As taxas de sobrevivência, ativação e crescimento foram avaliadas por histologia clássica e microscopia eletrônica de transmissão (MET). Após 7 dias de cultivo, a análise histológica demonstrou que a BMP-6 aumentou o percentual de folículos primordiais degenerados no dia 7 quando comparados ao controle fresco (D0). Além disso, houve um aumento significativo do diâmetro folicular e oocitário em ambos os períodos de cultivo em todos os tratamentos na presença de BMP-6. Com a progressão do cultivo do dia 1 para o dia 7, nos tratamentos com 1 ou 50ng/ml de BMP-6, foi observado um aumento significativo no diâmetro folicular. Entretanto, contrário ao observado no meio controle, a MET revelou que os folículos cultivados nesses tratamentos apresentavam sinais evidentes de atresia. Em conclusão, esse estudo demonstrou que a BMP-6 afeta negativamente a sobrevivência e a ultra-estrutura de folículos primordiais caprinos.(AU)

Função e regulação de membros da família TGF beta no crescimento folicular final e ovulação em bovinos

A foliculogênese antral culmina com a ovulação, sendo controlada primariamente por mecanismos endócrinos bem estabelecidos. Após a emergência folicular, em espécies monovulares, apenas um folículo é selecionado para continuar o desenvolvimento, enquanto que os demais entram em processo de atresia. Uma vez que todos os folículos encontram-se sob o mesmo ambiente endócrino, fica evidente que fatores produzidos no ovário são reguladores do crescimento e da diferenciação folicular. Neste contexto, destacam-se fatores pertencentes à superfamília dos fatores de crescimento transformantes beta (TGF-) e seus receptores. Apesar da grande relevância, a real função dos TGF- na fisiologia ovariana ainda é desconhecida. Desta forma, o presente estudo teve por objetivo avançar no entendimento da função e regulação de fatores locais no ovário bovino, avaliando a função do fator de crescimento e diferenciação 9 (GDF9) no crescimento folicular final. Além disso, testou-se a hipótese de que os membros da família TGF-, em especial as proteínas morfogenéticas ósseas (BMPs) e seus receptores, são regulados durante o processo de luteinização e ovulação em bovinos. A injeção intrafolicular de GDF9 nas concentrações finais de 100 ou 1000ng/mL não teve efeito sobre o crescimento folicular final, manifestação de estro e ovulação (P>0,05). Nas células da granulosa de folículos pré-ovulatórios (>12 mm), a expressão de RNAm das BMPs 1 e 4 não foi regulada pela aplicação i.m. de GnRH (hora 0), enquanto que a expressão de BMP2 aumentou significativamente 3 e 6 horas após (P<0,05). A expressão de RNAm dos receptores BMPR2 e TGFBR1 nas células da granulosa aumentou significativamente 12h após tratamento com GnRH. Os receptores BMPR1A e 1B foram mais expressos no momento do tratamento, diminuindo 3 e 6 h após, apresentando uma elevação às 12h, diminuindo novamente nas 24h. Houve uma correlação negativa entre a expressão dos receptores TGFBR1 (R2=0,46), BMPR1A (R2=0,5) e 1B (R2=0,5) e os níveis intrafoliculares de progesterona. Coletivamente, os dados sugerem que a elevação nos níveis de GDF9 em folículos diferenciados não altera o destino dos mesmos. A expressão da BMP2 sugere uma participação no processo de luteinização/ovulação enquanto que a expressão dos receptores sugere uma inibição no processo de luteinização. A elucidação do papel dos fatores locais na fisiologia ovariana pode contribuir com o entendimento de processos patológicos e no desenvolvimento de tecnologias que tenham por finalidade a contracepção ou o aumento da taxa ovulatória.

Antral follicle development culminates with ovulation, being mainly controlled by well-established endocrine mechanisms. After follicular emergence, in monovulatory species, only one follicle is selected to grow whereas all the others undergo atresia. During these processes, all the follicles are under the same endocrine environment, indicating the participation of locally produced factors in the regulation of follicular growth and differentiation. In this context, the involvement of transforming growth factors-beta (TGF-) family members and their receptors is highlighted. Despite their relevance, the real functions of TGF- proteins in ovarian physiology is still poorly understood. In this regard, the aim of this study was to gain insight into the function and regulation of ovarian factors, investigating the function of growth and differentiation factor 9 (GDF9) during dominant follicle growth. Furthermore, we tested the hypothesis that TGF- members, especially bone morphogenetic proteins (BMPs) and their receptors are regulated during luteinization and ovulation processes in cattle. The intrafollicular injection of GDF9 at final concentrations of 100 and 1000ng/mL did not affect follicular growth, estrus manifestation and ovulation (P>0.05). In granulosa cells from preovulatory follicles (>12mm), mRNA expression of BMPs 1 and 4 was not regulated after i.m. administration of GnRH (0h), while the BMP2 expression was significantly upregulated at 3 and 6h (P<0.05). The mRNA expression of BMPR2 and TGFBR1 in granulosa cells increased 12h after GnRH treatment (P<0.05). The receptors BMPR1A and 1B were more expressed at the moment of GnRH injection, decreasing at 3 and 6h, increasing at 12h and decreasing again at 24h. There was a negative correlation between mRNA expression of TGFBR1 (R2=0.46), BMPR1A (R2=0.5) and 1B (R2=0.5) and intrafollicular progesterone levels. Collectively, the results suggest that increasing the levels of GDF9 in differentiated follicles does not affect their fate. BMP2 expression pattern suggests an involvement in luteinization/ovulation processes, whereas the expression of TGF- receptors suggests an inhibitory action during luteinization. Elucidating the functions of local factors in ovarian physiology would allow to better understand pathological processes and the development of technologies aiming contraception or, paradoxally, increasing ovulation rates.

Genética da prolificidade e seu emprego na produção ovina / Genetics of prolificacy and its application to sheep production

A existência de rebanhos de ovinos que apresentam alta freqüência de partos múltiplos tem sido observada desde há muito tempo, mas apenas recentemente foi identificada a causa genética da prolificidade de algumas destas populações. Mutações nos genes das proteínas morfogenéticas de osso (BMP) e seu receptor foram apontadas como causadoras do aumento da taxa de ovulação e por conseqüência dos partos múltiplos de diversas populações de ovelhas dentre elas as conhecidas como Booroola. O desenvolvimento de testes de DNA eficazes com capacidade de identificação precoce e rápida destes haplótipos tornou possível a sua utilização na produção comercial de ovinos... (AU)

The existence of sheep flocks with high frequency of multiple births has been observed for some time, but only recently the genetic cause of the prolificacy of some of these populations has been identified. Mutations in the genes of the bone morphogenetic proteins and their receptor have been recognized as the cause of the increased ovulation rate and hence the occurrence of multiple births in several sheep populations among them those know as Booroola. The development of efficient DNA tests capable of early and quick detection of these haplotypes made possible their application in the commercial sheep industry...(AU)

Genética da prolificidade e seu emprego na produção ovina / Genetics of prolificacy and its application to sheep production

A existência de rebanhos de ovinos que apresentam alta freqüência de partos múltiplos tem sido observada desde há muito tempo, mas apenas recentemente foi identificada a causa genética da prolificidade de algumas destas populações. Mutações nos genes das proteínas morfogenéticas de osso (BMP) e seu receptor foram apontadas como causadoras do aumento da taxa de ovulação e por conseqüência dos partos múltiplos de diversas populações de ovelhas dentre elas as conhecidas como Booroola. O desenvolvimento de testes de DNA eficazes com capacidade de identificação precoce e rápida destes haplótipos tornou possível a sua utilização na produção comercial de ovinos...

The existence of sheep flocks with high frequency of multiple births has been observed for some time, but only recently the genetic cause of the prolificacy of some of these populations has been identified. Mutations in the genes of the bone morphogenetic proteins and their receptor have been recognized as the cause of the increased ovulation rate and hence the occurrence of multiple births in several sheep populations among them those know as Booroola. The development of efficient DNA tests capable of early and quick detection of these haplotypes made possible their application in the commercial sheep industry...

A superfamília dos fatores de crescimento transformante-β e o controle da foliculogênese em mamíferos / Transforming growth factors -β superfamily members and control of folliculogenesis in mammals

A foliculogênese ovariana é um processo complexo caracterizado pela formação, crescimento e maturação folicular. Esta revisão discute a localização, os sítios de ação e as funções de fatores da família TGF-β [proteínas morfogenéticas ósseas dos tipos 2 (BMP-2), 4 (BMP-4), 6 (BMP-6), 7 (BMP-7), 15 (BMP-15), fator de diferenciação do crescimento-9 (GDF-9), ativina-A, inibina, hormônio anti-Mülleriano (AMH) e fator de crescimento transformante-ß (TGF-ß)] na regulação da foliculogênese em mamíferos. Alguns fatores, como o AMH, atuam inibindo o crscimento dos folículos primordiais e reduzindo a sensibilidadade dos folículos em crescimento ao FSH, enquanto vários outros (BMP-2, 4, 7, 15, GDF-9, ativina-A e TGF-ß) estimulam o crecimento folicular. Em geral, a foliculogênese é regulada por uma complexa interação desses fatores de crescimento com as gonadotrofinas.(AU)

Ovarian folliculogenesis is a complex process that includes follicular formation, growth and maturation. This review discuss the localization and functions of TGF-β family members [bone morphogenetic proteins 2 (BMP-2), 4 (BMP-4), 6 (BMP-6), 7 (BMP-7), 15 (BMP-15), growth and differentiation factor-9 (GDF-9), activin-A, inibin, anti-Müllerian hormony (AMH) and transforming growth factor-ß (TGF-ß)] in the regulation of ovarian folliculogenesis in mammals. Some of these factors, such as AMH, inhibit growth of primoridal follicles and reduce sensitity of growing follicles to FSH, while various others (BMP-2, 4, 7, 15, GDF-9, activina-A and TGF-ß) stimulate follicular growth. In general, folliculogenesis is regulated by a complex interaction of these factors with gonadotrophins.(AU)

A superfamília dos fatores de crescimento transformante-β e o controle da foliculogênese em mamíferos / Transforming growth factors -β superfamily members and control of folliculogenesis in mammals

A foliculogênese ovariana é um processo complexo caracterizado pela formação, crescimento e maturação folicular. Esta revisão discute a localização, os sítios de ação e as funções de fatores da família TGF-β [proteínas morfogenéticas ósseas dos tipos 2 (BMP-2), 4 (BMP-4), 6 (BMP-6), 7 (BMP-7), 15 (BMP-15), fator de diferenciação do crescimento-9 (GDF-9), ativina-A, inibina, hormônio anti-Mülleriano (AMH) e fator de crescimento transformante-ß (TGF-ß)] na regulação da foliculogênese em mamíferos. Alguns fatores, como o AMH, atuam inibindo o crscimento dos folículos primordiais e reduzindo a sensibilidadade dos folículos em crescimento ao FSH, enquanto vários outros (BMP-2, 4, 7, 15, GDF-9, ativina-A e TGF-ß) estimulam o crecimento folicular. Em geral, a foliculogênese é regulada por uma complexa interação desses fatores de crescimento com as gonadotrofinas.

Ovarian folliculogenesis is a complex process that includes follicular formation, growth and maturation. This review discuss the localization and functions of TGF-β family members [bone morphogenetic proteins 2 (BMP-2), 4 (BMP-4), 6 (BMP-6), 7 (BMP-7), 15 (BMP-15), growth and differentiation factor-9 (GDF-9), activin-A, inibin, anti-Müllerian hormony (AMH) and transforming growth factor-ß (TGF-ß)] in the regulation of ovarian folliculogenesis in mammals. Some of these factors, such as AMH, inhibit growth of primoridal follicles and reduce sensitity of growing follicles to FSH, while various others (BMP-2, 4, 7, 15, GDF-9, activina-A and TGF-ß) stimulate follicular growth. In general, folliculogenesis is regulated by a complex interaction of these factors with gonadotrophins.

Proteínas morfogenéticas ósseas associadas a osso esponjoso autógeno na reparação de falhas experimentais na calota craniana de coelhos (Oryctolagus cuniculus) / Bone morphogenetic proteins associated with autogenous bone graft in the reparation of calvarial experimental defects of rabbits (Oryctolagus cuniculus)

Foi avaliada a reparação óssea após implantação de proteínas morfogenéticas ósseas (BMP) em diferentes concentrações e períodos de observação, carreadas por auto-enxerto ósseo esponjoso (EOE), em falhas ósseas, produzidas na região fronto-parietal do crânio de 20 coelhas. A falha I não foi preenchida, a II foi completamente preenchida com 3mg de EOE e as falhas III, IV, V e VI foram preenchidas com EOE associado a 0,5; 1; 2 e 5mg de BMP, respectivamente. Nas avaliações mesoscópicas, post mortem, verificou-se que, independentemente do período de tratamento, o preenchimento ósseo iniciou-se a partir das bordas para o centro e do fundo para a superfície das falhas. Na falha I manifestou-se o menor preenchimento ósseo quando comparada com as demais falhas, em todos os períodos, e nas que receberam 2mg de BMP exibiu-se a melhor cobertura óssea. Microscopicamente, verificou-se que, aos sete dias, o preenchimento ósseo iniciou-se a partir das bordas e do fundo da lesão, com mobilização e diferenciação de células provenientes do periósteo e das meninges, respectivamente e, nas avaliações subseqüentes, a atividade osteoblástica originou-se, também, de "ilhas de ossificação" semelhantes a centros de ossificação, localizadas no centro da falha. A formação trabecular aumentou, proporcionalmente, com a concentração utilizada de BMP, e a aposição e organização óssea aumentaram com o tempo de observação. Verificou-se também a presença de tecido cartilaginoso. A BMP associada ao EOE contribuiu para a formação de novo tecido ósseo, promovendo maior mobilização, diferenciação e organização celular, e abreviou o tempo de formação óssea, sugerindo processo de ossificação endocondral. Os melhores resultados foram observados com a associação de 2mg de BMP a 3mg de enxerto, e a adição de BMP, mesmo em menor quantidade, determinou precocidade de formação óssea. A maior quantidade de BMP não determinou maior preenchimento ósseo(AU)

Aspects of bone repair were evaluated after implantation of bone morphogenetic proteins (BMP) in different concentrations. They were carried by autogenous bone graft in defects created on skulls of 20 adult, young female rabbits, randomizedly divided into five experimental groups and were observed at five times. After exposure of skull bones, six bone defects on the fronto-parietal region of each animal were performed. The defect I was not filled, the II was completed filled with 3mg of autogenous bone graft and the defects III, IV, V, and VI were filled with autogenous bone graft associated with 0.5; 1; 2 and 5mg of BMP, respectively. In the post-mortem mesoscopic evaluations, it was observed that, independently of the treatment period of the defects, the bony filling began from the borders to the center, and from the botton to the surface of the lessions. The bony filling of the defect I was the smallest when compared with the others defects, in all the observation moments. It was also verified that until 2mg the higher the concentration of BMP used, better was the bone cover. Microscopically, it was verified in the first evaluations, on the seventh day, that the bony growth started from the borders and from the bottom of the lesion, with mobilization and differentiation of cells deriving from the periosteum and the meninges, respectively. In the subsequent evaluations, the osteoblastic activity also derived from "ossification islands" to ossification centers, located in the center of the flaw. The trabecular formation increased proportionally with the concentration of BMP used, and the apposition and bony organization increased proportionally with the time of observation. The presence of cartilaginous tissue was verified in all the flaws. In conclusion, the use the higher concentration of BMP did not determinate the better new bone formation. The association of BMP with autogenous bone graft contributed to the formation of new bony...(AU)