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Sample records for distinct anabolic signalling

  1. Mechanical signals as anabolic agents in bone

    PubMed Central

    Ozcivici, Engin; Luu, Yen Kim; Adler, Ben; Qin, Yi-Xian; Rubin, Janet; Judex, Stefan; Rubin, Clinton T.

    2013-01-01

    Aging and a sedentary lifestyle conspire to reduce bone quantity and quality, decrease muscle mass and strength, and undermine postural stability, culminating in an elevated risk of skeletal fracture. Concurrently, a marked reduction in the available bone-marrow-derived population of mesenchymal stem cells (MSCs) jeopardizes the regenerative potential that is critical to recovery from musculoskeletal injury and disease. A potential way to combat the deterioration involves harnessing the sensitivity of bone to mechanical signals, which is crucial in defining, maintaining and recovering bone mass. To effectively utilize mechanical signals in the clinic as a non-drug-based intervention for osteoporosis, it is essential to identify the components of the mechanical challenge that are critical to the anabolic process. Large, intense challenges to the skeleton are generally presumed to be the most osteogenic, but brief exposure to mechanical signals of high frequency and extremely low intensity, several orders of magnitude below those that arise during strenuous activity, have been shown to provide a significant anabolic stimulus to bone. Along with positively influencing osteoblast and osteocyte activity, these low-magnitude mechanical signals bias MSC differentiation towards osteoblastogenesis and away from adipogenesis. Mechanical targeting of the bone marrow stem-cell pool might, therefore, represent a novel, drug-free means of slowing the age-related decline of the musculoskeletal system. PMID:20046206

  2. Anabolic effects of IGF-1 signaling on the skeleton

    PubMed Central

    Tahimic, Candice G. T.; Wang, Yongmei; Bikle, Daniel D.

    2013-01-01

    This review focuses on the anabolic effects of IGF-1 signaling on the skeleton, emphasizing the requirement for IGF-1 signaling in normal bone formation and remodeling. We first discuss the genomic context, splicing variants, and species conservation of the IGF-1 locus. The modulation of IGF-1 action by growth hormone (GH) is then reviewed while also discussing the current model which takes into account the GH-independent actions of IGF-1. Next, the skeletal phenotypes of IGF-1-deficient animals are described in both embryonic and postnatal stages of development, which include severe dwarfism and an undermineralized skeleton. We then highlight two mechanisms by which IGF-1 exerts its anabolic action on the skeleton. Firstly, the role of IGF-1 signaling in the modulation of anabolic effects of parathyroid hormone (PTH) on bone will be discussed, presenting in vitro and in vivo studies that establish this concept and the proposed underlying molecular mechanisms involving Indian hedgehog (Ihh) and the ephrins. Secondly, the crosstalk of IGF-1 signaling with mechanosensing pathways will be discussed, beginning with the observation that animals subjected to skeletal unloading by hindlimb elevation are unable to mitigate cessation of bone growth despite infusion with IGF-1 and the failure of IGF-1 to activate its receptor in bone marrow stromal cell cultures from unloaded bone. Disrupted crosstalk between IGF-1 signaling and the integrin mechanotransduction pathways is discussed as one of the potential mechanisms for this IGF-1 resistance. Next, emerging paradigms on bone-muscle crosstalk are examined, focusing on the potential role of IGF-1 signaling in modulating such interactions. Finally, we present a future outlook on IGF research. PMID:23382729

  3. Changes in expression of proteolytic genes in response to anabolic and catabolic signals in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rates of protein accrual are largely affected by rates of protein degradation. Determining how proteolytic pathways are affected by catabolic and anabolic signals will contribute to the understanding of the impact and regulation these pathways have on protein turnover. Real time RT-PCR was used to...

  4. Intramuscular Anabolic Signaling and Endocrine Response Following Resistance Exercise: Implications for Muscle Hypertrophy.

    PubMed

    Gonzalez, Adam M; Hoffman, Jay R; Stout, Jeffrey R; Fukuda, David H; Willoughby, Darryn S

    2016-05-01

    Maintaining skeletal muscle mass and function is critical for disease prevention, mobility and quality of life, and whole-body metabolism. Resistance exercise is known to be a major regulator for promoting muscle protein synthesis and muscle mass accretion. Manipulation of exercise intensity, volume, and rest elicit specific muscular adaptations that can maximize the magnitude of muscle growth. The stimulus of muscle contraction that occurs during differing intensities of resistance exercise results in varying biochemical responses regulating the rate of protein synthesis, known as mechanotransduction. At the cellular level, skeletal muscle adaptation appears to be the result of the cumulative effects of transient changes in gene expression following acute bouts of exercise. Thus, maximizing the resistance exercise-induced anabolic response produces the greatest potential for hypertrophic adaptation with training. The mechanisms involved in converting mechanical signals into the molecular events that control muscle growth are not completely understood; however, skeletal muscle protein synthesis appears to be regulated by the multi-protein phosphorylation cascade, mTORC1 (mammalian/mechanistic target of rapamycin complex 1). The purpose of this review is to examine the physiological response to resistance exercise, with particular emphasis on the endocrine response and intramuscular anabolic signaling through mTORC1. It appears that resistance exercise protocols that maximize muscle fiber recruitment, time-under-tension, and metabolic stress will contribute to maximizing intramuscular anabolic signaling; however, the resistance exercise parameters for maximizing the anabolic response remain unclear.

  5. Optimal Distinctiveness Signals Membership Trust.

    PubMed

    Leonardelli, Geoffrey J; Loyd, Denise Lewin

    2016-07-01

    According to optimal distinctiveness theory, sufficiently small minority groups are associated with greater membership trust, even among members otherwise unknown, because the groups are seen as optimally distinctive. This article elaborates on the prediction's motivational and cognitive processes and tests whether sufficiently small minorities (defined by relative size; for example, 20%) are associated with greater membership trust relative to mere minorities (45%), and whether such trust is a function of optimal distinctiveness. Two experiments, examining observers' perceptions of minority and majority groups and using minimal groups and (in Experiment 2) a trust game, revealed greater membership trust in minorities than majorities. In Experiment 2, participants also preferred joining minorities over more powerful majorities. Both effects occurred only when minorities were 20% rather than 45%. In both studies, perceptions of optimal distinctiveness mediated effects. Discussion focuses on the value of relative size and optimal distinctiveness, and when membership trust manifests. PMID:27140657

  6. The anabolic steroid methandienone targets the hypothalamic-pituitary-testicular axis and myostatin signaling in a rat training model.

    PubMed

    Mosler, Stephanie; Pankratz, Carlos; Seyfried, Alexis; Piechotta, Marion; Diel, Patrick

    2012-01-01

    There is increasing evidence that the biological activity of myostatin (MSTN), a negative regulator of muscle growth, is affected by training but also anabolic steroids. In this study, we analyzed the effects of the frequently abused anabolic steroid methandienone (Md) on the hypothalamic-pituitary-testicular axis and androgen-sensitive tissues in intact rats performing a treadmill training to simulate the situation of abusing athletes. The anabolic effects were correlated with the expression of members of the MSTN signaling cascade. Md treatment resulted in a significant stimulation of anabolic activity of the levator ani muscle, which was further increased by training, while prostate and seminal vesicle weights decreased in conformance with hormone concentrations of LH and testosterone. In gastrocnemius muscle, mRNA expression of genes of the MSTN signaling cascade (MSTN, Smad7 and MyoD) was reduced by training but not after Md treatment, in soleus muscle MSTN and its inhibitors, follistatin (FLST) and Smad-7 were only affected after training in combination with Md treatment. In summary, our data demonstrate that Md treatment of intact rats results in anabolic effects which are enhanced in combination with physical activity. Interestingly, the anabolic activity on the levator ani was increased in combination with training, although the levator ani muscle was not specifically stimulated by our training protocol. In the m. gastrocnemius and soleus, the anabolic effects correlate with changes in the expression patterns of genes involved in MSTN signaling. Our data provide evidence that the decrease in the weight of androgen-sensitive sexual glands, observed after Md treatment, is caused by a suppression of endogenous testosterone synthesis. These observations provide new insights into the molecular mechanisms of the interaction between anabolic steroids, training and MSTN signaling during skeletal muscle adaptation. PMID:21818626

  7. The anabolic steroid methandienone targets the hypothalamic-pituitary-testicular axis and myostatin signaling in a rat training model.

    PubMed

    Mosler, Stephanie; Pankratz, Carlos; Seyfried, Alexis; Piechotta, Marion; Diel, Patrick

    2012-01-01

    There is increasing evidence that the biological activity of myostatin (MSTN), a negative regulator of muscle growth, is affected by training but also anabolic steroids. In this study, we analyzed the effects of the frequently abused anabolic steroid methandienone (Md) on the hypothalamic-pituitary-testicular axis and androgen-sensitive tissues in intact rats performing a treadmill training to simulate the situation of abusing athletes. The anabolic effects were correlated with the expression of members of the MSTN signaling cascade. Md treatment resulted in a significant stimulation of anabolic activity of the levator ani muscle, which was further increased by training, while prostate and seminal vesicle weights decreased in conformance with hormone concentrations of LH and testosterone. In gastrocnemius muscle, mRNA expression of genes of the MSTN signaling cascade (MSTN, Smad7 and MyoD) was reduced by training but not after Md treatment, in soleus muscle MSTN and its inhibitors, follistatin (FLST) and Smad-7 were only affected after training in combination with Md treatment. In summary, our data demonstrate that Md treatment of intact rats results in anabolic effects which are enhanced in combination with physical activity. Interestingly, the anabolic activity on the levator ani was increased in combination with training, although the levator ani muscle was not specifically stimulated by our training protocol. In the m. gastrocnemius and soleus, the anabolic effects correlate with changes in the expression patterns of genes involved in MSTN signaling. Our data provide evidence that the decrease in the weight of androgen-sensitive sexual glands, observed after Md treatment, is caused by a suppression of endogenous testosterone synthesis. These observations provide new insights into the molecular mechanisms of the interaction between anabolic steroids, training and MSTN signaling during skeletal muscle adaptation.

  8. Betaine supplementation enhances anabolic endocrine and Akt signaling in response to acute bouts of exercise.

    PubMed

    Apicella, Jenna M; Lee, Elaine C; Bailey, Brooke L; Saenz, Catherine; Anderson, Jeffrey M; Craig, Stuart A S; Kraemer, William J; Volek, Jeff S; Maresh, Carl M

    2013-03-01

    Our aim was to examine the effect of betaine supplementation on selected circulating hormonal measures and Akt muscle signaling proteins after an acute exercise session. Twelve trained men (age 19.7 ± 1.23 years) underwent 2 weeks of supplementation with either betaine (B) (1.25 g BID) or placebo (P). Following a 2-week washout period, subjects underwent supplementation with the other treatment (B or P). Before and after each 2-week period, subjects performed an acute exercise session (AES). Circulating GH, IGF-1, cortisol, and insulin were measured. Vastus lateralis samples were analyzed for signaling proteins (Akt, p70 S6k, AMPK). B (vs. P) supplementation approached a significant increase in GH (mean ± SD (Area under the curve, AUC), B: 40.72 ± 6.14, P: 38.28 ± 5.54, p = 0.060) and significantly increased IGF-1 (mean ± SD (AUC), B: 106.19 ± 13.45, P: 95.10 ± 14.23, p = 0.010), but significantly decreased cortisol (mean ± SD (AUC), B: 1,079.18 ± 110.02, P: 1,228.53 ± 130.32, p = 0.007). There was no difference in insulin (AUC). B increased resting Total muscle Akt (p = 0.003). B potentiated phosphorylation (relative to P) of Akt (Ser(473)) and p70 S6 k (Thr(389)) (p = 0.016 and p = 0.005, respectively). Phosphorylation of AMPK (Thr(172)) decreased during both treatments (both p = 0.001). Betaine (vs. placebo) supplementation enhanced both the anabolic endocrine profile and the corresponding anabolic signaling environment, suggesting increased protein synthesis.

  9. Transient anabolic effects accompany epidermal growth factor receptor signal activation in articular cartilage in vivo

    PubMed Central

    2013-01-01

    Introduction Signals from the epidermal growth factor receptor (EGFR) have typically been considered to provide catabolic activities in articular cartilage, and accordingly have been suggested to have a causal role in osteoarthritis progression. The aim of this study was to determine in vivo roles for endogenous EGFR signal activation in articular cartilage. Methods Transgenic mice with conditional, limb-targeted deletion of the endogenous intracellular EGFR inhibitor Mig-6 were generated using CreLoxP (Mig-6-flox; Prx1Cre) recombination. Histology, histochemical staining and immunohistochemistry were used to confirm activation of EGFR signaling in the articular cartilage and joints, and to analyze phenotypic consequences of Mig-6 loss on articular cartilage morphology, proliferation, expression of progenitor cell markers, presence of chondrocyte hypertrophy and degradation of articular cartilage matrix. Results The articular cartilage of Mig-6-conditional knockout (Mig-6-cko) mice was dramatically and significantly thicker than normal articular cartilage at 6 and 12 weeks of age. Mig-6-cko articular cartilage contained a population of chondrocytes in which EGFR signaling was activated, and which were three to four times more proliferative than normal Mig-6-flox articular chondrocytes. These cells expressed high levels of the master chondrogenic regulatory factor Sox9, as well as high levels of putative progenitor cell markers including superficial zone protein (SZP), growth and differentiation factor-5 (GDF-5) and Notch1. Expression levels were also high for activated β-catenin and the transforming growth factor beta (TGF-β) mediators phospho-Smad2/3 (pSmad2/3). Anabolic effects of EGFR activation in articular cartilage were followed by catabolic events, including matrix degradation, as determined by accumulation of aggrecan cleavage fragments, and onset of hypertrophy as determined by type × collagen expression. By 16 weeks of age, the articular cartilage of

  10. Anabolic steroids activate calcineurin-NFAT signaling and thereby increase myotube size and reduce denervation atrophy.

    PubMed

    Qin, Weiping; Pan, Jiangping; Wu, Yong; Bauman, William A; Cardozo, Christopher

    2015-01-01

    Anabolic androgens have been shown to reduce muscle loss due to immobilization, paralysis and many other medical conditions, but the molecular basis for these actions is poorly understood. We have recently demonstrated that nandrolone, a synthetic androgen, slows muscle atrophy after nerve transection associated with down-regulation of regulator of calcineurin 2 (RCAN2), a calcineurin inhibitor, suggesting a possible role of calcineurin-NFAT signaling. To test this possibility, rat gastrocnemius muscle was analyzed at 56 days after denervation. In denervated muscle, calcineurin activity declined and NFATc4 was excluded from the nucleus and these effects were reversed by nandrolone. Similarly, nandrolone increased calcineurin activity and nuclear NFATc4 levels in cultured L6 myotubes. Nandrolone also induced cell hypertrophy that was blocked by cyclosporin A or overexpression of RCAN2. Finally protection against denervation atrophy by nandrolone in rats was blocked by cyclosporin A. These results demonstrate for the first time that nandrolone activates calcineurin-NFAT signaling, and that such signaling is important in nandrolone-induced cell hypertrophy and protection against paralysis-induced muscle atrophy.

  11. Anabolic androgenic steroids and intracellular calcium signaling: a mini review on mechanisms and physiological implications.

    PubMed

    Vicencio, J M; Estrada, M; Galvis, D; Bravo, R; Contreras, A E; Rotter, D; Szabadkai, G; Hill, J A; Rothermel, B A; Jaimovich, E; Lavandero, S

    2011-05-01

    Increasing evidence suggests that nongenomic effects of testosterone and anabolic androgenic steroids (AAS) operate concertedly with genomic effects. Classically, these responses have been viewed as separate and independent processes, primarily because nongenomic responses are faster and appear to be mediated by membrane androgen receptors, whereas long-term genomic effects are mediated through cytosolic androgen receptors regulating transcriptional activity. Numerous studies have demonstrated increases in intracellular Ca2+ in response to AAS. These Ca2+ mediated responses have been seen in a diversity of cell types, including osteoblasts, platelets, skeletal muscle cells, cardiac myocytes and neurons. The versatility of Ca2+ as a second messenger provides these responses with a vast number of pathophysiological implications. In cardiac cells, testosterone elicits voltage-dependent Ca2+ oscillations and IP3R-mediated Ca2+ release from internal stores, leading to activation of MAPK and mTOR signaling that promotes cardiac hypertrophy. In neurons, depending upon concentration, testosterone can provoke either physiological Ca2+ oscillations, essential for synaptic plasticity, or sustained, pathological Ca2+ transients that lead to neuronal apoptosis. We propose therefore, that Ca2+ acts as an important point of crosstalk between nongenomic and genomic AAS signaling, representing a central regulator that bridges these previously thought to be divergent responses.

  12. Genetic predisposition to low bone mass is paralleled by an enhanced sensitivity to signals anabolic to the skeleton

    NASA Technical Reports Server (NTRS)

    Judex, Stefan; Donahue, Leah-Rae; Rubin, Clinton

    2002-01-01

    The structure of the adult skeleton is determined, in large part, by its genome. Whether genetic variations may influence the effectiveness of interventions to combat skeletal diseases remains unknown. The differential response of trabecular bone to an anabolic (low-level mechanical vibration) and a catabolic (disuse) mechanical stimulus were evaluated in three strains of adult mice. In low bone-mineral-density C57BL/6J mice, the low-level mechanical signal caused significantly larger bone formation rates (BFR) in the proximal tibia, but the removal of functional weight bearing did not significantly alter BFR. In mid-density BALB/cByJ mice, mechanical stimulation also increased BFR, whereas disuse significantly decreased BFR. In contrast, neither anabolic nor catabolic mechanical signals influenced any index of bone formation in high-density C3H/HeJ mice. Together, data from this study indicate that the sensitivity of trabecular tissue to both anabolic and catabolic stimuli is influenced by the genome. Extrapolated to humans, these results may explain in part why prophylaxes for low bone mass are not universally effective, yet also indicate that there may be a genotypic indication of people who are at reduced risk of suffering from bone loss.

  13. Modulation of the insulin anabolic signalling cascade in growing chickens by n-3 PUFA.

    PubMed

    Tesseraud, Sophie; Chartrin, Pascal; Métayer-Coustard, Sonia; Hermier, Dominique; Simon, Noémie; Peyronnet, Corinne; Lessire, Michel; Baéza, Elisabeth

    2014-03-14

    n-3 PUFA are crucial for health and development. Their effects as regulators of lipid and glucose metabolism are well documented. They also appear to affect protein metabolism, especially by acting on insulin sensitivity. The aim of the present study was to investigate the role of n-3 PUFA, i.e. the precursor α-linolenic acid (ALA) 18:3n-3 or long-chain PUFA (LC-PUFA), in chickens, by focusing on their potential function as co-regulators of the insulin anabolic signalling cascade. Ross male broilers were divided into six dietary treatment groups. Diets were isoproteic (22 % crude protein) and isoenergetic (12·54 MJ metabolisable energy/kg) and contained similar lipid levels (6 %) provided by different proportions of various lipid sources: oleic sunflower oil rich in 18:1n-9 as control; fish oil rich in LC-PUFA; rapeseed and linseed oils providing ALA. The provision of diets enriched with n-3 PUFA, i.e. rich in LC-PUFA or in the precursor ALA, for 3 weeks improved the growth performance of chickens, whereas that of only the ALA diet enhanced the development of the pectoralis major muscle. At 23 d of age, we studied the insulin sensitivity of the pectoralis major muscle and liver of chickens after an intravenous injection of insulin or saline. The present results indicate that the activation patterns of n-3 PUFA are different in the liver and muscles. An ALA-enriched diet may improve insulin sensitivity in muscles, with greater activation of the insulin-induced 70 kDa ribosomal protein S6 kinase/ribosomal protein S6 pathway involved in the translation of mRNA into proteins, thereby potentially increasing muscle protein synthesis and growth. Our findings provide a basis on which to optimise dietary fatty acid provision in growing animals.

  14. Anabolic Steroids

    MedlinePlus

    Anabolic steroids are man-made substances related to male sex hormones. Doctors use anabolic steroids to treat some hormone problems in men, delayed ... from some diseases. Bodybuilders and athletes often use anabolic steroids to build muscles and improve athletic performance. Using ...

  15. Effects of divergent resistance exercise contraction mode and dietary supplementation type on anabolic signalling, muscle protein synthesis and muscle hypertrophy.

    PubMed

    Rahbek, Stine Klejs; Farup, Jean; Møller, Andreas Buch; Vendelbo, Mikkel Holm; Holm, Lars; Jessen, Niels; Vissing, Kristian

    2014-10-01

    Greater force produced with eccentric (ECC) compared to concentric (CONC) contractions, may comprise a stronger driver of muscle growth, which may be further augmented by protein supplementation. We investigated the effect of differentiated contraction mode with either whey protein hydrolysate and carbohydrate (WPH + CHO) or isocaloric carbohydrate (CHO) supplementation on regulation of anabolic signalling, muscle protein synthesis (MPS) and muscle hypertrophy. Twenty-four human participants performed unilateral isolated maximal ECC versus CONC contractions during exercise habituation, single-bout exercise and 12 weeks of training combined with WPH + CHO or CHO supplements. In the exercise-habituated state, p-mTOR, p-p70S6K, p-rpS6 increased by approximately 42, 206 and 213 %, respectively, at 1 h post-exercise, with resistance exercise per se; whereas, the phosphorylation was exclusively maintained with ECC at 3 and 5 h post-exercise. This acute anabolic signalling response did not differ between the isocaloric supplement types, neither did protein fractional synthesis rate differ between interventions. Twelve weeks of ECC as well as CONC resistance training augmented hypertrophy with WPH + CHO group compared to the CHO group (7.3 ± 1.0 versus 3.4 ± 0.8 %), independently of exercise contraction type. Training did not produce major changes in basal levels of Akt-mTOR pathway components. In conclusion, maximal ECC contraction mode may constitute a superior driver of acute anabolic signalling that may not be mirrored in the muscle protein synthesis rate. Furthermore, with prolonged high-volume resistance training, contraction mode seems less influential on the magnitude of muscle hypertrophy, whereas protein and carbohydrate supplementation augments muscle hypertrophy as compared to isocaloric carbohydrate supplementation .

  16. Association between myosin heavy chain protein isoforms and intramuscular anabolic signaling following resistance exercise in trained men.

    PubMed

    Gonzalez, Adam M; Hoffman, Jay R; Townsend, Jeremy R; Jajtner, Adam R; Wells, Adam J; Beyer, Kyle S; Willoughby, Darryn S; Oliveira, Leonardo P; Fukuda, David H; Fragala, Maren S; Stout, Jeffrey R

    2015-01-01

    Resistance exercise stimulates an increase in muscle protein synthesis regulated by intracellular anabolic signaling molecules in a mammalian/mechanistic target of rapamycin (mTOR)-dependent pathway. The purpose of this study was to investigate acute anabolic signaling responses in experienced, resistance-trained men, and to examine the association between myosin heavy chain (MHC) isoform composition and the magnitude of anabolic signaling. Eight resistance-trained men (24.9 ± 4.3 years; 91.2 ± 12.4 kg; 176.7 ± 8.0 cm; 13.3 ± 3.9 body fat %) performed a whole body, high-volume resistance exercise protocol (REX) and a control protocol (CTL) in a balanced, randomized order. Participants were provided a standardized breakfast, recovery drink, and meal during each protocol. Fine needle muscle biopsies were completed at baseline (BL), 2 h (2H) and 6 h post-exercise (6H). BL biopsies were analyzed for MHC isoform composition. Phosphorylation of proteins specific to the Akt/mTOR signaling pathway and MHC mRNA expression was quantified. Phosphorylation of p70S6k was significantly greater in REX compared to CTL at 2H (P = 0.04). MHC mRNA expression and other targets in the Akt/mTOR pathway were not significantly influenced by REX. The percentage of type IIX isoform was inversely correlated (P < 0.05) with type I and type IIA MHC mRNA expression (r = -0.69 to -0.93). Maximal strength was also observed to be inversely correlated (P < 0.05) with Type I and Type IIA MHC mRNA expression (r = -0.75 to -0.77) and p70S6k phosphorylation (r = -0.75). Results indicate that activation of p70S6k occurs within 2-h following REX in experienced, resistance-trained men. Further, results also suggest that highly trained, stronger individuals have an attenuated acute anabolic response. PMID:25626869

  17. Association between myosin heavy chain protein isoforms and intramuscular anabolic signaling following resistance exercise in trained men

    PubMed Central

    Gonzalez, Adam M.; Hoffman, Jay R.; Townsend, Jeremy R.; Jajtner, Adam R.; Wells, Adam J.; Beyer, Kyle S.; Willoughby, Darryn S.; Oliveira, Leonardo P.; Fukuda, David H.; Fragala, Maren S.; Stout, Jeffrey R.

    2015-01-01

    Abstract Resistance exercise stimulates an increase in muscle protein synthesis regulated by intracellular anabolic signaling molecules in a mammalian/mechanistic target of rapamycin (mTOR)‐dependent pathway. The purpose of this study was to investigate acute anabolic signaling responses in experienced, resistance‐trained men, and to examine the association between myosin heavy chain (MHC) isoform composition and the magnitude of anabolic signaling. Eight resistance‐trained men (24.9 ± 4.3 years; 91.2 ± 12.4 kg; 176.7 ± 8.0 cm; 13.3 ± 3.9 body fat %) performed a whole body, high‐volume resistance exercise protocol (REX) and a control protocol (CTL) in a balanced, randomized order. Participants were provided a standardized breakfast, recovery drink, and meal during each protocol. Fine needle muscle biopsies were completed at baseline (BL), 2 h (2H) and 6 h post‐exercise (6H). BL biopsies were analyzed for MHC isoform composition. Phosphorylation of proteins specific to the Akt/mTOR signaling pathway and MHC mRNA expression was quantified. Phosphorylation of p70S6k was significantly greater in REX compared to CTL at 2H (P = 0.04). MHC mRNA expression and other targets in the Akt/mTOR pathway were not significantly influenced by REX. The percentage of type IIX isoform was inversely correlated (P < 0.05) with type I and type IIA MHC mRNA expression (r = −0.69 to −0.93). Maximal strength was also observed to be inversely correlated (P < 0.05) with Type I and Type IIA MHC mRNA expression (r = −0.75 to −0.77) and p70S6k phosphorylation (r = −0.75). Results indicate that activation of p70S6k occurs within 2‐h following REX in experienced, resistance‐trained men. Further, results also suggest that highly trained, stronger individuals have an attenuated acute anabolic response. PMID:25626869

  18. Association between myosin heavy chain protein isoforms and intramuscular anabolic signaling following resistance exercise in trained men.

    PubMed

    Gonzalez, Adam M; Hoffman, Jay R; Townsend, Jeremy R; Jajtner, Adam R; Wells, Adam J; Beyer, Kyle S; Willoughby, Darryn S; Oliveira, Leonardo P; Fukuda, David H; Fragala, Maren S; Stout, Jeffrey R

    2015-01-01

    Resistance exercise stimulates an increase in muscle protein synthesis regulated by intracellular anabolic signaling molecules in a mammalian/mechanistic target of rapamycin (mTOR)-dependent pathway. The purpose of this study was to investigate acute anabolic signaling responses in experienced, resistance-trained men, and to examine the association between myosin heavy chain (MHC) isoform composition and the magnitude of anabolic signaling. Eight resistance-trained men (24.9 ± 4.3 years; 91.2 ± 12.4 kg; 176.7 ± 8.0 cm; 13.3 ± 3.9 body fat %) performed a whole body, high-volume resistance exercise protocol (REX) and a control protocol (CTL) in a balanced, randomized order. Participants were provided a standardized breakfast, recovery drink, and meal during each protocol. Fine needle muscle biopsies were completed at baseline (BL), 2 h (2H) and 6 h post-exercise (6H). BL biopsies were analyzed for MHC isoform composition. Phosphorylation of proteins specific to the Akt/mTOR signaling pathway and MHC mRNA expression was quantified. Phosphorylation of p70S6k was significantly greater in REX compared to CTL at 2H (P = 0.04). MHC mRNA expression and other targets in the Akt/mTOR pathway were not significantly influenced by REX. The percentage of type IIX isoform was inversely correlated (P < 0.05) with type I and type IIA MHC mRNA expression (r = -0.69 to -0.93). Maximal strength was also observed to be inversely correlated (P < 0.05) with Type I and Type IIA MHC mRNA expression (r = -0.75 to -0.77) and p70S6k phosphorylation (r = -0.75). Results indicate that activation of p70S6k occurs within 2-h following REX in experienced, resistance-trained men. Further, results also suggest that highly trained, stronger individuals have an attenuated acute anabolic response.

  19. Protein supplementation does not alter intramuscular anabolic signaling or endocrine response after resistance exercise in trained men.

    PubMed

    Gonzalez, Adam M; Hoffman, Jay R; Jajtner, Adam R; Townsend, Jeremy R; Boone, Carleigh H; Beyer, Kyle S; Baker, Kayla M; Wells, Adam J; Church, David D; Mangine, Gerald T; Oliveira, Leonardo P; Moon, Jordan R; Fukuda, David H; Stout, Jeffrey R

    2015-11-01

    The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway appears to be the primary regulator of muscle protein synthesis. A variety of stimuli including resistance exercise, amino acids, and hormonal signals activate mTORC1 signaling. The purpose of this study was to investigate the effect of a protein supplement on mTORC1 signaling following a resistance exercise protocol designed to promote elevations in circulating hormone concentrations. We hypothesized that the protein supplement would augment the intramuscular anabolic signaling response. Ten resistance-trained men (age, 24.7 ± 3.4 years; weight, 90.1 ± 11.3 kg; height, 176.0 ± 4.9 cm) received either a placebo or a supplement containing 20 g protein, 6 g carbohydrates, and 1 g fat after high-volume, short-rest lower-body resistance exercise. Blood samples were obtained at baseline, immediately, 30 minutes, 1 hour, 2 hours, and 5 hours after exercise. Fine-needle muscle biopsies were completed at baseline, 1 hour, and 5 hours after exercise. Myoglobin, lactate dehydrogenase, and lactate concentrations were significantly elevated after resistance exercise (P < .0001); however, no differences were observed between trials. Resistance exercise also elicited a significant insulin, growth hormone, and cortisol response (P < .01); however, no differences were observed between trials for insulin-like growth factor-1, insulin, testosterone, growth hormone, or cortisol. Intramuscular anabolic signaling analysis revealed significant elevations in RPS6 phosphorylation after resistance exercise (P = .001); however, no differences were observed between trials for signaling proteins including Akt, mTOR, p70S6k, and RPS6. The endocrine response and phosphorylation status of signaling proteins within the mTORC1 pathway did not appear to be altered by ingestion of supplement after resistance exercise in resistance-trained men. PMID:26428621

  20. Protein supplementation does not alter intramuscular anabolic signaling or endocrine response after resistance exercise in trained men.

    PubMed

    Gonzalez, Adam M; Hoffman, Jay R; Jajtner, Adam R; Townsend, Jeremy R; Boone, Carleigh H; Beyer, Kyle S; Baker, Kayla M; Wells, Adam J; Church, David D; Mangine, Gerald T; Oliveira, Leonardo P; Moon, Jordan R; Fukuda, David H; Stout, Jeffrey R

    2015-11-01

    The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway appears to be the primary regulator of muscle protein synthesis. A variety of stimuli including resistance exercise, amino acids, and hormonal signals activate mTORC1 signaling. The purpose of this study was to investigate the effect of a protein supplement on mTORC1 signaling following a resistance exercise protocol designed to promote elevations in circulating hormone concentrations. We hypothesized that the protein supplement would augment the intramuscular anabolic signaling response. Ten resistance-trained men (age, 24.7 ± 3.4 years; weight, 90.1 ± 11.3 kg; height, 176.0 ± 4.9 cm) received either a placebo or a supplement containing 20 g protein, 6 g carbohydrates, and 1 g fat after high-volume, short-rest lower-body resistance exercise. Blood samples were obtained at baseline, immediately, 30 minutes, 1 hour, 2 hours, and 5 hours after exercise. Fine-needle muscle biopsies were completed at baseline, 1 hour, and 5 hours after exercise. Myoglobin, lactate dehydrogenase, and lactate concentrations were significantly elevated after resistance exercise (P < .0001); however, no differences were observed between trials. Resistance exercise also elicited a significant insulin, growth hormone, and cortisol response (P < .01); however, no differences were observed between trials for insulin-like growth factor-1, insulin, testosterone, growth hormone, or cortisol. Intramuscular anabolic signaling analysis revealed significant elevations in RPS6 phosphorylation after resistance exercise (P = .001); however, no differences were observed between trials for signaling proteins including Akt, mTOR, p70S6k, and RPS6. The endocrine response and phosphorylation status of signaling proteins within the mTORC1 pathway did not appear to be altered by ingestion of supplement after resistance exercise in resistance-trained men.

  1. Regulation of beta catenin signaling and parathyroid hormone anabolic effects in bone by the matricellular protein periostin.

    PubMed

    Bonnet, Nicolas; Conway, Simon J; Ferrari, Serge L

    2012-09-11

    Periostin (Postn) is a matricellular protein preferentially expressed by osteocytes and periosteal osteoblasts in response to mechanical stimulation and parathyroid hormone (PTH). Whether and how periostin expression influences bone anabolism, however, remains unknown. We investigated the skeletal response of adult Postn(-/-) and Postn(+/+) mice to intermittent PTH. Compared with Postn(+/+), Postn(-/-) mice had a lower bone mass, cortical bone volume, and strength response to PTH. PTH-stimulated bone-forming indices were all significantly lower in Postn(-/-) mice, particularly at the periosteum. Furthermore, in vivo stimulation of Wnt-β-catenin signaling by PTH, as evaluated in TOPGAL reporter mice, was inhibited in the absence of periostin (TOPGAL;Postn(-/-) mice). PTH stimulated periostin and inhibited MEF2C and sclerostin (Sost) expression in bone and osteoblasts in vitro. Recombinant periostin also suppressed Sost expression, which was mediated through the integrin αVβ3 receptor, whereas periostin-blocking antibody prevented inhibition of MEF2C and Sost by PTH. In turn, administration of a Sost-blocking antiboby partially restored the PTH-mediated increase in bone mass in Postn(-/-) mice. In addition, primary osteoblasts from Postn(-/-) mice showed a lower proliferation, mineralization, and migration, both spontaneously and in response to PTH. Osteoblastic gene expression levels confirmed a defect of Postn(-/-) osteoblast differentiation with and without PTH, as well as an increased osteoblast apoptosis in the absence of periostin. These data elucidate the complex role of periostin on bone anabolism, through the regulation of Sost, Wnt-β-catenin signaling, and osteoblast differentiation.

  2. Anabolic steroids.

    PubMed

    Kuhn, Cynthia M

    2002-01-01

    The term "anabolic steroids" refers to testosterone derivatives that are used either clinically or by athletes for their anabolic properties. However, scientists have questioned the anabolic effects of testosterone and its derivatives in normal men for decades. Most scientists concluded that anabolic steroids do not increase muscle size or strength in people with normal gonadal function and have discounted positive results as unduly influenced by positive expectations of athletes, inferior experimental design, or poor data analysis. There has been a tremendous disconnect between the conviction of athletes that these drugs are effective and the conviction of scientists that they aren't. In part, this disconnect results from the completely different dose regimens used by scientists to document the correction of deficiency states and by athletes striving to optimize athletic performance. Recently, careful scientific study of suprapharmacologic doses in clinical settings - including aging, human immunodeficiency virus, and other disease states - supports the efficacy of these regimens. However, the mechanism by which these doses act remains unclear. "Anabolism" is defined as any state in which nitrogen is differentially retained in lean body mass, either through stimulation of protein synthesis and/or decreased breakdown of protein anywhere in the body. Testosterone, the main gonadal steroid in males, has marked anabolic effects in addition to its effects on reproduction that are easily observed in developing boys and when hypogonadal men receive testosterone as replacement therapy. However, its efficacy in normal men, as during its use in athletes or in clinical situations in which men are eugonadal, has been debated. A growing literature suggests that use of suprapharmacologic doses can, indeed, be anabolic in certain situations; however, the clear identification of these situations and the mechanism by which anabolic effects occur are unclear. Furthermore, the

  3. Aposematic signals and the relationship between conspicuousness and distinctiveness.

    PubMed

    Merilaita, Sami; Ruxton, Graeme D

    2007-03-21

    It has long been recognized that prey that invest in toxic or other defenses often advertise these defenses by means of conspicuously coloured signals. One question that remains unanswered is why conspicuousness is such a universal trait of aposematic signals. Conspicuousness may allow more rapid avoidance learning by predators or improved retention of such learning. An alternative or complementary explanation is that defended species should adopt a conspicuous signal of their defence to make them visually distinct from inconspicuous undefended prey. Here, we use a neural network model of prey detection and attack decision making by a predator in combination with evolving, virtual prey to shed light on the relative importance of conspicuousness against the background and distinctiveness from other species as mechanisms underlying aposematic signalling. Our model suggests that prey conspicuousness may result from selection for distinctiveness, but that selection for distinctiveness does not result in maximization of conspicuousness. On the other hand, our model does not justify the exclusion of the possibility that conspicuousness as such may be a beneficial attribute of warning coloration. It is likely that the relative importance of the two selective forces (for conspicuousness and for distinctiveness) will differ on a case-by-case basis, however there is no empirical or logical reason for the current neglect of evolutionary pressure for distinctiveness. Thus, we suggest that description of aposematism as the teaming of a secondary defence with a conspicuous signal may be overly simplistic; we would rather that the signal were described as conspicuous and/or distinctive.

  4. Cyclic stretch reduces myofibrillar protein synthesis despite increases in FAK and anabolic signalling in L6 cells

    PubMed Central

    Atherton, P J; Szewczyk, N J; Selby, A; Rankin, D; Hillier, K; Smith, K; Rennie, M J; Loughna, P T

    2009-01-01

    Muscle protein synthesis is increased after exercise, but evidence is now accruing that during muscular activity it is suppressed. In life, muscles are subjected to shortening forces due to contraction, but may also be subject to stretching forces during lengthening. It would be biologically inefficient if contraction and stretch have different effects on muscle protein turnover, but little is known about the metabolic effects of stretch. To investigate this, we assessed myofibrillar and sarcoplasmic protein synthesis (MPS, SPS, respectively) by incorporation of [1-13C]proline (using gas chromatography–mass spectrometry) and anabolic signalling (by phospho-immunoblotting and kinase assays) in cultured L6 skeletal muscle cells during 30 min of cyclic stretch and over 30 min intervals for up to 120 min afterwards. SPS was unaffected, whereas MPS was suppressed by 40 ± 0.03% during stretch, before returning to basal rates by 90–20 min afterwards. Paradoxically, stretch stimulated anabolic signalling with peak values after 2–30 min: e.g. focal adhesion kinase (FAK Tyr576/577; +28 ± 6%), protein kinase B activity (Akt; +113 ± 31%), p70S6K1 (ribosomal S6 kinase Thr389; 25 ± 5%), 4E binding protein 1 (4EBP1 Thr37/46; 14 ± 3%), eukaryotic elongation factor 2 (eEF2 Thr56; −47 ± 4%), extracellular regulated protein kinase 1/2 (ERK1/2 Tyr202/204; +65%± 9%), eukaryotic initiation factor 2α (eIF2α Ser51; −20 ± 5%, P < 0.05) and eukaryotic initiation factor 4E (eIF4E Ser209; +33 ± 10%, P < 0.05). After stretch, except for Akt activity, stimulatory phosphorylations were sustained: e.g. FAK (+26 ± 11%) for ≥30 min, eEF2 for ≥60 min (peak −45 ± 4%), 4EBP1 for ≥90 min (+33 ± 5%), and p70S6K1 remained elevated throughout (peak +64 ± 7%). Adenosine monophosphate-activated protein kinase (AMPK) phosphorylation was unchanged throughout. We report for the first time that acute cyclic stretch specifically suppresses MPS, despite increases in activity

  5. Regulation of beta catenin signaling and parathyroid hormone anabolic effects in bone by the matricellular protein periostin

    PubMed Central

    Bonnet, Nicolas; Conway, Simon J.; Ferrari, Serge L.

    2012-01-01

    Periostin (Postn) is a matricellular protein preferentially expressed by osteocytes and periosteal osteoblasts in response to mechanical stimulation and parathyroid hormone (PTH). Whether and how periostin expression influences bone anabolism, however, remains unknown. We investigated the skeletal response of adult Postn−/− and Postn+/+ mice to intermittent PTH. Compared with Postn+/+, Postn−/− mice had a lower bone mass, cortical bone volume, and strength response to PTH. PTH-stimulated bone-forming indices were all significantly lower in Postn−/− mice, particularly at the periosteum. Furthermore, in vivo stimulation of Wnt-β-catenin signaling by PTH, as evaluated in TOPGAL reporter mice, was inhibited in the absence of periostin (TOPGAL;Postn−/− mice). PTH stimulated periostin and inhibited MEF2C and sclerostin (Sost) expression in bone and osteoblasts in vitro. Recombinant periostin also suppressed Sost expression, which was mediated through the integrin αVβ3 receptor, whereas periostin-blocking antibody prevented inhibition of MEF2C and Sost by PTH. In turn, administration of a Sost-blocking antiboby partially restored the PTH-mediated increase in bone mass in Postn−/− mice. In addition, primary osteoblasts from Postn−/− mice showed a lower proliferation, mineralization, and migration, both spontaneously and in response to PTH. Osteoblastic gene expression levels confirmed a defect of Postn−/− osteoblast differentiation with and without PTH, as well as an increased osteoblast apoptosis in the absence of periostin. These data elucidate the complex role of periostin on bone anabolism, through the regulation of Sost, Wnt-β-catenin signaling, and osteoblast differentiation. PMID:22927401

  6. Anabolic therapies.

    PubMed

    Lane, Nancy E; Silverman, Stuart L

    2010-03-01

    The striking clinical benefits of intermittent parathyroid hormone in osteoporosis have begun a new era of skeletal anabolic agents. Recombinant human parathyroid hormone (rhPTH) (1-34) is the first US Food and Drug Administration-approved anabolic therapy. Its use has been limited by the need for subcutaneous injection. Newer delivery systems include transdermal and oral preparations. Newer anabolic therapies include monoclonal antibody to sclerostin, a potent inhibitor of osteoblastogenesis; and use of bone morphogenetic proteins and parathyroid hormone-related protein PTHrP, a calcium-regulating hormone similar to PTH. PMID:20425087

  7. Anabolic steroids.

    PubMed

    Strauss, R H

    1984-07-01

    Anabolic-androgenic steroid hormones are used by athletes in an attempt to improve performance. Side effects include decreased testosterone and sperm production, acne, balding, and increased aggression. The long-term effects are not known.

  8. Diminished anabolic signaling response to insulin induced by intramuscular lipid accumulation is associated with inflammation in aging but not obesity.

    PubMed

    Rivas, Donato A; McDonald, Devin J; Rice, Nicholas P; Haran, Prashanth H; Dolnikowski, Gregory G; Fielding, Roger A

    2016-04-01

    The loss of skeletal muscle mass is observed in many pathophysiological conditions, including aging and obesity. The loss of muscle mass and function with aging is defined as sarcopenia and is characterized by a mismatch between skeletal muscle protein synthesis and breakdown. Characteristic metabolic features of both aging and obesity are increases in intramyocellular lipid (IMCL) content in muscle. IMCL accumulation may play a mechanistic role in the development of anabolic resistance and the progression of muscle atrophy in aging and obesity. In the present study, aged and high-fat fed mice were used to determine mechanisms leading to muscle loss. We hypothesized the accumulation of bioactive lipids in skeletal muscle, such as ceramide or diacylglycerols, leads to insulin resistance with aging and obesity and the inability to activate protein synthesis, contributing to skeletal muscle loss. We report a positive association between bioactive lipid accumulation and the loss of lean mass and muscle strength. Obese and aged animals had significantly higher storage of ceramide and diacylglycerol compared with young. Furthermore, there was an attenuated insulin response in components of the mTOR anabolic signaling pathway. We also observed differential increases in the expression of inflammatory cytokines and the phosphorylation of IκBα with aging and obesity. These data challenge the accepted role of increased inflammation in obesity-induced insulin resistance in skeletal muscle. Furthermore, we have now established IκBα with a novel function in aging-associated muscle loss that may be independent of its previously understood role as an NF-κB inhibitor.

  9. Mitochondrial mass, a new metabolic biomarker for stem-like cancer cells: Understanding WNT/FGF-driven anabolic signaling.

    PubMed

    Lamb, Rebecca; Bonuccelli, Gloria; Ozsvári, Béla; Peiris-Pagès, Maria; Fiorillo, Marco; Smith, Duncan L; Bevilacqua, Generoso; Mazzanti, Chiara Maria; McDonnell, Liam A; Naccarato, Antonio Giuseppe; Chiu, Maybo; Wynne, Luke; Martinez-Outschoorn, Ubaldo E; Sotgia, Federica; Lisanti, Michael P

    2015-10-13

    Here, we developed an isogenic cell model of "stemness" to facilitate protein biomarker discovery in breast cancer. For this purpose, we used knowledge gained previously from the study of the mouse mammary tumor virus (MMTV). MMTV initiates mammary tumorigenesis in mice by promoter insertion adjacent to two main integration sites, namely Int-1 (Wnt1) and Int-2 (Fgf3), which ultimately activates Wnt/β-catenin signaling, driving the propagation of mammary cancer stem cells (CSCs). Thus, to develop a humanized model of MMTV signaling, we over-expressed WNT1 and FGF3 in MCF7 cells, an ER(+) human breast cancer cell line. We then validated that MCF7 cells over-expressing both WNT1 and FGF3 show a 3.5-fold increase in mammosphere formation, and that conditioned media from these cells is also sufficient to promote stem cell activity in untransfected parental MCF7 and T47D cells, as WNT1 and FGF3 are secreted factors. Proteomic analysis of this model system revealed the induction of i) EMT markers, ii) mitochondrial proteins, iii) glycolytic enzymes and iv) protein synthesis machinery, consistent with an anabolic CSC phenotype. MitoTracker staining validated the expected WNT1/FGF3-induced increase in mitochondrial mass and activity, which presumably reflects increased mitochondrial biogenesis. Importantly, many of the proteins that were up-regulated by WNT/FGF-signaling in MCF7 cells, were also transcriptionally over-expressed in human breast cancer cells in vivo, based on the bioinformatic analysis of public gene expression datasets of laser-captured patient samples. As such, this isogenic cell model should accelerate the discovery of new biomarkers to predict clinical outcome in breast cancer, facilitating the development of personalized medicine.Finally, we used mitochondrial mass as a surrogate marker for increased mitochondrial biogenesis in untransfected MCF7 cells. As predicted, metabolic fractionation of parental MCF7 cells, via MitoTracker staining, indicated

  10. Reduction of anabolic signals and alteration of osteoblast nuclear morphology in microgravity.

    PubMed

    Hughes-Fulford, Millie; Rodenacker, Karsten; Jütting, Uta

    2006-10-01

    Bone loss has been repeatedly documented in astronauts after flight, yet little is known about the mechanism of bone loss in space flight. Osteoblasts were activated during space flight in microgravity (microg) with and without a 1 gravity (1 g) field and 24 genes were analyzed for early induction. Induction of proliferating cell nuclear antigen (PCNA), transforming growth factor beta (TGFbeta), cyclo-oxygenase-2 (cox-2), cpla2, osteocalcin (OC), c-myc, fibroblast growth factor-2 (fgf-2), bcl2, bax, and fgf-2 message as well as FGF-2 protein were significantly depressed in microg when compared to ground (gr). Artificial onboard gravity normalized the induction of c-myc, cox-2, TGFbeta, bax, bcl2, and fgf-2 message as well as FGF-2 protein synthesis in spaceflight samples. In normal gravity, FGF-2 induces bcl2 expression; we found that bcl2 expression was significantly reduced in microgravity conditions. Since nuclear shape is known to elongate in the absence of mitogens like FGF-2, we used high-resolution image-based morphometry to characterize changes in osteoblast nuclear architecture under microgravity, 1 g flight, and ground conditions. Besides changes in cell shape (roundish/elliptic), other high-resolution analyses show clear influences of gravity on the inner nuclear structure. These changes occur in the texture, arrangement, and contrast of nuclear particles and mathematical modeling defines the single cell classification of the osteoblasts. Changes in nuclear structure were evident as early as 24 h after exposure to microgravity. This documented alteration in nuclear architecture may be a direct result of decreased expression of autocrine and cell cycle genes, suggesting an inhibition of anabolic response in microg. Life on this planet has evolved in a normal gravity field and these data suggest that gravity plays a significant role in regulation of osteoblast transcription.

  11. Parathyroid hormone (PTH)/PTH-related peptide type 1 receptor (PPR) signaling in osteocytes regulates anabolic and catabolic skeletal responses to PTH.

    PubMed

    Saini, Vaibhav; Marengi, Dean A; Barry, Kevin J; Fulzele, Keertik S; Heiden, Erica; Liu, Xiaolong; Dedic, Christopher; Maeda, Akira; Lotinun, Sutada; Baron, Roland; Pajevic, Paola Divieti

    2013-07-12

    Parathyroid hormone (PTH) is the only Food and Drug Administration-approved anabolic agent to treat osteoporosis; however, the cellular targets of PTH action in bone remain controversial. PTH modulates bone turnover by binding to the PTH/PTH-related peptide (PTHrP) type 1 receptor (PPR), a G-protein-coupled receptor highly expressed in bone and kidneys. Osteocytes, the most abundant cells in adult bone, also express PPR. However, the physiological relevance of PPR signaling in osteocytes remains to be elucidated. Toward this goal, we generated mice with PPR deletion in osteocytes (Ocy-PPRKO). Skeletal analysis of these mice revealed a significant increase in bone mineral density and trabecular and cortical bone parameters. Osteoblast activities were reduced in these animals, as demonstrated by decreased collagen type I α1 mRNA and receptor activator of NF-κB ligand (RANKL) expression. Importantly, when subjected to an anabolic or catabolic PTH regimen, Ocy-PPRKO animals demonstrated blunted skeletal responses. PTH failed to suppress SOST/Sclerostin or induce RANKL expression in Ocy-PPRKO animals compared with controls. In vitro, osteoclastogenesis was significantly impaired in Ocy-PPRKO upon PTH administration, indicating that osteocytes control osteoclast formation through a PPR-mediated mechanism. Taken together, these data indicate that PPR signaling in osteocytes is required for bone remodeling, and receptor signaling in osteocytes is needed for anabolic and catabolic skeletal responses.

  12. Gene expression in distinct regions of rat tendons in response to jump training combined with anabolic androgenic steroid administration.

    PubMed

    Marqueti, Rita Cássia; Marqueti, Rita de Cássia; Heinemeier, Katja Maria; Durigan, João Luiz Quaglioti; de Andrade Perez, Sérgio Eduardo; Schjerling, Peter; Kjaer, Michael; Carvalho, Hernandes Faustino; Selistre-de-Araujo, Heloisa Sobreiro

    2012-04-01

    The aim of this study was to evaluate the expression of key genes responsible for tendon remodeling of the proximal and distal regions of calcaneal tendon (CT), intermediate and distal region of superficial flexor tendon (SFT) and proximal, intermediate and distal region of deep flexor tendon (DFT) submitted to 7 weeks of jumping water load exercise in combination with AAS administration. Wistar male rats were grouped as follows: sedentary (S), trained (jumping water load exercise) (T), sedentary animals treated with AAS (5 mg/kg, twice a week) and animals treated with AAS and trained (AAST). mRNA levels of COL1A1, COL3A1, TIMP-1, TIMP-2, MMP-2, IGF-IEa, GAPDH, CTGF and TGF-β-1 were evaluated by quantitative PCR. Our main results indicated that mRNA levels alter in different regions in each tendon of sedentary animals. The training did not alter the expression of COL1A1, COL3A, IGF-IEa and MMP-2 genes, while AAS administration or its combination with training reduced their expression. This study indicated that exercise did not alter the expression of collagen and related growth factors in different regions of rat tendon. Moreover, the pattern of gene expression was distinct in the different tendon regions of sedentary animals. Although, the RNA yield levels of CT, SFT and DFT were not distinct in each region, these regions possess not only the structural and biochemical difference, but also divergence in the expression of key genes involved in tendon adaptation.

  13. Gene expression in distinct regions of rat tendons in response to jump training combined with anabolic androgenic steroid administration.

    PubMed

    Marqueti, Rita Cássia; Marqueti, Rita de Cássia; Heinemeier, Katja Maria; Durigan, João Luiz Quaglioti; de Andrade Perez, Sérgio Eduardo; Schjerling, Peter; Kjaer, Michael; Carvalho, Hernandes Faustino; Selistre-de-Araujo, Heloisa Sobreiro

    2012-04-01

    The aim of this study was to evaluate the expression of key genes responsible for tendon remodeling of the proximal and distal regions of calcaneal tendon (CT), intermediate and distal region of superficial flexor tendon (SFT) and proximal, intermediate and distal region of deep flexor tendon (DFT) submitted to 7 weeks of jumping water load exercise in combination with AAS administration. Wistar male rats were grouped as follows: sedentary (S), trained (jumping water load exercise) (T), sedentary animals treated with AAS (5 mg/kg, twice a week) and animals treated with AAS and trained (AAST). mRNA levels of COL1A1, COL3A1, TIMP-1, TIMP-2, MMP-2, IGF-IEa, GAPDH, CTGF and TGF-β-1 were evaluated by quantitative PCR. Our main results indicated that mRNA levels alter in different regions in each tendon of sedentary animals. The training did not alter the expression of COL1A1, COL3A, IGF-IEa and MMP-2 genes, while AAS administration or its combination with training reduced their expression. This study indicated that exercise did not alter the expression of collagen and related growth factors in different regions of rat tendon. Moreover, the pattern of gene expression was distinct in the different tendon regions of sedentary animals. Although, the RNA yield levels of CT, SFT and DFT were not distinct in each region, these regions possess not only the structural and biochemical difference, but also divergence in the expression of key genes involved in tendon adaptation. PMID:21842416

  14. New anabolic therapies in osteoporosis.

    PubMed

    Rubin, Mishaela R; Bilezikian, John P

    2003-03-01

    Anabolic agents represent an important new advance in the therapy of osteoporosis. Their potential might be substantially greater than the anti-resorptives. Because the anti-resorptives and anabolic agents work by completely distinct mechanisms of action, it is possible that the combination of agents could be significantly more potent than either agent alone. Recent evidence suggests that a plateau in BMD might occur after prolonged exposure to PTH. Anti-resorptive therapy during or after anabolic therapy might prevent this skeletal adaptation. Protocols to consider anabolic agents as intermittent recycling therapy would be of interest. Of all the anabolics, PTH is the most promising. However, there are unanswered questions about PTH. More studies are needed to document an anabolic effect on cortical bone. More large-scale studies are needed to further determine the reduction in nonvertebral fractures with PTH, especially at the hip. In the future, PTH is likely to be modified for easier and more targeted delivery. Oral or transdermal delivery systems may become available. Recently, Gowen et al have described an oral calcilytic molecule that antagonizes the parathyroid cell calcium receptor, thus stimulating the endogenous release of PTH. This approach could represent a novel endogenous delivery system for intermittent PTH administration. Rising expectations that anabolic therapies for osteoporosis will soon play a major role in treating this disease are likely to fuel further studies and the development of even more novel approaches to therapy. PMID:12699304

  15. Anabolic steroids reduce spinal cord injury-related bone loss in rats associated with increased Wnt signaling

    PubMed Central

    Sun, Li; Pan, Jiangping; Peng, Yuanzhen; Wu, Yong; Li, Jianghua; Liu, Xuan; Qin, Yiwen; Bauman, William A.; Cardozo, Christopher; Zaidi, Mone; Qin, Weiping

    2013-01-01

    Background Spinal cord injury (SCI) causes severe bone loss. At present, there is no practical treatment to delay or prevent bone loss in individuals with motor-complete SCI. Hypogonadism is common in men after SCI and may exacerbate bone loss. The anabolic steroid nandrolone reduces bone loss due to microgravity or nerve transection. Objective To determine whether nandrolone reduced bone loss after SCI and, if so, to explore the mechanisms of nandrolone action. Methods Male rats with complete transection of the spinal cord were administered nandrolone combined with a physiological replacement dose of testosterone, or vehicle, beginning on day 29 after SCI and continued for 28 days. Results SCI reduced distal femoral and proximal tibial bone mineral density (BMD) by 25 and 16%, respectively, at 56 days. This bone loss was attenuated by nandrolone. In ex vivo osteoclasts cultures, SCI increased mRNA levels for tartrate-resistant acid phosphatase (TRAP) and calcitonin receptor; nandrolone-normalized expression levels of these transcripts. In ex vivo osteoblast cultures, SCI increased receptor activator of NF-kB ligand (RANKL) mRNA levels but did not alter osteoprotegerin (OPG) mRNA expression; nandrolone-increased expression of OPG and OPG/RANKL ratio. SCI reduced mRNA levels of Wnt signaling-related genes Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5), Fzd5, Tcf7, and ectodermal-neural cortex 1 (ENC1) in osteoblasts, whereas nandrolone increased expression of each of these genes. Conclusions The results demonstrate that nandrolone reduces bone loss after SCI. A potential mechanism is suggested by our findings wherein nandrolone modulates genes for differentiation and activity of osteoclasts and osteoblasts, at least in part, through the activation of Wnt signaling. PMID:24090150

  16. Distinct purinergic signaling pathways in prepubescent mouse spermatogonia.

    PubMed

    Fleck, David; Mundt, Nadine; Bruentgens, Felicitas; Geilenkirchen, Petra; Machado, Patricia A; Veitinger, Thomas; Veitinger, Sophie; Lipartowski, Susanne M; Engelhardt, Corinna H; Oldiges, Marco; Spehr, Jennifer; Spehr, Marc

    2016-09-01

    Spermatogenesis ranks among the most complex, yet least understood, developmental processes. The physiological principles that control male germ cell development in mammals are notoriously difficult to unravel, given the intricate anatomy and complex endo- and paracrinology of the testis. Accordingly, we lack a conceptual understanding of the basic signaling mechanisms within the testis, which control the seminiferous epithelial cycle and thus govern spermatogenesis. Here, we address paracrine signal transduction in undifferentiated male germ cells from an electrophysiological perspective. We identify distinct purinergic signaling pathways in prepubescent mouse spermatogonia, both in vitro and in situ. ATP-a dynamic, widespread, and evolutionary conserved mediator of cell to cell communication in various developmental contexts-activates at least two different spermatogonial purinoceptor isoforms. Both receptors operate within nonoverlapping stimulus concentration ranges, display distinct response kinetics and, in the juvenile seminiferous cord, are uniquely expressed in spermatogonia. We further find that spermatogonia express Ca(2+)-activated large-conductance K(+) channels that appear to function as a safeguard against prolonged ATP-dependent depolarization. Quantitative purine measurements additionally suggest testicular ATP-induced ATP release, a mechanism that could increase the paracrine radius of initially localized signaling events. Moreover, we establish a novel seminiferous tubule slice preparation that allows targeted electrophysiological recordings from identified testicular cell types in an intact epithelial environment. This unique approach not only confirms our in vitro findings, but also supports the notion of purinergic signaling during the early stages of spermatogenesis. PMID:27574293

  17. Intramuscular anabolic signaling and endocrine response following high volume and high intensity resistance exercise protocols in trained men

    PubMed Central

    Gonzalez, Adam M; Hoffman, Jay R; Townsend, Jeremy R; Jajtner, Adam R; Boone, Carleigh H; Beyer, Kyle S; Baker, Kayla M; Wells, Adam J; Mangine, Gerald T; Robinson, Edward H; Church, David D; Oliveira, Leonardo P; Willoughby, Darryn S; Fukuda, David H; Stout, Jeffrey R

    2015-01-01

    Resistance exercise paradigms are often divided into high volume (HV) or high intensity (HI) protocols, however, it is unknown whether these protocols differentially stimulate mTORC1 signaling. The purpose of this study was to examine mTORC1 signaling in conjunction with circulating hormone concentrations following a typical HV and HI lower-body resistance exercise protocol. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Fine needle muscle biopsies were completed at BL, 1H, and 5H. Electromyography of the vastus lateralis was also recorded during each protocol. HV and HI produced a similar magnitude of muscle activation across sets. Myoglobin and lactate dehydrogenase concentrations were significantly greater following HI compared to HV (P = 0.01–0.02), whereas the lactate response was significantly higher following HV compared to HI (P = 0.003). The growth hormone, cortisol, and insulin responses were significantly greater following HV compared to HI (P = 0.0001–0.04). No significant differences between protocols were observed for the IGF-1 or testosterone response. Intramuscular anabolic signaling analysis revealed a significantly greater (P = 0.03) phosphorylation of IGF-1 receptor at 1H following HV compared to HI. Phosphorylation status of all other signaling proteins including mTOR, p70S6k, and RPS6 were not significantly different between trials. Despite significant differences in markers of muscle damage and the endocrine response following HV and HI, both protocols appeared to elicit similar mTORC1 activation in resistance-trained men. PMID:26197935

  18. The beneficial effects of strength exercise on hippocampal cell proliferation and apoptotic signaling is impaired by anabolic androgenic steroids.

    PubMed

    Novaes Gomes, Fabiano Guimarães; Fernandes, Jansen; Vannucci Campos, Diego; Cassilhas, Ricardo Cardoso; Viana, Gustavo Monteiro; D'Almeida, Vânia; de Moraes Rêgo, Marta Karavisch; Buainain, Pedro Ivo; Cavalheiro, Esper Abrão; Arida, Ricardo Mario

    2014-12-01

    Previous studies have shown that strength exercise improves memory and increases expression of a myriad of proteins involved on neuronal survival and synaptic plasticity in the hippocampus. Conversely, chronic exposure to supraphysiological levels of anabolic androgenic steroids (AAS) can induce psychiatric abnormalities, cognitive deficits, impair neurotransmission, alter the levels of neurotrophic factors, decrease cell proliferation and neurogenesis, and enhance neuronal cell death. In the present study, we investigated the effects of the AAS nandrolone decanoate (ND) administration during a strength exercise program on cell proliferation, apoptotic status and brain-derived neurotrophic factor (BDNF) expression in the rat hippocampus. Adult male Wistar rats were subjected to 4 weeks of progressive strength exercise in a vertical ladder apparatus with or without daily doses (5.0 mg/kg, SC) of ND. Immunohistochemistry analysis revealed that strength exercise increased significantly the number of Ki-67-positive cells (a cell proliferation marker) in dentate gyrus (DG) of hippocampus. However, this effect was abrogated when strength exercise was combined with ND. Although western blot analysis of whole hippocampus showed no significant differences in Bax and Bcl-2 protein expression among groups, the immunoreactivity of the pro-apoptotic protein Bax was significantly increased in DG, CA1 and CA3 hippocampal subfields of sedentary rats treated with ND. Moreover, the increase in the immunoreactivity of anti-apoptotic protein Bcl-2 (DG and CA3) induced by strength exercise was diminished by ND. There were no significant differences in BDNF expression among experimental groups. Therefore, the present findings suggest that the beneficial effects of strength exercise on hippocampal cell proliferation and apoptotic signaling are impaired by ND.

  19. Anabolic and Catabolic Signaling Pathways in mouse Longissimus Dorsi after 30-day BION-M1 Spaceflight and Subsequent Recovery

    NASA Astrophysics Data System (ADS)

    Mirzoev, Timur; Blottner, Dieter; Shenkman, Boris; Lomonosova, Yulia; Vilchinskaya, Natalia; Nemirovskaya, Tatiana; Salanova, Michele

    The aim of the study was to analyze some of the key markers regulating anabolic and catabolic processes in mouse m. longissimus dorsi, an important back muscle system for trunk stabilization, following 30-day spaceflight and 8-day recovery period. C57/black mice were divided into 3 groups: 1) Vivarium Control (n=7), 2) Flight (n=5), 3) Recovery (n=5). The experiment was carried out in accordance with the rules of biomedical ethics certified by the Russian Academy of Sciences Committee on Bioethics. Using Western-blotting analysis we determined the content of IRS-1, p-AMPK, MURF-1 and eEF2 in m. longissimus dorsi. The content of IRS-1 in mice m. longissimus dorsi after the 30-day flight did not differ from the control group, however, in the Recovery group IRS-1 level was 80% higher (p<0.05) as compared to Control. Phospho-AMPK content remained unchanged. In the Recovery group there was an increase of eEF2 by 75% compared to the Control (p<0.05). After spaceflight MuRF-1 content was increased more than 2 times compared to the control animals. Thus, our findings showed that the work of the IRS-1 - dependent signaling pathway is only active in the recovery period. The content of the ubiquitin-ligase MURF-1 that takes parts in degrading myosin heavy chain was increased after the spaceflight, however, after 8-day recovery period MURF-1 level did not exceed the control indicating normalization of protein degradation in m. longissimus dorsi. The work was supported by the program of basic research of RAS and Federal Space Program of Russia for the period of 2006-2015.

  20. Rapid signalling in distinct dopaminergic axons during locomotion and reward.

    PubMed

    Howe, M W; Dombeck, D A

    2016-07-28

    Dopaminergic projection axons from the midbrain to the striatum are crucial for motor control, as their degeneration in Parkinson disease results in profound movement deficits. Paradoxically, most recording methods report rapid phasic dopamine signalling (~100-ms bursts) in response to unpredicted rewards, with little evidence for movement-related signalling. The leading model posits that phasic signalling in striatum-targeting dopamine neurons drives reward-based learning, whereas slow variations in firing (tens of seconds to minutes) in these same neurons bias animals towards or away from movement. However, current methods have provided little evidence to support or refute this model. Here, using new optical recording methods, we report the discovery of rapid phasic signalling in striatum-targeting dopaminergic axons that is associated with, and capable of triggering, locomotion in mice. Axons expressing these signals were largely distinct from those that responded to unexpected rewards. These results suggest that dopaminergic neuromodulation can differentially impact motor control and reward learning with sub-second precision, and indicate that both precise signal timing and neuronal subtype are important parameters to consider in the treatment of dopamine-related disorders. PMID:27398617

  1. Rapid signalling in distinct dopaminergic axons during locomotion and reward.

    PubMed

    Howe, M W; Dombeck, D A

    2016-07-28

    Dopaminergic projection axons from the midbrain to the striatum are crucial for motor control, as their degeneration in Parkinson disease results in profound movement deficits. Paradoxically, most recording methods report rapid phasic dopamine signalling (~100-ms bursts) in response to unpredicted rewards, with little evidence for movement-related signalling. The leading model posits that phasic signalling in striatum-targeting dopamine neurons drives reward-based learning, whereas slow variations in firing (tens of seconds to minutes) in these same neurons bias animals towards or away from movement. However, current methods have provided little evidence to support or refute this model. Here, using new optical recording methods, we report the discovery of rapid phasic signalling in striatum-targeting dopaminergic axons that is associated with, and capable of triggering, locomotion in mice. Axons expressing these signals were largely distinct from those that responded to unexpected rewards. These results suggest that dopaminergic neuromodulation can differentially impact motor control and reward learning with sub-second precision, and indicate that both precise signal timing and neuronal subtype are important parameters to consider in the treatment of dopamine-related disorders.

  2. Distinct signals generate repeating striped pattern in the embryonic parasegment.

    PubMed

    Hatini, V; DiNardo, S

    2001-01-01

    How repeating striped patterns arise across cellular fields is unclear. To address this we examined the repeating pattern of Stripe (Sr) expression across the parasegment (PS) in Drosophila. This pattern is generated in two steps. First, the ligands Hedgehog (Hh) and Wingless (Wg) subdivide the PS into smaller territories. Second, the ligands Hh, Spitz (Spi), and Wg each emanate from a specific territory and induce Sr expression in an adjacent territory. We also show that the width of Sr expression is determined by signaling strength. Finally, an enhancer trap in the sr gene detects the response to Spi and Wg, but not to Hh, implying the existence of separable control elements in the sr gene. Thus, a distinct inductive event is used to initiate each element of the repeating striped pattern.

  3. Constitutive and ligand-induced EGFR signaling triggers distinct and mutually exclusive downstream signaling networks

    PubMed Central

    Chakraborty, Sharmistha; Li, Li; Puliyappadamba, VineshkumarThidil; Guo, Gao; Hatanpaa, Kimmo J.; Mickey, Bruce; Souza, Rhonda F.; Vo, Peggy; Herz, Joachim; Chen, Mei-Ru; Boothman, David A.; Pandita, Tej K.; Wang, David H.; Sen, Ganes C.; Habib, Amyn A.

    2014-01-01

    EGFR overexpression plays an important oncogenic role in cancer. Regular EGFR protein levels are increased in cancer cells and the receptor then becomes constitutively active. However, downstream signals generated by constitutively activated EGFR are unknown. Here we report that the overexpressed EGFR oscillates between two distinct and mutually exclusive modes of signaling. Constitutive or non-canonical EGFR signaling activates the transcription factor IRF3 leading to expression of IFI27, IFIT1, and TRAIL. Ligand-mediated activation of EGFR switches off IRF3 dependent transcription, activates canonical ERK and Akt signals, and confers sensitivity to chemotherapy and virus-induced cell death. Mechanistically, the distinct downstream signals result from a switch of EGFR associated proteins. EGFR constitutively complexes with IRF3 and TBK1 leading to TBK1 and IRF3 phosphorylation. Addition of EGF dissociates TBK1, IRF3, and EGFR leading to a loss of IRF3 activity, Shc-EGFR association and ERK activation. Finally, we provide evidence for non-canonical EGFR signaling in glioblastoma. PMID:25503978

  4. Distinct signaling of Drosophila chemoreceptors in olfactory sensory neurons.

    PubMed

    Cao, Li-Hui; Jing, Bi-Yang; Yang, Dong; Zeng, Xiankun; Shen, Ying; Tu, Yuhai; Luo, Dong-Gen

    2016-02-16

    In Drosophila, olfactory sensory neurons (OSNs) rely primarily on two types of chemoreceptors, odorant receptors (Ors) and ionotropic receptors (Irs), to convert odor stimuli into neural activity. The cellular signaling of these receptors in their native OSNs remains unclear because of the difficulty of obtaining intracellular recordings from Drosophila OSNs. Here, we developed an antennal preparation that enabled the first recordings (to our knowledge) from targeted Drosophila OSNs through a patch-clamp technique. We found that brief odor pulses triggered graded inward receptor currents with distinct response kinetics and current-voltage relationships between Or- and Ir-driven responses. When stimulated with long-step odors, the receptor current of Ir-expressing OSNs did not adapt. In contrast, Or-expressing OSNs showed a strong Ca(2+)-dependent adaptation. The adaptation-induced changes in odor sensitivity obeyed the Weber-Fechner relation; however, surprisingly, the incremental sensitivity was reduced at low odor backgrounds but increased at high odor backgrounds. Our model for odor adaptation revealed two opposing effects of adaptation, desensitization and prevention of saturation, in dynamically adjusting odor sensitivity and extending the sensory operating range.

  5. Distinct signaling of Drosophila chemoreceptors in olfactory sensory neurons

    PubMed Central

    Cao, Li-Hui; Jing, Bi-Yang; Yang, Dong; Zeng, Xiankun; Shen, Ying; Tu, Yuhai; Luo, Dong-Gen

    2016-01-01

    In Drosophila, olfactory sensory neurons (OSNs) rely primarily on two types of chemoreceptors, odorant receptors (Ors) and ionotropic receptors (Irs), to convert odor stimuli into neural activity. The cellular signaling of these receptors in their native OSNs remains unclear because of the difficulty of obtaining intracellular recordings from Drosophila OSNs. Here, we developed an antennal preparation that enabled the first recordings (to our knowledge) from targeted Drosophila OSNs through a patch-clamp technique. We found that brief odor pulses triggered graded inward receptor currents with distinct response kinetics and current–voltage relationships between Or- and Ir-driven responses. When stimulated with long-step odors, the receptor current of Ir-expressing OSNs did not adapt. In contrast, Or-expressing OSNs showed a strong Ca2+-dependent adaptation. The adaptation-induced changes in odor sensitivity obeyed the Weber–Fechner relation; however, surprisingly, the incremental sensitivity was reduced at low odor backgrounds but increased at high odor backgrounds. Our model for odor adaptation revealed two opposing effects of adaptation, desensitization and prevention of saturation, in dynamically adjusting odor sensitivity and extending the sensory operating range. PMID:26831094

  6. Distinct roles of PTCH2 splice variants in Hedgehog signalling.

    PubMed Central

    Rahnama, Fahimeh; Toftgård, Rune; Zaphiropoulos, Peter G

    2004-01-01

    The human PTCH2 gene is highly similar to PTCH1, a tumour suppressor gene frequently mutated in basal cell carcinoma and several other tumour types. PTCH1 is a transmembrane protein believed to inhibit another transmembrane protein SMO (Smoothened), which mediates HH (Hedgehog) signalling. In this study, we analysed the biological properties of several PTCH2 splice variants. An mRNA form that lacked the last exon was abundantly expressed in all tissues examined, in contrast with the one that included it. Moreover, a transcript lacking exon 9, which is a part of a conserved sterol-sensing domain, was identified in intestine, prostate and cerebellum. In ovary, spleen, testis, cerebellum and skin, an mRNA lacking both exons 9 and 10 could also be observed. The different PTCH2 isoforms localized in the cytoplasm were capable of internalizing the N-terminal fragment of Sonic HH (Shh-N). Additionally, the PTCH2 gene was found to be a target of HH signalling. PTCH2 promoter regulation assays demonstrated that only one of the PTCH2 variants could inhibit the activity of SHH-N, whereas none was capable of inhibiting the activated form of SMO (SMO-M2) and this contrasts with PTCH1. Despite the fact that the PTCH2 isoforms lacked the ability to inhibit SMO-M2 activity, all PTCH2 variants as well as PTCH1, on co-transfection with Smo, were able to change Smo localization from being largely dispersed in the cytoplasm to the juxtanuclear region. Furthermore, the PTCH2 isoforms and PTCH1 co-localized in doubly transfected cells and an interaction between them was confirmed using immunoprecipitation assays. Using Ptch1-/- mouse cells, it was shown that the PTCH2 variants and PTCH1 differentially act to reconstitute not only the SHH but also the Desert HH-dependent transcriptional response. We conclude that in spite of their structural similarities, the PTCH2 isoforms have distinct functional properties when compared with PTCH1. PMID:14613484

  7. [Pharmacology of bone anabolic agents].

    PubMed

    Matsumoto, Toshio

    2015-10-01

    Bone is constantly remodeled to maintain its volume, structural integrity and strength Currently available bone anabolic agent is teriparatide. Teriparatide increases bone mass and strength via both remodeling-dependent and -independent mechanisms, although remodeling-dependent mechanism overweighs the other. Canonical Wnt signal plays an important role in enhancing osteoblast differentiation and bone formation, and its osteocyte-derived inhibitor, sclerostin, regulates bone formation via the regulation of Wnt signaling. Anti-sclerostin antibody stimulates Wnt signaling and enhances bone formation. Phase II clinical trials with anti-sclerostin antibodies, romosozumab and blosozumab, demonstrated a marked increase in bone mineral density after one year of treatment. The new modality of anabolic agents via remodeling-independent stimulation of bone formation may open up a new avenue for the treatment of osteoporosis.

  8. Cooperative unfolding of distinctive mechanoreceptor domains transduces force into signals

    PubMed Central

    Ju, Lining; Chen, Yunfeng; Xue, Lingzhou; Du, Xiaoping; Zhu, Cheng

    2016-01-01

    How cells sense their mechanical environment and transduce forces into biochemical signals is a crucial yet unresolved question in mechanobiology. Platelets use receptor glycoprotein Ib (GPIb), specifically its α subunit (GPIbα), to signal as they tether and translocate on von Willebrand factor (VWF) of injured arterial surfaces against blood flow. Force elicits catch bonds to slow VWF–GPIbα dissociation and unfolds the GPIbα leucine-rich repeat domain (LRRD) and juxtamembrane mechanosensitive domain (MSD). How these mechanical processes trigger biochemical signals remains unknown. Here we analyze these extracellular events and the resulting intracellular Ca2+ on a single platelet in real time, revealing that LRRD unfolding intensifies Ca2+ signal whereas MSD unfolding affects the type of Ca2+ signal. Therefore, LRRD and MSD are analog and digital force transducers, respectively. The >30 nm macroglycopeptide separating the two domains transmits force on the VWF–GPIbα bond (whose lifetime is prolonged by LRRD unfolding) to the MSD to enhance its unfolding, resulting in unfolding cooperativity at an optimal force. These elements may provide design principles for a generic mechanosensory protein machine. DOI: http://dx.doi.org/10.7554/eLife.15447.001 PMID:27434669

  9. [Anabolic steroids and sports].

    PubMed

    Kopera, H

    1986-09-30

    Anabolic steroids are derivatives of androgens with less androgenic and stronger anabolic actions. They should be used for therapeutic indications only. Their misuse to improve physical performance is unethical (doping), illegal and of doubtful pharmacological value. Together with intense muscular exercise and high-protein diet, anabolics due to their anabolic and anti-catabolic actions possibly increase physical performance and enhance recovery in athletes where added strength is a great advantage. In most sport disciplines a beneficial effect has not been demonstrated. Like all active drugs, anabolics can cause side-effects. They depend on structure, dosage and duration of administration. The misuse by athletes of high doses during long periods should be a particular motivation for doctors, teachers and coaches to discourage athletes from using anabolic drugs. The dangers of overdosing and long-term use are emphasized, search for untoward side- and after- effects by regular and careful controls is recommended.

  10. Mind Over Matter: Anabolic Steroids

    MedlinePlus

    ... Term(s): Teachers / NIDA Teaching Guide / Mind Over Matter Teaching Guide and Series / Anabolic Steroids Print Mind Over Matter: Anabolic Steroids Order Free Publication in: English Spanish Download PDF 830.69 KB Anabolic steroids are ...

  11. Two distinct phases of calcium signalling under flow

    PubMed Central

    Liu, Bo; Lu, Shaoying; Zheng, Shuai; Jiang, Zonglai; Wang, Yingxiao

    2011-01-01

    Aims High shear stress (HSS) can have significant impact on angiogenesis and atherosclerosis in collateral arteries near the bifurcation and curvature regions. Here, we investigate the spatiotemporal pattern of HSS-induced intracellular calcium alteration. Methods and results Genetically encoded biosensors based on fluorescence resonance energy transfer were targeted in the cytoplasm and the endoplasmic reticulum (ER) to visualize the subcellular calcium dynamics in bovine aortic endothelial cells under HSS (65 dyn/cm2). Upon HSS application, the intracellular Ca2+ concentration ([Ca2+]i) increased immediately and maintained a sustained high level, while the ER-stored calcium had a significant decrease only after 300 s. The perturbation of calcium influx across the plasma membrane (PM) by the removal of extracellular calcium or the blockage of membrane channels inhibited the early phase of [Ca2+]i increase upon HSS application, which was further shown to be sensitive to the magnitudes of shear stress and the integrity of cytoskeletal support. In contrast, Src, phospholipase C(PLC), and the inositol 1,4,5-trisphosphate receptor (IP3R) can regulate the late phase of HSS-induced [Ca2+]i increase via the promotion of the ER calcium efflux. Conclusion The HSS-induced [Ca2+]i increase consists of two well-co-ordinated phases with different sources and mechanisms: (i) an early phase due to the calcium influx across the PM which is dependent on the mechanical impact and cytoskeletal support and (ii) a late phase originated from the ER-calcium efflux which is regulated by the Src, PLC, and IP3R signalling pathway. Therefore, our work presented new molecular-level insights into systematic understanding of mechanotransduction in cardiovascular systems. PMID:21285296

  12. Anabolic steroid abuse.

    PubMed

    Landry, G L; Primos, W A

    1990-01-01

    Anabolic steroids are capable of increasing strength and muscle bulk in certain individuals when combined with a proper diet and an intense training program. Any steroid that is anabolic is also androgenic. Anabolic steroids are fraught with numerous side effects, a few of which are potentially life threatening, and some of which are permanent. Most of the side effects are mild and reversible. Use of anabolic steroids in sports is as much a moral issue as a medical one. Drug testing has not been a very successful means to eradicate abuse in the sporting arena. Education alone is probably not the answer to stopping anabolic steroid abuse but is an essential first step in combating this problem. Use of anabolic steroids in athletes is a form of cheating, and use will likely continue, especially if the rewards for success in sports remain so high. Physicians should avoid condemning individuals who choose to use anabolic steroids and encourage discussion of use with their health providers.

  13. Finding novel distinctions between the sAPPα-mediated anabolic biochemical pathways in Autism Spectrum Disorder and Fragile X Syndrome plasma and brain tissue

    PubMed Central

    Ray, Balmiki; Sokol, Deborah K.; Maloney, Bryan; Lahiri, Debomoy K.

    2016-01-01

    Autism spectrum disorder (ASD) and Fragile X syndrome (FXS) are developmental disorders. No validated blood-based biomarkers exist for either, which impedes bench-to-bedside approaches. Amyloid-β (Aβ) precursor protein (APP) and metabolites are usually associated with Alzheimer’s disease (AD). APP cleavage by α-secretase produces potentially neurotrophic secreted APPα (sAPPα) and the P3 peptide fragment. β-site APP cleaving enzyme (BACE1) cleavage produces secreted APPβ (sAPPβ) and intact Aβ. Excess Aβ is potentially neurotoxic and can lead to atrophy of brain regions such as amygdala in AD. By contrast, amygdala is enlarged in ASD but not FXS. We previously reported elevated levels of sAPPα in ASD and FXS vs. controls. We now report elevated plasma Aβ and total APP levels in FXS compared to both ASD and typically developing controls, and elevated levels of sAPPα in ASD and FXS vs. controls. By contrast, plasma and brain sAPPβ and Aβ were lower in ASD vs. controls but elevated in FXS plasma vs. controls. We also detected age-dependent increase in an α-secretase in ASD brains. We report a novel mechanistic difference in APP pathways between ASD (processing) and FXS (expression) leading to distinct APP metabolite profiles in these two disorders. These novel, distinctive biochemical differences between ASD and FXS pave the way for blood-based biomarkers for ASD and FXS. PMID:27212113

  14. Anabolic signaling and protein deposition are enhanced by intermittent compared with continuous feeding in skeletal muscle of neonates

    PubMed Central

    El-Kadi, Samer W.; Suryawan, Agus; Gazzaneo, Maria C.; Srivastava, Neeraj; Orellana, Renán A.; Nguyen, Hanh V.; Lobley, Gerald E.

    2012-01-01

    Orogastric tube feeding is indicated for neonates with impaired ability to ingest and can be administered by intermittent bolus or continuous schedule. Our aim was to determine whether feeding modalities affect muscle protein deposition and to identify mechanisms involved. Neonatal pigs were overnight fasted (FAS) or fed the same amount of food continuously (CON) or intermittently (INT; 7 × 4 h meals) for 29 h. For 8 h, between hours 20 and 28, pigs were infused with [2H5]phenylalanine and [2H2]tyrosine, and amino acid (AA) net balances were measured across the hindquarters. Insulin, branched-chain AA, phenylalanine, and tyrosine arterial concentrations and whole body phenylalanine and tyrosine fluxes were greater for INT after the meal than for CON or FAS. The activation of signaling proteins leading to initiation of mRNA translation, including eukaryotic initiation factor (eIF)4E·eIF4G complex formation in muscle, was enhanced by INT compared with CON feeding or FAS. Signaling proteins of protein degradation were not affected by feeding modalities except for microtubule-associated protein light chain 3-II, which was highest in the FAS. Across the hindquarters, AA net removal increased for INT but not for CON or FAS, with protein deposition greater for INT. This was because protein synthesis increased following feeding for INT but remained unchanged for CON and FAS, whereas there was no change in protein degradation across any dietary treatment. These results suggest that muscle protein accretion in neonates is enhanced with intermittent bolus to a greater extent than continuous feeding, mainly by increased protein synthesis. PMID:22215651

  15. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training

    PubMed Central

    Roberts, Llion A; Raastad, Truls; Markworth, James F; Figueiredo, Vandre C; Egner, Ingrid M; Shield, Anthony; Cameron-Smith, David; Coombes, Jeff S; Peake, Jonathan M

    2015-01-01

    two treatments on hypertrophy signalling pathways and satellite cell activity in skeletal muscle after acute strength exercise. Cold water immersion attenuated long term gains in muscle mass and strength. It also blunted the activation of key proteins and satellite cells in skeletal muscle up to 2 days after strength exercise. Individuals who use strength training to improve athletic performance, recover from injury or maintain their health should therefore reconsider whether to use cold water immersion as an adjuvant to their training. PMID:26174323

  16. Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways.

    PubMed

    Narayanan, Ramesh; Coss, Christopher C; Yepuru, Muralimohan; Kearbey, Jeffrey D; Miller, Duane D; Dalton, James T

    2008-11-01

    Androgen receptor (AR) ligands are important for the development and function of several tissues and organs. However, the poor oral bioavailability, pharmacokinetic properties, and receptor cross-reactivity of testosterone, coupled with side effects, place limits on its clinical use. Selective AR modulators (SARMs) elicit anabolic effects in muscle and bone, sparing reproductive organs like the prostate. However, molecular mechanisms underlying the tissue selectivity remain ambiguous. We performed a variety of in vitro studies to compare and define the molecular mechanisms of an aryl propionamide SARM, S-22, as compared with dihydrotestosterone (DHT). Studies indicated that S-22 increased levator ani muscle weight but decreased the size of prostate in rats. Analysis of the upstream intracellular signaling events indicated that S-22 and DHT mediated their actions through distinct pathways. Modulation of these pathways altered the recruitment of AR and its cofactors to the PSA enhancer in a ligand-dependent fashion. In addition, S-22 induced Xenopus laevis oocyte maturation and rapid phosphorylation of several kinases, through pathways distinct from steroids. These studies reveal novel differences in the molecular mechanisms by which S-22, a nonsteroidal SARM, and DHT mediate their pharmacological effects.

  17. Distinct palisade tissue development processes promoted by leaf autonomous signalling and long-distance signalling in Arabidopsis thaliana.

    PubMed

    Munekage, Yuri Nakajima; Inoue, Shio; Yoneda, Yuki; Yokota, Akiho

    2015-06-01

    Plants develop palisade tissue consisting of cylindrical mesophyll cells located at the adaxial side of leaves in response to high light. To understand high light signalling in palisade tissue development, we investigated leaf autonomous and long-distance signal responses of palisade tissue development using Arabidopsis thaliana. Illumination of a developing leaf with high light induced cell height elongation, whereas illumination of mature leaves with high light increased cell density and suppressed cell width expansion in palisade tissue of new leaves. Examination using phototropin1 phototropin2 showed that blue light signalling mediated by phototropins was involved in cell height elongation of the leaf autonomous response rather than the cell density increase induced by long-distance signalling. Hydrogen peroxide treatment induced cylindrical palisade tissue cell formation in both a leaf autonomous and long-distance manner, suggesting involvement of oxidative signals. Although constitutive expression of transcription factors involved in systemic-acquired acclimation to excess light, ZAT10 and ZAT12, induced cylindrical palisade tissue cell formation, knockout of these genes did not affect cylindrical palisade tissue cell formation. We conclude that two distinct signalling pathways - leaf autonomous signalling mostly dependent on blue light signalling and long-distance signalling from mature leaves that sense high light and oxidative stress - control palisade tissue development in A. thaliana.

  18. Distinct phases of Wnt/β-catenin signaling direct cardiomyocyte formation in zebrafish

    PubMed Central

    Dohn, Tracy E.; Waxman, Joshua S.

    2011-01-01

    Normal heart formation requires reiterative phases of canonical Wnt/β-catenin (Wnt) signaling. Understanding the mechanisms by which Wnt signaling directs cardiomyocyte (CM) formation in vivo is critical to being able to precisely direct differentiated CMs from stem cells in vitro. Here, we investigate the roles of Wnt signaling in zebrafish CM formation using heat-shock inducible transgenes that increase and decrease Wnt signaling. We find that there are three phases during which CM formation is sensitive to modulation of Wnt signaling through the first 24 hours of development. In addition to the previously recognized roles for Wnt signaling during mesoderm specification and in the pre-cardiac mesoderm, we find a previously unrecognized role during CM differentiation where Wnt signaling is necessary and sufficient to promote the differentiation of additional atrial cells. We also extend the previous studies of the roles of Wnt signaling during mesoderm specification and in pre-cardiac mesoderm. Importantly, in pre-cardiac mesoderm we define a new mechanism where Wnt signaling is sufficient to prevent CM differentiation, in contrast to a proposed role in inhibiting cardiac progenitor (CP) specification. The inability of the CPs to differentiate appears to lead to cell death through a p53/Caspase-3 independent mechanism. Together with a report for an even later role for Wnt signaling in restricting proliferation of differentiated ventricular CMs, our results indicate that during the first 3 days of development in zebrafish there are four distinct phases during which CMs are sensitive to Wnt signaling. PMID:22094017

  19. Abstract and Effector-Selective Decision Signals Exhibit Qualitatively Distinct Dynamics before Delayed Perceptual Reports

    PubMed Central

    Twomey, Deirdre M.; Kelly, Simon P.

    2016-01-01

    Electrophysiological research has isolated neural signatures of decision formation in a variety of brain regions. Studies in rodents and monkeys have focused primarily on effector-selective signals that translate the emerging decision into a specific motor plan, but, more recently, research on the human brain has identified an abstract signature of evidence accumulation that does not appear to play any direct role in action preparation. The functional dissociations between these distinct signal types have only begun to be characterized, and their dynamics during decisions with deferred actions with or without foreknowledge of stimulus-effector mapping, a commonly studied task scenario in single-unit and functional imaging investigations, have not been established. Here we traced the dynamics of distinct abstract and effector-selective decision signals in the form of the broad-band centro-parietal positivity (CPP) and limb-selective β-band (8–16 and 18–30 Hz) EEG activity, respectively, during delayed-reported motion direction decisions with and without foreknowledge of direction-response mapping. With foreknowledge, the CPP and β-band signals exhibited a similar gradual build-up following evidence onset, but whereas choice-predictive β-band activity persisted up until the delayed response, the CPP dropped toward baseline after peaking. Without foreknowledge, the CPP exhibited identical dynamics, whereas choice-selective β-band activity was eliminated. These findings highlight qualitative functional distinctions between effector-selective and abstract decision signals and are of relevance to the assumptions founding functional neuroimaging investigations of decision-making. SIGNIFICANCE STATEMENT Neural signatures of evidence accumulation have been isolated in numerous brain regions. Although animal neurophysiology has largely concentrated on effector-selective decision signals that translate the emerging decision into a specific motor plan, recent research

  20. Distinct dopamine neurons mediate reward signals for short- and long-term memories.

    PubMed

    Yamagata, Nobuhiro; Ichinose, Toshiharu; Aso, Yoshinori; Plaçais, Pierre-Yves; Friedrich, Anja B; Sima, Richard J; Preat, Thomas; Rubin, Gerald M; Tanimoto, Hiromu

    2015-01-13

    Drosophila melanogaster can acquire a stable appetitive olfactory memory when the presentation of a sugar reward and an odor are paired. However, the neuronal mechanisms by which a single training induces long-term memory are poorly understood. Here we show that two distinct subsets of dopamine neurons in the fly brain signal reward for short-term (STM) and long-term memories (LTM). One subset induces memory that decays within several hours, whereas the other induces memory that gradually develops after training. They convey reward signals to spatially segregated synaptic domains of the mushroom body (MB), a potential site for convergence. Furthermore, we identified a single type of dopamine neuron that conveys the reward signal to restricted subdomains of the mushroom body lobes and induces long-term memory. Constant appetitive memory retention after a single training session thus comprises two memory components triggered by distinct dopamine neurons.

  1. Distinct dopamine neurons mediate reward signals for short- and long-term memories

    PubMed Central

    Yamagata, Nobuhiro; Ichinose, Toshiharu; Aso, Yoshinori; Plaçais, Pierre-Yves; Friedrich, Anja B.; Sima, Richard J.; Preat, Thomas; Rubin, Gerald M.; Tanimoto, Hiromu

    2015-01-01

    Drosophila melanogaster can acquire a stable appetitive olfactory memory when the presentation of a sugar reward and an odor are paired. However, the neuronal mechanisms by which a single training induces long-term memory are poorly understood. Here we show that two distinct subsets of dopamine neurons in the fly brain signal reward for short-term (STM) and long-term memories (LTM). One subset induces memory that decays within several hours, whereas the other induces memory that gradually develops after training. They convey reward signals to spatially segregated synaptic domains of the mushroom body (MB), a potential site for convergence. Furthermore, we identified a single type of dopamine neuron that conveys the reward signal to restricted subdomains of the mushroom body lobes and induces long-term memory. Constant appetitive memory retention after a single training session thus comprises two memory components triggered by distinct dopamine neurons. PMID:25548178

  2. Distinct dopamine neurons mediate reward signals for short- and long-term memories.

    PubMed

    Yamagata, Nobuhiro; Ichinose, Toshiharu; Aso, Yoshinori; Plaçais, Pierre-Yves; Friedrich, Anja B; Sima, Richard J; Preat, Thomas; Rubin, Gerald M; Tanimoto, Hiromu

    2015-01-13

    Drosophila melanogaster can acquire a stable appetitive olfactory memory when the presentation of a sugar reward and an odor are paired. However, the neuronal mechanisms by which a single training induces long-term memory are poorly understood. Here we show that two distinct subsets of dopamine neurons in the fly brain signal reward for short-term (STM) and long-term memories (LTM). One subset induces memory that decays within several hours, whereas the other induces memory that gradually develops after training. They convey reward signals to spatially segregated synaptic domains of the mushroom body (MB), a potential site for convergence. Furthermore, we identified a single type of dopamine neuron that conveys the reward signal to restricted subdomains of the mushroom body lobes and induces long-term memory. Constant appetitive memory retention after a single training session thus comprises two memory components triggered by distinct dopamine neurons. PMID:25548178

  3. Pharmacology of anabolic steroids.

    PubMed

    Kicman, A T

    2008-06-01

    Athletes and bodybuilders have recognized for several decades that the use of anabolic steroids can promote muscle growth and strength but it is only relatively recently that these agents are being revisited for clinical purposes. Anabolic steroids are being considered for the treatment of cachexia associated with chronic disease states, and to address loss of muscle mass in the elderly, but nevertheless their efficacy still needs to be demonstrated in terms of improved physical function and quality of life. In sport, these agents are performance enhancers, this being particularly apparent in women, although there is a high risk of virilization despite the favourable myotrophic-androgenic dissociation that many xenobiotic steroids confer. Modulation of androgen receptor expression appears to be key to partial dissociation, with consideration of both intracellular steroid metabolism and the topology of the bound androgen receptor interacting with co-activators. An anticatabolic effect, by interfering with glucocorticoid receptor expression, remains an attractive hypothesis. Behavioural changes by non-genomic and genomic pathways probably help motivate training. Anabolic steroids continue to be the most common adverse finding in sport and, although apparently rare, designer steroids have been synthesized in an attempt to circumvent the dope test. Doping with anabolic steroids can result in damage to health, as recorded meticulously in the former German Democratic Republic. Even so, it is important not to exaggerate the medical risks associated with their administration for sporting or bodybuilding purposes but to emphasize to users that an attitude of personal invulnerability to their adverse effects is certainly misguided.

  4. Stat5 signaling specifies basal versus stress erythropoietic responses through distinct binary and graded dynamic modalities.

    PubMed

    Porpiglia, Ermelinda; Hidalgo, Daniel; Koulnis, Miroslav; Tzafriri, Abraham R; Socolovsky, Merav

    2012-08-01

    Erythropoietin (Epo)-induced Stat5 phosphorylation (p-Stat5) is essential for both basal erythropoiesis and for its acceleration during hypoxic stress. A key challenge lies in understanding how Stat5 signaling elicits distinct functions during basal and stress erythropoiesis. Here we asked whether these distinct functions might be specified by the dynamic behavior of the Stat5 signal. We used flow cytometry to analyze Stat5 phosphorylation dynamics in primary erythropoietic tissue in vivo and in vitro, identifying two signaling modalities. In later (basophilic) erythroblasts, Epo stimulation triggers a low intensity but decisive, binary (digital) p-Stat5 signal. In early erythroblasts the binary signal is superseded by a high-intensity graded (analog) p-Stat5 response. We elucidated the biological functions of binary and graded Stat5 signaling using the EpoR-HM mice, which express a "knocked-in" EpoR mutant lacking cytoplasmic phosphotyrosines. Strikingly, EpoR-HM mice are restricted to the binary signaling mode, which rescues these mice from fatal perinatal anemia by promoting binary survival decisions in erythroblasts. However, the absence of the graded p-Stat5 response in the EpoR-HM mice prevents them from accelerating red cell production in response to stress, including a failure to upregulate the transferrin receptor, which we show is a novel stress target. We found that Stat5 protein levels decline with erythroblast differentiation, governing the transition from high-intensity graded signaling in early erythroblasts to low-intensity binary signaling in later erythroblasts. Thus, using exogenous Stat5, we converted later erythroblasts into high-intensity graded signal transducers capable of eliciting a downstream stress response. Unlike the Stat5 protein, EpoR expression in erythroblasts does not limit the Stat5 signaling response, a non-Michaelian paradigm with therapeutic implications in myeloproliferative disease. Our findings show how the binary and

  5. Signaling profiling at the single-cell level identifies a distinct signaling signature in murine hematopoietic stem cells

    PubMed Central

    Du, Juan; Wang, Jinyong; Kong, Guangyao; Jiang, Jing; Zhang, Jingfang; Liu, Yangang; Tong, Wei; Zhang, Jing

    2012-01-01

    Hematopoietic stem cell (HSC) function is tightly regulated by cytokine signaling. Although phospho-flow cytometry allows us to study signaling in defined populations of cells, there has been tremendous hurdle to carry out this study in rare HSCs due to unrecoverable critical HSC markers, low HSC number, and poor cell recovery rate. Here, we overcame these difficulties and developed a “HSC phospho-flow” method to analyze cytokine signaling in murine HSCs at the single-cell level and compare HSC signaling profile to that of multipotent progenitors (MPPs), a cell type immediately downstream of HSCs, and commonly used Lin− cKit+ cells (LK cells, enriched for myeloid progenitors). We chose to study signaling evoked from three representative cytokines, stem cell factor (SCF) and thrombopoietin (TPO) that are essential for HSC function, and granulocyte macrophage-colony stimulating factor (GM-CSF) that is dispensable for HSCs. HSCs display a distinct TPO and GM-CSF signaling signature from MPPs and LK cells, which highly correlates with receptor surface expression. In contrast, although majority of LK cells express lower levels of cKit than HSCs and MPPs, SCF-evoked ERK1/2 activation in LK cells shows a significantly increased magnitude for a prolonged period. These results suggest that specific cellular context plays a more important role than receptor surface expression in SCF signaling. Our study of HSC signaling at the homeostasis stage paves the way to investigate signaling changes in HSCs under conditions of stress, aging, and hematopoietic diseases. PMID:22628264

  6. Evolution of identity signals: frequency-dependent benefits of distinctive phenotypes used for individual recognition.

    PubMed

    Sheehan, Michael J; Tibbetts, Elizabeth A

    2009-12-01

    Identifying broad-scale evolutionary processes that maintain phenotypic polymorphisms has been a major goal of modern evolutionary biology. There are numerous mechanisms, such as negative frequency-dependent selection, that may maintain polymorphisms, although it is unknown which mechanisms are prominent in nature. Traits used for individual recognition are strikingly variable and have evolved independently in numerous lineages, providing an excellent model to investigate which factors maintain ecologically relevant phenotypic polymorphisms. Theoretical models suggest that individuals may benefit by advertising their identities with distinctive, recognizable phenotypes. Here, we test the benefits of advertising one's identity with a distinctive phenotype. We manipulated the appearance of Polistes fuscatus paper wasp groups so that three individuals had the same appearance and one individual had a unique, easily recognizable appearance. We found that individuals with distinctive appearances received less aggression than individuals with nondistinctive appearances. Therefore, individuals benefit by advertising their identity with a unique phenotype. Our results provide a potential mechanism through which negative frequency-dependent selection may maintain the polymorphic identity signals in P. fuscatus. Given that recognition is important for many social interactions, selection for distinctive identity signals may be an underappreciated and widespread mechanism underlying the evolution of phenotypic polymorphisms in social taxa. PMID:19744121

  7. Signal peptides direct surface proteins to two distinct envelope locations of Staphylococcus aureus

    PubMed Central

    DeDent, Andrea; Bae, Taeok; Missiakas, Dominique M; Schneewind, Olaf

    2008-01-01

    Surface proteins of Gram-positive bacteria are covalently linked to the cell wall envelope by a mechanism requiring an N-terminal signal peptide and a C-terminal LPXTG motif sorting signal. We show here that surface proteins of Staphylococcus aureus arrive at two distinct destinations in the bacterial envelope, either distributed as a ring surrounding each cell or as discrete assembly sites. Proteins with ring-like distribution (clumping factor A (ClfA), Spa, fibronectin-binding protein B (FnbpB), serine-aspartate repeat protein C (SdrC) and SdrD) harbour signal peptides with a YSIRK/GS motif, whereas proteins directed to discrete assembly sites (S. aureus surface protein A (SasA), SasD, SasF and SasK) do not. Reciprocal exchange of signal peptides between surface proteins with (ClfA) or without the YSIRK/GS motif (SasF) directed recombinant products to the alternate destination, whereas mutations that altered only the YSIRK sequence had no effect. Our observations suggest that S. aureus distinguishes between signal peptides to address proteins to either the cell pole (signal peptides without YSIRK/GS) or the cross wall, the peptidoglycan layer that forms during cell division to separate new daughter cells (signal peptides with YISRK/GS motif). PMID:18800056

  8. Calpain inhibition induces activation of the distinct signalling pathways and cell migration in human monocytes.

    PubMed

    Noma, Haruyoshi; Kato, Takayuki; Fujita, Hisakazu; Kitagawa, Maki; Yamano, Tsunekazu; Kitagawa, Seiichi

    2009-09-01

    We have recently reported that constitutively active calpain negatively regulates activation of the distinct signalling pathways and cell migration in human neutrophils. Here, we report that a similar regulatory system is also functioning in human monocytes, but not lymphocytes. Calpain was constitutively active in resting human monocytes, but not lymphocytes. Mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), p38 and c-Jun N-terminal kinase (JNK), phosphatidylinositol 3-kinase (PI3K)/Akt and p21-activated kinase (PAK, an effector molecule of Rac) were rapidly (within 1 min) activated in monocytes, but not lymphocytes, upon exposure to calpain inhibitors (PD150606 and N-acetyl-Leu-Leu-Nle-CHO), but not PD145305 (the inactive analogue of PD150606). Following activation of these signalling pathways, monocytes displayed active migration within 5 min after exposure to calpain inhibitors, and active migration was sustained for more than 45 min. The micropipette method revealed that calpain inhibition-mediated monocyte migration was chemotaxis, not random migration. The studies with pharmacological inhibitors suggest that calpain inhibition-mediated monocyte migration is mediated by activation of ERK, p38, JNK, PI3K/Akt and Rac. NSC23766 (Rac inhibitor) and pertussis toxin (PTX) suppressed calpain inhibitor-induced phosphorylation of distinct signalling molecules (PAK, ERK, p38, JNK and Akt) as well as cell migration, suggesting that the PTX-sensitive G protein and Rac axis may be a possible key target of calpain inhibitors. These findings suggest that constitutively active calpain negatively regulates activation of the distinct signalling pathways and cell migration in resting monocytes, but not lymphocytes.

  9. Anabolic effects of PTH and the 'anabolic window'.

    PubMed

    Pazianas, Michael

    2015-03-01

    Maximization of the anabolic effects of intermittent administration of parathyroid hormone (PTH) has recently been at the forefront of clinical research in the area of osteoporosis, with the 'anabolic window' concept as its main driving force. The outcome of these attempts, however, has not been encouraging. This article examines whether the concept itself is based on sound evidence, related pathophysiological aspects, and whether the new anti-sclerostin antibodies could have extended anabolic action.

  10. Distinct G protein-coupled receptor recycling pathways allow spatial control of downstream G protein signaling.

    PubMed

    Bowman, Shanna Lynn; Shiwarski, Daniel John; Puthenveedu, Manojkumar A

    2016-09-26

    G protein-coupled receptors (GPCRs) are recycled via a sequence-dependent pathway that is spatially and biochemically distinct from bulk recycling. Why there are two distinct recycling pathways from the endosome is a fundamental question in cell biology. In this study, we show that the separation of these two pathways is essential for normal spatial encoding of GPCR signaling. The prototypical β-2 adrenergic receptor (B2AR) activates Gα stimulatory protein (Gαs) on the endosome exclusively in sequence-dependent recycling tubules marked by actin/sorting nexin/retromer tubular (ASRT) microdomains. B2AR was detected in an active conformation in bulk recycling tubules, but was unable to activate Gαs. Protein kinase A phosphorylation of B2AR increases the fraction of receptors localized to ASRT domains and biases the downstream transcriptional effects of B2AR to genes controlled by endosomal signals. Our results identify the physiological relevance of separating GPCR recycling from bulk recycling and suggest a mechanism to tune downstream responses of GPCR signaling by manipulating the spatial origin of G protein signaling. PMID:27646272

  11. Distinct spatiotemporal roles of hedgehog signalling during chick and mouse cranial base and axial skeleton development

    PubMed Central

    Balczerski, B.; Zakaria, S.; Tucker, A. S.; Borycki, A.G.; Koyama, E.; Pacifici, M.; Francis-West, P.

    2012-01-01

    The cranial base exerts a supportive role for the brain and includes the occipital, sphenoid and ethmoid bones that arise from cartilaginous precursors in the early embryo. As the occipital bone and the posterior part of the sphenoid are mesoderm derivatives that arise in close proximity to the notochord and floor plate, it has been assumed that their development, like the axial skeleton, is dependent on Sonic hedgehog (Shh) and modulation of bone morphogenetic protein (Bmp) signalling. Here we examined the development of the cranial base in chick and mouse embryos to compare the molecular signals that are required for chondrogenic induction in the trunk and head. We found that Shh signalling is required but the molecular network controlling cranial base development is distinct from that in the trunk. In the absence of Shh, the presumptive cranial base did not undergo chondrogenic commitment as determined by the loss of Sox9 expression and there was a decrease in cell survival. In contrast, induction of the otic capsule occurred normally demonstrating that induction of the cranial base is uncoupled from formation of the sensory capsules. Lastly, we found that the early cranial mesoderm is refractory to Shh signalling, likely accounting for why development of the cranial base occurs after the axial skeleton. Our data reveal that cranial and axial skeletal induction is controlled by conserved, yet spatiotemporally distinct mechanisms that co-ordinate development of the cranial base with that of the cranial musculature and the pharyngeal arches. PMID:23009899

  12. Distinct G protein-coupled receptor recycling pathways allow spatial control of downstream G protein signaling.

    PubMed

    Bowman, Shanna Lynn; Shiwarski, Daniel John; Puthenveedu, Manojkumar A

    2016-09-26

    G protein-coupled receptors (GPCRs) are recycled via a sequence-dependent pathway that is spatially and biochemically distinct from bulk recycling. Why there are two distinct recycling pathways from the endosome is a fundamental question in cell biology. In this study, we show that the separation of these two pathways is essential for normal spatial encoding of GPCR signaling. The prototypical β-2 adrenergic receptor (B2AR) activates Gα stimulatory protein (Gαs) on the endosome exclusively in sequence-dependent recycling tubules marked by actin/sorting nexin/retromer tubular (ASRT) microdomains. B2AR was detected in an active conformation in bulk recycling tubules, but was unable to activate Gαs. Protein kinase A phosphorylation of B2AR increases the fraction of receptors localized to ASRT domains and biases the downstream transcriptional effects of B2AR to genes controlled by endosomal signals. Our results identify the physiological relevance of separating GPCR recycling from bulk recycling and suggest a mechanism to tune downstream responses of GPCR signaling by manipulating the spatial origin of G protein signaling.

  13. Distinct microenvironmental cues stimulate divergent TLR4-mediated signaling pathways in macrophages.

    PubMed

    Piccinini, Anna M; Zuliani-Alvarez, Lorena; Lim, Jenny M P; Midwood, Kim S

    2016-01-01

    Macrophages exhibit a phenotypic plasticity that enables them to orchestrate specific immune responses to distinct threats. The microbial product lipopolysaccharide (LPS) and the extracellular matrix glycoprotein tenascin-C are released during bacterial infection and tissue injury, respectively, and both activate Toll-like receptor 4 (TLR4). We found that these two TLR4 ligands stimulated distinct signaling pathways in macrophages, resulting in cells with divergent phenotypes. Although macrophages activated by LPS or tenascin-C displayed some common features, including activation of nuclear factor κB and mitogen-activated protein kinase signaling and cytokine synthesis, each ligand stimulated the production of different subsets of cytokines and generated different phosphoproteomic signatures. Moreover, tenascin-C promoted the generation of macrophages that exhibited increased synthesis and phosphorylation of extracellular matrix components, whereas LPS stimulated the production of macrophages that exhibited an enhanced capacity to degrade the matrix. These data reveal how the activation of one pattern recognition receptor by different microenvironmental cues generates macrophage with distinct phenotypes. PMID:27577261

  14. Latent memory facilitates relearning through molecular signaling mechanisms that are distinct from original learning.

    PubMed

    Menges, Steven A; Riepe, Joshua R; Philips, Gary T

    2015-09-01

    A highly conserved feature of memory is that it can exist in a latent, non-expressed state which is revealed during subsequent learning by its ability to significantly facilitate (savings) or inhibit (latent inhibition) subsequent memory formation. Despite the ubiquitous nature of latent memory, the mechanistic nature of the latent memory trace and its ability to influence subsequent learning remains unclear. The model organism Aplysia californica provides the unique opportunity to make strong links between behavior and underlying cellular and molecular mechanisms. Using Aplysia, we have studied the mechanisms of savings due to latent memory for a prior, forgotten experience. We previously reported savings in the induction of three distinct temporal domains of memory: short-term (10min), intermediate-term (2h) and long-term (24h). Here we report that savings memory formation utilizes molecular signaling pathways that are distinct from original learning: whereas the induction of both original intermediate- and long-term memory in naïve animals requires mitogen activated protein kinase (MAPK) activation and ongoing protein synthesis, 2h savings memory is not disrupted by inhibitors of MAPK or protein synthesis, and 24h savings memory is not dependent on MAPK activation. Collectively, these findings reveal that during forgetting, latent memory for the original experience can facilitate relearning through molecular signaling mechanisms that are distinct from original learning. PMID:25957134

  15. Latent memory facilitates relearning through molecular signaling mechanisms that are distinct from original learning.

    PubMed

    Menges, Steven A; Riepe, Joshua R; Philips, Gary T

    2015-09-01

    A highly conserved feature of memory is that it can exist in a latent, non-expressed state which is revealed during subsequent learning by its ability to significantly facilitate (savings) or inhibit (latent inhibition) subsequent memory formation. Despite the ubiquitous nature of latent memory, the mechanistic nature of the latent memory trace and its ability to influence subsequent learning remains unclear. The model organism Aplysia californica provides the unique opportunity to make strong links between behavior and underlying cellular and molecular mechanisms. Using Aplysia, we have studied the mechanisms of savings due to latent memory for a prior, forgotten experience. We previously reported savings in the induction of three distinct temporal domains of memory: short-term (10min), intermediate-term (2h) and long-term (24h). Here we report that savings memory formation utilizes molecular signaling pathways that are distinct from original learning: whereas the induction of both original intermediate- and long-term memory in naïve animals requires mitogen activated protein kinase (MAPK) activation and ongoing protein synthesis, 2h savings memory is not disrupted by inhibitors of MAPK or protein synthesis, and 24h savings memory is not dependent on MAPK activation. Collectively, these findings reveal that during forgetting, latent memory for the original experience can facilitate relearning through molecular signaling mechanisms that are distinct from original learning.

  16. Distinct CCR7 glycosylation pattern shapes receptor signaling and endocytosis to modulate chemotactic responses.

    PubMed

    Hauser, Mark A; Kindinger, Ilona; Laufer, Julia M; Späte, Anne-Katrin; Bucher, Delia; Vanes, Sarah L; Krueger, Wolfgang A; Wittmann, Valentin; Legler, Daniel F

    2016-06-01

    The homeostatic chemokines CCL19 and CCL21 and their common cognate chemokine receptor CCR7 orchestrate immune cell trafficking by eliciting distinct signaling pathways. Here, we demonstrate that human CCR7 is N-glycosylated on 2 specific residues in the N terminus and the third extracellular loop. Conceptually, CCR7 glycosylation adds steric hindrance to the receptor N terminus and extracellular loop 3, acting as a "swinging door" to regulate receptor sensitivity and cell migration. We found that freshly isolated human B cells, as well as expanded T cells, but not naïve T cells, express highly sialylated CCR7. Moreover, we identified that human dendritic cells imprint T cell migration toward CCR7 ligands by secreting enzymes that deglycosylate CCR7, thereby boosting CCR7 signaling on T cells, permitting enhanced T cell locomotion, while simultaneously decreasing receptor endocytosis. In addition, dendritic cells proteolytically convert immobilized CCL21 to a soluble form that is more potent in triggering chemotactic movement and does not desensitize the receptor. Furthermore, we demonstrate that soluble CCL21 functionally resembles neither the CCL19 nor the CCL21 phenotype but acts as a chemokine with unique features. Thus, we advance the concept of dendritic cell-dependent generation of micromilieus and lymph node conditioning by demonstrating a novel layer of CCR7 regulation through CCR7 sialylation. In summary, we demonstrate that leukocyte subsets express distinct patterns of CCR7 sialylation that contribute to receptor signaling and fine-tuning chemotactic responses. PMID:26819318

  17. Regulation of Cell Contraction and Membrane Ruffling by Distinct Signals in Migratory Cells

    PubMed Central

    Cheresh, David A.; Leng, Jie; Klemke, Richard L.

    1999-01-01

    Cell migration and wound contraction requires assembly of actin into a functional myosin motor unit capable of generating force. However, cell migration also involves formation of actin-containing membrane ruffles. Evidence is provided that actin-myosin assembly and membrane ruffling are regulated by distinct signaling pathways in the migratory cell. Interaction of cells with extracellular matrix proteins or cytokines promote cell migration through activation of the MAP kinases ERK1 and ERK2 as well as the molecular coupling of the adaptor proteins p130CAS and c-CrkII. ERK signaling is independent of CAS/Crk coupling and regulates myosin light chain phosphorylation leading to actin-myosin assembly during cell migration and cell-mediated contraction of a collagen matrix. In contrast, membrane ruffling, but not cell contraction, requires Rac GTPase activity and the formation of a CAS/Crk complex that functions in the context of the Rac activating protein DOCK180. Thus, during cell migration ERK and CAS/Crk coupling operate as components of distinct signaling pathways that control actin assembly into myosin motors and membrane ruffles, respectively. PMID:10477763

  18. Alternative Activation Mechanisms of Protein Kinase B Trigger Distinct Downstream Signaling Responses*

    PubMed Central

    Balzano, Deborah; Fawal, Mohamad-Ali; Velázquez, Jose V.; Santiveri, Clara M.; Yang, Joshua; Pastor, Joaquín; Campos-Olivas, Ramón; Djouder, Nabil; Lietha, Daniel

    2015-01-01

    Protein kinase B (PKB/Akt) is an important mediator of signals that control various cellular processes including cell survival, growth, proliferation, and metabolism. PKB promotes these processes by phosphorylating many cellular targets, which trigger distinct downstream signaling events. However, how PKB is able to selectively target its substrates to induce specific cellular functions remains elusive. Here we perform a systematic study to dissect mechanisms that regulate intrinsic kinase activity versus mechanisms that specifically regulate activity toward specific substrates. We demonstrate that activation loop phosphorylation and the C-terminal hydrophobic motif are essential for high PKB activity in general. On the other hand, we identify membrane targeting, which for decades has been regarded as an essential step in PKB activation, as a mechanism mainly affecting substrate selectivity. Further, we show that PKB activity in cells can be triggered independently of PI3K by initial hydrophobic motif phosphorylation, presumably through a mechanism analogous to other AGC kinases. Importantly, different modes of PKB activation result in phosphorylation of distinct downstream targets. Our data indicate that specific mechanisms have evolved for signaling nodes, like PKB, to select between various downstream events. Targeting such mechanisms selectively could facilitate the development of therapeutics that might limit toxic side effects. PMID:26286748

  19. Epidermal β-catenin activation remodels the dermis via paracrine signalling to distinct fibroblast lineages.

    PubMed

    Lichtenberger, Beate M; Mastrogiannaki, Maria; Watt, Fiona M

    2016-01-01

    Sustained epidermal Wnt/β-catenin signalling expands the stem cell compartment and induces ectopic hair follicles (EFs). This is accompanied by extensive fibroblast proliferation and extracellular matrix (ECM) remodelling in the underlying dermis. Here we show that epidermal Hedgehog (Hh) and Transforming growth factor-beta (TGF-β) signalling mediate the dermal changes. Pharmacological inhibition or genetic deletion of these pathways prevents β-catenin-induced dermal reprogramming and EF formation. Epidermal Shh stimulates proliferation of the papillary fibroblast lineage, whereas TGF-β2 controls proliferation, differentiation and ECM production by reticular fibroblasts. Hh inhibitors do not affect TGF-β target gene expression in reticular fibroblasts, and TGF-β inhibition does not prevent Hh target gene induction in papillary fibroblasts. However, when Hh signalling is inhibited the reticular dermis does not respond to epidermal β-catenin activation. We conclude that the dermal response to epidermal Wnt/β-catenin signalling depends on distinct fibroblast lineages responding to different paracrine signals. PMID:26837596

  20. Leptin differentially regulates NPY secretion in hypothalamic cell lines through distinct intracellular signal transduction pathways.

    PubMed

    Dhillon, Sandeep S; Belsham, Denise D

    2011-04-11

    Leptin acts as a key peripheral hormone in distinct neurons in the hypothalamus to modulate both reproductive function and energy homeostasis. The control of neuropeptide Y (NPY) secretion is an example of a process that can be differentially regulated by leptin. In order to further understand these distinct modulatory effects, we have used immortalized, neuronal hypothalamic cell lines expressing NPY, mHypoE-38 and mHypoE-46. We found that these cell lines express the endogenous leptin receptor, ObRb, and secrete detectable levels of NPY. We exposed the neurons to 100nM leptin for 1h and determined that the basal levels of NPY in the cell lines were differentially regulated: NPY secretion was inhibited in mHypoE-46 neurons, whereas NPY secretion was induced in the mHypoE-38 neurons. In order to determine the mechanisms involved in the divergent regulation of NPY release, we analyzed the activity of a number of signaling components using phospho-specific antibodies directed towards specific proteins in the MAP kinase, PI3K, and AMPK pathways, among others. We found that leptin activated a different combination of second messengers in each cell line. Importantly, we could link the regulation of NPY secretion to different signaling pathways, AMPK in the mHypoE-46 and both MAPK and PI3K in the mHypoE-38 neurons. This is the first demonstration that leptin can specifically regulate individual NPY neuron secretory responses through distinct signaling pathways.

  1. Anabolic effect of plant brassinosteroid

    PubMed Central

    Esposito, Debora; Komarnytsky, Slavko; Shapses, Sue; Raskin, Ilya

    2011-01-01

    Brassinosteroids are plant-derived polyhydroxylated derivatives of 5a-cholestane, structurally similar to cholesterol-derived animal steroid hormones and insect ecdysteroids, with no known function in mammals. 28-Homobrassinolide (HB), a steroidal lactone with potent plant growth-promoting property, stimulated protein synthesis and inhibited protein degradation in L6 rat skeletal muscle cells (EC50 4 μM) mediated in part by PI3K/Akt signaling pathway. Oral administration of HB (20 or 60 mg/kg/d for 24 d) to healthy rats fed normal diet (protein content 23.9%) increased food intake, body weight gain, lean body mass, and gastrocnemius muscle mass as compared with vehicle-treated controls. The effect of HB administration increased slightly in animals fed a high-protein diet (protein content 39.4%). Both oral (up to 60 mg/kg) and subcutaneous (up to 4 mg/kg) administration of HB showed low androgenic activity when tested in the Hershberger assay. Moreover, HB showed no direct binding to the androgen receptor in vitro. HB treatment was also associated with an improved physical fitness of untrained healthy rats, as evident from a 6.7% increase in lower extremity strength, measured by grip test. In the gastrocnemius muscle of castrated animals, HB treatment significantly increased the number of type IIa and IIb fibers and the cross-sectional area of type I and type IIa fibers. These findings suggest that oral application of HB triggers selective anabolic response with minimal or no androgenic side-effects and begin to elucidate the putative cellular targets for plant brassinosteroids in mammals.—Esposito, D., Komarnytsky, S., Shapses, S., Raskin, I. Anabolic effect of plant brassinosteroid. PMID:21746867

  2. Distinct requirements for signal peptidase processing and function in the stable signal peptide subunit of the Junin virus envelope glycoprotein

    SciTech Connect

    York, Joanne; Nunberg, Jack H. . E-mail: jack.nunberg@umontana.edu

    2007-03-01

    The arenavirus envelope glycoprotein (GP-C) retains a cleaved and stable signal peptide (SSP) as an essential subunit of the mature complex. This 58-amino-acid residue peptide serves as a signal sequence and is additionally required to enable transit of the assembled GP-C complex to the Golgi, and for pH-dependent membrane fusion activity. We have investigated the C-terminal region of the Junin virus SSP to study the role of the cellular signal peptidase (SPase) in generating SSP. Site-directed mutagenesis at the cleavage site (positions - 1 and - 3) reveals a pattern of side-chain preferences consistent with those of SPase. Although position - 2 is degenerate for SPase cleavage, this residue in the arenavirus SSP is invariably a cysteine. In the Junin virus, this cysteine is not involved in disulfide bonding. We show that replacement with alanine or serine is tolerated for SPase cleavage but prevents the mutant SSP from associating with GP-C and enabling transport to the cell surface. Conversely, an arginine mutation at position - 1 that prevents SPase cleavage is fully compatible with GP-C-mediated membrane fusion activity when the mutant SSP is provided in trans. These results point to distinct roles of SSP sequences in SPase cleavage and GP-C biogenesis. Further studies of the unique structural organization of the GP-C complex will be important in identifying novel opportunities for antiviral intervention against arenaviral hemorrhagic disease.

  3. Two Anatomically and Computationally Distinct Learning Signals Predict Changes to Stimulus-Outcome Associations in Hippocampus

    PubMed Central

    Boorman, Erie D.; Rajendran, Vani G.; O’Reilly, Jill X.; Behrens, Tim E.

    2016-01-01

    Summary Complex cognitive processes require sophisticated local processing but also interactions between distant brain regions. It is therefore critical to be able to study distant interactions between local computations and the neural representations they act on. Here we report two anatomically and computationally distinct learning signals in lateral orbitofrontal cortex (lOFC) and the dopaminergic ventral midbrain (VM) that predict trial-by-trial changes to a basic internal model in hippocampus. To measure local computations during learning and their interaction with neural representations, we coupled computational fMRI with trial-by-trial fMRI suppression. We find that suppression in a medial temporal lobe network changes trial-by-trial in proportion to stimulus-outcome associations. During interleaved choice trials, we identify learning signals that relate to outcome type in lOFC and to reward value in VM. These intervening choice feedback signals predicted the subsequent change to hippocampal suppression, suggesting a convergence of signals that update the flexible representation of stimulus-outcome associations. PMID:26948895

  4. Two Anatomically and Computationally Distinct Learning Signals Predict Changes to Stimulus-Outcome Associations in Hippocampus.

    PubMed

    Boorman, Erie D; Rajendran, Vani G; O'Reilly, Jill X; Behrens, Tim E

    2016-03-16

    Complex cognitive processes require sophisticated local processing but also interactions between distant brain regions. It is therefore critical to be able to study distant interactions between local computations and the neural representations they act on. Here we report two anatomically and computationally distinct learning signals in lateral orbitofrontal cortex (lOFC) and the dopaminergic ventral midbrain (VM) that predict trial-by-trial changes to a basic internal model in hippocampus. To measure local computations during learning and their interaction with neural representations, we coupled computational fMRI with trial-by-trial fMRI suppression. We find that suppression in a medial temporal lobe network changes trial-by-trial in proportion to stimulus-outcome associations. During interleaved choice trials, we identify learning signals that relate to outcome type in lOFC and to reward value in VM. These intervening choice feedback signals predicted the subsequent change to hippocampal suppression, suggesting a convergence of signals that update the flexible representation of stimulus-outcome associations. PMID:26948895

  5. Nerve growth factor induces survival and differentiation through two distinct signaling cascades in PC12 cells.

    PubMed

    Klesse, L J; Meyers, K A; Marshall, C J; Parada, L F

    1999-03-25

    Nerve growth factor induces differentiation and survival of rat PC12 pheochromocytoma cells. The activation of the erk cascade has been implicated in transducing the multitude of signals induced by NGF. In order to explore the role of this signaling cascade in NGF mediated survival, differentiation and proliferation, we generated recombinant adenoviruses which express the intermediates of the erk cascade in their wild type, dominant negative and constitutively activated forms. We show that differentiation of PC12 cells requires activity of the ras/erk pathway, whereas inhibition of this pathway had no effect on survival or proliferation. Constitutively active forms of ras, raf and mek induced PC12 cell differentiation, while dominant interfering forms inhibited differentiation. Survival of PC12 cells in serum-free medium did not require activity of the ras/erk pathway. Instead, PI3 Kinase signaling was necessary for PC12 cell survival. Interestingly, constitutively activated versions of raf and mek were able to promote survival, but again this was dependent on activation of PI3 Kinase. Therefore, at least two distinct signaling pathways are required in PC12 cells for mediation of NGF functions.

  6. Distinct Signaling Mechanisms in Multiple Developmental Pathways by the SCRAMBLED Receptor of Arabidopsis1[OPEN

    PubMed Central

    Kwak, Su-Hwan; Woo, Sooah; Lee, Myeong Min; Schiefelbein, John

    2014-01-01

    SCRAMBLED (SCM), a leucine-rich repeat receptor-like kinase in Arabidopsis (Arabidopsis thaliana), is required for positional signaling in the root epidermis and for tissue/organ development in the shoot. To further understand SCM action, we generated a series of kinase domain variants and analyzed their ability to complement scm mutant defects. We found that the SCM kinase domain, but not kinase activity, is required for its role in root epidermal patterning, supporting the view that SCM is an atypical receptor kinase. We also describe a previously uncharacterized role for SCM in fruit dehiscence, because mature siliques from scm mutants fail to open properly. Interestingly, the kinase domain of SCM appears to be dispensable for this developmental process. Furthermore, we found that most of the SCM kinase domain mutations dramatically inhibit inflorescence development. Because this process is not affected in scm null mutants, it is likely that SCM acts redundantly to regulate inflorescence size. The importance of distinct kinase residues for these three developmental processes provides an explanation for the maintenance of the conserved kinase domain in the SCM protein, and it may generally explain its conservation in other atypical kinases. Furthermore, these results indicate that individual leucine-rich repeat receptor-like kinases may participate in multiple pathways using distinct signaling mechanisms to mediate diverse cellular communication events. PMID:25136062

  7. GABA Neural Signaling in the Latero-Anterior Hypothalamus Modulates Aggressive Behavior in Adolescent Anabolic/Androgenic Steroid-Treated Hamsters

    PubMed Central

    Morrison, Thomas R.; Ricci, Lesley A.; Melloni, Richard H.

    2014-01-01

    Male Syrian hamsters (Mesocricetus auratus) treated with anabolic/androgenic steroids (AAS) during adolescence (P27–P56) display highly escalated and mature forms of offensive aggression correlated with increased γ-aminobutyric acid (GABA) afferent development as well as decreased GABAA receptors in the latero-anterior hypothalamus (LAH) – an area of convergence for developmental and neuroplastic changes that underlie offensive aggressive behaviors in hamsters. This study investigated whether microinfusion of a GABAA receptor agonist (muscimol; 0.01 – 1.0 pM) or antagonist (bicuculline; 0.04 – 4.0 pM) directly into the LAH modulate adolescent AAS-induced offensive aggression. Activation of LAH GABAA receptors enhanced adolescent AAS-induced offensive aggression, beginning at the 0.1pM dose, when compared with AAS-treated animals injected with saline into the LAH. Importantly, GABAA receptor agonism within the LAH significantly increased the frequency of belly/rear attacks, while simultaneously decreasing the frequency of frontal attacks. These data identify a neuroanatomical locus where GABAA receptor activation functions to enhance aggression in adolescent AAS-treated animals, while also promoting the display of mature forms of aggression and suppressing juvenile play behaviors. PMID:25171080

  8. Anabolic Steroids...What's the Hype?...

    ERIC Educational Resources Information Center

    Landry, Gregory L.; Wagner, Lauris L.

    This pamphlet uses a question-and-answer format to examine the use and abuse of anabolic steroids. It begins by explaining that all steroids are not anabolic steroids and that anabolic steroids are those used specifically to build muscles quickly. Medical uses of anabolic steroids are reviewed; how people get steroids, how they take them, and…

  9. Neuropeptidomics Mass Spectrometry Reveals Signaling Networks Generated by Distinct Protease Pathways in Human Systems.

    PubMed

    Hook, Vivian; Bandeira, Nuno

    2015-12-01

    Neuropeptides regulate intercellular signaling as neurotransmitters of the central and peripheral nervous systems, and as peptide hormones in the endocrine system. Diverse neuropeptides of distinct primary sequences of various lengths, often with post-translational modifications, coordinate and integrate regulation of physiological functions. Mass spectrometry-based analysis of the diverse neuropeptide structures in neuropeptidomics research is necessary to define the full complement of neuropeptide signaling molecules. Human neuropeptidomics has notable importance in defining normal and dysfunctional neuropeptide signaling in human health and disease. Neuropeptidomics has great potential for expansion in translational research opportunities for defining neuropeptide mechanisms of human diseases, providing novel neuropeptide drug targets for drug discovery, and monitoring neuropeptides as biomarkers of drug responses. In consideration of the high impact of human neuropeptidomics for health, an observed gap in this discipline is the few published articles in human neuropeptidomics compared with, for example, human proteomics and related mass spectrometry disciplines. Focus on human neuropeptidomics will advance new knowledge of the complex neuropeptide signaling networks participating in the fine control of neuroendocrine systems. This commentary review article discusses several human neuropeptidomics accomplishments that illustrate the rapidly expanding diversity of neuropeptides generated by protease processing of pro-neuropeptide precursors occurring within the secretory vesicle proteome. Of particular interest is the finding that human-specific cathepsin V participates in producing enkephalin and likely other neuropeptides, indicating unique proteolytic mechanisms for generating human neuropeptides. The field of human neuropeptidomics has great promise to solve new mechanisms in disease conditions, leading to new drug targets and therapeutic agents for human

  10. Neuropeptidomics Mass Spectrometry Reveals Signaling Networks Generated by Distinct Protease Pathways in Human Systems.

    PubMed

    Hook, Vivian; Bandeira, Nuno

    2015-12-01

    Neuropeptides regulate intercellular signaling as neurotransmitters of the central and peripheral nervous systems, and as peptide hormones in the endocrine system. Diverse neuropeptides of distinct primary sequences of various lengths, often with post-translational modifications, coordinate and integrate regulation of physiological functions. Mass spectrometry-based analysis of the diverse neuropeptide structures in neuropeptidomics research is necessary to define the full complement of neuropeptide signaling molecules. Human neuropeptidomics has notable importance in defining normal and dysfunctional neuropeptide signaling in human health and disease. Neuropeptidomics has great potential for expansion in translational research opportunities for defining neuropeptide mechanisms of human diseases, providing novel neuropeptide drug targets for drug discovery, and monitoring neuropeptides as biomarkers of drug responses. In consideration of the high impact of human neuropeptidomics for health, an observed gap in this discipline is the few published articles in human neuropeptidomics compared with, for example, human proteomics and related mass spectrometry disciplines. Focus on human neuropeptidomics will advance new knowledge of the complex neuropeptide signaling networks participating in the fine control of neuroendocrine systems. This commentary review article discusses several human neuropeptidomics accomplishments that illustrate the rapidly expanding diversity of neuropeptides generated by protease processing of pro-neuropeptide precursors occurring within the secretory vesicle proteome. Of particular interest is the finding that human-specific cathepsin V participates in producing enkephalin and likely other neuropeptides, indicating unique proteolytic mechanisms for generating human neuropeptides. The field of human neuropeptidomics has great promise to solve new mechanisms in disease conditions, leading to new drug targets and therapeutic agents for human

  11. Signal Integration and Gene Induction by a Functionally Distinct STAT3 Phosphoform

    PubMed Central

    Waitkus, Matthew S.; Chandrasekharan, Unni M.; Willard, Belinda; Tee, Thomas L.; Hsieh, Jason K.; Przybycin, Christopher G.; Rini, Brian I.

    2014-01-01

    Aberrant activation of the ubiquitous transcription factor STAT3 is a major driver of solid tumor progression and pathological angiogenesis. STAT3 activity is regulated by numerous posttranslational modifications (PTMs), including Tyr705 phosphorylation, which is widely used as an indicator of canonical STAT3 function. Here, we report a noncanonical mechanism of STAT3 activation that occurs independently of Tyr705 phosphorylation. Using quantitative liquid chromatography-tandem mass spectrometry, we have discovered and characterized a novel STAT3 phosphoform that is simultaneously phosphorylated at Thr714 and Ser727 by glycogen synthase kinase 3α and -β (GSK-3α/β). Both Thr714 and Ser727 are required for STAT3-dependent gene induction in response to simultaneous activation of epidermal growth factor receptor (EGFR) and protease-activated receptor 1 (PAR-1) in endothelial cells. In this combinatorial signaling context, preventing formation of doubly phosphorylated STAT3 by depleting GSK-3α/β is sufficient to disrupt signal integration and inhibit STAT3-dependent gene expression. Levels of doubly phosphorylated STAT3 but not of Tyr705-phosphorylated STAT3 are remarkably elevated in clear-cell renal-cell carcinoma relative to adjacent normal tissue, suggesting that the GSK-3α/β–STAT3 pathway is active in the disease. Collectively, our results describe a functionally distinct, noncanonical STAT3 phosphoform that positively regulates target gene expression in a combinatorial signaling context and identify GSK-3α/β–STAT3 signaling as a potential therapeutic target in renal-cell carcinoma. PMID:24615012

  12. Neuropeptidomics Mass Spectrometry Reveals Signaling Networks Generated by Distinct Protease Pathways in Human Systems

    NASA Astrophysics Data System (ADS)

    Hook, Vivian; Bandeira, Nuno

    2015-12-01

    Neuropeptides regulate intercellular signaling as neurotransmitters of the central and peripheral nervous systems, and as peptide hormones in the endocrine system. Diverse neuropeptides of distinct primary sequences of various lengths, often with post-translational modifications, coordinate and integrate regulation of physiological functions. Mass spectrometry-based analysis of the diverse neuropeptide structures in neuropeptidomics research is necessary to define the full complement of neuropeptide signaling molecules. Human neuropeptidomics has notable importance in defining normal and dysfunctional neuropeptide signaling in human health and disease. Neuropeptidomics has great potential for expansion in translational research opportunities for defining neuropeptide mechanisms of human diseases, providing novel neuropeptide drug targets for drug discovery, and monitoring neuropeptides as biomarkers of drug responses. In consideration of the high impact of human neuropeptidomics for health, an observed gap in this discipline is the few published articles in human neuropeptidomics compared with, for example, human proteomics and related mass spectrometry disciplines. Focus on human neuropeptidomics will advance new knowledge of the complex neuropeptide signaling networks participating in the fine control of neuroendocrine systems. This commentary review article discusses several human neuropeptidomics accomplishments that illustrate the rapidly expanding diversity of neuropeptides generated by protease processing of pro-neuropeptide precursors occurring within the secretory vesicle proteome. Of particular interest is the finding that human-specific cathepsin V participates in producing enkephalin and likely other neuropeptides, indicating unique proteolytic mechanisms for generating human neuropeptides. The field of human neuropeptidomics has great promise to solve new mechanisms in disease conditions, leading to new drug targets and therapeutic agents for human

  13. CDC42 and FGD1 Cause Distinct Signaling and Transforming Activities

    PubMed Central

    Whitehead, Ian P.; Abe, Karon; Gorski, Jerome L.; Der, Channing J.

    1998-01-01

    Activated forms of different Rho family members (CDC42, Rac1, RhoA, RhoB, and RhoG) have been shown to transform NIH 3T3 cells as well as contribute to Ras transformation. Rho family guanine nucleotide exchange factors (GEFs) (also known as Dbl family proteins) that activate CDC42, Rac1, and RhoA also demonstrate oncogenic potential. The faciogenital dysplasia gene product, FGD1, is a Dbl family member that has recently been shown to function as a CDC42-specific GEF. Mutations within the FGD1 locus cosegregate with faciogenital dysplasia, a multisystemic disorder resulting in extensive growth impairments throughout the skeletal and urogenital systems. Here we demonstrate that FGD1 expression is sufficient to cause tumorigenic transformation of NIH 3T3 fibroblasts. Although both FGD1 and constitutively activated CDC42 cooperated with Raf and showed synergistic focus-forming activity, both quantitative and qualitative differences in their functions were seen. FGD1 and CDC42 also activated common nuclear signaling pathways. However, whereas both showed comparable activation of c-Jun, CDC42 showed stronger activation of serum response factor and FGD1 was consistently a better activator of Elk-1. Although coexpression of FGD1 with specific inhibitors of CDC42 function demonstrated the dependence of FGD1 signaling activity on CDC42 function, FGD1 signaling activities were not always consistent with the direct or exclusive stimulation of CDC42 function. In summary, FGD1 and CDC42 signaling and transformation are distinct, thus suggesting that FGD1 may be mediating some of its biological activities through non-CDC42 targets. PMID:9671479

  14. MAP kinases with distinct inhibitory functions impart signaling specificity during yeast differentiation.

    PubMed

    Madhani, H D; Styles, C A; Fink, G R

    1997-11-28

    Filamentous invasive growth of S. cerevisiae requires multiple elements of the mitogen-activated protein kinase (MAPK) signaling cascade that are also components of the mating pheromone response pathway. Here we show that, despite sharing several constituents, the two pathways use different MAP kinases. The Fus3 MAPK regulates mating, whereas the Kss1 MAPK regulates filamentation and invasion. Remarkably, in addition to their kinase-dependent activation functions, Kss1 and Fus3 each have a distinct kinase-independent inhibitory function. Kss1 inhibits the filamentation pathway by interacting with its target transcription factor Ste12. Fus3 has a different inhibitory activity that prevents the inappropriate activation of invasion by the pheromone response pathway. In the absence of Fus3, there is erroneous crosstalk in which mating pheromone now activates filamentation-specific gene expression using the Kss1 MAPK. PMID:9393860

  15. Rac-1 and Raf-1 kinases, components of distinct signaling pathways, activate myotonic dystrophy protein kinase

    NASA Technical Reports Server (NTRS)

    Shimizu, M.; Wang, W.; Walch, E. T.; Dunne, P. W.; Epstein, H. F.

    2000-01-01

    Myotonic dystrophy protein kinase (DMPK) is a serine-threonine protein kinase encoded by the myotonic dystrophy (DM) locus on human chromosome 19q13.3. It is a close relative of other kinases that interact with members of the Rho family of small GTPases. We show here that the actin cytoskeleton-linked GTPase Rac-1 binds to DMPK, and coexpression of Rac-1 and DMPK activates its transphosphorylation activity in a GTP-sensitive manner. DMPK can also bind Raf-1 kinase, the Ras-activated molecule of the MAP kinase pathway. Purified Raf-1 kinase phosphorylates and activates DMPK. The interaction of DMPK with these distinct signals suggests that it may play a role as a nexus for cross-talk between their respective pathways and may partially explain the remarkable pleiotropy of DM.

  16. Effects of Chronic Exposure to an Anabolic Androgenic Steroid Cocktail on α5-Receptor Mediated GABAergic Transmission and Neural Signaling in the Forebrain of Female Mice

    PubMed Central

    Penatti, Carlos A. A.; Costine, Beth A.; Porter, Donna M.; Henderson, Leslie P.

    2009-01-01

    Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone that are illicitly self-administered for enhancement of performance and body image, but which also have significant effects on the brain and on behavior. While the stereotypical AAS user is an adult male, AAS abuse in women is rapidly increasing, yet few studies have examined AAS effects in female subjects. We have assessed the effects in female mice of a combination of commonly abused AAS on neuronal activity and neurotransmission mediated by γ-aminobutyric acid type A (GABAA) receptors in the medial preoptic nucleus (MPN); a nexus in the circuits of the hypothalamus and forebrain that are critical for the expression of social behaviors known to be altered in AAS abuse. Our data indicate that chronic exposure to AAS resulted in androgen receptor (AR)-dependent upregulation of α5, β3 and δ subunit mRNA. Acute application of the α5 subunit-selective inverse agonist, L-655,708, indicated that a significant fraction of the synaptic current is carried by α5-containing receptors and that AAS treatment may enhance expression of α5-containing receptors contributing to synaptic, but not tonic, currents in the MPN. AAS treatment also resulted in a significant decrease in action potential frequency in MPN neurons that was also correlated with an increased sensitivity to L655,708. Our data demonstrate that chronic exposure to multiple AAS elicits significant changes in GABAergic transmission and neuronal activity that are likely to reflect changes in the expression of α5-containing synaptic receptors within the MPN. PMID:19324077

  17. Differing semaphorin 3A concentrations trigger distinct signaling mechanisms in growth cone collapse.

    PubMed

    Manns, Richard P C; Cook, Geoffrey M W; Holt, Christine E; Keynes, Roger J

    2012-06-20

    Semaphorin-3A (Sema3A) is a major guidance cue in the developing nervous system. Previous studies have revealed a dependence of responses to Sema3A on local protein synthesis (PS) in axonal growth cones, but a recent study has called this dependence into question. To understand the basis of this discrepancy we used the growth cone collapse assay on chick dorsal root ganglion neurons. We show that the dependence of growth cone collapse on protein synthesis varies according to Sema3A concentration, from near-total at low concentration (<100 ng/ml) to minimal at high concentration (>625 ng/ml). Further, we show that neuropilin-1 (NP-1) mediates both PS-dependent and PS-independent collapse. Our findings are consistent with the operation of at least two distinct Sema3A signaling pathways: one that is PS-dependent, involving mammalian target of rapamycin, and one that is PS-independent, involving GSK-3β activation and operative at all concentrations of Sema3A examined. The results provide a plausible explanation for the discrepancy in PS-dependence reported in the literature, and indicate that different signaling pathways activated within growth cones can be modulated by changing the concentration of the same guidance cue.

  18. A Large Bioactive BMP Ligand with Distinct Signaling Properties Is Produced by Alternative Proconvertase Processing

    PubMed Central

    Akiyama, Takuya; Marqués, Guillermo; Wharton, Kristi A.

    2013-01-01

    Dimers of conventional transforming growth factor–β (TGF-β) and bone morphogenetic protein (BMP) ligands are composed of two 100– to 140–amino acid peptides that are produced through the proteolytic processing of a proprotein precursor by proconvertases, such as furin. We report the identification of an evolutionarily conserved furin processing site in the amino terminus (NS) of the Glass bottom boat (Gbb; the Drosophila ortholog of vertebrate BMP5, 6, and 7) proprotein that generates a 328–amino acid, active BMP ligand distinct from the conventional 130–amino acid ligand. Gbb38, the large ligand form of Gbb, exhibited greater signaling activity and a longer range than the shorter form Gbb15. The abundance of Gbb15 and Gbb38 varied among different tissues, raising the possibility that differential processing could account for tissue-specific behaviors of BMPs. In human populations, mutations that abolished the NS cleavage site in BMP4, BMP15, or anti-Müllerian hormone were associated with cleft lip with or without cleft palate (BMP4), premature ovarian failure (BMP15), and persistent Müllerian duct syndrome (anti-Müllerian hormone), suggesting the importance of NS processing during development. The identification of this large BMP ligand form and the functional differences between large and small ligands exemplifies the potential for differential proprotein processing to substantially affect BMP and TGF-β signaling output in different tissue and cellular contexts. PMID:22472650

  19. Nonpolarized signaling reveals two distinct modes of 3D cell migration.

    PubMed

    Petrie, Ryan J; Gavara, Núria; Chadwick, Richard S; Yamada, Kenneth M

    2012-04-30

    We search in this paper for context-specific modes of three-dimensional (3D) cell migration using imaging for phosphatidylinositol (3,4,5)-trisphosphate (PIP3) and active Rac1 and Cdc42 in primary fibroblasts migrating within different 3D environments. In 3D collagen, PIP3 and active Rac1 and Cdc42 were targeted to the leading edge, consistent with lamellipodia-based migration. In contrast, elongated cells migrating inside dermal explants and the cell-derived matrix (CDM) formed blunt, cylindrical protrusions, termed lobopodia, and Rac1, Cdc42, and PIP3 signaling was nonpolarized. Reducing RhoA, Rho-associated protein kinase (ROCK), or myosin II activity switched the cells to lamellipodia-based 3D migration. These modes of 3D migration were regulated by matrix physical properties. Specifically, experimentally modifying the elasticity of the CDM or collagen gels established that nonlinear elasticity supported lamellipodia-based migration, whereas linear elasticity switched cells to lobopodia-based migration. Thus, the relative polarization of intracellular signaling identifies two distinct modes of 3D cell migration governed intrinsically by RhoA, ROCK, and myosin II and extrinsically by the elastic behavior of the 3D extracellular matrix.

  20. Differing Semaphorin 3A concentrations trigger distinct signaling mechanisms in growth cone collapse

    PubMed Central

    Manns, Richard P.C.; Cook, Geoffrey M.W.; Holt, Christine E.; Keynes, Roger J.

    2012-01-01

    Semaphorin-3A (Sema3A) is a major guidance cue in the developing nervous system. Previous studies have revealed a dependence of responses to Sema3A on local protein synthesis (PS) in axonal growth cones, but a recent study has called this dependence into question. To understand the basis of this discrepancy we used the growth cone collapse assay on chick dorsal root ganglion (DRG) neurons. We show that the dependence of growth cone collapse on protein synthesis varies according to Sema3A concentration, from near-total at low concentration (<100ng/ml) to minimal at high concentration (>625ng/ml). Further, we show that neuropilin-1 (NP-1) mediates both PS-dependent and PS–independent collapse. Our findings are consistent with the operation of at least two distinct Sema3A signaling pathways: one that is PS-dependent, involving mammalian target of rapamycin (mTOR), and one that is PS-independent, involving GSK-3β activation and operative at all concentrations of Sema3A examined. The results provide a plausible explanation for the discrepancy in PS-dependence reported in the literature, and indicate that different signaling pathways activated within growth cones can be modulated by changing the concentration of the same guidance cue. PMID:22723695

  1. Nuclear localization signals for four distinct karyopherin-β nuclear import systems.

    PubMed

    Soniat, Michael; Chook, Yuh Min

    2015-06-15

    The Karyopherin-β family of proteins mediates nuclear transport of macromolecules. Nuclear versus cytoplasmic localization of proteins is often suggested by the presence of NLSs (nuclear localization signals) or NESs (nuclear export signals). Import-Karyopherin-βs or Importins bind to NLSs in their protein cargos to transport them through nuclear pore complexes into the nucleus. Until recently, only two classes of NLS had been biochemically and structurally characterized: the classical NLS, which is recognized by the Importin-α/β heterodimer and the PY-NLS (proline-tyrosine NLS), which is recognized by Karyopherin-β2 or Transportin-1. Structures of two other Karyopherin-βs, Kap121 and Transportin-SR2, in complex with their respective cargos were reported for the first time recently, revealing two new distinct classes of NLSs. The present paper briefly describes the classical NLS, reviews recent literature on the PY-NLS and provides in-depth reviews of the two newly discovered classes of NLSs that bind Kap121p and Transportin-SR respectively.

  2. Nonpolarized signaling reveals two distinct modes of 3D cell migration

    PubMed Central

    Gavara, Núria; Chadwick, Richard S.

    2012-01-01

    We search in this paper for context-specific modes of three-dimensional (3D) cell migration using imaging for phosphatidylinositol (3,4,5)-trisphosphate (PIP3) and active Rac1 and Cdc42 in primary fibroblasts migrating within different 3D environments. In 3D collagen, PIP3 and active Rac1 and Cdc42 were targeted to the leading edge, consistent with lamellipodia-based migration. In contrast, elongated cells migrating inside dermal explants and the cell-derived matrix (CDM) formed blunt, cylindrical protrusions, termed lobopodia, and Rac1, Cdc42, and PIP3 signaling was nonpolarized. Reducing RhoA, Rho-associated protein kinase (ROCK), or myosin II activity switched the cells to lamellipodia-based 3D migration. These modes of 3D migration were regulated by matrix physical properties. Specifically, experimentally modifying the elasticity of the CDM or collagen gels established that nonlinear elasticity supported lamellipodia-based migration, whereas linear elasticity switched cells to lobopodia-based migration. Thus, the relative polarization of intracellular signaling identifies two distinct modes of 3D cell migration governed intrinsically by RhoA, ROCK, and myosin II and extrinsically by the elastic behavior of the 3D extracellular matrix. PMID:22547408

  3. A Distinct Layer of the Medulla Integrates Sky Compass Signals in the Brain of an Insect

    PubMed Central

    el Jundi, Basil; Pfeiffer, Keram; Homberg, Uwe

    2011-01-01

    Mass migration of desert locusts is a common phenomenon in North Africa and the Middle East but how these insects navigate is still poorly understood. Laboratory studies suggest that locusts are able to exploit the sky polarization pattern as a navigational cue. Like other insects locusts detect polarized light through a specialized dorsal rim area (DRA) of the eye. Polarization signals are transmitted through the optic lobe to the anterior optic tubercle (AOTu) and, finally, to the central complex in the brain. Whereas neurons of the AOTu integrate sky polarization and chromatic cues in a daytime dependent manner, the central complex holds a topographic representation of azimuthal directions suggesting a role as an internal sky compass. To understand further the integration of sky compass cues we studied polarization-sensitive (POL) neurons in the medulla that may be intercalated between DRA photoreceptors and AOTu neurons. Five types of POL-neuron were characterized and four of these in multiple recordings. All neurons had wide arborizations in medulla layer 4 and most, additionally, in the dorsal rim area of the medulla and in the accessory medulla, the presumed circadian clock. The neurons showed type-specific orientational tuning to zenithal polarized light and azimuth tuning to unpolarized green and UV light spots. In contrast to neurons of the AOTu, we found no evidence for color opponency and daytime dependent adjustment of sky compass signals. Therefore, medulla layer 4 is a distinct stage in the integration of sky compass signals that precedes the time-compensated integration of celestial cues in the AOTu. PMID:22114712

  4. Anabolic steroids and growth hormone.

    PubMed

    Haupt, H A

    1993-01-01

    Athletes are generally well educated regarding substances that they may use as ergogenic aids. This includes anabolic steroids and growth hormone. Fortunately, the abuse of growth hormone is limited by its cost and the fact that anabolic steroids are simply more enticing to the athlete. There are, however, significant potential adverse effects regarding its use that can be best understood by studying known growth hormone excess, as demonstrated in the acromegalic syndrome. Many athletes are unfamiliar with this syndrome and education of the potential consequences of growth hormone excess is important in counseling athletes considering its use. While athletes contemplating the use of anabolic steroids may correctly perceive their risks for significant physiologic effects to be small if they use the steroids for brief periods of time, many of these same athletes are unaware of the potential for habituation to the use of anabolic steroids. The result may be incessant use of steroids by an athlete who previously considered only short-term use. As we see athletes taking anabolic steroids for more prolonged periods, we are likely to see more severe medical consequences. Those who eventually do discontinue the steroids are dismayed to find that the improvements made with the steroids generally disappear and they have little to show for hours or even years of intense training beyond the psychological scars inherent with steroid use. Counseling of these athletes should focus on the potential adverse psychological consequences of anabolic steroid use and the significant risk for habituation.

  5. Distinct Forms of Mitochondrial TOM-TIM Supercomplexes Define Signal-Dependent States of Preprotein Sorting▿

    PubMed Central

    Chacinska, Agnieszka; van der Laan, Martin; Mehnert, Carola S.; Guiard, Bernard; Mick, David U.; Hutu, Dana P.; Truscott, Kaye N.; Wiedemann, Nils; Meisinger, Chris; Pfanner, Nikolaus; Rehling, Peter

    2010-01-01

    Mitochondrial import of cleavable preproteins occurs at translocation contact sites, where the translocase of the outer membrane (TOM) associates with the presequence translocase of the inner membrane (TIM23) in a supercomplex. Different views exist on the mechanism of how TIM23 mediates preprotein sorting to either the matrix or inner membrane. On the one hand, two TIM23 forms were proposed, a matrix transport form containing the presequence translocase-associated motor (PAM; TIM23-PAM) and a sorting form containing Tim21 (TIM23SORT). On the other hand, it was reported that TIM23 and PAM are permanently associated in a single-entity translocase. We have accumulated distinct transport intermediates of preproteins to analyze the translocases in their active, preprotein-carrying state. We identified two different forms of active TOM-TIM23 supercomplexes, TOM-TIM23SORT and TOM-TIM23-PAM. These two supercomplexes do not represent separate pathways but are in dynamic exchange during preprotein translocation and sorting. Depending on the signals of the preproteins, switches between the different forms of supercomplex and TIM23 are required for the completion of preprotein import. PMID:19884344

  6. Galectin-3-induced cell spreading and motility relies on distinct signaling mechanisms compared to fibronectin.

    PubMed

    More, Shyam K; Chiplunkar, Shubhada V; Kalraiya, Rajiv D

    2016-05-01

    Secreted galectin-3 often gets incorporated into extracellular matrix and is utilized by cancer cells for spreading, movement, and metastatic dissemination. Here we investigate molecular mechanisms by which galectin-3 brings about these effects and compare it with fibronectin. Imaging of cells spread on fibronectin showed stress fibers throughout cell body, however, galectin-3-induced formation of parallel actin bundles in the lamellipodial region resulting in unique morphological features. FRAP analysis showed that the actin turnover in the lamellipodial region was much higher in cells spread on galectin-3 as compared to that on fibronectin. Rac1 activation is correlated with lamellipodial organization on both the substrates. Activation of Akt and Rac1, the regulators of actin dynamics, show inverse correlation with each other on both galectin-3 and fibronectin. Activation of Erk however, remained similar. Further, inhibition of activation of Akt and Erk inhibited spreading and motility of cells on galectin-3 but not on fibronectin. The results very comprehensively demonstrate distinct signaling pathways that regulate microfilament organization, lamellipodial structures, spreading, and movement of cells plated on galectin-3 as opposed to fibronectin.

  7. Distinct roles of neuropilin 1 signaling for radial and tangential extension of callosal axons.

    PubMed

    Hatanaka, Yumiko; Matsumoto, Tomoko; Yanagawa, Yuchio; Fujisawa, Hajime; Murakami, Fujio; Masu, Masayuki

    2009-05-20

    Cortical excitatory neurons migrate from their origin in the ventricular zone (VZ) toward the pial surface. During migration, these neurons exhibit a stellate shape in the intermediate zone (IZ), transform into bipolar cells, and then initiate radial migration, extending a trailing process, which may lead to an axon. Here we examined the role of neuropilin 1 (NRP1) in these developmental events. Both NRP1 mRNA and protein were highly expressed in the IZ, where stellate-shaped cells were located. DiI labeling experiments showed that neuronal migration occurred normally in Nrp1 mutant mice up to embryonic day (E) 14.5, the latest day to which the mutant survives, with only subtle axonal defasciculation. However, interference with Nrp1 signaling at a later stage caused pathfinding errors: when a dominant negative form of Nrp1 was electroporated into the cortical VZ cells at E12.5 or E15.5 and examined perinatally, guidance errors were found in tangential axonal extension toward the midline. In contrast, no significant effect was noted on the migration of cortical excitatory neurons. These findings indicate that NRP1 plays an important role in the guidance of callosal axons originating from cortical excitatory neurons but does not support a role in their migration. Moreover, insofar as radial axonal extension within the cortical plate was unaffected, the present findings imply that molecular mechanisms for the axonal extension of excitatory neurons within the cortical plate are distinct from those in the white matter. PMID:19296474

  8. [Anabolic steroids in athletes].

    PubMed

    Yesalis, C E; Wright, J E; Lombardo, J A

    1992-01-01

    The use of anabolic-androgenic steroids (AS) to enhance appearance as well as physical/physiological capacities has increased dramatically over the past four decades in all age groups from early adolescence to adulthood. Although higher AS use rates are reported by elite and competitive athletes, a significant number of recreational athletes appear to be using AS. The scientific literature is inconsistent and at times at odds with the conventional wisdom and empirical experiences of the athletic community regarding the ergogenic effects of AS. However, individuals experienced in weight training, with an adequate diet, and who continue training during AS administration seem to consistently increase their strength and lean mass over what would have been expected from training alone. Previous research documenting deleterious but transient and mostly asymptomatic acute changes in physiology, risk factors and behavior has been inconclusive regarding the long term health impact. The abuse of AS constitutes a special challenge to society. AS are not euphorigenic or mood altering immediately following administration, as are other illicit drugs; the appetite for AS has been created predominantly by our societal fixations on winning and physical appearance. Consequently any successful intervention in this area must go beyond education, law enforcement and drug testing, and attempt to change a social environment which currently encourages the use of AS.

  9. Prolonged in vivo administration of testosterone-enanthate, the widely used and abused anabolic androgenic steroid, disturbs prolactin and cAMP signaling in Leydig cells of adult rats.

    PubMed

    Bjelic, Maja M; Stojkov, Natasa J; Radovic, Sava M; Baburski, Aleksandar Z; Janjic, Marija M; Kostic, Tatjana S; Andric, Silvana A

    2015-05-01

    This study was designed to systematically analyze and define the effects of 1-day, 2-weeks, 10-weeks intramuscular administration of testosterone-enanthate, widely used and abused anabolic androgenic steroid (AAS), on main regulators of steroidogenesis and steroidogenic genes expression in testosterone-producing Leydig cells of adult rats. The results showed that prolonged (10-weeks) intramuscular administration of testosterone-enanthate, in clinically relevant dose, significantly increased prolactin, but decreased Prlr2 and Gnrhr in pituitary of adult rat. The levels of testosterone, Insl3, cAMP and mitochondrial membrane potential of Leydig cells were significantly reduced. This was followed by decreased expression of some steroidogenic enzymes and regulatory proteins such as Lhcgr, Prlr1/2, Tspo, Star, Cyp11a1, Cyp17a1, Dax1. Oppositely, Hsd3b1/2, Hsd3b5, Hsd17b4, Ar, Arr19 increased. In the same cells, transcriptional milieu of cAMP signaling elements was disturbed with remarkable up-regulation of PRKA (the main regulator of steroidogenesis). Increased prolactin together with stimulated transcription of Jak2/Jak3 could account for increased Hsd3b1/2 and Hsd3b5 in Leydig cells following 10-weeks in vivo treatment with testosterone-enanthate. In vitro studies revealed that testosterone is capable to increase level of Prlr1, Prlr2, Hsd3b1/2, Hsd3b5 in Leydig cells. Accordingly, testosterone-induced changes in prolactin receptor signaling together with up-regulation of PRKA, Hsd3b1/2, Hsd3b5, Ar in Leydig cells, could be the possible mechanism that contribute to the establishment of a new adaptive response to maintain homeostasis and prevent loss of steroidogenic function. Presented data provide new molecular insights into the relationship between disturbed testosterone homeostasis and mammalian reproduction and are important in terms of wide use and abuse of AASs and human reproductive health.

  10. Signal recognition particle receptor is a complex that contains two distinct polypeptide chains

    SciTech Connect

    Tajima, S.; Lauffer, L.; Rath, V.L.; Walter, P.

    1986-10-01

    Signal recognition particle (SRP) and SRP receptor are known to be essential components of the cellular machinery that targets nascent secretory proteins to the endoplasmic reticulum (ER) membrane. Here the authors report that the SRP receptor contains, in addition to the previously identified and sequenced 69-kD polypeptide (..cap alpha..-subunit, SR..cap alpha..), a 30-kD ..beta..-subunit SR..beta..). When SRP receptor was purified by SRP-Sepharose affinity chromatography, they observed the co-purification of two other ER membrane proteins. Both proteins are approx.30 kD in size and are immunologically distinct from each other, as well as from SR..cap alpha.. and SRP proteins. One of the 30-kD proteins (SR..beta..) forms a tight complex with SR..cap alpha.. in detergent solution that is stable to high salt and can be immunoprecipitated with antibodies to either SR..cap alpha.. or SR..beta... Both subunits are present in the ER membrane in equimolar amounts and co-fractionate in constant stoichiometry when rough and smooth liver microsomes are separated on sucrose gradients. They therefore conclude that SR..beta.. is an integral component of SRP receptor. The presence of SR..beta.. was previously masked by proteolytic breakdown products of SR..cap alpha.. observed by others and by the presence of another 30-kD ER membrane protein (mp30) which co-purifies with SR..cap alpha... Mp30 binds to SRP-Sepharose directly and is present in the ER membrane in several-fold molar excess of SR..cap alpha.. and SR..beta... The affinity of mp30 for SRP suggests that it may serve a yet unknown function in protein translocation.

  11. MAPK signaling cascades mediate distinct glucocorticoid resistance mechanisms in pediatric leukemia

    PubMed Central

    Jones, Courtney L.; Gearheart, Christy M.; Fosmire, Susan; Delgado-Martin, Cristina; Evensen, Nikki A.; Bride, Karen; Waanders, Angela J.; Pais, Faye; Wang, Jinhua; Bhatla, Teena; Bitterman, Danielle S.; de Rijk, Simone R.; Bourgeois, Wallace; Dandekar, Smita; Park, Eugene; Burleson, Tamara M.; Madhusoodhan, Pillai Pallavi; Teachey, David T.; Raetz, Elizabeth A.; Hermiston, Michelle L.; Müschen, Markus; Loh, Mignon L.; Hunger, Stephen P.; Zhang, Jinghui; Garabedian, Michael J.; Porter, Christopher C.

    2015-01-01

    The outcome for pediatric acute lymphoblastic leukemia (ALL) patients who relapse is dismal. A hallmark of relapsed disease is acquired resistance to multiple chemotherapeutic agents, particularly glucocorticoids. In this study, we performed a genome-scale short hairpin RNA screen to identify mediators of prednisolone sensitivity in ALL cell lines. The incorporation of these data with an integrated analysis of relapse-specific genetic and epigenetic changes allowed us to identify the mitogen-activated protein kinase (MAPK) pathway as a mediator of prednisolone resistance in pediatric ALL. We show that knockdown of the specific MAPK pathway members MEK2 and MEK4 increased sensitivity to prednisolone through distinct mechanisms. MEK4 knockdown increased sensitivity specifically to prednisolone by increasing the levels of the glucocorticoid receptor. MEK2 knockdown increased sensitivity to all chemotherapy agents tested by increasing the levels of p53. Furthermore, we demonstrate that inhibition of MEK1/2 with trametinib increased sensitivity of ALL cells and primary samples to chemotherapy in vitro and in vivo. To confirm a role for MAPK signaling in patients with relapsed ALL, we measured the activation of the MEK1/2 target ERK in matched diagnosis-relapse primary samples and observed increased phosphorylated ERK levels at relapse. Furthermore, relapse samples have an enhanced response to MEK inhibition compared to matched diagnosis samples in xenograft models. Together, our data indicate that inhibition of the MAPK pathway increases chemosensitivity to glucocorticoids and possibly other agents and that the MAPK pathway is an attractive target for prevention and/or treatment of relapsed disease. PMID:26324703

  12. MAPK signaling cascades mediate distinct glucocorticoid resistance mechanisms in pediatric leukemia.

    PubMed

    Jones, Courtney L; Gearheart, Christy M; Fosmire, Susan; Delgado-Martin, Cristina; Evensen, Nikki A; Bride, Karen; Waanders, Angela J; Pais, Faye; Wang, Jinhua; Bhatla, Teena; Bitterman, Danielle S; de Rijk, Simone R; Bourgeois, Wallace; Dandekar, Smita; Park, Eugene; Burleson, Tamara M; Madhusoodhan, Pillai Pallavi; Teachey, David T; Raetz, Elizabeth A; Hermiston, Michelle L; Müschen, Markus; Loh, Mignon L; Hunger, Stephen P; Zhang, Jinghui; Garabedian, Michael J; Porter, Christopher C; Carroll, William L

    2015-11-01

    The outcome for pediatric acute lymphoblastic leukemia (ALL) patients who relapse is dismal. A hallmark of relapsed disease is acquired resistance to multiple chemotherapeutic agents, particularly glucocorticoids. In this study, we performed a genome-scale short hairpin RNA screen to identify mediators of prednisolone sensitivity in ALL cell lines. The incorporation of these data with an integrated analysis of relapse-specific genetic and epigenetic changes allowed us to identify the mitogen-activated protein kinase (MAPK) pathway as a mediator of prednisolone resistance in pediatric ALL. We show that knockdown of the specific MAPK pathway members MEK2 and MEK4 increased sensitivity to prednisolone through distinct mechanisms. MEK4 knockdown increased sensitivity specifically to prednisolone by increasing the levels of the glucocorticoid receptor. MEK2 knockdown increased sensitivity to all chemotherapy agents tested by increasing the levels of p53. Furthermore, we demonstrate that inhibition of MEK1/2 with trametinib increased sensitivity of ALL cells and primary samples to chemotherapy in vitro and in vivo. To confirm a role for MAPK signaling in patients with relapsed ALL, we measured the activation of the MEK1/2 target ERK in matched diagnosis-relapse primary samples and observed increased phosphorylated ERK levels at relapse. Furthermore, relapse samples have an enhanced response to MEK inhibition compared to matched diagnosis samples in xenograft models. Together, our data indicate that inhibition of the MAPK pathway increases chemosensitivity to glucocorticoids and possibly other agents and that the MAPK pathway is an attractive target for prevention and/or treatment of relapsed disease.

  13. Regulation of Endothelial Cell Proliferation and Vascular Assembly through Distinct mTORC2 Signaling Pathways

    PubMed Central

    Wang, Shan; Amato, Katherine R.; Song, Wenqiang; Youngblood, Victoria; Lee, Keunwook; Boothby, Mark; Brantley-Sieders, Dana M.

    2015-01-01

    Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates a diverse array of cellular processes, including cell growth, survival, metabolism, and cytoskeleton dynamics. mTOR functions in two distinct complexes, mTORC1 and mTORC2, whose activities and substrate specificities are regulated by complex specific cofactors, including Raptor and Rictor, respectively. Little is known regarding the relative contribution of mTORC1 versus mTORC2 in vascular endothelial cells. Using mouse models of Raptor or Rictor gene targeting, we discovered that Rictor ablation inhibited vascular endothelial growth factor (VEGF)-induced endothelial cell proliferation and assembly in vitro and angiogenesis in vivo, whereas the loss of Raptor had only a modest effect on endothelial cells (ECs). Mechanistically, the loss of Rictor reduced the phosphorylation of AKT, protein kinase Cα (PKCα), and NDRG1 without affecting the mTORC1 pathway. In contrast, the loss of Raptor increased the phosphorylation of AKT despite inhibiting the phosphorylation of S6K1, a direct target of mTORC1. Reconstitution of Rictor-null cells with myristoylated AKT (Myr-AKT) rescued vascular assembly in Rictor-deficient endothelial cells, whereas PKCα rescued proliferation defects. Furthermore, tumor neovascularization in vivo was significantly decreased upon EC-specific Rictor deletion in mice. These data indicate that mTORC2 is a critical signaling node required for VEGF-mediated angiogenesis through the regulation of AKT and PKCα in vascular endothelial cells. PMID:25582201

  14. Anabolic actions of Notch on mature bone

    PubMed Central

    Liu, Peng; Ping, Yilin; Ma, Meng; Zhang, Demao; Liu, Connie; Zaidi, Samir; Gao, Song; Ji, Yaoting; Lou, Feng; Yu, Fanyuan; Lu, Ping; Stachnik, Agnes; Bai, Mingru; Wei, Chengguo; Zhang, Liaoran; Wang, Ke; Chen, Rong; New, Maria I.; Rowe, David W.; Yuen, Tony; Sun, Li; Zaidi, Mone

    2016-01-01

    Notch controls skeletogenesis, but its role in the remodeling of adult bone remains conflicting. In mature mice, the skeleton can become osteopenic or osteosclerotic depending on the time point at which Notch is activated or inactivated. Using adult EGFP reporter mice, we find that Notch expression is localized to osteocytes embedded within bone matrix. Conditional activation of Notch signaling in osteocytes triggers profound bone formation, mainly due to increased mineralization, which rescues both age-associated and ovariectomy-induced bone loss and promotes bone healing following osteotomy. In parallel, mice rendered haploinsufficient in γ-secretase presenilin-1 (Psen1), which inhibits downstream Notch activation, display almost-absent terminal osteoblast differentiation. Consistent with this finding, pharmacologic or genetic disruption of Notch or its ligand Jagged1 inhibits mineralization. We suggest that stimulation of Notch signaling in osteocytes initiates a profound, therapeutically relevant, anabolic response. PMID:27036007

  15. Effect of resistance exercise intensity on the expression of PGC-1α isoforms and the anabolic and catabolic signaling mediators, IGF-1 and myostatin, in human skeletal muscle.

    PubMed

    Schwarz, Neil A; McKinley-Barnard, Sarah K; Spillane, Mike B; Andre, Thomas L; Gann, Joshua J; Willoughby, Darryn S

    2016-08-01

    The purpose of this study was to investigate the acute messenger (mRNA) expression of the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) isoforms, insulin-like growth factor-1Ea (IGF-1Ea), and myostatin in response to 2 resistance exercise intensities. In a uniform-balanced, crossover design, 10 participants performed 2 separate testing sessions involving a lower body resistance exercise component consisting of a lower intensity (50% of 1-repetition maximum; 1RM) protocol and a higher intensity (80% of 1RM) protocol of equal volumes. Muscle samples were obtained at before exercise, 45 min, 3 h, 24 h, and 48 h postexercise. Resistance exercise did not alter total PGC-1α mRNA expression; however, distinct responses of each PGC-1α isoform were observed. The response of each isoform was consistent between sessions, suggesting no effect of resistance exercise intensity on the complex transcriptional expression of the PGC-1α gene. IGF-1Ea mRNA expression significantly increased following the higher intensity session compared with pre-exercise and the lower intensity session. Myostatin mRNA expression was significantly reduced compared with pre-exercise values at all time points with no difference between exercise intensity. Further research is needed to determine the effects of the various isoforms of PGC-1α in human skeletal muscle on the translational level as well as their relation to the expression of IGF-1 and myostatin. PMID:27467217

  16. Effect of resistance exercise intensity on the expression of PGC-1α isoforms and the anabolic and catabolic signaling mediators, IGF-1 and myostatin, in human skeletal muscle.

    PubMed

    Schwarz, Neil A; McKinley-Barnard, Sarah K; Spillane, Mike B; Andre, Thomas L; Gann, Joshua J; Willoughby, Darryn S

    2016-08-01

    The purpose of this study was to investigate the acute messenger (mRNA) expression of the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) isoforms, insulin-like growth factor-1Ea (IGF-1Ea), and myostatin in response to 2 resistance exercise intensities. In a uniform-balanced, crossover design, 10 participants performed 2 separate testing sessions involving a lower body resistance exercise component consisting of a lower intensity (50% of 1-repetition maximum; 1RM) protocol and a higher intensity (80% of 1RM) protocol of equal volumes. Muscle samples were obtained at before exercise, 45 min, 3 h, 24 h, and 48 h postexercise. Resistance exercise did not alter total PGC-1α mRNA expression; however, distinct responses of each PGC-1α isoform were observed. The response of each isoform was consistent between sessions, suggesting no effect of resistance exercise intensity on the complex transcriptional expression of the PGC-1α gene. IGF-1Ea mRNA expression significantly increased following the higher intensity session compared with pre-exercise and the lower intensity session. Myostatin mRNA expression was significantly reduced compared with pre-exercise values at all time points with no difference between exercise intensity. Further research is needed to determine the effects of the various isoforms of PGC-1α in human skeletal muscle on the translational level as well as their relation to the expression of IGF-1 and myostatin.

  17. Adverse effects of anabolic steroids in athletes.

    PubMed

    Kibble, M W; Ross, M B

    1987-09-01

    The effects of anabolic steroid use on athletic performance and the adverse effects associated with the use of anabolic steroids are reviewed. Anabolic steroids increase protein synthesis in skeletal muscles and reverse catabolic processes. Because of these properties, some athletes use anabolic steroids in an attempt to improve their athletic performance. However, studies indicate that increases in muscle mass and strength during anabolic steroid administration are observed only in athletes who already are weight-trained and who continue intensive training while maintaining high-protein, high-calorie diets. Adverse effects attributed to anabolic steroid use occur frequently. Serious adverse effects include hepatic and endocrine dysfunction; cardiovascular and behavioral changes also are reported. Some of the adverse effects associated with the use of these agents are irreversible, particularly in women. The use of anabolic steroids to improve athletic performance has become prevalent. However, the reported benefits are tempered by numerous adverse reactions.

  18. Fish oil supplementation suppresses resistance exercise and feeding-induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men.

    PubMed

    McGlory, Chris; Wardle, Sophie L; Macnaughton, Lindsay S; Witard, Oliver C; Scott, Fraser; Dick, James; Bell, J Gordon; Phillips, Stuart M; Galloway, Stuart D R; Hamilton, D Lee; Tipton, Kevin D

    2016-03-01

    Fish oil (FO) supplementation potentiates muscle protein synthesis (MPS) in response to a hyperaminoacidemic-hyperinsulinemic infusion. Whether FO supplementation potentiates MPS in response to protein ingestion or when protein ingestion is combined with resistance exercise (RE) remains unknown. In a randomized, parallel group design, 20 healthy males were randomized to receive 5 g/day of either FO or coconut oil control (CO) for 8 weeks. After supplementation, participants performed a bout of unilateral RE followed by ingestion of 30 g of whey protein. Skeletal muscle biopsies were obtained before and after supplementation for assessment of muscle lipid composition and relevant protein kinase activities. Infusion of L-[ring-(13)C6] phenylalanine was used to measure basal myofibrillar MP Sat rest (REST), in a nonexercised leg following protein ingestion (FED) and following RE and protein ingestion (FEDEX).MPS was significantly elevated above REST during FEDEX in both the FO and CO groups, but there was no effect of supplementation. There was a significant increase in MPS in both groups above REST during FED but no effect of supplementation. Supplementation significantly decreased pan PKB activity at RESTin the FO group but not the CO group. There was a significant increase from REST at post-RE for PKB and AMPKα2 activity in the CO group but not in the FO group. In FEDEX, there was a significant increase in p70S6K1 activity from REST at 3 h in the CO group only. These data highlight that 8 weeks of FO supplementation alters kinase signaling activity in response to RE plus protein ingestion without influencing MPS. PMID:27009278

  19. Fish oil supplementation suppresses resistance exercise and feeding-induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men.

    PubMed

    McGlory, Chris; Wardle, Sophie L; Macnaughton, Lindsay S; Witard, Oliver C; Scott, Fraser; Dick, James; Bell, J Gordon; Phillips, Stuart M; Galloway, Stuart D R; Hamilton, D Lee; Tipton, Kevin D

    2016-03-01

    Fish oil (FO) supplementation potentiates muscle protein synthesis (MPS) in response to a hyperaminoacidemic-hyperinsulinemic infusion. Whether FO supplementation potentiates MPS in response to protein ingestion or when protein ingestion is combined with resistance exercise (RE) remains unknown. In a randomized, parallel group design, 20 healthy males were randomized to receive 5 g/day of either FO or coconut oil control (CO) for 8 weeks. After supplementation, participants performed a bout of unilateral RE followed by ingestion of 30 g of whey protein. Skeletal muscle biopsies were obtained before and after supplementation for assessment of muscle lipid composition and relevant protein kinase activities. Infusion of L-[ring-(13)C6] phenylalanine was used to measure basal myofibrillar MP Sat rest (REST), in a nonexercised leg following protein ingestion (FED) and following RE and protein ingestion (FEDEX).MPS was significantly elevated above REST during FEDEX in both the FO and CO groups, but there was no effect of supplementation. There was a significant increase in MPS in both groups above REST during FED but no effect of supplementation. Supplementation significantly decreased pan PKB activity at RESTin the FO group but not the CO group. There was a significant increase from REST at post-RE for PKB and AMPKα2 activity in the CO group but not in the FO group. In FEDEX, there was a significant increase in p70S6K1 activity from REST at 3 h in the CO group only. These data highlight that 8 weeks of FO supplementation alters kinase signaling activity in response to RE plus protein ingestion without influencing MPS.

  20. Exercise ameliorates insulin resistance via Ca2+ signals distinct from those of insulin for GLUT4 translocation in skeletal muscles.

    PubMed

    Park, Dae-Ryoung; Park, Kwang-Hyun; Kim, Byung-Ju; Yoon, Chung-Su; Kim, Uh-Hyun

    2015-04-01

    Muscle contraction and insulin induce glucose uptake in skeletal muscle through GLUT4 membrane translocation. Beneficial effects of exercise on glucose homeostasis in insulin-resistant individuals are known to be due to their distinct mechanism between contraction and insulin action on glucose uptake in skeletal muscle. However, the underlying mechanisms are not clear. Here we show that in skeletal muscle, distinct Ca(2+) second messengers regulate GLUT4 translocation by contraction and insulin treatment; d-myo-inositol 1,4,5-trisphosphate/nicotinic acid adenine dinucleotide phosphate (NAADP) and cyclic ADP-ribose/NAADP are main players for insulin- and contraction-induced glucose uptake, respectively. Different patterns of phosphorylation of AMPK and Ca(2+)/calmodulin-dependent protein kinase II were shown in electrical stimuli (ES)- and insulin-induced glucose uptake pathways. ES-induced Ca(2+) signals and glucose uptake are dependent on glycolysis, which influences formation of NAD(P)-derived signaling messengers, whereas insulin-induced signals are not. High-fat diet (HFD) induced a defect in only insulin-mediated, but not ES-mediated, Ca(2+) signaling for glucose uptake, which is related to a specifically lower NAADP formation. Exercise decreases blood glucose levels in HFD-induced insulin resistance mice via NAADP formation. Thus we conclude that different usage of Ca(2+) signaling in contraction/insulin-stimulated glucose uptake in skeletal muscle may account for the mechanism by which exercise ameliorates glucose homeostasis in individuals with type 2 diabetes.

  1. Distinct roles for Mind bomb, Neuralized and Epsin in mediating DSL endocytosis and signaling in Drosophila.

    PubMed

    Wang, Weidong; Struhl, Gary

    2005-06-01

    Ligands of the Delta/Serrate/Lag2 (DSL) family must normally be endocytosed in signal-sending cells to activate Notch in signal-receiving cells. DSL internalization and signaling are promoted in zebrafish and Drosophila, respectively, by the ubiquitin ligases Mind bomb (Mib) and Neuralized (Neur). DSL signaling activity also depends on Epsin, a conserved endocytic adaptor thought to target mono-ubiquitinated membrane proteins for internalization. Here, we present evidence that the Drosophila ortholog of Mib (Dmib) is required for ubiquitination and signaling activity of DSL ligands in cells that normally do not express Neur, and can be functionally replaced by ectopically expressed Neur. Furthermore, we show that both Dmib and Epsin are required in these cells for some of the endocytic events that internalize DSL ligands, and that the two Drosophila DSL ligands Delta and Serrate differ in their utilization of these Dmib- and Epsin-dependent pathways: most Serrate is endocytosed via the actions of Dmib and Epsin, whereas most Delta enters by other pathways. Nevertheless, only those Serrate and Delta proteins that are internalized via the action of Dmib and Epsin can signal. These results support and extend our previous proposal that mono-ubiquitination of DSL ligands allows them to gain access to a select, Epsin-dependent, endocytic pathway that they must normally enter to activate Notch.

  2. Wnt-Fzd signaling sensitizes peripheral sensory neurons via distinct noncanonical pathways.

    PubMed

    Simonetti, Manuela; Agarwal, Nitin; Stösser, Sebastian; Bali, Kiran Kumar; Karaulanov, Emil; Kamble, Rashmi; Pospisilova, Blanka; Kurejova, Martina; Birchmeier, Walter; Niehrs, Christof; Heppenstall, Paul; Kuner, Rohini

    2014-07-01

    Wnt signaling represents a highly versatile signaling system, which plays diverse and critical roles in various aspects of neural development. Sensory neurons of the dorsal root ganglia require Wnt signaling for initial cell-fate determination as well as patterning and synapse formation. Here we report that Wnt signaling pathways persist in adult sensory neurons and play a functional role in their sensitization in a pathophysiological context. We observed that Wnt3a recruits the Wnt-calcium signaling pathway and the Wnt planar cell polarity pathway in peripheral nerves to alter pain sensitivity in a modality-specific manner and we elucidated underlying mechanisms. In contrast, biochemical, pharmacological, and genetic studies revealed lack of functional relevance for the classical canonical β-catenin pathway in peripheral sensory neurons in acute modulation of nociception. Finally, this study provides proof-of-concept for a translational potential for Wnt3a-Frizzled3 signaling in alleviating disease-related pain hypersensitivity in cancer-associated pain in vivo.

  3. Modeling distinct imaging hemodynamics early after TBI: the relationship between signal amplitude and connectivity.

    PubMed

    Medaglia, John D; McAleavey, Andrew A; Rostami, Sohayla; Slocomb, Julia; Hillary, Frank G

    2015-06-01

    Over the past decade, fMRI studies of cognitive change following traumatic brain injury (TBI) have investigated blood oxygen level dependent (BOLD) activity during working memory (WM) performance in individuals in early and chronic phases of recovery. Recently, BOLD fMRI work has largely shifted to focus on WM and resting functional connectivity following TBI. However, fundamental questions in WM remain. Specifically, the effects of injury on the basic relationships between local and interregional functional neuroimaging signals during WM processing early following moderate to severe TBI have not been examined. This study employs a mixed effects model to examine prefrontal cortex and parietal lobe signal change during a WM task, the n-back, and whether there is covariance between regions of high amplitude signal change, (synchrony of elicited activity (SEA) very early following TBI. We also examined whether signal change and SEA differentially predict performance during WM. Overall, percent signal change in the right prefrontal cortex (rPFC) was and important predictor of both reaction time (RT) and SEA in early TBI and matched controls. Right prefrontal cortex (rPFC) percent signal change positively predicted SEA within and between persons regardless of injury status, suggesting that the link between these neurodynamic processes in WM-activated regions remains unaffected even very early after TBI. Additionally, rPFC activity was positively related to RT within and between persons in both groups. Right parietal (rPAR) activity was negatively related to RT within subjects in both groups. Thus, the local signal intensity of the rPFC in TBI appears to be a critical property of network functioning and performance in WM processing and may be a precursor to recruitment observed in chronic samples. The present results suggest that as much research moves toward large scale functional connectivity modeling, it will be essential to develop integrated models of how local and

  4. Distinct requirements for TrkB and TrkC signaling in target innervation by sensory neurons

    NASA Technical Reports Server (NTRS)

    Postigo, Antonio; Calella, Anna Maria; Fritzsch, Bernd; Knipper, Marlies; Katz, David; Eilers, Andreas; Schimmang, Thomas; Lewin, Gary R.; Klein, Rudiger; Minichiello, Liliana

    2002-01-01

    Signaling by brain-derived neurotrophic factor (BDNF) via the TrkB receptor, or by neurotrophin-3 (NT3) through the TrkC receptor support distinct populations of sensory neurons. The intracellular signaling pathways activated by Trk (tyrosine kinase) receptors, which in vivo promote neuronal survival and target innervation, are not well understood. Using mice with TrkB or TrkC receptors lacking the docking site for Shc adaptors (trkB(shc/shc) and trkC(shc/shc) mice), we show that TrkB and TrkC promote survival of sensory neurons mainly through Shc site-independent pathways, suggesting that these receptors use similar pathways to prevent apoptosis. In contrast, the regulation of target innervation appears different: in trkB(shc/shc) mice neurons lose target innervation, whereas in trkC(shc/shc) mice the surviving TrkC-dependent neurons maintain target innervation and function. Biochemical analysis indicates that phosphorylation at the Shc site positively regulates autophosphorylation of TrkB, but not of TrkC. Our findings show that although TrkB and TrkC signals mediating survival are largely similar, TrkB and TrkC signals required for maintenance of target innervation in vivo are regulated by distinct mechanisms.

  5. Distinct modes of inhibition by sclerostin on bone morphogenetic protein and Wnt signaling pathways.

    PubMed

    Krause, Carola; Korchynskyi, Olexandr; de Rooij, Karien; Weidauer, Stella E; de Gorter, David J J; van Bezooijen, Rutger L; Hatsell, Sarah; Economides, Aris N; Mueller, Thomas D; Löwik, Clemens W G M; ten Dijke, Peter

    2010-12-31

    Sclerostin is expressed by osteocytes and has catabolic effects on bone. It has been shown to antagonize bone morphogenetic protein (BMP) and/or Wnt activity, although at present the underlying mechanisms are unclear. Consistent with previous findings, Sclerostin opposed direct Wnt3a-induced but not direct BMP7-induced responses when both ligand and antagonist were provided exogenously to cells. However, we found that when both proteins are expressed in the same cell, sclerostin can antagonize BMP signaling directly by inhibiting BMP7 secretion. Sclerostin interacts with both the BMP7 mature domain and pro-domain, leading to intracellular retention and proteasomal degradation of BMP7. Analysis of sclerostin knock-out mice revealed an inhibitory action of sclerostin on Wnt signaling in both osteoblasts and osteocytes in cortical and cancellous bones. BMP7 signaling was predominantly inhibited by sclerostin in osteocytes of the calcaneus and the cortical bone of the tibia. Our results suggest that sclerostin exerts its potent bone catabolic effects by antagonizing Wnt signaling in a paracrine and autocrine manner and antagonizing BMP signaling selectively in the osteocytes that synthesize simultaneously both sclerostin and BMP7 proteins.

  6. Yeast nitrogen catabolite repression is sustained by signals distinct from glutamine and glutamate reservoirs.

    PubMed

    Fayyad-Kazan, Mohammad; Feller, A; Bodo, E; Boeckstaens, M; Marini, A M; Dubois, E; Georis, I

    2016-01-01

    Nitrogen catabolite repression (NCR) is a wide transcriptional regulation program enabling baker's yeast to downregulate genes involved in the utilization of poor nitrogen sources when preferred ones are available. Nowadays, glutamine and glutamate, the major nitrogen donors for biosyntheses, are assumed to be key metabolic signals regulating NCR. NCR is controlled by the conserved TORC1 complex, which integrates nitrogen signals among others to regulate cell growth. However, accumulating evidence indicate that the TORC1-mediated control of NCR is only partial, arguing for the existence of supplementary regulatory processes to be discovered. In this work, we developed a genetic screen to search for new players involved in NCR signaling. Our data reveal that the NADP-glutamate dehydrogenase activity of Gdh1 negatively regulates NCR-sensitive gene transcription. By determining the total, cytoplasmic and vacuolar pools of amino acids, we show that there is no positive correlation between glutamine/glutamate reservoirs and the extent of NCR. While our data indicate that glutamine could serve as initial trigger of NCR, they show that it is not a sufficient signal to sustain repression and point to the existence of yet unknown signals. Providing additional evidence uncoupling TORC1 activity and NCR, our work revisits the dogmas underlying NCR regulation. PMID:26419331

  7. Distinct Phosphorylation Clusters Determine the Signaling Outcome of Free Fatty Acid Receptor 4/G Protein-Coupled Receptor 120.

    PubMed

    Prihandoko, Rudi; Alvarez-Curto, Elisa; Hudson, Brian D; Butcher, Adrian J; Ulven, Trond; Miller, Ashley M; Tobin, Andrew B; Milligan, Graeme

    2016-05-01

    It is established that long-chain free fatty acids includingω-3 fatty acids mediate an array of biologic responses through members of the free fatty acid (FFA) receptor family, which includes FFA4. However, the signaling mechanisms and modes of regulation of this receptor class remain unclear. Here, we employed mass spectrometry to determine that phosphorylation of mouse (m)FFAR4 occurs at five serine and threonine residues clustered in two separable regions of the C-terminal tail, designated cluster 1 (Thr(347), Thr(349), and Ser(350)) and cluster 2 (Ser(357)and Ser(361)). Mutation of these phosphoacceptor sites to alanine completely prevented phosphorylation of mFFA4 but did not limit receptor coupling to extracellular signal regulated protein kinase 1 and 2 (ERK1/2) activation. Rather, an inhibitor of Gq/11proteins completely prevented receptor signaling to ERK1/2. By contrast, the recruitment of arrestin 3, receptor internalization, and activation of Akt were regulated by mFFA4 phosphorylation. The analysis of mFFA4 phosphorylation-dependent signaling was extended further by selective mutations of the phosphoacceptor sites. Mutations within cluster 2 did not affect agonist activation of Akt but instead significantly compromised receptor internalization and arrestin 3 recruitment. Distinctly, mutation of the phosphoacceptor sites within cluster 1 had no effect on receptor internalization and had a less extensive effect on arrestin 3 recruitment but significantly uncoupled the receptor from Akt activation. These unique observations define differential effects on signaling mediated by phosphorylation at distinct locations. This hallmark feature supports the possibility that the signaling outcome of mFFA4 activation can be determined by the pattern of phosphorylation (phosphorylation barcode) at the C terminus of the receptor.

  8. Gremlin 2 regulates distinct roles of BMP and Endothelin 1 signaling in dorsoventral patterning of the facial skeleton

    PubMed Central

    Zuniga, Elizabeth; Rippen, Marie; Alexander, Courtney; Schilling, Thomas F.; Crump, J. Gage

    2011-01-01

    Patterning of the upper versus lower face involves generating distinct pre-skeletal identities along the dorsoventral (DV) axes of the pharyngeal arches. Whereas previous studies have shown roles for BMPs, Endothelin 1 (Edn1) and Jagged1b-Notch2 in DV patterning of the facial skeleton, how these pathways are integrated to generate different skeletal fates has remained unclear. Here, we show that BMP and Edn1 signaling have distinct roles in development of the ventral and intermediate skeletons, respectively, of the zebrafish face. Using transgenic gain-of-function approaches and cell-autonomy experiments, we find that BMPs strongly promote hand2 and msxe expression in ventral skeletal precursors, while Edn1 promotes the expression of nkx3.2 and three Dlx genes (dlx3b, dlx5a and dlx6a) in intermediate precursors. Furthermore, Edn1 and Jagged1b pattern the intermediate and dorsal facial skeletons in part by inducing the BMP antagonist Gremlin 2 (Grem2), which restricts BMP activity to the ventral-most face. We therefore propose a model in which later cross-inhibitory interactions between BMP and Edn1 signaling, in part mediated by Grem2, separate an initially homogenous ventral region into distinct ventral and intermediate skeletal precursor domains. PMID:22031546

  9. Mitogen-activated protein kinases with distinct requirements for Ste5 scaffolding influence signaling specificity in Saccharomyces cerevisiae.

    PubMed

    Flatauer, Laura J; Zadeh, Sheena F; Bardwell, Lee

    2005-03-01

    Scaffold proteins are believed to enhance specificity in cell signaling when different pathways share common components. The prototype scaffold Ste5 binds to multiple components of the Saccharomyces cerevisiae mating pheromone response pathway, thereby conducting the mating signal to the Fus3 mitogen-activated protein kinase (MAPK). Some of the kinases that Ste5 binds to, however, are also shared with other pathways. Thus, it has been presumed that Ste5 prevents its bound kinases from transgressing into other pathways and protects them from intrusions from those pathways. Here we found that Fus3MAPK required Ste5 scaffolding to receive legitimate signals from the mating pathway as well as misdirected signals leaking from other pathways. Furthermore, increasing the cellular concentration of active Ste5 enhanced the channeling of inappropriate stimuli to Fus3. This aberrant signal crossover resulted in the erroneous induction of cell cycle arrest and mating. In contrast to Fus3, the Kss1 MAPK did not require Ste5 scaffolding to receive either authentic or leaking signals. Furthermore, the Ste11 kinase, once activated via Ste5, was able to signal to Kss1 independently of Ste5 scaffolding. These results argue that Ste5 does not act as a barrier that actively prevents signal crossover to Fus3 and that Ste5 may not effectively sequester its activated kinases away from other pathways. Rather, we suggest that specificity in this network is promoted by the selective activation of Ste5 and the distinct requirements of the MAPKs for Ste5 scaffolding. PMID:15713635

  10. The cold response of CBF genes in barley is regulated by distinct signaling mechanisms.

    PubMed

    Marozsán-Tóth, Zsuzsa; Vashegyi, Ildikó; Galiba, Gábor; Tóth, Balázs

    2015-06-01

    Cold acclimation ability is crucial in the winter survival of cereals. In this process CBF transcription factors play key role, therefore understanding the regulation of these genes might provide useful knowledge for molecular breeding. In the present study the signal transduction pathways leading to the cold induction of different CBF genes were investigated in barley cv. Nure using pharmacological approach. Our results showed that the cold induced expression of CBF9 and CBF14 transcription factors is regulated by phospholipase C, phospholipase D pathways and calcium. On the contrary, these pathways have negative effect on the cold induction of CBF12 that is regulated by a different, as yet unidentified pathway. The diversity in the regulation of these transcription factors corresponds to their sequence based phylogenetic relationships suggesting that their evolutionary separation happened on structural, functional and regulational levels as well. On the CBF effector gene level, the signaling regulation is more complex, resultant effect of multiple pathways.

  11. Can flavor physics hint at distinctive signals for R-parity violation at the LHC?

    SciTech Connect

    Bhattacherjee, Biplob; Raychaudhuri, Sreerup; Bhattacharyya, Gautam

    2011-10-01

    Observation of some low-energy processes in the flavor physics regime may require the existence of supersymmetry with two relatively large R-parity-violating couplings of the {lambda}{sup '}-type, together with reasonably light superparticles. At the LHC, such interactions would be expected to give rise to clear signals with convenient leptonic triggers, including some multileptons of the same sign. We undertake a detailed investigation of these signals taking care to correlate with low-energy requirements and taking proper account of the standard model backgrounds as well as the R-parity-conserving sector of the supersymmetric model. We find clear indications that R-parity violation as envisaged in this scenario can be detected at the LHC - even, perhaps, in the early runs.

  12. Cytokinin and Auxin Display Distinct but Interconnected Distribution and Signaling Profiles to Stimulate Cambial Activity.

    PubMed

    Immanen, Juha; Nieminen, Kaisa; Smolander, Olli-Pekka; Kojima, Mikiko; Alonso Serra, Juan; Koskinen, Patrik; Zhang, Jing; Elo, Annakaisa; Mähönen, Ari Pekka; Street, Nathaniel; Bhalerao, Rishikesh P; Paulin, Lars; Auvinen, Petri; Sakakibara, Hitoshi; Helariutta, Ykä

    2016-08-01

    Despite the crucial roles of phytohormones in plant development, comparison of the exact distribution profiles of different hormones within plant meristems has thus far remained scarce. Vascular cambium, a wide lateral meristem with an extensive developmental zonation, provides an optimal system for hormonal and genetic profiling. By taking advantage of this spatial resolution, we show here that two major phytohormones, cytokinin and auxin, display different yet partially overlapping distribution profiles across the cambium. In contrast to auxin, which has its highest concentration in the actively dividing cambial cells, cytokinins peak in the developing phloem tissue of a Populus trichocarpa stem. Gene expression patterns of cytokinin biosynthetic and signaling genes coincided with this hormonal gradient. To explore the functional significance of cytokinin signaling for cambial development, we engineered transgenic Populus tremula × tremuloides trees with an elevated cytokinin biosynthesis level. Confirming that cytokinins function as major regulators of cambial activity, these trees displayed stimulated cambial cell division activity resulting in dramatically increased (up to 80% in dry weight) production of the lignocellulosic trunk biomass. To connect the increased growth to hormonal status, we analyzed the hormone distribution and genome-wide gene expression profiles in unprecedentedly high resolution across the cambial zone. Interestingly, in addition to showing an elevated cambial cytokinin content and signaling level, the cambial auxin concentration and auxin-responsive gene expression were also increased in the transgenic trees. Our results indicate that cytokinin signaling specifies meristematic activity through a graded distribution that influences the amplitude of the cambial auxin gradient. PMID:27426519

  13. Distinct Signaling Requirements for the Establishment of ESC Pluripotency in Late-Stage EpiSCs

    PubMed Central

    Illich, Damir Jacob; Zhang, Miao; Ursu, Andrei; Osorno, Rodrigo; Kim, Kee-Pyo; Yoon, Juyong; Araúzo-Bravo, Marcos J.; Wu, Guangming; Esch, Daniel; Sabour, Davood; Colby, Douglas; Grassme, Kathrin S.; Chen, Jiayu; Greber, Boris; Höing, Susanne; Herzog, Wiebke; Ziegler, Slava; Chambers, Ian; Gao, Shaorong; Waldmann, Herbert; Schöler, Hans R.

    2016-01-01

    Summary It has previously been reported that mouse epiblast stem cell (EpiSC) lines comprise heterogeneous cell populations that are functionally equivalent to cells of either early- or late-stage postimplantation development. So far, the establishment of the embryonic stem cell (ESC) pluripotency gene regulatory network through the widely known chemical inhibition of MEK and GSK3beta has been impractical in late-stage EpiSCs. Here, we show that chemical inhibition of casein kinase 1alpha (CK1alpha) induces the conversion of recalcitrant late-stage EpiSCs into ESC pluripotency. CK1alpha inhibition directly results in the simultaneous activation of the WNT signaling pathway, together with inhibition of the TGFbeta/SMAD2 signaling pathway, mediating the rewiring of the gene regulatory network in favor of an ESC-like state. Our findings uncover a molecular mechanism that links CK1alpha to ESC pluripotency through the direct modulation of WNT and TGFbeta signaling. PMID:27149845

  14. Purified TPC Isoforms Form NAADP Receptors with Distinct Roles for Ca2+ Signaling and Endolysosomal Trafficking

    PubMed Central

    Ruas, Margarida; Rietdorf, Katja; Arredouani, Abdelilah; Davis, Lianne C.; Lloyd-Evans, Emyr; Koegel, Heidi; Funnell, Timothy M.; Morgan, Anthony J.; Ward, John A.; Watanabe, Keiko; Cheng, Xiaotong; Churchill, Grant C.; Zhu, Michael X.; Platt, Frances M.; Wessel, Gary M.; Parrington, John; Galione, Antony

    2010-01-01

    Summary Intracellular Ca2+ signals constitute key elements in signal transduction. Of the three major Ca2+ mobilizing messengers described, the most potent, nicotinic acid adenine dinucleotide phosphate (NAADP) is the least well understood in terms of its molecular targets [1]. Recently, we showed that heterologous expression of two-pore channel (TPC) proteins enhances NAADP-induced Ca2+ release, whereas the NAADP response was abolished in pancreatic beta cells from Tpcn2 gene knockout mice [2]. However, whether TPCs constitute native NAADP receptors is unclear. Here we show that immunopurified endogenous TPC complexes possess the hallmark properties ascribed to NAADP receptors, including nanomolar ligand affinity [3–5]. Our study also reveals important functional differences between the three TPC isoforms. Thus, TPC1 and TPC2 both mediate NAADP-induced Ca2+ release, but the subsequent amplification of this trigger Ca2+ by IP3Rs is more tightly coupled for TPC2. In contrast, TPC3 expression suppressed NAADP-induced Ca2+ release. Finally, increased TPC expression has dramatic and contrasting effects on endolysosomal structures and dynamics, implicating a role for NAADP in the regulation of vesicular trafficking. We propose that NAADP regulates endolysosomal Ca2+ storage and release via TPCs and coordinates endoplasmic reticulum Ca2+ release in a role that impacts on Ca2+ signaling in health and disease [6]. PMID:20346675

  15. Adaptive autoregressive modeling of non-stationary vibration signals under distinct gear states. Part 2: experimental analysis

    NASA Astrophysics Data System (ADS)

    Zhan, Y. M.; Jardine, A. K. S.

    2005-09-01

    Parametric time-frequency representation based on parametric models is more desirable for presenting highly precise time-frequency domain information due to its high-resolution property. However, the sensitivity and robustness of parametric models, in particular the parametric models on the basis of advanced adaptive filtering algorithms, has never been investigated for on-line condition monitoring of rotating machinery. Part 1 of this study proposed three adaptive parametric models based on three advanced adaptive filtering algorithms. Part 2 of this study is concerned with the effectiveness of the proposed models under distinct gear states, especially the highly non-stationary conditions accrued from advanced gear faults. Four gear states are considered: healthy state, adjacent gear tooth failure, non-adjacent gear tooth failure and distributed gear tooth failure. The vibration signals used in this study include the time-domain synchronous averaging signal and gear motion residual signal for each considered gear state. The test results demonstrate that the optimum filter behavior can readily be attained and the white Gaussian assumption of innovations can relatively be easily guaranteed for the NAKF-based model under distinct gear states and a wide variety of model initializations. On the other hand, the EKF- and MEKF-based models are capable of generating more accurate time-frequency representations than the NAKF-based model, but in general the optimality condition for white Gaussian assumption cannot be guaranteed for these two advanced models. Therefore, the NAKF-based model is preferred for automatic condition monitoring due to its appealing robustness to distinct gear states and arbitrary model initializations, whereas the EKF- and MEKF-based models are desirable when accurate time-frequency representation is concerned.

  16. Common and Distinct Roles of Juvenile Hormone Signaling Genes in Metamorphosis of Holometabolous and Hemimetabolous Insects

    PubMed Central

    Jindra, Marek

    2011-01-01

    Insect larvae metamorphose to winged and reproductive adults either directly (hemimetaboly) or through an intermediary pupal stage (holometaboly). In either case juvenile hormone (JH) prevents metamorphosis until a larva has attained an appropriate phase of development. In holometabolous insects, JH acts through its putative receptor Methoprene-tolerant (Met) to regulate Krüppel-homolog 1 (Kr-h1) and Broad-Complex (BR-C) genes. While Met and Kr-h1 prevent precocious metamorphosis in pre-final larval instars, BR-C specifies the pupal stage. How JH signaling operates in hemimetabolous insects is poorly understood. Here, we compare the function of Met, Kr-h1 and BR-C genes in the two types of insects. Using systemic RNAi in the hemimetabolous true bug, Pyrrhocoris apterus, we show that Met conveys the JH signal to prevent premature metamorphosis by maintaining high expression of Kr-h1. Knockdown of either Met or Kr-h1 (but not of BR-C) in penultimate-instar Pyrrhocoris larvae causes precocious development of adult color pattern, wings and genitalia. A natural fall of Kr-h1 expression in the last larval instar normally permits adult development, and treatment with an exogenous JH mimic methoprene at this time requires both Met and Kr-h1 to block the adult program and induce an extra larval instar. Met and Kr-h1 therefore serve as JH-dependent repressors of deleterious precocious metamorphic changes in both hemimetabolous and holometabolous juveniles, whereas BR-C has been recruited for a new role in specifying the holometabolous pupa. These results show that despite considerable evolutionary distance, insects with diverse developmental strategies employ a common-core JH signaling pathway to commit to adult morphogenesis. PMID:22174880

  17. Two distinct signaling pathways participate in auxin-induced swelling of pea epidermal protoplasts.

    PubMed

    Yamagami, Mutsumi; Haga, Ken; Napier, Richard M; Iino, Moritoshi

    2004-02-01

    Protoplast swelling was used to investigate auxin signaling in the growth-limiting stem epidermis. The protoplasts of epidermal cells were isolated from elongating internodes of pea (Pisum sativum). These protoplasts swelled in response to auxin, providing the clearest evidence that the epidermis can directly perceive auxin. The swelling response to the natural auxin IAA showed a biphasic dose response curve but that to the synthetic auxin 1-naphthalene acetic acid (NAA) showed a simple bell-shaped dose response curve. The responses to IAA and NAA were further analyzed using antibodies raised against ABP1 (auxin-binding protein 1), and their dependency on extracellular ions was investigated. Two signaling pathways were resolved for IAA, an ABP1-dependent pathway and an ABP1-independent pathway that is much more sensitive to IAA than the former. The response by the ABP1 pathway was eliminated by anti-ABP1 antibodies, had a higher sensitivity to NAA, and did not depend on extracellular Ca(2+). In contrast, the response by the non-ABP1 pathway was not affected by anti-ABP1 antibodies, had no sensitivity to NAA, and depended on extracellular Ca(2+). The swelling by either pathway required extracellular K(+) and Cl(-). The auxin-induced growth of pea internode segments showed similar response patterns, including the occurrence of two peaks in the dose response curve for IAA and the difference in Ca(2+) requirements. It is suggested that two signaling pathways participate in auxin-induced internode growth and that the non-ABP1 pathway is more likely to be involved in the control of growth by constitutive concentrations of endogenous auxin. PMID:14764902

  18. Endothelial juxtaposition of distinct adult stem cells activates angiogenesis signaling molecules in endothelial cells.

    PubMed

    Mohammadi, Elham; Nassiri, Seyed Mahdi; Rahbarghazi, Reza; Siavashi, Vahid; Araghi, Atefeh

    2015-12-01

    Efficacy of therapeutic angiogenesis needs a comprehensive understanding of endothelial cell (EC) function and biological factors and cells that interplay with ECs. Stem cells are considered the key components of pro- and anti-angiogenic milieu in a wide variety of physiopathological states, and interactions of EC-stem cells have been the subject of controversy in recent years. In this study, the potential effects of three tissue-specific adult stem cells, namely rat marrow-derived mesenchymal stem cells (rBMSCs), rat adipose-derived stem cells (rADSCs) and rat muscle-derived satellite cells (rSCs), on the endothelial activation of key angiogenic signaling molecules, including VEGF, Ang-2, VEGFR-2, Tie-2, and Tie2-pho, were investigated. Human umbilical vein endothelial cells (HUVECs) and rat lung microvascular endothelial cells (RLMECs) were cocultured with the stem cells or incubated with the stem cell-derived conditioned media on Matrigel. Following HUVEC-stem cell coculture, CD31-positive ECs were flow sorted and subjected to western blotting to analyze potential changes in the expression of the pro-angiogenic signaling molecules. Elongation and co-alignment of the stem cells were seen along the EC tubes in the EC-stem cell cocultures on Matrigel, with cell-to-cell dye communication in the EC-rBMSC cocultures. Moreover, rBMSCs and rADSCs significantly improved endothelial tubulogenesis in both juxtacrine and paracrine manners. These two latter stem cells dynamically up-regulated VEGF, Ang-2, VREGR-2, and Tie-2 but down-regulated Tie2-pho and the Tie2-pho/Tie-2 ratio in HUVECs. Induction of pro-angiogenic signaling in ECs by marrow- and adipose-derived MSCs further indicates the significance of stem cell milieu in angiogenesis dynamics. PMID:26068799

  19. RhoA Ambivalently Controls Prominent Myofibroblast Characteritics by Involving Distinct Signaling Routes

    PubMed Central

    Jatho, Aline; Hartmann, Svenja; Kittana, Naim; Mügge, Felicitas; Wuertz, Christina M.; Tiburcy, Malte; Zimmermann, Wolfram-Hubertus; Katschinski, Dörthe M.; Lutz, Susanne

    2015-01-01

    Introduction RhoA has been shown to be beneficial in cardiac disease models when overexpressed in cardiomyocytes, whereas its role in cardiac fibroblasts (CF) is still poorly understood. During cardiac remodeling CF undergo a transition towards a myofibroblast phenotype thereby showing an increased proliferation and migration rate. Both processes involve the remodeling of the cytoskeleton. Since RhoA is known to be a major regulator of the cytoskeleton, we analyzed its role in CF and its effect on myofibroblast characteristics in 2 D and 3D models. Results Downregulation of RhoA was shown to strongly affect the actin cytoskeleton. It decreased the myofibroblast marker α-sm-actin, but increased certain fibrosis-associated factors like TGF-β and collagens. Also, the detailed analysis of CTGF expression demonstrated that the outcome of RhoA signaling strongly depends on the involved stimulus. Furthermore, we show that proliferation of myofibroblasts rely on RhoA and tubulin acetylation. In assays accessing three different types of migration, we demonstrate that RhoA/ROCK/Dia1 are important for 2D migration and the repression of RhoA and Dia1 signaling accelerates 3D migration. Finally, we show that a downregulation of RhoA in CF impacts the viscoelastic and contractile properties of engineered tissues. Conclusion RhoA positively and negatively influences myofibroblast characteristics by differential signaling cascades and depending on environmental conditions. These include gene expression, migration and proliferation. Reduction of RhoA leads to an increased viscoelasticity and a decrease in contractile force in engineered cardiac tissue. PMID:26448568

  20. Two Distinct Signaling Pathways Participate in Auxin-Induced Swelling of Pea Epidermal Protoplasts

    PubMed Central

    Yamagami, Mutsumi; Haga, Ken; Napier, Richard M.; Iino, Moritoshi

    2004-01-01

    Protoplast swelling was used to investigate auxin signaling in the growth-limiting stem epidermis. The protoplasts of epidermal cells were isolated from elongating internodes of pea (Pisum sativum). These protoplasts swelled in response to auxin, providing the clearest evidence that the epidermis can directly perceive auxin. The swelling response to the natural auxin IAA showed a biphasic dose response curve but that to the synthetic auxin 1-naphthalene acetic acid (NAA) showed a simple bell-shaped dose response curve. The responses to IAA and NAA were further analyzed using antibodies raised against ABP1 (auxin-binding protein 1), and their dependency on extracellular ions was investigated. Two signaling pathways were resolved for IAA, an ABP1-dependent pathway and an ABP1-independent pathway that is much more sensitive to IAA than the former. The response by the ABP1 pathway was eliminated by anti-ABP1 antibodies, had a higher sensitivity to NAA, and did not depend on extracellular Ca2+. In contrast, the response by the non-ABP1 pathway was not affected by anti-ABP1 antibodies, had no sensitivity to NAA, and depended on extracellular Ca2+. The swelling by either pathway required extracellular K+ and Cl–. The auxin-induced growth of pea internode segments showed similar response patterns, including the occurrence of two peaks in the dose response curve for IAA and the difference in Ca2+ requirements. It is suggested that two signaling pathways participate in auxin-induced internode growth and that the non-ABP1 pathway is more likely to be involved in the control of growth by constitutive concentrations of endogenous auxin. PMID:14764902

  1. Brassinosteroids regulate plant growth through distinct signaling pathways in Selaginella and Arabidopsis.

    PubMed

    Cheon, Jinyeong; Fujioka, Shozo; Dilkes, Brian P; Choe, Sunghwa

    2013-01-01

    Brassinosteroids (BRs) are growth-promoting steroid hormones that regulate diverse physiological processes in plants. Most BR biosynthetic enzymes belong to the cytochrome P450 (CYP) family. The gene encoding the ultimate step of BR biosynthesis in Arabidopsis likely evolved by gene duplication followed by functional specialization in a dicotyledonous plant-specific manner. To gain insight into the evolution of BRs, we performed a genomic reconstitution of Arabidopsis BR biosynthetic genes in an ancestral vascular plant, the lycophyte Selaginella moellendorffii. Selaginella contains four members of the CYP90 family that cluster together in the CYP85 clan. Similar to known BR biosynthetic genes, the Selaginella CYP90s exhibit eight or ten exons and Selaginella produces a putative BR biosynthetic intermediate. Therefore, we hypothesized that Selaginella CYP90 genes encode BR biosynthetic enzymes. In contrast to typical CYPs in Arabidopsis, Selaginella CYP90E2 and CYP90F1 do not possess amino-terminal signal peptides, suggesting that they do not localize to the endoplasmic reticulum. In addition, one of the three putative CYP reductases (CPRs) that is required for CYP enzyme function co-localized with CYP90E2 and CYP90F1. Treatments with a BR biosynthetic inhibitor, propiconazole, and epi-brassinolide resulted in greatly retarded and increased growth, respectively. This suggests that BRs promote growth in Selaginella, as they do in Arabidopsis. However, BR signaling occurs through different pathways than in Arabidopsis. A sequence homologous to the Arabidopsis BR receptor BRI1 was absent in Selaginella, but downstream components, including BIN2, BSU1, and BZR1, were present. Thus, the mechanism that initiates BR signaling in Selaginella seems to differ from that in Arabidopsis. Our findings suggest that the basic physiological roles of BRs as growth-promoting hormones are conserved in both lycophytes and Arabidopsis; however, different BR molecules and BRI1-based

  2. Distinctive rings in the 21 cm signal of the epoch of reionization

    NASA Astrophysics Data System (ADS)

    Vonlanthen, P.; Semelin, B.; Baek, S.; Revaz, Y.

    2011-08-01

    Context. It is predicted that sources emitting UV radiation in the Lyman band during the epoch of reionization show a series of discontinuities in their Lyα flux radial profile as a consequence of the thickness of the Lyman-series lines in the primeval intergalactic medium. Through unsaturated Wouthuysen-Field coupling, these spherical discontinuities are also present in the 21 cm emission of the neutral IGM. Aims: We study the effects that these discontinuities have on the differential brightness temperature of the 21 cm signal of neutral hydrogen in a realistic setting that includes all other sources of fluctuations. We focus on the early phases of the epoch of reionization, and we address the question of the detectability by the planned Square Kilometre Array (SKA). Such a detection would be of great interest because these structures could provide an unambiguous diagnostic tool for the cosmological origin of the signal that remains after the foreground cleaning procedure. These structures could also be used as a new type of standard rulers. Methods: We determine the differential brightness temperature of the 21 cm signal in the presence of inhomogeneous Wouthuysen-Field effect using simulations that include (hydro)dynamics as well as ionizing and Lyman lines 3D radiative transfer with the code LICORICE. We include radiative transfer for the higher-order Lyman-series lines and consider also the effect of backreaction from recoils and spin diffusivity on the Lyα resonance. Results: We find that the Lyman horizons are difficult to indentify using the power spectrum of the 21 cm signal but are clearly visible in the maps and radial profiles around the first sources of our simulations, if only for a limited time interval, typically Δz ≈ 2 at z ~ 13. Stacking the profiles of the different sources of the simulation at a given redshift results in extending this interval to Δz ≈ 4. When we take into account the implementation and design planned for the SKA

  3. Distinct Signaling of Coreceptors Regulates Specific Metabolism Pathways and Impacts Memory Development in CAR T Cells.

    PubMed

    Kawalekar, Omkar U; O'Connor, Roddy S; Fraietta, Joseph A; Guo, Lili; McGettigan, Shannon E; Posey, Avery D; Patel, Prachi R; Guedan, Sonia; Scholler, John; Keith, Brian; Snyder, Nathaniel W; Snyder, Nathaniel; Blair, Ian A; Blair, Ian; Milone, Michael C; June, Carl H

    2016-02-16

    Chimeric antigen receptors (CARs) redirect T cell cytotoxicity against cancer cells, providing a promising approach to cancer immunotherapy. Despite extensive clinical use, the attributes of CAR co-stimulatory domains that impact persistence and resistance to exhaustion of CAR-T cells remain largely undefined. Here, we report the influence of signaling domains of coreceptors CD28 and 4-1BB on the metabolic characteristics of human CAR T cells. Inclusion of 4-1BB in the CAR architecture promoted the outgrowth of CD8(+) central memory T cells that had significantly enhanced respiratory capacity, increased fatty acid oxidation and enhanced mitochondrial biogenesis. In contrast, CAR T cells with CD28 domains yielded effector memory cells with a genetic signature consistent with enhanced glycolysis. These results provide, at least in part, a mechanistic insight into the differential persistence of CAR-T cells expressing 4-1BB or CD28 signaling domains in clinical trials and inform the design of future CAR T cell therapies. PMID:26885860

  4. Distinct signal transduction pathways for activation of rabbit alveolar macrophages in vitro by cotton bract tannin.

    PubMed

    Prévost, M C; Soulat, J M; Comminges, C; Maury, E; Aslane, R; Cohen-Jonathan, E; Cariven, C; Lauque, D; Chap, H

    1996-05-01

    These experiments were designed to study signal transduction pathways in alveolar macrophages stimulated by condensed tannin or zymosan. Condensed tannins, present in cotton mill dust, alter the host-defense function of alveolar macrophages and may contribute to the pathogenesis of byssinosis. We tried to determine the early steps in signal transduction mechanisms of cell activation by tannin. With the quantification of 51Cr release, we determined that tannin was cytotoxic for the cells after 30 min activation with 130 micrograms for 2 x 10(6) cells. 51Cr release was similar for control cells and zymosan- or 30 micrograms tannin-activated cells. Using the luciferine luciferase reaction, we showed that tannin markedly depleted ATP cell content. In inositol-labeled cells, tannin increased inositolphosphate release in a dose-dependent manner. In lysoPAF-labeled cells, tannin induced synthesis of phosphatidic acid and diglycerides. In the presence of ethanol, the level of tannin-induced phosphatidic acid was slightly reduced, and phosphatidylethanol was synthesized. No phosphatidylethanol was found in alveolar macrophages stimulated by zymosan in the presence of ethanol. GF 109203X, a specific inhibitor of protein kinase C decreased only tannin-induced phosphatidylethanol synthesis. In conclusion, tannin (at 30 or 130 micrograms/ml) activated an inositol phospholipase C in alveolar membranes. Phosphatidylcholine phospholipases C and D were found only at the higher concentration of tannin.

  5. Distinct Signaling of Coreceptors Regulates Specific Metabolism Pathways and Impacts Memory Development in CAR T Cells.

    PubMed

    Kawalekar, Omkar U; O'Connor, Roddy S; Fraietta, Joseph A; Guo, Lili; McGettigan, Shannon E; Posey, Avery D; Patel, Prachi R; Guedan, Sonia; Scholler, John; Keith, Brian; Snyder, Nathaniel W; Snyder, Nathaniel; Blair, Ian A; Blair, Ian; Milone, Michael C; June, Carl H

    2016-02-16

    Chimeric antigen receptors (CARs) redirect T cell cytotoxicity against cancer cells, providing a promising approach to cancer immunotherapy. Despite extensive clinical use, the attributes of CAR co-stimulatory domains that impact persistence and resistance to exhaustion of CAR-T cells remain largely undefined. Here, we report the influence of signaling domains of coreceptors CD28 and 4-1BB on the metabolic characteristics of human CAR T cells. Inclusion of 4-1BB in the CAR architecture promoted the outgrowth of CD8(+) central memory T cells that had significantly enhanced respiratory capacity, increased fatty acid oxidation and enhanced mitochondrial biogenesis. In contrast, CAR T cells with CD28 domains yielded effector memory cells with a genetic signature consistent with enhanced glycolysis. These results provide, at least in part, a mechanistic insight into the differential persistence of CAR-T cells expressing 4-1BB or CD28 signaling domains in clinical trials and inform the design of future CAR T cell therapies.

  6. Phosphorylation and ubiquitination of the IkappaB kinase complex by two distinct signaling pathways.

    PubMed

    Shambharkar, Prashant B; Blonska, Marzenna; Pappu, Bhanu P; Li, Hongxiu; You, Yun; Sakurai, Hiroaki; Darnay, Bryant G; Hara, Hiromitsu; Penninger, Josef; Lin, Xin

    2007-04-01

    The IkappaB kinase (IKK) complex serves as the master regulator for the activation of NF-kappaB by various stimuli. It contains two catalytic subunits, IKKalpha and IKKbeta, and a regulatory subunit, IKKgamma/NEMO. The activation of IKK complex is dependent on the phosphorylation of IKKalpha/beta at its activation loop and the K63-linked ubiquitination of NEMO. However, the molecular mechanism by which these inducible modifications occur remains undefined. Here, we demonstrate that CARMA1, a key scaffold molecule, is essential to regulate NEMO ubiquitination upon T-cell receptor (TCR) stimulation. However, the phosphorylation of IKKalpha/beta activation loop is independent of CARMA1 or NEMO ubiquitination. Further, we provide evidence that TAK1 is activated and recruited to the synapses in a CARMA1-independent manner and mediate IKKalpha/beta phosphorylation. Thus, our study provides the biochemical and genetic evidence that phosphorylation of IKKalpha/beta and ubiquitination of NEMO are regulated by two distinct pathways upon TCR stimulation.

  7. Cartography of Pathway Signal Perturbations Identifies Distinct Molecular Pathomechanisms in Malignant and Chronic Lung Diseases.

    PubMed

    Arakelyan, Arsen; Nersisyan, Lilit; Petrek, Martin; Löffler-Wirth, Henry; Binder, Hans

    2016-01-01

    Lung diseases are described by a wide variety of developmental mechanisms and clinical manifestations. Accurate classification and diagnosis of lung diseases are the bases for development of effective treatments. While extensive studies are conducted toward characterization of various lung diseases at molecular level, no systematic approach has been developed so far. Here we have applied a methodology for pathway-centered mining of high throughput gene expression data to describe a wide range of lung diseases in the light of shared and specific pathway activity profiles. We have applied an algorithm combining a Pathway Signal Flow (PSF) algorithm for estimation of pathway activity deregulation states in lung diseases and malignancies, and a Self Organizing Maps algorithm for classification and clustering of the pathway activity profiles. The analysis results allowed clearly distinguish between cancer and non-cancer lung diseases. Lung cancers were characterized by pathways implicated in cell proliferation, metabolism, while non-malignant lung diseases were characterized by deregulations in pathways involved in immune/inflammatory response and fibrotic tissue remodeling. In contrast to lung malignancies, chronic lung diseases had relatively heterogeneous pathway deregulation profiles. We identified three groups of interstitial lung diseases and showed that the development of characteristic pathological processes, such as fibrosis, can be initiated by deregulations in different signaling pathways. In conclusion, this paper describes the pathobiology of lung diseases from systems viewpoint using pathway centered high-dimensional data mining approach. Our results contribute largely to current understanding of pathological events in lung cancers and non-malignant lung diseases. Moreover, this paper provides new insight into molecular mechanisms of a number of interstitial lung diseases that have been studied to a lesser extent.

  8. Cartography of Pathway Signal Perturbations Identifies Distinct Molecular Pathomechanisms in Malignant and Chronic Lung Diseases

    PubMed Central

    Arakelyan, Arsen; Nersisyan, Lilit; Petrek, Martin; Löffler-Wirth, Henry; Binder, Hans

    2016-01-01

    Lung diseases are described by a wide variety of developmental mechanisms and clinical manifestations. Accurate classification and diagnosis of lung diseases are the bases for development of effective treatments. While extensive studies are conducted toward characterization of various lung diseases at molecular level, no systematic approach has been developed so far. Here we have applied a methodology for pathway-centered mining of high throughput gene expression data to describe a wide range of lung diseases in the light of shared and specific pathway activity profiles. We have applied an algorithm combining a Pathway Signal Flow (PSF) algorithm for estimation of pathway activity deregulation states in lung diseases and malignancies, and a Self Organizing Maps algorithm for classification and clustering of the pathway activity profiles. The analysis results allowed clearly distinguish between cancer and non-cancer lung diseases. Lung cancers were characterized by pathways implicated in cell proliferation, metabolism, while non-malignant lung diseases were characterized by deregulations in pathways involved in immune/inflammatory response and fibrotic tissue remodeling. In contrast to lung malignancies, chronic lung diseases had relatively heterogeneous pathway deregulation profiles. We identified three groups of interstitial lung diseases and showed that the development of characteristic pathological processes, such as fibrosis, can be initiated by deregulations in different signaling pathways. In conclusion, this paper describes the pathobiology of lung diseases from systems viewpoint using pathway centered high-dimensional data mining approach. Our results contribute largely to current understanding of pathological events in lung cancers and non-malignant lung diseases. Moreover, this paper provides new insight into molecular mechanisms of a number of interstitial lung diseases that have been studied to a lesser extent. PMID:27200087

  9. Alpha1a-adrenoceptor genetic variant induces cardiomyoblast-to-fibroblast-like cell transition via distinct signaling pathways.

    PubMed

    Kleine-Brueggeney, Maren; Gradinaru, Irina; Babaeva, Ekaterina; Schwinn, Debra A; Oganesian, Anush

    2014-09-01

    The role of naturally occurring human α1a-Adrenergic Receptor (α1aAR) genetic variants associated with cardiovascular disorders is poorly understood. Here, we present the novel findings that expression of human α1aAR-247R (247R) genetic variant in cardiomyoblasts leads to transition of cardiomyoblasts into a fibroblast-like phenotype, evidenced by morphology and distinct de novo expression of characteristic genes. These fibroblast-like cells exhibit constitutive, high proliferative capacity and agonist-induced hypertrophy compared with cells prior to transition. We demonstrate that constitutive, synergistic activation of EGFR, Src and ERK kinases is the potential molecular mechanism of this transition. We also demonstrate that 247R triggers two distinct EGFR transactivation-dependent signaling pathways: 1) constitutive Gq-independent β-arrestin-1/Src/MMP/EGFR/ERK-dependent hyperproliferation and 2) agonist-induced Gq- and EGFR/STAT-dependent hypertrophy. Interestingly, in cardiomyoblasts agonist-independent hyperproliferation is MMP-dependent, but in fibroblast-like cells it is MMP-independent, suggesting that expression of α1aAR genetic variant in cardiomyocytes may trigger extracellular matrix remodeling. Thus, these novel findings demonstrate that EGFR transactivation by α1aAR-247R leads to hyperproliferation, hypertrophy and alterations in cardiomyoblasts, suggesting that these unique genetically-mediated alterations in signaling pathways and cellular function may lead to myocardial fibrosis. Such extracellular matrix remodeling may contribute to the genesis of arrhythmias in certain types of heart failure.

  10. The regulation of p53 by phosphorylation: a model for how distinct signals integrate into the p53 pathway.

    PubMed

    Maclaine, Nicola J; Hupp, Ted R

    2009-05-01

    The tumour suppressor p53 is a transcription factor that has evolved the ability to integrate distinct environmental signals including DNA damage, virus infection, and cytokine signaling into a common biological outcome that maintains normal cellular control. Mutations in p53 switch the cellular transcription program resulting in deregulation of the stress responses that normally maintain cell and tissue integrity. Transgenic studies in mice have indicated that changes in the specific activity of p53 can have profound effects not only on cancer development, but also on organism aging. As the specific activity of p53 is regulated at a post-translational level by sets of enzymes that mediate phosphorylation, acetylation, methylation, and ubiquitin-like modifications, it is likely that physiological modifiers of the aging function of p53 would be enzymes that catalyze such covalent modifications. We demonstrate that distinct stress-activated kinases, including ataxia telangiectasia mutated (ATM), casein kinase 1 (CK1) and AMP-activated protein kinase (AMPK), mediate phosphorylation of a key phospho-acceptor site in the p53 transactivation domain in response to diverse stresses including ionizing radiation, DNA virus infection, and elevation in the intracellular AMP/ATP ratio. As diseases linked to aging can involve activation of p53-dependent changes in cellular protective pathways, the development of specific physiological models might further shed light on the role of p53 kinases in modifying age-related diseases. PMID:20157532

  11. Phenotypically distinct subtypes of psychosis accompany novel or rare variants in four different signaling genes

    PubMed Central

    Kranz, Thorsten M.; Berns, Adam; Shields, Jerry; Rothman, Karen; Walsh-Messinger, Julie; Goetz, Raymond R.; Chao, Moses V.; Malaspina, Dolores

    2016-01-01

    Background Rare gene variants are important sources of schizophrenia vulnerability that likely interact with polygenic susceptibility loci. This study examined if novel or rare missense coding variants in any of four different signaling genes in sporadic schizophrenia cases were associated with clinical phenotypes in an exceptionally well-characterized sample. Method Structured interviews, cognition, symptoms and life course features were assessed in 48 ethnically-diverse cases with psychosis who underwent targeted exome sequencing of PTPRG (Protein Tyrosine Phosphatase, Receptor Type G), SLC39A13 (Solute Carrier Family 39 (Zinc Transporter) Member 13), TGM5 (transglutaminase 5) and ARMS/KIDINS220 (Ankyrin repeat-rich membrane spanning protein or Kinase D-Interacting Substrate of 220 kDa). Cases harboring rare missense coding polymorphisms or novel mutations in one or more of these genes were compared to other cases not carrying any rare missense coding polymorphisms or novel mutations in these genes and healthy controls. Findings Fifteen of 48 cases (31.25%) carried rare or novel missense coding variants in one or more of these genes. The subgroups significantly differed in important features, including specific working memory deficits for PTPRG (n = 5); severe negative symptoms, global cognitive deficits and poor educational attainment, suggesting a developmental disorder, for SLC39A13 (n = 4); slow processing speed, childhood attention deficit disorder and milder symptoms for TGM5 (n = 4); and global cognitive deficits with good educational attainment suggesting neurodegeneration for ARMS/KIDINS220 (n = 5). Case vignettes are included in the appendix. Interpretation Genes prone to missense coding polymorphisms and/or mutations in sporadic cases may highlight influential genes for psychosis and illuminate heterogeneous pathways to schizophrenia. Ethnicity appears less important at the level of genetic variability. The sequence variations that potentially

  12. [Anabolic steroids and their abuse in sports].

    PubMed

    Bruno, M

    1990-11-15

    Anabolic steroids increase protein synthesis in skeletal muscles and reverse catabolic processes. Because of these properties some athletes use anabolic steroids in an attempt to improve their athletic performance. However, the latest studies indicate that limited increases in muscle mass and strength during anabolic steroid administration are observed only in athletes who already are weight-trained and who continue intensive training while consuming high-protein, high-calorie diets. Adverse effects attributed to anabolic steroid use occur frequently. Serious adverse effects include hepatic and endocrine dysfunction; cardiovascular and behavioral changes are also reported. Some of the adverse effects associated with the use of these agents are irreversible, particularly in women. The use of anabolic steroids to improve athletic performance has become prevalent; however the limited benefits reported are offset by numerous adverse reactions.

  13. Distinctive precursory air-sea signals between regular and super El Niños

    NASA Astrophysics Data System (ADS)

    Chen, Lin; Li, Tim; Behera, Swadhin K.; Doi, Takeshi

    2016-08-01

    Statistically different precursory air-sea signals between a super and a regular El Niño group are investigated, using observed SST and rainfall data, and oceanic and atmospheric reanalysis data. The El Niño events during 1958-2008 are first separated into two groups: a super El Niño group (S-group) and a regular El Niño group (R-group). Composite analysis shows that a significantly larger SST anomaly (SSTA) tendency appears in S-group than in R-group during the onset phase [April-May(0)], when the positive SSTA is very small. A mixed-layer heat budget analysis indicates that the tendency difference arises primarily from the difference in zonal advective feedback and the associated zonal current anomaly ( u'). This is attributed to the difference in the thermocline depth anomaly ( D') over the off-equatorial western Pacific prior to the onset phase, as revealed by three ocean assimilation products. Such a difference in D' is caused by the difference in the wind stress curl anomaly in situ, which is mainly regulated by the anomalous SST and precipitation over the Maritime Continent and equatorial Pacific.

  14. Paternal lineages signal distinct genetic contributions from British Loyalists and continental Africans among different Bahamian islands.

    PubMed

    Simms, Tanya M; Martinez, Emanuel; Herrera, Kristian J; Wright, Marisil R; Perez, Omar A; Hernandez, Michelle; Ramirez, Evelyn C; McCartney, Quinn; Herrera, Rene J

    2011-12-01

    Over the past 500 years, the Bahamas has been influenced by a wide array of settlers, some of whom have left marked genetic imprints throughout the archipelago. To assess the extent of each group's genetic contributions, high-resolution Y-chromosome analyses were performed, for the first time, to delineate the patriarchal ancestry of six islands in the Northwest (Abaco and Grand Bahama) and Central (Eleuthera, Exuma, Long Island, and New Providence) Bahamas and their genetic relationships with previously published reference populations. Our results reveal genetic signals emanating primarily from African and European sources, with the predominantly sub-Saharan African and Western European haplogroups E1b1a-M2 and R1b1b1-M269, respectively, accounting for greater than 75% of all Bahamian patrilineages. Surprisingly, we observe notable discrepancies among the six Bahamian populations in their distribution of these lineages, with E1b1a-M2 predominating Y-chromosomes in the collections from Abaco, Exuma, Eleuthera, Grand Bahama, and New Providence, whereas R1b1b1-M269 is found at elevated levels in the Long Island population. Substantial Y-STR haplotype variation within sub-haplogroups E1b1a7a-U174 and E1b1ba8-U175 (greater than any continental African collection) is also noted, possibly indicating genetic influences from a variety of West and Central African groups. Furthermore, differential European genetic contributions in each island (with the exception of Exuma) reflect settlement patterns of the British Loyalists subsequent to the American Revolution.

  15. Wnt/β-catenin signaling plays a distinct role in methyl gallate-mediated inhibition of adipogenesis.

    PubMed

    Jeon, Miso; Rahman, Naimur; Kim, Yong-Sik

    2016-10-01

    The canonical Wnt/β-catenin signaling not only features in many developmental processes but also recently emerged as an attractive negative regulator of differentiation of preadipocytes into adipocytes. Here, we show that β-catenin signaling plays a distinct role in methyl gallate (MG)-mediated inhibition of 3T3-L1 adipocytes differentiation. We found that the expression of β-catenin decreased after adipogenic hormonal induction, whereas incubation of the differentiating cells with a physiological concentration of MG during adipogenic hormonal induction significantly prevented β-catenin degradation by activating Wnt signaling components such as Wnt1, Wnt10b, Fzd1, Fzd2, Lrp5, Lrp6, Dvl1, and Dvl2. Mechanistic experiments revealed that MG treatment during early adipocytic differentiation specifically inhibited degradation of β-catenin caused by phosphorylation at serine-33. In addition, MG treatment led to phosphorylation of GSK3β, which is one of β-catenin-degrading enzymes. Consequently, MG treatment facilitated translocation of the stabilized β-catenin from the cytoplasm to nucleus, and activates its target genes cyclin D1 and c-Myc. Furthermore, MG-induced stabilization of β-catenin suppresses PPARγ expression. Moreover, pharmacological activation or inhibition of β-catenin signaling during adipocytes differentiation decreased and increased, respectively, the level of the key adipogenic marker, PPARγ, and of its downstream targets, aP2 and adiponectin while MG treatment effectively reversed their expression level. Collectively, our data suggest that MG is a novel pharmacological stimulator of canonical Wnt/β-catenin signaling, and therefore represents a promising therapeutic agent in obesity. PMID:27592552

  16. REDOX regulation of IL-13 signaling in intestinal epithelial cells: usage of alternate pathways mediates distinct gene expression patterns

    PubMed Central

    Mandal, Debasmita; Fu, Pingfu; Levine, Alan D.

    2010-01-01

    In the classic view interleukin-13 (IL-13) binds to a heterodimer protein complex of the IL-13Rα1 and IL-4Rα chains and signals through a janus kinase 1 (JAK1)-signal transducer and activator of transcription 6 (STAT6) mechanism. We recently reported that IL-13 also signals through the IL-13Rα2 chain initiating all three mitogen activated protein kinase (MAPK) pathways, and the relative expression of IL-13Rα1 and IL-13Rα2 modulates one another’s transduction pathway. Therefore we investigated whether generation of reactive oxygen species (ROS) as second messengers may serve as a common nexus between these two pathways emanating from the individual IL-13 receptor chains in intestinal epithelial cells (IEC). IL-13 stimulates intracellular ROS synthesis within 5 min via IL-13Rα1-JAK1-STAT6- and IL-13Rα2-MEK1/2-ERK1/2-dependent activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-1 (NOX-1). IL-13-induced ROS generation in turn positively regulates phosphorylation of ERK1/2 and STAT6, yielding a feed forward amplification loop. IL-13 also stimulates the stable, long-term gene expression of two other NADPH oxidases, NOX-4 and DUOX-2, which along with constitutive NOX-1, might facilitate elevated, continuous production of ROS in IL-13-activated IEC. The contribution of each signal transduction pathway initiated by IL-13 engagement to such biological functions as wound healing, inflammation, and apoptosis was mapped for representative, responsive genes. Distinct usage patterns were observed, demonstrating that not only is IL-13 signal transduction through STAT6, MAPK, and ROS regulated in both an antagonistic and cyclic fashion, but each pathway also plays a specific role in modulating the wound healing and anti-apoptotic capabilities of the intestinal epithelium. PMID:20570727

  17. Adverse effects of anabolic steroids.

    PubMed

    Hickson, R C; Ball, K L; Falduto, M T

    1989-01-01

    Anabolic steroids are used therapeutically for various disorders and as ergogenic aids by athletes to augment strength, muscular development, and to enhance performance. There is a wide range of concomitant temporary and permanent adverse effects with steroid administration. Several well-documented adverse actions of these hormones may develop rapidly within several weeks or less (i.e. altered reproductive function) or require up to several years of steroid intake (i.e. liver carcinoma). More recent studies indicate that glucose intolerance, insulin resistance, increased cardiovascular disease risk profiles, cerebral dangers, musculoskeletal injuries, prostate cancer, psychosis and schizophrenic episodes, among others, accompany anabolic steroid intake. There is, at present, no evidence to support the claim that athletes are less susceptible to adverse effects than those individuals receiving hormone treatment in a clinical setting. Based on the available information which has accumulated primarily from cross-sectional, short term longitudinal, and case studies, there is a need: (a) to develop a comprehensive battery of specific and sensitive markers of adverse effects, particularly those that would be able to detect the onset of adverse actions; and (b) to conduct controlled long term longitudinal studies in order to fully understand the extensiveness and mechanisms involved in the occurrence of adverse effects.

  18. Brachyury and SMAD signalling collaboratively orchestrate distinct mesoderm and endoderm gene regulatory networks in differentiating human embryonic stem cells.

    PubMed

    Faial, Tiago; Bernardo, Andreia S; Mendjan, Sasha; Diamanti, Evangelia; Ortmann, Daniel; Gentsch, George E; Mascetti, Victoria L; Trotter, Matthew W B; Smith, James C; Pedersen, Roger A

    2015-06-15

    The transcription factor brachyury (T, BRA) is one of the first markers of gastrulation and lineage specification in vertebrates. Despite its wide use and importance in stem cell and developmental biology, its functional genomic targets in human cells are largely unknown. Here, we use differentiating human embryonic stem cells to study the role of BRA in activin A-induced endoderm and BMP4-induced mesoderm progenitors. We show that BRA has distinct genome-wide binding landscapes in these two cell populations, and that BRA interacts and collaborates with SMAD1 or SMAD2/3 signalling to regulate the expression of its target genes in a cell-specific manner. Importantly, by manipulating the levels of BRA in cells exposed to different signalling environments, we demonstrate that BRA is essential for mesoderm but not for endoderm formation. Together, our data illuminate the function of BRA in the context of human embryonic development and show that the regulatory role of BRA is context dependent. Our study reinforces the importance of analysing the functions of a transcription factor in different cellular and signalling environments.

  19. Brachyury and SMAD signalling collaboratively orchestrate distinct mesoderm and endoderm gene regulatory networks in differentiating human embryonic stem cells

    PubMed Central

    Faial, Tiago; Bernardo, Andreia S.; Mendjan, Sasha; Diamanti, Evangelia; Ortmann, Daniel; Gentsch, George E.; Mascetti, Victoria L.; Trotter, Matthew W. B.; Smith, James C.; Pedersen, Roger A.

    2015-01-01

    The transcription factor brachyury (T, BRA) is one of the first markers of gastrulation and lineage specification in vertebrates. Despite its wide use and importance in stem cell and developmental biology, its functional genomic targets in human cells are largely unknown. Here, we use differentiating human embryonic stem cells to study the role of BRA in activin A-induced endoderm and BMP4-induced mesoderm progenitors. We show that BRA has distinct genome-wide binding landscapes in these two cell populations, and that BRA interacts and collaborates with SMAD1 or SMAD2/3 signalling to regulate the expression of its target genes in a cell-specific manner. Importantly, by manipulating the levels of BRA in cells exposed to different signalling environments, we demonstrate that BRA is essential for mesoderm but not for endoderm formation. Together, our data illuminate the function of BRA in the context of human embryonic development and show that the regulatory role of BRA is context dependent. Our study reinforces the importance of analysing the functions of a transcription factor in different cellular and signalling environments. PMID:26015544

  20. 21 CFR 1308.34 - Exempt anabolic steroid products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Exempt anabolic steroid products. 1308.34 Section... SUBSTANCES Exempt Anabolic Steroid Products § 1308.34 Exempt anabolic steroid products. The list of compounds, mixtures, or preparations that contain an anabolic steroid that have been exempted by the...

  1. 21 CFR 1308.34 - Exempt anabolic steroid products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Exempt anabolic steroid products. 1308.34 Section... SUBSTANCES Exempt Anabolic Steroid Products § 1308.34 Exempt anabolic steroid products. The list of compounds, mixtures, or preparations that contain an anabolic steroid that have been exempted by the...

  2. 21 CFR 1308.34 - Exempt anabolic steroid products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Exempt anabolic steroid products. 1308.34 Section... SUBSTANCES Exempt Anabolic Steroid Products § 1308.34 Exempt anabolic steroid products. The list of compounds, mixtures, or preparations that contain an anabolic steroid that have been exempted by the...

  3. 21 CFR 1308.34 - Exempt anabolic steroid products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Exempt anabolic steroid products. 1308.34 Section... SUBSTANCES Exempt Anabolic Steroid Products § 1308.34 Exempt anabolic steroid products. The list of compounds, mixtures, or preparations that contain an anabolic steroid that have been exempted by the...

  4. 21 CFR 1308.34 - Exempt anabolic steroid products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Exempt anabolic steroid products. 1308.34 Section... SUBSTANCES Exempt Anabolic Steroid Products § 1308.34 Exempt anabolic steroid products. The list of compounds, mixtures, or preparations that contain an anabolic steroid that have been exempted by the...

  5. ErbB-1 and ErbB-2 Acquire Distinct Signaling Properties Dependent upon Their Dimerization Partner

    PubMed Central

    Olayioye, Monilola A.; Graus-Porta, Diana; Beerli, Roger R.; Rohrer, Jack; Gay, Brigitte; Hynes, Nancy E.

    1998-01-01

    The different epidermal growth factor (EGF)-related peptides elicit a diverse array of biological responses as the result of their ability to activate distinct subsets of ErbB receptor dimers, leading to the recruitment of different intracellular signaling networks. To specifically examine dimerization-dependent modulation of receptor signaling, we constructed NIH 3T3 cell lines expressing ErbB-1 and ErbB-2 singly and in pairwise combinations with each other ErbB family member. This model system allowed the comparison of EGF-activated ErbB-1 with ErbB-1 activated by Neu differentiation factor (NDF)-induced heterodimerization with ErbB-4. In both cases, ErbB-1 coupled to the adaptor protein Shc, but only when activated by EGF was it able to interact with Grb2. Compared to the rapid internalization of EGF-activated ErbB-1, NDF-activated ErbB-1 showed delayed internalization characteristics. Furthermore, the p85 subunit of phosphatidylinositol kinase (PI3-K) associated with EGF-activated ErbB-1 in a biphasic manner, whereas association with ErbB-1 transactivated by ErbB-4 was monophasic. The signaling properties of ErbB-2 following heterodimerization with the other ErbB receptors or homodimerization induced by point mutation or monoclonal antibody treatment were also analyzed. ErbB-2 binding to peptides containing the Src homology 2 domain of Grb2 or p85 and the phosphotyrosine binding domain of Shc varied according to the mode of receptor activation. Finally, tryptic phosphopeptide mapping of both ErbB-1 and ErbB-2 revealed that receptor phosphorylation is dependent on the dimerization partner. Differential receptor phosphorylation may, therefore, be the basis for the differences in the signaling properties observed. PMID:9710588

  6. Anabolic-androgenic steroids. Current issues.

    PubMed

    Yesalis, C E; Bahrke, M S

    1995-05-01

    The use of drugs to enhance physical performance has been observed for thousands of years. Today, individuals continue to use a variety of substances, including anabolic-androgenic steroids, in the hope of enhancing their performance and appearance. Rumours persist regarding the incidence of the nonmedical use of anabolic steroids by athletes and nonathletes: however, true estimates are now available based on the results of systematic surveys. Although the vast majority of the athletic community accepts that anabolic steroids enhance performance and appearance, the extent to which this occurs and the factors influencing such effects remain incompletely understood and documented. Refinement of our knowledge of the ergogenic effects of anabolic steroids is not without merit; however, the existing scientific evidence coupled with an overwhelming number of anecdotal accounts argues against devoting significant resources to this area of investigation at present. The short term health effects of anabolic steroids have been increasingly studied and reviewed, and while anabolic steroid use has been associated with several adverse and even fatal effects, the incidence of serious effects thus far reported has been extremely low. The long term effects of anabolic steroid use are generally unknown. Unfortunately, the lack of scientific information on long term health effects has impeded, if not precluded, the formation of effective health education and drug abuse prevention strategies. Consequently, efforts should be expanded in the areas of prevention and education.

  7. Alpha1a-adrenoceptor genetic variant induces cardiomyoblast-to-fibroblast-like cell transition via distinct signaling pathways.

    PubMed

    Kleine-Brueggeney, Maren; Gradinaru, Irina; Babaeva, Ekaterina; Schwinn, Debra A; Oganesian, Anush

    2014-09-01

    The role of naturally occurring human α1a-Adrenergic Receptor (α1aAR) genetic variants associated with cardiovascular disorders is poorly understood. Here, we present the novel findings that expression of human α1aAR-247R (247R) genetic variant in cardiomyoblasts leads to transition of cardiomyoblasts into a fibroblast-like phenotype, evidenced by morphology and distinct de novo expression of characteristic genes. These fibroblast-like cells exhibit constitutive, high proliferative capacity and agonist-induced hypertrophy compared with cells prior to transition. We demonstrate that constitutive, synergistic activation of EGFR, Src and ERK kinases is the potential molecular mechanism of this transition. We also demonstrate that 247R triggers two distinct EGFR transactivation-dependent signaling pathways: 1) constitutive Gq-independent β-arrestin-1/Src/MMP/EGFR/ERK-dependent hyperproliferation and 2) agonist-induced Gq- and EGFR/STAT-dependent hypertrophy. Interestingly, in cardiomyoblasts agonist-independent hyperproliferation is MMP-dependent, but in fibroblast-like cells it is MMP-independent, suggesting that expression of α1aAR genetic variant in cardiomyocytes may trigger extracellular matrix remodeling. Thus, these novel findings demonstrate that EGFR transactivation by α1aAR-247R leads to hyperproliferation, hypertrophy and alterations in cardiomyoblasts, suggesting that these unique genetically-mediated alterations in signaling pathways and cellular function may lead to myocardial fibrosis. Such extracellular matrix remodeling may contribute to the genesis of arrhythmias in certain types of heart failure. PMID:24835978

  8. Targeted gene knockdown in zebrafish reveals distinct intraembryonic functions for insulin-like growth factor II signaling.

    PubMed

    White, Yvonne A R; Kyle, Joshua T; Wood, Antony W

    2009-09-01

    IGF-II is the predominant IGF ligand regulating prenatal growth in all vertebrates, including humans, but its central role in placental development has confounded efforts to fully elucidate its functions within the embryo. Here we use a nonplacental model vertebrate (zebrafish) to interrogate the intraembryonic functions of IGF-II signaling. The zebrafish genome contains two coorthologs of mammalian IGF2 (igf2a, igf2b), which exhibit distinct patterns of expression during embryogenesis. Expression of igf2a mRNA is restricted to the notochord, primarily during segmentation/neurulation. By contrast, igf2b mRNA is expressed in midline tissues adjacent to the notochord, with additional sites of expression in the ventral forebrain, and the pronephros. To identify their intraembryonic functions, we suppressed the expression of each gene with morpholino oligonucleotides. Knockdown of igf2a led to defects in dorsal midline development, characterized by delayed segmentation, notochord undulations, and ventral curvature. Similarly, suppression of igf2b led to defects in dorsal midline development but also induced ectopic fusion of the nephron primordia, and defects in ventral forebrain development. Subsequent onset of severe body edema in igf2b, but not igf2a morphants, further suggested a distinct role for igf2b in development of the embryonic kidney. Simultaneous knockdown of both genes increased the severity of dorsal midline defects, confirming a conserved role for both genes in dorsal midline development. Collectively, these data provide evidence that the zebrafish orthologs of IGF2 function in dorsal midline development during segmentation/neurulation, whereas one paralog, igf2b, has evolved additional, distinct functions during subsequent organogenesis.

  9. 17beta-estradiol and tamoxifen stimulate rapid and transient ERK activationin MCF-7 cells via distinct signaling mechanisms.

    PubMed

    Visram, Hasina; Greer, Peter A

    2006-12-01

    Traditionally, estrogen signaling was thought to be mediated strictly through genomic pathways. Recently, however, it has been demonstrated that estrogen stimulation of cells leads to rapid nongenomic effects including ERK activation. While the precise mechanism of this action is still under investigation, it is known that activation of the epidermal growth factor receptor, the Src tyrosine kinase, and metalloproteinases are involved in this process. More recently, tamoxifen, an anti-hormonal agent used to treat breast cancer, has been shown to also activate ERK. The pathways by which it does so, however, are not known. Using the MCF-7 human breast carcinoma cell line as a model system, we show that ERK is rapidly and transiently activated in cells challenged with epidermal growth factor (EGF), 17beta-estradiol (E2) or tamoxifen. The ERK activation response to E2 and tamoxifen was kinetically similar, although the response to tamoxifen was delayed relative to that of E2 stimulation. The effect of the EGFR inhibitor AG1517 revealed that E2 and tamoxifen were both equally dependent on EGFR for activation of ERK. In contrast, inhibition of Src or metalloproteinases caused distinct effects on ERK activation by E2 and tamoxifen. Thus, while both E2 and tamoxifen induced activation of ERK, the differences in the effects of inhibitors of Src or metalloproteinases on ERK activation indicated that E2 and tamoxifen do so via distinct molecular mechanisms.

  10. Cross-talk between non-genomic and genomic signalling pathways - Distinct effect profiles of environmental estrogens

    SciTech Connect

    Silva, Elisabete; Kabil, Alena; Kortenkamp, Andreas

    2010-06-01

    Estrogen receptor (ER) transcriptional cross-talk after activation by 17{beta}-estradiol (E2) has been studied in considerable detail, but comparatively little is known about the ways in which synthetic estrogen-like chemicals, so-called xenoestrogens, interfere with these signalling pathways. E2 can stimulate rapid, non-genomic signalling events, such as activation of the Src/Ras/Erk signalling pathway. We investigated how activation of this pathway by E2, the estrogenic environmental contaminants o,p'-DDT, {beta}-HCH and p,p'-DDE, and epidermal growth factor (EGF) influences the expression of ER target genes, such as TFF1, ER, PR, BRCA1 and CCND1, and the proliferation of breast cancer cells. Despite commonalities in their estrogenicity as judged by cell proliferation assays, the environmental contaminants exhibited striking differences in their non-genomic and genomic signalling. The gene expression profiles of o,p'-DDT and {beta}-HCH resembled the effects observed with E2. In the case of {beta}-HCH this is surprising, considering its reported lack of affinity to the 'classical' ER. The expression profiles seen with p,p'-DDE showed some similarities with E2, but overall, p,p'-DDE was a fairly weak transcriptional inducer of TFF1, ER, PR, BRCA1 and CCND1. We observed distinct differences in the non-genomic signalling of the tested compounds. p,p'-DDE was unable to stimulate Src and Erk1/Erk2 activations. The effects of E2 on Src and Erk1/Erk2 phosphorylation were transient and weak when compared to EGF, but {beta}-HCH induced strong and sustained activation of all tested kinases. Transcription of TFF1, ER, PR and BRCA1 by E2, o,p'-DDT and {beta}-HCH could be suppressed partially by inhibiting the Src/Ras/Erk pathway with PD 98059. However, this was not seen with p,p'-DDE. Our investigations show that the cellular activities of estrogens and xenoestrogens are the result of a combination of extranuclear (non-genomic) and nuclear (genomic) events and highlight the

  11. Characterization of CLL exosomes reveals a distinct microRNA signature and enhanced secretion by activation of BCR signaling

    PubMed Central

    Yeh, Yuh-Ying; Ozer, Hatice Gulcin; Lehman, Amy M.; Maddocks, Kami; Yu, Lianbo; Byrd, John C.

    2015-01-01

    Multiple studies show that chronic lymphocytic leukemia (CLL) cells are heavily dependent on their microenvironment for survival. Communication between CLL cells and the microenvironment is mediated through direct cell contact, soluble factors, and extracellular vesicles. Exosomes are small particles enclosed with lipids, proteins, and small RNAs that can convey biological materials to surrounding cells. Our data herein demonstrate that CLL cells release significant amounts of exosomes in plasma that exhibit abundant CD37, CD9, and CD63 expression. Our work also pinpoints the regulation of B-cell receptor (BCR) signaling in the release of CLL exosomes: BCR activation by α-immunoglobulin (Ig)M induces exosome secretion, whereas BCR inactivation via ibrutinib impedes α-IgM-stimulated exosome release. Moreover, analysis of serial plasma samples collected from CLL patients on an ibrutinib clinical trial revealed that exosome plasma concentration was significantly decreased following ibrutinib therapy. Furthermore, microRNA (miR) profiling of plasma-derived exosomes identified a distinct exosome microRNA signature, including miR-29 family, miR-150, miR-155, and miR-223 that have been associated with CLL disease. Interestingly, expression of exosome miR-150 and miR-155 increases with BCR activation. In all, this study successfully characterized CLL exosomes, demonstrated the control of BCR signaling in the release of CLL exosomes, and uncovered a disease-relevant exosome microRNA profile. PMID:25833959

  12. Oxylipin Signaling: A Distinct Role for the Jasmonic Acid Precursor cis-(+)-12-Oxo-Phytodienoic Acid (cis-OPDA)

    PubMed Central

    Dave, Anuja; Graham, Ian A.

    2012-01-01

    Oxylipins are lipid-derived compounds, many of which act as signals in the plant response to biotic and abiotic stress. They include the phytohormone jasmonic acid (JA) and related jasmonate metabolites cis-(+)-12-oxo-phytodienoic acid (cis-OPDA), methyl jasmonate, and jasmonoyl-L-isoleucine (JA-Ile). Besides the defense response, jasmonates are involved in plant growth and development and regulate a range of processes including glandular trichome development, reproduction, root growth, and senescence. cis-OPDA is known to possess a signaling role distinct from JA-Ile. The non-enzymatically derived phytoprostanes are structurally similar to cis-OPDA and induce a common set of genes that are not responsive to JA in Arabidopsis thaliana. A novel role for cis-OPDA in seed germination regulation has recently been uncovered based on evidence from double mutants and feeding experiments showing that cis-OPDA interacts with abscisic acid (ABA), inhibits seed germination, and increases ABA INSENSITIVE5 (ABI5) protein abundance. Large amounts of cis-OPDA are esterified to galactolipids in A. thaliana and the resulting compounds, known as Arabidopsides, are thought to act as a rapidly available source of cis-OPDA. PMID:22645585

  13. DeltaA/DeltaD regulate multiple and temporally distinct phases of notch signaling during dopaminergic neurogenesis in zebrafish.

    PubMed

    Mahler, Julia; Filippi, Alida; Driever, Wolfgang

    2010-12-01

    Dopaminergic neurons develop at distinct anatomical sites to form some of the major neuromodulatory systems in the vertebrate brain. Despite their relevance in neurodegenerative diseases and the interests in reconstitutive therapies from stem cells, mechanisms of the neurogenic switch from precursor populations to dopaminergic neurons are not well understood. Here, we investigated neurogenesis of different dopaminergic and noradrenergic neuron populations in the zebrafish embryo. Birth-dating analysis by EdU (5-ethynyl-2'-deoxyuridine) incorporation revealed temporal dynamics of catecholaminergic neurogenesis. Analysis of Notch signaling mutants and stage-specific pharmacological inhibition of Notch processing revealed that dopaminergic neurons form by temporally distinct mechanisms: dopaminergic neurons of the posterior tuberculum derive directly from neural plate cells during primary neurogenesis, whereas other dopaminergic groups form in continuous or wavelike neurogenesis phases from proliferating precursor pools. Systematic analysis of Notch ligands revealed that the two zebrafish co-orthologs of mammalian Delta1, DeltaA and DeltaD, control the neurogenic switch of all early developing dopaminergic neurons in a partially redundant manner. DeltaA/D may also be involved in maintenance of dopaminergic precursor pools, as olig2 expression in ventral diencephalic dopaminergic precursors is affected in dla/dld mutants. DeltaA/D act upstream of sim1a and otpa during dopaminergic specification. However, despite the fact that both dopaminergic and corticotropin-releasing hormone neurons derive from sim1a- and otpa-expressing precursors, DeltaA/D does not act as a lineage switch between these two neuronal types. Rather, DeltaA/D limits the size of the sim1a- and otpa-expressing precursor pool from which dopaminergic neurons differentiate. PMID:21148001

  14. Anabolic steroid use in high school students.

    PubMed

    Pallesen, Ståle; Jøsendal, Ola; Johnsen, Bjørn-Helge; Larsen, Svein; Molde, Helge

    2006-01-01

    A total of 1351 high school students (52.3% males, 47.7% females) with mean age 17.5 years (SD = 2.2) from randomized school classes in Hordaland County, Norway, participated in an Internet survey conducted in 2004 about the lifetime use of anabolic steroids and personal acquaintance with at least one user of anabolic steroids. In addition to questions about anabolic steroids the participants completed the Hospital Anxiety and Depression Scale and the Alcohol Use Disorders Identification Test. They also answered questions about demography, smoking, and narcotic use. The lifetime prevalence for use of anabolic steroids was 3.6% for males and 0.6% for females. In all, 27.9% of the respondents reported having at least one acquaintance that used or had used anabolic steroids. Use of anabolic steroids and having acquaintances using such drugs were strongly related to use of other drugs such as alcohol, nicotine, and narcotics. Implications for prevention are discussed and the study's limitations are noted. PMID:17118811

  15. Anabolic action of parathyroid hormone regulated by the β2-adrenergic receptor.

    PubMed

    Hanyu, Ryo; Wehbi, Vanessa L; Hayata, Tadayoshi; Moriya, Shuichi; Feinstein, Timothy N; Ezura, Yoichi; Nagao, Masashi; Saita, Yoshitomo; Hemmi, Hiroaki; Notomi, Takuya; Nakamoto, Tetsuya; Schipani, Ernestina; Takeda, Shu; Kaneko, Kazuo; Kurosawa, Hisashi; Karsenty, Gerard; Kronenberg, Henry M; Vilardaga, Jean-Pierre; Noda, Masaki

    2012-05-01

    Parathyroid hormone (PTH), the major calcium-regulating hormone, and norepinephrine (NE), the principal neurotransmitter of sympathetic nerves, regulate bone remodeling by activating distinct cell-surface G protein-coupled receptors in osteoblasts: the parathyroid hormone type 1 receptor (PTHR) and the β(2)-adrenergic receptor (β(2)AR), respectively. These receptors activate a common cAMP/PKA signal transduction pathway mediated through the stimulatory heterotrimeric G protein. Activation of β(2)AR via the sympathetic nervous system decreases bone formation and increases bone resorption. Conversely, daily injection of PTH (1-34), a regimen known as intermittent (i)PTH treatment, increases bone mass through the stimulation of trabecular and cortical bone formation and decreases fracture incidences in severe cases of osteoporosis. Here, we show that iPTH has no osteoanabolic activity in mice lacking the β(2)AR. β(2)AR deficiency suppressed both iPTH-induced increase in bone formation and resorption. We showed that the lack of β(2)AR blocks expression of iPTH-target genes involved in bone formation and resorption that are regulated by the cAMP/PKA pathway. These data implicate an unexpected functional interaction between PTHR and β(2)AR, two G protein-coupled receptors from distinct families, which control bone formation and PTH anabolism. PMID:22538810

  16. Melatonin Regulates Somatotrope and Lactotrope Function Through Common and Distinct Signaling Pathways in Cultured Primary Pituitary Cells From Female Primates

    PubMed Central

    Ibáñez-Costa, Alejandro; Córdoba-Chacón, José; Gahete, Manuel D.; Kineman, Rhonda D.; Castaño, Justo P.

    2015-01-01

    Melatonin (MT) is secreted by the pineal gland and exhibits a striking circadian rhythm in its release. Depending on the species studied, some pituitary hormones also display marked circadian/seasonal patterns and rhythms of secretion. However, the precise relationship between MT and pituitary function remains controversial, and studies focusing on the direct role of MT in normal pituitary cells are limited to nonprimate species. Here, adult normal primate (baboons) primary pituitary cell cultures were used to determine the direct impact of MT on the functioning of all pituitary cell types from the pars distalis. MT increased GH and prolactin (PRL) expression/release in a dose- and time-dependent fashion, a response that was blocked by somatostatin. However, MT did not significantly affect ACTH, FSH, LH, or TSH expression/release. MT did not alter GHRH- or ghrelin-induced GH and/or PRL secretions, suggesting that MT may activate similar signaling pathways as ghrelin/GHRH. The effects of MT on GH/PRL release, which are likely mediated through MT1 receptor, involve both common (adenylyl cyclase/protein kinase A/extracellular calcium-channels) and distinct (phospholipase C/intracellular calcium-channels) signaling pathways. Actions of MT on pituitary cells also included regulation of the expression of other key components for the control of somatotrope/lactotrope function (GHRH, ghrelin, and somatostatin receptors). These results show, for the first time in a primate model, that MT directly regulates somatotrope/lactotrope function, thereby lending support to the notion that the actions of MT on these cells might substantially contribute to the define daily patterns of GH and PRL observed in primates and perhaps in humans. PMID:25545385

  17. Distinct Signaling Pathways After Higher or Lower Doses of Radiation in Three Closely Related Human Lymphoblast Cell Lines

    SciTech Connect

    Lu, T.-P.; Lai, L.-C.; Lin, B.-I.; Chen, L.-H.; Hsiao, T.-H.; Liber, Howard L.; Cook, John A.; Mitchell, James B.; Tsai, M.-H.; Chuang, Eric Y.

    2010-01-15

    Purpose: The tumor suppressor p53 plays an essential role in cellular responses to DNA damage caused by ionizing radiation; therefore, this study aims to further explore the role that p53 plays at different doses of radiation. Materials and Methods: The global cellular responses to higher-dose (10 Gy) and lower dose (iso-survival dose, i.e., the respective D0 levels) radiation were analyzed using microarrays in three human lymphoblast cell lines with different p53 status: TK6 (wild-type p53), NH32 (p53-null), and WTK1 (mutant p53). Total RNAs were extracted from cells harvested at 0, 1, 3, 6, 9, and 24 h after higher and lower dose radiation exposures. Template-based clustering, hierarchical clustering, and principle component analysis were applied to examine the transcriptional profiles. Results: Differential expression profiles between 10 Gy and iso-survival radiation in cells with different p53 status were observed. Moreover, distinct gene expression patterns were exhibited among these three cells after 10 Gy radiation treatment, but similar transcriptional responses were observed in TK6 and NH32 cells treated with iso-survival radiation. Conclusions: After 10 Gy radiation exposure, the p53 signaling pathway played an important role in TK6, whereas the NFkB signaling pathway appeared to replace the role of p53 in WTK1. In contrast, after iso-survival radiation treatment, E2F4 seemed to play a dominant role independent of p53 status. This study dissected the impacts of p53, NFkB and E2F4 in response to higher or lower doses of gamma-irradiation.

  18. Distinctive Properties of the Nuclear Localization Signals of Inner Nuclear Membrane Proteins Heh1 and Heh2.

    PubMed

    Lokareddy, Ravi K; Hapsari, Rizqiya A; van Rheenen, Mathilde; Pumroy, Ruth A; Bhardwaj, Anshul; Steen, Anton; Veenhoff, Liesbeth M; Cingolani, Gino

    2015-07-01

    Targeting of ER-synthesized membrane proteins to the inner nuclear membrane (INM) has long been explained by the diffusion-retention model. However, several INM proteins contain non-classical nuclear localization signal (NLS) sequences, which, in a few instances, have been shown to promote importin α/β- and Ran-dependent translocation to the INM. Here, using structural and biochemical methods, we show that yeast INM proteins Heh2 and Src1/Heh1 contain bipartite import sequences that associate intimately with the minor NLS-binding pocket of yeast importin α and unlike classical NLSs efficiently displace the IBB domain in the absence of importin β. In vivo, the intimate interactions at the minor NLS-binding pocket make the h2NLS highly efficient at recruiting importin α at the ER and drive INM localization of endogenous Heh2. Thus, h1/h2NLSs delineate a novel class of super-potent, IBB-like membrane protein NLSs, distinct from classical NLSs found in soluble cargos and of general interest in biology.

  19. Distinct mechanisms regulating mechanical force-induced Ca2+ signals at the plasma membrane and the ER in human MSCs

    PubMed Central

    Kim, Tae-Jin; Joo, Chirlmin; Seong, Jihye; Vafabakhsh, Reza; Botvinick, Elliot L; Berns, Michael W; Palmer, Amy E; Wang, Ning; Ha, Taekjip; Jakobsson, Eric; Sun, Jie; Wang, Yingxiao

    2015-01-01

    It is unclear that how subcellular organelles respond to external mechanical stimuli. Here, we investigated the molecular mechanisms by which mechanical force regulates Ca2+ signaling at endoplasmic reticulum (ER) in human mesenchymal stem cells. Without extracellular Ca2+, ER Ca2+ release is the source of intracellular Ca2+ oscillations induced by laser-tweezer-traction at the plasma membrane, providing a model to study how mechanical stimuli can be transmitted deep inside the cell body. This ER Ca2+ release upon mechanical stimulation is mediated not only by the mechanical support of cytoskeleton and actomyosin contractility, but also by mechanosensitive Ca2+ permeable channels on the plasma membrane, specifically TRPM7. However, Ca2+ influx at the plasma membrane via mechanosensitive Ca2+ permeable channels is only mediated by the passive cytoskeletal structure but not active actomyosin contractility. Thus, active actomyosin contractility is essential for the response of ER to the external mechanical stimuli, distinct from the mechanical regulation at the plasma membrane. DOI: http://dx.doi.org/10.7554/eLife.04876.001 PMID:25667984

  20. Potent and efficacious inhibition of CXCR2 signaling by biparatopic nanobodies combining two distinct modes of action.

    PubMed

    Bradley, M E; Dombrecht, B; Manini, J; Willis, J; Vlerick, D; De Taeye, S; Van den Heede, K; Roobrouck, A; Grot, E; Kent, T C; Laeremans, T; Steffensen, S; Van Heeke, G; Brown, Z; Charlton, S J; Cromie, K D

    2015-02-01

    Chemokines and chemokine receptors are key modulators in inflammatory diseases and malignancies. Here, we describe the identification and pharmacologic characterization of nanobodies selectively blocking CXCR2, the most promiscuous of all chemokine receptors. Two classes of selective monovalent nanobodies were identified, and detailed epitope mapping showed that these bind to distinct, nonoverlapping epitopes on the CXCR2 receptor. The N-terminal-binding or class 1 monovalent nanobodies possessed potencies in the single-digit nanomolar range but lacked complete efficacy at high agonist concentrations. In contrast, the extracellular loop-binding or class 2 monovalent nanobodies were of lower potency but were more efficacious and competitively inhibited the CXCR2-mediated functional response in both recombinant and neutrophil in vitro assays. In addition to blocking CXCR2 signaling mediated by CXCL1 (growth-related oncogene α) and CXCL8 (interleukin-8), both classes of nanobodies displayed inverse agonist behavior. Bivalent and biparatopic nanobodies were generated, respectively combining nanobodies from the same or different classes via glycine/serine linkers. Interestingly, receptor mutation and competition studies demonstrated that the biparatopic nanobodies were able to avidly bind epitopes within one or across two CXCR2 receptor molecules. Most importantly, the biparatopic nanobodies were superior over their monovalent and bivalent counterparts in terms of potency and efficacy.

  1. Modulation of follistatin and myostatin propeptide by anabolic steroids and gender.

    PubMed

    Mosler, S; Geisler, S; Hengevoss, J; Schiffer, T; Piechotta, M; Adler, M; Diel, P

    2013-07-01

    The purpose of this pilot study was to investigate the impact of training, anabolic steroids and endogenous hormones on myostatin-interacting proteins in order to identify manipulations of myostatin signalling. To identify whether analysis of the myostatin interacting proteins follistatin and myostatin propeptide is suitable to detect the abuse of anabolic steroids, their serum concentrations were monitored in untrained males, bodybuilders using anabolic steroids and natural bodybuilders. In addition, we analysed follistatin and myostatin propeptide serum proteins in females during menstrual cycle. Our results showed increased follistatin concentrations in response to anabolic steroids. Furthermore, variations of sex steroid levels during the menstrual cycle had no impact on the expression of follistatin and myostatin propetide. In addition, we identified gender differences in the basal expression of the investigated proteins. In general, follistatin and myostatin propeptide concentrations were relatively stable within the same individual both in males and females. In conclusion, the current findings provide an insight into gender differences in myostatin-interacting proteins and their regulation in response to anabolic steroids and endogenous hormones. Therefore our data provide new aspects for the development of doping prevention strategies.

  2. Self-enforcing Feedback Activation between BCL6 and Pre-B Cell Receptor Signaling Defines a Distinct Subtype of Acute Lymphoblastic Leukemia

    PubMed Central

    Geng, Huimin; Hurtz, Christian; Lenz, Kyle B.; Chen, Zhengshan; Baumjohann, Dirk; Thompson, Sarah; Goloviznina, Natalya; Chen, Wei-Yi; Huan, Jianya; LaTocha, Dorian; Ballabio, Erica; Xiao, Gang; Lee, Jae-Woong; Deucher, Anne; Qi, Zhongxia; Park, Eugene; Huang, Chuanxin; Nahar, Rahul; Kweon, Soo-Mi; Shojaee, Seyedmehdi; Chan, Lai N.; Yu, Jingwei; Kornblau, Steven M.; Bijl, Janetta J.; Ye, B. Hilda; Ansel, Mark; Paietta, Elisabeth; Melnick, Ari; Hunger, Stephen P.; Kurre, Peter; Tyner, Jeffrey W.; Loh, Mignon L.; Roeder, Robert G.; Druker, Brian J.; Burger, Jan. A.; Milne, Thomas A.; Chang, Bill H.; Müschen, Markus

    2015-01-01

    SUMMARY Studying 830 pre-B ALL cases from four clinical trials, we found that human ALL can be divided into two fundamentally distinct subtypes based on pre-BCR function. While absent in the majority of ALL cases, tonic pre-BCR signaling was found in 112 cases (13.5%). In these cases, tonic pre-BCR signaling induced activation of BCL6, which in turn increased pre-BCR signaling output at the transcriptional level. Interestingly, inhibition of pre-BCR-related tyrosine kinases reduced constitutive BCL6 expression and selectively killed patient-derived pre-BCR+ ALL cells. These findings identify a genetically and phenotypically distinct subset of human ALL that critically depends on tonic pre-BCR signaling. In vivo treatment studies suggested that pre-BCR tyrosine kinase inhibitors are useful for the treatment of patients with pre-BCR+ ALL. PMID:25759025

  3. Ecdysteroids: A novel class of anabolic agents?

    PubMed Central

    Botrè, F; Naß, A; Hengevoss, J; Diel, P; Wolber, G

    2015-01-01

    Increasing numbers of dietary supplements with ecdysteroids are marketed as “natural anabolic agents”. Results of recent studies suggested that their anabolic effect is mediated by estrogen receptor (ER) binding. Within this study the anabolic potency of ecdysterone was compared to well characterized anabolic substances. Effects on the fiber sizes of the soleus muscle in rats as well the diameter of C2C12 derived myotubes were used as biological readouts. Ecdysterone exhibited a strong hypertrophic effect on the fiber size of rat soleus muscle that was found even stronger compared to the test compounds metandienone (dianabol), estradienedione (trenbolox), and SARM S 1, all administered in the same dose (5 mg/kg body weight, for 21 days). In C2C12 myotubes ecdysterone (1 µM) induced a significant increase of the diameter comparable to dihydrotestosterone (1 µM) and IGF 1 (1.3 nM). Molecular docking experiments supported the ERβ mediated action of ecdysterone. To clarify its status in sports, ecdysterone should be considered to be included in the class “S1.2 Other Anabolic Agents” of the list of prohibited substances of the World Anti-Doping Agency. PMID:26060342

  4. Ecdysteroids: A novel class of anabolic agents?

    PubMed

    Parr, M K; Botrè, F; Naß, A; Hengevoss, J; Diel, P; Wolber, G

    2015-06-01

    Increasing numbers of dietary supplements with ecdysteroids are marketed as "natural anabolic agents". Results of recent studies suggested that their anabolic effect is mediated by estrogen receptor (ER) binding. Within this study the anabolic potency of ecdysterone was compared to well characterized anabolic substances. Effects on the fiber sizes of the soleus muscle in rats as well the diameter of C2C12 derived myotubes were used as biological readouts. Ecdysterone exhibited a strong hypertrophic effect on the fiber size of rat soleus muscle that was found even stronger compared to the test compounds metandienone (dianabol), estradienedione (trenbolox), and SARM S 1, all administered in the same dose (5 mg/kg body weight, for 21 days). In C2C12 myotubes ecdysterone (1 µM) induced a significant increase of the diameter comparable to dihydrotestosterone (1 µM) and IGF 1 (1.3 nM). Molecular docking experiments supported the ERβ mediated action of ecdysterone. To clarify its status in sports, ecdysterone should be considered to be included in the class "S1.2 Other Anabolic Agents" of the list of prohibited substances of the World Anti-Doping Agency. PMID:26060342

  5. Short Anabolic Peptides for Bone Growth.

    PubMed

    Amso, Zaid; Cornish, Jillian; Brimble, Margaret A

    2016-07-01

    Loss of bone occurs in the age-related skeletal disorder, osteoporosis, leading to bone fragility and increased incidence of fractures, which are associated with enormous costs and substantial morbidity and mortality. Recent data indicate that osteoporotic fractures are more common than other diseases, which usually attract public attention (e.g., heart attack and breast cancer). The prevention and treatment of this skeletal disorder are therefore of paramount importance. Majority of osteoporosis medications restore skeletal balance by reducing osteoclastic activity, thereby reducing bone resorption. These agents, however, do not regenerate damaged bone tissue, leaving limited options for patients once bone loss has occurred. Recently, attention has turned to bone-anabolic agents. Such agents have the ability to increase bone mass and strength, potentially reversing structural damage. To date, only one bone-anabolic drug is available in the market. The discovery of more novel, cost-effective bone anabolic agents is therefore a priority to treat those suffering from this disabling condition. Short peptides offer an important alternative for the development of novel bone-anabolic agents given their high target binding specificity, which translates into potent activity with limited side effects. This review summarizes attempts in the identification of bone-anabolic peptides, and their development for promoting bone growth. PMID:27297498

  6. Short Anabolic Peptides for Bone Growth.

    PubMed

    Amso, Zaid; Cornish, Jillian; Brimble, Margaret A

    2016-07-01

    Loss of bone occurs in the age-related skeletal disorder, osteoporosis, leading to bone fragility and increased incidence of fractures, which are associated with enormous costs and substantial morbidity and mortality. Recent data indicate that osteoporotic fractures are more common than other diseases, which usually attract public attention (e.g., heart attack and breast cancer). The prevention and treatment of this skeletal disorder are therefore of paramount importance. Majority of osteoporosis medications restore skeletal balance by reducing osteoclastic activity, thereby reducing bone resorption. These agents, however, do not regenerate damaged bone tissue, leaving limited options for patients once bone loss has occurred. Recently, attention has turned to bone-anabolic agents. Such agents have the ability to increase bone mass and strength, potentially reversing structural damage. To date, only one bone-anabolic drug is available in the market. The discovery of more novel, cost-effective bone anabolic agents is therefore a priority to treat those suffering from this disabling condition. Short peptides offer an important alternative for the development of novel bone-anabolic agents given their high target binding specificity, which translates into potent activity with limited side effects. This review summarizes attempts in the identification of bone-anabolic peptides, and their development for promoting bone growth.

  7. Ecdysteroids: A novel class of anabolic agents?

    PubMed

    Parr, M K; Botrè, F; Naß, A; Hengevoss, J; Diel, P; Wolber, G

    2015-06-01

    Increasing numbers of dietary supplements with ecdysteroids are marketed as "natural anabolic agents". Results of recent studies suggested that their anabolic effect is mediated by estrogen receptor (ER) binding. Within this study the anabolic potency of ecdysterone was compared to well characterized anabolic substances. Effects on the fiber sizes of the soleus muscle in rats as well the diameter of C2C12 derived myotubes were used as biological readouts. Ecdysterone exhibited a strong hypertrophic effect on the fiber size of rat soleus muscle that was found even stronger compared to the test compounds metandienone (dianabol), estradienedione (trenbolox), and SARM S 1, all administered in the same dose (5 mg/kg body weight, for 21 days). In C2C12 myotubes ecdysterone (1 µM) induced a significant increase of the diameter comparable to dihydrotestosterone (1 µM) and IGF 1 (1.3 nM). Molecular docking experiments supported the ERβ mediated action of ecdysterone. To clarify its status in sports, ecdysterone should be considered to be included in the class "S1.2 Other Anabolic Agents" of the list of prohibited substances of the World Anti-Doping Agency.

  8. VEGF and thrombin induce MKP-1 through distinct signaling pathways: role for MKP-1 in endothelial cell migration.

    PubMed

    Kinney, Corttrell M; Chandrasekharan, Unni M; Mavrakis, Lori; DiCorleto, Paul E

    2008-01-01

    We have previously reported that MAPK phosphatase-1 (MKP-1/CL100) is a thrombin-responsive gene in endothelial cells (ECs). We now show that VEGF is another efficacious activator of MKP-1 expression in human umbilical vein ECs. VEGF-A and VEGF-E maximally induced MKP-1 expression in ECs; however, the other VEGF subtypes had no effect. Using specific neutralizing antibodies, we determined that VEGF induced MKP-1 specifically through VEGF receptor 2 (VEGFR-2), leading to the downstream activation of JNK. The VEGF-A(165) isoform stimulated MKP-1 expression, whereas the VEGF-A(162) isoform induced the gene to a lesser extent, and the VEGF-A(121) isoform had no effect. Furthermore, specific blocking antibodies against neuropilins, VEGFR-2 coreceptors, blocked MKP-1 induction. A Src kinase inhibitor (PP1) completely blocked both VEGF- and thrombin-induced MKP-1 expression. A dominant negative approach revealed that Src kinase was required for VEGF-induced MKP-1 expression, whereas Fyn kinase was critical for thrombin-induced MKP-1 expression. Moreover, VEGF-induced MKP-1 expression required JNK, whereas ERK was critical for thrombin-induced MKP-1 expression. In ECs treated with short interfering (si)RNA targeting MKP-1, JNK, ERK, and p38 phosphorylation were prolonged following VEGF stimulation. An ex vivo aortic angiogenesis assay revealed a reduction in VEGF- and thrombin-induced sprout outgrowth in segments from MKP-1-null mice versus wild-type controls. MKP-1 siRNA also significantly reduced VEGF-induced EC migration using a transwell assay system. Overall, these results demonstrate distinct MAPK signaling pathways for thrombin versus VEGF induction of MKP-1 in ECs and point to the importance of MKP-1 induction in VEGF-stimulated EC migration. PMID:18003751

  9. Anabolic steroids and cardiovascular risk.

    PubMed

    Angell, Peter; Chester, Neil; Green, Danny; Somauroo, John; Whyte, Greg; George, Keith

    2012-02-01

    Recent reports from needle exchange programmes and other public health initiatives have suggested growing use of anabolic steroids (AS) in the UK and other countries. Data indicate that AS use is not confined to body-builders or high-level sportsmen. Use has spread to professionals working in emergency services, casual fitness enthusiasts and subelite sportsmen and women. Although the precise health consequences of AS use is largely undefined, AS use represents a growing public health concern. Data regarding the consequences of AS use on cardiovascular health are limited to case studies and a modest number of small cohort studies. Numerous case studies have linked AS use with a variety of cardiovascular disease (CVD) events or endpoints, including myocardial infarction, stroke and death. Large-scale epidemiological studies to support these links are absent. Consequently, the impact of AS use upon known CVD risk factors has been studied in relatively small, case-series studies. Data relating AS use to elevated blood pressure, altered lipid profiles and ECG abnormalities have been reported, but are often limited in scope, and other studies have often produced equivocal outcomes. The use of AS has been linked to the appearance of concentric left ventricular hypertrophy as well as endothelial dysfunction but the data again remains controversial. The mechanisms responsible for the negative effect of AS on cardiovascular health are poorly understood, especially in humans. Possibilities include direct effects on myocytes and endothelial cells, reduced intracellular Ca2+ levels, increased release of apoptogenic factors, as well as increased collagen crosslinks between myocytes. New data relating AS use to cardiovascular health risks are emerging, as novel technologies are developed (especially in non-invasive imaging) that can assess physiological structure and function. Continued efforts to fully document the cardiovascular health consequences of AS use is important to

  10. Sexual functioning of male anabolic steroid abusers.

    PubMed

    Moss, H B; Panzak, G L; Tarter, R E

    1993-02-01

    The effects of anabolic steroid use on male sexual behavior were assessed using a structured clinical interview administered to male body builders currently using steroids, and to two comparison groups (body builders with a past but not current history of steroid use, and a group of "natural" body builders who had never used steroids). Current anabolic steroid users had a significantly higher coital and orgasmic frequency than did comparison athletes. They also reported a significantly higher incidence of erectile difficulties during the past month. Beliefs concerning the sexually stimulating effects of steroids did not correlate with the frequencies of specific sexual behaviors. The data support the contention that anabolic steroids, as androgenic compounds, enhance sexual desire.

  11. Pathological changes in anabolic androgenic steroid users.

    PubMed

    Lusetti, Monia; Licata, Manuela; Silingardi, Enrico; Reggiani Bonetti, Luca; Palmiere, Cristian

    2015-07-01

    Several classes of recreational and prescription drugs have additional effects on the heart and vasculature, which may significantly contribute to morbidity and mortality in chronic users. The study presented herein focuses on pathological changes involving the heart possibly due to anabolic androgenic steroid use. The role these hormones may play in their occurrence of sudden cardiac death is also investigated. 98 medico-legal cases including 6 anabolic androgenic steroid users were retrospectively reviewed. Autopsies, histology, immunohistochemistry, biochemistry and toxicology were performed in all cases. Pathological changes consisted of various degrees of interstitial and perivascular fibrosis as well as fibroadipous metaplasia and perineural fibrosis within the myocardium of the left ventricle. Within the limits of the small number of investigated cases, our results appear to confirm former observations on this topic and suggest anabolic androgenic steroid's potential causative role in the pathogenesis of sudden cardiac deaths in chronic users.

  12. Small molecule inhibitors of the Dishevelled-CXXC5 interaction are new drug candidates for bone anabolic osteoporosis therapy.

    PubMed

    Kim, Hyun-Yi; Choi, Sehee; Yoon, Ji-Hye; Lim, Hwan Jung; Lee, Hyuk; Choi, Jiwon; Ro, Eun Ji; Heo, Jung-Nyoung; Lee, Weontae; No, Kyoung Tai; Choi, Kang-Yell

    2016-01-01

    Bone anabolic agents promoting bone formation and rebuilding damaged bones would ideally overcome the limitations of anti-resorptive therapy, the current standard prescription for osteoporosis. However, the currently prescribed parathyroid hormone (PTH)-based anabolic drugs present limitations and adverse effects including osteosarcoma during long-term use. Also, the antibody-based anabolic drugs that are currently being developed present the potential limits in clinical application typical of macromolecule drugs. We previously identified that CXXC5 is a negative feedback regulator of the Wnt/β-catenin pathway via its interaction with Dishevelled (Dvl) and suggested the Dvl-CXXC5 interaction as a potential target for anabolic therapy of osteoporosis. Here, we screened small-molecule inhibitors of the Dvl-CXXC5 interaction via a newly established in vitro assay system. The screened compounds were found to activate the Wnt/β-catenin pathway and enhance osteoblast differentiation in primary osteoblasts. The bone anabolic effects of the compounds were shown using ex vivo-cultured calvaria. Nuclear magnetic resonance (NMR) titration analysis confirmed interaction between Dvl PDZ domain and KY-02061, a representative of the screened compounds. Oral administration of KY-02327, one of 55 newly synthesized KY-02061 analogs, successfully rescued bone loss in the ovariectomized (OVX) mouse model. In conclusion, small-molecule inhibitors of the Dvl-CXXC5 interaction that block negative feedback regulation of Wnt/β-catenin signaling are potential candidates for the development of bone anabolic anti-osteoporosis drugs.

  13. Androgenic anabolic steroids also impair right ventricular function.

    PubMed

    Kasikcioglu, Erdem; Oflaz, Huseyin; Umman, Berrin; Bugra, Zehra

    2009-05-01

    Chronic anabolic steroid use suppresses left ventricular functions. However, there is no information regarding the chronic effects of anabolic steroids on right ventricular function which also plays a key role in global cardiac function. The main objective of the present study was to investigate the effects of androgenic anabolic steroids usage among athletes on remodeling the right part of the heart. Androgenic-anabolic steroids-using bodybuilders had smaller diastolic velocities of both ventricles than drug-free bodybuilders and sedentary counterparts. This study shows that androgenic anabolic steroids-using bodybuilders exhibited depressed diastolic functions of both ventricles.

  14. The Rim15-Endosulfine-PP2ACdc55 Signalling Module Regulates Entry into Gametogenesis and Quiescence via Distinct Mechanisms in Budding Yeast

    PubMed Central

    Sarkar, Sourav; Dalgaard, Jacob Z.; Millar, Jonathan B. A.; Arumugam, Prakash

    2014-01-01

    Quiescence and gametogenesis represent two distinct survival strategies in response to nutrient starvation in budding yeast. Precisely how environmental signals are sensed by yeast cells to trigger quiescence and gametogenesis is not fully understood. A conserved signalling module consisting of Greatwall kinase, Endosulfine and Protein Phosphatase PP2ACdc55 proteins regulates entry into mitosis in Xenopus egg extracts and meiotic maturation in flies. We report here that an analogous signalling module consisting of the serine-threonine kinase Rim15, the Endosulfines Igo1 and Igo2 and the Protein Phosphatase PP2ACdc55, regulates entry into both quiescence and gametogenesis in budding yeast. PP2ACdc55 inhibits entry into gametogenesis and quiescence. Rim15 promotes entry into gametogenesis and quiescence by converting Igo1 into an inhibitor of PP2ACdc55 by phosphorylating at a conserved serine residue. Moreover, we show that the Rim15-Endosulfine-PP2ACdc55 pathway regulates entry into quiescence and gametogenesis by distinct mechanisms. In addition, we show that Igo1 and Igo2 are required for pre-meiotic autophagy but the lack of pre-meiotic autophagy is insufficient to explain the sporulation defect of igo1Δ igo2Δ cells. We propose that the Rim15-Endosulfine-PP2ACdc55 signalling module triggers entry into quiescence and gametogenesis by regulating dephosphorylation of distinct substrates. PMID:24968058

  15. Preventing Anabolic Steroid Use: Guidelines and Activities.

    ERIC Educational Resources Information Center

    Nutter, June; Rauhe, Betty

    1997-01-01

    Information about anabolic steroids should be included in the school health curriculum as early as possible. The paper presents suggestions for planning education programs and offers a variety of activities and strategies appropriate for many age groups, including case studies, story completion, posters, demonstrations, projects, creative writing,…

  16. Anabolic hormone profiles in elite military men.

    PubMed

    Taylor, Marcus K; Kviatkovsky, Shiloah A; Hernández, Lisa M; Sargent, Paul; Segal, Sabrina; Granger, Douglas A

    2016-06-01

    We recently characterized the awakening responses and daily profiles of the catabolic stress hormone cortisol in elite military men. Anabolic hormones follow a similar daily pattern and may counteract the catabolic effects of cortisol. This companion report is the first to characterize daily profiles of anabolic hormones dehydroepiandrosterone (DHEA) and testosterone in this population. Overall, the men in this study displayed anabolic hormone profiles comparable to that of healthy, athletic populations. Consistent with the cortisol findings in our prior report, summary parameters of magnitude (hormone output) within the first hour after awakening displayed superior stability versus summary parameters of pattern for both DHEA (r range: 0.77-0.82) and testosterone (r range: 0.62-0.69). Summary parameters of evening function were stable for the two hormones (both p<0.001), while the absolute decrease in testosterone across the day was a stable proxy of diurnal function (p<0.001). Removal of noncompliant subjects did not appreciably affect concentration estimates for either hormone at any time point, nor did it alter the repeatability of any summary parameter. The first of its kind, this report enables accurate estimations of anabolic balance and resultant effects upon health and human performance in this highly resilient yet chronically stressed population. PMID:27083310

  17. Anabolic hormone profiles in elite military men.

    PubMed

    Taylor, Marcus K; Kviatkovsky, Shiloah A; Hernández, Lisa M; Sargent, Paul; Segal, Sabrina; Granger, Douglas A

    2016-06-01

    We recently characterized the awakening responses and daily profiles of the catabolic stress hormone cortisol in elite military men. Anabolic hormones follow a similar daily pattern and may counteract the catabolic effects of cortisol. This companion report is the first to characterize daily profiles of anabolic hormones dehydroepiandrosterone (DHEA) and testosterone in this population. Overall, the men in this study displayed anabolic hormone profiles comparable to that of healthy, athletic populations. Consistent with the cortisol findings in our prior report, summary parameters of magnitude (hormone output) within the first hour after awakening displayed superior stability versus summary parameters of pattern for both DHEA (r range: 0.77-0.82) and testosterone (r range: 0.62-0.69). Summary parameters of evening function were stable for the two hormones (both p<0.001), while the absolute decrease in testosterone across the day was a stable proxy of diurnal function (p<0.001). Removal of noncompliant subjects did not appreciably affect concentration estimates for either hormone at any time point, nor did it alter the repeatability of any summary parameter. The first of its kind, this report enables accurate estimations of anabolic balance and resultant effects upon health and human performance in this highly resilient yet chronically stressed population.

  18. Review of Androgenic Anabolic Steroid Use

    SciTech Connect

    T. Borges; G. Eisele; C. Byrd

    2001-07-31

    An area that has been overlooked within personnel security evaluations is employee use of androgenic-anabolic steroids (AAS). Current drug testing within the federal government does not include testing for anabolic steroids, and the difficulties to implement such testing protocols-not to mention the cost involved-make AAS testing highly improbable. The basis of this report is to bring to the forefront the damage that anabolic steroids can cause from both a physical and a psychological standpoint. Most individuals who use AASs do so to increase their muscle mass because they wish to gain some type of competitive edge during athletic competition or they wish to enhance their physical features for self-satisfaction and self-esteem (i.e., body building). Security officers are one group of men who often take high doses of anabolic steroids, according to the Second Report of the Senate Standing Committee (1990). The negative psychological characteristics for AAS use is extensive and includes prominent hostility, aggressiveness, irritability, euphoria, grandiose beliefs, hyperactivity, reckless behavior, increased sexual appetite, unpredictability, poor impulse control, mood fluctuations, and insomnia. The drug may invoke a sense of power and invincibility (Leckman and Scahill, 1990). Depressive symptoms, such as anhedonia, fatigue, impaired concentration, decreased libido, and even suicidality (Pope and Katz, 1992) have been noted with steroid withdrawal. It appears that long-term users of AAS experience similar characteristics as other substance abusers (i.e., craving, dependence, and withdrawal symptoms).

  19. Behavioral and physiological responses to anabolic-androgenic steroids.

    PubMed

    Clark, Ann S; Henderson, Leslie P

    2003-08-01

    Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone originally designed for therapeutic uses to provide enhanced anabolic potency with negligible androgenic effects. Although AAS continue to be used clinically today, the medical benefits of low therapeutic doses of AAS stand in sharp contrast to the potential health risks associated with the excessive doses self-administered not only by elite athletes and body builders, but by a growing number of recreational users, including adolescent boys and girls. The deleterious effects of AAS on peripheral organs and the incidence of altered behaviors in AAS abusers have been well documented in a number of excellent current reviews for clinical populations. However, a comparable synthesis of nonclinical studies has not been made. Our purpose in this review is to summarize the literature for animal models of the effects of supraphysiological doses of AAS (e.g. those that mimic human abuse regimes) on behaviors and on the neural circuitry for these behaviors. In particular, we have focused on studies in rodents that have examined how AAS alter aggression, sexual behaviors, anxiety, reward, learning, and locomotion and how AAS alter the expression and function of neurotransmitter systems and other signaling molecules that underlie these behaviors.

  20. Comparative idiosyncrasies in life extension by reduced mTOR signalling and its distinctiveness from dietary restriction.

    PubMed

    Garratt, Michael; Nakagawa, Shinichi; Simons, Mirre J P

    2016-08-01

    Reduced mechanistic target of rapamycin (mTOR) signalling extends lifespan in yeast, nematodes, fruit flies and mice, highlighting a physiological pathway that could modulate aging in evolutionarily divergent organisms. This signalling system is also hypothesized to play a central role in lifespan extension via dietary restriction. By collating data from 48 available published studies examining lifespan with reduced mTOR signalling, we show that reduced mTOR signalling provides similar increases in median lifespan across species, with genetic mTOR manipulations consistently providing greater life extension than pharmacological treatment with rapamycin. In contrast to the consistency in changes in median lifespan, however, the demographic causes for life extension are highly species specific. Reduced mTOR signalling extends lifespan in nematodes by strongly reducing the degree to which mortality rates increase with age (aging rate). By contrast, life extension in mice and yeast occurs largely by pushing back the onset of aging, but not altering the shape of the mortality curve once aging starts. Importantly, in mice, the altered pattern of mortality induced by reduced mTOR signalling is different to that induced by dietary restriction, which reduces the rate of aging. Effects of mTOR signalling were also sex dependent, but only within mice, and not within flies, thus again species specific. An alleviation of age-associated mortality is not a shared feature of reduced mTOR signalling across model organisms and does not replicate the established age-related survival benefits of dietary restriction. PMID:27139919

  1. Distinct Sonic Hedgehog signaling dynamics specify floor plate and ventral neuronal progenitors in the vertebrate neural tube.

    PubMed

    Ribes, Vanessa; Balaskas, Nikolaos; Sasai, Noriaki; Cruz, Catarina; Dessaud, Eric; Cayuso, Jordi; Tozer, Samuel; Yang, Lin Lin; Novitch, Ben; Marti, Elisa; Briscoe, James

    2010-06-01

    The secreted ligand Sonic Hedgehog (Shh) organizes the pattern of cellular differentiation in the ventral neural tube. For the five neuronal subtypes, increasing levels and durations of Shh signaling direct progenitors to progressively more ventral identities. Here we demonstrate that this mode of action is not applicable to the generation of the most ventral cell type, the nonneuronal floor plate (FP). In chick and mouse embryos, FP specification involves a biphasic response to Shh signaling that controls the dynamic expression of key transcription factors. During gastrulation and early somitogenesis, FP induction depends on high levels of Shh signaling. Subsequently, however, prospective FP cells become refractory to Shh signaling, and this is a prerequisite for the elaboration of their identity. This prompts a revision to the model of graded Shh signaling in the neural tube, and provides insight into how the dynamics of morphogen signaling are deployed to extend the patterning capacity of a single ligand. In addition, we provide evidence supporting a common scheme for FP specification by Shh signaling that reconciles mechanisms of FP development in teleosts and amniotes.

  2. Acute bile nephropathy secondary to anabolic steroids.

    PubMed

    Alkhunaizi, Ahmed M; ElTigani, Mohamed A; Rabah, Rola S; Nasr, Samih H

    2016-02-01

    Renal dysfunction in cholestatic liver disease is multifactorial. Acute kidney injury may develop secondary to renal vasoconstriction in the setting of peripheral vasodilation and relative hypovolemia, tubular obstruction by bile casts, and direct tubular toxicity from bile. Anabolic steroids are frequently used by athletes to boost endurance and increase muscle mass. These agents are a recently recognized cause of hepatotoxicity and jaundice and may lead to acute kidney injury. To increase awareness about this growing problem and to characterize the pathology of acute kidney injury in this setting, we report on a young male who developed acute kidney injury in the setting of severe cholestatic jaundice related to ingestion of anabolic steroids used for bodybuilding. Kidney biopsy showed bile casts within distal tubular lumina, filamentous bile inclusions within tubular cells, and signs of acute tubular injury. This report supports the recently re-emerged concept of bile nephropathy cholemic nephrosis.

  3. Acute bile nephropathy secondary to anabolic steroids.

    PubMed

    Alkhunaizi, Ahmed M; ElTigani, Mohamed A; Rabah, Rola S; Nasr, Samih H

    2016-02-01

    Renal dysfunction in cholestatic liver disease is multifactorial. Acute kidney injury may develop secondary to renal vasoconstriction in the setting of peripheral vasodilation and relative hypovolemia, tubular obstruction by bile casts, and direct tubular toxicity from bile. Anabolic steroids are frequently used by athletes to boost endurance and increase muscle mass. These agents are a recently recognized cause of hepatotoxicity and jaundice and may lead to acute kidney injury. To increase awareness about this growing problem and to characterize the pathology of acute kidney injury in this setting, we report on a young male who developed acute kidney injury in the setting of severe cholestatic jaundice related to ingestion of anabolic steroids used for bodybuilding. Kidney biopsy showed bile casts within distal tubular lumina, filamentous bile inclusions within tubular cells, and signs of acute tubular injury. This report supports the recently re-emerged concept of bile nephropathy cholemic nephrosis. PMID:26587777

  4. Disruption of aminergic signalling reveals novel compounds with distinct inhibitory effects on mosquito reproduction, locomotor function and survival

    PubMed Central

    Fuchs, Silke; Rende, Ermelinda; Crisanti, Andrea; Nolan, Tony

    2014-01-01

    Insecticide resistance amongst disease vectors is a growing problem and novel compounds are needed. Biogenic amines are important for neurotransmission and we have recently shown a potential role for these in mosquito fertility. Here, we dissected the relative contribution of different aminergic signalling pathways to biological processes essential for vectorial capacity such as fertility, locomotion and survival by injecting agonists and antagonists and showed that octopaminergic/tyraminergic signalling is essential for oviposition and hatching rate. We show that egg melanisation is regulated by adrenergic signalling, whose disruption causes premature melanisation specifically through the action of tyramine. In addition to this, co-injection of tyramine with DOPA, the precursor of melanin, had a strong cumulative negative effect on mosquito locomotion and survival. Dopaminergic and serotonergic antagonists such as amitriptyline and citalopram recapitulate this effect. Together these results reveal potential new target sites for the development of future mosquito sterilants and insecticides. PMID:24984706

  5. Disruption of aminergic signalling reveals novel compounds with distinct inhibitory effects on mosquito reproduction, locomotor function and survival

    NASA Astrophysics Data System (ADS)

    Fuchs, Silke; Rende, Ermelinda; Crisanti, Andrea; Nolan, Tony

    2014-07-01

    Insecticide resistance amongst disease vectors is a growing problem and novel compounds are needed. Biogenic amines are important for neurotransmission and we have recently shown a potential role for these in mosquito fertility. Here, we dissected the relative contribution of different aminergic signalling pathways to biological processes essential for vectorial capacity such as fertility, locomotion and survival by injecting agonists and antagonists and showed that octopaminergic/tyraminergic signalling is essential for oviposition and hatching rate. We show that egg melanisation is regulated by adrenergic signalling, whose disruption causes premature melanisation specifically through the action of tyramine. In addition to this, co-injection of tyramine with DOPA, the precursor of melanin, had a strong cumulative negative effect on mosquito locomotion and survival. Dopaminergic and serotonergic antagonists such as amitriptyline and citalopram recapitulate this effect. Together these results reveal potential new target sites for the development of future mosquito sterilants and insecticides.

  6. Disruption of aminergic signalling reveals novel compounds with distinct inhibitory effects on mosquito reproduction, locomotor function and survival.

    PubMed

    Fuchs, Silke; Rende, Ermelinda; Crisanti, Andrea; Nolan, Tony

    2014-01-01

    Insecticide resistance amongst disease vectors is a growing problem and novel compounds are needed. Biogenic amines are important for neurotransmission and we have recently shown a potential role for these in mosquito fertility. Here, we dissected the relative contribution of different aminergic signalling pathways to biological processes essential for vectorial capacity such as fertility, locomotion and survival by injecting agonists and antagonists and showed that octopaminergic/tyraminergic signalling is essential for oviposition and hatching rate. We show that egg melanisation is regulated by adrenergic signalling, whose disruption causes premature melanisation specifically through the action of tyramine. In addition to this, co-injection of tyramine with DOPA, the precursor of melanin, had a strong cumulative negative effect on mosquito locomotion and survival. Dopaminergic and serotonergic antagonists such as amitriptyline and citalopram recapitulate this effect. Together these results reveal potential new target sites for the development of future mosquito sterilants and insecticides.

  7. Distinct Integrin-Dependent Signals Define Requirements for Lytic Granule Convergence and Polarization in Natural Killer Cells

    PubMed Central

    Hsu, Hsiang-Ting; Orange, Jordan S.

    2015-01-01

    Lytic granules in natural killer (NK) cells represent a dangerous cargo that is targeted for secretion to destroy diseased cells. The appropriate management of these organelles enables the mounting of a precise and valuable host defense. The process of NK cell adhesion to a target cell through engagement of the integrin LFA-1 (lymphocyte function–associated antigen 1) promotes lytic granule organization through complex cellular mechanics and a signaling pathway characterized by Zhang et al. in this issue of Science Signaling. A limited, partially overlapping set of signaling molecules can be distinguished for their ability to promote the convergence of NK cell lytic granules on the microtubule organizing center and their polarization as they progress en masse toward the interface with a target cell. PMID:25292212

  8. Anabolic steroid use by male adolescents.

    PubMed

    Johnson, M D; Jay, M S; Shoup, B; Rickert, V I

    1989-06-01

    Anabolic steroids have recently been used by professional and college athletes to improve athletic ability by increasing muscle size and strength. A study was done to determine the extent of steroid use and knowledge about these drugs in a population of high school male adolescents in a southern state. A self-report questionnaire, which allowed multiple answers for each question, was administered to 853 male students in six high schools. Results indicated that an average of 11% had used or were using anabolic steroids. The following were assessed: the reasons for steroid use, the sources from which the students received information about steroids, their familiarity with the physiologic effects and complications of steroid use, and the extent of their involvement in sports. The results suggest that a segment of male adolescents are using anabolic steroids without fully understanding the risks of such behavior. Health care providers need to become knowledgeable about steroids so that they may better educate adolescents about the potential deleterious effects of these agents.

  9. Anabolic steroids abuse and male infertility.

    PubMed

    El Osta, Rabih; Almont, Thierry; Diligent, Catherine; Hubert, Nicolas; Eschwège, Pascal; Hubert, Jacques

    2016-01-01

    For several decades, testosterone and its synthetic derivatives have been used with anabolic and androgenic purposes. These substances were first restricted to professional bodybuilders, but become more and more popular among recreational athletes. Up to date, 3,000,000 anabolic-androgenic steroids (AAS) users have been reported in the United States with an increasing prevalence, making AAS consumption a major public health growing concern. Infertility is defined by the WHO as the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse and a male factor is present in up to 50 % of all infertile couples. Several conditions may be related to male infertility. Substance abuse, including AAS, is commonly associated to transient or persistent impairment on male reproductive function, through different pathways. Herein, a brief overview on AAS is offered. Steroids biochemistry, patterns of use, physiological and clinical issues are enlightened. A further review about fertility outcomes among male AAS abusers is also presented, including the classic reports on transient anabolic steroid-induced hypogonadism (ASIH), and the more recent experimental reports on structural and genetic sperm damage.

  10. Anabolic steroids abuse and male infertility.

    PubMed

    El Osta, Rabih; Almont, Thierry; Diligent, Catherine; Hubert, Nicolas; Eschwège, Pascal; Hubert, Jacques

    2016-01-01

    For several decades, testosterone and its synthetic derivatives have been used with anabolic and androgenic purposes. These substances were first restricted to professional bodybuilders, but become more and more popular among recreational athletes. Up to date, 3,000,000 anabolic-androgenic steroids (AAS) users have been reported in the United States with an increasing prevalence, making AAS consumption a major public health growing concern. Infertility is defined by the WHO as the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse and a male factor is present in up to 50 % of all infertile couples. Several conditions may be related to male infertility. Substance abuse, including AAS, is commonly associated to transient or persistent impairment on male reproductive function, through different pathways. Herein, a brief overview on AAS is offered. Steroids biochemistry, patterns of use, physiological and clinical issues are enlightened. A further review about fertility outcomes among male AAS abusers is also presented, including the classic reports on transient anabolic steroid-induced hypogonadism (ASIH), and the more recent experimental reports on structural and genetic sperm damage. PMID:26855782

  11. Current concepts in anabolic-androgenic steroids.

    PubMed

    Evans, Nick A

    2004-03-01

    Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone. According to surveys and media reports, the legal and illegal use of these drugs is gaining popularity. Testosterone restores sex drive and boosts muscle mass, making it central to 2 of society's rising preoccupations: perfecting the male body and sustaining the male libido. The anabolic effects of AAS have been questioned for decades, but recent scientific investigation of supraphysiologic doses supports the efficacy of these regimens. Testosterone has potent anabolic effects on the musculoskeletal system, including an increase in lean body mass, a dose-related hypertrophy of muscle fibers, and an increase in muscle strength. For athletes requiring speed and strength and men desiring a cosmetic muscle makeover, illegal steroids are a powerful lure, despite the risk of subjective side effects. Recent clinical studies have discovered novel therapeutic uses for physiologic doses of AAS, without any significant adverse effects in the short term. In the wake of important scientific advances during the past decade, the positive and negative effects of AAS warrant reevaluation. Guidelines for the clinical evaluation of AAS users will be presented for sports medicine practitioners.

  12. Anabolic-androgenic steroids: use and abuse in pediatric patients.

    PubMed

    Kerr, Julie M; Congeni, Joseph A

    2007-08-01

    The "win at all costs" mentality fuels athletes to seek performance-enhancing substances, such as anabolic-androgenic steroids, to gain an advantage over their opponents. Nonathletes espouse this same attitude to "win" the battle of attractiveness. An enhanced understanding of anabolic-androgenic steroids and the motivations behind their abuse will arm pediatricians with the ability to engage their patients in a balanced discussion of the benefits and costly risks of anabolic-androgenic steroids and successfully deter further use.

  13. Anabolic agent use in adults with cystic fibrosis.

    PubMed

    Green, Heather D; Barry, Peter J; Jones, Andrew M

    2015-10-01

    The use of non-prescribed anabolic agents amongst non-athletes is increasing with young, adult males with cystic fibrosis (CF) in the highest risk demographic. There is evidence that anabolic agents increase weight and muscle mass in adults with a variety of catabolic conditions but there is no evidence for their use in hormone sufficient adults with CF. We report a case of anabolic agent use in a male adult with CF and review the clinical features of anabolic agent use with a focus on adults with CF.

  14. Anabolic agent use in adults with cystic fibrosis.

    PubMed

    Green, Heather D; Barry, Peter J; Jones, Andrew M

    2015-10-01

    The use of non-prescribed anabolic agents amongst non-athletes is increasing with young, adult males with cystic fibrosis (CF) in the highest risk demographic. There is evidence that anabolic agents increase weight and muscle mass in adults with a variety of catabolic conditions but there is no evidence for their use in hormone sufficient adults with CF. We report a case of anabolic agent use in a male adult with CF and review the clinical features of anabolic agent use with a focus on adults with CF. PMID:26410285

  15. Functional connectivity delineates distinct roles of the inferior frontal cortex and pre-supplementary motor area in stop signal inhibition

    PubMed Central

    Duann, Jeng-Ren; Ide, Jaime S.; Luo, Xi; Li, Chiang-shan Ray

    2009-01-01

    The neural basis of motor response inhibition has drawn considerable attention in recent imaging literature. Many studies have employed the go/no-go or stop signal task to examine the neural processes underlying motor response inhibition. In particular, showing greater activity during no-go (stop) as compared to go trials and during stop success as compared to stop error trials, the right inferior prefrontal cortex (IFC) has been suggested by numerous studies as the cortical area mediating response inhibition. Many of these same studies as well as others have also implicated the pre-supplementary motor area (preSMA) in this process, in accord with a function of the medial prefrontal cortex in goal-directed action. Here we employed connectivity analyses to delineate the roles of IFC and preSMA during stop signal inhibition. Specifically, we hypothesized that, as an integral part of the ventral attention system, the IFC responds to a stop signal and expedites the stop process in the preSMA, the primary site of motor response inhibition. This hypothesis predicted that preSMA and primary motor cortex would show functional interconnectivity via the basal ganglia circuitry to mediate response execution or inhibition, whereas the IFC would influence the basal ganglia circuitry via connectivity with preSMA. The results of Granger causality analyses in 57 participants confirmed this hypothesis. Furthermore, psychophysiological interaction showed that, as compared to stop errors, stop successes evoked greater effective connectivity between the IFC and preSMA, providing additional support for this hypothesis. These new findings provided evidence critically differentiating the roles of IFC and preSMA during stop signal inhibition and have important implications for our understanding of the component processes of inhibitory control. PMID:19675251

  16. Interference with distinct steps of sphingolipid synthesis and signaling attenuates proliferation of U87MG glioma cells

    PubMed Central

    Bernhart, Eva; Damm, Sabine; Wintersperger, Andrea; Nusshold, Christoph; Brunner, Anna Martina; Plastira, Ioanna; Rechberger, Gerald; Reicher, Helga; Wadsack, Christian; Zimmer, Andreas; Malle, Ernst; Sattler, Wolfgang

    2015-01-01

    Glioblastoma is the most common malignant brain tumor, which, despite combined radio- and chemotherapy, recurs and is invariably fatal for affected patients. Members of the sphingolipid (SL) family are potent effectors of glioma cell proliferation. In particular sphingosine-1-phosphate (S1P) and the corresponding G protein-coupled S1P receptors transmit proliferative signals to glioma cells. To investigate the contribution to glioma cell proliferation we inhibited the first step of de novo SL synthesis in p53wt and p53mut glioma cells, and interfered with S1P signaling specifically in p53wt U87MG cells. Subunit silencing (RNAi) or pharmacological antagonism (using myriocin) of serine palmitoyltransferase (SPT; catalyzing the first committed step of SL biosynthesis) reduced proliferation of p53wt but not p53mut GBM cells. In U87MG cells these observations were accompanied by decreased ceramide, sphingomyelin, and S1P content. Inhibition of SPT upregulated p53 and p21 expression and induced an increase in early and late apoptotic U87MG cells. Exogenously added S1P (complexed to physiological carriers) increased U87MG proliferation. In line, silencing of individual members of the S1P receptor family decreased U87MG proliferation. Silencing and pharmacological inhibition of the ATP-dependent cassette transporter A1 (ABCA1) that facilitates S1P efflux in astrocytes attenuated U87MG growth. Glyburide-mediated inhibition of ABCA1 resulted in intracellular accumulation of S1P raising the possibility that ABCA1 promotes S1P efflux in U87MG glioma cells thereby contributing to inside-out signaling. Our findings indicate that de novo SL synthesis, S1P receptor-mediated signaling, and ABCA1-mediated S1P efflux could provide pharmacological targets to interfere with glioma cell proliferation. PMID:26002572

  17. Two distinct domains of the UVR8 photoreceptor interact with COP1 to initiate UV-B signaling in Arabidopsis.

    PubMed

    Yin, Ruohe; Arongaus, Adriana B; Binkert, Melanie; Ulm, Roman

    2015-01-01

    UV-B photon reception by the Arabidopsis thaliana homodimeric UV RESISTANCE LOCUS8 (UVR8) photoreceptor leads to its monomerization and a crucial interaction with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). Relay of the subsequent signal regulates UV-B-induced photomorphogenesis and stress acclimation. Here, we report that two separate domains of UVR8 interact with COP1: the β-propeller domain of UVR8 mediates UV-B-dependent interaction with the WD40 repeats-based predicted β-propeller domain of COP1, whereas COP1 activity is regulated by interaction through the UVR8 C-terminal C27 domain. We show not only that the C27 domain is required for UVR8 activity but also that chemically induced expression of the C27 domain is sufficient to mimic UV-B signaling. We further show, in contrast with COP1, that the WD40 repeat proteins REPRESSOR OF UV-B PHOTOMORPHOGENESIS1 (RUP1) and RUP2 interact only with the UVR8 C27 domain. This coincides with their facilitation of UVR8 reversion to the ground state by redimerization and their potential to interact with UVR8 in a UV-B-independent manner. Collectively, our results provide insight into a key mechanism of photoreceptor-mediated signaling and its negative feedback regulation.

  18. Unique and shared signaling pathways cooperate to regulate the differentiation of human CD4+ T cells into distinct effector subsets.

    PubMed

    Ma, Cindy S; Wong, Natalie; Rao, Geetha; Nguyen, Akira; Avery, Danielle T; Payne, Kathryn; Torpy, James; O'Young, Patrick; Deenick, Elissa; Bustamante, Jacinta; Puel, Anne; Okada, Satoshi; Kobayashi, Masao; Martinez-Barricarte, Ruben; Elliott, Michael; Sebnem Kilic, Sara; El Baghdadi, Jamila; Minegishi, Yoshiyuki; Bousfiha, Aziz; Robertson, Nic; Hambleton, Sophie; Arkwright, Peter D; French, Martyn; Blincoe, Annaliesse K; Hsu, Peter; Campbell, Dianne E; Stormon, Michael O; Wong, Melanie; Adelstein, Stephen; Fulcher, David A; Cook, Matthew C; Stepensky, Polina; Boztug, Kaan; Beier, Rita; Ikincioğullari, Aydan; Ziegler, John B; Gray, Paul; Picard, Capucine; Boisson-Dupuis, Stéphanie; Phan, Tri Giang; Grimbacher, Bodo; Warnatz, Klaus; Holland, Steven M; Uzel, Gulbu; Casanova, Jean-Laurent; Tangye, Stuart G

    2016-07-25

    Naive CD4(+) T cells differentiate into specific effector subsets-Th1, Th2, Th17, and T follicular helper (Tfh)-that provide immunity against pathogen infection. The signaling pathways involved in generating these effector cells are partially known. However, the effects of mutations underlying human primary immunodeficiencies on these processes, and how they compromise specific immune responses, remain unresolved. By studying individuals with mutations in key signaling pathways, we identified nonredundant pathways regulating human CD4(+) T cell differentiation in vitro. IL12Rβ1/TYK2 and IFN-γR/STAT1 function in a feed-forward loop to induce Th1 cells, whereas IL-21/IL-21R/STAT3 signaling is required for Th17, Tfh, and IL-10-secreting cells. IL12Rβ1/TYK2 and NEMO are also required for Th17 induction. Strikingly, gain-of-function STAT1 mutations recapitulated the impact of dominant-negative STAT3 mutations on Tfh and Th17 cells, revealing a putative inhibitory effect of hypermorphic STAT1 over STAT3. These findings provide mechanistic insight into the requirements for human T cell effector function, and explain clinical manifestations of these immunodeficient conditions. Furthermore, they identify molecules that could be targeted to modulate CD4(+) T cell effector function in the settings of infection, vaccination, or immune dysregulation. PMID:27401342

  19. Mitogen-Activated Protein Kinase Signaling in Plant-Interacting Fungi: Distinct Messages from Conserved Messengers[W

    PubMed Central

    Hamel, Louis-Philippe; Nicole, Marie-Claude; Duplessis, Sébastien; Ellis, Brian E.

    2012-01-01

    Mitogen-activated protein kinases (MAPKs) are evolutionarily conserved proteins that function as key signal transduction components in fungi, plants, and mammals. During interaction between phytopathogenic fungi and plants, fungal MAPKs help to promote mechanical and/or enzymatic penetration of host tissues, while plant MAPKs are required for activation of plant immunity. However, new insights suggest that MAPK cascades in both organisms do not operate independently but that they mutually contribute to a highly interconnected molecular dialogue between the plant and the fungus. As a result, some pathogenesis-related processes controlled by fungal MAPKs lead to the activation of plant signaling, including the recruitment of plant MAPK cascades. Conversely, plant MAPKs promote defense mechanisms that threaten the survival of fungal cells, leading to a stress response mediated in part by fungal MAPK cascades. In this review, we make use of the genomic data available following completion of whole-genome sequencing projects to analyze the structure of MAPK protein families in 24 fungal taxa, including both plant pathogens and mycorrhizal symbionts. Based on conserved patterns of sequence diversification, we also propose the adoption of a unified fungal MAPK nomenclature derived from that established for the model species Saccharomyces cerevisiae. Finally, we summarize current knowledge of the functions of MAPK cascades in phytopathogenic fungi and highlight the central role played by MAPK signaling during the molecular dialogue between plants and invading fungal pathogens. PMID:22517321

  20. Insulin-mimetic signaling by the sulfonylurea glimepiride and phosphoinositolglycans involves distinct mechanisms for redistribution of lipid raft components.

    PubMed

    Müller, G; Jung, C; Wied, S; Welte, S; Frick, W

    2001-12-01

    The insulin signal transduction cascade provides a number of sites downstream of the insulin receptor (IR) for cross-talk from other signaling pathways. Tyrosine phosphorylation of the IR substrates IRS-1/2 and metabolic insulin-mimetic activity in insulin-responsive cells can be provoked by soluble phosphoinositolglycans (PIG), which trigger redistribution from detergent-insoluble glycolipid-enriched raft domains (DIGs) to other areas of the plasma membrane and thereby activation of nonreceptor tyrosine kinases (NRTK) [Müller, G., Jung, C., Wied, S., Welte, S., Jordan, H., and Frick, W. (2001) Mol. Cell. Biol. 21, 4553-4567]. Here we describe that stimulation of glucose transport in isolated rat adipocytes by a different stimulus, the sulfonylurea glimepiride, is also based on IRS-1/2 tyrosine phosphorylation and downstream insulin-mimetic signaling involving activation of the NRTK, pp59(Lyn), and pp125(Fak), as well as tyrosine phosphoryation of the DIGs component caveolin. As is the case for PIG 41, glimepiride causes the concentration-dependent dissociation of pp59(Lyn) from caveolin and release of this NRTK and the glycosyl-phosphatidylinositol-anchored (GPI) proteins, Gce1 and 5'-nucleotidase, from total and anti-caveolin-immunoisolated DIGs. This results in their movement to detergent-insoluble raft domains of higher buoyant density (non-DIGs areas). IRS-1/2 tyrosine phosphorylation and glucose transport activation by both glimepiride and PIG are blocked by introduction into adipocytes of the caveolin scaffolding domain peptide which mimicks the negative effect of caveolin on pp59(Lyn) activity. Tyrosine phosphorylation of the NRTK, IRS-1/2, and caveolin as well as release of the NRTK and GPI proteins from DIGs and their redistribution into non-DIGs areas in response to PIG is also inhibited by treatment of intact adipocytes with either trypsin plus salt or N-ethylmaleimide (NEM). In contrast, the putative trypsin/salt/NEM-sensitive cell surface component

  1. Erythropoietin activates two distinct signaling pathways required for the initiation and the elongation of c-myc

    NASA Technical Reports Server (NTRS)

    Chen, C.; Sytkowski, A. J.

    2001-01-01

    Erythropoietin (Epo) stimulation of erythroid cells results in the activation of several kinases and a rapid induction of c-myc expression. Protein kinase C is necessary for Epo up-regulation of c-myc by promoting elongation at the 3'-end of exon 1. PKCepsilon mediates this signal. We now show that Epo triggers two signaling pathways to c-myc. Epo rapidly up-regulated Myc protein in BaF3-EpoR cells. The phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 blocked Myc up-regulation in a concentration-dependent manner but had no effect on the Epo-induced phosphorylation of ERK1 and ERK2. LY294002 also had no effect on Epo up-regulation of c-fos. MEK1 inhibitor PD98059 blocked both the c-myc and the c-fos responses to Epo. PD98059 and the PKC inhibitor H7 also blocked the phosphorylation of ERK1 and ERK2. PD98059 but not LY294002 inhibited Epo induction of ERK1 and ERK2 phosphorylation in normal erythroid cells. LY294002 blocked transcription of c-myc at exon 1. PD98059 had no effect on transcription from exon 1 but, rather, blocked Epo-induced c-myc elongation at the 3'-end of exon 1. These results identify two Epo signaling pathways to c-myc, one of which is PI3K-dependent operating on transcriptional initiation, whereas the other is mitogen-activated protein kinase-dependent operating on elongation.

  2. Signals involved in T cell activation. II. Distinct roles of intact accessory cells, phorbol esters, and interleukin 1 in activation and cell cycle progression of resting T lymphocytes

    SciTech Connect

    Davis, L.; Lipsky, P.E.

    1986-05-15

    The signals involved in the initiation of mitogen-induced activation of resting guinea pig T cells were examined. The combination of phytohemagglutinin (PHA) and 4..beta..-phorbol 12-myristate 13-acetate (PMA) stimulated DNA synthesis by accessory cell (AC)-depleted T cells cultured at high density, but the use of low density cultures indicated that intact AC were absolutely necessary for PHA-stimulated T cell DNA synthesis even in the presence of PMA, interleukin 1 (IL 1), or interleukin 2 (IL 2). In contrast, AC-depleted T cells were able to respond to the combination of the calcium ionophore, ionomycin, and PMA regardless of the cell density at which they were cultured. Results of cell cycle analysis support the conclusion that intact AC, IL 1, and a PMA-like signal play distinct roles in the progression of mitogen stimulated T cells through the first round of the cell cycle.

  3. Two distinct oncornaviruses harbor an intracytoplasmic tyrosine-based basolateral targeting signal in their viral envelope glycoprotein.

    PubMed Central

    Lodge, R; Delamarre, L; Lalonde, J P; Alvarado, J; Sanders, D A; Dokhélar, M C; Cohen, E A; Lemay, G

    1997-01-01

    It has been clearly established that the budding of the human immunodeficiency virus (HIV-1), a lentivirus, occurs specifically through the basolateral membrane in polarized epithelial cells. More recently, the signal was assigned to a tyrosine-based motif located in the intracytoplasmic domain of the envelope glycoprotein, as previously observed on various other viral and cellular basolateral proteins. In the present study, expression of human T-cell leukemia virus type 1 (HTLV-1) or Moloney murine leukemia virus envelope glycoproteins was used for trans-complementation of an envelope-negative HIV-1. This demonstrated the potential of oncornaviral retrovirus envelope glycoproteins to confer polarized basolateral budding in epithelial Madin-Darby canine kidney cells (MDCK cells). Site-directed mutagenesis confirmed the importance of a common motif encompassing at least one crucial membrane-proximal intracytoplasmic tyrosine residue. The conservation of a similar basolateral maturation signal in different retroviruses further supports its importance in the biology of this group of viruses. PMID:9188652

  4. RNA and Imidazoquinolines are sensed by distinct TLR7/8 ectodomain sites resulting in functionally disparate signaling events

    PubMed Central

    Colak, Elif; Leslie, Alasdair; Zausmer, Kieran; Khatamzas, Elham; Kubarenko, Andriy V.; Pichulik, Tica; Klimosch, Sascha N.; Mayer, Alice; Siggs, Owen; Hector, Andreas; Fischer, Roman; Klesser, Benedikt; Rautanen, Anna; Frank, Martin; Hill, Adrian V. S.; Manoury, Bénédicte; Beutler, Bruce; Hartl, Dominik; Simmons, Alison; Weber, Alexander N. R.

    2014-01-01

    Toll-like receptors (TLR) 7 and 8 are pattern recognition receptors controlling antiviral host defense or autoimmune diseases. Apart from foreign and host RNA, synthetic RNA oligoribonucleotides (ORN) or small molecules of the imidazoquinoline family activate TLR7 and 8 and are being developed as therapeutic agonists. The structure-function relationships for RNA ORN and imidazoquinoline sensing and consequent downstream signaling by human TLR7 and TLR8 are unknown. Proteome- and genome-wide analyses in primary human monocyte-derived dendritic cells here showed that TLR8 sensing of RNA ORN vs. imidazoquinoline translates to ligand-specific differential phosphorylation and transcriptional events. Additionally, TLR7 and 8 ectodomains were found to discriminate between RNA ORN and imidazoquinolines by overlapping and non-overlapping recognition sites to which murine loss-of-function mutations and human naturally occurring hyporesponsive polymorphisms map. Our data suggest TLR7 and TLR8 can signal in two different ‘modes’ depending on the class of ligand. Considering RNA ORN and imidazoquinolines have been regarded as functionally interchangeable, our study highlights important functional incongruities whose understanding will be important for developing TLR7 or 8 therapeutics with desirable effector and safety profiles for in vivo application. PMID:24813206

  5. Role of endocannabinoid signalling in the dorsolateral periaqueductal grey in the modulation of distinct panic-like responses.

    PubMed

    Batista, Luara A; Bastos, Juliana R; Moreira, Fabricio A

    2015-03-01

    Panic attacks, a major feature of panic disorder, can be modelled in rats by exposing animals to stimuli that induce escape reactions, such as the elevated T-maze or the activation of the dorsolateral periaqueductal grey. Since the cannabinoid CB1 receptor modulates various types of aversive responses, this study tested the hypothesis that enhancement of endocannabinoid signalling in the dorsolateral periaqueductal grey inhibits panic-like reactions in rats. Local injection of the CB1 agonist, arachidonoyl 2-Chloroethylamide (0.005-0.5 pmol), attenuated the escape response from the open arm of the elevated T-maze, a panicolytic effect. The anandamide hydrolysis inhibitor, URB597 (0.3-3 nmol), did not induce consistent results. In the test of dorsolateral periaqueductal grey stimulation with d,l-homocysteic acid, arachidonoyl 2-Chloroethylamide, at the lowest dose, attenuated the escape reaction. The highest dose of URB597 also inhibited this response, contrary to the result obtained in the elevated T-maze. This effect was reversed by the CB1 antagonist, AM251 (100 pmol). The present results confirm the anti-aversive property of direct CB1 receptor activation in the dorsolateral periaqueductal grey. The effect of the anandamide hydrolysis inhibitor, however, could be detected only in a model employing direct stimulation of this structure. Altogether, these results suggest that anandamide signalling is recruited only under certain types of aversive stimuli.

  6. Distinct contributions by ionotropic purinoceptor subtypes to ATP-evoked calcium signals in mouse parotid acinar cells

    PubMed Central

    Bhattacharya, Sumit; Verrill, Douglas S; Carbone, Kristopher M; Brown, Stefanie; Yule, David I; Giovannucci, David R

    2012-01-01

    There is emerging consensus that P2X4 and P2X7 ionotropic purinoceptors (P2X4R and P2X7R) are critical players in regulating [Ca2+]i dynamics and fluid secretion in the salivary gland. In contrast, details regarding their compartmentalization and selective activation, contributions to the spatiotemporal properties of intracellular signals and roles in regulating protein exocytosis and ion channel activity have remained largely undefined. To address these concerns, we profiled mouse parotid acinar cells using live-cell imaging to follow the spatial and temporal features of ATP-evoked Ca2+ dynamics and exocytotic activity. Selective activation of P2X7Rs revealed an apical-to-basal [Ca2+]i signal that initiated at the sub-luminal border and propagated with a wave speed estimated at 17.3 ± 4.3 μm s−1 (n = 6). The evoked Ca2+ spike consisted of Ca2+ influx and Ca2+-induced Ca2+ release from intracellular Ca2+ channels. In contrast, selective activation of P2X4Rs induced a Ca2+ signal that initiated basally and propagated toward the lumen with a wave speed of 4.3 ± 0.2 μm s−1 (n = 8) that was largely independent of intracellular Ca2+ channel blockade. Consistent with these observations, P2X7R expression was enriched in the sub-luminal regions of acinar cells while P2X4R appeared localized to basal areas. In addition, we showed that P2X4R and P2X7R activation evokes exocytosis in parotid acinar cells. Our studies also demonstrate that the P2X4R-mediated [Ca2+]i rise and subsequent protein exocytosis was enhanced by ivermectin (IVR). Thus, in addition to furthering our understanding of salivary gland physiology, this study identifies P2X4R as a potential target for treatment of salivary hypofunction diseases. PMID:22451435

  7. Distinct effects of loss of classical estrogen receptor signaling versus complete deletion of estrogen receptor alpha on bone

    PubMed Central

    Syed, Farhan A.; Fraser, Daniel G.; Monroe, David G.; Khosla, Sundeep

    2011-01-01

    Estrogen receptor (ER)α is a major regulator of bone metabolism which can modulate gene expression via a “classical” pathway involving direct DNA binding to estrogen-response elements (EREs) or via “non-classical” pathways involving protein-protein interactions. While the skeletal consequences of loss of ERE binding by ERα have been described, a significant unresolved question is how loss of ERE binding differs from complete loss of ERα. Thus, we compared the skeletal phenotype of wild-type (ERα+/+) and ERα knock out (ERα−/−) mice with that of mice in which the only ERα present had a knock-in mutation abolishing ERE binding (non-classical ERα knock-in [NERKI], ERα−/NERKI). All three groups were in the same genetic background (C57BL/6). As compared to both ERα+/+ and ERα−/− mice, ERα−/NERKI mice had significantly reduced cortical volumetric bone mineral density and thickness at the tibial diaphysis; this was accompanied by significant decreases in periosteal and endocortical mineral apposition rates. Colony forming unit (CFU)-fibroblast, CFU-alkaline phosphatase, and CFU-osteoblast numbers were all increased in ERα−/− compared to ERα+/+ mice, but reduced in ERα−/NERKI mice compared to the two other groups. Thus, using mice in identical genetic backgrounds, our data indicate that the presence of an ERα that cannot bind DNA but can function through protein-protein interactions may have more deleterious skeletal effects than complete loss of ERα. These findings suggest that shifting the balance of classical versus non-classical ERα signaling triggers pathways that impair bone formation. Further studies defining these pathways may lead to novel approaches to selectively modulate ER signaling for beneficial skeletal effects. PMID:21458604

  8. The endocannabinoid system in renal cells: regulation of Na+ transport by CB1 receptors through distinct cell signalling pathways

    PubMed Central

    Sampaio, L S; Taveira Da Silva, R; Lima, D; Sampaio, C L C; Iannotti, F A; Mazzarella, E; Di Marzo, V; Vieyra, A; Reis, R A M; Einicker-Lamas, M

    2015-01-01

    Background and Purpose The function of the endocannabinoid system (ECS) in renal tissue is not completely understood. Kidney function is closely related to ion reabsorption in the proximal tubule, the nephron segment responsible for the re-absorption of 70–80% of the filtrate. We studied the effect of compounds modulating the activity of cannabinoid (CB) receptors on the active re-absorption of Na+ in LLC-PK1 cells. Experimental Approach Changes in Na+/K+-ATPase activity were assessed after treatment with WIN55,212-2 (WIN), a non-selective lipid agonist, and haemopressin (HP), an inverse peptide agonist at CB1 receptors. Pharmacological tools were used to investigate the signalling pathways involved in the modulation of Na+ transport. Key Results In addition to CB1 and CB2 receptors and TRPV1 channels, the mRNAs encoding for enzymes of the ECS were also expressed in LLC-PK1. WIN (10−7 M) and HP (10−6 M) altered Na+ re-absorption in LLC-PK1 in a dual manner. They both acutely (after 1 min) increased Na+/K+-ATPase activity in a TRPV1 antagonist-sensitive way. WIN's stimulating effect persisted for 30 min, and this effect was partially blocked by a CB1 antagonist or a PKC inhibitor. In contrast, HP inhibited Na+/K+-ATPase after 30 min incubation, and this effect was attenuated by a CB1 antagonist or a PKA inhibitor. Conclusion and Implications The ECS is expressed in LLC-PK1 cells. Both CB1 receptors and TRPV1 channels regulate Na+/K+-ATPase activity in these cells, and are modulated by lipid and peptide CB1 receptor ligands, which act via different signalling pathways. PMID:25537261

  9. Molecular Basis for the Recognition of Structurally Distinct Autoinducer Mimics by the Pseudomonas aeruginosa LasR Quorum-Sensing Signaling Receptor

    SciTech Connect

    Zou, Yaozhong; Nair, Satish K.

    2010-01-12

    The human pathogen Pseudomonas aeruginosa coordinates the expression of virulence factors using quorum sensing, a signaling cascade triggered by the activation of signal receptors by small-molecule autoinducers. These homoserine lactone autoinducers stabilize their cognate receptors and activate their functions as transcription factors. Because quorum sensing regulates the progression of infection and host immune resistance, significant efforts have been devoted toward the identification of small molecules that disrupt this process. Screening efforts have identified a class of triphenyl compounds that are structurally distinct from the homoserine lactone autoinducer, yet interact specifically and potently with LasR receptor to modulate quorum sensing (Muh et al., 2006a). Here we present the high-resolution crystal structures of the ligand binding domain of LasR in complex with the autoinducer N-3-oxo-dodecanoyl homoserine lactone (1.4 {angstrom} resolution), and with the triphenyl mimics TP-1, TP-3, and TP-4 (to between 1.8 {angstrom} and 2.3 {angstrom} resolution). These crystal structures provide a molecular rationale for understanding how chemically distinct compounds can be accommodated by a highly selective receptor, and provide the framework for the development of novel quorum-sensing regulators, utilizing the triphenyl scaffold.

  10. Differential regulation of oxidative burst by distinct β-glucan-binding receptors and signaling pathways in human peripheral blood mononuclear cells.

    PubMed

    Bose, Nandita; Wurst, Lindsay R; Chan, Anissa S H; Dudney, Christine M; LeRoux, Megan L; Danielson, Michael E; Will, Paul M; Nodland, Sonja E; Patchen, Myra L; Dalle Lucca, Jurandir J; Lebeda, Frank J; Vasilakos, John P

    2014-04-01

    β-Glucans possess broad immunomodulatory properties, including activation of innate immune functions such as oxidative burst activity. The differential roles of complement receptor type 3 (CR3) and Dectin-1, the known β-glucan receptors, and their associated signaling pathways in the generation of oxidative burst induced by different physical forms of Saccharomyces cerevisiae-derived β-glucan were examined in human peripheral blood mononuclear cells (PBMC). In this study whole glucan particle (WGP) or immobilized soluble β-glucan (ISG) was used to represent the phagocytizable or the nonphagocytizable form of a fungus, respectively. Oxidative burst as measured by the formation of superoxide (SO) was detected in PBMC in response to WGP and ISG. SO induction with WGP was concluded to be Dectin-1-mediated and required Src family kinases, phosphatidylinositol-3 kinase and protein kinase B/Akt. In contrast, the SO induction generated by ISG was CR3-mediated and required focal adhesion kinase, spleen tyrosine kinase, phosphatidylinositol-3 kinase, Akt, p38 mitogen activated protein kinase, phospholipase C and protein kinase C. The study results support the hypothesis that human PBMC, specifically monocytes, utilize distinct receptors and overlapping, but distinct, signaling pathways for the oxidative burst in response to challenge by different physical forms of β-glucan.

  11. A nursing perspective on the misuse of anabolic steroids.

    PubMed

    Rollo, Ian

    There is widespread use of anabolic steroids in the athletic community (Windsor and Dumitru, 1988). The potential health complications associated with this represents a serious risk to an otherwise healthy population. It is important for nurses to be knowledgeable about anabolic steroid abuse and to be able to identify users and populations most exposed to these drugs.

  12. The Buzz About Anabolic Androgenic Steroids: Electrophysiological Effects in Excitable Tissues

    PubMed Central

    Oberlander, Joseph G.; Penatti, Carlos A. A.; Porter, Donna M.; Henderson, Leslie P.

    2012-01-01

    Anabolic androgenic steroids (AAS) comprise a large and growing class of synthetic androgens used clinically to promote tissue-building in individuals suffering from genetic disorders, injuries and diseases. Despite these beneficial therapeutic applications, the predominant use of AAS is illicit: these steroids are self-administered to promote athletic performance and body image. Hand in hand with the desired anabolic actions of the AAS are untoward effects on the brain and behavior. While the signaling routes by which the AAS impose both beneficial and harmful actions may be quite diverse, key endpoints are likely to include ligand-gated and voltage-dependent ion channels that govern the activity of electrically excitable tissues. Here we review the known effects of AAS on molecular targets that play critical roles in controlling electrical activity, with a specific focus on the effects of AAS on neurotransmission mediated by GABAA receptors in the central nervous system (CNS). PMID:22576754

  13. Androgens and skeletal muscle: cellular and molecular action mechanisms underlying the anabolic actions.

    PubMed

    Dubois, Vanessa; Laurent, Michaël; Boonen, Steven; Vanderschueren, Dirk; Claessens, Frank

    2012-05-01

    Androgens increase both the size and strength of skeletal muscle via diverse mechanisms. The aim of this review is to discuss the different cellular targets of androgens in skeletal muscle as well as the respective androgen actions in these cells leading to changes in proliferation, myogenic differentiation, and protein metabolism. Androgens bind and activate a specific nuclear receptor which will directly affect the transcription of target genes. These genes encode muscle-specific transcription factors, enzymes, structural proteins, as well as microRNAs. In addition, anabolic action of androgens is partly established through crosstalk with other signaling molecules such as Akt, myostatin, IGF-I, and Notch. Finally, androgens may also exert non-genomic effects in muscle by increasing Ca(2+) uptake and modulating kinase activities. In conclusion, the anabolic effect of androgens on skeletal muscle is not only explained by activation of the myocyte androgen receptor but is also the combined result of many genomic and non-genomic actions.

  14. Differential Control of Ethylene Responses by GREEN-RIPE and GREEN-RIPE LIKE1 Provides Evidence for Distinct Ethylene Signaling Modules in Tomato1[W][OA

    PubMed Central

    Ma, Qian; Du, Wenyan; Brandizzi, Federica; Giovannoni, James J.; Barry, Cornelius S.

    2012-01-01

    The factors that mediate specific responses to the plant hormone ethylene are not fully defined. In particular, it is not known how signaling at the receptor complex can control distinct subsets of ethylene responses. Mutations at the Green-ripe (Gr) and reversion to ethylene sensitivity1 (rte1) loci, which encode homologous proteins of unknown function, influence ethylene responses in tomato (Solanum lycopersicum) and Arabidopsis (Arabidopsis thaliana), respectively. In Arabidopsis, AtRTE1 is required for function of the ETR1 ethylene receptor and acts predominantly through this receptor via direct protein-protein interaction. While most eudicot families including the Brassicaceae possess a single gene that is closely related to AtRTE1, we report that members of the Solanaceae family contain two phylogenetically distinct genes defined by GR and GREEN-RIPE LIKE1 (GRL1), creating the possibility of subfunctionalization. We also show that SlGR and SlGRL1 are differentially expressed in tomato tissues and encode proteins predominantly localized to the Golgi. A combination of overexpression in tomato and complementation of the rte1-3 mutant allele indicates that SlGR and SlGRL1 influence distinct but overlapping ethylene responses. Overexpression of SlGRL1 in the Gr mutant background provides evidence for the existence of different ethylene signaling modules in tomato that are influenced by GR, GRL1, or both. In addition, overexpression of AtRTE1 in tomato leads to reduced ethylene responsiveness in a subset of tissues but does not mimic the Gr mutant phenotype. Together, these data reveal species-specific heterogeneity in the control of ethylene responses mediated by members of the GR/RTE1 family. PMID:23043080

  15. Distinct Signaling Pathways from the Circadian Clock Participate in Regulation of Rhythmic Conidiospore Development in Neurospora crassa

    PubMed Central

    Correa, Alejandro; Bell-Pedersen, Deborah

    2002-01-01

    Several different environmental signals can induce asexual spore development (conidiation) and expression of developmentally regulated genes in Neurospora crassa. However, under constant conditions, where no environmental cues for conidiation are present, the endogenous circadian clock in N. crassa promotes daily rhythms in expression of known developmental genes and of conidiation. We anticipated that the same pathway of gene regulation would be followed during clock-controlled conidiation and environmental induction of conidiation and that the circadian clock would need only to control the initial developmental switch. Previous experiments showed that high-level developmental induction of the clock-controlled genes eas (ccg-2) and ccg-1 requires the developmental regulatory proteins FL and ACON-2, respectively, and normal developmental induction of fl mRNA expression requires ACON-2. We demonstrate that the circadian clock regulates rhythmic fl gene expression and that fl rhythmicity requires ACON-2. However, we find that clock regulation of eas (ccg-2) is normal in an fl mutant strain and ccg-1 expression is rhythmic in an acon-2 mutant strain. Together, these data point to the endogenous clock and the environment following separate pathways to regulate conidiation-specific gene expression. PMID:12455961

  16. Signal detection theory, the exclusion failure paradigm and weak consciousness--evidence for the access/phenomenal distinction?

    PubMed

    Irvine, Elizabeth

    2009-06-01

    Block [Block, N. (2005). Two neural correlates of consciousness. Trends in Cognitive Science, 9, 46-52] and Snodgrass (2006) claim that a signal detection theory (SDT) analysis of qualitative difference paradigms, in particular the exclusion failure paradigm, reveals cases of phenomenal consciousness without access consciousness. This claim is unwarranted on several grounds. First, partial cognitive access rather than a total lack of cognitive access can account for exclusion failure results. Second, Snodgrass's Objective Threshold/Strategic (OT/S) model of perception relies on a problematic 'enable' approach to perception that denies the possibility of intentional control of unconscious perception and any effect of following different task instructions on the presence/absence of phenomenal consciousness. Many of Block's purported examples of phenomenal consciousness without cognitive access also rely on this problematic approach. Third, qualitative difference paradigms may index only a subset of access consciousness. Thus, qualitative difference paradigms like exclusion failure cannot be used to isolate phenomenal consciousness, any attempt to do so still faces serious methodological problems.

  17. Different sensitivity to wortmannin of two vacuolar sorting signals indicates the presence of distinct sorting machineries in tobacco cells

    PubMed Central

    1995-01-01

    Vacuolar matrix proteins in plant cells are sorted from the secretory pathway to the vacuoles at the Golgi apparatus. Previously, we reported that the NH2-terminal propeptide (NTPP) of the sporamin precursor and the COOH-terminal propeptide (CTPP) of the barley lectin precursor contain information for vacuolar sorting. To analyze whether these propeptides are interchangeable, we expressed constructs consisting of wild-type or mutated NTPP with the mature part of barley lectin and sporamin with CTPP and mutated NTPP in tobacco BY-2 cells. The vacuolar localization of these constructs indicated that the signals were interchangeable. We next analyzed the effect of wortmannin, a specific inhibitor of mammalian phosphatidylinositol (PI) 3-kinase on vacuolar delivery by NTPP and CTPP in tobacco cells. Pulse-chase analysis indicated that 33 microM wortmannin caused almost complete inhibition of CTPP-mediated transport to the vacuoles, while NTPP-mediated transport displayed almost no sensitivity to wortmannin at this concentration. This indicates that there are at least two different mechanisms for vacuolar sorting in tobacco cells, and the CTPP-mediated pathway is sensitive to wortmannin. We compared the dose dependencies of wortmannin on the inhibition of CTPP-mediated vacuolar delivery of proteins and on the inhibition of the synthesis of phospholipids in tobacco cells. Wortmannin inhibited PI 3- and PI 4-kinase activities and phospholipid synthesis. Missorting caused by wortmannin displays a dose dependency that is similar to the dose dependency for the inhibition of synthesis of PI 4-phosphate and major phospholipids. This is different, however, than the inhibition of synthesis of PI 3- phosphate. Thus, the synthesis of phospholipids could be involved in CTPP-mediated vacuolar transport. PMID:7559754

  18. IL-7R expression and IL-7 signaling confer a distinct phenotype on developing human B-lineage cells

    PubMed Central

    Nodland, Sonja E.; Berkowska, Magdalena A.; Bajer, Anna A.; Shah, Nisha; de Ridder, Dick; van Dongen, Jacques J. M.; van Zelm, Menno C.

    2011-01-01

    IL-7 is an important cytokine for lymphocyte differentiation. Similar to what occurs in vivo, human CD19+ cells developing in human/murine xenogeneic cultures show differential expression of the IL-7 receptor α (IL-7Rα) chain (CD127). We now describe the relationship between CD127 expression/signaling and Ig gene rearrangement. In the present study, < 10% of CD19+CD127+ and CD19+CD127− populations had complete VDJH rearrangements. IGH locus conformation measurements by 3D FISH revealed that CD127+ and CD127− cells were less contracted than pediatric BM pro-B cells that actively rearrange the IGH locus. Complete IGH rearrangements in CD127+ and CD127− cells had smaller CDR3 lengths and fewer N-nucleotide insertions than pediatric BM B-lineage cells. Despite the paucity of VDJH rearrangements, microarray analysis indicated that CD127+ cells resembled large pre-B cells, which is consistent with their low level of Ig light-chain rearrangements. Unexpectedly, CD127− cells showed extensive Ig light-chain rearrangements in the absence of IGH rearrangements and resembled small pre-B cells. Neutralization of IL-7 in xenogeneic cultures led to an increase in Ig light-chain rearrangements in CD127+ cells, but no change in complete IGH rearrangements. We conclude that IL-7–mediated suppression of premature Ig light-chain rearrangement is the most definitive function yet described for IL-7 in human B-cell development. PMID:21680796

  19. A Minimal Dose of Electrically Induced Muscle Activity Regulates Distinct Gene Signaling Pathways in Humans with Spinal Cord Injury

    PubMed Central

    Petrie, Michael A.; Suneja, Manish; Faidley, Elizabeth; Shields, Richard K.

    2014-01-01

    Paralysis after a spinal cord injury (SCI) induces physiological adaptations that compromise the musculoskeletal and metabolic systems. Unlike non-SCI individuals, people with spinal cord injury experience minimal muscle activity which compromises optimal glucose utilization and metabolic control. Acute or chronic muscle activity, induced through electrical stimulation, may regulate key genes that enhance oxidative metabolism in paralyzed muscle. We investigated the short and long term effects of electrically induced exercise on mRNA expression of human paralyzed muscle. We developed an exercise dose that activated the muscle for only 0.6% of the day. The short term effects were assessed 3 hours after a single dose of exercise, while the long term effects were assessed after training 5 days per week for at least one year (adherence 81%). We found a single dose of exercise regulated 117 biological pathways as compared to 35 pathways after one year of training. A single dose of electrical stimulation increased the mRNA expression of transcriptional, translational, and enzyme regulators of metabolism important to shift muscle toward an oxidative phenotype (PGC-1α, NR4A3, IFRD1, ABRA, PDK4). However, chronic training increased the mRNA expression of specific metabolic pathway genes (BRP44, BRP44L, SDHB, ACADVL), mitochondrial fission and fusion genes (MFF, MFN1, MFN2), and slow muscle fiber genes (MYH6, MYH7, MYL3, MYL2). These findings support that a dose of electrical stimulation (∼10 minutes/day) regulates metabolic gene signaling pathways in human paralyzed muscle. Regulating these pathways early after SCI may contribute to reducing diabetes in people with longstanding paralysis from SCI. PMID:25531450

  20. Phytochrome-dependent coordinate control of distinct aspects of nuclear and plastid gene expression during anterograde signaling and photomorphogenesis

    PubMed Central

    Oh, Sookyung; Montgomery, Beronda L.

    2014-01-01

    Light perception by photoreceptors impacts plastid transcription, development, and differentiation. This photoreceptor-dependent activity suggests a mechanism for photoregulation of gene expression in the nucleus and plastid that serves to coordinate expression of critical genes of these two organelles. This coordinate expression is required for proper stoichiometric accumulation of components needed for assembly of plastids, photosynthetic light-harvesting complexes and components such as phytochromes. Chloroplast-targeted sigma factors, which function together with the plastid-encoded RNA polymerase to regulate expression of plastid-encoded genes, and nuclear-encoded plastid development factors, such as GLK1 and GLK2, are targets of phytochrome regulation. Such phytochrome-dependent functions are hypothesized to allow light-dependent regulation, and feasibly tuning, of plastid components and function in response to changes in the external environment, which directly affects photosynthesis and the potential for light-induced damage. When the size and protein composition of the light-harvesting complexes are not tuned to the external environment, imbalances in electron transport can impact the cellular redox state and cause cellular damage. We show that phytochromes specifically regulate the expression of multiple factors that function to modulate plastid transcription and, thus, provide a paradigm for coordinate expression of the nuclear and plastid genomes in response to changes in external light conditions. As phytochromes respond to changes in the prevalent wavelengths of light and light intensity, we propose that specific phytochrome-dependent molecular mechanisms are used during light-dependent signaling between the nucleus and chloroplast during photomorphogenesis to coordinate chloroplast development with plant developmental stage and the external environment. PMID:24817873

  1. Sepsis attenuates the anabolic response to skeletal muscle contraction

    PubMed Central

    Steiner, Jennifer L.; Lang, Charles H.

    2014-01-01

    Electrically stimulated muscle contraction is a potential clinical therapy to treat sepsis-induced myopathy; however, whether sepsis alters contraction-induced anabolic signaling is unknown. Polymicrobial peritonitis was produced by cecal ligation and puncture (CLP) in male C57BL/6 mice and time-matched, pair-fed controls (CON). At ~24 h post-CLP, the right hindlimb was electrically stimulated via the sciatic nerve to evoke maximal muscle contractions and the gastrocnemius was collected 2 h later. Protein synthesis was increased by muscle contraction in CON mice. Sepsis suppressed the rate of synthesis in both the non-stimulated (31%) and stimulated (57%) muscle versus CON. Contraction of muscle in CON mice increased the phosphorylation of mTORC1 substrates S6K1 Thr389 (8-fold), S6K1 Thr421/Ser424 (7-fold) and 4E-BP1 Ser65 (11-fold). Sepsis blunted the contraction-induced phosphorylation of S6K1 Thr389 (67%), S6K1 Thr421/Ser424 (46%) and 4E-BP1 Ser65 (85%). Conversely, sepsis did not appear to modulate protein elongation as eEF2 Thr56 phosphorylation was decreased similarly by muscle contraction in both groups. MAPK signaling was discordant following muscle contraction in septic muscle; phosphorylation of ERK Thr202/Tyr204 and p38 Thr180/Tyr182 was increased similarly in both CON and CLP mice while sepsis prevented the contraction-induced phosphorylation of JNK Thr183/Tyr185 and c-JUN Ser63. The expression of IL-6 and TNF-α mRNA in muscle was increased by sepsis, and contraction increased TNF-α to a greater extent in muscle from septic than CON mice. Injection of the mTOR inhibitor Torin2 in separate mice confirmed that contraction-induced increases in S6K1 and 4E-BP1 were mTOR-mediated. These findings demonstrate that resistance to contraction-induced anabolic signaling occurs during sepsis and is predominantly mTORC1-dependent. PMID:25423127

  2. MRI active guidewire with an embedded temperature probe and providing a distinct tip signal to enhance clinical safety

    PubMed Central

    2012-01-01

    Background The field of interventional cardiovascular MRI is hampered by the unavailability of active guidewires that are both safe and conspicuous. Heating of conductive guidewires is difficult to predict in vivo and disruptive to measure using external probes. We describe a clinical-grade 0.035” (0.89 mm) guidewire for MRI right and left heart catheterization at 1.5 T that has an internal probe to monitor temperature in real-time, and that has both tip and shaft visibility as well as suitable flexibility. Methods The design has an internal fiberoptic temperature probe, as well as a distal solenoid to enhance tip visibility on a loopless antenna. We tested different tip-solenoid configurations to balance heating and signal profiles. We tested mechanical performance in vitro and in vivo in comparison with a popular clinical nitinol guidewire. Results The solenoid displaced the point of maximal heating (“hot spot”) from the tip to a more proximal location where it can be measured without impairing guidewire flexion. Probe pullback allowed creation of lengthwise guidewire temperature maps that allowed rapid evaluation of design prototypes. Distal-only solenoid attachment offered the best compromise between tip visibility and heating among design candidates. When fixed at the hot spot, the internal probe consistently reflected the maximum temperature compared external probes. Real-time temperature monitoring was performed during porcine left heart catheterization. Heating was negligible using normal operating parameters (flip angle, 45°; SAR, 1.01 W/kg); the temperature increased by 4.2°C only during high RF power mode (flip angle, 90°; SAR, 3.96 W/kg) and only when the guidewire was isolated from blood cooling effects by an introducer sheath. The tip flexibility and in vivo performance of the final guidewire design were similar to a popular commercial guidewire. Conclusions We integrated a fiberoptic temperature probe inside a 0.035” MRI guidewire

  3. Nalbuphine hydrochloride dependence in anabolic steroid users.

    PubMed

    Wines, J D; Gruber, A J; Pope, H G; Lukas, S E

    1999-01-01

    Nalbuphine hydrochloride, a nonscheduled opioid agonist/antagonist analgesic, is currently approved for the treatment of pain. Recently, nalbuphine dependence was reported in three anabolic steroid users in Britain. To further document this phenomenon, we conducted interviews on eleven subjects who reported nalbuphine use. Eight subjects were clinically dependent on nalbuphine, and seven of the subjects who were asked about tolerance and withdrawal with nalbuphine acknowledged these symptoms. Eight subjects, who had never used drugs intravenously before, reported using nalbuphine by this route. Nalbuphine-related morbidity was extensive and included medical complications and psychiatric symptoms. Nalbuphine users also exhibited a high rate of comorbid Axis I disorders, including other substance misuse. Virtually all subjects described widespread nalbuphine use in the gymnasiums they frequented. These observations, together with the recent increase in nalbuphine-related articles in the lay press, suggest that nalbuphine may represent a new drug of abuse among athletes, especially those using anabolic steroids, and that nalbuphine's scheduling status may need to be re-evaluated.

  4. Distinct abscisic acid signaling pathways for modulation of guard cell versus mesophyll cell potassium channels revealed by expression studies in Xenopus laevis oocytes

    NASA Technical Reports Server (NTRS)

    Sutton, F.; Paul, S. S.; Wang, X. Q.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    2000-01-01

    Regulation of guard cell ion transport by abscisic acid (ABA) and in particular ABA inhibition of a guard cell inward K(+) current (I(Kin)) is well documented. However, little is known concerning ABA effects on ion transport in other plant cell types. Here we applied patch clamp techniques to mesophyll cell protoplasts of fava bean (Vicia faba cv Long Pod) plants and demonstrated ABA inhibition of an outward K(+) current (I(Kout)). When mesophyll cell protoplast mRNA (mesophyll mRNA) was expressed in Xenopus laevis oocytes, I(Kout) was generated that displayed similar properties to I(Kout) observed from direct analysis of mesophyll cell protoplasts. I(Kout) expressed by mesophyll mRNA-injected oocytes was inhibited by ABA, indicating that the ABA signal transduction pathway observed in mesophyll cells was preserved in the frog oocytes. Co-injection of oocytes with guard cell protoplast mRNA and cRNA for KAT1, an inward K(+) channel expressed in guard cells, resulted in I(Kin) that was similarly inhibited by ABA. However, oocytes co-injected with mesophyll mRNA and KAT1 cRNA produced I(Kin) that was not inhibited by ABA. These results demonstrate that the mesophyll-encoded signaling mechanism could not substitute for the guard cell pathway. These findings indicate that mesophyll cells and guard cells use distinct and different receptor types and/or signal transduction pathways in ABA regulation of K(+) channels.

  5. Critical but Distinct Roles for the Pleckstrin Homology and Cysteine-Rich Domains as Positive Modulators of Vav2 Signaling and Transformation

    PubMed Central

    Booden, Michelle A.; Campbell, Sharon L.; Der, Channing J.

    2002-01-01

    Vav2, like all Dbl family proteins, possesses tandem Dbl homology (DH) and pleckstrin homology (PH) domains and functions as a guanine nucleotide exchange factor for Rho family GTPases. Whereas the PH domain is a critical positive regulator of DH domain function for a majority of Dbl family proteins, the PH domains of the related Vav and Vav3 proteins are dispensable for DH domain activity. Instead, Vav proteins contain a cysteine-rich domain (CRD) critical for DH domain function. We evaluated the contribution of the PH domain and the CRD to Vav2 guanine nucleotide exchange, signaling, and transforming activity. Unexpectedly, we found that mutations of the PH domain impaired Vav2 signaling, transforming activity, and membrane association. However, these mutations do not influence exchange activity on Rac and only slightly affect exchange on RhoA and Cdc42. We also found that the CRD was critical for the exchange activity in vitro and contributed to Vav2 membrane localization. Finally, we found that phosphoinositol 3-kinase activation synergistically enhanced Vav2 transforming and signaling activity by stimulating exchange activity but not membrane association. In conclusion, the PH domain and CRD are mechanistically distinct, positive modulators of Vav2 DH domain function in vivo. PMID:11909943

  6. Distinct abscisic acid signaling pathways for modulation of guard cell versus mesophyll cell potassium channels revealed by expression studies in Xenopus laevis oocytes.

    PubMed

    Sutton, F; Paul, S S; Wang, X Q; Assmann, S M

    2000-09-01

    Regulation of guard cell ion transport by abscisic acid (ABA) and in particular ABA inhibition of a guard cell inward K(+) current (I(Kin)) is well documented. However, little is known concerning ABA effects on ion transport in other plant cell types. Here we applied patch clamp techniques to mesophyll cell protoplasts of fava bean (Vicia faba cv Long Pod) plants and demonstrated ABA inhibition of an outward K(+) current (I(Kout)). When mesophyll cell protoplast mRNA (mesophyll mRNA) was expressed in Xenopus laevis oocytes, I(Kout) was generated that displayed similar properties to I(Kout) observed from direct analysis of mesophyll cell protoplasts. I(Kout) expressed by mesophyll mRNA-injected oocytes was inhibited by ABA, indicating that the ABA signal transduction pathway observed in mesophyll cells was preserved in the frog oocytes. Co-injection of oocytes with guard cell protoplast mRNA and cRNA for KAT1, an inward K(+) channel expressed in guard cells, resulted in I(Kin) that was similarly inhibited by ABA. However, oocytes co-injected with mesophyll mRNA and KAT1 cRNA produced I(Kin) that was not inhibited by ABA. These results demonstrate that the mesophyll-encoded signaling mechanism could not substitute for the guard cell pathway. These findings indicate that mesophyll cells and guard cells use distinct and different receptor types and/or signal transduction pathways in ABA regulation of K(+) channels. PMID:10982437

  7. 21 CFR 1308.33 - Exemption of certain anabolic steroid products; application.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Exemption of certain anabolic steroid products... SCHEDULES OF CONTROLLED SUBSTANCES Exempt Anabolic Steroid Products § 1308.33 Exemption of certain anabolic... compound, mixture, or preparation containing an anabolic steroid as defined in part 1300 of this...

  8. 21 CFR 1308.33 - Exemption of certain anabolic steroid products; application.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Exemption of certain anabolic steroid products... SCHEDULES OF CONTROLLED SUBSTANCES Exempt Anabolic Steroid Products § 1308.33 Exemption of certain anabolic... compound, mixture, or preparation containing an anabolic steroid as defined in part 1300 of this...

  9. 21 CFR 1308.26 - Excluded veterinary anabolic steroid implant products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Excluded veterinary anabolic steroid implant... SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.26 Excluded veterinary anabolic steroid implant products. (a) Products containing an anabolic steroid, that are...

  10. 21 CFR 1308.33 - Exemption of certain anabolic steroid products; application.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Exemption of certain anabolic steroid products... SCHEDULES OF CONTROLLED SUBSTANCES Exempt Anabolic Steroid Products § 1308.33 Exemption of certain anabolic... compound, mixture, or preparation containing an anabolic steroid as defined in part 1300 of this...

  11. 21 CFR 1308.33 - Exemption of certain anabolic steroid products; application.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Exemption of certain anabolic steroid products... SCHEDULES OF CONTROLLED SUBSTANCES Exempt Anabolic Steroid Products § 1308.33 Exemption of certain anabolic... compound, mixture, or preparation containing an anabolic steroid as defined in part 1300 of this...

  12. 21 CFR 1308.26 - Excluded veterinary anabolic steroid implant products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Excluded veterinary anabolic steroid implant... SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.26 Excluded veterinary anabolic steroid implant products. (a) Products containing an anabolic steroid, that are...

  13. 21 CFR 1308.33 - Exemption of certain anabolic steroid products; application.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Exemption of certain anabolic steroid products... SCHEDULES OF CONTROLLED SUBSTANCES Exempt Anabolic Steroid Products § 1308.33 Exemption of certain anabolic... compound, mixture, or preparation containing an anabolic steroid as defined in part 1300 of this...

  14. 21 CFR 1308.26 - Excluded veterinary anabolic steroid implant products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Excluded veterinary anabolic steroid implant... SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.26 Excluded veterinary anabolic steroid implant products. (a) Products containing an anabolic steroid, that are...

  15. 21 CFR 1308.26 - Excluded veterinary anabolic steroid implant products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Excluded veterinary anabolic steroid implant... SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.26 Excluded veterinary anabolic steroid implant products. (a) Products containing an anabolic steroid, that are...

  16. 21 CFR 1308.26 - Excluded veterinary anabolic steroid implant products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Excluded veterinary anabolic steroid implant... SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.26 Excluded veterinary anabolic steroid implant products. (a) Products containing an anabolic steroid, that are...

  17. Distinct Kv Channel Subtypes Contribute to Differences in Spike Signaling Properties in the Axon Initial Segment and Presynaptic Boutons of Cerebellar Interneurons

    PubMed Central

    Rowan, Matthew J. M.; Tranquil, Elizabeth

    2014-01-01

    The discrete arrangement of voltage-gated K+ (Kv) channels in axons may impart functional advantages in action potential (AP) signaling yet, in compact cell types, the organization of Kv channels is poorly understood. We find that in cerebellar stellate cell interneurons of mice, the composition and influence of Kv channels populating the axon is diverse and depends on location allowing axonal compartments to differentially control APs in a local manner. Kv1 channels determine AP repolarization at the spike initiation site but not at more distal sites, limiting the expression of use-dependent spike broadening to the most proximal axon region, likely a key attribute informing spiking phenotype. Local control of AP repolarization at presynaptic boutons depends on Kv3 channels keeping APs brief, thus limiting Ca2+ influx and synaptic strength. These observations suggest that AP repolarization is tuned by the local influence of distinct Kv channel types, and this organization enhances the functional segregation of axonal compartments. PMID:24806686

  18. The Use of Anabolic Agents in Catabolic States

    PubMed Central

    Demling, Robert

    2007-01-01

    Objective: We plan to review the current problem of lean mass erosion in catabolic states, caused by injury and critical illness. This protein loss is driven by the hormonal imbalance and excess inflammation referred to as the “stress response to injury.” We then plan to provide the current concepts on the use of available anabolic agents to attenuate the excess catabolism. Data Source: The available published literature on the pathogenesis of acute catabolic states and the use of anabolic and anticatabolic agents, their indications, mechanism of action, and potential complications was reviewed. Data Extraction: The current understanding and experience of the available anabolic and anticatabolic agents as well as the rationale for the use of each anabolic agent are described. Conclusion: We conclude that the preservation of lean body mass (body protein) is extremely important in the management of critical care populations, as lean mass loss leads to severe morbidity and increased mortality. Essentially, all of the available anabolic agents stimulate protein synthesis and decrease protein breakdown, but all have different mechanisms of action. Adequate nutrition, especially protein intake, is essential for any anabolism to occur. Combined anabolic therapy also appears to be advantageous. Although controlling the inflammatory response would also be of major benefit in further controlling protein loss, effective and safe anti-inflammatory agents have not yet become clinically available for this purpose. PMID:17364003

  19. Creb coactivators direct anabolic responses and enhance performance of skeletal muscle.

    PubMed

    Bruno, Nelson E; Kelly, Kimberly A; Hawkins, Richard; Bramah-Lawani, Mariam; Amelio, Antonio L; Nwachukwu, Jerome C; Nettles, Kendall W; Conkright, Michael D

    2014-05-01

    During the stress response to intense exercise, the sympathetic nervous system (SNS) induces rapid catabolism of energy reserves through the release of catecholamines and subsequent activation of protein kinase A (PKA). Paradoxically, chronic administration of sympathomimetic drugs (β-agonists) leads to anabolic adaptations in skeletal muscle, suggesting that sympathetic outflow also regulates myofiber remodeling. Here, we show that β-agonists or catecholamines released during intense exercise induce Creb-mediated transcriptional programs through activation of its obligate coactivators Crtc2 and Crtc3. In contrast to the catabolic activity normally associated with SNS function, activation of the Crtc/Creb transcriptional complex by conditional overexpression of Crtc2 in the skeletal muscle of transgenic mice fostered an anabolic state of energy and protein balance. Crtc2-overexpressing mice have increased myofiber cross-sectional area, greater intramuscular triglycerides and glycogen content. Moreover, maximal exercise capacity was enhanced after induction of Crtc2 expression in transgenic mice. Collectively these findings demonstrate that the SNS-adrenergic signaling cascade coordinates a transient catabolic stress response during high-intensity exercise, which is followed by transcriptional reprogramming that directs anabolic changes for recovery and that augments subsequent exercise performance.

  20. ["No" for stacked young bodybuilders, "yes" for manthers: the biomedical discourse on anabolic steroids and health].

    PubMed

    Moraes, Danielle Ribeiro de; Castiel, Luis David; Ribeiro, Ana Paula Pereira da Gama Alves

    2015-06-01

    The article addresses the use of anabolic androgenic steroids (AAS), synthetic drugs whose abuse has been characterized as a public health problem, operated in the opposition between "medical" and "non-medical" uses. A qualitative approach was used to analyze the text in 76 biomedical articles published from 2002 to 2012. The discourse shows a persistent ban on non-medically regulated use of AAS by young people, while the limits on clinically qualified use appear to expand among older people, even given the contradictions straining the argument on the prevention of health risks. Moralizing biopolitical stances appear, based on gender distinctions or under the aegis of criminalizing drug use. PMID:26200362

  1. Initiating Hox gene expression: in the early chick neural tube differential sensitivity to FGF and RA signaling subdivides the HoxB genes in two distinct groups.

    PubMed

    Bel-Vialar, Sophie; Itasaki, Nobue; Krumlauf, Robb

    2002-11-01

    Initiation of Hox genes requires interactions between numerous factors and signaling pathways in order to establish their precise domain boundaries in the developing nervous system. There are distinct differences in the expression and regulation of members of Hox genes within a complex suggesting that multiple competing mechanisms are used to initiate their expression domains in early embryogenesis. In this study, by analyzing the response of HoxB genes to both RA and FGF signaling in neural tissue during early chick embryogenesis (HH stages 7-15), we have defined two distinct groups of Hox genes based on their reciprocal sensitivity to RA or FGF during this developmental period. We found that the expression domain of 5' members from the HoxB complex (Hoxb6-Hoxb9) can be expanded anteriorly in the chick neural tube up to the level of the otic vesicle following FGF treatment and that these same genes are refractory to RA treatment at these stages. Furthermore, we showed that the chick caudal-related genes, cdxA and cdxB, are also responsive to FGF signaling in neural tissue and that their anterior expansion is also limited to the level of the otic vesicle. Using a dominant negative form of a Xenopus Cdx gene (XcadEnR) we found that the effect of FGF treatment on 5' HoxB genes is mediated in part through the activation and function of CDX activity. Conversely, the 3' HoxB genes (Hoxb1 and Hoxb3-Hoxb5) are sensitive to RA but not FGF treatments at these stages. We demonstrated by in ovo electroporation of a dominant negative retinoid receptor construct (dnRAR) that retinoid signaling is required to initiate expression. Elevating CDX activity by ectopic expression of an activated form of a Xenopus Cdx gene (XcadVP16) in the hindbrain ectopically activates and anteriorly expands Hoxb4 expression. In a similar manner, when ectopic expression of XcadVP16 is combined with FGF treatment, we found that Hoxb9 expression expands anteriorly into the hindbrain region. Our

  2. [Research progresses of anabolic steroids analysis in doping control].

    PubMed

    Long, Yuanyuan; Wang, Dingzhong; Li, Ke'an; Liu, Feng

    2008-07-01

    Anabolic steroids, a kind of physiological active substance, are widely abused to improve athletic performance in human sports. They have been forbidden in sports by the International Olympic Committee since 1983. Since then, many researchers have been focusing their attentions on the establishment of reliable detection methods. In this paper, we review the research progresses of different analytical methods for anabolic steroids since 2002, such as gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, immunoassay, electrochemistry analysis and mass spectrometry. The developing prospect of anabolic steroids analysis is also discussed.

  3. The MAPKERK-1,2 pathway integrates distinct and antagonistic signals from TGF alpha and FGF7 in morphogenesis of mouse mammary epithelium

    SciTech Connect

    Fata, Jimmie E; Mori, Hidetoshi; Ewald, Andrew J; Zhang, Hui; Yao, Evelyn; Werb, Zena; Bissell, Mina J

    2006-10-03

    Transforming growth factor-{alpha} (TGF{alpha}) and fibroblast growth factor-7 (FGF7) exhibit distinct expression patterns in the mammary gland. Both factors signal through mitogen-activated kinase/extracellular regulated kinase-1,2 (MAPK{sup ERK1,2}); however, their unique and/or combined contributions to mammary morphogenesis have not been examined. In ex vivo mammary explants, we show that a sustained activation of MAPK{sup ERK1,2} for 1 h, induced by TGF{alpha}, was necessary and sufficient to initiate branching morphogenesis, whereas a transient activation (15 min) of MAPK{sup ERK1,2}, induced by FGF7, led to growth without branching. Unlike TGF{alpha}, FGF7 promoted sustained proliferation as well as ectopic localization of, and increase in, keratin-6 expressing cells. The response of the explants to FGF10 was similar to that to FGF7. Simultaneous stimulation by FGF7 and TGF{alpha} indicated that the FGF7-induced MAPK{sup ERK1,2} signaling and associated phenotypes were dominant: FGF7 may prevent branching by suppression of two necessary TGF{alpha}-induced morphogenetic effectors, matrix metalloproteinase-3 (MMP-3/stromelysin-1), and fibronectin. Our findings indicate that expression of morphogenetic effectors, proliferation, and cell-type decisions during mammary organoid morphogenesis are intimately dependent on the duration of activation of MAPK{sup ERK1,2} activation.

  4. The ARG1-LIKE2 gene of Arabidopsis functions in a gravity signal transduction pathway that is genetically distinct from the PGM pathway

    NASA Technical Reports Server (NTRS)

    Guan, Changhui; Rosen, Elizabeth S.; Boonsirichai, Kanokporn; Poff, Kenneth L.; Masson, Patrick H.

    2003-01-01

    The arl2 mutants of Arabidopsis display altered root and hypocotyl gravitropism, whereas their inflorescence stems are fully gravitropic. Interestingly, mutant roots respond like the wild type to phytohormones and an inhibitor of polar auxin transport. Also, their cap columella cells accumulate starch similarly to wild-type cells, and mutant hypocotyls display strong phototropic responses to lateral light stimulation. The ARL2 gene encodes a DnaJ-like protein similar to ARG1, another protein previously implicated in gravity signal transduction in Arabidopsis seedlings. ARL2 is expressed at low levels in all organs of seedlings and plants. arl2-1 arg1-2 double mutant roots display kinetics of gravitropism similar to those of single mutants. However, double mutants carrying both arl2-1 and pgm-1 (a mutation in the starch-biosynthetic gene PHOSPHOGLUCOMUTASE) at the homozygous state display a more pronounced root gravitropic defect than the single mutants. On the other hand, seedlings with a null mutation in ARL1, a paralog of ARG1 and ARL2, behave similarly to the wild type in gravitropism and other related assays. Taken together, the results suggest that ARG1 and ARL2 function in the same gravity signal transduction pathway in the hypocotyl and root of Arabidopsis seedlings, distinct from the pathway involving PGM.

  5. Insulin, insulin-like growth factor-I, and platelet-derived growth factor activate extracellular signal-regulated kinase by distinct pathways in muscle cells.

    PubMed

    Tsakiridis, T; Tsiani, E; Lekas, P; Bergman, A; Cherepanov, V; Whiteside, C; Downey, G P

    2001-10-19

    We have investigated the signaling pathways initiated by insulin, insulin-like growth factor-1 (IGF-I), and platelet-derived growth factor (PDGF) leading to activation of the extracellular signal-regulated kinase (ERK) in L6 myotubes. Insulin but not IGF-I or PDGF-induced ERK activation was abrogated by Ras inhibition, either by treatment with the farnesyl transferase inhibitor FTP III, or by actin disassembly by cytochalasin D, previously shown to inhibit Ras activation. The protein kinase C (PKC) inhibitor bisindolylmaleimide abolished PDGF but not IGF-I or insulin-induced ERK activation. ERK activation by insulin, IGF-I, or PDGF was unaffected by the phosphatidylinositol 3-kinase inhibitor wortmannin but was abolished by the MEK inhibitor PD98059. In contrast, activation of the pathway involving phosphatidylinositol 3-kinase (PI3k), protein kinase B, and glycogen synthase kinase 3 (GSK3) was mediated similarly by all three receptors, through a PI 3-kinase-dependent but Ras- and actin-independent pathway. We conclude that ERK activation is mediated by distinct pathways including: (i) a cytoskeleton- and Ras-dependent, PKC-independent, pathway utilized by insulin, (ii) a PKC-dependent, cytoskeleton- and Ras-independent pathway used by PDGF, and (iii) a cytoskeleton-, Ras-, and PKC-independent pathway utilized by IGF-I.

  6. The ARG1-LIKE2 Gene of Arabidopsis Functions in a Gravity Signal Transduction Pathway That Is Genetically Distinct from the PGM Pathway1

    PubMed Central

    Guan, Changhui; Rosen, Elizabeth S.; Boonsirichai, Kanokporn; Poff, Kenneth L.; Masson, Patrick H.

    2003-01-01

    The arl2 mutants of Arabidopsis display altered root and hypocotyl gravitropism, whereas their inflorescence stems are fully gravitropic. Interestingly, mutant roots respond like the wild type to phytohormones and an inhibitor of polar auxin transport. Also, their cap columella cells accumulate starch similarly to wild-type cells, and mutant hypocotyls display strong phototropic responses to lateral light stimulation. The ARL2 gene encodes a DnaJ-like protein similar to ARG1, another protein previously implicated in gravity signal transduction in Arabidopsis seedlings. ARL2 is expressed at low levels in all organs of seedlings and plants. arl2-1 arg1-2 double mutant roots display kinetics of gravitropism similar to those of single mutants. However, double mutants carrying both arl2-1 and pgm-1 (a mutation in the starch-biosynthetic gene PHOSPHOGLUCOMUTASE) at the homozygous state display a more pronounced root gravitropic defect than the single mutants. On the other hand, seedlings with a null mutation in ARL1, a paralog of ARG1 and ARL2, behave similarly to the wild type in gravitropism and other related assays. Taken together, the results suggest that ARG1 and ARL2 function in the same gravity signal transduction pathway in the hypocotyl and root of Arabidopsis seedlings, distinct from the pathway involving PGM. PMID:12970478

  7. [Control measures for anabolic androgenic steroid medicines].

    PubMed

    Vázquez-Mourelle, Raquel; Carracedo-Martínez, Eduardo; Ces Gens, Eugenio; Cadórniga Valiño, Luis; Álvaro Esteban, Pilar; Pose Reino, José Manuel

    2015-01-01

    Anabolic androgenic steroids (AAS) can cause serious adverse effects when used without a therapeutic purpose. This article aims to show that the AAS are susceptible to being sold on the black market. We also aim to describe how certain limitations on the health inspection services of the Galician health service to pursue these illegal actions prompted a regulatory initiative demanding that additional actions be granted to community pharmacies when dispensing AAS. Four pharmacy inspections detected the diversion of a total of 3118 packages of AAS, which led to the opening of four disciplinary proceedings. In two of these, specialized police forces were called in as there was sufficient evidence of possible diversion to gymnasiums, resulting in a police operation called Operation Fitness. PMID:25778637

  8. Anabolic androgenic steroids abuse and liver toxicity.

    PubMed

    Neri, M; Bello, S; Bonsignore, A; Cantatore, S; Riezzo, I; Turillazzi, E; Fineschi, V

    2011-05-01

    In the athletes the wide use of Anabolic Androgenic Steroids (AAS) cause series damage in various organs, in particular, analyzing the liver, elevation on the levels of liver enzymes, cholestatic jaundice, liver tumors, both benign and malignant, and peliosis hepatis are described. A prolonged AAS administration provokes an increase in the activities of liver lysosomal hydrolases and a decrease in some components of the microsomal drug-metabolizing system and in the activity of the mitochondrial respiratory chain complexes without modifying classical serum indicators of hepatic function. Liver is a key organ actively involved in numerous metabolic and detoxifying functions. As a consequence, it is continuously exposed to high levels of endogenous and exogenous oxidants that are by-products of many biochemical pathways and, in fact, it has been demonstrated that intracellular oxidant production is more active in liver than in tissues, like the increase of inflammatory cytokines, apoptosis and the inhibitors of apoptosis NF- κB and Heat Shock Proteins.

  9. [Control measures for anabolic androgenic steroid medicines].

    PubMed

    Vázquez-Mourelle, Raquel; Carracedo-Martínez, Eduardo; Ces Gens, Eugenio; Cadórniga Valiño, Luis; Álvaro Esteban, Pilar; Pose Reino, José Manuel

    2015-01-01

    Anabolic androgenic steroids (AAS) can cause serious adverse effects when used without a therapeutic purpose. This article aims to show that the AAS are susceptible to being sold on the black market. We also aim to describe how certain limitations on the health inspection services of the Galician health service to pursue these illegal actions prompted a regulatory initiative demanding that additional actions be granted to community pharmacies when dispensing AAS. Four pharmacy inspections detected the diversion of a total of 3118 packages of AAS, which led to the opening of four disciplinary proceedings. In two of these, specialized police forces were called in as there was sufficient evidence of possible diversion to gymnasiums, resulting in a police operation called Operation Fitness.

  10. Anabolic androgenic steroid-induced hepatotoxicity.

    PubMed

    Bond, Peter; Llewellyn, William; Van Mol, Peter

    2016-08-01

    Anabolic androgenic steroids (AAS) have been abused for decades by both professional and amateur athletes in order to improve physical performance or muscle mass. AAS abuse can cause adverse effects, among which are hepatotoxic effects. These effects include cholestatic icterus and possibly peliosis hepatis and hepatocellular carcinoma or adenoma. In particular, 17α-alkylated AAS appear to be hepatotoxic, whereas nonalkylated AAS appear not to be. The 17α-alkyl substitution retards hepatic metabolism of the AAS rendering it orally bioavailable. The mechanism responsible for the hepatotoxicity induced by 17α-alkylated AAS remains poorly understood. However, oxidative stress has been repeatedly shown to be associated with it. In this manuscript we present a hypothesis which describes a potential mechanism responsible for AAS-induced hepatotoxicity, based on several observations from the literature which suggest oxidative stress being a causal factor. PMID:27372877

  11. Anabolic androgenic steroid-induced hepatotoxicity.

    PubMed

    Bond, Peter; Llewellyn, William; Van Mol, Peter

    2016-08-01

    Anabolic androgenic steroids (AAS) have been abused for decades by both professional and amateur athletes in order to improve physical performance or muscle mass. AAS abuse can cause adverse effects, among which are hepatotoxic effects. These effects include cholestatic icterus and possibly peliosis hepatis and hepatocellular carcinoma or adenoma. In particular, 17α-alkylated AAS appear to be hepatotoxic, whereas nonalkylated AAS appear not to be. The 17α-alkyl substitution retards hepatic metabolism of the AAS rendering it orally bioavailable. The mechanism responsible for the hepatotoxicity induced by 17α-alkylated AAS remains poorly understood. However, oxidative stress has been repeatedly shown to be associated with it. In this manuscript we present a hypothesis which describes a potential mechanism responsible for AAS-induced hepatotoxicity, based on several observations from the literature which suggest oxidative stress being a causal factor.

  12. Distinct structural specificities for functional coupling of the epidermal growth factor receptor to calcium-signalling versus phospholipase A2 responses.

    PubMed

    Hack, N; Margolis, B L; Ullrich, A; Schlessinger, J; Skorecki, K L

    1991-05-01

    Activation of phospholipase C (PLC), leading to a rise in cytosolic Ca2+, and of phospholipase A2 (PLA2) leading to a release of arachidonic acid, are among the early transmembrane signalling events that have been demonstrated in response to occupancy of the epidermal growth factor (EGF) receptor. The tyrosine kinase activity of the receptor has been shown to be necessary for both of these responses. This requirement for the tyrosine kinase activity could conceivably implicate a role for receptor autophosphorylation in the activation of PLA2. We now demonstrate that coupling of the EGF receptor to PLA2 was not impaired in a deletion mutant (CD126) devoid of the 126 amino acids from the C-terminus which include four major autophosphorylation sites. Functional coupling of the EGF receptor to PLA2 was demonstrated using three different experimental designs: (1) release of [14C]arachidonic acid from prelabelled intact cells. (2) release of [3H]arachidonic acid from prelabelled cells permeabilized with glass beads, and (3) direct measurement of PLA2 enzymic activity in cell-free extracts using an 'in vitro' assay employing exogenous phospholipid substrate. Functional coupling of the EGF receptor to PLA2 occurred despite the absence of a demonstrable Ca(2+)-signalling response and the detection of diminished but persistent PLC-gamma phosphorylation on tyrosine residues in the CD126 deletion mutants. These results point to a clear distinction in the biochemical mechanism and role for receptor autophosphorylation in functional coupling of the EGF receptor to PLA2 activation versus Ca2+ signalling.

  13. Epstein-Barr virus LMP1 induction of the epidermal growth factor receptor is mediated through a TRAF signaling pathway distinct from NF-kappaB activation.

    PubMed Central

    Miller, W E; Mosialos, G; Kieff, E; Raab-Traub, N

    1997-01-01

    The Epstein-Barr virus (EBV)-encoded LMP1 protein induces several cellular changes including induction of epidermal growth factor receptor (EGFR) expression and activation of the NF-kappaB transcription factor. Two domains within the carboxy terminus have been identified that activate NF-kappaB. In this study, mutational analysis of the LMP1 protein indicated that the proximal NF-kappaB activation domain, which is identical to the TRAF interaction domain (amino acids 187 to 231), is essential for induction of the EGFR. The distal NF-kappaB activation domain (amino acids 352 to 386) did not induce expression of the EGFR. In contrast, the two domains both independently activated a kappaB-CAT reporter gene and induced expression of the NF-kappaB-regulated A20 gene in C33A epithelial cells. These results indicate that induction of the EGFR by LMP1 involves the TRAF interaction domain and that activation of NF-kappaB alone is not sufficient. Northern blot analysis revealed that induction of EGFR and A20 expression is likely to be at the transcriptional level. Interestingly expression of CD40 in the C33A cells also induced expression of the EGFR. Overexpression of either TRAF3 or an amino-terminal-truncated form of TRAF3 (TRAF3-C) inhibited signaling from the LMP1 TRAF interaction domain but did not affect signaling from the distal NF-kappaB activation domain. These data further define the mechanism by which LMP1 induces expression of the EGFR and indicate that TRAF signaling from LMP1 and CD40 activates a downstream transcription pathway distinct from NF-kappaB that induces expression of the EGFR. PMID:8985387

  14. [Hormones and osteoporosis update. Mechanisms of anabolic and catabolic effects of PTH on bone].

    PubMed

    Kobayashi, Tatsuya

    2009-07-01

    Treatment of osteoporosis aims to increase bone mass by suppressing bone resorption and/or stimulating bone formation. Among drugs clinically available for treatment of osteoporosis, only PTH stimulates bone formation. However, the mechanism by which PTH promotes bone formation is not clearly understood. PTH signaling in osteoblasts increases osteoblast progenitors. It appears that this effect of PTH is exerted mainly through multiple indirect pathways. Among them, the Wnt signaling pathway is of particular interest because of the strong human genetic evidence that Wnt signaling positively regulates bone mass. Activation of the PTH receptor increases Wnt signaling by down-regulating expression of Dkk1 and sclerostin, endogenous inhibitors for Wnt signaling, and by directly activating LRP6, a Wnt co-receptor. Understanding the mechanisms of the anabolic effect of PTH may lead to development of novel drugs to stimulate bone formation. PMID:19567985

  15. Insulin resistance is a two-sided mechanism acting under opposite catabolic and anabolic conditions.

    PubMed

    Schwartsburd, Polina

    2016-04-01

    The survival of multi-cellular organisms depends on the organism ability to maintain glucose homeostasis for time of low/high nutrient availability or high energy needs, and the ability to fight infections or stress. These effects are realized through the insulin controlled transport of blood glucose into the insulin-responsive cells such as muscle, fat and liver cells. Reduction in the ability of these cells to take glucose from the blood in response to normal circulating levels of insulin is known as insulin resistance (IR). Chronic IR is a key pathological feature of obesity, type 2 diabetes, sepsis and cancer cachexia, however temporal IR are widely met in fasting/ hibernation, pregnancy, anti-bacterial immunity, exercise and stress. Paradoxically, a certain part of the IR-cases is associated with catabolic metabolism, whereas the other is related to anabolic pathways. How can this paradoxical IR-response be explained? What is the metabolic basis of this IR variability and its physiological and pathological impacts? An answer to these questions might be achieved through the hypothesis in which IR is considered as a two-sided mechanism acting under opposite metabolic conditions (catabolism and anabolism) but with the common aim to sustain glucose homeostasis in a wide metabolic range. To test this hypothesis, I examined the main metabolic distinctions between the varied IR-cases and their dependence on the blood glucose concentration, level of the IR-threshold, and catabolic/anabolic activation. On the basis of the established interrelations, a simple model of IR-distribution has been developed. The model revealed the «U-type distribution» form with separation into two main IR-groups, each determined in the catabolic or anabolic conditions with one exception - type 2 diabetes and its paradoxical catabolic activation in anabolic conditions. The dual opposing (or complementary) role for the IR opens a new possibility for better understanding the cause and

  16. Insulin resistance is a two-sided mechanism acting under opposite catabolic and anabolic conditions.

    PubMed

    Schwartsburd, Polina

    2016-04-01

    The survival of multi-cellular organisms depends on the organism ability to maintain glucose homeostasis for time of low/high nutrient availability or high energy needs, and the ability to fight infections or stress. These effects are realized through the insulin controlled transport of blood glucose into the insulin-responsive cells such as muscle, fat and liver cells. Reduction in the ability of these cells to take glucose from the blood in response to normal circulating levels of insulin is known as insulin resistance (IR). Chronic IR is a key pathological feature of obesity, type 2 diabetes, sepsis and cancer cachexia, however temporal IR are widely met in fasting/ hibernation, pregnancy, anti-bacterial immunity, exercise and stress. Paradoxically, a certain part of the IR-cases is associated with catabolic metabolism, whereas the other is related to anabolic pathways. How can this paradoxical IR-response be explained? What is the metabolic basis of this IR variability and its physiological and pathological impacts? An answer to these questions might be achieved through the hypothesis in which IR is considered as a two-sided mechanism acting under opposite metabolic conditions (catabolism and anabolism) but with the common aim to sustain glucose homeostasis in a wide metabolic range. To test this hypothesis, I examined the main metabolic distinctions between the varied IR-cases and their dependence on the blood glucose concentration, level of the IR-threshold, and catabolic/anabolic activation. On the basis of the established interrelations, a simple model of IR-distribution has been developed. The model revealed the «U-type distribution» form with separation into two main IR-groups, each determined in the catabolic or anabolic conditions with one exception - type 2 diabetes and its paradoxical catabolic activation in anabolic conditions. The dual opposing (or complementary) role for the IR opens a new possibility for better understanding the cause and

  17. Pulmonary hemorrhage following anabolic agent abuse: Two cases.

    PubMed

    Hvid-Jensen, Helene S; Rasmussen, Finn; Bendstrup, Elisabeth

    2016-01-01

    Numerous adverse effects follow anabolic agent abuse. Pulmonary hemorrhage is not considered one of them. We present two cases of young male bodybuilders who developed diffuse alveolar bleeding as a result of anabolic steroid abuse. Diffuse alveolar hemorrhage associated with anabolic agent abuse has not been described previously in the literature. Both patients developed acute dyspnea and hemoptysis with consistent radiological findings. In both cases symptoms promptly resolved with cessation of exposure and no medical intervention was required and no signs of persistent lung damage were seen. It is crucial to be aware of pulmonary hemorrhage as an acute complication of anabolic agent abuse. It should be considered an important differential diagnosis in the athletic patient presenting with respiratory symptoms.

  18. Multiple arterial thromboses associated with anabolic androgenic steroids.

    PubMed

    McCulloch, Neil Arthur; Abbas, Jonathan Raihan; Simms, Malcolm Harold

    2014-03-01

    The use of supraphysiological doses of anabolic androgenic steroids can have serious side effects. This article reports the case of a young man who suffered potentially life-threatening arterial thromboses following the use of these drugs.

  19. T cell-expressed CD40L potentiates the bone anabolic activity of intermittent PTH treatment.

    PubMed

    Robinson, Jerid W; Li, Jau-Yi; Walker, Lindsey D; Tyagi, Abdul Malik; Reott, Michael A; Yu, Mingcan; Adams, Jonathan; Weitzmann, M Neale; Pacifici, Roberto

    2015-04-01

    T cells are known to potentiate the bone anabolic activity of intermittent parathyroid hormone (iPTH) treatment. One of the involved mechanisms is increased T cell secretion of Wnt10b, a potent osteogenic Wnt ligand that activates Wnt signaling in stromal cells (SCs). However, additional mechanisms might play a role, including direct interactions between surface receptors expressed by T cells and SCs. Here we show that iPTH failed to promote SC proliferation and differentiation into osteoblasts (OBs) and activate Wnt signaling in SCs of mice with a global or T cell-specific deletion of the T cell costimulatory molecule CD40 ligand (CD40L). Attesting to the relevance of T cell-expressed CD40L, iPTH induced a blunted increase in bone formation and failed to increase trabecular bone volume in CD40L(-/-) mice and mice with a T cell-specific deletion of CD40L. CD40L null mice exhibited a blunted increase in T cell production of Wnt10b and abrogated CD40 signaling in SCs in response to iPTH treatment. Therefore, expression of the T cell surface receptor CD40L enables iPTH to exert its bone anabolic activity by activating CD40 signaling in SCs and maximally stimulating T cell production of Wnt10b.

  20. Dying to be big: a review of anabolic steroid use.

    PubMed Central

    Perry, H M; Wright, D; Littlepage, B N

    1992-01-01

    Anabolic steroids use is commonly perceived to be the domain of the higher echelons of competitive athletes. However, a great deal of anabolic steroid use occurs in private gymnasia (non-local authority) among non-competitive recreational athletes. Our study has attempted to give an insight into the prevalence of the use of these drugs, the hazards associated with it, and the public health responses which we have adopted. PMID:1490220

  1. Dying to be big: a review of anabolic steroid use.

    PubMed

    Perry, H M; Wright, D; Littlepage, B N

    1992-12-01

    Anabolic steroids use is commonly perceived to be the domain of the higher echelons of competitive athletes. However, a great deal of anabolic steroid use occurs in private gymnasia (non-local authority) among non-competitive recreational athletes. Our study has attempted to give an insight into the prevalence of the use of these drugs, the hazards associated with it, and the public health responses which we have adopted.

  2. EphB2 tyrosine kinase-dependent forward signaling in migration of neuronal progenitors that populate and form a distinct region of the dentate niche.

    PubMed

    Catchpole, Timothy; Henkemeyer, Mark

    2011-08-10

    The dentate gyrus (DG) is one of two areas in the mature brain where stem cells reside to continuously produce new neurons throughout adulthood. While much research has focused on the DG for its roles in adult neurogenesis, little is known regarding how this key region of the brain initially develops to form its distinct architecture. We show here that the murine EphB2 receptor tyrosine kinase is critical for embryonic/postnatal development of a specific region of the DG known as the lateral suprapyramidal blade (LSB). Intracellular truncation and point mutants demonstrate that EphB2 catalytic activity is essential for LSB formation. This is consistent with expression of EphB2 in nestin-positive neural progenitor cells that migrate medially from the lateral ventricle dentate notch neuroepithelium to populate the tertiary matrix and form the DG near the midline of the brain. Animals lacking ephrin-B1 recapitulate loss of the receptor and show that this molecule acts as the ligand to stimulate EphB2 forward signaling and direct migration of the neural progenitors into the dorsal compartment of the tertiary matrix and form the LSB. Immunoreactivity against the extracellular matrix protein Reelin in a region directly above the developing LSB is dramatically reduced when EphB2 forward signaling is disrupted. Together, these results indicate ephrin-B1 interacting with EphB2 controls the migration of dentate progenitor cells into the dorsal half of the developing DG, perhaps in part by affecting Reelin expression in a key compartment directly above the LSB.

  3. The KdpD Sensor Kinase of Escherichia coli Responds to Several Distinct Signals To Turn on Expression of the Kdp Transport System

    PubMed Central

    2015-01-01

    ABSTRACT Kdp, one of three saturable K+ uptake systems in Escherichia coli, is the system with the highest affinity for K+ and the only one whose expression is strongly controlled by medium K+ concentration. Expression is controlled by a two-component system of KdpD, the sensor kinase, and KdpE, the response regulator. There is general agreement that expression occurs when the growth rate of cells begins to become limited by K+ availability. How K+ limitation results in expression has been controversial. Studying the roles of the major components of the growth medium shows that KdpD senses at least two distinct signals inside the cell, those of Na+ and NH4+, and it probably senses other monovalent cations in the cell. KdpD does not sense turgor. IMPORTANCE The expression of the Kdp K+ transport system of E. coli occurs when cells become limited in their growth rate by the availability of K+. Cells sense limited K+ and try to compensate by taking up other monovalent cations, particularly Na+ and NH4+. These cations are sensed in the cytoplasm by the KdpD response regulator, presumably to stimulate its kinase activity. It is shown that KdpD does not sense turgor, as was suggested earlier. PMID:26350129

  4. The two SAMP repeats and their phosphorylation state in Drosophila Adenomatous polyposis coli-2 play mechanistically distinct roles in negatively regulating Wnt signaling

    PubMed Central

    Kunttas-Tatli, Ezgi; Von Kleeck, Ryan A.; Greaves, Bradford D.; Vinson, David; Roberts, David M.; McCartney, Brooke M.

    2015-01-01

    The tumor suppressor Adenomatous polyposis coli (APC) plays a key role in regulating the canonical Wnt signaling pathway as an essential component of the β-catenin destruction complex. C-terminal truncations of APC are strongly implicated in both sporadic and familial forms of colorectal cancer. However, many questions remain as to how these mutations interfere with APC’s tumor suppressor activity. One set of motifs frequently lost in these cancer-associated truncations is the SAMP repeats that mediate interactions between APC and Axin. APC proteins in both vertebrates and Drosophila contain multiple SAMP repeats that lack high sequence conservation outside of the Axin-binding motif. In this study, we tested the functional redundancy between different SAMPs and how these domains are regulated, using Drosophila APC2 and its two SAMP repeats as our model. Consistent with sequence conservation–based predictions, we show that SAMP2 has stronger binding activity to Axin in vitro, but SAMP1 also plays an essential role in the Wnt destruction complex in vivo. In addition, we demonstrate that the phosphorylation of SAMP repeats is a potential mechanism to regulate their activity. Overall our findings support a model in which each SAMP repeat plays a mechanistically distinct role but they cooperate for maximal destruction complex function. PMID:26446838

  5. Distinct mechanisms regulating mechanical force-induced Ca²⁺ signals at the plasma membrane and the ER in human MSCs.

    PubMed

    Kim, Tae-Jin; Joo, Chirlmin; Seong, Jihye; Vafabakhsh, Reza; Botvinick, Elliot L; Berns, Michael W; Palmer, Amy E; Wang, Ning; Ha, Taekjip; Jakobsson, Eric; Sun, Jie; Wang, Yingxiao

    2015-02-10

    It is unclear that how subcellular organelles respond to external mechanical stimuli. Here, we investigated the molecular mechanisms by which mechanical force regulates Ca(2+) signaling at endoplasmic reticulum (ER) in human mesenchymal stem cells. Without extracellular Ca(2+), ER Ca(2+) release is the source of intracellular Ca(2+) oscillations induced by laser-tweezer-traction at the plasma membrane, providing a model to study how mechanical stimuli can be transmitted deep inside the cell body. This ER Ca(2+) release upon mechanical stimulation is mediated not only by the mechanical support of cytoskeleton and actomyosin contractility, but also by mechanosensitive Ca(2+) permeable channels on the plasma membrane, specifically TRPM7. However, Ca(2+) influx at the plasma membrane via mechanosensitive Ca(2+) permeable channels is only mediated by the passive cytoskeletal structure but not active actomyosin contractility. Thus, active actomyosin contractility is essential for the response of ER to the external mechanical stimuli, distinct from the mechanical regulation at the plasma membrane.

  6. The two SAMP repeats and their phosphorylation state in Drosophila Adenomatous polyposis coli-2 play mechanistically distinct roles in negatively regulating Wnt signaling.

    PubMed

    Kunttas-Tatli, Ezgi; Von Kleeck, Ryan A; Greaves, Bradford D; Vinson, David; Roberts, David M; McCartney, Brooke M

    2015-12-01

    The tumor suppressor Adenomatous polyposis coli (APC) plays a key role in regulating the canonical Wnt signaling pathway as an essential component of the β-catenin destruction complex. C-terminal truncations of APC are strongly implicated in both sporadic and familial forms of colorectal cancer. However, many questions remain as to how these mutations interfere with APC's tumor suppressor activity. One set of motifs frequently lost in these cancer-associated truncations is the SAMP repeats that mediate interactions between APC and Axin. APC proteins in both vertebrates and Drosophila contain multiple SAMP repeats that lack high sequence conservation outside of the Axin-binding motif. In this study, we tested the functional redundancy between different SAMPs and how these domains are regulated, using Drosophila APC2 and its two SAMP repeats as our model. Consistent with sequence conservation-based predictions, we show that SAMP2 has stronger binding activity to Axin in vitro, but SAMP1 also plays an essential role in the Wnt destruction complex in vivo. In addition, we demonstrate that the phosphorylation of SAMP repeats is a potential mechanism to regulate their activity. Overall our findings support a model in which each SAMP repeat plays a mechanistically distinct role but they cooperate for maximal destruction complex function.

  7. Human and mouse monocytes display distinct signalling and cytokine profiles upon stimulation with FFAR2/FFAR3 short-chain fatty acid receptor agonists

    PubMed Central

    Ang, Zhiwei; Er, Jun Zhi; Tan, Nguan Soon; Lu, Jinhua; Liou, Yih-Cherng; Grosse, Johannes; Ding, Jeak Ling

    2016-01-01

    Knockout mice studies implicate the mammalian short-chain fatty acid (SCFA) receptors, FFAR2 and FFAR3– in colitis, arthritis and asthma. However, the correlation with human biology is uncertain. Here, we detected FFAR2 and FFAR3 expression in human monocytes via immunohistochemistry. Upon treatment with acetate SCFA or FFAR2- and FFAR3-specific synthetic agonists, human monocytes displayed elevated p38 phosphorylation and attenuated C5, CCL1, CCL2, GM-CSF, IL-1α, IL-1β and ICAM-1 inflammatory cytokine expression. Acetate and FFAR2 agonist treatment also repressed Akt and ERK2 signalling. Surprisingly, mouse monocytes displayed a distinct response to acetate treatment, elevating GM-CSF, IL-1α, and IL-1β cytokine expression. This effect persisted in FFAR2/3-knockout mouse monocytes and was not reproduced by synthetic agonists, suggesting a FFAR2/3 independent mechanism in mice. Collectively, we show that SCFAs act via FFAR2/3 to modulate human monocyte inflammatory responses– a pathway that is absent in mouse monocytes. PMID:27667443

  8. The energetics of anabolism in natural settings.

    PubMed

    LaRowe, Douglas E; Amend, Jan P

    2016-06-01

    The environmental conditions that describe an ecosystem define the amount of energy available to the resident organisms and the amount of energy required to build biomass. Here, we quantify the amount of energy required to make biomass as a function of temperature, pressure, redox state, the sources of C, N and S, cell mass and the time that an organism requires to double or replace its biomass. Specifically, these energetics are calculated from 0 to 125 °C, 0.1 to 500 MPa and -0.38 to +0.86 V using CO2, acetate or CH4 for C, NO3(-) or NH4(+) for N and SO4(2-) or HS(-) for S. The amounts of energy associated with synthesizing the biomolecules that make up a cell, which varies over 39 kJ (g cell)(-1), are then used to compute energy-based yield coefficients for a vast range of environmental conditions. Taken together, environmental variables and the range of cell sizes leads to a ~4 orders of magnitude difference between the number of microbial cells that can be made from a Joule of Gibbs energy under the most (5.06 × 10(11) cells J(-1)) and least (5.21 × 10(7) cells J(-1)) ideal conditions. When doubling/replacement time is taken into account, the range of anabolism energies can expand even further. PMID:26859771

  9. Anabolic-androgenic steroids and brain reward.

    PubMed

    Clark, A S; Lindenfeld, R C; Gibbons, C H

    1996-03-01

    Anabolic-androgenic steroid (AAS) effects on brain reward were investigated in male rats with electrodes implanted in the lateral hypothalamus using the rate-frequency curve shift paradigm of brain stimulation reward. In the first experiment, treatment for 2 weeks with the AAS methandrostenolone had no effect on either the reward or performance components of intracranial self-stimulation. In the second experiment, treatment for 15 weeks with an AAS "cocktail" consisting of testosterone cypionate, nandrolone decanoate, and boldenone undecylenate did not alter brain reward but did produce a slight but significant change in bar press rate. In addition to the AAS treatment, animals in the second study were administered a single injection of d-amphetamine before and after 15 weeks of AAS exposure. The rate-frequency curve shift observed in response to a systemic injection of amphetamine was significantly greater in animals after 15 weeks of treatment with the AAS cocktail. Although AAS do not appear to alter the rewarding properties of brain stimulation, AAS may influence the sensitivity of brain reward systems. PMID:8866980

  10. Dermatologists and anabolic-androgenic drug abuse.

    PubMed

    Scott, M J; Scott, M J

    1989-07-01

    The use of huge self-administered dosages of anabolic-androgenic steroids by athletes and body builders is widespread in the United States, increasing at a rapid rate among athletes of both sexes and involving an ever-expanding age group. Athletes are very wary of revealing steroid use to their physicians, so a high index of suspicion is a prerequisite in diagnosing the use of these agents. Since many of the side effects of steroids are manifested in the skin, dermatologists are in a unique and favorable position to detect their use, if they are aware of such clinical signs. Once alerted to this possibility during a dermatologic examination, the dermatologist has an excellent opportunity to make users aware of the potential hazards and dangers of taking such drugs. Counselling these athletes can do much to stem the tide against the rising problem of drug abuse. It is a worthwhile service to sports in general as well as to the patient's personal health. Many of our conclusions are based on our personal experience with elite and Olympic athletes in almost every sport, body builders, and junior high school, high school, and college students and athletes.

  11. Anabolic-androgenic steroids and the adolescent.

    PubMed

    Rogol, A D; Yesalis, C E

    1992-03-01

    This article has reviewed some of the hormonal and behavioral maturation that occurs during adolescence, which are characterized by remarkable physical changes and behavioral vulnerability. Risk taking of many varieties is common and drugs (including anabolic-androgenic steroids) form a part of the prevailing culture in many places. These steroids probably are not severe health hazards when taken intermittently and in low to moderate doses. The 17-alkylated derivatives are clearly the more likely to cause hepatotoxicity. Thus, the scare tactics formerly used (severe constitutional side effects) are doomed to failure. The tenuous link between these drugs and objective behavioral and addictive effects must be strengthened before health strategies based on this issue can be validated. Clearly, the lack of scientific information has impeded, if not precluded, the formulation of an effective health education strategy. The most potent deterrent to the use of steroid drugs by athletes must be the moral issue of fair play and maintaining a "level playing field." We strongly support directed research in these areas and hope that the credibility of the scientific community can be regained after its faulted "stop steroid use" campaigns based on the lack of steroid efficacy in bringing about desired results or on their dire consequences have been replaced with credible evidence to refute their use on these and other grounds.

  12. Illicit anabolic-androgenic steroid use.

    PubMed

    Kanayama, Gen; Hudson, James I; Pope, Harrison G

    2010-06-01

    The anabolic-androgenic steroids (AAS) are a family of hormones that includes testosterone and its derivatives. These substances have been used by elite athletes since the 1950s, but they did not become widespread drugs of abuse in the general population until the 1980s. Thus, knowledge of the medical and behavioral effects of illicit AAS use is still evolving. Surveys suggest that many millions of boys and men, primarily in Western countries, have abused AAS to enhance athletic performance or personal appearance. AAS use among girls and women is much less common. Taken in supraphysiologic doses, AAS show various long-term adverse medical effects, especially cardiovascular toxicity. Behavioral effects of AAS include hypomanic or manic symptoms, sometimes accompanied by aggression or violence, which usually occur while taking AAS, and depressive symptoms occurring during AAS withdrawal. However, these symptoms are idiosyncratic and afflict only a minority of illicit users; the mechanism of these idiosyncratic responses remains unclear. AAS users may also ingest a range of other illicit drugs, including both "body image" drugs to enhance physical appearance or performance, and classical drugs of abuse. In particular, AAS users appear particularly prone to opioid use. There may well be a biological basis for this association, since both human and animal data suggest that AAS and opioids may share similar brain mechanisms. Finally, AAS may cause a dependence syndrome in a substantial minority of users. AAS dependence may pose a growing public health problem in future years but remains little studied.

  13. Illicit Anabolic-Androgenic Steroid Use

    PubMed Central

    Kanayama, Gen; Hudson, James I.; Pope, Harrison G.

    2009-01-01

    The anabolic-androgenic steroids (AAS) are a family of hormones that includes testosterone and its derivatives. These substances have been used by elite athletes since the 1950s, but they did not become widespread drugs of abuse in the general population until the 1980s. Thus, knowledge of the medical and behavioral effects of illicit AAS use is still evolving. Surveys suggest that many millions of boys and men, primarily in Western countries, have abused AAS to enhance athletic performance or personal appearance. AAS use among girls and women is much less common. Taken in supraphysiologic doses, AAS show various long-term adverse medical effects, especially cardiovascular toxicity. Behavioral effects of AAS include hypomanic or manic symptoms, sometimes accompanied by aggression or violence, which usually occur while taking AAS, and depressive symptoms occurring during AAS withdrawal. However, these symptoms are idiosyncratic and afflict only a minority of illicit users; the mechanism of these idiosyncratic responses remains unclear. AAS users may also ingest a range of other illicit drugs, including both “body-image” drugs to enhance physical appearance or performance, and classical drugs of abuse. In particular, AAS users appear particularly prone to opioid use. There may well be a biological basis for this association, since both human and animal data suggest that AAS and opioids may share similar brain mechanisms. Finally, AAS may cause a dependence syndrome in a substantial minority of users. AAS dependence may pose a growing public health problem in future years, but remains little studied. PMID:19769977

  14. Behavioural manifestations of anabolic steroid use.

    PubMed

    Trenton, Adam J; Currier, Glenn W

    2005-01-01

    The use of anabolic androgenic steroids (AAS) for gains in strength and muscle mass is relatively common among certain subpopulations, including athletes, bodybuilders, adolescents and young adults. Adverse physical effects associated with steroid abuse are well documented, but more recently, increased attention has been given to the adverse psychiatric effects of these compounds. Steroids may be used in oral, 17alpha-alkylated, or intramuscular, 17beta-esterified, preparations. Commonly, steroid users employ these agents at levels 10- to 100-fold in excess of therapeutic doses and use multiple steroids simultaneously, a practice known as 'stacking'. Significant psychiatric symptoms including aggression and violence, mania, and less frequently psychosis and suicide have been associated with steroid abuse. Long-term steroid abusers may develop symptoms of dependence and withdrawal on discontinuation of AAS. Treatment of AAS abusers should address both acute physical and behavioural symptoms as well as long-term abstinence and recovery. To date, limited information is available regarding specific pharmacological treatments for individuals recovering from steroid abuse. This paper reviews the published literature concerning the recognition and treatment of behavioural manifestations of AAS abuse.

  15. Clenbuterol: a substitute for anabolic steroids?

    PubMed

    Prather, I D; Brown, D E; North, P; Wilson, J R

    1995-08-01

    Clenbuterol is a recently popular drug used by athletes in many sports for its purported anabolic effects and reduction of subcutaneous fat. It is a beta-2 (beta 2) agonist prescribed overseas as a bronchodilator, but not approved for use in this country. It is on the banned substance list of the United States Olympic Committee. To avoid any erosion of confidence, physicians caring for athletes need accurate information regarding clenbuterol. Such information is unavailable within the routine medical environs. A review of the literature of animal husbandry reveals that this drug, when administered in doses far greater than those required for bronchodilation, does indeed increase the deposition rate of lean mass and retard adipose gain. There are no human studies available. Animal studies were conducted on laboratory and slaughter stock. No investigation into long-term cardiovascular side effects has been undertaken. The rate of extrapolation from animal studies to unsupervised human usage is alarming. If this category of drugs does preserve lean mass in humans, there are legitimate medical applications. Trials of efficacy and safety are needed.

  16. Cardiac autonomic dysfunction in anabolic steroid users.

    PubMed

    Maior, A S; Carvalho, A R; Marques-Neto, S R; Menezes, P; Soares, P P; Nascimento, J H M

    2013-10-01

    This study aimed to evaluate if androgenic-anabolic steroids (AAS) abuse may induce cardiac autonomic dysfunction in recreational trained subjects. Twenty-two men were volunteered for the study. The AAS group (n = 11) utilized AAS at mean dosage of 410 ± 78.6 mg/week. All of them were submitted to submaximal exercise testing using an Astrand-Rhyming protocol. Electrocardiogram (ECG) and respired gas analysis were monitored at rest, during, and post-effort. Mean values of VO2 , VCO2 , and VE were higher in AAS group only at rest. The heart rate variability variables were calculated from ECG using MATLAB-based algorithms. At rest, AAS group showed lower values of the standard deviation of R-R intervals, the proportion of adjacent R-R intervals differing by more than 50 ms (pNN50), the root mean square of successive differences (RMSSD), and the total, the low-frequency (LF) and the high-frequency (HF) spectral power, as compared to Control group. After submaximal exercise testing, pNN50, RMSSD, and HF were lower, and the LF/HF ratio was higher in AAS group when compared to control group. Thus, the use of supraphysiological doses of AAS seems to induce dysfunction in tonic cardiac autonomic regulation in recreational trained subjects.

  17. Recent developments in the toxicology of anabolic steroids.

    PubMed

    Graham, S; Kennedy, M

    1990-01-01

    Anabolic steroids are extensively abused as ergogenic aids by athletes (and others). A number of features of anabolic steroid use and toxicology have been recently reviewed in the Journal, and a large body of data has accumulated concerning their toxic nature. The lipoprotein profile induced by anabolic steroids carries a markedly adverse cardiovascular risk. Glucose metabolism is significantly altered and includes peripheral insulin resistance, hyperinsulinaemia and attenuated responses to glucagon. Hypertension has been noted. Psychiatric and psychological alterations are major toxicities of anabolic steroids, and probably constitute the major mechanism of their action. Hepatic neoplasia occurs in the setting of abuse of this class of drugs, and may be related to their use, although there is no convincing evidence that other malignancies are induced in athletes who abuse them. Gross disturbance of reproductive function occurs in both sexes: hypogonadal states are common and prolonged. The anabolic steroids are toxic drugs with both long and short term effects. Their abuse by athletes is to be decried, particularly in view of the frequent and prolonged use by the young.

  18. Androgenic-anabolic activities of some new synthesized steroidal pyrane, pyridine and thiopyrimidine derivatives.

    PubMed

    Abdalla, Mohamed M; Amr, Abd El-Galil E; Al-Omar, Mohamed A; Hussain, Azza A; Amer, Mohamed S

    2014-01-01

    In continuation of our previous work, fused steroidal derivatives with pyrane, pyridine, pyrimidine moieties were synthesized and evaluated as androgenic-anabolic agents. Some of the newly synthesized compounds are exhibited pronounced androgenic-anabolic activities.

  19. Bleeding oesophageal varices associated with anabolic steroid use in an athlete.

    PubMed Central

    Winwood, P. J.; Robertson, D. A.; Wright, R.

    1990-01-01

    A 30 year old bodybuilder who had been taking anabolic steroids for 18 months presented with bleeding oesophageal varices. Serious liver disease secondary to anabolic steroids including peliosis hepatis, nodular hyperplasia and malignant change is well recognized. We report what is, to our knowledge, the first case of bleeding oesophageal varices associated with the use of anabolic steroids. PMID:2099434

  20. 21 CFR 1308.25 - Exclusion of a veterinary anabolic steroid implant product; application.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Exclusion of a veterinary anabolic steroid implant... OF JUSTICE SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.25 Exclusion of a veterinary anabolic steroid implant product; application. (a) Any person...

  1. 21 CFR 1308.25 - Exclusion of a veterinary anabolic steroid implant product; application.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Exclusion of a veterinary anabolic steroid implant... OF JUSTICE SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.25 Exclusion of a veterinary anabolic steroid implant product; application. (a) Any person...

  2. 21 CFR 1308.25 - Exclusion of a veterinary anabolic steroid implant product; application.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Exclusion of a veterinary anabolic steroid implant... OF JUSTICE SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.25 Exclusion of a veterinary anabolic steroid implant product; application. (a) Any person...

  3. 21 CFR 1308.25 - Exclusion of a veterinary anabolic steroid implant product; application.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Exclusion of a veterinary anabolic steroid implant... OF JUSTICE SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.25 Exclusion of a veterinary anabolic steroid implant product; application. (a) Any person...

  4. The Effect of Anabolic Steroid Education on Knowledge and Attitudes of At-Risk Preadolescents.

    ERIC Educational Resources Information Center

    Trenhaile, Jay; Choi, Hee-Sook; Proctor, Theron B.; Work, Patricia

    1998-01-01

    Investigates the effect of anabolic steroid education on preadolescents' knowledge of and attitudes toward anabolic steroids with 35 male athletes. Information on psychological and physiological aspects of anabolic steroid use, weight training techniques, nutrition, social decision making, and self-esteem training were provided. Participants…

  5. Knowledge about Anabolic Steroids of Rhode Island Adolescents: Implications for Education Programs.

    ERIC Educational Resources Information Center

    Nutter, June

    Although anabolic steroids are associated with short term behavior and long term health problems, few schools address this issue. Adolescents were surveyed to determine their general knowledge of anabolic steroids, attitudes related to fair play, and interest in limiting anabolic steroid use. Data from 322 boys and 331 girls in grades 7-12 were…

  6. 21 CFR 1308.25 - Exclusion of a veterinary anabolic steroid implant product; application.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Exclusion of a veterinary anabolic steroid implant... OF JUSTICE SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.25 Exclusion of a veterinary anabolic steroid implant product; application. (a) Any person...

  7. Acute Anabolic Response and Muscular Adaptation After Hypertrophy-Style and Strength-Style Resistance Exercise.

    PubMed

    Gonzalez, Adam M

    2016-10-01

    Gonzalez, AM. Acute anabolic response and muscular adaptation after hypertrophy-style and strength-style resistance exercise. J Strength Cond Res 30(10): 2959-2964, 2016-Resistance training paradigms are often divided into protocols designed to promote an increase in either hypertrophy or strength. Hypertrophy-style protocols (HYPs) typically involve greater volume (3-6 sets; 8-12 repetitions), moderate intensities (<85% 1 repetition maximum [1RM]), and short rest intervals (30-90 seconds), whereas strength-style protocols (STRs) typically involve higher intensities (≥85% 1RM), low volumes (2-6 sets; ≤6 repetitions), and longer rest intervals (3-5 minutes). However, the literature supporting such classifications is surprisingly sparse in trained individuals, and the distinct classifications of such protocols may be an oversimplification. Thus, the purpose of this review was to examine the acute anabolic responses and training-induced muscular adaptations after HYP and STR styles of resistance exercise in trained individuals. Despite the classification of training paradigms, HYP and STR resistance training routines appear to elicit similar magnitudes of muscle growth, although STR routines appear to be more conducive to increasing strength in resistance-trained individuals. Current evidence suggests that the classification of HYP and STR is an oversimplification, and practitioners are advised to look beyond the classification of resistance exercise protocols when aiming to elicit specific physiological responses.

  8. Adolescent ischemic stroke associated with anabolic steroid and cannabis abuse.

    PubMed

    El Scheich, Tarik; Weber, Artur-Aron; Klee, Dirk; Schweiger, Daniel; Mayatepek, Ertan; Karenfort, Michael

    2013-01-01

    We report on a 16-year-old body builder who suffered from an acute ischemic stroke. In the urine, cannabis metabolites as well as metabolites of the oral androgenic-anabolic steroid methandrostenolone were detected, both known to be associated with stroke events. This report highlights the role of cannabis and steroid abuse that induce strokes in the absence of arteriopathy, cardioembolism or thrombophilia. Owing to new upcoming socio-behavioral aspects of late childhood and early adolescent life, this formally rare abuse of cannabis and/or anabolic steroids as well as their associations with strokes becomes more current than ever. PMID:23382306

  9. On the Free Energy That Drove Primordial Anabolism

    PubMed Central

    Kaufmann, Michael

    2009-01-01

    A key problem in understanding the origin of life is to explain the mechanism(s) that led to the spontaneous assembly of molecular building blocks that ultimately resulted in the appearance of macromolecular structures as they are known in modern biochemistry today. An indispensable thermodynamic prerequisite for such a primordial anabolism is the mechanistic coupling to processes that supplied the free energy required. Here I review different sources of free energy and discuss the potential of each form having been involved in the very first anabolic reactions that were fundamental to increase molecular complexity and thus were essential for life. PMID:19468343

  10. Structural characteristics of anabolic androgenic steroids contributing to binding to the androgen receptor and to their anabolic and androgenic activities. Applied modifications in the steroidal structure.

    PubMed

    Fragkaki, A G; Angelis, Y S; Koupparis, M; Tsantili-Kakoulidou, A; Kokotos, G; Georgakopoulos, C

    2009-02-01

    Anabolic androgenic steroids (AAS) are synthetic derivatives of testosterone introduced for therapeutic purposes providing enhanced anabolic potency with reduced androgenic effects. Androgens mediate their action through their binding to the androgen receptor (AR) which is mainly expressed in androgen target tissues, such as the prostate, skeletal muscle, liver and central nervous system. This paper reviews some of the wide spectrum of testosterone and synthetic AAS structure modifications related to the intended enhancement in anabolic activity. The structural features of steroids necessary for effective binding to the AR and those which contribute to the stipulation of the androgenic and anabolic activities are also presented.

  11. Chronic Ethanol Consumption Inhibits Postlactational Anabolic Rebuilding in Female Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite significant loss of bone during lactation, bone mineral density (BMD) is restored by a powerful anabolic rebuilding process following weaning. A significant number of women resume alcohol consumption after weaning their offspring from breast feeding. The objectives of the present study were ...

  12. Psychological Predictors of Anabolic Steroid Use: An Exploratory Study.

    ERIC Educational Resources Information Center

    Schwerin, Michael J.; Corcoran, Kevin J.; LaFleur, Bonnie J.; Fisher, Leslee; Patterson, David; Olrich, Tracy

    1997-01-01

    Examined social physique anxiety, upper body esteem, social anxiety, and body dissatisfaction as possible predictors of anabolic steroid (AS) use. Results based on 185 AS-using bodybuilders and various control groups indicated that the upper body strength subscale of two measures, along with age, were significant predictors of AS use. (RJM)

  13. Anabolic Steroid Use: Indications of Habituation among Adolescents.

    ERIC Educational Resources Information Center

    Yesalis, Charles E.; And Others

    1989-01-01

    Identified characteristics of adolescent male anabolic steroid (AS) user and addictive potential. Found AS user population different from nonuser in self-perceptions of health and strength, interest in controlling AS use, and perception of peer AS use. Found subgroups with significantly different attitudes and/or behaviors. Suggests prevention…

  14. Psychological and Behavioral Effects of Anabolic-Androgenic Steroids.

    ERIC Educational Resources Information Center

    Bahrke, Michael S.

    This review of the literature on the psychological and behavioral effects of anabolic-androgenic steroids (AS) first looks at aspects of the history and prevalence of AS use in competitive sports. Research suggests that one-quarter to one-half million adolescents in the United States have used, or are currently using AS. Some effects of androgens…

  15. The Incidence of Anabolic Steroid Use among Competitive Bodybuilders.

    ERIC Educational Resources Information Center

    Tricker, Ray; And Others

    1989-01-01

    Investigated incidence of anabolic steroid use among 380 competitive male and female bodybuilders in Kansas and Missouri. Results indicated more than half (54 percent) of the male bodybuilders were using steroids on a regular basis compared to 10 percent of the female competitors. Found main reason for use of steroids was desire to win. (Author/TE)

  16. Hypercholesterolemia in Male Power Lifters Using Anabolic-Androgenic Steroids.

    ERIC Educational Resources Information Center

    Cohen, Jonathan C.; And Others

    1988-01-01

    Measurement of serum cholesterol concentrations in male power lifters who used anabolic-androgenic steroids for eight weeks, three years, or eight years indicated that mean serum cholesterol levels increased with drug use, but decreased promptly to near pre-steroid levels after steroid use ended. (Author/CB)

  17. Project Right Way: An Anabolic Steroid Education Program.

    ERIC Educational Resources Information Center

    Nutter, June

    There is increasing concern by medical experts in this country about the use of anabolic steroids by teenagers. Over one million Americans are believed to be currently using or have used the synthetic hormones in the past. While drug testing and a reduction in the supply of the drugs appear to be reducing the number of adult users, use by…

  18. Anabolic steroid usage in athletics: facts, fiction, and public relations.

    PubMed

    Berning, Joseph M; Adams, Kent J; Stamford, Bryant A

    2004-11-01

    Anecdotal evidence suggests the widespread usage of anabolic steroids among athletes (20-90%), particularly at the professional and elite amateur levels. In contrast, scientific studies indicate that usage is rare and no higher than 6%. Conclusions from scientific studies suggest that anabolic steroid usage declines progressively from high school to college and beyond; however, anecdotal evidence claims the opposite trend. In this clash between "hard" scientific data vs. "soft" anecdotal information, it is natural that professionals would gravitate toward scientifically based conclusions. However, in the case of anabolic steroids (a stigmatized and illegal substance), should word-of-mouth testimony from individuals closest to the issues--those who have participated in and coached sports, those who have served as drug-testing overseers, and journalists who relentlessly track leads and verify sources--be set aside as irrelevant? Not if a complete picture is to emerge. In this review, hard scientific evidence is placed on the table side-by-side with soft anecdotal evidence, without weighting or bias. The purpose is to allow the opportunity for each to illuminate the other and, in so doing, potentially bring us a step closer to determining the true extent of anabolic steroid usage in athletics. PMID:15574100

  19. Combined administration of testosterone plus an ornithine decarboxylase inhibitor as a selective prostate-sparing anabolic therapy

    PubMed Central

    Jasuja, Ravi; Costello, James C; Singh, Rajan; Gupta, Vandana; Spina, Catherine S; Toraldo, Gianluca; Jang, Hyeran; Li, Hu; Serra, Carlo; Guo, Wen; Chauhan, Pratibha; Narula, Navjot S; Guarneri, Tyler; Ergun, Ayla; Travison, Thomas G; Collins, James J; Bhasin, Shalender

    2014-01-01

    Because of its anabolic effects on muscle, testosterone is being explored as a function-promoting anabolic therapy for functional limitations associated with aging; however, concerns about testosterone’s adverse effects on prostate have inspired efforts to develop strategies that selectively increase muscle mass while sparing the prostate. Testosterone’s promyogenic effects are mediated through upregulation of follistatin. We show here that the administration of recombinant follistatin (rFst) increased muscle mass in mice, but had no effect on prostate mass. Consistent with the results of rFst administration, follistatin transgenic mice with constitutively elevated follistatin levels displayed greater muscle mass than controls, but had similar prostate weights. To elucidate signaling pathways regulated differentially by testosterone and rFst in prostate and muscle, we performed microarray analysis of mRNAs from prostate and levator ani of castrated male mice treated with vehicle, testosterone, or rFst. Testosterone and rFst shared the regulation of many transcripts in levator ani; however, in prostate, 593 transcripts in several growth-promoting pathways were differentially expressed after testosterone treatment, while rFst showed a negligible effect with only 9 transcripts differentially expressed. Among pathways that were differentially responsive to testosterone in prostate, we identified ornithine decarboxylase (Odc1), an enzyme in polyamine biosynthesis, as a testosterone-responsive gene that is unresponsive to rFst. Accordingly, we administered testosterone with and without α-difluoromethylornithine (DFMO), an Odc1 inhibitor, to castrated mice. DFMO selectively blocked testosterone’s effects on prostate, but did not affect testosterone’s anabolic effects on muscle. Co-administration of testosterone and Odc1 inhibitor presents a novel therapeutic strategy for prostate-sparing anabolic therapy. PMID:24305501

  20. Detection, quantification and confirmation of anabolic steroids in equine plasma by liquid chromatography and tandem mass spectrometry.

    PubMed

    Guan, Fuyu; Uboh, Cornelius E; Soma, Lawrence R; Luo, Yi; Rudy, Jeffery; Tobin, Thomas

    2005-12-27

    Anabolic androgenic steroids are related to the male sex hormones and are abused in equine sports. In an effort to deter the abuse of anabolic steroids, a sensitive LC-MS/MS method was developed for detection, quantification and confirmation of eight major anabolic steroids (testosterone, normethandrolone, nandrolone, boldenone, methandrostenolone, tetrahydrogestrinone (THG), trenbolone, and stanozolol) in equine plasma. Formation of solvent adduct ions of the analytes was observed under electrospray ionization (ESI) conditions, and desolvation of the solvent adduct ions by source collision-induced decomposition (CID) increased the abundance of the [M+H]+ ions as well as the multiple-reaction monitoring (MRM) signals. ESI (+) and APCI (+) were compared with respect to sensitivity for the analytes and the former provided better sensitivity. The matrix effect on ion suppression or enhancement was evaluated, and was negligible. Confirmation of the analytes was performed using criteria of three ion transitions and LC retention time of each analyte. The limit of detection (LOD) and quantification (LOQ) was 25 pg/mL. The limit of confirmation (LOC) was 25 pg/mL for boldenone; 50 pg/mL for normethandrolone, nandrolone, and methandrostenolone; and 100 pg/mL for testosterone, THG, trenbolone, and stanozolol. The analytes were evaluated for stability and found to be stable in plasma for 24h at room temperature, 13 days at 4 degrees C, and 34 days at -20 and -70 degrees C. The method was successfully applied to analyses of equine plasma samples for pharmacokinetics study. This method is sensitive and useful for detection, quantification and confirmation of these anabolic steroids in equine plasma. PMID:16289956

  1. Combined administration of testosterone plus an ornithine decarboxylase inhibitor as a selective prostate-sparing anabolic therapy.

    PubMed

    Jasuja, Ravi; Costello, James C; Singh, Rajan; Gupta, Vandana; Spina, Catherine S; Toraldo, Gianluca; Jang, Hyeran; Li, Hu; Serra, Carlo; Guo, Wen; Chauhan, Pratibha; Narula, Navjot S; Guarneri, Tyler; Ergun, Ayla; Travison, Thomas G; Collins, James J; Bhasin, Shalender

    2014-04-01

    Because of its anabolic effects on muscle, testosterone is being explored as a function-promoting anabolic therapy for functional limitations associated with aging; however, concerns about testosterone's adverse effects on prostate have inspired efforts to develop strategies that selectively increase muscle mass while sparing the prostate. Testosterone's promyogenic effects are mediated through upregulation of follistatin. We show here that the administration of recombinant follistatin (rFst) increased muscle mass in mice, but had no effect on prostate mass. Consistent with the results of rFst administration, follistatin transgenic mice with constitutively elevated follistatin levels displayed greater muscle mass than controls, but had similar prostate weights. To elucidate signaling pathways regulated differentially by testosterone and rFst in prostate and muscle, we performed microarray analysis of mRNAs from prostate and levator ani of castrated male mice treated with vehicle, testosterone, or rFst. Testosterone and rFst shared the regulation of many transcripts in levator ani; however, in prostate, 593 transcripts in several growth-promoting pathways were differentially expressed after testosterone treatment, while rFst showed a negligible effect with only 9 transcripts differentially expressed. Among pathways that were differentially responsive to testosterone in prostate, we identified ornithine decarboxylase (Odc1), an enzyme in polyamine biosynthesis, as a testosterone-responsive gene that is unresponsive to rFst. Accordingly, we administered testosterone with and without α-difluoromethylornithine (DFMO), an Odc1 inhibitor, to castrated mice. DFMO selectively blocked testosterone's effects on prostate, but did not affect testosterone's anabolic effects on muscle. Co-administration of testosterone and Odc1 inhibitor presents a novel therapeutic strategy for prostate-sparing anabolic therapy.

  2. Lysobacter enzymogenes Uses Two Distinct Cell-Cell Signaling Systems for Differential Regulation of Secondary-Metabolite Biosynthesis and Colony Morphology

    PubMed Central

    Qian, Guoliang; Wang, Yulan; Liu, Yiru; Xu, Feifei; He, Ya-Wen; Du, Liangcheng; Venturi, Vittorio; Fan, Jiaqin; Hu, Baishi

    2013-01-01

    Lysobacter enzymogenes is a ubiquitous environmental bacterium that is emerging as a potentially novel biological control agent and a new source of bioactive secondary metabolites, such as the heat-stable antifungal factor (HSAF) and photoprotective polyene pigments. Thus far, the regulatory mechanism(s) for biosynthesis of these bioactive secondary metabolites remains largely unknown in L. enzymogenes. In the present study, the diffusible signal factor (DSF) and diffusible factor (DF)-mediated cell-cell signaling systems were identified for the first time from L. enzymogenes. The results show that both Rpf/DSF and DF signaling systems played critical roles in modulating HSAF biosynthesis in L. enzymogenes. Rpf/DSF signaling and DF signaling played negative and positive effects in polyene pigment production, respectively, with DF playing a more important role in regulating this phenotype. Interestingly, only Rpf/DSF, but not the DF signaling system, regulated colony morphology of L. enzymgenes. Both Rpf/DSF and DF signaling systems were involved in the modulation of expression of genes with diverse functions in L. enzymogenes, and their own regulons exhibited only a few loci that were regulated by both systems. These findings unveil for the first time new roles of the Rpf/DSF and DF signaling systems in secondary metabolite biosynthesis of L. enzymogenes. PMID:23974132

  3. Apoptosis Induced by Tanshinone IIA and Cryptotanshinone Is Mediated by Distinct JAK/STAT3/5 and SHP1/2 Signaling in Chronic Myeloid Leukemia K562 Cells

    PubMed Central

    Jung, Ji Hoon; Kwon, Tae-Rin; Jeong, Soo-Jin; Kim, Eun-Ok; Sohn, Eun Jung; Yun, Miyong; Kim, Sung-Hoon

    2013-01-01

    Though tanshinone IIA and cryptotanshinone possess a variety of biological effects such as anti-inflammatory, antioxidative, antimetabolic, and anticancer effects, the precise molecular targets or pathways responsible for anticancer activities of tanshinone IIA and cryptotanshinone in chronic myeloid leukemia (CML) still remain unclear. In the present study, we investigated the effect of tanshinone IIA and cryptotanshinone on the Janus activated kinase (JAK)/signal transducer and activator of transcription (STAT) signaling during apoptotic process. We found that both tanshinone IIA and cryptotanshinone induced apoptosis by activation of caspase-9/3 and Sub-G1 accumulation in K562 cells. However, they have the distinct JAK/STAT pathway, in which tanshinone IIA inhibits JAK2/STAT5 signaling, whereas cryptotanshinone targets the JAK2/STAT3. In addition, tanshinone IIA enhanced the expression of both SHP-1 and -2, while cryptotanshinone regulated the expression of only SHP-1. Both tanshinone IIA and cryptotanshinone attenuated the expression of bcl-xL, survivin, and cyclin D1. Furthermore, tanshinone IIA augmented synergy with imatinib, a CML chemotherapeutic drug, better than cryptotanshinone in K562 cells. Overall, our findings suggest that the anticancer activity of tanshinone IIA and cryptotanshinone is mediated by the distinct the JAK/STAT3/5 and SHP1/2 signaling, and tanshinone IIA has the potential for combination therapy with imatinib in K562 CML cells. PMID:23878608

  4. Two distinct types of mouse melanocyte: differential signaling requirement for the maintenance of non-cutaneous and dermal versus epidermal melanocytes.

    PubMed

    Aoki, Hitomi; Yamada, Yasuhiro; Hara, Akira; Kunisada, Takahiro

    2009-08-01

    Unlike the thoroughly investigated melanocyte population in the hair follicle of the epidermis, the growth and differentiation requirements of the melanocytes in the eye, harderian gland and inner ear - the so-called non-cutaneous melanocytes - remain unclear. In this study, we investigated the in vitro and in vivo effects of the factors that regulate melanocyte development on the stem cells or the precursors of these non-cutaneous melanocytes. In general, a reduction in KIT receptor tyrosine kinase signaling leads to disordered melanocyte development. However, melanocytes in the eye, ear and harderian gland were revealed to be less sensitive to KIT signaling than cutaneous melanocytes. Instead, melanocytes in the eye and harderian gland were stimulated more effectively by endothelin 3 (ET3) or hepatocyte growth factor (HGF) signals than by KIT signaling, and the precursors of these melanocytes expressed the lowest amount of KIT. The growth and differentiation of these non-cutaneous melanocytes were specifically inhibited by antagonists for ET3 and HGF. In transgenic mice induced to express ET3 or HGF in their skin and epithelial tissues from human cytokeratin 14 promoters, the survival and differentiation of non-cutaneous and dermal melanocytes, but not epidermal melanocytes, were enhanced, apparently irrespective of KIT signaling. These results provide a molecular basis for the clear discrimination between non-cutaneous or dermal melanocytes and epidermal melanocytes, a difference that might be important in the pathogenesis of melanocyte-related diseases and melanomas.

  5. [Determination of three anabolic steroids by liquid chromatography-mass spectrometry].

    PubMed

    Qin, Yang; Liu, Xin; Wang, Zhanliang; Wu, Moutian

    2008-07-01

    A high performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI/MS) was developed to screen and determine trenbolone, tetrahydrogestrinone and gestrinone in human urine. The urine sample was enzymatically hydrolyzed with beta-glucuronidase, then extracted with methyl tert-butyl ether. Chromatographic separation was performed on a Zorbax SB-C18 column (150 mm x 2.1 mm, 5 microm) with ammonium formate buffer (pH 3.5) and acetonitrile as mobile phase. Using positive electrospray ionization mode, the effect of different parameters from electrospray chamber was investigated. The limits of detection based on signal noise ratio of 3 were between 1 and 5 ng. The method can be applied in screening and confirmation of the anabolic steroids in doping control.

  6. The Sturm und Drang of anabolic steroid use: angst, anxiety, and aggression

    PubMed Central

    Oberlander, Joseph G.; Henderson, Leslie P.

    2014-01-01

    Anabolic androgenic steroids (AAS) are illicitly administered to enhance athletic performance and body image. Although conferring positive actions on performance, steroid abuse is associated with changes in anxiety and aggression. AAS users are often keenly invested in understanding the biological actions of these drugs. Thus, mechanistic information on AAS actions is important not only for the biomedical community, but also for steroid users. Here we review findings from animal studies on the impact of AAS exposure on neural systems that are crucial for the production of anxiety and aggression, and compare the effects of the different classes of AAS and their potential signaling mechanisms, as well as context-, age- and sex-dependent aspects of their actions. PMID:22516619

  7. The Sturm und Drang of anabolic steroid use: angst, anxiety, and aggression.

    PubMed

    Oberlander, Joseph G; Henderson, Leslie P

    2012-06-01

    Anabolic androgenic steroids (AAS) are illicitly administered to enhance athletic performance and body image. Although conferring positive actions on performance, steroid abuse is associated with changes in anxiety and aggression. AAS users are often keenly invested in understanding the biological actions of these drugs. Thus, mechanistic information on AAS actions is important not only for the biomedical community, but also for steroid users. Here we review findings from animal studies on the impact of AAS exposure on neural systems that are crucial for the production of anxiety and aggression, and compare the effects of the different classes of AAS and their potential signaling mechanisms, as well as context-, age- and sex-dependent aspects of their actions.

  8. Targeting the osteoblast: approved and experimental anabolic agents for the treatment of osteoporosis.

    PubMed

    Toulis, Konstantinos A; Anastasilakis, Athanasios D; Polyzos, Stergios A; Makras, Polyzois

    2011-01-01

    Targeting osteoblast may be the means of effectively improving both bone quality and mass, thus offering an intriguing alternative in the treatment of osteoporosis. Aside from injectable parathyroid hormone (PTH) and its novel preparations, PTH-related peptide (PTHrP), calcilytics, beta-adrenergic receptors, enhancement of Wnt signaling (mainly via sclerostin and Dickkopf-1 neutralization), regulation of low-density lipoprotein receptor-related protein (LPR) 5/osteoblast axis, activin, IGF-1, and bone morphogenic proteins (BMPs) are reviewed for their basic rationale and evidence of bone anabolic potential. Sclerostin neutralizing antibody, teriparatide transdermal patch, and PTHrP (1-36) are currently at an advanced stage of research. Safety and tissue specificity are the prerequisites in the development of a novel treatment, especially when addressing a chronic condition such as osteoporosis.

  9. ANABOLIC-ANDROGENIC STEROID DEPENDENCE? INSIGHTS FROM ANIMALS AND HUMANS

    PubMed Central

    Wood, Ruth I.

    2008-01-01

    Anabolic-androgenic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, with negative health consequences. As a result, in 1991 testosterone and related AAS were declared controlled substances. However, the relative abuse and dependence liability of AAS have not been fully characterized. In humans, it is difficult to separate the direct psychoactive effects of AAS from reinforcement due to their systemic anabolic effects. However, using conditioned place preference and self-administration, studies in animals have demonstrated that AAS are reinforcing in a context where athletic performance is irrelevant. Furthermore, AAS share brain sites of action and neurotransmitter systems in common with other drugs of abuse. In particular, recent evidence links AAS with opioids. In humans, AAS abuse is associated with prescription opioid use. In animals, AAS overdose produces symptoms resembling opioid overdose, and AAS modify the activity of the endogenous opioid system. PMID:18275992

  10. Adverse effects of anabolic steroids in athletes. A constant threat.

    PubMed

    Maravelias, C; Dona, A; Stefanidou, M; Spiliopoulou, C

    2005-09-15

    Anabolic-androgenic steroids (AAS) are used as ergogenic aids by athletes and non-athletes to enhance performance by augmenting muscular development and strength. AAS administration is often associated with various adverse effects that are generally dose related. High and multi-doses of AAS used for athletic enhancement can lead to serious and irreversible organ damage. Among the most common adverse effects of AAS are some degree of reduced fertility and gynecomastia in males and masculinization in women and children. Other adverse effects include hypertension and atherosclerosis, blood clotting, jaundice, hepatic neoplasms and carcinoma, tendon damage, psychiatric and behavioral disorders. More specifically, this article reviews the reproductive, hepatic, cardiovascular, hematological, cerebrovascular, musculoskeletal, endocrine, renal, immunologic and psychologic effects. Drug-prevention counseling to athletes is highlighted and the use of anabolic steroids is must be avoided, emphasizing that sports goals may be met within the framework of honest competition, free of doping substances.

  11. Anabolic-androgenic steroid dependence? Insights from animals and humans.

    PubMed

    Wood, Ruth I

    2008-10-01

    Anabolic-androgenic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, with negative health consequences. As a result, in 1991 testosterone and related AAS were declared controlled substances. However, the relative abuse and dependence liability of AAS have not been fully characterized. In humans, it is difficult to separate the direct psychoactive effects of AAS from reinforcement due to their systemic anabolic effects. However, using conditioned place preference and self-administration, studies in animals have demonstrated that AAS are reinforcing in a context where athletic performance is irrelevant. Furthermore, AAS share brain sites of action and neurotransmitter systems in common with other drugs of abuse. In particular, recent evidence links AAS with opioids. In humans, AAS abuse is associated with prescription opioid use. In animals, AAS overdose produces symptoms resembling opioid overdose, and AAS modify the activity of the endogenous opioid system.

  12. Current trends in biologics delivery to restore intervertebral disc anabolism.

    PubMed

    Fontana, Gianluca; See, Eugene; Pandit, Abhay

    2015-04-01

    Low back pain is generally attributed to intervertebral disc (IVD) degeneration. This is a multifactorial disease induced by genetic and environmental factors and that progresses with aging. Disc degeneration is characterized by a limited ability of IVD cells to produce functional matrix while producing abnormal amounts of matrix-degrading enzymes. The prolonged imbalance between anabolism and catabolism in degenerative discs alters their composition and hydration. In turn, this results in increased angiogenesis and the loss of the disc's ability to maintain its aneural condition. Inflammation in the IVD, in particular the presence of pro-inflammatory cytokines, was found to favor innervation and also sensitization of the nociceptive pathways, thereby exacerbating degenerative symptoms. In this review, we discuss anti-inflammatory approaches to encounter disc catabolism, potential treatments to lower discogenic pain and pro-anabolic approaches in the form of protein delivery, gene therapy and cell delivery, to trigger regeneration in the IVD.

  13. Blood chemistry of current and previous anabolic steroid users.

    PubMed

    O'Connor, J S; Baldini, F D; Skinner, J S; Einstein, M

    1990-02-01

    While the use of anabolic-androgenic steroids appears to be increasing, little is known about the long-term effects of these drugs. This study compared selected blood profiles of current and former steroid-using athletes to expected values for non-drug-using populations. The results are consistent with previous research findings that steroids can have acute negative effects on liver function, lipoprotein fractions, and testosterone production. The results suggest that side effects vary widely among individuals and are drug and dose dependent. Normal function appears to return after drug use is discontinued. These data emphasize the difficulty physicians have interpreting clinical tests when dealing with those who use or have used anabolic steroids. Clearly more research is needed regarding the effects of these drugs.

  14. The Metabolomic Signature of Malignant Glioma Reflects Accelerated Anabolic Metabolism

    PubMed Central

    Chinnaiyan, Prakash; Kensicki, Elizabeth; Bloom, Gregory; Prabhu, Antony; Sarcar, Bhaswati; Kahali, Soumen; Eschrich, Steven; Qu, Xiaotao; Forsyth, Peter; Gillies, Robert

    2015-01-01

    Although considerable progress has been made toward understanding glioblastoma biology through large-scale genetic and protein expression analyses, little is known about the underlying metabolic alterations promoting their aggressive phenotype. We conducted global metabolomic profiling on patient-derived glioma specimens and identified specific metabolic programs differentiating low- and high-grade tumors, with the metabolic signature of glioblastoma reflecting accelerated anabolic metabolism. When coupled with transcriptional profiles, we identified the metabolic phenotype of the mesenchymal subtype to consist of accumulation of the glycolytic intermediate phosphoenolpyruvate and decreased pyruvate kinase activity. Unbiased hierarchical clustering of metabolomic profiles identified three subclasses, which we term energetic, anabolic, and phospholipid catabolism with prognostic relevance. These studies represent the first global metabolomic profiling of glioma, offering a previously undescribed window into their metabolic heterogeneity, and provide the requisite framework for strategies designed to target metabolism in this rapidly fatal malignancy. PMID:23026133

  15. Nucleolar localization of SmMAK16 protein from Schistosoma mansoni is regulated by three distinct signals that function independent of pH or phosphorylation status.

    PubMed

    Hoellerich, Elisa; Dunagan, Christie; Maring, Daniel; Wong, Yun-Lan C; Shouldice, Daniel; Stripe, Jennifer; Kline, Tayah; Albert, Thomas J; Milhon, Jon L

    2014-01-01

    SmMAK16 from the trematode Schistosoma mansoni is a protein that is known to localize in the nucleolus. Recent findings show that SmMAK16 is involved in 60S ribosomal subunit synthesis. Although the SmMAK16 protein contains putative nuclear localization signals (NLS), little is known about their precise function, redundancy or regulation. The goal of the current study was to identify and characterize the presence and functional regulation of the localization signals in SmMAK16. The SmMAK16 coding sequence and specific fragments were individually cloned in-frame into the pEGFP-C2 expression vector to encode Green Fluorescent Protein (GFP) fusion proteins. Constructs were individually transfected into COS-7 cells and fluorescent microscopy used to determine the cellular location and thus the presence of signals regulating nuclear and nucleolar localization. SmMAK16 was found to contain two NLSs and one nucleolar localization signal (NoLS). One of the signals contains a sequence identical to an established nucleolar detention signal that reportedly functions only under acidic cellular conditions. The localization of the SmMAK16-GFP constructs was analyzed under acidic conditions; however, altering pH did not influence the localization of SmMAK16. It has been previously reported that casein kinase 2 (CK2) can phosphorylate SmMAK16 at serines adjacent to one of the NLSs. One of these CK2 sites and the adjacent NLS are conserved with that of the SV40 Large T Antigen (LTA) and phosphorylation of this site in the SV40 LTA regulates the kinetics of the NLS. To discover if kinetic regulation also occurs in SmMAK16, mutant and wild type SmMAK16-GFP proteins were purified and injected into individual COS-7 cells. No difference in the rate of transport was found between wt and mutant SmMAK16 proteins. Therefore, SmMAK16 localizes to the nucleolus using three separate signals, two NLSs and one NoLS, however, these signals appear to function independently of pH and

  16. Nucleolar localization of SmMAK16 protein from Schistosoma mansoni is regulated by three distinct signals that function independent of pH or phosphorylation status.

    PubMed

    Hoellerich, Elisa; Dunagan, Christie; Maring, Daniel; Wong, Yun-Lan C; Shouldice, Daniel; Stripe, Jennifer; Kline, Tayah; Albert, Thomas J; Milhon, Jon L

    2014-01-01

    SmMAK16 from the trematode Schistosoma mansoni is a protein that is known to localize in the nucleolus. Recent findings show that SmMAK16 is involved in 60S ribosomal subunit synthesis. Although the SmMAK16 protein contains putative nuclear localization signals (NLS), little is known about their precise function, redundancy or regulation. The goal of the current study was to identify and characterize the presence and functional regulation of the localization signals in SmMAK16. The SmMAK16 coding sequence and specific fragments were individually cloned in-frame into the pEGFP-C2 expression vector to encode Green Fluorescent Protein (GFP) fusion proteins. Constructs were individually transfected into COS-7 cells and fluorescent microscopy used to determine the cellular location and thus the presence of signals regulating nuclear and nucleolar localization. SmMAK16 was found to contain two NLSs and one nucleolar localization signal (NoLS). One of the signals contains a sequence identical to an established nucleolar detention signal that reportedly functions only under acidic cellular conditions. The localization of the SmMAK16-GFP constructs was analyzed under acidic conditions; however, altering pH did not influence the localization of SmMAK16. It has been previously reported that casein kinase 2 (CK2) can phosphorylate SmMAK16 at serines adjacent to one of the NLSs. One of these CK2 sites and the adjacent NLS are conserved with that of the SV40 Large T Antigen (LTA) and phosphorylation of this site in the SV40 LTA regulates the kinetics of the NLS. To discover if kinetic regulation also occurs in SmMAK16, mutant and wild type SmMAK16-GFP proteins were purified and injected into individual COS-7 cells. No difference in the rate of transport was found between wt and mutant SmMAK16 proteins. Therefore, SmMAK16 localizes to the nucleolus using three separate signals, two NLSs and one NoLS, however, these signals appear to function independently of pH and

  17. PTH and PTHrP Signaling in Osteoblasts

    PubMed Central

    Datta, Nabanita S.; Abou-Samra, Abdul B.

    2009-01-01

    The striking clinical benefit of PTH in osteoporosis began a new era of skeletal anabolic agents. Several studies have been performed, new studies are emerging out and yet controversies remain on PTH anabolic action in bone. This review focuses on the molecular aspects of PTH and PTHrP signaling in light of old players and recent advances in understanding the control of osteoblast proliferation, differentiation and function. PMID:19249350

  18. Nutrition, Anabolism, and the Wound Healing Process: An Overview

    PubMed Central

    Demling, Robert H.

    2009-01-01

    Objective: To develop a clear, concise, and up-to-date treatise on the role of anabolism from nutrition in wound healing. Special emphasis was to be placed on the effect of the stress response to wounding and its effect. Methods: A compilation of both the most important and most recent reports in the literature was used to also develop the review. The review was divided into sections to emphasize specific nutrition concepts of importance. Results: General and specific concepts were developed from this material. Topics included body composition and lean body mass, principles of macronutritional utilization, the stress response to wounding, nutritional assessment, nutritional support, and use of anabolic agents. Conclusions: We found that nutrition is a critical component in all the wound healing processes. The stress response to injury and any preexistent protein-energy malnutrition will alter this response, impeding healing and leading to potential severe morbidity. A decrease in lean body mass is of particular concern as this component is responsible for all protein synthesis necessary for healing. Nutritional assessment and support needs to be well orchestrated and precise. The use of anabolic agents can significantly increase overall lean mass synthesis and directly or indirectly improves healing by increasing protein synthesis. PMID:19274069

  19. Mineral catalyzed hydrothermal reactions as precursors to extant anabolic pathways

    NASA Astrophysics Data System (ADS)

    Cody, G. D.

    Investigations into hydrothermal reactions under conditions of moderate hydrostatic pressure and in the presence of transition metal sulfides reveal reaction pathways the bear remarkable similarity with extant anabolic reactions. First, it is seen that most common transition metal sulfides are capable of promoting all of the key reactions at the core of Acetyl Co-A synthesis. These include CO reduction to methyl groups and carbonyl insertion to form transferable acetyl groups. The synthesis of alpha-keto acids are also promoted, presumably by double carbonylation. A pathway starting with CO2 and H2 has been identified leading to the synthesis of citric acid. Citric acid provides a crucial abiotic, anabolic, branch point to the prebiotic synthesis of various amino acids, as well. As the pyrimidines, orotic acid and uracil. In many cases the abiotic reaction pathways differ slightly from extant anabolic pathways by shunting past particularly reactive intermediates, e.g. oxaloacetic acid. These reactions have the capacity to provide the prebiotic world with many, but not all, of the molecular constituents to aid the emergence of an RNA world.

  20. Sudden cardiac arrest following ventricular fibrillation attributed to anabolic steroid use in an adolescent.

    PubMed

    Lichtenfeld, Jana; Deal, Barbara J; Crawford, Susan

    2016-06-01

    Anabolic androgenic steroids are synthetic derivatives of testosterone that promote the growth of skeletal muscles and have many recognised cardiovascular effects. We report the clinical presentation and pathological findings of an adolescent male whose sudden cardiac arrest following ventricular fibrillation was attributed to anabolic androgenic steroid use. The age of our patient reflects the usage of anabolic androgenic steroids among younger athletes and highlights the need for increased awareness among practitioners. PMID:26980272

  1. Sudden cardiac arrest following ventricular fibrillation attributed to anabolic steroid use in an adolescent.

    PubMed

    Lichtenfeld, Jana; Deal, Barbara J; Crawford, Susan

    2016-06-01

    Anabolic androgenic steroids are synthetic derivatives of testosterone that promote the growth of skeletal muscles and have many recognised cardiovascular effects. We report the clinical presentation and pathological findings of an adolescent male whose sudden cardiac arrest following ventricular fibrillation was attributed to anabolic androgenic steroid use. The age of our patient reflects the usage of anabolic androgenic steroids among younger athletes and highlights the need for increased awareness among practitioners.

  2. Pulmonary embolism associated with protein C deficiency and abuse of anabolic-androgen steroids.

    PubMed

    Alhadad, Alaa; Acosta, Stefan; Sarabi, Latif; Kölbel, Tilo

    2010-04-01

    We present the case of a 19-year-old male athlete with protein C deficiency who developed proximal deep venous thrombosis and pulmonary embolism while abusing anabolic-androgenic steroids. Anabolic-androgenic steroids have been reported to have anticoagulatory and profibrinolytic effects in patients with protein C deficiency. Despite these antithrombotic effects, the patient developed repeated venous thromboembolism during treatment with low-molecular-weight heparin. The net effect of anabolic-androgenic steroids on the haemostatic system may change from antithrombotic to prothrombotic in male abusers of anabolic steroids with protein C deficiency. PMID:18977778

  3. [Successive ruptures of patellar and Achilles tendons. Anabolic steroids in competitive sports].

    PubMed

    Isenberg, J; Prokop, A; Skouras, E

    2008-01-01

    Derivatives of testosterone or of 19-nor-testosterone are used as anabolics for the purpose of improving performance although the effect of anabolics is known still to be under discussion. The use of anabolic steroids continues among competitive athletes despite increased controls and increasingly frequent dramatic incidents connected with them. Whereas metabolic dysfunction during anabolic use is well documented, ruptures of the large tendons are rarely reported. Within 18 months, a 29-year-old professional footballer needed surgery for rupture of the patellar tendon and of both Achilles tendons. Carefully directed questioning elicited confirmation that he had taken different anabolic steroids regularly for 3 years with the intention of improving his strength. After each operation anabolic steroids were taken again at a high dosage during early convalescence and training. Minimally invasive surgery and open suturing techniques led to complete union of the Achilles tendons in good time. Training and anabolic use (metenolon 300 mg per week) started early after suturing of the patellar tendon including bone tunnels culminated in histologically confirmed rerupture after 8 weeks. After a ligament reconstruction with a semitendinosus tendon graft with subsequent infection, the tendon and reserve traction apparatus were lost. Repeated warnings of impaired healing if anabolic use was continued had been given without success. In view of the high number of unrecorded cases in competitive and athletic sports, we can assume that the use of anabolic steroids is also of quantitative relevance in the operative treatment of tendon ruptures.

  4. Two Distinct Domains of the UVR8 Photoreceptor Interact with COP1 to Initiate UV-B Signaling in Arabidopsis[OPEN

    PubMed Central

    Yin, Ruohe; Arongaus, Adriana B.; Binkert, Melanie; Ulm, Roman

    2015-01-01

    UV-B photon reception by the Arabidopsis thaliana homodimeric UV RESISTANCE LOCUS8 (UVR8) photoreceptor leads to its monomerization and a crucial interaction with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). Relay of the subsequent signal regulates UV-B-induced photomorphogenesis and stress acclimation. Here, we report that two separate domains of UVR8 interact with COP1: the β-propeller domain of UVR8 mediates UV-B-dependent interaction with the WD40 repeats-based predicted β-propeller domain of COP1, whereas COP1 activity is regulated by interaction through the UVR8 C-terminal C27 domain. We show not only that the C27 domain is required for UVR8 activity but also that chemically induced expression of the C27 domain is sufficient to mimic UV-B signaling. We further show, in contrast with COP1, that the WD40 repeat proteins REPRESSOR OF UV-B PHOTOMORPHOGENESIS1 (RUP1) and RUP2 interact only with the UVR8 C27 domain. This coincides with their facilitation of UVR8 reversion to the ground state by redimerization and their potential to interact with UVR8 in a UV-B-independent manner. Collectively, our results provide insight into a key mechanism of photoreceptor-mediated signaling and its negative feedback regulation. PMID:25627067

  5. Dysregulated signaling hubs of liver lipid metabolism reveal hepatocellular carcinoma pathogenesis

    PubMed Central

    Lee, Sunjae; Mardinoglu, Adil; Zhang, Cheng; Lee, Doheon; Nielsen, Jens

    2016-01-01

    Hepatocellular carcinoma (HCC) has a high mortality rate and early detection of HCC is crucial for the application of effective treatment strategies. HCC is typically caused by either viral hepatitis infection or by fatty liver disease. To diagnose and treat HCC it is necessary to elucidate the underlying molecular mechanisms. As a major cause for development of HCC is fatty liver disease, we here investigated anomalies in regulation of lipid metabolism in the liver. We applied a tailored network-based approach to identify signaling hubs associated with regulation of this part of metabolism. Using transcriptomics data of HCC patients, we identified significant dysregulated expressions of lipid-regulated genes, across many different lipid metabolic pathways. Our findings, however, show that viral hepatitis causes HCC by a distinct mechanism, less likely involving lipid anomalies. Based on our analysis we suggest signaling hub genes governing overall catabolic or anabolic pathways, as novel drug targets for treatment of HCC that involves lipid anomalies. PMID:27216817

  6. Serotonin modulates anxiety-like behaviors during withdrawal from adolescent anabolic-androgenic steroid exposure in Syrian hamsters.

    PubMed

    Ricci, Lesley A; Morrison, Thomas R; Melloni, Richard H

    2012-11-01

    From the U.S. to Europe and Australia anabolic steroid abuse remains high in the adolescent population. This is concerning given that anabolic steroid use is associated with a higher incidence of pathological anxiety that often appears during withdrawal from use. This study uses pubertal Syrian hamsters (Mesocricetus auratus) to investigate the hypothesis that adolescent anabolic/androgenic steroid (AAS) exposure predisposes hamsters to heightened levels of anxiety during AAS withdrawal that is modulated by serotonin (5HT) neural signaling. In the first two sets of experiments, adolescent AAS-treated hamsters were tested for anxiety 21 days after the cessation of AAS administration (i.e., during AAS withdrawal) using the elevated plus maze (EPM), dark/light (DL), and seed finding (SF) tests and then examined for differences in 5HT afferent innervation to select areas of the brain important for anxiety. In the EPM and DL tests, adolescent AAS exposure leads to significant increases in anxiety-like response during AAS withdrawal. AAS-treated hamsters showed long-term reductions in 5HT innervation within several areas of the hamster brain implicated in anxiety, most notably the anterior hypothalamus and the central and medial amygdala. However, no differences in 5HT were found in other anxiety areas, e.g., frontal cortex and lateral septum. In the last experiment, adolescent AAS-treated hamsters were scored for anxiety on the 21st day of AAS withdrawal following the systemic administration of saline or one of three doses of fluoxetine, a selective serotonin reuptake inhibitor. Saline-treated hamsters showed high levels of AAS withdrawal-induced anxiety, while treatment with fluoxetine reduced AAS withdrawal-induced anxiety. These findings indicate that early AAS exposure has potent anxiogenic effects during AAS withdrawal that are modulated, in part, by 5HT signaling.

  7. Pseudomonas aeruginosa Possesses Two Putative Type I Signal Peptidases, LepB and PA1303, Each with Distinct Roles in Physiology and Virulence

    PubMed Central

    Rose, Ruth S.; Rangarajan, Minnie; Aduse-Opoku, Joseph; Hashim, Ahmed; Curtis, Michael A.

    2012-01-01

    Type I signal peptidases (SPases) cleave signal peptides from proteins during translocation across biological membranes and hence play a vital role in cellular physiology. SPase activity is also of fundamental importance to the pathogenesis of infection for many bacteria, including Pseudomonas aeruginosa, which utilizes a variety of secreted virulence factors, such as proteases and toxins. P. aeruginosa possesses two noncontiguous SPase homologues, LepB (PA0768) and PA1303, which share 43% amino acid identity. Reverse transcription (RT)-PCR showed that both proteases were expressed, while a FRET-based assay using a peptide based on the signal sequence cleavage region of the secreted LasB elastase showed that recombinant LepB and PA1303 enzymes were both active. LepB is positioned within a genetic locus that resembles the locus containing the extensively characterized SPase of E. coli and is of similar size and topology. It was also shown to be essential for viability and to have high sequence identity with SPases from other pseudomonads (≥78%). In contrast, PA1303, which is small for a Gram-negative SPase (20 kDa), was found to be dispensable. Mutation of PA1303 resulted in an altered protein secretion profile and increased N-butanoyl homoserine lactone production and influenced several quorum-sensing-controlled phenotypic traits, including swarming motility and the production of rhamnolipid and elastinolytic activity. The data indicate different cellular roles for these P. aeruginosa SPase paralogues; the role of PA1303 is integrated with the quorum-sensing cascade and includes the suppression of virulence factor secretion and virulence-associated phenotypes, while LepB is the primary SPase. PMID:22730125

  8. Distinct roles for extracellular-signal-regulated protein kinase (ERK) mitogen-activated protein kinases and phosphatidylinositol 3-kinase in the regulation of Mcl-1 synthesis.

    PubMed Central

    Schubert, K M; Duronio, V

    2001-01-01

    Alterations in the expression of various Bcl-2 family members may act as one means by which a cell's survival may be regulated. The mechanism by which cytokines regulate expression of Bcl-2 family members was examined in the haemopoietic cell line TF-1. Cytokine-induced Mcl-1 protein expression was shown to be controlled through a pathway dependent upon phosphatidylinositol 3-kinase (PI 3-kinase). The cytokine-induced increase in mRNA transcription was not dependent upon PI 3-kinase, thus dissociating the immediate-early transcription factors responsible for Mcl-1 transcription from the PI 3-kinase signalling pathway. In contrast, Mcl-1 mRNA levels were dependent upon MEK [mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated protein kinase kinase] activation, suggesting a role for the Ras/MEK/MAPK pathway in Mcl-1 transcription. Activation of PI 3-kinase was shown to be necessary to stimulate Mcl-1 protein translation. This was not due to any effect on prolonging the half-life of the protein. Finally, the lipid second messenger ceramide was shown to cause a reduction in Mcl-1 protein translation, probably via its ability to inhibit protein kinase B activation, providing further clues regarding the death-inducing effect of this lipid. PMID:11368774

  9. Nutritional Omega-3 Deficiency Alters Glucocorticoid Receptor-Signaling Pathway and Neuronal Morphology in Regionally Distinct Brain Structures Associated with Emotional Deficits

    PubMed Central

    Larrieu, Thomas; Hilal, Muna L.; De Smedt-Peyrusse, Véronique; Sans, Nathalie; Layé, Sophie

    2016-01-01

    Extensive evidence suggests that long term dietary n-3 polyunsaturated fatty acids (PUFAs) deficiency results in altered emotional behaviour. We have recently demonstrated that n-3 PUFAs deficiency induces emotional alterations through abnormal corticosterone secretion which leads to altered dendritic arborisation in the prefrontal cortex (PFC). Here we show that hypothalamic-pituitary-adrenal (HPA) axis feedback inhibition was not compromised in n-3 deficient mice. Rather, glucocorticoid receptor (GR) signaling pathway was inactivated in the PFC but not in the hippocampus of n-3 deficient mice. Consequently, only dendritic arborisation in PFC was affected by dietary n-3 PUFAs deficiency. In addition, occlusion experiment with GR blockade altered GR signaling in the PFC of control mice, with no further alterations in n-3 deficient mice. In conclusion, n-3 PUFAs deficiency compromised PFC, leading to dendritic atrophy, but did not change hippocampal GR function and dendritic arborisation. We argue that this GR sensitivity contributes to n-3 PUFAs deficiency-related emotional behaviour deficits. PMID:27057368

  10. The Plexin PLX-2 and the Ephrin EFN-4 Have Distinct Roles in MAB-20/Semaphorin 2A Signaling in Caenorhabditis elegans Morphogenesis

    PubMed Central

    Nakao, Fumi; Hudson, Martin L.; Suzuki, Motoshi; Peckler, Zachary; Kurokawa, Rie; Liu, Zhicen; Gengyo-Ando, Keiko; Nukazuka, Akira; Fujii, Takashi; Suto, Fumikazu; Shibata, Yukimasa; Shioi, Go; Fujisawa, Hajime; Mitani, Shohei; Chisholm, Andrew D.; Takagi, Shin

    2007-01-01

    Semaphorins are extracellular proteins that regulate axon guidance and morphogenesis by interacting with a variety of cell surface receptors. Most semaphorins interact with plexin-containing receptor complexes, although some interact with non-plexin receptors. Class 2 semaphorins are secreted molecules that control axon guidance and epidermal morphogenesis in Drosophila and Caenorhabditis elegans. We show that the C. elegans class 2 semaphorin MAB-20 binds the plexin PLX-2. plx-2 mutations enhance the phenotypes of hypomorphic mab-20 alleles but not those of mab-20 null alleles, indicating that plx-2 and mab-20 act in a common pathway. Both mab-20 and plx-2 mutations affect epidermal morphogenesis during embryonic and in postembryonic development. In both contexts, plx-2 null mutant phenotypes are much less severe than mab-20 null phenotypes, indicating that PLX-2 is not essential for MAB-20 signaling. Mutations in the ephrin efn-4 do not synergize with mab-20, indicating that EFN-4 may act in MAB-20 signaling. EFN-4 and PLX-2 are coexpressed in the late embryonic epidermis where they play redundant roles in MAB-20-dependent cell sorting. PMID:17507686

  11. Helicobacter pylori CheZ(HP) and ChePep form a novel chemotaxis-regulatory complex distinct from the core chemotaxis signaling proteins and the flagellar motor.

    PubMed

    Lertsethtakarn, Paphavee; Howitt, Michael R; Castellon, Juan; Amieva, Manuel R; Ottemann, Karen M

    2015-09-01

    Chemotaxis is important for Helicobacter pylori to colonize the stomach. Like other bacteria, H. pylori uses chemoreceptors and conserved chemotaxis proteins to phosphorylate the flagellar rotational response regulator, CheY, and modulate the flagellar rotational direction. Phosphorylated CheY is returned to its non-phosphorylated state by phosphatases such as CheZ. In previously studied cases, chemotaxis phosphatases localize to the cellular poles by interactions with either the CheA chemotaxis kinase or flagellar motor proteins. We report here that the H. pylori CheZ, CheZ(HP), localizes to the poles independently of the flagellar motor, CheA, and all typical chemotaxis proteins. Instead, CheZ(HP) localization depends on the chemotaxis regulatory protein ChePep, and reciprocally, ChePep requires CheZ(HP) for its polar localization. We furthermore show that these proteins interact directly. Functional domain mapping of CheZ(HP) determined the polar localization motif lies within the central domain of the protein and that the protein has regions outside of the active site that participate in chemotaxis. Our results suggest that CheZ(HP) and ChePep form a distinct complex. These results therefore suggest the intriguing idea that some phosphatases localize independently of the other chemotaxis and motility proteins, possibly to confer unique regulation on these proteins' activities.

  12. Helicobacter pylori CheZHP and ChePep form a novel chemotaxis-regulatory complex distinct from the core chemotaxis signaling proteins and the flagellar motor

    PubMed Central

    Lertsethtakarn, Paphavee; Howitt, Michael R.; Castellon, Juan; Amieva, Manuel R.; Ottemann, Karen M.

    2015-01-01

    Chemotaxis is important for Helicobacter pylori to colonize the stomach. Like other bacteria, H. pylori uses chemoreceptors and conserved chemotaxis proteins to phosphorylate the flagellar rotational response regulator, CheY, and modulate the flagellar rotational direction. Phosphorylated CheY is returned to its non-phosphorylated state by phosphatases such as CheZ. In previously studied cases, chemotaxis phosphatases localize to the cellular poles by interactions with either the CheA chemotaxis kinase or flagellar motor proteins. We report here that the H. pylori CheZ, CheZHP, localizes to the poles independently of the flagellar motor, CheA, and all typical chemotaxis proteins. Instead, CheZHP localization depends on the chemotaxis regulatory protein ChePep and reciprocally, ChePep requires CheZHP for its polar localization. We furthermore show that these proteins interact directly. Functional domain mapping of CheZHP determined the polar localization motif lies within the central domain of the protein, and that the protein has regions outside of the active site that participate in chemotaxis. Our results suggest that CheZHP and ChePep form a distinct complex. These results therefore suggest the intriguing idea that some phosphatases localize independently of the other chemotaxis and motility proteins, possibly to confer unique regulation on these proteins’ activities. PMID:26061894

  13. Distinctive expression patterns of Hedgehog pathway genes in the Ciona intestinalis larva: implications for a role of Hedgehog signaling in postembryonic development and chordate evolution.

    PubMed

    Islam, A F M Tariqul; Moly, Pricila Khan; Miyamoto, Yuki; Kusakabe, Takehiro G

    2010-02-01

    Members of the Hedgehog (Hh) family are soluble ligands that orchestrate a wide spectrum of developmental processes ranging from left-right axis determination of the embryo to tissue patterning and organogenesis. Tunicates, including ascidians, are the closest relatives of vertebrates, and elucidation of Hh signaling in ascidians should provide an important clue towards better understanding the role of this pathway in development. In previous studies, expression patterns of genes encoding Hh and its downstream factor Gli have been examined up to the tailbud stage in the ascidian embryo, but their expression in the larva has not been reported. Here we show the spatial expression patterns of hedgehog (Ci-hh1, Ci-hh2), patched (Ci-ptc), smoothened (Ci-smo), and Gli (Ci-Gli) orthologs in larvae of the ascidian Ciona intestinalis. The expression patterns of Ci-hh2 and Ci-Gli dramatically change during the period between the late tailbud embryo and the swimming larva. At the larval stage, expression of Ci-Gli was found in a central part of the endoderm and in the visceral ganglion, while Ci-hh2 was expressed in two discrete endodermal regions, anteriorly and posteriorly adjacent to the cells expressing Gli. The expression patterns of these genes suggest that the Hh ligand controls postembryonic development of the endoderm and the central nervous system. Expression of a gene encoding Hh in the anterior and/or pharyngeal endoderm is probably an ancient chordate character; diversification of regulation and targets of the Hh signaling in this region may have played a major role in the evolution of chordate body structures.

  14. Distinct leaf developmental and gene expression responses to light quantity depend on blue-photoreceptor or plastid-derived signals, and can occur in the absence of phototropins.

    PubMed

    López-Juez, Enrique; Bowyer, John R; Sakai, Tatsuya

    2007-12-01

    Leaf palisade cell development and the composition of chloroplasts respond to the fluence rate of light to maximise photosynthetic light capture while minimising photodamage. The underlying light sensory mechanisms are probably multiple and remain only partially understood. Phototropins (PHOT1 and PHOT2) are blue light receptors regulating responses which are light quantity-dependent and which include the control of leaf expansion. Here we show that genes for proteins in the reaction centres show long-term responses in wild type plants, and single blue photoreceptor mutants, to light fluence rate consistent with regulation by photosynthetic redox signals. Using contrasting intensities of white or broad-band red or blue light, we observe that increased fluence rate results in thicker leaves and greater number of palisade cells, but the anticlinal elongation of those cells is specifically responsive to the fluence rate of blue light. This palisade cell elongation response is still quantitatively normal in fully light-exposed regions of phot1 phot2 double mutants under increased fluence rate of white light. Plants grown at high light display elevated expression of RBCS (for the Rubisco small subunit) which, together with expected down-regulation of LHCB1 (for the photosynthetic antenna primarily of photosystem II), is also observed in phot double mutants. We conclude that an unknown blue light photoreceptor, or combination thereof, controls the development of a typical palisade cell morphology, but phototropins are not essential for either this response or acclimation-related gene expression changes. Together with previous evidence, our data further demonstrate that photosynthetic (chloroplast-derived) signals play a central role in the majority of acclimation responses.

  15. Immunoreceptor tyrosine-based inhibitory motif (ITIM)-mediated inhibitory signaling is regulated by sequential phosphorylation mediated by distinct nonreceptor tyrosine kinases: a case study involving PECAM-1.

    PubMed

    Tourdot, Benjamin E; Brenner, Michelle K; Keough, Kathleen C; Holyst, Trudy; Newman, Peter J; Newman, Debra K

    2013-04-16

    The activation state of many blood and vascular cells is tightly controlled by a delicate balance between receptors that contain immunoreceptor tyrosine-based activation motifs (ITAMs) and those that contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs). Precisely how the timing of cellular activation by ITAM-coupled receptors is regulated by ITIM-containing receptors is, however, poorly understood. Using platelet endothelial cell adhesion molecule 1 (PECAM-1) as a prototypical ITIM-bearing receptor, we demonstrate that initiation of inhibitory signaling occurs via a novel, sequential process in which Src family kinases phosphorylate the C-terminal ITIM, thereby enabling phosphorylation of the N-terminal ITIM of PECAM-1 by other Src homology 2 domain-containing nonreceptor tyrosine kinases (NRTKs). NRTKs capable of mediating the second phosphorylation event include C-terminal Src kinase (Csk) and Bruton's tyrosine kinase (Btk). Btk and Csk function downstream of phosphatidylinositol 3-kinase (PI3K) activation during ITAM-dependent platelet activation. In ITAM-activated platelets that were treated with a PI3K inhibitor, PECAM-1 was phosphorylated but did not bind the tandem SH2 domain-containing tyrosine phosphatase SHP-2, indicating that it was not phosphorylated on its N-terminal ITIM. Csk bound to and phosphorylated PECAM-1 more efficiently than did Btk and required its SH2 domain to perform these functions. Additionally, the phosphorylation of the N-terminal ITIM of Siglec-9 by Csk is enhanced by the prior phosphorylation of its C-terminal ITIM, providing evidence that the ITIMs of other dual ITIM-containing receptors are also sequentially phosphorylated. On the basis of these findings, we propose that sequential ITIM phosphorylation provides a general mechanism for precise temporal control over the recruitment and activation of tandem SH2 domain-containing tyrosine phosphatases that dampen ITAM-dependent signals. PMID:23418871

  16. Galloflavin, a new lactate dehydrogenase inhibitor, induces the death of human breast cancer cells with different glycolytic attitude by affecting distinct signaling pathways.

    PubMed

    Farabegoli, F; Vettraino, M; Manerba, M; Fiume, L; Roberti, M; Di Stefano, G

    2012-11-20

    Galloflavin (GF), a recently identified lactate dehydrogenase inhibitor, hinders the proliferation of cancer cells by blocking glycolysis and ATP production. The aim of the present experiments was to study the effect of this compound on breast cancer cell lines reproducing different pathological subtypes of this tumor: MCF-7 (the well differentiated form), MDA-MB-231 (the aggressive triple negative tumor) and MCF-Tam (a sub-line of MCF-7 with acquired tamoxifen resistance). We observed marked differences in the energetic metabolism of these cell lines. Compared to MCF-7 cells, both MDA-MB-231 and MCF-Tam cells exhibited higher LDH levels and glucose uptake and showed lower capacity of oxygen consumption. In spite of these differences, GF exerted similar growth inhibitory effects. This result was explained by the finding of a constitutively activated stress response in MDA-MB-231 and MCF-Tam cells, which reproduce the poor prognosis tumor forms. As a further proof, different signaling pathways were found to be involved in the antiproliferative action of GF. In MCF-7 cells we observed a down regulation of the ERα-mediated signaling needed for cell survival. On the contrary, in MCF-Tam and MDA-MB-231 cells growth inhibition appeared to be contributed by an oxidative stress condition. The prevalent mechanism of cell death was found to be apoptosis induction. Because of the clinical relevance of breast cancer forms having the triple negative and/or chemoresistant phenotype, our results showing comparable effects of GF even on aggressively growing cells encourage further studies to verify the potential of this compound in improving the chemotherapy of breast cancer.

  17. Bilateral deltoid myositis ossificans in a weightlifter using anabolic steroids.

    PubMed

    Schultzel, Mark M; Johnson, Michael H; Rosenthal, Howard G

    2014-09-01

    A 40-year-old male weightlifter presented with a 6-month history of a painless mass in the right deltoid. He had no history of trauma to the shoulder other than an arthroscopic rotator cuff repair a few weeks earlier. Physical examination showed a firm, nontender mass located longitudinally and coinciding with the deltoid, measuring 12×14×4 cm. There was no limitation in range of motion or functioning. Magnetic resonance imaging (MRI) and computed tomography (CT) scans suggested a lobulated, heterogeneous mass with multiple areas of calcification that raised suspicion for soft tissue sarcoma vs myositis ossificans. Marginal resection of the soft tissue mass was performed, and pathologic studies confirmed the diagnosis of xanthogranulomatous myositis ossificans with dystrophic calcifications and central cystic degeneration. At 2-week follow-up, the patient had improved range of motion and pain, but he noted a second soft tissue mass in the left deltoid. The MRI and CT scans showed a 10.5×16×3.4-cm linear, lobulated lesion with multiple calcifications, similar in appearance to the contralateral deltoid. The patient admitted to frequently injecting anabolic steroids into his deltoids. Because the patient was asymptomatic on the left side and the MRI appearance of the left deltoid mass was similar to that of the myositis ossificans seen on the right side, the patient opted for nonsurgical treatment. This is a rare case of myositis ossificans occurring bilaterally in the deltoids after repeated injections of anabolic steroids. There is currently no known association between anabolic steroids and myositis ossificans. This condition often mimics malignant neoplasms, illustrating the necessity of resection for diagnostic confirmation.

  18. 76 FR 72355 - Classification of Two Steroids, Prostanozol and Methasterone, as Schedule III Anabolic Steroids...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... steroids and ] depend on several factors (e.g., age, sex, anabolic steroid used, the amount used, and the.... Evaluation of Statutory Factors for Classification as an Anabolic Steroid DEA is proposing by this NPRM to... interaction with DNA. In this study, transcription of a reporter gene provides information as to a...

  19. Anabolic androgenic steroids, an easily forgotten cause of polycythaemia and cerebral infarction.

    PubMed

    Low, M S Y; Vilcassim, S; Fedele, P; Grigoriadis, G

    2016-04-01

    Excessive anabolic androgenic steroids (both exogenous and endogenous) are known causes of polycythaemia and ischaemic cardiovascular events. Despite this, they are commonly forgotten in the workup of patients. We report a case of exogenous anabolic androgenic steroid-induced polycythaemia and stroke and explore possible pitfalls for clinicians.

  20. Anabolic Steroids: A Threat to Body and Mind. National Institute on Drug Abuse Research Report Series.

    ERIC Educational Resources Information Center

    National Inst. on Drug Abuse (DHHS/PHS), Rockville, MD.

    This report, based on findings of recent studies on the use of anabolic steroids in the United States, was written to educate the public about these drugs and the dangers of misusing them. It notes that the nonmedical use of anabolic/androgenic steroids among adolescents and young adults is of growing concern, with possibly as many as half a…

  1. Anabolic androgenic steroids, an easily forgotten cause of polycythaemia and cerebral infarction.

    PubMed

    Low, M S Y; Vilcassim, S; Fedele, P; Grigoriadis, G

    2016-04-01

    Excessive anabolic androgenic steroids (both exogenous and endogenous) are known causes of polycythaemia and ischaemic cardiovascular events. Despite this, they are commonly forgotten in the workup of patients. We report a case of exogenous anabolic androgenic steroid-induced polycythaemia and stroke and explore possible pitfalls for clinicians. PMID:27062206

  2. Transcription, Signaling Receptor Activity, Oxidative Phosphorylation, and Fatty Acid Metabolism Mediate the Presence of Closely Related Species in Distinct Intertidal and Cold-Seep Habitats.

    PubMed

    Van Campenhout, Jelle; Vanreusel, Ann; Van Belleghem, Steven; Derycke, Sofie

    2016-01-01

    Bathyal cold seeps are isolated extreme deep-sea environments characterized by low species diversity while biomass can be high. The Håkon Mosby mud volcano (Barents Sea, 1,280 m) is a rather stable chemosynthetic driven habitat characterized by prominent surface bacterial mats with high sulfide concentrations and low oxygen levels. Here, the nematode Halomonhystera hermesi thrives in high abundances (11,000 individuals 10 cm(-2)). Halomonhystera hermesi is a member of the intertidal Halomonhystera disjuncta species complex that includes five cryptic species (GD1-5). GD1-5's common habitat is characterized by strong environmental fluctuations. Here, we compared the transcriptomes of H. hermesi and GD1, H. hermesi's closest relative. Genes encoding proteins involved in oxidative phosphorylation are more strongly expressed in H. hermesi than in GD1, and many genes were only observed in H. hermesi while being completely absent in GD1. Both observations could in part be attributed to high sulfide concentrations and low oxygen levels. Additionally, fatty acid elongation was also prominent in H. hermesi confirming the importance of highly unsaturated fatty acids in this species. Significant higher amounts of transcription factors and genes involved in signaling receptor activity were observed in GD1 (many of which were completely absent in H. hermesi), allowing fast signaling and transcriptional reprogramming which can mediate survival in dynamic intertidal environments. GC content was approximately 8% higher in H. hermesi coding unigenes resulting in differential codon usage between both species and a higher proportion of amino acids with GC-rich codons in H. hermesi. In general our results showed that most pathways were active in both environments and that only three genes are under natural selection. This indicates that also plasticity should be taken in consideration in the evolutionary history of Halomonhystera species. Such plasticity, as well as possible

  3. Transcription, Signaling Receptor Activity, Oxidative Phosphorylation, and Fatty Acid Metabolism Mediate the Presence of Closely Related Species in Distinct Intertidal and Cold-Seep Habitats

    PubMed Central

    Van Campenhout, Jelle; Vanreusel, Ann; Van Belleghem, Steven; Derycke, Sofie

    2016-01-01

    Bathyal cold seeps are isolated extreme deep-sea environments characterized by low species diversity while biomass can be high. The Håkon Mosby mud volcano (Barents Sea, 1,280 m) is a rather stable chemosynthetic driven habitat characterized by prominent surface bacterial mats with high sulfide concentrations and low oxygen levels. Here, the nematode Halomonhystera hermesi thrives in high abundances (11,000 individuals 10 cm−2). Halomonhystera hermesi is a member of the intertidal Halomonhystera disjuncta species complex that includes five cryptic species (GD1-5). GD1-5’s common habitat is characterized by strong environmental fluctuations. Here, we compared the transcriptomes of H. hermesi and GD1, H. hermesi’s closest relative. Genes encoding proteins involved in oxidative phosphorylation are more strongly expressed in H. hermesi than in GD1, and many genes were only observed in H. hermesi while being completely absent in GD1. Both observations could in part be attributed to high sulfide concentrations and low oxygen levels. Additionally, fatty acid elongation was also prominent in H. hermesi confirming the importance of highly unsaturated fatty acids in this species. Significant higher amounts of transcription factors and genes involved in signaling receptor activity were observed in GD1 (many of which were completely absent in H. hermesi), allowing fast signaling and transcriptional reprogramming which can mediate survival in dynamic intertidal environments. GC content was approximately 8% higher in H. hermesi coding unigenes resulting in differential codon usage between both species and a higher proportion of amino acids with GC-rich codons in H. hermesi. In general our results showed that most pathways were active in both environments and that only three genes are under natural selection. This indicates that also plasticity should be taken in consideration in the evolutionary history of Halomonhystera species. Such plasticity, as well as possible

  4. Side Effects of Anabolic Steroids in Weight-Trained Men.

    PubMed

    Strauss, R H; Wright, J E; Finerman, G A; Catlin, D H

    1983-12-01

    In brief: This study documents the patterns of use of anabolic steroids in 32 body builders and power lifters. These subjects and seven control athletes who had never used steroids were interviewed and underwent a medical examination including 28 diagnostic blood tests and a urinalysis. Gynecomastia was detected in 4 of the 20 current users and 1 of the other 19 subjects. Sixty-seven percent of users reported temporary changes in libido, and 56% reported a temporary increase in irritability or aggressive behavior. Physicians should tell patients about the possible adverse side effects of such agents.

  5. Peroxisome proliferator-activated receptor γ regulates genes involved in insulin/insulin-like growth factor signaling and lipid metabolism during adipogenesis through functionally distinct enhancer classes.

    PubMed

    Oger, Frédérik; Dubois-Chevalier, Julie; Gheeraert, Céline; Avner, Stéphane; Durand, Emmanuelle; Froguel, Philippe; Salbert, Gilles; Staels, Bart; Lefebvre, Philippe; Eeckhoute, Jérôme

    2014-01-10

    The nuclear receptor peroxisome proliferator-activated receptor (PPAR) is a transcription factor whose expression is induced during adipogenesis and that is required for the acquisition and control of mature adipocyte functions. Indeed, PPAR induces the expression of genes involved in lipid synthesis and storage through enhancers activated during adipocyte differentiation. Here, we show that PPAR also binds to enhancers already active in preadipocytes as evidenced by an active chromatin state including lower DNA methylation levels despite higher CpG content. These constitutive enhancers are linked to genes involved in the insulin/insulin-like growth factor signaling pathway that are transcriptionally induced during adipogenesis but to a lower extent than lipid metabolism genes, because of stronger basal expression levels in preadipocytes. This is consistent with the sequential involvement of hormonal sensitivity and lipid handling during adipocyte maturation and correlates with the chromatin structure dynamics at constitutive and activated enhancers. Interestingly, constitutive enhancers are evolutionary conserved and can be activated in other tissues, in contrast to enhancers controlling lipid handling genes whose activation is more restricted to adipocytes. Thus, PPAR utilizes both broadly active and cell type-specific enhancers to modulate the dynamic range of activation of genes involved in the adipogenic process.

  6. Extracellular signal-regulated kinase pathway play distinct role in acetochlor-mediated toxicity and intrinsic apoptosis in A549 cells.

    PubMed

    Zerin, Tamanna; Song, Ho-Yeon; Kim, Yong-Sik

    2015-02-01

    Acetochlor (ACETO), a member of the chloroacetanilide family of herbicides, is widely used globally and is very frequently detected in watersheds of agricultural lands and fresh water streams. The human health consequences of environmental exposure to ACETO are unknown. This study was designed to elucidate the effect and molecular mechanisms of ACETO on human alveolar A549 cells. Established assays of cell viability and cytotoxicity were performed to detect the potential effects of ACETO on A549 cells. ACETO generated reactive oxygen species, which may have been crucial to apoptosis-mediated cytotoxicity. ACETO-treatment showed a concentration dependent up-regulation of pro-apoptotic proteins including Bax, Bak, BID and Bad, but a differential level of expression of anti-apoptotic proteins were observed, leading to the release of cytochrome c from mitochondria to the cytoplasm as well as activation of caspase-3, and cleavage of caspase-9 and PARP. ACETO also induced activation of extracellular signal-regulated kinase (ERK). Inhibition of the expression of ERK by PD98059 partially reversed ACETO-induced cytotoxicity, apoptosis and the expression of caspase-3, -9 and PARP in A549 cells. Comparative evaluation of the results indicates that the principal mechanism underlying ACETO-mediated cytotoxicity is likely to be through ERK-mediated intrinsic pathway of apoptosis. PMID:25291404

  7. Two distinct alpha-interferon-dependent signal transduction pathways may contribute to activation of transcription of the guanylate-binding protein gene

    SciTech Connect

    Decker, T.; Lew, D.J.; Darnell, J.E. Jr. )

    1991-10-01

    The promoter of the gene encoding a cytoplasmic guanylate-binding (GBP) contains two overlapping elements: the interferon stimulation response element (ISRE), which mediates alpha interferon (IFN-{alpha})-dependent transcription, and the IFN-{gamma} activation site (GAS), which is required for INF-{gamma}-mediated stimulation. The ISRE binds a factor called ISGF-3 that is activated by IFN-{alpha} but not by IFN-{gamma}. The GAS binds a protein that is activated by IFN-{gamma}, which the authors have termed GAF. The authors now find that the GAS is also an IFN-{alpha}-responsive element in vivo and that IFN-{alpha} (in addition to activating ISGF-3) rapidly activates a GAS-binding factor, the IFN-{alpha} activation factor (AAF). The AAF has characteristics very similar to those of the previously described GAF. Through the use of inhibitors of protein synthesis and inhibitors of protein kinases, the activation conditions of AAF, GAF, and ISGF-3 could be distinguished. Therefore, not only do IFN-{alpha} and IFN-{gamma} stimulate transcription of GBP through different receptors linked to different signaling molecules, but occupation of the IFN-{alpha} receptor apparently leads to the rapid activation of two different DNA-binding proteins through the use of different intracellular pathways.

  8. Peroxisome Proliferator-activated Receptor γ Regulates Genes Involved in Insulin/Insulin-like Growth Factor Signaling and Lipid Metabolism during Adipogenesis through Functionally Distinct Enhancer Classes*

    PubMed Central

    Oger, Frédérik; Dubois-Chevalier, Julie; Gheeraert, Céline; Avner, Stéphane; Durand, Emmanuelle; Froguel, Philippe; Salbert, Gilles; Staels, Bart; Lefebvre, Philippe; Eeckhoute, Jérôme

    2014-01-01

    The nuclear receptor peroxisome proliferator-activated receptor (PPAR) γ is a transcription factor whose expression is induced during adipogenesis and that is required for the acquisition and control of mature adipocyte functions. Indeed, PPARγ induces the expression of genes involved in lipid synthesis and storage through enhancers activated during adipocyte differentiation. Here, we show that PPARγ also binds to enhancers already active in preadipocytes as evidenced by an active chromatin state including lower DNA methylation levels despite higher CpG content. These constitutive enhancers are linked to genes involved in the insulin/insulin-like growth factor signaling pathway that are transcriptionally induced during adipogenesis but to a lower extent than lipid metabolism genes, because of stronger basal expression levels in preadipocytes. This is consistent with the sequential involvement of hormonal sensitivity and lipid handling during adipocyte maturation and correlates with the chromatin structure dynamics at constitutive and activated enhancers. Interestingly, constitutive enhancers are evolutionary conserved and can be activated in other tissues, in contrast to enhancers controlling lipid handling genes whose activation is more restricted to adipocytes. Thus, PPARγ utilizes both broadly active and cell type-specific enhancers to modulate the dynamic range of activation of genes involved in the adipogenic process. PMID:24288131

  9. [Comparative study of anabolizing activity of apilac and methandrostenolone on a model of isolated overload of the rat skeletal muscle].

    PubMed

    Gadzhieva, D M; Paniushkin, V V; Seĭfulla, R D; Ordzhonikidze, Z G

    2002-01-01

    The anabolic activity of apilac was studied in rats in comparison to methanrdostenolone A 10-day administration of apilac (200 mg/kg) produced a pronounced anabolic effect manifested by a hypertrophy of m. soleus. Methanrdostenolone (10 mg/kg) also favored a gain in the muscle weight. The anabolic action of apilac was comparable to that of methanrdostenolone. PMID:12025788

  10. Deficient Mechanical Activation of Anabolic Transcripts and Post-Traumatic Cartilage Degeneration in Matrilin-1 Knockout Mice

    PubMed Central

    Chen, Yupeng; Cossman, Jack; Jayasuriya, Chathuraka T.; Li, Xin; Guan, Yingjie; Fonseca, Vera; Yang, Kun; Charbonneau, Cherie; Yu, Hongchuan; Kanbe, Katsuaki; Ma, Peter; Darling, Eric; Chen, Qian

    2016-01-01

    Matrilin-1 (Matn1), a cartilage-specific peri-cellular and extracellular matrix (ECM) protein, has been hypothesized to regulate ECM interactions and transmit mechanical signals in cartilage. Since Matn1 knock-out (Matn1-/-) mice exhibit a normal skeleton, its function in vivo is unclear. In this study, we found that the anabolic Acan and Col2a transcript levels were significantly higher in wildtype (Matn1+/+) mouse cartilage than that of MATN1-/- mice in vivo. However, such difference was not observed between Matn1+/+ and MATN1-/- chondrocytes cultured under stationary conditions in vitro. Cyclic loading significantly stimulated Acan and Col2a transcript levels in Matn1+/+ but not in MATN1-/- chondrocytes. This suggests that, while Matn1+/+ chondrocytes increase their anabolic gene expression in response to mechanical loading, the MATN1-/- chondrocytes fail to do so because of the deficiency in mechanotransduction. We also found that altered elastic modulus of cartilage matrix in Matn1-/- mice, suggesting the mechanotransduction has changed due to the deficiency of Matn1. To understand the impact of such deficiency on joint disease, mechanical loading was altered in vivo by destabilization of medial meniscus. While Matn1+/+ mice exhibited superficial fissures and clefts consistent with mechanical damage to the articular joint, Matn1-/- mice presented more severe cartilage lesions characterized by proteoglycan loss and disorganization of cells and ECM. This suggests that Matn1 deficiency affects pathogenesis of post-traumatic osteoarthritis by failing to up-regulate anabolic gene expression. This is the first demonstration of Matn1 function in vivo, which suggests its protective role in cartilage degeneration under altered mechanical environment. PMID:27270603

  11. Pregnancy-associated plasma protein-A modulates the anabolic effects of parathyroid hormone in mouse bone.

    PubMed

    Clifton, Kari B; Conover, Cheryl A

    2015-12-01

    Intermittent parathyroid hormone (PTH) is a potent anabolic therapy for bone, and several studies have implicated local insulin-like growth factor (IGF) signaling in mediating this effect. The IGF system is complex and includes ligands and receptors, as well as IGF binding proteins (IGFBPs) and IGFBP proteases. Pregnancy-associated plasma protein-A (PAPP-A) is a metalloprotease expressed by osteoblasts in vitro that has been shown to enhance local IGF action through cleavage of inhibitory IGFBP-4. This study was set up to test two specific hypotheses: 1) Intermittent PTH treatment increases the expression of IGF-I, IGFBP-4 and PAPP-A in bone in vivo, thereby increasing local IGF activity. 2) In the absence of PAPP-A, local IGF activity and the anabolic effects of PTH on bone are reduced. Wild-type (WT) and PAPP-A knock-out (KO) mice were treated with 80 μg/kg human PTH 1-34 or vehicle by subcutaneous injection five days per week for six weeks. IGF-I, IGFBP-4 and PAPP-A mRNA expression in bone were significantly increased in response to PTH treatment. PTH treatment of WT mice, but not PAPP-A KO mice, significantly increased expression of an IGF-responsive gene. Bone mineral density (BMD), as measured by DEXA, was significantly decreased in femurs of PAPP-A KO compared to WT mice with PTH treatment. Volumetric BMD, as measured by pQCT, was significantly decreased in femoral midshaft (primarily cortical bone), but not metaphysis (primarily trabecular bone), of PAPP-A KO compared to WT mice with PTH treatment. These data suggest that stimulation of PAPP-A expression by intermittent PTH treatment contributes to PTH bone anabolism in mice.

  12. Deficient Mechanical Activation of Anabolic Transcripts and Post-Traumatic Cartilage Degeneration in Matrilin-1 Knockout Mice.

    PubMed

    Chen, Yupeng; Cossman, Jack; Jayasuriya, Chathuraka T; Li, Xin; Guan, Yingjie; Fonseca, Vera; Yang, Kun; Charbonneau, Cherie; Yu, Hongchuan; Kanbe, Katsuaki; Ma, Peter; Darling, Eric; Chen, Qian

    2016-01-01

    Matrilin-1 (Matn1), a cartilage-specific peri-cellular and extracellular matrix (ECM) protein, has been hypothesized to regulate ECM interactions and transmit mechanical signals in cartilage. Since Matn1 knock-out (Matn1-/-) mice exhibit a normal skeleton, its function in vivo is unclear. In this study, we found that the anabolic Acan and Col2a transcript levels were significantly higher in wildtype (Matn1+/+) mouse cartilage than that of MATN1-/- mice in vivo. However, such difference was not observed between Matn1+/+ and MATN1-/- chondrocytes cultured under stationary conditions in vitro. Cyclic loading significantly stimulated Acan and Col2a transcript levels in Matn1+/+ but not in MATN1-/- chondrocytes. This suggests that, while Matn1+/+ chondrocytes increase their anabolic gene expression in response to mechanical loading, the MATN1-/- chondrocytes fail to do so because of the deficiency in mechanotransduction. We also found that altered elastic modulus of cartilage matrix in Matn1-/- mice, suggesting the mechanotransduction has changed due to the deficiency of Matn1. To understand the impact of such deficiency on joint disease, mechanical loading was altered in vivo by destabilization of medial meniscus. While Matn1+/+ mice exhibited superficial fissures and clefts consistent with mechanical damage to the articular joint, Matn1-/- mice presented more severe cartilage lesions characterized by proteoglycan loss and disorganization of cells and ECM. This suggests that Matn1 deficiency affects pathogenesis of post-traumatic osteoarthritis by failing to up-regulate anabolic gene expression. This is the first demonstration of Matn1 function in vivo, which suggests its protective role in cartilage degeneration under altered mechanical environment. PMID:27270603

  13. Rapid activation of sodium-proton exchange and extracellular signal-regulated protein kinase in fibroblasts by G protein-coupled 5-HT1A receptor involves distinct signalling cascades.

    PubMed Central

    Garnovskaya, M N; Mukhin, Y; Raymond, J R

    1998-01-01

    These experiments tested the hypothesis that signalling elements involved in the activation of the extracellular signal-regulated protein kinase (ERK) mediate rapid activation of sodium-proton exchange (NHE) in fibroblasts when both signals are initiated by a single G protein-coupled receptor, the 5-HT1A receptor. Similarities between the two processes were comparable concentration-response curves and time-courses, and overlapping sensitivity to some pharmacological inhibitors of tyrosine kinases (staurosporine and genistein), and phosphoinositide 3'-kinase (wortmannin and LY204002). Activation of NHE was much more sensitive to the phosphatidylcholine-specific phospholipase inhibitor (D609) than was ERK. Neither pathway was sensitive to manoeuvres designed to block PKC. In contrast, Src or related kinases appear to be required to activate ERK, but not NHE. Transfection of cDNA constructs encoding inactive mutant phosphoinositide 3'-kinase, Grb2, Sos, Ras, and Raf molecules were successful in attenuating ERK, but had essentially no effect upon NHE activation. Finally, PD98059, an inhibitor of mitogen activated/extracellular signal regulated kinase kinase, blocked ERK but not NHE activation. Thus, in CHO fibroblast cells, activation by the 5-HT1A receptor of ERK and NHE share a number of overlapping features. However, our studies do not support a major role for ERK, when activated by the 5-HT1A receptor, as a short-term upstream regulator of NHE activity. PMID:9461547

  14. Lipopolysaccharide of Aggregatibacter actinomycetemcomitans induces the expression of chemokines MCP-1, MIP-1α, and IP-10 via similar but distinct signaling pathways in murine macrophages.

    PubMed

    Park, Ok-Jin; Cho, Min-Kyung; Yun, Cheol-Heui; Han, Seung Hyun

    2015-09-01

    Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium frequently isolated from lesions of patients with localized aggressive periodontitis. Lipopolysaccharide (LPS), a major cell wall component of Gram-negative bacteria, stimulates innate immune cells via Toll-like receptor 4 (TLR4) to initiate inflammatory responses. In this study, we purified LPS from A. actinomycetemcomitans (AaLPS) and investigated its ability to induce the expression of chemokines, which play an important role in recruitment of leukocytes to the infection site. AaLPS induced the expression of chemokines, MCP-1, MIP-1α, and IP-10 in murine macrophages, leading to the infiltration of peripheral blood mononuclear cells in a transwell system. Although TLR4 was essential for the induction of all these chemokines by AaLPS, MCP-1 and MIP-1α expressions were MyD88-dependent, but IP-10 expression was MyD88-independent, as determined using macrophages from mice deficient in TLR4 or MyD88. Furthermore, the activation of ERK and JNK were necessary for the expression of MCP-1 and MIP-1α, whereas p38 MAP kinase and JNK activations were required for IP-10 expression. In addition, IFN-β/STAT1 signaling was exclusively involved in IP-10 expression but not in MCP-1 or MIP-1α expression. AaLPS also activated the transcription factors, NF-κB, AP-1, NF-IL6, and ISRE, all of which are involved in chemokine gene expression. These results suggest that AaLPS induces the expression of chemokines MCP-1, MIP-1α, and IP-10 through TLR4 in murine macrophages. Further, the induction of MCP-1 and MIP-1α requires MyD88, ERK, and JNK, whereas the induction of IP-10 requires JNK, p38 MAP kinase, and IFN-β/STAT1.

  15. Distinctive EPR signals provide an understanding of the affinity of bis-(3-hydroxy-4-pyridinonato) copper(II) complexes for hydrophobic environments.

    PubMed

    Rangel, Maria; Leite, Andreia; Silva, André M N; Moniz, Tânia; Nunes, Ana; Amorim, M João; Queirós, Carla; Cunha-Silva, Luís; Gameiro, Paula; Burgess, John

    2014-07-01

    In this work we report the synthesis and characterization of a set of 3-hydroxy-4-pyridinone copper(ii) complexes with variable lipophilicity. EPR spectroscopy was used to characterize the structure of copper(ii) complexes in solution, and as a tool to gain insight into solvent interactions. EPR spectra of solutions of the [CuL2] complexes recorded in different solvents reveal the presence of two copper species whose ratio depends on the nature of the solvent. Investigation of EPR spectra in the pure solvents methanol, dimethylsulfoxide, dichloromethane and their 50% (v/v) mixtures with toluene allowed the characterization of two types of copper signals (gzz = 2.30 and gzz = 2.26) whose spin-Hamiltonian parameters are consistent with solvated and non-solvated square-planar copper(ii) complexes. Regarding the potential biological application of ligands and complexes and to get insight into the partition properties in water-membrane interfaces, EPR spectra were also obtained in water-saturated octanol, an aqueous solution buffered at pH = 7.4 and liposome suspensions, for three compounds representative of different hydro-lipophilic balances. Analysis of the EPR spectra obtained in liposomes allowed establishment of the location of the complexes in the water and lipid phases. In view of the results of this work we put forward the use of EPR spectroscopy to assess the affinity of copper(ii) complexes for a hydrophobic environment and also to obtain indirect information about the lipophilicity of the ligands and similar EPR silent complexes.

  16. Prostaglandins and muscarinic agonists induce cyclic AMP attenuation by two distinct mechanisms in the pregnant-rat myometrium. Interaction between cyclic AMP and Ca2+ signals.

    PubMed Central

    Goureau, O; Tanfin, Z; Harbon, S

    1990-01-01

    In pregnant-rat myometrium (day 21 of gestation), isoprenaline-induced cyclic AMP accumulation, resulting from receptor-mediated activation of adenylate cyclase, was negatively regulated by prostaglandins [PGE2, PGF2 alpha; EC50 (concn. giving 50% of maximal response) = 2 nM] and by the muscarinic agonist carbachol (EC50 = 2 microM). PG-induced inhibition was prevented by pertussis-toxin treatment, supporting the idea that it was mediated by the inhibitory G-protein Gi through the inhibitory pathway of the adenylate cyclase. Both isoprenaline-induced stimulation and PG-evoked inhibition of cyclic AMP were insensitive to Ca2+ depletion. By contrast, carbachol-evoked attenuation of cyclic AMP accumulation was dependent on Ca2+ and was insensitive to pertussis toxin. The inhibitory effect of carbachol was mimicked by ionomycin. Indirect evidence was thus provided for the enhancement of cyclic AMP degradation by a Ca2(+)-dependent phosphodiesterase activity in the muscarinic-mediated effect. The attenuation of cyclic AMP elicited by carbachol coincided with carbachol-stimulated inositol phosphate (InsP3, InsP2 and InsP) generation, which displayed an almost identical EC50 (3 microM) and was similarly unaffected by pertussis toxin. Both carbachol effects were reproduced by oxotremorine, whereas pilocarpine (a partial muscarinic agonist) failed to induce any decrease in cyclic AMP accumulation and concurrently was unable to stimulate the generation of inositol phosphates. These data support our proposal for a carbachol-mediated enhancement of a Ca2(+)-dependent phosphodiesterase activity, compatible with the rises in Ca2+ associated with muscarinic-induced increased generation of inositol phosphates. They further illustrate that a cross-talk between the two major transmembrane signalling systems contributed to an ultimate decrease in cyclic AMP in the pregnant-rat myometrium near term. PMID:1700899

  17. Research of stimulants and anabolic steroids in dietary supplements.

    PubMed

    Baume, N; Mahler, N; Kamber, M; Mangin, P; Saugy, M

    2006-02-01

    The purpose of this study was to analyze the composition of 103 dietary supplements bought on the internet. The supplements were dispatched in four different categories according to their announced contents [creatine, prohormones, "mental enhancers" and branched chain amino acids (BCAA)]. All the supplements were screened for the presence of stimulants and main anabolic steroids parent compounds. At the same time, the research was focused on the precursors and metabolites of testosterone and nandrolone. The study pointed out three products containing an anabolic steroid, metandienone, in a very high amount. The ingestion of such products induced a high quantity of metandienone metabolites in urines that would be considered as a positive antidoping test. The results have also shown that one creatine product and three "mental enhancers" contained traces of hormones or prohormones not claimed on the labels and 14 prohormone products contained substances other than those indicated by the manufacturer. The oral intake of the creatine product revealed the presence of the two main nandrolone metabolites (19-norandrosterone and 19-noretiocholanolone) in urine. PMID:16430680

  18. Anabolic steroids and the athlete: a case study

    PubMed Central

    Oklobdzija, Edward; Weyrauch, David

    1989-01-01

    This paper examines the pharmacokinetic activities of anabolic steroids and their potential deleterious effects. A review of literature reveals the most significant pathological sequelae resulting from anabolic use to be peliosis hepatis and liver cell carcinoma. These ill effects have been more closely associated with those steroids whose chemical structures are specifically alkylated at the 17th carbon in the Alpha position as opposed to their Beta esterified counterparts. Testing of these drugs was attempted by way of a single case study. A 23 yr old male bodybuilder was subject to both oral and parenteral forms of steroid over a six week period of his training program. Serum, urinalysis and subjective parameters were monitored before during and after steroid administration. The results show elevated levels of urea, creatinine, bilirubin, CPK, AST, ALT and LDH. In this case study, the elevated parameters appear to be more a function of muscle breakdown induced by a combination of severe exercise and intramuscular injection than a measure of organ (liver) pathology.

  19. Catabolic and anabolic actions of parathyroid hormone on the skeleton.

    PubMed

    Silva, B C; Costa, A G; Cusano, N E; Kousteni, S; Bilezikian, J P

    2011-11-01

    PTH, an 84-amino acid peptide hormone synthesized by the parathyroid glands, is essential for the maintenance of calcium homeostasis.While in its traditional metabolic role, PTH helps to maintain the serum calcium concentration within narrow, normal limits and participates as a determinant of bone remodeling, more specific actions, described as catabolic and anabolic are also well known. Clinically, the catabolic effect of PTH is best represented by primary hyperparathyroidism (PHPT), while the osteoanabolic effect of PTH is best seen when PTH or its biological amino-terminal fragment [PTH(1-34)] is used as a therapy for osteoporosis. These dual functions of PTH are unmasked under very specific pathological (PHPT) or therapeutic conditions. At the cellular level, PTH favors bone resorption, mostly by affecting the receptor activator of nuclear factor κ-B (RANK) ligand (RANKL)-osteoprotegerin- RANK system, leading to an increase in osteoclast formation and activity. Increased bone formation due to PTH therapy is explained best by its ability to enhance osteoblastogenesis and/or osteoblast survival. The PTH-induced bone formation is mediated, in part, by a decrease in SOST/sclerostin expression in osteocytes. This review focuses on the dual anabolic and catabolic actions of PTH on bone, situations where one is enhanced over the other, and the cellular and molecular mechanisms by which these actions are mediated.

  20. Research of stimulants and anabolic steroids in dietary supplements.

    PubMed

    Baume, N; Mahler, N; Kamber, M; Mangin, P; Saugy, M

    2006-02-01

    The purpose of this study was to analyze the composition of 103 dietary supplements bought on the internet. The supplements were dispatched in four different categories according to their announced contents [creatine, prohormones, "mental enhancers" and branched chain amino acids (BCAA)]. All the supplements were screened for the presence of stimulants and main anabolic steroids parent compounds. At the same time, the research was focused on the precursors and metabolites of testosterone and nandrolone. The study pointed out three products containing an anabolic steroid, metandienone, in a very high amount. The ingestion of such products induced a high quantity of metandienone metabolites in urines that would be considered as a positive antidoping test. The results have also shown that one creatine product and three "mental enhancers" contained traces of hormones or prohormones not claimed on the labels and 14 prohormone products contained substances other than those indicated by the manufacturer. The oral intake of the creatine product revealed the presence of the two main nandrolone metabolites (19-norandrosterone and 19-noretiocholanolone) in urine.

  1. Hormone Treatment and Muscle Anabolism during Aging: Androgens

    PubMed Central

    Dillon, E. Lichar; Durham, William J.; Urban, Randall J.; Sheffield-Moore, Melinda

    2010-01-01

    Aging is associated with a gradual decline in circulating testosterone concentrations and decreased musculature in men. While testosterone administration is often considered when symptoms of hypogonadism are presented, the long-term effects of androgen use on muscle physiology are not yet fully understood. The definition of hypogonadism in men remains obscure but is generally indicated by total testosterone concentrations less than a threshold value of 300-500 ng/dL. Androgen replacement therapy is generally safe in men and women with low endogenous testosterone concentrations. The development of selective androgen receptor modulators (SARMs) may provide additional options in treatment of hypogonadism while lowering the potential of side effects often associated with long-term androgen use. Androgen administration, either alone or in combination with other treatments, can be successful in improving muscle mass by increasing protein anabolism and reducing protein catabolism in men and women. Further research is necessary to optimize the anabolic and anticatabolic properties of androgens for treatment and prevention of muscle loss in men and women. PMID:20452103

  2. Effects of anabolic-androgens on brain reward function

    PubMed Central

    Mhillaj, Emanuela; Morgese, Maria G.; Tucci, Paolo; Bove, Maria; Schiavone, Stefania; Trabace, Luigia

    2015-01-01

    Androgens are mainly prescribed to treat several diseases caused by testosterone deficiency. However, athletes try to promote muscle growth by manipulating testosterone levels or assuming androgen anabolic steroids (AAS). These substances were originally synthesized to obtain anabolic effects greater than testosterone. Although AAS are rarely prescribed compared to testosterone, their off-label utilization is very wide. Furthermore, combinations of different steroids and doses generally higher than those used in therapy are common. Symptoms of the chronic use of supra-therapeutic doses of AAS include anxiety, depression, aggression, paranoia, distractibility, confusion, amnesia. Interestingly, some studies have shown that AAS elicited electroencephalographic changes similar to those observed with amphetamine abuse. The frequency of side effects is higher among AAS abusers, with psychiatric complications such as labile mood, lack of impulse control and high violence. On the other hand, AAS addiction studies are complex because data collection is very difficult due to the subjects' reticence and can be biased by many variables, including physical exercise, that alter the reward system. Moreover, it has been reported that AAS may imbalance neurotransmitter systems involved in the reward process, leading to increased sensitivity toward opioid narcotics and central stimulants. The goal of this article is to review the literature on steroid abuse and changes to the reward system in preclinical and clinical studies. PMID:26379484

  3. [Anabolic-catabolic balance in depression: an effect of coaxil].

    PubMed

    Kochetkov, Ia A; Bel'tikova, K V; Gorobets, L N

    2006-01-01

    Correlation between anabolic and catabolic process in terms of neuroendocrine changes in depression has been studied before and after coaxil therapy. The index of catabolic processes was cortisol blood level and that of anabolic processes--dehydroepiandrosterone (dehydroepiandrosterone sulfate, DHEA-S) level. The total of 39 patients of middle age were studied: 25 of the study group treated with coaxil (37.5 mg/day during 4 weeks) and 14 of the comparison group treated with sertraline (50 mg/day during 4 weeks). A mean level of cortisol was higher than normal one in patients with depression. Coaxil and sertraline decreased the mean cortisol level, no significant differences being found between these drugs. There was negative correlation between the DHEA-S level and severity of depression before the treatment. Unlike sertraline, coaxil caused an increase of this parameter in patients with decreased DHEA-S level. The ratio cortisol/ DHEA-S decreased during the treatment with either coaxil or sertraline but in the former case it was more pronounced (p = 0.003). The authors considered the data obtained in the aspect of concept of allostasis--the ability of the organism to achieve changes (stress reaction).

  4. [Insulin as an anabolic: hypoglycemia in the bodybuilding world].

    PubMed

    Konrad, C; Schüpfer, G; Wietlisbach, M; Gerber, H

    1998-07-01

    Excessive body building may be dangerous. To promote athletic performance and to improve physical appearance many of the body builders abuse anabolic-androgenic steroids and other drugs. The abuse of insulin as an anabolic medication in this athletic community was followed by a case of severe hypoglycaemia in a body builder. A 30-year old male presented with cerebral symptoms of hypoglycaemia. Directly before an international competition he tried to stimulate muscle growth by using the hypoglycaemic stimulus to the growth hormone. To achieve this he injected 70 IE of a short-acting insulin subcutaneously, resulting in severe hypoglycaemia. After the initial administration of intravenous glucose by the paramedics, he lost consciousness and showed signs of convulsions. After orotracheal intubation by an emergency physician, despite of ongoing infusion of glucose the blood glucose concentration remained low as measured in the out-of-hospital setting. Finally administration of additional glucose and glucagon in the intensive care unit was able to stabilize the metabolic system. In any case of severe hypoglycaemia, repetitive measurements of blood glucose even in the prehospital setting should be performed to detect the hypoglycaemia especially if athletes are concerned.

  5. [Body cult and use of anabolic steroids by bodybuilders].

    PubMed

    Iriart, Jorge Alberto Bernstein; Chaves, José Carlos; Orleans, Roberto Ghignone de

    2009-04-01

    This study focused on the reasons for practicing bodybuilding and the use of anabolic steroids, as well as the social representations and uses of the body among bodybuilding steroid users. This ethnographic study involved participant observation in middle and lower-class bodybuilding gyms in Salvador, Bahia State, Brazil, and 43 in-depth interviews with steroid users. Aesthetic reasons are the main motivation for bodybuilding and steroid use in both middle and lower-class users. Dissatisfaction with one's real body as compared to the ideal standard flaunted by the mass media, fear of being devalued or shunned by one's peer groups, the symbolic capital associated with a 'pumped-up' body, and the sense of immediacy in obtaining results all contributed to steroid use. Preventive campaigns are needed, targeting young people and combining a critical view and deconstruction of the values assigned to the body by consumer society, counteracted by high-quality information on the health risks associated with anabolic steroid use.

  6. Nitrogen anabolism underlies the importance of glutaminolysis in proliferating cells.

    PubMed

    Meng, Meng; Chen, Shuyang; Lao, Taotao; Liang, Dongming; Sang, Nianli

    2010-10-01

    Glutaminolysis and Warburg effect are the two most noticeable metabolic features of tumor cells whereas their biological significance in cell proliferation remains elusive. A widely accepted current hypothesis is that tumor cells use glutamine as a preferred carbon source for energy and reducing power, which has been used to explain both glutaminolysis and the Warburg effect. Here we provide evidence to show that supplying nitrogen, not the carbon skeleton, underlies the major biological importance of glutaminolysis for proliferating cells. We show alternative nitrogen supplying mechanisms rescue cell proliferation in glutamine-free media. Particularly, we show that ammonia is sufficient to maintain a long-term survival and proliferation of Hep3B in glutamine-free media. We also observed that nitrogen source restriction repressed carbon metabolic pathways including glucose utilization. Based on these new observations and metabolic pathways well established in published literature, we propose an alternative model that cellular demand for glutamate as a key molecule in nitrogen anabolism is the driving force of glutaminolysis in proliferating cells. Our model suggests that the Warburg effect may be a metabolic consequence secondary to the nitrogen anabolism.

  7. Effects of anabolic-androgens on brain reward function.

    PubMed

    Mhillaj, Emanuela; Morgese, Maria G; Tucci, Paolo; Bove, Maria; Schiavone, Stefania; Trabace, Luigia

    2015-01-01

    Androgens are mainly prescribed to treat several diseases caused by testosterone deficiency. However, athletes try to promote muscle growth by manipulating testosterone levels or assuming androgen anabolic steroids (AAS). These substances were originally synthesized to obtain anabolic effects greater than testosterone. Although AAS are rarely prescribed compared to testosterone, their off-label utilization is very wide. Furthermore, combinations of different steroids and doses generally higher than those used in therapy are common. Symptoms of the chronic use of supra-therapeutic doses of AAS include anxiety, depression, aggression, paranoia, distractibility, confusion, amnesia. Interestingly, some studies have shown that AAS elicited electroencephalographic changes similar to those observed with amphetamine abuse. The frequency of side effects is higher among AAS abusers, with psychiatric complications such as labile mood, lack of impulse control and high violence. On the other hand, AAS addiction studies are complex because data collection is very difficult due to the subjects' reticence and can be biased by many variables, including physical exercise, that alter the reward system. Moreover, it has been reported that AAS may imbalance neurotransmitter systems involved in the reward process, leading to increased sensitivity toward opioid narcotics and central stimulants. The goal of this article is to review the literature on steroid abuse and changes to the reward system in preclinical and clinical studies. PMID:26379484

  8. Effects of anabolic-androgens on brain reward function.

    PubMed

    Mhillaj, Emanuela; Morgese, Maria G; Tucci, Paolo; Bove, Maria; Schiavone, Stefania; Trabace, Luigia

    2015-01-01

    Androgens are mainly prescribed to treat several diseases caused by testosterone deficiency. However, athletes try to promote muscle growth by manipulating testosterone levels or assuming androgen anabolic steroids (AAS). These substances were originally synthesized to obtain anabolic effects greater than testosterone. Although AAS are rarely prescribed compared to testosterone, their off-label utilization is very wide. Furthermore, combinations of different steroids and doses generally higher than those used in therapy are common. Symptoms of the chronic use of supra-therapeutic doses of AAS include anxiety, depression, aggression, paranoia, distractibility, confusion, amnesia. Interestingly, some studies have shown that AAS elicited electroencephalographic changes similar to those observed with amphetamine abuse. The frequency of side effects is higher among AAS abusers, with psychiatric complications such as labile mood, lack of impulse control and high violence. On the other hand, AAS addiction studies are complex because data collection is very difficult due to the subjects' reticence and can be biased by many variables, including physical exercise, that alter the reward system. Moreover, it has been reported that AAS may imbalance neurotransmitter systems involved in the reward process, leading to increased sensitivity toward opioid narcotics and central stimulants. The goal of this article is to review the literature on steroid abuse and changes to the reward system in preclinical and clinical studies.

  9. Brassinosteroid signalling

    PubMed Central

    Zhu, Jia-Ying; Sae-Seaw, Juthamas; Wang, Zhi-Yong

    2013-01-01

    The brassinosteroid (BR) class of steroid hormones regulates plant development and physiology. The BR signal is transduced by a receptor kinase-mediated signal transduction pathway, which is distinct from animal steroid signalling systems. Recent studies have fully connected the BR signal transduction chain and have identified thousands of BR target genes, linking BR signalling to numerous cellular processes. Molecular links between BR and several other signalling pathways have also been identified. Here, we provide an overview of the highly integrated BR signalling network and explain how this steroid hormone functions as a master regulator of plant growth, development and metabolism. PMID:23533170

  10. Distinct MAPK signaling pathways, p21 up-regulation and caspase-mediated p21 cleavage establishes the fate of U937 cells exposed to 3-hydrogenkwadaphnin: Differentiation versus apoptosis

    SciTech Connect

    Moosavi, Mohammad Amin; Yazdanparast, Razieh

    2008-07-01

    Despite the depth of knowledge concerning the pathogenesis of acute myeloblastic leukemia (AML), long-term survival remains unresolved. Therefore, new agents that act more selectively and more potently are required. In that line, we have recently characterized a novel diterpene ester, called 3-hydrogenkwadaphnin (3-HK), with capability to induce both differentiation and apoptosis in various leukemia cell lines. These effects of 3-HK were mediated through inhibition of inosine 5'-monophosphate dehydrogenase, a selective up-regulated enzyme in cancerous cells, especially leukemia. However, it remains elusive to understand how cells display different fates in response to 3-HK. Here, we report the distinct molecular signaling pathways involved in forcing of 3-HK-treated U937 cells to undergo differentiation and apoptosis. After 3-HK (15 nM) treatment, a portion of U937 cells adhered to the culture plates and showed macrophage criteria while others remained in suspension and underwent apoptosis. The differentiated cells arrested in G{sub 0}/G{sub 1} phase of cell cycle and showed early activation of ERK1/2 pathway (3 h) along with ERK-dependent p21{sup Cip/WAF1} (p21) up-regulation and expression of p27{sup Kip1} and Bcl-2. In contrast, the suspension cells underwent apoptosis through Fas/FasL and mitochondrial pathways. The occurrence of apoptosis in these cells were accompanied with caspase-8-mediated p21 cleavage and delayed activation (24 h) of JNK1/2 and p38 MAPK. Taken together, these results suggest that distinct signaling pathways play a pivotal role in fates of drug-treated leukemia cells, thus this may pave some novel therapeutical utilities.

  11. Central effects of the anabolic steroid 17alpha methyltestosterone in female anxiety.

    PubMed

    Rivera-Arce, Juan Carlos; Morales-Crespo, Lizannette; Vargas-Pinto, Noelia; Velázquez, Kandy T; Jorge, Juan Carlos

    2006-06-01

    The androgen 17alpha-methyltestosterone (17alpha-meT) is one of the most commonly abused anabolic androgenic steroids (AAS). We assessed the impact of 17alpha-meT after bilateral infusion into the dorsomedial hypothalamus (DMH) in female anxiety. A paradoxical effect in Vogel conflict test (VCT) behavior was noted: while AAS infusion induced an increase in the latency to display the appetitive reaction of the task, it also increased the number of punished responses. No changes in elevated plus maze (EPM) behavior were noted. However, AAS infusion induced an increase in social interactions. Changes in social interactions were mimicked by muscimol infusion and counteracted by co-infusion of AAS plus the GABAA receptor (GABAA-R) antagonist GABAzine. A reduction of systolic blood pressure was registered after AAS infusion in the DMH. No changes in fluid intake or locomotor behaviors were noted. We conclude that the AAS 17alpha-meT modulates distinct anxiety domains in females through a fast-acting mechanism.

  12. Anabolic and antiresorptive therapy for osteoporosis: combination and sequential approaches.

    PubMed

    Cosman, Felicia

    2014-12-01

    In the recent Bone Key Reports review, it was noted that combinations of anabolic and antiresorptive agents have potential to improve bone density and bone strength more than either agent as monotherapy. Small clinical trials have been performed evaluating combinations of PTH1-34 (TPTD) or PTH1-84 (PTH) with a variety of antiresorptives including hormone/estrogen therapy, raloxifene, alendronate, risedronate, ibandronate, zoledronic acid, and denosumab. Most of the studies evaluate dual-energy X-ray absorptiometry outcomes, and a few trials report volumetric mineral density (BMD) by quantitative computed tomography, followed by finite element modeling to calculate bone strength. None of the studies has been powered to assess differences in fracture incidence between combination therapy and monotherapy. BMD outcomes vary based on the timing of introduction of the anabolic agent (before, during, or after antiresorptive treatment), as well as the specific anabolic and antiresorptive used. Furthermore, effects of combination therapies are site-dependent. The most consistent effect of combining antiresorptive agents with PTH or TPTD is a superior hip BMD outcome compared with TPTD/PTH alone. This is most evident when TPTD/PTH is combined with a bisphosphonate or denosumab. In contrast to findings in the hip, in the majority of studies, there is no benefit to spine BMD with combination therapy vs monotherapy. The 2 exceptions to this are when TPTD is combined with denosumab and when TPTD is given as monotherapy first for 9 months, followed by the addition of alendronate (with continuation administration of TPTD). Based on what we now know, in patients previously treated with bisphosphonates who suffer hip fractures or who have very low or declining hip BMD, strong consideration should be given to starting TPTD and continuing a potent antiresorptive agent (possibly switching to zoledronic acid or denosumab) to improve hip BMD and strength quickly. Furthermore, in

  13. [Coronary thrombosis and ectasia of coronary arteries after long-term use of anabolic steroids].

    PubMed

    Tischer, K-H; Heyny-von Haussen, R; Mall, G; Doenecke, P

    2003-04-01

    Chronic abuse of anabolic steroids is widespread. Hypertrophy of skeletal and heart muscle is a well-known effect of chronic anabolic steroid abuse. Structural alterations of blood vessels are new side effects. We report a case of a 32-year-old bodybuilder after long-term use of anabolic steroids who died of cardiac arrest. Coronary angiography and autopsy findings showed especially a hypertrophic heart, structural changes of coronary arteries, intracoronary thrombosis and myocardial infarction, ventricular thrombosis and systemic embolism PMID:12707792

  14. Anabolic steroid use and perceived effects in ten weight-trained women athletes.

    PubMed

    Strauss, R H; Liggett, M T; Lanese, R R

    1985-05-17

    Ten women athletes who consistently used anabolic steroids were interviewed about their patterns of drug use and the perceived effects. Anabolic steroids were used in a cyclical manner, often with several drugs taken simultaneously. All participants believed that muscle size and strength were increased in association with anabolic steroid use. Most also noted a deepening of the voice, increased facial hair, increased aggressiveness, clitoral enlargement, and menstrual irregularities. The participants were willing to tolerate these side effects but thought that such changes might be unacceptable to many women.

  15. National Athletic Trainers' Association Position Statement: Anabolic-Androgenic Steroids

    PubMed Central

    Kersey, Robert D.; Elliot, Diane L.; Goldberg, Linn; Kanayama, Gen; Leone, James E.; Pavlovich, Mike; Pope, Harrison G.

    2012-01-01

    This NATA position statement was developed by the NATA Research & Education Foundation. Objective This manuscript summarizes the best available scholarly evidence related to anabolic-androgenic steroids (AAS) as a reference for health care professionals, including athletic trainers, educators, and interested others. Background Health care professionals associated with sports or exercise should understand and be prepared to educate others about AAS. These synthetic, testosterone-based derivatives are widely abused by athletes and nonathletes to gain athletic performance advantages, develop their physiques, and improve their body image. Although AAS can be ergogenic, their abuse may lead to numerous negative health effects. Recommendations Abusers of AAS often rely on questionable information sources. Sports medicine professionals can therefore serve an important role by providing accurate, reliable information. The recommendations provide health care professionals with a current and accurate synopsis of the AAS-related research. PMID:23068595

  16. When color fails: illicit blue tablets containing anabolic androgen steroids.

    PubMed

    Favretto, Donata; Castagna, Franca; Maietti, Sergio; Boscolo-Berto, Rafael; Ferrara, Santo Davide

    2013-09-01

    The necessity of specific, confirmatory tests in the identification of seized illicit products was highlighted by the analysis of eighteen heart shaped, blue tablets confiscated by Police at a street control in the North East of Italy. The tablets responded as amphetamines to a preliminary color test (Marquis); a subsequent, confirmatory assay by gas chromatography-mass spectrometry revealed the presence of two anabolic androgen steroids (AAS), methandienone and methyltestosterone, in concentration of 1.7 and 1.5mg respectively per tablet; no trace of amphetamine-like or nitrogen containing compounds was found. The observed orange coloration was due to the reaction of concentrated sulphuric acid, contained in the Marquis reagent, with the Δ(4) C-3 keto group of steroids. The two AAS, banned under the world antidoping code, are not considered as psychoactive drugs of abuse in most countries, although their trafficking may entangle severe public health concerns. PMID:23770638

  17. CNS effects and abuse liability of anabolic-androgenic steroids.

    PubMed

    Lukas, S E

    1996-01-01

    Anabolic-androgenic steroids (AAS) have become more widely used and abused not only by elite athletes, but by nonathletes as well. It appears that these drugs are being used for cosmetic purposes as well as for promoting aggressive behavior. However, AASs may also be used in combination with other drugs such as ethyl alcohol and cocaine--a practice that may contribute to the observed increase in aggressive behavior. As there are no reliable animal models of AAS self-administration, it has been difficult to characterize the abuse liability and physical dependence potential of this class of drugs. A better understanding of neuroactive steroids, improved methods for assessing AAS abuse, and a revised interpretation of drug-seeking behavior is needed to develop improved treatment strategies for this emerging health-related problem.

  18. [Recent aspects of therapy with androgenic and anabolic steroids].

    PubMed

    Schambach, H; Nitschke, U; Kröhne, H J

    1983-11-15

    From the pharmacology of the therapeutically available androgen preparations and the clinical experience results that a highly dosed androgen long-term therapy is effectively possible only by testosterone esters which are to be injected intramuscularly (e.g. testosterone oenanthate). It is indicated in all forms of endocrine hypogonadism, certain aplastic anaemias and if necessary in extreme male high growth. In partial androgen deficiency (pubertas tarda, Klinefelter's syndrome, climacterium virile and others) orally applicable androgens such as testosterone-undecanoate (Andriol) and mesterolone (Vistimon) can be used. The latter is to be preferred when a hyperoestrogenism is present, e.g. in liver cirrhosis. When 17-alpha-alkylated oral androgens are used, their often not sufficiently confirmed anabolic effect and their potential liver toxicity should more be taken into consideration. PMID:6666179

  19. Inherited antithrombin deficiency and anabolic steroids: a risky combination.

    PubMed

    Choe, Hannah; Elfil, Mohamed; DeSancho, Maria T

    2016-09-01

    A 20-year-old male with asymptomatic inherited type 1 antithrombin deficiency and a family history of thrombosis started injecting himself with testosterone 250 mg intramuscularly twice weekly for 5 weeks. He presented to the hospital with progressive dyspnea on exertion, chest pain and hemoptysis. Workup revealed bilateral submassive pulmonary embolism and proximal right lower extremity deep vein thrombosis. He was treated with intravenous (IV) unfractionated heparin and underwent catheter-directed thrombolysis with alteplase to the main pulmonary arteries. Postprocedure, he remained on IV alteplase infusion for 24 h and unfractionated heparin in the intensive care unit. Concomitantly he received plasma-derived antithrombin concentrate. He was transitioned to subcutaneous enoxaparin twice daily and discharged from the hospital on oral rivaroxaban 15 mg twice a day. This case highlights the heightened thrombogenic effect of anabolic steroids in the setting of underlying thrombophilia especially in younger subjects.

  20. When color fails: illicit blue tablets containing anabolic androgen steroids.

    PubMed

    Favretto, Donata; Castagna, Franca; Maietti, Sergio; Boscolo-Berto, Rafael; Ferrara, Santo Davide

    2013-09-01

    The necessity of specific, confirmatory tests in the identification of seized illicit products was highlighted by the analysis of eighteen heart shaped, blue tablets confiscated by Police at a street control in the North East of Italy. The tablets responded as amphetamines to a preliminary color test (Marquis); a subsequent, confirmatory assay by gas chromatography-mass spectrometry revealed the presence of two anabolic androgen steroids (AAS), methandienone and methyltestosterone, in concentration of 1.7 and 1.5mg respectively per tablet; no trace of amphetamine-like or nitrogen containing compounds was found. The observed orange coloration was due to the reaction of concentrated sulphuric acid, contained in the Marquis reagent, with the Δ(4) C-3 keto group of steroids. The two AAS, banned under the world antidoping code, are not considered as psychoactive drugs of abuse in most countries, although their trafficking may entangle severe public health concerns.

  1. Inherited antithrombin deficiency and anabolic steroids: a risky combination.

    PubMed

    Choe, Hannah; Elfil, Mohamed; DeSancho, Maria T

    2016-09-01

    A 20-year-old male with asymptomatic inherited type 1 antithrombin deficiency and a family history of thrombosis started injecting himself with testosterone 250 mg intramuscularly twice weekly for 5 weeks. He presented to the hospital with progressive dyspnea on exertion, chest pain and hemoptysis. Workup revealed bilateral submassive pulmonary embolism and proximal right lower extremity deep vein thrombosis. He was treated with intravenous (IV) unfractionated heparin and underwent catheter-directed thrombolysis with alteplase to the main pulmonary arteries. Postprocedure, he remained on IV alteplase infusion for 24 h and unfractionated heparin in the intensive care unit. Concomitantly he received plasma-derived antithrombin concentrate. He was transitioned to subcutaneous enoxaparin twice daily and discharged from the hospital on oral rivaroxaban 15 mg twice a day. This case highlights the heightened thrombogenic effect of anabolic steroids in the setting of underlying thrombophilia especially in younger subjects. PMID:26588446

  2. Anabolic steroids in the training and treatment of athletes.

    PubMed

    Limbird, T J

    1985-01-01

    The use of anabolic steroids has become widespread in the athletic population in the hope of developing a competitive edge. The theoretical advantages of increases in lean body mass, body weight, and muscle strength have been difficult to document in the athletic population because of an inability to define a satisfactory placebo or safely test the extremely high doses of steroid purportedly used by the athletic population. Those studies that are available suggest that while some mild weight gain and lean body mass increase may be noted, athletic performance itself is not significantly altered by steroid use. The significant negative side effects that can occur, particularly those that alter liver function and endocrine balance, suggest that there is little to support the use and abuse of these drugs in the treatment and training of athletes.

  3. Aortic elastic properties in athletes using anabolic-androgenic steroids.

    PubMed

    Kasikcioglu, Erdem; Oflaz, Huseyin; Arslan, Armagan; Topcu, Berrin; Kasikcioglu, Hulya A; Umman, Berrin; Bugra, Zehra; Kayserilioglu, Abidin

    2007-01-01

    The use of anabolic-androgenic steroids (AAS) has been linked to acute cardiovascular events in athletes. The purpose of the present study was to investigate the aortic elastic properties in athletes who had been self-administering AAS compared with a group of athletes not using these drugs. Fourteen male bodybuilders using AAS and 27 male wrestlers (non-users) volunteered to the study. All subjects were placed in a mild recumbent position and the ascending aorta was recorded in the two-dimensional guided M-mode tracings. Although the aortic distensibility was found to be reduced in user athletes (2.1+/-1.1 vs. 3.8+/-1.4 cm(2) dyn(-1) 10(-6), p=0.01; 9.3+/-3.7 vs. 5.9+/-2.5, p=0.003, respectively). The results of this study indicate that aortic stiffness is increasing in athletes using AAS.

  4. Anabolic steroid abuse and dependence in clinical practice.

    PubMed

    Brower, Kirk J

    2009-12-01

    The nonmedical use of anabolic-androgenic steroids (AAS) appeals to athletes across several sports, particularly those whose activity makes muscle size and strength advantageous, and in individuals (usually men) with body dysmorphic disorder. Patterns of nonmedical use, including supratherapeutic doses of illicitly obtained drugs, increase the risk for adverse psychiatric and other medical consequences. Although AAS users may be more likely to consult physicians for nonpsychiatric medical consequences than changes in their mental status, it is argued that the motivation for persistent use despite adverse consequences is sustained in large part by psychological variables. Therefore, all physicians who treat nonmedical AAS users will benefit from an understanding of these psychological variables, including the potential for AAS to cause dependence. This article aims to aid such understanding, and guidelines are suggested for assessment and treatment of nonmedical AAS users.

  5. Anabolic Steroid Abuse among Teenage Girls: An Illusory Problem?

    PubMed Central

    Kanayama, Gen; Boynes, Matthew; Hudson, James I.; Field, Alison E.; Pope, Harrison G.

    2007-01-01

    Background Recent media reports have portrayed an alarming increase in apparent anabolic-androgenic steroid (AAS) use among American teenage girls; Congress even held hearings on the subject in June 2005. We questioned whether AAS use among teenage girls was as widespread as claimed. Methods We reviewed four large national surveys and many smaller surveys examining the prevalence of AAS use among teenage girls. Virtually all of these surveys used anonymous questionnaires. We asked particularly whether the language of survey questions might generate false-positive responses among girls who misinterpreted the term “steroid.” We also reviewed data from other countries, together with results from the only recent study (to our knowledge) in which investigators personally interviewed female AAS users. Results The surveys produced remarkably disparate findings, with the lifetime prevalence of AAS use estimated as high as 7.3% among ninth-grade girls in one study, but only 0.1% among teenage girls in several others. Upon examining the surveys reporting an elevated prevalence, it appeared that most used questions that failed to distinguish between anabolic steroids, corticosteroids, and over-the-counter supplements that respondents might confuse with “steroids.” Other features in the phrasing of certain questions also seemed likely to further bias results in favor of false-positive responses. Conclusions Many anonymous surveys, using imprecise questions, appear to have greatly overestimated the lifetime prevalence of AAS use among teenage girls; the true lifetime prevalence may well be as low as 0.1%. Future studies can test this impression by using a carefully phrased question regarding AAS use. PMID:17127018

  6. Unfocused extracorporeal shock waves induce anabolic effects in osteoporotic rats.

    PubMed

    van der Jagt, Olav P; Waarsing, Jan H; Kops, Nicole; Schaden, Wolfgang; Jahr, Holger; Verhaar, Jan A N; Weinans, Harrie

    2013-05-01

    Unfocused extracorporeal shock waves (UESW) have been shown to have an anabolic effect on bone mass. Therefore we investigated the effects of UESW on bone in osteoporotic rats with and without anti-resorptive treatment. Twenty-week-old rats were ovariectomized (n = 27). One group was treated with saline and another group with Alendronate (ALN) 2.4 µg/kg, 3×/week. UESW were applied 2 weeks after ovariectomy. Thousand UESW were applied to one hind leg, the contra-lateral hind leg was not treated and served as control. With the use of in vivo micro-CT scanning it was shown that in saline treated rats trabecular bone volume fraction (BV/TV) was higher at 2 weeks follow-up in UESW treated legs compared to control legs. However, at 4 and 10 weeks no difference was found. In ALN treated animals UESW led to a pronounced anabolic response resulting in an increase in BV/TV at all time-points. Furthermore, UESW resulted in increased cortical volume (CtV), higher trabecular connectivity and, more plate-like and thicker trabeculae. Biomechanical testing showed that UESW lead to a higher maximum force before failure and higher stiffness in all treatment groups. With histology abundant areas of intramembranous bone formation along the periosteal cortex and within the bone marrow were observed. In conclusion this study shows promising results for the use of UESW in the treatment of osteoporosis, especially when this treatment is combined with an anti-resorptive treatment. PMID:23239548

  7. Anabolic steroids and male infertility: a comprehensive review.

    PubMed

    de Souza, Guilherme Leme; Hallak, Jorge

    2011-12-01

    What's known on the subject? and What does the study add? The negative impact of AAS abuse on male fertility is well known by urologists. The secondary hypogonadotropic hypogonadism is often highlighted when AAS and fertility are being discussed. On the other hand, the patterns of use, mechanisms of action and direct effects over the testicle are usually overseen. The present study reviews the vast formal and "underground" culture of AAS, as well as their overall implications. Specific considerations about their impact on the male reproductive system are made, with special attention to the recent data on direct damage to the testicle. To our knowledge this kind of overview is absolutely unique, offering a distinguished set of information to the day-by-day urologists. For several decades, testosterone and its synthetic derivatives have been used with anabolic and androgenic purposes. Initially, these substances were restricted to professional bodybuilders, becoming gradually more popular among recreational power athletes. Currently, as many as 3 million anabolic-androgenic steroids (AAS) users have been reported in the United States, and considering its increasing prevalence, it has become an issue of major concern. Infertility is defined as the failure to achieve a successful pregnancy after 12 months or more of regular unprotected intercourse, with male factor being present in up to 50% of all infertile couples. Several conditions may be related to male infertility. Substance abuse, including AAS, is commonly associated to transient or persistent impairment on male reproductive function, through different pathways. Herein, a brief overview on AAS, specially oriented to urologists, is offered. Steroids biochemistry, patterns of use, physiological and clinical issues are enlightened. A further review about fertility outcomes among male AAS abusers is also presented, including the classic reports on transient axial inhibition, and the more recent experimental reports

  8. Endopeptidase Cleavage Generates a Functionally Distinct Isoform of C1q/Tumor Necrosis Factor-related Protein-12 (CTRP12) with an Altered Oligomeric State and Signaling Specificity*

    PubMed Central

    Wei, Zhikui; Lei, Xia; Seldin, Marcus M.; Wong, G. William

    2012-01-01

    Adipose tissue-derived adipokines are an important class of secreted metabolic regulators that mediate tissue cross-talk to control systemic energy balance. We recently described C1q/TNF-related protein-12 (CTRP12), a novel insulin-sensitizing adipokine that regulates glucose metabolism in liver and adipose tissue. However, the biochemical properties of CTRP12 and its naturally occurring cleaved isoform have not been characterized. Here, we show that CTRP12 is a secreted hormone subjected to multiple functionally relevant posttranslational modifications at highly conserved residues. For example, Asn39 is glycosylated, whereas Cys85 mediates the assembly of higher order oligomeric structure. Endopeptidase cleavage at Lys91 generates a cleaved globular gCTRP12 isoform, the expression of which is increased by insulin. PCSK3/furin was identified as the major proprotein convertase expressed by adipocytes that mediates the endogenous cleavage of CTRP12. Cleavage at Lys91 is context-dependent: mutation of the charged Arg93 to Ala on the P2′ position enhanced cleavage, and triple mutations (K90A/K91A/R93A) abolished cleavage. Importantly, the two isoforms of CTRP12 differ in oligomeric structures and are functionally distinct. The full-length protein forms trimers and larger complexes, and the cleaved isoform consisted of predominantly dimers. Whereas full-length fCTRP12 strongly activated Akt signaling in H4IIE hepatocytes and 3T3-L1 adipocytes, gCTRP12 preferentially activated MAP kinase (ERK1/2 and p38 MAPK) signaling. Further, only fCTRP12 improved insulin-stimulated glucose uptake in adipocytes. These results reveal a novel mechanism controlling signaling specificity and function of a hormone via cleavage-dependent alteration in oligomeric state. PMID:22942287

  9. Two distinct forms of M-locus protein kinase localize to the plasma membrane and interact directly with S-locus receptor kinase to transduce self-incompatibility signaling in Brassica rapa.

    PubMed

    Kakita, Mitsuru; Murase, Kohji; Iwano, Megumi; Matsumoto, Tomohito; Watanabe, Masao; Shiba, Hiroshi; Isogai, Akira; Takayama, Seiji

    2007-12-01

    Many flowering plants possess systems of self-incompatibility (SI) to prevent inbreeding. In Brassica, SI recognition is controlled by the multiallelic gene complex (S-haplotypes) at the S-locus, which encodes both the male determinant S-locus protein 11 (SP11/SCR) and the female determinant S-receptor kinase (SRK). Upon self-pollination, the S-haplotype-specific interaction between the pollen-borne SP11 and the cognate stigmatic SRK receptor induces SI signaling in the stigmatic papilla cell and results in rejection of the self-pollen. Our genetic analysis of a self-compatible mutant revealed the involvement of a cytoplasmic protein kinase, M-locus protein kinase (MLPK), in the SI signaling, but its exact physiological function remains unknown. In this study, we identified two different MLPK transcripts, MLPKf1 and MLPKf2, which are produced using alternative transcriptional initiation sites and encode two isoforms that differ only at the N termini. While MLPKf1 and MLPKf2 exhibited distinct expression profiles, both were expressed in papilla cells. MLPKf1 localizes to the plasma membrane through its N-terminal myristoylation motif, while MLPKf2 localizes to the plasma membrane through its N-terminal hydrophobic region. Although both MLPKf1 and MLPKf2 could independently complement the mlpk/mlpk mutation, their mutant forms that lack the plasma membrane localization motifs failed to complement the mutation. Furthermore, a bimolecular fluorescence complementation assay revealed direct interactions between SRK and the MLPK isoforms in planta. These results suggest that MLPK isoforms localize to the papilla cell membrane and interact directly with SRK to transduce SI signaling.

  10. Altered Serum Lipoprotein Profiles in Male and Female Power Lifters Ingesting Anabolic Steroids.

    ERIC Educational Resources Information Center

    Cohen, Jonathan C.; And Others

    1986-01-01

    Serum lipoprotein profiles were measured in nine male and three female weightlifters who were taking anabolic steroids. The profiles suggest that steriod users may face an increased risk of coronary artery disease. (Author/MT)

  11. The Use and Abuse of Anabolic Steroids: A Discussion for Health and Physical Education Teachers

    ERIC Educational Resources Information Center

    Thomas, John A.; And Others

    1973-01-01

    This article reviews research on anabolic steroids, indicating that athletes are mistaken in believing that taking them will improve their physical performance. Dangerous side-effects are also discussed. (JA)

  12. Anabolic Steroids: Metabolism, Doping and Detection in Human and Equestrian Sports

    NASA Astrophysics Data System (ADS)

    Kicman, A. T.; Houghton, E.; Gower, D. B.

    This chapter highlights the important aspects of detection of doping with synthetic anabolic steroids and discusses some of the problems with, and solutions to, the detection of misuse of the naturally occurring ones.

  13. Interactions between opioids and anabolic androgenic steroids: implications for the development of addictive behavior.

    PubMed

    Nyberg, Fred; Hallberg, Mathias

    2012-01-01

    Over the past decades, research on doping agents, such as anabolic androgenic steroids (AAS), has revealed that these compounds are often used in combination with other drugs of abuse. It seems that misuse of AAS probably involves more than a desire to enhance appearance or sports performance and studies have revealed that steroids are commonly connected with alcohol, opioids, tobacco, and psychotropic drugs. We have observed that AAS may interact with the endogenous opioids, excitatory amino acids, and dopaminergic pathways involved in the brain reward system. Furthermore, our studies provide evidence that AAS may induce an imbalance in these signal systems leading to an increased sensitivity toward opioid narcotics and central stimulants. In fact, studies performed in various clinics have shown that individuals taking AAS are likely to get addicted to opioids like heroin. This chapter reviews current knowledge on interactions between AAS and endogenous as well as exogenous opioids based not only on research in our laboratory but also on research carried out by several other clinical and preclinical investigators.

  14. Dasatinib as a Bone-Modifying Agent: Anabolic and Anti-Resorptive Effects

    PubMed Central

    Garcia-Gomez, Antonio; Ocio, Enrique M.; Crusoe, Edvan; Santamaria, Carlos; Hernández-Campo, Pilar; Blanco, Juan F.; Sanchez-Guijo, Fermin M.; Hernández-Iglesias, Teresa; Briñón, Jesús G.; Fisac-Herrero, Rosa M.; Lee, Francis Y.; Pandiella, Atanasio; San Miguel, Jesús F.; Garayoa, Mercedes

    2012-01-01

    Background Bone loss, in malignant or non-malignant diseases, is caused by increased osteoclast resorption and/or reduced osteoblast bone formation, and is commonly associated with skeletal complications. Thus, there is a need to identify new agents capable of influencing bone remodeling. We aimed to further pre-clinically evaluate the effects of dasatinib (BMS-354825), a multitargeted tyrosine kinase inhibitor, on osteoblast and osteoclast differentiation and function. Methods For studies on osteoblasts, primary human bone marrow mensenchymal stem cells (hMSCs) together with the hMSC-TERT and the MG-63 cell lines were employed. Osteoclasts were generated from peripheral blood mononuclear cells (PBMC) of healthy volunteers. Skeletally-immature CD1 mice were used in the in vivo model. Results Dasatinib inhibited the platelet derived growth factor receptor-β (PDGFR-β), c-Src and c-Kit phosphorylation in hMSC-TERT and MG-63 cell lines, which was associated with decreased cell proliferation and activation of canonical Wnt signaling. Treatment of MSCs from healthy donors, but also from multiple myeloma patients with low doses of dasatinib (2–5 nM), promoted its osteogenic differentiation and matrix mineralization. The bone anabolic effect of dasatinib was also observed in vivo by targeting endogenous osteoprogenitors, as assessed by elevated serum levels of bone formation markers, and increased trabecular microarchitecture and number of osteoblast-like cells. By in vitro exposure of hemopoietic progenitors to a similar range of dasatinib concentrations (1–2 nM), novel biological sequelae relative to inhibition of osteoclast formation and resorptive function were identified, including F-actin ring disruption, reduced levels of c-Fos and of nuclear factor of activated T cells 1 (NFATc1) in the nucleus, together with lowered cathepsin K, αVβ3 integrin and CCR1 expression. Conclusions Low dasatinib concentrations show convergent bone anabolic and reduced bone

  15. Role of paraoxonase-1 in bone anabolic effects of parathyroid hormone in hyperlipidemic mice

    SciTech Connect

    Lu, Jinxiu; Cheng, Henry; Atti, Elisa; Shih, Diana M.; Demer, Linda L.; Tintut, Yin

    2013-02-01

    Highlights: ► Anabolic effects of PTH were tested in hyperlipidemic mice overexpressing PON1. ► Expression of antioxidant regulatory genes was induced in PON1 overexpression. ► Bone resorptive activity was reduced in PON1 overexpressing hyperlipidemic mice. ► PON1 restored responsiveness to intermittent PTH in bones of hyperlipidemic mice. -- Abstract: Hyperlipidemia blunts anabolic effects of intermittent parathyroid hormone (PTH) on cortical bone, and the responsiveness to PTH are restored in part by oral administration of the antioxidant ApoA-I mimetic peptide, D-4F. To evaluate the mechanism of this rescue, hyperlipidemic mice overexpressing the high-density lipoprotein-associated antioxidant enzyme, paraoxonase 1 (Ldlr{sup −/−}PON1{sup tg}) were generated, and daily PTH injections were administered to Ldlr{sup −/−}PON1{sup tg} and to littermate Ldlr{sup −/−} mice. Expression of bone regulatory genes was determined by realtime RT-qPCR, and cortical bone parameters of the femoral bones by micro-computed tomographic analyses. PTH-treated Ldlr{sup −/−}PON1{sup tg} mice had significantly greater expression of PTH receptor (PTH1R), activating transcription factor-4 (ATF4), and osteoprotegerin (OPG) in femoral cortical bone, as well as significantly greater cortical bone mineral content, thickness, and area in femoral diaphyses compared with untreated Ldlr{sup −/−}PON1{sup tg} mice. In contrast, in control mice (Ldlr{sup −/−}) without PON1 overexpression, PTH treatment did not induce these markers. Calvarial bone of PTH-treated Ldlr{sup −/−}PON1{sup tg} mice also had significantly greater expression of osteoblastic differentiation marker genes as well as BMP-2-target and Wnt-target genes. Untreated Ldlr{sup −/−}PON1{sup tg} mice had significantly greater expression of PTHR1 than untreated Ldlr{sup −/−} mice, whereas sclerostin expression was reduced. In femoral cortical bones, expression levels of transcription factors, Fox

  16. Systemic lupus erythematosus with membranous glomerulonephritis and transverse myelitis associated with anabolic steroid use.

    PubMed

    Radis, C D; Callis, K P

    1997-10-01

    This report describes a 29-year-old bodybuilder taking anabolic steroids who presented with urinary retention, arthralgias, and peripheral edema, subsequently developed acute lower-extremity paralysis, and was diagnosed as having transverse myelitis and membranous glomerulonephritis secondary to systemic lupus erythematosus (SLE). The association of anabolic steroid use and hyperprolactinemia, and their possible link to the development of SLE, are reviewed. PMID:9336429

  17. Prevalence of Use of Anabolic Steroids by Bodybuilders Using Three Methods in a City of Iran

    PubMed Central

    Nakhaee, Mohammad Reza; Pakravan, Faezeh; Nakhaee, Nouzar

    2013-01-01

    Background The prevalence of substance use among bodybuilding athletes has been poorly studied in Iran. This study was conducted to examine the prevalence of drug use, especially anabolic steroids, among bodybuilding athletes. Methods This cross-sectional study was conducted in the first half of 2013 among body building athletes referring to gyms located in Kerman, Iran. Five gyms were selected randomly and 380 athletes were invited to complete a self-administered anonymous questionnaire, consecutively. The questionnaire included two parts; baseline characteristics and substance related questions. The prevalence of anabolic steroids was estimated based on three methods; self-report, projective question, and crosswise model. Findings We enrolled 298 male athletes in the final analysis. Mean ± SD age of subjects was 25.9 ± 8.4. The most frequent recent (past 30 days) drug use was waterpipe smoking (45%). The second most frequently used drug was alcohol (26.5%, recent use). Based on self-reports, the prevalence of lifetime anabolic steroid use was calculated to be 24.5%. The corresponding figure based on crosswise method was obtained to be 56.8%. Participants believed that a median of 40% of athletes had used anabolic steroids in their lifetime. The prevalence of anabolic steroid was higher in single and less educated individuals (P < 0.05). The main reason for using anabolic steroids was to increase muscle size. Conclusion The prevalence of drug use, especially tobacco, alcohol, and anabolic steroids, was high among bodybuilding athletes. We could not rely on self-reports to examine anabolic steroid use. PMID:24494162

  18. The use and abuse of anabolic steroids in Olympic-caliber athletes.

    PubMed

    Bergman, R; Leach, R E

    1985-09-01

    Self-medication with anabolic steroids by athletes, particularly in the sports of weight lifting and track and field, has become increasingly popular. In the 1983 Pan American Games, 15 athletes were disqualified for taking anabolic steroids. Athletes take steroids believing the steroids will allow increased periods of intensive training and will increase muscle strength with proper weight training. The athletes assume this increased strength and training will translate into better athletic performance. Most athletes taking anabolic steroids are taking very large doses with no thought as to the potential adverse side effects. They ignore the possibility of long-term problems relating to hypertension, liver dysfunction, and atherosclerosis for what they see as the immediate performance benefits. In an attempt to keep sports competition "clean" and to help protect athletes from harmful drugs, the International Olympic Committee (IOC) and the United States Olympic Committee have rules stating that the use of anabolic steroids is illegal. Drug testing is performed in Olympic and in many international competitions. Those people found using anabolic steroids are disqualified. This use of anabolic steroids indicates that for some athletes the need to win or to maximize performance supersedes any worries about future health. PMID:4028547

  19. The use and abuse of anabolic steroids in Olympic-caliber athletes.

    PubMed

    Bergman, R; Leach, R E

    1985-09-01

    Self-medication with anabolic steroids by athletes, particularly in the sports of weight lifting and track and field, has become increasingly popular. In the 1983 Pan American Games, 15 athletes were disqualified for taking anabolic steroids. Athletes take steroids believing the steroids will allow increased periods of intensive training and will increase muscle strength with proper weight training. The athletes assume this increased strength and training will translate into better athletic performance. Most athletes taking anabolic steroids are taking very large doses with no thought as to the potential adverse side effects. They ignore the possibility of long-term problems relating to hypertension, liver dysfunction, and atherosclerosis for what they see as the immediate performance benefits. In an attempt to keep sports competition "clean" and to help protect athletes from harmful drugs, the International Olympic Committee (IOC) and the United States Olympic Committee have rules stating that the use of anabolic steroids is illegal. Drug testing is performed in Olympic and in many international competitions. Those people found using anabolic steroids are disqualified. This use of anabolic steroids indicates that for some athletes the need to win or to maximize performance supersedes any worries about future health.

  20. Neuronal apoptosis induced by selective inhibition of Rac GTPase versus global suppression of Rho family GTPases is mediated by alterations in distinct mitogen-activated protein kinase signaling cascades.

    PubMed

    Stankiewicz, Trisha R; Ramaswami, Sai Anandi; Bouchard, Ron J; Aktories, Klaus; Linseman, Daniel A

    2015-04-10

    Rho family GTPases play integral roles in neuronal differentiation and survival. We have shown previously that Clostridium difficile toxin B (ToxB), an inhibitor of RhoA, Rac1, and Cdc42, induces apoptosis of cerebellar granule neurons (CGNs). In this study, we compared the effects of ToxB to a selective inhibitor of the Rac-specific guanine nucleotide exchange factors Tiam1 and Trio (NSC23766). In a manner similar to ToxB, selective inhibition of Rac induces CGN apoptosis associated with enhanced caspase-3 activation and reduced phosphorylation of the Rac effector p21-activated kinase. In contrast to ToxB, caspase inhibitors do not protect CGNs from targeted inhibition of Rac. Also dissimilar to ToxB, selective inhibition of Rac does not inhibit MEK1/2/ERK1/2 or activate JNK/c-Jun. Instead, targeted inhibition of Rac suppresses distinct MEK5/ERK5, p90Rsk, and Akt-dependent signaling cascades known to regulate the localization and expression of the Bcl-2 homology 3 domain-only protein Bad. Adenoviral expression of a constitutively active mutant of MEK5 is sufficient to attenuate neuronal cell death induced by selective inhibition of Rac with NSC23766 but not apoptosis induced by global inhibition of Rho GTPases with ToxB. Collectively, these data demonstrate that global suppression of Rho family GTPases with ToxB causes a loss of MEK1/2/ERK1/2 signaling and activation of JNK/c-Jun, resulting in diminished degradation and enhanced transcription of the Bcl-2 homology 3 domain-only protein Bim. In contrast, selective inhibition of Rac induces CGN apoptosis by repressing unique MEK5/ERK5, p90Rsk, and Akt-dependent prosurvival pathways, ultimately leading to enhanced expression, dephosphorylation, and mitochondrial localization of proapoptotic Bad.

  1. Neuronal Apoptosis Induced by Selective Inhibition of Rac GTPase versus Global Suppression of Rho Family GTPases Is Mediated by Alterations in Distinct Mitogen-activated Protein Kinase Signaling Cascades*

    PubMed Central

    Stankiewicz, Trisha R.; Ramaswami, Sai Anandi; Bouchard, Ron J.; Aktories, Klaus; Linseman, Daniel A.

    2015-01-01

    Rho family GTPases play integral roles in neuronal differentiation and survival. We have shown previously that Clostridium difficile toxin B (ToxB), an inhibitor of RhoA, Rac1, and Cdc42, induces apoptosis of cerebellar granule neurons (CGNs). In this study, we compared the effects of ToxB to a selective inhibitor of the Rac-specific guanine nucleotide exchange factors Tiam1 and Trio (NSC23766). In a manner similar to ToxB, selective inhibition of Rac induces CGN apoptosis associated with enhanced caspase-3 activation and reduced phosphorylation of the Rac effector p21-activated kinase. In contrast to ToxB, caspase inhibitors do not protect CGNs from targeted inhibition of Rac. Also dissimilar to ToxB, selective inhibition of Rac does not inhibit MEK1/2/ERK1/2 or activate JNK/c-Jun. Instead, targeted inhibition of Rac suppresses distinct MEK5/ERK5, p90Rsk, and Akt-dependent signaling cascades known to regulate the localization and expression of the Bcl-2 homology 3 domain-only protein Bad. Adenoviral expression of a constitutively active mutant of MEK5 is sufficient to attenuate neuronal cell death induced by selective inhibition of Rac with NSC23766 but not apoptosis induced by global inhibition of Rho GTPases with ToxB. Collectively, these data demonstrate that global suppression of Rho family GTPases with ToxB causes a loss of MEK1/2/ERK1/2 signaling and activation of JNK/c-Jun, resulting in diminished degradation and enhanced transcription of the Bcl-2 homology 3 domain-only protein Bim. In contrast, selective inhibition of Rac induces CGN apoptosis by repressing unique MEK5/ERK5, p90Rsk, and Akt-dependent prosurvival pathways, ultimately leading to enhanced expression, dephosphorylation, and mitochondrial localization of proapoptotic Bad. PMID:25666619

  2. Targeting of androgen receptor in bone reveals a lack of androgen anabolic action and inhibition of osteogenesis: a model for compartment-specific androgen action in the skeleton.

    PubMed

    Wiren, Kristine M; Semirale, Anthony A; Zhang, Xiao-Wei; Woo, Adrian; Tommasini, Steven M; Price, Christopher; Schaffler, Mitchell B; Jepsen, Karl J

    2008-09-01

    Androgens are anabolic hormones that affect many tissues, including bone. However, an anabolic effect of androgen treatment on bone in eugonadal subjects has not been observed and clinical trials have been disappointing. The androgen receptor (AR) mediates biological responses to androgens. In bone tissue, both AR and the estrogen receptor (ER) are expressed. Since androgens can be converted into estrogen, the specific role of the AR in maintenance of skeletal homoeostasis remains controversial. The goal of this study was to use skeletally targeted overexpression of AR in differentiated osteoblasts as a means of elucidating the specific role(s) for AR transactivation in the mature bone compartment. Transgenic mice overexpressing AR under the control of the 2.3-kb alpha1(I)-collagen promoter fragment showed no difference in body composition, testosterone, or 17ss-estradiol levels. However, transgenic males have reduced serum osteocalcin, CTx and TRAPC5b levels, and a bone phenotype was observed. In cortical bone, high-resolution micro-computed tomography revealed no difference in periosteal perimeter but a significant reduction in cortical bone area due to an enlarged marrow cavity. Endocortical bone formation rate was also significantly inhibited. Biomechanical analyses showed decreased whole bone strength and quality, with significant reductions in all parameters tested. Trabecular morphology was altered, with increased bone volume comprised of more trabeculae that were closer together but not thicker. Expression of genes involved in bone formation and bone resorption was significantly reduced. The consequences of androgen action are compartment-specific; anabolic effects are exhibited exclusively at periosteal surfaces, but in mature osteoblasts androgens inhibited osteogenesis with detrimental effects on matrix quality, bone fragility and whole bone strength. Thus, the present data demonstrate that enhanced androgen signaling targeted to bone results in low bone

  3. [Specific toxicological considerations on anabolic agents; transmitted toxicity].

    PubMed

    Ferrando, R; Truhaut, R

    1976-01-01

    The growth of populations and the spread of urbanization, resulting in new agricultural structures, have entailed a concentration of livestock production and recourse to new techniques. Of some importance among these techniques is the enteric or parenteral administration of substances in very low doses. These substances include anabolic agents, some of which, like many natural feeds, exhibit hormonal activity. They may be divided into two classes: --those of the DES type, synthetic compounds non-existent in the natural state, --natural agents, which are normally distributed throughout the animal and human organism, and hence in food of animal origin---milk, meat, eggs. The compounds belonging to the second class may also be synthesized and the main toxicological consideration is that they then have to meet clear-cut standards of identity and purity. A compound belonging to the first class, diethylstilbestrol (DES), administered to rats in doses as small as 60 mug/kg of feed or even smaller, causes in general lower growth rates as well as alterations in the genital system and reproductive functions. In long-term experiments (12 months) using rats and mice and applying so-called toxicity "de relais" tests, developed and described by the authors, it also appeared that meat from calves in which DES pellets were implanted under normal rearing conditions, inhibits growth and reproduction in mice and rats fed a diet containing 20% of this meat. Studies in which the livers from treated calves constituted 6% of the diet of these two rodent species also led to the conclusion that fertility was impaired in the second reproduction test. The authors also recall cases of vaginal cancer observed in young girls whose mothers had been treated with DES during pregnancy. Compounds belonging to the second class (estradiol-progesterone and estradiol-testosterone) gave no evidence of harmful effects upon rats when mixed with their rations during short and medium-term trials. Similar

  4. A Lys49 Phospholipase A2, Isolated from Bothrops asper Snake Venom, Induces Lipid Droplet Formation in Macrophages Which Depends on Distinct Signaling Pathways and the C-Terminal Region

    PubMed Central

    Cristina Giannotti, Karina; Leiguez, Elbio; Moreira, Vanessa; Nascimento, Neide Galvão; Lomonte, Bruno; Gutiérrez, José Maria; Lopes de Melo, Robson; Teixeira, Catarina

    2013-01-01

    MT-II, a Lys49PLA2 homologue devoid of catalytic activity from B. asper venom, stimulates inflammatory events in macrophages. We investigated the ability of MT-II to induce formation of lipid droplets (LDs), key elements of inflammatory responses, in isolated macrophages and participation of protein kinases and intracellular PLA2s in this effect. Influence of MT-II on PLIN2 recruitment and expression was assessed, and the effects of some synthetic peptides on LD formation were further evaluated. At noncytotoxic concentrations, MT-II directly activated macrophages to form LDs. This effect was reproduced by a synthetic peptide corresponding to the C-terminal sequence 115–129 of MT-II, evidencing the critical role of C-terminus for MT-II-induced effect. Moreover, MT-II induced expression and recruitment of PLIN2. Pharmacological interventions with specific inhibitors showed that PKC, PI3K, ERK1/2, and iPLA2, but not P38MAPK or cPLA2, signaling pathways are involved in LD formation induced by MT-II. This sPLA2 homologue also induced synthesis of PGE2 that colocalized to LDs. In conclusion, MT-II is able to induce formation of LDs committed to PGE2 formation in a process dependent on C-terminal loop engagement and regulated by distinct protein kinases and iPLA2. LDs may constitute an important inflammatory mechanism triggered by MT-II in macrophages. PMID:23509782

  5. The anabolic activity of bone tissue, suppressed by disuse, is normalized by brief exposure to extremely low-magnitude mechanical stimuli

    NASA Technical Reports Server (NTRS)

    Rubin, C.; Xu, G.; Judex, S.

    2001-01-01

    It is generally believed that mechanical signals must be large in order to be anabolic to bone tissue. Recent evidence indicates, however, that extremely low-magnitude (<10 microstrain) mechanical signals readily stimulate bone formation if induced at a high frequency. We examined the ability of extremely low-magnitude, high-frequency mechanical signals to restore anabolic bone cell activity inhibited by disuse. Adult female rats were randomly assigned to six groups: baseline control, age-matched control, mechanically stimulated for 10 min/day, disuse (hind limb suspension), disuse interrupted by 10 min/day of weight bearing, and disuse interrupted by 10 min/day of mechanical stimulation. After a 28 day protocol, bone formation rates (BFR) in the proximal tibia of mechanically stimulated rats increased compared with age-matched control (+97%). Disuse alone reduced BFR (-92%), a suppression only slightly curbed when disuse was interrupted by 10 min of weight bearing (-61%). In contrast, disuse interrupted by 10 min per day of low-level mechanical intervention normalized BFR to values seen in age-matched controls. This work indicates that this noninvasive, extremely low-level stimulus may provide an effective biomechanical intervention for the bone loss that plagues long-term space flight, bed rest, or immobilization caused by paralysis.

  6. Associations between academic performance of division 1 college athletes and their perceptions of the effects of anabolic steroids.

    PubMed

    Perko, M A; Cowdery, J; Wang, M Q; Yesalis, C S

    1995-02-01

    Data on the relationship between academic performance (grade point average) of college athletes and their perceptions of the effects of anabolic steroids on their sport and their performance were collected from Division 1 athletes (N = 1,638) representing 12 varsity sports chosen from five universities nationwide. The response rate was 74%. Analysis yielded differences between athletes with high and low GPAs in perceptions of the effects of anabolic steroids. The lower the GPA, the less likely the athletes were to believe that anabolic steroids are a threat to health, are a problem in their sport, and are addictive. Also, they were more likely to believe that anabolic steroids enhance performance.

  7. Anabolic function of phenylalanine hydroxylase in Caenorhabditis elegans.

    PubMed

    Calvo, Ana C; Pey, Angel L; Ying, Ming; Loer, Curtis M; Martinez, Aurora

    2008-08-01

    In humans, liver phenylalanine hydroxylase (PAH) has an established catabolic function, and mutations in PAH cause phenylketonuria, a genetic disease characterized by neurological damage, if not treated. To obtain novel evolutionary insights and information on molecular mechanisms operating in phenylketonuria, we investigated PAH in the nematode Caenorhabditis elegans (cePAH), where the enzyme is coded by the pah-1 gene, expressed in the hypodermis. CePAH presents similar molecular and kinetic properties to human PAH [S(0.5)(L-Phe) approximately 150 microM; K(m) for tetrahydrobiopterin (BH(4)) approximately 35 microM and comparable V(max)], but cePAH is devoid of positive cooperativity for L-Phe, an important regulatory mechanism of mammalian PAH that protects the nervous system from excess L-Phe. Pah-1 knockout worms show no obvious neurological defects, but in combination with a second cuticle synthesis mutation, they display serious cuticle abnormalities. We found that pah-1 knockouts lack a yellow-orange pigment in the cuticle, identified as melanin by spectroscopic techniques, and which is detected in C. elegans for the first time. Pah-1 mutants show stimulation of superoxide dismutase activity, suggesting that cuticle melanin functions as oxygen radical scavenger. Our results uncover both an important anabolic function of PAH and the change in regulation of the enzyme along evolution. PMID:18460651

  8. Sudden or unnatural deaths involving anabolic-androgenic steroids.

    PubMed

    Darke, Shane; Torok, Michelle; Duflou, Johan

    2014-07-01

    Anabolic-androgenic steroids (AASs) are frequently misused. To determine causes of death, characteristics, toxicology, and pathology of AAS positive cases, all cases (n = 24) presenting to the New South Wales Department of Forensic Medicine (1995-2012) were retrieved. All were male, and the mean age was 31.7 years. Deaths were mainly due to accidental drug toxicity (62.5%), then suicide (16.7%) and homicide (12.5%). Abnormal testosterone/epitestosterone ratios were reported in 62.5%, followed by metabolites of nandrolone (58.3%), stanozolol (33.3%), and methandienone (20.8%). In 23 of 24 cases, substances other than steroids were detected, most commonly psychostimulants (66.7%). In nearly half, testicular atrophy was noted, as was testicular fibrosis and arrested spermatogenesis. Left ventricular hypertrophy was noted in 30.4%, and moderate to severe narrowing of the coronary arteries in 26.1%. To summarize, the typical case was a male polydrug user aged in their thirties, with death due to drug toxicity. Extensive cardiovascular disease was particularly notable. PMID:24611438

  9. Personality profile of men using anabolic androgenic steroids.

    PubMed

    Galligani, N; Renck, A; Hansen, S

    1996-06-01

    The present study assessed personality traits in three groups of strength athletes, who self-administered anabolic androgenic steroids (AAS) at the time of testing, had stopped using AAS since at least 6 months, or had never used AAS. The subjects (n = 14/group) completed the Karolinska Scales of Personality, an inventory consisting of 15 subscales measuring traits related to anxiety proneness, extraversion, and aggression-hostility. Current AAS users differed significantly from the other two groups with respect to Verbal aggression. In comparison to subjects with no ongoing AAS exposure (i.e., previous AAS users and drug-free controls), AAS users were also significantly different with respect to Muscular tension, Social desirability, Impulsiveness, and Indirect aggression. On several subscales, the scores of the AAS users were clearly outside the normal range observed in general population. The present results confirm earlier studies that AAS use is associated with enhanced aggressiveness. Our study also suggests that self-administration of AAS might pave the way for disinhibitory psychopathology by amplifying extraversion-related risk factors.

  10. Risk factors for anabolic-androgenic steroid use in men.

    PubMed

    Brower, K J; Blow, F C; Hill, E M

    1994-01-01

    The illicit use of anabolic steroids to enhance athletic performance and physical appearance can cause numerous psychiatric and other adverse effects. In order to prevent steroid use and its negative consequences, knowledge of risk factors is needed. We conducted an anonymous survey of 404 male weight lifters from community gymnasiums who completed a 20-min, self-administered questionnaire. The sample for this study included all 35 men who were thinking about using steroids ("high-risk" nonusers), 50 randomly selected nonusers who were not thinking about using steroids ("low-risk" nonusers) and all 49 steroid users. The three groups differed in age, training characteristics, other performance-enhancers tried, body image, acquaintance with steroid users, and perception of negative consequences. When groups were compared along a continuum from low risk to high risk and from high risk to actual use, we found increasing amounts of competitive bodybuilding, performance-enhancers tried, and steroid-using acquaintances. Groups did not differ in their use of addictive substances. Nearly three-fourths of the high-risk group felt "not big enough," compared to 21% of the low-risk group and 38% of the steroid users (p < .001). These data suggest that steroids do work to increase satisfaction with body size, and that dissatisfaction with body size may contribute to the risk of using steroids.

  11. Biochemistry and physiology of anabolic androgenic steroids doping.

    PubMed

    Lippi, G; Franchini, M; Banfi, G

    2011-05-01

    Anabolic Androgenic Steroids (AASs) are chemical and pharmacological derivatives of the male hormone testosterone which are widely used for increasing burst and sprinting activities in sports. Although AASs are thought to be transversal to the plurality of sports disciplines, they are principally misused by bodybuilders, weightlifters, shot, hammer, discus or javelin throwers, rugby and American football players as well as by swimmers and runners. AAS exert a kaleidoscope of effects on human biology, principally through the 5-α-reductase-mediated conversion into dihydrotestosterone, the aromatase-mediated conversion into female sex hormones, a competitive antagonism to the glucocorticoid receptors, the potential stimulation of erythropoietin secretion as well as psychoactive effects on the brain. The influence of AASs on physical performance is still undefined, since the large number of studies published so far have described discordant and often contradictory outcomes. Nevertheless, animal and human investigations support the hypothesis that the administration of AASs might increase lean body mass, muscle mass, and maximal voluntary strength especially in men, so that they would represent an appealing form of doping for increasing power capacity, sustaining intensive training periods and, last but not least, as a cosmetic muscle makeover. The aim of this article is to review the biochemistry, physiology and the ergogenic effects of AASs.

  12. Synthetic anabolic agents: steroids and nonsteroidal selective androgen receptor modulators.

    PubMed

    Thevis, Mario; Schänzer, Wilhelm

    2010-01-01

    The central role of testosterone in the development of male characteristics, as well as its beneficial effects on physical performance and muscle growth, has led to the search for synthetic alternatives with improved pharmacological profiles. Hundreds of steroidal analogs have been prepared with a superior oral bioavailability, which should also possess reduced undesirable effects. However, only a few entered the pharmaceutical market due to severe toxicological incidences that were mainly attributed to the lack of tissue selectivity. Prominent representatives of anabolic-androgenic steroids (AAS) are for instance methyltestosterone, metandienone and stanozolol, which are discussed as model compounds with regard to general pharmacological aspects of synthetic AAS. Recently, nonsteroidal alternatives to AAS have been developed that selectively activate the androgen receptor in either muscle tissue or bones. These so-called selective androgen receptor modulators (SARMs) are currently undergoing late clinical trials (IIb) and will be prohibited by the World Anti-Doping Agency from January 2008. Their entirely synthetic structures are barely related to steroids, but particular functional groups allow for the tissue-selective activation or inhibition of androgen receptors and, thus, the stimulation of muscle growth without the risk of severe undesirable effects commonly observed in steroid replacement therapies. Hence, these compounds possess a high potential for misuse in sports and will be the subject of future doping control assays.

  13. Sudden or unnatural deaths involving anabolic-androgenic steroids.

    PubMed

    Darke, Shane; Torok, Michelle; Duflou, Johan

    2014-07-01

    Anabolic-androgenic steroids (AASs) are frequently misused. To determine causes of death, characteristics, toxicology, and pathology of AAS positive cases, all cases (n = 24) presenting to the New South Wales Department of Forensic Medicine (1995-2012) were retrieved. All were male, and the mean age was 31.7 years. Deaths were mainly due to accidental drug toxicity (62.5%), then suicide (16.7%) and homicide (12.5%). Abnormal testosterone/epitestosterone ratios were reported in 62.5%, followed by metabolites of nandrolone (58.3%), stanozolol (33.3%), and methandienone (20.8%). In 23 of 24 cases, substances other than steroids were detected, most commonly psychostimulants (66.7%). In nearly half, testicular atrophy was noted, as was testicular fibrosis and arrested spermatogenesis. Left ventricular hypertrophy was noted in 30.4%, and moderate to severe narrowing of the coronary arteries in 26.1%. To summarize, the typical case was a male polydrug user aged in their thirties, with death due to drug toxicity. Extensive cardiovascular disease was particularly notable.

  14. [Doping--anabolic steroid abuse--careless homicide].

    PubMed

    Schneider, V; Klug, E

    1996-06-01

    Proceeding from a case requiring an expert's opinion (competitive athlete from the GDR), the question of damage to the health after the abuse of anabolic preparations is being discussed once again. In this connection, however, it is not only necessary to look at the cases that have come to light in the competitive sports sector (doping) but also at cases involving the body-building movement. Damages to the liver, in particular liver tumors, are described, among others. But vascular diseases are also described. Auto-aggression and aggression toward others can, however, also entail a forensic/psychiatric report, and, finally, the forensic-medicine expert can be challenged when manipulations of the urine specimens to be examined are involved (DNA analyses). From the legal point of view, doping cases will constantly pose the question of whether the athletes concerned knew what they were being "treated" with. Quite apart from forensic questions, however, it will also be necessary to discuss the overall complex from the point of view of medical ethics. Every time a case becomes known, damage is done once again to the idea that sports are supposed to bring nations together and promote peace.

  15. Violence toward women and illicit androgenic-anabolic steroid use.

    PubMed

    Choi, P Y; Pope, H G

    1994-03-01

    Substantial evidence now suggests that increased aggression is associated with illicit use of anabolic-androgenic steroids (AAS) by athletes. Anecdotal reports claim that wives and girlfriends of the athlete sometimes become victims of physical abuse when their significant other is using these drugs. We sought to investigate these claims empirically. Twenty-three AAS user strength athletes and 14 nonuser athletes, recruited in the course of a larger study, were interviewed using the Dyadic Adjustment Scale and the Conflict Tactics Scales to assess their relationships with their significant other. AAS users were asked about their relationship during their most recent "cycle" of AAS use and their most recent AAS-free period. Nonusers were asked about their relationship in the last 3 months. AAS users reported significantly more fights, verbal aggression, and violence toward their significant others when using AAS than when not using AAS. The AAS users on-drug differed significantly from nonusers on two of these indices, but AAS users off-drug did not significantly differ from nonusers. These findings support the anecdotal evidence that wives and girlfriends of AAS users may be at risk of serious injury from users while they are on-drug. Thus, AAS use may impose risks not only to the user, but also to the women close to them.

  16. Intake of low-dose leucine-rich essential amino acids stimulates muscle anabolism equivalently to bolus whey protein in older women at rest and after exercise.

    PubMed

    Bukhari, Syed S I; Phillips, Bethan E; Wilkinson, Daniel J; Limb, Marie C; Rankin, Debbie; Mitchell, William K; Kobayashi, Hisamine; Greenhaff, Paul L; Smith, Kenneth; Atherton, Philip J

    2015-06-15

    Dysregulated anabolic responses to nutrition/exercise may contribute to sarcopenia; however, these characteristics are poorly defined in female populations. We determined the effects of two feeding regimes in older women (66 ± 2.5 yr; n = 8/group): bolus whey protein (WP-20 g) or novel low-dose leucine-enriched essential amino acids (EAA) [LEAA; 3 g (40% leucine)]. Using [(13)C6]phenylalanine infusions, we quantified muscle (MPS) and albumin (APS) protein synthesis at baseline and in response to both feeding (FED) and feeding plus exercise (FED-EX; 6 × 8 knee extensions at 75% 1-repetition maximum). We also quantified plasma insulin/AA concentrations, whole leg (LBF)/muscle microvascular blood flow (MBF), and muscle anabolic signaling by phosphoimmunoblotting. Plasma insulinemia and EAA/aemia were markedly greater after WP than LEAA (P < 0.001). Neither LEAA nor WP modified LBF in response to FED or FED-EX, whereas MBF increased to a similar extent in both groups only after FED-EX (P < 0.05). In response to FED, both WP and LEAA equally stimulated MPS 0-2 h (P < 0.05), abating thereafter (0-4 h, P > 0.05). In contrast, after FED-EX, MPS increased at 0-2 h and remained elevated at 0-4 h (P < 0.05) with both WP and LEAA. No anabolic signals quantifiably increased after FED, but p70 S6K1 Thr(389) increased after FED-EX (2 h, P < 0.05). APS increased similarly after WP and LEAA. Older women remain subtly responsive to nutrition ± exercise. Intriguingly though, bolus WP offers no trophic advantage over LEAA. PMID:25827594

  17. Loss of Gsα in the Postnatal Skeleton Leads to Low Bone Mass and a Blunted Response to Anabolic Parathyroid Hormone Therapy.

    PubMed

    Sinha, Partha; Aarnisalo, Piia; Chubb, Rhiannon; Poulton, Ingrid J; Guo, Jun; Nachtrab, Gregory; Kimura, Takaharu; Swami, Srilatha; Saeed, Hamid; Chen, Min; Weinstein, Lee S; Schipani, Ernestina; Sims, Natalie A; Kronenberg, Henry M; Wu, Joy Y

    2016-01-22

    Parathyroid hormone (PTH) is an important regulator of osteoblast function and is the only anabolic therapy currently approved for treatment of osteoporosis. The PTH receptor (PTH1R) is a G protein-coupled receptor that signals via multiple G proteins including Gsα. Mice expressing a constitutively active mutant PTH1R exhibited a dramatic increase in trabecular bone that was dependent upon expression of Gsα in the osteoblast lineage. Postnatal removal of Gsα in the osteoblast lineage (P-Gsα(OsxKO) mice) yielded markedly reduced trabecular and cortical bone mass. Treatment with anabolic PTH(1-34) (80 μg/kg/day) for 4 weeks failed to increase trabecular bone volume or cortical thickness in male and female P-Gsα(OsxKO) mice. Surprisingly, in both male and female mice, PTH administration significantly increased osteoblast numbers and bone formation rate in both control and P-Gsα(OsxKO) mice. In mice that express a mutated PTH1R that activates adenylyl cyclase and protein kinase A (PKA) via Gsα but not phospholipase C via Gq/11 (D/D mice), PTH significantly enhanced bone formation, indicating that phospholipase C activation is not required for increased bone turnover in response to PTH. Therefore, although the anabolic effect of intermittent PTH treatment on trabecular bone volume is blunted by deletion of Gsα in osteoblasts, PTH can stimulate osteoblast differentiation and bone formation. Together these findings suggest that alternative signaling pathways beyond Gsα and Gq/11 act downstream of PTH on osteoblast differentiation.

  18. Intake of low-dose leucine-rich essential amino acids stimulates muscle anabolism equivalently to bolus whey protein in older women at rest and after exercise.

    PubMed

    Bukhari, Syed S I; Phillips, Bethan E; Wilkinson, Daniel J; Limb, Marie C; Rankin, Debbie; Mitchell, William K; Kobayashi, Hisamine; Greenhaff, Paul L; Smith, Kenneth; Atherton, Philip J

    2015-06-15

    Dysregulated anabolic responses to nutrition/exercise may contribute to sarcopenia; however, these characteristics are poorly defined in female populations. We determined the effects of two feeding regimes in older women (66 ± 2.5 yr; n = 8/group): bolus whey protein (WP-20 g) or novel low-dose leucine-enriched essential amino acids (EAA) [LEAA; 3 g (40% leucine)]. Using [(13)C6]phenylalanine infusions, we quantified muscle (MPS) and albumin (APS) protein synthesis at baseline and in response to both feeding (FED) and feeding plus exercise (FED-EX; 6 × 8 knee extensions at 75% 1-repetition maximum). We also quantified plasma insulin/AA concentrations, whole leg (LBF)/muscle microvascular blood flow (MBF), and muscle anabolic signaling by phosphoimmunoblotting. Plasma insulinemia and EAA/aemia were markedly greater after WP than LEAA (P < 0.001). Neither LEAA nor WP modified LBF in response to FED or FED-EX, whereas MBF increased to a similar extent in both groups only after FED-EX (P < 0.05). In response to FED, both WP and LEAA equally stimulated MPS 0-2 h (P < 0.05), abating thereafter (0-4 h, P > 0.05). In contrast, after FED-EX, MPS increased at 0-2 h and remained elevated at 0-4 h (P < 0.05) with both WP and LEAA. No anabolic signals quantifiably increased after FED, but p70 S6K1 Thr(389) increased after FED-EX (2 h, P < 0.05). APS increased similarly after WP and LEAA. Older women remain subtly responsive to nutrition ± exercise. Intriguingly though, bolus WP offers no trophic advantage over LEAA.

  19. Anabolic-Androgenic Steroid Use Among California Community College Student-Athletes

    PubMed Central

    Kersey, Robert D.

    1996-01-01

    Objective: To determine the incidence of anabolic- androgenic steroid use among a sample of community college student-athletes; also, to compare various aspects of users and nonusers, as well as to describe usage patterns. Design and Setting: A survey following random stratified cluster sampling techniques was administered to 10 California community colleges. Subjects: A group of 1,185 male and female student- athletes. Measurements: An anonymous 27-item, valid, and reliable questionnaire was administered surveying anabolic-androgenic steroid use and usage patterns. Results: Of all student-athletes sampled, 3.3% were anabolic -androgenic steroid users. Gender-specific incidence rates were 4.2% for males and 1.2% for females. Anabolic- androgenic steroid users tended to be older males, usually in their second year of college. The users were more often minorities. Users believed that they were knowledgeable about anabolic-androgenic steroids, and that the rates of usage were higher than reported. Their sources of steroid information were often lifting partners and fellow athletes. Use of these drugs was most often in cycles (mean of 6.7 weeks) and was frequently done using multiple anabolic-androgenic steroids at a time. The average number of cycles completed was 2.9. A wide variety of steroids were used by the student-athletes, of which most were obtained from illegal sources. Conclusions: Anabolic-androgenic steroid use among Califonia community college student-athletes were similar to other previous research studies involving high school and university student-athletes. PMID:16558405

  20. Self-Perceived Weight and Anabolic Steroid Misuse Among US Adolescent Boys

    PubMed Central

    Jampel, Jonathan D.; Murray, Stuart B.; Griffiths, Scott; Blashill, Aaron J.

    2016-01-01

    Purpose Anabolic steroid misuse is a growing concern among adolescent boys, and chronic misuse is associated with multisystemic health consequences. However, little is known about weight related predictors of anabolic steroid misuse. We examined the prediction of lifetime anabolic steroid misuse as a function of self-perceived weight status among US adolescent boys. Methods Analysis was undertaken using the 2013 Youth Risk Behavior Survey, a nationally representative data set sampling public and private high school students throughout the United States. Data from a total of 6,000 US adolescent boys were used in the present study. Results The prevalence of ever misusing anabolic androgenic steroids was 12.6% among boys who viewed themselves as very underweight, 11.9% for boys who viewed themselves as very overweight, compared with 3.8% for boys who viewed themselves as about the right weight. Compared to boys who viewed themselves as about the right weight, boys who self-perceived themselves as very underweight (adjusted odds ratio = 6.9, 95% confidence interval: 2.7–17.7, p < .001) and very overweight (adjusted odds ratio = 3.8, 95% confidence interval: 1.8–7.7, p < .001) were significantly associated with increased risk of anabolic androgenic steroid misuse. Conclusions Large effect size estimates were revealed, suggesting that anabolic androgenic steroid misuse is not solely a function of boys desiring increased mass; boys who desire leanness are also likely to misuse anabolic androgenic steroids. Future prevention efforts should target not only boys who view themselves as underweight but also those who perceive themselves as overweight. PMID:26598061

  1. Genetic and environmental modulation of neurotrophic and anabolic stress response: Counterbalancing forces.

    PubMed

    Taylor, Marcus K; Carpenter, Jennifer; Stone, Michael; Hernandez, Lisa M; Rauh, Mitchell J; Laurent, Heidemarie K; Granger, Douglas A

    2015-11-01

    The serotonin transporter genetic variant 5HTTLPR influences activation and feedback control of the hypothalamic-pituitary-adrenal axis, and has been shown to influence the effect of stressful life events on behavioral health. We recently reported that 5HTTLPR modulates cortisol response in healthy military men exposed to intense stress. Less is known of its combined effects with environmental factors in this context, or of its effect on neuroprotective stress responses. In this follow-up study, we examined the unique and combined effects of 5HTTLPR and prior trauma exposure on neuroprotective (salivary nerve growth factor [sNGF]), anabolic (dehydroepiandrosterone sulfate [DHEAS] and testosterone), and catabolic (cortisol) stress responses. Ninety-three healthy, active-duty military men were studied before, during, and 24h after a stressful 12-day survival course. Distinct and interactive effects of 5HTTLPR long allele carriage [L] versus homozygous short allele carriage [SS]) and prior trauma exposure (low versus high) were evaluated, after which a priori group comparisons were performed between hypothesized high resilience (L/low) and low resilience (SS/high) groups. For sNGF, L/low produced the greatest sNGF throughout stress exposure while SS/high demonstrated the smallest; L/high and SS/low bisected these two extremes and were nearly identical to each other (i.e., SS/high < SS/low = L/high < L/low). Thus, 5HTTLPR and prior trauma exposure demonstrated counterbalancing (additive) forces. Similar patterns were found for DHEAS. To our knowledge, this study is the first to report counterbalancing genetic and environmental effects on novel biomarkers related to resilience in humans exposed to real-world stress. These findings have profound implications for health, performance and training in high-stress occupational settings.

  2. Genetic and environmental modulation of neurotrophic and anabolic stress response: Counterbalancing forces.

    PubMed

    Taylor, Marcus K; Carpenter, Jennifer; Stone, Michael; Hernandez, Lisa M; Rauh, Mitchell J; Laurent, Heidemarie K; Granger, Douglas A

    2015-11-01

    The serotonin transporter genetic variant 5HTTLPR influences activation and feedback control of the hypothalamic-pituitary-adrenal axis, and has been shown to influence the effect of stressful life events on behavioral health. We recently reported that 5HTTLPR modulates cortisol response in healthy military men exposed to intense stress. Less is known of its combined effects with environmental factors in this context, or of its effect on neuroprotective stress responses. In this follow-up study, we examined the unique and combined effects of 5HTTLPR and prior trauma exposure on neuroprotective (salivary nerve growth factor [sNGF]), anabolic (dehydroepiandrosterone sulfate [DHEAS] and testosterone), and catabolic (cortisol) stress responses. Ninety-three healthy, active-duty military men were studied before, during, and 24h after a stressful 12-day survival course. Distinct and interactive effects of 5HTTLPR long allele carriage [L] versus homozygous short allele carriage [SS]) and prior trauma exposure (low versus high) were evaluated, after which a priori group comparisons were performed between hypothesized high resilience (L/low) and low resilience (SS/high) groups. For sNGF, L/low produced the greatest sNGF throughout stress exposure while SS/high demonstrated the smallest; L/high and SS/low bisected these two extremes and were nearly identical to each other (i.e., SS/high < SS/low = L/high < L/low). Thus, 5HTTLPR and prior trauma exposure demonstrated counterbalancing (additive) forces. Similar patterns were found for DHEAS. To our knowledge, this study is the first to report counterbalancing genetic and environmental effects on novel biomarkers related to resilience in humans exposed to real-world stress. These findings have profound implications for health, performance and training in high-stress occupational settings. PMID:26136163

  3. FoxC2 Enhances BMP7-Mediated Anabolism in Nucleus Pulposus Cells of the Intervertebral Disc

    PubMed Central

    Wang, Zheng; Fu, Changfeng; Chen, Yong; Xu, Feng; Wang, Zhenyu; Qu, Zhigang; Liu, Yi

    2016-01-01

    Bone-morphogenetic protein-7 (BMP-7) is a growth factor that plays a major role in mediating anabolism and anti-catabolism of the intervertebral disc matrix and cell homeostasis. In osteoblasts, Forkhead box protein C2 (FoxC2) is a downstream target of BMPs and promotes cell proliferation and differentiation. However, the role FoxC2 may play in degenerative human intervertebral disc tissue and the relationship between FoxC2 and BMP-7 in nucleus pulposus (NP) cells remain to be elucidated. This study aims to investigate the presence and signaling mechanisms of FoxC2 in degenerative human intervertebral disc tissue and NP cells. Western blot and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analyses were used to measure FoxC2 expression in the NP tissue and cells. Transfections were carried out to measure the effect of FoxC2 on BMP-7-mediated extracellular matrix upregulation. Adenoviral knock-down of Smad1 was performed to investigate the mechanism of BMP-7-induced FoxC2 expression. In degenerative NP tissue, FoxC2 was markedly upregulated and positively correlated with increased disc degeneration. Induction of NP cell proliferation was confirmed by using cell counting kit-8 assay, immunocytochemistry and real-time qRT-PCR for Ki67. FoxC2 led to decreased noggin expression and increased Smad1/5/8 phosphorylation. During combined treatment with BMP-7, FoxC2 greatly potentiated anabolism through synergistic mechanisms on ECM formation. Combination therapy using BMP-7 and FoxC2 may be beneficial to the treatment of intervertebral disc degeneration. PMID:26824865

  4. Identification of an anabolic selective androgen receptor modulator that actively induces death of androgen-independent prostate cancer cells.

    PubMed

    Schmidt, Azriel; Meissner, Robert S; Gentile, Michael A; Chisamore, Michael J; Opas, Evan E; Scafonas, Angela; Cusick, Tara E; Gambone, Carlo; Pennypacker, Brenda; Hodor, Paul; Perkins, James J; Bai, Chang; Ferraro, Damien; Bettoun, David J; Wilkinson, Hilary A; Alves, Stephen E; Flores, Osvaldo; Ray, William J

    2014-09-01

    Prostate cancer (PCa) initially responds to inhibition of androgen receptor (AR) signaling, but inevitably progresses to hormone ablation-resistant disease. Much effort is focused on optimizing this androgen deprivation strategy by improving hormone depletion and AR antagonism. However we found that bicalutamide, a clinically used antiandrogen, actually resembles a selective AR modulator (SARM), as it partially regulates 24% of endogenously 5α-dihydrotestosterone (DHT)-responsive genes in AR(+) MDA-MB-453 breast cancer cells. These data suggested that passive blocking of all AR functions is not required for PCa therapy. Hence, we adopted an active strategy that calls for the development of novel SARMs, which induce a unique gene expression profile that is intolerable to PCa cells. Therefore, we screened 3000 SARMs for the ability to arrest the androgen-independent growth of AR(+) 22Rv1 and LNCaP PCa cells but not AR(-) PC3 or DU145 cells. We identified only one such compound; the 4-aza-steroid, MK-4541, a potent and selective SARM. MK-4541 induces caspase-3 activity and cell death in both androgen-independent, AR(+) PCa cell lines but spares AR(-) cells or AR(+) non-PCa cells. This activity correlates with its promoter context- and cell-type dependent transcriptional effects. In rats, MK-4541 inhibits the trophic effects of DHT on the prostate, but not the levator ani muscle, and triggers an anabolic response in the periosteal compartment of bone. Therefore, MK-4541 has the potential to effectively manage prostatic hypertrophic diseases owing to its antitumor SARM-like mechanism, while simultaneously maintaining the anabolic benefits of natural androgens. PMID:24565564

  5. FoxC2 Enhances BMP7-Mediated Anabolism in Nucleus Pulposus Cells of the Intervertebral Disc.

    PubMed

    Wang, Zheng; Fu, Changfeng; Chen, Yong; Xu, Feng; Wang, Zhenyu; Qu, Zhigang; Liu, Yi

    2016-01-01

    Bone-morphogenetic protein-7 (BMP-7) is a growth factor that plays a major role in mediating anabolism and anti-catabolism of the intervertebral disc matrix and cell homeostasis. In osteoblasts, Forkhead box protein C2 (FoxC2) is a downstream target of BMPs and promotes cell proliferation and differentiation. However, the role FoxC2 may play in degenerative human intervertebral disc tissue and the relationship between FoxC2 and BMP-7 in nucleus pulposus (NP) cells remain to be elucidated. This study aims to investigate the presence and signaling mechanisms of FoxC2 in degenerative human intervertebral disc tissue and NP cells. Western blot and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analyses were used to measure FoxC2 expression in the NP tissue and cells. Transfections were carried out to measure the effect of FoxC2 on BMP-7-mediated extracellular matrix upregulation. Adenoviral knock-down of Smad1 was performed to investigate the mechanism of BMP-7-induced FoxC2 expression. In degenerative NP tissue, FoxC2 was markedly upregulated and positively correlated with increased disc degeneration. Induction of NP cell proliferation was confirmed by using cell counting kit-8 assay, immunocytochemistry and real-time qRT-PCR for Ki67. FoxC2 led to decreased noggin expression and increased Smad1/5/8 phosphorylation. During combined treatment with BMP-7, FoxC2 greatly potentiated anabolism through synergistic mechanisms on ECM formation. Combination therapy using BMP-7 and FoxC2 may be beneficial to the treatment of intervertebral disc degeneration. PMID:26824865

  6. Role of the alpha subunit in the modulation of GABA(A) receptors by anabolic androgenic steroids.

    PubMed

    Yang, Paul; Jones, Brian L; Henderson, Leslie P

    2005-09-01

    Neural transmission mediated by circuits expressing alpha2 subunit-containing gamma-aminobutyric acid type A (GABA(A)) receptors is critical for the expression of behaviors known to be altered by anabolic androgenic steroids (AAS). Here we show that micromolar concentrations of AAS, which reflect levels found in steroid abusers, induce positive modulation of currents from alpha2beta3 gamma2L recombinant receptors elicited by pulses of GABA that mimic synaptic conditions in a manner that is mechanistically distinct from modulation induced at alpha1beta3 gamma2L receptors. Specifically, at alpha2-containing receptors, the AAS, 17alpha-methyltestosterone (17alpha-MeT) enhanced peak current, slowed deactivation, diminished desensitization, and promoted entry of receptors into more distal states along the activation pathway. Analysis of GABA(A) receptor-mediated synaptic currents in primary cortical neurons followed by single cell real-time RT-PCR demonstrated that 17alpha-MeT enhancement of synaptic currents is proportional to the ratio of alpha2 to alpha1 subunit mRNA. Finally, we show that the modulation elicited by AAS is not comparable to that produced by micromolar concentrations of other positive allosteric modulators at alpha2-containing receptors. In sum, these data indicate that AAS elicit effects on GABA(A) receptor function that depend significantly on alpha subunit composition and that the mechanism of AAS modulation of GABA(A) receptors is distinct from that of other positive allosteric modulators.

  7. Aging related ER stress is not responsible for anabolic resistance in mouse skeletal muscle.

    PubMed

    Chalil, Sreeda; Pierre, Nicolas; Bakker, Astrid D; Manders, Ralph J; Pletsers, Annelies; Francaux, Marc; Klein-Nulend, Jenneke; Jaspers, Richard T; Deldicque, Louise

    2015-12-25

    Anabolic resistance reflects the inability of skeletal muscle to maintain protein mass by appropriate stimulation of protein synthesis. We hypothesized that endoplasmic reticulum (ER) stress contributes to anabolic resistance in skeletal muscle with aging. Muscles were isolated from adult (8 mo) and old (26 mo) mice and weighed. ER stress markers in each muscle were quantified, and the anabolic response to leucine was assessed by measuring the phosphorylation state of S6K1 in soleus and EDL using an ex vivo muscle model. Aging reduced the muscle-to-body weight ratio in soleus, gastrocnemius, and plantaris, but not in EDL and tibialis anterior. Compared to adult mice, the expression of ER stress markers BiP and IRE1α was higher in EDL, and phospho-eIF2α was higher in soleus and EDL of old mice. S6K1 response to leucine was impaired in soleus, but not in EDL, suggesting that anabolic resistance contributes to soleus weight loss in old mice. Pre-incubation with ER stress inducer tunicamycin before leucine stimulation increased S6K1 phosphorylation beyond the level reached by leucine alone. Since tunicamycin did not impair leucine-induced S6K1 response, and based on the different ER stress marker regulation patterns, ER stress is probably not involved in anabolic resistance in skeletal muscle with aging.

  8. Direct determination of anabolic steroids in pig urine by a new SPME-GC-MS method.

    PubMed

    Zhang, Zhuomin; Duan, Hongbin; Zhang, Lan; Chen, Xi; Liu, Wei; Chen, Guonan

    2009-05-15

    A new solid phase microextraction (SPME) method coupled with gas chromatography-mass spectrometry (GC-MS) was developed for rapid determination of four anabolic steroids such as 3alpha-hydroxy-5alpha-androstane-17-one (HA), dihydrotestosterone (DHT), androstenedione (AD) and methyltestosterone (MT) in pig urine. SPME was used to extract the four anabolic compounds directly without derivatization. The optimum SPME sampling conditions were based on the home-made carbowax-divinylbenzene (CW-DVB) fiber coating during extraction at 40 degrees C for 50 min with 0.18 g/mL NaCl solution and 750 rpm stirring speed. The linear ranges of the proposed method were in the range of 8-640 pg/mL for HA and DHT and 16-510 pg/mL for AD and MT, respectively. The detection limits (S/N=3) were from 2 to 8 pg/mL for the four anabolic steroids. This SPME method provided very high enrichment factors for the four anabolic steroids, which were 1063-fold and 965-fold for HA and DHT at the concentration of 8 pg/mL and 207-fold and 451-fold for AD and MT at the concentration of 16 pg/mL, respectively. The recoveries ranged from 71.3 to 121%, and the RSDs were lower than 12.9%. The method was sensitive and reliable for determination of trace anabolic steroids in biological samples.

  9. Serious cardiovascular side effects of large doses of anabolic steroids in weight lifters.

    PubMed

    Nieminen, M S; Rämö, M P; Viitasalo, M; Heikkilä, P; Karjalainen, J; Mäntysaari, M; Heikkilä, J

    1996-10-01

    Pathological cardiovascular manifestations are reported in four male patients, who had taken massive amounts of anabolic steroids while undergoing many years of strength training. One patient was referred because of ventricular fibrillation during exercise, one because of clinically manifest heart failure, and one because of arterial thrombus in his lower left leg. The fourth patient was persuaded to attend for a check-up because of a long history of massive use of anabolic steroids. All four patients had cardiac hypertrophy. Two of the patients had symptoms and signs of heart failure, and one of these two had a massive thrombosis in both right and left ventricles of his heart. After cessation of the use of anabolic steroids in the other patient with heart failure, left ventricular wall thickness reduced quickly from 12 to 10.5 mm, and fractional shortening increased from 14% to 27%. Endomyocardial biopsy revealed increased fibrosis in the myocardium in two of the three cases. HDL-cholesterol was 0.58 mmol.l-1 and 0.35 mmol.l-1 in the two patients still using multiple anabolic steroids at the time of investigation. The cardiovascular findings described in the present paper should warn all physicians and athletes about the possible serious acute and long-term side effects of the massive use of anabolic steroids.

  10. Anabolic Steroid Use: Federal Efforts to Prevent and Reduce Anabolic Steroid Abuse among Teenagers. Report to the Committee on Oversight and Government Reform, House of Representatives. GAO-08-15

    ERIC Educational Resources Information Center

    Government Accountability Office, 2007

    2007-01-01

    The abuse of anabolic steroids by teenagers--that is, their use without a prescription--is a health concern. Anabolic steroids are synthetic forms of the hormone testosterone that can be taken orally, injected, or rubbed on the skin. Although a 2006 survey funded by the National Institute on Drug Abuse (NIDA) found that less than 3 percent of 12th…

  11. Energetics of bacterial growth: balance of anabolic and catabolic reactions.

    PubMed Central

    Russell, J B; Cook, G M

    1995-01-01

    Biomass formation represents one of the most basic aspects of bacterial metabolism. While there is an abundance of information concerning individual reactions that result in cell duplication, there has been surprisingly little information on the bioenergetics of growth. For many years, it was assumed that biomass production (anabolism) was proportional to the amount of ATP which could be derived from energy-yielding pathways (catabolism), but later work showed that the ATP yield (YATP) was not necessarily a constant. Continuous-culture experiments indicated that bacteria utilized ATP for metabolic reactions that were not directly related to growth (maintenance functions). Mathematical derivations showed that maintenance energy appeared to be a growth rate-independent function of the cell mass and time. Later work, however, showed that maintenance energy alone could not account for all the variations in yield. Because only some of the discrepancy could be explained by the secretion of metabolites (overflow metabolism) or the diversion of catabolism to metabolic pathways which produced less ATP, it appeared that energy-excess cultures had mechanisms of spilling energy. Bacteria have the potential to spill excess ATP in futile enzyme cycles, but there has been little proof that such cycles are significant. Recent work indicated that bacteria can also use futile cycles of potassium, ammonia, and protons through the cell membrane to dissipate ATP either directly or indirectly. The utility of energy spilling in bacteria has been a curiosity. The deprivation of energy from potential competitors is at best a teleological explanation that cannot be easily supported by standard theories of natural selection. The priming of intracellular intermediates for future growth or protection of cells from potentially toxic end products (e.g., methylglyoxal) seems a more plausible explanation. PMID:7708012

  12. Molecular and cellular mechanisms of the anabolic effect of intermittent PTH.

    PubMed

    Jilka, Robert L

    2007-06-01

    Intermittent administration of parathyroid hormone (PTH) stimulates bone formation by increasing osteoblast number, but the molecular and cellular mechanisms underlying this effect are not completely understood. In vitro and in vivo studies have shown that PTH directly activates survival signaling in osteoblasts; and that delay of osteoblast apoptosis is a major contributor to the increased osteoblast number, at least in mice. This effect requires Runx2-dependent expression of anti-apoptotic genes like Bcl-2. PTH also causes exit of replicating progenitors from the cell cycle by decreasing expression of cyclin D and increasing expression of several cyclin-dependent kinase inhibitors. Exit from the cell cycle may set the stage for pro-differentiating and pro-survival effects of locally produced growth factors and cytokines, the level and/or activity of which are known to be influenced by PTH. Observations from genetically modified mice suggest that the anabolic effect of intermittent PTH requires insulin-like growth factor-I (IGF-I), fibroblast growth factor-2 (FGF-2), and perhaps Wnts. Attenuation of the negative effects of PPAR gamma may also lead to increased osteoblast number. Daily injections of PTH may add to the pro-differentiating and pro-survival effects of locally produced PTH related protein (PTHrP). As a result, osteoblast number increases beyond that needed to replace the bone removed by osteoclasts during bone remodeling. The pleiotropic effects of intermittent PTH, each of which alone may increase osteoblast number, may explain why this therapy reverses bone loss in most osteoporotic individuals regardless of the underlying pathophysiology.

  13. [Dangers and risks of black market anabolic steroid abuse in sports --gas chromatography-mass spectrometry analyses].

    PubMed

    Ritsch, M; Musshoff, F

    2000-03-01

    Anabolic steroids have become increasingly popular among athletes even at subcompetitive or recreational level instead of extensive doping tests, educational campaigns and lethal incidents. Nowadays, the fitness boom has also produced a population of steroid users at high school level and also under non-sports practicing children. After opening the borders to East Europe an explosion of the black-market for anabolic steroids occurred. Beside the well-known side effects of anabolic steroids new problems and risks occurred due to fake drugs from the black market. This review ist subdivided into two parts: We provide a detailed review of the literature an anabolic steroids to the reader the information needed to make an informed decision an the relative risks and benefits of anabolic steroids. Secondly, we evaluated 40 "anabolic steroids" obtained from the black market using mass spectrometry or gas chromatography analysis to evaluate the real pharmacological compounds. As the results of this analysis, we found that 15 (37.5%) these drugs contained different or any pharmacological compounds as labeled. From the external packing, a differentiation between original and the fake drugs was impossible. Therefore, a large information and credibility gap concerning anabolic steroids particular those from the black market exists between the athletes and the medical and scientific communities. We believe that this gap can only be closed if both groups are be better informed about anabolic steroids.

  14. Anabolic steroid-induced cardiomyopathy underlying acute liver failure in a young bodybuilder

    PubMed Central

    Bispo, Miguel; Valente, Ana; Maldonado, Rosário; Palma, Rui; Glória, Helena; Nóbrega, João; Alexandrino, Paula

    2009-01-01

    Heart failure may lead to subclinical circulatory disturbances and remain an unrecognized cause of ischemic liver injury. We present the case of a previously healthy 40-year-old bodybuilder, referred to our Intensive-Care Unit of Hepatology for treatment of severe acute liver failure, with the suspicion of toxic hepatitis associated with anabolic steroid abuse. Despite the absence of symptoms and signs of congestive heart failure at admission, an anabolic steroid-induced dilated cardiomyopathy with a large thrombus in both ventricles was found to be the underlying cause of the liver injury. Treatment for the initially unrecognized heart failure rapidly restored liver function to normal. To our knowledge, this is the first reported case of severe acute liver failure due to an unrecognized anabolic steroid-induced cardiomyopathy. Awareness of this unique presentation will allow for prompt treatment of this potentially fatal cause of liver failure. PMID:19533818

  15. Clenbuterol and anabolic steroids: a previously unreported cause of myocardial infarction with normal coronary arteriograms.

    PubMed

    Goldstein, D R; Dobbs, T; Krull, B; Plumb, V J

    1998-08-01

    During the last 10 years, several cases of myocardial infarction associated with anabolic steroid use have been reported. Postulated mechanisms to explain this association have included changes in lipid levels, the fibrinolytic system, and platelet aggregation. Clenbuterol is a beta 2-agonist with anabolic properties that has not been seen previously with myocardial infarction. We report a case of myocardial infarction in an otherwise healthy 26-year-old body-builder who recently used clenbuterol and anabolic steroids. In this case, synergistic effects of the two agents seem likely to have played a role in the infarct. The normal coronary arteriograms before any anticoagulant or thrombolytic therapy strongly suggest coronary spasm as the mechanism of the infarct. PMID:9715231

  16. Imitation of phase I oxidative metabolism of anabolic steroids by titanium dioxide photocatalysis.

    PubMed

    Ruokolainen, Miina; Valkonen, Minna; Sikanen, Tiina; Kotiaho, Tapio; Kostiainen, Risto

    2014-12-18

    The aim of this study was to investigate the feasibility of titanium dioxide (TiO2) photocatalysis for oxidation of anabolic steroids and for imitation of their phase I metabolism. The photocatalytic reaction products of five anabolic steroids were compared to their phase I in vitro metabolites produced by human liver microsomes (HLM). The same main reaction types - hydroxylation, dehydrogenation and combination of these two - were observed both in TiO2 photocatalysis and in microsomal incubations. Several isomers of each product type were formed in both systems. Based on the same mass, retention time and similarity of the product ion spectra, many of the products observed in HLM reactions were also formed in TiO2 photocatalytic reactions. However, products characteristic to only either one of the systems were also formed. In conclusion, TiO2 photocatalysis is a rapid, simple and inexpensive method for imitation of phase I metabolism of anabolic steroids and production of metabolite standards.

  17. Examining athletes' attitudes toward using anabolic steroids and their knowledge of the possible effects.

    PubMed

    Anshel, M H; Russell, K G

    1997-01-01

    One goal of contemporary sports leaders is to eradicate the use of banned drugs in competitive sport. A common approach to achieving this outcome is to provide athletes with adequate education about the effects of drug use. Ostensibly, educational programs about the deleterious effects of using anabolic steroids are thought to discourage their intake. Thus, the purpose of this study was to examine the relationships between the athletes' knowledge about the long-term effects of anabolic steroids and their attitudes toward this type of drug. Multiple regression analyses indicated relatively low R2's and correlations between the various components of subjects' knowledge and their attitude toward steroid ingestion. This suggests that educational programs for athletes about taking anabolic steroids may have limited value in terms of creating appropriate, responsible attitudes toward this illegal, unethical, and medically questionable practice.

  18. Effect of testosterone and anabolic steroids on the size of sebaceous glands in power athletes.

    PubMed

    Király, C L; Collan, Y; Alén, M

    1987-12-01

    The effect of testosterone and anabolic steroids on the size of sebaceous glands was studied by means of interactive morphometry in skin biopsies of power athletes. The subjects used self-administered high doses of testosterone and anabolic steroids during a 4-week strength training period. After 4 weeks' use of hormones, the area of sectioned sebaceous glands enlarged significantly by a factor of 89.2% (p less than 0.005). The number of cells in the so-called differentiating cell pool (DCP) and in the undifferentiated cell pool (UCP) also increased significantly (p less than 0.025, p less than 0.05, respectively). The size of the area occupied by UCP cells increased significantly (p less than 0.05). The study suggests that high doses of testosterone and anabolic steroids lead to an enlargement of sebaceous glands in male power athletes.

  19. Wernicke's encephalopathy and anabolic steroid drug abuse. Is there any possible relation?

    PubMed

    Christopoulos, P; Katsanoulas, C; Timplalexi, G; Lathyris, D; Vasiliagkou, S; Antoniadou, E

    2012-10-01

    Wernicke's encephalopathy is a reversible, neurologic disorder due to thiamine deficiency which is mainly related to chronic alcohol abuse. We report a case of a young male patient, who was bodybuilder and anabolic drug user, in whom encephalopathy was diagnosed after a short medical course in the ICU after a major upper gastrointestinal bleeding (Mallory-Weiss syndrome) and hypovolemic shock. His clinical condition was typical for Wernicke's encephalopathy and although neuroimaging tests were not indicative, the patient received thiamine supplement therapy, which resulted in rapid clinical improvement. The diagnosis was based only on clinical sings and anabolic drug abuse was considered as a possible predisposing factor for the manifestation of the syndrome.

  20. The relationship between anabolic androgenic steroids and muscle dysmorphia: a review.

    PubMed

    Rohman, Lebur

    2009-01-01

    This review explores the condition of muscle dysmorphia (MD) and its relationship with anabolic androgenic steroids (AAS). Particular emphasis is placed upon whether anabolic steroids are a predisposing, precipitating or perpetuating factor of MD. Furthermore, psychiatric complications of AAS abuse are examined. The current evidence from the literature suggests that AAS (ab)use is possibly a perpetuating factor in the evolution of MD. Psychiatric complications of AAS include mood and behavior changes, perceptual abnormalities, and withdrawal symptoms. In addition, there appears to be a credible dependence theory to AAS in fruition. PMID:19391018

  1. Cardiac effects of anabolic steroids: hypertrophy, ischemia and electrical remodelling as potential triggers of sudden death.

    PubMed

    Nascimento, J H M; Medei, E

    2011-05-01

    Anabolic-androgenic steroids (AAS) are synthetic testosterone derivatives developed to maximise anabolic activity and minimise androgenic activity. AAS abuse is widespread among both athletes and non-athletes at fitness centres and is becoming a public health issue. In addition to their atherogenic, thrombogenic and spastic effects, AAS have direct cardiotoxic effects by causing hypertrophy, electrical and structural remodelling, and contractile dysfunction and by increasing the susceptibility to ischemic injuries. All of these factors contribute to an increased risk of ventricular arrhythmias and sudden cardiac death.

  2. Invasive fungal sinusitis in a healthy athlete due to long-term anabolic steroid use.

    PubMed

    Kim, Irene A; Thompson, Christopher F; Kedeshian, Paul A; Palma-Diaz, Fernando; Suh, Jeffrey D

    2014-08-01

    Invasive fungal rhinosinusitis is a potentially fatal infection that affects immunocompromised patients. Prognosis is generally poor despite aggressive medical and surgical treatments. We present the first reported case of invasive fungal sinusitis in a healthy 18-year-old male athlete who was taking anabolic androgenic steroids (AAS). The effects of excessive AAS use on the immune system are not fully understood, but there may be consequences at supraphysiological concentrations. This case demonstrates potential immunomodulatory effects of anabolic steroids and highlights a previously unknown cause of invasive fungal sinusitis.

  3. Deregulation of bone forming cells in bone diseases and anabolic effects of strontium-containing agents and biomaterials.

    PubMed

    Tan, Shuang; Zhang, Binbin; Zhu, Xiaomei; Ao, Ping; Guo, Huajie; Yi, Weihong; Zhou, Guang-Qian

    2014-01-01

    Age-related bone loss and osteoporosis are associated with bone remodeling changes that are featured with decreased trabecular and periosteal bone formation relative to bone resorption. Current anticatabolic therapies focusing on the inhibition of bone resorption may not be sufficient in the prevention or reversal of age-related bone deterioration and there is a big need in promoting osteoblastogenesis and bone formation. Enhanced understanding of the network formed by key signaling pathways and molecules regulating bone forming cells in health and diseases has therefore become highly significant. The successful development of agonist/antagonist of the PTH and Wnt signaling pathways are profits of the understanding of these key pathways. As the core component of an approved antiosteoporosis agent, strontium takes its effect on osteoblasts at multilevel through multiple pathways, representing a good example in revealing and exploring anabolic mechanisms. The recognition of strontium effects on bone has led to its expected application in a variety of biomaterial scaffolds used in tissue engineering strategies aiming at bone repairing and regeneration. While summarizing the recent progress in these respects, this review also proposes the new approaches such as systems biology in order to reveal new insights in the pathology of osteoporosis as well as possible discovery of new therapies. PMID:24800251

  4. Deregulation of Bone Forming Cells in Bone Diseases and Anabolic Effects of Strontium-Containing Agents and Biomaterials

    PubMed Central

    Tan, Shuang; Zhang, Binbin; Zhu, Xiaomei; Ao, Ping; Guo, Huajie; Yi, Weihong; Zhou, Guang-Qian

    2014-01-01

    Age-related bone loss and osteoporosis are associated with bone remodeling changes that are featured with decreased trabecular and periosteal bone formation relative to bone resorption. Current anticatabolic therapies focusing on the inhibition of bone resorption may not be sufficient in the prevention or reversal of age-related bone deterioration and there is a big need in promoting osteoblastogenesis and bone formation. Enhanced understanding of the network formed by key signaling pathways and molecules regulating bone forming cells in health and diseases has therefore become highly significant. The successful development of agonist/antagonist of the PTH and Wnt signaling pathways are profits of the understanding of these key pathways. As the core component of an approved antiosteoporosis agent, strontium takes its effect on osteoblasts at multilevel through multiple pathways, representing a good example in revealing and exploring anabolic mechanisms. The recognition of strontium effects on bone has led to its expected application in a variety of biomaterial scaffolds used in tissue engineering strategies aiming at bone repairing and regeneration. While summarizing the recent progress in these respects, this review also proposes the new approaches such as systems biology in order to reveal new insights in the pathology of osteoporosis as well as possible discovery of new therapies. PMID:24800251

  5. Deregulation of bone forming cells in bone diseases and anabolic effects of strontium-containing agents and biomaterials.

    PubMed

    Tan, Shuang; Zhang, Binbin; Zhu, Xiaomei; Ao, Ping; Guo, Huajie; Yi, Weihong; Zhou, Guang-Qian

    2014-01-01

    Age-related bone loss and osteoporosis are associated with bone remodeling changes that are featured with decreased trabecular and periosteal bone formation relative to bone resorption. Current anticatabolic therapies focusing on the inhibition of bone resorption may not be sufficient in the prevention or reversal of age-related bone deterioration and there is a big need in promoting osteoblastogenesis and bone formation. Enhanced understanding of the network formed by key signaling pathways and molecules regulating bone forming cells in health and diseases has therefore become highly significant. The successful development of agonist/antagonist of the PTH and Wnt signaling pathways are profits of the understanding of these key pathways. As the core component of an approved antiosteoporosis agent, strontium takes its effect on osteoblasts at multilevel through multiple pathways, representing a good example in revealing and exploring anabolic mechanisms. The recognition of strontium effects on bone has led to its expected application in a variety of biomaterial scaffolds used in tissue engineering strategies aiming at bone repairing and regeneration. While summarizing the recent progress in these respects, this review also proposes the new approaches such as systems biology in order to reveal new insights in the pathology of osteoporosis as well as possible discovery of new therapies.

  6. A new mixed micellar electrokinetic chromatography method for analysis of natural and synthetic anabolic steroids.

    PubMed

    Zhang, Lan; Chen, Jinfeng; He, Yu; Chi, Yuwu; Chen, Guonan

    2009-01-15

    A simple, rapid and low-costing new mixed surfactant MEKC method has been developed for the analysis of five neutral anabolic steroids in this paper. It was found that the bile salt coupling with Triton X-100 was a suitable bi-micellar surfactant for the separation of these anabolic steroids with similar structure. The separation conditions were optimized in detail. The five natural and synthetic anabolic steroids, such as androstenedione (AD), 19-norandrostenedione (NAD), 1,4-androstadiene-3,17-dione (ADD), methandrostenolone (MA) and methyltestosterone (MT) were separated and detected in an alkaline buffer system (pH 9.0) containing 15 mM Britton-Robinson (BR) buffer, 50mM sodium cholate (SC) and 0.1% (v/v) Triton X-100 with detection wavelength at 241 nm and 18 kV of separation voltage. Under the optimal conditions, five coexistence neutral steroids were completely separated within 12 min with the detection limits ranged from 0.20 to 0.51 microg/mL. This method was successfully used for detection and confirmation of the anabolic steroid methandrostenolone in methandrostenolone tablets and in the real human urine, GC-MS method was applied to confirm the free methandrostenolone existence in the urine sample in order to validate the reliability of MEKC method. PMID:19064082

  7. Validation of a GC-MS screening method for anabolizing agents in aqueous nutritional supplements.

    PubMed

    Thuyne, W Van; Delbeke, F T

    2005-01-01

    A sensitive and selective method for the screening of anabolizing agents in aqueous nutritional supplements is described and validated. A total of 28 different anabolizing agents are screened for, including testosterone and prohormones, nandrolone and prohormones, stanozolol, and metandienone. The different analytes are extracted from the aqueous nutritional supplements by liquid-liquid extraction with a mixture of pentane and freshly distilled diethylether (1:1) after the supplements have been made alkaline with a NaHCO3-K2CO3 (2:1) buffer. The anabolizing agents are derivatized with a mixture of MSTFA-NH4I-ethanethiol (320:1:2) as routinely used for the screening of anabolic steroids extracted from urine. The derivatives are analyzed by gas chromatography (GC)-mass spectrometry (MS) in the selective ion monitoring mode. The limits of detection range from 1 to 10 ng/mL. One aqueous nutritional supplement (creatine serum) was analyzed with this screening method and was found to contain dehydroepiandrosterone (DHEA) at very low concentrations. The presence of DHEA could be confirmed with GC-MS-MS. Results of the application of this method and a similar method for solid nutritional supplements previously described are given. PMID:15808000

  8. Qualitative description of the prevalence and use of anabolic androgenic steroids by United States powerlifters.

    PubMed

    Curry, L A; Wagman, D F

    1999-02-01

    Powerlifters have been suspected to be a population wherein use of anabolic androgenic steroids is prevalent (Yesalis, Herrick, & Buckley, 1988). To access commentary from these athletes on issues related to these drugs and the effectiveness of doping controls, a survey was developed. From 28 U.S. Powerlifting Team members who competed internationally since 1988, 26 were contacted by mail, and 15 questionnaires were returned. The questionnaire solicited yes/no responses and qualitative descriptions about current and previous use of anabolic androgenic steroids in powerlifting. Analysis indicated that ten U.S. Powerlifting Team members admitted to using these drugs, and five athletes admitted to beating the International Olympic Committee's doping control procedures. Reported use of anabolic androgenic steroids by these athletes was consistent with data presented by Yesalis, et al. and illustrated continued discrepancy between admitted use of these drugs prior to or during national and international events and the lack of reported positive test data. Discussion focused on the value of this study to elicit in an athlete's own words commentary specific to the use of anabolic androgenic steroids and the need for more effective doping controls.

  9. Psychological and behavioural effects of endogenous testosterone and anabolic-androgenic steroids. An update.

    PubMed

    Bahrke, M S; Yesalis, C E; Wright, J E

    1996-12-01

    Endogenous testosterone levels have been linked to aggressive behaviour in both animals and humans. Studies administering moderate doses of exogenous testosterone for contraceptive and clinical purposes reveal essentially no adverse effects on male sexual and aggressive behaviour. However, investigations and case reports of athletes, usually involving higher doses, demonstrate an association between anabolic-androgenic steroid use and affective and psychotic syndromes and psychological dependence. Efforts to study the psychological and behavioural effects of anabolic-androgenic steroids are complicated by a variety of methodological limitations. Only 3 prospective, blinded studies demonstrating aggression or adverse overt behaviour resulting from anabolic-androgenic steroid use have been reported. With estimates of over 1 million past or current users in the US, an extremely small percentage of individuals using anabolic-androgenic steroids appear to experience mental disturbances severe enough to result in clinical treatment and medical case reports. Even among those so affected, the roles of previous psychiatric history, genetic susceptibility to addictions or mental disorders, environmental and peer influences, and individual expectations remain unclear.

  10. Anabolic agents: recent strategies for their detection and protection from inadvertent doping

    PubMed Central

    Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2014-01-01

    According to the World Anti-Doping Agency (WADA) Prohibited List, anabolic agents consist of exogenous anabolic androgenic steroids (AAS), endogenous AAS and other anabolic agents such as clenbuterol and selective androgen receptor modulators (SARMs). Currently employed strategies for their improved detection include the prolongation of the detection windows for exogenous AAS, non-targeted and indirect analytical approaches for the detection of modified steroids (designer steroids), the athlete’s biological passport and isotope ratio mass spectrometry for the detection of the misuse of endogenous AAS, as well as preventive doping research for the detection of SARMs. The recent use of these strategies led to 4–80-fold increases of adverse analytical findings for exogenous AAS, to the detection of the misuse of new designer steroids, to adverse analytical findings of different endogenous AAS and to the first adverse analytical findings of SARMs. The strategies of the antidoping research are not only focused on the development of methods to catch the cheating athlete but also to protect the clean athlete from inadvertent doping. Within the past few years several sources of inadvertent doping with anabolic agents have been identified. Among these are nutritional supplements adulterated with AAS, meat products contaminated with clenbuterol, mycotoxin (zearalenone) contamination leading to zeranol findings, and natural products containing endogenous AAS. The protection strategy consists of further investigations in case of reasonable suspicion of inadvertent doping, publication of the results, education of athletes and development of methods to differentiate between intentional and unintentional doping. PMID:24632537

  11. Antiresorptives and anabolic therapy in sequence or combination for postmenopausal osteoporosis.

    PubMed

    Palacios, S; Mejía, A

    2015-01-01

    Osteoporosis is a chronic disease which may require treatment for many years and requires not only individual management but often sequential or combination treatments. Monotherapy with antiresorptives is usually the first choice. Sometimes, it is necessary to modify this option for therapeutic failure or for the time of use and risk of side-effects. Due to their different mode of action, therapy with anabolic drugs has increased our options in the treatment of osteoporosis. Postmenopausal women and men with severe and progressive osteoporosis despite antiresorptive treatment ('therapeutic failure') should be evaluated for treatment with an anabolic option. Moreover, anabolic agents are indicated for 18-24 months in patients at high risk. Then, sequential antiresorptive therapy is recommended to maintain drug increases in bone mass and support secondary mineralization of the newly formed bone. Combination therapies of antiresorptives and anabolic agents have shown a significant increase in bone mineral density compared to monotherapies. However, none of the combinations have been studied for the prevention of fractures. Combination therapy may not be recommended because of the possible increase in cost.

  12. Drug insight: Testosterone and selective androgen receptor modulators as anabolic therapies for chronic illness and aging.

    PubMed

    Bhasin, Shalender; Calof, Olga M; Storer, Thomas W; Lee, Martin L; Mazer, Norman A; Jasuja, Ravi; Montori, Victor M; Gao, Wenqing; Dalton, James T

    2006-03-01

    Several regulatory concerns have hindered development of androgens as anabolic therapies, despite unequivocal evidence that testosterone supplementation increases muscle mass and strength in men; it induces hypertrophy of type I and II muscle fibers, and increases myonuclear and satellite cell number. Androgens promote differentiation of mesenchymal multipotent cells into the myogenic lineage and inhibit their adipogenic differentiation, by facilitating association of androgen receptors with beta-catenin and activating T-cell factor 4. Meta-analyses indicate that testosterone supplementation increases fat-free mass and muscle strength in HIV-positive men with weight loss, glucocorticoid-treated men, and older men with low or low-normal testosterone levels. The effects of testosterone on physical function and outcomes important to patients have not, however, been studied. In older men, increased hematocrit and increased risk of prostate biopsy and detection of prostate events are the most frequent, testosterone-related adverse events. Concerns about long-term risks have restrained enthusiasm for testosterone use as anabolic therapy. Selective androgen-receptor modulators that are preferentially anabolic and that spare the prostate hold promise as anabolic therapies. We need more studies to determine whether testosterone or selective androgen-receptor modulators can induce meaningful improvements in physical function and patient-important outcomes in patients with physical dysfunction associated with chronic illness or aging.

  13. Body image, disordered eating and anabolic steroid use in female bodybuilders.

    PubMed

    Goldfield, Gary S

    2009-01-01

    Body dissatisfaction and unhealthy eating practices are common among sports and activities that require low body fat or low body weight for enhanced performance. Competitive Bodybuilding is a sport that requires participants to be exceptionally lean and mesomorphic, thus participants may be vulnerable to developing unhealthy eating and weight control practices, as well as using anabolic steroids. This study compares competitive female bodybuilders (CFBBs) and recreational female weight-training controls (RFWTs) on a broad scope of eating related and general psychological characteristics. Anonymous questionnaires, designed to assess eating attitudes, body image, weight and shape preoccupation, prevalence of binge eating, body modification practices (including anabolic steroids), lifetime rates of eating disorders, and general psychological characteristics, were completed by 20 CFBBs and 25 RFWTs. High rates of weight and shape preoccupation, body dissatisfaction, bulimic practices, and anabolic steroid use were reported among CFBBs, and to a lesser degree, RFWTs. Differences between groups on general psychological factors were not statistically significant and effect sizes were small. CFBBs appear to share many eating-related features with women with bulimia nervosa but few psychological traits. Longitudinal research is needed to ascertain whether women with disordered eating or a history of bulimia nervosa disproportionately gravitate to competitive bodybuilding, and/or whether competitive bodybuilding fosters body dissatisfaction, disordered eating, bulimia nervosa, and anabolic steroid use.

  14. The effect of anabolic steroids on the gastrointestinal system, kidneys, and adrenal glands.

    PubMed

    Modlinski, Ryan; Fields, Karl B

    2006-04-01

    Over the past several decades we have seen an increase in the prevalence of anabolic steroid use by athletes. Because use of anabolic steroids is illicit, much of our knowledge of their side effects is derived from case reports, retrospective studies, or comparisons with studies in other similar patient groups. It has been shown that high-dose anabolic steroids have an effect on lowering high-density lipoprotein, increasing low-density lipoprotein, and increasing the atherogenic-promoting apolipoprotein A. Steroid abuse can also be hepatotoxic, promoting disturbances such as biliary stasis, peliosis hepatis, and even hepatomas, which are all usually reversible upon discontinuation. Suppression of the hypothalamic adrenal axis can also lead to profound adrenal changes that are also reversible with time. Although rare, renal side effects have also been documented, leading to acute renal failure and even Wilms' tumors in isolated cases. Much of our knowledge of these potentially severe but usually limited side effects is confounded by use of combinations of different steroid preparations and by the concomitant use with other substances. Physicians must target their efforts at counseling adolescents and other athletes about the potential harms of androgenic anabolic steroids and the legal options to improve strength and performance.

  15. Amphiregulin lacks an essential role for the bone anabolic action of parathyroid hormone.

    PubMed

    Jay, Freya F; Vaidya, Mithila; Porada, Sabrina M; Andrukhova, Olena; Schneider, Marlon R; Erben, Reinhold G

    2015-12-01

    Although parathyroid hormone (PTH) has long been known to act as a bone anabolic agent when administered intermittently, the exact underlying mechanisms remain largely unknown. Amphiregulin (AREG), a ligand of the epidermal growth factor receptor, has been identified to be a PTH target gene in vitro and in vivo. Here, we used female global AREG knockout (AREG-KO) mice to explore the role of AREG in mediating the bone anabolic effects of PTH. AREG-KO mice were characterized by unchanged distal femoral cancellous bone mass and only subtle decreases in bone mineral density (BMD) and cortical thickness at the femoral midshaft at 3 and 8 months of age, relative to wildtype controls. AREG deficiency was associated with complex changes in the mRNA expression of other EGFR ligands in femoral cancellous bone osteoblasts in situ in 3-week-old mice. To examine the bone anabolic effects of PTH in the absence and presence of AREG, we injected 3-month-old AREG-KO females and wildtype control littermates with 80 μg/kg PTH or vehicle 5 times per week over 4 weeks. Intermittent PTH treatment of AREG-KO mice led to increases in femoral trabecular and cortical BMD, cortical thickness, endocortical and periosteal bone formation, cancellous bone formation rate, and serum osteocalcin, comparable to those observed in wildtype control mice. In conclusion, our data indicate that the bone anabolic effects of PTH do not require AREG, at least in 3-month-old female mice.

  16. Long-chain n-3 fatty acids - New anabolic compounds improving protein metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous animal studies demonstrated that chronic feeding of long-chain n-3 polyunsaturated fatty acids (LCn-3PUFA) that modifies muscle membrane fatty acid composition promotes protein anabolism by blunting the age-associated deterioration in insulin sensitivity. The current study assessed, as a pr...

  17. Anabolic-Androgenic Steroids: Prevalence, Knowledge, and Attitudes in Junior and Senior High School Students.

    ERIC Educational Resources Information Center

    Luetkemeier, Maurie J.; And Others

    1995-01-01

    Reports a survey of junior and senior high school students that investigated the prevalence of anabolic-androgenic steroid use and examined gender, sports participation, and illicit drug use. Results indicated the prevalence of steroid use was 3.3%. Steroid use was greater for males, users of other drugs, and strength trainers. (SM)

  18. Anabolic-Androgenic Steroid Use Among 1,010 College Men.

    ERIC Educational Resources Information Center

    Pope, Harrison G., Jr.; And Others

    1988-01-01

    Two percent of 1,010 male college students responding to a questionnaire about anabolic-androgenic steroid use reported using steroids; most of the users were competitive athletes, although some used steroids to improve their physical appearance. Users were not distinguished from non-users in terms of academic achievement or use of other illicit…

  19. Anabolic agents: recent strategies for their detection and protection from inadvertent doping.

    PubMed

    Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2014-05-01

    According to the World Anti-Doping Agency (WADA) Prohibited List, anabolic agents consist of exogenous anabolic androgenic steroids (AAS), endogenous AAS and other anabolic agents such as clenbuterol and selective androgen receptor modulators (SARMs). Currently employed strategies for their improved detection include the prolongation of the detection windows for exogenous AAS, non-targeted and indirect analytical approaches for the detection of modified steroids (designer steroids), the athlete's biological passport and isotope ratio mass spectrometry for the detection of the misuse of endogenous AAS, as well as preventive doping research for the detection of SARMs. The recent use of these strategies led to 4-80-fold increases of adverse analytical findings for exogenous AAS, to the detection of the misuse of new designer steroids, to adverse analytical findings of different endogenous AAS and to the first adverse analytical findings of SARMs. The strategies of the antidoping research are not only focused on the development of methods to catch the cheating athlete but also to protect the clean athlete from inadvertent doping. Within the past few years several sources of inadvertent doping with anabolic agents have been identified. Among these are nutritional supplements adulterated with AAS, meat products contaminated with clenbuterol, mycotoxin (zearalenone) contamination leading to zeranol findings, and natural products containing endogenous AAS. The protection strategy consists of further investigations in case of reasonable suspicion of inadvertent doping, publication of the results, education of athletes and development of methods to differentiate between intentional and unintentional doping.

  20. Commentary: Synthetic Anabolic-Androgenic Steroids: A Plea for Controlled Substance Status.

    ERIC Educational Resources Information Center

    Taylor, William N.

    1987-01-01

    The widespread abuse of synthetic anabolic-androgenic steriods, their habit-forming properties, and their other adverse effects are good reasons for reclassification of steriods as controlled substances under federal law, a step which may combat their abuse. (Author/CB)

  1. Effects of Anabolic Steroids on Lipoprotein Profiles of Female Weight Lifters.

    ERIC Educational Resources Information Center

    Moffatt, Robert J.; And Others

    1990-01-01

    This study examined the effects of resistance exercise and anabolic steroids on lipoprotein profiles of female weightlifters. The study found that women who participate in resistance training have better lipoprotein profiles than their sedentary counterparts, but these changes do not offset the deleterious effects of steroid use. (SM)

  2. Anabolic Androgenic Steroids: Use and Perceived Use in Nonathlete College Students

    ERIC Educational Resources Information Center

    Berning, Joseph M.; Adams, Kent J.; Debeliso, Mark; Stamford, Bryant A.; Newman, Ian M.

    2008-01-01

    Objective: The authors investigated the use and perceived use of anabolic androgenic steroids (AAS) among nonathlete college students. Participants: The authors surveyed a sample of 485 nonathlete college students at a major metropolitan university. Methods: They administered a survey on use and perceived use of AAS to the students. Results:…

  3. Anabolic Androgenic Steroid Use in Teens: Prevalence, Demographics, and Perception of Effects

    ERIC Educational Resources Information Center

    Lorang, Melissa; Callahan, Bryan; Cummins, Kevin M.; Achar, Suraj; Brown, Sandra A.

    2011-01-01

    Multiple risks are associated with early use of anabolic androgenic steroids, yet public understanding is limited and teen use not uncommon. The present study surveyed 4,231 high school students to understand prevalence of use, association with athletics and other substance use and expectations of drug effects. While overall rates of steroid use…

  4. Examining Athletes' Attitudes toward Using Anabolic Steroids and Their Knowledge of the Possible Effects.

    ERIC Educational Resources Information Center

    Anshel, Mark H.; Russell, Kenneth G.

    1997-01-01

    Examined the relationships between athletes' (N=291) knowledge about the long-term effects of anabolic steroids and their attitudes toward this type of drug. Results show low correlation between greater knowledge and attitudes about the use of steroids in sports, suggesting that drug education programs regarding steroids may have limited value.…

  5. Self-Treatment of Gynecomastia in Bodybuilders Who Use Anabolic Steroids. Case Reports.

    ERIC Educational Resources Information Center

    Friedl, Karl E.; Yesalis, Charles E.

    1989-01-01

    Presents four case reports of bodybuilders whose self-administered anabolic steroid programs resulted in gynecomastia, and discusses treatment strategies advocated by some bodybuilders. The actual recommended treatment is complete cessation of drugs. By dispelling unfounded treatment methods, physicians might help discourage such drug use. (SM)

  6. Psychomotor and Motor Speed in Power Athletes Self-Administering Testosterone and Anabolic Steroids.

    ERIC Educational Resources Information Center

    Era, Pertti; And Others

    1988-01-01

    Self-administered testosterone and anabolic steroids resulted in insignificant improvement in psychomotor and motor speed tests of power athletes. This study is part of a larger study on the effects of such drugs on endocrinology, metabolism and neuromuscular functions. Methodolgy and results are discussed. (Author/JL)

  7. Anabolic Steroid Abuse. National Institute on Drug Abuse Research Report Series.

    ERIC Educational Resources Information Center

    National Inst. on Drug Abuse (DHHS/PHS), Bethesda, MD.

    The use of anabolic steroids is on the increase among athletes as well as other segments of the population. Data from the "Monitoring the Future" study showed a significant increase from 1998 to 1999 in steroid abuse among middle school students. During the same year, there was a decline in the percentage of 12th graders who believed that taking…

  8. Anabolic-Androgenic Steroids: Knowledge about, Attitude toward, and Extent of Use by High School Students.

    ERIC Educational Resources Information Center

    Yonker, R. J.; And Others

    Anabolic-androgenic steroids (AS) are pharmacologic derivatives of the hormone testosterone. They have therapeutic merit when used under a physician's prescription to treat certain hormonal imbalances and some forms of anemia; however, when taken in high doses they have a number of virilizing, feminizing, toxic, and psychological effects. This…

  9. Determinants of Anabolic-Androgenic Steroid Risk Perceptions in Youth Populations: A Multivariate Analysis

    ERIC Educational Resources Information Center

    Denham, Bryan E.

    2009-01-01

    Grounded conceptually in social cognitive theory, this research examines how personal, behavioral, and environmental factors are associated with risk perceptions of anabolic-androgenic steroids. Ordinal logistic regression and logit log-linear models applied to data gathered from high-school seniors (N = 2,160) in the 2005 Monitoring the Future…

  10. Doping in sport and exercise: anabolic, ergogenic, health and clinical issues.

    PubMed

    Bird, Stephen R; Goebel, Catrin; Burke, Louise M; Greaves, Ronda F

    2016-03-01

    The use of doping agents is evident within competitive sport in senior and junior age groups, where they are taken by non-elite as well as elite participants. They are also taken in non-sporting contexts by individuals seeking to 'improve' their physique through an increase in muscle and/or decrease in fat mass. While attaining accurate data on the prevalence of their use has limitations, studies suggest the illicit use of doping agents by athletes and non-athletes may be 1-5% in the population and greater than 50% in some groups; with the prevalence being higher in males. There is conclusive evidence that some doping agents are anabolic and ergogenic. There is also evidence that the use of doping agents such as anabolic androgenic steroids, growth hormone and other anabolic agents, erythropoietin and stimulants conveys considerable health risks that include, but are not limited to: cardiovascular disease, diabetes, cancer, mental health issues, virilisation in females and the suppression of naturally produced androgens in males. This review will outline the anabolic, ergogenic and health impacts of selected doping agents and methods that may be used in both the sporting and physique development contexts. It also provides a brief tabulated overview of the history of doping and how doping agents may impact upon the analyses of clinical samples. PMID:26384361

  11. The effects of anabolic steroids on rat tendon. An ultrastructural, biomechanical, and biochemical analysis.

    PubMed

    Inhofe, P D; Grana, W A; Egle, D; Min, K W; Tomasek, J

    1995-01-01

    Forty-eight male rats were randomly separated into four groups: a control group, a group treated with anabolic steroids, a group treated with daily exercise, and a group treated with both steroids and exercise. At 6 weeks, biomechanical, ultrastructural, and biochemical testing was performed on the Achilles tendons of half of the rats in each group. The remaining rats continued in the experimental protocol, but steroid administration was discontinued. Similar testing was then performed on the remaining rats at 12 weeks. Testing showed anabolic steroids produced a stiffer tendon that absorbs less energy and fails with less elongation; tendon strength was unaffected. Effects were entirely reversible on discontinuation of the steroids. Light microscopic analysis revealed no changes in the appearance of the fibrils. No change in fibril diameter or shape was noted on electron microscopic analysis. Biochemical testing revealed no change in qualitative immunofluorescence staining with Type III collagen or fibronectin. Abuse of anabolic steroids is a widespread problem among competitive athletes; consequently, complications after their use are seen with increasing frequency. Knowledge of the effects of these drugs on tendon and the musculotendinous unit may prove helpful in counseling athletes who use anabolic steroids.

  12. Doping in sport and exercise: anabolic, ergogenic, health and clinical issues.

    PubMed

    Bird, Stephen R; Goebel, Catrin; Burke, Louise M; Greaves, Ronda F

    2016-03-01

    The use of doping agents is evident within competitive sport in senior and junior age groups, where they are taken by non-elite as well as elite participants. They are also taken in non-sporting contexts by individuals seeking to 'improve' their physique through an increase in muscle and/or decrease in fat mass. While attaining accurate data on the prevalence of their use has limitations, studies suggest the illicit use of doping agents by athletes and non-athletes may be 1-5% in the population and greater than 50% in some groups; with the prevalence being higher in males. There is conclusive evidence that some doping agents are anabolic and ergogenic. There is also evidence that the use of doping agents such as anabolic androgenic steroids, growth hormone and other anabolic agents, erythropoietin and stimulants conveys considerable health risks that include, but are not limited to: cardiovascular disease, diabetes, cancer, mental health issues, virilisation in females and the suppression of naturally produced androgens in males. This review will outline the anabolic, ergogenic and health impacts of selected doping agents and methods that may be used in both the sporting and physique development contexts. It also provides a brief tabulated overview of the history of doping and how doping agents may impact upon the analyses of clinical samples.

  13. The anabolic steroids testosterone propionate and nandrolone, but not 17alpha-methyltestosterone, induce conditioned place preference in adult mice.

    PubMed

    Parrilla-Carrero, Jeffrey; Figueroa, Orialis; Lugo, Alejandro; García-Sosa, Rebecca; Brito-Vargas, Paul; Cruz, Beatriz; Rivera, Mélanis; Barreto-Estrada, Jennifer L

    2009-02-01

    Anabolic androgenic steroids (AAS) are often misused by adolescents and athletes. Their effects vary according to chemical structure and metabolism, route of administration, and AAS regimen. In this study, adult C57Bl/6 male mice were systemically exposed to testosterone propionate (TP), nandrolone or 17alpha-methyltestosterone (17alpha-meT), type I, type II and type III AAS, respectively, in order to determine the hedonic or aversive properties of each drug. For this purpose, the conditioned place preference (CPP) test was employed at three different AAS doses (0.075, 0.75 and 7.5 mg/kg). Other behavioral domains monitored were light-dark transitions (side changes) and general activity. TP shifted place preference at all doses tested, and nandrolone shifted place preference at 0.75 and 7.5 mg/kg, but not at 0.075 mg/kg, the lower dose tested. Conversely, mice receiving 17alpha-meT did not show alteration in the preference score. The lower dose of nandrolone did modify exploratory-based anxiety showing a decrease in light-dark transitions if compared to vehicle-treated animals, while mice treated with TP or 17alpha-meT were not affected. Our data suggest that when studying hedonic and rewarding properties of synthetic androgens, distinction has to be made based on type of AAS and metabolism.

  14. THE ANABOLIC STEROIDS TESTOSTERONE PROPIONATE AND NANDROLONE, BUT NOT 17α-METHYLTESTOSTERONE, INDUCE CONDITIONED PLACE PREFERENCE IN ADULT MICE

    PubMed Central

    Parrilla-Carrero, Jeffrey; Figueroa, Orialis; Lugo, Alejandro; García-Sosa, Rebecca; Brito-Vargas, Paul; Cruz, Beatriz; Rivera, Melanis; Barreto-Estrada, Jennifer L.

    2009-01-01

    Anabolic androgenic steroids (AAS) are often misused by adolescents and athletes. Their effects vary according to chemical structure and metabolism, route of administration, and AAS regimen. In this study, adult C57Bl/6 male mice were systemically exposed to testosterone propionate (TP), nandrolone or 17α-methyltestosterone (17α-meT), type I, type II and type III AAS, respectively, in order to determine the hedonic or aversive properties of each drug. For this purpose, the conditioned place preference (CPP) test was employed at three different AAS doses (0.075, 0.75 and 7.5 mg/kg). Other behavioral domains monitored were light-dark transitions (side changes) and general activity. TP shifted place preference at all doses tested, and nandrolone shifted place preference at 0.75 and 7.5mg/kg, but not at 0.075 mg/kg, the lower dose tested. Conversely, mice receiving 17α-meT did not show alteration in the preference score. The lower dose of nandrolone did modify exploratory based-anxiety showing a decrease in light-dark transitions if compared to vehicle-treated animals, while mice treated with TP or 17α-meT were not affected. Our data suggest that when studying hedonic and rewarding properties of synthetic androgens, distinction has to be made based on type of AAS and metabolism. PMID:19028026

  15. Adolescent anabolic/androgenic steroids: Aggression and anxiety during exposure predict behavioral responding during withdrawal in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Ricci, Lesley A; Morrison, Thomas R; Melloni, Richard H

    2013-11-01

    In the U.S. and worldwide anabolic/androgenic steroid use remains high in the adolescent population. This is concerning given that anabolic/androgenic steroid use is associated with a higher incidence of aggressive behavior during exposure and anxiety during withdrawal. This study uses pubertal Syrian hamsters (Mesocricetus auratus) to investigate the hypothesis that an inverse behavioral relationship exists between anabolic/androgenic steroid-induced aggression and anxiety across adolescent exposure and withdrawal. In the first experiment, we examined aggression and anxiety during adolescent anabolic/androgenic steroid exposure and withdrawal. Adolescent anabolic/androgenic steroid administration produced significant increases in aggression and decreases in anxiety during the exposure period followed by significant decreases in aggression and increases in anxiety during anabolic/androgenic steroid withdrawal. In a second experiment, anabolic/androgenic steroid exposed animals were separated into groups based on their aggressive response during the exposure period and then tested for anxiety during exposure and then for both aggression and anxiety during withdrawal. Data were analyzed using a within-subjects repeated measures predictive analysis. Linear regression analysis revealed that the difference in aggressive responding between the anabolic/androgenic steroid exposure and withdrawal periods was a significant predictor of differences in anxiety for both days of testing. Moreover, the combined data suggest that the decrease in aggressive behavior from exposure to withdrawal predicts an increase in anxiety-like responding within these same animals during this time span. Together these findings indicate that early anabolic/androgenic steroid exposure has potent aggression- and anxiety-eliciting effects and that these behavioral changes occur alongside a predictive relationship that exists between these two behaviors over time.

  16. Screening of anabolic steroids in horse urine by liquid chromatography-tandem mass spectrometry.

    PubMed

    Yu, Nola H; Ho, Emmie N M; Leung, David K K; Wan, Terence S M

    2005-04-29

    Anabolic steroids have the capability of improving athletic performance and are banned substances in the Olympic games as well as in horseracing and equestrian competitions. The control of their abuse in racehorses is traditionally performed by detecting the presence of anabolic steroids and/or their metabolite(s) in urine samples using gas chromatography-mass spectrometry (GC-MS). However, this approach usually requires tedious sample processing and chemical derivatisation steps and could be very insensitive in detecting certain steroids. This paper describes a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) method for the detection of anabolic steroids that are poorly covered by GC-MS. Enzyme-treated urine was processed by solid-phase extraction (SPE) using a Bond Elut Certify cartridge, followed by a base wash for further cleanup. Separation of the steroids was carried out on a reversed-phase DB-8 column using 0.1% acetic acid and methanol as the mobile phase in a gradient elution programme. The mass spectrometer for the detection of the steroids was operated in the positive electrospray ionisation (ESI) mode with multiple reaction monitoring (MRM). Urine samples fortified with 15 anabolic steroids (namely, androstadienone, 1-androstenedione, bolasterone, boldione, 4-estrenedione, gestrinone, methandrostenolone, methenolone, 17alpha-methyltestosterone, norbolethone, normethandrolone, oxandrolone, stenbolone, trenbolone and turinabol) at low ng/mL levels were consistently detected. No significant matrix interference was observed at the retention times of the targeted ion masses in blank urine samples. The method specificity, sensitivity, precision, recoveries, and the performance of the enzyme hydrolysis step were evaluated. The successful application of the method to analyse methenolone acetate administration urine samples demonstrated that the method could be effective in detecting anabolic steroids and their metabolites in horse

  17. Selling androgenic anabolic steroids by the pound: identification and analysis of popular websites on the Internet.

    PubMed

    Cordaro, F G; Lombardo, S; Cosentino, M

    2011-12-01

    Internet websites offering androgenic anabolic steroids (AAS) were identified and available products were examined. Keywords for the website search were: "anabolic steroids," "anabolic steroids buy," "anabolic steroid purchase." The first 10 websites offering AAS in the first 10 pages of results were considered. At least two AAS-containing products per website were selected. Thirty AAS-selling websites were identified, mainly located in the United States (46.7%) and Europe (30%). Most websites sold other anabolic/ergogenic products (clenbuterol, 76.7%; GH/IGF, 60.0%; thyroid hormones, 46.7%; erythropoietin, 30.0%; insulin, 20.0%) or products for AAS-related adverse effects (mainly: estrogen antagonists, 63.3%; products for erectile dysfunction, 56.7%; 5α-reductase inhibitors, 33.3%; anti-acne products, 33.3%). AAS were sold as medicines (69.6%) or as dietary supplements (30.4%). AAS in medicines were mainly: nandronole (20.4%), methandrostenolone (18.4%), and testosterone (12.2%). Dietary supplements contained mainly DHEA and included several fake compounds. Manufacturers were declared for 97.9% of medicines and 66.7% of dietary supplements; however, several manufacturers were not found on the Internet. Described benefits were usually few adverse effects and no estrogenicity. Toxicity was seldom reported and presented as mild. Recommended doses were two-fourfold higher than current medical recommendations. In conclusion, misleading information and deceiving practices were common findings on AAS-selling websites, indicating their deleterious potential for public health. PMID:21210860

  18. The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption.

    PubMed

    van Vliet, Stephan; Burd, Nicholas A; van Loon, Luc J C

    2015-09-01

    Clinical and consumer market interest is increasingly directed toward the use of plant-based proteins as dietary components aimed at preserving or increasing skeletal muscle mass. However, recent evidence suggests that the ingestion of the plant-based proteins in soy and wheat results in a lower muscle protein synthetic response when compared with several animal-based proteins. The possible lower anabolic properties of plant-based protein sources may be attributed to the lower digestibility of plant-based sources, in addition to greater splanchnic extraction and subsequent urea synthesis of plant protein-derived amino acids compared with animal-based proteins. The latter may be related to the relative lack of specific essential amino acids in plant- as opposed to animal-based proteins. Furthermore, most plant proteins have a relatively low leucine content, which may further reduce their anabolic properties when compared with animal proteins. However, few studies have actually assessed the postprandial muscle protein synthetic response to the ingestion of plant proteins, with soy and wheat protein being the primary sources studied. Despite the proposed lower anabolic properties of plant vs. animal proteins, various strategies may be applied to augment the anabolic properties of plant proteins. These may include the following: 1) fortification of plant-based protein sources with the amino acids methionine, lysine, and/or leucine; 2) selective breeding of plant sources to improve amino acid profiles; 3) consumption of greater amounts of plant-based protein sources; or 4) ingesting multiple protein sources to provide a more balanced amino acid profile. However, the efficacy of such dietary strategies on postprandial muscle protein synthesis remains to be studied. Future research comparing the anabolic properties of a variety of plant-based proteins should define the preferred protein sources to be used in nutritional interventions to support skeletal muscle mass gain

  19. DECREASED OXIDATIVE STRESS AND GREATER BONE ANABOLISM IN THE AGED, AS COMPARED TO THE YOUNG, MURINE SKELETON BY PARATHYROID HORMONE

    PubMed Central

    Jilka, R.L.; Almeida, M.; Ambrogini, E.; Han, L.; Roberson, P. K.; Weinstein, R.S.; Manolagas, S.C.

    2010-01-01

    Summary Because of recent insights into the pathogenesis of age-related bone loss, we investigated whether intermittent parathyroid hormone (PTH) administration antagonizes the molecular mechanisms of the adverse effects of aging on bone. PTH produced a greater increase in vertebral trabecular bone mineral density and bone volume as well as a greater expansion of the endocortical bone surface in the femur of 26 as compared to 6 month old female C57BL/6 mice. Moreover, PTH increased trabecular connectivity in vertebrae and the toughness of both vertebrae and femora in old, but not young, mice. PTH also increased the rate of bone formation and reduced osteoblast apoptosis to a greater extent in the old mice. Most strikingly, PTH reduced reactive oxygen species (ROS), p66Shc phosphorylation and expression of the lipoxygenase Alox15; and it increase