bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dissociation of the Early Decline in Serum T3 Concentration and Serum IL-6 Rise and TNFα in Nonthyroidal Illness Syndrome Induced by Abdominal Surgery
Authors: Michalaki Marina , Vagenakis Apostolos G. , Makri Maria , Kalfarentzos Fotios , Kyriazopoulou Venetsana 
Published: January 2014

The etiology of the prompt decline in serum T3 in patients with nonthyroidal illness syndrome has not been adequately explained. It has been attributed to various parameters, including test artifacts, inhibitors of T4 and T3 binding to proteins, decreased 5′-deiodinase activity, and circulating cytokines. Currently, much attention is centered on the role of IL-6 and TNFα in developing the nonthyroidal illness syndrome through an effect on the hypothalamus, pituitary, and possibly 5′-deiodinase activity.
We therefore studied the relation of the endogenous serum IL-6 and TNFα rise early in the course of nonthyroidal illness syndrome to the early decline in serum T3 in 19 apparently healthy individuals, aged 43 ± 16 yr, who underwent elective abdominal surgery for cholelithiasis or gastroplasty. Serum T3, free T3, T4, free T4, rT3, TSH, IL-6, and TNFα were measured before and at various time intervals up to 42 h after skin incision. We observed a prompt decline in serum T3 30 min before skin incision, which continued to decline throughout the observational period. The magnitude of the decline reached 20% from the baseline value at 2 h. The early decline of T3 was attenuated and lasted from the 2–8 h, probably due to the sharp increase in serum TSH that started immediately after the entrance to the operating room and lasted for 2 h. In contrast, serum T4 and free T4 concentrations were increased soon after skin incision and remained elevated during the first postoperative day. Serum rT3 increased approximately 6 h after the initiation of surgery and remained elevated thereafter. Serum IL-6 remained essentially undetectable for 2 h after skin incision, whereas serum T3 was low. Two hours after skin incision, serum IL-6 increased sharply and remained elevated throughout the observational period. Serum TNFα remained essentially undetectable throughout the postoperative period. Serum cortisol increased rapidly upon entrance to the operating room and remained elevated throughout the postoperative period.
We conclude that the decline in serum T3 early in the course of nonthyroidal illness syndrome is not due to increased serum IL-6 or TNFα levels. The brisk TSH secretion soon after the onset of the syndrome attenuates the decline in serum T3 due to T3 secretion from the thyroid. The early and brisk cortisol response to surgery may at least in part explain the early decrease in serum T3 in nonthyroidal illness syndrome.
Decreased Plasma Adiponectin Concentrations in Women with Dyslipidemia
Authors: Matsubara Miyao , Maruoka Shoji , Katayose Shinji 
Published: January 2014

Adiponectin, the gene product of the adipose most abundant gene transcript 1, is a novel adipocyte-derived peptide that has been considered to have antiinflammatory and antiatherogenic effects. To characterize the relationship between adiponectin and lipids metabolism, we measured fasting plasma adiponectin concentration by ELISA, serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), and apolipoprotein (apo) levels in 352 nondiabetic women, 16–86 yr old, with a wide range of body weight [body mass index (BMI), 14.8−36.3 kg/m2].
Plasma adiponectin concentrations in women with the highest tertile of TG (1.69 mm ≤ ∼) were decreased, compared with the middle (1.13 ≤ ∼ &lt;1.69) or lowest tertile of TG (∼ &lt;1.13) (5.9 ± 0.5 vs. 7.5 ± 0.3, 9.2 ± 0.2 μg/ml; P &lt; 0.005, 0.001). Plasma adiponectin with the lowest tertile of HDL-C (∼ &lt;1.16 mm) was decreased, compared with the middle (1.16 ≤ ∼ &lt; 1.81) or highest tertile of HDL-C (1.81 ≤ ∼) (5.7 ± 0.5 vs. 7.8 ± 0.2, 10.1 ± 0.4 μg/ml; both P &lt; 0.001). These relationships had similar tendencies after adjustment for BMI, body fat mass, age, or diastolic blood pressure. Adiponectin was negatively correlated with serum TG (r = −0.33, P &lt; 0.0001), atherogenic index [(total cholesterol − HDL-C)/HDL-C] (r = −0.34, P &lt; 0.0001), apo B (r = −0.45, P &lt; 0.0001), or apo E (r = −0.29, P &lt; 0.05), and positively correlated with serum HDL-C (r = 0.39, P &lt; 0.0001) or apo A-I levels (r = 0.42, P &lt; 0.002). Those negative relationships became stronger after adjusting for BMI or body fat mass. The slightly positive correlation between adiponectin and age, blood urea nitrogen, or creatinine levels was also observed (all P &lt; 0.001).
These results indicate that high-TGnemia and low-HDL-Cnemia are associated with low plasma adiponectin concentrations in nondiabetic women. Further efforts must now be targeted to determine whether adiponectin causes these lipid abnormalities and thus whether it is partly responsible for the atherogenic risk seen in the metabolic syndrome.
Inefficient Secretion of Human H27A-Prolactin, a Mutant That Does Not Bind Zn2+
Authors: Sun Zhenyu , Lee Min S. , Rhee Harrison K. , Arrandale Joanne M. , Dannies Priscilla S. 
Published: January 2014

AbstractHuman PRL binds Zn2+, but the function of the binding is not known. We investigated the effect on PRL production in pituitary cells by obtaining clones of GH4C1 cells stably transfected with human H27A-PRL, a mutant that does not bind Zn2+. Unexpectedly, clones transfected with the mutant human PRL made little rat PRL. Untransfected GH4C1 cells made between 0.5 to 10 μg rat PRL/105 cells in 24 h. Clones transfected with vector alone (four of four), wild type human PRL (six of six), or with human K69A-PRL (two of two) made amounts of rat PRL in the same range. Clones transfected with human H27A-PRL (five of five) made 0.003–0.1 μg rat PRL/105 cells in 24 h, and the production of rat PRL mRNA was reduced. Human H27A-PRL was not efficiently secreted; 20–40% newly synthesized H27A-PRL was degraded by 60 min, and there was usually a delay in release of newly synthesized H27A-PRL. Reduction of rat PRL production is not mediated through the PRL receptor, because no sequences for the receptor in GH4C1 cells were detected by RT-PCR. Proteins involved in folding, such as BiP, were not specifically elevated in the H27A-PRL clones. In transient transfections, in which cells have not undergone selection, we found no evidence for disulfide-bonded aggregates of the mutant protein. The results indicate that Zn2+ binding stabilizes PRL in the secretory pathway; the instablility of the mutant protein may trigger effects that suppress rat PRL production directly or that indirectly result in selection of clones with low rat PRL production.
Expression of the Parathyroid Hormone-Related Peptide Gene in Retinoic Acid-Induced Differentiation: Involvement of ETS and Sp1
Authors: Karperien Marcel , Farih-Sips Hetty , Löwik Clemens W.G.M. , de Laat Siegfried W. , Boonstra Johannes , Defize Libert H.K. 
Published: January 2014

AbstractDifferentiation of P19 embryonal carcinoma (EC) and embryonal stem (ES)-5 cells with retinoic acid (RA) induces expression of PTH-related peptide (PTHrP) mRNA. In this study we have characterized a region between nucleotide (nt) −88 and −58 relative to the transcription start site in the murine PTHrP gene that was involved in this expression. Sequence analysis identified two partially overlapping binding sites for the Ets family of transcription factors and an inverted Sp1-binding site. Two major specific bands were detected in a bandshift assay using an oligonucleotide spanning nt −88 and −58 as a probe and nuclear extracts from both undifferentiated and RA-differentiated P19 EC cells. The lower complex consisted of Ets-binding proteins as demonstrated by competition with consensus Ets-binding sites, while the upper complex contained Sp1-binding activity as demonstrated by competition with consensus Sp1-binding sites. The observed bandshift patterns using nuclear extracts of undifferentiated or RA-differentiated P19 cells were indistinguishable, suggesting that the differentiation-mediated expression was not caused by the induction of expression of new transcription factors. Mutations in either of the Ets-binding sites or the Sp1-binding site completely abolished RA-induced expression of PTHrP promoter reporter constructs, indicating that the RA effect was dependent on the simultaneous action of both Ets- and Sp1-like activities. Furthermore, these mutations also abolished promoter activity in cells that constitutively expressed PTHrP mRNA, suggesting a central role for the Ets and Sp1 families of transcription factors in the expression regulation of the mouse PTHrP gene.
Localization of Agonist- and Antagonist-Binding Domains of Human Corticotropin-Releasing Factor Receptors
Authors: Liaw Chen W. , Grigoriadis Dimitri E. , Lorang Marge T. , De Souza Errol B. , Maki Richard A. 
Published: January 2014

AbstractThe CRF receptors, CRFR1 and CRFR2, are members of the G protein-coupled receptor superfamily. Despite their considerable sequence similarity, CRFR1 and CRFR2 have quite different affinities for the peptide ligand rat/human CRF. Previous studies using chimeric receptors between human CRFR1 and CRFR2 have identified three potentially important regions in the second and third extracellular domains of CRF receptor for the binding of rat/human CRF. The present report further demonstrates that these same three regions also affect the binding of urocortin and sauvagine, two other members of the CRF peptide family, albeit to different extents. We also show that a fourth region in the third extracellular domain, Asp254, has been identified to be important for sauvagine but not CRF or urocortin binding. Thus, the three peptide ligands not only interact with a different set of regions on CRFR1 and CRFR2 but also differentially interact with some of the same regions. These data could, at least in part, account for the much higher affinity of CRFR2 for urocortin and sauvagine compared with rat/human CRF. We have also identified two amino acid residues, His199 in the third transmembrane domain and Met276 in the fifth transmembrane domain, that are important for binding the non-peptide high-affinity CRFR1 antagonist NBI 27914. Mutations of His199 and Met276 to the corresponding amino acids in CRFR2 each decreased the binding affinity of NBI 27914 for CRFR1 by 40- and 200-fold, respectively. This suggests that the transmembrane regions are critically important in forming the binding pocket for the non-peptide antagonist.
Cloning, Chromosomal Localization, and Functional Analysis of the Murine Estrogen Receptor β
Authors: Tremblay Gilles B. , Tremblay André , Copeland Neal G. , Gilbert Debra J. , Jenkins Nancy A. , Labrie Fernand , Giguère Vincent 
Published: January 2014

AbstractEstrogen receptor β (ERβ) is a novel steroid receptor that is expressed in rat prostate and ovary. We have cloned the mouse homolog of ERβ and mapped the gene, designated Estrb, to the central region of chromosome 12. The cDNA encodes a protein of 485 amino acids that shares, respectively, 97% and 60% identity with the DNA- and ligand-binding domains of mouse (m) ERα. Mouse ERβ binds to an inverted repeat spaced by three nucleotides in a gel mobility shift assay and transactivates promoters containing synthetic or natural estrogen response elements in an estradiol (E2)-dependent manner. Scatchard analysis indicates that mERβ has slightly lower affinity for E2 [dissociation constant (Kd) = 0.5 nm] when compared with mERα (Kd = 0.2 nm). Antiestrogens, including 4-hydroxytamoxifen (OHT), ICI 182,780, and a novel compound, EM-800, inhibit E2-dependent transactivation efficiently. However, while OHT displays partial agonistic activity with ERα on a basal promoter linked to estrogen response elements in Cos-1 cells, this effect is not observed with mERβ. Cotransfection of mERβ and H-RasV12 causes enhanced activation in the presence of E2. Mutagenesis of a serine residue (position 60), located within a mitogen-activated protein kinase consensus phosphorylation site abolishes the stimulatory effect of Ras, suggesting that the activity of mERβ is also regulated by the mitogen-activated protein kinase pathway. Surprisingly, the coactivator SRC-1 up-regulates mERβ transactivation both in the absence and presence of E2, and in vitro interaction between SRC-1 and the ERβ ligand-binding domain is enhanced by E2. Moreover, the ligand-independent stimulatory effect of SRC-1 on ERβ transcriptional activity is abolished by ICI 182,780, but not by OHT. Our results demonstrate that while ERβ shares many of the functional characteristics of ERα, the molecular mechanisms regulating the transcriptional activity of mERβ may be distinct from those of ERα.
The Thyrotrope-Restricted Isoform of the Retinoid-X Receptor-γ1 Mediates 9-cis-Retinoic Acid Suppression of Thyrotropin-β Promoter Activity
Authors: Haugen Bryan R. , Brown Nicole S. , Wood William M. , Gordon David F. , Ridgway E. Chester 
Published: January 2014

AbstractTSHβ is a subunit of TSH that is uniquely expressed and regulated in the thyrotrope cells of the anterior pituitary gland. Thyroid hormone receptors (TR) are known to mediate T3 suppression of TSHβ gene expression at the level of promoter activity. The role of other nuclear receptors in regulation of this gene is less clearly defined. Retinoid X receptors (RXR) are a family of nuclear transcription factors that function both as 9-cis-retinoic acid (RA) ligand-dependent receptors and heterodimeric partners with TR and other nuclear receptors. Recently, the RXR isoform, RXRγ, has been identified in the anterior pituitary gland and found to be restricted to thyrotrope cells within the pitutiary. In this report, we have further characterized the distribution of RXRγ1, the thyrotrope-restricted isoform of RXRγ, in murine tissues and different cell types. We have found that RXRγ1 mRNA and protein are expressed in the TtT-97 thyrotropic tumor, but not the thyrotrope-variant αTSH cells or somatotrope-derived GH3 cells. Furthermore, we have studied the effects of RXRγ1 on TSHβ promoter activity and hormone regulation in these pituitary-derived cell types. Both T3 and 9-cis-RA independently suppressed promoter activity in the TtT-97 thyrotropes. Interestingly, the combination of ligands suppressed promoter activity more than either alone, indicating that these hormones may act cooperatively to regulate TSHβ gene expression in thyrotropes. The RXRγ1 isoform was necessary for the 9-cis-RA-mediated suppression of TSHβ promoter activity in αTSH and GH3 cells, both of which lack this isoform. RXRβ, a more widely distributed isoform, did not mediate these effects. Finally, we showed that the murine TSHβ promoter region between −200 and −149 mediated a majority of the 9-cis-RA suppression of promoter activity in thyrotropes. This region is distinct from the T3-mediated response region near the transcription start site. These data suggest that retinoids can mediate TSHβ gene regulation in thyrotropes and the thyrotrope-restricted isoform, RXRγ1, is required for this effect.
An X-Linked NDI Mutation Reveals a Requirement for Cell Surface V2R Expression
Authors: Sadeghi Hamid M. , Innamorati Giulio , Birnbaumer Mariel 
Published: January 2014

AbstractFunction and biochemical properties of the V2 vasopressin receptor (V2R) mutant R337ter, identified in patients suffering from X-linked recessive nephrogenic diabetes insipidus, were investigated by expression in COS.M6 or HEK293 cells. Binding assays and measurements of adenylyl cyclase activity failed to detect function for the truncated receptor, although metabolic labeling demonstrated normal levels of protein synthesis. ELISA assays performed on cells expressing the receptors tagged at the amino terminus with the HA epitope failed to detect V2R R337ter on the plasma membrane. Treatment with endoglycosidase H revealed that the receptor was present only as a precursor form because the mature R337ter V2R, resistant to endoglycosidase H treatment, was not detected. The precursor of V2R-R337ter had a longer half-life than that of the wild type V2R, suggesting that arrested maturation may slow the degradation of the precursor. Unrelated experiments had demonstrated that V2R-G345ter, containing eight additional amino acids, was expressed on the plasma membrane and functioned normally. Receptor truncations longer than 337ter revealed that four of the eight amino acids identified initially provided the minimum length required for the protein to acquire cell surface expression. This was shown by the production of mature receptor (V2R-341ter) detectable in SDS-PAGE, which mediated arginine vasopressin stimulation of adenylyl cyclase activity and bound ligand. In addition, the identity of amino acid 340 was found to play a role in this phenomenon. In conclusion, these data demonstrate that the V2R R337ter is nonfunctional because it does not reach the plasma membrane and that the minimal protein length required for translocation of the V2R to the cell surface is sufficient to confer function to the receptor protein. They also suggest the existence of a protein quality control in the endoplasmic reticulum independent of glycosylation.
Progesterone Receptor (PR) Inhibits Expression of Insulin-Like Growth Factor-Binding Protein-1 (IGFBP-1) in Human Endometrial Cell Line HEC-1B: Characterization of the Inhibitory Effect of PR on the Distal Promoter Region of the IGFBP-1 Gene
Authors: Gao Jiaguo , Tseng Linda 
Published: January 2014

Abstract
Progestin has been shown to have both stimulatory and inhibitory effects on the expression of insulin-like growth factor binding protein-1 (IGFBP-1) in human endometrial cells. In this study, progestin was found to reduce levels of secreted IGFBP-1 and IGFBP-1 messenger RNA and IGFBP-1 promoter activity after stably transfecting a progesterone receptor (PR; B form) expression vector into HEC-1B cells. Deletion analysis of the IGFBP-1 promoter revealed that PR specifically inhibited promoter activity derived from a 59-bp distal BsaHI/RsaI fragment. It was concluded that PR inhibited the promoter activity through protein-protein interactions based on the facts that 1) no progesterone-responsive element was revealed by a series block mutation in the BsaHI/RsaI fragment; 2) PR bound by the antiprogesterone ZK98299 inhibited IGFBP-1 promoter activity; 3) a DNA-binding mutant of PR inhibited the IGFBP-1 promoter activity; and 4) in an in vivo competition assay, the DNA-binding domain of PR did not release the inhibitory effect of intact PR. Analysis of PR deletion mutants indicated that both transcriptional activation domains of PR (TAF-1 and TAF-2) were involved in the inhibition of IGFBP-1 expression. Thus, our data may explain the superinduction of IGFBP-1 in human endometrial cells after progestin withdrawal or progestin replacement with antiprogestin.
Growth Hormone Stimulates Transcription of the Gene Encoding the Acid-Labile Subunit (ALS) of the Circulating Insulin-Like Growth Factor-Binding Protein Complex and ALS Promoter Activity in Rat Liver
Authors: Ooi Guck T. , Cohen Fredric J. , Tseng Lucy Y.-H. , Rechler Matthew M. , Boisclair Yves R. 
Published: January 2014

AbstractThe growth-promoting activity of GH, the principal hormonal determinant of body size, is mediated by insulin-like growth factor I (IGF-I). Most of the IGF-I in plasma circulates in a 150-kDa complex that contains IGF-binding protein-3 (IGFBP-3) and an acid-labile subunit (ALS). The 150-kDa complex serves as a reservoir of IGF-I and determines its bioavailability to the tissues. Formation of the 150-kDa complex depends upon the synthesis of ALS, which is synthesized primarily in liver and is regulated by GH. The present study demonstrates that GH stimulates ALS gene transcription in rat liver and ALS promoter activity in a rat hepatoma cell line. ALS messenger RNA (mRNA) and ALS nuclear transcripts were decreased to similar extents in the livers of GH-deficient hypophysectomized rats. GH increased hepatic ALS mRNA within 3–4 h to about 65% of the levels seen in sham-operated control rats. To confirm that GH stimulated ALS gene transcription, we transiently transfected an ALS promoter-luciferase reporter gene construct into H4-II-E rat hepatoma cells and primary rat hepatocytes. Recombinant human GH (hGH) stimulated promoter activity about 3-fold. In contrast, basal promoter activity was lower, and GH stimulation was absent when the ALS reporter construct was transfected into GH-responsive 3T3-F442A mouse preadipocyte fibroblasts. GH stimulation of ALS promoter activity in H4-II-E cells was mediated by functional GH receptors; nonprimate (rat and bovine) GH gave identical stimulation to hGH, and stimulation by hGH occurred at physiological concentrations. Reverse transcriptase-PCR analysis indicated that GH receptor mRNA was present in H4-II-E cells at approximately 40% of the level seen in rat liver. GH also induced the expression of the endogenous c-fos gene, indicating that the signaling pathway necessary for the activation of gene expression by GH was intact in H4-II-E cells. Thus, H4-II-E cells are a GH-responsive liver cell line that should provide a useful system in which to study the molecular mechanism of transcriptional regulation by GH of ALS and other hepatic genes.
A 6-kb Promoter Fragment Mimics in Transgenic Mice the Prostate-Specific and Androgen-Regulated Expression of the Endogenous Prostate-Specific Antigen Gene in Humans
Authors: Cleutjens Kitty B. J .M. , van der Korput Hetty A. G. M. , Ehren-van Eekelen Conny C. , Sikes Robert A. , Fasciana Claudia , Chung Leland W. , Trapman Jan 
Published: January 2014

AbstractProstate-specific antigen (PSA) is a kallikrein-like serine protease, which is almost exclusively synthesized in the luminal epithelial cells of the human prostate. PSA expression is androgen regulated. Previously, we characterized in vitro the proximal promoter, and a strong enhancer region, approximately 4 kb upstream of the PSA gene. Both regions are needed for high, androgen-regulated activity of the PSA promoter in LNCaP cells. The goal of the present study is the in vivo characterization of the PSA promoter. Three transgenic mouse lines carrying the Escherichia coli LacZ gene, driven by the 632-bp proximal PSA promoter, and three lines with LacZ, driven by the 6-kb PSA promoter, were generated. Expression of the LacZ reporter gene was analyzed in a large series of tissues. Transgene expression could not be demonstrated in any of the transgenic animals carrying the proximal PSA promoter. All three lines carrying the 6-kb PSA promoter showed lateral prostate-specific β-galactosidase activity. Transgene expression was undetectable until 8 weeks after birth. Upon castration,β -galactosidase activity rapidly declined. It could be restored by subsequent androgen administration. A search for mouse PSA-related kallikrein genes expressed in the prostate led to the identification of mGK22, which was previously demonstrated to be expressed in the submandibular salivary gland. Therefore, the 6-kb PSA-LacZ transgene followed the expression pattern of the PSA gene in humans, which is almost completely prostate-specific, rather than that of mGK22 in mice. In conclusion, the 6-kb promoter fragment appears to contain most, if not all, information for androgen regulation and prostate specificity of the PSA gene.