RESUMEN
Phosphoenolpyruvate carboxykinase (PEPCK) catalyses the reversible reaction of decarboxylation and phosphorylation of oxaloacetate (OAA) to generate phosphoenolpyruvate (PEP) and CO2 playing mainly a gluconeogenic role in green algae. We found two PEPCK isoforms in Chlamydomonas reinhardtii and we cloned, purified and characterised both enzymes. ChlrePEPCK1 is more active as decarboxylase than ChlrePEPCK2. ChlrePEPCK1 is hexameric and its activity is affected by citrate, phenylalanine and malate, while ChlrePEPCK2 is monomeric and it is regulated by citrate, phenylalanine and glutamine. We postulate that the two PEPCK isoforms found originate from alternative splicing of the gene or regulated proteolysis of the enzyme. The presence of these two isoforms would be part of a mechanism to finely regulate the biological activity of PEPCKs.
Asunto(s)
Chlamydomonas reinhardtii , Fosfoenolpiruvato , Chlamydomonas reinhardtii/genética , Fosfoenolpiruvato Carboxiquinasa (ATP)/genética , Isoformas de Proteínas , Fenilalanina , CitratosRESUMEN
Heat stress has been widely studied in relation to its effects on the production and reproduction of dairy cattle. However, the long-term effects of heat stress during intrauterine development on adult cows have been scarcely considered. Thus, the aim of this study was to evaluate possible changes in the reproductive performance of Holstein cows gestated under different values of the Temperature-Humidity Index (THI) during their intrauterine development. Data collected from a database of reproductive and productive records of 10,790 Holstein cows from the central region of Argentina and the THI data from the agrometeorological station of the Instituto Nacional de Tecnología Agropecuaria (INTA) EEA Rafaela, Santa Fe, Argentina, were used. The gestation of the cows evaluated was divided into trimesters, in which the highest THI cycles (sum of three or more consecutive days of exposure to a THI ≥72 during each trimester) and number of days with a THI ≥ 72 were calculated. The calving-to-conception and calving-to-first-service intervals of the cows evaluated were considered as reproductive variables associated with their first lactation. Generalized Linear Mixed Models were used, considering the cow's dairy farm as a random factor within the model. The exposure of the animals to environments with a THI ≥72 during the first trimester of gestation had a negative impact on the reproductive efficiency parameters analyzed. The results obtained indicate that the exposure of pregnant females to high THI values has a long-term impact on their daughters, which may contribute to a decrease in their reproductive performance, possibly through inherited epigenetic characteristics that remain in later generations through fetal programming.
Asunto(s)
Trastornos de Estrés por Calor , Leche , Animales , Argentina , Bovinos , Femenino , Trastornos de Estrés por Calor/veterinaria , Respuesta al Choque Térmico , Humedad , Lactancia , EmbarazoRESUMEN
Ovarian cystic follicles are the sign of important causes of reproductive failure in numerous species. In this review, some morphological, endocrinological and clinical aspects of cystic follicles in women, cows, mares, sows and bitches are discussed. Follicular cysts are the consequence of the failure of a mature follicle to ovulate at the appointed time of ovulation in the estrous cycle. Although the etiology of follicular cysts remains unknown, this review examines the evidence about the role of endocrine signaling systems in the specific disease or syndrome in each of the species mentioned above. This review also describes, the changes in the pathways of endocrine mechanisms that would trigger disturbances in the intraovarian component underlying the aberrant persistence of follicular cysts. The knowledge of the morphological and endocrinological nature of cystic follicles in different species can provide relevant information to better understand specific diseases when it is integrally analyzed from the comparative medicine viewpoint.
Asunto(s)
Quiste Folicular/metabolismo , Quistes Ováricos/metabolismo , Femenino , Quiste Folicular/patología , Humanos , Quistes Ováricos/patologíaRESUMEN
Cystic ovarian disease (COD) is an important cause of subfertility in dairy cattle. Bone morphogenetic proteins (BMPs), mainly BMP2, BMP4 and BMP6, play a key role in female fertility. In this study, we hypothesized that an altered BMP system is associated with ovarian alterations contributing to COD pathogenesis. Therefore, we examined the expression of BMP2, BMP4 and BMP6 and BMP receptor 1B (BMPR1B) in the ovaries of animals with spontaneous or ACTH-induced COD, as well as during the development of the disease, in a model of follicular persistence induced by low doses of progesterone (at 5, 10 and 15 days of follicular persistence). Results showed changes in BMP2, BMP4 and BMP6 expression during folliculogenesis, in granulosa and theca cells in the COD groups, as well as at different stages of follicular persistence. Results also showed changes in BMPR1B expression in developing follicles in animals with COD, and at the initial stages of follicular persistence (P5). Comparison between groups showed significant differences, mainly in BMP4 and BMP6 expression, in granulosa and theca cells of different follicular categories. The expression of these BMPs also increased in cystic and persistent follicles, in relation to antral follicles of the control group. BMPR1B showed high expression in cystic follicles. Together, these results may indicate an alteration in BMPs, especially in BMP4 and BMP6, as well as in BMPR1B, which occurs early in folliculogenesis and incipiently during the development of COD, which could be a major cause of recurrence of this disease in cattle.Free Spanish abstract: A Spanish translation of this abstract is freely available at http://www.reproduction-online.org/content/early/2016/08/01/REP-15-0315/suppl/DC1.
Asunto(s)
Proteína Morfogenética Ósea 2/metabolismo , Proteína Morfogenética Ósea 4/metabolismo , Proteína Morfogenética Ósea 6/metabolismo , Receptores de Proteínas Morfogenéticas Óseas/metabolismo , Enfermedades de los Bovinos/patología , Quistes Ováricos/patología , Folículo Ovárico/patología , Animales , Proteína Morfogenética Ósea 2/genética , Proteína Morfogenética Ósea 4/genética , Proteína Morfogenética Ósea 6/genética , Receptores de Proteínas Morfogenéticas Óseas/genética , Bovinos , Enfermedades de los Bovinos/genética , Enfermedades de los Bovinos/metabolismo , Células Cultivadas , Femenino , Células de la Granulosa/metabolismo , Células de la Granulosa/patología , Quistes Ováricos/genética , Quistes Ováricos/metabolismo , Folículo Ovárico/metabolismo , Células Tecales/metabolismo , Células Tecales/patologíaRESUMEN
The aim of this study was to characterize the expression of glucocorticoid receptor (GR) in the components of normal bovine ovary and in animals with cystic ovarian disease (COD). Changes in the protein and mRNA expression levels were determined in control cows and cows with COD by immunohistochemistry and real-time PCR. GR protein expression in granulosa cells was higher in cysts from animals with spontaneous COD and adrenocorticotropic hormone-induced COD than in tertiary follicles from control animals. In theca interna cells, GR expression was higher in cysts from animals with spontaneous COD than in tertiary follicles from control animals. The increase in GR expression observed in cystic follicles suggests a mechanism of action for cortisol and its receptor through the activation/inactivation of specific transcription factors. These factors could be related to the pathogenesis of COD in cattle.
Asunto(s)
Quistes Ováricos/veterinaria , Ovario/patología , Receptores de Glucocorticoides/análisis , Receptores de Glucocorticoides/genética , Hormona Adrenocorticotrópica , Animales , Bovinos , Femenino , Regulación de la Expresión Génica , Células de la Granulosa/metabolismo , Células de la Granulosa/patología , Quistes Ováricos/inducido químicamente , Quistes Ováricos/genética , Quistes Ováricos/patología , Folículo Ovárico/metabolismo , Folículo Ovárico/patología , Ovario/metabolismo , ARN Mensajero/genéticaRESUMEN
Cystic ovarian disease (COD) is an important cause of infertility in dairy cattle. Although many researchers have focused their work on the endocrine changes related to this disease, evidence indicates that intraovarian components play an important role in follicular persistence. Activin, inhibin, and follistatin participate as intraovarian regulatory molecules involved in follicular cell proliferation, differentiation, steroidogenesis, oocyte maturation, and corpus luteum function. Given the importance of these factors in folliculogenesis, we examined the expression and immunolocalization of activin/inhibin ßA-subunit, inhibin α-subunit, and follistatin in the ovaries of healthy estrus-synchronized cows and in those of cows with spontaneous or adrenocorticotropic hormone (ACTH)-induced COD. We also studied inhibin B (α ßB) levels in serum and follicular fluid. We found an increased expression of the ßA-subunit of activin A/inhibin A, the α-subunit of inhibin, and follistatin in granulosa cells of spontaneous follicular cysts by immunohistochemistry, and decreased concentrations of inhibin B (α ßB) in the follicular fluid of spontaneous follicular cysts. These results, together with those previously obtained, indicate that the expression of the components of the activin-inhibin-follistatin system is altered. This could lead to multiple alterations in important functions in the ovary like the balance between pro- and anti-apoptotic factors, follicular proliferation/apoptosis, and steroidogenesis, which may contribute to the follicular persistence and endocrine changes found in cattle with COD.
Asunto(s)
Enfermedades de los Bovinos/etiología , Folistatina/fisiología , Subunidades beta de Inhibinas/fisiología , Inhibinas/fisiología , Quistes Ováricos/etiología , Hormona Adrenocorticotrópica , Animales , Sangre/metabolismo , Estudios de Casos y Controles , Bovinos , Enfermedades de los Bovinos/diagnóstico por imagen , Enfermedades de los Bovinos/metabolismo , Femenino , Líquido Folicular/metabolismo , Folistatina/metabolismo , Subunidades beta de Inhibinas/metabolismo , Inhibinas/metabolismo , Quistes Ováricos/diagnóstico por imagen , Quistes Ováricos/metabolismo , Quistes Ováricos/veterinaria , Subunidades de Proteína , UltrasonografíaRESUMEN
Ovarian cysts are one of the major causes of infertility in dairy cows. The development is associated with an endocrine imbalance in the hypothalamo-hypophyseal-gonadal axis in which endocrine factors participate in follicular growth and differentiation and in the secretion of ovarian hormones. Insulin-like growth factor family are essential local regulators of ovarian follicle development and functionality and actions are mediated by binding protein activity. The aim of the present study was to analyze the expression of IGFBP-2 and IGFBP-3 in developing follicles of normal estrous cycling animals and with spontaneous and induced cystic ovarian disease (COD) to determine IGF bioavailability. The mRNA of IGFBP-2 and IGFBP-3 in follicular walls was quantified by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. Protein expression was analyzed by immunohistochemistry. The results demonstrated reduced amounts of mRNA of both IGFBPs in the granulosa cells of ovarian follicles of animals with COD (P<0.05). The present study suggests that the IGF system or imbalances between IGFs and IGFBPs may be involved in COD of cattle.