bluuebunny/crossref_metadata_2025_split huggingface dataset:
Opposite Effects of Androgens and Estrogens on Adipogenesis in Rat Preadipocytes: Evidence for Sex and Site-Related Specificities and Possible Involvement of Insulin-Like Growth Factor 1 Receptor and Peroxisome Proliferator-Activated Receptorγ 21
Authors: Dieudonne M. N. , Pecquery R. , Leneveu M. C. , Giudicelli Y. 
Published: January 2014

AbstractTo investigate the role of sex steroid hormones in adipose tissue development and distribution, we have studied the effect of various sex steroids (testosterone, dihydrotestosterone (DHT), and 17β-estradiol) in vitro, on the proliferation and differentiation processes in rat preadipocytes from deep (epididymal and parametrial) and superficial (femoral sc) fat deposits. All added steroids failed to affect the growth rate of preadipocytes from male rats when determined from day 1 to day 4 after plating, whether FCS was present or not in the culture medium. In contrast, in preadipocytes from female rats, we observed a positive effect (×2) of 17β-estradiol (0.01μ m) on the proliferative capacities of sc but not parametrial preadipocytes. When preadipocytes were exposed to testosterone or DHT (0.1 μm) during the differentiation process, the glycerol 3-phosphate dehydrogenase activity was significantly decreased in epididymal preadipocytes only. When preadipocytes from male rats were exposed to 17β-estradiol (0.01μ m), the differentiation capacities of preadipocytes were not modified. However, in parametrial preadipocytes from ovariectomized female rats, 17β-estradiol significantly increased (×1.34) the glycerol 3-phosphate dehydrogenase activity. In differentiated preadipocytes that had been exposed to sex steroids, expression of peroxisome proliferator-activated receptor γ2 was up-regulated by 17β-estradiol but not by androgens. As described in other cell types, sex steroids modulate insulin growth factor 1 receptor (IGF1R) expression in preadipocytes. Indeed, IGF1R levels were either enhanced by 17 β-estradiol (0.01 μm) in sc preadipocytes from female ovariectomized rats or decreased by DHT (0.01 μm) in epididymal preadipocytes. These effects were reversed by simultaneous exposure to androgen or estrogen receptor antagonists. In conclusion, this study demonstrates that, in rat preadipocytes kept in primary culture and chronically exposed to sex hormones, androgens elicit an antiadipogenic effect, whereas estrogens behave as proadipogenic hormones. Moreover, our results suggest that these opposite effects could be related to changes in IGF1R (androgens and estrogens) and peroxisome proliferator-activated receptor γ2 expression (estrogens).
Immortalized Luteinizing Hormone-Releasing Hormone Neurons Show a Different Migratory Activity in Vitro*
Authors: Maggi Roberto , Pimpinelli Federica , Molteni Laura , Milani Mario , Martini Luciano , Piva Flavio 
Published: January 2014

AbstractThe development of two cell lines (GT1 and GN) of immortalized LHRH neurons has allowed an accurate study of the mechanisms controlling the synthesis and the secretion of LHRH. These cell lines, obtained in mice by genetic targeted tumorigenesis, retain many of the phenotypic characteristics of LHRH neurons. Of interest, GT1 cells derive from an hypothalamic tumor, whereas GN cells were obtained from a tumor localized in the olfactory bulb. The different origin of these cell lines lead to hypothesize that they might represent hypothalamic postmigratory neurons (GT1 cells), or LHRH neurons blocked at an early stage of their migration (GN cells). Using different experimental procedures, we found that the two cell subclones GT1–7 and GN11 express a different morphology and migratory behavior in vitro. In particular, we found that GN11 cells, but not GT1–7 cells, show the morphological shape of migrating neurons. When analyzing the spontaneous motility we found that only GN11 cells express a high capacity of migrating in a matrix of collagen gel. Moreover, in a chemomigratory assay GN11 cells did show a significant response to the chemotactic stimulus represented by the FBS. On the contrary, GT1–7 cells show very low spontaneous motility and appear insensitive to the FBS stimulus. These results suggest that the simultaneous use of the GT1–7/GN11 cells may represent an experimental tool for screening the factors possibly involved in the control of the migratory processes of LHRH neurons in normal and in pathological conditions, such as those due to their impaired migration, like it happens in Kallmann’s syndrome.
Transforming Growth Factor-β Stimulates Inorganic Phosphate Transport and Expression of the Type III Phosphate Transporter Glvr-1 in Chondrogenic ATDC5 Cells*
Authors: Palmer Gaby , Guicheux Jerôme , Bonjour Jean-Philippe , Caverzasio Joseph 
Published: January 2014

Abstract
Members of the transforming growth factor (TGF)-β family are important regulators of skeletal development. In this study, we investigated the effect of TGF-β1 on inorganic phosphate (Pi) transport and on expression of the type III Pi carriers Glvr-1 and Ram-1 in murine ATDC5 chondrocytes. TGF-β1 induced a selective, dose- and time-dependent increase in sodium-dependent Pi transport in ATDC5 cells. This response was dependent on RNA and protein synthesis and reflected a change in the maximal rate of the transport system, suggesting that TGF-β1 induces the synthesis of new Pi carriers and their insertion into the plasma membrane. Consistently, Northern blotting analysis showed a dose-dependent increase in Glvr-1 messenger RNA expression in response to TGF-β1, which preceded the maximal stimulation of Pi transport by several hours. Glvr-1 thus likely mediates at least part of the increase in Pi uptake induced by TGF-β1. Ram-1 messenger RNA expression was not affected by TGF-β1. TGF-β1 activated the Smad signaling pathway and the mitogen-activated protein kinases ERK and p38 in ATDC5 cells. Unlike the regulation of Pi transport by receptor tyrosine kinase agonists in osteoblasts, the effect of TGF-β1 on Pi uptake in ATDC5 cells did not involve protein kinase C or mitogen-activated protein kinases, suggesting that a specific, possibly Smad-dependent, signal mediates this response. In conclusion, TGF-β1 stimulates Pi transport and Glvr-1 expression in chondrocytes, suggesting that, like proliferation, differentiation, and matrix synthesis, Pi handling is subject to regulation by TGF-β family members in bone-forming cells.
Thyroid Hormone Regulation of Phospholamban Phosphorylation in the Rat Heart*
Authors: Ojamaa Kaie , Kenessey Agnes , Klein Irwin 
Published: January 2014

AbstractThyroid hormone exerts predictable effects on the contractile performance of the heart in part by regulating the transcription of genes encoding specific calcium transporter proteins. In a rat model of hypothyroidism, left ventricular (LV) contractile function as measured by ejection fraction was decreased by 22% (P &lt; 0.05), and this was returned to control values with T3 treatment. In confirmation of prior studies, LV phospholamban (PLB) protein content was significantly decreased by 25% and 40% compared with hypothyroid LV when the animals were treated with T3 at two doses, 2.5 and 7.0 μg/day, respectively. The ratio of sarcoplasmic reticulum calcium adenosine triphosphatase (SERCA2) to PLB protein content was thus increased by 171% and 207%, respectively (P &lt; 0.01). Resolution of the phosphorylated PLB pentamers by SDS-PAGE showed that T3 infusion at 2.5 and 7.0 μg/day decreased (P &lt; 0.001) the amount nonphosphorylated pentamers by 82% and 95%, respectively, in a dose-dependent manner. T3 treatment produced an increase in the proportion of highly phosphorylated PLB pentamers (more than five phosphates) when expressed as a fraction of total pentameric molecules (P &lt; 0.05). Site-specific antibodies showed that the T3-induced increase in phosphorylated PLB pentamers was the result of an increase in both serine 16 and threonine 17 phosphorylation. We conclude that thyroid hormone, in addition to regulating the expression of cardiac PLB, is able to alter the degree of PLB phosphorylation, which correlates with enhancement of LV contractile function. These studies suggest that T3 may augment myocyte calcium cycling via changes in both cAMP- and calcium/calmodulin-dependent protein kinase activities.
Establishment and Characterization of a Human Adrenocortical Carcinoma Xenograft Model*
Authors: Logié Armelle , Boudou Philippe , Boccon-Gibod Liliane , Baudin Eric , Vassal Gilles , Schlumberger Martin , Le Bouc Yves , Gicquel Christine 
Published: January 2014

Abstract
Adrenocortical carcinomas are rare malignant tumors. They have a poor prognosis, as they are often diagnosed late and are usually resistant to chemotherapy. The lack of a suitable animal model for these tumors has been a major obstacle to the evaluation of new therapeutic agents. The aim of this study was to establish and characterize xenografts of the human adrenocortical carcinoma NCI H295R cell line as a model of adrenocortical carcinoma for future therapeutic trials. This cell line was sc injected (6 × 106 cells) into nude mice (n = 20). Solid tumors were locally measurable after 45 days at 90% of the inoculation sites. The xenografts were similar histologically to the original adrenocortical carcinoma from which the cell line was derived. The xenografts precisely reproduced the dysregulation of the insulin-like growth factor (IGF) system[ overexpression of the IGF-II and IGF-binding protein-2 (IGFBP-2) genes] typical of adrenocortical carcinoma. Similarly to adrenocortical carcinomas, human IGFBP-2 (but not IGF-II) was secreted in mouse plasma. We analyzed steroid production (cortisol, 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone,Δ 4-androstenedione, 11-deoxycortisol, corticosterone, and testosterone). Xenografts produced all three class of steroids, with the preferential production of androgens of the Δ4 pathway.
The H295R xenograft model is a good model of human adrenocortical carcinoma, as it mimics dysregulation of the IGF system usually found in these tumors. It also produces IGFBP-2 and steroids that can be used as tumor markers. This model may therefore be useful for evaluating therapeutic agents.
Anti-Müllerian Hormone Attenuates the Effects of FSH on Follicle Development in the Mouse Ovary
Authors: Durlinger Alexandra L. L. , Gruijters Maria J. G. , Kramer Piet , Karels Bas , Kumar T. Rajendra , Matzuk Martin M. , Rose Ursula M. , de Jong Frank H. , Uilenbroek Jan Th. J. , Grootegoed J. Anton , Themmen Axel P. N. 
Published: January 2014

AbstractAlthough ovarian follicle growth is under the influence of many growth factors and hormones of which FSH remains one of the most prominent regulators. Therefore, factors affecting the sensitivity of ovarian follicles to FSH are also important for follicle growth. The aim of the present study was to investigate whether anti-Müllerian hormone (AMH) has an inhibitory effect on follicle growth by decreasing the sensitivity of ovarian follicles to FSH. Furthermore, the combined action of AMH and FSH on ovarian follicle development was examined. Three different experiments were performed. Using an in vitro follicle culture system it was shown that FSH-stimulated preantral follicle growth is attenuated in the presence of AMH. This observation was confirmed by an in vivo experiment showing that in immature AMH-deficient females, more follicles start to grow under the influence of exogenous FSH than in their wild-type littermates. In a third experiment, examination of the follicle population of 4-month-old wild-type, FSHβ-, AMH-, and AMH-/FSHβ-deficient females revealed that loss of FSH expression has no impact on the number of primordial and preantral follicles, but the loss of inhibitory action of AMH on the recruitment of primordial follicles in AMH-deficient mice is increased in the absence of FSH. In conclusion, these studies show that AMH inhibits FSH-stimulated follicle growth in the mouse, suggesting that AMH is one of the factors determining the sensitivity of ovarian follicles for FSH and that AMH is a dominant regulator of early follicle growth.
Impaired Interaction of Mutant Thyroid Hormone Receptors Associated with Human Hepatocellular Carcinoma with Transcriptional Coregulators**This work was supported by grants from Chang-Gung University (CMRP 737, CMRP893, NMRP 407) and the National Science Council of the Republic of China (NSC 87-2316-B-182002).
Authors: Lin Kwang-huei , Wu Yi-hsin , chen shen-liang 
Published: January 2014

AbstractThyroid hormone (T3) exerts its many biological activities through interaction with specific nuclear receptors (TRs) that function as ligand-dependent transcription factors at genes that contain a thyroid hormone response element (TRE). Mutant TRs have been detected in human hepatocellular carcinoma cell lines and tissue, but their contribution to carcinogenesis has remained unclear. The interaction of four such mutant TRs (J7-TRα1, J7-TRβ1, H-TRα1, and l-TRα1) with transcriptional coregulators has now been investigated. With the exception of J7-TRα1, which in the absence of T3 exhibited transcriptional silencing activity with a TRE-reporter gene construct in transfected cells, the mutant TRs had little effect (compared with that of wild-type receptors) on transcriptional activity of the reporter gene in the absence or presence of T3, of the transcriptional corepressors SMRT, NCoR or of the transcriptional coactivator SRC. Electrophoretic mobility-shift assays revealed that, in the presence of T3, the J7-TRβ1 mutant did not interact with SRC, whereas J7-TRα1 and H-TRα1 exhibited reduced abilities to associate with this coactivator and l-TRα1 showed an ability to interact with SRC similar to that of wild-type TRα1. The dominant negative activity of the mutant TRs in transfected cells appeared inversely related to the ability of the receptors to interact with SRC. Whereas J7-TRβ1, H-TRα1, and l-TRα1 did not interact with SMRT, and NCoR. J7-TRα1 bind to corepressors but failed to dissociate from them in the presence of T3. These aberrant interactions between the mutant TRs and transcriptional coregulators may contribute to the highly variable clinical characteristics of human hepatocellular carcinoma.
The Expression of Thyrotropin Receptor in the Brain**This work was supported in part by a grant from the Faculté de Médecine de Bicêtre (Université Paris XI, Orsay, France) and Program Tournesol (Ministère des Affaires Etrangères, Paris, France).
Authors: Crisanti Patricia , Omri Boubaker , Hughes Eleanor J. , Meduri Geri , Hery Christiane , Clauser Eric , Jacquemin Claude , Saunier Bertrand 
Published: January 2014

AbstractThe regulation of the thyroid gland by TSH is mediated by a heterotrimeric G protein-coupled receptor. Nonthyroid effects of TSH have been reported, and expression of its receptor has been described in adipocytes and lymphocytes. We have previously reported the existence of specific and saturable binding sites of TSH and specific TSH effects in primary cultured rat brain astroglial cells. We now report expression of the TSH receptor gene in these cells; the coding sequence of the corresponding complementary DNA is identical to that previously established in thyroid. Using specific antisense RNA probe, expression of this gene was detected in some isolated or clustered glial fibrillary acidic protein-positive primary cultured cells by in situ hybridization. With this technique, we further detected TSH receptor messenger RNA (mRNA) expression in rat brain cryoslices in both neuronal cells and astrocytes. Its presence predominated in neuron-rich areas (pyriform and postcingulate cortex, hippocampus, and hypothalamic nuclei) and was mostly colocalized with neuron-specific enolase. In astrocytes, this mRNA was detected in the ependymal cell layer and the subependymal zone, and several isolated cells were also found in the brain parenchyma. We also detected TSH receptor mRNA and protein in primary cultured human astrocytes. The protein was detected as well in both rat and human brain cryoslices. Together, these findings clearly demonstrate the expression of the TSH receptor gene in the brain in both neuronal cells and astrocytes.
Pregnancy and Murine Thyroiditis: Thyroglobulin Immunization Leads to Fetal Loss in Specific Allogeneic Pregnancies**This work was supported in part by NIH Grants DK-52464, DK-35764, and DK-45011 (to T.F.D.), Cellular and Molecular Endocrinology Training Grant DK-07645 (to L.A.) and the David Owen Segal Endowment (to M.I. and M.K.).
Authors: Imaizumi M. , Pritsker A. , Kita M. , Ahmad L. , Unger P. , Davies T. F. 
Published: January 2014

AbstractThyroid autoantibodies are risk factors in human pregnancy. To investigate the influence of autoimmune thyroiditis on pregnancy, we have studied the impact of murine experimental autoimmune thyroiditis (EAT) on pregnancy outcome by using thyroglobulin (Tg) immunized CBA/J (H2k) female mice. When Tg immunized mice were mated with BALB/c (H2d) males, only 57% (47/83) of pregnant mice maintained their conceptions compared with &gt;85% of other strain combinations (P &lt; 0.05). We also found that MHC class II antigens were expressed on placental cells from Tg immunized pregnant mice but not in control normal pregnancies. Furthermore, the frequency and severity of thyroiditis, assessed by histological analyses, was also increased in Tg immunized mice mated with the BALB/c strain compared with syngeneic pregnancies (P &lt; 0.05). In these pregnant mice mated with BALB/c, interleukin-4 secretion by mitogen-stimulated spleen cells was significantly suppressed and interferon-γ secretion by mixed lymphocyte reactions with BALB/c cells was significantly increased. These data demonstrated enhanced Th1 cell proliferation and fetal loss in CBA/J X BALB/c pregnancies. We concluded, therefore, that pregnancy loss was increased in experimental autoimmune thyroiditis in a manner that was dependent on paternal antigens. These observations have broad implications for understanding the immunology of pregnancy.
Targeted Protein Kinase A and PP-2B Regulate Insulin Secretion through Reversible Phosphorylation*
Authors: Lester Linda B. , Faux Maree C. , Nauert J. Brian , Scott John D. 
Published: January 2014

AbstractProtein kinases and phosphatases play key roles in integrating signals from various insulin secretagogues. In this study, we show that the activities of the cAMP-dependent protein kinase (PKA) and the calcium/calmodulin-dependent phosphatase, PP-2B are coordinated resulting in the regulation of insulin secretion. Transient inhibition of PP-2B, using the immunosuppressant FK506, increased forskolin stimulated insulin secretion by 2.5-fold ± 0.3 (n = 6) in rat islets and RINm5F cells. Surprisingly, forskolin treatment resulted in the dephosphorylation of the vesicle-associated protein synapsin 1 and increased PP-2B activity by 2.98 ± 0.97-fold (n = 4). One potential explanation for the observed coordination of PKA and PP-2B activity is their colocalization through a mutual anchoring protein, AKAP79/150. Accordingly, RINm5F cells expressing AKAP79 exhibited decreased insulin secretion, reduced PP-2B activity and were insensitive to FK506. This suggests that AKAP targeting of PKA and PP-2B maintains a signal transduction complex that may regulate reversible phosphorylation events involved in insulin secretion.
Selective Delivery of Estradiol to Bone by Aspartic Acid Oligopeptide and Its Effects on Ovariectomized Mice
Authors: Yokogawa Koichi , Miya Kazuhiro , Sekido Tohru , Higashi Yasuhiko , Nomura Masaaki , Fujisawa Ryuichi , Morito Keiko , Masamune Yukito , Waki Yoshihiro , Kasugai Shohei , Miyamoto Ken-ichi 
Published: January 2014

AbstractWe have developed a novel osteotropic prodrug of estradiol (E2) conjugated with l-Asp-hexapeptide (E2·3D6), which has very low affinity for estrogen receptors, and in this study, we examined its pharmacokinetic behavior and pharmacological potential. After a single iv injection of E2·3D6 to mice, the half-time for elimination from plasma was about 100 min; however, E2 was selectively delivered to the bone and eliminated very slowly, declining to the endogenous level at about 7 days. After a single iv injection of E2, the half-time in plasma was about 70 min, whereas E2 was highly distributed to the uterus, and the bone concentration of E2 was only slightly increased at 6 h. When E2 (0.37 μmol/kg, sc, every third day) or E2·3D6 (0.11 to 1.1 μmol/kg, sc, every seventh day) was administered to OVX mice for 4 weeks, E2 increased the bone mineral density (BMD) together with weights of liver and uterus, whereas E2·3D6 increased only the BMD, in a dose-dependent manner. E2·3D6 enhanced the expression of messenger RNAs of bone matrix proteins (osteopontin, bone sialoprotein, type I collagen α) of OVX mice at 4 h after administration, but E2 did very slightly. These results indicate that the E2 prodrug was delivered to the bone, where it gradually released E2, thereby ameliorating bone loss. This acidic oligopeptide appears to be a good candidate for selective drug delivery to bone.
Comprehensive Messenger Ribonucleic Acid Profiling Reveals That Peroxisome Proliferator-Activated Receptor γ Activation Has Coordinate Effects on Gene Expression in Multiple Insulin-Sensitive Tissues
Authors: Way James M. , Harrington W. Wallace , Brown Kathleen K. , Gottschalk William K. , Sundseth Scott S. , Mansfield Traci A. , Ramachandran Ravi K. , Willson Timothy M. , Kliewer Steven A. 
Published: January 2014

AbstractPeroxisome proliferator-activated receptor γ (PPARγ) agonists, including the glitazone class of drugs, are insulin sensitizers that reduce glucose and lipid levels in patients with type 2 diabetes mellitus. To more fully understand the molecular mechanisms underlying their therapeutic actions, we have characterized the effects of the potent, tyrosine-based PPARγ ligand GW1929 on serum glucose and lipid parameters and gene expression in Zucker diabetic fatty rats. In time-course studies, GW1929 treatment decreased circulating FFA levels before reducing glucose and triglyceride levels. We used a comprehensive and unbiased messenger RNA profiling technique to identify genes regulated either directly or indirectly by PPARγ in epididymal white adipose tissue, interscapular brown adipose tissue, liver, and soleus skeletal muscle. PPARγ activation stimulated the expression of a large number of genes involved in lipogenesis and fatty acid metabolism in both white adipose tissue and brown adipose tissue. In muscle, PPARγ agonist treatment decreased the expression of pyruvate dehydrogenase kinase 4, which represses oxidative glucose metabolism, and also decreased the expression of genes involved in fatty acid transport and oxidation. These changes suggest a molecular basis for PPARγ-mediated increases in glucose utilization in muscle. In liver, PPARγ activation coordinately decreased the expression of genes involved in gluconeogenesis. We conclude from these studies that the antidiabetic actions of PPARγ agonists are probably the consequence of 1) their effects on FFA levels, and 2), their coordinate effects on gene expression in multiple insulin-sensitive tissues.