bluuebunny/crossref_metadata_2025_split huggingface dataset:
Male Reproductive Defects Caused by Puromycin-Sensitive Aminopeptidase Deficiency in Mice
Authors: Osada Tomoharu , Watanabe Gen , Kondo Shunzo , Toyoda Masashi , Sakaki Yoshiyuki , Takeuchi Takashi 
Published: January 2014

Abstract
Male reproductive performance is composed of two principal elements, copulation and spermatogenesis. A wealth of literature has described the intricate web of endocrine events underlying these biological processes. In the present study we show that puromycin-sensitive aminopeptidase (Psa)-deficient mice are infertile, lack copulatory behavior, and have impaired spermatogenesis. The reproductive deficits of the mutants are not restored by androgen administration, although no aberrant localization of the sex steroid receptors was detectable in their brains and testes. Considering the strong expression of the Psa gene in the brain and Sertoli cells and the degenerative morphology of Sertoli cells in Psa-deficient mice, Psa may participate in testosterone-mediated reproductive signal pathways in the brain and testis.
Differential Expression of Ionic Channels in Rat Anterior Pituitary Cells
Authors: Van Goor Fredrick , Zivadinovic Dragoslava , Stojilkovic Stanko S. 
Published: January 2014

AbstractSecretory anterior pituitary cells are of the same origin, but exhibit cell type-specific patterns of spontaneous intracellular Ca2+ signaling and basal hormone secretion. To understand the underlying ionic mechanisms mediating these differences, we compared the ionic channels expressed in somatotrophs, lactotrophs, and gonadotrophs from randomly cycling female rats under identical cell culture and recording conditions. Our results indicate that a similar group of ionic channels are expressed in each cell type, including transient and sustained voltage-gated Ca2+ channels, tetrodotoxin-sensitive Na+ channels, transient and delayed rectifying K+ channels, and multiple Ca2+-sensitive K+ channel subtypes. However, there were marked differences in the expression levels of some of the ionic channels. Specifically, lactotrophs and somatotrophs exhibited low expression levels of tetrodotoxin-sensitive Na+ channels and high expression levels of the large-conductance, Ca2+-activated K+ channel compared with those observed in gonadotrophs. In addition, functional expression of the transient K+ channel was much higher in lactotrophs and gonadotrophs than in somatotrophs. Finally, the expression of the transient voltage-gated Ca2+ channels was higher in somatotrophs than in lactotrophs and gonadotrophs. These results indicate that there are cell type-specific patterns of ionic channel expression, which may be of physiological significance for the control of Ca2+ homeostasis and secretion in unstimulated and receptor-stimulated anterior pituitary cells.
Domain Interactions between Coregulator ARA70 and the Androgen Receptor (AR)
Authors: Zhou Zhong-xun , He Bin , Hall Susan H. , Wilson Elizabeth M. , French Frank S. 
Published: January 2014

AbstractThe coregulator function of AR-associated protein 70 (ARA70) was investigated to further characterize its interaction with the AR. Using a yeast two-hybrid assay, androgen-dependent binding of ARA70 deletion mutants to the AR ligand-binding domain (LBD) was strongest with ARA70 amino acids 321–441 of the 614 amino acid ARA70 protein. Mutations adjacent to or within an FxxLF motif in this 120-amino acid region abolished androgen-dependent binding to the AR-LBD both in yeast and in glutathione-S-transferase affinity matrix assays. Yeast one-hybrid assays revealed an intrinsic ARA70 transcriptional activation domain within amino acids 296–441. In yeast assays the ARA70 domains for transcriptional activation and for binding to the AR-LBD were inhibited by the C-terminal region of ARA70. Full-length ARA70 increased androgen-dependent AR transactivation in transient cotransfection assays using a mouse mammary tumor virus-luciferase reporter in CV1 cells. ARA70 also increased constitutive transcriptional activity of an AR NH2-terminal-DNA binding domain fragment and bound this region in glutathione-S-transferase affinity matrix assays. Binding was independent of the ARA70 FxxLF motif. The results identify an ARA70 motif required for androgen-dependent interaction with the AR-LBD and demonstrate that ARA70 can interact with the NH2-terminal and carboxyl-terminal regions of AR.
Induction of Human Liver X Receptor α Gene Expression Via an Autoregulatory Loop Mechanism
Authors: Li Yu , Bolten Charles , Bhat B. Ganesh , Woodring-Dietz Jessica , Li Suzhen , Prayaga Sudhirdas K. , Xia Chunsheng , Lala Deepak S. 
Published: January 2014

AbstractThe liver X receptors (LXRs), members of the nuclear receptor superfamily, play an important role in controlling lipid homeostasis by activating several genes involved in reverse cholesterol transport. These include members of the ATP binding cassette (ABC) superfamily of transporter proteins ABCA1 and ABCG1, surface constituents of plasma lipoproteins like apolipoprotein E, and cholesterol ester transport protein. They also play an important role in fatty acid metabolism by activating the sterol regulatory element-binding protein 1c gene. Here, we identify human LXRα (hLXRα) as an autoinducible gene. Induction in response to LXR ligands is observed in multiple human cell types including macrophages and occurs within 2–4 h. Analysis of the hLXRα promoter revealed three LXR response elements (LXREs); one exhibits strong affinity for both LXRα:RXR and LXRβ:RXR (a type I LXRE), and deletion and mutational studies indicate it plays a critical role in LXR-mediated induction. The other two LXREs are identical to each other, exist within highly conserved Alu repeats, and exhibit selective binding to LXRα:RXR (type II LXREs). In transfections, the type I LXRE acts as a strong mediator of both LXRα and LXRβ activity, whereas the type II LXRE acts as a weaker and selective mediator of LXRα activity. Our data suggest a model in which LXR ligands trigger an autoregulatory loop leading to selective induction of hLXRα gene expression. This would lead to increased hLXRα levels and transcription of its downstream target genes such as ABCA1, providing a simple yet exquisite mechanism for cells to respond to LXR ligands and cholesterol loading.
The Amino Terminus of the Human AR Is Target for Corepressor Action and Antihormone Agonism
Authors: Dotzlaw Helmut , Moehren Udo , Mink Sigrun , Cato Andrew C. B. , Iñiguez Lluhí Jorge A. , Baniahmad Aria 
Published: January 2014

Abstract
Antiandrogens inhibit the ligand-induced transactivation by the androgen receptor (AR) and have a widespread use in the treatment of prostate cancer but their mode of action is not fully understood. Here we show that the ability of the antiandrogen cyproterone acetate (CPA) to inhibit transactivation by the human AR (hAR) involves the corepressor SMRT (silencing mediator for retinoic acid and thyroid hormone receptor). We detect binding of SMRT to hAR when treating with the antiandrogen CPA, but not with the antihormones casodex or hydroxyflutamide. Interestingly, we find that SMRT binds to the N terminus of the hAR. Thereby, SMRT modulates the activity of hAR in receptor-negative CV1 cells. In addition, we have used receptor point mutants that exhibit normal transactivation potential and unchanged partial agonistic activity when treated with CPA, but lack both SMRT binding and SMRT-mediated inhibition of CPA-bound AR. This indicates that mechanisms involved in hAR-mediated transactivation are distinct from antihormone-induced receptor inactivation. Furthermore, we show that treatment of transfected cells with a cAMP analog or coexpression of the catalytic subunit of PKA, known to activate hAR, inhibits the binding of SMRT to the AR.
This suggests that the association of SMRT with hAR is regulated at the level of cross-talk mechanisms and that ligand-independent receptor activation is due to corepressor dissociation. Taken together, we provide novel insights in AR regulation, antihormone action, and functional nuclear receptor-corepressor interaction.
Minireview: Genomics Versus Orphan Nuclear Receptors—A Half-Time Report
Authors: Willson Timothy M. , Moore John T. 
Published: January 2014

AbstractFollowing the successful cloning of the orphan nuclear receptors during the 1990s we entered the 21st century with knowledge of the full complement of human nuclear receptors. Many of these proteins are ligand-activated transcription factors that act as the cognate receptors for steroid, retinoid, and thyroid hormones. In addition to these well characterized endocrine hormone receptors, there are a large number of orphan receptors of which less is known about the nature and function of their ligands. The task of deciphering the physiological function of these orphan receptors has been aided by a new generation of genomic technologies. Through application of chemical, structural, and functional genomics, several orphan nuclear receptors have emerged as pharmaceutical drug targets for the treatment of important human diseases. The significant progress that has been made in the functional analysis of more than half of the nuclear receptor gene family provides an opportunity to review the impact of genomics in this endeavor.
Coupling of GnRH Concentration and the GnRH Receptor-Activated Gene Program
Authors: Yuen Tony , Wurmbach Elisa , Ebersole Barbara J. , Ruf Frederique , Pfeffer Robert L. , Sealfon Stuart C. 
Published: January 2014

Abstract
The initial waves of gene induction caused by GnRH in the LβT2 gonadotrope cell line have recently been identified using microarrays. We now investigate the relationship of the concentration of GnRH to the level of biosynthesis induced. Using an optimized custom cDNA microarray, we show that a large number of genes are induced in a concentration-dependent fashion. Detailed time course studies of the induction of six induced transcripts using quantitative real-time PCR suggest that the amplitude, but not the temporal pattern, depends on the concentration of GnRH. The early genes appear to show a delay in gene induction, followed by a linear phase of increase. The relationship of rate of synthesis and GnRH concentration was studied by mathematical modeling of the induction of two genes, gly96 and tis11. In both cases, only the rates of increase, but not the lag times, are influenced by the concentration of GnRH exposure. Western blot analyses for c-Jun and Egr1 show that the levels of nuclear protein for these transcription factors also depend on the concentration of GnRH. These studies indicate that, despite the complex signaling network connecting the receptor to the activated genes, the biosynthetic rate of RNA polymerase at induced genes is correlated with the concentration of GnRH at the GnRH receptor.
Growth Hormone (GH) Deficiency Type II: A Novel GH-1 Gene Mutation (GH-R178H) Affecting Secretion and Action
Authors: Petkovic Vibor , Godi Michela , Pandey Amit V. , Lochmatter Didier , Buchanan Charles R. , Dattani Mehul T. , Eblé Andrée , Flück Christa E. , Mullis Primus E. 
Published: January 2014

ABSTRACT

Context and Objective
Main features of the autosomal dominant form of GH deficiency (IGHD II) include markedly reduced secretion of GH combined with low concentrations of IGF-I leading to short stature.

Design, Setting, and Patients
A female patient presented with short stature (height −6.0 sd score) and a delayed bone age of 2 yr at the chronological age of 5 yr. Later, at the age of 9 yr, GHD was confirmed by standard GH provocation test, which revealed subnormal concentrations of GH and a very low IGF-I. Genetic analysis of the GH-1 gene revealed the presence of a heterozygous R178H mutation.

Interventions and Results
AtT-20 cells coexpressing both wt-GH and GH-R178H showed a reduced GH secretion after forskolin stimulation compared with the cells expressing only wt-GH, supporting the diagnosis of IGHD II. Because reduced GH concentrations found in the circulation of our untreated patient could not totally explain her severe short stature, functional characterization of the GH-R178H performed by studies of GH receptor binding and activation of the Janus kinase-2/signal transducer and activator of transcription-5 pathway revealed a reduced binding affinity of GH-R178H for GH receptor and signaling compared with the wt-GH.

Conclusion
This is the first report of a patient suffering from short stature caused by a GH-1 gene alteration affecting not only GH secretion (IGHD II) but also GH binding and signaling, highlighting the necessity of functional analysis of any GH variant, even in the alleged situation of IGHD II.
Macrophage Migration Inhibitory Factor Elicits an Angiogenic Phenotype in Human Ectopic Endometrial Cells and Triggers the Production of Major Angiogenic Factors via CD44, CD74, and MAPK Signaling Pathways
Authors: Veillat Véronique , Carli Cédric , Metz Christine N. , Al-Abed Yousef , Naccache Paul H. , Akoum Ali 
Published: January 2014

Abstract
Context: An active angiogenesis is required for ectopic endometrial tissue growth. Our previous studies led to the identification of macrophage migration inhibitory factor (MIF), which is markedly elevated in active, vascularized, and early-stage endometriotic lesions, as a potent mitogenic factor for endothelial cells.
Objective: Our objective was to study the mechanisms by which MIF may stimulate angiogenesis in ectopic endometrial implantation sites.
Design: Primary cultures of ectopic endometrial cells were exposed to MIF, and the release of major angiogenic factors with targeted disruption of MIF signaling pathways was assessed.
Patients: Patients were women found to have endometriosis during laparoscopy.
Setting: The study was conducted at a hospital and reproduction research laboratory.
Interventions: Biopsies were removed from endometriotic lesions.
Main Outcome Measures: Vascular endothelial cell growth factor (VEGF), IL-8, and monocyte chemotactic protein-1 (MCP-1) mRNA and protein levels and expression and small interfering RNA silencing of MIF CD74/CD44 receptor complex and phosphorylation of ERK and p38 MAPKs were evaluated.
Results: MIF markedly up-regulated VEGF, IL-8, and MCP-1 expression in endometriotic cells. Such an effect was abolished by (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), a specific inhibitor of MIF, and significantly down-regulated after specific small interfering RNA silencing of CD44 or CD74. MIF treatment strongly activated ERK and p38 MAPKs, and specific inhibitors of both pathways completely blocked basal and MIF-induced VEGF, IL-8, and MCP-1 synthesis.
Conclusions: These results show for the first time that MIF exerts a potent indirect angiogenic effect by interacting with ectopic endometrial cells and inducing the secretion of major angiogenic factors via CD44, CD74, and MAPK signaling pathways and provide evidence for a possible new mechanism underlying endometriosis development and pathophysiology.
Demethylation of TMS1 Gene Sensitizes Thyroid Cancer Cells to TRAIL-Induced Apoptosis
Authors: Siraj Abdul K. , Hussain Azhar R. , Al-Rasheed Maha , Ahmed Maqbool , Bavi Prashant , Alsobhi Saif Al-Deen Suliman , Al-Nuaim Abdurahman , Uddin Shahab , Al-Kuraya Khawla 
Published: January 2014

Abstract
Context: TMS1 is a tumor suppressor gene that encodes for caspase recruitment domain containing regulatory protein and has been shown to be hypermethylated in various cancers. However, its methylation status has not been investigated in thyroid cancer. Therefore, we studied the methylation of TMS1 and its functional consequence in thyroid cancer.
Design: The methylation status of the promoter region of the TMS1 gene was determined using methylation-specific PCR in 40 papillary thyroid cancer samples, 10 normal thyroid tissue, and seven thyroid cancer cell lines. RT-PCR and Western blot analysis were used to assess the expression levels. 5-aza-2′-deoxycytidine was used to demethylate the thyroid cancer cell lines. Cell viability and apoptosis was determined by dimethylthiazoldiphenyltetra-zoliumbromide and flow cytometry.
Results: Twenty-three percent of the papillary thyroid carcinoma samples were found to be methylated for the TMS1 gene. Two of seven thyroid cell lines were either completely or partially methylated for the TMS1 gene. The treatment of methylated thyroid cancer cell lines with 5-aza-2′-deoxycytidine resulted in the demethylation of the TMS1 gene leading to the restoration of its expression. After demethylation, treatment of cells with TNF-related apoptosis-inducing ligand (TRAIL) led to the induction of apoptosis via activation of caspases-8, caspase-3, and poly(ADP-ribose) polymerase. Interestingly, gene silencing of TMS1 using TMS1-specific small interfering RNA prevented TRAIL-mediated apoptosis.
Conclusion: Our results demonstrated that the TMSI gene is methylated in thyroid cancer cells and repression of methylation by 5-aza-2′-deoxycytidine restored expression of the TMS1 gene and sensitized cells to TRAIL-induced apoptosis. These findings suggest that the TMS1 gene can be targeted by combination of demethylating agents with TRAIL to induce efficient apoptosis in thyroid cancer cells.
Elevated FGF23 Levels Are Associated with Impaired Calcium-Mediated Suppression of PTH in ESRD
Authors: Wetmore James B. , Santos Peter , Mahnken Jonathan D. , Krebill Ron , Menard Rochelle , Gutta Hema , Quarles L. Darryl 
Published: January 2014

Abstract
Context: The positive association of elevated fibroblast growth factor-23 (FGF23) with PTH levels in the setting of secondary hyperparathyroidism is paradoxical to the purported effects of FGF23 to suppress PTH secretion.
Objective: We used dynamic calcium-mediated suppression of PTH levels in hemodialysis (HD) patients to determine the relationship between FGF23 levels and parathyroid gland function.
Design: HD patients with elevated PTH were washed out of vitamin D analogs and/or calcimimetics and then exposed them to a high-calcium dialysate bath designed to suppress PTH.
Setting: The study was conducted at an outpatient HD unit of an academic medical center.
Participants: Eighteen maintenance HD patients with elevated PTH levels participated in the study.
Main Outcome Measures: Ionized calcium (iCa), PTH, and FGF23 levels were measured during HD. The slope of the relationship between iCa and PTH (a marker of parathyroid gland mass) and the iCa level required for a 50% reduction in PTH were determined, and the association of these with FGF23 levels was determined.
Results: Increased baseline log FGF23 levels were associated with putative alterations in gland mass as estimated by significantly shallower slopes of the iCa/PTH suppression curves (P = 0.0004), but there was no association between FGF23 and calcium sensing as measured by ionized Ca associated with a 50% suppression of PTH (P = 0.38). FGF23 levels decreased significantly during HD, but this change was not correlated with decrements in either renal phosphate or PTH.
Conclusions: High FGF23 levels may be a marker for parathyroid gland hyperplasia in HD patients. Acute reductions in neither PTH nor renal phosphate during dialysis correlated with PTH suppression.
Chemerin, A Novel Adipokine in the Regulation of Angiogenesis
Authors: Bozaoglu Kiymet , Curran Joanne E. , Stocker Claire J. , Zaibi Mohamed S. , Segal David , Konstantopoulos Nicky , Morrison Shona , Carless Melanie , Dyer Thomas D. , Cole Shelley A. , Goring Harald H. H. , Moses Eric K. , Walder Ken , Cawthorne Michael A. , Blangero John , Jowett Jeremy B. M. 
Published: January 2014

Abstract
Context: Chemerin is a new adipokine associated with obesity and the metabolic syndrome. Gene expression levels of chemerin were elevated in the adipose depots of obese compared with lean animals and was markedly elevated during differentiation of fibroblasts into mature adipocytes.
Objective: To identify factors that affect the regulation and potential function of chemerin using a genetics approach.
Design, setting, patients and intervention: Plasma chemerin levels were measured in subjects from the San Antonio Family Heart Study (SAFHS), a large family-based genetic epidemiological study including 1354 Mexican American individuals. Individuals were randomly sampled without regard to phenotype or disease status.
Main Outcome Measures: A genome wide association analysis using 542,944 SNPs in a subset of 523 of the same subjects was undertaken. The effect of chemerin on angiogenesis was measured using human endothelial cells and interstitial cells in co-culture in a specially formulated medium.
Results: Serum chemerin levels were found to be highly heritable (h2 = 0.25; P = 1.4 x 10−9). The SNP showing strongest evidence of association (rs347344; P = 1.4 x 10−6) was located within the gene encoding EDIL3, which has a known role in angiogenesis. Functional angiogenesis assays in human endothelial cells confirmed that chemerin significantly mediated the formation of blood vessels to a similar extent as VEGF.
Conclusion: Here we demonstrate for the first time that plasma chemerin levels are significantly heritable and identified a novel role for chemerin as a stimulator of angiogenesis.
Insulin Stimulates Human Skeletal Muscle Protein Synthesis via an Indirect Mechanism Involving Endothelial-Dependent Vasodilation and Mammalian Target of Rapamycin Complex 1 Signaling
Authors: Timmerman Kyle L. , Lee Jessica L. , Dreyer Hans C. , Dhanani Shaheen , Glynn Erin L. , Fry Christopher S. , Drummond Micah J. , Sheffield-Moore Melinda , Rasmussen Blake B. , Volpi Elena 
Published: January 2014

Abstract
Objective: Our objective was to determine whether endothelial-dependent vasodilation is an essential mechanism by which insulin stimulates human skeletal muscle protein synthesis and anabolism.
Subjects: Subjects were healthy young adults (n = 14) aged 31 ± 2 yr.
Design: Subjects were studied at baseline and during local leg infusion of insulin alone (control, n = 7) or insulin plus the nitric oxide synthase inhibitor NG-monomethyl-l-arginine (L-NMMA, n = 7) to prevent insulin-induced vasodilation.
Methods: We measured skeletal muscle protein metabolism with stable isotope tracers, blood flow with indocyanine green, capillary recruitment with contrast enhanced ultrasound, glucose metabolism with stable isotope tracers, and phosphorylation of proteins associated with insulin (Akt) and amino acid-induced mammalian target of rapamycin(mTOR) complex 1 (mTORC1) signaling (mTOR, S6 kinase 1, and eukaryotic initiation factor 4Ebinding protein 1) with Western blot analysis.
Results: No basal differences between groups were detected. During insulin infusion, blood flow and capillary recruitment increased in the control (P &lt; 0.05) group only; Akt phosphorylation and glucose uptake increased in both groups (P &lt; 0.05), with no group differences; and mTORC1 signaling increased more in control (P &lt; 0.05) than in l-NMMA. Phenylalanine net balance increased (P &lt; 0.05) in both groups, but with opposite mechanisms: increased protein synthesis (basal, 0.051 ± 0.006%/h; insulin, 0.077 ± 0.008%/h; P &lt; 0.05) with no change in proteolysis in control and decreased proteolysis (P &lt; 0.05) with no change in synthesis (basal, 0.061 ± 0.004%/h; insulin, 0.050 ± 0.006%/h; P value not significant) in l-NMMA.
Conclusions: Endothelial-dependent vasodilation and the consequent increase in nutritive flow and mTORC1 signaling, rather than Akt signaling, are fundamental mechanisms by which insulin stimulates muscle protein synthesis in humans. Additionally, these data underscore that insulin modulates skeletal muscle proteolysis according to its effects on nutritive flow.