{"title":"Editorial: Centennial Celebration - An interview with Dr Trudy Kohout on \"Targeting Endocrine GPCRs for Better Health\".","authors":"T. Kohout","doi":"10.1210/me.2016-1028","DOIUrl":"https://doi.org/10.1210/me.2016-1028","url":null,"abstract":"","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 4 1","pages":"399-401"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2016-1028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yasmin M Vasquez, San-pin Wu, Matthew L. Anderson, S. Hawkins, C. Creighton, Madhumita Ray, S. Tsai, M. Tsai, J. Lydon, F. DeMayo
Epigenetic silencing of steroidogenic factor 1 (SF1) is lost in endometriosis, potentially contributing to de novo local steroidogenesis favoring inflammation and growth of ectopic endometrial tissue. In this study, we examine the impact of SF1 expression in the eutopic uterus by a novel mouse model that conditionally expresses SF1 in endometrium. In vivo SF1 expression promoted the development of enlarged endometrial glands and attenuated estrogen and progesterone responsiveness. Endometriosis induction by autotransplantation of uterine tissue to the mesenteric membrane resulted in the increase in size of ectopic lesions from SF1-expressing mice. By integrating the SF1-dependent transcriptome with the whole genome binding profile of SF1, we identified uterine-specific SF1-regulated genes involved in Wingless and Progesterone receptor-Hedgehog-Chicken ovalbumin upstream promoter transcription factor II signaling for gland development and epithelium-stroma interaction, respectively. The present results indicate that SF1 directly contributes to the abnormal uterine gland morphogenesis, an inhibition of steroid hormone signaling and activation of an immune response, in addition to previously postulated estrogen production.
{"title":"Endometrial Expression of Steroidogenic Factor 1 Promotes Cystic Glandular Morphogenesis.","authors":"Yasmin M Vasquez, San-pin Wu, Matthew L. Anderson, S. Hawkins, C. Creighton, Madhumita Ray, S. Tsai, M. Tsai, J. Lydon, F. DeMayo","doi":"10.1210/me.2015-1215","DOIUrl":"https://doi.org/10.1210/me.2015-1215","url":null,"abstract":"Epigenetic silencing of steroidogenic factor 1 (SF1) is lost in endometriosis, potentially contributing to de novo local steroidogenesis favoring inflammation and growth of ectopic endometrial tissue. In this study, we examine the impact of SF1 expression in the eutopic uterus by a novel mouse model that conditionally expresses SF1 in endometrium. In vivo SF1 expression promoted the development of enlarged endometrial glands and attenuated estrogen and progesterone responsiveness. Endometriosis induction by autotransplantation of uterine tissue to the mesenteric membrane resulted in the increase in size of ectopic lesions from SF1-expressing mice. By integrating the SF1-dependent transcriptome with the whole genome binding profile of SF1, we identified uterine-specific SF1-regulated genes involved in Wingless and Progesterone receptor-Hedgehog-Chicken ovalbumin upstream promoter transcription factor II signaling for gland development and epithelium-stroma interaction, respectively. The present results indicate that SF1 directly contributes to the abnormal uterine gland morphogenesis, an inhibition of steroid hormone signaling and activation of an immune response, in addition to previously postulated estrogen production.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"47 1","pages":"518-32"},"PeriodicalIF":0.0,"publicationDate":"2016-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2015-1215","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li Mo, Jing Shen, Qinhui Liu, Yuwei Zhang, Jiangying Kuang, Shiyun Pu, Shihai Cheng, M. Zou, Wei Jiang, Changtao Jiang, Aijuan Qu, Jinhan He
Irisin, a hormone proteolytically processed from fibronectin type III domain-containing protein 5 (FNDC5), has been reported to induce the browning of sc adipocytes by increasing the level of uncoupling protein 1. In this study, we showed that activation of the nuclear receptor constitutive androstane receptor induced FNDC5 mRNA expression in the liver and increased the circulating level of irisin in mice. FNDC5/irisin is a direct transcriptional target of constitutive androstane receptor. Hepatic-released irisin functioned as a paracrine/autocrine factor that inhibited lipogenesis and gluconeogenesis via the Adenosine 5'-monophosphate (AMP)-activated protein kinase pathway. Adenovirus-overexpressed irisin improved hepatic steatosis and insulin resistance in genetic-induced obese mice. Irisin transgenic mice were also protected against high-fat diet-induced obesity and insulin resistance. In conclusion, our results reveal a novel pathway in regulating FNDC5/irisin expression and identify a physiological role for this hepatic hormone in glucose and lipid homeostasis.
{"title":"Irisin Is Regulated by CAR in Liver and Is a Mediator of Hepatic Glucose and Lipid Metabolism.","authors":"Li Mo, Jing Shen, Qinhui Liu, Yuwei Zhang, Jiangying Kuang, Shiyun Pu, Shihai Cheng, M. Zou, Wei Jiang, Changtao Jiang, Aijuan Qu, Jinhan He","doi":"10.1210/me.2015-1292","DOIUrl":"https://doi.org/10.1210/me.2015-1292","url":null,"abstract":"Irisin, a hormone proteolytically processed from fibronectin type III domain-containing protein 5 (FNDC5), has been reported to induce the browning of sc adipocytes by increasing the level of uncoupling protein 1. In this study, we showed that activation of the nuclear receptor constitutive androstane receptor induced FNDC5 mRNA expression in the liver and increased the circulating level of irisin in mice. FNDC5/irisin is a direct transcriptional target of constitutive androstane receptor. Hepatic-released irisin functioned as a paracrine/autocrine factor that inhibited lipogenesis and gluconeogenesis via the Adenosine 5'-monophosphate (AMP)-activated protein kinase pathway. Adenovirus-overexpressed irisin improved hepatic steatosis and insulin resistance in genetic-induced obese mice. Irisin transgenic mice were also protected against high-fat diet-induced obesity and insulin resistance. In conclusion, our results reveal a novel pathway in regulating FNDC5/irisin expression and identify a physiological role for this hepatic hormone in glucose and lipid homeostasis.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 5 1","pages":"533-42"},"PeriodicalIF":0.0,"publicationDate":"2016-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2015-1292","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Liu, Yue Zhang, Jing Jiang, P. Lobie, R. Paulmurugan, J. Langenheim, Wen Y. Chen, K. Zinn, S. Frank
GH receptor (GHR) and prolactin (PRL) receptor (PRLR) are homologous transmembrane cytokine receptors. Each prehomodimerizes and ligand binding activates Janus Kinase 2 (JAK2)-signal transducer and activator of transcription (STAT) signaling pathways by inducing conformational changes within receptor homodimers. In humans, GHR is activated by GH, whereas PRLR is activated by both GH and PRL. We previously devised a split luciferase complementation assay, in which 1 receptor is fused to an N-terminal luciferase (Nluc) fragment, and the other receptor is fused to a C-terminal luciferase (Cluc) fragment. When receptors approximate, luciferase activity (complementation) results. Using this assay, we reported ligand-independent GHR-GHR complementation and GH-induced complementation changes characterized by acute augmentation above basal signal, consistent with induction of conformational changes that bring GHR cytoplasmic tails closer. We also demonstrated association between GHR and PRLR in T47D human breast cancer cells by coimmunoprecipitation, suggesting that, in addition to forming homodimers, these receptors form hetero-assemblages with functional consequences. We now extend these analyses to examine basal and ligand-induced complementation of coexpressed PRLR-Nluc and PRLR-Cluc chimeras and coexpressed GHR-Nluc and PRLR-Cluc chimeras. We find that PRLR-PRLR and GHR-PRLR form specifically interacting ligand-independent assemblages and that either GH or PRL augments PRLR-PRLR complementation, much like the GH-induced changes in GHR-GHR dimers. However, in contrast to the complementation patterns for GHR-GHR or PRLR-PRLR homomers, both GH and PRL caused decline in luciferase activity for GHR-PRLR heteromers. These and other data suggest that GHR and PRLR associate in complexes comprised of GHR-GHR/PRLR-PRLR heteromers consisting of GHR homodimers and PRLR homodimers, rather than GHR-PRLR heterodimers.
{"title":"GHR/PRLR Heteromultimer Is Composed of GHR Homodimers and PRLR Homodimers.","authors":"Y. Liu, Yue Zhang, Jing Jiang, P. Lobie, R. Paulmurugan, J. Langenheim, Wen Y. Chen, K. Zinn, S. Frank","doi":"10.1210/me.2015-1319","DOIUrl":"https://doi.org/10.1210/me.2015-1319","url":null,"abstract":"GH receptor (GHR) and prolactin (PRL) receptor (PRLR) are homologous transmembrane cytokine receptors. Each prehomodimerizes and ligand binding activates Janus Kinase 2 (JAK2)-signal transducer and activator of transcription (STAT) signaling pathways by inducing conformational changes within receptor homodimers. In humans, GHR is activated by GH, whereas PRLR is activated by both GH and PRL. We previously devised a split luciferase complementation assay, in which 1 receptor is fused to an N-terminal luciferase (Nluc) fragment, and the other receptor is fused to a C-terminal luciferase (Cluc) fragment. When receptors approximate, luciferase activity (complementation) results. Using this assay, we reported ligand-independent GHR-GHR complementation and GH-induced complementation changes characterized by acute augmentation above basal signal, consistent with induction of conformational changes that bring GHR cytoplasmic tails closer. We also demonstrated association between GHR and PRLR in T47D human breast cancer cells by coimmunoprecipitation, suggesting that, in addition to forming homodimers, these receptors form hetero-assemblages with functional consequences. We now extend these analyses to examine basal and ligand-induced complementation of coexpressed PRLR-Nluc and PRLR-Cluc chimeras and coexpressed GHR-Nluc and PRLR-Cluc chimeras. We find that PRLR-PRLR and GHR-PRLR form specifically interacting ligand-independent assemblages and that either GH or PRL augments PRLR-PRLR complementation, much like the GH-induced changes in GHR-GHR dimers. However, in contrast to the complementation patterns for GHR-GHR or PRLR-PRLR homomers, both GH and PRL caused decline in luciferase activity for GHR-PRLR heteromers. These and other data suggest that GHR and PRLR associate in complexes comprised of GHR-GHR/PRLR-PRLR heteromers consisting of GHR homodimers and PRLR homodimers, rather than GHR-PRLR heterodimers.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 5 1","pages":"504-17"},"PeriodicalIF":0.0,"publicationDate":"2016-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2015-1319","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brain-derived neurotrophic factor (BDNF) expressed in the paraventricular hypothalamus (PVH) has been shown to play a key role in regulating energy intake and energy expenditure. BDNF is also expressed in other hypothalamic nuclei; however, the role in the control of energy balance for BDNF produced in these structures remains largely unknown. We found that deleting the Bdnf gene in the ventromedial hypothalamus (VMH) during embryogenesis using the Sf1-Cre transgene had no effect on body weight in mice. In contrast, deleting the Bdnf gene in the adult VMH using Cre-expressing virus led to significant hyperphagia and obesity. These observations indicate that the lack of a hyperphagia phenotype in the Sf1-Cre/Bdnf mutant mice is likely due to developmental compensation. To investigate the role of BDNF expressed in other hypothalamic areas, we employed the hypothalamus-specific Nkx2.1-Cre transgene to delete the Bdnf gene. We found that the Nkx2.1-Cre transgene could abolish BDNF expression in many hypothalamic nuclei, but not in the PVH, and that the resulting mutant mice developed modest obesity due to reduced energy expenditure. Thus, BDNF produced in the VMH plays a role in regulating energy intake. Furthermore, BDNF expressed in hypothalamic areas other than PVH and VMH is also involved in the control of energy expenditure.
{"title":"Regulation of Energy Balance via BDNF Expressed in Nonparaventricular Hypothalamic Neurons.","authors":"Haili Yang, J. An, Chao Sun, Baoji Xu","doi":"10.1210/me.2015-1329","DOIUrl":"https://doi.org/10.1210/me.2015-1329","url":null,"abstract":"Brain-derived neurotrophic factor (BDNF) expressed in the paraventricular hypothalamus (PVH) has been shown to play a key role in regulating energy intake and energy expenditure. BDNF is also expressed in other hypothalamic nuclei; however, the role in the control of energy balance for BDNF produced in these structures remains largely unknown. We found that deleting the Bdnf gene in the ventromedial hypothalamus (VMH) during embryogenesis using the Sf1-Cre transgene had no effect on body weight in mice. In contrast, deleting the Bdnf gene in the adult VMH using Cre-expressing virus led to significant hyperphagia and obesity. These observations indicate that the lack of a hyperphagia phenotype in the Sf1-Cre/Bdnf mutant mice is likely due to developmental compensation. To investigate the role of BDNF expressed in other hypothalamic areas, we employed the hypothalamus-specific Nkx2.1-Cre transgene to delete the Bdnf gene. We found that the Nkx2.1-Cre transgene could abolish BDNF expression in many hypothalamic nuclei, but not in the PVH, and that the resulting mutant mice developed modest obesity due to reduced energy expenditure. Thus, BDNF produced in the VMH plays a role in regulating energy intake. Furthermore, BDNF expressed in hypothalamic areas other than PVH and VMH is also involved in the control of energy expenditure.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 5 1","pages":"494-503"},"PeriodicalIF":0.0,"publicationDate":"2016-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2015-1329","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Marcelo, T. Ribar, Christopher R. Means, A. Tsimelzon, R. Stevens, O. Ilkayeva, J. Bain, S. Hilsenbeck, C. Newgard, A. Means, B. York
A number of epidemiological studies have implicated calcium (Ca(2+)) signaling as a major factor in obesity that contributes to aberrant systems metabolism. Somewhat paradoxically, obesity correlates with decreased circulating Ca(2+) levels, leading to increased release of intracellular Ca(2+) stores from the endoplasmic reticulum. These findings suggest that insulin resistance associated with the obese state is linked to activation of canonical Ca(2+) signaling pathways. Mechanistically, increased intracellular Ca(2+) binds calmodulin (CaM) to activate a set of Ca(2+)/CaM-dependent protein kinases. In this research resource, we explore the metabolic functions and implications of Ca(2+)/CaM-dependent protein kinase kinase 2 (CaMKK2) as a metabolic effector of Ca(2+)/CaM action. We reveal the importance of CaMKK2 for gating insulin release from pancreatic β-cells while concomitantly influencing the sensitivity of insulin-responsive tissues. To provide a better understanding of the metabolic impact of CaMKK2 loss, we performed targeted metabolomic analyses of key metabolic byproducts of glucose, fatty acid, and amino acid metabolism in mice null for CaMKK2. We quantified amino acids and acyl carnitines in 3 insulin-sensitive tissues (liver, skeletal muscle, plasma) isolated from CaMKK2(-/-) mice and their wild-type littermates under conditions of dietary stress (low-fat diet, normal chow, high-fat diet, and fasting), thereby unveiling unique metabolic functions of CaMKK2. Our findings highlight CaMKK2 as a molecular rheostat for insulin action and emphasize the importance of Ca(2+)/CaM/CaMKK2 in regulation of whole-body metabolism. These findings reveal that CaMKK2 may be an attractive therapeutic target for combatting comorbidities associated with perturbed insulin signaling.
{"title":"Research Resource: Roles for Calcium/Calmodulin-Dependent Protein Kinase Kinase 2 (CaMKK2) in Systems Metabolism.","authors":"K. Marcelo, T. Ribar, Christopher R. Means, A. Tsimelzon, R. Stevens, O. Ilkayeva, J. Bain, S. Hilsenbeck, C. Newgard, A. Means, B. York","doi":"10.1210/me.2016-1021","DOIUrl":"https://doi.org/10.1210/me.2016-1021","url":null,"abstract":"A number of epidemiological studies have implicated calcium (Ca(2+)) signaling as a major factor in obesity that contributes to aberrant systems metabolism. Somewhat paradoxically, obesity correlates with decreased circulating Ca(2+) levels, leading to increased release of intracellular Ca(2+) stores from the endoplasmic reticulum. These findings suggest that insulin resistance associated with the obese state is linked to activation of canonical Ca(2+) signaling pathways. Mechanistically, increased intracellular Ca(2+) binds calmodulin (CaM) to activate a set of Ca(2+)/CaM-dependent protein kinases. In this research resource, we explore the metabolic functions and implications of Ca(2+)/CaM-dependent protein kinase kinase 2 (CaMKK2) as a metabolic effector of Ca(2+)/CaM action. We reveal the importance of CaMKK2 for gating insulin release from pancreatic β-cells while concomitantly influencing the sensitivity of insulin-responsive tissues. To provide a better understanding of the metabolic impact of CaMKK2 loss, we performed targeted metabolomic analyses of key metabolic byproducts of glucose, fatty acid, and amino acid metabolism in mice null for CaMKK2. We quantified amino acids and acyl carnitines in 3 insulin-sensitive tissues (liver, skeletal muscle, plasma) isolated from CaMKK2(-/-) mice and their wild-type littermates under conditions of dietary stress (low-fat diet, normal chow, high-fat diet, and fasting), thereby unveiling unique metabolic functions of CaMKK2. Our findings highlight CaMKK2 as a molecular rheostat for insulin action and emphasize the importance of Ca(2+)/CaM/CaMKK2 in regulation of whole-body metabolism. These findings reveal that CaMKK2 may be an attractive therapeutic target for combatting comorbidities associated with perturbed insulin signaling.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 5 1","pages":"557-72"},"PeriodicalIF":0.0,"publicationDate":"2016-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2016-1021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stable somatostatin analogues and dopamine receptor agonists are the mainstay for the pharmacological treatment of functional pituitary adenomas; however, only a few cellular assays have been developed to detect receptor activation of novel compounds without disrupting cells to obtain the second messenger content. Here, we adapted a novel fluorescence-based membrane potential assay to characterize receptor signaling in a time-dependent manner. This minimally invasive technique provides a robust and reliable read-out for ligand-induced receptor activation in permanent and primary pituitary cells. The mouse corticotropic cell line AtT-20 endogenously expresses both the somatostatin receptors 2 (sst2) and 5 (sst5). Exposure of wild-type AtT-20 cells to the sst2- and sst5-selective agonists BIM-23120 and BIM-23268, respectively, promoted a pertussis toxin- and tertiapin-Q-sensitive reduction in fluorescent signal intensity, which is indicative of activation of G protein-coupled inwardly rectifying potassium (GIRK) channels. After heterologous expression, sst1, sst3, and sst4 receptors also coupled to GIRK channels in AtT-20 cells. Similar activation of GIRK channels by dopamine required overexpression of dopamine D2 receptors (D2Rs). Interestingly, the presence of D2Rs in AtT-20 cells strongly facilitated GIRK channel activation elicited by the sst2-D2 chimeric ligand BIM-23A760, suggesting a synergistic action of sst2 and D2Rs. Furthermore, stable somatostatin analogues produced strong responses in primary pituitary cultures from wild-type mice; however, in cultures from sst2 receptor-deficient mice, only pasireotide and somatoprim, but not octreotide, induced a reduction in fluorescent signal intensity, suggesting that octreotide mediates its pharmacological action primarily via the sst2 receptor.
{"title":"Research Resource: Real-Time Analysis of Somatostatin and Dopamine Receptor Signaling in Pituitary Cells Using a Fluorescence-Based Membrane Potential Assay.","authors":"T. Günther, M. Culler, S. Schulz","doi":"10.1210/me.2015-1241","DOIUrl":"https://doi.org/10.1210/me.2015-1241","url":null,"abstract":"Stable somatostatin analogues and dopamine receptor agonists are the mainstay for the pharmacological treatment of functional pituitary adenomas; however, only a few cellular assays have been developed to detect receptor activation of novel compounds without disrupting cells to obtain the second messenger content. Here, we adapted a novel fluorescence-based membrane potential assay to characterize receptor signaling in a time-dependent manner. This minimally invasive technique provides a robust and reliable read-out for ligand-induced receptor activation in permanent and primary pituitary cells. The mouse corticotropic cell line AtT-20 endogenously expresses both the somatostatin receptors 2 (sst2) and 5 (sst5). Exposure of wild-type AtT-20 cells to the sst2- and sst5-selective agonists BIM-23120 and BIM-23268, respectively, promoted a pertussis toxin- and tertiapin-Q-sensitive reduction in fluorescent signal intensity, which is indicative of activation of G protein-coupled inwardly rectifying potassium (GIRK) channels. After heterologous expression, sst1, sst3, and sst4 receptors also coupled to GIRK channels in AtT-20 cells. Similar activation of GIRK channels by dopamine required overexpression of dopamine D2 receptors (D2Rs). Interestingly, the presence of D2Rs in AtT-20 cells strongly facilitated GIRK channel activation elicited by the sst2-D2 chimeric ligand BIM-23A760, suggesting a synergistic action of sst2 and D2Rs. Furthermore, stable somatostatin analogues produced strong responses in primary pituitary cultures from wild-type mice; however, in cultures from sst2 receptor-deficient mice, only pasireotide and somatoprim, but not octreotide, induced a reduction in fluorescent signal intensity, suggesting that octreotide mediates its pharmacological action primarily via the sst2 receptor.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 4 1","pages":"479-90"},"PeriodicalIF":0.0,"publicationDate":"2016-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2015-1241","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Varun Sondhi, B. Owen, Jiayan Liu, Robert Chomic, S. Kliewer, B. Hughes, W. Arlt, D. Mangelsdorf, R. Auchus
Androgen and estrogen biosynthesis in mammals requires the 17,20-lyase activity of cytochrome P450 17A1 (steroid 17-hydroxylase/17,20-lyase). Maximal 17,20-lyase activity in vitro requires the presence of cytochrome b5 (b5), and rare cases of b5 deficiency in human beings causes isolated 17,20-lyase deficiency. To study the consequences of conditional b5 removal from testicular Leydig cells in an animal model, we generated Cyb5flox/flox:Sf1-Cre (LeyKO) mice. The LeyKO male mice had normal body weights, testis and sex organ weights, and fertility compared with littermates. Basal serum and urine steroid profiles of LeyKO males were not significantly different than littermates. In contrast, marked 17-hydroxyprogesterone accumulation (100-fold basal) and reduced testosterone synthesis (27% of littermates) were observed after human chorionic gonadotropin stimulation in LeyKO animals. Testis homogenates from LeyKO mice showed reduced 17,20-lyase activity and a 3-fold increased 17-hydroxylase to 17,20-lyase activity ratio, which were restored to normal upon addition of recombinant b5. We conclude that Leydig cell b5 is required for maximal androgen synthesis and to prevent 17-hydroxyprogesterone accumulation in the mouse testis; however, the b5-independent 17,20-lyase activity of mouse steroid 17-hydroxylase/17,20-lyase is sufficient for normal male genital development and fertility. LeyKO male mice are a good model for the biochemistry but not the physiology of isolated 17,20-lyase deficiency in human beings.
{"title":"Impaired 17,20-Lyase Activity in Male Mice Lacking Cytochrome b5 in Leydig Cells","authors":"Varun Sondhi, B. Owen, Jiayan Liu, Robert Chomic, S. Kliewer, B. Hughes, W. Arlt, D. Mangelsdorf, R. Auchus","doi":"10.1210/me.2015-1282","DOIUrl":"https://doi.org/10.1210/me.2015-1282","url":null,"abstract":"Androgen and estrogen biosynthesis in mammals requires the 17,20-lyase activity of cytochrome P450 17A1 (steroid 17-hydroxylase/17,20-lyase). Maximal 17,20-lyase activity in vitro requires the presence of cytochrome b5 (b5), and rare cases of b5 deficiency in human beings causes isolated 17,20-lyase deficiency. To study the consequences of conditional b5 removal from testicular Leydig cells in an animal model, we generated Cyb5flox/flox:Sf1-Cre (LeyKO) mice. The LeyKO male mice had normal body weights, testis and sex organ weights, and fertility compared with littermates. Basal serum and urine steroid profiles of LeyKO males were not significantly different than littermates. In contrast, marked 17-hydroxyprogesterone accumulation (100-fold basal) and reduced testosterone synthesis (27% of littermates) were observed after human chorionic gonadotropin stimulation in LeyKO animals. Testis homogenates from LeyKO mice showed reduced 17,20-lyase activity and a 3-fold increased 17-hydroxylase to 17,20-lyase activity ratio, which were restored to normal upon addition of recombinant b5. We conclude that Leydig cell b5 is required for maximal androgen synthesis and to prevent 17-hydroxyprogesterone accumulation in the mouse testis; however, the b5-independent 17,20-lyase activity of mouse steroid 17-hydroxylase/17,20-lyase is sufficient for normal male genital development and fertility. LeyKO male mice are a good model for the biochemistry but not the physiology of isolated 17,20-lyase deficiency in human beings.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 1","pages":"469 - 478"},"PeriodicalIF":0.0,"publicationDate":"2016-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2015-1282","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. A. O'Hare, L. Yerges-Armstrong, J. Perry, A. Shuldiner, N. Zaghloul
Type 2 diabetes (T2D) has been associated with a large number of genomic loci, many of which encompass multiple genes without a definitive causal gene. This complexity has hindered efforts to clearly identify functional candidate genes and interpret their role in mediating susceptibility to disease. Here we examined the relevance of individual genes found at T2D-associated loci by assessing their potential contribution to a phenotype relevant to the disease state: production and maintenance of β-cell mass. Using transgenic zebrafish in which β-cell mass could be rapidly visualized in vivo, we systematically suppressed the expression of orthologs of genes found at T2D-associated genomic loci. Overall, we tested 67 orthologs, many of which had no known relevance to β-cell mass, at 62 human T2D-associated loci, including eight loci with multiple candidate genes. In total we identified 25 genes that were necessary for proper β-cell mass, providing functional evidence for their role in a physiological phenotype directly related to T2D. Of these, 16 had not previously been implicated in the regulation of β-cell mass. Strikingly, we identified single functional candidate genes at the majority of the loci for which multiple genes were analyzed. Further investigation into the contribution of the 25 genes to the adaptive capacity of β-cells suggested that the majority of genes were not required for glucose-induced expansion of β-cell mass but were significantly necessary for the regeneration of β-cells. These findings suggest that genetically programmed deficiencies in β-cell mass may be related to impaired maintenance. Finally, we investigated the relevance of our findings to human T2D onset in diabetic individuals from the Old Order Amish and found that risk alleles in β-cell mass genes were associated with significantly younger age of onset and lower body mass index. Taken together, our study offers a functional approach to assign relevance to genes at T2D-associated loci and offers experimental evidence for the defining role of β-cell mass maintenance in genetic susceptibility to T2D onset.
{"title":"Assignment of Functional Relevance to Genes at Type 2 Diabetes-Associated Loci Through Investigation of β-Cell Mass Deficits.","authors":"E. A. O'Hare, L. Yerges-Armstrong, J. Perry, A. Shuldiner, N. Zaghloul","doi":"10.1210/me.2015-1243","DOIUrl":"https://doi.org/10.1210/me.2015-1243","url":null,"abstract":"Type 2 diabetes (T2D) has been associated with a large number of genomic loci, many of which encompass multiple genes without a definitive causal gene. This complexity has hindered efforts to clearly identify functional candidate genes and interpret their role in mediating susceptibility to disease. Here we examined the relevance of individual genes found at T2D-associated loci by assessing their potential contribution to a phenotype relevant to the disease state: production and maintenance of β-cell mass. Using transgenic zebrafish in which β-cell mass could be rapidly visualized in vivo, we systematically suppressed the expression of orthologs of genes found at T2D-associated genomic loci. Overall, we tested 67 orthologs, many of which had no known relevance to β-cell mass, at 62 human T2D-associated loci, including eight loci with multiple candidate genes. In total we identified 25 genes that were necessary for proper β-cell mass, providing functional evidence for their role in a physiological phenotype directly related to T2D. Of these, 16 had not previously been implicated in the regulation of β-cell mass. Strikingly, we identified single functional candidate genes at the majority of the loci for which multiple genes were analyzed. Further investigation into the contribution of the 25 genes to the adaptive capacity of β-cells suggested that the majority of genes were not required for glucose-induced expansion of β-cell mass but were significantly necessary for the regeneration of β-cells. These findings suggest that genetically programmed deficiencies in β-cell mass may be related to impaired maintenance. Finally, we investigated the relevance of our findings to human T2D onset in diabetic individuals from the Old Order Amish and found that risk alleles in β-cell mass genes were associated with significantly younger age of onset and lower body mass index. Taken together, our study offers a functional approach to assign relevance to genes at T2D-associated loci and offers experimental evidence for the defining role of β-cell mass maintenance in genetic susceptibility to T2D onset.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 4 1","pages":"429-45"},"PeriodicalIF":0.0,"publicationDate":"2016-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2015-1243","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66016025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Maekawa, Shun Sato, Maki Okada, L. Lee, I. Tamura, Kosuke Jozaki, Takuya Kajimura, H. Asada, Y. Yamagata, H. Tamura, S. Yamamoto, N. Sugino
The mechanism controlling tissue-specific expression of estrogen receptor 1 (ESR1) is unclear. In other genes, DNA methylation of a region called the tissue-dependent and differentially methylated region (T-DMR) has been associated with tissue-specific gene expression. This study investigated whether human ESR1 has a T-DMR and whether DNA methylation of the T-DMR regulates its expression. ESR1 expression was tissue-specific, being high in the endometrium and mammary gland and low/nil in the placenta and skin. Therefore, DNA methylation profiles of the promoter of ESR1 were analyzed in these tissues and in breast cancer tissues. In all of the normal tissues, the proximal promoter regions were unmethylated. On the other hand, the distal regions (T-DMR) were unmethylated in the endometrium and mammary gland, but were moderately methylated and hypermethylated in the placenta and skin, respectively. T-DMR-methylated reporter assay was performed to examine whether DNA methylation at the T-DMR suppresses ESR1 transcription. T-DMR, but not the promoter region, had transcriptional activities and DNA methylation of the T-DMR suppressed ESR1 transcription. Early growth response protein 1 was shown to be a possible transcription factor to bind the T-DMR and up-regulate ESR1 expression. ESR1 has several upstream exons, and each upstream exon, Exon-A/Exon-B/Exon-C, had its own T-DMR. In some breast cancer cases and breast cancer cell lines, ESR1 expression was not regulated by DNA methylation at T-DMR as it is in normal tissues. In conclusion, ESR1 has a T-DMR. DNA methylation status at the T-DMR is involved in tissue-specific ESR1 expression in normal tissues but not always in breast cancer.
调控雌激素受体1 (ESR1)组织特异性表达的机制尚不清楚。在其他基因中，称为组织依赖和差异甲基化区域(T-DMR)的DNA甲基化与组织特异性基因表达有关。本研究调查了人类ESR1是否具有T-DMR，以及T-DMR的DNA甲基化是否调节其表达。ESR1表达具有组织特异性，在子宫内膜和乳腺中表达量高，在胎盘和皮肤中表达量低或为零。因此，我们在这些组织和乳腺癌组织中分析了ESR1启动子的DNA甲基化谱。在所有正常组织中，近端启动子区域未甲基化。另一方面，远端区域(T-DMR)在子宫内膜和乳腺中未甲基化，但在胎盘和皮肤中分别中度甲基化和高甲基化。采用T-DMR甲基化报告基因检测来检测T-DMR DNA甲基化是否抑制ESR1转录。T-DMR而非启动子区域具有转录活性，并且T-DMR的DNA甲基化抑制了ESR1的转录。早期生长反应蛋白1可能是结合T-DMR并上调ESR1表达的转录因子。ESR1有几个上游外显子，每个上游外显子exon - a / exon - b / exon - c都有自己的T-DMR。在一些乳腺癌病例和乳腺癌细胞系中，ESR1的表达不像在正常组织中那样受到T-DMR DNA甲基化的调节。总之，ESR1具有T-DMR。在正常组织中，T-DMR的DNA甲基化状态与组织特异性ESR1表达有关，但在乳腺癌中并不总是如此。
{"title":"Tissue-Specific Expression of Estrogen Receptor 1 Is Regulated by DNA Methylation in a T-DMR.","authors":"R. Maekawa, Shun Sato, Maki Okada, L. Lee, I. Tamura, Kosuke Jozaki, Takuya Kajimura, H. Asada, Y. Yamagata, H. Tamura, S. Yamamoto, N. Sugino","doi":"10.1210/me.2015-1058","DOIUrl":"https://doi.org/10.1210/me.2015-1058","url":null,"abstract":"The mechanism controlling tissue-specific expression of estrogen receptor 1 (ESR1) is unclear. In other genes, DNA methylation of a region called the tissue-dependent and differentially methylated region (T-DMR) has been associated with tissue-specific gene expression. This study investigated whether human ESR1 has a T-DMR and whether DNA methylation of the T-DMR regulates its expression. ESR1 expression was tissue-specific, being high in the endometrium and mammary gland and low/nil in the placenta and skin. Therefore, DNA methylation profiles of the promoter of ESR1 were analyzed in these tissues and in breast cancer tissues. In all of the normal tissues, the proximal promoter regions were unmethylated. On the other hand, the distal regions (T-DMR) were unmethylated in the endometrium and mammary gland, but were moderately methylated and hypermethylated in the placenta and skin, respectively. T-DMR-methylated reporter assay was performed to examine whether DNA methylation at the T-DMR suppresses ESR1 transcription. T-DMR, but not the promoter region, had transcriptional activities and DNA methylation of the T-DMR suppressed ESR1 transcription. Early growth response protein 1 was shown to be a possible transcription factor to bind the T-DMR and up-regulate ESR1 expression. ESR1 has several upstream exons, and each upstream exon, Exon-A/Exon-B/Exon-C, had its own T-DMR. In some breast cancer cases and breast cancer cell lines, ESR1 expression was not regulated by DNA methylation at T-DMR as it is in normal tissues. In conclusion, ESR1 has a T-DMR. DNA methylation status at the T-DMR is involved in tissue-specific ESR1 expression in normal tissues but not always in breast cancer.","PeriodicalId":18812,"journal":{"name":"Molecular endocrinology","volume":"30 3 1","pages":"335-47"},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1210/me.2015-1058","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66015727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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