bluuebunny/crossref_metadata_2025_split huggingface dataset:
Missense Mutations in the Melanocortin 2 Receptor Accessory Protein That Lead to Late Onset Familial Glucocorticoid Deficiency Type 2
Authors: Hughes C. R. , Chung T. T. , Habeb A. M. , Kelestimur F. , Clark A. J. L. , Metherell L. A. 
Published: January 2014

ABSTRACT

Background
Familial glucocorticoid deficiency (FGD) is an autosomal recessive disorder characterized by isolated glucocorticoid deficiency. Mutations in the ACTH receptor [melanocortin 2 receptor (MC2R)] or the MC2R accessory protein (MRAP) cause FGD types 1 and 2, respectively. Typically, type 2 patients present early (median age, 0.1 yr), and no patient reported to date has presented after 1.6 yr.

Aim
The aim of this study was to investigate the cause of disease in two families with late-onset FGD.

Patients
The proband in family 1 was diagnosed at age 4 yr. Family review revealed two older siblings with undiagnosed FGD. One sibling was well, whereas the second had cerebral palsy secondary to hypoglycemic seizures. The proband in family 2 was diagnosed at age 18 yr with symptoms of fatigue, weight loss, and depression.

Methods
The coding exons of MC2R and MRAP were sequenced. ACTH dose-response curves were generated for MC2R when transfected with wild-type or mutant MRAP constructs using HEK293 cells. MC2R trafficking with both mutant MRAPs was investigated using immunocytochemistry.

Results
MRAP gene analysis identified two novel homozygous missense mutations, c.175T&gt;G (pY59D) in family 1 and c.76T&gt;C (p.V26A) in family 2.
In vitro analysis showed that the Y59D mutant had significant impairment of cAMP generation, and both mutants caused a shift in the dose-response curve to the right when compared to wild type. Immunocytochemistry showed normal trafficking of MC2R when transfected with both mutant MRAPs, indicating a probable signaling defect.

Conclusion
These results indicate that missense MRAP mutations present with a variable phenotype of ACTH resistance and can present late in life.
Targeted Disruption of Mapk14 (p38MAPKα) in Granulosa Cells and Cumulus Cells Causes Cell-Specific Changes in Gene Expression Profiles that Rescue Cell-Oocyte Complex Expansion and Maintain Fertility
Authors: Liu Zhilin , Fan Heng-Yu , Wang Yibin , Richards JoAnne S. 
Published: January 2014

Abstract
MAPK14 (p38MAPKα) is critical for FSH and prostaglandin E (PGE)2 signaling cascades in granulosa cells (GCs) and cumulus cell-oocyte complexes (COCs) in culture, indicating that this kinase might impact follicular development and COC expansion in vivo. Because Mapk14 knockout mice are embryonic lethal, we generated GC specific Mapk14 knockout mice (Mapk14gc−/−) by mating Mapk14fl/fl and Cyp19a1-Cre mice. Unexpectedly, the Mapk14gc−/− female mice were fertile. Analyses of gene expression patterns showed that amphiregulin (Areg) and epiregulin (Ereg), two key regulators of ovulation and COC expansion, were up-regulated in the GCs but down-regulated in cumulus cells of the mutant mice in vivo. COCs from the mutant mice expanded and expressed matrix-related genes, if cultured with AREG, but not when cultured with forskolin or PGE2, the latter being a key factor regulating MAPK14 activity in cumulus cells. Conversely, when GCs from the Mapk14gc−/− mice were cultured with forskolin, they produced more Areg and Ereg mRNA than did wild-type GCs. These results indicate that disruption of Mapk14 selectively alters the expression of Areg and other genes in each cell type. Greater AREG and EREG produced by the GCs appears to by-pass and compensate for the critical need for MAPK14 signaling and induction of Areg/Ereg (and hence matrix genes) by PGE2 in cumulus cells of the mutant mice. In conclusion, although MAPK14 is not overtly essential for preovulatory follicle development or events associated with ovulation and luteinization in vivo, it does impact gene expression profiles.
Implication of Oxygen-Regulated Protein 150 (ORP150) in Apoptosis Induced by Proteasome Inhibitors in Human Thyroid Cancer Cells
Authors: Gao Yan-Yan , Liu Bao-Qin , Du Zhen-Xian , Zhang Hai-Yan , Niu Xiao-Fang , Wang Hua-Qin 
Published: January 2014

ABSTRACT

Context
The inhibition of the 26S proteasome may lead to endoplasmic reticulum stress, which has been shown to be implicated in the antitumoral effects of proteasome inhibitors. Oxygen-regulated protein 150 (ORP150) is an inducible endoplasmic reticulum chaperone that is up-regulated after numerous cellular insults and has a cytoprotective role for the maintenance of cellular viability.

Objective
The purpose of this study was to determine the involvement of ORP150 in cytotoxicity of thyroid cancer cells mediated by proteasome inhibition.

Design
The effects of proteasome inhibition on the expression of ORP150 were analyzed using real-time RT-PCR and Western blot. To ascertain the effect of ORP150, cells were transfected with ORP150 plasmid or small interfering RNA (siRNA) against ORP150, apoptotic cells, and induction of CCAAT/enhancer-binding protein homologous transcription factor (CHOP) mediated by proteasome inhibition were investigated.

Results
ORP150 was induced in thyroid cancer cells after proteasome inhibition. Suppression of activating transcription factor 4 expression by siRNA inhibited the up-regulation of ORP150 mediated by proteasome inhibitors. siRNA for ORP150 stimulated MG132-mediated apoptosis and induction of CHOP, a transcription factor with apoptosis-inducing activity. In contrast, ORP150-overexpressing cells demonstrated less susceptibility to MG132-induced apoptosis and displayed less up-regulation of CHOP. In addition, the sensitizing effect of small interfering ORP150 on apoptosis was suppressed by siRNA for CHOP.

Conclusions
These results suggest that up-regulation of ORP150 in thyroid cancer cells inhibits MG132-induced apoptosis via suppression of CHOP induction, thereby decreasing the potential antitumor activity of MG132.
CXCL9 and CXCL11 Chemokines Modulation by Peroxisome Proliferator-Activated Receptor-α Agonists Secretion in Graves’ and Normal Thyrocytes
Authors: Antonelli Alessandro , Ferrari Silvia Martina , Frascerra Silvia , Pupilli Cinzia , Mancusi Caterina , Metelli Maria Rita , Orlando Claudio , Ferrannini Ele , Fallahi Poupak 
Published: January 2014

ABSTRACT

Context
Peroxisome proliferator-activated receptor (PPAR)-α has been shown to exert immunomodulatory effects in autoimmune disorders. However, until now, no data were present in the literature about the effect of PPARα activation on CXCL9 and CXCL11 chemokines in general or on secretion of these chemokines in thyroid cells.

Objective and Design
The presence of PPARα and PPARγ has been evaluated by RT-PCR in Graves’ disease (GD) and control cells in primary culture. Furthermore, we have tested the role of PPARα and PPARγ activation on CXCL9 and CXCL11 secretion in GD and control cells after stimulation of these chemokines secretion with IFNγ and TNFα.

Results
This study shows the presence of PPARα and PPARγ in GD and control cells. A potent dose-dependent inhibition by PPARα-agonists was observed on the cytokines-stimulated secretion of CXCL9 and CXCL11 in GD and control cells. The potency of the PPARα agonists used was maximum on the secretion of CXCL9, reaching about 90% of inhibition by fenofibrate and 85% by ciprofibrate. The relative potency of the compounds was different with each chemokine; for example, gemfibrozil exerted a 55% inhibition on CXCL11, whereas it had a weaker activity on CXCL9 (40% inhibition). PPARα agonists were stronger (ANOVA, P &lt; 0.001) inhibitors of CXCL9 and CXCL11 secretion in thyrocytes than PPARγ agonists.

Conclusions
Our study shows the presence of PPARα in GD and control thyrocytes. PPARα activators are potent inhibitors of the secretion of CXCL9 and CXCL11, suggesting that PPARα may be involved in the modulation of the immune response in the thyroid.
Loss of the C Terminus of Melanocortin Receptor 2 (MC2R) Results in Impaired Cell Surface Expression and ACTH Insensitivity
Authors: Hirsch Andrea , Meimaridou Eirini , Fernandez-Cancio Monica , Pandey Amit V. , Clemente María , Audi Laura , Clark Adrian J. L. , Flück Christa E. 
Published: January 2014

Objective
Mutations in melanocortin receptor 2 (MC2R) and its related melanocortin receptor accessory protein (MRAP) cause familial glucocorticoid deficiency. We identified a novel MC2R mutation, K289fs. This unique mutation in the C terminus of MC2R is located in the intracellular part of the protein for which the exact function is unknown.

Setting
A 6-wk-old boy presented with severe hypoglycemia, unmeasurable cortisol, and grossly elevated ACTH but normal electrolytes. Genetic analysis revealed homozygote K289fs mutation in MC2R. His parents and siblings were heterozygous but phenotypically normal.

Intervention and Results
The role of the C terminus of MC2R was studied in two cell systems. Because the K289fs mutant changes the last eight amino acids of the protein and leads to protein elongation, wild-type MC2R and C-terminally mutated constructs were tested for activity to respond to ACTH in an OS3 cell-based reporter assay. Wild-type and alanine-substituted constructs responded normally to ACTH. By contrast K289fs and M290X had a total loss of activity. Cell surface assays and confocal localization studies revealed that K289fs and M290X receptors were not found at the cell surface, indicating that their transport from the endoplasmic reticulum to the cell membrane is disrupted. Interestingly, coimmunoprecipitation experiments showed no alteration in the interaction of mutant MC2R with MRAP, suggesting that interaction between these two proteins does not guarantee normal localization.

Conclusions
Loss of the C terminus of MC2R impairs cell surface expression and ACTH sensitivity but does not disrupt interaction of MC2R with MRAP. These findings highlight the extreme sensitivity of MC2R to structural disruption.
Depression in Women with Spontaneous 46, XX Primary Ovarian Insufficiency
Authors: Schmidt Peter J. , Luff Jamie A. , Haq Nazli A. , Vanderhoof Vien H. , Koziol Deloris E. , Calis Karim A. , Rubinow David R. , Nelson Lawrence M. 
Published: January 2014

Context
A high prevalence of depressive symptoms is observed in women with primary ovarian insufficiency (POI) compared with women in whom the menopause is normally timed. Indeed, studies suggest that depression and/or its pharmacological treatment contribute to the onset of POI.

Objectives
We characterize the prevalence of psychiatric disorders and the timing of onset of clinically significant depression relative to both the diagnosis of POI and the onset of menstrual irregularity in women with POI.

Design and Setting
We conducted a cross-sectional clinic-based study at the National Institutes of Health Clinical Research Center.

Patients
A total of 174 women with spontaneous 46, XX POI and 100 women with Turner syndrome participated in the study.

Main Outcome Measures
The structured clinical interview for DSM-IV was performed.

Results
Lifetime histories of depression in POI exceeded rates of depression reported in women with Turner syndrome and community-based samples of women (P &lt; 0.001). The onset of depression frequently preceded the diagnosis of POI but occurred after the onset of menstrual irregularity. Analyses standardizing the periods of risk for depression showed that similar numbers of depressions occurred before and after these events.

Conclusions
POI is associated with an increased lifetime risk for major depression. Attention to the presence of depression in POI should become an important part of the care for these women. The onset of depression frequently occurs after signs of altered ovarian function but before the diagnosis of POI. Thus, in some women the association between POI and depression suggests an overlapping pathophysiology rather than a causal relationship.
Sphingosine 1-Phosphate Mobilizes Sequestered Calcium, Activates Calcium Entry, and Stimulates Deoxyribonucleic Acid Synthesis in Thyroid FRTL-5 Cells*
Authors: Törnquist Kid , Saarinen Pia , Vainio Minna , Ahlström Mikael 
Published: January 2014

AbstractSphingosine 1-phosphate (SPP) potently mobilizes sequestered calcium and is a mitogen in several cell types. In the present investigation, we have evaluated the effect of SPP on intracellular free calcium concentration ([Ca2+]i) and synthesis of DNA in thyroid FRTL-5 cells. SPP rapidly and transiently mobilized sequestered calcium and stimulated entry of extracellular calcium. The entry of calcium, but not the mobilization, was in part inhibited by pretreatment with pertussis toxin (Ptx), and by activation of protein kinase C. SPP did not stimulate the production of inositol 1,4,5-trisphosphate. SPP stimulated the incorporation of 3H-thymidine in a time- and dose-dependent manner. The effect was not inhibited by Ptx. Furthermore, SPP stimulated the activation of the proto-oncogene c-fos. SPP rapidly tyrosine-phosphorylated an approximately 66 kDa protein. This phosphorylation persisted for at least 1 h. Pretreatment of the cells with genistein abolished the SPP-evoked tyrosine phosphorylation, and attenuated the SPP-evoked increase in[ Ca2+]i. Furthermore, the SPP-evoked activation of Na+-H+ exchange was inhibited by genistein. The phosphorylation was not attenuated by pretreatment of the cells with Ptx. SPP per se did not affect cellular cAMP levels but attenuated the TSH-evoked increase in cAMP. As the effect of SPP might be due to activation of phospholipase D, we tested whether phosphatidic acid (PA) mobilized calcium or stimulated the incorporation of 3H-thymidine. PA mobilized sequestered calcium but did not stimulate calcium entry. PA very modestly enhanced the incorporation of 3H-thymidine. Our results suggest, that SPP stimulates DNA synthesis and activates entry of calcium in FRTL-5 cells. The effect on calcium entry appears to be dependent, at least in part, on one or several tyrosine kinases.
Hepatic Expression of ErbB3 Is Repressed by Insulin in a Pathway Sensitive to PI-3 Kinase Inhibitors*
Authors: Carver Robert S. , Mathew Puthenpurackal M. , Russell William E. 
Published: January 2014

AbstractErbB3 is an epidermal growth factor receptor-related type I tyrosine kinase receptor capable, in conjunction with ErbB2 or epidermal growth factor receptor, of transmitting proliferative and differentiative signals in a variety of cell types. We previously showed that ErbB3 messenger RNA and protein increase in cultured hepatocytes during the first 12 h in culture, as does the binding of heregulin β1, a ligand for ErbB3. Insulin inhibits the increase in heregulin β1 binding, as well as the increase in ErbB3 messenger RNA and protein. Two models of insulin deficiency in vivo (diabetes and fasting) demonstrated elevated levels of hepatic ErbB3 protein, strengthening the relevance of our observations in vitro. Using chemical activators or antagonists, we sought to identify the signaling pathways that link insulin to ErbB3 expression. The PI-3 kinase inhibitors, wortmannin and LY294002, completely blocked the inhibition of ErbB3 protein expression by insulin, suggesting a role for PI-3 kinase in the regulation of this growth factor receptor. Rapamycin, an inhibitor of p70 S6 kinase, an enzyme downstream of PI-3 kinase, failed to block the effect of insulin on ErbB3 expression. These results suggest a complex regulatory paradigm for ErbB3 that includes PI-3 kinase and may be linked, via insulin, to the metabolic status of the animal.
Changes in Facilitative Glucose Transporter Messenger Ribonucleic Acid Levels in the Diabetic Rat Kidney*
Authors: Chin Edward , Zamah A. Musa , Landau Daniel , Gronboek Henning , Flyvbjerg Allan , LeRoith Derek , Bondy Carolyn A. 
Published: January 2014

Abstract
Facilitative glucose transporter (GLUTs 1, 2, 4, and 5) messenger RNAs (mRNAs) are differentially distributed in the rat nephron: GLUT1 is widely expressed, GLUT4 is selectively concentrated in thick ascending limbs, and GLUT2 and 5 are exclusively localized in proximal tubules, consistent with differential roles for these transporters in renal glucose handling. In the present study, quantitative in situ hybridization was used to evaluate changes in these mRNA levels during acute (2 and 7 days) and chronic (30, 90, and 180 days) streptozotocin-induced diabetes mellitus (STZ-DM). Medullary GLUT1 and GLUT4 mRNA levels were significantly increased during the acute phase but returned to normal after 1 week. Cortical GLUT1 mRNA levels, however, were decreased significantly from 7 days through 6 months of STZ-DM. Cortical GLUT2 mRNA was slightly increased acutely and increased 5-fold in chronic STZ-DM, with the largest increase focally concentrated in the convoluted portion of the proximal tubule. Proximal tubule GLUT5 mRNA levels also were increased significantly during chronic STZ-DM.
In summary, medullary GLUT1 and GLUT4 mRNA levels are acutely increased in STZ-DM, paralleling the increased renal epithelial metabolic activity accompanying early diabetes. Proximal tubular GLUT2 and 5 mRNA levels were increased in chronic STZ-DM, possibly adapting to the increased need for glucose transport out of these epithelial cells, whereas the concomitant decrease in cortical GLUT1 expression may reflect the decreased requirement for basolateral import of glucose into these same cells. Thus, renal GLUTs demonstrate complex, nephron segment-specific and duration-dependent responses to the effects of STZ-DM.
Purification and Characterization of the Insulin-Like Growth Factor-Binding Protein-1 Phosphoform Found in Normal Plasma*
Authors: Westwood Melissa , Gibson J Martin , White Anne 
Published: January 2014

AbstractOur previous work has shown that, in the normal circulation, insulin-like growth factor-binding protein-1 (IGFBP-1) is present as a single highly phosphorylated species. In this study, we have purified this previously uncharacterized isoform of IGFBP-1 to determine its ligand-binding affinity and the potential significance of highly phosphorylated IGFBP-1. Immunoaffinity chromatography was used to isolate IGFBP-1 from normal human plasma and from human hepatoma (Hep G2) cell medium as an alternative source of the IGFBP-1 phosphoform in the circulation. The affinity of this highly phosphorylated IGFBP-1 was compared with that of nonphosphorylated IGFBP-1 and recombinant human (rh) IGFBP-3 by equilibrium binding to IGF-I and IGF-II.Anion-exchange (IEX) HPLC, nondenaturing electrophoresis, alkaline phosphatase treatment, and ligand-binding studies indicated that the highly phosphorylated IGFBP-1 from HepG2 cells was comparable with IGFBP-1 from plasma. In binding to IGF-I, the plasma phosphoform of IGFBP-1 was found to have a higher affinity (2.3 ± 1.1 × 1010m−1) than nonphosphorylated IGFBP-1 (2.5 ± 1.7 × 109m−1, P &lt; 0.002). However, when binding to IGF-II, phosphorylation had no affect on the affinity of IGFBP-1 (3.6 ± 2 × 109m−1vs. 1.8 ± 3 × 109m−1, P not significant). Therefore, in the circulation, IGF-I has a considerably higher affinity than IGF-II for IGFBP-1 (P &lt; 0.02). The affinity of phosphorylated IGFBP-1 from plasma (2.3 ± 1.1 × 1010m−1) also was significantly higher than the affinity of IGFBP-3 for IGF-I (5.6 ± 4.2 × 109m−1, P &lt; 0.005).These data suggest that the highly phosphorylated IGFBP-1 in the normal circulation will preferentially bind IGF-I rather than IGF-II, whereas in pregnancy, the affinity of IGFBP-1 for IGF-I will be reduced because of the appearance of non- and lesser-phosphorylated forms. This lends support to the theory that changes in IGFBP-1 phosphorylation may influence the modulatory effects of IGFBP-1 on IGF bioavailability.
Liver and Kidney Growth Hormone (GH) Receptors Are Regulated Differently in Diabetic GH and GH Antagonist Transgenic Mice*
Authors: Chen Nian-yi , Chen Wen Y. , Kopchick John J. 
Published: January 2014

AbstractElevated GH levels are frequently seen in poorly controlled type I diabetics and have been implicated in diabetic complications. Studies of GH and GH antagonist (GHA) transgenic mice with streptozotocin (STZ)-induced diabetes have revealed that GH has a permissive effect for diabetic nephropathy, and that expression of a GHA gene protected mice against diabetic kidney lesions. To investigate whether kidney GH receptor (GHR) and/or GH-binding protein may play a role in diabetic nephropathy, we evaluated GH-specific binding and messenger RNA levels for GHR/GH-binding protein in mouse livers and kidneys from bovine (b) GH or bGHA transgenic (Tg) mice and their nontransgenic (NTg) littermates with or without STZ-induced diabetes. We found that liver-specific GH binding is significantly higher in both bGH- and bGHA-Tg mice compared to that in their NTg controls. In contrast, kidney GH binding is significantly lower in bGH-Tg mice compared to that in NTg littermates. These results indicate that regulation of mouse GHR expression is tissue specific. STZ-induced diabetes decreased GH-specific binding in both liver and kidney of NTg and GHA-Tg mice, but not in bGH-Tg mice. The lowered GHR binding in diabetic NTg and GHA-Tg mice suggests the involvement of insulin in the regulation of GHR expression. The down-regulation of kidney GHR in GHA-Tg mice in combination with the presence of GHA may partially explain the protective mechanism of GHA against diabetic kidney lesions.
Correlation of the Activation of Ca2+/Calmodulin-Dependent Protein Kinase II with the Initiation of Insulin Secretion from Perifused Pancreatic Islets*
Authors: Easom Richard A. , Filler Natalie R. , Ings Emma M. , Tarpley Jim , Landt Michael 
Published: January 2014

AbstractAn experimental procedure has been designed to permit the simultaneous assessment of the activation status of the multifunctional Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) with insulin secretion in perifused islets. By this procedure, the activation of CaM kinase II by glucose correlated closely with the initial and sustained phases of insulin secretion within a 30-min test period. By contrast, islets (160–200/tube) in static incubations neither supported second-phase insulin secretion nor CaM kinase II activation beyond 10–15 min. This was not the result of the accumulation of insulin, because the introduction of insulin (40–160 ng/ml) into the perifusion medium failed to mimic the suppression of glucose-induced insulin secretion or CaM kinase II activation. A similar addition of SRIF (0.01–1 μm) or epinephrine (1μ m) profoundly suppressed insulin secretion although failing to significantly influence CaM kinase II activation. Finally, on withdrawal of glucose from perifused islets, insulin secretion rapidly returned to basal rates, but CaM kinase II deactivation was significantly delayed. The correlation of kinase activation with the initiation of insulin secretion suggests that CaM kinase II may be important in the regulation of glucose-induced insulin secretion. The observed dissociation of these parameters in the presence of inhibitory hormones or after the withdrawal of a glucose stimulus, however, suggests that the kinase is not directly involved in the final steps of insulin exocytosis.