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1.
Peptides ; 170: 171112, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37918484

RESUMO

Growth differentiation factor-15 (GDF15) is a stress-activated cytokine that regulates cell growth and inflammatory and stress responses. We previously reported the role and regulation of GDF15 in pituitary corticotrophs. Dexamethasone increases Gdf15 gene expression levels and production. GDF15 suppresses adrenocorticotropic hormone synthesis in pituitary corticotrophs and subsequently mediates the negative feedback effect of glucocorticoids. Here, we analyzed corticotropin-releasing factor (Crf) promoter activity in hypothalamic 4B cells transfected with promoter-driven luciferase reporter constructs. The effects of time and GDF15 concentration on Crf mRNA levels were analyzed using quantitative real-time polymerase chain reaction. Glial cell-derived neurotrophic factor family receptor α-like (GFRAL) protein is expressed in 4B cells. GDF15 increased Crf promoter activity and Crf mRNA levels in 4B cells. The protein kinase A and C pathways also contributed to the GDF15-induced increase in Crf gene expression. GDF15 stimulates GFRAL, subsequently increasing the phosphorylation of AKT, an extracellular signal-related kinase, and the cAMP response element-binding protein. Therefore, GDF15-dependent pathways may be involved in regulating Crf expression under stressful conditions in hypothalamic cells.


Assuntos
Hormônio Liberador da Corticotropina , Fator 15 de Diferenciação de Crescimento , Hipotálamo , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/metabolismo , Fatores de Diferenciação de Crescimento/genética , Fatores de Diferenciação de Crescimento/metabolismo , Fatores de Diferenciação de Crescimento/farmacologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Regiões Promotoras Genéticas , Receptores de Hormônio Liberador da Corticotropina/genética , Receptores de Hormônio Liberador da Corticotropina/metabolismo , RNA Mensageiro/metabolismo , Animais , Ratos , Fator 15 de Diferenciação de Crescimento/metabolismo , Fator 15 de Diferenciação de Crescimento/farmacologia , Humanos
2.
Proc Natl Acad Sci U S A ; 120(28): e2216564120, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37379351

RESUMO

Patients with permanent hypoparathyroidism require lifelong replacement therapy to avoid life-threatening complications, The benefits of conventional treatment are limited, however. Transplanting a functional parathyroid gland (PTG) would yield better results. Parathyroid gland cells generated from pluripotent stem cells in vitro to date cannot mimic the physiological responses to extracellular calcium that are essential for calcium homeostasis. We thus hypothesized that blastocyst complementation (BC) could be a better strategy for generating functional PTG cells and compensating loss of parathyroid function. We here describe generation of fully functional PTGs from mouse embryonic stem cells (mESCs) with single-step BC. Using CRISPR-Cas9 knockout of Glial cells missing2 (Gcm2), we efficiently produced aparathyroid embryos for BC. In these embryos, mESCs differentiated into endocrinologically mature PTGs that rescued Gcm2-/- mice from neonatal death. The mESC-derived PTGs responded to extracellular calcium, restoring calcium homeostasis on transplantation into mice surgically rendered hypoparathyroid. We also successfully generated functional interspecies PTGs in Gcm2-/- rat neonates, an accomplishment with potential for future human PTG therapy using xenogeneic animal BC. Our results demonstrate that BC can produce functional endocrine organs and constitute a concept in treatment of hypoparathyroidism.


Assuntos
Hipoparatireoidismo , Glândulas Paratireoides , Humanos , Animais , Camundongos , Ratos , Cálcio , Hipoparatireoidismo/genética , Hipoparatireoidismo/terapia , Cálcio da Dieta , Blastocisto
3.
J Endocr Soc ; 7(4): bvad023, 2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36860907

RESUMO

Context: The COVID-19 pandemic challenged undertaking gradual educational activities for residency and fellowship trainees. However, recent technological advances have enabled broadening active learning opportunities through international online conferences. Objective: The format of our international online endocrine case conference, launched during the pandemic, is introduced. The objective impact of this program on trainees is described. Methods: Four academic facilities developed a semiannual international collaborative endocrinology case conference. Experts were invited as commentators to facilitate in-depth discussion. Six conferences were held between 2020 and 2022. After the fourth and sixth conferences, anonymous multiple-choice online surveys were administered to all attendees. Results: Participants included trainees and faculty. At each conference, 3 to 5 cases of rare endocrine diseases from up to 4 institutions were presented, mainly by trainees. Sixty-two percent of attendees reported 4 facilities as the appropriate size for the collaboration to maintain active learning in case conferences. Eighty-two percent of attendees preferred a semiannual conference. The survey also revealed the positive impact on trainees' learning regarding diversity of medical practice, academic career development, and confidence in honing of presentation skills. Conclusion: We present an example of our successful virtual global case conference to enhance learning about rare endocrine cases. For the success of the collaborative case conference, we suggest smaller cross-country institutional collaborations. Preferably, they would be international, semiannually based, and with recognized experts as commentators. Since our conference has engendered multiple positive effects on trainees and faculty, continuation of virtual education should be considered even after the pandemic era.

4.
Endocrinology ; 163(12)2022 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-36240318

RESUMO

Endogenous Cushing's syndrome is characterized by unique clinical features and comorbidities, and progress in the analysis of its genetic pathogenesis has been achieved. Moreover, prescribed glucocorticoids are also associated with exogenous Cushing's syndrome. Several animal models have been established to explore the pathophysiology and develop treatments for Cushing's syndrome. Here, we review recent studies reporting animal models of Cushing's syndrome with different features and complications induced by glucocorticoid excess. Exogenous corticosterone (CORT) administration in drinking water is widely utilized, and we found that CORT pellet implantation in mice successfully leads to a Cushing's phenotype. Corticotropin-releasing hormone overexpression mice and adrenal-specific Prkar1a-deficient mice have been developed, and AtT20 transplantation methods have been designed to examine the medical treatments for adrenocorticotropic hormone-producing pituitary neuroendocrine tumors. We also review recent advances in the molecular pathogenesis of glucocorticoid-induced complications using animal models.


Assuntos
Síndrome de Cushing , Neoplasias Hipofisárias , Camundongos , Animais , Síndrome de Cushing/etiologia , Hormônio Adrenocorticotrópico , Glucocorticoides , Hormônio Liberador da Corticotropina , Modelos Animais , Hidrocortisona
5.
Cancers (Basel) ; 14(15)2022 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-35892862

RESUMO

Prolactinomas comprise 30-50% of all pituitary neuroendocrine tumors, frequently occur in females aged 20 to 50, and cause hypogonadism and infertility. In typical cases, female patients exhibit galactorrhea and amenorrhea due to serum prolactin (PRL) elevation, and patients during pregnancy should be carefully treated. During diagnosis, other causes of hyperprolactinemia must be excluded, and an MRI is useful for detecting pituitary neuroendocrine tumors. For treating prolactinoma, dopamine agonists (DAs) are effective for decreasing PRL levels and shrinking tumor size in most patients. Some DA-resistant cases and the molecular mechanisms of resistance to a DA are partially clarified. The side effects of a DA include cardiac valve alterations and impulse control disorders. Although surgical therapies are invasive, recent analysis shows that long-term remission rates are higher than from medical therapies. The treatments for giant or malignant prolactinomas are challenging, and the combination of medication, surgery, and radiation therapy should be considered. Regarding pathogenesis, somatic SF3B1 mutations were recently identified even though molecular mechanisms in most cases of prolactinoma have not been elucidated. To understand the pathogenesis of prolactinomas, the development of new therapeutic approaches for treatment-resistant patients is expected. This review updates the recent advances in understanding the pathogenesis, diagnosis, and therapy of prolactinoma.

6.
Peptides ; 155: 170841, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35868568

RESUMO

Growth differentiation factor-15 (GDF15) is a stress-responsive cytokine that plays important roles in regulation of inflammatory responses, cell growth, and cell differentiation. However, the nature of these roles remains unclear. Here, we aimed to examine the regulatory effects of dexamethasone on Gdf15 expression in murine AtT-20 corticotroph cells. Human Gdf15 promoter-driven luciferase reporter constructs were transfected into corticotroph cells to analyze their promoter activity. The effects of time and concentration of dexamethasone on Gdf15 and proopiomelanocortin (Pomc) mRNA levels were assessed using quantitative real-time polymerase chain reaction. Dexamethasone induced Gdf15 transcription and mRNA levels as well as GDF15 production in transfected cells, whereas reduced the Pomc mRNA levels. GDF15 modulated adrenocorticotropic hormone (ACTH) synthesis, and the dexamethasone-mediated reduction in Pomc mRNA levels were partially relieved upon Gdf15 knockdown. We concluded that GDF15 modulated ACTH production in pituitary corticotrophs in an autocrine manner by suppressing Pomc expression and subsequently mediating the negative feedback effect of glucocorticoids, thereby contributing to pituitary stress response and homeostasis.


Assuntos
Hormônio Adrenocorticotrópico , Corticotrofos , Fator 15 de Diferenciação de Crescimento , Hormônio Adrenocorticotrópico/metabolismo , Animais , Corticotrofos/química , Corticotrofos/metabolismo , Hormônio Liberador da Corticotropina/metabolismo , Dexametasona/farmacologia , Expressão Gênica , Fator 15 de Diferenciação de Crescimento/metabolismo , Humanos , Camundongos , Pró-Opiomelanocortina/genética , Pró-Opiomelanocortina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
7.
Steroids ; 183: 109021, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35339573

RESUMO

The 11ß hydroxysteroid dehydrogenase type-1 (11ßHSD-1) is a predominant 11ß-reductase regenerating bioactive glucocorticoids (cortisol, corticosterone) from inactive 11-keto forms (cortisone, dehydrocorticosterone), expressed mainly in the brain, liver and adipose tissue. Although the expression levels of 11ß HSD-1 mRNA are known to be influenced by glucocorticoids, its tissue-specific regulation is not completely elucidated. In this study, we examined the effect of persistent glucocorticoid excess on the expression of 11ß HSD-1 mRNA in the hippocampus, liver, and abdominal adipose tissue in vivo using quantitative real-time PCR. We found that, in C57BL/6J mice treated with corticosterone (CORT) pellet for 2 weeks, 11ß HSD-1 mRNA decreased in the hippocampus (HIPP) and liver, whereas it increased in the abdominal fat (FAT), compared with placebo treatment [HIPP: placebo 1.00 ± 0.14, CORT 0.63 ± 0.04; liver: placebo 1.00 ± 0.08, CORT 0.73 ± 0.06; FAT: placebo 1.00 ± 0.16, CORT 2.26 ± 0.39]. Moreover, in CRH transgenic mice, an animal model of Cushing's syndrome with high plasma CORT level, 11ß HSD-1 mRNA was also decreased in the hippocampus and liver, and increased in the abdominal adipose tissue compared to that in wild-type mice. These changes were reversed after adrenalectomy in CRH-Tg mice. Altogether, these results reveal the differential regulation of 11ß HSD-1 mRNA by glucocorticoid among the tissues examined.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1 , Síndrome de Cushing , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/genética , Animais , Corticosterona/metabolismo , Síndrome de Cushing/genética , Modelos Animais de Doenças , Glucocorticoides/farmacologia , Hidroxiesteroide Desidrogenases/genética , Hidroxiesteroide Desidrogenases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
8.
Endocr J ; 69(9): 1053-1060, 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-35296577

RESUMO

Cushing's disease is an endocrine disorder characterized by hypercortisolism, mainly caused by autonomous production of ACTH from pituitary adenomas. Autonomous ACTH secretion results in excess cortisol production from the adrenal glands, and corticotroph adenoma cells disrupt the normal cortisol feedback mechanism. Pan-histone deacetylase (HDAC) inhibitors inhibit cell proliferation and ACTH production in AtT-20 corticotroph tumor cells. A selective HDAC6 inhibitor has been known to exert antitumor effects and reduce adverse effects related to the inhibition of other HDACs. The current study demonstrated that the potent and selective HDAC6 inhibitor tubastatin A has inhibitory effects on proopiomelanocortin (Pomc) and pituitary tumor-transforming gene 1 (Pttg1) mRNA expression, involved in cell proliferation. The phosphorylated Akt/Akt protein levels were increased after treatment with tubastatin A. Therefore, the proliferation of corticotroph cells may be regulated through the Akt-Pttg1 pathway. Dexamethasone treatment also decreased the Pomc mRNA level. Combined tubastatin A and dexamethasone treatment showed additive effects on the Pomc mRNA level. Thus, tubastatin A may have applications in the treatment of Cushing's disease.


Assuntos
Adenoma Hipofisário Secretor de ACT , Adenoma , Hipersecreção Hipofisária de ACTH , Adenoma Hipofisário Secretor de ACT/metabolismo , Adenoma/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Proliferação de Células , Corticotrofos , Dexametasona/farmacologia , Histona Desacetilases/metabolismo , Histona Desacetilases/farmacologia , Humanos , Hidrocortisona/metabolismo , Ácidos Hidroxâmicos , Indóis , Hipersecreção Hipofisária de ACTH/metabolismo , Pró-Opiomelanocortina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/metabolismo
9.
Mol Metab ; 59: 101458, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35189429

RESUMO

OBJECTIVE: The intestine is an important organ for nutrient metabolism via absorption and endocrine systems. Nutrients regulate O-GlcNAcylation, a post-translational modification of various proteins by O-GlcNAc transferase (OGT). We have previously shown that general OGT knockout induced severe weight loss and hypoglycaemia in mice, but little is known about how O-GlcNAcylation in the intestine modulates nutrient metabolism, especially glucose metabolism, through absorption. We aimed to reveal the roles of O-GlcNAcylation in glucose absorption by the small intestine and elucidate the mechanism by which O-GlcNAcylation regulates sodium-glucose cotransporter 1 (SGLT1) expression. METHODS: First, we fasted normal mice and examined the changes in glucose transporters and O-GlcNAcylation in the intestine. Then, we generated two lines of small intestine-specific OGT-deficient mice (congenital: Ogt-VKO, tamoxifen-inducible: Ogt-iVKO) and observed the changes in body weight and in glucose and lipid metabolism. Finally, we investigated Sglt1 gene regulation by O-GlcNAcylation using enteroendocrine STC-1 cells. RESULTS: Fasting decreased O-GlcNAcylation in the intestinal epithelium of normal mice. The Ogt-VKO mice showed significantly lower non-fasted blood glucose levels and were underweight compared with litter matched controls. Glycaemic excursion in the Ogt-VKO mice was significantly lower during the oral glucose tolerance test but comparable during the intraperitoneal glucose tolerance test. Furthermore, the Ogt-VKO mice exhibited lower Sglt1 expression in the small intestine compared with the control mice. We obtained similar results using the Ogt-iVKO mice only after tamoxifen administration. The oral d-xylose administration test revealed that the intestinal sugar absorption was diminished in the Ogt-iVKO mice and that GLP-1 secretion did not sufficiently increase after glucose gavage in the Ogt-iVKO mice. When using STC-1 cells, O-GlcNAcylation increased Sglt1 mRNA via a PKA/CREB-dependent pathway. CONCLUSION: Collectively, loss of O-GlcNAcylation in the intestine reduced glucose absorption via suppression of SGLT1 expression; this may lead to new treatments for malabsorption, obesity and diabetes.


Assuntos
Glicemia , Peso Corporal , Intestinos , Transportador 1 de Glucose-Sódio , Animais , Glicemia/metabolismo , Glucose/metabolismo , Intestinos/metabolismo , Camundongos , Obesidade , Transportador 1 de Glucose-Sódio/genética , Tamoxifeno
10.
Int J Mol Sci ; 22(22)2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34830130

RESUMO

This review addresses the molecular mechanisms of corticotropin-releasing factor (CRF) regulation in the hypothalamus under stress and stress resilience. CRF in the hypothalamus plays a central role in regulating the stress response. CRF stimulates adrenocorticotropic hormone (ACTH) release from the anterior pituitary. ACTH stimulates glucocorticoid secretion from the adrenal glands. Glucocorticoids are essential for stress coping, stress resilience, and homeostasis. The activated hypothalamic-pituitary-adrenal axis is suppressed by the negative feedback from glucocorticoids. Glucocorticoid-dependent repression of cAMP-stimulated Crf promoter activity is mediated by both the negative glucocorticoid response element and the serum response element. Conversely, the inducible cAMP-early repressor can suppress the stress response via inhibition of the cAMP-dependent Crf gene, as can the suppressor of cytokine signaling-3 in the hypothalamus. CRF receptor type 1 is mainly involved in a stress response, depression, anorexia, and seizure, while CRF receptor type 2 mediates "stress coping" mechanisms such as anxiolysis in the brain. Differential effects of FK506-binding immunophilins, FKBP4 and FKBP5, contribute to the efficiency of glucocorticoids under stress resilience. Together, a variety of factors contribute to stress resilience. All these factors would have the differential roles under stress resilience.


Assuntos
Adaptação Fisiológica/fisiologia , Hormônio Liberador da Corticotropina/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Hipotálamo/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Estresse Fisiológico/fisiologia , Hormônio Adrenocorticotrópico/metabolismo , Animais , Humanos , Modelos Biológicos
11.
Diabetol Int ; 12(4): 480-484, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34567928

RESUMO

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is characterized by bilateral multiple adrenal macro-nodules that often cause mild over-secretion of cortisol in the form of subclinical Cushing's syndrome. We herein describe a case, wherein unilateral adrenalectomy partially improved hyperglycemia in a patient with PBMAH and suggest the usefulness and limitations of this surgical strategy. A 64-year-old woman with type 2 diabetes had an incidental diagnosis of bilateral adrenal lesions. She had a family history of type 2 diabetes, and her HbA1c level was 8.9% under insulin therapy. She did not present with any symptoms associated with Cushing's syndrome. The basal cortisol level was in the normal range (12.0 µg/dL); however, the adrenocorticotropic hormone (ACTH) level was suppressed (2.1 pg/mL) and the serum cortisol level was not suppressed in the dexamethasone test. Computed tomography and magnetic resonance imaging showed bilateral adrenal macro-nodules and 131I-adosterol accumulated in the bilateral adrenal lesions. Collectively, she was diagnosed with subclinical Cushing's syndrome due to PBMAH complicated with diabetes mellitus, hypertension, and dyslipidemia. Laparoscopic left adrenalectomy was performed, and the pathologic findings were consistent with PBMAH. After unilateral adrenalectomy, serum cortisol levels decreased, and hypertension improved. Both HbA1c levels and insulin requirement also decreased, but insulin therapy was continuously needed. It should be noted that hyperglycemia may not be cured after successful surgery in a patient with PBMAH. Additional operation or medical therapy should be considered if unilateral adrenalectomy is unable to correct hypercortisolism in PBMAH patients.

12.
Int J Mol Sci ; 22(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34072036

RESUMO

The hypothalamic-pituitary-adrenal axis is stimulated in response to stress. When activated, it is suppressed by the negative feedback effect of glucocorticoids. Glucocorticoids directly inhibit proopiomelanocortin (Pomc) gene expression in the pituitary. Glucocorticoid signaling is mediated via glucocorticoid receptors, 11ß-hydroxysteroid dehydrogenases, and the FK506-binding immunophilins, Fkbp4 and Fkbp5. Fkbp4 and Fkbp5 differentially regulate dynein interaction and nuclear translocation of the glucocorticoid receptor, resulting in modulation of the glucocorticoid action. Here, we explored the regulation of Fkbp4 and Fkbp5 genes and their proteins with dexamethasone, a major synthetic glucocorticoid drug, in murine AtT-20 corticotroph cells. To elucidate further roles of Fkbp4 and Fkbp5, we examined their effects on Pomc mRNA levels in corticotroph cells. Dexamethasone decreased Pomc mRNA levels as well as Fkpb4 mRNA levels in mouse corticotroph cells. Dexamethasone tended to decrease Fkbp4 protein levels, while it increased Fkpb5 mRNA and its protein levels. The dexamethasone-induced decreases in Pomc mRNA levels were partially canceled by Fkbp4 knockdown. Alternatively, Pomc mRNA levels were further decreased by Fkbp5 knockdown. Thus, Fkbp4 contributes to the negative feedback of glucocorticoids, and Fkbp5 reduces the efficiency of the glucocorticoid effect on Pomc gene expression in pituitary corticotroph cells.


Assuntos
Corticotrofos/metabolismo , Regulação da Expressão Gênica , Pró-Opiomelanocortina/genética , Proteínas de Ligação a Tacrolimo/metabolismo , Animais , Biomarcadores , Corticotrofos/citologia , Dexametasona/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Glucocorticoides/metabolismo , Camundongos , Modelos Biológicos , Ligação Proteica , RNA Mensageiro/genética , Receptores de Glucocorticoides/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas de Ligação a Tacrolimo/genética
13.
J Neuroendocrinol ; 32(4): e12851, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32319174

RESUMO

Transcription factor cAMP responsive element-binding protein 3 like 1 (Creb3l1) is a non-classical endoplasmic reticulum stress molecule that is emerging as an important component for cellular homeostasis, particularly within cell types with high peptide secretory capabilities. We have previously shown that Creb3l1 serves an important role in body fluid homeostasis through its transcriptional control of the gene coding for antidiuretic hormone arginine vasopressin in the neuropeptide-rich magnocellular neurones of the supraoptic nucleus. In response to osmotic stimuli such as dehydration, vasopressin magnocellular neurones undergo remarkable transcriptome changes, including increased Creb3l1 expression, to ensure that the supply of vasopressin meets demand. To determine where else Creb3l1 fits into the secretory cell supply chain, we performed RNA-sequencing of Creb3l1 knockdown anterior pituitary mouse corticotroph cell line AtT20. The target chosen for further investigation was Pcsk1, which encodes proprotein convertase enzyme 1 (PC1/3). PC1/3 is crucial for processing of neuropeptides and peptide hormones such as pro-opiomelanocortin (POMC), proinsulin, proglucagon, vasopressin and oxytocin. Viral manipulations in supraoptic nuclei by over-expression of Creb3l1 increased Pcsk1, whereas Creb3l1 knockdown decreased Pcsk1 expression. In vitro promoter activity and binding studies showed that Creb3l1 was a transcription factor of the Pcsk1 gene binding directly to a G-box motif in the promoter. In the dehydrated rat anterior pituitary, Creb3l1 and Pcsk1 expression decreased in parallel compared to control, supporting our findings from manipulations in AtT20 cells and the supraoptic nucleus. No relationship was observed between Creb3l1 and Pcsk1 expression in the neurointermediate lobe of the pituitary, indicating a different mechanism of PC1/3 synthesis by these POMC-synthesising cells. Therefore, Creb3l1, by regulating the expression of Pcsk1, does not control the processing of POMC peptides in the intermediate lobe.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Pressão Osmótica/fisiologia , Hipófise/metabolismo , Pró-Proteína Convertase 1/metabolismo , Núcleo Supraóptico/metabolismo , Animais , Linhagem Celular , Regulação da Expressão Gênica , Masculino , Camundongos , Pró-Opiomelanocortina/metabolismo , Ratos , Ratos Sprague-Dawley
14.
Endocrinology ; 160(1): 38-54, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30364965

RESUMO

Glucocorticoids (GCs) are essential for stress adaptation, acting centrally and in the periphery. Corticotropin-releasing factor (CRF), a major regulator of adrenal GC synthesis, is produced in the paraventricular nucleus of the hypothalamus (PVH), which contains multiple neuroendocrine and preautonomic neurons. GCs may be involved in diverse regulatory mechanisms in the PVH, but the target genes of GCs are largely unexplored except for the CRF gene (Crh), a well-known target for GC negative feedback. Using a genome-wide RNA-sequencing analysis, we identified transcripts that changed in response to either high-dose corticosterone (Cort) exposure for 12 days (12-day high Cort), corticoid deprivation for 7 days (7-day ADX), or acute Cort administration. Among others, canonical GC target genes were upregulated prominently by 12-day high Cort. Crh was upregulated or downregulated most prominently by either 7-day ADX or 12-day high Cort, emphasizing the recognized feedback effects of GC on the hypothalamic-pituitary-adrenal (HPA) axis. Concomitant changes in vasopressin and apelin receptor gene expression are likely to contribute to HPA repression. In keeping with the pleotropic cellular actions of GCs, 7-day ADX downregulated numerous genes of a broad functional spectrum. The transcriptome response signature differed markedly between acute Cort injection and 12-day high Cort. Remarkably, six immediate early genes were upregulated 1 hour after Cort injection, which was confirmed by quantitative reverse transcription PCR and semiquantitative in situ hybridization. This study may provide a useful database for studying the regulatory mechanisms of GC-dependent gene expression and repression in the PVH.


Assuntos
Corticosterona/metabolismo , Genoma , Glucocorticoides/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Transcrição Gênica , Animais , Receptores de Apelina/genética , Receptores de Apelina/metabolismo , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/metabolismo , Glucocorticoides/genética , Masculino , Sistema Hipófise-Suprarrenal/metabolismo , Ratos , Ratos Wistar , Vasopressinas/genética , Vasopressinas/metabolismo
15.
J Biol Chem ; 292(26): 10791-10800, 2017 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-28465347

RESUMO

Selenoprotein P (encoded by SELENOP in humans, Selenop in rat), a liver-derived secretory protein, induces resistance to insulin and vascular endothelial growth factor (VEGF) in type 2 diabetes. Suppression of selenoprotein P may provide a novel therapeutic approach to treating type 2 diabetes; however, few drugs inhibiting SELENOP expression in hepatocytes have been identified. The present findings demonstrate that eicosapentaenoic acid (EPA) suppresses SELENOP expression by inactivating sterol regulatory element-binding protein-1c (SREBP-1c, encoded by Srebf1 in rat) in H4IIEC3 hepatocytes. Treatment with EPA caused concentration- and time-dependent reduction in SELENOP promoter activity. EPA activated AMP-activated protein kinase (AMPK); however, the inhibitory effect of EPA on SELENOP promoter activity was not canceled with an AMPK inhibitor compound C and dominant-negative AMPK transfection. Deletion mutant promoter assays and computational analysis of transcription factor-binding sites conserved among the species resulted in identification of a sterol regulatory element (SRE)-like site in the SELENOP promoter. A chromatin immunoprecipitation (ChIP) assay revealed that EPA decreases binding of SREBP-1c to the SELENOP promoter. Knockdown of Srebf1 resulted in a significant down-regulation of Selenop expression. Conversely, SREBP-1c overexpression inhibited the suppressive effect of EPA. These data provide a novel mechanism of action for EPA involving improvement of systemic insulin sensitivity through the regulation of selenoprotein P production independently of the AMPK pathway and suggest an additional approach to developing anti-diabetic drugs.


Assuntos
Regulação para Baixo/efeitos dos fármacos , Ácido Eicosapentaenoico/farmacologia , Hepatócitos/metabolismo , Selenoproteína P/biossíntese , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Ratos , Selenoproteína P/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/genética
16.
PLoS One ; 12(4): e0175435, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28406939

RESUMO

The mechanism of the negative regulation of proopiomelanocortin gene (Pomc) by glucocorticoids (Gcs) is still unclear in many points. Here, we demonstrated the involvement of neurogenic differentiation factor 1 (NeuroD1) in the Gc-mediated negative regulation of Pomc. Murine pituitary adrenocorticotropic hormone (ACTH) producing corticotroph tumor-derived AtT20 cells were treated with dexamethasone (DEX) (1-100 nM) and cultured for 24 hrs. Thereafter, Pomc mRNA expression was studied by quantitative real-time PCR and rat Pomc promoter (-703/+58) activity was examined by luciferase assay. Both Pomc mRNA expression and Pomc promoter activity were inhibited by DEX in a dose-dependent manner. Deletion and point mutant analyses of Pomc promoter suggested that the DEX-mediated transcriptional repression was mediated via E-box that exists at -376/-371 in the promoter. Since NeuroD1 is known to bind to and activate E-box of the Pomc promoter, we next examined the effect of DEX on NeuroD1 expression. Interestingly, DEX dose-dependently inhibited NeuroD1 mRNA expression, mouse NeuroD1 promoter (-2.2-kb) activity, and NeuroD1 protein expression in AtT20 cells. In addition, we confirmed the inhibitory effect of DEX on the interaction of NeuroD1 and E-box on Pomc promoter by chromatin immunoprecipitation (ChIP) assay. Finally, overexpression of mouse NeuroD1 could rescue the DEX-mediated inhibition of Pomc mRNA expression and Pomc promoter activity. Taken together, it is suggested that the suppression of NeuroD1 expression and the inhibition of NeuroD1/E-box interaction may play an important role in the Gc-mediated negative regulation of Pomc.


Assuntos
Adenoma Hipofisário Secretor de ACT/metabolismo , Adenoma/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Dexametasona/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/farmacologia , Proteínas de Neoplasias/biossíntese , Adenoma Hipofisário Secretor de ACT/genética , Adenoma Hipofisário Secretor de ACT/patologia , Adenoma/patologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Camundongos , Pró-Opiomelanocortina/genética , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , Ratos
17.
Sci Rep ; 6: 39182, 2016 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-27982131

RESUMO

CREB3L3 is involved in fatty acid oxidation and ketogenesis in a mutual manner with PPARα. To evaluate relative contribution, a combination of knockout and transgenic mice was investigated. On a ketogenic-diet (KD) that highlights capability of hepatic ketogenesis, Creb3l3-/- mice exhibited reduction of expression of genes for fatty oxidation and ketogenesis comparable to Ppara-/- mice. Most of the genes were further suppressed in double knockout mice indicating independent contribution of hepatic CREB3L3. During fasting, dependency of ketogenesis on CREB3L3 is lesser extents than Ppara-/- mice suggesting importance of adipose PPARα for supply of FFA and hyperlipidemia in Creb3l3-/- mice. In conclusion CREB3L3 plays a crucial role in hepatic adaptation to energy starvation via two pathways: direct related gene regulation and an auto-loop activation of PPARα. Furthermore, as KD-fed Creb3l3-/- mice exhibited severe fatty liver, activating inflammation, CREB3L3 could be a therapeutic target for NAFLD.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Ácidos Graxos/química , PPAR alfa/genética , Adenoviridae/genética , Animais , Glicemia/análise , Carnitina O-Palmitoiltransferase/química , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Linhagem Celular Tumoral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/deficiência , Dieta Cetogênica , Metabolismo Energético , Ácidos Graxos/metabolismo , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Fatores de Crescimento de Fibroblastos/sangue , Expressão Gênica , Peroxidação de Lipídeos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , PPAR alfa/deficiência , Plasmídeos/genética , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Triglicerídeos/sangue
18.
Endocr J ; 63(9): 765-784, 2016 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-27350721

RESUMO

This clinical practice guideline of the diagnosis and treatment of adrenal insufficiency (AI) including adrenal crisis was produced on behalf of the Japan Endocrine Society. This evidence-based guideline was developed by a committee including all authors, and was reviewed by a subcommittee of the Japan Endocrine Society. The Japanese version has already been published, and the essential points have been summarized in this English language version. We recommend diagnostic tests, including measurement of basal cortisol and ACTH levels in combination with a rapid ACTH (250 µg corticotropin) test, the CRH test, and for particular situations the insulin tolerance test. Cut-off values in basal and peak cortisol levels after the rapid ACTH or CRH tests are proposed based on the assumption that a peak cortisol level ≥18 µg/dL in the insulin tolerance test indicates normal adrenal function. In adult AI patients, 15-25 mg hydrocortisone (HC) in 2-3 daily doses, depending on adrenal reserve and body weight, is a basic replacement regime for AI. In special situations such as sickness, operations, pregnancy and drug interactions, cautious HC dosing or the correct choice of glucocorticoids is necessary. From long-term treatment, optimal diurnal rhythm and concentration of serum cortisol are important for the prevention of cardiovascular disease and osteoporosis. In maintenance therapy during the growth period of patients with 21-hydroxylase deficiency, proper doses of HC should be used, and long-acting glucocorticoids should not be used. Education and carrying an emergency card are essential for the prevention and rapid treatment of adrenal crisis.


Assuntos
Insuficiência Adrenal/diagnóstico , Insuficiência Adrenal/terapia , Hormônio Adrenocorticotrópico/análise , Hormônio Adrenocorticotrópico/sangue , Adulto , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Hormônio Liberador da Corticotropina/sangue , Feminino , Humanos , Hidrocortisona/sangue , Insulina/sangue , Japão , Testes de Função Adreno-Hipofisária/métodos , Testes de Função Adreno-Hipofisária/normas , Gravidez , Sociedades Médicas
19.
J Med Chem ; 59(10): 5035-50, 2016 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-27058681

RESUMO

Accumulating evidence suggests that G-quadruplexes play vital roles in gene expression, DNA replication, and recombination. Three distinct promoters (PI, PII, and PIII) regulate human acetyl-CoA carboxylase 1 (ACC1) gene expression. In this study, we asked whether the G-rich sequences within the human ACC1 (PI and PII) promoters can form G-quadruplex structures and regulate normal DNA transactions. Using multiple complementary methods, we show that G-rich sequences of PI and PII promoters form intramolecular G-quadruplex structures and then establish unambiguously the topologies of these structures. Importantly, G-quadruplex formation in ACC1 gene promoter region blocks DNA replication and suppresses transcription, and this effect was further augmented by G-quadruplex stabilizing ligands. Altogether, these results are consistent with the notion that G-quadruplex structures exist within the human ACC1 gene promoter region, whose activity can be suppressed by G-quadruplex stabilizing ligands, thereby revealing a novel regulatory mechanism of ACC1 gene expression and as a possible therapeutic target.


Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Descoberta de Drogas , Quadruplex G/efeitos dos fármacos , Conformação de Ácido Nucleico , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Transcrição Gênica/efeitos dos fármacos , Acetil-CoA Carboxilase/metabolismo , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Ligantes , Estrutura Molecular , Conformação de Ácido Nucleico/efeitos dos fármacos , Relação Estrutura-Atividade , Transcrição Gênica/genética , Células Tumorais Cultivadas
20.
Acute Med Surg ; 3(3): 230-236, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-29123790

RESUMO

Aim: Reporting of the analytical and clinical findings of synthetic cannabinoids and cathinones is essential in carrying out a complete clinical assessment of new psychoactive substances. Methods: From 2012 to 2014, we examined synthetic cathinone and cannabinoid poisoning in six patients aged 22-42 years old. Analyses of these compounds were carried out using liquid chromatography-tandem mass spectrometry. Results: The observed clinical symptoms were similar to those reported for intoxication with synthetic cathinones and cannabinoids. In cases of intoxication with synthetic cathinones, the psychiatric and neurological symptoms were long-lasting, and these compounds were detected in serum for 15-48 h after use. Although the clinical symptoms induced by the synthetic cannabinoids disappeared within several hours after use, the range of serum concentrations of these compounds was ≤5 ng/mL for 1-3 h after use. In one fatal case, in which high serum concentrations of synthetic cathinones and cannabinoids were detected, the most plausible cause of death was heart failure due to overdose with these drugs. The long-lasting symptoms induced by synthetic cathinones correlated with the long detection window in serum, whereas the early disappearance of symptoms induced by synthetic cannabinoids corresponded to the short detection window in serum. Conclusions: This study shows that the profiles of synthetic cathinones and cannabinoids in serum are closely related to the duration of the toxic symptoms and that concomitant use of two psychoactive drugs with different pharmacological actions may have the potential for fatal cardiotoxicity.

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