RESUMO
Studies in cows have reported that ovulation, steroidogenesis and angiogenesis are affected by stress and consequently fertility decreases. The purpose of this study was to evaluate the effects of ACTH administration during the preovulatory period on the expression of growth factors (CD-31, PDGF-A, PDGF-B, VEGFA-164, VEGFA-164b, VEGF-R1 and VEGF-R2) associated with the angiogenic process by immunohistochemistry in cows (n = 14). Results evidenced the expression of these growth factors in theca and granulosa cells from antral, atretic and dominant preovulatory follicles of ACTH-treated cows, suggesting that, under stress conditions, their expression continues to be required. VEGFA-164, VEGF-R1 and VEGF-R2 expression was greater in theca cells of dominant preovulatory follicles of the ACTH-treated group than in those of the control group. CD-31 protein expression was lower in the dominant preovulatory follicles of the ACTH-treated group than in those of the control group. PDGF-A and PDGF-B expression did not differ between groups, either in granulosa or in theca cells. These results suggest that VEGFA-164, its receptors and CD-31 are actors in the normal cycle of the ovaries and could have greater pathophysiological importance in the altered angiogenic process and other events that occur during anovulation and stress conditions. This dysregulation reinforces the importance of the angiogenic process in the pathophysiology of cystic ovarian disease in cows. This is the first report on the expression and localization of components of the VEGF and PDGF systems and CD-31 in cells from dominant preovulatory follicles after ACTH administration.
Assuntos
Folículo Ovariano , Fator A de Crescimento do Endotélio Vascular , Feminino , Bovinos , Animais , Folículo Ovariano/fisiologia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Células da Granulosa , Células Tecais , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Hormônio Adrenocorticotrópico/metabolismoRESUMO
Before ovulation, the ovary exhibits signs of local inflammation. However, the effects of adrenocorticotropin (ACTH) on the complexity of this inflammatory response are not yet well described. Thus, the aim of this study was to evaluate the effects of ACTH administered to dairy cows during the preovulatory period on the local distribution of different subsets of leukocytes infiltrated in the ovary, along with the gene expression of relevant chemokines (C-C motif chemokine ligand-2 (CCL2), C-X-C motif chemokine ligand-8 (CXCL8), CCL25 and CXCL1) involved in leukocyte chemotaxis and blood perfusion on the follicular wall of dominant follicles. Also, the direct effect of ACTH on chemokine gene expression was addressed in cultured antral follicular walls. For this purpose, both an in vivo and an in vitro experiment were performed. For the in vivo experiment, exogenous ACTH (100 IU) was administered intramuscularly to Holstein cows (n = 12) during proestrus every 12 h for four days before ovulation, when ovariectomy was performed (day 18). Daily ovarian Doppler ultrasonography was used to evaluate the percentage of irrigated area, the pulsatility index and the resistance index in the dominant follicles. The distribution of monocytes-macrophages (CD14), T- (CD2) and B-lymphocytes (CD79a) and granulocytes (CH138A) in the ovary was analyzed by immunohistochemistry. In follicular wall samples, gene expression of CCL2, CXCL8, CXCL1 and CCL25 was evaluated, whereas IL-17A expression was analyzed by Western blot. The total number of CD14, CD79a and CD2 infiltrated cells was lower in the ACTH-treated group than in the control group (p < 0.05). Chemokine gene expression showed lower mRNA of CCL2, CCL25 and CXCL1 (p < 0.05) in the ACTH-treated group. Meanwhile, IL-17A protein expression and hemodynamic parameters were similar between groups (p > 0.05). In the in vitro assay, antral follicular walls were stimulated with ACTH to corroborate the gene expression profile of chemokines. mRNA expression of CCL2 tended to be lower in the stimulated follicular walls (p = 0.092). Our results suggest that exogenous ACTH stimulus during the preovulatory period reduces the number of infiltrated leukocytes in the bovine ovary and this could be due to a lower chemotaxis capacity of the ovary.
Assuntos
Hormônio Adrenocorticotrópico , Ovário , Feminino , Bovinos , Animais , Hormônio Adrenocorticotrópico/farmacologia , Interleucina-17 , Ligantes , LeucócitosRESUMO
This research paper addresses the hypothesis that stress, induced by ACTH administration and cortisol release increases somatic cell count (SCC) in mammary secretion, and improves the effectiveness of dry off in goats. We report indicators of milk synthesis and mammary gland involution during dry off. Thirty Saanen goats were subjected to abrupt dry off and treatments: (1) ACTH administration (ACTH) or (2) placebo (Control) on days 1, 3, 6, 9, 12, 15, 30, and 60 of dry off. The expression of target genes in mammary tissue that are related to milk synthesis and cell survival such as insulin-like growth factor 1 receptor (IGF1R), phosphatidylinositol-3-kinase (PIK3CA), protein kinase B (AKT1) and mechanistic target of rapamycin (MTOR), casein (CSN2), lactalbumin (LALBA) and lactoferrin (LF) were evaluated, and plasma cortisol concentration, SCC, leucocyte count, and microbiological analyses in milk and mammary secretions were assessed. ACTH significantly downregulated the expression of IGF1R and upregulated the expression of PIK3CA in mammary tissue, increased lactoferrin concentration and SCC, and changed immune cell levels in mammary secretions compared to Control. Furthermore, ACTH administration increased the percentage of dry goats compared to the Control (73 vs. 46%, respectively). We conclude that the effect of stress via ACTH administration and cortisol release accelerated mammary involution during the early dry-off period.
Assuntos
Lactação , Leite , Feminino , Animais , Leite/metabolismo , Lactação/fisiologia , Hidrocortisona , Lactoferrina/genética , Glândulas Mamárias Animais/metabolismo , Apoptose , Cabras/fisiologia , Hormônio Adrenocorticotrópico/farmacologiaRESUMO
PURPOSE: To investigate the effects of Periplaneta americana L. on ulcerative colitis (UC) induced by a combination of chronic stress (CS) and 2,4,6-trinitrobenzene sulfonic acid enema (TNBS) in rats. METHODS: The experiment UC model with CS was established in rats by a combination of chronic restraint stress, excess failure, improper, and TNBS. The body weight, disease activity index (DAI), colonic mucosal injury index (CMDI), histopathological score (HS) and pro-inflammatory mediators were measured. The content of corticotropin-releasing hormone (CRH) in hypothalamus or adrenocorticotropic hormone (ACTH) and corticosteroids (CORT) in plasma were evaluated by enzyme-linked immunosorbent assay. The proportion of T lymphocyte subsets was detected by flow cytometry, and gut microbiota was detected by 16S rDNA amplicon sequencing. RESULTS: Weight loss, DAI, CMDI, HS and proinflammatory mediators were reversed in rats by P. americana L. treatment after UC with CS. Increased epidermal growth factor (EGF) was observed in P. americana L. groups. In addition, P. americana L. could reduce the content of CRH and ACTH and regulate the ratio of CD3+, CD3+CD8+ and CD3+CD4+CD25+/CD4+ in spleen. Comparably, P. americana L. changes composition of gut microbiota. CONCLUSIONS: The ethanol extract of Periplaneta Americana L. improves UC induced by a combination of CS and TNBS in rats.
Assuntos
Colite Ulcerativa , Colite , Periplaneta , Hormônio Adrenocorticotrópico/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Hormônio Adrenocorticotrópico/uso terapêutico , Animais , Colite/patologia , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colo/patologia , Modelos Animais de Doenças , Enema , Etanol/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ratos , Ácido Trinitrobenzenossulfônico/metabolismoRESUMO
Background: The expression and overexpression of luteinizing hormone (LH) receptors in the canine adrenal gland cortex have been reported. Therefore, it was hypothesized that a LH-dependent form of Cushing's syndrome (CS) could exist in dogs. Aim: To assess whether the adrenal gland post-ovariectomy (OVx) exhibits a greater response to adrenocorticotrophin (ACTH) stimulation; to evaluate whether the adrenal gland responds to human chorionic gonadotropin (hCG) stimulation by increasing the release of cortisol; and to consider whether hCG stimulus testing would be useful as a diagnosis for possible cases of LH-dependent CS. Methods: Cortisol concentrations were measured from healthy female dogs (n=16) at baseline and following ACTH stimulation before and 2 months after gonadectomy (OVx). Cortisol concentrations were also measured for female dogs with CS (n = 14) following administration of hCG (5000 IU). A post-hCG cortisol concentration greater than 140 nmol/l was used to define dogs with LH-dependent Cushing's syndrome. Results: In normal female dogs, both pre- and post-stimulation cortisol concentrations increased following OVx (p = 0.002 and p = 0.0003, respectively). In female dogs with CS, cortisol concentrations increased following stimulation with hCG in 57% (8/14; p = 0.002). Age at the time of OVx was associated (p = 0.015) with the cortisol response to hCG [8 (5-9) years vs. 3.5 (2-6) years, p = 0.0013). Conclusion: Based on these results, an LH-dependent form of CS occurs in spayed female dogs, and that it is more likely to occur when female dogs are spayed later in life.
Assuntos
Córtex Suprarrenal , Síndrome de Cushing , Hormônio Adrenocorticotrópico/farmacologia , Animais , Gonadotropina Coriônica/farmacologia , Cães , Feminino , HidrocortisonaRESUMO
CONTEXT: The low-dose (1 µg) ACTH test (LDT) is widely used to assess central adrenal insufficiency (CAI); however, the serum cortisol cutoff value is controversial. Salivary cortisol (SC) may be a more accurate measurement for CAI. OBJECTIVE: To assess a new maximum cutoff value of serum cortisol after LDT in pediatric patients, taking into account serum and SC measurements. DESIGN AND SETTING: Prospective study in a pediatric tertiary referral center. WORKING HYPOTHESIS: The combined analysis of serum and SC response to LDT might improve LDT for CAI diagnosis. PARTICIPANT AND OUTCOME MEASUREMENT: A total of 145 pediatric patients underwent LDT. Serum and SC levels were measured. A central adrenal sufficient (CAS) response was established according to the reference serum cortisol cutoff value of ≥497 nmol/L. RESULTS: The LDT study showed central adrenal sufficiency in 72 patients and CAI in 73 patients. Considering the lower quartile of maximum SC value (21 nmol/L) in the CAS group, an intermediate CAI (InCAI) group and a real CAI (RCAI) group were defined. Regarding the median maximum value of serum cortisol levels in the InCAI group, a new serum cortisol cutoff value of 450 nmol/L was established. Furthermore, 91% of the patients in the RCAI group were below this cutoff value. CONCLUSION: The combined evaluation of maximum serum and SC levels to LDT might be useful to define an InCAI group and to avoid unnecessary hormone replacement therapy. However, rigorous patient follow-up is required.
Assuntos
Insuficiência Adrenal/diagnóstico , Hormônio Adrenocorticotrópico/farmacologia , Hidrocortisona/sangue , Sistema Hipófise-Suprarrenal/fisiopatologia , Glândulas Salivares/metabolismo , Adolescente , Insuficiência Adrenal/sangue , Hormônio Adrenocorticotrópico/sangue , Criança , Estudos de Coortes , Feminino , Humanos , Masculino , Pediatria , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Estudos Prospectivos , Curva ROC , Sensibilidade e EspecificidadeRESUMO
The participation of aberrant receptors and intra-adrenal ACTH in hyperplastic tissue are considered mechanisms that regulate hypercortisolism in PMAH. Additionally, germline ARMC5 mutations have been described as the most frequent genetic abnormality found in patients diagnosed with PMAH. Previous functional studies analyzed ARMC5 role using H295R cells. Therefore, we investigated the role of ARMC5 in cell cultures obtained from PMAH nodules containing steroidogenic cells, aberrant receptors and intra-adrenal ACTH. ARMC5 silencing in non-mutated PMAH cell cultures decreased steroidogenesis-related genes and increased CCNE1 mRNA expression and proliferative capacity without affecting cell viability. Additionally, ARMC5 overexpression induced cell death in PMAH mutated cell cultures, thereby decreasing cell viability. We confirmed the role of ARMC5 as an important pro-apoptotic protein involved in PMAH-related steroidogenesis. We also report for the first time the involvement of ARMC5 in controlling proliferation and regulating cell cycle in PMAH cell cultures; these effects need to be explored further.
Assuntos
Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Proteínas Supressoras de Tumor/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Idoso , Proteínas do Domínio Armadillo , Células Cultivadas , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Humanos , Hiperplasia , Gotículas Lipídicas/efeitos dos fármacos , Gotículas Lipídicas/metabolismo , Masculino , Pessoa de Meia-Idade , Mutação/genética , Pró-Opiomelanocortina/metabolismo , Progesterona Redutase/genética , Progesterona Redutase/metabolismo , Receptor Tipo 2 de Melanocortina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Análise de Sequência de DNA , Coloração e Rotulagem , Esteroide 17-alfa-Hidroxilase/genética , Esteroide 17-alfa-Hidroxilase/metabolismo , Proteínas Supressoras de Tumor/genética , Vasopressinas/farmacologiaRESUMO
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
In addition to the well-known function of ACTH as the main regulator of adrenal steroidogenesis, we have previously demonstrated its effect on the transcriptional stimulation of HO-1 expression, a component of the cellular antioxidant defense system. In agreement, we hereby demonstrate that, in adrenocortical Y1 cells, HO-1 induction correlates with a significant prevention of the generation of reactive oxygen species induced by H2O2/Fe(2+) ACTH/cAMP-dependent activation of redox-imbalanced related factors such as NRF2 or NFκB and the participation of MAPKs in this mechanism was, however, discarded based on results with specific inhibitors and reporter plasmids. We suggest the involvement of CREB in HO-1 induction by ACTH/cAMP, as transfection of cells with a dominant-negative isoform of CREB (DN-CREB-M1) decreased, while overexpression of CREB increased HO-1 protein levels. Sequence screening of the murine HO-1 promoter revealed CRE-like sites located at -146 and -37 of the transcription start site and ChIP studies indicated that this region recruits phosphorylated CREB (pCREB) upon cAMP stimulation in Y1 cells. In agreement, H89 (PKA inhibitor) or cotransfection with DN-CREB-M1 prevented the 8Br-cAMP-dependent increase in luciferase activity in cells transfected with pHO-1[-295/+74].LUC. ACTH and cAMP treatment induced the activation of the PI3K/Akt signaling pathway in a PKA-independent mechanism. Inhibition of this pathway prevented the cAMP-dependent increase in HO-1 protein levels and luciferase activity in cells transfected with pHO-1[-295/+74].LUC. Finally, here we show a crosstalk between the cAMP/PKA and PI3K pathways that affects the binding of p-CREB to its cognate element in the murine promoter of the Hmox1 gene.
Assuntos
Glândulas Suprarrenais/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulação da Expressão Gênica , Heme Oxigenase-1/genética , Hormônio Adrenocorticotrópico/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Animais , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Camundongos , Modelos Biológicos , Fosfatidilinositol 3-Quinases/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Adrenocorticotropic hormone (ACTH) treatment has been proven to promote paxillin dephosphorylation and increase soluble protein tyrosine phosphatase (PTP) activity in rat adrenal zona fasciculata (ZF). Also, in-gel PTP assays have shown the activation of a 115-kDa PTP (PTP115) by ACTH. In this context, the current work presents evidence that PTP115 is PTP-PEST, a PTP that recognizes paxillin as substrate. PTP115 was partially purified from rat adrenal ZF and PTP-PEST was detected through Western blot in bioactive samples taken in each purification step. Immunohistochemical and RT-PCR studies revealed PTP-PEST expression in rat ZF and Y1 adrenocortical cells. Moreover, a PTP-PEST siRNA decreased the expression of this phosphatase. PKA phosphorylation of purified PTP115 isolated from non-ACTH-treated rats increased KM and VM . Finally, in-gel PTP assays of immunoprecipitated paxillin from control and ACTH-treated rats suggested a hormone-mediated increase in paxillin-PTP115 interaction, while PTP-PEST and paxillin co-localize in Y1 cells. Taken together, these data demonstrate PTP-PEST expression in adrenal ZF and its regulation by ACTH/PKA and also suggest an ACTH-induced PTP-PEST-paxillin interaction. J. Cell. Biochem. 117: 2170-2181, 2016. © 2016 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.
Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Paxilina/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 12/biossíntese , Zona Fasciculada/metabolismo , Animais , Linhagem Celular Tumoral , Proteínas Quinases Dependentes de AMP Cíclico/genética , Camundongos , Paxilina/genética , Ligação Proteica/efeitos dos fármacos , Proteína Tirosina Fosfatase não Receptora Tipo 12/genética , Ratos , Zona Fasciculada/citologiaRESUMO
The adrenal gland is a dynamic organ that undergoes constant cell turnover. This allows for rapid organ remodeling in response to the physiological demands of the HPA axis, which is controlled by proopiomelanocortin (POMC)-derived peptides, such as adrenocorticotropic hormone (ACTH) and N-Terminal peptides (N-POMC). In the rat adrenal cortex, POMC-derived peptides trigger a mitogenic effect, and this process increases cyclins D and E, while inhibiting p27Kip1. The goal of the present study was to further explore the mitogenic effect of ACTH and synthetic N-POMC1-28 peptides by investigating the differences in the expression of key genes involved in the cell cycle of the rat adrenal cortex, following inhibition of the HPA axis. Moreover, we evaluated the differences between the inner and outer fractions of the adrenal cortex (ZF-fraction and ZG-fraction) in terms of their response patterns to different stimuli. In the current study, the inhibition of the HPA axis repressed the expression of Ccnb2, Camk2a, and Nek2 genes throughout the adrenal cortex, while treatments with POMC-derived peptides stimulated Nek2, gene and protein expression, and Notch2 gene expression. Furthermore, Notch1 protein expression was restricted to the subcapsular region of the cortex, an area of the adrenal cortex that is well-known for proliferation. We also showed that different regions of the adrenal cortex respond to HPA-axis inhibition and to induction with POMC-derived peptides at different times. These results suggest that cells in the ZG and ZF fractions could be at different phases of the cell cycle. Our results contribute to the understanding of the mechanisms involved in cell cycle regulation in adrenocortical cells triggered by N-POMC peptides and ACTH, and highlight the involvement of genes such as Nek2 and Notch.
Assuntos
Córtex Suprarrenal/efeitos dos fármacos , Hormônio Adrenocorticotrópico/farmacologia , Proliferação de Células/efeitos dos fármacos , Dexametasona/farmacologia , Fragmentos de Peptídeos/farmacologia , Pró-Opiomelanocortina/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Receptor Notch1/metabolismo , Córtex Suprarrenal/citologia , Córtex Suprarrenal/metabolismo , Animais , Proliferação de Células/fisiologia , RatosRESUMO
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), which is considered one of the most important causes of reproductive failure in dairy cattle, induces intraovarian changes in the expression of numerous genes. The purpose of this study was to analyze the changes in the expression of Heat Shock Proteins (HSPs) in ovaries from bovines with cystic ovarian disease induced by ACTH. Immunoreactivity for Heat Shock Proteins (HSPs) in ovaries of cows with induced COD showed differential expression patterns in growing follicles from the control group. The immunopositive area for Hsp27 and Hsp60 in granulosa cells showed significant differences between tertiary follicles from normal cycling animals and those from animals with induced COD. The cysts showed increased Hsp27 immunostaining in theca cells in relation to tertiary follicles from normal cycling cows. Hsp70 immunostaining was more intense in cystic follicles than in other follicular categories from animals with induced COD, in both granulosa and theca cells. In granulosa cells, tertiary follicles from the control group showed higher levels of Hsp90 than cysts. These results demonstrate that there are differences in HSP protein expression when COD is induced. In fact, HSP expression would be part of the functional response to the changes in hormones and neurotransmitters induced by stress, indicating that HSPs can control hormonal functions and vice versa.
Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Doenças dos Bovinos/metabolismo , Proteínas de Choque Térmico/biossíntese , Cistos Ovarianos/veterinária , Ovário/metabolismo , Animais , Bovinos , Doenças dos Bovinos/induzido quimicamente , Chaperonina 60/biossíntese , Chaperonina 60/fisiologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/metabolismo , Proteínas de Choque Térmico HSP27/biossíntese , Proteínas de Choque Térmico HSP27/fisiologia , Proteínas de Choque Térmico/fisiologia , Cistos Ovarianos/induzido quimicamente , Cistos Ovarianos/metabolismo , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/metabolismo , Ovário/efeitos dos fármacos , Células Tecais/efeitos dos fármacos , Células Tecais/metabolismoRESUMO
OBJECTIVES: To determine which biological or clinical variables may predict cortisol response to low-dose adrenocorticotropic hormone (ACTH) stimulation following supraphysiological doses of glucocorticoids in children. STUDY DESIGN: This retrospective study included all patients who underwent ACTH testing (1 µg) between October 2008 and June 2010 at the Sainte-Justine University Hospital Center, Montreal, after supraphysiological doses of glucocorticoids. RESULTS: Data from 103 patients (median age, 8.0 years; range, 0.6-18.5 years; 57 girls) were analyzed, revealing growth deceleration in 37% and excessive weight gain in 33%. Reasons for glucocorticoid treatment included asthma (n = 30) and hematologic (n = 22), dermatologic (n = 19), rheumatologic (n = 16), and miscellaneous (n = 16) disorders. The following information was recorded: duration of glucocorticoid treatment (median, 374 days; range, 5-4226 days); duration of physiological hydrocortisone replacement (median, 118 days; range, 0-1089 days); maximum daily (median, 200 mg/m(2)/day; range, 12-3750 mg/m(2)/day) and cumulative (median, 16â728 mg/m(2); range, 82-178â209 mg/m(2)) doses, in hydrocortisone equivalents; and interval since the last dose (median, 43 days; range, 1-1584 days). Sixty-two patients (58%) exhibited a normal response (ie, peak cortisol >500 nmol/L) to ACTH stimulation. Peak cortisol level was not related to sex, prior morning cortisol level, duration of treatment, or cumulative glucocorticoid dose; 28% of the patients with normal baseline cortisol levels nevertheless demonstrated a subnormal response to ACTH. CONCLUSION: Given the absence of clinical or biological predictors of the cortisol response to ACTH after suppressive doses of glucocorticoids, physicians have only 2 options: (1) empirically advocate glucocorticoid stress coverage during 18 months after cessation of high-dose glucocorticoid treatment; or (2) perform serial ACTH testing in all such patients until a normal peak cortisol level is attained.
Assuntos
Hormônio Adrenocorticotrópico/administração & dosagem , Dexametasona/administração & dosagem , Glucocorticoides/administração & dosagem , Hidrocortisona/administração & dosagem , Hidrocortisona/sangue , Prednisona/administração & dosagem , Adolescente , Hormônio Adrenocorticotrópico/farmacologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos RetrospectivosRESUMO
The Adrenocorticotropic hormone (ACTH) and Pro-opimelanocortin (POMC) 1-28N-terminal peptide (N-POMC(1-28)) have been shown to act as an adrenal mitogen in vivo. A possible role for cyclin E in the zona glomerulosa (ZG) proliferation, following ACTH and/or N-POMC(1-28) administration, has been previously demonstrated. In this study, we investigated the effect of ACTH and N-POMC(1-28) on the expression of adrenal cortex proteins related to cell cycle control such as cyclins D and P27(kip1). The administration of N-POMC upregulated cyclin D1 and D2 expression in the outer zone of the adrenal cortex; cyclin D3 expression was upregulated in the cortex inner zone even after administration of ACTH. Both ACTH and N-POMC peptides induced a decrease in the P27(kip1) expression in the ZG. These novel findings suggest that the POMC-derivate peptides, ACTH and N-POMC, promote proliferation in the adrenal cortex by upregulating the D2 and D3 cyclins and downregulating the P27(kip1) expression.
Assuntos
Córtex Suprarrenal/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Ciclina D/biossíntese , Inibidor de Quinase Dependente de Ciclina p27/biossíntese , Fragmentos de Peptídeos/farmacologia , Pró-Opiomelanocortina/farmacologia , Córtex Suprarrenal/efeitos dos fármacos , Hormônio Adrenocorticotrópico/metabolismo , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Pontos de Checagem do Ciclo Celular , Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células , Ciclina D1/biossíntese , Ciclina D2/biossíntese , Ciclina D3/biossíntese , Regulação para Baixo , Masculino , Fragmentos de Peptídeos/metabolismo , Pró-Opiomelanocortina/metabolismo , Ratos , Ratos Sprague-Dawley , Regulação para Cima , Zona Glomerulosa/metabolismoRESUMO
Surprisingly, in our modern 24/7 society, there is scant information on the impact of developmental chronodisruption like the one experienced by shift worker pregnant women on fetal and postnatal physiology. There are important differences between the maternal and fetal circadian systems; for instance, the suprachiasmatic nucleus is the master clock in the mother but not in the fetus. Despite this, several tissues/organs display circadian oscillations in the fetus. Our hypothesis is that the maternal plasma melatonin rhythm drives the fetal circadian system, which in turn relies this information to other fetal tissues through corticosterone rhythmic signaling. The present data show that suppression of the maternal plasma melatonin circadian rhythm, secondary to exposure of pregnant rats to constant light along the second half of gestation, had several effects on fetal development. First, it induced intrauterine growth retardation. Second, in the fetal adrenal in vivo it markedly affected the mRNA expression level of clock genes and clock-controlled genes as well as it lowered the content and precluded the rhythm of corticosterone. Third, an altered in vitro fetal adrenal response to ACTH of both, corticosterone production and relative expression of clock genes and steroidogenic genes was observed. All these changes were reversed when the mother received a daily dose of melatonin during the subjective night; supporting a role of melatonin on overall fetal development and pointing to it as a 'time giver' for the fetal adrenal gland. Thus, the present results collectively support that the maternal circadian rhythm of melatonin is a key signal for the generation and/or synchronization of the circadian rhythms in the fetal adrenal gland. In turn, low levels and lack of a circadian rhythm of fetal corticosterone may be responsible of fetal growth restriction; potentially inducing long term effects in the offspring, possibility that warrants further research.
Assuntos
Glândulas Suprarrenais/embriologia , Relógios Circadianos/efeitos dos fármacos , Relógios Circadianos/efeitos da radiação , Feto/fisiologia , Luz/efeitos adversos , Melatonina/farmacologia , Mães , Fatores de Transcrição ARNTL/genética , Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/fisiologia , Glândulas Suprarrenais/efeitos da radiação , Hormônio Adrenocorticotrópico/farmacologia , Animais , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/efeitos da radiação , Corticosterona/sangue , Proteína 1 de Resposta de Crescimento Precoce/genética , Feminino , Feto/efeitos dos fármacos , Feto/embriologia , Feto/efeitos da radiação , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Proteínas Circadianas Period/genética , Fosfoproteínas/genética , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Melatonina/genética , Fatores de TempoRESUMO
The possibility of assessing endogenous adrenal activity in the collared peccary (Pecari tajacu) was tested by using an adrenocorticotropic hormone (ACTH) challenge in a fecal glucocorticoid metabolite (FGM) assay. Feces were collected from 12 captive adult male peccaries beginning 48 hr prior to challenge; six of these animals received the challenge as an ACTH injection and the other six were injected with saline solution. Feces collection ended 120 hr after injections. As a control, feces were collected for eight consecutive days from another six adult male peccaries that remained in their original mixed-sex herds in semiconfined paddocks. All feces samples were freeze-dried, extracted by an ethanol vortex method, and assayed for glucocorticoids by means of an enzyme immunoassay. FGM concentrations were compared between the treatments by a repeated measures analysis of variance (ANOVA) followed by a post hoc Tukey test. The assay is reliable but, instead of the usual proportion of 1:50 in ethanol (fecal mass:solvent), 1:10 is recommended for best extraction of FGM. Baseline FGM concentrations were similar among the ACTH, saline, and control treatments (29.7 +/- 11.2 ng/g(-1) dry feces) during the 48 hr before the challenge. The ACTH group reached an FGM excretion peak at 24 hr post-treatment, followed by a decline, while in the control and saline groups FGM levels remained relatively constant. Therefore, the fecal glucocorticoid metabolite assay reflects endogenous adrenal activity in the collared peccary and is a powerful tool for noninvasive stress monitoring in peccaries.
Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Artiodáctilos/fisiologia , Fezes/química , Glucocorticoides/química , Glucocorticoides/metabolismo , Hormônio Adrenocorticotrópico/química , Hormônio Adrenocorticotrópico/metabolismo , Bem-Estar do Animal , Animais , Animais de Zoológico , Imunoensaio/veterinária , Masculino , Reprodutibilidade dos TestesRESUMO
It has been hypothesized that deviations in glucocorticoid secretion and/or action may contribute to somatic and biochemical changes observed in patients with and animal models of insulin resistance (IR). In this study, we analyzed changes in rat adrenocortical function and morphology associated with the development of IR, generated in male adult rats by the addition of 30% sucrose to the drinking water. Caloric intake, body and adipose tissue weights, and biochemical parameters associated with IR were determined. Expression levels of Star, Cyp11A1, Mc2r, Pparγ (Pparg), and Cd36 were evaluated by real-time PCR, histochemical analysis of the adrenal cortex was performed using Masson's trichrome and Sudan III staining, and corticosterone levels were measured by RIA. After 7 weeks of sucrose administration, higher serum glucose, insulin, and triglyceride levels and an altered glycemic response to an i.p. insulin test were detected. Adrenal glands showed a neutral lipid infiltration. An increase in Star, Cyp11A1, Mc2r, Pparg and Cd36 and a decrease in Mc2r levels were also found. Furthermore, sucrose-treated animals exhibited higher basal corticosterone levels and a blunted response to ACTH injection. Noteworthy, the adrenocortical (functional and histological) abnormalities were prevented in sucrose-treated rats by the simultaneous administration of an insulin-sensitizing PPARγ agonist. In conclusion, sucrose-induced IR affects adrenocortical morphology and function possibly via the generation of adipokines or lipid metabolites within the adrenal gland. These abnormalities are prevented by the administration of a PPARγ agonist by mechanisms involving both extra- and intra-adrenal effects.
Assuntos
Córtex Suprarrenal/metabolismo , Sacarose Alimentar/farmacologia , Resistência à Insulina/fisiologia , Transtornos do Metabolismo dos Lipídeos/prevenção & controle , PPAR gama/agonistas , Tiazolidinedionas/farmacologia , Córtex Suprarrenal/patologia , Hormônio Adrenocorticotrópico/farmacologia , Animais , Corticosterona/sangue , Ingestão de Energia/efeitos dos fármacos , Ingestão de Energia/fisiologia , Hormônios/farmacologia , Hipoglicemiantes/farmacologia , Insulina/sangue , Insulina/farmacologia , Transtornos do Metabolismo dos Lipídeos/metabolismo , Transtornos do Metabolismo dos Lipídeos/patologia , Masculino , PPAR gama/metabolismo , Ratos , Ratos Wistar , Rosiglitazona , Triglicerídeos/sangueRESUMO
There is evidence that pro-opiomelanocortin (POMC)-derived peptides other than adrenocorticotropic hormone (ACTH) have a role in adrenal cell proliferation. We compared the activity of synthetic rat N-terminal POMC fragment 1-28 with disulfide bridges (N-POMC(w)) and without disulfide bridges (N-POMC(w/o)), with the activity of fibroblast growth factor (FGF2), a widely studied adrenal growth factor, and ACTH, in well-characterized pure cultures of both isolated adrenal Glomerulosa (G) and Fasciculata/Reticularis (F/R) cells. Three days of FGF2-treatment had a proliferative effect similar to serum, and synthetic peptide N-POMC(w) induced proliferation more efficiently than N-POMC(w/o). Moreover, both induced proliferation via the ERK1/2 pathway. In contrast, sustained ACTH treatment decreased proliferation and viability through apoptosis induction, but not necrosis, and independently of PKA and PKC pathways. Further elucidation of 1-28 POMC signal transduction is of interest, and primary cultures of adrenal cells were found to be useful for examining the trophic activity of this peptide.