bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Oct-2 POU Domain Gene in the Neuroendocrine Brain: A Transcriptional Regulator of Mammalian Puberty*
Authors: Ojeda Sergio R. , Hill Jennifer , Hill Diane F. , Costa Maria E. , Tapia Veronica , Cornea Anda , Ma Ying J. 
Published: January 2014

AbstractPOU homeodomain genes are transcriptional regulators that control development of the mammalian forebrain. Although they are mostly active during embryonic life, some of them remain expressed in the postnatal hypothalamus, suggesting their involvement in regulating differentiated functions of the neuroendocrine brain. We show here that Oct-2, a POU domain gene originally described in cells of the immune system, is one of the controlling components of the cell-cell signaling process underlying the hypothalamic regulation of female puberty. Lesions of the anterior hypothalamus cause sexual precocity and recapitulate some of the events leading to the normal initiation of puberty. Prominent among these events is an increased astrocytic expression of the gene encoding transforming growth factor-α (TGFα), a tropic polypeptide involved in the stimulatory control of LHRH secretion. The present study shows that such lesions result in the rapid and selective increase in Oct-2 transcripts in TGFα-containing astrocytes surrounding the lesion site. In both lesion-induced and normal puberty, there is a preferential increase in hypothalamic expression of the Oct-2a and Oct-2c alternatively spliced messenger RNA forms of the Oct-2 gene, with an increase in 2a messenger RNA levels preceding that in 2c and antedating the peripubertal activation of gonadal steroid secretion. Both Oct-2a and 2c trans-activate the TGFα gene via recognition motifs contained in the TGFα gene promoter. Inhibition of Oct-2 synthesis reduces TGFα expression in astroglial cells and delays the initiation of puberty. These results suggest that the Oct-2 gene is one of the upstream components of the glia to neuron signaling process that controls the onset of female puberty in mammals.
The Pancreatic Homeodomain Transcription Factor IDX1/IPF1 Is Expressed in Neural Cells during Brain Development
Authors: Perez-Villamil Beatriz , Schwartz Petra T. , Vallejo Mario 
Published: January 2014

Abstract
Expression of the homeodomain transcription factor IDX1/IPF1 has been shown to be restricted to cells in the developing foregut that form the pancreatic primordium. In the adult, IDX1/IPF1 is expressed in the duodenum and pancreatic islets. The IDX1/IPF1 gene is required for pancreatic development, and in the human, heterozygous mutations have been linked to diabetes mellitus. In the present communication, we report that IDX1/IPF1 is expressed in discrete cells of the rat central nervous system during embryonic development. Using RT-PCR, IDX1/IPF1 mRNA was detected in neural precursor RC2.E10 cells, as well as in both forebrain and hindbrain of developing rats at embryonic day 15 (E15). The presence of IDX1/IPF1 protein was confirmed by Western immunoblotting. Immunohistochemical analyses of sagittal sections of E15 rats demonstrated the presence of scattered IDX1/IPF1-immunopositive cells in the forebrain. Finally, electrophoretic mobility shift assays using nuclear extracts from neural cells revealed the presence of IDX1/IPF1 bound to a putative homeodomain protein DNA-binding site present in the promoter of the glial fibrillary acidic protein gene. Our results suggest that IDX1/IPF1 may have previously unsuspected extrapancreatic functions during development of neural cells in the central nervous system.
Expression and Localization of Serum/Glucocorticoid-Induced Kinase in the Rat Ovary: Relation to Follicular Growth and Differentiation1
Authors: Alliston Tamara N. , Gonzalez-Robayna Ignacio J. , Buse Patricia , Firestone Gary L. , Richards JoAnne S. 
Published: January 2014

AbstractExpression of serum/glucocorticoid-inducible kinase (Sgk), one member of an inducible serine/threonine kinase family, is induced by FSH/cAMP in rat granulosa cells cultured in defined medium. The FSH-stimulated pattern of sgk expression is biphasic, and transcriptional activation of the sgk gene depends on an intact Sp1/Sp3 binding site within the proximal promoter. To determine whether sgk was expressed in a hormone-dependent and physiologically relevant manner in vivo, the cellular levels of sgk messenger RNA (mRNA) and protein as well as the subcellular localization of this kinase were analyzed in ovaries containing follicles and corpora lutea at specific stages of differentiation. To stimulate follicular development and luteinization, hypophysectomized (H) rats were treated with estradiol (E; HE) and FSH (FSH; HEF) followed by hCG (hCG; HEF/hCG). To analyze Sgk in functional corpora lutea, PRL was administered to HEF/hCG rats, or ovaries of pregnant rats were obtained on day 7, 15, or 22 of gestation. In situ hybridization indicated that sgk mRNA was low/undetectable in granulosa cells of H and HE rats. An acute injection (iv) of FSH to HE rats rapidly increased sgk mRNA at 2 and 8 h. Sgk mRNA was also elevated in granulosa cells of preovulatory follicles of HEF rats and in luteal cells of HEF/hCG and pregnant rats. Northern blots and Western blots confirmed the in situ hybridization data, indicating that the amount and cellular localization Sgk protein were related to that of sgk mRNA. When the subcellular localization of this kinase was analyzed by immunohistochemistry, Sgk protein was nuclear in granulosa cells and some thecal cells of large preovulatory follicles. In contrast, Sgk protein was cytoplasmic in luteal cells as well as some cells within the stromal compartment. Intense immunostaining was also observed in oocytes present in primordial follicles, but not in growing follicles. Collectively, these results show that FSH and LH stimulate marked increases in the cellular content of Sgk, as well as dramatic changes in the subcellular distribution of this kinase. The specific nuclear vs. cytoplasmic compartmentalization of Sgk in granulosa cells and luteal cells, respectively, indicates that Sgk controls distinct functions in proliferative vs. terminally differentiated granulosa cells.
Cholestenoic Acid Is a Naturally Occurring Ligand for Liver X Receptor α**This work was supported by NIH grants.
Authors: Song Ching , Liao Shutsung 
Published: January 2014

AbstractExcessive cholesterol is eliminated from extrahepatic cells by reverse cholesterol transport, a process by which neutral sterols are transferred to extracellular acceptor lipoproteins for further transport to the liver. Another process independent of lipoproteins involves excretion of 3β-hydroxy-5-cholesten-25(R)-26-carboxylic (cholestenoic) acid, a metabolite of 27-hydroxycholesterol. Physiological concentrations of cholestenoic acid activated the nuclear receptor liver X receptor α (LXRα; NR1H3), but not other oxysterol receptors. As a ligand, cholestenoic acid modulated interaction of LXRα with the nuclear receptor coactivator Grip-1. Cholestenoic acid, therefore, may function as a signaling molecule for regulation of lipid metabolism via LXRα.
Breeding Stock-Specific Variation in Peptidylglycineα-Amidating Monooxygenase Messenger Ribonucleic Acid Splicing in Rat Pituitary1
Authors: Ciccotosto Giuseppe D. , Hand Tracey A. , Mains Richard E. , Eipper Betty A. 
Published: January 2014

AbstractPeptidylglycine α-amidating monooxygenase (PAM) is a bifunctional enzyme that catalyzes the carboxyl-terminal amidation of glycine-extended peptides in a two-step reaction involving a monooxygenase and a lyase. Several forms of PAM messenger RNA result from alternative splicing of the single copy PAM gene. The presence of alternately spliced exon A between the two enzymatic domains allows endoproteolytic cleavage to occur in selected tissues, generating soluble monooxygenase and membrane lyase from integral membrane PAM. While using an exon A antiserum, we made the unexpected observation that Charles River Sprague Dawley rats expressed forms of PAM containing exon A in their pituitaries, whereas Harlan Sprague Dawley rats did not. Forms of PAM containing exon A were expressed in the atrium and hypothalamus of both types of Sprague Dawley rat, although in different proportions. PAM transmembrane domain splicing also differed between rat breeders, and full-length PAM-1 was not prevalent in the anterior pituitary of either type of rat. Despite striking differences in PAM splicing, no differences in levels of monooxygenase or lyase activity were observed in tissue or serum samples. The splicing patterns of other alternatively spliced genes, pituitary adenylate cyclase-activating polypeptide receptor type 1 and cardiac troponin T, did not vary with rat breeder. Strain-specific variations in the splicing of transcripts such as PAM must be taken into account in analyzing the resultant proteins, and knowledge of these differences should identify variations with functional significance.
The Role of the Dorsal Vagal Complex and the Vagus Nerve in Feeding Effects of Melanocortin-3/4 Receptor Stimulation*
Authors: Williams Diana L. , Kaplan Joel M. , Grill Harvey J. 
Published: January 2014

Abstract
Fourth intracerebroventricular (4th-icv) administration of the melanocortin-3/4 receptor (MC3/4-R) agonist, MTII, reduces food intake; the antagonist, SHU9119, increases feeding. The dorsal motor nucleus of the vagus nerve (DMX) contains the highest density of MC4-R messenger RNA in the brain. To explore the possibility that the DMX contributes to 4th-icv MC4-R effects, we delivered doses of MTII and SHU9119 that are subthreshold for ventricular response unilaterally through a cannula centered above the DMX. MTII markedly suppressed 2-h (50%), 4-h (50%), and 24-h (33%) intake. Feeding was significantly increased 4 h (50%) and 24 h (20%) after SHU9119 injections. These results suggest that receptors in the DMX, or the dorsal vagal complex more generally, underlie effects obtained with 4th-icv administration of these ligands. We investigated possible vagal mediation of 4th-icv MTII effects by giving the agonist to rats with subdiaphragmatic vagotomy. MTII suppressed 2-, 4-, and 24-h liquid diet intake (∼80%) to the same extent in vagotomized and surgical control rats. We conclude that stimulation or antagonism of MC3/4-Rs in the dorsal vagal complex yields effects on food intake that do not require an intact vagus nerve.
The gp130 Cytokines Interleukin-11 and Ciliary Neurotropic Factor Regulate through Specific Receptors the Function and Growth of Lactosomatotropic and Folliculostellate Pituitary Cell Lines*
Authors: Castro Carolina Perez , Nagashima Alberto Carbia , Pereda Marcelo Páez , Goldberg Victoria , Chervin Alberto , Largen Penny , Renner Ulrich , Stalla Günter K. , Arzt Eduardo 
Published: January 2014

AbstractTwo of the most potent cytokines regulating anterior pituitary cell function are leukemia inhibitory factor and interleukin-6 (IL-6), which belong to the cytokine receptor family using the common gp130 signal transducer. We studied the actions of two other members of this family, IL-11 and ciliary neurotropic factor (CNTF), on folliculostellate (FS) cells (TtT/GF cell line) and lactosomatotropic cells (GH3 cell line). The messenger RNA (mRNA) for the α-chain specific for the IL-11 receptor (1.7 kb) and CNTF receptor (2 kb) are expressed on both cell types. In addition, we detected CNTF receptor mRNA in normal rat anterior pituitary cells. IL-11 (1.25–5 nm) dose dependently stimulated the proliferation of FS cells. CNTF, at doses from 0.4–2 nm, also significantly stimulated the growth of these cells. In addition, both cytokines significantly stimulated proliferation of lactosomatotropic GH3 cells, and CNTF stimulated hormone production (GH and PRL) at 24 h by these cells. At 16–72 h, IL-11 stimulates the secretion of the angiogenic factor vascular endothelial growth factor by FS cells. In addition, both GH3 and FS cells express CNTF mRNA. These data suggest that IL-11 and CNTF may act as growth and regulatory factors in anterior pituitary cells.
The Distribution of Cells Containing Estrogen Receptor-α (ERα) and ERβ Messenger Ribonucleic Acid in the Preoptic Area and Hypothalamus of the Sheep: Comparison of Males and Females
Authors: Scott Christopher J. , Tilbrook Alan J. , Simmons Donna M. , Rawson John A. , Chu Simon , Fuller Peter J. , Ing Nancy H. , Clarke Iain J. 
Published: January 2014

We have used in situ hybridization to compare the distributions of estrogen receptor α (ERα) and ERβ messenger RNA (mRNA)-containing cells in the preoptic area and hypothalamus of ewes and rams. Perfusion-fixed brain tissue was collected from luteal phase ewes and intact rams (n = 4) during the breeding season. Matched pairs of sections were hybridized with sheep-specific, 35S-labeled riboprobes, and semiquantitative image analysis was performed on emulsion-dipped slides.
A number of sex differences were observed, with females having a greater density of labeled cells than males (P &lt; 0.001) and a greater number of silver grains per cell (P &lt; 0.01) in the ventromedial nucleus for both ER subtypes. In addition, in the retrochiasmatic area, males had a greater (P &lt; 0.05) cell density for ERα mRNA-containing cells than females, whereas in the paraventricular nucleus, females had a greater density (P &lt; 0.05) of ERα mRNA-containing cells than males. There was a trend (P = 0.068) in the arcuate nucleus for males to have a greater number of silver grains per cell labeled for ERα mRNA.
In both sexes, there was considerable overlap in the distributions of ERα and ERβ mRNA-containing cells, but the density of labeled cells within each nucleus differed in a number of instances. Nuclei that contained a higher (P &lt; 0.001) density of ERα than ERβ mRNA-containing cells included the preoptic area, bed nucleus of the stria terminalis, and ventromedial nucleus, whereas the subfornical organ (P &lt; 0.001), paraventricular nucleus (males only, P &lt; 0.05), and retrochiasmatic nucleus (females only, P &lt; 0.05) had a greater density of ERα than ERβ mRNA-containing cells. The anterior hypothalamic area and supraoptic nucleus had similar densities of cells containing both ER subtypes. The lateral septum and arcuate nucleus contained only ERα, whereas only ERβ mRNA-containing cells were seen in the zona incerta.
The sex differences in the populations of ER mRNA-containing cells in the ventromedial and arcuate nuclei may explain in part the sex differences in the neuroendocrine and behavioral responses to localized estrogen treatment in these nuclei. Within sexes, the differences between the distributions of ERα and ERβ mRNA-containing cells may reflect differential regulation of the actions of estrogen in the sheep hypothalamus. Low levels of ERβ mRNA in the preoptic area and ventromedial and arcuate nuclei, regions known to be important for the regulation of reproduction, suggest that ERβ may not be involved in these functions.
Minireview: Insights into G Protein-Coupled Receptor Function Using Molecular Models**The work from our laboratories was supported by USPHS Grant DK-43036.
Authors: Gershengorn Marvin C. , Osman Roman 
Published: January 2014

AbstractG protein-coupled receptors (GPCRs) represent the largest family of signal-transducing molecules known. They convey signals for light and many extracellular regulatory molecules. GPCRs have been found to be dysfunctional/dysregulated in a growing number of human diseases and have been estimated to be the targets of more than 30% of the drugs used in clinical medicine today. Thus, understanding how GPCRs function at the molecular level is an important goal of biological research. In order to understand function at this level, it is necessary to delineate the 3D structure of these receptors. Recently, the 3D structure of rhodopsin has been resolved, but in the absence of experimentally determined 3D structures of other GPCRs, a powerful approach is to construct a theoretical model for the receptor and refine it based on experimental results. Computer-generated models for many GPCRs have been constructed. In this article, we will review these studies. We will place the greatest emphasis on an iterative, bi-directional approach in which models are used to generate hypotheses that are tested by experimentation and the experimental findings are, in turn, used to refine the model. The success of this approach is due to the synergistic interaction between theory and experiment.
PPARγ/RXRα Heterodimers Are Involved in Human CGβ Synthesis and Human Trophoblast Differentiation
Authors: Tarrade Anne , Schoonjans Kristina , Guibourdenche Jean , Bidart Jean Michel , Vidaud Michel , Auwerx Johan , Rochette-Egly Cécile , Evain-Brion Danièle 
Published: January 2014

AbstractRecent studies performed with null mice suggested a role of either RXRα or PPARγ in murine placental development. We report here that both PPARγ and RXRα are strongly expressed in human villous cytotrophoblasts and syncytiotrophoblasts. Moreover, specific ligands for RXRs or PPARγ (but not for PPARα or PPARδ) increase both human CGβ transcript levels and the secretion of human CG and its free β-subunit. When combined, these ligands have an additive effect on human CG secretion. Pan-RXR and PPARγ ligands also have an additive effect on the synthesis of other syncytiotrophoblast hormones such as human placental lactogen, human placental GH, and leptin. Therefore, in human placenta, PPARγ/RXRα heterodimers are functional units during cytotrophoblast differentiation into the syncytiotrophoblast in vitro. Elements located in the regulatory region of the human CGβ gene (β5) were found to bind RXRα and PPARγ from human cytotrophoblast nuclear extracts, suggesting that PPARγ/RXRα heterodimers directly regulate human CGβ transcription. Altogether, these data show that PPARγ/RXRα heterodimers play an important role in human placental development.
Parallel Declines in Fos Activation of the Medial Anteroventral Periventricular Nucleus and LHRH Neurons in Middle-Aged Rats
Authors: Le W.-W. , Wise P. M. , Murphy A. Z. , Coolen L. M. , Hoffman G. E. 
Published: January 2014

Abstract
The middle-age decline in reproductive function is manifested by reduced LHRH release, resulting in a decreased magnitude and delay of onset of the LH surge. Earlier studies suggested that the reductions in LHRH neural activation in middle-aged rats resulted from deficits in the afferent drive to the LHRH neurons. One critical afferent to the LHRH neurons lies in the anteroventral periventricular preoptic area (AVPv) nucleus. The neurons of the medial AVPv are synchronously activated to express Fos with LHRH neurons at the time of an LH surge in young adult animals. The present study examined whether, in middle age, reductions in the activation of AVPv neurons accompany the reduction in Fos activation in LHRH neurons.
Young (3- to 4-month-old) and middle-aged (10- to 12-month-old) spontaneously cycling and ovariectomized steroid-replaced rats were killed during peak and early descending phase of the LH surge, and their brains were examined for Fos in LHRH and AVPv neurons. Young animals had a characteristic increase in Fos expression in both LHRH and AVPv neurons. In middle-aged rats, the proportion of LHRH neurons expressing Fos at the time of an LH surge was reduced by approximately 50%, irrespective of whether surges were spontaneous or induced by exogenous steroids. A similar reduction in the number of Fos+ cells (by approximately 50%) was noted in the medial AVPv. Linear regression analysis of the relationship between the extent of Fos activation in LHRH and AVPv neurons revealed a strong positive correlation (r2 = 0.66; P &lt; 0.01), suggesting that changes in the AVPv’s drive to LHRH neurons underlie the decrease in LHRH activity in middle age.
A second series of experiments examined whether decreased input from the AVPv could account for reduced Fos activation in LHRH neurons seen in middle-aged animals. When the medial AVPv was lesioned, LHRH neurons failed to express Fos on the side ipsilateral to the lesion. Animals with lesioned medial AVPv also had significantly lower LH values than animals with an intact medial AVPv. Taken together, these data suggest that a principal deficit in middle-aged rats is the ability of the medial AVPv to stimulate LHRH neurons.
Development of an ER Action Indicator Mouse for the Study of Estrogens, Selective ER Modulators (SERMs), and Xenobiotics
Authors: Nagel Susan C. , Hagelbarger Jennifer L. , McDonnell Donald P. 
Published: January 2014

AbstractWe have developed a transgenic mouse that functions as a reporter of ER activity, termed ER action indicator (ERIN), by incorporating a transgene with an estrogen-responsive promoter (three copies of the vitellogenin estrogen response element with a minimal thymidine kinase promoter) linked to the reporter gene β-galactosidase. Evaluation of ER activity in female ERIN mice demonstrated estrogen-inducible expression of the reporter gene in the uterus, pituitary, and hypothalamus; established targets of estrogen action. Importantly, we also identified ER activity in a number of nonclassical estrogen target tissues, including kidney, liver, adrenal, and thyroid gland. ERIN provides a system to measure the same end point (transgene regulation) in different target tissues, permitting separation of the contributions of cell- and promoter-specific factors in determining ER pharmacology. In this regard we observed that on this specific promoter the pituitary gland was 25-fold more sensitive than the uterus to the estrogen diethylstilbestrol, implying the existence of cell-specific factors that influence ligand sensitivity. Our studies also identified considerable difference in the efficacy and potency of ER ligands in the uterus when ER transcriptional activity was assayed vs. uterine weight gain. Specifically, we observed that the environmental estrogen bisphenol A was a potent agonist in stimulating ER transcriptional activity, whereas it exhibited little uterotropic activity. In contrast to bisphenol A, tamoxifen significantly increased uterine weight, but minimally induced ER reporter activity in this tissue. Given the results of these studies, we believe that ERIN will be a useful model to evaluate ER ligand pharmacology and will assist in defining the cellular and molecular mechanisms that determine agonist and antagonist activity.
Identification of Specific Inhibin A-Binding Proteins on Mouse Leydig (TM3) and Sertoli (TM4) Cell Lines*
Authors: Harrison Craig A. , Farnworth Paul G. , Chan Karen L. , Stanton Peter G. , Ooi Guck T. , Findlay Jock K. , Robertson David M. 
Published: January 2014

AbstractThe binding of human inhibin A to cell surface binding proteins of mouse Leydig (TM3) and Sertoli (TM4) cell lines was investigated. Scatchard analysis identified two classes of inhibin A-binding sites on TM3 (Kd(1) = 85 pm and 4,160 sites/cell; Kd(2) = 520 pm and 12,500 sites/cell) and TM4 (Kd(1) = 61 pm and 2,620 sites/cell; Kd(2) = 520 pm and 10,400 sites/cell) cells. Compared with inhibin A, inhibin B only partially competed[ 125I]inhibin A binding (6–8%), whereas activin A competed weakly (&lt;0.01%). Chemical cross-linking of[ 125I]inhibin A to both cell lines identified five[ 125I]inhibin A binding complexes with apparent molecular masses of 70, 95, 145, 155, and more than 200 kDa. Inhibin A displacement of [125I]inhibin A from each of these cross-linked species (ED50 = 60–110 pm) closely resembled displacement from intact TM3 (ED50 = 97 ± 32 pm) and TM4 (ED50 = 75± 28 pm) cells, suggesting that all of these proteins are involved in the high affinity inhibin A binding complex. Immunoprecipitation of iodinated inhibin A complexed to TM3 and TM4 cells with an antibody against human betaglycan identified protein complexes of more than 200, 145, and 95 kDa. It is concluded that the high affinity binding complex for inhibin A found in these cell lines consists of betaglycan and several proteins of unknown identity and may represent the putative inhibin receptor complex.