RESUMO
The alteration of signaling molecules involved in the general metabolism of animals can negatively influence reproduction. In dairy cattle, the development of follicular cysts and the subsequent appearance of ovarian cystic disease (COD) often lead to decreased reproductive efficiency in the herd. The objective of this review is to summarize the contribution of relevant metabolic and nutritional sensors to the development of COD in dairy cows. In particular, we focus on the study of alterations of the insulin signaling pathway, adiponectin, and other sensors and metabolites relevant to ovarian functionality, which may be related to the development of follicular persistence and follicular formation of cysts in dairy cattle. The results of these studies support the hypothesis that systemic factors could alter the local scenario in the follicle, generating an adverse microenvironment for the resumption of ovarian activity and possibly leading to the persistence of follicles and to the development and recurrence of COD.
Assuntos
Doenças dos Bovinos , Cistos Ovarianos , Feminino , Bovinos , Animais , Cistos Ovarianos/veterinária , Cistos Ovarianos/metabolismo , Folículo Ovariano/metabolismo , Reprodução , Insulina/metabolismo , Doenças dos Bovinos/metabolismo , Microambiente TumoralRESUMO
Stressors activate the hypothalamic-pituitary-adrenal (HPA) axis, reducing fertility by interfering with the mechanisms that regulate the timing of events within the follicular phase of the estrous cycle. In the HPA axis, melanocortin 2 receptor (MC2R) mediates responses to adrenocorticotropic hormone (ACTH) in concert with melanocortin receptor accessory protein 2 (MRAP2). The aims of the present study were: (1) to evaluate the effects of ACTH administered in cows in the preovulatory period on the expression of the MC2R/MRAP2 complex in the dominant follicle; and (2) to analyze the involvement of Extracellular signal Regulated Kinase 1 (ERK1) signaling in the activation of MC2R and the expression of key enzymes involved in the biosynthesis of glucocorticoids (GCs) in the dominant follicle. To this end, 100 IU ACTH was administered to Holstein cows from a local dairy farm during pro-estrus every 12 h for four days until ovariectomy, which was performed before ovulation. Protein immunostaining of MC2R was higher in the dominant follicles of ACTH-treated cows (p < 0.05). Also, Western blot analysis showed higher activation of the ERK1 signaling pathway in ACTH-treated cows (p < 0.05). Finally, immunohistochemistry performed in the dominant follicles of ACTH-treated cows detected higher expression of CYP17A1 and CYP21A2 (p < 0.05). These results suggest that the bovine ovary is able to respond locally to ACTH as a consequence of stress altering the expression of relevant steroidogenic enzymes. The results also confirm that the complete GC biosynthesis pathway is present in bovine dominant follicle and therefore GCs could be produced locally.
Assuntos
Hormônio Adrenocorticotrópico , Sistema Hipotálamo-Hipofisário , Hormônio Adrenocorticotrópico/metabolismo , Animais , Bovinos , Feminino , Sistema Hipotálamo-Hipofisário/metabolismo , Ovulação , Sistema Hipófise-Suprarrenal , Receptor Tipo 2 de Melanocortina/metabolismoRESUMO
Cystic ovarian disease (COD) is one of the main causes of infertility in dairy cattle. It has been postulated that the insulin-like growth factor (IGF) system may contribute to follicular persistence and development of COD. The initiation of the IGF response is a result of interactions between IGF-binding proteins (IGFBPs) and IGFBP proteases, mainly pregnancy-associated plasma protein A (PAPP-A). IGFBPs bind IGFs with high affinity and consequently regulate their access to IGF receptors (IGFRs). The aim of this research was to determine variations in components of the IGF system in the ovaries of cows with persistent follicles induced by long-term administration of progesterone. Proteins of the IGF system were evaluated at 0 (expected day of ovulation), 5, 10 and 15 days of follicular persistence to determine whether the changes occur early in the development of COD. The concentrations of IGF1 and IGFBP4 in follicular fluid were similar in all groups with follicular persistence and in control antral follicles. IGFR1 and IGFBP4 expression in situ were higher in granulose cells in persistent follicles than in control follicles. No differences were found in PAPP-A concentration within follicular fluid in persistent follicles relative to control antral follicles. These data support the hypothesis that the IGF system is altered in the initial stages of development of follicular persistence and has a determinant role in ovarian function in cattle.
Assuntos
Doenças dos Bovinos/metabolismo , Cistos Ovarianos/veterinária , Somatomedinas/metabolismo , Animais , Bovinos , Doenças dos Bovinos/patologia , Feminino , Folículo Ovariano/patologiaRESUMO
In dairy cattle, cystic ovarian disease (COD) is an important cause of subfertility, and two of the main signs are ovulation failure and follicular persistence. The aim of this study was to examine the expression of the cytokines IL-1α, IL-6, IL-8 and TNF-α in ovarian follicular structures at different times of persistence in a model of follicular persistence induced by prolonged treatment with progesterone in dairy cows. Protein expression of IL-1α, IL-6, IL-8 and TNF-α was evaluated by immunohistochemistry. Additionally, IL-6 concentration in follicular fluid and serum was determined by ELISA. IL-1α, IL-6, IL-8 and TNF-α expression was increased in follicles with different persistence times in relation to the control dominant follicles, in granulosa cells. For IL-6, IL-8 and TNF-α, this increase was detected early (P0: expected time of ovulation and/or P5: 5 days of follicular persistence). Additionally, theca cells showed an increase in IL-6 in antral (groups P10 and P15) and persistent follicles (group P10) related to dominant follicles from the control group (p < 0.05). Serum concentration of IL-6 was higher in groups P5, P10 and P15 than in control cows (p < 0.05). The results show evidence that early development of COD in cows is concurrent with altered expression of these cytokines in different ovarian follicular structures and may contribute to the follicular persistence and endocrine changes found in cattle with follicular cysts.
Assuntos
Bovinos/fisiologia , Citocinas/metabolismo , Folículo Ovariano/fisiologia , Animais , Busserrelina/administração & dosagem , Busserrelina/farmacologia , Cloprostenol/administração & dosagem , Cloprostenol/farmacologia , Citocinas/genética , Sincronização do Estro/efeitos dos fármacos , Feminino , Fármacos para a Fertilidade Feminina/administração & dosagem , Fármacos para a Fertilidade Feminina/farmacologia , Hormônio Liberador de Gonadotropina/administração & dosagem , Hormônio Liberador de Gonadotropina/farmacologia , Interleucina-1alfa/genética , Interleucina-1alfa/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Luteolíticos/administração & dosagem , Luteolíticos/farmacologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Glucocorticoids (GCs) such as cortisol and corticosterone are important steroid hormones with different functions in intermediate metabolism, development, cell differentiation, immune response and reproduction. In response to physiological and immunological stress, adrenocorticotropic hormone (ACTH) acts on the adrenal gland by stimulating the synthesis and secretion of GCs. However, there is increasing evidence that GCs may also be synthesized by extra-adrenal tissues. Here, we examined the gene and protein expression of the enzyme 11ß-hydroxylase P450c11 (CYP11B1), involved in the conversion of 11-deoxycortisol to cortisol, in the different components of the bovine ovary and determined the functionality of CYP11B1 in vitro CYP11B1 mRNA was expressed in granulosa and theca cells in small, medium and large antral ovarian follicles, and CYP11B1 protein was expressed in medium and large antral follicles. After stimulation by ACTH, we observed an increased secretion of cortisol by the wall of large antral follicles. We also observed a concentration-dependent decrease in the concentration of cortisol in response to metyrapone, an inhibitor of CYP11B1. This decrease was significant at 10-5 µM metyrapone. In conclusion, this study demonstrated for the first time the presence of CYP11B1 in the bovine ovary. This confirms that there could be a local synthesis of GCs in the bovine ovary and therefore a potential endocrine responder to stress through these hormones.
Assuntos
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Folículo Ovariano/enzimologia , Esteroide 11-beta-Hidroxilase/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Animais , Bovinos , Células Cultivadas , Feminino , Hormônios/farmacologia , Hidrocortisona/metabolismo , Folículo Ovariano/citologia , Esteroide 11-beta-Hidroxilase/genéticaRESUMO
Cystic ovarian disease (COD) is one of the main causes of infertility in dairy cattle. It has been shown that intra-ovarian factors, such as members of the insulin-like growth factor (IGF) system, may contribute to follicular persistence. The bioavailability of IGF to initiate its response by binding to specific receptors (IGFRs) depends on interactions with related compounds, such as pregnancy-associated plasma protein A (PAPP-A). The aim of this study was to determine IGFR1 and PAPP-A expression both in follicles at different stages of development and in cysts, to evaluate the roles in the etiopathogenesis of COD in cattle. The mRNA expression of PAPP-A was higher in granulosa cells of large tertiary follicles than in cysts, whereas the protein PAPP-A present in the follicular fluid from these follicles showed no differences. Although no PAPP-A mRNA expression was detected in smaller tertiary follicles, in their follicular fluid, this protease was detected in lesser concentration than in cysts. The mRNA expression of IGFR1 was lower in granulosa cells from cystic follicles than in those from tertiary ones. However, the protein expression of this receptor presented the highest levels in cystic structures, probably to increase the possibility of IGF response. The data obtained would indicate that animals with COD have an altered regulation of the IGF system in the ovary, which could be involved in the pathogenesis of this disease in cattle.
Assuntos
Doenças dos Bovinos/fisiopatologia , Cistos Ovarianos/veterinária , Proteína Plasmática A Associada à Gravidez/fisiologia , Receptor IGF Tipo 1/fisiologia , Animais , Bovinos , Doenças dos Bovinos/etiologia , Feminino , Líquido Folicular/química , Expressão Gênica , Células da Granulosa/química , Imuno-Histoquímica , Cistos Ovarianos/química , Cistos Ovarianos/fisiopatologia , Folículo Ovariano/química , Gravidez , Proteína Plasmática A Associada à Gravidez/análise , Proteína Plasmática A Associada à Gravidez/genética , RNA Mensageiro/análise , Receptor IGF Tipo 1/análise , Receptor IGF Tipo 1/genéticaRESUMO
A growing body of evidence suggests that ovulation shares many of the features of an inflammatory reaction and that cytokines play many diverse and important roles in reproductive biology. The aim of this study was to examine the expression of the pro-inflammatory cytokines interleukin (IL)-1α, IL-6 and tumour necrosis factor (TNF)-α in ovarian cells from cows with cystic ovarian disease (COD) as compared with that in ovarian structures from regularly cycling cows. Expression of genes encoding IL-1α, IL-6 and TNF-α was detected by real-time polymerase chain reaction in follicular cells from ovaries from healthy cows and cows with COD with no significant differences. However, immunohistochemistry showed increased expression of IL-1α, IL-6 and TNF-α in cystic follicles, suggesting that this expression may be related to the persistence of follicular cysts. The effect of COD was evident for IL-1α and TNF-α, and a follicular structure-disease interaction was observed in the expression of all the cytokines evaluated. Thus, altered expression of these proinflammatory cytokines may be related to ovulation failure and development of follicular cysts.
Assuntos
Doenças dos Bovinos/patologia , Citocinas/biossíntese , Cistos Ovarianos/veterinária , Folículo Ovariano/patologia , Animais , Western Blotting , Bovinos , Doenças dos Bovinos/imunologia , Citocinas/análise , Feminino , Imuno-Histoquímica , Cistos Ovarianos/imunologia , Cistos Ovarianos/patologia , Folículo Ovariano/imunologia , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Cystic ovarian disease (COD) is an important cause of infertility in dairy cattle. Follicular cell steroidogenesis and proliferation in ovulatory follicles is stimulated by hormones such as insulin and its necessary post-receptor response. The aim of this study was to determine the expression of insulin receptor (IR), IR substrate-1 (IRS1) and phosphatidylinositol 3-kinase (PI3K), key intermediates in the insulin pathway, in control cows and cows with spontaneous COD and ACTH-induced COD. IR and IRS1 mRNA levels were greater in granulosa cells and lower in follicular cysts than in control tertiary follicles. PI3K mRNA levels were similar in all follicles evaluated, whereas the expression of IR, IRS1 and PI3K was similar in theca cells. Protein expression of IR was higher in control tertiary follicles than in the same structures in animals with COD and with cysts. IRS1 and PI3K protein expression showed the same pattern in tertiary and cystic follicles. However, the protein expression of subunit alpha p85 of PI3K was greater in theca cells from tertiary follicles than in cystic follicles. These results provide new insights into the insulin response in cows with COD. The lower gene and protein expressions of some insulin downstream effectors at an early stage of the signaling pathway could negatively influence the functionality of ovaries and contribute to follicle persistence.
Assuntos
Doenças dos Bovinos/metabolismo , Insulina/fisiologia , Cistos Ovarianos/veterinária , Folículo Ovariano/metabolismo , Ácido 3-Hidroxibutírico/sangue , Ácido 3-Hidroxibutírico/metabolismo , Animais , Bovinos , Feminino , Regulação da Expressão Gênica/fisiologia , Insulina/sangue , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Cistos Ovarianos/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Receptor de Insulina/sangue , Receptor de Insulina/metabolismo , Transdução de SinaisRESUMO
Obesity and overweight are health problems of multifactorial etiology, which may include changes in the microbiome. In Mexico, more than 30 % of the child population between 5 and 11 years of age suffer from being overweight or are obese, which makes it a public health issue in progress. The purpose of this work was to measure the short-chain fatty acid concentration by high-performance liquid chromatography (HPLC), and to characterize the bacterial diversity by ion torrent semiconductor sequencing, of 16S rDNA libraries prepared from stools collected from a sample of well-characterized Mexican children for normal weight, overweight, and obese conditions by anthropometric and biochemical criteria. We found that triglyceride levels are increased in overweight and obese children, who presented altered propionic and butyric acid concentrations in feces. In addition, although the colon microbiota did not show a clear bacterial dysbiosis among the three conditions, the abundance of some particular bacteria was changed with respect to normal controls. We conclude from our results that the imbalance in the abundance of at least nine different bacteria as well as altered short-chain fatty acid concentration in feces is associated to the overweight and obese conditions of Mexican children.
Assuntos
Bactérias/metabolismo , Biodiversidade , Ácidos Graxos/biossíntese , Microbiota , Obesidade/etiologia , Sobrepeso/etiologia , Bactérias/classificação , Bactérias/genética , Estudos de Casos e Controles , Criança , Fezes/química , Fezes/microbiologia , Feminino , Humanos , Metabolismo dos Lipídeos , Masculino , México , Obesidade/metabolismo , Sobrepeso/metabolismo , FenótipoRESUMO
Cystic ovarian disease (COD) is an important cause of infertility in cattle, and ACTH has been involved in regulatory mechanisms related to ovarian function associated with ovulation, steroidogenesis, and luteal function. Here, we examined the localization of 11ß-hydroxysteroid dehydrogenase type 1 (11ßHSD1) and 11ßHSD2 proteins in the ovary of healthy cows and animals with spontaneous and ACTH-induced COD and the in vitro response of the follicular wall exposed to ACTH. After stimulation by ACTH, we documented changes in 11ßHSD expression and cortisol secretion by the follicular wall of large antral and follicular cysts. Follicular cysts showed a higher constitutive expression of both enzymes, whereas ACTH induced an increase in 11ßHSD1 in tertiary follicles and follicular cysts and a decrease in 11ßHSD2 in follicular cysts. Moderate expression of 11ßHSD1 was observed by immunohistochemistry in granulosa of control animals, with an increase (P < 0.05) from primary to secondary, tertiary, and atretic follicles. The level of immunostaining in theca interna was lower than that in granulosa. The expression of 11ßHSD2 was lower in the granulosa of primary follicles than in that of secondary, tertiary, and atretic follicles and was lower in the theca interna than in the granulosa. In ACTH-induced and spontaneously occurring follicular cysts, differences from controls were observed only in the expression of 11ßHSD1 in the granulosa, being higher (P < 0.05) than in tertiary follicles. These findings indicate that follicular cysts may be exposed to high local concentrations of active glucocorticoids and indicate a local role for cortisol in COD pathogenesis and in regulatory mechanisms of ovarian function.
Assuntos
11-beta-Hidroxiesteroide Desidrogenases/análise , Hormônio Adrenocorticotrópico/farmacologia , Doenças dos Bovinos/enzimologia , Cistos Ovarianos/veterinária , Ovário/enzimologia , Animais , Bovinos , Doenças dos Bovinos/patologia , Estradiol/sangue , Feminino , Células da Granulosa/enzimologia , Hidrocortisona/sangue , Imuno-Histoquímica , Microscopia Eletrônica de Varredura/veterinária , Cistos Ovarianos/induzido quimicamente , Cistos Ovarianos/enzimologia , Folículo Ovariano/enzimologia , Folículo Ovariano/metabolismo , Folículo Ovariano/patologia , Progesterona/sangue , Testosterona/sangue , Ultrassonografia/veterináriaRESUMO
Cystic ovarian disease (COD) is one of the main factors responsible for reproductive disorders in cattle. Although the pathogenesis and mechanism of cyst formation are not fully understood, it has been proposed that the IGF system could play an essential role, as it is a key intraovarian regulator. The aim of the present study was to determine whether the altered levels in IGF1 detected in bovines with COD are associated with changes at mRNA level or with differential modulation by IGFBPs. The mRNA levels of the IGF components studied were analyzed by real time PCR and in situ hybridization, and IGFBP expression and activity were assayed by immunohistochemistry and ligand blot, respectively. Results showed a decreased IGF1 mRNA level due to a lower granulosa cell gene expression in cystic follicles (P<0.05). Results also showed variations in IGFBP expression in the intraovarian cellular compartment and concentration in follicular fluid, and suggest that IGFBP3 is a key regulator of intrafollicular IGF1 in animals with COD.
Assuntos
Bovinos/metabolismo , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Cistos Ovarianos/veterinária , Animais , Western Blotting/veterinária , Feminino , Líquido Folicular/metabolismo , Imuno-Histoquímica/veterinária , Hibridização In Situ/veterinária , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/genética , Fator de Crescimento Insulin-Like I/genética , Cistos Ovarianos/metabolismo , RNA Mensageiro/química , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real/veterináriaRESUMO
Cystic ovarian disease (COD) is one of the most common reproductive disorders of cattle and is considered to have multifactorial aetiology. An accepted hypothesis involves neuroendocrinological dysfunction of the hypothalamic-pituitary-gonadal axis; however, the role of growth factors in COD has not been extensively investigated. The present study examines the potential role of members of the insulin-like growth factor (IGF) family in COD. Expression of genes encoding IGF-II and insulin-like growth factor-binding proteins (IGFBPs) was examined and the distribution of IGF-II within the follicular wall was assessed immunohistochemically. Finally, the concentration of IGF-II protein was determined in follicular fluid. There was increased IGF-II mRNA in the wall of cystic follicles, mainly associated with granulosa cells. Additionally, there was significantly more IGF-II protein in granulosa and theca cells in cystic follicles, but no change in the concentration of IGF-II in follicular fluid. Total IGFBPs, assessed by western blotting, were similar in different structures. However, by discriminating each IGFBP a decrease was detected in IGFBP-2 expression in cystic follicles that may be related to the observed higher expression of IGF-II. In summary, the present study provides evidence to suggest that COD in cattle is associated with modifications in the IGF-II system.
Assuntos
Doenças dos Bovinos/metabolismo , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Cistos Ovarianos/veterinária , Análise de Variância , Animais , Western Blotting , Bovinos , Doenças dos Bovinos/patologia , Ensaio de Imunoadsorção Enzimática , Feminino , Líquido Folicular/química , Células da Granulosa/metabolismo , Células da Granulosa/patologia , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Hibridização In Situ , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/genética , Fator de Crescimento Insulin-Like II/análise , Fator de Crescimento Insulin-Like II/genética , Cistos Ovarianos/metabolismo , Cistos Ovarianos/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The objectives of this study were to compare the efficacy and safety of orally administered ondansetron 8 mg b.i.d., 24 mg q.d., and 32 mg q.d. in the prevention of nausea and vomiting associated with high-dose cisplatin-based chemotherapy (cisplatin > or = 50 mg/m2). This was a randomized, parallel-group, double-blind study conducted in North America. It was planned that all patients would receive one of the following orally administered ondansetron treatments 30 min before starting cisplatin dosing (administered over < or = 3 h): 8 mg b.i.d. with 8 h between doses (124 patients), 24 mg q.d. (116 patients), and 32 mg q.d. (117 patients). Use of prophylactic corticosteroids was not permitted. During the 24-h study period, the highest complete response rate (no emesis, rescue antiemetic therapy, or withdrawal) occurred in patients who received ondansetron 24 mg q.d.: 76/115 or 66%, as against 68/124 (55%) after ondansetron 8 mg b.i.d. and 64/117 (55%) after ondansetron 32 mg q.d. Complete control of nausea (no nausea, no rescue, no withdrawal) occurred in more patients in the ondansetron 24 mg q.d. group (64/114, 56%) than in the ondansetron 8 mg b.i.d. group (43/121, 36%) or in the ondansetron 32 mg group (55/117, 50%). These results demonstrate that following highly emetogenic cisplatin-based chemotherapy (> or =2 50 mg/m2), oral ondansetron 24 mg q.d. is more effective than 8 mg b.i.d. for overall control of nausea, and at least as effective if not more effective in the control of acute vomiting than 8 mg b.i.d. or 32 mg q.d. Ondansetron 24 mg q.d. was well tolerated, and no new or unexpected adverse events were identified.