bluuebunny/crossref_metadata_2025_split huggingface dataset:
Male Germ Cells Regulate Transcription of the Cathepsin L Gene by Rat Sertoli Cells*
Authors: Zabludoff Sonya D. , Charron Martin , DeCerbo Joshua N. , Simukova Natalia , Wright William W. 
Published: January 2014

AbstractIt is well known that male germ cells regulate the steady state levels of numerous transcripts expressed by Sertoli cells. To date, however, there has been no direct test of whether this regulation reflects changes in gene transcription and/or transcript stability. This study used two experimental approaches to test the hypothesis that germ cells regulate transcription of the cathepsin L gene by rat Sertoli cells. We examined this gene because, in vivo, steady state levels of cath L messenger RNA in Sertoli cells change in a stage-specific manner as the surrounding germ cells progress through the 14 stages of the cycle of the seminiferous epithelium. In the first experimental approach, seminiferous tubules at stages VI–VII and stages IX–XII were incubated for 1 h in 4-thiouridine, and the amount of metabolically labeled cath L messenger RNA was quantified. The results demonstrate that transcription of the cath L gene by Sertoli cells is 7-fold higher at stages VI–VII than at stages IX–XII. The second experimental approach examined the ability of germ cells to regulate the activity of cath L reporter constructs in mature Sertoli cells. Before these studies, we isolated a cath L genomic clone and demonstrated that this clone contains the transcription start site of the cath L gene expressed by Sertoli cells. Transient transfection analysis then demonstrated that two reporter constructs, containing 244 and about 2.1 kb of sequence upstream from the transcription start site, had similar activities in mature Sertoli cells. However, germ cells only affected the activity of the larger construct in Sertoli cells, which was reduced by 30%. We conclude that germ cells regulate transcription of the cath L gene by Sertoli cells and that repressive effects of germ cells are mediated by elements upstream from nucleotide− 244 of this gene.
Expression of the mRNAs and Proteins for the Na+/H+ Exchangers and Their Regulatory Factors in Baboon and Human Placental Syncytiotrophoblast
Authors: Pepe Gerald J. , Burch Marcia G. , Sibley Colin P. , Davies William A. , Albrecht Eugene D. 
Published: January 2014

AbstractIn polarized epithelial cells of several organ systems, e.g. the kidney, a family of Na+/H+ exchangers (e.g. Na+/H+ exchanger-1 and -3) and their regulatory proteins, Na+/H+ exchanger regulatory factor and Na+/H+ exchanger-3 kinase A regulatory protein play a major role in regulating Na+/H+ exchange integral to cellular homeostasis. Because the primate placenta regulates exchange of Na+ and H+ between the mother and fetus critical to fetal-placental homeostasis, the current study determined whether Na+/H+ exchanger-1 and -3 were compartmentalized and associated with expression of Na+/H+ exchanger regulatory factor and Na+/H+ exchanger-3 kinase A regulatory protein in baboon and human syncytiotrophoblast. Using RT-PCR, single 413-bp Na+/H+ exchanger-1 and 190-bp Na+/H+ exchanger-3 products were expressed by baboon and human syncytiotrophoblasts. The 104-kDa Na+/H+ exchanger-1 protein was detected by Western blot in microvillus membranes and to a much lesser extent in the basal membranes of the baboon and human syncytiotrophoblasts. In contrast, the 85-kDa Na+/H+ exchanger-3 protein was detected primarily in membranes contiguous with the basal membranes of the syncytiotrophoblast of both species. Differential localization of Na+/H+ exchanger-1 and -3 was confirmed by immunocytochemistry. The Na+/H+ exchanger-3 regulatory protein, Na+/H+ exchanger-3 kinase A regulatory protein, resided almost exclusively in the basal membranes, whereas Na+/H+ exchanger regulatory factor was localized primarily to the microvillus membranes in the baboon and human syncytiotrophoblast. Collectively, these results are the first to show that the baboon and human term placental syncytiotrophoblast expressed the mRNAs and proteins for Na+/H+ exchanger-1 and -3 and their regulatory factors and that Na+/H+ exchanger-1 and Na+/H+ exchanger regulatory factor resided primarily in the microvillus membranes, whereas Na+/H+ exchanger-3 and Na+/H+ exchanger-3 kinase A regulatory protein were localized to membranes contiguous with the basal membranes and to the basal membranes, respectively. We conclude that a complete Na+/H+ exchange system is present in the baboon and human term placental syncytiotrophoblast and suggest that the primate placenta exhibits polarity with respect to the capacity for regulation of Na+/H+ exchange between the placenta and the maternal and fetal circulations.
The C-Terminal Region of PTHrP, in Addition to the Nuclear Localization Signal, Is Essential for the Intracrine Stimulation of Proliferation in Vascular Smooth Muscle Cells
Authors: de Miguel F. , Fiaschi-Taesch N. , López-Talavera J. C. , Takane K. K. , Massfelder T. , Helwig J.-J. , Stewart A. F. 
Published: January 2014

AbstractPTHrP is secreted by most cell types. In addition to a paracrine/autocrine role, PTHrP has “intracrine” actions, entering the nuclear compartment under the direction of a classic bipartite nuclear localization signal. In vascular smooth muscle cells, nuclear entry stimulates mitogenesis. In the current study, we sought to more precisely define the regions of PTHrP required for the activation of mitogenesis in vascular smooth muscle cells. PTHrP deletion mutants missing large regions [i.e. the signal peptide, N terminus (1–36), mid region (38–86), nuclear localization signal, C terminus (108–139), or combinations of the above] were expressed in A-10 vascular smooth muscle cells. The consequences on nuclear localization and proliferation were examined. Deletion of the nuclear localization signal prevented nuclear entry and slowed proliferation. Deletion of the highly conserved N terminus or mid region had no impact on nuclear localization or on proliferation. Deletion of the C terminus had no deleterious effect on nuclear localization but dramatically reduced proliferation. Thus, the nuclear localization signal is both necessary and sufficient for nuclear localization of PTHrP. In contrast, activation of proliferation in vascular smooth muscle cells requires both an intact nuclear localization signal and an intact C terminus. Whereas the nuclear localization signal is required for nuclear entry, the C terminus may serve a trans-activating function to stimulate mitogenesis once inside the nucleus of vascular smooth muscle cells.
The Vasopressin Receptors Colocalize with Vasopressin in the Magnocellular Neurons of the Rat Supraoptic Nucleus and Are Modulated by Water Balance
Authors: Hurbin Amandine , Orcel Hélène , Alonso Gérard , Moos Françoise , Rabié Alain 
Published: January 2014

AbstractActivity of the magnocellular neurons that synthesize vasopressin in the supraoptic and paraventricular nuclei of the hypothalamus is modulated by local release of the neuropeptide within the nuclei. V1a and V1b vasopressin receptor genes are expressed in these cells. The present study reports the localization of V1a and V1b receptors using multiple labeling immunocytochemistry. Both receptors are mainly located in vasopressinergic magnocellular neurons and colocalized with vasopressin in cytoplasmic vesicles dispersed throughout the cell. Possible functional modifications of the mRNA and protein levels of the V1a receptor, the major isoform, were also investigated by semiquantitative in situ hybridization and immunocytochemistry in rats submitted to reduced or increased water intake. V1a mRNA and receptor levels varied with water balance. V1a mRNA level dropped in rats submitted to high water intake. Conversely, dehydration up-regulated the V1a receptor content. These observations suggest that the pathways that regulate the expression of the genes encoding vasopressin and the V1a receptor are linked, which fits the present findings that the two partners are colocalized in cytoplasmic vesicles. Colocalization might explain how V1 autoreceptors are controlled by cell activity and/or local concentration of vasopressin (released locally by the neurons themselves), allowing fine adjustment of magnocellular neuron activity.
Distribution, Neuronal Colocalization, and 17β-E2 Modulation of Small Conductance Calcium-Activated K+ Channel (SK3) mRNA in the Guinea Pig Brain
Authors: Bosch Martha A. , Kelly Martin J. , Rønnekleiv Oline K. 
Published: January 2014

Abstract
Molecular cloning has revealed the existence of three distinct small conductance (SK1–3) Ca2+-activated K+ channels. Because SK channels underlie the afterhyperpolarization (AHP) that is critical for sculpturing phasic firing in hypothalamic neurons, we investigated the distribution of these channels in the female guinea pig. Both SK1 and SK3 cDNA fragments were cloned using PCR, and ribonuclease protection assay as well as in situ hybridization analysis illustrated that the SK3 channel was the predominant subtype expressed in the guinea pig hypothalamus. Combined in situ hybridization and fluorescence immunocytochemistry revealed that SK3 mRNA was expressed in GnRH, dopamine, and vasopressin neurons, and all of these neurons exhibited an AHP current. Moreover, SK3 mRNA was found in other brain areas, including the septum, bed nucleus, amygdala, thalamus, midbrain, and hippocampus. Using quantitative ribonuclease protection assay, the rank order of SK3 mRNA expression was septum ≥ midbrain &gt; rostral thalamus ≥ rostral basal hypothalamus ≥ caudal thalamus ≥ preoptic area ≫ caudal basal hypothalamus ≥ hippocampus. Moreover, 17β-E2 treatment, which reduces plasma LH during the negative feedback phase, significantly increased SK3 mRNA levels in the rostral basal hypothalamus (P &lt; 0.05; n = 6). Therefore, these findings suggest that estrogen increases the mRNA expression of SK3 channels, which may represent a mechanism by which estrogen regulates hypothalamic neuronal excitability during negative feedback.
Cbl, IRS-1, and IRS-2 Mediate Effects of Rosiglitazone on PI3K, PKC-λ, and Glucose Transport in 3T3/L1 Adipocytes
Authors: Standaert Mary L. , Kanoh Yoshinori , Sajan Mini P. , Bandyopadhyay Gautam , Farese Robert V. 
Published: January 2014

AbstractThe thiazolidenedione, rosiglitazone, increases basal and/or insulin-stimulated glucose transport in various cell types by diverse but uncertain mechanisms that may involve insulin receptor substrate (IRS)-1-dependent PI3K. Presently, in 3T3/L1 adipocytes, rosiglitazone induced sizable increases in basal glucose transport that were: dependent on PI3K, 3-phosphoinositide-dependent protein kinase-1 (PDK-1), and PKC-λ; accompanied by increases in tyrosine phosphorylation of Cbl and Cbl-dependent increases in PI3K and PKC-λ activity; but not accompanied by increases in IRS-1/2-dependent PI3K or protein kinase B activity. Additionally, rosiglitazone increased IRS-1 and IRS-2 levels, thereby enhancing insulin effects on IRS-1- and IRS-2-dependent PI3K and downstream signaling factors PKC-λ and protein kinase B. Our findings suggest that Cbl participates in mediating effects of rosiglitazone on PI3K, PDK-1, and PKC-λ and the glucose transport system and that this Cbl-dependent pathway complements the IRS-1 and IRS-2 pathways for activating PI3K, PDK-1, and PKC-λ during combined actions of rosiglitazone and insulin in 3T3/L1 cells.
Minireview: Neuro-Immuno-Endocrine Modulation of the Hypothalamic-Pituitary-Adrenal (HPA) Axis by gp130 Signaling Molecules
Authors: Chesnokova Vera , Melmed Shlomo 
Published: January 2014

Abstract
The neuroendocrine and immune systems communicate bidirectionally. The neuro-immune-endocrine interface is mediated by cytokines acting as auto/paracrine or endocrine factors regulating pituitary development, cell proliferation, hormone secretion, and feedback control of the hypothalamic-pituitary-adrenal (HPA) axis. At birth or during neonatal ontogenesis, cytokines produce permanent alterations of HPA axis function and the stress response. Overexpressing IL-6 or leukemia inhibitory factor leads to significant changes in pituitary development and functions. Pituitary corticotroph POMC gene expression is regulated by CRH as well as several gp130 cytokines acting as neuro-immuno-endocrine modulators. Conversely, HPA axis functions modulate susceptibility or resistance to inflammatory disease. Cytokines (including IL-1, TNF, and members of the gp130 cytokine family) participate as mediators of a complex HPA axis response to stress and inflammation. Prolonged exposure to proinflammatory cytokines increases levels of the dominant negative glucocorticoid receptor isoform. Nonresponsiveness of the HPA axis to glucocorticoid negative feedback control provides a defense from destructive effects of cytokine excess. At the same time, gp130 cytokines stimulate pituitary suppressor of cytokine signaling (SOCS)-3, which represses cytokine signaling and abrogates cytokine-induced corticotroph POMC gene transcription and ACTH secretion.
The Estrogen-Occupied Estrogen Receptor Functions as a Negative Regulator to Inhibit Cell Proliferation Induced by Insulin/IGF-1: A Cell Context-Specific Antimitogenic Action of Estradiol on Rat Lactotrophs in Culture
Authors: Kawashima Kengo , Yamakawa Koji , Takahashi Wakaba , Takizawa Soichi , Yin Ping , Sugiyama Nobuhiro , Kanba Shigenobu , Arita Jun 
Published: January 2014

Abstract
Estrogens stimulate cell proliferation in typical estrogen-responsive tissues including the anterior pituitary gland. Here we report that 17-β estradiol (E2) has estrogen receptor-mediated mitogenic and antimitogenic actions on rat lactotrophs in primary culture, depending on the cell context. E2 did not affect basal proliferation at 2 d after treatment, but it increased it at 4 d. Insulin markedly increased proliferative activity, which was inhibited by simultaneous treatment with E2, even after only 2 d of treatment. This antimitogenic action on insulin-induced proliferation was also observed with other estrogens but not with nonestrogenic steroids. Treatment with antiestrogens in combination with E2 antagonized both the mitogenic and antimitogenic actions of E2. Antiestrogen treatment alone inhibited basal proliferation, and it mimicked the inhibitory action of E2 on insulin-induced proliferation with less potency. In parallel with cell proliferation, an insulin-induced increase in the cell number of cyclin D1-immunoreactive lactotrophs was inhibited by E2 treatment. Although the antimitogenic action of E2 was seen with a wide range of doses of insulin or IGF-1, proliferation was stimulated rather than inhibited by E2 when cells were treated with serum or forskolin/isobutylmethylxanthine instead of insulin, indicating a mitogen-specific, but not proliferative activity-dependent, inhibition by E2. The results of estrogen-occupied estrogen receptors as negative regulators of proliferation suggest a novel interaction between estrogen and growth factors in the regulation of proliferation in estrogen-responsive cells.
The Association of Endogenous Sex Hormones, Adiposity, and Insulin Resistance with Incident Diabetes in Postmenopausal Women
Authors: Kalyani Rita Rastogi , Franco Manuel , Dobs Adrian S. , Ouyang Pamela , Vaidya Dhananjay , Bertoni Alain , Gapstur Susan M. , Golden Sherita Hill 
Published: January 2014

ABSTRACT

Context:
In postmenopausal women, endogenous bioavailable testosterone (T) and estradiol (E2) have been positively associated, and SHBG has been negatively associated, with incident type 2 diabetes (T2DM). Previous studies have not explored possible factors explaining these relationships.

Objective:
Our objective was to examine the association of endogenous sex hormones with incident T2DM in postmenopausal women and possible explanatory factors.

Design, Setting, and Participants:
The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective study that included 1612 postmenopausal women aged 45–84 yr, followed between the years 2000-2006, who were not taking hormone replacement therapy, had no prevalent cardiovascular disease or diabetes, and had complete ascertainment of sex hormones.

Main Outcome Measures:
T2DM was defined based on fasting glucose and/or treatment for diabetes.

Results:
There were 116 incident cases of diabetes during follow-up. Across higher quartiles of bioavailable T and E2 and lower quartiles of SHBG, we found significantly greater hazards of developing incident T2DM (all P for trend ≤ 0.001). After adjustment for body mass index and insulin resistance estimated by homeostasis model assessment of insulin resistance, bioavailable T was no longer associated with incident T2DM. The associations of E2 and SHBG with incident T2DM were partially explained by body mass index and insulin resistance but persisted in fully adjusted models (both P for trend &lt; 0.02). Dehydroepiandrosterone had no relationship with incident T2DM.

Conclusions:
Adiposity and insulin resistance explained most of the association of bioavailable T but only partially explained the associations of E2 and SHBG with incident T2DM among postmenopausal women.
Identification of Adipocyte Genes Regulated by Caloric Intake
Authors: Franck Niclas , Gummesson Anders , Jernås Margareta , Glad Camilla , Svensson Per-Arne , Guillot Gilles , Rudemo Mats , Nyström Fredrik H , Carlsson Lena M. S. , Olsson Bob 
Published: January 2014

Context: Changes in energy intake have marked and rapid effects on metabolic functions, and some of these effects may be due to changes in adipocyte gene expression that precede alterations in body weight.
Objective: The aim of the study was to identify adipocyte genes regulated by changes in caloric intake independent of alterations in body weight.
Research Design and Methods: Obese subjects given a very low-caloric diet followed by gradual reintroduction of ordinary food and healthy subjects subjected to overfeeding were investigated. Adipose tissue biopsies were taken at multiple time-points, and gene expression was measured by DNA microarray. Genes regulated in the obese subjects undergoing caloric restriction followed by refeeding were identified using two-way ANOVA corrected with Bonferroni. From these, genes regulated by caloric restriction and oppositely during the weight-stable refeeding phase were identified in the obese subjects. The genes that were also regulated, in the same direction as the refeeding phase, in the healthy subjects after overfeeding were defined as being regulated by caloric intake. Results were confirmed using real-time PCR or immunoassay.
Results: Using a significance level of P &lt; 0.05 for all comparisons, 52 genes were down-regulated, and 50 were up-regulated by caloric restriction and regulated in the opposite direction by refeeding and overfeeding. Among these were genes involved in lipogenesis (ACLY, ACACA, FASN, SCD), control of protein synthesis (4EBP1, 4EBP2), β-oxidation (CPT1B), and insulin resistance (PEDF, SPARC).
Conclusions: Metabolic genes involved in lipogenesis, protein synthesis, and insulin resistance are central in the transcriptional response of adipocytes to changes in caloric intake.
Insufficient Activation of Autophagy Allows Cellular Damage to Accumulate in Critically Ill Patients
Authors: Vanhorebeek Ilse , Gunst Jan , Derde Sarah , Derese Inge , Boussemaere Magaly , Güiza Fabian , Martinet Wim , Timmermans Jean-Pierre , D'Hoore André , Wouters Pieter J. , Van den Berghe Greet 
Published: January 2014

Abstract

Context:
Responses to critical illness, such as excessive inflammation and hyperglycemia, may trigger detrimental chain reactions that damage cellular proteins and organelles. Such responses to illness contribute to the risk of (nonresolving) multiple organ dysfunction and adverse outcome.

Objective:
We studied autophagy as a bulk degradation pathway able to remove toxic protein aggregates and damaged organelles and how these are affected by preventing hyperglycemia with insulin during critical illness.

Design and Setting:
Patients participated in a randomized study, conducted at a university hospital surgical/medical intensive care unit.

Patients:
We studied adult prolonged critically ill patients vs. controls.

Interventions:
Tolerating excessive hyperglycemia was compared with intensive insulin therapy targeting normoglycemia.

Main Outcome Measures:
We quantified (ultra)structural abnormalities and hepatic and skeletal muscle protein levels of key players in autophagy.

Results:
Morphologically, both liver and muscle revealed an autophagy-deficiency phenotype. Proteins involved in initiation and elongation steps of autophagy were induced 1.3- to 6.5-fold by critical illness (P &lt; 0.01), but mature autophagic vacuole formation was 62% impaired (P = 0.05) and proteins normally degraded by autophagy accumulated up to 97-fold (P &lt; 0.03). Mitophagy markers were unaltered or down-regulated (P = 0.05). Although insulin preserved hepatocytic mitochondrial integrity (P = 0.05), it further reduced the number of autophagic vacuoles by 80% (P = 0.05).

Conclusions:
Insufficient autophagy in prolonged critical illness may cause inadequate removal of damaged proteins and mitochondria. Such incomplete clearance of cellular damage, inflicted by illness and aggravated by hyperglycemia, could explain lack of recovery from organ failure in prolonged critically ill patients. These data open perspectives for therapies that activate autophagy during critical illness.
Reversal of the Sex Difference in Serum Leptin Levels upon Cross-Sex Hormone Administration in Transsexuals*
Authors: Elbers Jolanda M. H. , Asscheman Henk , Seidell Jacob C. , Frölich Marijke , Meinders A. Edo , Gooren Louis J. G. 
Published: January 2014

Abstract
Women have higher circulating leptin levels than men. This sex difference is not simply explained by differences in the amount of body fat and is possibly influenced by their different sex steroid milieus. This prompted us to study prospectively the effects of cross-sex steroid hormones on serum leptin levels in 17 male to female transsexuals and 15 female to male transsexuals. Male to female transsexuals were treated with 100 μg ethinyl estradiol and 100 mg cyproterone acetate (antiandrogen) daily, and female to male transsexuals received testosterone esters (250 mg/2 weeks, im). Before and after 4 and 12 months of cross-sex hormone treatment, serum leptin levels and measures of body fatness were assessed. Before treatment, female subjects had higher serum leptin levels than male subjects independently of the amount of body fat (P &lt; 0.01). Cross-sex hormone administration induced a reversal of the sex difference in serum leptin levels. Estrogen treatment in combination with antiandrogens in male subjects increased median serum leptin levels from 1.9 ng/mL before treatment to 4.8 ng/mL after 4 months and 5.5 ng/mL after 12 months of treatment (P &lt; 0.0001). Testosterone administration in female subjects decreased median serum leptin levels from 5.6 to 2.6 ng/mL after 4 months and to 2.5 ng/mL after 12 months (P &lt; 0.0001). Analysis of covariance revealed that the changes in serum leptin levels were independent of changes in body fatness in both groups (P &lt; 0.01).
In conclusion, these results indicate that sex steroid hormones, in particular testosterone, play an important role in the regulation of serum leptin levels. The prevailing sex steroid milieu, not genetic sex, is a significant determinant of the sex difference in serum leptin levels.